kernel/trace/trace_events_stage_3.h

   1 /*
   2  * Stage 3 of the trace events.
   3  *
   4  * Override the macros in <trace/trace_event_types.h> to include the following:
   5  *
   6  * static void ftrace_event_<call>(proto)
   7  * {
   8  *      event_trace_printk(_RET_IP_, "<call>: " <fmt>);
   9  * }
  10  *
  11  * static int ftrace_reg_event_<call>(void)
  12  * {
  13  *      int ret;
  14  *
  15  *      ret = register_trace_<call>(ftrace_event_<call>);
  16  *      if (!ret)
  17  *              pr_info("event trace: Could not activate trace point "
  18  *                      "probe to  <call>");
  19  *      return ret;
  20  * }
  21  *
  22  * static void ftrace_unreg_event_<call>(void)
  23  * {
  24  *      unregister_trace_<call>(ftrace_event_<call>);
  25  * }
  26  *
  27  * For those macros defined with TRACE_FORMAT:
  28  *
  29  * static struct ftrace_event_call __used
  30  * __attribute__((__aligned__(4)))
  31  * __attribute__((section("_ftrace_events"))) event_<call> = {
  32  *      .name                   = "<call>",
  33  *      .regfunc                = ftrace_reg_event_<call>,
  34  *      .unregfunc              = ftrace_unreg_event_<call>,
  35  * }
  36  *
  37  *
  38  * For those macros defined with TRACE_EVENT:
  39  *
  40  * static struct ftrace_event_call event_<call>;
  41  *
  42  * static void ftrace_raw_event_<call>(proto)
  43  * {
  44  *      struct ring_buffer_event *event;
  45  *      struct ftrace_raw_<call> *entry; <-- defined in stage 1
  46  *      unsigned long irq_flags;
  47  *      int pc;
  48  *
  49  *      local_save_flags(irq_flags);
  50  *      pc = preempt_count();
  51  *
  52  *      event = trace_current_buffer_lock_reserve(event_<call>.id,
  53  *                                sizeof(struct ftrace_raw_<call>),
  54  *                                irq_flags, pc);
  55  *      if (!event)
  56  *              return;
  57  *      entry   = ring_buffer_event_data(event);
  58  *
  59  *      <assign>;  <-- Here we assign the entries by the __field and
  60  *                      __array macros.
  61  *
  62  *      trace_current_buffer_unlock_commit(event, irq_flags, pc);
  63  * }
  64  *
  65  * static int ftrace_raw_reg_event_<call>(void)
  66  * {
  67  *      int ret;
  68  *
  69  *      ret = register_trace_<call>(ftrace_raw_event_<call>);
  70  *      if (!ret)
  71  *              pr_info("event trace: Could not activate trace point "
  72  *                      "probe to <call>");
  73  *      return ret;
  74  * }
  75  *
  76  * static void ftrace_unreg_event_<call>(void)
  77  * {
  78  *      unregister_trace_<call>(ftrace_raw_event_<call>);
  79  * }
  80  *
  81  * static struct trace_event ftrace_event_type_<call> = {
  82  *      .trace                  = ftrace_raw_output_<call>, <-- stage 2
  83  * };
  84  *
  85  * static int ftrace_raw_init_event_<call>(void)
  86  * {
  87  *      int id;
  88  *
  89  *      id = register_ftrace_event(&ftrace_event_type_<call>);
  90  *      if (!id)
  91  *              return -ENODEV;
  92  *      event_<call>.id = id;
  93  *      return 0;
  94  * }
  95  *
  96  * static struct ftrace_event_call __used
  97  * __attribute__((__aligned__(4)))
  98  * __attribute__((section("_ftrace_events"))) event_<call> = {
  99  *      .name                   = "<call>",
 100  *      .system                 = "<system>",
 101  *      .raw_init               = ftrace_raw_init_event_<call>,
 102  *      .regfunc                = ftrace_reg_event_<call>,
 103  *      .unregfunc              = ftrace_unreg_event_<call>,
 104  *      .show_format            = ftrace_format_<call>,
 105  * }
 106  *
 107  */
 108
 109 #undef TP_FMT
 110 #define TP_FMT(fmt, args...)    fmt "\n", ##args
 111
 112 #define _TRACE_FORMAT(call, proto, args, fmt)                           \
 113 static void ftrace_event_##call(proto)                                  \
 114 {                                                                       \
 115         event_trace_printk(_RET_IP_, #call ": " fmt);                   \
 116 }                                                                       \
 117                                                                         \
 118 static int ftrace_reg_event_##call(void)                                \
 119 {                                                                       \
 120         int ret;                                                        \
 121                                                                         \
 122         ret = register_trace_##call(ftrace_event_##call);               \
 123         if (ret)                                                        \
 124                 pr_info("event trace: Could not activate trace point "  \
 125                         "probe to " #call "\n");                        \
 126         return ret;                                                     \
 127 }                                                                       \
 128                                                                         \
 129 static void ftrace_unreg_event_##call(void)                             \
 130 {                                                                       \
 131         unregister_trace_##call(ftrace_event_##call);                   \
 132 }                                                                       \
 133
 134
 135 #undef TRACE_FORMAT
 136 #define TRACE_FORMAT(call, proto, args, fmt)                            \
 137 _TRACE_FORMAT(call, PARAMS(proto), PARAMS(args), PARAMS(fmt))           \
 138 static struct ftrace_event_call __used                                  \
