* Re: [PATCH RFC V2] kernel/trace: move functions in trace_probe_tmpl.h to trace_probe.c
2022-11-14 14:23 ` [PATCH RFC V2] kernel/trace: move functions in trace_probe_tmpl.h to trace_probe.c Masami Hiramatsu
@ 2022-11-15 2:51 ` Song Chen
0 siblings, 0 replies; 2+ messages in thread
From: Song Chen @ 2022-11-15 2:51 UTC (permalink / raw)
To: Masami Hiramatsu (Google); +Cc: rostedt, linux-kernel, Linux Trace Kernel
Hi,
在 2022/11/14 22:23, Masami Hiramatsu (Google) 写道:
> Hi Song,
>
> On Mon, 14 Nov 2022 15:51:29 +0800
> Song Chen <chensong_2000@189.cn> wrote:
>
>> I found there are simlilar implementation of functions like
>> process_fetch_insn, fetch_store* and probe_mem* respectively in
>> kprobe/uprobe/eprobe, they have a lot in common and their differences
>> can be merged.
>
> Yes, it was intended to be implemented differently to avoid
> involving errors while adding a new feature, and make it
> inlined to avoid calling much functions from inside the
> probe event code.
>
>> I have tried this idea in them and passed the selftest,
>> below is the report:
>>
>> 1, sudo ./ftracetest test.d/kprobe/
>> [sudo] kylin 的密码：
>> === Ftrace unit tests ===
>> [1] Kprobe dynamic event - adding and removing [PASS]
>> ......
>> [12] Kprobe dynamic event - probing module [UNRESOLVED]
>> ......
>> [21] Uprobe event parser error log check [PASS]
>>
>> 2, sudo ./ftracetest test.d/dynevent/
>> === Ftrace unit tests ===
>> [1] Generic dynamic event - add/remove eprobe events [PASS]
>> [2] Generic dynamic event - add/remove kprobe events [PASS]
>> ......
>>
>> You may have had the same idea at the first place, then turned to
>> put those functions in trace_probe_tmpl.h for the reason i'm not
>> aware of. Nevertheless, let me know if you like this idea.
>
> Anyway, the same idea is on my TODO list.
> So thanks for working on that :).
>
> And let me check it carefully, the test code itself may
> not be enough for this big change. (I had some error reports
> which was not caught by this test recently.)
>
> If you can, can you split this into several parts? e.g.
> series of patches for each function? That is very helpful
> for us to review and easy to bisect if any issue happens.
>
> Also, please Cc to linux-trace-kernel@vger.kernel.org too,
> that is where we manage the patches for tracing.
>
> Thank you!
>
yes i can, will do, many thanks.
/Song
>>
>> ---
>> v2:
>> 1, bugfix:error: no member named 'utask' in 'struct task_struct'
>>
>> Signed-off-by: Song Chen <chensong_2000@189.cn>
>> Reported-by: kernel test robot <lkp@intel.com>
>
> Do you have any errors about the code duplication from test bot?
> If not, you don't need to put it.
>
>> ---
>> kernel/trace/trace_eprobe.c | 194 +--------------
>> kernel/trace/trace_kprobe.c | 125 +---------
>> kernel/trace/trace_probe.c | 472 ++++++++++++++++++++++++++++++++++++
>> kernel/trace/trace_probe.h | 11 +
>> kernel/trace/trace_uprobe.c | 177 +-------------
>> 5 files changed, 503 insertions(+), 476 deletions(-)
>>
>> diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
>> index 5dd0617e5df6..e6de612aa4e0 100644
>> --- a/kernel/trace/trace_eprobe.c
>> +++ b/kernel/trace/trace_eprobe.c
>> @@ -15,8 +15,6 @@
>>
>> #include "trace_dynevent.h"
>> #include "trace_probe.h"
>> -#include "trace_probe_tmpl.h"
>> -#include "trace_probe_kernel.h"
>>
>> #define EPROBE_EVENT_SYSTEM "eprobes"
>>
>> @@ -310,7 +308,7 @@ print_eprobe_event(struct trace_iterator *iter, int flags,
>>
>> trace_seq_putc(s, ')');
>>
>> - if (print_probe_args(s, tp->args, tp->nr_args,
>> + if (trace_probe_print_args(s, tp->args, tp->nr_args,
>> (u8 *)&field[1], field) < 0)
>> goto out;
>>
>> @@ -319,192 +317,6 @@ print_eprobe_event(struct trace_iterator *iter, int flags,
>> return trace_handle_return(s);
>> }
>>
>> -static unsigned long get_event_field(struct fetch_insn *code, void *rec)
>> -{
>> - struct ftrace_event_field *field = code->data;
>> - unsigned long val;
>> - void *addr;
>> -
>> - addr = rec + field->offset;
>> -
>> - if (is_string_field(field)) {
>> - switch (field->filter_type) {
>> - case FILTER_DYN_STRING:
>> - val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff));
>> - break;
>> - case FILTER_RDYN_STRING:
>> - val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff));
>> - break;
>> - case FILTER_STATIC_STRING:
>> - val = (unsigned long)addr;
>> - break;
>> - case FILTER_PTR_STRING:
>> - val = (unsigned long)(*(char *)addr);
>> - break;
>> - default:
>> - WARN_ON_ONCE(1);
>> - return 0;
>> - }
>> - return val;
>> - }
>> -
>> - switch (field->size) {
>> - case 1:
>> - if (field->is_signed)
>> - val = *(char *)addr;
>> - else
>> - val = *(unsigned char *)addr;
>> - break;
>> - case 2:
>> - if (field->is_signed)
>> - val = *(short *)addr;
>> - else
>> - val = *(unsigned short *)addr;
>> - break;
>> - case 4:
>> - if (field->is_signed)
>> - val = *(int *)addr;
>> - else
>> - val = *(unsigned int *)addr;
>> - break;
>> - default:
>> - if (field->is_signed)
>> - val = *(long *)addr;
>> - else
>> - val = *(unsigned long *)addr;
>> - break;
>> - }
>> - return val;
>> -}
>> -
>> -static int get_eprobe_size(struct trace_probe *tp, void *rec)
>> -{
>> - struct fetch_insn *code;
>> - struct probe_arg *arg;
