* [PATCH 1/3] tracing: Modify is_delete, is_return from int to bool @ 2012-04-09 9:11 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-09 9:11 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> is_delete and is_return can take utmost 2 values and are better of being a boolean than a int. There are no functional changes. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog: (v5): - separated out as different patch on Masami's suggestion. kernel/trace/trace_kprobe.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 580a05e..4f935f8 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -651,7 +651,7 @@ static struct trace_probe *alloc_trace_probe(const char *group, void *addr, const char *symbol, unsigned long offs, - int nargs, int is_return) + int nargs, bool is_return) { struct trace_probe *tp; int ret = -ENOMEM; @@ -944,7 +944,7 @@ static int split_symbol_offset(char *symbol, unsigned long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -977,7 +977,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -1089,7 +1089,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, int is_return) + struct probe_arg *parg, bool is_return) { const char *t; int ret; @@ -1162,7 +1162,7 @@ static int create_trace_probe(int argc, char **argv) */ struct trace_probe *tp; int i, ret = 0; - int is_return = 0, is_delete = 0; + bool is_return = false, is_delete = false; char *symbol = NULL, *event = NULL, *group = NULL; char *arg; unsigned long offset = 0; @@ -1171,11 +1171,11 @@ static int create_trace_probe(int argc, char **argv) /* argc must be >= 1 */ if (argv[0][0] == 'p') - is_return = 0; + is_return = false; else if (argv[0][0] == 'r') - is_return = 1; + is_return = true; else if (argv[0][0] == '-') - is_delete = 1; + is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH 1/3] tracing: Modify is_delete, is_return from int to bool @ 2012-04-09 9:11 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-09 9:11 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> is_delete and is_return can take utmost 2 values and are better of being a boolean than a int. There are no functional changes. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog: (v5): - separated out as different patch on Masami's suggestion. kernel/trace/trace_kprobe.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 580a05e..4f935f8 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -651,7 +651,7 @@ static struct trace_probe *alloc_trace_probe(const char *group, void *addr, const char *symbol, unsigned long offs, - int nargs, int is_return) + int nargs, bool is_return) { struct trace_probe *tp; int ret = -ENOMEM; @@ -944,7 +944,7 @@ static int split_symbol_offset(char *symbol, unsigned long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -977,7 +977,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -1089,7 +1089,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, int is_return) + struct probe_arg *parg, bool is_return) { const char *t; int ret; @@ -1162,7 +1162,7 @@ static int create_trace_probe(int argc, char **argv) */ struct trace_probe *tp; int i, ret = 0; - int is_return = 0, is_delete = 0; + bool is_return = false, is_delete = false; char *symbol = NULL, *event = NULL, *group = NULL; char *arg; unsigned long offset = 0; @@ -1171,11 +1171,11 @@ static int create_trace_probe(int argc, char **argv) /* argc must be >= 1 */ if (argv[0][0] == 'p') - is_return = 0; + is_return = false; else if (argv[0][0] == 'r') - is_return = 1; + is_return = true; else if (argv[0][0] == '-') - is_delete = 1; + is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH 2/3] tracing: Extract out common code for kprobes/uprobes trace events 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-04-09 9:11 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-09 9:11 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Move parts of trace_kprobe.c that can be shared with upcoming trace_uprobe.c. Common code to kernel/trace/trace_probe.h and kernel/trace/trace_probe.c. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog: (v5) - Handle regressions in changes pointed by Steven Rostedt. - Extracted out int to bool changes to a separate patch. - Fix a bug in kprobe_trace_self_tests_init that was introduced in previous patchset. (v7) - Modified Copyright as suggested by Steven Rostedt. kernel/trace/Kconfig | 4 kernel/trace/Makefile | 1 kernel/trace/trace_kprobe.c | 889 +------------------------------------------ kernel/trace/trace_probe.c | 833 ++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 160 ++++++++ 5 files changed, 1016 insertions(+), 871 deletions(-) create mode 100644 kernel/trace/trace_probe.c create mode 100644 kernel/trace/trace_probe.h diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a1d2849..ce5a5c5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -373,6 +373,7 @@ config KPROBE_EVENT depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" select TRACING + select PROBE_EVENTS default y help This allows the user to add tracing events (similar to tracepoints) @@ -385,6 +386,9 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config PROBE_EVENTS + def_bool n + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 5f39a07..fa10d5c 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -61,5 +61,6 @@ endif ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif +obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4f935f8..f8b7773 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -19,547 +19,15 @@ #include <linux/module.h> #include <linux/uaccess.h> -#include <linux/kprobes.h> -#include <linux/seq_file.h> -#include <linux/slab.h> -#include <linux/smp.h> -#include <linux/debugfs.h> -#include <linux/types.h> -#include <linux/string.h> -#include <linux/ctype.h> -#include <linux/ptrace.h> -#include <linux/perf_event.h> -#include <linux/stringify.h> -#include <linux/limits.h> -#include <asm/bitsperlong.h> - -#include "trace.h" -#include "trace_output.h" - -#define MAX_TRACE_ARGS 128 -#define MAX_ARGSTR_LEN 63 -#define MAX_EVENT_NAME_LEN 64 -#define MAX_STRING_SIZE PATH_MAX -#define KPROBE_EVENT_SYSTEM "kprobes" - -/* Reserved field names */ -#define FIELD_STRING_IP "__probe_ip" -#define FIELD_STRING_RETIP "__probe_ret_ip" -#define FIELD_STRING_FUNC "__probe_func" - -const char *reserved_field_names[] = { - "common_type", - "common_flags", - "common_preempt_count", - "common_pid", - "common_tgid", - FIELD_STRING_IP, - FIELD_STRING_RETIP, - FIELD_STRING_FUNC, -}; - -/* Printing function type */ -typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, - void *); -#define PRINT_TYPE_FUNC_NAME(type) print_type_##type -#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type - -/* Printing in basic type function template */ -#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ -static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent)\ -{ \ - return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ -} \ -static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; - -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) -DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) - -/* data_rloc: data relative location, compatible with u32 */ -#define make_data_rloc(len, roffs) \ - (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) -#define get_rloc_len(dl) ((u32)(dl) >> 16) -#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) - -static inline void *get_rloc_data(u32 *dl) -{ - return (u8 *)dl + get_rloc_offs(*dl); -} - -/* For data_loc conversion */ -static inline void *get_loc_data(u32 *dl, void *ent) -{ - return (u8 *)ent + get_rloc_offs(*dl); -} - -/* - * Convert data_rloc to data_loc: - * data_rloc stores the offset from data_rloc itself, but data_loc - * stores the offset from event entry. - */ -#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) - -/* For defining macros, define string/string_size types */ -typedef u32 string; -typedef u32 string_size; - -/* Print type function for string type */ -static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, - const char *name, - void *data, void *ent) -{ - int len = *(u32 *)data >> 16; - - if (!len) - return trace_seq_printf(s, " %s=(fault)", name); - else - return trace_seq_printf(s, " %s=\"%s\"", name, - (const char *)get_loc_data(data, ent)); -} -static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; - -/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); - -struct fetch_param { - fetch_func_t fn; - void *data; -}; - -static __kprobes void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - -#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - -#define CHECK_FETCH_FUNCS(method, fn) \ - (((FETCH_FUNC_NAME(method, u8) == fn) || \ - (FETCH_FUNC_NAME(method, u16) == fn) || \ - (FETCH_FUNC_NAME(method, u32) == fn) || \ - (FETCH_FUNC_NAME(method, u64) == fn) || \ - (FETCH_FUNC_NAME(method, string) == fn) || \ - (FETCH_FUNC_NAME(method, string_size) == fn)) \ - && (fn != NULL)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -#define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_retval(type) \ -static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - long ret; - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - u8 *src = addr; - mm_segment_t old_fs = get_fs(); - if (!maxlen) - return; - /* - * Try to get string again, since the string can be changed while - * probing. - */ - set_fs(KERNEL_DS); - pagefault_disable(); - do - ret = __copy_from_user_inatomic(dst++, src++, 1); - while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); - dst[-1] = '\0'; - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) { /* Failed to fetch string */ - ((u8 *)get_rloc_data(dest))[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else - *(u32 *)dest = make_data_rloc(src - (u8 *)addr, - get_rloc_offs(*(u32 *)dest)); -} -/* Return the length of string -- including null terminal byte */ -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - int ret, len = 0; - u8 c; - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - pagefault_disable(); - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} - -/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -static unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - if (sc->addr) - sc->addr += sc->offset; - return sc->addr; -} - -static void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - return sc; -} - -#define DEFINE_FETCH_symbol(type) \ -static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; -}; - -#define DEFINE_FETCH_deref(type) \ -static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - fetch_memory_##type(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string) -DEFINE_FETCH_deref(string_size) - -static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Bitfield fetch function */ -struct bitfield_fetch_param { - struct fetch_param orig; - unsigned char hi_shift; - unsigned char low_shift; -}; +#include "trace_probe.h" -#define DEFINE_FETCH_bitfield(type) \ -static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct bitfield_fetch_param *bprm = data; \ - type buf = 0; \ - call_fetch(&bprm->orig, regs, &buf); \ - if (buf) { \ - buf <<= bprm->hi_shift; \ - buf >>= bprm->low_shift; \ - } \ - *(type *)dest = buf; \ -} -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -static __kprobes void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Default (unsigned long) fetch type */ -#define __DEFAULT_FETCH_TYPE(t) u##t -#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) -#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) -#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) - -/* Fetch types */ -enum { - FETCH_MTD_reg = 0, - FETCH_MTD_stack, - FETCH_MTD_retval, - FETCH_MTD_memory, - FETCH_MTD_symbol, - FETCH_MTD_deref, - FETCH_MTD_bitfield, - FETCH_MTD_END, -}; - -#define ASSIGN_FETCH_FUNC(method, type) \ - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) - -#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ - {.name = _name, \ - .size = _size, \ - .is_signed = sign, \ - .print = PRINT_TYPE_FUNC_NAME(ptype), \ - .fmt = PRINT_TYPE_FMT_NAME(ptype), \ - .fmttype = _fmttype, \ - .fetch = { \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ - } \ - } - -#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) - -#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 - -/* Fetch type information table */ -static const struct fetch_type { - const char *name; /* Name of type */ - size_t size; /* Byte size of type */ - int is_signed; /* Signed flag */ - print_type_func_t print; /* Print functions */ - const char *fmt; /* Fromat string */ - const char *fmttype; /* Name in format file */ - /* Fetch functions */ - fetch_func_t fetch[FETCH_MTD_END]; -} fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), -}; - -static const struct fetch_type *find_fetch_type(const char *type) -{ - int i; - - if (!type) - type = DEFAULT_FETCH_TYPE_STR; - - /* Special case: bitfield */ - if (*type == 'b') { - unsigned long bs; - type = strchr(type, '/'); - if (!type) - goto fail; - type++; - if (strict_strtoul(type, 0, &bs)) - goto fail; - switch (bs) { - case 8: - return find_fetch_type("u8"); - case 16: - return find_fetch_type("u16"); - case 32: - return find_fetch_type("u32"); - case 64: - return find_fetch_type("u64"); - default: - goto fail; - } - } - - for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) - if (strcmp(type, fetch_type_table[i].name) == 0) - return &fetch_type_table[i]; -fail: - return NULL; -} - -/* Special function : only accept unsigned long */ -static __kprobes void fetch_stack_address(struct pt_regs *regs, - void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} - -static fetch_func_t get_fetch_size_function(const struct fetch_type *type, - fetch_func_t orig_fn) -{ - int i; - - if (type != &fetch_type_table[FETCH_TYPE_STRING]) - return NULL; /* Only string type needs size function */ - for (i = 0; i < FETCH_MTD_END; i++) - if (type->fetch[i] == orig_fn) - return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; - - WARN_ON(1); /* This should not happen */ - return NULL; -} +#define KPROBE_EVENT_SYSTEM "kprobes" /** * Kprobe event core functions */ -struct probe_arg { - struct fetch_param fetch; - struct fetch_param fetch_size; - unsigned int offset; /* Offset from argument entry */ - const char *name; /* Name of this argument */ - const char *comm; /* Command of this argument */ - const struct fetch_type *type; /* Type of this argument */ -}; - -/* Flags for trace_probe */ -#define TP_FLAG_TRACE 1 -#define TP_FLAG_PROFILE 2 -#define TP_FLAG_REGISTERED 4 - struct trace_probe { struct list_head list; struct kretprobe rp; /* Use rp.kp for kprobe use */ @@ -631,18 +99,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); -/* Check the name is good for event/group/fields */ -static int is_good_name(const char *name) -{ - if (!isalpha(*name) && *name != '_') - return 0; - while (*++name != '\0') { - if (!isalpha(*name) && !isdigit(*name) && *name != '_') - return 0; - } - return 1; -} - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -702,34 +158,12 @@ static struct trace_probe *alloc_trace_probe(const char *group, return ERR_PTR(ret); } -static void update_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - update_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - update_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - update_symbol_cache(arg->fetch.data); -} - -static void free_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - free_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - kfree(arg->name); - kfree(arg->comm); -} - static void free_trace_probe(struct trace_probe *tp) { int i; for (i = 0; i < tp->nr_args; i++) - free_probe_arg(&tp->args[i]); + traceprobe_free_probe_arg(&tp->args[i]); kfree(tp->call.class->system); kfree(tp->call.name); @@ -787,7 +221,7 @@ static int __register_trace_probe(struct trace_probe *tp) return -EINVAL; for (i = 0; i < tp->nr_args; i++) - update_probe_arg(&tp->args[i]); + traceprobe_update_arg(&tp->args[i]); /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(tp)) @@ -919,227 +353,6 @@ static struct notifier_block trace_probe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; -/* Split symbol and offset. */ -static int split_symbol_offset(char *symbol, unsigned long *offset) -{ - char *tmp; - int ret; - - if (!offset) - return -EINVAL; - - tmp = strchr(symbol, '+'); - if (tmp) { - /* skip sign because strict_strtol doesn't accept '+' */ - ret = strict_strtoul(tmp + 1, 0, offset); - if (ret) - return ret; - *tmp = '\0'; - } else - *offset = 0; - return 0; -} - -#define PARAM_MAX_ARGS 16 -#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) - -static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - - if (strcmp(arg, "retval") == 0) { - if (is_return) - f->fn = t->fetch[FETCH_MTD_retval]; - else - ret = -EINVAL; - } else if (strncmp(arg, "stack", 5) == 0) { - if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) - f->fn = fetch_stack_address; - else - ret = -EINVAL; - } else if (isdigit(arg[5])) { - ret = strict_strtoul(arg + 5, 10, ¶m); - if (ret || param > PARAM_MAX_STACK) - ret = -EINVAL; - else { - f->fn = t->fetch[FETCH_MTD_stack]; - f->data = (void *)param; - } - } else - ret = -EINVAL; - } else - ret = -EINVAL; - return ret; -} - -/* Recursive argument parser */ -static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - long offset; - char *tmp; - - switch (arg[0]) { - case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return); - break; - case '%': /* named register */ - ret = regs_query_register_offset(arg + 1); - if (ret >= 0) { - f->fn = t->fetch[FETCH_MTD_reg]; - f->data = (void *)(unsigned long)ret; - ret = 0; - } - break; - case '@': /* memory or symbol */ - if (isdigit(arg[1])) { - ret = strict_strtoul(arg + 1, 0, ¶m); - if (ret) - break; - f->fn = t->fetch[FETCH_MTD_memory]; - f->data = (void *)param; - } else { - ret = split_symbol_offset(arg + 1, &offset); - if (ret) - break; - f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->fetch[FETCH_MTD_symbol]; - } - break; - case '+': /* deref memory */ - arg++; /* Skip '+', because strict_strtol() rejects it. */ - case '-': - tmp = strchr(arg, '('); - if (!tmp) - break; - *tmp = '\0'; - ret = strict_strtol(arg, 0, &offset); - if (ret) - break; - arg = tmp + 1; - tmp = strrchr(arg, ')'); - if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2 = find_fetch_type(NULL); - *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), - GFP_KERNEL); - if (!dprm) - return -ENOMEM; - dprm->offset = offset; - ret = __parse_probe_arg(arg, t2, &dprm->orig, - is_return); - if (ret) - kfree(dprm); - else { - f->fn = t->fetch[FETCH_MTD_deref]; - f->data = (void *)dprm; - } - } - break; - } - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ - pr_info("%s type has no corresponding fetch method.\n", - t->name); - ret = -EINVAL; - } - return ret; -} - -#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) - -/* Bitfield type needs to be parsed into a fetch function */ -static int __parse_bitfield_probe_arg(const char *bf, - const struct fetch_type *t, - struct fetch_param *f) -{ - struct bitfield_fetch_param *bprm; - unsigned long bw, bo; - char *tail; - - if (*bf != 'b') - return 0; - - bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - return -ENOMEM; - bprm->orig = *f; - f->fn = t->fetch[FETCH_MTD_bitfield]; - f->data = (void *)bprm; - - bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ - if (bw == 0 || *tail != '@') - return -EINVAL; - - bf = tail + 1; - bo = simple_strtoul(bf, &tail, 0); - if (tail == bf || *tail != '/') - return -EINVAL; - - bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); - bprm->low_shift = bprm->hi_shift + bo; - return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; -} - -/* String length checking wrapper */ -static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, bool is_return) -{ - const char *t; - int ret; - - if (strlen(arg) > MAX_ARGSTR_LEN) { - pr_info("Argument is too long.: %s\n", arg); - return -ENOSPC; - } - parg->comm = kstrdup(arg, GFP_KERNEL); - if (!parg->comm) { - pr_info("Failed to allocate memory for command '%s'.\n", arg); - return -ENOMEM; - } - t = strchr(parg->comm, ':'); - if (t) { - arg[t - parg->comm] = '\0'; - t++; - } - parg->type = find_fetch_type(t); - if (!parg->type) { - pr_info("Unsupported type: %s\n", t); - return -EINVAL; - } - parg->offset = tp->size; - tp->size += parg->type->size; - ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); - if (ret >= 0 && t != NULL) - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); - if (ret >= 0) { - parg->fetch_size.fn = get_fetch_size_function(parg->type, - parg->fetch.fn); - parg->fetch_size.data = parg->fetch.data; - } - return ret; -} - -/* Return 1 if name is reserved or already used by another argument */ -static int conflict_field_name(const char *name, - struct probe_arg *args, int narg) -{ - int i; - for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) - if (strcmp(reserved_field_names[i], name) == 0) - return 1; - for (i = 0; i < narg; i++) - if (strcmp(args[i].name, name) == 0) - return 1; - return 0; -} - static int create_trace_probe(int argc, char **argv) { /* @@ -1240,7 +453,7 @@ static int create_trace_probe(int argc, char **argv) /* a symbol specified */ symbol = argv[1]; /* TODO: support .init module functions */ - ret = split_symbol_offset(symbol, &offset); + ret = traceprobe_split_symbol_offset(symbol, &offset); if (ret) { pr_info("Failed to parse symbol.\n"); return ret; @@ -1302,7 +515,8 @@ static int create_trace_probe(int argc, char **argv) goto error; } - if (conflict_field_name(tp->args[i].name, tp->args, i)) { + if (traceprobe_conflict_field_name(tp->args[i].name, + tp->args, i)) { pr_info("Argument[%d] name '%s' conflicts with " "another field.\n", i, argv[i]); ret = -EINVAL; @@ -1310,7 +524,8 @@ static int create_trace_probe(int argc, char **argv) } /* Parse fetch argument */ - ret = parse_probe_arg(arg, tp, &tp->args[i], is_return); + ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], + is_return); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -1412,70 +627,11 @@ static int probes_open(struct inode *inode, struct file *file) return seq_open(file, &probes_seq_op); } -static int command_trace_probe(const char *buf) -{ - char **argv; - int argc = 0, ret = 0; - - argv = argv_split(GFP_KERNEL, buf, &argc); - if (!argv) - return -ENOMEM; - - if (argc) - ret = create_trace_probe(argc, argv); - - argv_free(argv); - return ret; -} - -#define WRITE_BUFSIZE 4096 - static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { - char *kbuf, *tmp; - int ret; - size_t done; - size_t size; - - kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - ret = done = 0; - while (done < count) { - size = count - done; - if (size >= WRITE_BUFSIZE) - size = WRITE_BUFSIZE - 1; - if (copy_from_user(kbuf, buffer + done, size)) { - ret = -EFAULT; - goto out; - } - kbuf[size] = '\0'; - tmp = strchr(kbuf, '\n'); - if (tmp) { - *tmp = '\0'; - size = tmp - kbuf + 1; - } else if (done + size < count) { - pr_warning("Line length is too long: " - "Should be less than %d.", WRITE_BUFSIZE); - ret = -EINVAL; - goto out; - } - done += size; - /* Remove comments */ - tmp = strchr(kbuf, '#'); - if (tmp) - *tmp = '\0'; - - ret = command_trace_probe(kbuf); - if (ret) - goto out; - } - ret = done; -out: - kfree(kbuf); - return ret; + return traceprobe_probes_write(file, buffer, count, ppos, + create_trace_probe); } static const struct file_operations kprobe_events_ops = { @@ -1711,16 +867,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, return TRACE_TYPE_PARTIAL_LINE; } -#undef DEFINE_FIELD -#define DEFINE_FIELD(type, item, name, is_signed) \ - do { \ - ret = trace_define_field(event_call, #type, name, \ - offsetof(typeof(field), item), \ - sizeof(field.item), is_signed, \ - FILTER_OTHER); \ - if (ret) \ - return ret; \ - } while (0) static int kprobe_event_define_fields(struct ftrace_event_call *event_call) { @@ -2051,8 +1197,9 @@ static __init int kprobe_trace_self_tests_init(void) pr_info("Testing kprobe tracing: "); - ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " - "$stack $stack0 +0($stack)"); + ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " + "$stack $stack0 +0($stack)", + create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function entry.\n"); warn++; @@ -2066,8 +1213,8 @@ static __init int kprobe_trace_self_tests_init(void) enable_trace_probe(tp, TP_FLAG_TRACE); } - ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " - "$retval"); + ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " + "$retval", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function return.\n"); warn++; @@ -2101,13 +1248,13 @@ static __init int kprobe_trace_self_tests_init(void) } else disable_trace_probe(tp, TP_FLAG_TRACE); - ret = command_trace_probe("-:testprobe"); + ret = traceprobe_command("-:testprobe", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; } - ret = command_trace_probe("-:testprobe2"); + ret = traceprobe_command("-:testprobe2", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c new file mode 100644 index 0000000..8e526b9 --- /dev/null +++ b/kernel/trace/trace_probe.c @@ -0,0 +1,833 @@ +/* + * Common code for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include "trace_probe.h" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + FIELD_STRING_IP, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + +/* Printing function type */ +#define PRINT_TYPE_FUNC_NAME(type) print_type_##type +#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type + +/* Printing in basic type function template */ +#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ +static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ + const char *name, \ + void *data, void *ent)\ +{ \ + return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ +} \ +static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; + +DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) + +static inline void *get_rloc_data(u32 *dl) +{ + return (u8 *)dl + get_rloc_offs(*dl); +} + +/* For data_loc conversion */ +static inline void *get_loc_data(u32 *dl, void *ent) +{ + return (u8 *)ent + get_rloc_offs(*dl); +} + +/* For defining macros, define string/string_size types */ +typedef u32 string; +typedef u32 string_size; + +/* Print type function for string type */ +static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, + const char *name, + void *data, void *ent) +{ + int len = *(u32 *)data >> 16; + + if (!len) + return trace_seq_printf(s, " %s=(fault)", name); + else + return trace_seq_printf(s, " %s=\"%s\"", name, + (const char *)get_loc_data(data, ent)); +} + +static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; + +#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type +/* + * Define macro for basic types - we don't need to define s* types, because + * we have to care only about bitwidth at recording time. + */ +#define DEFINE_BASIC_FETCH_FUNCS(method) \ +DEFINE_FETCH_##method(u8) \ +DEFINE_FETCH_##method(u16) \ +DEFINE_FETCH_##method(u32) \ +DEFINE_FETCH_##method(u64) + +#define CHECK_FETCH_FUNCS(method, fn) \ + (((FETCH_FUNC_NAME(method, u8) == fn) || \ + (FETCH_FUNC_NAME(method, u16) == fn) || \ + (FETCH_FUNC_NAME(method, u32) == fn) || \ + (FETCH_FUNC_NAME(method, u64) == fn) || \ + (FETCH_FUNC_NAME(method, string) == fn) || \ + (FETCH_FUNC_NAME(method, string_size) == fn)) \ + && (fn != NULL)) + +/* Data fetch function templates */ +#define DEFINE_FETCH_reg(type) \ +static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_register(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(reg) +/* No string on the register */ +#define fetch_reg_string NULL +#define fetch_reg_string_size NULL + +#define DEFINE_FETCH_stack(type) \ +static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) +/* No string on the stack entry */ +#define fetch_stack_string NULL +#define fetch_stack_string_size NULL + +#define DEFINE_FETCH_retval(type) \ +static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ + void *dummy, void *dest) \ +{ \ + *(type *)dest = (type)regs_return_value(regs); \ +} +DEFINE_BASIC_FETCH_FUNCS(retval) +/* No string on the retval */ +#define fetch_retval_string NULL +#define fetch_retval_string_size NULL + +#define DEFINE_FETCH_memory(type) \ +static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ + void *addr, void *dest) \ +{ \ + type retval; \ + if (probe_kernel_address(addr, retval)) \ + *(type *)dest = 0; \ + else \ + *(type *)dest = retval; \ +} +DEFINE_BASIC_FETCH_FUNCS(memory) +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max + * length and relative data location. + */ +static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) +{ + long ret; + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + u8 *src = addr; + mm_segment_t old_fs = get_fs(); + + if (!maxlen) + return; + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + set_fs(KERNEL_DS); + pagefault_disable(); + + do + ret = __copy_from_user_inatomic(dst++, src++, 1); + while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); + + dst[-1] = '\0'; + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) { /* Failed to fetch string */ + ((u8 *)get_rloc_data(dest))[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); + } else { + *(u32 *)dest = make_data_rloc(src - (u8 *)addr, + get_rloc_offs(*(u32 *)dest)); + } +} + +/* Return the length of string -- including null terminal byte */ +static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) /* Failed to check the length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + + if (sc->addr) + sc->addr += sc->offset; + + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + update_symbol_cache(sc); + + return sc; +} + +#define DEFINE_FETCH_symbol(type) \ +static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct symbol_cache *sc = data; \ + if (sc->addr) \ + fetch_memory_##type(regs, (void *)sc->addr, dest); \ + else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(symbol) +DEFINE_FETCH_symbol(string) +DEFINE_FETCH_symbol(string_size) + +/* Dereference memory access function */ +struct deref_fetch_param { + struct fetch_param orig; + long offset; +}; + +#define DEFINE_FETCH_deref(type) \ +static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct deref_fetch_param *dprm = data; \ + unsigned long addr; \ + call_fetch(&dprm->orig, regs, &addr); \ + if (addr) { \ + addr += dprm->offset; \ + fetch_memory_##type(regs, (void *)addr, dest); \ + } else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(deref) +DEFINE_FETCH_deref(string) +DEFINE_FETCH_deref(string_size) + +static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/* Bitfield fetch function */ +struct bitfield_fetch_param { + struct fetch_param orig; + unsigned char hi_shift; + unsigned char low_shift; +}; + +#define DEFINE_FETCH_bitfield(type) \ +static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct bitfield_fetch_param *bprm = data; \ + type buf = 0; \ + call_fetch(&bprm->orig, regs, &buf); \ + if (buf) { \ + buf <<= bprm->hi_shift; \ + buf >>= bprm->low_shift; \ + } \ + *(type *)dest = buf; \ +} + +DEFINE_BASIC_FETCH_FUNCS(bitfield) +#define fetch_bitfield_string NULL +#define fetch_bitfield_string_size NULL + +static __kprobes void +update_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void +free_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + + kfree(data); +} + +/* Default (unsigned long) fetch type */ +#define __DEFAULT_FETCH_TYPE(t) u##t +#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) +#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) +#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) + +#define ASSIGN_FETCH_FUNC(method, type) \ + [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) + +#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ + {.name = _name, \ + .size = _size, \ + .is_signed = sign, \ + .print = PRINT_TYPE_FUNC_NAME(ptype), \ + .fmt = PRINT_TYPE_FMT_NAME(ptype), \ + .fmttype = _fmttype, \ + .fetch = { \ +ASSIGN_FETCH_FUNC(reg, ftype), \ +ASSIGN_FETCH_FUNC(stack, ftype), \ +ASSIGN_FETCH_FUNC(retval, ftype), \ +ASSIGN_FETCH_FUNC(memory, ftype), \ +ASSIGN_FETCH_FUNC(symbol, ftype), \ +ASSIGN_FETCH_FUNC(deref, ftype), \ +ASSIGN_FETCH_FUNC(bitfield, ftype), \ + } \ + } + +#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ + __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) + +#define FETCH_TYPE_STRING 0 +#define FETCH_TYPE_STRSIZE 1 + +/* Fetch type information table */ +static const struct fetch_type fetch_type_table[] = { + /* Special types */ + [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, + sizeof(u32), 1, "__data_loc char[]"), + [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, + string_size, sizeof(u32), 0, "u32"), + /* Basic types */ + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), +}; + +static const struct fetch_type *find_fetch_type(const char *type) +{ + int i; + + if (!type) + type = DEFAULT_FETCH_TYPE_STR; + + /* Special case: bitfield */ + if (*type == 'b') { + unsigned long bs; + + type = strchr(type, '/'); + if (!type) + goto fail; + + type++; + if (strict_strtoul(type, 0, &bs)) + goto fail; + + switch (bs) { + case 8: + return find_fetch_type("u8"); + case 16: + return find_fetch_type("u16"); + case 32: + return find_fetch_type("u32"); + case 64: + return find_fetch_type("u64"); + default: + goto fail; + } + } + + for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) + if (strcmp(type, fetch_type_table[i].name) == 0) + return &fetch_type_table[i]; + +fail: + return NULL; +} + +/* Special function : only accept unsigned long */ +static __kprobes void fetch_stack_address(struct pt_regs *regs, + void *dummy, void *dest) +{ + *(unsigned long *)dest = kernel_stack_pointer(regs); +} + +static fetch_func_t get_fetch_size_function(const struct fetch_type *type, + fetch_func_t orig_fn) +{ + int i; + + if (type != &fetch_type_table[FETCH_TYPE_STRING]) + return NULL; /* Only string type needs size function */ + + for (i = 0; i < FETCH_MTD_END; i++) + if (type->fetch[i] == orig_fn) + return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; + + WARN_ON(1); /* This should not happen */ + + return NULL; +} + +/* Split symbol and offset. */ +int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtoul(tmp + 1, 0, offset); + if (ret) + return ret; + + *tmp = '\0'; + } else + *offset = 0; + + return 0; +} + +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_probe_vars(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + int ret = 0; + unsigned long param; + + if (strcmp(arg, "retval") == 0) { + if (is_return) + f->fn = t->fetch[FETCH_MTD_retval]; + else + ret = -EINVAL; + } else if (strncmp(arg, "stack", 5) == 0) { + if (arg[5] == '\0') { + if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) + f->fn = fetch_stack_address; + else + ret = -EINVAL; + } else if (isdigit(arg[5])) { + ret = strict_strtoul(arg + 5, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + f->fn = t->fetch[FETCH_MTD_stack]; + f->data = (void *)param; + } + } else + ret = -EINVAL; + } else + ret = -EINVAL; + + return ret; +} + +/* Recursive argument parser */ +static int parse_probe_arg(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + unsigned long param; + long offset; + char *tmp; + int ret; + + ret = 0; + switch (arg[0]) { + case '$': + ret = parse_probe_vars(arg + 1, t, f, is_return); + break; + + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + f->fn = t->fetch[FETCH_MTD_reg]; + f->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + + f->fn = t->fetch[FETCH_MTD_memory]; + f->data = (void *)param; + } else { + ret = traceprobe_split_symbol_offset(arg + 1, &offset); + if (ret) + break; + + f->data = alloc_symbol_cache(arg + 1, offset); + if (f->data) + f->fn = t->fetch[FETCH_MTD_symbol]; + } + break; + + case '+': /* deref memory */ + arg++; /* Skip '+', because strict_strtol() rejects it. */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) + break; + + *tmp = '\0'; + ret = strict_strtol(arg, 0, &offset); + + if (ret) + break; + + arg = tmp + 1; + tmp = strrchr(arg, ')'); + + if (tmp) { + struct deref_fetch_param *dprm; + const struct fetch_type *t2; + + t2 = find_fetch_type(NULL); + *tmp = '\0'; + dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); + + if (!dprm) + return -ENOMEM; + + dprm->offset = offset; + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + if (ret) + kfree(dprm); + else { + f->fn = t->fetch[FETCH_MTD_deref]; + f->data = (void *)dprm; + } + } + break; + } + if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ + pr_info("%s type has no corresponding fetch method.\n", t->name); + ret = -EINVAL; + } + + return ret; +} + +#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) + +/* Bitfield type needs to be parsed into a fetch function */ +static int __parse_bitfield_probe_arg(const char *bf, + const struct fetch_type *t, + struct fetch_param *f) +{ + struct bitfield_fetch_param *bprm; + unsigned long bw, bo; + char *tail; + + if (*bf != 'b') + return 0; + + bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + if (!bprm) + return -ENOMEM; + + bprm->orig = *f; + f->fn = t->fetch[FETCH_MTD_bitfield]; + f->data = (void *)bprm; + bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ + + if (bw == 0 || *tail != '@') + return -EINVAL; + + bf = tail + 1; + bo = simple_strtoul(bf, &tail, 0); + + if (tail == bf || *tail != '/') + return -EINVAL; + + bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); + bprm->low_shift = bprm->hi_shift + bo; + + return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; +} + +/* String length checking wrapper */ +int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return) +{ + const char *t; + int ret; + + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument is too long.: %s\n", arg); + return -ENOSPC; + } + parg->comm = kstrdup(arg, GFP_KERNEL); + if (!parg->comm) { + pr_info("Failed to allocate memory for command '%s'.\n", arg); + return -ENOMEM; + } + t = strchr(parg->comm, ':'); + if (t) { + arg[t - parg->comm] = '\0'; + t++; + } + parg->type = find_fetch_type(t); + if (!parg->type) { + pr_info("Unsupported type: %s\n", t); + return -EINVAL; + } + parg->offset = *size; + *size += parg->type->size; + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + + if (ret >= 0 && t != NULL) + ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); + + if (ret >= 0) { + parg->fetch_size.fn = get_fetch_size_function(parg->type, + parg->fetch.fn); + parg->fetch_size.data = parg->fetch.data; + } + + return ret; +} + +/* Return 1 if name is reserved or already used by another argument */ +int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + + return 0; +} + +void traceprobe_update_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + update_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + update_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + update_symbol_cache(arg->fetch.data); +} + +void traceprobe_free_probe_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + free_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + free_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + free_symbol_cache(arg->fetch.data); + + kfree(arg->name); + kfree(arg->comm); +} + +int traceprobe_command(const char *buf, int (*createfn)(int, char **)) +{ + char **argv; + int argc, ret; + + argc = 0; + ret = 0; + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = createfn(argc, argv); + + argv_free(argv); + + return ret; +} + +#define WRITE_BUFSIZE 4096 + +ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos, + int (*createfn)(int, char **)) +{ + char *kbuf, *tmp; + int ret = 0; + size_t done = 0; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + while (done < count) { + size = count - done; + + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + + if (tmp) + *tmp = '\0'; + + ret = traceprobe_command(kbuf, createfn); + if (ret) + goto out; + } + ret = done; + +out: + kfree(kbuf); + + return ret; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h new file mode 100644 index 0000000..2df9a18 --- /dev/null +++ b/kernel/trace/trace_probe.h @@ -0,0 +1,160 @@ +/* + * Common header file for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.h written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/debugfs.