Re: [PATCH 08/17] tracing/probes: Split [ku]probes_fetch_type_table

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

(2013/12/10 13:41), Namhyung Kim wrote:
>>From 9f7e24f9d97440a015d7fa6562bce462fcf1f230 Mon Sep 17 00:00:00 2001
> From: Namhyung Kim <namhyung.kim@lge.com>
> Date: Tue, 26 Nov 2013 14:56:28 +0900
> Subject: [PATCH v8.1 08/17] tracing/probes: Split [ku]probes_fetch_type_table
> 
> Use separate fetch_type_table for kprobes and uprobes.  It currently
> shares all fetch methods but some of them will be implemented
> differently later.
> 
> This is not to break build if [ku]probes is configured alone (like
> !CONFIG_KPROBE_EVENT and CONFIG_UPROBE_EVENT).  So I added '__weak'
> to the table declaration so that it can be safely omitted when it
> configured out.
> 
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>

This looks OK for me ;)

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thank you!

> ---
>  kernel/trace/trace_kprobe.c | 20 ++++++++++++
>  kernel/trace/trace_probe.c  | 65 ++++++++++++++++----------------------
>  kernel/trace/trace_probe.h  | 76 ++++++++++++++++++++++++++++++++++++++-------
>  kernel/trace/trace_uprobe.c | 20 ++++++++++++
>  4 files changed, 131 insertions(+), 50 deletions(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 62d6c961bbce..23c6c3feff82 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -88,6 +88,26 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
>  static int kretprobe_dispatcher(struct kretprobe_instance *ri,
>  				struct pt_regs *regs);
>  
> +/* Fetch type information table */
> +const struct fetch_type kprobes_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),
> +
> +	ASSIGN_FETCH_TYPE_END
> +};
> +
>  /*
>   * Allocate new trace_probe and initialize it (including kprobes).
>   */
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index c26bc9eaa2ac..541036ec7392 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -54,10 +54,6 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
>  DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
>  DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
>  
> -/* For defining macros, define string/string_size types */
> -typedef u32 string;
> -typedef u32 string_size;
> -
>  /* Print type function for string type */
>  __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
>  						  const char *name,
> @@ -74,7 +70,6 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
>  
>  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.
> @@ -359,25 +354,8 @@ free_bitfield_fetch_param(struct bitfield_fetch_param *data)
>  	kfree(data);
>  }
>  
> -/* 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)
> +static const struct fetch_type *find_fetch_type(const char *type,
> +						const struct fetch_type *ftbl)
>  {
>  	int i;
>  
> @@ -398,21 +376,22 @@ static const struct fetch_type *find_fetch_type(const char *type)
>  
>  		switch (bs) {
>  		case 8:
> -			return find_fetch_type("u8");
> +			return find_fetch_type("u8", ftbl);
>  		case 16:
> -			return find_fetch_type("u16");
> +			return find_fetch_type("u16", ftbl);
>  		case 32:
> -			return find_fetch_type("u32");
> +			return find_fetch_type("u32", ftbl);
>  		case 64:
> -			return find_fetch_type("u64");
> +			return find_fetch_type("u64", ftbl);
>  		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];
> +	for (i = 0; ftbl[i].name; i++) {
> +		if (strcmp(type, ftbl[i].name) == 0)
> +			return &ftbl[i];
> +	}
>  
>  fail:
>  	return NULL;
> @@ -426,16 +405,17 @@ static __kprobes void fetch_stack_address(struct pt_regs *regs,
>  }
>  
>  static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
> -					fetch_func_t orig_fn)
> +					    fetch_func_t orig_fn,
> +					    const struct fetch_type *ftbl)
>  {
>  	int i;
>  
> -	if (type != &fetch_type_table[FETCH_TYPE_STRING])
> +	if (type != &ftbl[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];
> +			return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
>  
>  	WARN_ON(1);	/* This should not happen */
>  
> @@ -504,12 +484,14 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
>  static int parse_probe_arg(char *arg, const struct fetch_type *t,
>  		     struct fetch_param *f, bool is_return, bool is_kprobe)
>  {
> +	const struct fetch_type *ftbl;
>  	unsigned long param;
>  	long offset;
>  	char *tmp;
> -	int ret;
> +	int ret = 0;
>  
> -	ret = 0;
> +	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
> +	BUG_ON(ftbl == NULL);
>  
>  	/* Until uprobe_events supports only reg arguments */
>  	if (!is_kprobe && arg[0] != '%')
> @@ -568,7 +550,7 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
>  			struct deref_fetch_param	*dprm;
>  			const struct fetch_type		*t2;
>  
> -			t2 = find_fetch_type(NULL);
> +			t2 = find_fetch_type(NULL, ftbl);
>  			*tmp = '\0';
>  			dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