>> - int i, len, ret = 0;
>> -
>> - for (i = 0; i < tp->nr_args; i++) {
>> - arg = tp->args + i;
>> - if (arg->dynamic) {
>> - unsigned long val;
>> -
>> - code = arg->code;
>> - retry:
>> - switch (code->op) {
>> - case FETCH_OP_TP_ARG:
>> - val = get_event_field(code, rec);
>> - break;
>> - case FETCH_OP_IMM:
>> - val = code->immediate;
>> - break;
>> - case FETCH_OP_COMM:
>> - val = (unsigned long)current->comm;
>> - break;
>> - case FETCH_OP_DATA:
>> - val = (unsigned long)code->data;
>> - break;
>> - case FETCH_NOP_SYMBOL: /* Ignore a place holder */
>> - code++;
>> - goto retry;
>> - default:
>> - continue;
>> - }
>> - code++;
>> - len = process_fetch_insn_bottom(code, val, NULL, NULL);
>> - if (len > 0)
>> - ret += len;
>> - }
>> - }
>> -
>> - return ret;
>> -}
>> -
>> -/* Kprobe specific fetch functions */
>> -
>> -/* Note that we don't verify it, since the code does not come from user space */
>> -static int
>> -process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
>> - void *base)
>> -{
>> - unsigned long val;
>> -
>> - retry:
>> - switch (code->op) {
>> - case FETCH_OP_TP_ARG:
>> - val = get_event_field(code, rec);
>> - break;
>> - case FETCH_OP_IMM:
>> - val = code->immediate;
>> - break;
>> - case FETCH_OP_COMM:
>> - val = (unsigned long)current->comm;
>> - break;
>> - case FETCH_OP_DATA:
>> - val = (unsigned long)code->data;
>> - break;
>> - case FETCH_NOP_SYMBOL: /* Ignore a place holder */
>> - code++;
>> - goto retry;
>> - default:
>> - return -EILSEQ;
>> - }
>> - code++;
>> - return process_fetch_insn_bottom(code, val, dest, base);
>> -}
>> -NOKPROBE_SYMBOL(process_fetch_insn)
>> -
>> -/* Return the length of string -- including null terminal byte */
>> -static nokprobe_inline int
>> -fetch_store_strlen_user(unsigned long addr)
>> -{
>> - return kern_fetch_store_strlen_user(addr);
>> -}
>> -
>> -/* Return the length of string -- including null terminal byte */
>> -static nokprobe_inline int
>> -fetch_store_strlen(unsigned long addr)
>> -{
>> - return kern_fetch_store_strlen(addr);
>> -}
>> -
>> -/*
>> - * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
>> - * with max length and relative data location.
>> - */
>> -static nokprobe_inline int
>> -fetch_store_string_user(unsigned long addr, void *dest, void *base)
>> -{
>> - return kern_fetch_store_string_user(addr, dest, base);
>> -}
>> -
>> -/*
>> - * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
>> - * length and relative data location.
>> - */
>> -static nokprobe_inline int
>> -fetch_store_string(unsigned long addr, void *dest, void *base)
>> -{
>> - return kern_fetch_store_string(addr, dest, base);
>> -}
>> -
>> -static nokprobe_inline int
>> -probe_mem_read_user(void *dest, void *src, size_t size)
>> -{
>> - const void __user *uaddr = (__force const void __user *)src;
>> -
>> - return copy_from_user_nofault(dest, uaddr, size);
>> -}
>> -
>> -static nokprobe_inline int
>> -probe_mem_read(void *dest, void *src, size_t size)
>> -{
>> -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
>> - if ((unsigned long)src < TASK_SIZE)
>> - return probe_mem_read_user(dest, src, size);
>> -#endif
>> - return copy_from_kernel_nofault(dest, src, size);
>> -}
>> -
>> /* eprobe handler */
>> static inline void
>> __eprobe_trace_func(struct eprobe_data *edata, void *rec)
>> @@ -520,7 +332,7 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec)
>> if (trace_trigger_soft_disabled(edata->file))
>> return;
>>
>> - dsize = get_eprobe_size(&edata->ep->tp, rec);
>> + dsize = trace_probe_get_data_size(&edata->ep->tp, rec);
>>
>> entry = trace_event_buffer_reserve(&fbuffer, edata->file,
>> sizeof(*entry) + edata->ep->tp.size + dsize);
>> @@ -529,7 +341,7 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec)
>> return;
>>
>> entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
>> - store_trace_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize);
>> + trace_probe_store_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize);
>>
>> trace_event_buffer_commit(&fbuffer);
>> }
>> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
>> index 5a75b039e586..d734602f2898 100644
>> --- a/kernel/trace/trace_kprobe.c
>> +++ b/kernel/trace/trace_kprobe.c
>> @@ -19,8 +19,6 @@
>> #include "trace_dynevent.h"
>> #include "trace_kprobe_selftest.h"
>> #include "trace_probe.h"
>> -#include "trace_probe_tmpl.h"
>> -#include "trace_probe_kernel.h"
>>
>> #define KPROBE_EVENT_SYSTEM "kprobes"
>> #define KRETPROBE_MAXACTIVE_MAX 4096
>> @@ -1218,109 +1216,6 @@ static const struct file_operations kprobe_profile_ops = {
>> .release = seq_release,
>> };
>>
>> -/* Kprobe specific fetch functions */
>> -
>> -/* Return the length of string -- including null terminal byte */
>> -static nokprobe_inline int
>> -fetch_store_strlen_user(unsigned long addr)
>> -{
>> - return kern_fetch_store_strlen_user(addr);
>> -}
>> -
>> -/* Return the length of string -- including null terminal byte */
>> -static nokprobe_inline int
>> -fetch_store_strlen(unsigned long addr)
>> -{
>> - return kern_fetch_store_strlen(addr);
>> -}
>> -
>> -/*
>> - * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
>> - * with max length and relative data location.
