tracing: Extract out common code for kprobes/uprobes trace events
authorSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Mon, 9 Apr 2012 09:11:44 +0000 (14:41 +0530)
committerIngo Molnar <mingo@kernel.org>
Mon, 7 May 2012 12:29:57 +0000 (14:29 +0200)
Move parts of trace_kprobe.c that can be shared with upcoming
trace_uprobe.c. Common code to kernel/trace/trace_probe.h and
kernel/trace/trace_probe.c. There are no functional changes.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120409091144.8343.76218.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/trace/Kconfig
kernel/trace/Makefile
kernel/trace/trace_kprobe.c
kernel/trace/trace_probe.c [new file with mode: 0644]
kernel/trace/trace_probe.h [new file with mode: 0644]

index a1d2849..ce5a5c5 100644 (file)
@@ -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
index 5f39a07..fa10d5c 100644 (file)
@@ -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
index 4f935f8..f8b7773 100644 (file)
 
 #include <linux/module.h>
 #include <linux/uaccess.h>
-#include <linux/kprobes.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-#include <linux/smp.h>
-#include <linux/debugfs.h>
-#include <linux/types.h>
-#include <linux/string.h>
-#include <linux/ctype.h>
-#include <linux/ptrace.h>
-#include <linux/perf_event.h>
-#include <linux/stringify.h>
-#include <linux/limits.h>
-#include <asm/bitsperlong.h>
-
-#include "trace.h"
-#include "trace_output.h"
-
-#define MAX_TRACE_ARGS 128
-#define MAX_ARGSTR_LEN 63
-#define MAX_EVENT_NAME_LEN 64
-#define MAX_STRING_SIZE PATH_MAX
-#define KPROBE_EVENT_SYSTEM "kprobes"
-
-/* Reserved field names */
-#define FIELD_STRING_IP "__probe_ip"
-#define FIELD_STRING_RETIP "__probe_ret_ip"
-#define FIELD_STRING_FUNC "__probe_func"
-
-const char *reserved_field_names[] = {
-       "common_type",
-       "common_flags",
-       "common_preempt_count",
-       "common_pid",
-       "common_tgid",
-       FIELD_STRING_IP,
-       FIELD_STRING_RETIP,
-       FIELD_STRING_FUNC,
-};
-
-/* Printing function type */
-typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
-                                void *);
-#define PRINT_TYPE_FUNC_NAME(type)     print_type_##type
-#define PRINT_TYPE_FMT_NAME(type)      print_type_format_##type
-
-/* Printing  in basic type function template */
-#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast)                  \
-static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,   \
-                                               const char *name,       \
-                                               void *data, void *ent)\
-{                                                                      \
-       return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
-}                                                                      \
-static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
-
-DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
-DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
-
-/* data_rloc: data relative location, compatible with u32 */
-#define make_data_rloc(len, roffs)     \
-       (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
-#define get_rloc_len(dl)       ((u32)(dl) >> 16)
-#define get_rloc_offs(dl)      ((u32)(dl) & 0xffff)
-
-static inline void *get_rloc_data(u32 *dl)
-{
-       return (u8 *)dl + get_rloc_offs(*dl);
-}
-
-/* For data_loc conversion */
-static inline void *get_loc_data(u32 *dl, void *ent)
-{
-       return (u8 *)ent + get_rloc_offs(*dl);
-}
-
-/*
- * Convert data_rloc to data_loc:
- *  data_rloc stores the offset from data_rloc itself, but data_loc
- *  stores the offset from event entry.
- */
-#define convert_rloc_to_loc(dl, offs)  ((u32)(dl) + (offs))
-
-/* For defining macros, define string/string_size types */
-typedef u32 string;
-typedef u32 string_size;
-
-/* Print type function for string type */
-static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
-                                                 const char *name,
-                                                 void *data, void *ent)
-{
-       int len = *(u32 *)data >> 16;
-
-       if (!len)
-               return trace_seq_printf(s, " %s=(fault)", name);
-       else
-               return trace_seq_printf(s, " %s=\"%s\"", name,
-                                       (const char *)get_loc_data(data, ent));
-}
-static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
-
-/* Data fetch function type */
-typedef        void (*fetch_func_t)(struct pt_regs *, void *, void *);
-
-struct fetch_param {
-       fetch_func_t    fn;
-       void *data;
-};
-
-static __kprobes void call_fetch(struct fetch_param *fprm,
-                                struct pt_regs *regs, void *dest)
-{
-       return fprm->fn(regs, fprm->data, dest);
-}
-
-#define FETCH_FUNC_NAME(method, type)  fetch_##method##_##type
-/*
- * Define macro for basic types - we don't need to define s* types, because
- * we have to care only about bitwidth at recording time.
- */
-#define DEFINE_BASIC_FETCH_FUNCS(method) \
-DEFINE_FETCH_##method(u8)              \
-DEFINE_FETCH_##method(u16)             \
-DEFINE_FETCH_##method(u32)             \
-DEFINE_FETCH_##method(u64)
-
-#define CHECK_FETCH_FUNCS(method, fn)                  \
-       (((FETCH_FUNC_NAME(method, u8) == fn) ||        \
-         (FETCH_FUNC_NAME(method, u16) == fn) ||       \
-         (FETCH_FUNC_NAME(method, u32) == fn) ||       \
-         (FETCH_FUNC_NAME(method, u64) == fn) ||       \
-         (FETCH_FUNC_NAME(method, string) == fn) ||    \
-         (FETCH_FUNC_NAME(method, string_size) == fn)) \
-        && (fn != NULL))
-
-/* Data fetch function templates */
-#define DEFINE_FETCH_reg(type)                                         \
-static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
-                                       void *offset, void *dest)       \
-{                                                                      \
-       *(type *)dest = (type)regs_get_register(regs,                   \
-                               (unsigned int)((unsigned long)offset)); \
-}
-DEFINE_BASIC_FETCH_FUNCS(reg)
-/* No string on the register */
-#define fetch_reg_string NULL
-#define fetch_reg_string_size NULL
-
-#define DEFINE_FETCH_stack(type)                                       \
-static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
-                                         void *offset, void *dest)     \
-{                                                                      \
-       *(type *)dest = (type)regs_get_kernel_stack_nth(regs,           \
-                               (unsigned int)((unsigned long)offset)); \
-}
-DEFINE_BASIC_FETCH_FUNCS(stack)
-/* No string on the stack entry */
-#define fetch_stack_string NULL
-#define fetch_stack_string_size NULL
-
-#define DEFINE_FETCH_retval(type)                                      \
-static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
-                                         void *dummy, void *dest)      \
-{                                                                      \
-       *(type *)dest = (type)regs_return_value(regs);                  \
-}
-DEFINE_BASIC_FETCH_FUNCS(retval)
-/* No string on the retval */
-#define fetch_retval_string NULL
-#define fetch_retval_string_size NULL
-
-#define DEFINE_FETCH_memory(type)                                      \
-static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
-                                         void *addr, void *dest)       \
-{                                                                      \
-       type retval;                                                    \
-       if (probe_kernel_address(addr, retval))                         \
-               *(type *)dest = 0;                                      \
-       else                                                            \
-               *(type *)dest = retval;                                 \
-}
-DEFINE_BASIC_FETCH_FUNCS(memory)
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
- * length and relative data location.
- */
-static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
-                                                     void *addr, void *dest)
-{
-       long ret;
-       int maxlen = get_rloc_len(*(u32 *)dest);
-       u8 *dst = get_rloc_data(dest);
-       u8 *src = addr;
-       mm_segment_t old_fs = get_fs();
-       if (!maxlen)
-               return;
-       /*
-        * Try to get string again, since the string can be changed while
-        * probing.
-        */
-       set_fs(KERNEL_DS);
-       pagefault_disable();
-       do
-               ret = __copy_from_user_inatomic(dst++, src++, 1);
-       while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
-       dst[-1] = '\0';
-       pagefault_enable();
-       set_fs(old_fs);
-
-       if (ret < 0) {  /* Failed to fetch string */
-               ((u8 *)get_rloc_data(dest))[0] = '\0';
-               *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
-       } else
-               *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
-                                             get_rloc_offs(*(u32 *)dest));
-}
-/* Return the length of string -- including null terminal byte */
-static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
-                                                       void *addr, void *dest)
-{
-       int ret, len = 0;
-       u8 c;
-       mm_segment_t old_fs = get_fs();
-
-       set_fs(KERNEL_DS);
-       pagefault_disable();
-       do {
-               ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
-               len++;
-       } while (c && ret == 0 && len < MAX_STRING_SIZE);
-       pagefault_enable();
-       set_fs(old_fs);
-
-       if (ret < 0)    /* Failed to check the length */
-               *(u32 *)dest = 0;
-       else
-               *(u32 *)dest = len;
-}
-
-/* Memory fetching by symbol */
-struct symbol_cache {
-       char *symbol;
-       long offset;
-       unsigned long addr;
-};
-
-static unsigned long update_symbol_cache(struct symbol_cache *sc)
-{
-       sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
-       if (sc->addr)
-               sc->addr += sc->offset;
-       return sc->addr;
-}
-
-static void free_symbol_cache(struct symbol_cache *sc)
-{
-       kfree(sc->symbol);
-       kfree(sc);
-}
-
-static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
-{
-       struct symbol_cache *sc;
-
-       if (!sym || strlen(sym) == 0)
-               return NULL;
-       sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
-       if (!sc)
-               return NULL;
-
-       sc->symbol = kstrdup(sym, GFP_KERNEL);
-       if (!sc->symbol) {
-               kfree(sc);
-               return NULL;
-       }
-       sc->offset = offset;
 
