include/trace/ftrace.h

   1 /*
   2  * Stage 1 of the trace events.
   3  *
   4  * Override the macros in <trace/trace_events.h> to include the following:
   5  *
   6  * struct ftrace_raw_<call> {
   7  *      struct trace_entry              ent;
   8  *      <type>                          <item>;
   9  *      <type2>                         <item2>[<len>];
  10  *      [...]
  11  * };
  12  *
  13  * The <type> <item> is created by the __field(type, item) macro or
  14  * the __array(type2, item2, len) macro.
  15  * We simply do "type item;", and that will create the fields
  16  * in the structure.
  17  */
  18
  19 #include <linux/ftrace_event.h>
  20
  21 #undef TRACE_FORMAT
  22 #define TRACE_FORMAT(call, proto, args, fmt)
  23
  24 #undef __array
  25 #define __array(type, item, len)        type    item[len];
  26
  27 #undef __field
  28 #define __field(type, item)             type    item;
  29
  30 #undef TP_STRUCT__entry
  31 #define TP_STRUCT__entry(args...) args
  32
  33 #undef TRACE_EVENT
  34 #define TRACE_EVENT(name, proto, args, tstruct, assign, print)  \
  35         struct ftrace_raw_##name {                              \
  36                 struct trace_entry      ent;                    \
  37                 tstruct                                         \
  38         };                                                      \
  39         static struct ftrace_event_call event_##name
  40
  41 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
  42
  43 /*
  44  * Stage 2 of the trace events.
  45  *
  46  * Override the macros in <trace/trace_events.h> to include the following:
  47  *
  48  * enum print_line_t
  49  * ftrace_raw_output_<call>(struct trace_iterator *iter, int flags)
  50  * {
  51  *      struct trace_seq *s = &iter->seq;
  52  *      struct ftrace_raw_<call> *field; <-- defined in stage 1
  53  *      struct trace_entry *entry;
  54  *      int ret;
  55  *
  56  *      entry = iter->ent;
  57  *
  58  *      if (entry->type != event_<call>.id) {
  59  *              WARN_ON_ONCE(1);
  60  *              return TRACE_TYPE_UNHANDLED;
  61  *      }
  62  *
  63  *      field = (typeof(field))entry;
  64  *
  65  *      ret = trace_seq_printf(s, <TP_printk> "\n");
  66  *      if (!ret)
  67  *              return TRACE_TYPE_PARTIAL_LINE;
  68  *
  69  *      return TRACE_TYPE_HANDLED;
  70  * }
  71  *
  72  * This is the method used to print the raw event to the trace
  73  * output format. Note, this is not needed if the data is read
  74  * in binary.
  75  */
  76
  77 #undef __entry
  78 #define __entry field
  79
  80 #undef TP_printk
  81 #define TP_printk(fmt, args...) fmt "\n", args
  82
  83 #undef TRACE_EVENT
  84 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
  85 enum print_line_t                                                       \
  86 ftrace_raw_output_##call(struct trace_iterator *iter, int flags)        \
  87 {                                                                       \
  88         struct trace_seq *s = &iter->seq;                               \
  89         struct ftrace_raw_##call *field;                                \
  90         struct trace_entry *entry;                                      \
  91         int ret;                                                        \
  92                                                                         \
  93         entry = iter->ent;                                              \
  94                                                                         \
  95         if (entry->type != event_##call.id) {                           \
  96                 WARN_ON_ONCE(1);                                        \
  97                 return TRACE_TYPE_UNHANDLED;                            \
  98         }                                                               \
  99                                                                         \
 100         field = (typeof(field))entry;                                   \
 101                                                                         \
 102         ret = trace_seq_printf(s, #call ": " print);                    \
 103         if (!ret)                                                       \
 104                 return TRACE_TYPE_PARTIAL_LINE;                         \
 105                                                                         \
 106         return TRACE_TYPE_HANDLED;                                      \
 107 }
 108
 109 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 110
 111 /*
 112  * Setup the showing format of trace point.