>> - */
>> -static nokprobe_inline int
>> -fetch_store_string_user(unsigned long addr, void *dest, void *base)
>> -{
>> - return kern_fetch_store_string_user(addr, dest, base);
>> -}
>> -
>> -/*
>> - * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
>> - * length and relative data location.
>> - */
>> -static nokprobe_inline int
>> -fetch_store_string(unsigned long addr, void *dest, void *base)
>> -{
>> - return kern_fetch_store_string(addr, dest, base);
>> -}
>> -
>> -static nokprobe_inline int
>> -probe_mem_read_user(void *dest, void *src, size_t size)
>> -{
>> - const void __user *uaddr = (__force const void __user *)src;
>> -
>> - return copy_from_user_nofault(dest, uaddr, size);
>> -}
>> -
>> -static nokprobe_inline int
>> -probe_mem_read(void *dest, void *src, size_t size)
>> -{
>> -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
>> - if ((unsigned long)src < TASK_SIZE)
>> - return probe_mem_read_user(dest, src, size);
>> -#endif
>> - return copy_from_kernel_nofault(dest, src, size);
>> -}
>> -
>> -/* Note that we don't verify it, since the code does not come from user space */
>> -static int
>> -process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
>> - void *base)
>> -{
>> - struct pt_regs *regs = rec;
>> - unsigned long val;
>> -
>> -retry:
>> - /* 1st stage: get value from context */
>> - switch (code->op) {
>> - case FETCH_OP_REG:
>> - val = regs_get_register(regs, code->param);
>> - break;
>> - case FETCH_OP_STACK:
>> - val = regs_get_kernel_stack_nth(regs, code->param);
>> - break;
>> - case FETCH_OP_STACKP:
>> - val = kernel_stack_pointer(regs);
>> - break;
>> - case FETCH_OP_RETVAL:
>> - val = regs_return_value(regs);
>> - break;
>> - case FETCH_OP_IMM:
>> - val = code->immediate;
>> - break;
>> - case FETCH_OP_COMM:
>> - val = (unsigned long)current->comm;
>> - break;
>> - case FETCH_OP_DATA:
>> - val = (unsigned long)code->data;
>> - break;
>> -#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
>> - case FETCH_OP_ARG:
>> - val = regs_get_kernel_argument(regs, code->param);
>> - break;
>> -#endif
>> - case FETCH_NOP_SYMBOL: /* Ignore a place holder */
>> - code++;
>> - goto retry;
>> - default:
>> - return -EILSEQ;
>> - }
>> - code++;
>> -
>> - return process_fetch_insn_bottom(code, val, dest, base);
>> -}
>> -NOKPROBE_SYMBOL(process_fetch_insn)
>> -
>> /* Kprobe handler */
>> static nokprobe_inline void
>> __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>> @@ -1336,7 +1231,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>> if (trace_trigger_soft_disabled(trace_file))
>> return;
>>
>> - dsize = __get_data_size(&tk->tp, regs);
>> + dsize = trace_probe_get_data_size(&tk->tp, regs);
>>
>> entry = trace_event_buffer_reserve(&fbuffer, trace_file,
>> sizeof(*entry) + tk->tp.size + dsize);
>> @@ -1346,7 +1241,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>> fbuffer.regs = regs;
>> entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
>> entry->ip = (unsigned long)tk->rp.kp.addr;
>> - store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>> + trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>>
>> trace_event_buffer_commit(&fbuffer);
>> }
>> @@ -1377,7 +1272,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>> if (trace_trigger_soft_disabled(trace_file))
>> return;
>>
>> - dsize = __get_data_size(&tk->tp, regs);
>> + dsize = trace_probe_get_data_size(&tk->tp, regs);
>>
>> entry = trace_event_buffer_reserve(&fbuffer, trace_file,
>> sizeof(*entry) + tk->tp.size + dsize);
>> @@ -1388,7 +1283,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>> entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
>> entry->func = (unsigned long)tk->rp.kp.addr;
>> entry->ret_ip = get_kretprobe_retaddr(ri);
>> - store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>> + trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>>
>> trace_event_buffer_commit(&fbuffer);
>> }
>> @@ -1426,7 +1321,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
>>
>> trace_seq_putc(s, ')');
>>
>> - if (print_probe_args(s, tp->args, tp->nr_args,
>> + if (trace_probe_print_args(s, tp->args, tp->nr_args,
>> (u8 *)&field[1], field) < 0)
>> goto out;
>>
>> @@ -1461,7 +1356,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
>>
>> trace_seq_putc(s, ')');
>>
>> - if (print_probe_args(s, tp->args, tp->nr_args,