-       update_symbol_cache(sc);
-       return sc;
-}
-
-#define DEFINE_FETCH_symbol(type)                                      \
-static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
-                                         void *data, void *dest)       \
-{                                                                      \
-       struct symbol_cache *sc = data;                                 \
-       if (sc->addr)                                                   \
-               fetch_memory_##type(regs, (void *)sc->addr, dest);      \
-       else                                                            \
-               *(type *)dest = 0;                                      \
-}
-DEFINE_BASIC_FETCH_FUNCS(symbol)
-DEFINE_FETCH_symbol(string)
-DEFINE_FETCH_symbol(string_size)
-
-/* Dereference memory access function */
-struct deref_fetch_param {
-       struct fetch_param orig;
-       long offset;
-};
-
-#define DEFINE_FETCH_deref(type)                                       \
-static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
-                                           void *data, void *dest)     \
-{                                                                      \
-       struct deref_fetch_param *dprm = data;                          \
-       unsigned long addr;                                             \
-       call_fetch(&dprm->orig, regs, &addr);                           \
-       if (addr) {                                                     \
-               addr += dprm->offset;                                   \
-               fetch_memory_##type(regs, (void *)addr, dest);          \
-       } else                                                          \
-               *(type *)dest = 0;                                      \
-}
-DEFINE_BASIC_FETCH_FUNCS(deref)
-DEFINE_FETCH_deref(string)
-DEFINE_FETCH_deref(string_size)
-
-static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
-{
-       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
-               update_deref_fetch_param(data->orig.data);
-       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
-               update_symbol_cache(data->orig.data);
-}
-
-static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
-{
-       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
-               free_deref_fetch_param(data->orig.data);
-       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
-               free_symbol_cache(data->orig.data);
-       kfree(data);
-}
-
-/* Bitfield fetch function */
-struct bitfield_fetch_param {
-       struct fetch_param orig;
-       unsigned char hi_shift;
-       unsigned char low_shift;
-};
+#include "trace_probe.h"
 