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/ptrace.h> +#include <linux/perf_event.h> +#include <linux/kprobes.h> +#include <linux/stringify.h> +#include <linux/limits.h> +#include <linux/uaccess.h> +#include <asm/bitsperlong.h> + +#include "trace.h" +#include "trace_output.h" + +#define MAX_TRACE_ARGS 128 +#define MAX_ARGSTR_LEN 63 +#define MAX_EVENT_NAME_LEN 64 +#define MAX_STRING_SIZE PATH_MAX + +/* Reserved field names */ +#define FIELD_STRING_IP "__probe_ip" +#define FIELD_STRING_RETIP "__probe_ret_ip" +#define FIELD_STRING_FUNC "__probe_func" + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + + +/* Flags for trace_probe */ +#define TP_FLAG_TRACE 1 +#define TP_FLAG_PROFILE 2 +#define TP_FLAG_REGISTERED 4 + + +/* data_rloc: data relative location, compatible with u32 */ +#define make_data_rloc(len, roffs) \ + (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) +#define get_rloc_len(dl) ((u32)(dl) >> 16) +#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) + +/* + * Convert data_rloc to data_loc: + * data_rloc stores the offset from data_rloc itself, but data_loc + * stores the offset from event entry. + */ +#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) + +/* Data fetch function type */ +typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); +/* Printing function type */ +typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); + +/* Fetch types */ +enum { + FETCH_MTD_reg = 0, + FETCH_MTD_stack, + FETCH_MTD_retval, + FETCH_MTD_memory, + FETCH_MTD_symbol, + FETCH_MTD_deref, + FETCH_MTD_bitfield, + FETCH_MTD_END, +}; + +/* Fetch type information table */ +struct fetch_type { + const char *name; /* Name of type */ + size_t size; /* Byte size of type */ + int is_signed; /* Signed flag */ + print_type_func_t print; /* Print functions */ + const char *fmt; /* Fromat string */ + const char *fmttype; /* Name in format file */ + /* Fetch functions */ + fetch_func_t fetch[FETCH_MTD_END]; +}; + +struct fetch_param { + fetch_func_t fn; + void *data; +}; + +struct probe_arg { + struct fetch_param fetch; + struct fetch_param fetch_size; + unsigned int offset; /* Offset from argument entry */ + const char *name; /* Name of this argument */ + const char *comm; /* Command of this argument */ + const struct fetch_type *type; /* Type of this argument */ +}; + +static inline __kprobes void call_fetch(struct fetch_param *fprm, + struct pt_regs *regs, void *dest) +{ + return fprm->fn(regs, fprm->data, dest); +} + +/* Check the name is good for event/group/fields */ +static inline int is_good_name(const char *name) +{ + if (!isalpha(*name) && *name != '_') + return 0; + while (*++name != '\0') { + if (!isalpha(*name) && !isdigit(*name) && *name != '_') + return 0; + } + return 1; +} + +extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return); + +extern int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg); + +extern void traceprobe_update_arg(struct probe_arg *arg); +extern void traceprobe_free_probe_arg(struct probe_arg *arg); + +extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); + +extern ssize_t traceprobe_probes_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos, + int (*createfn)(int, char**)); + +extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH 2/3] tracing: Extract out common code for kprobes/uprobes trace events @ 2012-04-09 9:11 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-09 9:11 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Move parts of trace_kprobe.c that can be shared with upcoming trace_uprobe.c. Common code to kernel/trace/trace_probe.h and kernel/trace/trace_probe.c. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog: (v5) - Handle regressions in changes pointed by Steven Rostedt. - Extracted out int to bool changes to a separate patch. - Fix a bug in kprobe_trace_self_tests_init that was introduced in previous patchset. (v7) - Modified Copyright as suggested by Steven Rostedt. kernel/trace/Kconfig | 4 kernel/trace/Makefile | 1 kernel/trace/trace_kprobe.c | 889 +------------------------------------------ kernel/trace/trace_probe.c | 833 ++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 160 ++++++++ 5 files changed, 1016 insertions(+), 871 deletions(-) create mode 100644 kernel/trace/trace_probe.c create mode 100644 kernel/trace/trace_probe.h diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a1d2849..ce5a5c5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -373,6 +373,7 @@ config KPROBE_EVENT depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" select TRACING + select PROBE_EVENTS default y help This allows the user to add tracing events (similar to tracepoints) @@ -385,6 +386,9 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config PROBE_EVENTS + def_bool n + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 5f39a07..fa10d5c 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -61,5 +61,6 @@ endif ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif +obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4f935f8..f8b7773 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -19,547 +19,15 @@ #include <linux/module.h> #include <linux/uaccess.h> -#include <linux/kprobes.h> -#include <linux/seq_file.h> -#include <linux/slab.h> -#include <linux/smp.h> -#include <linux/debugfs.h> -#include <linux/types.h> -#include <linux/string.h> -#include <linux/ctype.h> -#include <linux/ptrace.h> -#include <linux/perf_event.h> -#include <linux/stringify.h> -#include <linux/limits.h> -#include <asm/bitsperlong.h> - -#include "trace.h" -#include "trace_output.h" - -#define MAX_TRACE_ARGS 128 -#define MAX_ARGSTR_LEN 63 -#define MAX_EVENT_NAME_LEN 64 -#define MAX_STRING_SIZE PATH_MAX -#define KPROBE_EVENT_SYSTEM "kprobes" - -/* Reserved field names */ -#define FIELD_STRING_IP "__probe_ip" -#define FIELD_STRING_RETIP "__probe_ret_ip" -#define FIELD_STRING_FUNC "__probe_func" - -const char *reserved_field_names[] = { - "common_type", - "common_flags", - "common_preempt_count", - "common_pid", - "common_tgid", - FIELD_STRING_IP, - FIELD_STRING_RETIP, - FIELD_STRING_FUNC, -}; - -/* Printing function type */ -typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, - void *); -#define PRINT_TYPE_FUNC_NAME(type) print_type_##type -#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type - -/* Printing in basic type function template */ -#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ -static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent)\ -{ \ - return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ -} \ -static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; - -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) -DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) - -/* data_rloc: data relative location, compatible with u32 */ -#define make_data_rloc(len, roffs) \ - (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) -#define get_rloc_len(dl) ((u32)(dl) >> 16) -#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) - -static inline void *get_rloc_data(u32 *dl) -{ - return (u8 *)dl + get_rloc_offs(*dl); -} - -/* For data_loc conversion */ -static inline void *get_loc_data(u32 *dl, void *ent) -{ - return (u8 *)ent + get_rloc_offs(*dl); -} - -/* - * Convert data_rloc to data_loc: - * data_rloc stores the offset from data_rloc itself, but data_loc - * stores the offset from event entry. - */ -#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) - -/* For defining macros, define string/string_size types */ -typedef u32 string; -typedef u32 string_size; - -/* Print type function for string type */ -static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, - const char *name, - void *data, void *ent) -{ - int len = *(u32 *)data >> 16; - - if (!len) - return trace_seq_printf(s, " %s=(fault)", name); - else - return trace_seq_printf(s, " %s=\"%s\"", name, - (const char *)get_loc_data(data, ent)); -} -static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; - -/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); - -struct fetch_param { - fetch_func_t fn; - void *data; -}; - -static __kprobes void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - -#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - -#define CHECK_FETCH_FUNCS(method, fn) \ - (((FETCH_FUNC_NAME(method, u8) == fn) || \ - (FETCH_FUNC_NAME(method, u16) == fn) || \ - (FETCH_FUNC_NAME(method, u32) == fn) || \ - (FETCH_FUNC_NAME(method, u64) == fn) || \ - (FETCH_FUNC_NAME(method, string) == fn) || \ - (FETCH_FUNC_NAME(method, string_size) == fn)) \ - && (fn != NULL)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -#define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_retval(type) \ -static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - long ret; - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - u8 *src = addr; - mm_segment_t old_fs = get_fs(); - if (!maxlen) - return; - /* - * Try to get string again, since the string can be changed while - * probing. - */ - set_fs(KERNEL_DS); - pagefault_disable(); - do - ret = __copy_from_user_inatomic(dst++, src++, 1); - while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); - dst[-1] = '\0'; - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) { /* Failed to fetch string */ - ((u8 *)get_rloc_data(dest))[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else - *(u32 *)dest = make_data_rloc(src - (u8 *)addr, - get_rloc_offs(*(u32 *)dest)); -} -/* Return the length of string -- including null terminal byte */ -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - int ret, len = 0; - u8 c; - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - pagefault_disable(); - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} - -/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -static unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - if (sc->addr) - sc->addr += sc->offset; - return sc->addr; -} - -static void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - return sc; -} - -#define DEFINE_FETCH_symbol(type) \ -static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; -}; - -#define DEFINE_FETCH_deref(type) \ -static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - fetch_memory_##type(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string) -DEFINE_FETCH_deref(string_size) - -static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Bitfield fetch function */ -struct bitfield_fetch_param { - struct fetch_param orig; - unsigned char hi_shift; - unsigned char low_shift; -}; +#include "trace_probe.h" -#define DEFINE_FETCH_bitfield(type) \ -static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct bitfield_fetch_param *bprm = data; \ - type buf = 0; \ - call_fetch(&bprm->orig, regs, &buf); \ - if (buf) { \ - buf <<= bprm->hi_shift; \ - buf >>= bprm->low_shift; \ - } \ - *(type *)dest = buf; \ -} -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -static __kprobes void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Default (unsigned long) fetch type */ -#define __DEFAULT_FETCH_TYPE(t) u##t -#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) -#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) -#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) - -/* Fetch types */ -enum { - FETCH_MTD_reg = 0, - FETCH_MTD_stack, - FETCH_MTD_retval, - FETCH_MTD_memory, - FETCH_MTD_symbol, - FETCH_MTD_deref, - FETCH_MTD_bitfield, - FETCH_MTD_END, -}; - -#define ASSIGN_FETCH_FUNC(method, type) \ - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) - -#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ - {.name = _name, \ - .size = _size, \ - .is_signed = sign, \ - .print = PRINT_TYPE_FUNC_NAME(ptype), \ - .fmt = PRINT_TYPE_FMT_NAME(ptype), \ - .fmttype = _fmttype, \ - .fetch = { \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ - } \ - } - -#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) - -#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 - -/* Fetch type information table */ -static const struct fetch_type { - const char *name; /* Name of type */ - size_t size; /* Byte size of type */ - int is_signed; /* Signed flag */ - print_type_func_t print; /* Print functions */ - const char *fmt; /* Fromat string */ - const char *fmttype; /* Name in format file */ - /* Fetch functions */ - fetch_func_t fetch[FETCH_MTD_END]; -} fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), -}; - -static const struct fetch_type *find_fetch_type(const char *type) -{ - int i; - - if (!type) - type = DEFAULT_FETCH_TYPE_STR; - - /* Special case: bitfield */ - if (*type == 'b') { - unsigned long bs; - type = strchr(type, '/'); - if (!type) - goto fail; - type++; - if (strict_strtoul(type, 0, &bs)) - goto fail; - switch (bs) { - case 8: - return find_fetch_type("u8"); - case 16: - return find_fetch_type("u16"); - case 32: - return find_fetch_type("u32"); - case 64: - return find_fetch_type("u64"); - default: - goto fail; - } - } - - for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) - if (strcmp(type, fetch_type_table[i].name) == 0) - return &fetch_type_table[i]; -fail: - return NULL; -} - -/* Special function : only accept unsigned long */ -static __kprobes void fetch_stack_address(struct pt_regs *regs, - void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} - -static fetch_func_t get_fetch_size_function(const struct fetch_type *type, - fetch_func_t orig_fn) -{ - int i; - - if (type != &fetch_type_table[FETCH_TYPE_STRING]) - return NULL; /* Only string type needs size function */ - for (i = 0; i < FETCH_MTD_END; i++) - if (type->fetch[i] == orig_fn) - return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; - - WARN_ON(1); /* This should not happen */ - return NULL; -} +#define KPROBE_EVENT_SYSTEM "kprobes" /** * Kprobe event core functions */ -struct probe_arg { - struct fetch_param fetch; - struct fetch_param fetch_size; - unsigned int offset; /* Offset from argument entry */ - const char *name; /* Name of this argument */ - const char *comm; /* Command of this argument */ - const struct fetch_type *type; /* Type of this argument */ -}; - -/* Flags for trace_probe */ -#define TP_FLAG_TRACE 1 -#define TP_FLAG_PROFILE 2 -#define TP_FLAG_REGISTERED 4 - struct trace_probe { struct list_head list; struct kretprobe rp; /* Use rp.kp for kprobe use */ @@ -631,18 +99,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); -/* Check the name is good for event/group/fields */ -static int is_good_name(const char *name) -{ - if (!isalpha(*name) && *name != '_') - return 0; - while (*++name != '\0') { - if (!isalpha(*name) && !isdigit(*name) && *name != '_') - return 0; - } - return 1; -} - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -702,34 +158,12 @@ static struct trace_probe *alloc_trace_probe(const char *group, return ERR_PTR(ret); } -static void update_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - update_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - update_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - update_symbol_cache(arg->fetch.data); -} - -static void free_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - free_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - kfree(arg->name); - kfree(arg->comm); -} - static void free_trace_probe(struct trace_probe *tp) { int i; for (i = 0; i < tp->nr_args; i++) - free_probe_arg(&tp->args[i]); + traceprobe_free_probe_arg(&tp->args[i]); kfree(tp->call.class->system); kfree(tp->call.name); @@ -787,7 +221,7 @@ static int __register_trace_probe(struct trace_probe *tp) return -EINVAL; for (i = 0; i < tp->nr_args; i++) - update_probe_arg(&tp->args[i]); + traceprobe_update_arg(&tp->args[i]); /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(tp)) @@ -919,227 +353,6 @@ static struct notifier_block trace_probe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; -/* Split symbol and offset. */ -static int split_symbol_offset(char *symbol, unsigned long *offset) -{ - char *tmp; - int ret; - - if (!offset) - return -EINVAL; - - tmp = strchr(symbol, '+'); - if (tmp) { - /* skip sign because strict_strtol doesn't accept '+' */ - ret = strict_strtoul(tmp + 1, 0, offset); - if (ret) - return ret; - *tmp = '\0'; - } else - *offset = 0; - return 0; -} - -#define PARAM_MAX_ARGS 16 -#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) - -static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - - if (strcmp(arg, "retval") == 0) { - if (is_return) - f->fn = t->fetch[FETCH_MTD_retval]; - else - ret = -EINVAL; - } else if (strncmp(arg, "stack", 5) == 0) { - if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) - f->fn = fetch_stack_address; - else - ret = -EINVAL; - } else if (isdigit(arg[5])) { - ret = strict_strtoul(arg + 5, 10, ¶m); - if (ret || param > PARAM_MAX_STACK) - ret = -EINVAL; - else { - f->fn = t->fetch[FETCH_MTD_stack]; - f->data = (void *)param; - } - } else - ret = -EINVAL; - } else - ret = -EINVAL; - return ret; -} - -/* Recursive argument parser */ -static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - long offset; - char *tmp; - - switch (arg[0]) { - case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return); - break; - case '%': /* named register */ - ret = regs_query_register_offset(arg + 1); - if (ret >= 0) { - f->fn = t->fetch[FETCH_MTD_reg]; - f->data = (void *)(unsigned long)ret; - ret = 0; - } - break; - case '@': /* memory or symbol */ - if (isdigit(arg[1])) { - ret = strict_strtoul(arg + 1, 0, ¶m); - if (ret) - break; - f->fn = t->fetch[FETCH_MTD_memory]; - f->data = (void *)param; - } else { - ret = split_symbol_offset(arg + 1, &offset); - if (ret) - break; - f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->fetch[FETCH_MTD_symbol]; - } - break; - case '+': /* deref memory */ - arg++; /* Skip '+', because strict_strtol() rejects it. */ - case '-': - tmp = strchr(arg, '('); - if (!tmp) - break; - *tmp = '\0'; - ret = strict_strtol(arg, 0, &offset); - if (ret) - break; - arg = tmp + 1; - tmp = strrchr(arg, ')'); - if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2 = find_fetch_type(NULL); - *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), - GFP_KERNEL); - if (!dprm) - return -ENOMEM; - dprm->offset = offset; - ret = __parse_probe_arg(arg, t2, &dprm->orig, - is_return); - if (ret) - kfree(dprm); - else { - f->fn = t->fetch[FETCH_MTD_deref]; - f->data = (void *)dprm; - } - } - break; - } - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ - pr_info("%s type has no corresponding fetch method.\n", - t->name); - ret = -EINVAL; - } - return ret; -} - -#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) - -/* Bitfield type needs to be parsed into a fetch function */ -static int __parse_bitfield_probe_arg(const char *bf, - const struct fetch_type *t, - struct fetch_param *f) -{ - struct bitfield_fetch_param *bprm; - unsigned long bw, bo; - char *tail; - - if (*bf != 'b') - return 0; - - bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - return -ENOMEM; - bprm->orig = *f; - f->fn = t->fetch[FETCH_MTD_bitfield]; - f->data = (void *)bprm; - - bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ - if (bw == 0 || *tail != '@') - return -EINVAL; - - bf = tail + 1; - bo = simple_strtoul(bf, &tail, 0); - if (tail == bf || *tail != '/') - return -EINVAL; - - bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); - bprm->low_shift = bprm->hi_shift + bo; - return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; -} - -/* String length checking wrapper */ -static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, bool is_return) -{ - const char *t; - int ret; - - if (strlen(arg) > MAX_ARGSTR_LEN) { - pr_info("Argument is too long.: %s\n", arg); - return -ENOSPC; - } - parg->comm = kstrdup(arg, GFP_KERNEL); - if (!parg->comm) { - pr_info("Failed to allocate memory for command '%s'.\n", arg); - return -ENOMEM; - } - t = strchr(parg->comm, ':'); - if (t) { - arg[t - parg->comm] = '\0'; - t++; - } - parg->type = find_fetch_type(t); - if (!parg->type) { - pr_info("Unsupported type: %s\n", t); - return -EINVAL; - } - parg->offset = tp->size; - tp->size += parg->type->size; - ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); - if (ret >= 0 && t != NULL) - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); - if (ret >= 0) { - parg->fetch_size.fn = get_fetch_size_function(parg->type, - parg->fetch.fn); - parg->fetch_size.data = parg->fetch.data; - } - return ret; -} - -/* Return 1 if name is reserved or already used by another argument */ -static int conflict_field_name(const char *name, - struct probe_arg *args, int narg) -{ - int i; - for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) - if (strcmp(reserved_field_names[i], name) == 0) - return 1; - for (i = 0; i < narg; i++) - if (strcmp(args[i].name, name) == 0) - return 1; - return 0; -} - static int create_trace_probe(int argc, char **argv) { /* @@ -1240,7 +453,7 @@ static int create_trace_probe(int argc, char **argv) /* a symbol specified */ symbol = argv[1]; /* TODO: support .init module functions */ - ret = split_symbol_offset(symbol, &offset); + ret = traceprobe_split_symbol_offset(symbol, &offset); if (ret) { pr_info("Failed to parse symbol.\n"); return ret; @@ -1302,7 +515,8 @@ static int create_trace_probe(int argc, char **argv) goto error; } - if (conflict_field_name(tp->args[i].name, tp->args, i)) { + if (traceprobe_conflict_field_name(tp->args[i].name, + tp->args, i)) { pr_info("Argument[%d] name '%s' conflicts with " "another field.\n", i, argv[i]); ret = -EINVAL; @@ -1310,7 +524,8 @@ static int create_trace_probe(int argc, char **argv) } /* Parse fetch argument */ - ret = parse_probe_arg(arg, tp, &tp->args[i], is_return); + ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], + is_return); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -1412,70 +627,11 @@ static int probes_open(struct inode *inode, struct file *file) return seq_open(file, &probes_seq_op); } -static int command_trace_probe(const char *buf) -{ - char **argv; - int argc = 0, ret = 0; - - argv = argv_split(GFP_KERNEL, buf, &argc); - if (!argv) - return -ENOMEM; - - if (argc) - ret = create_trace_probe(argc, argv); - - argv_free(argv); - return ret; -} - -#define WRITE_BUFSIZE 4096 - static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { - char *kbuf, *tmp; - int ret; - size_t done; - size_t size; - - kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - ret = done = 0; - while (done < count) { - size = count - done; - if (size >= WRITE_BUFSIZE) - size = WRITE_BUFSIZE - 1; - if (copy_from_user(kbuf, buffer + done, size)) { - ret = -EFAULT; - goto out; - } - kbuf[size] = '\0'; - tmp = strchr(kbuf, '\n'); - if (tmp) { - *tmp = '\0'; - size = tmp - kbuf + 1; - } else if (done + size < count) { - pr_warning("Line length is too long: " - "Should be less than %d.", WRITE_BUFSIZE); - ret = -EINVAL; - goto out; - } - done += size; - /* Remove comments */ - tmp = strchr(kbuf, '#'); - if (tmp) - *tmp = '\0'; - - ret = command_trace_probe(kbuf); - if (ret) - goto out; - } - ret = done; -out: - kfree(kbuf); - return ret; + return traceprobe_probes_write(file, buffer, count, ppos, + create_trace_probe); } static const struct file_operations kprobe_events_ops = { @@ -1711,16 +867,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, return TRACE_TYPE_PARTIAL_LINE; } -#undef DEFINE_FIELD -#define DEFINE_FIELD(type, item, name, is_signed) \ - do { \ - ret = trace_define_field(event_call, #type, name, \ - offsetof(typeof(field), item), \ - sizeof(field.item), is_signed, \ - FILTER_OTHER); \ - if (ret) \ - return ret; \ - } while (0) static int kprobe_event_define_fields(struct ftrace_event_call *event_call) { @@ -2051,8 +1197,9 @@ static __init int kprobe_trace_self_tests_init(void) pr_info("Testing kprobe tracing: "); - ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " - "$stack $stack0 +0($stack)"); + ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " + "$stack $stack0 +0($stack)", + create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function entry.\n"); warn++; @@ -2066,8 +1213,8 @@ static __init int kprobe_trace_self_tests_init(void) enable_trace_probe(tp, TP_FLAG_TRACE); } - ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " - "$retval"); + ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " + "$retval", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function return.\n"); warn++; @@ -2101,13 +1248,13 @@ static __init int kprobe_trace_self_tests_init(void) } else disable_trace_probe(tp, TP_FLAG_TRACE); - ret = command_trace_probe("-:testprobe"); + ret = traceprobe_command("-:testprobe", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; } - ret = command_trace_probe("-:testprobe2"); + ret = traceprobe_command("-:testprobe2", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c new file mode 100644 index 0000000..8e526b9 --- /dev/null +++ b/kernel/trace/trace_probe.c @@ -0,0 +1,833 @@ +/* + * Common code for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include "trace_probe.h" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + FIELD_STRING_IP, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + +/* Printing function type */ +#define PRINT_TYPE_FUNC_NAME(type) print_type_##type +#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type + +/* Printing in basic type function template */ +#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ +static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ + const char *name, \ + void *data, void *ent)\ +{ \ + return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ +} \ +static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; + +DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) + +static inline void *get_rloc_data(u32 *dl) +{ + return (u8 *)dl + get_rloc_offs(*dl); +} + +/* For data_loc conversion */ +static inline void *get_loc_data(u32 *dl, void *ent) +{ + return (u8 *)ent + get_rloc_offs(*dl); +} + +/* For defining macros, define string/string_size types */ +typedef u32 string; +typedef u32 string_size; + +/* Print type function for string type */ +static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, + const char *name, + void *data, void *ent) +{ + int len = *(u32 *)data >> 16; + + if (!len) + return trace_seq_printf(s, " %s=(fault)", name); + else + return trace_seq_printf(s, " %s=\"%s\"", name, + (const char *)get_loc_data(data, ent)); +} + +static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; + +#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type +/* + * Define macro for basic types - we don't need to define s* types, because + * we have to care only about bitwidth at recording time. + */ +#define DEFINE_BASIC_FETCH_FUNCS(method) \ +DEFINE_FETCH_##method(u8) \ +DEFINE_FETCH_##method(u16) \ +DEFINE_FETCH_##method(u32) \ +DEFINE_FETCH_##method(u64) + +#define CHECK_FETCH_FUNCS(method, fn) \ + (((FETCH_FUNC_NAME(method, u8) == fn) || \ + (FETCH_FUNC_NAME(method, u16) == fn) || \ + (FETCH_FUNC_NAME(method, u32) == fn) || \ + (FETCH_FUNC_NAME(method, u64) == fn) || \ + (FETCH_FUNC_NAME(method, string) == fn) || \ + (FETCH_FUNC_NAME(method, string_size) == fn)) \ + && (fn != NULL)) + +/* Data fetch function templates */ +#define DEFINE_FETCH_reg(type) \ +static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_register(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(reg) +/* No string on the register */ +#define fetch_reg_string NULL +#define fetch_reg_string_size NULL + +#define DEFINE_FETCH_stack(type) \ +static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) +/* No string on the stack entry */ +#define fetch_stack_string NULL +#define fetch_stack_string_size NULL + +#define DEFINE_FETCH_retval(type) \ +static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ + void *dummy, void *dest) \ +{ \ + *(type *)dest = (type)regs_return_value(regs); \ +} +DEFINE_BASIC_FETCH_FUNCS(retval) +/* No string on the retval */ +#define fetch_retval_string NULL +#define fetch_retval_string_size NULL + +#define DEFINE_FETCH_memory(type) \ +static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ + void *addr, void *dest) \ +{ \ + type retval; \ + if (probe_kernel_address(addr, retval)) \ + *(type *)dest = 0; \ + else \ + *(type *)dest = retval; \ +} +DEFINE_BASIC_FETCH_FUNCS(memory) +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max + * length and relative data location. + */ +static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) +{ + long ret; + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + u8 *src = addr; + mm_segment_t old_fs = get_fs(); + + if (!maxlen) + return; + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + set_fs(KERNEL_DS); + pagefault_disable(); + + do + ret = __copy_from_user_inatomic(dst++, src++, 1); + while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); + + dst[-1] = '\0'; + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) { /* Failed to fetch string */ + ((u8 *)get_rloc_data(dest))[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); + } else { + *(u32 *)dest = make_data_rloc(src - (u8 *)addr, + get_rloc_offs(*(u32 *)dest)); + } +} + +/* Return the length of string -- including null terminal byte */ +static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) /* Failed to check the length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + + if (sc->addr) + sc->addr += sc->offset; + + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + update_symbol_cache(sc); + + return sc; +} + +#define DEFINE_FETCH_symbol(type) \ +static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct symbol_cache *sc = data; \ + if (sc->addr) \ + fetch_memory_##type(regs, (void *)sc->addr, dest); \ + else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(symbol) +DEFINE_FETCH_symbol(string) +DEFINE_FETCH_symbol(string_size) + +/* Dereference memory access function */ +struct deref_fetch_param { + struct fetch_param orig; + long offset; +}; + +#define DEFINE_FETCH_deref(type) \ +static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct deref_fetch_param *dprm = data; \ + unsigned long addr; \ + call_fetch(&dprm->orig, regs, &addr); \ + if (addr) { \ + addr += dprm->offset; \ + fetch_memory_##type(regs, (void *)addr, dest); \ + } else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(deref) +DEFINE_FETCH_deref(string) +DEFINE_FETCH_deref(string_size) + +static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/* Bitfield fetch function */ +struct bitfield_fetch_param { + struct fetch_param orig; + unsigned char hi_shift; + unsigned char low_shift; +}; + +#define DEFINE_FETCH_bitfield(type) \ +static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct bitfield_fetch_param *bprm = data; \ + type buf = 0; \ + call_fetch(&bprm->orig, regs, &buf); \ + if (buf) { \ + buf <<= bprm->hi_shift; \ + buf >>= bprm->low_shift; \ + } \ + *(type *)dest = buf; \ +} + +DEFINE_BASIC_FETCH_FUNCS(bitfield) +#define fetch_bitfield_string NULL +#define fetch_bitfield_string_size NULL + +static __kprobes void +update_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void +free_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + + kfree(data); +} + +/* Default (unsigned long) fetch type */ +#define __DEFAULT_FETCH_TYPE(t) u##t +#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) +#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) +#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) + +#define ASSIGN_FETCH_FUNC(method, type) \ + [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) + +#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ + {.name = _name, \ + .size = _size, \ + .is_signed = sign, \ + .print = PRINT_TYPE_FUNC_NAME(ptype), \ + .fmt = PRINT_TYPE_FMT_NAME(ptype), \ + .fmttype = _fmttype, \ + .fetch = { \ +ASSIGN_FETCH_FUNC(reg, ftype), \ +ASSIGN_FETCH_FUNC(stack, ftype), \ +ASSIGN_FETCH_FUNC(retval, ftype), \ +ASSIGN_FETCH_FUNC(memory, ftype), \ +ASSIGN_FETCH_FUNC(symbol, ftype), \ +ASSIGN_FETCH_FUNC(deref, ftype), \ +ASSIGN_FETCH_FUNC(bitfield, ftype), \ + } \ + } + +#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ + __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) + +#define FETCH_TYPE_STRING 0 +#define FETCH_TYPE_STRSIZE 1 + +/* Fetch type information table */ +static const struct fetch_type fetch_type_table[] = { + /* Special types */ + [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, + sizeof(u32), 1, "__data_loc char[]"), + [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, + string_size, sizeof(u32), 0, "u32"), + /* Basic types */ + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), +}; + +static const struct fetch_type *find_fetch_type(const char *type) +{ + int i; + + if (!type) + type = DEFAULT_FETCH_TYPE_STR; + + /* Special case: bitfield */ + if (*type == 'b') { + unsigned long bs; + + type = strchr(type, '/'); + if (!type) + goto fail; + + type++; + if (strict_strtoul(type, 0, &bs)) + goto fail; + + switch (bs) { + case 8: + return find_fetch_type("u8"); + case 16: + return find_fetch_type("u16"); + case 32: + return find_fetch_type("u32"); + case 64: + return find_fetch_type("u64"); + default: + goto fail; + } + } + + for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) + if (strcmp(type, fetch_type_table[i].name) == 0) + return &fetch_type_table[i]; + +fail: + return NULL; +} + +/* Special function : only accept unsigned long */ +static __kprobes void fetch_stack_address(struct pt_regs *regs, + void *dummy, void *dest) +{ + *(unsigned long *)dest = kernel_stack_pointer(regs); +} + +static fetch_func_t get_fetch_size_function(const struct fetch_type *type, + fetch_func_t orig_fn) +{ + int i; + + if (type != &fetch_type_table[FETCH_TYPE_STRING]) + return NULL; /* Only string type needs size function */ + + for (i = 0; i < FETCH_MTD_END; i++) + if (type->fetch[i] == orig_fn) + return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; + + WARN_ON(1); /* This should not happen */ + + return NULL; +} + +/* Split symbol and offset. */ +int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtoul(tmp + 1, 0, offset); + if (ret) + return ret; + + *tmp = '\0'; + } else + *offset = 0; + + return 0; +} + +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_probe_vars(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + int ret = 0; + unsigned long param; + + if (strcmp(arg, "retval") == 0) { + if (is_return) + f->fn = t->fetch[FETCH_MTD_retval]; + else + ret = -EINVAL; + } else if (strncmp(arg, "stack", 5) == 0) { + if (arg[5] == '\0') { + if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) + f->fn = fetch_stack_address; + else + ret = -EINVAL; + } else if (isdigit(arg[5])) { + ret = strict_strtoul(arg + 5, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + f->fn = t->fetch[FETCH_MTD_stack]; + f->data = (void *)param; + } + } else + ret = -EINVAL; + } else + ret = -EINVAL; + + return ret; +} + +/* Recursive argument parser */ +static int parse_probe_arg(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + unsigned long param; + long offset; + char *tmp; + int ret; + + ret = 0; + switch (arg[0]) { + case '$': + ret = parse_probe_vars(arg + 1, t, f, is_return); + break; + + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + f->fn = t->fetch[FETCH_MTD_reg]; + f->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + + f->fn = t->fetch[FETCH_MTD_memory]; + f->data = (void *)param; + } else { + ret = traceprobe_split_symbol_offset(arg + 1, &offset); + if (ret) + break; + + f->data = alloc_symbol_cache(arg + 1, offset); + if (f->data) + f->fn = t->fetch[FETCH_MTD_symbol]; + } + break; + + case '+': /* deref memory */ + arg++; /* Skip '+', because strict_strtol() rejects it. */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) + break; + + *tmp = '\0'; + ret = strict_strtol(arg, 0, &offset); + + if (ret) + break; + + arg = tmp + 1; + tmp = strrchr(arg, ')'); + + if (tmp) { + struct deref_fetch_param *dprm; + const struct fetch_type *t2; + + t2 = find_fetch_type(NULL); + *tmp = '\0'; + dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); + + if (!dprm) + return -ENOMEM; + + dprm->offset = offset; + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + if (ret) + kfree(dprm); + else { + f->fn = t->fetch[FETCH_MTD_deref]; + f->data = (void *)dprm; + } + } + break; + } + if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ + pr_info("%s type has no corresponding fetch method.\n", t->name); + ret = -EINVAL; + } + + return ret; +} + +#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) + +/* Bitfield type needs to be parsed into a fetch function */ +static int __parse_bitfield_probe_arg(const char *bf, + const struct fetch_type *t, + struct fetch_param *f) +{ + struct bitfield_fetch_param *bprm; + unsigned long bw, bo; + char *tail; + + if (*bf != 'b') + return 0; + + bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + if (!bprm) + return -ENOMEM; + + bprm->orig = *f; + f->fn = t->fetch[FETCH_MTD_bitfield]; + f->data = (void *)bprm; + bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ + + if (bw == 0 || *tail != '@') + return -EINVAL; + + bf = tail + 1; + bo = simple_strtoul(bf, &tail, 0); + + if (tail == bf || *tail != '/') + return -EINVAL; + + bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); + bprm->low_shift = bprm->hi_shift + bo; + + return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; +} + +/* String length checking wrapper */ +int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return) +{ + const char *t; + int ret; + + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument is too long.: %s\n", arg); + return -ENOSPC; + } + parg->comm = kstrdup(arg, GFP_KERNEL); + if (!parg->comm) { + pr_info("Failed to allocate memory for command '%s'.\n", arg); + return -ENOMEM; + } + t = strchr(parg->comm, ':'); + if (t) { + arg[t - parg->comm] = '\0'; + t++; + } + parg->type = find_fetch_type(t); + if (!parg->type) { + pr_info("Unsupported type: %s\n", t); + return -EINVAL; + } + parg->offset = *size; + *size += parg->type->size; + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + + if (ret >= 0 && t != NULL) + ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); + + if (ret >= 0) { + parg->fetch_size.fn = get_fetch_size_function(parg->type, + parg->fetch.fn); + parg->fetch_size.data = parg->fetch.data; + } + + return ret; +} + +/* Return 1 if name is reserved or already used by another argument */ +int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + + return 0; +} + +void traceprobe_update_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + update_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + update_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + update_symbol_cache(arg->fetch.data); +} + +void traceprobe_free_probe_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + free_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + free_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + free_symbol_cache(arg->fetch.data); + + kfree(arg->name); + kfree(arg->comm); +} + +int traceprobe_command(const char *buf, int (*createfn)(int, char **)) +{ + char **argv; + int argc, ret; + + argc = 0; + ret = 0; + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = createfn(argc, argv); + + argv_free(argv); + + return ret; +} + +#define WRITE_BUFSIZE 4096 + +ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos, + int (*createfn)(int, char **)) +{ + char *kbuf, *tmp; + int ret = 0; + size_t done = 0; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + while (done < count) { + size = count - done; + + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + + if (tmp) + *tmp = '\0'; + + ret = traceprobe_command(kbuf, createfn); + if (ret) + goto out; + } + ret = done; + +out: + kfree(kbuf); + + return ret; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h new file mode 100644 index 0000000..2df9a18 --- /dev/null +++ b/kernel/trace/trace_probe.h @@ -0,0 +1,160 @@ +/* + * Common header file for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.h written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/debugfs.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/ptrace.h> +#include <linux/perf_event.h> +#include <linux/kprobes.h> +#include <linux/stringify.h> +#include <linux/limits.h> +#include <linux/uaccess.h> +#include <asm/bitsperlong.h> + +#include "trace.h" +#include "trace_output.h" + +#define MAX_TRACE_ARGS 128 +#define MAX_ARGSTR_LEN 63 +#define MAX_EVENT_NAME_LEN 64 +#define MAX_STRING_SIZE PATH_MAX + +/* Reserved field names */ +#define FIELD_STRING_IP "__probe_ip" +#define FIELD_STRING_RETIP "__probe_ret_ip" +#define FIELD_STRING_FUNC "__probe_func" + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + + +/* Flags for trace_probe */ +#define TP_FLAG_TRACE 1 +#define TP_FLAG_PROFILE 2 +#define TP_FLAG_REGISTERED 4 + + +/* data_rloc: data relative location, compatible with u32 */ +#define make_data_rloc(len, roffs) \ + (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) +#define get_rloc_len(dl) ((u32)(dl) >> 16) +#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) + +/* + * Convert data_rloc to data_loc: + * data_rloc stores the offset from data_rloc itself, but data_loc + * stores the offset from event entry. + */ +#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) + +/* Data fetch function type */ +typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); +/* Printing function type */ +typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); + +/* Fetch types */ +enum { + FETCH_MTD_reg = 0, + FETCH_MTD_stack, + FETCH_MTD_retval, + FETCH_MTD_memory, + FETCH_MTD_symbol, + FETCH_MTD_deref, + FETCH_MTD_bitfield, + FETCH_MTD_END, +}; + +/* Fetch type information table */ +struct fetch_type { + const char *name; /* Name of type */ + size_t size; /* Byte size of type */ + int is_signed; /* Signed flag */ + print_type_func_t print; /* Print functions */ + const char *fmt; /* Fromat string */ + const char *fmttype; /* Name in format file */ + /* Fetch functions */ + fetch_func_t fetch[FETCH_MTD_END]; +}; + +struct fetch_param { + fetch_func_t fn; + void *data; +}; + +struct probe_arg { + struct fetch_param fetch; + struct fetch_param fetch_size; + unsigned int offset; /* Offset from argument entry */ + const char *name; /* Name of this argument */ + const char *comm; /* Command of this argument */ + const struct fetch_type *type; /* Type of this argument */ +}; + +static inline __kprobes void call_fetch(struct fetch_param *fprm, + struct pt_regs *regs, void *dest) +{ + return fprm->fn(regs, fprm->data, dest); +} + +/* Check the name is good for event/group/fields */ +static inline int is_good_name(const char *name) +{ + if (!isalpha(*name) && *name != '_') + return 0; + while (*++name != '\0') { + if (!isalpha(*name) && !isdigit(*name) && *name != '_') + return 0; + } + return 1; +} + +extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return); + +extern int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg); + +extern void traceprobe_update_arg(struct probe_arg *arg); +extern void traceprobe_free_probe_arg(struct probe_arg *arg); + +extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); + +extern ssize_t traceprobe_probes_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos, + int (*createfn)(int, char**)); + +extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); ^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH 2/3] tracing: Extract out common code for kprobes/uprobes trace events 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-04-12 12:47 ` Masami Hiramatsu -1 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-12 12:47 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/09 18:11), Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Move parts of trace_kprobe.c that can be shared with upcoming > trace_uprobe.c. Common code to kernel/trace/trace_probe.h and > kernel/trace/trace_probe.c. There are no functional changes. Note: No functional change, means it does cosmetic changes. :) I've checked that all those cosmetic changes are acceptable. > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH 2/3] tracing: Extract out common code for kprobes/uprobes trace events @ 2012-04-12 12:47 ` Masami Hiramatsu 0 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-12 12:47 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/09 18:11), Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Move parts of trace_kprobe.c that can be shared with upcoming > trace_uprobe.c. Common code to kernel/trace/trace_probe.h and > kernel/trace/trace_probe.c. There are no functional changes. Note: No functional change, means it does cosmetic changes. :) I've checked that all those cosmetic changes are acceptable. > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com ^ permalink raw reply [flat|nested] 42+ messages in thread