>> + if (trace_probe_print_args(s, tp->args, tp->nr_args,
>> (u8 *)&field[1], field) < 0)
>> goto out;
>>
>> @@ -1536,7 +1431,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
>> if (hlist_empty(head))
>> return 0;
>>
>> - dsize = __get_data_size(&tk->tp, regs);
>> + dsize = trace_probe_get_data_size(&tk->tp, regs);
>> __size = sizeof(*entry) + tk->tp.size + dsize;
>> size = ALIGN(__size + sizeof(u32), sizeof(u64));
>> size -= sizeof(u32);
>> @@ -1547,7 +1442,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
>>
>> entry->ip = (unsigned long)tk->rp.kp.addr;
>> memset(&entry[1], 0, dsize);
>> - store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>> + trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>> perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
>> head, NULL);
>> return 0;
>> @@ -1572,7 +1467,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>> if (hlist_empty(head))
>> return;
>>
>> - dsize = __get_data_size(&tk->tp, regs);
>> + dsize = trace_probe_get_data_size(&tk->tp, regs);
>> __size = sizeof(*entry) + tk->tp.size + dsize;
>> size = ALIGN(__size + sizeof(u32), sizeof(u64));
>> size -= sizeof(u32);
>> @@ -1583,7 +1478,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>>
>> entry->func = (unsigned long)tk->rp.kp.addr;
>> entry->ret_ip = get_kretprobe_retaddr(ri);
>> - store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>> + trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
>> perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
>> head, NULL);
>> }
>> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
>> index 36dff277de46..b2aa1f08ee3a 100644
>> --- a/kernel/trace/trace_probe.c
>> +++ b/kernel/trace/trace_probe.c
>> @@ -12,6 +12,7 @@
>> #define pr_fmt(fmt) "trace_probe: " fmt
>>
>> #include "trace_probe.h"
>> +#include "trace_probe_kernel.h"
>>
>> #undef C
>> #define C(a, b) b
>> @@ -1218,3 +1219,474 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char
>>
>> return ret;
>> }
>> +
>> +/*
>> + * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
>> + * length and relative data location.
>> + */
>> +static nokprobe_inline int
>> +user_fetch_store_string(unsigned long addr, void *dest, void *base)
>> +{
>> + long ret;
>> + u32 loc = *(u32 *)dest;
>> + int maxlen = get_loc_len(loc);
>> + u8 *dst = get_loc_data(dest, base);
>> + void __user *src = (void __force __user *) addr;
>> +
>> + if (unlikely(!maxlen))
>> + return -ENOMEM;
>> +
>> + if (addr == FETCH_TOKEN_COMM)
>> + ret = strlcpy(dst, current->comm, maxlen);
>> + else
>> + ret = strncpy_from_user(dst, src, maxlen);
>> + if (ret >= 0) {
>> + if (ret == maxlen)
>> + dst[ret - 1] = '\0';
>> + else
>> + /*
>> + * Include the terminating null byte. In this case it
>> + * was copied by strncpy_from_user but not accounted
>> + * for in ret.
>> + */
>> + ret++;
>> + *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static nokprobe_inline int
>> +user_fetch_store_string_user(unsigned long addr, void *dest, void *base)
>> +{
>> + return user_fetch_store_string(addr, dest, base);
>> +}
>> +
>> +/* Return the length of string -- including null terminal byte */
>> +static nokprobe_inline int
>> +user_fetch_store_strlen(unsigned long addr)
>> +{
>> + int len;
>> + void __user *vaddr = (void __force __user *) addr;
>> +
>> + if (addr == FETCH_TOKEN_COMM)
>> + len = strlen(current->comm) + 1;
>> + else
>> + len = strnlen_user(vaddr, MAX_STRING_SIZE);
>> +
>> + return (len > MAX_STRING_SIZE) ? 0 : len;
>> +}
>> +
>> +static nokprobe_inline int
>> +user_fetch_store_strlen_user(unsigned long addr)
>> +{
>> + return user_fetch_store_strlen(addr);
>> +}
>> +
>> +static nokprobe_inline void
>> +fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf)
>> +{
>> + switch (code->size) {
>> + case 1:
>> + *(u8 *)buf = (u8)val;
>> + break;
>> + case 2:
>> + *(u16 *)buf = (u16)val;
>> + break;
>> + case 4:
>> + *(u32 *)buf = (u32)val;
>> + break;
>> + case 8:
>> + //TBD: 32bit signed
>> + *(u64 *)buf = (u64)val;
>> + break;
>> + default:
>> + *(unsigned long *)buf = val;
>> + }
>> +}
>> +
>> +static nokprobe_inline void
>> +fetch_apply_bitfield(struct fetch_insn *code, void *buf)
>> +{
>> + switch (code->basesize) {
>> + case 1:
>> + *(u8 *)buf <<= code->lshift;
>> + *(u8 *)buf >>= code->rshift;
>> + break;