-#define DEFINE_FETCH_bitfield(type)                                    \
-static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
-                                           void *data, void *dest)     \
-{                                                                      \
-       struct bitfield_fetch_param *bprm = data;                       \
-       type buf = 0;                                                   \
-       call_fetch(&bprm->orig, regs, &buf);                            \
-       if (buf) {                                                      \
-               buf <<= bprm->hi_shift;                                 \
-               buf >>= bprm->low_shift;                                \
-       }                                                               \
-       *(type *)dest = buf;                                            \
-}
-DEFINE_BASIC_FETCH_FUNCS(bitfield)
-#define fetch_bitfield_string NULL
-#define fetch_bitfield_string_size NULL
-
-static __kprobes void
-update_bitfield_fetch_param(struct bitfield_fetch_param *data)
-{
-       /*
-        * Don't check the bitfield itself, because this must be the
-        * last fetch function.
-        */
-       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
-               update_deref_fetch_param(data->orig.data);
-       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
-               update_symbol_cache(data->orig.data);
-}
-
-static __kprobes void
-free_bitfield_fetch_param(struct bitfield_fetch_param *data)
-{
-       /*
-        * Don't check the bitfield itself, because this must be the
-        * last fetch function.
-        */
-       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
-               free_deref_fetch_param(data->orig.data);
-       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
-               free_symbol_cache(data->orig.data);
-       kfree(data);
-}
-
-/* Default (unsigned long) fetch type */
-#define __DEFAULT_FETCH_TYPE(t) u##t
-#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
-#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
-#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
-
-/* Fetch types */
-enum {
-       FETCH_MTD_reg = 0,
-       FETCH_MTD_stack,
-       FETCH_MTD_retval,
-       FETCH_MTD_memory,
-       FETCH_MTD_symbol,
-       FETCH_MTD_deref,
-       FETCH_MTD_bitfield,
-       FETCH_MTD_END,
-};
-
-#define ASSIGN_FETCH_FUNC(method, type)        \
-       [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
-
-#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)        \
-       {.name = _name,                         \
-        .size = _size,                                 \
-        .is_signed = sign,                             \
-        .print = PRINT_TYPE_FUNC_NAME(ptype),          \
-        .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
-        .fmttype = _fmttype,                           \
-        .fetch = {                                     \
-ASSIGN_FETCH_FUNC(reg, ftype),                         \
-ASSIGN_FETCH_FUNC(stack, ftype),                       \
-ASSIGN_FETCH_FUNC(retval, ftype),                      \
-ASSIGN_FETCH_FUNC(memory, ftype),                      \
-ASSIGN_FETCH_FUNC(symbol, ftype),                      \
-ASSIGN_FETCH_FUNC(deref, ftype),                       \
-ASSIGN_FETCH_FUNC(bitfield, ftype),                    \
-         }                                             \
-       }
-
-#define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                  \
-       __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
-
-#define FETCH_TYPE_STRING 0
-#define FETCH_TYPE_STRSIZE 1
-
-/* Fetch type information table */
-static const struct fetch_type {
-       const char      *name;          /* Name of type */
-       size_t          size;           /* Byte size of type */
-       int             is_signed;      /* Signed flag */
-       print_type_func_t       print;  /* Print functions */
-       const char      *fmt;           /* Fromat string */
-       const char      *fmttype;       /* Name in format file */
-       /* Fetch functions */
-       fetch_func_t    fetch[FETCH_MTD_END];
-} fetch_type_table[] = {
-       /* Special types */
-       [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
-                                       sizeof(u32), 1, "__data_loc char[]"),
-       [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
-                                       string_size, sizeof(u32), 0, "u32"),
-       /* Basic types */
-       ASSIGN_FETCH_TYPE(u8,  u8,  0),
-       ASSIGN_FETCH_TYPE(u16, u16, 0),
-       ASSIGN_FETCH_TYPE(u32, u32, 0),
-       ASSIGN_FETCH_TYPE(u64, u64, 0),
-       ASSIGN_FETCH_TYPE(s8,  u8,  1),
-       ASSIGN_FETCH_TYPE(s16, u16, 1),
-       ASSIGN_FETCH_TYPE(s32, u32, 1),
-       ASSIGN_FETCH_TYPE(s64, u64, 1),
-};
-
-static const struct fetch_type *find_fetch_type(const char *type)
-{
-       int i;
-
-       if (!type)
-               type = DEFAULT_FETCH_TYPE_STR;
-
-       /* Special case: bitfield */
-       if (*type == 'b') {
-               unsigned long bs;
-               type = strchr(type, '/');
-               if (!type)
-                       goto fail;
-               type++;
-               if (strict_strtoul(type, 0, &bs))
-                       goto fail;
-               switch (bs) {
-               case 8:
-                       return find_fetch_type("u8");
-               case 16:
-                       return find_fetch_type("u16");
-               case 32:
-                       return find_fetch_type("u32");
-               case 64:
-                       return find_fetch_type("u64");
-               default:
-                       goto fail;
-               }
-       }
-
-       for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
-               if (strcmp(type, fetch_type_table[i].name) == 0)
-                       return &fetch_type_table[i];
-fail:
-       return NULL;
-}
-
-/* Special function : only accept unsigned long */
-static __kprobes void fetch_stack_address(struct pt_regs *regs,
-                                         void *dummy, void *dest)
-{
-       *(unsigned long *)dest = kernel_stack_pointer(regs);
-}
-
-static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
-                                           fetch_func_t orig_fn)
-{
-       int i;
-
-       if (type != &fetch_type_table[FETCH_TYPE_STRING])
-               return NULL;    /* Only string type needs size function */
-       for (i = 0; i < FETCH_MTD_END; i++)
-               if (type->fetch[i] == orig_fn)
-                       return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
-
-       WARN_ON(1);     /* This should not happen */
-       return NULL;
-}
+#define KPROBE_EVENT_SYSTEM "kprobes"
 
