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 struct ftrace_event_class event_class_ftrace = {
  22         .system                 = __stringify(TRACE_SYSTEM),
  23 };
  24
  25 /* not needed for this file */
  26 #undef __field_struct
  27 #define __field_struct(type, item)
  28
  29 #undef __field
  30 #define __field(type, item)                             type item;
  31
  32 #undef __field_desc
  33 #define __field_desc(type, container, item)             type item;
  34
  35 #undef __array
  36 #define __array(type, item, size)                       type item[size];
  37
  38 #undef __array_desc
  39 #define __array_desc(type, container, item, size)       type item[size];
  40
  41 #undef __dynamic_array
  42 #define __dynamic_array(type, item)                     type item[];
  43
  44 #undef F_STRUCT
  45 #define F_STRUCT(args...)                               args
  46
  47 #undef F_printk
  48 #define F_printk(fmt, args...) fmt, args
  49
  50 #undef FTRACE_ENTRY
  51 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  52 struct ____ftrace_##name {                                      \
  53         tstruct                                                 \
  54 };                                                              \
  55 static void __always_unused ____ftrace_check_##name(void)       \
  56 {                                                               \
  57         struct ____ftrace_##name *__entry = NULL;               \
  58                                                                 \
  59         /* force compile-time check on F_printk() */            \
  60         printk(print);                                          \
  61 }
  62
  63 #undef FTRACE_ENTRY_DUP
  64 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print) \
  65         FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
  66
  67 #include "trace_entries.h"
  68
  69 #undef __field
  70 #define __field(type, item)                                             \
  71         ret = trace_define_field(event_call, #type, #item,              \
  72                                  offsetof(typeof(field), item),         \
  73                                  sizeof(field.item),                    \
  74                                  is_signed_type(type), FILTER_OTHER);   \
  75         if (ret)                                                        \
  76                 return ret;
  77
  78 #undef __field_desc
  79 #define __field_desc(type, container, item)     \
  80         ret = trace_define_field(event_call, #type, #item,              \
  81                                  offsetof(typeof(field),                \
  82                                           container.item),              \
  83                                  sizeof(field.container.item),          \
  84                                  is_signed_type(type), FILTER_OTHER);   \
  85         if (ret)                                                        \
  86                 return ret;
  87
  88 #undef __array
  89 #define __array(type, item, len)                                        \
  90         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
  91         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
  92                                  offsetof(typeof(field), item),         \
  93                                  sizeof(field.item),                    \
  94                                  is_signed_type(type), FILTER_OTHER);   \
  95         if (ret)                                                        \
  96                 return ret;
  97
  98 #undef __array_desc
  99 #define __array_desc(type, container, item, len)                        \
 100         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 101         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 102                                  offsetof(typeof(field),                \
 103                                           container.item),              \
 104                                  sizeof(field.container.item),          \
 105                                  is_signed_type(type), FILTER_OTHER);   \
 106         if (ret)                                                        \
 107                 return ret;
 108
 109 #undef __dynamic_array
 110 #define __dynamic_array(type, item)                                     \
 111         ret = trace_define_field(event_call, #type, #item,              \
 112                                  offsetof(typeof(field), item),         \
 113                                  0, is_signed_type(type), FILTER_OTHER);\
 114         if (ret)                                                        \
 115                 return ret;
 116
 117 #undef FTRACE_ENTRY
 118 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)             \
 119 int                                                                     \
 120 ftrace_define_fields_##name(struct ftrace_event_call *event_call)       \
 121 {                                                                       \
 122         struct struct_name field;                                       \
 123         int ret;                                                        \
 124                                                                         \
 125         tstruct;                                                        \
 126                                                                         \
 127         return ret;                                                     \
 128 }
 129
 130 #include "trace_entries.h"
 131
 132 static int ftrace_raw_init_event(struct ftrace_event_call *call)
 133 {
 134         INIT_LIST_HEAD(&call->fields);
 135         return 0;
 136 }
 137
 138 #undef __entry
 139 #define __entry REC
 140
 141 #undef __field
 142 #define __field(type, item)
 143
 144 #undef __field_desc
 145 #define __field_desc(type, container, item)
 146
 147 #undef __array
 148 #define __array(type, item, len)
 149
 150 #undef __array_desc
 151 #define __array_desc(type, container, item, len)
 152
 153 #undef __dynamic_array
 154 #define __dynamic_array(type, item)
 155
 156 #undef F_printk
 157 #define F_printk(fmt, args...) #fmt ", "  __stringify(args)
 158
 159 #undef FTRACE_ENTRY
 160 #define FTRACE_ENTRY(call, struct_name, type, tstruct, print)           \
 161                                                                         \
 162 struct ftrace_event_call __used                                         \
 163 __attribute__((__aligned__(4)))                                         \
 164 __attribute__((section("_ftrace_events"))) event_##call = {             \
 165         .name                   = #call,                                \
 166         .id                     = type,                                 \
 167         .class                  = &event_class_ftrace,                  \
 168         .raw_init               = ftrace_raw_init_event,                \
 169         .print_fmt              = print,                                \
 170         .define_fields          = ftrace_define_fields_##call,          \
 171 };                                                                      \
 172
 173 #include "trace_entries.h"