tracing/kprobes: Support basic types on dynamic events
authorMasami Hiramatsu <mhiramat@redhat.com>
Mon, 12 Apr 2010 17:17:08 +0000 (13:17 -0400)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 14 Apr 2010 20:26:28 +0000 (17:26 -0300)
Support basic types of integer (u8, u16, u32, u64, s8, s16, s32, s64) in
kprobe tracer. With this patch, users can specify above basic types on
each arguments after ':'. If omitted, the argument type is set as
unsigned long (u32 or u64, arch-dependent).

 e.g.
  echo 'p account_system_time+0 hardirq_offset=%si:s32' > kprobe_events

  adds a probe recording hardirq_offset in signed-32bits value on the
  entry of account_system_time.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100412171708.3790.18599.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Documentation/trace/kprobetrace.txt
kernel/trace/trace.h
kernel/trace/trace_kprobe.c

index a9100b28eb844da1974dd24dcaa2a320887eddda..ec94748ae65bf1c55c1359c5c9d71aac714b2e5e 100644 (file)
@@ -40,7 +40,9 @@ Synopsis of kprobe_events
   $stack       : Fetch stack address.
   $retval      : Fetch return value.(*)
   +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
-  NAME=FETCHARG: Set NAME as the argument name of FETCHARG.
+  NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
+  FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
+                 (u8/u16/u32/u64/s8/s16/s32/s64) are supported.
 
   (*) only for return probe.
   (**) this is useful for fetching a field of data structures.
index bec2c973ff0c91ff3e8bbac336a749463096e5ab..3ebdb6bd2362a68e9121c1d0aeb5acb31229fa60 100644 (file)
@@ -102,29 +102,17 @@ struct syscall_trace_exit {
        long                    ret;
 };
 
-struct kprobe_trace_entry {
+struct kprobe_trace_entry_head {
        struct trace_entry      ent;
        unsigned long           ip;
-       int                     nargs;
-       unsigned long           args[];
 };
 
-#define SIZEOF_KPROBE_TRACE_ENTRY(n)                   \
-       (offsetof(struct kprobe_trace_entry, args) +    \
-       (sizeof(unsigned long) * (n)))
-
-struct kretprobe_trace_entry {
+struct kretprobe_trace_entry_head {
        struct trace_entry      ent;
        unsigned long           func;
        unsigned long           ret_ip;
-       int                     nargs;
-       unsigned long           args[];
 };
 
-#define SIZEOF_KRETPROBE_TRACE_ENTRY(n)                        \
-       (offsetof(struct kretprobe_trace_entry, args) + \
-       (sizeof(unsigned long) * (n)))
-
 /*
  * trace_flag_type is an enumeration that holds different
  * states when a trace occurs. These are:
index 1251e367bae9efe6a0e460861abecb4049296b5a..a7514326052b658b88e69029a7754e197b7c2f56 100644 (file)
@@ -29,6 +29,8 @@
 #include <linux/ctype.h>
 #include <linux/ptrace.h>
 #include <linux/perf_event.h>
+#include <linux/stringify.h>
+#include <asm/bitsperlong.h>
 
 #include "trace.h"
 #include "trace_output.h"
@@ -40,7 +42,6 @@
 
 /* Reserved field names */
 #define FIELD_STRING_IP "__probe_ip"
-#define FIELD_STRING_NARGS "__probe_nargs"
 #define FIELD_STRING_RETIP "__probe_ret_ip"
 #define FIELD_STRING_FUNC "__probe_func"
 
@@ -52,56 +53,102 @@ const char *reserved_field_names[] = {
        "common_tgid",
        "common_lock_depth",
        FIELD_STRING_IP,
-       FIELD_STRING_NARGS,
        FIELD_STRING_RETIP,
        FIELD_STRING_FUNC,
 };
 
