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