 /**
  * Kprobe event core functions
  */
 
-struct probe_arg {
-       struct fetch_param      fetch;
-       struct fetch_param      fetch_size;
-       unsigned int            offset; /* Offset from argument entry */
-       const char              *name;  /* Name of this argument */
-       const char              *comm;  /* Command of this argument */
-       const struct fetch_type *type;  /* Type of this argument */
-};
-
-/* Flags for trace_probe */
-#define TP_FLAG_TRACE  1
-#define TP_FLAG_PROFILE        2
-#define TP_FLAG_REGISTERED 4
-
 struct trace_probe {
        struct list_head        list;
        struct kretprobe        rp;     /* Use rp.kp for kprobe use */
@@ -631,18 +99,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
                                struct pt_regs *regs);
 
-/* Check the name is good for event/group/fields */
-static int is_good_name(const char *name)
-{
-       if (!isalpha(*name) && *name != '_')
-               return 0;
-       while (*++name != '\0') {
-               if (!isalpha(*name) && !isdigit(*name) && *name != '_')
-                       return 0;
-       }
-       return 1;
-}
-
 /*
  * Allocate new trace_probe and initialize it (including kprobes).
  */
@@ -702,34 +158,12 @@ error:
        return ERR_PTR(ret);
 }
 
-static void update_probe_arg(struct probe_arg *arg)
-{
-       if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
-               update_bitfield_fetch_param(arg->fetch.data);
-       else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
-               update_deref_fetch_param(arg->fetch.data);
-       else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
-               update_symbol_cache(arg->fetch.data);
-}
-
-static void free_probe_arg(struct probe_arg *arg)
-{
-       if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
-               free_bitfield_fetch_param(arg->fetch.data);
-       else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
-               free_deref_fetch_param(arg->fetch.data);
-       else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
-               free_symbol_cache(arg->fetch.data);
-       kfree(arg->name);
-       kfree(arg->comm);
-}
-
 static void free_trace_probe(struct trace_probe *tp)
 {
        int i;
 
        for (i = 0; i < tp->nr_args; i++)
-               free_probe_arg(&tp->args[i]);
+               traceprobe_free_probe_arg(&tp->args[i]);
 
        kfree(tp->call.class->system);
        kfree(tp->call.name);
@@ -787,7 +221,7 @@ static int __register_trace_probe(struct trace_probe *tp)
                return -EINVAL;
 
        for (i = 0; i < tp->nr_args; i++)
-               update_probe_arg(&tp->args[i]);
+               traceprobe_update_arg(&tp->args[i]);
 
        /* Set/clear disabled flag according to tp->flag */
        if (trace_probe_is_enabled(tp))
@@ -919,227 +353,6 @@ static struct notifier_block trace_probe_module_nb = {
        .priority = 1   /* Invoked after kprobe module callback */
 };
 
-/* Split symbol and offset. */
-static int split_symbol_offset(char *symbol, unsigned long *offset)
-{
-       char *tmp;
-       int ret;
-
-       if (!offset)
-               return -EINVAL;
-
-       tmp = strchr(symbol, '+');
-       if (tmp) {
-               /* skip sign because strict_strtol doesn't accept '+' */
-               ret = strict_strtoul(tmp + 1, 0, offset);
-               if (ret)
-                       return ret;
-               *tmp = '\0';
-       } else
-               *offset = 0;
-       return 0;
-}
-
-#define PARAM_MAX_ARGS 16
-#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
-
-static int parse_probe_vars(char *arg, const struct fetch_type *t,
-                           struct fetch_param *f, bool is_return)
-{
-       int ret = 0;
-       unsigned long param;
-
-       if (strcmp(arg, "retval") == 0) {
-               if (is_return)
-                       f->fn = t->fetch[FETCH_MTD_retval];
-               else
-                       ret = -EINVAL;
-       } else if (strncmp(arg, "stack", 5) == 0) {
-               if (arg[5] == '\0') {
-                       if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
-                               f->fn = fetch_stack_address;
-                       else
-                               ret = -EINVAL;
-               } else if (isdigit(arg[5])) {
-                       ret = strict_strtoul(arg + 5, 10, &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 @@ partial:
        return TRACE_TYPE_PARTIAL_LINE;
 }
 
-#undef DEFINE_FIELD
-#define DEFINE_FIELD(type, item, name, is_signed)                      \
-       do {                                                            \
-               ret = trace_define_field(event_call, #type, name,       \
-                                        offsetof(typeof(field), item), \
-                                        sizeof(field.item), is_signed, \
-                                        FILTER_OTHER);                 \
-               if (ret)                                                \
-                       return ret;                                     \
-       } while (0)
 
 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
 {
@@ -2051,8 +1197,9 @@ static __init int kprobe_trace_self_tests_init(void)
 
        pr_info("Testing kprobe tracing: ");
 
-       ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
-                                 "$stack $stack0 +0($stack)");
+       ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
+                                 "$stack $stack0 +0($stack)",
+                                 create_trace_probe);
        if (WARN_ON_ONCE(ret)) {
                pr_warning("error on probing function entry.\n");
                warn++;
@@ -2066,8 +1213,8 @@ static __init int kprobe_trace_self_tests_init(void)
                        enable_trace_probe(tp, TP_FLAG_TRACE);
        }
 