 113  *
 114  * int
 115  * ftrace_format_##call(struct trace_seq *s)
 116  * {
 117  *      struct ftrace_raw_##call field;
 118  *      int ret;
 119  *
 120  *      ret = trace_seq_printf(s, #type " " #item ";"
 121  *                             " offset:%u; size:%u;\n",
 122  *                             offsetof(struct ftrace_raw_##call, item),
 123  *                             sizeof(field.type));
 124  *
 125  * }
 126  */
 127
 128 #undef TP_STRUCT__entry
 129 #define TP_STRUCT__entry(args...) args
 130
 131 #undef __field
 132 #define __field(type, item)                                     \
 133         ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"      \
 134                                "offset:%u;\tsize:%u;\n",                \
 135                                (unsigned int)offsetof(typeof(field), item), \
 136                                (unsigned int)sizeof(field.item));       \
 137         if (!ret)                                                       \
 138                 return 0;
 139
 140 #undef __array
 141 #define __array(type, item, len)                                                \
 142         ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t"    \
 143                                "offset:%u;\tsize:%u;\n",                \
 144                                (unsigned int)offsetof(typeof(field), item), \
 145                                (unsigned int)sizeof(field.item));       \
 146         if (!ret)                                                       \
 147                 return 0;
 148
 149 #undef __entry
 150 #define __entry REC
 151
 152 #undef TP_printk
 153 #define TP_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
 154
 155 #undef TP_fast_assign
 156 #define TP_fast_assign(args...) args
 157
 158 #undef TRACE_EVENT
 159 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 160 static int                                                              \
 161 ftrace_format_##call(struct trace_seq *s)                               \
 162 {                                                                       \
 163         struct ftrace_raw_##call field __attribute__((unused));         \
 164         int ret = 0;                                                    \
 165                                                                         \
 166         tstruct;                                                        \
 167                                                                         \
 168         trace_seq_printf(s, "\nprint fmt: " print);                     \
 169                                                                         \
 170         return ret;                                                     \
 171 }
 172
 173 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 174
 175 #undef __field
 176 #define __field(type, item)                                             \
 177         ret = trace_define_field(event_call, #type, #item,              \
 178                                  offsetof(typeof(field), item),         \
 179                                  sizeof(field.item));                   \
 180         if (ret)                                                        \
 181                 return ret;
 182
 183 #undef __array
 184 #define __array(type, item, len)                                        \
 185         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 186         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 187                                  offsetof(typeof(field), item),         \
 188                                  sizeof(field.item));                   \
 189         if (ret)                                                        \
 190                 return ret;
 191
 192 #undef TRACE_EVENT
 193 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 194 int                                                                     \
 195 ftrace_define_fields_##call(void)                                       \
 196 {                                                                       \
 197         struct ftrace_raw_##call field;                                 \
 198         struct ftrace_event_call *event_call = &event_##call;           \
 199         int ret;                                                        \
 200                                                                         \
 201         __common_field(unsigned char, type);                            \
 202         __common_field(unsigned char, flags);                           \
 203         __common_field(unsigned char, preempt_count);                   \
 204         __common_field(int, pid);                                       \
 205         __common_field(int, tgid);                                      \
 206                                                                         \
 207         tstruct;                                                        \
 208                                                                         \
 209         return ret;                                                     \
 210 }
 211
 212 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 213
 214 /*
 215  * Stage 3 of the trace events.
 216  *
 217  * Override the macros in <trace/trace_events.h> to include the following:
 218  *
 219  * static void ftrace_event_<call>(proto)
 220  * {
 221  *      event_trace_printk(_RET_IP_, "<call>: " <fmt>);
 222  * }
 223  *
 224  * static int ftrace_reg_event_<call>(void)
 225  * {
 226  *      int ret;
 227  *
 228  *      ret = register_trace_<call>(ftrace_event_<call>);
 229  *      if (!ret)
 230  *              pr_info("event trace: Could not activate trace point "
 231  *                      "probe to  <call>");
 232  *      return ret;
 233  * }
 234  *
 235  * static void ftrace_unreg_event_<call>(void)
 236  * {
 237  *      unregister_trace_<call>(ftrace_event_<call>);
 238  * }
 239  *
 240  * For those macros defined with TRACE_FORMAT:
 241  *
 242  * static struct ftrace_event_call __used
 243  * __attribute__((__aligned__(4)))
 244  * __attribute__((section("_ftrace_events"))) event_<call> = {
 245  *      .name                   = "<call>",
 246  *      .regfunc                = ftrace_reg_event_<call>,
 247  *      .unregfunc              = ftrace_unreg_event_<call>,
 248  * }
 249  *
 250  *
 251  * For those macros defined with TRACE_EVENT:
 252  *
 253  * static struct ftrace_event_call event_<call>;
 254  *
 255  * static void ftrace_raw_event_<call>(proto)
 256  * {
 257  *      struct ring_buffer_event *event;
 258  *      struct ftrace_raw_<call> *entry; <-- defined in stage 1
 259  *      unsigned long irq_flags;
 260  *      int pc;
 261  *
 262  *      local_save_flags(irq_flags);
 263  *      pc = preempt_count();
 264  *
 265  *      event = trace_current_buffer_lock_reserve(event_<call>.id,
 266  *                                sizeof(struct ftrace_raw_<call>),
 267  *                                irq_flags, pc);
 268  *      if (!event)
 269  *              return;
 270  *      entry   = ring_buffer_event_data(event);
 271  *
 272  *      <assign>;  <-- Here we assign the entries by the __field and
 273  *                      __array macros.
