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 /* not needed for this file */
  22 #undef __field_struct
  23 #define __field_struct(type, item)
  24
  25 #undef __field
  26 #define __field(type, item)                             type item;
  27
  28 #undef __field_desc
  29 #define __field_desc(type, container, item)             type item;
  30
  31 #undef __array
  32 #define __array(type, item, size)                       type item[size];
  33
  34 #undef __array_desc
  35 #define __array_desc(type, container, item, size)       type item[size];
  36
  37 #undef __dynamic_array
  38 #define __dynamic_array(type, item)                     type item[];
  39
  40 #undef F_STRUCT
  41 #define F_STRUCT(args...)                               args
  42
  43 #undef F_printk
  44 #define F_printk(fmt, args...) fmt, args
  45
  46 #undef FTRACE_ENTRY
  47 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  48 struct ____ftrace_##name {                                      \
  49         tstruct                                                 \
  50 };                                                              \
  51 static void __always_unused ____ftrace_check_##name(void)       \
  52 {                                                               \
  53         struct ____ftrace_##name *__entry = NULL;               \
  54                                                                 \
  55         /* force compile-time check on F_printk() */            \
  56         printk(print);                                          \
  57 }
  58
  59 #undef FTRACE_ENTRY_DUP
  60 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print) \
  61         FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
  62
  63 #include "trace_entries.h"
  64
  65 #undef __field
  66 #define __field(type, item)                                             \
  67         ret = trace_define_field(event_call, #type, #item,              \
  68                                  offsetof(typeof(field), item),         \
  69                                  sizeof(field.item),                    \
  70                                  is_signed_type(type), FILTER_OTHER);   \
  71         if (ret)                                                        \
  72                 return ret;
  73
  74 #undef __field_desc
  75 #define __field_desc(type, container, item)     \
  76         ret = trace_define_field(event_call, #type, #item,              \
  77                                  offsetof(typeof(field),                \
  78                                           container.item),              \
  79                                  sizeof(field.container.item),          \
  80                                  is_signed_type(type), FILTER_OTHER);   \
  81         if (ret)                                                        \
  82                 return ret;
  83
  84 #undef __array
  85 #define __array(type, item, len)                                        \
  86         do {                                                            \
  87                 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                 \
  88                 mutex_lock(&event_storage_mutex);                       \
  89                 snprintf(event_storage, sizeof(event_storage),          \
  90                          "%s[%d]", #type, len);                         \
  91                 ret = trace_define_field(event_call, event_storage, #item, \
  92                                  offsetof(typeof(field), item),         \
  93                                  sizeof(field.item),                    \
  94                                  is_signed_type(type), FILTER_OTHER);   \
  95                 mutex_unlock(&event_storage_mutex);                     \
  96                 if (ret)                                                \
  97                         return ret;                                     \
  98         } while (0);
  99
 100 #undef __array_desc
 101 #define __array_desc(type, container, item, len)                        \
 102         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 103         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 104                                  offsetof(typeof(field),                \
 105                                           container.item),              \
 106                                  sizeof(field.container.item),          \
 107                                  is_signed_type(type), FILTER_OTHER);   \
 108         if (ret)                                                        \
 109                 return ret;
 110
 111 #undef __dynamic_array
 112 #define __dynamic_array(type, item)                                     \
 113         ret = trace_define_field(event_call, #type, #item,              \
 114                                  offsetof(typeof(field), item),         \
 115                                  0, is_signed_type(type), FILTER_OTHER);\
 116         if (ret)                                                        \
 117                 return ret;
 118
 119 #undef FTRACE_ENTRY
 120 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)             \
 121 int                                                                     \
 122 ftrace_define_fields_##name(struct ftrace_event_call *event_call)       \
 123 {                                                                       \
 124         struct struct_name field;                                       \
 125         int ret;                                                        \
 126                                                                         \
 127         tstruct;                                                        \
 128                                                                         \
 129         return ret;                                                     \
 130 }
 131
 132 #include "trace_entries.h"
 133
 134 #undef __entry
 135 #define __entry REC
 136
 137 #undef __field
 138 #define __field(type, item)
 139
 140 #undef __field_desc
 141 #define __field_desc(type, container, item)
 142
 143 #undef __array
 144 #define __array(type, item, len)
 145
 146 #undef __array_desc
 147 #define __array_desc(type, container, item, len)
 148
 149 #undef __dynamic_array
 150 #define __dynamic_array(type, item)
 151
 152 #undef F_printk
 153 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
 154
 155 #undef FTRACE_ENTRY
 156 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)          \
 157                                                                         \
 158 struct ftrace_event_class event_class_ftrace_##call = {                 \
 159         .system                 = __stringify(TRACE_SYSTEM),            \
 160         .define_fields          = ftrace_define_fields_##call,          \
 161         .fields                 = LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
 162 };                                                                      \
 163                                                                         \
 164 struct ftrace_event_call __used event_##call = {                        \
 165         .name                   = #call,                                \
 166         .event.type             = etype,                                \
 167         .class                  = &event_class_ftrace_##call,           \
 168         .print_fmt              = print,                                \
 169 };                                                                      \
 170 struct ftrace_event_call __used                                         \
 171 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
 172
 173 #include "trace_entries.h"