Re: [PATCH 2/3] tracing: Extract out common code for kprobes/uprobes traceevents

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On Tue, 2012-04-03 at 06:34 +0530, Srikar Dronamraju wrote:
> From: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxxxxxxx>

Masami,

Can you ack this patch if you agree with it.

Thanks,

-- Steve

> ---
> 
> Changelog:
> (v5)
> - 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  |  835 ++++++++++++++++++++++++++++++++++++++++
>  kernel/trace/trace_probe.h  |  160 ++++++++
>  5 files changed, 1018 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, &param);
> -			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, &param);
> -			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..deb375a
> --- /dev/null
> +++ b/kernel/trace/trace_probe.c
> @@ -0,0 +1,835 @@
> +/*
> + * 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@xxxxxxxxxxx>
> + *
> + * 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)
> +{
> +	int maxlen;
> +	long ret;
> +
> +	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, &param);
> +			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, &param);
> +			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 128
> +
> +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@xxxxxxxxxxx>
> + *
> + * 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**));
> 


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