-       ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
-                                 "$retval");
+       ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
+                                 "$retval", create_trace_probe);
        if (WARN_ON_ONCE(ret)) {
                pr_warning("error on probing function return.\n");
                warn++;
@@ -2101,13 +1248,13 @@ static __init int kprobe_trace_self_tests_init(void)
        } else
                disable_trace_probe(tp, TP_FLAG_TRACE);
 
-       ret = command_trace_probe("-:testprobe");
+       ret = traceprobe_command("-:testprobe", create_trace_probe);
        if (WARN_ON_ONCE(ret)) {
                pr_warning("error on deleting a probe.\n");
                warn++;
        }
 
-       ret = command_trace_probe("-:testprobe2");
+       ret = traceprobe_command("-:testprobe2", create_trace_probe);
        if (WARN_ON_ONCE(ret)) {
                pr_warning("error on deleting a probe.\n");
                warn++;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
new file mode 100644 (file)
index 0000000..8e526b9
--- /dev/null
@@ -0,0 +1,833 @@
+/*
+ * Common code for probe-based Dynamic events.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This code was copied from kernel/trace/trace_kprobe.c written by
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Updates to make this generic:
+ * Copyright (C) IBM Corporation, 2010-2011
+ * Author:     Srikar Dronamraju
+ */
+
+#include "trace_probe.h"
+
+const char *reserved_field_names[] = {
+       "common_type",
+       "common_flags",
+       "common_preempt_count",
+       "common_pid",
+       "common_tgid",
+       FIELD_STRING_IP,
+       FIELD_STRING_RETIP,
+       FIELD_STRING_FUNC,
+};
+
+/* Printing function type */
+#define PRINT_TYPE_FUNC_NAME(type)     print_type_##type
+#define PRINT_TYPE_FMT_NAME(type)      print_type_format_##type
+
+/* Printing  in basic type function template */
+#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast)                  \
+static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,   \
+                                               const char *name,       \
+                                               void *data, void *ent)\
+{                                                                      \
+       return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
+}                                                                      \
+static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
+
+DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
+
+static inline void *get_rloc_data(u32 *dl)
+{
+       return (u8 *)dl + get_rloc_offs(*dl);
+}
+
+/* For data_loc conversion */
+static inline void *get_loc_data(u32 *dl, void *ent)
+{
+       return (u8 *)ent + get_rloc_offs(*dl);
+}
+
+/* For defining macros, define string/string_size types */
+typedef u32 string;
+typedef u32 string_size;
+
+/* Print type function for string type */
+static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
+                                                 const char *name,
+                                                 void *data, void *ent)
+{
+       int len = *(u32 *)data >> 16;
+
+       if (!len)
+               return trace_seq_printf(s, " %s=(fault)", name);
+       else
+               return trace_seq_printf(s, " %s=\"%s\"", name,
+                                       (const char *)get_loc_data(data, ent));
+}
+
+static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
+
+#define FETCH_FUNC_NAME(method, type)  fetch_##method##_##type
+/*
+ * Define macro for basic types - we don't need to define s* types, because
+ * we have to care only about bitwidth at recording time.
+ */
+#define DEFINE_BASIC_FETCH_FUNCS(method) \
+DEFINE_FETCH_##method(u8)              \
+DEFINE_FETCH_##method(u16)             \
+DEFINE_FETCH_##method(u32)             \
+DEFINE_FETCH_##method(u64)
+
+#define CHECK_FETCH_FUNCS(method, fn)                  \
+       (((FETCH_FUNC_NAME(method, u8) == fn) ||        \
+         (FETCH_FUNC_NAME(method, u16) == fn) ||       \
+         (FETCH_FUNC_NAME(method, u32) == fn) ||       \
+         (FETCH_FUNC_NAME(method, u64) == fn) ||       \
+         (FETCH_FUNC_NAME(method, string) == fn) ||    \
+         (FETCH_FUNC_NAME(method, string_size) == fn)) \
+        && (fn != NULL))
+
+/* Data fetch function templates */
+#define DEFINE_FETCH_reg(type)                                         \
+static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
+                                       void *offset, void *dest)       \
+{                                                                      \
+       *(type *)dest = (type)regs_get_register(regs,                   \
+                               (unsigned int)((unsigned long)offset)); \
+}
+DEFINE_BASIC_FETCH_FUNCS(reg)
+/* No string on the register */
+#define fetch_reg_string       NULL
+#define fetch_reg_string_size  NULL
+
+#define DEFINE_FETCH_stack(type)                                       \
+static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
+                                         void *offset, void *dest)     \
+{                                                                      \
+       *(type *)dest = (type)regs_get_kernel_stack_nth(regs,           \
+                               (unsigned int)((unsigned long)offset)); \
+}
+DEFINE_BASIC_FETCH_FUNCS(stack)
+/* No string on the stack entry */
+#define fetch_stack_string     NULL
+#define fetch_stack_string_size        NULL
+
+#define DEFINE_FETCH_retval(type)                                      \
+static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
+                                         void *dummy, void *dest)      \
+{                                                                      \
+       *(type *)dest = (type)regs_return_value(regs);                  \
+}
+DEFINE_BASIC_FETCH_FUNCS(retval)
+/* No string on the retval */
+#define fetch_retval_string            NULL
+#define fetch_retval_string_size       NULL
+
+#define DEFINE_FETCH_memory(type)                                      \
+static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
+                                         void *addr, void *dest)       \
+{                                                                      \
+       type retval;                                                    \
+       if (probe_kernel_address(addr, retval))                         \
+               *(type *)dest = 0;                                      \
+       else                                                            \