-struct fetch_func {
-       unsigned long (*func)(struct pt_regs *, void *);
+/* Printing function type */
+typedef int (*print_type_func_t)(struct trace_seq *, const char *, 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)\
+{                                                                      \
+       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 fetch function type */
+typedef        void (*fetch_func_t)(struct pt_regs *, void *, void *);
+
+struct fetch_param {
+       fetch_func_t    fn;
        void *data;
 };
 
-static __kprobes unsigned long call_fetch(struct fetch_func *f,
-                                         struct pt_regs *regs)
+static __kprobes void call_fetch(struct fetch_param *fprm,
+                                struct pt_regs *regs, void *dest)
 {
-       return f->func(regs, f->data);
+       return fprm->fn(regs, fprm->data, dest);
 }
 
-/* fetch handlers */
-static __kprobes unsigned long fetch_register(struct pt_regs *regs,
-                                             void *offset)
-{
-       return regs_get_register(regs, (unsigned int)((unsigned long)offset));
+#define FETCH_FUNC_NAME(kind, type)    fetch_##kind##_##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(kind)  \
+DEFINE_FETCH_##kind(u8)                        \
+DEFINE_FETCH_##kind(u16)               \
+DEFINE_FETCH_##kind(u32)               \
+DEFINE_FETCH_##kind(u64)
+
+#define CHECK_BASIC_FETCH_FUNCS(kind, fn)      \
+       ((FETCH_FUNC_NAME(kind, u8) == fn) ||   \
+        (FETCH_FUNC_NAME(kind, u16) == fn) ||  \
+        (FETCH_FUNC_NAME(kind, u32) == fn) ||  \
+        (FETCH_FUNC_NAME(kind, u64) == fn))
+
+/* 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)); \
 }
-
-static __kprobes unsigned long fetch_stack(struct pt_regs *regs,
-                                          void *num)
-{
-       return regs_get_kernel_stack_nth(regs,
-                                        (unsigned int)((unsigned long)num));
+DEFINE_BASIC_FETCH_FUNCS(reg)
+
+#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)
 
-static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr)
-{
-       unsigned long retval;
-
-       if (probe_kernel_address(addr, retval))
-               return 0;
-       return retval;
+#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);                  \
 }
-
-static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
-                                             void *dummy)
-{
-       return regs_return_value(regs);
-}
-
-static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
-                                                  void *dummy)
-{
-       return kernel_stack_pointer(regs);
+DEFINE_BASIC_FETCH_FUNCS(retval)
+
+#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)
 
 /* Memory fetching by symbol */
 struct symbol_cache {
@@ -145,51 +192,126 @@ static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
        return sc;
 }
 
-static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
-{
-       struct symbol_cache *sc = data;
-
-       if (sc->addr)
-               return fetch_memory(regs, (void *)sc->addr);
-       else
-               return 0;
+#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)
 
-/* Special indirect memory access interface */
-struct indirect_fetch_data {
-       struct fetch_func orig;
+/* Dereference memory access function */
+struct deref_fetch_param {
+       struct fetch_param orig;
        long offset;
 };
 
-static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
-{
-       struct indirect_fetch_data *ind = data;
-       unsigned long addr;
-
-       addr = call_fetch(&ind->orig, regs);
-       if (addr) {
-               addr += ind->offset;
-               return fetch_memory(regs, (void *)addr);
-       } else
-               return 0;
+#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)
 
-static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
+static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
 {
-       if (data->orig.func == fetch_indirect)
-               free_indirect_fetch_data(data->orig.data);
-       else if (data->orig.func == fetch_symbol)
+       if (CHECK_BASIC_FETCH_FUNCS(deref, data->orig.fn))
+               free_deref_fetch_param(data->orig.data);
+       else if (CHECK_BASIC_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(kind, type)  \
+       .kind = FETCH_FUNC_NAME(kind, type)
+
+#define ASSIGN_FETCH_TYPE(ptype, ftype, sign)  \
+       {.name = #ptype,                        \
+        .size = sizeof(ftype),                 \
+        .is_signed = sign,                     \
+        .print = PRINT_TYPE_FUNC_NAME(ptype),  \
+        .fmt = PRINT_TYPE_FMT_NAME(ptype),     \
+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),               \
+       }
+
+/* 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 */
+       /* Fetch functions */
+       fetch_func_t    reg;
+       fetch_func_t    stack;
+       fetch_func_t    retval;
+       fetch_func_t    memory;
+       fetch_func_t    symbol;
+       fetch_func_t    deref;
+} fetch_type_table[] = {
+       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;
+
+       for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
+               if (strcmp(type, fetch_type_table[i].name) == 0)
+                       return &fetch_type_table[i];
+       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);
+}
+
 /**
  * Kprobe event core functions
  */
 