 139 __attribute__((__aligned__(4)))                                         \
 140 __attribute__((section("_ftrace_events"))) event_##call = {             \
 141         .name                   = #call,                                \
 142         .system                 = __stringify(TRACE_SYSTEM),            \
 143         .regfunc                = ftrace_reg_event_##call,              \
 144         .unregfunc              = ftrace_unreg_event_##call,            \
 145 }
 146
 147 #undef __entry
 148 #define __entry entry
 149
 150 #undef TRACE_EVENT
 151 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 152                                                                         \
 153 static struct ftrace_event_call event_##call;                           \
 154                                                                         \
 155 static void ftrace_raw_event_##call(proto)                              \
 156 {                                                                       \
 157         struct ring_buffer_event *event;                                \
 158         struct ftrace_raw_##call *entry;                                \
 159         unsigned long irq_flags;                                        \
 160         int pc;                                                         \
 161                                                                         \
 162         local_save_flags(irq_flags);                                    \
 163         pc = preempt_count();                                           \
 164                                                                         \
 165         event = trace_current_buffer_lock_reserve(event_##call.id,      \
 166                                   sizeof(struct ftrace_raw_##call),     \
 167                                   irq_flags, pc);                       \
 168         if (!event)                                                     \
 169                 return;                                                 \
 170         entry   = ring_buffer_event_data(event);                        \
 171                                                                         \
 172         assign;                                                         \
 173                                                                         \
 174         trace_current_buffer_unlock_commit(event, irq_flags, pc);       \
 175 }                                                                       \
 176                                                                         \
 177 static int ftrace_raw_reg_event_##call(void)                            \
 178 {                                                                       \
 179         int ret;                                                        \
 180                                                                         \
 181         ret = register_trace_##call(ftrace_raw_event_##call);           \
 182         if (ret)                                                        \
 183                 pr_info("event trace: Could not activate trace point "  \
 184                         "probe to " #call "\n");                        \
 185         return ret;                                                     \
 186 }                                                                       \
 187                                                                         \
 188 static void ftrace_raw_unreg_event_##call(void)                         \
 189 {                                                                       \
 190         unregister_trace_##call(ftrace_raw_event_##call);               \
 191 }                                                                       \
 192                                                                         \
 193 static struct trace_event ftrace_event_type_##call = {                  \
 194         .trace                  = ftrace_raw_output_##call,             \
 195 };                                                                      \
 196                                                                         \
 197 static int ftrace_raw_init_event_##call(void)                           \
 198 {                                                                       \
 199         int id;                                                         \
 200                                                                         \
 201         id = register_ftrace_event(&ftrace_event_type_##call);          \
 202         if (!id)                                                        \
 203                 return -ENODEV;                                         \
 204         event_##call.id = id;                                           \
 205         return 0;                                                       \
 206 }                                                                       \
 207                                                                         \
 208 static struct ftrace_event_call __used                                  \
 209 __attribute__((__aligned__(4)))                                         \
 210 __attribute__((section("_ftrace_events"))) event_##call = {             \
 211         .name                   = #call,                                \
 212         .system                 = __stringify(TRACE_SYSTEM),            \
 213         .raw_init               = ftrace_raw_init_event_##call,         \
 214         .regfunc                = ftrace_raw_reg_event_##call,          \
 215         .unregfunc              = ftrace_raw_unreg_event_##call,        \
 216         .show_format            = ftrace_format_##call,                 \
 217 }