 274  *
 275  *      trace_current_buffer_unlock_commit(event, irq_flags, pc);
 276  * }
 277  *
 278  * static int ftrace_raw_reg_event_<call>(void)
 279  * {
 280  *      int ret;
 281  *
 282  *      ret = register_trace_<call>(ftrace_raw_event_<call>);
 283  *      if (!ret)
 284  *              pr_info("event trace: Could not activate trace point "
 285  *                      "probe to <call>");
 286  *      return ret;
 287  * }
 288  *
 289  * static void ftrace_unreg_event_<call>(void)
 290  * {
 291  *      unregister_trace_<call>(ftrace_raw_event_<call>);
 292  * }
 293  *
 294  * static struct trace_event ftrace_event_type_<call> = {
 295  *      .trace                  = ftrace_raw_output_<call>, <-- stage 2
 296  * };
 297  *
 298  * static int ftrace_raw_init_event_<call>(void)
 299  * {
 300  *      int id;
 301  *
 302  *      id = register_ftrace_event(&ftrace_event_type_<call>);
 303  *      if (!id)
 304  *              return -ENODEV;
 305  *      event_<call>.id = id;
 306  *      return 0;
 307  * }
 308  *
 309  * static struct ftrace_event_call __used
 310  * __attribute__((__aligned__(4)))
 311  * __attribute__((section("_ftrace_events"))) event_<call> = {
 312  *      .name                   = "<call>",
 313  *      .system                 = "<system>",
 314  *      .raw_init               = ftrace_raw_init_event_<call>,
 315  *      .regfunc                = ftrace_reg_event_<call>,
 316  *      .unregfunc              = ftrace_unreg_event_<call>,
 317  *      .show_format            = ftrace_format_<call>,
 318  * }
 319  *
 320  */
 321
 322 #undef TP_FMT
 323 #define TP_FMT(fmt, args...)    fmt "\n", ##args
 324
 325 #ifdef CONFIG_EVENT_PROFILE
 326 #define _TRACE_PROFILE(call, proto, args)                               \
 327 static void ftrace_profile_##call(proto)                                \
 328 {                                                                       \
 329         extern void perf_tpcounter_event(int);                          \
 330         perf_tpcounter_event(event_##call.id);                          \
 331 }                                                                       \
 332                                                                         \
 333 static int ftrace_profile_enable_##call(struct ftrace_event_call *call) \
 334 {                                                                       \
 335         int ret = 0;                                                    \
 336                                                                         \
 337         if (!atomic_inc_return(&call->profile_count))                   \
 338                 ret = register_trace_##call(ftrace_profile_##call);     \
 339                                                                         \
 340         return ret;                                                     \
 341 }                                                                       \
 342                                                                         \
 343 static void ftrace_profile_disable_##call(struct ftrace_event_call *call) \
 344 {                                                                       \
 345         if (atomic_add_negative(-1, &call->profile_count))              \
 346                 unregister_trace_##call(ftrace_profile_##call);         \
 347 }
 348
 349 #define _TRACE_PROFILE_INIT(call)                                       \
 350         .profile_count = ATOMIC_INIT(-1),                               \
 351         .profile_enable = ftrace_profile_enable_##call,                 \
 352         .profile_disable = ftrace_profile_disable_##call,
 353
 354 #else
 355 #define _TRACE_PROFILE(call, proto, args)
 356 #define _TRACE_PROFILE_INIT(call)
 357 #endif
 358
 359 #define _TRACE_FORMAT(call, proto, args, fmt)                           \
 360 static void ftrace_event_##call(proto)                                  \
 361 {                                                                       \
 362         event_trace_printk(_RET_IP_, #call ": " fmt);                   \
 363 }                                                                       \
 364                                                                         \
 365 static int ftrace_reg_event_##call(void)                                \
 366 {                                                                       \
 367         int ret;                                                        \
 368                                                                         \
 369         ret = register_trace_##call(ftrace_event_##call);               \
 370         if (ret)                                                        \
 371                 pr_info("event trace: Could not activate trace point "  \
 372                         "probe to " #call "\n");                        \
 373         return ret;                                                     \
 374 }                                                                       \
 375                                                                         \
 376 static void ftrace_unreg_event_##call(void)                             \
 377 {                                                                       \
 378         unregister_trace_##call(ftrace_event_##call);                   \
 379 }                                                                       \
 380                                                                         \
 381 static struct ftrace_event_call event_##call;                           \
 382                                                                         \
 383 static int ftrace_init_event_##call(void)                               \
 384 {                                                                       \
 385         int id;                                                         \
 386                                                                         \
 387         id = register_ftrace_event(NULL);                               \
 388         if (!id)                                                        \
 389                 return -ENODEV;                                         \
 390         event_##call.id = id;                                           \
 391         return 0;                                                       \
 392 }
 393
 394 #undef TRACE_FORMAT
 395 #define TRACE_FORMAT(call, proto, args, fmt)                            \
 396 _TRACE_FORMAT(call, PARAMS(proto), PARAMS(args), PARAMS(fmt))           \
 397 _TRACE_PROFILE(call, PARAMS(proto), PARAMS(args))                       \
 398 static struct ftrace_event_call __used                                  \