 struct probe_arg {
-       struct fetch_func       fetch;
-       const char              *name;
+       struct fetch_param      fetch;
+       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 */
@@ -204,6 +326,7 @@ struct trace_probe {
        const char              *symbol;        /* symbol name */
        struct ftrace_event_call        call;
        struct trace_event              event;
+       ssize_t                 size;           /* trace entry size */
        unsigned int            nr_args;
        struct probe_arg        args[];
 };
@@ -212,6 +335,7 @@ struct trace_probe {
        (offsetof(struct trace_probe, args) +   \
        (sizeof(struct probe_arg) * (n)))
 
+
 static __kprobes int probe_is_return(struct trace_probe *tp)
 {
        return tp->rp.handler != NULL;
@@ -222,49 +346,6 @@ static __kprobes const char *probe_symbol(struct trace_probe *tp)
        return tp->symbol ? tp->symbol : "unknown";
 }
 
-static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
-{
-       int ret = -EINVAL;
-
-       if (ff->func == fetch_register) {
-               const char *name;
-               name = regs_query_register_name((unsigned int)((long)ff->data));
-               ret = snprintf(buf, n, "%%%s", name);
-       } else if (ff->func == fetch_stack)
-               ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
-       else if (ff->func == fetch_memory)
-               ret = snprintf(buf, n, "@0x%p", ff->data);
-       else if (ff->func == fetch_symbol) {
-               struct symbol_cache *sc = ff->data;
-               if (sc->offset)
-                       ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
-                                       sc->offset);
-               else
-                       ret = snprintf(buf, n, "@%s", sc->symbol);
-       } else if (ff->func == fetch_retvalue)
-               ret = snprintf(buf, n, "$retval");
-       else if (ff->func == fetch_stack_address)
-               ret = snprintf(buf, n, "$stack");
-       else if (ff->func == fetch_indirect) {
-               struct indirect_fetch_data *id = ff->data;
-               size_t l = 0;
-               ret = snprintf(buf, n, "%+ld(", id->offset);
-               if (ret >= n)
-                       goto end;
-               l += ret;
-               ret = probe_arg_string(buf + l, n - l, &id->orig);
-               if (ret < 0)
-                       goto end;
-               l += ret;
-               ret = snprintf(buf + l, n - l, ")");
-               ret += l;
-       }
-end:
-       if (ret >= n)
-               return -ENOSPC;
-       return ret;
-}
-
 static int register_probe_event(struct trace_probe *tp);
 static void unregister_probe_event(struct trace_probe *tp);
 
@@ -347,11 +428,12 @@ error:
 
 static void free_probe_arg(struct probe_arg *arg)
 {
-       if (arg->fetch.func == fetch_symbol)
+       if (CHECK_BASIC_FETCH_FUNCS(deref, arg->fetch.fn))
+               free_deref_fetch_param(arg->fetch.data);
+       else if (CHECK_BASIC_FETCH_FUNCS(symbol, arg->fetch.fn))
                free_symbol_cache(arg->fetch.data);
-       else if (arg->fetch.func == fetch_indirect)
-               free_indirect_fetch_data(arg->fetch.data);
        kfree(arg->name);
+       kfree(arg->comm);
 }
 
 static void free_trace_probe(struct trace_probe *tp)
@@ -457,28 +539,30 @@ static int split_symbol_offset(char *symbol, unsigned long *offset)
 #define PARAM_MAX_ARGS 16
 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
 