>> + case 2:
>> + *(u16 *)buf <<= code->lshift;
>> + *(u16 *)buf >>= code->rshift;
>> + break;
>> + case 4:
>> + *(u32 *)buf <<= code->lshift;
>> + *(u32 *)buf >>= code->rshift;
>> + break;
>> + case 8:
>> + *(u64 *)buf <<= code->lshift;
>> + *(u64 *)buf >>= code->rshift;
>> + break;
>> + }
>> +}
>> +
>> +static nokprobe_inline int
>> +probe_mem_read_user(void *dest, void *src, size_t size)
>> +{
>> + const void __user *uaddr = (__force const void __user *)src;
>> +
>> + return copy_from_user_nofault(dest, uaddr, size);
>> +}
>> +
>> +static nokprobe_inline int
>> +probe_mem_read(void *dest, void *src, size_t size)
>> +{
>> +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
>> + if ((unsigned long)src < TASK_SIZE)
>> + return probe_mem_read_user(dest, src, size);
>> +#endif
>> + return copy_from_kernel_nofault(dest, src, size);
>> +}
>> +
>> +/* From the 2nd stage, routine is same */
>> +static nokprobe_inline int
>> +process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
>> + void *dest, void *base, int flags)
>> +{
>> + struct fetch_insn *s3 = NULL;
>> + int total = 0, ret = 0, i = 0;
>> + u32 loc = 0;
>> + unsigned long lval = val;
>> + int is_uprobe = flags & TRACE_EVENT_FL_UPROBE;
>> +
>> +stage2:
>> + /* 2nd stage: dereference memory if needed */
>> + do {
>> + if (code->op == FETCH_OP_DEREF) {
>> + lval = val;
>> + ret = probe_mem_read(&val, (void *)val + code->offset,
>> + sizeof(val));
>> + } else if (code->op == FETCH_OP_UDEREF) {
>> + lval = val;
>> + ret = probe_mem_read_user(&val,
>> + (void *)val + code->offset, sizeof(val));
>> + } else
>> + break;
>> + if (ret)
>> + return ret;
>> + code++;
>> + } while (1);
>> +
>> + s3 = code;
>> +stage3:
>> + /* 3rd stage: store value to buffer */
>> + if (unlikely(!dest)) {
>> + if (code->op == FETCH_OP_ST_STRING) {
>> + if (is_uprobe)
>> + ret = user_fetch_store_strlen(val + code->offset);
>> + else
>> + ret = kern_fetch_store_strlen(val + code->offset);
>> + code++;
>> + goto array;
>> + } else if (code->op == FETCH_OP_ST_USTRING) {
>> + if (is_uprobe)
>> + ret += user_fetch_store_strlen_user(val + code->offset);
>> + else
>> + ret += kern_fetch_store_strlen_user(val + code->offset);
>> + code++;
>> + goto array;
>> + } else
>> + return -EILSEQ;
>> + }
>> +
>> + switch (code->op) {
>> + case FETCH_OP_ST_RAW:
>> + fetch_store_raw(val, code, dest);
>> + break;
>> + case FETCH_OP_ST_MEM:
>> + probe_mem_read(dest, (void *)val + code->offset, code->size);
>> + break;
>> + case FETCH_OP_ST_UMEM:
>> + probe_mem_read_user(dest, (void *)val + code->offset, code->size);
>> + break;
>> + case FETCH_OP_ST_STRING:
>> + loc = *(u32 *)dest;
>> + if (is_uprobe)
>> + ret = user_fetch_store_string(val + code->offset, dest, base);
>> + else
>> + ret = kern_fetch_store_string(val + code->offset, dest, base);
>> + break;
>> + case FETCH_OP_ST_USTRING:
>> + loc = *(u32 *)dest;
>> + if (is_uprobe)
>> + ret = user_fetch_store_string_user(val + code->offset, dest, base);
>> + else
>> + ret = kern_fetch_store_string_user(val + code->offset, dest, base);
>> + break;
>> + default:
>> + return -EILSEQ;
>> + }
>> + code++;
>> +
>> + /* 4th stage: modify stored value if needed */
>> + if (code->op == FETCH_OP_MOD_BF) {
>> + fetch_apply_bitfield(code, dest);
>> + code++;
>> + }
>> +
>> +array:
>> + /* the last stage: Loop on array */
>> + if (code->op == FETCH_OP_LP_ARRAY) {
>> + total += ret;
>> + if (++i < code->param) {
>> + code = s3;
>> + if (s3->op != FETCH_OP_ST_STRING &&
>> + s3->op != FETCH_OP_ST_USTRING) {
>> + dest += s3->size;
>> + val += s3->size;
>> + goto stage3;
>> + }
>> + code--;
>> + val = lval + sizeof(char *);
>> + if (dest) {
>> + dest += sizeof(u32);
>> + *(u32 *)dest = update_data_loc(loc, ret);
>> + }
>> + goto stage2;
>> + }
>> + code++;
>> + ret = total;
>> + }
>> +
>> + return code->op == FETCH_OP_END ? ret : -EILSEQ;
>> +}
>> +
>> +static unsigned long get_event_field(struct fetch_insn *code, void *rec)
>> +{
>> + struct ftrace_event_field *field = code->data;
>> + unsigned long val;
>> + void *addr;
>> +
>> + addr = rec + field->offset;
>> +
>> + if (is_string_field(field)) {
>> + switch (field->filter_type) {
>> + case FILTER_DYN_STRING:
>> + val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff));
>> + break;
>> + case FILTER_RDYN_STRING:
>> + val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff));
>> + break;
>> + case FILTER_STATIC_STRING:
>> + val = (unsigned long)addr;
>> + break;
>> + case FILTER_PTR_STRING:
>> + val = (unsigned long)(*(char *)addr);
>> + break;
>> + default:
>> + WARN_ON_ONCE(1);
>> + return 0;
>> + }
>> + return val;
>> + }
>> +
>> + switch (field->size) {
>> + case 1:
>> + if (field->is_signed)
>> + val = *(char *)addr;
>> + else
>> + val = *(unsigned char *)addr;
>> + break;
>> + case 2:
>> + if (field->is_signed)
>> + val = *(short *)addr;
>> + else
>> + val = *(unsigned short *)addr;
>> + break;
>> + case 4:
>> + if (field->is_signed)
>> + val = *(int *)addr;
>> + else
>> + val = *(unsigned int *)addr;
>> + break;
>> + default:
>> + if (field->is_signed)
>> + val = *(long *)addr;
>> + else
>> + val = *(unsigned long *)addr;
>> + break;
>> + }
>> + return val;
>> +}
>> +
>> +#ifdef CONFIG_STACK_GROWSUP
>> +static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
>> +{
>> + return addr - (n * sizeof(long));
>> +}
>> +#else
>> +static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
>> +{
>> + return addr + (n * sizeof(long));
>> +}
>> +#endif
>> +
>> +static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
>> +{
>> + unsigned long ret;
>> + unsigned long addr = user_stack_pointer(regs);
>> +
>> + addr = adjust_stack_addr(addr, n);
>> +
>> + if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
>> + return 0;
>> +
>> + return ret;
>> +}
>> +
>> +#ifdef CONFIG_UPROBES
>> +static unsigned long translate_user_vaddr(unsigned long file_offset)
>> +{
>> + unsigned long base_addr;
>> + struct uprobe_dispatch_data *udd;
>> +
>> + udd = (void *) current->utask->vaddr;
>> +
>> + base_addr = udd->bp_addr - udd->offset;
>> + return base_addr + file_offset;
>> +}
>> +#endif
>> +
>> +/* Note that we don't verify it, since the code does not come from user space */
>> +static int
>> +process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
>> + void *base, int flags)
>> +{
>> + struct pt_regs *regs = rec;
>> + unsigned long val;
>> + int is_uprobe = flags & TRACE_EVENT_FL_UPROBE;
>> +
>> +retry:
>> + /* 1st stage: get value from context */
>> + switch (code->op) {
>> + case FETCH_OP_REG:
>> + val = regs_get_register(regs, code->param);
>> + break;
>> + case FETCH_OP_STACK:
>> + if (is_uprobe)
>> + val = get_user_stack_nth(regs, code->param);
>> + else
>> + val = regs_get_kernel_stack_nth(regs, code->param);
>> + break;
>> + case FETCH_OP_STACKP:
>> + if (is_uprobe)
>> + val = user_stack_pointer(regs);
>> + else
>> + val = kernel_stack_pointer(regs);
>> + break;
>> + case FETCH_OP_RETVAL:
>> + val = regs_return_value(regs);
>> + break;
>> + case FETCH_OP_IMM:
>> + val = code->immediate;
>> + break;
>> + case FETCH_OP_COMM:
>> + val = (unsigned long)current->comm;
>> + break;
>> + case FETCH_OP_DATA:
>> + val = (unsigned long)code->data;
>> + break;
>> +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
>> + case FETCH_OP_ARG:
>> + val = regs_get_kernel_argument(regs, code->param);
>> + break;
>> +#endif
>> + case FETCH_NOP_SYMBOL: /* Ignore a place holder */
>> + code++;
>> + goto retry;
>> + case FETCH_OP_TP_ARG:
>> + val = get_event_field(code, rec);
>> + break;
>> +#ifdef CONFIG_UPROBES
>> + case FETCH_OP_FOFFS:
>> + val = translate_user_vaddr(code->immediate);
>> + break;
>> +#endif
>> + default:
>> + return -EILSEQ;
>> + }
>> + code++;
>> +
>> + return process_fetch_insn_bottom(code, val, dest, base, flags);
>> +}
>> +NOKPROBE_SYMBOL(process_fetch_insn)
>> +
>> +/* Sum up total data length for dynamic arrays (strings) */
>> +int trace_probe_get_data_size(struct trace_probe *tp, struct pt_regs *regs)
>> +{
>> + struct probe_arg *arg;
>> + int i, len, ret = 0;
>> + struct trace_event_call *call = trace_probe_event_call(tp);
>> +
>> + for (i = 0; i < tp->nr_args; i++) {
>> + arg = tp->args + i;
>> + if (unlikely(arg->dynamic)) {
>> + len = process_fetch_insn(arg->code, regs, NULL, NULL, call->flags);
>> + if (len > 0)
>> + ret += len;
>> + }
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +void trace_probe_store_args(void *data, struct trace_probe *tp, void *rec,
>> + int header_size, int maxlen)
>> +{
>> + struct probe_arg *arg;
>> + void *base = data - header_size;
>> + void *dyndata = data + tp->size;
>> + u32 *dl; /* Data location */
