kernel/trace/trace_export.c

   1 /*
   2  * trace_export.c - export basic ftrace utilities to user space
   3  *
   4  * Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>
   5  */
   6 #include <linux/stringify.h>
   7 #include <linux/kallsyms.h>
   8 #include <linux/seq_file.h>
   9 #include <linux/debugfs.h>
  10 #include <linux/uaccess.h>
  11 #include <linux/ftrace.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/fs.h>
  15
  16 #include "trace_output.h"
  17
  18 #undef TRACE_SYSTEM
  19 #define TRACE_SYSTEM    ftrace
  20
  21 /*
  22  * The FTRACE_ENTRY_REG macro allows ftrace entry to define register
  23  * function and thus become accesible via perf.
  24  */
  25 #undef FTRACE_ENTRY_REG
  26 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
  27                          filter, regfn) \
  28         FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
  29                      filter)
  30
  31 /* not needed for this file */
  32 #undef __field_struct
  33 #define __field_struct(type, item)
  34
  35 #undef __field
  36 #define __field(type, item)                             type item;
  37
  38 #undef __field_desc
  39 #define __field_desc(type, container, item)             type item;
  40
  41 #undef __array
  42 #define __array(type, item, size)                       type item[size];
  43
  44 #undef __array_desc
  45 #define __array_desc(type, container, item, size)       type item[size];
  46
  47 #undef __dynamic_array
  48 #define __dynamic_array(type, item)                     type item[];
  49
  50 #undef F_STRUCT
  51 #define F_STRUCT(args...)                               args
  52
  53 #undef F_printk
  54 #define F_printk(fmt, args...) fmt, args
  55
  56 #undef FTRACE_ENTRY
  57 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)     \
  58 struct ____ftrace_##name {                                              \
  59         tstruct                                                         \
  60 };                                                                      \
  61 static void __always_unused ____ftrace_check_##name(void)               \
  62 {                                                                       \
  63         struct ____ftrace_##name *__entry = NULL;                       \
  64                                                                         \
  65         /* force compile-time check on F_printk() */                    \
  66         printk(print);                                                  \
  67 }
  68
  69 #undef FTRACE_ENTRY_DUP
  70 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print, filter) \
  71         FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
  72                      filter)
  73
  74 #include "trace_entries.h"
  75
  76 #undef __field
  77 #define __field(type, item)                                             \
  78         ret = trace_define_field(event_call, #type, #item,              \
  79                                  offsetof(typeof(field), item),         \
  80                                  sizeof(field.item),                    \
  81                                  is_signed_type(type), filter_type);    \
  82         if (ret)                                                        \
  83                 return ret;
  84
  85 #undef __field_desc
  86 #define __field_desc(type, container, item)     \
  87         ret = trace_define_field(event_call, #type, #item,              \
  88                                  offsetof(typeof(field),                \
  89                                           container.item),              \
  90                                  sizeof(field.container.item),          \
  91                                  is_signed_type(type), filter_type);    \
  92         if (ret)                                                        \
  93                 return ret;
  94
  95 #undef __array
  96 #define __array(type, item, len)                                        \
  97         do {                                                            \
  98                 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                 \
  99                 mutex_lock(&event_storage_mutex);                       \
 100                 snprintf(event_storage, sizeof(event_storage),          \
 101                          "%s[%d]", #type, len);                         \
 102                 ret = trace_define_field(event_call, event_storage, #item, \
 103                                  offsetof(typeof(field), item),         \
 104                                  sizeof(field.item),                    \
 105                                  is_signed_type(type), filter_type);    \
 106                 mutex_unlock(&event_storage_mutex);                     \
 107                 if (ret)                                                \
 108                         return ret;                                     \
 109         } while (0);
 110
 111 #undef __array_desc
 112 #define __array_desc(type, container, item, len)                        \
 113         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 114         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 115                                  offsetof(typeof(field),                \
 116                                           container.item),              \
 117                                  sizeof(field.container.item),          \
 118                                  is_signed_type(type), filter_type);    \
 119         if (ret)                                                        \
 120                 return ret;
 121
 122 #undef __dynamic_array
 123 #define __dynamic_array(type, item)                                     \
 124         ret = trace_define_field(event_call, #type, #item,              \
 125                                  offsetof(typeof(field), item),         \
 126                                  0, is_signed_type(type), filter_type);\
 127         if (ret)                                                        \
 128                 return ret;
 129
 130 #undef FTRACE_ENTRY
 131 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)     \
 132 static int __init                                                       \
 133 ftrace_define_fields_##name(struct ftrace_event_call *event_call)       \
 134 {                                                                       \
 135         struct struct_name field;                                       \
 136         int ret;                                                        \
 137         int filter_type = filter;                                       \
 138                                                                         \
 139         tstruct;                                                        \
 140                                                                         \
 141         return ret;                                                     \
 142 }
 143
 144 #include "trace_entries.h"
 145
 146 #undef __entry
 147 #define __entry REC
 148
 149 #undef __field
 150 #define __field(type, item)
 151
 152 #undef __field_desc
 153 #define __field_desc(type, container, item)
 154
 155 #undef __array
 156 #define __array(type, item, len)
 157
 158 #undef __array_desc
 159 #define __array_desc(type, container, item, len)
 160
 161 #undef __dynamic_array
 162 #define __dynamic_array(type, item)
 163
 164 #undef F_printk
 165 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
 166
 167 #undef FTRACE_ENTRY_REG
 168 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
 169                          regfn)                                         \
 170                                                                         \
 171 struct ftrace_event_class __refdata event_class_ftrace_##call = {       \
 172         .system                 = __stringify(TRACE_SYSTEM),            \
 173         .define_fields          = ftrace_define_fields_##call,          \
 174         .fields                 = LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
 175         .reg                    = regfn,                                \
 176 };                                                                      \
 177                                                                         \
 178 struct ftrace_event_call __used event_##call = {                        \
 179         .name                   = #call,                                \
 180         .event.type             = etype,                                \
 181         .class                  = &event_class_ftrace_##call,           \
 182         .print_fmt              = print,                                \
 183         .flags                  = TRACE_EVENT_FL_IGNORE_ENABLE | TRACE_EVENT_FL_USE_CALL_FILTER, \
 184 };                                                                      \
 185 struct ftrace_event_call __used                                         \
 186 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
 187
 188 #undef FTRACE_ENTRY
 189 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print, filter)  \
 190         FTRACE_ENTRY_REG(call, struct_name, etype,                      \
 191                          PARAMS(tstruct), PARAMS(print), filter, NULL)
 192
 193 int ftrace_event_is_function(struct ftrace_event_call *call)
 194 {
 195         return call == &event_function;
 196 }
 197
 198 #include "trace_entries.h"