-static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
+static int parse_probe_vars(char *arg, const struct fetch_type *t,
+                           struct fetch_param *f, int is_return)
 {
        int ret = 0;
        unsigned long param;
 
        if (strcmp(arg, "retval") == 0) {
-               if (is_return) {
-                       ff->func = fetch_retvalue;
-                       ff->data = NULL;
-               } else
+               if (is_return)
+                       f->fn = t->retval;
+               else
                        ret = -EINVAL;
        } else if (strncmp(arg, "stack", 5) == 0) {
                if (arg[5] == '\0') {
-                       ff->func = fetch_stack_address;
-                       ff->data = NULL;
+                       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 {
-                               ff->func = fetch_stack;
-                               ff->data = (void *)param;
+                               f->fn = t->stack;
+                               f->data = (void *)param;
                        }
                } else
                        ret = -EINVAL;
@@ -488,7 +572,8 @@ static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
 }
 
 /* Recursive argument parser */
-static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
+static int __parse_probe_arg(char *arg, const struct fetch_type *t,
+                            struct fetch_param *f, int is_return)
 {
        int ret = 0;
        unsigned long param;
@@ -497,13 +582,13 @@ static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
 
        switch (arg[0]) {
        case '$':
-               ret = parse_probe_vars(arg + 1, ff, is_return);
+               ret = parse_probe_vars(arg + 1, t, f, is_return);
                break;
        case '%':       /* named register */
                ret = regs_query_register_offset(arg + 1);
                if (ret >= 0) {
-                       ff->func = fetch_register;
-                       ff->data = (void *)(unsigned long)ret;
+                       f->fn = t->reg;
+                       f->data = (void *)(unsigned long)ret;
                        ret = 0;
                }
                break;
@@ -512,26 +597,22 @@ static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
                        ret = strict_strtoul(arg + 1, 0, &param);
                        if (ret)
                                break;
-                       ff->func = fetch_memory;
-                       ff->data = (void *)param;
+                       f->fn = t->memory;
+                       f->data = (void *)param;
                } else {
                        ret = split_symbol_offset(arg + 1, &offset);
                        if (ret)
                                break;
-                       ff->data = alloc_symbol_cache(arg + 1, offset);
-                       if (ff->data)
-                               ff->func = fetch_symbol;
-                       else
-                               ret = -EINVAL;
+                       f->data = alloc_symbol_cache(arg + 1, offset);
+                       if (f->data)
+                               f->fn = t->symbol;
                }
                break;
-       case '+':       /* indirect memory */
+       case '+':       /* deref memory */
        case '-':
                tmp = strchr(arg, '(');
-               if (!tmp) {
-                       ret = -EINVAL;
+               if (!tmp)
                        break;
-               }
                *tmp = '\0';
                ret = strict_strtol(arg + 1, 0, &offset);
                if (ret)
@@ -541,38 +622,58 @@ static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
                arg = tmp + 1;
                tmp = strrchr(arg, ')');
                if (tmp) {
-                       struct indirect_fetch_data *id;
+                       struct deref_fetch_param *dprm;
+                       const struct fetch_type *t2 = find_fetch_type(NULL);
                        *tmp = '\0';
-                       id = kzalloc(sizeof(struct indirect_fetch_data),
-                                    GFP_KERNEL);
-                       if (!id)
+                       dprm = kzalloc(sizeof(struct deref_fetch_param),
+                                      GFP_KERNEL);
+                       if (!dprm)
                                return -ENOMEM;
-                       id->offset = offset;
-                       ret = __parse_probe_arg(arg, &id->orig, is_return);
+                       dprm->offset = offset;
+                       ret = __parse_probe_arg(arg, t2, &dprm->orig,
+                                               is_return);
                        if (ret)
-                               kfree(id);
+                               kfree(dprm);
                        else {
-                               ff->func = fetch_indirect;
-                               ff->data = (void *)id;
+                               f->fn = t->deref;
+                               f->data = (void *)dprm;
                        }
-               } else
-                       ret = -EINVAL;
+               }
                break;
-       default:
-               /* TODO: support custom handler */
-               ret = -EINVAL;
        }
+       if (!ret && !f->fn)
+               ret = -EINVAL;
        return ret;
 }
 
