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
  66 #undef __field
  67 #define __field(type, item)                                             \
  68         ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"      \
  69                                "offset:%zu;\tsize:%zu;\tsigned:%u;\n",  \
  70                                offsetof(typeof(field), item),           \
  71                                sizeof(field.item), is_signed_type(type)); \
  72         if (!ret)                                                       \
  73                 return 0;
  74
  75 #undef __field_desc
  76 #define __field_desc(type, container, item)                             \
  77         ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"      \
  78                                "offset:%zu;\tsize:%zu;\tsigned:%u;\n",  \
  79                                offsetof(typeof(field), container.item), \
  80                                sizeof(field.container.item),            \
  81                                is_signed_type(type));                   \
  82         if (!ret)                                                       \
  83                 return 0;
  84
  85 #undef __array
  86 #define __array(type, item, len)                                        \
  87         ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
  88                                "offset:%zu;\tsize:%zu;\tsigned:%u;\n",  \
  89                                offsetof(typeof(field), item),           \
  90                                sizeof(field.item), is_signed_type(type)); \
  91         if (!ret)                                                       \
  92                 return 0;
  93
  94 #undef __array_desc
  95 #define __array_desc(type, container, item, len)                        \
  96         ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
  97                                "offset:%zu;\tsize:%zu;\tsigned:%u;\n",  \
  98                                offsetof(typeof(field), container.item), \
  99                                sizeof(field.container.item),            \
 100                                is_signed_type(type));                   \
 101         if (!ret)                                                       \
 102                 return 0;
 103
 104 #undef __dynamic_array
 105 #define __dynamic_array(type, item)                                     \
 106         ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"      \
 107                                "offset:%zu;\tsize:0;\tsigned:%u;\n",    \
 108                                offsetof(typeof(field), item),           \
 109                                is_signed_type(type));                   \
 110         if (!ret)                                                       \
 111                 return 0;
 112
 113 #undef F_printk
 114 #define F_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
 115
 116 #undef __entry
 117 #define __entry REC
 118
 119 #undef FTRACE_ENTRY
 120 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)             \
 121 static int                                                              \
 122 ftrace_format_##name(struct ftrace_event_call *unused,                  \
 123                      struct trace_seq *s)                               \
 124 {                                                                       \
 125         struct struct_name field __attribute__((unused));               \
 126         int ret = 0;                                                    \
 127                                                                         \
 128         tstruct;                                                        \
 129                                                                         \
 130         trace_seq_printf(s, "\nprint fmt: " print);                     \
 131                                                                         \
 132         return ret;                                                     \
 133 }
 134
 135 #include "trace_entries.h"
 136
 137 #undef __field
 138 #define __field(type, item)                                             \
 139         ret = trace_define_field(event_call, #type, #item,              \
 140                                  offsetof(typeof(field), item),         \
 141                                  sizeof(field.item),                    \
 142                                  is_signed_type(type), FILTER_OTHER);   \
 143         if (ret)                                                        \
 144                 return ret;
 145
 146 #undef __field_desc
 147 #define __field_desc(type, container, item)     \
 148         ret = trace_define_field(event_call, #type, #item,              \
 149                                  offsetof(typeof(field),                \
 150                                           container.item),              \
 151                                  sizeof(field.container.item),          \
 152                                  is_signed_type(type), FILTER_OTHER);   \
 153         if (ret)                                                        \
 154                 return ret;
 155
 156 #undef __array
 157 #define __array(type, item, len)                                        \
 158         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 159         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 160                                  offsetof(typeof(field), item),         \
 161                                  sizeof(field.item),                    \
 162                                  is_signed_type(type), FILTER_OTHER);   \
 163         if (ret)                                                        \
 164                 return ret;
 165
 166 #undef __array_desc
 167 #define __array_desc(type, container, item, len)                        \
 168         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 169         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 170                                  offsetof(typeof(field),                \
 171                                           container.item),              \
 172                                  sizeof(field.container.item),          \
 173                                  is_signed_type(type), FILTER_OTHER);   \
 174         if (ret)                                                        \
 175                 return ret;
 176
 177 #undef __dynamic_array
 178 #define __dynamic_array(type, item)
 179
 180 #undef FTRACE_ENTRY
 181 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)             \
 182 int                                                                     \
 183 ftrace_define_fields_##name(struct ftrace_event_call *event_call)       \
 184 {                                                                       \
 185         struct struct_name field;                                       \
 186         int ret;                                                        \
 187                                                                         \
 188         tstruct;                                                        \
 189                                                                         \
 190         return ret;                                                     \
 191 }
 192
 193 #include "trace_entries.h"
 194
 195 static int ftrace_raw_init_event(struct ftrace_event_call *call)
 196 {
 197         INIT_LIST_HEAD(&call->fields);
 198         return 0;
 199 }
 200
 201 #undef __field
 202 #define __field(type, item)
 203
 204 #undef __field_desc
 205 #define __field_desc(type, container, item)
 206
 207 #undef __array
 208 #define __array(type, item, len)
 209
 210 #undef __array_desc
 211 #define __array_desc(type, container, item, len)
 212
 213 #undef __dynamic_array
 214 #define __dynamic_array(type, item)
 215
 216 #undef FTRACE_ENTRY
 217 #define FTRACE_ENTRY(call, struct_name, type, tstruct, print)           \
 218                                                                         \
 219 struct ftrace_event_call __used                                         \
 220 __attribute__((__aligned__(4)))                                         \
 221 __attribute__((section("_ftrace_events"))) event_##call = {             \
 222         .name                   = #call,                                \
 223         .id                     = type,                                 \
 224         .system                 = __stringify(TRACE_SYSTEM),            \
 225         .raw_init               = ftrace_raw_init_event,                \
 226         .show_format            = ftrace_format_##call,                 \
 227         .define_fields          = ftrace_define_fields_##call,          \
 228 };                                                                      \
 229
 230 #include "trace_entries.h"