 399 __attribute__((__aligned__(4)))                                         \
 400 __attribute__((section("_ftrace_events"))) event_##call = {             \
 401         .name                   = #call,                                \
 402         .system                 = __stringify(TRACE_SYSTEM),            \
 403         .raw_init               = ftrace_init_event_##call,             \
 404         .regfunc                = ftrace_reg_event_##call,              \
 405         .unregfunc              = ftrace_unreg_event_##call,            \
 406         _TRACE_PROFILE_INIT(call)                                       \
 407 }
 408
 409 #undef __entry
 410 #define __entry entry
 411
 412 #undef TRACE_EVENT
 413 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 414 _TRACE_PROFILE(call, PARAMS(proto), PARAMS(args))                       \
 415                                                                         \
 416 static struct ftrace_event_call event_##call;                           \
 417                                                                         \
 418 static void ftrace_raw_event_##call(proto)                              \
 419 {                                                                       \
 420         struct ftrace_event_call *call = &event_##call;                 \
 421         struct ring_buffer_event *event;                                \
 422         struct ftrace_raw_##call *entry;                                \
 423         unsigned long irq_flags;                                        \
 424         int pc;                                                         \
 425                                                                         \
 426         local_save_flags(irq_flags);                                    \
 427         pc = preempt_count();                                           \
 428                                                                         \
 429         event = trace_current_buffer_lock_reserve(event_##call.id,      \
 430                                   sizeof(struct ftrace_raw_##call),     \
 431                                   irq_flags, pc);                       \
 432         if (!event)                                                     \
 433                 return;                                                 \
 434         entry   = ring_buffer_event_data(event);                        \
 435                                                                         \
 436         assign;                                                         \
 437                                                                         \
 438         if (!filter_current_check_discard(call, entry, event))          \
 439                 trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
 440 }                                                                       \
 441                                                                         \
 442 static int ftrace_raw_reg_event_##call(void)                            \
 443 {                                                                       \
 444         int ret;                                                        \
 445                                                                         \
 446         ret = register_trace_##call(ftrace_raw_event_##call);           \
 447         if (ret)                                                        \
 448                 pr_info("event trace: Could not activate trace point "  \
 449                         "probe to " #call "\n");                        \
 450         return ret;                                                     \
 451 }                                                                       \
 452                                                                         \
 453 static void ftrace_raw_unreg_event_##call(void)                         \
 454 {                                                                       \
 455         unregister_trace_##call(ftrace_raw_event_##call);               \
 456 }                                                                       \
 457                                                                         \
 458 static struct trace_event ftrace_event_type_##call = {                  \
 459         .trace                  = ftrace_raw_output_##call,             \
 460 };                                                                      \
 461                                                                         \
 462 static int ftrace_raw_init_event_##call(void)                           \
 463 {                                                                       \
 464         int id;                                                         \
 465                                                                         \
 466         id = register_ftrace_event(&ftrace_event_type_##call);          \
 467         if (!id)                                                        \
 468                 return -ENODEV;                                         \
 469         event_##call.id = id;                                           \
 470         INIT_LIST_HEAD(&event_##call.fields);                           \
 471         init_preds(&event_##call);                                      \
 472         return 0;                                                       \
 473 }                                                                       \
 474                                                                         \
 475 static struct ftrace_event_call __used                                  \
 476 __attribute__((__aligned__(4)))                                         \
 477 __attribute__((section("_ftrace_events"))) event_##call = {             \
 478         .name                   = #call,                                \
 479         .system                 = __stringify(TRACE_SYSTEM),            \
 480         .event                  = &ftrace_event_type_##call,            \
 481         .raw_init               = ftrace_raw_init_event_##call,         \
 482         .regfunc                = ftrace_raw_reg_event_##call,          \
 483         .unregfunc              = ftrace_raw_unreg_event_##call,        \
 484         .show_format            = ftrace_format_##call,                 \
 485         .define_fields          = ftrace_define_fields_##call,          \
 486         _TRACE_PROFILE_INIT(call)                                       \
 487 }
 488
 489 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 490
 491 #undef _TRACE_PROFILE
 492 #undef _TRACE_PROFILE_INIT
 493