 /* String length checking wrapper */
-static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
+static int parse_probe_arg(char *arg, struct trace_probe *tp,
+                          struct probe_arg *parg, int is_return)
 {
+       const char *t;
+
        if (strlen(arg) > MAX_ARGSTR_LEN) {
                pr_info("Argument is too long.: %s\n",  arg);
                return -ENOSPC;
        }
-       return __parse_probe_arg(arg, ff, is_return);
+       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;
+       return __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
 }
 
 /* Return 1 if name is reserved or already used by another argument */
@@ -602,15 +703,18 @@ static int create_trace_probe(int argc, char **argv)
         *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
         *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
         *  %REG        : fetch register REG
-        * Indirect memory fetch:
+        * Dereferencing memory fetch:
         *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
         * Alias name of args:
         *  NAME=FETCHARG : set NAME as alias of FETCHARG.
+        * Type of args:
+        *  FETCHARG:TYPE : use TYPE instead of unsigned long.
         */
        struct trace_probe *tp;
        int i, ret = 0;
        int is_return = 0, is_delete = 0;
-       char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
+       char *symbol = NULL, *event = NULL, *group = NULL;
+       char *arg, *tmp;
        unsigned long offset = 0;
        void *addr = NULL;
        char buf[MAX_EVENT_NAME_LEN];
@@ -723,13 +827,6 @@ static int create_trace_probe(int argc, char **argv)
                else
                        arg = argv[i];
 
-               if (conflict_field_name(argv[i], tp->args, i)) {
-                       pr_info("Argument%d name '%s' conflicts with "
-                               "another field.\n", i, argv[i]);
-                       ret = -EINVAL;
-                       goto error;
-               }
-
                tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
                if (!tp->args[i].name) {
                        pr_info("Failed to allocate argument%d name '%s'.\n",
@@ -737,9 +834,19 @@ static int create_trace_probe(int argc, char **argv)
                        ret = -ENOMEM;
                        goto error;
                }
+               tmp = strchr(tp->args[i].name, ':');
+               if (tmp)
+                       *tmp = '_';     /* convert : to _ */
+
+               if (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;
+                       goto error;
+               }
 
                /* Parse fetch argument */
-               ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
+               ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
                if (ret) {
                        pr_info("Parse error at argument%d. (%d)\n", i, ret);
                        kfree(tp->args[i].name);
@@ -794,8 +901,7 @@ static void probes_seq_stop(struct seq_file *m, void *v)
 static int probes_seq_show(struct seq_file *m, void *v)
 {
        struct trace_probe *tp = v;
-       int i, ret;
-       char buf[MAX_ARGSTR_LEN + 1];
+       int i;
 
        seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
        seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
@@ -807,15 +913,10 @@ static int probes_seq_show(struct seq_file *m, void *v)
        else
                seq_printf(m, " %s", probe_symbol(tp));
 
-       for (i = 0; i < tp->nr_args; i++) {
-               ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
-               if (ret < 0) {
-                       pr_warning("Argument%d decoding error(%d).\n", i, ret);
-                       return ret;
-               }
-               seq_printf(m, " %s=%s", tp->args[i].name, buf);
-       }
+       for (i = 0; i < tp->nr_args; i++)
+               seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
        seq_printf(m, "\n");
+
        return 0;
 }
 
@@ -945,9 +1046,10 @@ static const struct file_operations kprobe_profile_ops = {
 static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
 {
        struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
-       struct kprobe_trace_entry *entry;
+       struct kprobe_trace_entry_head *entry;
        struct ring_buffer_event *event;
        struct ring_buffer *buffer;
+       u8 *data;
        int size, i, pc;
        unsigned long irq_flags;
        struct ftrace_event_call *call = &tp->call;
@@ -957,7 +1059,7 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
        local_save_flags(irq_flags);
        pc = preempt_count();
 