+               *(type *)dest = retval;                                 \
+}
+DEFINE_BASIC_FETCH_FUNCS(memory)
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
+ * length and relative data location.
+ */
+static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
+                                                     void *addr, void *dest)
+{
+       long ret;
+       int maxlen = get_rloc_len(*(u32 *)dest);
+       u8 *dst = get_rloc_data(dest);
+       u8 *src = addr;
+       mm_segment_t old_fs = get_fs();
+
+       if (!maxlen)
+               return;
+
+       /*
+        * Try to get string again, since the string can be changed while
+        * probing.
+        */
+       set_fs(KERNEL_DS);
+       pagefault_disable();
+
+       do
+               ret = __copy_from_user_inatomic(dst++, src++, 1);
+       while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
+
+       dst[-1] = '\0';
+       pagefault_enable();
+       set_fs(old_fs);
+
+       if (ret < 0) {  /* Failed to fetch string */
+               ((u8 *)get_rloc_data(dest))[0] = '\0';
+               *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
+       } else {
+               *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
+                                             get_rloc_offs(*(u32 *)dest));
+       }
+}
+
+/* Return the length of string -- including null terminal byte */
+static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
+                                                       void *addr, void *dest)
+{
+       mm_segment_t old_fs;
+       int ret, len = 0;
+       u8 c;
+
+       old_fs = get_fs();
+       set_fs(KERNEL_DS);
+       pagefault_disable();
+
+       do {
+               ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+               len++;
+       } while (c && ret == 0 && len < MAX_STRING_SIZE);
+
+       pagefault_enable();
+       set_fs(old_fs);
+
+       if (ret < 0)    /* Failed to check the length */
+               *(u32 *)dest = 0;
+       else
+               *(u32 *)dest = len;
+}
+
+/* Memory fetching by symbol */
+struct symbol_cache {
+       char            *symbol;
+       long            offset;
+       unsigned long   addr;
+};
+
+static unsigned long update_symbol_cache(struct symbol_cache *sc)
+{
+       sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
+
+       if (sc->addr)
+               sc->addr += sc->offset;
+
+       return sc->addr;
+}
+
+static void free_symbol_cache(struct symbol_cache *sc)
+{
+       kfree(sc->symbol);
+       kfree(sc);
+}
+
+static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
+{
+       struct symbol_cache *sc;
+
+       if (!sym || strlen(sym) == 0)
+               return NULL;
+
+       sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
+       if (!sc)
+               return NULL;
+
+       sc->symbol = kstrdup(sym, GFP_KERNEL);
+       if (!sc->symbol) {
+               kfree(sc);
+               return NULL;
+       }
+       sc->offset = offset;
+       update_symbol_cache(sc);
+
+       return sc;
+}
+
+#define DEFINE_FETCH_symbol(type)                                      \
+static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
+                                         void *data, void *dest)       \
+{                                                                      \
+       struct symbol_cache *sc = data;                                 \
+       if (sc->addr)                                                   \
+               fetch_memory_##type(regs, (void *)sc->addr, dest);      \
+       else                                                            \
+               *(type *)dest = 0;                                      \
+}
+DEFINE_BASIC_FETCH_FUNCS(symbol)
+DEFINE_FETCH_symbol(string)
+DEFINE_FETCH_symbol(string_size)
+
+/* Dereference memory access function */
+struct deref_fetch_param {
+       struct fetch_param      orig;
+       long                    offset;
+};
+
+#define DEFINE_FETCH_deref(type)                                       \
+static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
+                                           void *data, void *dest)     \
+{                                                                      \
+       struct deref_fetch_param *dprm = data;                          \
+       unsigned long addr;                                             \
+       call_fetch(&dprm->orig, regs, &addr);                           \
+       if (addr) {                                                     \
+               addr += dprm->offset;                                   \
+               fetch_memory_##type(regs, (void *)addr, dest);          \
+       } else                                                          \
+               *(type *)dest = 0;                                      \
+}
+DEFINE_BASIC_FETCH_FUNCS(deref)
+DEFINE_FETCH_deref(string)
+DEFINE_FETCH_deref(string_size)
+
+static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
+{
+       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+               update_deref_fetch_param(data->orig.data);
+       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+               update_symbol_cache(data->orig.data);
+}
+
+static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
+{
+       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+               free_deref_fetch_param(data->orig.data);
+       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+               free_symbol_cache(data->orig.data);
+       kfree(data);
+}
+
+/* Bitfield fetch function */
+struct bitfield_fetch_param {
+       struct fetch_param      orig;
+       unsigned char           hi_shift;
+       unsigned char           low_shift;
+};
+
+#define DEFINE_FETCH_bitfield(type)                                    \
+static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
+                                           void *data, void *dest)     \
+{                                                                      \
+       struct bitfield_fetch_param *bprm = data;                       \
+       type buf = 0;                                                   \
+       call_fetch(&bprm->orig, regs, &buf);                            \
+       if (buf) {                                                      \
+               buf <<= bprm->hi_shift;                                 \
+               buf >>= bprm->low_shift;                                \
+       }                                                               \
+       *(type *)dest = buf;                                            \
+}
+
+DEFINE_BASIC_FETCH_FUNCS(bitfield)