* [tip:perf/uprobes] tracing: Extract out common code for kprobes/ uprobes trace events 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-05-08 4:08 ` tip-bot for Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: tip-bot for Srikar Dronamraju @ 2012-05-08 4:08 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, torvalds, peterz, anton, jkenisto, rostedt, oleg, tglx, linux-mm, hpa, linux-kernel, andi, hch, ananth, masami.hiramatsu.pt, acme, srikar Commit-ID: 8ab83f56475ec9151645a888dfe1941f4a92091d Gitweb: http://git.kernel.org/tip/8ab83f56475ec9151645a888dfe1941f4a92091d Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Mon, 9 Apr 2012 14:41:44 +0530 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 7 May 2012 14:29:57 +0200 tracing: Extract out common code for kprobes/uprobes trace events Move parts of trace_kprobe.c that can be shared with upcoming trace_uprobe.c. Common code to kernel/trace/trace_probe.h and kernel/trace/trace_probe.c. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120409091144.8343.76218.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/trace/Kconfig | 4 + kernel/trace/Makefile | 1 + kernel/trace/trace_kprobe.c | 889 +------------------------------------------ kernel/trace/trace_probe.c | 833 ++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 160 ++++++++ 5 files changed, 1016 insertions(+), 871 deletions(-) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a1d2849..ce5a5c5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -373,6 +373,7 @@ config KPROBE_EVENT depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" select TRACING + select PROBE_EVENTS default y help This allows the user to add tracing events (similar to tracepoints) @@ -385,6 +386,9 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config PROBE_EVENTS + def_bool n + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 5f39a07..fa10d5c 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -61,5 +61,6 @@ endif ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif +obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4f935f8..f8b7773 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -19,547 +19,15 @@ #include <linux/module.h> #include <linux/uaccess.h> -#include <linux/kprobes.h> -#include <linux/seq_file.h> -#include <linux/slab.h> -#include <linux/smp.h> -#include <linux/debugfs.h> -#include <linux/types.h> -#include <linux/string.h> -#include <linux/ctype.h> -#include <linux/ptrace.h> -#include <linux/perf_event.h> -#include <linux/stringify.h> -#include <linux/limits.h> -#include <asm/bitsperlong.h> - -#include "trace.h" -#include "trace_output.h" - -#define MAX_TRACE_ARGS 128 -#define MAX_ARGSTR_LEN 63 -#define MAX_EVENT_NAME_LEN 64 -#define MAX_STRING_SIZE PATH_MAX -#define KPROBE_EVENT_SYSTEM "kprobes" - -/* Reserved field names */ -#define FIELD_STRING_IP "__probe_ip" -#define FIELD_STRING_RETIP "__probe_ret_ip" -#define FIELD_STRING_FUNC "__probe_func" - -const char *reserved_field_names[] = { - "common_type", - "common_flags", - "common_preempt_count", - "common_pid", - "common_tgid", - FIELD_STRING_IP, - FIELD_STRING_RETIP, - FIELD_STRING_FUNC, -}; - -/* Printing function type */ -typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, - void *); -#define PRINT_TYPE_FUNC_NAME(type) print_type_##type -#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type - -/* Printing in basic type function template */ -#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ -static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent)\ -{ \ - return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ -} \ -static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; - -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) -DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) - -/* data_rloc: data relative location, compatible with u32 */ -#define make_data_rloc(len, roffs) \ - (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) -#define get_rloc_len(dl) ((u32)(dl) >> 16) -#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) - -static inline void *get_rloc_data(u32 *dl) -{ - return (u8 *)dl + get_rloc_offs(*dl); -} - -/* For data_loc conversion */ -static inline void *get_loc_data(u32 *dl, void *ent) -{ - return (u8 *)ent + get_rloc_offs(*dl); -} - -/* - * Convert data_rloc to data_loc: - * data_rloc stores the offset from data_rloc itself, but data_loc - * stores the offset from event entry. - */ -#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) - -/* For defining macros, define string/string_size types */ -typedef u32 string; -typedef u32 string_size; - -/* Print type function for string type */ -static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, - const char *name, - void *data, void *ent) -{ - int len = *(u32 *)data >> 16; - - if (!len) - return trace_seq_printf(s, " %s=(fault)", name); - else - return trace_seq_printf(s, " %s=\"%s\"", name, - (const char *)get_loc_data(data, ent)); -} -static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; - -/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); - -struct fetch_param { - fetch_func_t fn; - void *data; -}; - -static __kprobes void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - -#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - -#define CHECK_FETCH_FUNCS(method, fn) \ - (((FETCH_FUNC_NAME(method, u8) == fn) || \ - (FETCH_FUNC_NAME(method, u16) == fn) || \ - (FETCH_FUNC_NAME(method, u32) == fn) || \ - (FETCH_FUNC_NAME(method, u64) == fn) || \ - (FETCH_FUNC_NAME(method, string) == fn) || \ - (FETCH_FUNC_NAME(method, string_size) == fn)) \ - && (fn != NULL)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -#define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_retval(type) \ -static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - long ret; - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - u8 *src = addr; - mm_segment_t old_fs = get_fs(); - if (!maxlen) - return; - /* - * Try to get string again, since the string can be changed while - * probing. - */ - set_fs(KERNEL_DS); - pagefault_disable(); - do - ret = __copy_from_user_inatomic(dst++, src++, 1); - while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); - dst[-1] = '\0'; - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) { /* Failed to fetch string */ - ((u8 *)get_rloc_data(dest))[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else - *(u32 *)dest = make_data_rloc(src - (u8 *)addr, - get_rloc_offs(*(u32 *)dest)); -} -/* Return the length of string -- including null terminal byte */ -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - int ret, len = 0; - u8 c; - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - pagefault_disable(); - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} - -/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -static unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - if (sc->addr) - sc->addr += sc->offset; - return sc->addr; -} - -static void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - return sc; -} - -#define DEFINE_FETCH_symbol(type) \ -static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; -}; - -#define DEFINE_FETCH_deref(type) \ -static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - fetch_memory_##type(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string) -DEFINE_FETCH_deref(string_size) - -static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Bitfield fetch function */ -struct bitfield_fetch_param { - struct fetch_param orig; - unsigned char hi_shift; - unsigned char low_shift; -}; +#include "trace_probe.h" -#define DEFINE_FETCH_bitfield(type) \ -static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct bitfield_fetch_param *bprm = data; \ - type buf = 0; \ - call_fetch(&bprm->orig, regs, &buf); \ - if (buf) { \ - buf <<= bprm->hi_shift; \ - buf >>= bprm->low_shift; \ - } \ - *(type *)dest = buf; \ -} -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -static __kprobes void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Default (unsigned long) fetch type */ -#define __DEFAULT_FETCH_TYPE(t) u##t -#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) -#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) -#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) - -/* Fetch types */ -enum { - FETCH_MTD_reg = 0, - FETCH_MTD_stack, - FETCH_MTD_retval, - FETCH_MTD_memory, - FETCH_MTD_symbol, - FETCH_MTD_deref, - FETCH_MTD_bitfield, - FETCH_MTD_END, -}; - -#define ASSIGN_FETCH_FUNC(method, type) \ - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) - -#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ - {.name = _name, \ - .size = _size, \ - .is_signed = sign, \ - .print = PRINT_TYPE_FUNC_NAME(ptype), \ - .fmt = PRINT_TYPE_FMT_NAME(ptype), \ - .fmttype = _fmttype, \ - .fetch = { \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ - } \ - } - -#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) - -#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 - -/* Fetch type information table */ -static const struct fetch_type { - const char *name; /* Name of type */ - size_t size; /* Byte size of type */ - int is_signed; /* Signed flag */ - print_type_func_t print; /* Print functions */ - const char *fmt; /* Fromat string */ - const char *fmttype; /* Name in format file */ - /* Fetch functions */ - fetch_func_t fetch[FETCH_MTD_END]; -} fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), -}; - -static const struct fetch_type *find_fetch_type(const char *type) -{ - int i; - - if (!type) - type = DEFAULT_FETCH_TYPE_STR; - - /* Special case: bitfield */ - if (*type == 'b') { - unsigned long bs; - type = strchr(type, '/'); - if (!type) - goto fail; - type++; - if (strict_strtoul(type, 0, &bs)) - goto fail; - switch (bs) { - case 8: - return find_fetch_type("u8"); - case 16: - return find_fetch_type("u16"); - case 32: - return find_fetch_type("u32"); - case 64: - return find_fetch_type("u64"); - default: - goto fail; - } - } - - for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) - if (strcmp(type, fetch_type_table[i].name) == 0) - return &fetch_type_table[i]; -fail: - return NULL; -} - -/* Special function : only accept unsigned long */ -static __kprobes void fetch_stack_address(struct pt_regs *regs, - void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} - -static fetch_func_t get_fetch_size_function(const struct fetch_type *type, - fetch_func_t orig_fn) -{ - int i; - - if (type != &fetch_type_table[FETCH_TYPE_STRING]) - return NULL; /* Only string type needs size function */ - for (i = 0; i < FETCH_MTD_END; i++) - if (type->fetch[i] == orig_fn) - return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; - - WARN_ON(1); /* This should not happen */ - return NULL; -} +#define KPROBE_EVENT_SYSTEM "kprobes" /** * Kprobe event core functions */ -struct probe_arg { - struct fetch_param fetch; - struct fetch_param fetch_size; - unsigned int offset; /* Offset from argument entry */ - const char *name; /* Name of this argument */ - const char *comm; /* Command of this argument */ - const struct fetch_type *type; /* Type of this argument */ -}; - -/* Flags for trace_probe */ -#define TP_FLAG_TRACE 1 -#define TP_FLAG_PROFILE 2 -#define TP_FLAG_REGISTERED 4 - struct trace_probe { struct list_head list; struct kretprobe rp; /* Use rp.kp for kprobe use */ @@ -631,18 +99,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); -/* Check the name is good for event/group/fields */ -static int is_good_name(const char *name) -{ - if (!isalpha(*name) && *name != '_') - return 0; - while (*++name != '\0') { - if (!isalpha(*name) && !isdigit(*name) && *name != '_') - return 0; - } - return 1; -} - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -702,34 +158,12 @@ error: return ERR_PTR(ret); } -static void update_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - update_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - update_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - update_symbol_cache(arg->fetch.data); -} - -static void free_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - free_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - kfree(arg->name); - kfree(arg->comm); -} - static void free_trace_probe(struct trace_probe *tp) { int i; for (i = 0; i < tp->nr_args; i++) - free_probe_arg(&tp->args[i]); + traceprobe_free_probe_arg(&tp->args[i]); kfree(tp->call.class->system); kfree(tp->call.name); @@ -787,7 +221,7 @@ static int __register_trace_probe(struct trace_probe *tp) return -EINVAL; for (i = 0; i < tp->nr_args; i++) - update_probe_arg(&tp->args[i]); + traceprobe_update_arg(&tp->args[i]); /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(tp)) @@ -919,227 +353,6 @@ static struct notifier_block trace_probe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; -/* Split symbol and offset. */ -static int split_symbol_offset(char *symbol, unsigned long *offset) -{ - char *tmp; - int ret; - - if (!offset) - return -EINVAL; - - tmp = strchr(symbol, '+'); - if (tmp) { - /* skip sign because strict_strtol doesn't accept '+' */ - ret = strict_strtoul(tmp + 1, 0, offset); - if (ret) - return ret; - *tmp = '\0'; - } else - *offset = 0; - return 0; -} - -#define PARAM_MAX_ARGS 16 -#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) - -static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - - if (strcmp(arg, "retval") == 0) { - if (is_return) - f->fn = t->fetch[FETCH_MTD_retval]; - else - ret = -EINVAL; - } else if (strncmp(arg, "stack", 5) == 0) { - if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) - f->fn = fetch_stack_address; - else - ret = -EINVAL; - } else if (isdigit(arg[5])) { - ret = strict_strtoul(arg + 5, 10, ¶m); - if (ret || param > PARAM_MAX_STACK) - ret = -EINVAL; - else { - f->fn = t->fetch[FETCH_MTD_stack]; - f->data = (void *)param; - } - } else - ret = -EINVAL; - } else - ret = -EINVAL; - return ret; -} - -/* Recursive argument parser */ -static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - long offset; - char *tmp; - - switch (arg[0]) { - case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return); - break; - case '%': /* named register */ - ret = regs_query_register_offset(arg + 1); - if (ret >= 0) { - f->fn = t->fetch[FETCH_MTD_reg]; - f->data = (void *)(unsigned long)ret; - ret = 0; - } - break; - case '@': /* memory or symbol */ - if (isdigit(arg[1])) { - ret = strict_strtoul(arg + 1, 0, ¶m); - if (ret) - break; - f->fn = t->fetch[FETCH_MTD_memory]; - f->data = (void *)param; - } else { - ret = split_symbol_offset(arg + 1, &offset); - if (ret) - break; - f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->fetch[FETCH_MTD_symbol]; - } - break; - case '+': /* deref memory */ - arg++; /* Skip '+', because strict_strtol() rejects it. */ - case '-': - tmp = strchr(arg, '('); - if (!tmp) - break; - *tmp = '\0'; - ret = strict_strtol(arg, 0, &offset); - if (ret) - break; - arg = tmp + 1; - tmp = strrchr(arg, ')'); - if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2 = find_fetch_type(NULL); - *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), - GFP_KERNEL); - if (!dprm) - return -ENOMEM; - dprm->offset = offset; - ret = __parse_probe_arg(arg, t2, &dprm->orig, - is_return); - if (ret) - kfree(dprm); - else { - f->fn = t->fetch[FETCH_MTD_deref]; - f->data = (void *)dprm; - } - } - break; - } - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ - pr_info("%s type has no corresponding fetch method.\n", - t->name); - ret = -EINVAL; - } - return ret; -} - -#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) - -/* Bitfield type needs to be parsed into a fetch function */ -static int __parse_bitfield_probe_arg(const char *bf, - const struct fetch_type *t, - struct fetch_param *f) -{ - struct bitfield_fetch_param *bprm; - unsigned long bw, bo; - char *tail; - - if (*bf != 'b') - return 0; - - bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - return -ENOMEM; - bprm->orig = *f; - f->fn = t->fetch[FETCH_MTD_bitfield]; - f->data = (void *)bprm; - - bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ - if (bw == 0 || *tail != '@') - return -EINVAL; - - bf = tail + 1; - bo = simple_strtoul(bf, &tail, 0); - if (tail == bf || *tail != '/') - return -EINVAL; - - bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); - bprm->low_shift = bprm->hi_shift + bo; - return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; -} - -/* String length checking wrapper */ -static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, bool is_return) -{ - const char *t; - int ret; - - if (strlen(arg) > MAX_ARGSTR_LEN) { - pr_info("Argument is too long.: %s\n", arg); - return -ENOSPC; - } - parg->comm = kstrdup(arg, GFP_KERNEL); - if (!parg->comm) { - pr_info("Failed to allocate memory for command '%s'.\n", arg); - return -ENOMEM; - } - t = strchr(parg->comm, ':'); - if (t) { - arg[t - parg->comm] = '\0'; - t++; - } - parg->type = find_fetch_type(t); - if (!parg->type) { - pr_info("Unsupported type: %s\n", t); - return -EINVAL; - } - parg->offset = tp->size; - tp->size += parg->type->size; - ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); - if (ret >= 0 && t != NULL) - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); - if (ret >= 0) { - parg->fetch_size.fn = get_fetch_size_function(parg->type, - parg->fetch.fn); - parg->fetch_size.data = parg->fetch.data; - } - return ret; -} - -/* Return 1 if name is reserved or already used by another argument */ -static int conflict_field_name(const char *name, - struct probe_arg *args, int narg) -{ - int i; - for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) - if (strcmp(reserved_field_names[i], name) == 0) - return 1; - for (i = 0; i < narg; i++) - if (strcmp(args[i].name, name) == 0) - return 1; - return 0; -} - static int create_trace_probe(int argc, char **argv) { /* @@ -1240,7 +453,7 @@ static int create_trace_probe(int argc, char **argv) /* a symbol specified */ symbol = argv[1]; /* TODO: support .init module functions */ - ret = split_symbol_offset(symbol, &offset); + ret = traceprobe_split_symbol_offset(symbol, &offset); if (ret) { pr_info("Failed to parse symbol.\n"); return ret; @@ -1302,7 +515,8 @@ static int create_trace_probe(int argc, char **argv) goto error; } - if (conflict_field_name(tp->args[i].name, tp->args, i)) { + if (traceprobe_conflict_field_name(tp->args[i].name, + tp->args, i)) { pr_info("Argument[%d] name '%s' conflicts with " "another field.\n", i, argv[i]); ret = -EINVAL; @@ -1310,7 +524,8 @@ static int create_trace_probe(int argc, char **argv) } /* Parse fetch argument */ - ret = parse_probe_arg(arg, tp, &tp->args[i], is_return); + ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], + is_return); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -1412,70 +627,11 @@ static int probes_open(struct inode *inode, struct file *file) return seq_open(file, &probes_seq_op); } -static int command_trace_probe(const char *buf) -{ - char **argv; - int argc = 0, ret = 0; - - argv = argv_split(GFP_KERNEL, buf, &argc); - if (!argv) - return -ENOMEM; - - if (argc) - ret = create_trace_probe(argc, argv); - - argv_free(argv); - return ret; -} - -#define WRITE_BUFSIZE 4096 - static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { - char *kbuf, *tmp; - int ret; - size_t done; - size_t size; - - kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - ret = done = 0; - while (done < count) { - size = count - done; - if (size >= WRITE_BUFSIZE) - size = WRITE_BUFSIZE - 1; - if (copy_from_user(kbuf, buffer + done, size)) { - ret = -EFAULT; - goto out; - } - kbuf[size] = '\0'; - tmp = strchr(kbuf, '\n'); - if (tmp) { - *tmp = '\0'; - size = tmp - kbuf + 1; - } else if (done + size < count) { - pr_warning("Line length is too long: " - "Should be less than %d.", WRITE_BUFSIZE); - ret = -EINVAL; - goto out; - } - done += size; - /* Remove comments */ - tmp = strchr(kbuf, '#'); - if (tmp) - *tmp = '\0'; - - ret = command_trace_probe(kbuf); - if (ret) - goto out; - } - ret = done; -out: - kfree(kbuf); - return ret; + return traceprobe_probes_write(file, buffer, count, ppos, + create_trace_probe); } static const struct file_operations kprobe_events_ops = { @@ -1711,16 +867,6 @@ partial: return TRACE_TYPE_PARTIAL_LINE; } -#undef DEFINE_FIELD -#define DEFINE_FIELD(type, item, name, is_signed) \ - do { \ - ret = trace_define_field(event_call, #type, name, \ - offsetof(typeof(field), item), \ - sizeof(field.item), is_signed, \ - FILTER_OTHER); \ - if (ret) \ - return ret; \ - } while (0) static int kprobe_event_define_fields(struct ftrace_event_call *event_call) { @@ -2051,8 +1197,9 @@ static __init int kprobe_trace_self_tests_init(void) pr_info("Testing kprobe tracing: "); - ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " - "$stack $stack0 +0($stack)"); + ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " + "$stack $stack0 +0($stack)", + create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function entry.\n"); warn++; @@ -2066,8 +1213,8 @@ static __init int kprobe_trace_self_tests_init(void) enable_trace_probe(tp, TP_FLAG_TRACE); } - ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " - "$retval"); + ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " + "$retval", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function return.\n"); warn++; @@ -2101,13 +1248,13 @@ static __init int kprobe_trace_self_tests_init(void) } else disable_trace_probe(tp, TP_FLAG_TRACE); - ret = command_trace_probe("-:testprobe"); + ret = traceprobe_command("-:testprobe", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; } - ret = command_trace_probe("-:testprobe2"); + ret = traceprobe_command("-:testprobe2", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c new file mode 100644 index 0000000..8e526b9 --- /dev/null +++ b/kernel/trace/trace_probe.c @@ -0,0 +1,833 @@ +/* + * Common code for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include "trace_probe.h" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + FIELD_STRING_IP, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + +/* Printing function type */ +#define PRINT_TYPE_FUNC_NAME(type) print_type_##type +#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type + +/* Printing in basic type function template */ +#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ +static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ + const char *name, \ + void *data, void *ent)\ +{ \ + return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ +} \ +static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; + +DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) + +static inline void *get_rloc_data(u32 *dl) +{ + return (u8 *)dl + get_rloc_offs(*dl); +} + +/* For data_loc conversion */ +static inline void *get_loc_data(u32 *dl, void *ent) +{ + return (u8 *)ent + get_rloc_offs(*dl); +} + +/* For defining macros, define string/string_size types */ +typedef u32 string; +typedef u32 string_size; + +/* Print type function for string type */ +static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, + const char *name, + void *data, void *ent) +{ + int len = *(u32 *)data >> 16; + + if (!len) + return trace_seq_printf(s, " %s=(fault)", name); + else + return trace_seq_printf(s, " %s=\"%s\"", name, + (const char *)get_loc_data(data, ent)); +} + +static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; + +#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type +/* + * Define macro for basic types - we don't need to define s* types, because + * we have to care only about bitwidth at recording time. + */ +#define DEFINE_BASIC_FETCH_FUNCS(method) \ +DEFINE_FETCH_##method(u8) \ +DEFINE_FETCH_##method(u16) \ +DEFINE_FETCH_##method(u32) \ +DEFINE_FETCH_##method(u64) + +#define CHECK_FETCH_FUNCS(method, fn) \ + (((FETCH_FUNC_NAME(method, u8) == fn) || \ + (FETCH_FUNC_NAME(method, u16) == fn) || \ + (FETCH_FUNC_NAME(method, u32) == fn) || \ + (FETCH_FUNC_NAME(method, u64) == fn) || \ + (FETCH_FUNC_NAME(method, string) == fn) || \ + (FETCH_FUNC_NAME(method, string_size) == fn)) \ + && (fn != NULL)) + +/* Data fetch function templates */ +#define DEFINE_FETCH_reg(type) \ +static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_register(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(reg) +/* No string on the register */ +#define fetch_reg_string NULL +#define fetch_reg_string_size NULL + +#define DEFINE_FETCH_stack(type) \ +static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) +/* No string on the stack entry */ +#define fetch_stack_string NULL +#define fetch_stack_string_size NULL + +#define DEFINE_FETCH_retval(type) \ +static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ + void *dummy, void *dest) \ +{ \ + *(type *)dest = (type)regs_return_value(regs); \ +} +DEFINE_BASIC_FETCH_FUNCS(retval) +/* No string on the retval */ +#define fetch_retval_string NULL +#define fetch_retval_string_size NULL + +#define DEFINE_FETCH_memory(type) \ +static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ + void *addr, void *dest) \ +{ \ + type retval; \ + if (probe_kernel_address(addr, retval)) \ + *(type *)dest = 0; \ + else \ + *(type *)dest = retval; \ +} +DEFINE_BASIC_FETCH_FUNCS(memory) +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max + * length and relative data location. + */ +static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) +{ + long ret; + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + u8 *src = addr; + mm_segment_t old_fs = get_fs(); + + if (!maxlen) + return; + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + set_fs(KERNEL_DS); + pagefault_disable(); + + do + ret = __copy_from_user_inatomic(dst++, src++, 1); + while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); + + dst[-1] = '\0'; + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) { /* Failed to fetch string */ + ((u8 *)get_rloc_data(dest))[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); + } else { + *(u32 *)dest = make_data_rloc(src - (u8 *)addr, + get_rloc_offs(*(u32 *)dest)); + } +} + +/* Return the length of string -- including null terminal byte */ +static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) /* Failed to check the length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + + if (sc->addr) + sc->addr += sc->offset; + + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + update_symbol_cache(sc); + + return sc; +} + +#define DEFINE_FETCH_symbol(type) \ +static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct symbol_cache *sc = data; \ + if (sc->addr) \ + fetch_memory_##type(regs, (void *)sc->addr, dest); \ + else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(symbol) +DEFINE_FETCH_symbol(string) +DEFINE_FETCH_symbol(string_size) + +/* Dereference memory access function */ +struct deref_fetch_param { + struct fetch_param orig; + long offset; +}; + +#define DEFINE_FETCH_deref(type) \ +static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct deref_fetch_param *dprm = data; \ + unsigned long addr; \ + call_fetch(&dprm->orig, regs, &addr); \ + if (addr) { \ + addr += dprm->offset; \ + fetch_memory_##type(regs, (void *)addr, dest); \ + } else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(deref) +DEFINE_FETCH_deref(string) +DEFINE_FETCH_deref(string_size) + +static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/* Bitfield fetch function */ +struct bitfield_fetch_param { + struct fetch_param orig; + unsigned char hi_shift; + unsigned char low_shift; +}; + +#define DEFINE_FETCH_bitfield(type) \ +static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct bitfield_fetch_param *bprm = data; \ + type buf = 0; \ + call_fetch(&bprm->orig, regs, &buf); \ + if (buf) { \ + buf <<= bprm->hi_shift; \ + buf >>= bprm->low_shift; \ + } \ + *(type *)dest = buf; \ +} + +DEFINE_BASIC_FETCH_FUNCS(bitfield) +#define fetch_bitfield_string NULL +#define fetch_bitfield_string_size NULL + +static __kprobes void +update_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void +free_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + + kfree(data); +} + +/* Default (unsigned long) fetch type */ +#define __DEFAULT_FETCH_TYPE(t) u##t +#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) +#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) +#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) + +#define ASSIGN_FETCH_FUNC(method, type) \ + [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) + +#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ + {.name = _name, \ + .size = _size, \ + .is_signed = sign, \ + .print = PRINT_TYPE_FUNC_NAME(ptype), \ + .fmt = PRINT_TYPE_FMT_NAME(ptype), \ + .fmttype = _fmttype, \ + .fetch = { \ +ASSIGN_FETCH_FUNC(reg, ftype), \ +ASSIGN_FETCH_FUNC(stack, ftype), \ +ASSIGN_FETCH_FUNC(retval, ftype), \ +ASSIGN_FETCH_FUNC(memory, ftype), \ +ASSIGN_FETCH_FUNC(symbol, ftype), \ +ASSIGN_FETCH_FUNC(deref, ftype), \ +ASSIGN_FETCH_FUNC(bitfield, ftype), \ + } \ + } + +#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ + __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) + +#define FETCH_TYPE_STRING 0 +#define FETCH_TYPE_STRSIZE 1 + +/* Fetch type information table */ +static const struct fetch_type fetch_type_table[] = { + /* Special types */ + [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, + sizeof(u32), 1, "__data_loc char[]"), + [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, + string_size, sizeof(u32), 0, "u32"), + /* Basic types */ + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), +}; + +static const struct fetch_type *find_fetch_type(const char *type) +{ + int i; + + if (!type) + type = DEFAULT_FETCH_TYPE_STR; + + /* Special case: bitfield */ + if (*type == 'b') { + unsigned long bs; + + type = strchr(type, '/'); + if (!type) + goto fail; + + type++; + if (strict_strtoul(type, 0, &bs)) + goto fail; + + switch (bs) { + case 8: + return find_fetch_type("u8"); + case 16: + return find_fetch_type("u16"); + case 32: + return find_fetch_type("u32"); + case 64: + return find_fetch_type("u64"); + default: + goto fail; + } + } + + for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) + if (strcmp(type, fetch_type_table[i].name) == 0) + return &fetch_type_table[i]; + +fail: + return NULL; +} + +/* Special function : only accept unsigned long */ +static __kprobes void fetch_stack_address(struct pt_regs *regs, + void *dummy, void *dest) +{ + *(unsigned long *)dest = kernel_stack_pointer(regs); +} + +static fetch_func_t get_fetch_size_function(const struct fetch_type *type, + fetch_func_t orig_fn) +{ + int i; + + if (type != &fetch_type_table[FETCH_TYPE_STRING]) + return NULL; /* Only string type needs size function */ + + for (i = 0; i < FETCH_MTD_END; i++) + if (type->fetch[i] == orig_fn) + return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; + + WARN_ON(1); /* This should not happen */ + + return NULL; +} + +/* Split symbol and offset. */ +int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtoul(tmp + 1, 0, offset); + if (ret) + return ret; + + *tmp = '\0'; + } else + *offset = 0; + + return 0; +} + +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_probe_vars(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + int ret = 0; + unsigned long param; + + if (strcmp(arg, "retval") == 0) { + if (is_return) + f->fn = t->fetch[FETCH_MTD_retval]; + else + ret = -EINVAL; + } else if (strncmp(arg, "stack", 5) == 0) { + if (arg[5] == '\0') { + if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) + f->fn = fetch_stack_address; + else + ret = -EINVAL; + } else if (isdigit(arg[5])) { + ret = strict_strtoul(arg + 5, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + f->fn = t->fetch[FETCH_MTD_stack]; + f->data = (void *)param; + } + } else + ret = -EINVAL; + } else + ret = -EINVAL; + + return ret; +} + +/* Recursive argument parser */ +static int parse_probe_arg(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + unsigned long param; + long offset; + char *tmp; + int ret; + + ret = 0; + switch (arg[0]) { + case '$': + ret = parse_probe_vars(arg + 1, t, f, is_return); + break; + + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + f->fn = t->fetch[FETCH_MTD_reg]; + f->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + + f->fn = t->fetch[FETCH_MTD_memory]; + f->data = (void *)param; + } else { + ret = traceprobe_split_symbol_offset(arg + 1, &offset); + if (ret) + break; + + f->data = alloc_symbol_cache(arg + 1, offset); + if (f->data) + f->fn = t->fetch[FETCH_MTD_symbol]; + } + break; + + case '+': /* deref memory */ + arg++; /* Skip '+', because strict_strtol() rejects it. */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) + break; + + *tmp = '\0'; + ret = strict_strtol(arg, 0, &offset); + + if (ret) + break; + + arg = tmp + 1; + tmp = strrchr(arg, ')'); + + if (tmp) { + struct deref_fetch_param *dprm; + const struct fetch_type *t2; + + t2 = find_fetch_type(NULL); + *tmp = '\0'; + dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); + + if (!dprm) + return -ENOMEM; + + dprm->offset = offset; + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + if (ret) + kfree(dprm); + else { + f->fn = t->fetch[FETCH_MTD_deref]; + f->data = (void *)dprm; + } + } + break; + } + if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ + pr_info("%s type has no corresponding fetch method.\n", t->name); + ret = -EINVAL; + } + + return ret; +} + +#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) + +/* Bitfield type needs to be parsed into a fetch function */ +static int __parse_bitfield_probe_arg(const char *bf, + const struct fetch_type *t, + struct fetch_param *f) +{ + struct bitfield_fetch_param *bprm; + unsigned long bw, bo; + char *tail; + + if (*bf != 'b') + return 0; + + bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + if (!bprm) + return -ENOMEM; + + bprm->orig = *f; + f->fn = t->fetch[FETCH_MTD_bitfield]; + f->data = (void *)bprm; + bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ + + if (bw == 0 || *tail != '@') + return -EINVAL; + + bf = tail + 1; + bo = simple_strtoul(bf, &tail, 0); + + if (tail == bf || *tail != '/') + return -EINVAL; + + bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); + bprm->low_shift = bprm->hi_shift + bo; + + return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; +} + +/* String length checking wrapper */ +int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return) +{ + const char *t; + int ret; + + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument is too long.: %s\n", arg); + return -ENOSPC; + } + parg->comm = kstrdup(arg, GFP_KERNEL); + if (!parg->comm) { + pr_info("Failed to allocate memory for command '%s'.\n", arg); + return -ENOMEM; + } + t = strchr(parg->comm, ':'); + if (t) { + arg[t - parg->comm] = '\0'; + t++; + } + parg->type = find_fetch_type(t); + if (!parg->type) { + pr_info("Unsupported type: %s\n", t); + return -EINVAL; + } + parg->offset = *size; + *size += parg->type->size; + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + + if (ret >= 0 && t != NULL) + ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); + + if (ret >= 0) { + parg->fetch_size.fn = get_fetch_size_function(parg->type, + parg->fetch.fn); + parg->fetch_size.data = parg->fetch.data; + } + + return ret; +} + +/* Return 1 if name is reserved or already used by another argument */ +int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + + return 0; +} + +void traceprobe_update_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + update_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + update_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + update_symbol_cache(arg->fetch.data); +} + +void traceprobe_free_probe_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + free_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + free_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + free_symbol_cache(arg->fetch.data); + + kfree(arg->name); + kfree(arg->comm); +} + +int traceprobe_command(const char *buf, int (*createfn)(int, char **)) +{ + char **argv; + int argc, ret; + + argc = 0; + ret = 0; + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = createfn(argc, argv); + + argv_free(argv); + + return ret; +} + +#define WRITE_BUFSIZE 4096 + +ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos, + int (*createfn)(int, char **)) +{ + char *kbuf, *tmp; + int ret = 0; + size_t done = 0; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + while (done < count) { + size = count - done; + + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + + if (tmp) + *tmp = '\0'; + + ret = traceprobe_command(kbuf, createfn); + if (ret) + goto out; + } + ret = done; + +out: + kfree(kbuf); + + return ret; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h new file mode 100644 index 0000000..2df9a18 --- /dev/null +++ b/kernel/trace/trace_probe.h @@ -0,0 +1,160 @@ +/* + * Common header file for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.h written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/debugfs.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/ptrace.h> +#include <linux/perf_event.h> +#include <linux/kprobes.h> +#include <linux/stringify.h> +#include <linux/limits.h> +#include <linux/uaccess.h> +#include <asm/bitsperlong.h> + +#include "trace.h" +#include "trace_output.h" + +#define MAX_TRACE_ARGS 128 +#define MAX_ARGSTR_LEN 63 +#define MAX_EVENT_NAME_LEN 64 +#define MAX_STRING_SIZE PATH_MAX + +/* Reserved field names */ +#define FIELD_STRING_IP "__probe_ip" +#define FIELD_STRING_RETIP "__probe_ret_ip" +#define FIELD_STRING_FUNC "__probe_func" + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + + +/* Flags for trace_probe */ +#define TP_FLAG_TRACE 1 +#define TP_FLAG_PROFILE 2 +#define TP_FLAG_REGISTERED 4 + + +/* data_rloc: data relative location, compatible with u32 */ +#define make_data_rloc(len, roffs) \ + (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) +#define get_rloc_len(dl) ((u32)(dl) >> 16) +#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) + +/* + * Convert data_rloc to data_loc: + * data_rloc stores the offset from data_rloc itself, but data_loc + * stores the offset from event entry. + */ +#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) + +/* Data fetch function type */ +typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); +/* Printing function type */ +typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); + +/* Fetch types */ +enum { + FETCH_MTD_reg = 0, + FETCH_MTD_stack, + FETCH_MTD_retval, + FETCH_MTD_memory, + FETCH_MTD_symbol, + FETCH_MTD_deref, + FETCH_MTD_bitfield, + FETCH_MTD_END, +}; + +/* Fetch type information table */ +struct fetch_type { + const char *name; /* Name of type */ + size_t size; /* Byte size of type */ + int is_signed; /* Signed flag */ + print_type_func_t print; /* Print functions */ + const char *fmt; /* Fromat string */ + const char *fmttype; /* Name in format file */ + /* Fetch functions */ + fetch_func_t fetch[FETCH_MTD_END]; +}; + +struct fetch_param { + fetch_func_t fn; + void *data; +}; + +struct probe_arg { + struct fetch_param fetch; + struct fetch_param fetch_size; + unsigned int offset; /* Offset from argument entry */ + const char *name; /* Name of this argument */ + const char *comm; /* Command of this argument */ + const struct fetch_type *type; /* Type of this argument */ +}; + +static inline __kprobes void call_fetch(struct fetch_param *fprm, + struct pt_regs *regs, void *dest) +{ + return fprm->fn(regs, fprm->data, dest); +} + +/* Check the name is good for event/group/fields */ +static inline int is_good_name(const char *name) +{ + if (!isalpha(*name) && *name != '_') + return 0; + while (*++name != '\0') { + if (!isalpha(*name) && !isdigit(*name) && *name != '_') + return 0; + } + return 1; +} + +extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return); + +extern int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg); + +extern void traceprobe_update_arg(struct probe_arg *arg); +extern void traceprobe_free_probe_arg(struct probe_arg *arg); + +extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); + +extern ssize_t traceprobe_probes_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos, + int (*createfn)(int, char**)); + +extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:perf/uprobes] tracing: Extract out common code for kprobes/ uprobes trace events @ 2012-05-08 4:08 ` tip-bot for Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: tip-bot for Srikar Dronamraju @ 2012-05-08 4:08 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, torvalds, peterz, anton, jkenisto, rostedt, oleg, tglx, linux-mm, hpa, linux-kernel, andi, hch, ananth, masami.hiramatsu.pt, acme, srikar Commit-ID: 8ab83f56475ec9151645a888dfe1941f4a92091d Gitweb: http://git.kernel.org/tip/8ab83f56475ec9151645a888dfe1941f4a92091d Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Mon, 9 Apr 2012 14:41:44 +0530 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 7 May 2012 14:29:57 +0200 tracing: Extract out common code for kprobes/uprobes trace events Move parts of trace_kprobe.c that can be shared with upcoming trace_uprobe.c. Common code to kernel/trace/trace_probe.h and kernel/trace/trace_probe.c. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120409091144.8343.76218.