-       size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
+       size = sizeof(*entry) + tp->size;
 
        event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
                                                  irq_flags, pc);
@@ -965,10 +1067,10 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
                return;
 
        entry = ring_buffer_event_data(event);
-       entry->nargs = tp->nr_args;
        entry->ip = (unsigned long)kp->addr;
+       data = (u8 *)&entry[1];
        for (i = 0; i < tp->nr_args; i++)
-               entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+               call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
 
        if (!filter_current_check_discard(buffer, call, entry, event))
                trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -979,9 +1081,10 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
                                          struct pt_regs *regs)
 {
        struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
-       struct kretprobe_trace_entry *entry;
+       struct kretprobe_trace_entry_head *entry;
        struct ring_buffer_event *event;
        struct ring_buffer *buffer;
+       u8 *data;
        int size, i, pc;
        unsigned long irq_flags;
        struct ftrace_event_call *call = &tp->call;
@@ -989,7 +1092,7 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
        local_save_flags(irq_flags);
        pc = preempt_count();
 
-       size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
+       size = sizeof(*entry) + tp->size;
 
        event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
                                                  irq_flags, pc);
@@ -997,11 +1100,11 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
                return;
 
        entry = ring_buffer_event_data(event);
-       entry->nargs = tp->nr_args;
        entry->func = (unsigned long)tp->rp.kp.addr;
        entry->ret_ip = (unsigned long)ri->ret_addr;
+       data = (u8 *)&entry[1];
        for (i = 0; i < tp->nr_args; i++)
-               entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+               call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
 
        if (!filter_current_check_discard(buffer, call, entry, event))
                trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -1011,13 +1114,14 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
 enum print_line_t
 print_kprobe_event(struct trace_iterator *iter, int flags)
 {
-       struct kprobe_trace_entry *field;
+       struct kprobe_trace_entry_head *field;
        struct trace_seq *s = &iter->seq;
        struct trace_event *event;
        struct trace_probe *tp;
+       u8 *data;
        int i;
 
-       field = (struct kprobe_trace_entry *)iter->ent;
+       field = (struct kprobe_trace_entry_head *)iter->ent;
        event = ftrace_find_event(field->ent.type);
        tp = container_of(event, struct trace_probe, event);
 
@@ -1030,9 +1134,10 @@ print_kprobe_event(struct trace_iterator *iter, int flags)
        if (!trace_seq_puts(s, ")"))
                goto partial;
 
-       for (i = 0; i < field->nargs; i++)
-               if (!trace_seq_printf(s, " %s=%lx",
-                                     tp->args[i].name, field->args[i]))
+       data = (u8 *)&field[1];
+       for (i = 0; i < tp->nr_args; i++)
+               if (!tp->args[i].type->print(s, tp->args[i].name,
+                                            data + tp->args[i].offset))
                        goto partial;
 
        if (!trace_seq_puts(s, "\n"))
@@ -1046,13 +1151,14 @@ partial:
 enum print_line_t
 print_kretprobe_event(struct trace_iterator *iter, int flags)
 {
-       struct kretprobe_trace_entry *field;
+       struct kretprobe_trace_entry_head *field;
        struct trace_seq *s = &iter->seq;
        struct trace_event *event;
        struct trace_probe *tp;
+       u8 *data;
        int i;
 
-       field = (struct kretprobe_trace_entry *)iter->ent;
+       field = (struct kretprobe_trace_entry_head *)iter->ent;
        event = ftrace_find_event(field->ent.type);
        tp = container_of(event, struct trace_probe, event);
 
@@ -1071,9 +1177,10 @@ print_kretprobe_event(struct trace_iterator *iter, int flags)
        if (!trace_seq_puts(s, ")"))
                goto partial;
 