+#define fetch_bitfield_string          NULL
+#define fetch_bitfield_string_size     NULL
+
+static __kprobes void
+update_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+       /*
+        * Don't check the bitfield itself, because this must be the
+        * last fetch function.
+        */
+       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+               update_deref_fetch_param(data->orig.data);
+       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+               update_symbol_cache(data->orig.data);
+}
+
+static __kprobes void
+free_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+       /*
+        * Don't check the bitfield itself, because this must be the
+        * last fetch function.
+        */
+       if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+               free_deref_fetch_param(data->orig.data);
+       else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+               free_symbol_cache(data->orig.data);
+
+       kfree(data);
+}
+
+/* Default (unsigned long) fetch type */
+#define __DEFAULT_FETCH_TYPE(t) u##t
+#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
+#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
+#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
+
+#define ASSIGN_FETCH_FUNC(method, type)        \
+       [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
+
+#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)        \
+       {.name = _name,                         \
+        .size = _size,                                 \
+        .is_signed = sign,                             \
+        .print = PRINT_TYPE_FUNC_NAME(ptype),          \
+        .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
+        .fmttype = _fmttype,                           \
+        .fetch = {                                     \
+ASSIGN_FETCH_FUNC(reg, ftype),                         \
+ASSIGN_FETCH_FUNC(stack, ftype),                       \
+ASSIGN_FETCH_FUNC(retval, ftype),                      \
+ASSIGN_FETCH_FUNC(memory, ftype),                      \
+ASSIGN_FETCH_FUNC(symbol, ftype),                      \
+ASSIGN_FETCH_FUNC(deref, ftype),                       \
+ASSIGN_FETCH_FUNC(bitfield, ftype),                    \
+         }                                             \
+       }
+
+#define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                  \
+       __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+
+#define FETCH_TYPE_STRING      0
+#define FETCH_TYPE_STRSIZE     1
+
+/* Fetch type information table */
+static const struct fetch_type fetch_type_table[] = {
+       /* Special types */
+       [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
+                                       sizeof(u32), 1, "__data_loc char[]"),
+       [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
+                                       string_size, sizeof(u32), 0, "u32"),
+       /* Basic types */
+       ASSIGN_FETCH_TYPE(u8,  u8,  0),
+       ASSIGN_FETCH_TYPE(u16, u16, 0),
+       ASSIGN_FETCH_TYPE(u32, u32, 0),
+       ASSIGN_FETCH_TYPE(u64, u64, 0),
+       ASSIGN_FETCH_TYPE(s8,  u8,  1),
+       ASSIGN_FETCH_TYPE(s16, u16, 1),
+       ASSIGN_FETCH_TYPE(s32, u32, 1),
+       ASSIGN_FETCH_TYPE(s64, u64, 1),
+};
+
+static const struct fetch_type *find_fetch_type(const char *type)
+{
+       int i;
+
+       if (!type)
+               type = DEFAULT_FETCH_TYPE_STR;
+
+       /* Special case: bitfield */
+       if (*type == 'b') {
+               unsigned long bs;
+
+               type = strchr(type, '/');
+               if (!type)
+                       goto fail;
+
+               type++;
+               if (strict_strtoul(type, 0, &bs))
+                       goto fail;
+
+               switch (bs) {
+               case 8:
+                       return find_fetch_type("u8");
+               case 16:
+                       return find_fetch_type("u16");
+               case 32:
+                       return find_fetch_type("u32");
+               case 64:
+                       return find_fetch_type("u64");
+               default:
+                       goto fail;
+               }
+       }
+
+       for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
+               if (strcmp(type, fetch_type_table[i].name) == 0)
+                       return &fetch_type_table[i];
+
+fail:
+       return NULL;
+}
+
+/* Special function : only accept unsigned long */
+static __kprobes void fetch_stack_address(struct pt_regs *regs,
+                                       void *dummy, void *dest)
+{
+       *(unsigned long *)dest = kernel_stack_pointer(regs);
+}
+
+static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
+                                       fetch_func_t orig_fn)
+{
+       int i;
+
+       if (type != &fetch_type_table[FETCH_TYPE_STRING])
+               return NULL;    /* Only string type needs size function */
+
+       for (i = 0; i < FETCH_MTD_END; i++)
+               if (type->fetch[i] == orig_fn)
+                       return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
+
+       WARN_ON(1);     /* This should not happen */
+
+       return NULL;
+}
+
+/* Split symbol and offset. */
+int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
+{
+       char *tmp;
+       int ret;
+
+       if (!offset)
+               return -EINVAL;
+
+       tmp = strchr(symbol, '+');
+       if (tmp) {
+               /* skip sign because strict_strtol doesn't accept '+' */
+               ret = strict_strtoul(tmp + 1, 0, offset);
+               if (ret)
+                       return ret;
+
+               *tmp = '\0';
+       } else
+               *offset = 0;
+
+       return 0;
+}
+
+#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
+
+static int parse_probe_vars(char *arg, const struct fetch_type *t,
+                           struct fetch_param *f, bool is_return)
+{
+       int ret = 0;
+       unsigned long param;
+
+       if (strcmp(arg, "retval") == 0) {
+               if (is_return)
+                       f->fn = t->fetch[FETCH_MTD_retval];
+               else
+                       ret = -EINVAL;
+       } else if (strncmp(arg, "stack", 5) == 0) {
+               if (arg[5] == '\0') {
+                       if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
+                               f->fn = fetch_stack_address;
+                       else
+                               ret = -EINVAL;
+               } else if (isdigit(arg[5])) {
+                       ret = strict_strtoul(arg + 5, 10, &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  4096
+
+ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