>  
> @@ -637,9 +619,13 @@ static int __parse_bitfield_probe_arg(const char *bf,
>  int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
>  		struct probe_arg *parg, bool is_return, bool is_kprobe)
>  {
> +	const struct fetch_type *ftbl;
>  	const char *t;
>  	int ret;
>  
> +	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
> +	BUG_ON(ftbl == NULL);
> +
>  	if (strlen(arg) > MAX_ARGSTR_LEN) {
>  		pr_info("Argument is too long.: %s\n",  arg);
>  		return -ENOSPC;
> @@ -654,7 +640,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
>  		arg[t - parg->comm] = '\0';
>  		t++;
>  	}
> -	parg->type = find_fetch_type(t);
> +	parg->type = find_fetch_type(t, ftbl);
>  	if (!parg->type) {
>  		pr_info("Unsupported type: %s\n", t);
>  		return -EINVAL;
> @@ -668,7 +654,8 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
>  
>  	if (ret >= 0) {
>  		parg->fetch_size.fn = get_fetch_size_function(parg->type,
> -							      parg->fetch.fn);
> +							      parg->fetch.fn,
> +							      ftbl);
>  		parg->fetch_size.data = parg->fetch.data;
>  	}
>  
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 7c6be146f444..5b77798d1130 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -126,24 +126,70 @@ struct fetch_param {
>  	void 			*data;
>  };
>  
> +/* For defining macros, define string/string_size types */
> +typedef u32 string;
> +typedef u32 string_size;
> +
>  #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 DECLARE_BASIC_PRINT_TYPE_FUNC(type, fmt)			\
> +#define DECLARE_BASIC_PRINT_TYPE_FUNC(type)				\
>  __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,		\
>  					 const char *name,		\
>  					 void *data, void *ent);	\
> -extern const char PRINT_TYPE_FMT_NAME(type)[];
> -
> -DECLARE_BASIC_PRINT_TYPE_FUNC(u8 , "%x")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(u16, "%x")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(u32, "%x")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(u64, "%Lx")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(s8,  "%d")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
> -DECLARE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
> +extern const char PRINT_TYPE_FMT_NAME(type)[]
> +
> +DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
> +DECLARE_BASIC_PRINT_TYPE_FUNC(string);
> +
> +#define FETCH_FUNC_NAME(method, type)	fetch_##method##_##type
> +
> +/* Declare macro for basic types */
> +#define DECLARE_FETCH_FUNC(method, type)				\
> +extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, 	\
> +					  void *data, void *dest)
> +
> +#define DECLARE_BASIC_FETCH_FUNCS(method) 	\
> +DECLARE_FETCH_FUNC(method, u8);			\
> +DECLARE_FETCH_FUNC(method, u16);		\
> +DECLARE_FETCH_FUNC(method, u32);		\
> +DECLARE_FETCH_FUNC(method, u64)
> +
> +DECLARE_BASIC_FETCH_FUNCS(reg);
> +#define fetch_reg_string			NULL
> +#define fetch_reg_string_size			NULL
> +
> +DECLARE_BASIC_FETCH_FUNCS(stack);
> +#define fetch_stack_string			NULL
> +#define fetch_stack_string_size			NULL
> +
> +DECLARE_BASIC_FETCH_FUNCS(retval);
> +#define fetch_retval_string			NULL
> +#define fetch_retval_string_size		NULL
> +
> +DECLARE_BASIC_FETCH_FUNCS(memory);
> +DECLARE_FETCH_FUNC(memory, string);
> +DECLARE_FETCH_FUNC(memory, string_size);
> +
> +DECLARE_BASIC_FETCH_FUNCS(symbol);
> +DECLARE_FETCH_FUNC(symbol, string);
> +DECLARE_FETCH_FUNC(symbol, string_size);
> +
> +DECLARE_BASIC_FETCH_FUNCS(deref);
> +DECLARE_FETCH_FUNC(deref, string);
> +DECLARE_FETCH_FUNC(deref, string_size);
> +
> +DECLARE_BASIC_FETCH_FUNCS(bitfield);
> +#define fetch_bitfield_string			NULL
> +#define fetch_bitfield_string_size		NULL
>  
>  /* Default (unsigned long) fetch type */
>  #define __DEFAULT_FETCH_TYPE(t) u##t
> @@ -175,9 +221,17 @@ ASSIGN_FETCH_FUNC(bitfield, ftype),			\
>  #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)			\
>  	__ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
>  
> +#define ASSIGN_FETCH_TYPE_END {}
> +
>  #define FETCH_TYPE_STRING	0
>  #define FETCH_TYPE_STRSIZE	1
>  
> +/*
> + * Fetch type information table.
> + * It's declared as a weak symbol due to conditional compilation.
> + */
> +extern __weak const struct fetch_type kprobes_fetch_type_table[];
> +extern __weak const struct fetch_type uprobes_fetch_type_table[];
>  
>  struct probe_arg {
>  	struct fetch_param	fetch;
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index b233d9cb1216..2c60925ea073 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -74,6 +74,26 @@ 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);
>  
> +/* Fetch type information table */
> +const struct fetch_type uprobes_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),
> +
> +	ASSIGN_FETCH_TYPE_END
> +};
> +
>  static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
>  {
>  	rwlock_init(&filter->rwlock);
> 


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com