-       for (i = 0; i < field->nargs; i++)
-               if (!trace_seq_printf(s, " %s=%lx",
-                                     tp->args[i].name, field->args[i]))
+       data = (u8 *)&field[1];
+       for (i = 0; i < tp->nr_args; i++)
+               if (!tp->args[i].type->print(s, tp->args[i].name,
+                                            data + tp->args[i].offset))
                        goto partial;
 
        if (!trace_seq_puts(s, "\n"))
@@ -1129,29 +1236,43 @@ static int probe_event_raw_init(struct ftrace_event_call *event_call)
 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
 {
        int ret, i;
-       struct kprobe_trace_entry field;
+       struct kprobe_trace_entry_head field;
        struct trace_probe *tp = (struct trace_probe *)event_call->data;
 
        DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
-       DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
        /* Set argument names as fields */
-       for (i = 0; i < tp->nr_args; i++)
-               DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
+       for (i = 0; i < tp->nr_args; i++) {
+               ret = trace_define_field(event_call, tp->args[i].type->name,
+                                        tp->args[i].name,
+                                        sizeof(field) + tp->args[i].offset,
+                                        tp->args[i].type->size,
+                                        tp->args[i].type->is_signed,
+                                        FILTER_OTHER);
+               if (ret)
+                       return ret;
+       }
        return 0;
 }
 
 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
 {
        int ret, i;
-       struct kretprobe_trace_entry field;
+       struct kretprobe_trace_entry_head field;
        struct trace_probe *tp = (struct trace_probe *)event_call->data;
 
        DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
        DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
-       DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
        /* Set argument names as fields */
-       for (i = 0; i < tp->nr_args; i++)
-               DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
+       for (i = 0; i < tp->nr_args; i++) {
+               ret = trace_define_field(event_call, tp->args[i].type->name,
+                                        tp->args[i].name,
+                                        sizeof(field) + tp->args[i].offset,
+                                        tp->args[i].type->size,
+                                        tp->args[i].type->is_signed,
+                                        FILTER_OTHER);
+               if (ret)
+                       return ret;
+       }
        return 0;
 }
 
@@ -1176,8 +1297,8 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
        pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
 
        for (i = 0; i < tp->nr_args; i++) {
-               pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
-                               tp->args[i].name);
+               pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
+                               tp->args[i].name, tp->args[i].type->fmt);
        }
 
        pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
@@ -1219,12 +1340,13 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
 {
        struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
        struct ftrace_event_call *call = &tp->call;
-       struct kprobe_trace_entry *entry;
+       struct kprobe_trace_entry_head *entry;
+       u8 *data;
        int size, __size, i;
        unsigned long irq_flags;
        int rctx;
 
-       __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
+       __size = sizeof(*entry) + tp->size;
        size = ALIGN(__size + sizeof(u32), sizeof(u64));
        size -= sizeof(u32);
        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
@@ -1235,10 +1357,10 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
        if (!entry)
                return;
 
-       entry->nargs = tp->nr_args;
        entry->ip = (unsigned long)kp->addr;
+       data = (u8 *)&entry[1];
        for (i = 0; i < tp->nr_args; i++)
-               entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+               call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
 
        perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs);
 }
@@ -1249,12 +1371,13 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
 {
        struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
        struct ftrace_event_call *call = &tp->call;
-       struct kretprobe_trace_entry *entry;
+       struct kretprobe_trace_entry_head *entry;
+       u8 *data;
        int size, __size, i;
        unsigned long irq_flags;
        int rctx;
 
-       __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
+       __size = sizeof(*entry) + tp->size;
        size = ALIGN(__size + sizeof(u32), sizeof(u64));
        size -= sizeof(u32);
        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
@@ -1265,11 +1388,11 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
        if (!entry)
                return;
 
-       entry->nargs = tp->nr_args;
        entry->func = (unsigned long)tp->rp.kp.addr;
        entry->ret_ip = (unsigned long)ri->ret_addr;
+       data = (u8 *)&entry[1];
        for (i = 0; i < tp->nr_args; i++)
-               entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+               call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
 
        perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1,
                               irq_flags, regs);