+                               size_t count, loff_t *ppos,
+                               int (*createfn)(int, char **))
+{
+       char *kbuf, *tmp;
+       int ret = 0;
+       size_t done = 0;
+       size_t size;
+
+       kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
+       if (!kbuf)
+               return -ENOMEM;
+
+       while (done < count) {
+               size = count - done;
+
+               if (size >= WRITE_BUFSIZE)
+                       size = WRITE_BUFSIZE - 1;
+
+               if (copy_from_user(kbuf, buffer + done, size)) {
+                       ret = -EFAULT;
+                       goto out;
+               }
+               kbuf[size] = '\0';
+               tmp = strchr(kbuf, '\n');
+
+               if (tmp) {
+                       *tmp = '\0';
+                       size = tmp - kbuf + 1;
+               } else if (done + size < count) {
+                       pr_warning("Line length is too long: "
+                                  "Should be less than %d.", WRITE_BUFSIZE);
+                       ret = -EINVAL;
+                       goto out;
+               }
+               done += size;
+               /* Remove comments */
+               tmp = strchr(kbuf, '#');
+
+               if (tmp)
+                       *tmp = '\0';
+
+               ret = traceprobe_command(kbuf, createfn);
+               if (ret)
+                       goto out;
+       }
+       ret = done;
+
+out:
+       kfree(kbuf);
+
+       return ret;
+}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
new file mode 100644 (file)
index 0000000..2df9a18
--- /dev/null
@@ -0,0 +1,160 @@
+/*
+ * Common header file for probe-based Dynamic events.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This code was copied from kernel/trace/trace_kprobe.h written by
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Updates to make this generic:
+ * Copyright (C) IBM Corporation, 2010-2011
+ * Author:     Srikar Dronamraju
+ */
+
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/debugfs.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/ptrace.h>
+#include <linux/perf_event.h>
+#include <linux/kprobes.h>
+#include <linux/stringify.h>
+#include <linux/limits.h>
+#include <linux/uaccess.h>
+#include <asm/bitsperlong.h>
+
+#include "trace.h"
+#include "trace_output.h"
+
+#define MAX_TRACE_ARGS         128
+#define MAX_ARGSTR_LEN         63
+#define MAX_EVENT_NAME_LEN     64
+#define MAX_STRING_SIZE                PATH_MAX
+
+/* Reserved field names */
+#define FIELD_STRING_IP                "__probe_ip"
+#define FIELD_STRING_RETIP     "__probe_ret_ip"
+#define FIELD_STRING_FUNC      "__probe_func"
+
+#undef DEFINE_FIELD
+#define DEFINE_FIELD(type, item, name, is_signed)                      \
+       do {                                                            \
+               ret = trace_define_field(event_call, #type, name,       \
+                                        offsetof(typeof(field), item), \
+                                        sizeof(field.item), is_signed, \
+                                        FILTER_OTHER);                 \
+               if (ret)                                                \
+                       return ret;                                     \
+       } while (0)
+
+
+/* Flags for trace_probe */
+#define TP_FLAG_TRACE          1
+#define TP_FLAG_PROFILE                2
+#define TP_FLAG_REGISTERED     4
+
+
+/* data_rloc: data relative location, compatible with u32 */
+#define make_data_rloc(len, roffs)     \
+       (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
+#define get_rloc_len(dl)               ((u32)(dl) >> 16)
+#define get_rloc_offs(dl)              ((u32)(dl) & 0xffff)
+
+/*
+ * Convert data_rloc to data_loc:
+ *  data_rloc stores the offset from data_rloc itself, but data_loc
+ *  stores the offset from event entry.
+ */
+#define convert_rloc_to_loc(dl, offs)  ((u32)(dl) + (offs))
+
+/* Data fetch function type */
+typedef        void (*fetch_func_t)(struct pt_regs *, void *, void *);
+/* Printing function type */
+typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
+
+/* Fetch types */
+enum {
+       FETCH_MTD_reg = 0,
+       FETCH_MTD_stack,
+       FETCH_MTD_retval,
+       FETCH_MTD_memory,
+       FETCH_MTD_symbol,
+       FETCH_MTD_deref,
+       FETCH_MTD_bitfield,
+       FETCH_MTD_END,
+};
+
+/* Fetch type information table */
+struct fetch_type {
+       const char              *name;          /* Name of type */
+       size_t                  size;           /* Byte size of type */
+       int                     is_signed;      /* Signed flag */
+       print_type_func_t       print;          /* Print functions */
+       const char              *fmt;           /* Fromat string */
+       const char              *fmttype;       /* Name in format file */
+       /* Fetch functions */
+       fetch_func_t            fetch[FETCH_MTD_END];
+};
+
+struct fetch_param {
+       fetch_func_t            fn;
+       void                    *data;
+};
+
+struct probe_arg {
+       struct fetch_param      fetch;
+       struct fetch_param      fetch_size;
+       unsigned int            offset; /* Offset from argument entry */
+       const char              *name;  /* Name of this argument */
+       const char              *comm;  /* Command of this argument */
+       const struct fetch_type *type;  /* Type of this argument */
+};
+
+static inline __kprobes void call_fetch(struct fetch_param *fprm,
+                                struct pt_regs *regs, void *dest)
+{
+       return fprm->fn(regs, fprm->data, dest);
+}
+
+/* Check the name is good for event/group/fields */
+static inline int is_good_name(const char *name)
+{
+       if (!isalpha(*name) && *name != '_')
+               return 0;
+       while (*++name != '\0') {
+               if (!isalpha(*name) && !isdigit(*name) && *name != '_')
+                       return 0;
+       }
+       return 1;
+}
+
+extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
+                  struct probe_arg *parg, bool is_return);
+
+extern int traceprobe_conflict_field_name(const char *name,
+                              struct probe_arg *args, int narg);
+
+extern void traceprobe_update_arg(struct probe_arg *arg);
+extern void traceprobe_free_probe_arg(struct probe_arg *arg);
+
+extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
+
+extern ssize_t traceprobe_probes_write(struct file *file,
+               const char __user *buffer, size_t count, loff_t *ppos,
+               int (*createfn)(int, char**));
+
+extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));