>> + int ret, i;
>> + struct trace_event_call *call = trace_probe_event_call(tp);
>> +
>> + for (i = 0; i < tp->nr_args; i++) {
>> + arg = tp->args + i;
>> + dl = data + arg->offset;
>> + /* Point the dynamic data area if needed */
>> + if (unlikely(arg->dynamic))
>> + *dl = make_data_loc(maxlen, dyndata - base);
>> + ret = process_fetch_insn(arg->code, rec, dl, base, call->flags);
>> + if (unlikely(ret < 0 && arg->dynamic)) {
>> + *dl = make_data_loc(0, dyndata - base);
>> + } else {
>> + dyndata += ret;
>> + maxlen -= ret;
>> + }
>> + }
>> +}
>> +
>> +int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
>> + u8 *data, void *field)
>> +{
>> + void *p;
>> + int i, j;
>> +
>> + for (i = 0; i < nr_args; i++) {
>> + struct probe_arg *a = args + i;
>> +
>> + trace_seq_printf(s, " %s=", a->name);
>> + if (likely(!a->count)) {
>> + if (!a->type->print(s, data + a->offset, field))
>> + return -ENOMEM;
>> + continue;
>> + }
>> + trace_seq_putc(s, '{');
>> + p = data + a->offset;
>> + for (j = 0; j < a->count; j++) {
>> + if (!a->type->print(s, p, field))
>> + return -ENOMEM;
>> + trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
>> + p += a->type->size;
>> + }
>> + }
>> + return 0;
>> +}
>> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
>> index de38f1c03776..918466087583 100644
>> --- a/kernel/trace/trace_probe.h
>> +++ b/kernel/trace/trace_probe.h
>> @@ -223,6 +223,12 @@ struct probe_arg {
>> const struct fetch_type *type; /* Type of this argument */
>> };
>>
>> +struct uprobe_dispatch_data {
>> + struct trace_uprobe *tu;
>> + unsigned long bp_addr;
>> + unsigned long offset;
>> +};
>> +
>> struct trace_uprobe_filter {
>> rwlock_t rwlock;
>> int nr_systemwide;
>> @@ -343,6 +349,11 @@ int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
>> bool trace_probe_match_command_args(struct trace_probe *tp,
>> int argc, const char **argv);
>> int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));
>> +int trace_probe_get_data_size(struct trace_probe *tp, struct pt_regs *regs);
>> +void trace_probe_store_args(void *data, struct trace_probe *tp, void *rec,
>> + int header_size, int maxlen);
>> +int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
>> + u8 *data, void *field);
>>
>> #define trace_probe_for_each_link(pos, tp) \
>> list_for_each_entry(pos, &(tp)->event->files, list)
>> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
>> index fb58e86dd117..abce09295f05 100644
>> --- a/kernel/trace/trace_uprobe.c
>> +++ b/kernel/trace/trace_uprobe.c
>> @@ -20,7 +20,6 @@
>>
>> #include "trace_dynevent.h"
>> #include "trace_probe.h"
>> -#include "trace_probe_tmpl.h"
>>
>> #define UPROBE_EVENT_SYSTEM "uprobes"
>>
>> @@ -88,174 +87,10 @@ static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
>> static int register_uprobe_event(struct trace_uprobe *tu);
>> static int unregister_uprobe_event(struct trace_uprobe *tu);
>>
>> -struct uprobe_dispatch_data {
>> - struct trace_uprobe *tu;
>> - unsigned long bp_addr;
>> -};
>> -
>> static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
>> static int uretprobe_dispatcher(struct uprobe_consumer *con,
>> unsigned long func, struct pt_regs *regs);
>>
>> -#ifdef CONFIG_STACK_GROWSUP
>> -static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
>> -{
>> - return addr - (n * sizeof(long));
>> -}
>> -#else
>> -static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
>> -{
>> - return addr + (n * sizeof(long));
>> -}
>> -#endif
>> -
>> -static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
>> -{
>> - unsigned long ret;
>> - unsigned long addr = user_stack_pointer(regs);
>> -
>> - addr = adjust_stack_addr(addr, n);
>> -
>> - if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
>> - return 0;
>> -
>> - return ret;
>> -}
>> -
>> -/*
>> - * Uprobes-specific fetch functions
>> - */
>> -static nokprobe_inline int
>> -probe_mem_read(void *dest, void *src, size_t size)
>> -{
>> - void __user *vaddr = (void __force __user *)src;
>> -
>> - return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
>> -}
>> -
>> -static nokprobe_inline int
>> -probe_mem_read_user(void *dest, void *src, size_t size)
>> -{
>> - return probe_mem_read(dest, src, size);
>> -}
>> -
>> -/*
>> - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
>> - * length and relative data location.