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/trace/Kconfig | 4 + kernel/trace/Makefile | 1 + kernel/trace/trace_kprobe.c | 889 +------------------------------------------ kernel/trace/trace_probe.c | 833 ++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 160 ++++++++ 5 files changed, 1016 insertions(+), 871 deletions(-) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a1d2849..ce5a5c5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -373,6 +373,7 @@ config KPROBE_EVENT depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" select TRACING + select PROBE_EVENTS default y help This allows the user to add tracing events (similar to tracepoints) @@ -385,6 +386,9 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config PROBE_EVENTS + def_bool n + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 5f39a07..fa10d5c 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -61,5 +61,6 @@ endif ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif +obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4f935f8..f8b7773 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -19,547 +19,15 @@ #include <linux/module.h> #include <linux/uaccess.h> -#include <linux/kprobes.h> -#include <linux/seq_file.h> -#include <linux/slab.h> -#include <linux/smp.h> -#include <linux/debugfs.h> -#include <linux/types.h> -#include <linux/string.h> -#include <linux/ctype.h> -#include <linux/ptrace.h> -#include <linux/perf_event.h> -#include <linux/stringify.h> -#include <linux/limits.h> -#include <asm/bitsperlong.h> - -#include "trace.h" -#include "trace_output.h" - -#define MAX_TRACE_ARGS 128 -#define MAX_ARGSTR_LEN 63 -#define MAX_EVENT_NAME_LEN 64 -#define MAX_STRING_SIZE PATH_MAX -#define KPROBE_EVENT_SYSTEM "kprobes" - -/* Reserved field names */ -#define FIELD_STRING_IP "__probe_ip" -#define FIELD_STRING_RETIP "__probe_ret_ip" -#define FIELD_STRING_FUNC "__probe_func" - -const char *reserved_field_names[] = { - "common_type", - "common_flags", - "common_preempt_count", - "common_pid", - "common_tgid", - FIELD_STRING_IP, - FIELD_STRING_RETIP, - FIELD_STRING_FUNC, -}; - -/* Printing function type */ -typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, - void *); -#define PRINT_TYPE_FUNC_NAME(type) print_type_##type -#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type - -/* Printing in basic type function template */ -#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ -static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent)\ -{ \ - return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ -} \ -static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; - -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) -DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) - -/* data_rloc: data relative location, compatible with u32 */ -#define make_data_rloc(len, roffs) \ - (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) -#define get_rloc_len(dl) ((u32)(dl) >> 16) -#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) - -static inline void *get_rloc_data(u32 *dl) -{ - return (u8 *)dl + get_rloc_offs(*dl); -} - -/* For data_loc conversion */ -static inline void *get_loc_data(u32 *dl, void *ent) -{ - return (u8 *)ent + get_rloc_offs(*dl); -} - -/* - * Convert data_rloc to data_loc: - * data_rloc stores the offset from data_rloc itself, but data_loc - * stores the offset from event entry. - */ -#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) - -/* For defining macros, define string/string_size types */ -typedef u32 string; -typedef u32 string_size; - -/* Print type function for string type */ -static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, - const char *name, - void *data, void *ent) -{ - int len = *(u32 *)data >> 16; - - if (!len) - return trace_seq_printf(s, " %s=(fault)", name); - else - return trace_seq_printf(s, " %s=\"%s\"", name, - (const char *)get_loc_data(data, ent)); -} -static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; - -/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); - -struct fetch_param { - fetch_func_t fn; - void *data; -}; - -static __kprobes void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - -#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - -#define CHECK_FETCH_FUNCS(method, fn) \ - (((FETCH_FUNC_NAME(method, u8) == fn) || \ - (FETCH_FUNC_NAME(method, u16) == fn) || \ - (FETCH_FUNC_NAME(method, u32) == fn) || \ - (FETCH_FUNC_NAME(method, u64) == fn) || \ - (FETCH_FUNC_NAME(method, string) == fn) || \ - (FETCH_FUNC_NAME(method, string_size) == fn)) \ - && (fn != NULL)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -#define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_retval(type) \ -static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - long ret; - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - u8 *src = addr; - mm_segment_t old_fs = get_fs(); - if (!maxlen) - return; - /* - * Try to get string again, since the string can be changed while - * probing. - */ - set_fs(KERNEL_DS); - pagefault_disable(); - do - ret = __copy_from_user_inatomic(dst++, src++, 1); - while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); - dst[-1] = '\0'; - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) { /* Failed to fetch string */ - ((u8 *)get_rloc_data(dest))[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else - *(u32 *)dest = make_data_rloc(src - (u8 *)addr, - get_rloc_offs(*(u32 *)dest)); -} -/* Return the length of string -- including null terminal byte */ -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - int ret, len = 0; - u8 c; - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - pagefault_disable(); - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} - -/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -static unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - if (sc->addr) - sc->addr += sc->offset; - return sc->addr; -} - -static void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - return sc; -} - -#define DEFINE_FETCH_symbol(type) \ -static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; -}; - -#define DEFINE_FETCH_deref(type) \ -static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - fetch_memory_##type(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string) -DEFINE_FETCH_deref(string_size) - -static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Bitfield fetch function */ -struct bitfield_fetch_param { - struct fetch_param orig; - unsigned char hi_shift; - unsigned char low_shift; -}; +#include "trace_probe.h" -#define DEFINE_FETCH_bitfield(type) \ -static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct bitfield_fetch_param *bprm = data; \ - type buf = 0; \ - call_fetch(&bprm->orig, regs, &buf); \ - if (buf) { \ - buf <<= bprm->hi_shift; \ - buf >>= bprm->low_shift; \ - } \ - *(type *)dest = buf; \ -} -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -static __kprobes void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static __kprobes void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Default (unsigned long) fetch type */ -#define __DEFAULT_FETCH_TYPE(t) u##t -#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) -#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) -#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) - -/* Fetch types */ -enum { - FETCH_MTD_reg = 0, - FETCH_MTD_stack, - FETCH_MTD_retval, - FETCH_MTD_memory, - FETCH_MTD_symbol, - FETCH_MTD_deref, - FETCH_MTD_bitfield, - FETCH_MTD_END, -}; - -#define ASSIGN_FETCH_FUNC(method, type) \ - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) - -#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ - {.name = _name, \ - .size = _size, \ - .is_signed = sign, \ - .print = PRINT_TYPE_FUNC_NAME(ptype), \ - .fmt = PRINT_TYPE_FMT_NAME(ptype), \ - .fmttype = _fmttype, \ - .fetch = { \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ - } \ - } - -#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) - -#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 - -/* Fetch type information table */ -static const struct fetch_type { - const char *name; /* Name of type */ - size_t size; /* Byte size of type */ - int is_signed; /* Signed flag */ - print_type_func_t print; /* Print functions */ - const char *fmt; /* Fromat string */ - const char *fmttype; /* Name in format file */ - /* Fetch functions */ - fetch_func_t fetch[FETCH_MTD_END]; -} fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), -}; - -static const struct fetch_type *find_fetch_type(const char *type) -{ - int i; - - if (!type) - type = DEFAULT_FETCH_TYPE_STR; - - /* Special case: bitfield */ - if (*type == 'b') { - unsigned long bs; - type = strchr(type, '/'); - if (!type) - goto fail; - type++; - if (strict_strtoul(type, 0, &bs)) - goto fail; - switch (bs) { - case 8: - return find_fetch_type("u8"); - case 16: - return find_fetch_type("u16"); - case 32: - return find_fetch_type("u32"); - case 64: - return find_fetch_type("u64"); - default: - goto fail; - } - } - - for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) - if (strcmp(type, fetch_type_table[i].name) == 0) - return &fetch_type_table[i]; -fail: - return NULL; -} - -/* Special function : only accept unsigned long */ -static __kprobes void fetch_stack_address(struct pt_regs *regs, - void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} - -static fetch_func_t get_fetch_size_function(const struct fetch_type *type, - fetch_func_t orig_fn) -{ - int i; - - if (type != &fetch_type_table[FETCH_TYPE_STRING]) - return NULL; /* Only string type needs size function */ - for (i = 0; i < FETCH_MTD_END; i++) - if (type->fetch[i] == orig_fn) - return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; - - WARN_ON(1); /* This should not happen */ - return NULL; -} +#define KPROBE_EVENT_SYSTEM "kprobes" /** * Kprobe event core functions */ -struct probe_arg { - struct fetch_param fetch; - struct fetch_param fetch_size; - unsigned int offset; /* Offset from argument entry */ - const char *name; /* Name of this argument */ - const char *comm; /* Command of this argument */ - const struct fetch_type *type; /* Type of this argument */ -}; - -/* Flags for trace_probe */ -#define TP_FLAG_TRACE 1 -#define TP_FLAG_PROFILE 2 -#define TP_FLAG_REGISTERED 4 - struct trace_probe { struct list_head list; struct kretprobe rp; /* Use rp.kp for kprobe use */ @@ -631,18 +99,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); -/* Check the name is good for event/group/fields */ -static int is_good_name(const char *name) -{ - if (!isalpha(*name) && *name != '_') - return 0; - while (*++name != '\0') { - if (!isalpha(*name) && !isdigit(*name) && *name != '_') - return 0; - } - return 1; -} - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -702,34 +158,12 @@ error: return ERR_PTR(ret); } -static void update_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - update_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - update_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - update_symbol_cache(arg->fetch.data); -} - -static void free_probe_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - free_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - kfree(arg->name); - kfree(arg->comm); -} - static void free_trace_probe(struct trace_probe *tp) { int i; for (i = 0; i < tp->nr_args; i++) - free_probe_arg(&tp->args[i]); + traceprobe_free_probe_arg(&tp->args[i]); kfree(tp->call.class->system); kfree(tp->call.name); @@ -787,7 +221,7 @@ static int __register_trace_probe(struct trace_probe *tp) return -EINVAL; for (i = 0; i < tp->nr_args; i++) - update_probe_arg(&tp->args[i]); + traceprobe_update_arg(&tp->args[i]); /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(tp)) @@ -919,227 +353,6 @@ static struct notifier_block trace_probe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; -/* Split symbol and offset. */ -static int split_symbol_offset(char *symbol, unsigned long *offset) -{ - char *tmp; - int ret; - - if (!offset) - return -EINVAL; - - tmp = strchr(symbol, '+'); - if (tmp) { - /* skip sign because strict_strtol doesn't accept '+' */ - ret = strict_strtoul(tmp + 1, 0, offset); - if (ret) - return ret; - *tmp = '\0'; - } else - *offset = 0; - return 0; -} - -#define PARAM_MAX_ARGS 16 -#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) - -static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - - if (strcmp(arg, "retval") == 0) { - if (is_return) - f->fn = t->fetch[FETCH_MTD_retval]; - else - ret = -EINVAL; - } else if (strncmp(arg, "stack", 5) == 0) { - if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) - f->fn = fetch_stack_address; - else - ret = -EINVAL; - } else if (isdigit(arg[5])) { - ret = strict_strtoul(arg + 5, 10, ¶m); - if (ret || param > PARAM_MAX_STACK) - ret = -EINVAL; - else { - f->fn = t->fetch[FETCH_MTD_stack]; - f->data = (void *)param; - } - } else - ret = -EINVAL; - } else - ret = -EINVAL; - return ret; -} - -/* Recursive argument parser */ -static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) -{ - int ret = 0; - unsigned long param; - long offset; - char *tmp; - - switch (arg[0]) { - case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return); - break; - case '%': /* named register */ - ret = regs_query_register_offset(arg + 1); - if (ret >= 0) { - f->fn = t->fetch[FETCH_MTD_reg]; - f->data = (void *)(unsigned long)ret; - ret = 0; - } - break; - case '@': /* memory or symbol */ - if (isdigit(arg[1])) { - ret = strict_strtoul(arg + 1, 0, ¶m); - if (ret) - break; - f->fn = t->fetch[FETCH_MTD_memory]; - f->data = (void *)param; - } else { - ret = split_symbol_offset(arg + 1, &offset); - if (ret) - break; - f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->fetch[FETCH_MTD_symbol]; - } - break; - case '+': /* deref memory */ - arg++; /* Skip '+', because strict_strtol() rejects it. */ - case '-': - tmp = strchr(arg, '('); - if (!tmp) - break; - *tmp = '\0'; - ret = strict_strtol(arg, 0, &offset); - if (ret) - break; - arg = tmp + 1; - tmp = strrchr(arg, ')'); - if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2 = find_fetch_type(NULL); - *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), - GFP_KERNEL); - if (!dprm) - return -ENOMEM; - dprm->offset = offset; - ret = __parse_probe_arg(arg, t2, &dprm->orig, - is_return); - if (ret) - kfree(dprm); - else { - f->fn = t->fetch[FETCH_MTD_deref]; - f->data = (void *)dprm; - } - } - break; - } - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ - pr_info("%s type has no corresponding fetch method.\n", - t->name); - ret = -EINVAL; - } - return ret; -} - -#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) - -/* Bitfield type needs to be parsed into a fetch function */ -static int __parse_bitfield_probe_arg(const char *bf, - const struct fetch_type *t, - struct fetch_param *f) -{ - struct bitfield_fetch_param *bprm; - unsigned long bw, bo; - char *tail; - - if (*bf != 'b') - return 0; - - bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - return -ENOMEM; - bprm->orig = *f; - f->fn = t->fetch[FETCH_MTD_bitfield]; - f->data = (void *)bprm; - - bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ - if (bw == 0 || *tail != '@') - return -EINVAL; - - bf = tail + 1; - bo = simple_strtoul(bf, &tail, 0); - if (tail == bf || *tail != '/') - return -EINVAL; - - bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); - bprm->low_shift = bprm->hi_shift + bo; - return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; -} - -/* String length checking wrapper */ -static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, bool is_return) -{ - const char *t; - int ret; - - if (strlen(arg) > MAX_ARGSTR_LEN) { - pr_info("Argument is too long.: %s\n", arg); - return -ENOSPC; - } - parg->comm = kstrdup(arg, GFP_KERNEL); - if (!parg->comm) { - pr_info("Failed to allocate memory for command '%s'.\n", arg); - return -ENOMEM; - } - t = strchr(parg->comm, ':'); - if (t) { - arg[t - parg->comm] = '\0'; - t++; - } - parg->type = find_fetch_type(t); - if (!parg->type) { - pr_info("Unsupported type: %s\n", t); - return -EINVAL; - } - parg->offset = tp->size; - tp->size += parg->type->size; - ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); - if (ret >= 0 && t != NULL) - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); - if (ret >= 0) { - parg->fetch_size.fn = get_fetch_size_function(parg->type, - parg->fetch.fn); - parg->fetch_size.data = parg->fetch.data; - } - return ret; -} - -/* Return 1 if name is reserved or already used by another argument */ -static int conflict_field_name(const char *name, - struct probe_arg *args, int narg) -{ - int i; - for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) - if (strcmp(reserved_field_names[i], name) == 0) - return 1; - for (i = 0; i < narg; i++) - if (strcmp(args[i].name, name) == 0) - return 1; - return 0; -} - static int create_trace_probe(int argc, char **argv) { /* @@ -1240,7 +453,7 @@ static int create_trace_probe(int argc, char **argv) /* a symbol specified */ symbol = argv[1]; /* TODO: support .init module functions */ - ret = split_symbol_offset(symbol, &offset); + ret = traceprobe_split_symbol_offset(symbol, &offset); if (ret) { pr_info("Failed to parse symbol.\n"); return ret; @@ -1302,7 +515,8 @@ static int create_trace_probe(int argc, char **argv) goto error; } - if (conflict_field_name(tp->args[i].name, tp->args, i)) { + if (traceprobe_conflict_field_name(tp->args[i].name, + tp->args, i)) { pr_info("Argument[%d] name '%s' conflicts with " "another field.\n", i, argv[i]); ret = -EINVAL; @@ -1310,7 +524,8 @@ static int create_trace_probe(int argc, char **argv) } /* Parse fetch argument */ - ret = parse_probe_arg(arg, tp, &tp->args[i], is_return); + ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], + is_return); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -1412,70 +627,11 @@ static int probes_open(struct inode *inode, struct file *file) return seq_open(file, &probes_seq_op); } -static int command_trace_probe(const char *buf) -{ - char **argv; - int argc = 0, ret = 0; - - argv = argv_split(GFP_KERNEL, buf, &argc); - if (!argv) - return -ENOMEM; - - if (argc) - ret = create_trace_probe(argc, argv); - - argv_free(argv); - return ret; -} - -#define WRITE_BUFSIZE 4096 - static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { - char *kbuf, *tmp; - int ret; - size_t done; - size_t size; - - kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - ret = done = 0; - while (done < count) { - size = count - done; - if (size >= WRITE_BUFSIZE) - size = WRITE_BUFSIZE - 1; - if (copy_from_user(kbuf, buffer + done, size)) { - ret = -EFAULT; - goto out; - } - kbuf[size] = '\0'; - tmp = strchr(kbuf, '\n'); - if (tmp) { - *tmp = '\0'; - size = tmp - kbuf + 1; - } else if (done + size < count) { - pr_warning("Line length is too long: " - "Should be less than %d.", WRITE_BUFSIZE); - ret = -EINVAL; - goto out; - } - done += size; - /* Remove comments */ - tmp = strchr(kbuf, '#'); - if (tmp) - *tmp = '\0'; - - ret = command_trace_probe(kbuf); - if (ret) - goto out; - } - ret = done; -out: - kfree(kbuf); - return ret; + return traceprobe_probes_write(file, buffer, count, ppos, + create_trace_probe); } static const struct file_operations kprobe_events_ops = { @@ -1711,16 +867,6 @@ partial: return TRACE_TYPE_PARTIAL_LINE; } -#undef DEFINE_FIELD -#define DEFINE_FIELD(type, item, name, is_signed) \ - do { \ - ret = trace_define_field(event_call, #type, name, \ - offsetof(typeof(field), item), \ - sizeof(field.item), is_signed, \ - FILTER_OTHER); \ - if (ret) \ - return ret; \ - } while (0) static int kprobe_event_define_fields(struct ftrace_event_call *event_call) { @@ -2051,8 +1197,9 @@ static __init int kprobe_trace_self_tests_init(void) pr_info("Testing kprobe tracing: "); - ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " - "$stack $stack0 +0($stack)"); + ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " + "$stack $stack0 +0($stack)", + create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function entry.\n"); warn++; @@ -2066,8 +1213,8 @@ static __init int kprobe_trace_self_tests_init(void) enable_trace_probe(tp, TP_FLAG_TRACE); } - ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " - "$retval"); + ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " + "$retval", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on probing function return.\n"); warn++; @@ -2101,13 +1248,13 @@ static __init int kprobe_trace_self_tests_init(void) } else disable_trace_probe(tp, TP_FLAG_TRACE); - ret = command_trace_probe("-:testprobe"); + ret = traceprobe_command("-:testprobe", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; } - ret = command_trace_probe("-:testprobe2"); + ret = traceprobe_command("-:testprobe2", create_trace_probe); if (WARN_ON_ONCE(ret)) { pr_warning("error on deleting a probe.\n"); warn++; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c new file mode 100644 index 0000000..8e526b9 --- /dev/null +++ b/kernel/trace/trace_probe.c @@ -0,0 +1,833 @@ +/* + * Common code for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include "trace_probe.h" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + FIELD_STRING_IP, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + +/* Printing function type */ +#define PRINT_TYPE_FUNC_NAME(type) print_type_##type +#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type + +/* Printing in basic type function template */ +#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ +static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ + const char *name, \ + void *data, void *ent)\ +{ \ + return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ +} \ +static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; + +DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) + +static inline void *get_rloc_data(u32 *dl) +{ + return (u8 *)dl + get_rloc_offs(*dl); +} + +/* For data_loc conversion */ +static inline void *get_loc_data(u32 *dl, void *ent) +{ + return (u8 *)ent + get_rloc_offs(*dl); +} + +/* For defining macros, define string/string_size types */ +typedef u32 string; +typedef u32 string_size; + +/* Print type function for string type */ +static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, + const char *name, + void *data, void *ent) +{ + int len = *(u32 *)data >> 16; + + if (!len) + return trace_seq_printf(s, " %s=(fault)", name); + else + return trace_seq_printf(s, " %s=\"%s\"", name, + (const char *)get_loc_data(data, ent)); +} + +static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; + +#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type +/* + * Define macro for basic types - we don't need to define s* types, because + * we have to care only about bitwidth at recording time. + */ +#define DEFINE_BASIC_FETCH_FUNCS(method) \ +DEFINE_FETCH_##method(u8) \ +DEFINE_FETCH_##method(u16) \ +DEFINE_FETCH_##method(u32) \ +DEFINE_FETCH_##method(u64) + +#define CHECK_FETCH_FUNCS(method, fn) \ + (((FETCH_FUNC_NAME(method, u8) == fn) || \ + (FETCH_FUNC_NAME(method, u16) == fn) || \ + (FETCH_FUNC_NAME(method, u32) == fn) || \ + (FETCH_FUNC_NAME(method, u64) == fn) || \ + (FETCH_FUNC_NAME(method, string) == fn) || \ + (FETCH_FUNC_NAME(method, string_size) == fn)) \ + && (fn != NULL)) + +/* Data fetch function templates */ +#define DEFINE_FETCH_reg(type) \ +static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_register(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(reg) +/* No string on the register */ +#define fetch_reg_string NULL +#define fetch_reg_string_size NULL + +#define DEFINE_FETCH_stack(type) \ +static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) +/* No string on the stack entry */ +#define fetch_stack_string NULL +#define fetch_stack_string_size NULL + +#define DEFINE_FETCH_retval(type) \ +static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ + void *dummy, void *dest) \ +{ \ + *(type *)dest = (type)regs_return_value(regs); \ +} +DEFINE_BASIC_FETCH_FUNCS(retval) +/* No string on the retval */ +#define fetch_retval_string NULL +#define fetch_retval_string_size NULL + +#define DEFINE_FETCH_memory(type) \ +static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ + void *addr, void *dest) \ +{ \ + type retval; \ + if (probe_kernel_address(addr, retval)) \ + *(type *)dest = 0; \ + else \ + *(type *)dest = retval; \ +} +DEFINE_BASIC_FETCH_FUNCS(memory) +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max + * length and relative data location. + */ +static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) +{ + long ret; + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + u8 *src = addr; + mm_segment_t old_fs = get_fs(); + + if (!maxlen) + return; + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + set_fs(KERNEL_DS); + pagefault_disable(); + + do + ret = __copy_from_user_inatomic(dst++, src++, 1); + while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); + + dst[-1] = '\0'; + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) { /* Failed to fetch string */ + ((u8 *)get_rloc_data(dest))[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); + } else { + *(u32 *)dest = make_data_rloc(src - (u8 *)addr, + get_rloc_offs(*(u32 *)dest)); + } +} + +/* Return the length of string -- including null terminal byte */ +static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) /* Failed to check the length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + + if (sc->addr) + sc->addr += sc->offset; + + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + update_symbol_cache(sc); + + return sc; +} + +#define DEFINE_FETCH_symbol(type) \ +static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct symbol_cache *sc = data; \ + if (sc->addr) \ + fetch_memory_##type(regs, (void *)sc->addr, dest); \ + else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(symbol) +DEFINE_FETCH_symbol(string) +DEFINE_FETCH_symbol(string_size) + +/* Dereference memory access function */ +struct deref_fetch_param { + struct fetch_param orig; + long offset; +}; + +#define DEFINE_FETCH_deref(type) \ +static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct deref_fetch_param *dprm = data; \ + unsigned long addr; \ + call_fetch(&dprm->orig, regs, &addr); \ + if (addr) { \ + addr += dprm->offset; \ + fetch_memory_##type(regs, (void *)addr, dest); \ + } else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(deref) +DEFINE_FETCH_deref(string) +DEFINE_FETCH_deref(string_size) + +static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/* Bitfield fetch function */ +struct bitfield_fetch_param { + struct fetch_param orig; + unsigned char hi_shift; + unsigned char low_shift; +}; + +#define DEFINE_FETCH_bitfield(type) \ +static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct bitfield_fetch_param *bprm = data; \ + type buf = 0; \ + call_fetch(&bprm->orig, regs, &buf); \ + if (buf) { \ + buf <<= bprm->hi_shift; \ + buf >>= bprm->low_shift; \ + } \ + *(type *)dest = buf; \ +} + +DEFINE_BASIC_FETCH_FUNCS(bitfield) +#define fetch_bitfield_string NULL +#define fetch_bitfield_string_size NULL + +static __kprobes void +update_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + update_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + update_symbol_cache(data->orig.data); +} + +static __kprobes void +free_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + + kfree(data); +} + +/* Default (unsigned long) fetch type */ +#define __DEFAULT_FETCH_TYPE(t) u##t +#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) +#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) +#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) + +#define ASSIGN_FETCH_FUNC(method, type) \ + [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) + +#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ + {.name = _name, \ + .size = _size, \ + .is_signed = sign, \ + .print = PRINT_TYPE_FUNC_NAME(ptype), \ + .fmt = PRINT_TYPE_FMT_NAME(ptype), \ + .fmttype = _fmttype, \ + .fetch = { \ +ASSIGN_FETCH_FUNC(reg, ftype), \ +ASSIGN_FETCH_FUNC(stack, ftype), \ +ASSIGN_FETCH_FUNC(retval, ftype), \ +ASSIGN_FETCH_FUNC(memory, ftype), \ +ASSIGN_FETCH_FUNC(symbol, ftype), \ +ASSIGN_FETCH_FUNC(deref, ftype), \ +ASSIGN_FETCH_FUNC(bitfield, ftype), \ + } \ + } + +#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ + __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) + +#define FETCH_TYPE_STRING 0 +#define FETCH_TYPE_STRSIZE 1 + +/* Fetch type information table */ +static const struct fetch_type fetch_type_table[] = { + /* Special types */ + [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, + sizeof(u32), 1, "__data_loc char[]"), + [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, + string_size, sizeof(u32), 0, "u32"), + /* Basic types */ + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), +}; + +static const struct fetch_type *find_fetch_type(const char *type) +{ + int i; + + if (!type) + type = DEFAULT_FETCH_TYPE_STR; + + /* Special case: bitfield */ + if (*type == 'b') { + unsigned long bs; + + type = strchr(type, '/'); + if (!type) + goto fail; + + type++; + if (strict_strtoul(type, 0, &bs)) + goto fail; + + switch (bs) { + case 8: + return find_fetch_type("u8"); + case 16: + return find_fetch_type("u16"); + case 32: + return find_fetch_type("u32"); + case 64: + return find_fetch_type("u64"); + default: + goto fail; + } + } + + for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) + if (strcmp(type, fetch_type_table[i].name) == 0) + return &fetch_type_table[i]; + +fail: + return NULL; +} + +/* Special function : only accept unsigned long */ +static __kprobes void fetch_stack_address(struct pt_regs *regs, + void *dummy, void *dest) +{ + *(unsigned long *)dest = kernel_stack_pointer(regs); +} + +static fetch_func_t get_fetch_size_function(const struct fetch_type *type, + fetch_func_t orig_fn) +{ + int i; + + if (type != &fetch_type_table[FETCH_TYPE_STRING]) + return NULL; /* Only string type needs size function */ + + for (i = 0; i < FETCH_MTD_END; i++) + if (type->fetch[i] == orig_fn) + return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; + + WARN_ON(1); /* This should not happen */ + + return NULL; +} + +/* Split symbol and offset. */ +int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtoul(tmp + 1, 0, offset); + if (ret) + return ret; + + *tmp = '\0'; + } else + *offset = 0; + + return 0; +} + +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_probe_vars(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + int ret = 0; + unsigned long param; + + if (strcmp(arg, "retval") == 0) { + if (is_return) + f->fn = t->fetch[FETCH_MTD_retval]; + else + ret = -EINVAL; + } else if (strncmp(arg, "stack", 5) == 0) { + if (arg[5] == '\0') { + if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) + f->fn = fetch_stack_address; + else + ret = -EINVAL; + } else if (isdigit(arg[5])) { + ret = strict_strtoul(arg + 5, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + f->fn = t->fetch[FETCH_MTD_stack]; + f->data = (void *)param; + } + } else + ret = -EINVAL; + } else + ret = -EINVAL; + + return ret; +} + +/* Recursive argument parser */ +static int parse_probe_arg(char *arg, const struct fetch_type *t, + struct fetch_param *f, bool is_return) +{ + unsigned long param; + long offset; + char *tmp; + int ret; + + ret = 0; + switch (arg[0]) { + case '$': + ret = parse_probe_vars(arg + 1, t, f, is_return); + break; + + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + f->fn = t->fetch[FETCH_MTD_reg]; + f->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + + f->fn = t->fetch[FETCH_MTD_memory]; + f->data = (void *)param; + } else { + ret = traceprobe_split_symbol_offset(arg + 1, &offset); + if (ret) + break; + + f->data = alloc_symbol_cache(arg + 1, offset); + if (f->data) + f->fn = t->fetch[FETCH_MTD_symbol]; + } + break; + + case '+': /* deref memory */ + arg++; /* Skip '+', because strict_strtol() rejects it. */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) + break; + + *tmp = '\0'; + ret = strict_strtol(arg, 0, &offset); + + if (ret) + break; + + arg = tmp + 1; + tmp = strrchr(arg, ')'); + + if (tmp) { + struct deref_fetch_param *dprm; + const struct fetch_type *t2; + + t2 = find_fetch_type(NULL); + *tmp = '\0'; + dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); + + if (!dprm) + return -ENOMEM; + + dprm->offset = offset; + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + if (ret) + kfree(dprm); + else { + f->fn = t->fetch[FETCH_MTD_deref]; + f->data = (void *)dprm; + } + } + break; + } + if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ + pr_info("%s type has no corresponding fetch method.\n", t->name); + ret = -EINVAL; + } + + return ret; +} + +#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) + +/* Bitfield type needs to be parsed into a fetch function */ +static int __parse_bitfield_probe_arg(const char *bf, + const struct fetch_type *t, + struct fetch_param *f) +{ + struct bitfield_fetch_param *bprm; + unsigned long bw, bo; + char *tail; + + if (*bf != 'b') + return 0; + + bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + if (!bprm) + return -ENOMEM; + + bprm->orig = *f; + f->fn = t->fetch[FETCH_MTD_bitfield]; + f->data = (void *)bprm; + bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ + + if (bw == 0 || *tail != '@') + return -EINVAL; + + bf = tail + 1; + bo = simple_strtoul(bf, &tail, 0); + + if (tail == bf || *tail != '/') + return -EINVAL; + + bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); + bprm->low_shift = bprm->hi_shift + bo; + + return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; +} + +/* String length checking wrapper */ +int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return) +{ + const char *t; + int ret; + + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument is too long.: %s\n", arg); + return -ENOSPC; + } + parg->comm = kstrdup(arg, GFP_KERNEL); + if (!parg->comm) { + pr_info("Failed to allocate memory for command '%s'.\n", arg); + return -ENOMEM; + } + t = strchr(parg->comm, ':'); + if (t) { + arg[t - parg->comm] = '\0'; + t++; + } + parg->type = find_fetch_type(t); + if (!parg->type) { + pr_info("Unsupported type: %s\n", t); + return -EINVAL; + } + parg->offset = *size; + *size += parg->type->size; + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + + if (ret >= 0 && t != NULL) + ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); + + if (ret >= 0) { + parg->fetch_size.fn = get_fetch_size_function(parg->type, + parg->fetch.fn); + parg->fetch_size.data = parg->fetch.data; + } + + return ret; +} + +/* Return 1 if name is reserved or already used by another argument */ +int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + + return 0; +} + +void traceprobe_update_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + update_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + update_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + update_symbol_cache(arg->fetch.data); +} + +void traceprobe_free_probe_arg(struct probe_arg *arg) +{ + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + free_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + free_deref_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) + free_symbol_cache(arg->fetch.data); + + kfree(arg->name); + kfree(arg->comm); +} + +int traceprobe_command(const char *buf, int (*createfn)(int, char **)) +{ + char **argv; + int argc, ret; + + argc = 0; + ret = 0; + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = createfn(argc, argv); + + argv_free(argv); + + return ret; +} + +#define WRITE_BUFSIZE 4096 + +ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos, + int (*createfn)(int, char **)) +{ + char *kbuf, *tmp; + int ret = 0; + size_t done = 0; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + while (done < count) { + size = count - done; + + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + + if (tmp) + *tmp = '\0'; + + ret = traceprobe_command(kbuf, createfn); + if (ret) + goto out; + } + ret = done; + +out: + kfree(kbuf); + + return ret; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h new file mode 100644 index 0000000..2df9a18 --- /dev/null +++ b/kernel/trace/trace_probe.h @@ -0,0 +1,160 @@ +/* + * Common header file for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This code was copied from kernel/trace/trace_kprobe.h written by + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Updates to make this generic: + * Copyright (C) IBM Corporation, 2010-2011 + * Author: Srikar Dronamraju + */ + +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/debugfs.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/ptrace.h> +#include <linux/perf_event.h> +#include <linux/kprobes.h> +#include <linux/stringify.h> +#include <linux/limits.h> +#include <linux/uaccess.h> +#include <asm/bitsperlong.h> + +#include "trace.h" +#include "trace_output.h" + +#define MAX_TRACE_ARGS 128 +#define MAX_ARGSTR_LEN 63 +#define MAX_EVENT_NAME_LEN 64 +#define MAX_STRING_SIZE PATH_MAX + +/* Reserved field names */ +#define FIELD_STRING_IP "__probe_ip" +#define FIELD_STRING_RETIP "__probe_ret_ip" +#define FIELD_STRING_FUNC "__probe_func" + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + + +/* Flags for trace_probe */ +#define TP_FLAG_TRACE 1 +#define TP_FLAG_PROFILE 2 +#define TP_FLAG_REGISTERED 4 + + +/* data_rloc: data relative location, compatible with u32 */ +#define make_data_rloc(len, roffs) \ + (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) +#define get_rloc_len(dl) ((u32)(dl) >> 16) +#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) + +/* + * Convert data_rloc to data_loc: + * data_rloc stores the offset from data_rloc itself, but data_loc + * stores the offset from event entry. + */ +#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) + +/* Data fetch function type */ +typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); +/* Printing function type */ +typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); + +/* Fetch types */ +enum { + FETCH_MTD_reg = 0, + FETCH_MTD_stack, + FETCH_MTD_retval, + FETCH_MTD_memory, + FETCH_MTD_symbol, + FETCH_MTD_deref, + FETCH_MTD_bitfield, + FETCH_MTD_END, +}; + +/* Fetch type information table */ +struct fetch_type { + const char *name; /* Name of type */ + size_t size; /* Byte size of type */ + int is_signed; /* Signed flag */ + print_type_func_t print; /* Print functions */ + const char *fmt; /* Fromat string */ + const char *fmttype; /* Name in format file */ + /* Fetch functions */ + fetch_func_t fetch[FETCH_MTD_END]; +}; + +struct fetch_param { + fetch_func_t fn; + void *data; +}; + +struct probe_arg { + struct fetch_param fetch; + struct fetch_param fetch_size; + unsigned int offset; /* Offset from argument entry */ + const char *name; /* Name of this argument */ + const char *comm; /* Command of this argument */ + const struct fetch_type *type; /* Type of this argument */ +}; + +static inline __kprobes void call_fetch(struct fetch_param *fprm, + struct pt_regs *regs, void *dest) +{ + return fprm->fn(regs, fprm->data, dest); +} + +/* Check the name is good for event/group/fields */ +static inline int is_good_name(const char *name) +{ + if (!isalpha(*name) && *name != '_') + return 0; + while (*++name != '\0') { + if (!isalpha(*name) && !isdigit(*name) && *name != '_') + return 0; + } + return 1; +} + +extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, bool is_return); + +extern int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg); + +extern void traceprobe_update_arg(struct probe_arg *arg); +extern void traceprobe_free_probe_arg(struct probe_arg *arg); + +extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); + +extern ssize_t traceprobe_probes_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos, + int (*createfn)(int, char**)); + +extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH 3/3] tracing: Provide trace events interface for uprobes 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-04-09 9:11 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-09 9:11 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog (since v9) - Handle comments from Steven Rostedt about uprobe tracer documentation. - Disable preemption while in perf handler as suggested by Jiri Olsa. Changelog (since v5) - Added uprobe tracer documentation to this patch. Documentation/trace/uprobetracer.txt | 95 ++++ kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 kernel/trace/trace.h | 5 kernel/trace/trace_kprobe.c | 2 kernel/trace/trace_probe.c | 14 - kernel/trace/trace_probe.h | 3 kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ 8 files changed, 918 insertions(+), 6 deletions(-) create mode 100644 Documentation/trace/uprobetracer.txt create mode 100644 kernel/trace/trace_uprobe.c diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt new file mode 100644 index 0000000..eae40a0 --- /dev/null +++ b/Documentation/trace/uprobetracer.txt @@ -0,0 +1,95 @@ + Uprobe-tracer: Uprobe-based Event Tracing + ========================================= + Documentation written by Srikar Dronamraju + +Overview +-------- +Uprobe based trace events are similar to kprobe based trace events. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. + +Similar to the kprobe-event tracer, this doesn't need to be activated via +current_tracer. Instead of that, add probe points via +/sys/kernel/debug/tracing/uprobe_events, and enable it via +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. + +However unlike kprobe-event tracer, the uprobe event interface expects the +user to calculate the offset of the probepoint in the object + +Synopsis of uprobe_tracer +------------------------- + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe + + GRP : Group name. If omitted, use "uprobes" for it. + EVENT : Event name. If omitted, the event name is generated + based on SYMBOL+offs. + PATH : path to an executable or a library. + SYMBOL[+offs] : Symbol+offset where the probe is inserted. + + FETCHARGS : Arguments. Each probe can have up to 128 args. + %REG : Fetch register REG + +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/uprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + +Usage examples +-------------- +To add a probe as a new event, write a new definition to uprobe_events +as below. + + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events + + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash + + echo > /sys/kernel/debug/tracing/uprobe_events + + This clears all probe points. + +The following example shows how to dump the instruction pointer and %ax +a register at the probed text address. Here we are trying to probe +function zfree in /bin/zsh + + # cd /sys/kernel/debug/tracing/ + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh + # objdump -T /bin/zsh | grep -w zfree + 0000000000446420 g DF .text 0000000000000012 Base zfree + +0x46420 is the offset of zfree in object /bin/zsh that is loaded at +0x00400000. Hence the command to probe would be : + + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events + +Please note: User has to explicitly calculate the offset of the probepoint +in the object. We can see the events that are registered by looking at the +uprobe_events file. + + # cat uprobe_events + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 + +Right after definition, each event is disabled by default. For tracing these +events, you need to enable it by: + + # echo 1 > events/uprobes/enable + +Lets disable the event after sleeping for some time. + # sleep 20 + # echo 0 > events/uprobes/enable + +And you can see the traced information via /sys/kernel/debug/tracing/trace. + + # cat trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + +Each line shows us probes were triggered for a pid 24842 with ip being +0x446421 and contents of ax register being 79. diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ce5a5c5..ea4bff6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -386,6 +386,22 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config UPROBE_EVENT + bool "Enable uprobes-based dynamic events" + depends on ARCH_SUPPORTS_UPROBES + depends on MMU + select UPROBES + select PROBE_EVENTS + select TRACING + default n + help + This allows the user to add tracing events on top of userspace + dynamic events (similar to tracepoints) on the fly via the trace + events interface. Those events can be inserted wherever uprobes + can probe, and record various registers. + This option is required if you plan to use perf-probe subcommand + of perf tools on user space applications. + config PROBE_EVENTS def_bool n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index fa10d5c..1734c03 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -62,5 +62,6 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o +obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f0..1bcdbec 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8b7773..b31d3d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -525,7 +525,7 @@ static int create_trace_probe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], - is_return); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8e526b9..daa9980 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -550,7 +550,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, bool is_kprobe) { unsigned long param; long offset; @@ -558,6 +558,11 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; ret = 0; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + switch (arg[0]) { case '$': ret = parse_probe_vars(arg + 1, t, f, is_return); @@ -619,7 +624,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, + is_kprobe); if (ret) kfree(dprm); else { @@ -677,7 +683,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return) + struct probe_arg *parg, bool is_return, bool is_kprobe) { const char *t; int ret; @@ -703,7 +709,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); if (ret >= 0 && t != NULL) ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2df9a18..9337086 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,6 +66,7 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 +#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ @@ -143,7 +144,7 @@ static inline int is_good_name(const char *name) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return); + struct probe_arg *parg, bool is_return, bool is_kprobe); extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c new file mode 100644 index 0000000..c3cb32d --- /dev/null +++ b/kernel/trace/trace_uprobe.c @@ -0,0 +1,788 @@ +/* + * uprobes-based tracing events + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010-2012 + * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/uprobes.h> +#include <linux/namei.h> + +#include "trace_probe.h" + +#define UPROBE_EVENT_SYSTEM "uprobes" + +/* + * uprobe event core functions + */ +struct trace_uprobe; +struct uprobe_trace_consumer { + struct uprobe_consumer cons; + struct trace_uprobe *tu; +}; + +struct trace_uprobe { + struct list_head list; + struct ftrace_event_class class; + struct ftrace_event_call call; + struct uprobe_trace_consumer *consumer; + struct inode *inode; + char *filename; + unsigned long offset; + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + ssize_t size; /* trace entry size */ + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_UPROBE(n) \ + (offsetof(struct trace_uprobe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static int register_uprobe_event(struct trace_uprobe *tu); +static void unregister_uprobe_event(struct trace_uprobe *tu); + +static DEFINE_MUTEX(uprobe_lock); +static LIST_HEAD(uprobe_list); + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); + +/* + * Allocate new trace_uprobe and initialize it (including uprobes). + */ +static struct trace_uprobe * +alloc_trace_uprobe(const char *group, const char *event, int nargs) +{ + struct trace_uprobe *tu; + + if (!event || !is_good_name(event)) + return ERR_PTR(-EINVAL); + + if (!group || !is_good_name(group)) + return ERR_PTR(-EINVAL); + + tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + if (!tu) + return ERR_PTR(-ENOMEM); + + tu->call.class = &tu->class; + tu->call.name = kstrdup(event, GFP_KERNEL); + if (!tu->call.name) + goto error; + + tu->class.system = kstrdup(group, GFP_KERNEL); + if (!tu->class.system) + goto error; + + INIT_LIST_HEAD(&tu->list); + return tu; + +error: + kfree(tu->call.name); + kfree(tu); + + return ERR_PTR(-ENOMEM); +} + +static void free_trace_uprobe(struct trace_uprobe *tu) +{ + int i; + + for (i = 0; i < tu->nr_args; i++) + traceprobe_free_probe_arg(&tu->args[i]); + + iput(tu->inode); + kfree(tu->call.class->system); + kfree(tu->call.name); + kfree(tu->filename); + kfree(tu); +} + +static struct trace_uprobe *find_probe_event(const char *event, const char *group) +{ + struct trace_uprobe *tu; + + list_for_each_entry(tu, &uprobe_list, list) + if (strcmp(tu->call.name, event) == 0 && + strcmp(tu->call.class->system, group) == 0) + return tu; + + return NULL; +} + +/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ +static void unregister_trace_uprobe(struct trace_uprobe *tu) +{ + list_del(&tu->list); + unregister_uprobe_event(tu); + free_trace_uprobe(tu); +} + +/* Register a trace_uprobe and probe_event */ +static int register_trace_uprobe(struct trace_uprobe *tu) +{ + struct trace_uprobe *old_tp; + int ret; + + mutex_lock(&uprobe_lock); + + /* register as an event */ + old_tp = find_probe_event(tu->call.name, tu->call.class->system); + if (old_tp) + /* delete old event */ + unregister_trace_uprobe(old_tp); + + ret = register_uprobe_event(tu); + if (ret) { + pr_warning("Failed to register probe event(%d)\n", ret); + goto end; + } + + list_add_tail(&tu->list, &uprobe_list); + +end: + mutex_unlock(&uprobe_lock); + + return ret; +} + +/* + * Argument syntax: + * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * + * - Remove uprobe: -:[GRP/]EVENT + */ +static int create_trace_uprobe(int argc, char **argv) +{ + struct trace_uprobe *tu; + struct inode *inode; + char *arg, *event, *group, *filename; + char buf[MAX_EVENT_NAME_LEN]; + struct path path; + unsigned long offset; + bool is_delete; + int i, ret; + + inode = NULL; + ret = 0; + is_delete = false; + arg = NULL; + event = NULL; + group = NULL; + + /* argc must be >= 1 */ + if (argv[0][0] == '-') + is_delete = true; + else if (argv[0][0] != 'p') { + pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + + if (strchr(event, '/')) { + group = event; + event = strchr(group, '/') + 1; + event[-1] = '\0'; + + if (strlen(group) == 0) { + pr_info("Group name is not specified\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specified\n"); + return -EINVAL; + } + } + if (!group) + group = UPROBE_EVENT_SYSTEM; + + if (is_delete) { + if (!event) { + pr_info("Delete command needs an event name.\n"); + return -EINVAL; + } + mutex_lock(&uprobe_lock); + tu = find_probe_event(event, group); + + if (!tu) { + mutex_unlock(&uprobe_lock); + pr_info("Event %s/%s doesn't exist.\n", group, event); + return -ENOENT; + } + /* delete an event */ + unregister_trace_uprobe(tu); + mutex_unlock(&uprobe_lock); + return 0; + } + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + if (isdigit(argv[1][0])) { + pr_info("probe point must be have a filename.\n"); + return -EINVAL; + } + arg = strchr(argv[1], ':'); + if (!arg) + goto fail_address_parse; + + *arg++ = '\0'; + filename = argv[1]; + ret = kern_path(filename, LOOKUP_FOLLOW, &path); + if (ret) + goto fail_address_parse; + + ret = strict_strtoul(arg, 0, &offset); + if (ret) + goto fail_address_parse; + + inode = igrab(path.dentry->d_inode); + + argc -= 2; + argv += 2; + + /* setup a probe */ + if (!event) { + char *tail = strrchr(filename, '/'); + char *ptr; + + ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL); + if (!ptr) { + ret = -ENOMEM; + goto fail_address_parse; + } + + tail = ptr; + ptr = strpbrk(tail, ".-_"); + if (ptr) + *ptr = '\0'; + + snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); + event = buf; + kfree(tail); + } + + tu = alloc_trace_uprobe(group, event, argc); + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); + ret = PTR_ERR(tu); + goto fail_address_parse; + } + tu->offset = offset; + tu->inode = inode; + tu->filename = kstrdup(filename, GFP_KERNEL); + + if (!tu->filename) { + pr_info("Failed to allocate filename.\n"); + ret = -ENOMEM; + goto error; + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Increment count for freeing args in error case */ + tu->nr_args++; + + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) { + *arg++ = '\0'; + tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); + } else { + arg = argv[i]; + /* If argument name is omitted, set "argN" */ + snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); + tu->args[i].name = kstrdup(buf, GFP_KERNEL); + } + + if (!tu->args[i].name) { + pr_info("Failed to allocate argument[%d] name.\n", i); + ret = -ENOMEM; + goto error; + } + + if (!is_good_name(tu->args[i].name)) { + pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); + ret = -EINVAL; + goto error; + } + + if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { + pr_info("Argument[%d] name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + /* Parse fetch argument */ + ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); + if (ret) { + pr_info("Parse error at argument[%d]. (%d)\n", i, ret); + goto error; + } + } + + ret = register_trace_uprobe(tu); + if (ret) + goto error; + return 0; + +error: + free_trace_uprobe(tu); + return ret; + +fail_address_parse: + if (inode) + iput(inode); + + pr_info("Failed to parse address.\n"); + + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_uprobe *tu; + + mutex_lock(&uprobe_lock); + while (!list_empty(&uprobe_list)) { + tu = list_entry(uprobe_list.next, struct trace_uprobe, list); + unregister_trace_uprobe(tu); + } + mutex_unlock(&uprobe_lock); +} + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&uprobe_lock); + return seq_list_start(&uprobe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &uprobe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&uprobe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + int i; + + seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + + for (i = 0; i < tu->nr_args; i++) + seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); + + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); +} + +static const struct file_operations uprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + + seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations uprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* uprobe handler */ +static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct uprobe_trace_entry_head *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + u8 *data; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tu->call; + + tu->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = sizeof(*entry) + tu->size; + + event = trace_current_buffer_lock_reserve(&buffer, call->event.type, + size, irq_flags, pc); + if (!event) + return; + + entry = ring_buffer_event_data(event); + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); +} + +/* Event entry printers */ +static enum print_line_t +print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) +{ + struct uprobe_trace_entry_head *field; + struct trace_seq *s = &iter->seq; + struct trace_uprobe *tu; + u8 *data; + int i; + + field = (struct uprobe_trace_entry_head *)iter->ent; + tu = container_of(event, struct trace_uprobe, call.event); + + if (!trace_seq_printf(s, "%s: (", tu->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + data = (u8 *)&field[1]; + for (i = 0; i < tu->nr_args; i++) { + if (!tu->args[i].type->print(s, tu->args[i].name, + data + tu->args[i].offset, field)) + goto partial; + } + + if (trace_seq_puts(s, "\n")) + return TRACE_TYPE_HANDLED; + +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct trace_uprobe *tu, int flag) +{ + struct uprobe_trace_consumer *utc; + int ret = 0; + + if (!tu->inode || tu->consumer) + return -EINTR; + + utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); + if (!utc) + return -EINTR; + + utc->cons.handler = uprobe_dispatcher; + utc->cons.filter = NULL; + ret = uprobe_register(tu->inode, tu->offset, &utc->cons); + if (ret) { + kfree(utc); + return ret; + } + + tu->flags |= flag; + utc->tu = tu; + tu->consumer = utc; + + return 0; +} + +static void probe_event_disable(struct trace_uprobe *tu, int flag) +{ + if (!tu->inode || !tu->consumer) + return; + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + tu->flags &= ~flag; + kfree(tu->consumer); + tu->consumer = NULL; +} + +static int uprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct uprobe_trace_entry_head field; + struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + /* Set argument names as fields */ + for (i = 0; i < tu->nr_args; i++) { + ret = trace_define_field(event_call, tu->args[i].type->fmttype, + tu->args[i].name, + sizeof(field) + tu->args[i].offset, + tu->args[i].type->size, + tu->args[i].type->is_signed, + FILTER_OTHER); + + if (ret) + return ret; + } + return 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) +{ + const char *fmt, *arg; + int i; + int pos = 0; + + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + + /* When len=0, we just calculate the needed length */ + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", + tu->args[i].name, tu->args[i].type->fmt); + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", + tu->args[i].name); + } + + return pos; /* return the length of print_fmt */ +} +#undef LEN_OR_ZERO + +static int set_print_fmt(struct trace_uprobe *tu) +{ + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_print_fmt(tu, NULL, 0); + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_print_fmt(tu, print_fmt, len + 1); + tu->call.print_fmt = print_fmt; + + return 0; +} + +#ifdef CONFIG_PERF_EVENTS +/* uprobe profile handler */ +static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct ftrace_event_call *call = &tu->call; + struct uprobe_trace_entry_head *entry; + struct hlist_head *head; + u8 *data; + int size, __size, i; + int rctx; + + __size = sizeof(*entry) + tu->size; + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) + return; + + preempt_disable(); + + entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); + if (!entry) + goto out; + + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + head = this_cpu_ptr(call->perf_events); + perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); + + out: + preempt_enable(); +} +#endif /* CONFIG_PERF_EVENTS */ + +static +int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) +{ + struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + + switch (type) { + case TRACE_REG_REGISTER: + return probe_event_enable(tu, TP_FLAG_TRACE); + + case TRACE_REG_UNREGISTER: + probe_event_disable(tu, TP_FLAG_TRACE); + return 0; + +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + return probe_event_enable(tu, TP_FLAG_PROFILE); + + case TRACE_REG_PERF_UNREGISTER: + probe_event_disable(tu, TP_FLAG_PROFILE); + return 0; +#endif + default: + return 0; + } + return 0; +} + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct uprobe_trace_consumer *utc; + struct trace_uprobe *tu; + + utc = container_of(con, struct uprobe_trace_consumer, cons); + tu = utc->tu; + if (!tu || tu->consumer != utc) + return 0; + + if (tu->flags & TP_FLAG_TRACE) + uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + uprobe_perf_func(tu, regs); +#endif + return 0; +} + +static struct trace_event_functions uprobe_funcs = { + .trace = print_uprobe_event +}; + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct ftrace_event_call *call = &tu->call; + int ret; + + /* Initialize ftrace_event_call */ + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &uprobe_funcs; + call->class->define_fields = uprobe_event_define_fields; + + if (set_print_fmt(tu) < 0) + return -ENOMEM; + + ret = register_ftrace_event(&call->event); + if (!ret) { + kfree(call->print_fmt); + return -ENODEV; + } + call->flags = 0; + call->class->reg = trace_uprobe_register; + call->data = tu; + ret = trace_add_event_call(call); + + if (ret) { + pr_info("Failed to register uprobe event: %s\n", call->name); + kfree(call->print_fmt); + unregister_ftrace_event(&call->event); + } + + return ret; +} + +static void unregister_uprobe_event(struct trace_uprobe *tu) +{ + /* tu->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tu->call); + kfree(tu->call.print_fmt); + tu->call.print_fmt = NULL; +} + +/* Make a trace interface for controling probe points */ +static __init int init_uprobe_trace(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("uprobe_events", 0644, d_tracer, + NULL, &uprobe_events_ops); + /* Profile interface */ + trace_create_file("uprobe_profile", 0444, d_tracer, + NULL, &uprobe_profile_ops); + return 0; +} + +fs_initcall(init_uprobe_trace); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-09 9:11 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-09 9:11 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog (since v9) - Handle comments from Steven Rostedt about uprobe tracer documentation. - Disable preemption while in perf handler as suggested by Jiri Olsa. Changelog (since v5) - Added uprobe tracer documentation to this patch. Documentation/trace/uprobetracer.txt | 95 ++++ kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 kernel/trace/trace.h | 5 kernel/trace/trace_kprobe.c | 2 kernel/trace/trace_probe.c | 14 - kernel/trace/trace_probe.h | 3 kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ 8 files changed, 918 insertions(+), 6 deletions(-) create mode 100644 Documentation/trace/uprobetracer.txt create mode 100644 kernel/trace/trace_uprobe.c diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt new file mode 100644 index 0000000..eae40a0 --- /dev/null +++ b/Documentation/trace/uprobetracer.txt @@ -0,0 +1,95 @@ + Uprobe-tracer: Uprobe-based Event Tracing + ========================================= + Documentation written by Srikar Dronamraju + +Overview +-------- +Uprobe based trace events are similar to kprobe based trace events. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. + +Similar to the kprobe-event tracer, this doesn't need to be activated via +current_tracer. Instead of that, add probe points via +/sys/kernel/debug/tracing/uprobe_events, and enable it via +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. + +However unlike kprobe-event tracer, the uprobe event interface expects the +user to calculate the offset of the probepoint in the object + +Synopsis of uprobe_tracer +------------------------- + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe + + GRP : Group name. If omitted, use "uprobes" for it. + EVENT : Event name. If omitted, the event name is generated + based on SYMBOL+offs. + PATH : path to an executable or a library. + SYMBOL[+offs] : Symbol+offset where the probe is inserted. + + FETCHARGS : Arguments. Each probe can have up to 128 args. + %REG : Fetch register REG + +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/uprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + +Usage examples +-------------- +To add a probe as a new event, write a new definition to uprobe_events +as below. + + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events + + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash + + echo > /sys/kernel/debug/tracing/uprobe_events + + This clears all probe points. + +The following example shows how to dump the instruction pointer and %ax +a register at the probed text address. Here we are trying to probe +function zfree in /bin/zsh + + # cd /sys/kernel/debug/tracing/ + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh + # objdump -T /bin/zsh | grep -w zfree + 0000000000446420 g DF .text 0000000000000012 Base zfree + +0x46420 is the offset of zfree in object /bin/zsh that is loaded at +0x00400000. Hence the command to probe would be : + + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events + +Please note: User has to explicitly calculate the offset of the probepoint +in the object. We can see the events that are registered by looking at the +uprobe_events file. + + # cat uprobe_events + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 + +Right after definition, each event is disabled by default. For tracing these +events, you need to enable it by: + + # echo 1 > events/uprobes/enable + +Lets disable the event after sleeping for some time. + # sleep 20 + # echo 0 > events/uprobes/enable + +And you can see the traced information via /sys/kernel/debug/tracing/trace. + + # cat trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + +Each line shows us probes were triggered for a pid 24842 with ip being +0x446421 and contents of ax register being 79. diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ce5a5c5..ea4bff6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -386,6 +386,22 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config UPROBE_EVENT + bool "Enable uprobes-based dynamic events" + depends on ARCH_SUPPORTS_UPROBES + depends on MMU + select UPROBES + select PROBE_EVENTS + select TRACING + default n + help + This allows the user to add tracing events on top of userspace + dynamic events (similar to tracepoints) on the fly via the trace + events interface. Those events can be inserted wherever uprobes + can probe, and record various registers. + This option is required if you plan to use perf-probe subcommand + of perf tools on user space applications. + config PROBE_EVENTS def_bool n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index fa10d5c..1734c03 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -62,5 +62,6 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o +obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f0..1bcdbec 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8b7773..b31d3d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -525,7 +525,7 @@ static int create_trace_probe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], - is_return); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8e526b9..daa9980 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -550,7 +550,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, bool is_kprobe) { unsigned long param; long offset; @@ -558,6 +558,11 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; ret = 0; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + switch (arg[0]) { case '$': ret = parse_probe_vars(arg + 1, t, f, is_return); @@ -619,7 +624,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, + is_kprobe); if (ret) kfree(dprm); else { @@ -677,7 +683,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return) + struct probe_arg *parg, bool is_return, bool is_kprobe) { const char *t; int ret; @@ -703,7 +709,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); if (ret >= 0 && t != NULL) ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2df9a18..9337086 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,6 +66,7 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 +#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ @@ -143,7 +144,7 @@ static inline int is_good_name(const char *name) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return); + struct probe_arg *parg, bool is_return, bool is_kprobe); extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c new file mode 100644 index 0000000..c3cb32d --- /dev/null +++ b/kernel/trace/trace_uprobe.c @@ -0,0 +1,788 @@ +/* + * uprobes-based tracing events + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010-2012 + * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/uprobes.h> +#include <linux/namei.h> + +#include "trace_probe.h" + +#define UPROBE_EVENT_SYSTEM "uprobes" + +/* + * uprobe event core functions + */ +struct trace_uprobe; +struct uprobe_trace_consumer { + struct uprobe_consumer cons; + struct trace_uprobe *tu; +}; + +struct trace_uprobe { + struct list_head list; + struct ftrace_event_class class; + struct ftrace_event_call call; + struct uprobe_trace_consumer *consumer; + struct inode *inode; + char *filename; + unsigned long offset; + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + ssize_t size; /* trace entry size */ + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_UPROBE(n) \ + (offsetof(struct trace_uprobe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static int register_uprobe_event(struct trace_uprobe *tu); +static void unregister_uprobe_event(struct trace_uprobe *tu); + +static DEFINE_MUTEX(uprobe_lock); +static LIST_HEAD(uprobe_list); + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); + +/* + * Allocate new trace_uprobe and initialize it (including uprobes). + */ +static struct trace_uprobe * +alloc_trace_uprobe(const char *group, const char *event, int nargs) +{ + struct trace_uprobe *tu; + + if (!event || !is_good_name(event)) + return ERR_PTR(-EINVAL); + + if (!group || !is_good_name(group)) + return ERR_PTR(-EINVAL); + + tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + if (!tu) + return ERR_PTR(-ENOMEM); + + tu->call.class = &tu->class; + tu->call.name = kstrdup(event, GFP_KERNEL); + if (!tu->call.name) + goto error; + + tu->class.system = kstrdup(group, GFP_KERNEL); + if (!tu->class.system) + goto error; + + INIT_LIST_HEAD(&tu->list); + return tu; + +error: + kfree(tu->call.name); + kfree(tu); + + return ERR_PTR(-ENOMEM); +} + +static void free_trace_uprobe(struct trace_uprobe *tu) +{ + int i; + + for (i = 0; i < tu->nr_args; i++) + traceprobe_free_probe_arg(&tu->args[i]); + + iput(tu->inode); + kfree(tu->call.class->system); + kfree(tu->call.name); + kfree(tu->filename); + kfree(tu); +} + +static struct trace_uprobe *find_probe_event(const char *event, const char *group) +{ + struct trace_uprobe *tu; + + list_for_each_entry(tu, &uprobe_list, list) + if (strcmp(tu->call.name, event) == 0 && + strcmp(tu->call.class->system, group) == 0) + return tu; + + return NULL; +} + +/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ +static void unregister_trace_uprobe(struct trace_uprobe *tu) +{ + list_del(&tu->list); + unregister_uprobe_event(tu); + free_trace_uprobe(tu); +} + +/* Register a trace_uprobe and probe_event */ +static int register_trace_uprobe(struct trace_uprobe *tu) +{ + struct trace_uprobe *old_tp; + int ret; + + mutex_lock(&uprobe_lock); + + /* register as an event */ + old_tp = find_probe_event(tu->call.name, tu->call.class->system); + if (old_tp) + /* delete old event */ + unregister_trace_uprobe(old_tp); + + ret = register_uprobe_event(tu); + if (ret) { + pr_warning("Failed to register probe event(%d)\n", ret); + goto end; + } + + list_add_tail(&tu->list, &uprobe_list); + +end: + mutex_unlock(&uprobe_lock); + + return ret; +} + +/* + * Argument syntax: + * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * + * - Remove uprobe: -:[GRP/]EVENT + */ +static int create_trace_uprobe(int argc, char **argv) +{ + struct trace_uprobe *tu; + struct inode *inode; + char *arg, *event, *group, *filename; + char buf[MAX_EVENT_NAME_LEN]; + struct path path; + unsigned long offset; + bool is_delete; + int i, ret; + + inode = NULL; + ret = 0; + is_delete = false; + arg = NULL; + event = NULL; + group = NULL; + + /* argc must be >= 1 */ + if (argv[0][0] == '-') + is_delete = true; + else if (argv[0][0] != 'p') { + pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + + if (strchr(event, '/')) { + group = event; + event = strchr(group, '/') + 1; + event[-1] = '\0'; + + if (strlen(group) == 0) { + pr_info("Group name is not specified\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specified\n"); + return -EINVAL; + } + } + if (!group) + group = UPROBE_EVENT_SYSTEM; + + if (is_delete) { + if (!event) { + pr_info("Delete command needs an event name.\n"); + return -EINVAL; + } + mutex_lock(&uprobe_lock); + tu = find_probe_event(event, group); + + if (!tu) { + mutex_unlock(&uprobe_lock); + pr_info("Event %s/%s doesn't exist.\n", group, event); + return -ENOENT; + } + /* delete an event */ + unregister_trace_uprobe(tu); + mutex_unlock(&uprobe_lock); + return 0; + } + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + if (isdigit(argv[1][0])) { + pr_info("probe point must be have a filename.\n"); + return -EINVAL; + } + arg = strchr(argv[1], ':'); + if (!arg) + goto fail_address_parse; + + *arg++ = '\0'; + filename = argv[1]; + ret = kern_path(filename, LOOKUP_FOLLOW, &path); + if (ret) + goto fail_address_parse; + + ret = strict_strtoul(arg, 0, &offset); + if (ret) + goto fail_address_parse; + + inode = igrab(path.dentry->d_inode); + + argc -= 2; + argv += 2; + + /* setup a probe */ + if (!event) { + char *tail = strrchr(filename, '/'); + char *ptr; + + ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL); + if (!ptr) { + ret = -ENOMEM; + goto fail_address_parse; + } + + tail = ptr; + ptr = strpbrk(tail, ".-_"); + if (ptr) + *ptr = '\0'; + + snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); + event = buf; + kfree(tail); + } + + tu = alloc_trace_uprobe(group, event, argc); + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); + ret = PTR_ERR(tu); + goto fail_address_parse; + } + tu->offset = offset; + tu->inode = inode; + tu->filename = kstrdup(filename, GFP_KERNEL); + + if (!tu->filename) { + pr_info("Failed to allocate filename.\n"); + ret = -ENOMEM; + goto error; + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Increment count for freeing args in error case */ + tu->nr_args++; + + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) { + *arg++ = '\0'; + tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); + } else { + arg = argv[i]; + /* If argument name is omitted, set "argN" */ + snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); + tu->args[i].name = kstrdup(buf, GFP_KERNEL); + } + + if (!tu->args[i].name) { + pr_info("Failed to allocate argument[%d] name.\n", i); + ret = -ENOMEM; + goto error; + } + + if (!is_good_name(tu->args[i].name)) { + pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); + ret = -EINVAL; + goto error; + } + + if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { + pr_info("Argument[%d] name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + /* Parse fetch argument */ + ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); + if (ret) { + pr_info("Parse error at argument[%d]. (%d)\n", i, ret); + goto error; + } + } + + ret = register_trace_uprobe(tu); + if (ret) + goto error; + return 0; + +error: + free_trace_uprobe(tu); + return ret; + +fail_address_parse: + if (inode) + iput(inode); + + pr_info("Failed to parse address.\n"); + + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_uprobe *tu; + + mutex_lock(&uprobe_lock); + while (!list_empty(&uprobe_list)) { + tu = list_entry(uprobe_list.next, struct trace_uprobe, list); + unregister_trace_uprobe(tu); + } + mutex_unlock(&uprobe_lock); +} + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&uprobe_lock); + return seq_list_start(&uprobe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &uprobe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&uprobe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + int i; + + seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + + for (i = 0; i < tu->nr_args; i++) + seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); + + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); +} + +static const struct file_operations uprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + + seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations uprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* uprobe handler */ +static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct uprobe_trace_entry_head *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + u8 *data; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tu->call; + + tu->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = sizeof(*entry) + tu->size; + + event = trace_current_buffer_lock_reserve(&buffer, call->event.type, + size, irq_flags, pc); + if (!event) + return; + + entry = ring_buffer_event_data(event); + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); +} + +/* Event entry printers */ +static enum print_line_t +print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) +{ + struct uprobe_trace_entry_head *field; + struct trace_seq *s = &iter->seq; + struct trace_uprobe *tu; + u8 *data; + int i; + + field = (struct uprobe_trace_entry_head *)iter->ent; + tu = container_of(event, struct trace_uprobe, call.event); + + if (!trace_seq_printf(s, "%s: (", tu->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + data = (u8 *)&field[1]; + for (i = 0; i < tu->nr_args; i++) { + if (!tu->args[i].type->print(s, tu->args[i].name, + data + tu->args[i].offset, field)) + goto partial; + } + + if (trace_seq_puts(s, "\n")) + return TRACE_TYPE_HANDLED; + +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct trace_uprobe *tu, int flag) +{ + struct uprobe_trace_consumer *utc; + int ret = 0; + + if (!tu->inode || tu->consumer) + return -EINTR; + + utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); + if (!utc) + return -EINTR; + + utc->cons.handler = uprobe_dispatcher; + utc->cons.filter = NULL; + ret = uprobe_register(tu->inode, tu->offset, &utc->cons); + if (ret) { + kfree(utc); + return ret; + } + + tu->flags |= flag; + utc->tu = tu; + tu->consumer = utc; + + return 0; +} + +static void probe_event_disable(struct trace_uprobe *tu, int flag) +{ + if (!tu->inode || !tu->consumer) + return; + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + tu->flags &= ~flag; + kfree(tu->consumer); + tu->consumer = NULL; +} + +static int uprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct uprobe_trace_entry_head field; + struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + /* Set argument names as fields */ + for (i = 0; i < tu->nr_args; i++) { + ret = trace_define_field(event_call, tu->args[i].type->fmttype, + tu->args[i].name, + sizeof(field) + tu->args[i].offset, + tu->args[i].type->size, + tu->args[i].type->is_signed, + FILTER_OTHER); + + if (ret) + return ret; + } + return 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) +{ + const char *fmt, *arg; + int i; + int pos = 0; + + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + + /* When len=0, we just calculate the needed length */ + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", + tu->args[i].name, tu->args[i].type->fmt); + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", + tu->args[i].name); + } + + return pos; /* return the length of print_fmt */ +} +#undef LEN_OR_ZERO + +static int set_print_fmt(struct trace_uprobe *tu) +{ + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_print_fmt(tu, NULL, 0); + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_print_fmt(tu, print_fmt, len + 1); + tu->call.print_fmt = print_fmt; + + return 0; +} + +#ifdef CONFIG_PERF_EVENTS +/* uprobe profile handler */ +static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct ftrace_event_call *call = &tu->call; + struct uprobe_trace_entry_head *entry; + struct hlist_head *head; + u8 *data; + int size, __size, i; + int rctx; + + __size = sizeof(*entry) + tu->size; + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) + return; + + preempt_disable(); + + entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); + if (!entry) + goto out; + + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + head = this_cpu_ptr(call->perf_events); + perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); + + out: + preempt_enable(); +} +#endif /* CONFIG_PERF_EVENTS */ + +static +int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) +{ + struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + + switch (type) { + case TRACE_REG_REGISTER: + return probe_event_enable(tu, TP_FLAG_TRACE); + + case TRACE_REG_UNREGISTER: + probe_event_disable(tu, TP_FLAG_TRACE); + return 0; + +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + return probe_event_enable(tu, TP_FLAG_PROFILE); + + case TRACE_REG_PERF_UNREGISTER: + probe_event_disable(tu, TP_FLAG_PROFILE); + return 0; +#endif + default: + return 0; + } + return 0; +} + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct uprobe_trace_consumer *utc; + struct trace_uprobe *tu; + + utc = container_of(con, struct uprobe_trace_consumer, cons); + tu = utc->tu; + if (!tu || tu->consumer != utc) + return 0; + + if (tu->flags & TP_FLAG_TRACE) + uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + uprobe_perf_func(tu, regs); +#endif + return 0; +} + +static struct trace_event_functions uprobe_funcs = { + .trace = print_uprobe_event +}; + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct ftrace_event_call *call = &tu->call; + int ret; + + /* Initialize ftrace_event_call */ + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &uprobe_funcs; + call->class->define_fields = uprobe_event_define_fields; + + if (set_print_fmt(tu) < 0) + return -ENOMEM; + + ret = register_ftrace_event(&call->event); + if (!ret) { + kfree(call->print_fmt); + return -ENODEV; + } + call->flags = 0; + call->class->reg = trace_uprobe_register; + call->data = tu; + ret = trace_add_event_call(call); + + if (ret) { + pr_info("Failed to register uprobe event: %s\n", call->name); + kfree(call->print_fmt); + unregister_ftrace_event(&call->event); + } + + return ret; +} + +static void unregister_uprobe_event(struct trace_uprobe *tu) +{ + /* tu->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tu->call); + kfree(tu->call.print_fmt); + tu->call.print_fmt = NULL; +} + +/* Make a trace interface for controling probe points */ +static __init int init_uprobe_trace(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("uprobe_events", 0644, d_tracer, + NULL, &uprobe_events_ops); + /* Profile interface */ + trace_create_file("uprobe_profile", 0444, d_tracer, + NULL, &uprobe_profile_ops); + return 0; +} + +fs_initcall(init_uprobe_trace); ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-04-11 10:30 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-11 10:30 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog (since v9) - Handle comments from Steven Rostedt about uprobe tracer documentation. - Disable preemption while in perf handler as suggested by Jiri Olsa. Changelog (since v5) - Added uprobe tracer documentation to this patch. Documentation/trace/uprobetracer.txt | 95 ++++ arch/Kconfig | 2 kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 kernel/trace/trace.h | 5 kernel/trace/trace_kprobe.c | 2 kernel/trace/trace_probe.c | 14 - kernel/trace/trace_probe.h | 3 kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ 9 files changed, 919 insertions(+), 7 deletions(-) create mode 100644 Documentation/trace/uprobetracer.txt create mode 100644 kernel/trace/trace_uprobe.c diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt new file mode 100644 index 0000000..eae40a0 --- /dev/null +++ b/Documentation/trace/uprobetracer.txt @@ -0,0 +1,95 @@ + Uprobe-tracer: Uprobe-based Event Tracing + ========================================= + Documentation written by Srikar Dronamraju + +Overview +-------- +Uprobe based trace events are similar to kprobe based trace events. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. + +Similar to the kprobe-event tracer, this doesn't need to be activated via +current_tracer. Instead of that, add probe points via +/sys/kernel/debug/tracing/uprobe_events, and enable it via +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. + +However unlike kprobe-event tracer, the uprobe event interface expects the +user to calculate the offset of the probepoint in the object + +Synopsis of uprobe_tracer +------------------------- + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe + + GRP : Group name. If omitted, use "uprobes" for it. + EVENT : Event name. If omitted, the event name is generated + based on SYMBOL+offs. + PATH : path to an executable or a library. + SYMBOL[+offs] : Symbol+offset where the probe is inserted. + + FETCHARGS : Arguments. Each probe can have up to 128 args. + %REG : Fetch register REG + +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/uprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + +Usage examples +-------------- +To add a probe as a new event, write a new definition to uprobe_events +as below. + + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events + + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash + + echo > /sys/kernel/debug/tracing/uprobe_events + + This clears all probe points. + +The following example shows how to dump the instruction pointer and %ax +a register at the probed text address. Here we are trying to probe +function zfree in /bin/zsh + + # cd /sys/kernel/debug/tracing/ + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh + # objdump -T /bin/zsh | grep -w zfree + 0000000000446420 g DF .text 0000000000000012 Base zfree + +0x46420 is the offset of zfree in object /bin/zsh that is loaded at +0x00400000. Hence the command to probe would be : + + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events + +Please note: User has to explicitly calculate the offset of the probepoint +in the object. We can see the events that are registered by looking at the +uprobe_events file. + + # cat uprobe_events + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 + +Right after definition, each event is disabled by default. For tracing these +events, you need to enable it by: + + # echo 1 > events/uprobes/enable + +Lets disable the event after sleeping for some time. + # sleep 20 + # echo 0 > events/uprobes/enable + +And you can see the traced information via /sys/kernel/debug/tracing/trace. + + # cat trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + +Each line shows us probes were triggered for a pid 24842 with ip being +0x446421 and contents of ax register being 79. diff --git a/arch/Kconfig b/arch/Kconfig index e5d3778..0f8f968 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -78,7 +78,7 @@ config OPTPROBES config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" - depends on ARCH_SUPPORTS_UPROBES && PERF_EVENTS + depends on UPROBE_EVENTS && PERF_EVENTS default n help Uprobes is the user-space counterpart to kprobes: they diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ce5a5c5..ea4bff6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -386,6 +386,22 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config UPROBE_EVENT + bool "Enable uprobes-based dynamic events" + depends on ARCH_SUPPORTS_UPROBES + depends on MMU + select UPROBES + select PROBE_EVENTS + select TRACING + default n + help + This allows the user to add tracing events on top of userspace + dynamic events (similar to tracepoints) on the fly via the trace + events interface. Those events can be inserted wherever uprobes + can probe, and record various registers. + This option is required if you plan to use perf-probe subcommand + of perf tools on user space applications. + config PROBE_EVENTS def_bool n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index fa10d5c..1734c03 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -62,5 +62,6 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o +obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f0..1bcdbec 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8b7773..b31d3d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -525,7 +525,7 @@ static int create_trace_probe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], - is_return); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8e526b9..daa9980 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -550,7 +550,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, bool is_kprobe) { unsigned long param; long offset; @@ -558,6 +558,11 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; ret = 0; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + switch (arg[0]) { case '$': ret = parse_probe_vars(arg + 1, t, f, is_return); @@ -619,7 +624,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, + is_kprobe); if (ret) kfree(dprm); else { @@ -677,7 +683,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return) + struct probe_arg *parg, bool is_return, bool is_kprobe) { const char *t; int ret; @@ -703,7 +709,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); if (ret >= 0 && t != NULL) ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2df9a18..9337086 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,6 +66,7 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 +#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ @@ -143,7 +144,7 @@ static inline int is_good_name(const char *name) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return); + struct probe_arg *parg, bool is_return, bool is_kprobe); extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c new file mode 100644 index 0000000..2b36ac6 --- /dev/null +++ b/kernel/trace/trace_uprobe.c @@ -0,0 +1,788 @@ +/* + * uprobes-based tracing events + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010-2012 + * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/uprobes.h> +#include <linux/namei.h> + +#include "trace_probe.h" + +#define UPROBE_EVENT_SYSTEM "uprobes" + +/* + * uprobe event core functions + */ +struct trace_uprobe; +struct uprobe_trace_consumer { + struct uprobe_consumer cons; + struct trace_uprobe *tu; +}; + +struct trace_uprobe { + struct list_head list; + struct ftrace_event_class class; + struct ftrace_event_call call; + struct uprobe_trace_consumer *consumer; + struct inode *inode; + char *filename; + unsigned long offset; + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + ssize_t size; /* trace entry size */ + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_UPROBE(n) \ + (offsetof(struct trace_uprobe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static int register_uprobe_event(struct trace_uprobe *tu); +static void unregister_uprobe_event(struct trace_uprobe *tu); + +static DEFINE_MUTEX(uprobe_lock); +static LIST_HEAD(uprobe_list); + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); + +/* + * Allocate new trace_uprobe and initialize it (including uprobes). + */ +static struct trace_uprobe * +alloc_trace_uprobe(const char *group, const char *event, int nargs) +{ + struct trace_uprobe *tu; + + if (!event || !is_good_name(event)) + return ERR_PTR(-EINVAL); + + if (!group || !is_good_name(group)) + return ERR_PTR(-EINVAL); + + tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + if (!tu) + return ERR_PTR(-ENOMEM); + + tu->call.class = &tu->class; + tu->call.name = kstrdup(event, GFP_KERNEL); + if (!tu->call.name) + goto error; + + tu->class.system = kstrdup(group, GFP_KERNEL); + if (!tu->class.system) + goto error; + + INIT_LIST_HEAD(&tu->list); + return tu; + +error: + kfree(tu->call.name); + kfree(tu); + + return ERR_PTR(-ENOMEM); +} + +static void free_trace_uprobe(struct trace_uprobe *tu) +{ + int i; + + for (i = 0; i < tu->nr_args; i++) + traceprobe_free_probe_arg(&tu->args[i]); + + iput(tu->inode); + kfree(tu->call.class->system); + kfree(tu->call.name); + kfree(tu->filename); + kfree(tu); +} + +static struct trace_uprobe *find_probe_event(const char *event, const char *group) +{ + struct trace_uprobe *tu; + + list_for_each_entry(tu, &uprobe_list, list) + if (strcmp(tu->call.name, event) == 0 && + strcmp(tu->call.class->system, group) == 0) + return tu; + + return NULL; +} + +/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ +static void unregister_trace_uprobe(struct trace_uprobe *tu) +{ + list_del(&tu->list); + unregister_uprobe_event(tu); + free_trace_uprobe(tu); +} + +/* Register a trace_uprobe and probe_event */ +static int register_trace_uprobe(struct trace_uprobe *tu) +{ + struct trace_uprobe *old_tp; + int ret; + + mutex_lock(&uprobe_lock); + + /* register as an event */ + old_tp = find_probe_event(tu->call.name, tu->call.class->system); + if (old_tp) + /* delete old event */ + unregister_trace_uprobe(old_tp); + + ret = register_uprobe_event(tu); + if (ret) { + pr_warning("Failed to register probe event(%d)\n", ret); + goto end; + } + + list_add_tail(&tu->list, &uprobe_list); + +end: + mutex_unlock(&uprobe_lock); + + return ret; +} + +/* + * Argument syntax: + * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * + * - Remove uprobe: -:[GRP/]EVENT + */ +static int create_trace_uprobe(int argc, char **argv) +{ + struct trace_uprobe *tu; + struct inode *inode; + char *arg, *event, *group, *filename; + char buf[MAX_EVENT_NAME_LEN]; + struct path path; + unsigned long offset; + bool is_delete; + int i, ret; + + inode = NULL; + ret = 0; + is_delete = false; + event = NULL; + group = NULL; + + /* argc must be >= 1 */ + if (argv[0][0] == '-') + is_delete = true; + else if (argv[0][0] != 'p') { + pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + arg = strchr(event, '/'); + + if (arg) { + group = event; + event = arg + 1; + event[-1] = '\0'; + + if (strlen(group) == 0) { + pr_info("Group name is not specified\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specified\n"); + return -EINVAL; + } + } + if (!group) + group = UPROBE_EVENT_SYSTEM; + + if (is_delete) { + if (!event) { + pr_info("Delete command needs an event name.\n"); + return -EINVAL; + } + mutex_lock(&uprobe_lock); + tu = find_probe_event(event, group); + + if (!tu) { + mutex_unlock(&uprobe_lock); + pr_info("Event %s/%s doesn't exist.\n", group, event); + return -ENOENT; + } + /* delete an event */ + unregister_trace_uprobe(tu); + mutex_unlock(&uprobe_lock); + return 0; + } + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + if (isdigit(argv[1][0])) { + pr_info("probe point must be have a filename.\n"); + return -EINVAL; + } + arg = strchr(argv[1], ':'); + if (!arg) + goto fail_address_parse; + + *arg++ = '\0'; + filename = argv[1]; + ret = kern_path(filename, LOOKUP_FOLLOW, &path); + if (ret) + goto fail_address_parse; + + ret = strict_strtoul(arg, 0, &offset); + if (ret) + goto fail_address_parse; + + inode = igrab(path.dentry->d_inode); + + argc -= 2; + argv += 2; + + /* setup a probe */ + if (!event) { + char *tail = strrchr(filename, '/'); + char *ptr; + + ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL); + if (!ptr) { + ret = -ENOMEM; + goto fail_address_parse; + } + + tail = ptr; + ptr = strpbrk(tail, ".-_"); + if (ptr) + *ptr = '\0'; + + snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); + event = buf; + kfree(tail); + } + + tu = alloc_trace_uprobe(group, event, argc); + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); + ret = PTR_ERR(tu); + goto fail_address_parse; + } + tu->offset = offset; + tu->inode = inode; + tu->filename = kstrdup(filename, GFP_KERNEL); + + if (!tu->filename) { + pr_info("Failed to allocate filename.\n"); + ret = -ENOMEM; + goto error; + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Increment count for freeing args in error case */ + tu->nr_args++; + + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) { + *arg++ = '\0'; + tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); + } else { + arg = argv[i]; + /* If argument name is omitted, set "argN" */ + snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); + tu->args[i].name = kstrdup(buf, GFP_KERNEL); + } + + if (!tu->args[i].name) { + pr_info("Failed to allocate argument[%d] name.\n", i); + ret = -ENOMEM; + goto error; + } + + if (!is_good_name(tu->args[i].name)) { + pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); + ret = -EINVAL; + goto error; + } + + if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { + pr_info("Argument[%d] name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + /* Parse fetch argument */ + ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); + if (ret) { + pr_info("Parse error at argument[%d]. (%d)\n", i, ret); + goto error; + } + } + + ret = register_trace_uprobe(tu); + if (ret) + goto error; + return 0; + +error: + free_trace_uprobe(tu); + return ret; + +fail_address_parse: + if (inode) + iput(inode); + + pr_info("Failed to parse address.\n"); + + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_uprobe *tu; + + mutex_lock(&uprobe_lock); + while (!list_empty(&uprobe_list)) { + tu = list_entry(uprobe_list.next, struct trace_uprobe, list); + unregister_trace_uprobe(tu); + } + mutex_unlock(&uprobe_lock); +} + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&uprobe_lock); + return seq_list_start(&uprobe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &uprobe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&uprobe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + int i; + + seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + + for (i = 0; i < tu->nr_args; i++) + seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); + + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); +} + +static const struct file_operations uprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + + seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations uprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* uprobe handler */ +static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct uprobe_trace_entry_head *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + u8 *data; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tu->call; + + tu->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = sizeof(*entry) + tu->size; + + event = trace_current_buffer_lock_reserve(&buffer, call->event.type, + size, irq_flags, pc); + if (!event) + return; + + entry = ring_buffer_event_data(event); + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); +} + +/* Event entry printers */ +static enum print_line_t +print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) +{ + struct uprobe_trace_entry_head *field; + struct trace_seq *s = &iter->seq; + struct trace_uprobe *tu; + u8 *data; + int i; + + field = (struct uprobe_trace_entry_head *)iter->ent; + tu = container_of(event, struct trace_uprobe, call.event); + + if (!trace_seq_printf(s, "%s: (", tu->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + data = (u8 *)&field[1]; + for (i = 0; i < tu->nr_args; i++) { + if (!tu->args[i].type->print(s, tu->args[i].name, + data + tu->args[i].offset, field)) + goto partial; + } + + if (trace_seq_puts(s, "\n")) + return TRACE_TYPE_HANDLED; + +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct trace_uprobe *tu, int flag) +{ + struct uprobe_trace_consumer *utc; + int ret = 0; + + if (!tu->inode || tu->consumer) + return -EINTR; + + utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); + if (!utc) + return -EINTR; + + utc->cons.handler = uprobe_dispatcher; + utc->cons.filter = NULL; + ret = uprobe_register(tu->inode, tu->offset, &utc->cons); + if (ret) { + kfree(utc); + return ret; + } + + tu->flags |= flag; + utc->tu = tu; + tu->consumer = utc; + + return 0; +} + +static void probe_event_disable(struct trace_uprobe *tu, int flag) +{ + if (!tu->inode || !tu->consumer) + return; + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + tu->flags &= ~flag; + kfree(tu->consumer); + tu->consumer = NULL; +} + +static int uprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct uprobe_trace_entry_head field; + struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + /* Set argument names as fields */ + for (i = 0; i < tu->nr_args; i++) { + ret = trace_define_field(event_call, tu->args[i].type->fmttype, + tu->args[i].name, + sizeof(field) + tu->args[i].offset, + tu->args[i].type->size, + tu->args[i].type->is_signed, + FILTER_OTHER); + + if (ret) + return ret; + } + return 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) +{ + const char *fmt, *arg; + int i; + int pos = 0; + + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + + /* When len=0, we just calculate the needed length */ + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", + tu->args[i].name, tu->args[i].type->fmt); + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", + tu->args[i].name); + } + + return pos; /* return the length of print_fmt */ +} +#undef LEN_OR_ZERO + +static int set_print_fmt(struct trace_uprobe *tu) +{ + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_print_fmt(tu, NULL, 0); + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_print_fmt(tu, print_fmt, len + 1); + tu->call.print_fmt = print_fmt; + + return 0; +} + +#ifdef CONFIG_PERF_EVENTS +/* uprobe profile handler */ +static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct ftrace_event_call *call = &tu->call; + struct uprobe_trace_entry_head *entry; + struct hlist_head *head; + u8 *data; + int size, __size, i; + int rctx; + + __size = sizeof(*entry) + tu->size; + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) + return; + + preempt_disable(); + + entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); + if (!entry) + goto out; + + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + head = this_cpu_ptr(call->perf_events); + perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); + + out: + preempt_enable(); +} +#endif /* CONFIG_PERF_EVENTS */ + +static +int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) +{ + struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + + switch (type) { + case TRACE_REG_REGISTER: + return probe_event_enable(tu, TP_FLAG_TRACE); + + case TRACE_REG_UNREGISTER: + probe_event_disable(tu, TP_FLAG_TRACE); + return 0; + +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + return probe_event_enable(tu, TP_FLAG_PROFILE); + + case TRACE_REG_PERF_UNREGISTER: + probe_event_disable(tu, TP_FLAG_PROFILE); + return 0; +#endif + default: + return 0; + } + return 0; +} + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct uprobe_trace_consumer *utc; + struct trace_uprobe *tu; + + utc = container_of(con, struct uprobe_trace_consumer, cons); + tu = utc->tu; + if (!tu || tu->consumer != utc) + return 0; + + if (tu->flags & TP_FLAG_TRACE) + uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + uprobe_perf_func(tu, regs); +#endif + return 0; +} + +static struct trace_event_functions uprobe_funcs = { + .trace = print_uprobe_event +}; + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct ftrace_event_call *call = &tu->call; + int ret; + + /* Initialize ftrace_event_call */ + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &uprobe_funcs; + call->class->define_fields = uprobe_event_define_fields; + + if (set_print_fmt(tu) < 0) + return -ENOMEM; + + ret = register_ftrace_event(&call->event); + if (!ret) { + kfree(call->print_fmt); + return -ENODEV; + } + call->flags = 0; + call->class->reg = trace_uprobe_register; + call->data = tu; + ret = trace_add_event_call(call); + + if (ret) { + pr_info("Failed to register uprobe event: %s\n", call->name); + kfree(call->print_fmt); + unregister_ftrace_event(&call->event); + } + + return ret; +} + +static void unregister_uprobe_event(struct trace_uprobe *tu) +{ + /* tu->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tu->call); + kfree(tu->call.print_fmt); + tu->call.print_fmt = NULL; +} + +/* Make a trace interface for controling probe points */ +static __init int init_uprobe_trace(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("uprobe_events", 0644, d_tracer, + NULL, &uprobe_events_ops); + /* Profile interface */ + trace_create_file("uprobe_profile", 0444, d_tracer, + NULL, &uprobe_profile_ops); + return 0; +} + +fs_initcall(init_uprobe_trace); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-11 10:30 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-11 10:30 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog (since v9) - Handle comments from Steven Rostedt about uprobe tracer documentation. - Disable preemption while in perf handler as suggested by Jiri Olsa. Changelog (since v5) - Added uprobe tracer documentation to this patch. Documentation/trace/uprobetracer.txt | 95 ++++ arch/Kconfig | 2 kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 kernel/trace/trace.h | 5 kernel/trace/trace_kprobe.c | 2 kernel/trace/trace_probe.c | 14 - kernel/trace/trace_probe.h | 3 kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ 9 files changed, 919 insertions(+), 7 deletions(-) create mode 100644 Documentation/trace/uprobetracer.txt create mode 100644 kernel/trace/trace_uprobe.c diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt new file mode 100644 index 0000000..eae40a0 --- /dev/null +++ b/Documentation/trace/uprobetracer.txt @@ -0,0 +1,95 @@ + Uprobe-tracer: Uprobe-based Event Tracing + ========================================= + Documentation written by Srikar Dronamraju + +Overview +-------- +Uprobe based trace events are similar to kprobe based trace events. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. + +Similar to the kprobe-event tracer, this doesn't need to be activated via +current_tracer. Instead of that, add probe points via +/sys/kernel/debug/tracing/uprobe_events, and enable it via +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. + +However unlike kprobe-event tracer, the uprobe event interface expects the +user to calculate the offset of the probepoint in the object + +Synopsis of uprobe_tracer +------------------------- + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe + + GRP : Group name. If omitted, use "uprobes" for it. + EVENT : Event name. If omitted, the event name is generated + based on SYMBOL+offs. + PATH : path to an executable or a library. + SYMBOL[+offs] : Symbol+offset where the probe is inserted. + + FETCHARGS : Arguments. Each probe can have up to 128 args. + %REG : Fetch register REG + +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/uprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + +Usage examples +-------------- +To add a probe as a new event, write a new definition to uprobe_events +as below. + + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events + + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash + + echo > /sys/kernel/debug/tracing/uprobe_events + + This clears all probe points. + +The following example shows how to dump the instruction pointer and %ax +a register at the probed text address. Here we are trying to probe +function zfree in /bin/zsh + + # cd /sys/kernel/debug/tracing/ + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh + # objdump -T /bin/zsh | grep -w zfree + 0000000000446420 g DF .text 0000000000000012 Base zfree + +0x46420 is the offset of zfree in object /bin/zsh that is loaded at +0x00400000. Hence the command to probe would be : + + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events + +Please note: User has to explicitly calculate the offset of the probepoint +in the object. We can see the events that are registered by looking at the +uprobe_events file. + + # cat uprobe_events + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 + +Right after definition, each event is disabled by default. For tracing these +events, you need to enable it by: + + # echo 1 > events/uprobes/enable + +Lets disable the event after sleeping for some time. + # sleep 20 + # echo 0 > events/uprobes/enable + +And you can see the traced information via /sys/kernel/debug/tracing/trace. + + # cat trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + +Each line shows us probes were triggered for a pid 24842 with ip being +0x446421 and contents of ax register being 79. diff --git a/arch/Kconfig b/arch/Kconfig index e5d3778..0f8f968 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -78,7 +78,7 @@ config OPTPROBES config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" - depends on ARCH_SUPPORTS_UPROBES && PERF_EVENTS + depends on UPROBE_EVENTS && PERF_EVENTS default n help Uprobes is the user-space counterpart to kprobes: they diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ce5a5c5..ea4bff6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -386,6 +386,22 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config UPROBE_EVENT + bool "Enable uprobes-based dynamic events" + depends on ARCH_SUPPORTS_UPROBES + depends on MMU + select UPROBES + select PROBE_EVENTS + select TRACING + default n + help + This allows the user to add tracing events on top of userspace + dynamic events (similar to tracepoints) on the fly via the trace + events interface. Those events can be inserted wherever uprobes + can probe, and record various registers. + This option is required if you plan to use perf-probe subcommand + of perf tools on user space applications. + config PROBE_EVENTS def_bool n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index fa10d5c..1734c03 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -62,5 +62,6 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o +obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f0..1bcdbec 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8b7773..b31d3d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -525,7 +525,7 @@ static int create_trace_probe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], - is_return); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8e526b9..daa9980 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -550,7 +550,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, bool is_kprobe) { unsigned long param; long offset; @@ -558,6 +558,11 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; ret = 0; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + switch (arg[0]) { case '$': ret = parse_probe_vars(arg + 1, t, f, is_return); @@ -619,7 +624,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, + is_kprobe); if (ret) kfree(dprm); else { @@ -677,7 +683,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return) + struct probe_arg *parg, bool is_return, bool is_kprobe) { const char *t; int ret; @@ -703,7 +709,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); if (ret >= 0 && t != NULL) ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2df9a18..9337086 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,6 +66,7 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 +#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ @@ -143,7 +144,7 @@ static inline int is_good_name(const char *name) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return); + struct probe_arg *parg, bool is_return, bool is_kprobe); extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c new file mode 100644 index 0000000..2b36ac6 --- /dev/null +++ b/kernel/trace/trace_uprobe.c @@ -0,0 +1,788 @@ +/* + * uprobes-based tracing events + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010-2012 + * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/uprobes.h> +#include <linux/namei.h> + +#include "trace_probe.h" + +#define UPROBE_EVENT_SYSTEM "uprobes" + +/* + * uprobe event core functions + */ +struct trace_uprobe; +struct uprobe_trace_consumer { + struct uprobe_consumer cons; + struct trace_uprobe *tu; +}; + +struct trace_uprobe { + struct list_head list; + struct ftrace_event_class class; + struct ftrace_event_call call; + struct uprobe_trace_consumer *consumer; + struct inode *inode; + char *filename; + unsigned long offset; + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + ssize_t size; /* trace entry size */ + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_UPROBE(n) \ + (offsetof(struct trace_uprobe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static int register_uprobe_event(struct trace_uprobe *tu); +static void unregister_uprobe_event(struct trace_uprobe *tu); + +static DEFINE_MUTEX(uprobe_lock); +static LIST_HEAD(uprobe_list); + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); + +/* + * Allocate new trace_uprobe and initialize it (including uprobes). + */ +static struct trace_uprobe * +alloc_trace_uprobe(const char *group, const char *event, int nargs) +{ + struct trace_uprobe *tu; + + if (!event || !is_good_name(event)) + return ERR_PTR(-EINVAL); + + if (!group || !is_good_name(group)) + return ERR_PTR(-EINVAL); + + tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + if (!tu) + return ERR_PTR(-ENOMEM); + + tu->call.class = &tu->class; + tu->call.name = kstrdup(event, GFP_KERNEL); + if (!tu->call.name) + goto error; + + tu->class.system = kstrdup(group, GFP_KERNEL); + if (!tu->class.system) + goto error; + + INIT_LIST_HEAD(&tu->list); + return tu; + +error: + kfree(tu->call.name); + kfree(tu); + + return ERR_PTR(-ENOMEM); +} + +static void free_trace_uprobe(struct trace_uprobe *tu) +{ + int i; + + for (i = 0; i < tu->nr_args; i++) + traceprobe_free_probe_arg(&tu->args[i]); + + iput(tu->inode); + kfree(tu->call.class->system); + kfree(tu->call.name); + kfree(tu->filename); + kfree(tu); +} + +static struct trace_uprobe *find_probe_event(const char *event, const char *group) +{ + struct trace_uprobe *tu; + + list_for_each_entry(tu, &uprobe_list, list) + if (strcmp(tu->call.name, event) == 0 && + strcmp(tu->call.class->system, group) == 0) + return tu; + + return NULL; +} + +/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ +static void unregister_trace_uprobe(struct trace_uprobe *tu) +{ + list_del(&tu->list); + unregister_uprobe_event(tu); + free_trace_uprobe(tu); +} + +/* Register a trace_uprobe and probe_event */ +static int register_trace_uprobe(struct trace_uprobe *tu) +{ + struct trace_uprobe *old_tp; + int ret; + + mutex_lock(&uprobe_lock); + + /* register as an event */ + old_tp = find_probe_event(tu->call.name, tu->call.class->system); + if (old_tp) + /* delete old event */ + unregister_trace_uprobe(old_tp); + + ret = register_uprobe_event(tu); + if (ret) { + pr_warning("Failed to register probe event(%d)\n", ret); + goto end; + } + + list_add_tail(&tu->list, &uprobe_list); + +end: + mutex_unlock(&uprobe_lock); + + return ret; +} + +/* + * Argument syntax: + * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * + * - Remove uprobe: -:[GRP/]EVENT + */ +static int create_trace_uprobe(int argc, char **argv) +{ + struct trace_uprobe *tu; + struct inode *inode; + char *arg, *event, *group, *filename; + char buf[MAX_EVENT_NAME_LEN]; + struct path path; + unsigned long offset; + bool is_delete; + int i, ret; + + inode = NULL; + ret = 0; + is_delete = false; + event = NULL; + group = NULL; + + /* argc must be >= 1 */ + if (argv[0][0] == '-') + is_delete = true; + else if (argv[0][0] != 'p') { + pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + arg = strchr(event, '/'); + + if (arg) { + group = event; + event = arg + 1; + event[-1] = '\0'; + + if (strlen(group) == 0) { + pr_info("Group name is not specified\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specified\n"); + return -EINVAL; + } + } + if (!group) + group = UPROBE_EVENT_SYSTEM; + + if (is_delete) { + if (!event) { + pr_info("Delete command needs an event name.\n"); + return -EINVAL; + } + mutex_lock(&uprobe_lock); + tu = find_probe_event(event, group); + + if (!tu) { + mutex_unlock(&uprobe_lock); + pr_info("Event %s/%s doesn't exist.\n", group, event); + return -ENOENT; + } + /* delete an event */ + unregister_trace_uprobe(tu); + mutex_unlock(&uprobe_lock); + return 0; + } + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + if (isdigit(argv[1][0])) { + pr_info("probe point must be have a filename.\n"); + return -EINVAL; + } + arg = strchr(argv[1], ':'); + if (!arg) + goto fail_address_parse; + + *arg++ = '\0'; + filename = argv[1]; + ret = kern_path(filename, LOOKUP_FOLLOW, &path); + if (ret) + goto fail_address_parse; + + ret = strict_strtoul(arg, 0, &offset); + if (ret) + goto fail_address_parse; + + inode = igrab(path.dentry->d_inode); + + argc -= 2; + argv += 2; + + /* setup a probe */ + if (!event) { + char *tail = strrchr(filename, '/'); + char *ptr; + + ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL); + if (!ptr) { + ret = -ENOMEM; + goto fail_address_parse; + } + + tail = ptr; + ptr = strpbrk(tail, ".-_"); + if (ptr) + *ptr = '\0'; + + snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); + event = buf; + kfree(tail); + } + + tu = alloc_trace_uprobe(group, event, argc); + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); + ret = PTR_ERR(tu); + goto fail_address_parse; + } + tu->offset = offset; + tu->inode = inode; + tu->filename = kstrdup(filename, GFP_KERNEL); + + if (!tu->filename) { + pr_info("Failed to allocate filename.\n"); + ret = -ENOMEM; + goto error; + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Increment count for freeing args in error case */ + tu->nr_args++; + + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) { + *arg++ = '\0'; + tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); + } else { + arg = argv[i]; + /* If argument name is omitted, set "argN" */ + snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); + tu->args[i].name = kstrdup(buf, GFP_KERNEL); + } + + if (!tu->args[i].name) { + pr_info("Failed to allocate argument[%d] name.\n", i); + ret = -ENOMEM; + goto error; + } + + if (!is_good_name(tu->args[i].name)) { + pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); + ret = -EINVAL; + goto error; + } + + if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { + pr_info("Argument[%d] name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + /* Parse fetch argument */ + ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); + if (ret) { + pr_info("Parse error at argument[%d]. (%d)\n", i, ret); + goto error; + } + } + + ret = register_trace_uprobe(tu); + if (ret) + goto error; + return 0; + +error: + free_trace_uprobe(tu); + return ret; + +fail_address_parse: + if (inode) + iput(inode); + + pr_info("Failed to parse address.\n"); + + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_uprobe *tu; + + mutex_lock(&uprobe_lock); + while (!list_empty(&uprobe_list)) { + tu = list_entry(uprobe_list.next, struct trace_uprobe, list); + unregister_trace_uprobe(tu); + } + mutex_unlock(&uprobe_lock); +} + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&uprobe_lock); + return seq_list_start(&uprobe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &uprobe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&uprobe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + int i; + + seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + + for (i = 0; i < tu->nr_args; i++) + seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); + + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); +} + +static const struct file_operations uprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + + seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations uprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* uprobe handler */ +static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct uprobe_trace_entry_head *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + u8 *data; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tu->call; + + tu->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = sizeof(*entry) + tu->size; + + event = trace_current_buffer_lock_reserve(&buffer, call->event.type, + size, irq_flags, pc); + if (!event) + return; + + entry = ring_buffer_event_data(event); + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); +} + +/* Event entry printers */ +static enum print_line_t +print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) +{ + struct uprobe_trace_entry_head *field; + struct trace_seq *s = &iter->seq; + struct trace_uprobe *tu; + u8 *data; + int i; + + field = (struct uprobe_trace_entry_head *)iter->ent; + tu = container_of(event, struct trace_uprobe, call.event); + + if (!trace_seq_printf(s, "%s: (", tu->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + data = (u8 *)&field[1]; + for (i = 0; i < tu->nr_args; i++) { + if (!tu->args[i].type->print(s, tu->args[i].name, + data + tu->args[i].offset, field)) + goto partial; + } + + if (trace_seq_puts(s, "\n")) + return TRACE_TYPE_HANDLED; + +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct trace_uprobe *tu, int flag) +{ + struct uprobe_trace_consumer *utc; + int ret = 0; + + if (!tu->inode || tu->consumer) + return -EINTR; + + utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); + if (!utc) + return -EINTR; + + utc->cons.handler = uprobe_dispatcher; + utc->cons.filter = NULL; + ret = uprobe_register(tu->inode, tu->offset, &utc->cons); + if (ret) { + kfree(utc); + return ret; + } + + tu->flags |= flag; + utc->tu = tu; + tu->consumer = utc; + + return 0; +} + +static void probe_event_disable(struct trace_uprobe *tu, int flag) +{ + if (!tu->inode || !tu->consumer) + return; + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + tu->flags &= ~flag; + kfree(tu->consumer); + tu->consumer = NULL; +} + +static int uprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct uprobe_trace_entry_head field; + struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + /* Set argument names as fields */ + for (i = 0; i < tu->nr_args; i++) { + ret = trace_define_field(event_call, tu->args[i].type->fmttype, + tu->args[i].name, + sizeof(field) + tu->args[i].offset, + tu->args[i].type->size, + tu->args[i].type->is_signed, + FILTER_OTHER); + + if (ret) + return ret; + } + return 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) +{ + const char *fmt, *arg; + int i; + int pos = 0; + + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + + /* When len=0, we just calculate the needed length */ + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", + tu->args[i].name, tu->args[i].type->fmt); + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", + tu->args[i].name); + } + + return pos; /* return the length of print_fmt */ +} +#undef LEN_OR_ZERO + +static int set_print_fmt(struct trace_uprobe *tu) +{ + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_print_fmt(tu, NULL, 0); + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_print_fmt(tu, print_fmt, len + 1); + tu->call.print_fmt = print_fmt; + + return 0; +} + +#ifdef CONFIG_PERF_EVENTS +/* uprobe profile handler */ +static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct ftrace_event_call *call = &tu->call; + struct uprobe_trace_entry_head *entry; + struct hlist_head *head; + u8 *data; + int size, __size, i; + int rctx; + + __size = sizeof(*entry) + tu->size; + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) + return; + + preempt_disable(); + + entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); + if (!entry) + goto out; + + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + head = this_cpu_ptr(call->perf_events); + perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); + + out: + preempt_enable(); +} +#endif /* CONFIG_PERF_EVENTS */ + +static +int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) +{ + struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + + switch (type) { + case TRACE_REG_REGISTER: + return probe_event_enable(tu, TP_FLAG_TRACE); + + case TRACE_REG_UNREGISTER: + probe_event_disable(tu, TP_FLAG_TRACE); + return 0; + +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + return probe_event_enable(tu, TP_FLAG_PROFILE); + + case TRACE_REG_PERF_UNREGISTER: + probe_event_disable(tu, TP_FLAG_PROFILE); + return 0; +#endif + default: + return 0; + } + return 0; +} + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct uprobe_trace_consumer *utc; + struct trace_uprobe *tu; + + utc = container_of(con, struct uprobe_trace_consumer, cons); + tu = utc->tu; + if (!tu || tu->consumer != utc) + return 0; + + if (tu->flags & TP_FLAG_TRACE) + uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + uprobe_perf_func(tu, regs); +#endif + return 0; +} + +static struct trace_event_functions uprobe_funcs = { + .trace = print_uprobe_event +}; + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct ftrace_event_call *call = &tu->call; + int ret; + + /* Initialize ftrace_event_call */ + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &uprobe_funcs; + call->class->define_fields = uprobe_event_define_fields; + + if (set_print_fmt(tu) < 0) + return -ENOMEM; + + ret = register_ftrace_event(&call->event); + if (!ret) { + kfree(call->print_fmt); + return -ENODEV; + } + call->flags = 0; + call->class->reg = trace_uprobe_register; + call->data = tu; + ret = trace_add_event_call(call); + + if (ret) { + pr_info("Failed to register uprobe event: %s\n", call->name); + kfree(call->print_fmt); + unregister_ftrace_event(&call->event); + } + + return ret; +} + +static void unregister_uprobe_event(struct trace_uprobe *tu) +{ + /* tu->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tu->call); + kfree(tu->call.print_fmt); + tu->call.print_fmt = NULL; +} + +/* Make a trace interface for controling probe points */ +static __init int init_uprobe_trace(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("uprobe_events", 0644, d_tracer, + NULL, &uprobe_events_ops); + /* Profile interface */ + trace_create_file("uprobe_profile", 0444, d_tracer, + NULL, &uprobe_profile_ops); + return 0; +} + +fs_initcall(init_uprobe_trace); ^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-11 10:30 ` Srikar Dronamraju @ 2012-04-12 13:02 ` Masami Hiramatsu -1 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-12 13:02 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/11 19:30), Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Implements trace_event support for uprobes. In its current form it can > be used to put probes at a specified offset in a file and dump the > required registers when the code flow reaches the probed address. > > The following example shows how to dump the instruction pointer and %ax > a register at the probed text address. Here we are trying to probe > zfree in /bin/zsh > > # cd /sys/kernel/debug/tracing/ > # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > # objdump -T /bin/zsh | grep -w zfree > 0000000000446420 g DF .text 0000000000000012 Base zfree > # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > # cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > # echo 1 > events/uprobes/enable > # sleep 20 > # echo 0 > events/uprobes/enable > # cat trace > # tracer: nop > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > --- > > Changelog (since v9) > - Handle comments from Steven Rostedt about uprobe tracer documentation. > - Disable preemption while in perf handler as suggested by Jiri Olsa. > > Changelog (since v5) > - Added uprobe tracer documentation to this patch. > > Documentation/trace/uprobetracer.txt | 95 ++++ > arch/Kconfig | 2 > kernel/trace/Kconfig | 16 + > kernel/trace/Makefile | 1 > kernel/trace/trace.h | 5 > kernel/trace/trace_kprobe.c | 2 > kernel/trace/trace_probe.c | 14 - > kernel/trace/trace_probe.h | 3 > kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ > 9 files changed, 919 insertions(+), 7 deletions(-) > create mode 100644 Documentation/trace/uprobetracer.txt > create mode 100644 kernel/trace/trace_uprobe.c > > diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt > new file mode 100644 > index 0000000..eae40a0 > --- /dev/null > +++ b/Documentation/trace/uprobetracer.txt > @@ -0,0 +1,95 @@ > + Uprobe-tracer: Uprobe-based Event Tracing > + ========================================= > + Documentation written by Srikar Dronamraju > + > +Overview > +-------- > +Uprobe based trace events are similar to kprobe based trace events. > +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. > + > +Similar to the kprobe-event tracer, this doesn't need to be activated via > +current_tracer. Instead of that, add probe points via > +/sys/kernel/debug/tracing/uprobe_events, and enable it via > +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. > + > +However unlike kprobe-event tracer, the uprobe event interface expects the > +user to calculate the offset of the probepoint in the object > + > +Synopsis of uprobe_tracer > +------------------------- > + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe > + > + GRP : Group name. If omitted, use "uprobes" for it. > + EVENT : Event name. If omitted, the event name is generated > + based on SYMBOL+offs. > + PATH : path to an executable or a library. > + SYMBOL[+offs] : Symbol+offset where the probe is inserted. > + > + FETCHARGS : Arguments. Each probe can have up to 128 args. > + %REG : Fetch register REG > + > +Event Profiling > +--------------- > + You can check the total number of probe hits and probe miss-hits via > +/sys/kernel/debug/tracing/uprobe_profile. > + The first column is event name, the second is the number of probe hits, > +the third is the number of probe miss-hits. > + > +Usage examples > +-------------- > +To add a probe as a new event, write a new definition to uprobe_events > +as below. > + > + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events > + > + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash > + > + echo > /sys/kernel/debug/tracing/uprobe_events > + > + This clears all probe points. > + > +The following example shows how to dump the instruction pointer and %ax > +a register at the probed text address. Here we are trying to probe > +function zfree in /bin/zsh > + > + # cd /sys/kernel/debug/tracing/ > + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > + # objdump -T /bin/zsh | grep -w zfree > + 0000000000446420 g DF .text 0000000000000012 Base zfree > + > +0x46420 is the offset of zfree in object /bin/zsh that is loaded at > +0x00400000. Hence the command to probe would be : > + > + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > + > +Please note: User has to explicitly calculate the offset of the probepoint > +in the object. We can see the events that are registered by looking at the > +uprobe_events file. > + > + # cat uprobe_events > + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 Doesn't uprobe_events show the arguments of existing events? And also, could you add an event format of above event here? Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-12 13:02 ` Masami Hiramatsu 0 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-12 13:02 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/11 19:30), Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Implements trace_event support for uprobes. In its current form it can > be used to put probes at a specified offset in a file and dump the > required registers when the code flow reaches the probed address. > > The following example shows how to dump the instruction pointer and %ax > a register at the probed text address. Here we are trying to probe > zfree in /bin/zsh > > # cd /sys/kernel/debug/tracing/ > # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > # objdump -T /bin/zsh | grep -w zfree > 0000000000446420 g DF .text 0000000000000012 Base zfree > # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > # cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > # echo 1 > events/uprobes/enable > # sleep 20 > # echo 0 > events/uprobes/enable > # cat trace > # tracer: nop > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > --- > > Changelog (since v9) > - Handle comments from Steven Rostedt about uprobe tracer documentation. > - Disable preemption while in perf handler as suggested by Jiri Olsa. > > Changelog (since v5) > - Added uprobe tracer documentation to this patch. > > Documentation/trace/uprobetracer.txt | 95 ++++ > arch/Kconfig | 2 > kernel/trace/Kconfig | 16 + > kernel/trace/Makefile | 1 > kernel/trace/trace.h | 5 > kernel/trace/trace_kprobe.c | 2 > kernel/trace/trace_probe.c | 14 - > kernel/trace/trace_probe.h | 3 > kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ > 9 files changed, 919 insertions(+), 7 deletions(-) > create mode 100644 Documentation/trace/uprobetracer.txt > create mode 100644 kernel/trace/trace_uprobe.c > > diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt > new file mode 100644 > index 0000000..eae40a0 > --- /dev/null > +++ b/Documentation/trace/uprobetracer.txt > @@ -0,0 +1,95 @@ > + Uprobe-tracer: Uprobe-based Event Tracing > + ========================================= > + Documentation written by Srikar Dronamraju > + > +Overview > +-------- > +Uprobe based trace events are similar to kprobe based trace events. > +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. > + > +Similar to the kprobe-event tracer, this doesn't need to be activated via > +current_tracer. Instead of that, add probe points via > +/sys/kernel/debug/tracing/uprobe_events, and enable it via > +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. > + > +However unlike kprobe-event tracer, the uprobe event interface expects the > +user to calculate the offset of the probepoint in the object > + > +Synopsis of uprobe_tracer > +------------------------- > + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe > + > + GRP : Group name. If omitted, use "uprobes" for it. > + EVENT : Event name. If omitted, the event name is generated > + based on SYMBOL+offs. > + PATH : path to an executable or a library. > + SYMBOL[+offs] : Symbol+offset where the probe is inserted. > + > + FETCHARGS : Arguments. Each probe can have up to 128 args. > + %REG : Fetch register REG > + > +Event Profiling > +--------------- > + You can check the total number of probe hits and probe miss-hits via > +/sys/kernel/debug/tracing/uprobe_profile. > + The first column is event name, the second is the number of probe hits, > +the third is the number of probe miss-hits. > + > +Usage examples > +-------------- > +To add a probe as a new event, write a new definition to uprobe_events > +as below. > + > + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events > + > + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash > + > + echo > /sys/kernel/debug/tracing/uprobe_events > + > + This clears all probe points. > + > +The following example shows how to dump the instruction pointer and %ax > +a register at the probed text address. Here we are trying to probe > +function zfree in /bin/zsh > + > + # cd /sys/kernel/debug/tracing/ > + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > + # objdump -T /bin/zsh | grep -w zfree > + 0000000000446420 g DF .text 0000000000000012 Base zfree > + > +0x46420 is the offset of zfree in object /bin/zsh that is loaded at > +0x00400000. Hence the command to probe would be : > + > + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > + > +Please note: User has to explicitly calculate the offset of the probepoint > +in the object. We can see the events that are registered by looking at the > +uprobe_events file. > + > + # cat uprobe_events > + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 Doesn't uprobe_events show the arguments of existing events? And also, could you add an event format of above event here? Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-12 13:02 ` Masami Hiramatsu @ 2012-04-12 14:49 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-12 14:49 UTC (permalink / raw) To: Masami Hiramatsu Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov > > + > > + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > > + > > +Please note: User has to explicitly calculate the offset of the probepoint > > +in the object. We can see the events that are registered by looking at the > > +uprobe_events file. > > + > > + # cat uprobe_events > > + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > > Doesn't uprobe_events show the arguments of existing events? > And also, could you add an event format of above event here? > [root@f14kvm tracing]# cat uprobe_events [root@f14kvm tracing]# echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events [root@f14kvm tracing]# cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax [root@f14kvm tracing]# cat events/uprobes/p_zsh_0x46420/format name: p_zsh_0x46420 ID: 922 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:int common_padding; offset:8; size:4; signed:1; field:unsigned long __probe_ip; offset:12; size:4; signed:0; field:u32 arg1; offset:16; size:4; signed:0; field:u32 arg2; offset:20; size:4; signed:0; print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2 [root@f14kvm tracing]# Will update the Documentation file with correct output of "cat uprobe_events". Do you want the format file to be added to the Documentation? -- Thanks and Regards Srikar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-12 14:49 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-12 14:49 UTC (permalink / raw) To: Masami Hiramatsu Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov > > + > > + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > > + > > +Please note: User has to explicitly calculate the offset of the probepoint > > +in the object. We can see the events that are registered by looking at the > > +uprobe_events file. > > + > > + # cat uprobe_events > > + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > > Doesn't uprobe_events show the arguments of existing events? > And also, could you add an event format of above event here? > [root@f14kvm tracing]# cat uprobe_events [root@f14kvm tracing]# echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events [root@f14kvm tracing]# cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax [root@f14kvm tracing]# cat events/uprobes/p_zsh_0x46420/format name: p_zsh_0x46420 ID: 922 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:int common_padding; offset:8; size:4; signed:1; field:unsigned long __probe_ip; offset:12; size:4; signed:0; field:u32 arg1; offset:16; size:4; signed:0; field:u32 arg2; offset:20; size:4; signed:0; print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2 [root@f14kvm tracing]# Will update the Documentation file with correct output of "cat uprobe_events". Do you want the format file to be added to the Documentation? -- Thanks and Regards Srikar ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-12 14:49 ` Srikar Dronamraju @ 2012-04-13 2:28 ` Masami Hiramatsu -1 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-13 2:28 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/12 23:49), Srikar Dronamraju wrote: >>> + >>> + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events >>> + >>> +Please note: User has to explicitly calculate the offset of the probepoint >>> +in the object. We can see the events that are registered by looking at the >>> +uprobe_events file. >>> + >>> + # cat uprobe_events >>> + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 >> >> Doesn't uprobe_events show the arguments of existing events? >> And also, could you add an event format of above event here? >> > > [root@f14kvm tracing]# cat uprobe_events > [root@f14kvm tracing]# echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > [root@f14kvm tracing]# cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax > [root@f14kvm tracing]# cat events/uprobes/p_zsh_0x46420/format > name: p_zsh_0x46420 > ID: 922 > format: > field:unsigned short common_type; offset:0; size:2; signed:0; > field:unsigned char common_flags; offset:2; size:1; signed:0; > field:unsigned char common_preempt_count; offset:3; size:1; signed:0; > field:int common_pid; offset:4; size:4; signed:1; > field:int common_padding; offset:8; size:4; signed:1; > > field:unsigned long __probe_ip; offset:12; size:4; signed:0; > field:u32 arg1; offset:16; size:4; signed:0; > field:u32 arg2; offset:20; size:4; signed:0; > > print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2 > [root@f14kvm tracing]# > > Will update the Documentation file with correct output of "cat > uprobe_events". Do you want the format file to be added to the > Documentation? Yes, I want, please :) Thank you! -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-13 2:28 ` Masami Hiramatsu 0 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-13 2:28 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/12 23:49), Srikar Dronamraju wrote: >>> + >>> + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events >>> + >>> +Please note: User has to explicitly calculate the offset of the probepoint >>> +in the object. We can see the events that are registered by looking at the >>> +uprobe_events file. >>> + >>> + # cat uprobe_events >>> + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 >> >> Doesn't uprobe_events show the arguments of existing events? >> And also, could you add an event format of above event here? >> > > [root@f14kvm tracing]# cat uprobe_events > [root@f14kvm tracing]# echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > [root@f14kvm tracing]# cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax > [root@f14kvm tracing]# cat events/uprobes/p_zsh_0x46420/format > name: p_zsh_0x46420 > ID: 922 > format: > field:unsigned short common_type; offset:0; size:2; signed:0; > field:unsigned char common_flags; offset:2; size:1; signed:0; > field:unsigned char common_preempt_count; offset:3; size:1; signed:0; > field:int common_pid; offset:4; size:4; signed:1; > field:int common_padding; offset:8; size:4; signed:1; > > field:unsigned long __probe_ip; offset:12; size:4; signed:0; > field:u32 arg1; offset:16; size:4; signed:0; > field:u32 arg2; offset:20; size:4; signed:0; > > print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2 > [root@f14kvm tracing]# > > Will update the Documentation file with correct output of "cat > uprobe_events". Do you want the format file to be added to the > Documentation? Yes, I want, please :) Thank you! -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-11 10:30 ` Srikar Dronamraju @ 2012-04-12 13:14 ` Steven Rostedt -1 siblings, 0 replies; 42+ messages in thread From: Steven Rostedt @ 2012-04-12 13:14 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov On Wed, 2012-04-11 at 16:00 +0530, Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Implements trace_event support for uprobes. In its current form it can > be used to put probes at a specified offset in a file and dump the > required registers when the code flow reaches the probed address. > > The following example shows how to dump the instruction pointer and %ax > a register at the probed text address. Here we are trying to probe > zfree in /bin/zsh > > # cd /sys/kernel/debug/tracing/ > # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > # objdump -T /bin/zsh | grep -w zfree > 0000000000446420 g DF .text 0000000000000012 Base zfree > # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > # cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > # echo 1 > events/uprobes/enable > # sleep 20 > # echo 0 > events/uprobes/enable > # cat trace > # tracer: nop > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> I'm fine with what I see here (still need to fix what Masami suggested). Acked-by: Steven Rostedt <rostedt@goodmis.org> -- Steve -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-12 13:14 ` Steven Rostedt 0 siblings, 0 replies; 42+ messages in thread From: Steven Rostedt @ 2012-04-12 13:14 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov On Wed, 2012-04-11 at 16:00 +0530, Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Implements trace_event support for uprobes. In its current form it can > be used to put probes at a specified offset in a file and dump the > required registers when the code flow reaches the probed address. > > The following example shows how to dump the instruction pointer and %ax > a register at the probed text address. Here we are trying to probe > zfree in /bin/zsh > > # cd /sys/kernel/debug/tracing/ > # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > # objdump -T /bin/zsh | grep -w zfree > 0000000000446420 g DF .text 0000000000000012 Base zfree > # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > # cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > # echo 1 > events/uprobes/enable > # sleep 20 > # echo 0 > events/uprobes/enable > # cat trace > # tracer: nop > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> I'm fine with what I see here (still need to fix what Masami suggested). Acked-by: Steven Rostedt <rostedt@goodmis.org> -- Steve ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-12 13:14 ` Steven Rostedt @ 2012-04-14 11:12 ` Ingo Molnar -1 siblings, 0 replies; 42+ messages in thread From: Ingo Molnar @ 2012-04-14 11:12 UTC (permalink / raw) To: Steven Rostedt Cc: Srikar Dronamraju, Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Steven Rostedt <rostedt@goodmis.org> wrote: > I'm fine with what I see here (still need to fix what Masami > suggested). > > Acked-by: Steven Rostedt <rostedt@goodmis.org> Ok - Srikar, mind sending the latest (3-patch?) series again, with all suggestions and acks incorporated? Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-14 11:12 ` Ingo Molnar 0 siblings, 0 replies; 42+ messages in thread From: Ingo Molnar @ 2012-04-14 11:12 UTC (permalink / raw) To: Steven Rostedt Cc: Srikar Dronamraju, Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Steven Rostedt <rostedt@goodmis.org> wrote: > I'm fine with what I see here (still need to fix what Masami > suggested). > > Acked-by: Steven Rostedt <rostedt@goodmis.org> Ok - Srikar, mind sending the latest (3-patch?) series again, with all suggestions and acks incorporated? Thanks, Ingo ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-14 11:12 ` Ingo Molnar @ 2012-04-16 9:22 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-16 9:22 UTC (permalink / raw) To: Ingo Molnar Cc: Steven Rostedt, Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Ingo Molnar <mingo@kernel.org> [2012-04-14 13:12:06]: > > * Steven Rostedt <rostedt@goodmis.org> wrote: > > > I'm fine with what I see here (still need to fix what Masami > > suggested). > > > > Acked-by: Steven Rostedt <rostedt@goodmis.org> > > Ok - Srikar, mind sending the latest (3-patch?) series again, > with all suggestions and acks incorporated? > Just sent out the 3 patches incorporation all suggestions including the last one from Stephen Boyd. -- Thanks and Regards Srikar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-16 9:22 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-16 9:22 UTC (permalink / raw) To: Ingo Molnar Cc: Steven Rostedt, Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Ingo Molnar <mingo@kernel.org> [2012-04-14 13:12:06]: > > * Steven Rostedt <rostedt@goodmis.org> wrote: > > > I'm fine with what I see here (still need to fix what Masami > > suggested). > > > > Acked-by: Steven Rostedt <rostedt@goodmis.org> > > Ok - Srikar, mind sending the latest (3-patch?) series again, > with all suggestions and acks incorporated? > Just sent out the 3 patches incorporation all suggestions including the last one from Stephen Boyd. -- Thanks and Regards Srikar ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-14 11:12 ` Ingo Molnar @ 2012-04-20 9:57 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-20 9:57 UTC (permalink / raw) To: Ingo Molnar Cc: Steven Rostedt, Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov Hi Ingo, * Ingo Molnar <mingo@kernel.org> [2012-04-14 13:12:06]: > > * Steven Rostedt <rostedt@goodmis.org> wrote: > > > I'm fine with what I see here (still need to fix what Masami > > suggested). > > > > Acked-by: Steven Rostedt <rostedt@goodmis.org> > > Ok - Srikar, mind sending the latest (3-patch?) series again, > with all suggestions and acks incorporated? > I had re-posted the tracing bits http://lkml.org/lkml/2012/4/16/109 Masami has added his ack to the last patch. So all the three patches are acked by Masami and Steven Rostedt. Also the perf bits were posted here http://lkml.org/lkml/2012/4/16/175. Any reason why these arent pulled in? -- thanks and regards Srikar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-04-20 9:57 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-04-20 9:57 UTC (permalink / raw) To: Ingo Molnar Cc: Steven Rostedt, Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov Hi Ingo, * Ingo Molnar <mingo@kernel.org> [2012-04-14 13:12:06]: > > * Steven Rostedt <rostedt@goodmis.org> wrote: > > > I'm fine with what I see here (still need to fix what Masami > > suggested). > > > > Acked-by: Steven Rostedt <rostedt@goodmis.org> > > Ok - Srikar, mind sending the latest (3-patch?) series again, > with all suggestions and acks incorporated? > I had re-posted the tracing bits http://lkml.org/lkml/2012/4/16/109 Masami has added his ack to the last patch. So all the three patches are acked by Masami and Steven Rostedt. Also the perf bits were posted here http://lkml.org/lkml/2012/4/16/175. Any reason why these arent pulled in? -- thanks and regards Srikar ^ permalink raw reply [flat|nested] 42+ messages in thread
* [tip:perf/uprobes] tracing: Provide trace events interface for uprobes 2012-04-11 10:30 ` Srikar Dronamraju @ 2012-05-08 4:09 ` tip-bot for Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: tip-bot for Srikar Dronamraju @ 2012-05-08 4:09 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, torvalds, peterz, anton, jkenisto, rostedt, oleg, tglx, linux-mm, hpa, linux-kernel, andi, hch, ananth, masami.hiramatsu.pt, acme, srikar Commit-ID: f3f096cfedf8113380c56fc855275cc75cd8cf55 Gitweb: http://git.kernel.org/tip/f3f096cfedf8113380c56fc855275cc75cd8cf55 Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Wed, 11 Apr 2012 16:00:43 +0530 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 7 May 2012 14:30:17 +0200 tracing: Provide trace events interface for uprobes Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh: # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- Documentation/trace/uprobetracer.txt | 95 ++++ arch/Kconfig | 2 +- kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 + kernel/trace/trace.h | 5 + kernel/trace/trace_kprobe.c | 2 +- kernel/trace/trace_probe.c | 14 +- kernel/trace/trace_probe.h | 3 +- kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ 9 files changed, 919 insertions(+), 7 deletions(-) diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt new file mode 100644 index 0000000..eae40a0 --- /dev/null +++ b/Documentation/trace/uprobetracer.txt @@ -0,0 +1,95 @@ + Uprobe-tracer: Uprobe-based Event Tracing + ========================================= + Documentation written by Srikar Dronamraju + +Overview +-------- +Uprobe based trace events are similar to kprobe based trace events. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. + +Similar to the kprobe-event tracer, this doesn't need to be activated via +current_tracer. Instead of that, add probe points via +/sys/kernel/debug/tracing/uprobe_events, and enable it via +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. + +However unlike kprobe-event tracer, the uprobe event interface expects the +user to calculate the offset of the probepoint in the object + +Synopsis of uprobe_tracer +------------------------- + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe + + GRP : Group name. If omitted, use "uprobes" for it. + EVENT : Event name. If omitted, the event name is generated + based on SYMBOL+offs. + PATH : path to an executable or a library. + SYMBOL[+offs] : Symbol+offset where the probe is inserted. + + FETCHARGS : Arguments. Each probe can have up to 128 args. + %REG : Fetch register REG + +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/uprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + +Usage examples +-------------- +To add a probe as a new event, write a new definition to uprobe_events +as below. + + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events + + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash + + echo > /sys/kernel/debug/tracing/uprobe_events + + This clears all probe points. + +The following example shows how to dump the instruction pointer and %ax +a register at the probed text address. Here we are trying to probe +function zfree in /bin/zsh + + # cd /sys/kernel/debug/tracing/ + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh + # objdump -T /bin/zsh | grep -w zfree + 0000000000446420 g DF .text 0000000000000012 Base zfree + +0x46420 is the offset of zfree in object /bin/zsh that is loaded at +0x00400000. Hence the command to probe would be : + + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events + +Please note: User has to explicitly calculate the offset of the probepoint +in the object. We can see the events that are registered by looking at the +uprobe_events file. + + # cat uprobe_events + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 + +Right after definition, each event is disabled by default. For tracing these +events, you need to enable it by: + + # echo 1 > events/uprobes/enable + +Lets disable the event after sleeping for some time. + # sleep 20 + # echo 0 > events/uprobes/enable + +And you can see the traced information via /sys/kernel/debug/tracing/trace. + + # cat trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + +Each line shows us probes were triggered for a pid 24842 with ip being +0x446421 and contents of ax register being 79. diff --git a/arch/Kconfig b/arch/Kconfig index e5d3778..0f8f968 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -78,7 +78,7 @@ config OPTPROBES config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" - depends on ARCH_SUPPORTS_UPROBES && PERF_EVENTS + depends on UPROBE_EVENTS && PERF_EVENTS default n help Uprobes is the user-space counterpart to kprobes: they diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ce5a5c5..ea4bff6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -386,6 +386,22 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config UPROBE_EVENT + bool "Enable uprobes-based dynamic events" + depends on ARCH_SUPPORTS_UPROBES + depends on MMU + select UPROBES + select PROBE_EVENTS + select TRACING + default n + help + This allows the user to add tracing events on top of userspace + dynamic events (similar to tracepoints) on the fly via the trace + events interface. Those events can be inserted wherever uprobes + can probe, and record various registers. + This option is required if you plan to use perf-probe subcommand + of perf tools on user space applications. + config PROBE_EVENTS def_bool n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index fa10d5c..1734c03 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -62,5 +62,6 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o +obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f0..1bcdbec 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8b7773..b31d3d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -525,7 +525,7 @@ static int create_trace_probe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], - is_return); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8e526b9..daa9980 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -550,7 +550,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, bool is_kprobe) { unsigned long param; long offset; @@ -558,6 +558,11 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; ret = 0; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + switch (arg[0]) { case '$': ret = parse_probe_vars(arg + 1, t, f, is_return); @@ -619,7 +624,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, + is_kprobe); if (ret) kfree(dprm); else { @@ -677,7 +683,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return) + struct probe_arg *parg, bool is_return, bool is_kprobe) { const char *t; int ret; @@ -703,7 +709,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); if (ret >= 0 && t != NULL) ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2df9a18..9337086 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,6 +66,7 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 +#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ @@ -143,7 +144,7 @@ static inline int is_good_name(const char *name) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return); + struct probe_arg *parg, bool is_return, bool is_kprobe); extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c new file mode 100644 index 0000000..2b36ac6 --- /dev/null +++ b/kernel/trace/trace_uprobe.c @@ -0,0 +1,788 @@ +/* + * uprobes-based tracing events + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010-2012 + * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/uprobes.h> +#include <linux/namei.h> + +#include "trace_probe.h" + +#define UPROBE_EVENT_SYSTEM "uprobes" + +/* + * uprobe event core functions + */ +struct trace_uprobe; +struct uprobe_trace_consumer { + struct uprobe_consumer cons; + struct trace_uprobe *tu; +}; + +struct trace_uprobe { + struct list_head list; + struct ftrace_event_class class; + struct ftrace_event_call call; + struct uprobe_trace_consumer *consumer; + struct inode *inode; + char *filename; + unsigned long offset; + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + ssize_t size; /* trace entry size */ + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_UPROBE(n) \ + (offsetof(struct trace_uprobe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static int register_uprobe_event(struct trace_uprobe *tu); +static void unregister_uprobe_event(struct trace_uprobe *tu); + +static DEFINE_MUTEX(uprobe_lock); +static LIST_HEAD(uprobe_list); + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); + +/* + * Allocate new trace_uprobe and initialize it (including uprobes). + */ +static struct trace_uprobe * +alloc_trace_uprobe(const char *group, const char *event, int nargs) +{ + struct trace_uprobe *tu; + + if (!event || !is_good_name(event)) + return ERR_PTR(-EINVAL); + + if (!group || !is_good_name(group)) + return ERR_PTR(-EINVAL); + + tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + if (!tu) + return ERR_PTR(-ENOMEM); + + tu->call.class = &tu->class; + tu->call.name = kstrdup(event, GFP_KERNEL); + if (!tu->call.name) + goto error; + + tu->class.system = kstrdup(group, GFP_KERNEL); + if (!tu->class.system) + goto error; + + INIT_LIST_HEAD(&tu->list); + return tu; + +error: + kfree(tu->call.name); + kfree(tu); + + return ERR_PTR(-ENOMEM); +} + +static void free_trace_uprobe(struct trace_uprobe *tu) +{ + int i; + + for (i = 0; i < tu->nr_args; i++) + traceprobe_free_probe_arg(&tu->args[i]); + + iput(tu->inode); + kfree(tu->call.class->system); + kfree(tu->call.name); + kfree(tu->filename); + kfree(tu); +} + +static struct trace_uprobe *find_probe_event(const char *event, const char *group) +{ + struct trace_uprobe *tu; + + list_for_each_entry(tu, &uprobe_list, list) + if (strcmp(tu->call.name, event) == 0 && + strcmp(tu->call.class->system, group) == 0) + return tu; + + return NULL; +} + +/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ +static void unregister_trace_uprobe(struct trace_uprobe *tu) +{ + list_del(&tu->list); + unregister_uprobe_event(tu); + free_trace_uprobe(tu); +} + +/* Register a trace_uprobe and probe_event */ +static int register_trace_uprobe(struct trace_uprobe *tu) +{ + struct trace_uprobe *old_tp; + int ret; + + mutex_lock(&uprobe_lock); + + /* register as an event */ + old_tp = find_probe_event(tu->call.name, tu->call.class->system); + if (old_tp) + /* delete old event */ + unregister_trace_uprobe(old_tp); + + ret = register_uprobe_event(tu); + if (ret) { + pr_warning("Failed to register probe event(%d)\n", ret); + goto end; + } + + list_add_tail(&tu->list, &uprobe_list); + +end: + mutex_unlock(&uprobe_lock); + + return ret; +} + +/* + * Argument syntax: + * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * + * - Remove uprobe: -:[GRP/]EVENT + */ +static int create_trace_uprobe(int argc, char **argv) +{ + struct trace_uprobe *tu; + struct inode *inode; + char *arg, *event, *group, *filename; + char buf[MAX_EVENT_NAME_LEN]; + struct path path; + unsigned long offset; + bool is_delete; + int i, ret; + + inode = NULL; + ret = 0; + is_delete = false; + event = NULL; + group = NULL; + + /* argc must be >= 1 */ + if (argv[0][0] == '-') + is_delete = true; + else if (argv[0][0] != 'p') { + pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + arg = strchr(event, '/'); + + if (arg) { + group = event; + event = arg + 1; + event[-1] = '\0'; + + if (strlen(group) == 0) { + pr_info("Group name is not specified\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specified\n"); + return -EINVAL; + } + } + if (!group) + group = UPROBE_EVENT_SYSTEM; + + if (is_delete) { + if (!event) { + pr_info("Delete command needs an event name.\n"); + return -EINVAL; + } + mutex_lock(&uprobe_lock); + tu = find_probe_event(event, group); + + if (!tu) { + mutex_unlock(&uprobe_lock); + pr_info("Event %s/%s doesn't exist.\n", group, event); + return -ENOENT; + } + /* delete an event */ + unregister_trace_uprobe(tu); + mutex_unlock(&uprobe_lock); + return 0; + } + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + if (isdigit(argv[1][0])) { + pr_info("probe point must be have a filename.\n"); + return -EINVAL; + } + arg = strchr(argv[1], ':'); + if (!arg) + goto fail_address_parse; + + *arg++ = '\0'; + filename = argv[1]; + ret = kern_path(filename, LOOKUP_FOLLOW, &path); + if (ret) + goto fail_address_parse; + + ret = strict_strtoul(arg, 0, &offset); + if (ret) + goto fail_address_parse; + + inode = igrab(path.dentry->d_inode); + + argc -= 2; + argv += 2; + + /* setup a probe */ + if (!event) { + char *tail = strrchr(filename, '/'); + char *ptr; + + ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL); + if (!ptr) { + ret = -ENOMEM; + goto fail_address_parse; + } + + tail = ptr; + ptr = strpbrk(tail, ".-_"); + if (ptr) + *ptr = '\0'; + + snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); + event = buf; + kfree(tail); + } + + tu = alloc_trace_uprobe(group, event, argc); + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); + ret = PTR_ERR(tu); + goto fail_address_parse; + } + tu->offset = offset; + tu->inode = inode; + tu->filename = kstrdup(filename, GFP_KERNEL); + + if (!tu->filename) { + pr_info("Failed to allocate filename.\n"); + ret = -ENOMEM; + goto error; + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Increment count for freeing args in error case */ + tu->nr_args++; + + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) { + *arg++ = '\0'; + tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); + } else { + arg = argv[i]; + /* If argument name is omitted, set "argN" */ + snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); + tu->args[i].name = kstrdup(buf, GFP_KERNEL); + } + + if (!tu->args[i].name) { + pr_info("Failed to allocate argument[%d] name.\n", i); + ret = -ENOMEM; + goto error; + } + + if (!is_good_name(tu->args[i].name)) { + pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); + ret = -EINVAL; + goto error; + } + + if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { + pr_info("Argument[%d] name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + /* Parse fetch argument */ + ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); + if (ret) { + pr_info("Parse error at argument[%d]. (%d)\n", i, ret); + goto error; + } + } + + ret = register_trace_uprobe(tu); + if (ret) + goto error; + return 0; + +error: + free_trace_uprobe(tu); + return ret; + +fail_address_parse: + if (inode) + iput(inode); + + pr_info("Failed to parse address.\n"); + + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_uprobe *tu; + + mutex_lock(&uprobe_lock); + while (!list_empty(&uprobe_list)) { + tu = list_entry(uprobe_list.next, struct trace_uprobe, list); + unregister_trace_uprobe(tu); + } + mutex_unlock(&uprobe_lock); +} + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&uprobe_lock); + return seq_list_start(&uprobe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &uprobe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&uprobe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + int i; + + seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + + for (i = 0; i < tu->nr_args; i++) + seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); + + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); +} + +static const struct file_operations uprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + + seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations uprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* uprobe handler */ +static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct uprobe_trace_entry_head *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + u8 *data; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tu->call; + + tu->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = sizeof(*entry) + tu->size; + + event = trace_current_buffer_lock_reserve(&buffer, call->event.type, + size, irq_flags, pc); + if (!event) + return; + + entry = ring_buffer_event_data(event); + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); +} + +/* Event entry printers */ +static enum print_line_t +print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) +{ + struct uprobe_trace_entry_head *field; + struct trace_seq *s = &iter->seq; + struct trace_uprobe *tu; + u8 *data; + int i; + + field = (struct uprobe_trace_entry_head *)iter->ent; + tu = container_of(event, struct trace_uprobe, call.event); + + if (!trace_seq_printf(s, "%s: (", tu->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + data = (u8 *)&field[1]; + for (i = 0; i < tu->nr_args; i++) { + if (!tu->args[i].type->print(s, tu->args[i].name, + data + tu->args[i].offset, field)) + goto partial; + } + + if (trace_seq_puts(s, "\n")) + return TRACE_TYPE_HANDLED; + +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct trace_uprobe *tu, int flag) +{ + struct uprobe_trace_consumer *utc; + int ret = 0; + + if (!tu->inode || tu->consumer) + return -EINTR; + + utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); + if (!utc) + return -EINTR; + + utc->cons.handler = uprobe_dispatcher; + utc->cons.filter = NULL; + ret = uprobe_register(tu->inode, tu->offset, &utc->cons); + if (ret) { + kfree(utc); + return ret; + } + + tu->flags |= flag; + utc->tu = tu; + tu->consumer = utc; + + return 0; +} + +static void probe_event_disable(struct trace_uprobe *tu, int flag) +{ + if (!tu->inode || !tu->consumer) + return; + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + tu->flags &= ~flag; + kfree(tu->consumer); + tu->consumer = NULL; +} + +static int uprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct uprobe_trace_entry_head field; + struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + /* Set argument names as fields */ + for (i = 0; i < tu->nr_args; i++) { + ret = trace_define_field(event_call, tu->args[i].type->fmttype, + tu->args[i].name, + sizeof(field) + tu->args[i].offset, + tu->args[i].type->size, + tu->args[i].type->is_signed, + FILTER_OTHER); + + if (ret) + return ret; + } + return 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) +{ + const char *fmt, *arg; + int i; + int pos = 0; + + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + + /* When len=0, we just calculate the needed length */ + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", + tu->args[i].name, tu->args[i].type->fmt); + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", + tu->args[i].name); + } + + return pos; /* return the length of print_fmt */ +} +#undef LEN_OR_ZERO + +static int set_print_fmt(struct trace_uprobe *tu) +{ + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_print_fmt(tu, NULL, 0); + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_print_fmt(tu, print_fmt, len + 1); + tu->call.print_fmt = print_fmt; + + return 0; +} + +#ifdef CONFIG_PERF_EVENTS +/* uprobe profile handler */ +static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct ftrace_event_call *call = &tu->call; + struct uprobe_trace_entry_head *entry; + struct hlist_head *head; + u8 *data; + int size, __size, i; + int rctx; + + __size = sizeof(*entry) + tu->size; + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) + return; + + preempt_disable(); + + entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); + if (!entry) + goto out; + + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + head = this_cpu_ptr(call->perf_events); + perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); + + out: + preempt_enable(); +} +#endif /* CONFIG_PERF_EVENTS */ + +static +int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) +{ + struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + + switch (type) { + case TRACE_REG_REGISTER: + return probe_event_enable(tu, TP_FLAG_TRACE); + + case TRACE_REG_UNREGISTER: + probe_event_disable(tu, TP_FLAG_TRACE); + return 0; + +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + return probe_event_enable(tu, TP_FLAG_PROFILE); + + case TRACE_REG_PERF_UNREGISTER: + probe_event_disable(tu, TP_FLAG_PROFILE); + return 0; +#endif + default: + return 0; + } + return 0; +} + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct uprobe_trace_consumer *utc; + struct trace_uprobe *tu; + + utc = container_of(con, struct uprobe_trace_consumer, cons); + tu = utc->tu; + if (!tu || tu->consumer != utc) + return 0; + + if (tu->flags & TP_FLAG_TRACE) + uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + uprobe_perf_func(tu, regs); +#endif + return 0; +} + +static struct trace_event_functions uprobe_funcs = { + .trace = print_uprobe_event +}; + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct ftrace_event_call *call = &tu->call; + int ret; + + /* Initialize ftrace_event_call */ + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &uprobe_funcs; + call->class->define_fields = uprobe_event_define_fields; + + if (set_print_fmt(tu) < 0) + return -ENOMEM; + + ret = register_ftrace_event(&call->event); + if (!ret) { + kfree(call->print_fmt); + return -ENODEV; + } + call->flags = 0; + call->class->reg = trace_uprobe_register; + call->data = tu; + ret = trace_add_event_call(call); + + if (ret) { + pr_info("Failed to register uprobe event: %s\n", call->name); + kfree(call->print_fmt); + unregister_ftrace_event(&call->event); + } + + return ret; +} + +static void unregister_uprobe_event(struct trace_uprobe *tu) +{ + /* tu->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tu->call); + kfree(tu->call.print_fmt); + tu->call.print_fmt = NULL; +} + +/* Make a trace interface for controling probe points */ +static __init int init_uprobe_trace(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("uprobe_events", 0644, d_tracer, + NULL, &uprobe_events_ops); + /* Profile interface */ + trace_create_file("uprobe_profile", 0444, d_tracer, + NULL, &uprobe_profile_ops); + return 0; +} + +fs_initcall(init_uprobe_trace); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:perf/uprobes] tracing: Provide trace events interface for uprobes @ 2012-05-08 4:09 ` tip-bot for Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: tip-bot for Srikar Dronamraju @ 2012-05-08 4:09 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, torvalds, peterz, anton, jkenisto, rostedt, oleg, tglx, linux-mm, hpa, linux-kernel, andi, hch, ananth, masami.hiramatsu.pt, acme, srikar Commit-ID: f3f096cfedf8113380c56fc855275cc75cd8cf55 Gitweb: http://git.kernel.org/tip/f3f096cfedf8113380c56fc855275cc75cd8cf55 Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Wed, 11 Apr 2012 16:00:43 +0530 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 7 May 2012 14:30:17 +0200 tracing: Provide trace events interface for uprobes Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh: # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- Documentation/trace/uprobetracer.txt | 95 ++++ arch/Kconfig | 2 +- kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 + kernel/trace/trace.h | 5 + kernel/trace/trace_kprobe.c | 2 +- kernel/trace/trace_probe.c | 14 +- kernel/trace/trace_probe.h | 3 +- kernel/trace/trace_uprobe.c | 788 ++++++++++++++++++++++++++++++++++ 9 files changed, 919 insertions(+), 7 deletions(-) diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt new file mode 100644 index 0000000..eae40a0 --- /dev/null +++ b/Documentation/trace/uprobetracer.txt @@ -0,0 +1,95 @@ + Uprobe-tracer: Uprobe-based Event Tracing + ========================================= + Documentation written by Srikar Dronamraju + +Overview +-------- +Uprobe based trace events are similar to kprobe based trace events. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. + +Similar to the kprobe-event tracer, this doesn't need to be activated via +current_tracer. Instead of that, add probe points via +/sys/kernel/debug/tracing/uprobe_events, and enable it via +/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled. + +However unlike kprobe-event tracer, the uprobe event interface expects the +user to calculate the offset of the probepoint in the object + +Synopsis of uprobe_tracer +------------------------- + p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe + + GRP : Group name. If omitted, use "uprobes" for it. + EVENT : Event name. If omitted, the event name is generated + based on SYMBOL+offs. + PATH : path to an executable or a library. + SYMBOL[+offs] : Symbol+offset where the probe is inserted. + + FETCHARGS : Arguments. Each probe can have up to 128 args. + %REG : Fetch register REG + +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/uprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + +Usage examples +-------------- +To add a probe as a new event, write a new definition to uprobe_events +as below. + + echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events + + This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash + + echo > /sys/kernel/debug/tracing/uprobe_events + + This clears all probe points. + +The following example shows how to dump the instruction pointer and %ax +a register at the probed text address. Here we are trying to probe +function zfree in /bin/zsh + + # cd /sys/kernel/debug/tracing/ + # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp + 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh + # objdump -T /bin/zsh | grep -w zfree + 0000000000446420 g DF .text 0000000000000012 Base zfree + +0x46420 is the offset of zfree in object /bin/zsh that is loaded at +0x00400000. Hence the command to probe would be : + + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events + +Please note: User has to explicitly calculate the offset of the probepoint +in the object. We can see the events that are registered by looking at the +uprobe_events file. + + # cat uprobe_events + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 + +Right after definition, each event is disabled by default. For tracing these +events, you need to enable it by: + + # echo 1 > events/uprobes/enable + +Lets disable the event after sleeping for some time. + # sleep 20 + # echo 0 > events/uprobes/enable + +And you can see the traced information via /sys/kernel/debug/tracing/trace. + + # cat trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 + +Each line shows us probes were triggered for a pid 24842 with ip being +0x446421 and contents of ax register being 79. diff --git a/arch/Kconfig b/arch/Kconfig index e5d3778..0f8f968 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -78,7 +78,7 @@ config OPTPROBES config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" - depends on ARCH_SUPPORTS_UPROBES && PERF_EVENTS + depends on UPROBE_EVENTS && PERF_EVENTS default n help Uprobes is the user-space counterpart to kprobes: they diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ce5a5c5..ea4bff6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -386,6 +386,22 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config UPROBE_EVENT + bool "Enable uprobes-based dynamic events" + depends on ARCH_SUPPORTS_UPROBES + depends on MMU + select UPROBES + select PROBE_EVENTS + select TRACING + default n + help + This allows the user to add tracing events on top of userspace + dynamic events (similar to tracepoints) on the fly via the trace + events interface. Those events can be inserted wherever uprobes + can probe, and record various registers. + This option is required if you plan to use perf-probe subcommand + of perf tools on user space applications. + config PROBE_EVENTS def_bool n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index fa10d5c..1734c03 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -62,5 +62,6 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o +obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f0..1bcdbec 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8b7773..b31d3d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -525,7 +525,7 @@ static int create_trace_probe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], - is_return); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8e526b9..daa9980 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -550,7 +550,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, bool is_kprobe) { unsigned long param; long offset; @@ -558,6 +558,11 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; ret = 0; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + switch (arg[0]) { case '$': ret = parse_probe_vars(arg + 1, t, f, is_return); @@ -619,7 +624,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return); + ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, + is_kprobe); if (ret) kfree(dprm); else { @@ -677,7 +683,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return) + struct probe_arg *parg, bool is_return, bool is_kprobe) { const char *t; int ret; @@ -703,7 +709,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); if (ret >= 0 && t != NULL) ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2df9a18..9337086 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,6 +66,7 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 +#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ @@ -143,7 +144,7 @@ static inline int is_good_name(const char *name) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return); + struct probe_arg *parg, bool is_return, bool is_kprobe); extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c new file mode 100644 index 0000000..2b36ac6 --- /dev/null +++ b/kernel/trace/trace_uprobe.c @@ -0,0 +1,788 @@ +/* + * uprobes-based tracing events + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010-2012 + * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/uprobes.h> +#include <linux/namei.h> + +#include "trace_probe.h" + +#define UPROBE_EVENT_SYSTEM "uprobes" + +/* + * uprobe event core functions + */ +struct trace_uprobe; +struct uprobe_trace_consumer { + struct uprobe_consumer cons; + struct trace_uprobe *tu; +}; + +struct trace_uprobe { + struct list_head list; + struct ftrace_event_class class; + struct ftrace_event_call call; + struct uprobe_trace_consumer *consumer; + struct inode *inode; + char *filename; + unsigned long offset; + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + ssize_t size; /* trace entry size */ + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_UPROBE(n) \ + (offsetof(struct trace_uprobe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static int register_uprobe_event(struct trace_uprobe *tu); +static void unregister_uprobe_event(struct trace_uprobe *tu); + +static DEFINE_MUTEX(uprobe_lock); +static LIST_HEAD(uprobe_list); + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); + +/* + * Allocate new trace_uprobe and initialize it (including uprobes). + */ +static struct trace_uprobe * +alloc_trace_uprobe(const char *group, const char *event, int nargs) +{ + struct trace_uprobe *tu; + + if (!event || !is_good_name(event)) + return ERR_PTR(-EINVAL); + + if (!group || !is_good_name(group)) + return ERR_PTR(-EINVAL); + + tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + if (!tu) + return ERR_PTR(-ENOMEM); + + tu->call.class = &tu->class; + tu->call.name = kstrdup(event, GFP_KERNEL); + if (!tu->call.name) + goto error; + + tu->class.system = kstrdup(group, GFP_KERNEL); + if (!tu->class.system) + goto error; + + INIT_LIST_HEAD(&tu->list); + return tu; + +error: + kfree(tu->call.name); + kfree(tu); + + return ERR_PTR(-ENOMEM); +} + +static void free_trace_uprobe(struct trace_uprobe *tu) +{ + int i; + + for (i = 0; i < tu->nr_args; i++) + traceprobe_free_probe_arg(&tu->args[i]); + + iput(tu->inode); + kfree(tu->call.class->system); + kfree(tu->call.name); + kfree(tu->filename); + kfree(tu); +} + +static struct trace_uprobe *find_probe_event(const char *event, const char *group) +{ + struct trace_uprobe *tu; + + list_for_each_entry(tu, &uprobe_list, list) + if (strcmp(tu->call.name, event) == 0 && + strcmp(tu->call.class->system, group) == 0) + return tu; + + return NULL; +} + +/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ +static void unregister_trace_uprobe(struct trace_uprobe *tu) +{ + list_del(&tu->list); + unregister_uprobe_event(tu); + free_trace_uprobe(tu); +} + +/* Register a trace_uprobe and probe_event */ +static int register_trace_uprobe(struct trace_uprobe *tu) +{ + struct trace_uprobe *old_tp; + int ret; + + mutex_lock(&uprobe_lock); + + /* register as an event */ + old_tp = find_probe_event(tu->call.name, tu->call.class->system); + if (old_tp) + /* delete old event */ + unregister_trace_uprobe(old_tp); + + ret = register_uprobe_event(tu); + if (ret) { + pr_warning("Failed to register probe event(%d)\n", ret); + goto end; + } + + list_add_tail(&tu->list, &uprobe_list); + +end: + mutex_unlock(&uprobe_lock); + + return ret; +} + +/* + * Argument syntax: + * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * + * - Remove uprobe: -:[GRP/]EVENT + */ +static int create_trace_uprobe(int argc, char **argv) +{ + struct trace_uprobe *tu; + struct inode *inode; + char *arg, *event, *group, *filename; + char buf[MAX_EVENT_NAME_LEN]; + struct path path; + unsigned long offset; + bool is_delete; + int i, ret; + + inode = NULL; + ret = 0; + is_delete = false; + event = NULL; + group = NULL; + + /* argc must be >= 1 */ + if (argv[0][0] == '-') + is_delete = true; + else if (argv[0][0] != 'p') { + pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + arg = strchr(event, '/'); + + if (arg) { + group = event; + event = arg + 1; + event[-1] = '\0'; + + if (strlen(group) == 0) { + pr_info("Group name is not specified\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specified\n"); + return -EINVAL; + } + } + if (!group) + group = UPROBE_EVENT_SYSTEM; + + if (is_delete) { + if (!event) { + pr_info("Delete command needs an event name.\n"); + return -EINVAL; + } + mutex_lock(&uprobe_lock); + tu = find_probe_event(event, group); + + if (!tu) { + mutex_unlock(&uprobe_lock); + pr_info("Event %s/%s doesn't exist.\n", group, event); + return -ENOENT; + } + /* delete an event */ + unregister_trace_uprobe(tu); + mutex_unlock(&uprobe_lock); + return 0; + } + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + if (isdigit(argv[1][0])) { + pr_info("probe point must be have a filename.\n"); + return -EINVAL; + } + arg = strchr(argv[1], ':'); + if (!arg) + goto fail_address_parse; + + *arg++ = '\0'; + filename = argv[1]; + ret = kern_path(filename, LOOKUP_FOLLOW, &path); + if (ret) + goto fail_address_parse; + + ret = strict_strtoul(arg, 0, &offset); + if (ret) + goto fail_address_parse; + + inode = igrab(path.dentry->d_inode); + + argc -= 2; + argv += 2; + + /* setup a probe */ + if (!event) { + char *tail = strrchr(filename, '/'); + char *ptr; + + ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL); + if (!ptr) { + ret = -ENOMEM; + goto fail_address_parse; + } + + tail = ptr; + ptr = strpbrk(tail, ".-_"); + if (ptr) + *ptr = '\0'; + + snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); + event = buf; + kfree(tail); + } + + tu = alloc_trace_uprobe(group, event, argc); + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); + ret = PTR_ERR(tu); + goto fail_address_parse; + } + tu->offset = offset; + tu->inode = inode; + tu->filename = kstrdup(filename, GFP_KERNEL); + + if (!tu->filename) { + pr_info("Failed to allocate filename.\n"); + ret = -ENOMEM; + goto error; + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Increment count for freeing args in error case */ + tu->nr_args++; + + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) { + *arg++ = '\0'; + tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); + } else { + arg = argv[i]; + /* If argument name is omitted, set "argN" */ + snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); + tu->args[i].name = kstrdup(buf, GFP_KERNEL); + } + + if (!tu->args[i].name) { + pr_info("Failed to allocate argument[%d] name.\n", i); + ret = -ENOMEM; + goto error; + } + + if (!is_good_name(tu->args[i].name)) { + pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); + ret = -EINVAL; + goto error; + } + + if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { + pr_info("Argument[%d] name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + /* Parse fetch argument */ + ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); + if (ret) { + pr_info("Parse error at argument[%d]. (%d)\n", i, ret); + goto error; + } + } + + ret = register_trace_uprobe(tu); + if (ret) + goto error; + return 0; + +error: + free_trace_uprobe(tu); + return ret; + +fail_address_parse: + if (inode) + iput(inode); + + pr_info("Failed to parse address.\n"); + + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_uprobe *tu; + + mutex_lock(&uprobe_lock); + while (!list_empty(&uprobe_list)) { + tu = list_entry(uprobe_list.next, struct trace_uprobe, list); + unregister_trace_uprobe(tu); + } + mutex_unlock(&uprobe_lock); +} + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&uprobe_lock); + return seq_list_start(&uprobe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &uprobe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&uprobe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + int i; + + seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + + for (i = 0; i < tu->nr_args; i++) + seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); + + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); +} + +static const struct file_operations uprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_uprobe *tu = v; + + seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations uprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* uprobe handler */ +static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct uprobe_trace_entry_head *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + u8 *data; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tu->call; + + tu->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = sizeof(*entry) + tu->size; + + event = trace_current_buffer_lock_reserve(&buffer, call->event.type, + size, irq_flags, pc); + if (!event) + return; + + entry = ring_buffer_event_data(event); + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); +} + +/* Event entry printers */ +static enum print_line_t +print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) +{ + struct uprobe_trace_entry_head *field; + struct trace_seq *s = &iter->seq; + struct trace_uprobe *tu; + u8 *data; + int i; + + field = (struct uprobe_trace_entry_head *)iter->ent; + tu = container_of(event, struct trace_uprobe, call.event); + + if (!trace_seq_printf(s, "%s: (", tu->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + data = (u8 *)&field[1]; + for (i = 0; i < tu->nr_args; i++) { + if (!tu->args[i].type->print(s, tu->args[i].name, + data + tu->args[i].offset, field)) + goto partial; + } + + if (trace_seq_puts(s, "\n")) + return TRACE_TYPE_HANDLED; + +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct trace_uprobe *tu, int flag) +{ + struct uprobe_trace_consumer *utc; + int ret = 0; + + if (!tu->inode || tu->consumer) + return -EINTR; + + utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); + if (!utc) + return -EINTR; + + utc->cons.handler = uprobe_dispatcher; + utc->cons.filter = NULL; + ret = uprobe_register(tu->inode, tu->offset, &utc->cons); + if (ret) { + kfree(utc); + return ret; + } + + tu->flags |= flag; + utc->tu = tu; + tu->consumer = utc; + + return 0; +} + +static void probe_event_disable(struct trace_uprobe *tu, int flag) +{ + if (!tu->inode || !tu->consumer) + return; + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + tu->flags &= ~flag; + kfree(tu->consumer); + tu->consumer = NULL; +} + +static int uprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct uprobe_trace_entry_head field; + struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + /* Set argument names as fields */ + for (i = 0; i < tu->nr_args; i++) { + ret = trace_define_field(event_call, tu->args[i].type->fmttype, + tu->args[i].name, + sizeof(field) + tu->args[i].offset, + tu->args[i].type->size, + tu->args[i].type->is_signed, + FILTER_OTHER); + + if (ret) + return ret; + } + return 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) +{ + const char *fmt, *arg; + int i; + int pos = 0; + + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + + /* When len=0, we just calculate the needed length */ + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", + tu->args[i].name, tu->args[i].type->fmt); + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); + + for (i = 0; i < tu->nr_args; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", + tu->args[i].name); + } + + return pos; /* return the length of print_fmt */ +} +#undef LEN_OR_ZERO + +static int set_print_fmt(struct trace_uprobe *tu) +{ + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_print_fmt(tu, NULL, 0); + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_print_fmt(tu, print_fmt, len + 1); + tu->call.print_fmt = print_fmt; + + return 0; +} + +#ifdef CONFIG_PERF_EVENTS +/* uprobe profile handler */ +static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + struct ftrace_event_call *call = &tu->call; + struct uprobe_trace_entry_head *entry; + struct hlist_head *head; + u8 *data; + int size, __size, i; + int rctx; + + __size = sizeof(*entry) + tu->size; + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) + return; + + preempt_disable(); + + entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); + if (!entry) + goto out; + + entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); + data = (u8 *)&entry[1]; + for (i = 0; i < tu->nr_args; i++) + call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); + + head = this_cpu_ptr(call->perf_events); + perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); + + out: + preempt_enable(); +} +#endif /* CONFIG_PERF_EVENTS */ + +static +int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) +{ + struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + + switch (type) { + case TRACE_REG_REGISTER: + return probe_event_enable(tu, TP_FLAG_TRACE); + + case TRACE_REG_UNREGISTER: + probe_event_disable(tu, TP_FLAG_TRACE); + return 0; + +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + return probe_event_enable(tu, TP_FLAG_PROFILE); + + case TRACE_REG_PERF_UNREGISTER: + probe_event_disable(tu, TP_FLAG_PROFILE); + return 0; +#endif + default: + return 0; + } + return 0; +} + +static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct uprobe_trace_consumer *utc; + struct trace_uprobe *tu; + + utc = container_of(con, struct uprobe_trace_consumer, cons); + tu = utc->tu; + if (!tu || tu->consumer != utc) + return 0; + + if (tu->flags & TP_FLAG_TRACE) + uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + uprobe_perf_func(tu, regs); +#endif + return 0; +} + +static struct trace_event_functions uprobe_funcs = { + .trace = print_uprobe_event +}; + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct ftrace_event_call *call = &tu->call; + int ret; + + /* Initialize ftrace_event_call */ + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &uprobe_funcs; + call->class->define_fields = uprobe_event_define_fields; + + if (set_print_fmt(tu) < 0) + return -ENOMEM; + + ret = register_ftrace_event(&call->event); + if (!ret) { + kfree(call->print_fmt); + return -ENODEV; + } + call->flags = 0; + call->class->reg = trace_uprobe_register; + call->data = tu; + ret = trace_add_event_call(call); + + if (ret) { + pr_info("Failed to register uprobe event: %s\n", call->name); + kfree(call->print_fmt); + unregister_ftrace_event(&call->event); + } + + return ret; +} + +static void unregister_uprobe_event(struct trace_uprobe *tu) +{ + /* tu->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tu->call); + kfree(tu->call.print_fmt); + tu->call.print_fmt = NULL; +} + +/* Make a trace interface for controling probe points */ +static __init int init_uprobe_trace(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("uprobe_events", 0644, d_tracer, + NULL, &uprobe_events_ops); + /* Profile interface */ + trace_create_file("uprobe_profile", 0444, d_tracer, + NULL, &uprobe_profile_ops); + return 0; +} + +fs_initcall(init_uprobe_trace); ^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-04-11 10:30 ` Srikar Dronamraju @ 2012-05-08 4:12 ` Ingo Molnar -1 siblings, 0 replies; 42+ messages in thread From: Ingo Molnar @ 2012-05-08 4:12 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov FYI, this warning started to trigger in -tip, with the latest uprobes patches: warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-05-08 4:12 ` Ingo Molnar 0 siblings, 0 replies; 42+ messages in thread From: Ingo Molnar @ 2012-05-08 4:12 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov FYI, this warning started to trigger in -tip, with the latest uprobes patches: warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) Thanks, Ingo ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-05-08 4:12 ` Ingo Molnar @ 2012-05-08 8:30 ` Peter Zijlstra -1 siblings, 0 replies; 42+ messages in thread From: Peter Zijlstra @ 2012-05-08 8:30 UTC (permalink / raw) To: Ingo Molnar Cc: Srikar Dronamraju, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > FYI, this warning started to trigger in -tip, with the latest > uprobes patches: > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) this looks to be the only UPROBE_EVENTS instance, is that a typo? --- arch/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/Kconfig b/arch/Kconfig index 9e2fbb5..c160d92 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -78,7 +78,7 @@ config OPTPROBES config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" - depends on UPROBE_EVENTS && PERF_EVENTS + depends on UPROBE_EVENT && PERF_EVENTS default n help Uprobes is the user-space counterpart to kprobes: they -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-05-08 8:30 ` Peter Zijlstra 0 siblings, 0 replies; 42+ messages in thread From: Peter Zijlstra @ 2012-05-08 8:30 UTC (permalink / raw) To: Ingo Molnar Cc: Srikar Dronamraju, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > FYI, this warning started to trigger in -tip, with the latest > uprobes patches: > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) this looks to be the only UPROBE_EVENTS instance, is that a typo? --- arch/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/Kconfig b/arch/Kconfig index 9e2fbb5..c160d92 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -78,7 +78,7 @@ config OPTPROBES config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" - depends on UPROBE_EVENTS && PERF_EVENTS + depends on UPROBE_EVENT && PERF_EVENTS default n help Uprobes is the user-space counterpart to kprobes: they ^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-05-08 8:30 ` Peter Zijlstra @ 2012-05-08 8:50 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-05-08 8:50 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Peter Zijlstra <peterz@infradead.org> [2012-05-08 10:30:08]: > On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > > FYI, this warning started to trigger in -tip, with the latest > > uprobes patches: > > > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) > > this looks to be the only UPROBE_EVENTS instance, is that a typo? I think I corrected this in the latest posting I sent on April 16th. Ingo, Since you had asked me to send the patch series again after handling comments and acks, I had sent the set. At that time, I had handled this change as part of a comment from Stephen Boyd. I had mentioned this in the changelog. Would it be possible for you to accept the patches from https://lkml.org/lkml/2012/4/16/109 with message id: Message-Id: <20120416091936.19174.2641.sendpatchset@srdronam.in.ibm.com> Currently you seem to have picked from https://lkml.org/lkml/2012/4/11/117 -- Thanks and Regards Srikar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-05-08 8:50 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-05-08 8:50 UTC (permalink / raw) To: Peter Zijlstra, Ingo Molnar, Ingo Molnar Cc: Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Peter Zijlstra <peterz@infradead.org> [2012-05-08 10:30:08]: > On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > > FYI, this warning started to trigger in -tip, with the latest > > uprobes patches: > > > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) > > this looks to be the only UPROBE_EVENTS instance, is that a typo? I think I corrected this in the latest posting I sent on April 16th. Ingo, Since you had asked me to send the patch series again after handling comments and acks, I had sent the set. At that time, I had handled this change as part of a comment from Stephen Boyd. I had mentioned this in the changelog. Would it be possible for you to accept the patches from https://lkml.org/lkml/2012/4/16/109 with message id: Message-Id: <20120416091936.19174.2641.sendpatchset@srdronam.in.ibm.com> Currently you seem to have picked from https://lkml.org/lkml/2012/4/11/117 -- Thanks and Regards Srikar ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-05-08 8:50 ` Srikar Dronamraju @ 2012-05-08 9:20 ` Ingo Molnar -1 siblings, 0 replies; 42+ messages in thread From: Ingo Molnar @ 2012-05-08 9:20 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote: > * Peter Zijlstra <peterz@infradead.org> [2012-05-08 10:30:08]: > > > On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > > > FYI, this warning started to trigger in -tip, with the latest > > > uprobes patches: > > > > > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) > > > > this looks to be the only UPROBE_EVENTS instance, is that a typo? > > > I think I corrected this in the latest posting I sent on April 16th. > > Ingo, > > Since you had asked me to send the patch series again > after handling comments and acks, I had sent the set. [...] Mind sending a delta patch instead? The patches are now reasonably well tested and don't seem to break in any functional way, so unless the delta patch is really ugly we should try that instead of rebasing the branch. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-05-08 9:20 ` Ingo Molnar 0 siblings, 0 replies; 42+ messages in thread From: Ingo Molnar @ 2012-05-08 9:20 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote: > * Peter Zijlstra <peterz@infradead.org> [2012-05-08 10:30:08]: > > > On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > > > FYI, this warning started to trigger in -tip, with the latest > > > uprobes patches: > > > > > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) > > > > this looks to be the only UPROBE_EVENTS instance, is that a typo? > > > I think I corrected this in the latest posting I sent on April 16th. > > Ingo, > > Since you had asked me to send the patch series again > after handling comments and acks, I had sent the set. [...] Mind sending a delta patch instead? The patches are now reasonably well tested and don't seem to break in any functional way, so unless the delta patch is really ugly we should try that instead of rebasing the branch. Thanks, Ingo ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes 2012-05-08 9:20 ` Ingo Molnar @ 2012-05-08 9:19 ` Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-05-08 9:19 UTC (permalink / raw) To: Ingo Molnar Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Ingo Molnar <mingo@kernel.org> [2012-05-08 11:20:41]: > > * Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote: > > > * Peter Zijlstra <peterz@infradead.org> [2012-05-08 10:30:08]: > > > > > On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > > > > FYI, this warning started to trigger in -tip, with the latest > > > > uprobes patches: > > > > > > > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) > > > > > > this looks to be the only UPROBE_EVENTS instance, is that a typo? > > > > > > I think I corrected this in the latest posting I sent on April 16th. > > > > Ingo, > > > > Since you had asked me to send the patch series again > > after handling comments and acks, I had sent the set. [...] > > Mind sending a delta patch instead? The patches are now > reasonably well tested and don't seem to break in any functional > way, so unless the delta patch is really ugly we should try that > instead of rebasing the branch. > Okay .. will send the delta patch now -- Thanks and Regards Srikar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH UPDATED 3/3] tracing: Provide trace events interface for uprobes @ 2012-05-08 9:19 ` Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: Srikar Dronamraju @ 2012-05-08 9:19 UTC (permalink / raw) To: Ingo Molnar Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Masami Hiramatsu, Thomas Gleixner, Anton Arapov * Ingo Molnar <mingo@kernel.org> [2012-05-08 11:20:41]: > > * Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote: > > > * Peter Zijlstra <peterz@infradead.org> [2012-05-08 10:30:08]: > > > > > On Tue, 2012-05-08 at 06:12 +0200, Ingo Molnar wrote: > > > > FYI, this warning started to trigger in -tip, with the latest > > > > uprobes patches: > > > > > > > > warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) > > > > > > this looks to be the only UPROBE_EVENTS instance, is that a typo? > > > > > > I think I corrected this in the latest posting I sent on April 16th. > > > > Ingo, > > > > Since you had asked me to send the patch series again > > after handling comments and acks, I had sent the set. [...] > > Mind sending a delta patch instead? The patches are now > reasonably well tested and don't seem to break in any functional > way, so unless the delta patch is really ugly we should try that > instead of rebasing the branch. > Okay .. will send the delta patch now -- Thanks and Regards Srikar ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH 1/3] tracing: Modify is_delete, is_return from int to bool 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-04-12 12:42 ` Masami Hiramatsu -1 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-12 12:42 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/09 18:11), Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > is_delete and is_return can take utmost 2 values and are better of > being a boolean than a int. There are no functional changes. > > Acked-by: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> OK, this should be changed. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH 1/3] tracing: Modify is_delete, is_return from int to bool @ 2012-04-12 12:42 ` Masami Hiramatsu 0 siblings, 0 replies; 42+ messages in thread From: Masami Hiramatsu @ 2012-04-12 12:42 UTC (permalink / raw) To: Srikar Dronamraju Cc: Peter Zijlstra, Ingo Molnar, Andrew Morton, Linus Torvalds, Ananth N Mavinakayanahalli, Jim Keniston, LKML, Linux-mm, Oleg Nesterov, Andi Kleen, Christoph Hellwig, Steven Rostedt, Arnaldo Carvalho de Melo, Thomas Gleixner, Anton Arapov (2012/04/09 18:11), Srikar Dronamraju wrote: > From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > is_delete and is_return can take utmost 2 values and are better of > being a boolean than a int. There are no functional changes. > > Acked-by: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> OK, this should be changed. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com ^ permalink raw reply [flat|nested] 42+ messages in thread
* [tip:perf/uprobes] tracing: Modify is_delete, is_return from int to bool 2012-04-09 9:11 ` Srikar Dronamraju @ 2012-05-08 4:07 ` tip-bot for Srikar Dronamraju -1 siblings, 0 replies; 42+ messages in thread From: tip-bot for Srikar Dronamraju @ 2012-05-08 4:07 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, torvalds, peterz, anton, jkenisto, rostedt, oleg, tglx, linux-mm, hpa, linux-kernel, andi, hch, ananth, masami.hiramatsu.pt, acme, srikar Commit-ID: 3a6b76661da8e92124a813b43607f5bec1a618de Gitweb: http://git.kernel.org/tip/3a6b76661da8e92124a813b43607f5bec1a618de Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Mon, 9 Apr 2012 14:41:33 +0530 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 7 May 2012 14:29:35 +0200 tracing: Modify is_delete, is_return from int to bool is_delete and is_return can take utmost 2 values and are better of being a boolean than a int. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120409091133.8343.65289.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/trace/trace_kprobe.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 580a05e..4f935f8 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -651,7 +651,7 @@ static struct trace_probe *alloc_trace_probe(const char *group, void *addr, const char *symbol, unsigned long offs, - int nargs, int is_return) + int nargs, bool is_return) { struct trace_probe *tp; int ret = -ENOMEM; @@ -944,7 +944,7 @@ static int split_symbol_offset(char *symbol, unsigned long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -977,7 +977,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -1089,7 +1089,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, int is_return) + struct probe_arg *parg, bool is_return) { const char *t; int ret; @@ -1162,7 +1162,7 @@ static int create_trace_probe(int argc, char **argv) */ struct trace_probe *tp; int i, ret = 0; - int is_return = 0, is_delete = 0; + bool is_return = false, is_delete = false; char *symbol = NULL, *event = NULL, *group = NULL; char *arg; unsigned long offset = 0; @@ -1171,11 +1171,11 @@ static int create_trace_probe(int argc, char **argv) /* argc must be >= 1 */ if (argv[0][0] == 'p') - is_return = 0; + is_return = false; else if (argv[0][0] == 'r') - is_return = 1; + is_return = true; else if (argv[0][0] == '-') - is_delete = 1; + is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:perf/uprobes] tracing: Modify is_delete, is_return from int to bool @ 2012-05-08 4:07 ` tip-bot for Srikar Dronamraju 0 siblings, 0 replies; 42+ messages in thread From: tip-bot for Srikar Dronamraju @ 2012-05-08 4:07 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, torvalds, peterz, anton, jkenisto, rostedt, oleg, tglx, linux-mm, hpa, linux-kernel, andi, hch, ananth, masami.hiramatsu.pt, acme, srikar Commit-ID: 3a6b76661da8e92124a813b43607f5bec1a618de Gitweb: http://git.kernel.org/tip/3a6b76661da8e92124a813b43607f5bec1a618de Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Mon, 9 Apr 2012 14:41:33 +0530 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 7 May 2012 14:29:35 +0200 tracing: Modify is_delete, is_return from int to bool is_delete and is_return can take utmost 2 values and are better of being a boolean than a int. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120409091133.8343.65289.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/trace/trace_kprobe.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 580a05e..4f935f8 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -651,7 +651,7 @@ static struct trace_probe *alloc_trace_probe(const char *group, void *addr, const char *symbol, unsigned long offs, - int nargs, int is_return) + int nargs, bool is_return) { struct trace_probe *tp; int ret = -ENOMEM; @@ -944,7 +944,7 @@ static int split_symbol_offset(char *symbol, unsigned long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -977,7 +977,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, /* Recursive argument parser */ static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) + struct fetch_param *f, bool is_return) { int ret = 0; unsigned long param; @@ -1089,7 +1089,7 @@ static int __parse_bitfield_probe_arg(const char *bf, /* String length checking wrapper */ static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, int is_return) + struct probe_arg *parg, bool is_return) { const char *t; int ret; @@ -1162,7 +1162,7 @@ static int create_trace_probe(int argc, char **argv) */ struct trace_probe *tp; int i, ret = 0; - int is_return = 0, is_delete = 0; + bool is_return = false, is_delete = false; char *symbol = NULL, *event = NULL, *group = NULL; char *arg; unsigned long offset = 0; @@ -1171,11 +1171,11 @@ static int create_trace_probe(int argc, char **argv) /* argc must be >= 1 */ if (argv[0][0] == 'p') - is_return = 0; + is_return = false; else if (argv[0][0] == 'r') - is_return = 1; + is_return = true; else if (argv[0][0] == '-') - is_delete = 1; + is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); ^ permalink raw reply related [flat|nested] 42+ messages in thread
end of thread, other threads:[~2012-05-08 9:31 UTC | newest] Thread overview: 42+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-04-09 9:11 [PATCH 1/3] tracing: Modify is_delete, is_return from int to bool Srikar Dronamraju 2012-04-09 9:11 ` Srikar Dronamraju 2012-04-09 9:11 ` [PATCH 2/3] tracing: Extract out common code for kprobes/uprobes trace events Srikar Dronamraju 2012-04-09 9:11 ` Srikar Dronamraju 2012-04-12 12:47 ` Masami Hiramatsu 2012-04-12 12:47 ` Masami Hiramatsu 2012-05-08 4:08 ` [tip:perf/uprobes] tracing: Extract out common code for kprobes/ uprobes " tip-bot for Srikar Dronamraju 2012-05-08 4:08 ` tip-bot for Srikar Dronamraju 2012-04-09 9:11 ` [PATCH 3/3] tracing: Provide trace events interface for uprobes Srikar Dronamraju 2012-04-09 9:11 ` Srikar Dronamraju 2012-04-11 10:30 ` [PATCH UPDATED " Srikar Dronamraju 2012-04-11 10:30 ` Srikar Dronamraju 2012-04-12 13:02 ` Masami Hiramatsu 2012-04-12 13:02 ` Masami Hiramatsu 2012-04-12 14:49 ` Srikar Dronamraju 2012-04-12 14:49 ` Srikar Dronamraju 2012-04-13 2:28 ` Masami Hiramatsu 2012-04-13 2:28 ` Masami Hiramatsu 2012-04-12 13:14 ` Steven Rostedt 2012-04-12 13:14 ` Steven Rostedt 2012-04-14 11:12 ` Ingo Molnar 2012-04-14 11:12 ` Ingo Molnar 2012-04-16 9:22 ` Srikar Dronamraju 2012-04-16 9:22 ` Srikar Dronamraju 2012-04-20 9:57 ` Srikar Dronamraju 2012-04-20 9:57 ` Srikar Dronamraju 2012-05-08 4:09 ` [tip:perf/uprobes] " tip-bot for Srikar Dronamraju 2012-05-08 4:09 ` tip-bot for Srikar Dronamraju 2012-05-08 4:12 ` [PATCH UPDATED 3/3] " Ingo Molnar 2012-05-08 4:12 ` Ingo Molnar 2012-05-08 8:30 ` Peter Zijlstra 2012-05-08 8:30 ` Peter Zijlstra 2012-05-08 8:50 ` Srikar Dronamraju 2012-05-08 8:50 ` Srikar Dronamraju 2012-05-08 9:20 ` Ingo Molnar 2012-05-08 9:20 ` Ingo Molnar 2012-05-08 9:19 ` Srikar Dronamraju 2012-05-08 9:19 ` Srikar Dronamraju 2012-04-12 12:42 ` [PATCH 1/3] tracing: Modify is_delete, is_return from int to bool Masami Hiramatsu 2012-04-12 12:42 ` Masami Hiramatsu 2012-05-08 4:07 ` [tip:perf/uprobes] " tip-bot for Srikar Dronamraju 2012-05-08 4:07 ` tip-bot for Srikar Dronamraju
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