>> - */
>> -static nokprobe_inline int
>> -fetch_store_string(unsigned long addr, void *dest, void *base)
>> -{
>> - long ret;
>> - u32 loc = *(u32 *)dest;
>> - int maxlen = get_loc_len(loc);
>> - u8 *dst = get_loc_data(dest, base);
>> - void __user *src = (void __force __user *) addr;
>> -
>> - if (unlikely(!maxlen))
>> - return -ENOMEM;
>> -
>> - if (addr == FETCH_TOKEN_COMM)
>> - ret = strlcpy(dst, current->comm, maxlen);
>> - else
>> - ret = strncpy_from_user(dst, src, maxlen);
>> - if (ret >= 0) {
>> - if (ret == maxlen)
>> - dst[ret - 1] = '\0';
>> - else
>> - /*
>> - * Include the terminating null byte. In this case it
>> - * was copied by strncpy_from_user but not accounted
>> - * for in ret.
>> - */
>> - ret++;
>> - *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
>> - }
>> -
>> - return ret;
>> -}
>> -
>> -static nokprobe_inline int
>> -fetch_store_string_user(unsigned long addr, void *dest, void *base)
>> -{
>> - return fetch_store_string(addr, dest, base);
>> -}
>> -
>> -/* Return the length of string -- including null terminal byte */
>> -static nokprobe_inline int
>> -fetch_store_strlen(unsigned long addr)
>> -{
>> - int len;
>> - void __user *vaddr = (void __force __user *) addr;
>> -
>> - if (addr == FETCH_TOKEN_COMM)
>> - len = strlen(current->comm) + 1;
>> - else
>> - len = strnlen_user(vaddr, MAX_STRING_SIZE);
>> -
>> - return (len > MAX_STRING_SIZE) ? 0 : len;
>> -}
>> -
>> -static nokprobe_inline int
>> -fetch_store_strlen_user(unsigned long addr)
>> -{
>> - return fetch_store_strlen(addr);
>> -}
>> -
>> -static unsigned long translate_user_vaddr(unsigned long file_offset)
>> -{
>> - unsigned long base_addr;
>> - struct uprobe_dispatch_data *udd;
>> -
>> - udd = (void *) current->utask->vaddr;
>> -
>> - base_addr = udd->bp_addr - udd->tu->offset;
>> - return base_addr + file_offset;
>> -}
>> -
>> -/* Note that we don't verify it, since the code does not come from user space */
>> -static int
>> -process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
>> - void *base)
>> -{
>> - struct pt_regs *regs = rec;
>> - unsigned long val;
>> -
>> - /* 1st stage: get value from context */
>> - switch (code->op) {
>> - case FETCH_OP_REG:
>> - val = regs_get_register(regs, code->param);
>> - break;
>> - case FETCH_OP_STACK:
>> - val = get_user_stack_nth(regs, code->param);
>> - break;
>> - case FETCH_OP_STACKP:
>> - val = user_stack_pointer(regs);
>> - break;
>> - case FETCH_OP_RETVAL:
>> - val = regs_return_value(regs);
>> - break;
>> - case FETCH_OP_IMM:
>> - val = code->immediate;
>> - break;
>> - case FETCH_OP_COMM:
>> - val = FETCH_TOKEN_COMM;
>> - break;
>> - case FETCH_OP_DATA:
>> - val = (unsigned long)code->data;
>> - break;
>> - case FETCH_OP_FOFFS:
>> - val = translate_user_vaddr(code->immediate);
>> - break;
>> - default:
>> - return -EILSEQ;
>> - }
>> - code++;
>> -
>> - return process_fetch_insn_bottom(code, val, dest, base);
>> -}
>> -NOKPROBE_SYMBOL(process_fetch_insn)
>> -
>> static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
>> {
>> rwlock_init(&filter->rwlock);
>> @@ -1041,7 +876,7 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
>> data = DATAOF_TRACE_ENTRY(entry, false);
>> }
>>
>> - if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
>> + if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
>> goto out;
>>
>> trace_seq_putc(s, '\n');
>> @@ -1485,6 +1320,7 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
>> tu->nhit++;
>>
>> udd.tu = tu;
>> + udd.offset = tu->offset;
>> udd.bp_addr = instruction_pointer(regs);
>>
>> current->utask->vaddr = (unsigned long) &udd;
>> @@ -1492,11 +1328,11 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
>> if (WARN_ON_ONCE(!uprobe_cpu_buffer))
>> return 0;
>>
>> - dsize = __get_data_size(&tu->tp, regs);
>> + dsize = trace_probe_get_data_size(&tu->tp, regs);
>> esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
>>
>> ucb = uprobe_buffer_get();
>> - store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
>> + trace_probe_store_args(ucb->buf, &tu->tp, regs, esize, dsize);
>>
>> if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
>> ret |= uprobe_trace_func(tu, regs, ucb, dsize);
>> @@ -1520,6 +1356,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
>> tu = container_of(con, struct trace_uprobe, consumer);
>>
>> udd.tu = tu;
>> + udd.offset = tu->offset;
>> udd.bp_addr = func;
>>
>> current->utask->vaddr = (unsigned long) &udd;
>> @@ -1527,11 +1364,11 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
>> if (WARN_ON_ONCE(!uprobe_cpu_buffer))
>> return 0;
>>
>> - dsize = __get_data_size(&tu->tp, regs);
>> + dsize = trace_probe_get_data_size(&tu->tp, regs);
>> esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
>>
>> ucb = uprobe_buffer_get();
>> - store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
>> + trace_probe_store_args(ucb->buf, &tu->tp, regs, esize, dsize);
>>
>> if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
>> uretprobe_trace_func(tu, func, regs, ucb, dsize);
>> --
>> 2.25.1
>>
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread