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 /*
  22  * DECLARE_EVENT_CLASS can be used to add a generic function
  23  * handlers for events. That is, if all events have the same
  24  * parameters and just have distinct trace points.
  25  * Each tracepoint can be defined with DEFINE_EVENT and that
  26  * will map the DECLARE_EVENT_CLASS to the tracepoint.
  27  *
  28  * TRACE_EVENT is a one to one mapping between tracepoint and template.
  29  */
  30 #undef TRACE_EVENT
  31 #define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
  32         DECLARE_EVENT_CLASS(name,                              \
  33                              PARAMS(proto),                    \
  34                              PARAMS(args),                     \
  35                              PARAMS(tstruct),                  \
  36                              PARAMS(assign),                   \
  37                              PARAMS(print));                   \
  38         DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
  39
  40
  41 #undef __field
  42 #define __field(type, item)             type    item;
  43
  44 #undef __field_ext
  45 #define __field_ext(type, item, filter_type)    type    item;
  46
  47 #undef __array
  48 #define __array(type, item, len)        type    item[len];
  49
  50 #undef __dynamic_array
  51 #define __dynamic_array(type, item, len) u32 __data_loc_##item;
  52
  53 #undef __string
  54 #define __string(item, src) __dynamic_array(char, item, -1)
  55
  56 #undef TP_STRUCT__entry
  57 #define TP_STRUCT__entry(args...) args
  58
  59 #undef DECLARE_EVENT_CLASS
  60 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)  \
  61         struct ftrace_raw_##name {                                      \
  62                 struct trace_entry      ent;                            \
  63                 tstruct                                                 \
  64                 char                    __data[0];                      \
  65         };                                                              \
  66                                                                         \
  67         static struct ftrace_event_class event_class_##name;
  68
  69 #undef DEFINE_EVENT
  70 #define DEFINE_EVENT(template, name, proto, args)       \
  71         static struct ftrace_event_call __used          \
  72         __attribute__((__aligned__(4))) event_##name
  73
  74 #undef DEFINE_EVENT_PRINT
  75 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
  76         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
  77
  78 /* Callbacks are meaningless to ftrace. */
  79 #undef TRACE_EVENT_FN
  80 #define TRACE_EVENT_FN(name, proto, args, tstruct,                      \
  81                 assign, print, reg, unreg)                              \
  82         TRACE_EVENT(name, PARAMS(proto), PARAMS(args),                  \
  83                 PARAMS(tstruct), PARAMS(assign), PARAMS(print))         \
  84
  85 #undef TRACE_EVENT_FLAGS
  86 #define TRACE_EVENT_FLAGS(name, value)                                  \
  87         __TRACE_EVENT_FLAGS(name, value)
  88
  89 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
  90
  91
  92 /*
  93  * Stage 2 of the trace events.
  94  *
  95  * Include the following:
  96  *
  97  * struct ftrace_data_offsets_<call> {
  98  *      u32                             <item1>;
  99  *      u32                             <item2>;
 100  *      [...]
 101  * };
 102  *
 103  * The __dynamic_array() macro will create each u32 <item>, this is
 104  * to keep the offset of each array from the beginning of the event.
 105  * The size of an array is also encoded, in the higher 16 bits of <item>.
 106  */
 107
 108 #undef __field
 109 #define __field(type, item)
 110
 111 #undef __field_ext
 112 #define __field_ext(type, item, filter_type)
 113
 114 #undef __array
 115 #define __array(type, item, len)
 116
 117 #undef __dynamic_array
 118 #define __dynamic_array(type, item, len)        u32 item;
 119
 120 #undef __string
 121 #define __string(item, src) __dynamic_array(char, item, -1)
 122
 123 #undef DECLARE_EVENT_CLASS
 124 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 125         struct ftrace_data_offsets_##call {                             \
 126                 tstruct;                                                \
 127         };
 128
 129 #undef DEFINE_EVENT
 130 #define DEFINE_EVENT(template, name, proto, args)
 131
 132 #undef DEFINE_EVENT_PRINT
 133 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 134         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 135
 136 #undef TRACE_EVENT_FLAGS
 137 #define TRACE_EVENT_FLAGS(event, flag)
 138
 139 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 140
 141 /*
 142  * Stage 3 of the trace events.
 143  *
 144  * Override the macros in <trace/trace_events.h> to include the following:
 145  *
 146  * enum print_line_t
 147  * ftrace_raw_output_<call>(struct trace_iterator *iter, int flags)
 148  * {
 149  *      struct trace_seq *s = &iter->seq;
 150  *      struct ftrace_raw_<call> *field; <-- defined in stage 1
 151  *      struct trace_entry *entry;
 152  *      struct trace_seq *p = &iter->tmp_seq;
 153  *      int ret;
 154  *
 155  *      entry = iter->ent;
 156  *
 157  *      if (entry->type != event_<call>->event.type) {
 158  *              WARN_ON_ONCE(1);
 159  *              return TRACE_TYPE_UNHANDLED;
 160  *      }
 161  *
 162  *      field = (typeof(field))entry;
 163  *
 164  *      trace_seq_init(p);
 165  *      ret = trace_seq_printf(s, "%s: ", <call>);
 166  *      if (ret)
 167  *              ret = trace_seq_printf(s, <TP_printk> "\n");
 168  *      if (!ret)
 169  *              return TRACE_TYPE_PARTIAL_LINE;
 170  *
 171  *      return TRACE_TYPE_HANDLED;
 172  * }
 173  *
 174  * This is the method used to print the raw event to the trace
 175  * output format. Note, this is not needed if the data is read
 176  * in binary.
 177  */
 178
 179 #undef __entry
 180 #define __entry field
 181
 182 #undef TP_printk
 183 #define TP_printk(fmt, args...) fmt "\n", args
 184
 185 #undef __get_dynamic_array
 186 #define __get_dynamic_array(field)      \
 187                 ((void *)__entry + (__entry->__data_loc_##field & 0xffff))
 188
 189 #undef __get_str
 190 #define __get_str(field) (char *)__get_dynamic_array(field)
 191
 192 #undef __print_flags
 193 #define __print_flags(flag, delim, flag_array...)                       \
 194         ({                                                              \
 195                 static const struct trace_print_flags __flags[] =       \
 196                         { flag_array, { -1, NULL }};                    \
 197                 ftrace_print_flags_seq(p, delim, flag, __flags);        \
 198         })
 199
 200 #undef __print_symbolic
 201 #define __print_symbolic(value, symbol_array...)                        \
 202         ({                                                              \
 203                 static const struct trace_print_flags symbols[] =       \
 204                         { symbol_array, { -1, NULL }};                  \
 205                 ftrace_print_symbols_seq(p, value, symbols);            \
 206         })
 207
 208 #undef __print_hex
 209 #define __print_hex(buf, buf_len) ftrace_print_hex_seq(p, buf, buf_len)
 210
 211 #undef DECLARE_EVENT_CLASS
 212 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 213 static notrace enum print_line_t                                        \
 214 ftrace_raw_output_##call(struct trace_iterator *iter, int flags,        \
 215                          struct trace_event *trace_event)               \
 216 {                                                                       \
 217         struct ftrace_event_call *event;                                \
 218         struct trace_seq *s = &iter->seq;                               \
 219         struct ftrace_raw_##call *field;                                \
 220         struct trace_entry *entry;                                      \
 221         struct trace_seq *p = &iter->tmp_seq;                           \
 222         int ret;                                                        \
 223                                                                         \
 224         event = container_of(trace_event, struct ftrace_event_call,     \
 225                              event);                                    \
 226                                                                         \
 227         entry = iter->ent;                                              \
 228                                                                         \
 229         if (entry->type != event->event.type) {                         \
 230                 WARN_ON_ONCE(1);                                        \
 231                 return TRACE_TYPE_UNHANDLED;                            \
 232         }                                                               \
 233                                                                         \
 234         field = (typeof(field))entry;                                   \
 235                                                                         \
 236         trace_seq_init(p);                                              \
 237         ret = trace_seq_printf(s, "%s: ", event->name);                 \
 238         if (ret)                                                        \
 239                 ret = trace_seq_printf(s, print);                       \
 240         if (!ret)                                                       \
 241                 return TRACE_TYPE_PARTIAL_LINE;                         \
 242                                                                         \
 243         return TRACE_TYPE_HANDLED;                                      \
 244 }                                                                       \
 245 static struct trace_event_functions ftrace_event_type_funcs_##call = {  \
 246         .trace                  = ftrace_raw_output_##call,             \
 247 };
 248
 249 #undef DEFINE_EVENT_PRINT
 250 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)          \
 251 static notrace enum print_line_t                                        \
 252 ftrace_raw_output_##call(struct trace_iterator *iter, int flags,        \
 253                          struct trace_event *event)                     \
 254 {                                                                       \
 255         struct trace_seq *s = &iter->seq;                               \
 256         struct ftrace_raw_##template *field;                            \
 257         struct trace_entry *entry;                                      \
 258         struct trace_seq *p = &iter->tmp_seq;                           \
 259         int ret;                                                        \
 260                                                                         \
 261         entry = iter->ent;                                              \
 262                                                                         \
 263         if (entry->type != event_##call.event.type) {                   \
 264                 WARN_ON_ONCE(1);                                        \
 265                 return TRACE_TYPE_UNHANDLED;                            \
 266         }                                                               \
 267                                                                         \
 268         field = (typeof(field))entry;                                   \
 269                                                                         \
 270         trace_seq_init(p);                                              \
 271         ret = trace_seq_printf(s, "%s: ", #call);                       \
 272         if (ret)                                                        \
 273                 ret = trace_seq_printf(s, print);                       \
 274         if (!ret)                                                       \
 275                 return TRACE_TYPE_PARTIAL_LINE;                         \
 276                                                                         \
 277         return TRACE_TYPE_HANDLED;                                      \
 278 }                                                                       \
 279 static struct trace_event_functions ftrace_event_type_funcs_##call = {  \
 280         .trace                  = ftrace_raw_output_##call,             \
 281 };
 282
 283 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 284
 285 #undef __field_ext
 286 #define __field_ext(type, item, filter_type)                            \
 287         ret = trace_define_field(event_call, #type, #item,              \
 288                                  offsetof(typeof(field), item),         \
 289                                  sizeof(field.item),                    \
 290                                  is_signed_type(type), filter_type);    \
 291         if (ret)                                                        \
 292                 return ret;
 293
 294 #undef __field
 295 #define __field(type, item)     __field_ext(type, item, FILTER_OTHER)
 296
 297 #undef __array
 298 #define __array(type, item, len)                                        \
 299         do {                                                            \
 300                 mutex_lock(&event_storage_mutex);                       \
 301                 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                 \
 302                 snprintf(event_storage, sizeof(event_storage),          \
 303                          "%s[%d]", #type, len);                         \
 304                 ret = trace_define_field(event_call, event_storage, #item, \
 305                                  offsetof(typeof(field), item),         \
 306                                  sizeof(field.item),                    \
 307                                  is_signed_type(type), FILTER_OTHER);   \
 308                 mutex_unlock(&event_storage_mutex);                     \
 309                 if (ret)                                                \
 310                         return ret;                                     \
 311         } while (0);
 312
 313 #undef __dynamic_array
 314 #define __dynamic_array(type, item, len)                                       \
 315         ret = trace_define_field(event_call, "__data_loc " #type "[]", #item,  \
 316                                  offsetof(typeof(field), __data_loc_##item),   \
 317                                  sizeof(field.__data_loc_##item),              \
 318                                  is_signed_type(type), FILTER_OTHER);
 319
 320 #undef __string
 321 #define __string(item, src) __dynamic_array(char, item, -1)
 322
 323 #undef DECLARE_EVENT_CLASS
 324 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)    \
 325 static int notrace                                                      \
 326 ftrace_define_fields_##call(struct ftrace_event_call *event_call)       \
 327 {                                                                       \
 328         struct ftrace_raw_##call field;                                 \
 329         int ret;                                                        \
 330                                                                         \
 331         tstruct;                                                        \
 332                                                                         \
 333         return ret;                                                     \
 334 }
 335
 336 #undef DEFINE_EVENT
 337 #define DEFINE_EVENT(template, name, proto, args)
 338
 339 #undef DEFINE_EVENT_PRINT
 340 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 341         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 342
 343 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 344
 345 /*
 346  * remember the offset of each array from the beginning of the event.
 347  */
 348
 349 #undef __entry
 350 #define __entry entry
 351
 352 #undef __field
 353 #define __field(type, item)
 354
 355 #undef __field_ext
 356 #define __field_ext(type, item, filter_type)
 357
 358 #undef __array
 359 #define __array(type, item, len)
 360
 361 #undef __dynamic_array
 362 #define __dynamic_array(type, item, len)                                \
 363         __data_offsets->item = __data_size +                            \
 364                                offsetof(typeof(*entry), __data);        \
 365         __data_offsets->item |= (len * sizeof(type)) << 16;             \
 366         __data_size += (len) * sizeof(type);
 367
 368 #undef __string
 369 #define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)
 370
 371 #undef DECLARE_EVENT_CLASS
 372 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 373 static inline notrace int ftrace_get_offsets_##call(                    \
 374         struct ftrace_data_offsets_##call *__data_offsets, proto)       \
 375 {                                                                       \
 376         int __data_size = 0;                                            \
 377         struct ftrace_raw_##call __maybe_unused *entry;                 \
 378                                                                         \
 379         tstruct;                                                        \
 380                                                                         \
 381         return __data_size;                                             \
 382 }
 383
 384 #undef DEFINE_EVENT
 385 #define DEFINE_EVENT(template, name, proto, args)
 386
 387 #undef DEFINE_EVENT_PRINT
 388 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 389         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 390
 391 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 392
 393 /*
 394  * Stage 4 of the trace events.
 395  *
 396  * Override the macros in <trace/trace_events.h> to include the following:
 397  *
 398  * For those macros defined with TRACE_EVENT:
 399  *
 400  * static struct ftrace_event_call event_<call>;
 401  *
 402  * static void ftrace_raw_event_<call>(void *__data, proto)
 403  * {
 404  *      struct ftrace_event_call *event_call = __data;
 405  *      struct ftrace_data_offsets_<call> __maybe_unused __data_offsets;
 406  *      struct ring_buffer_event *event;
 407  *      struct ftrace_raw_<call> *entry; <-- defined in stage 1
 408  *      struct ring_buffer *buffer;
 409  *      unsigned long irq_flags;
 410  *      int __data_size;
 411  *      int pc;
 412  *
 413  *      local_save_flags(irq_flags);
 414  *      pc = preempt_count();
 415  *
 416  *      __data_size = ftrace_get_offsets_<call>(&__data_offsets, args);
 417  *
 418  *      event = trace_current_buffer_lock_reserve(&buffer,
 419  *                                event_<call>->event.type,
 420  *                                sizeof(*entry) + __data_size,
 421  *                                irq_flags, pc);
 422  *      if (!event)
 423  *              return;
 424  *      entry   = ring_buffer_event_data(event);
 425  *
 426  *      { <assign>; }  <-- Here we assign the entries by the __field and
 427  *                         __array macros.
 428  *
 429  *      if (!filter_current_check_discard(buffer, event_call, entry, event))
 430  *              trace_current_buffer_unlock_commit(buffer,
 431  *                                                 event, irq_flags, pc);
 432  * }
 433  *
 434  * static struct trace_event ftrace_event_type_<call> = {
 435  *      .trace                  = ftrace_raw_output_<call>, <-- stage 2
 436  * };
 437  *
 438  * static const char print_fmt_<call>[] = <TP_printk>;
 439  *
 440  * static struct ftrace_event_class __used event_class_<template> = {
 441  *      .system                 = "<system>",
 442  *      .define_fields          = ftrace_define_fields_<call>,
 443  *      .fields                 = LIST_HEAD_INIT(event_class_##call.fields),
 444  *      .raw_init               = trace_event_raw_init,
 445  *      .probe                  = ftrace_raw_event_##call,
 446  *      .reg                    = ftrace_event_reg,
 447  * };
 448  *
 449  * static struct ftrace_event_call __used
 450  * __attribute__((__aligned__(4)))
 451  * __attribute__((section("_ftrace_events"))) event_<call> = {
 452  *      .name                   = "<call>",
 453  *      .class                  = event_class_<template>,
 454  *      .event                  = &ftrace_event_type_<call>,
 455  *      .print_fmt              = print_fmt_<call>,
 456  * };
 457  *
 458  */
 459
 460 #ifdef CONFIG_PERF_EVENTS
 461
 462 #define _TRACE_PERF_PROTO(call, proto)                                  \
 463         static notrace void                                             \
 464         perf_trace_##call(void *__data, proto);
 465
 466 #define _TRACE_PERF_INIT(call)                                          \
 467         .perf_probe             = perf_trace_##call,
 468
 469 #else
 470 #define _TRACE_PERF_PROTO(call, proto)
 471 #define _TRACE_PERF_INIT(call)
 472 #endif /* CONFIG_PERF_EVENTS */
 473
 474 #undef __entry
 475 #define __entry entry
 476
 477 #undef __field
 478 #define __field(type, item)
 479
 480 #undef __array
 481 #define __array(type, item, len)
 482
 483 #undef __dynamic_array
 484 #define __dynamic_array(type, item, len)                                \
 485         __entry->__data_loc_##item = __data_offsets.item;
 486
 487 #undef __string
 488 #define __string(item, src) __dynamic_array(char, item, -1)             \
 489
 490 #undef __assign_str
 491 #define __assign_str(dst, src)                                          \
 492         strcpy(__get_str(dst), src);
 493
 494 #undef TP_fast_assign
 495 #define TP_fast_assign(args...) args
 496
 497 #undef TP_perf_assign
 498 #define TP_perf_assign(args...)
 499
 500 #undef DECLARE_EVENT_CLASS
 501 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 502                                                                         \
 503 static notrace void                                                     \
 504 ftrace_raw_event_##call(void *__data, proto)                            \
 505 {                                                                       \
 506         struct ftrace_event_call *event_call = __data;                  \
 507         struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
 508         struct ring_buffer_event *event;                                \
 509         struct ftrace_raw_##call *entry;                                \
 510         struct ring_buffer *buffer;                                     \
 511         unsigned long irq_flags;                                        \
 512         int __data_size;                                                \
 513         int pc;                                                         \
 514                                                                         \
 515         local_save_flags(irq_flags);                                    \
 516         pc = preempt_count();                                           \
 517                                                                         \
 518         __data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
 519                                                                         \
 520         event = trace_current_buffer_lock_reserve(&buffer,              \
 521                                  event_call->event.type,                \
 522                                  sizeof(*entry) + __data_size,          \
 523                                  irq_flags, pc);                        \
 524         if (!event)                                                     \
 525                 return;                                                 \
 526         entry   = ring_buffer_event_data(event);                        \
 527                                                                         \
 528         tstruct                                                         \
 529                                                                         \
 530         { assign; }                                                     \
 531                                                                         \
 532         if (!filter_current_check_discard(buffer, event_call, entry, event)) \
 533                 trace_nowake_buffer_unlock_commit(buffer,               \
 534                                                   event, irq_flags, pc); \
 535 }
 536 /*
 537  * The ftrace_test_probe is compiled out, it is only here as a build time check
 538  * to make sure that if the tracepoint handling changes, the ftrace probe will
 539  * fail to compile unless it too is updated.
 540  */
 541
 542 #undef DEFINE_EVENT
 543 #define DEFINE_EVENT(template, call, proto, args)                       \
 544 static inline void ftrace_test_probe_##call(void)                       \
 545 {                                                                       \
 546         check_trace_callback_type_##call(ftrace_raw_event_##template);  \
 547 }
 548
 549 #undef DEFINE_EVENT_PRINT
 550 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)
 551
 552 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 553
 554 #undef __entry
 555 #define __entry REC
 556
 557 #undef __print_flags
 558 #undef __print_symbolic
 559 #undef __get_dynamic_array
 560 #undef __get_str
 561
 562 #undef TP_printk
 563 #define TP_printk(fmt, args...) "\"" fmt "\", "  __stringify(args)
 564
 565 #undef DECLARE_EVENT_CLASS
 566 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 567 _TRACE_PERF_PROTO(call, PARAMS(proto));                                 \
 568 static const char print_fmt_##call[] = print;                           \
 569 static struct ftrace_event_class __used event_class_##call = {          \
 570         .system                 = __stringify(TRACE_SYSTEM),            \
 571         .define_fields          = ftrace_define_fields_##call,          \
 572         .fields                 = LIST_HEAD_INIT(event_class_##call.fields),\
 573         .raw_init               = trace_event_raw_init,                 \
 574         .probe                  = ftrace_raw_event_##call,              \
 575         .reg                    = ftrace_event_reg,                     \
 576         _TRACE_PERF_INIT(call)                                          \
 577 };
 578
 579 #undef DEFINE_EVENT
 580 #define DEFINE_EVENT(template, call, proto, args)                       \
 581                                                                         \
 582 static struct ftrace_event_call __used                                  \
 583 __attribute__((__aligned__(4)))                                         \
 584 __attribute__((section("_ftrace_events"))) event_##call = {             \
 585         .name                   = #call,                                \
 586         .class                  = &event_class_##template,              \
 587         .event.funcs            = &ftrace_event_type_funcs_##template,  \
 588         .print_fmt              = print_fmt_##template,                 \
 589 };
 590
 591 #undef DEFINE_EVENT_PRINT
 592 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)          \
 593                                                                         \
 594 static const char print_fmt_##call[] = print;                           \
 595                                                                         \
 596 static struct ftrace_event_call __used                                  \
 597 __attribute__((__aligned__(4)))                                         \
 598 __attribute__((section("_ftrace_events"))) event_##call = {             \
 599         .name                   = #call,                                \
 600         .class                  = &event_class_##template,              \
 601         .event.funcs            = &ftrace_event_type_funcs_##call,      \
 602         .print_fmt              = print_fmt_##call,                     \
 603 }
 604
 605 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 606
 607 /*
 608  * Define the insertion callback to perf events
 609  *
 610  * The job is very similar to ftrace_raw_event_<call> except that we don't
 611  * insert in the ring buffer but in a perf counter.
 612  *
 613  * static void ftrace_perf_<call>(proto)
 614  * {
 615  *      struct ftrace_data_offsets_<call> __maybe_unused __data_offsets;
 616  *      struct ftrace_event_call *event_call = &event_<call>;
 617  *      extern void perf_tp_event(int, u64, u64, void *, int);
 618  *      struct ftrace_raw_##call *entry;
 619  *      struct perf_trace_buf *trace_buf;
 620  *      u64 __addr = 0, __count = 1;
 621  *      unsigned long irq_flags;
 622  *      struct trace_entry *ent;
 623  *      int __entry_size;
 624  *      int __data_size;
 625  *      int __cpu
 626  *      int pc;
 627  *
 628  *      pc = preempt_count();
 629  *
 630  *      __data_size = ftrace_get_offsets_<call>(&__data_offsets, args);
 631  *
 632  *      // Below we want to get the aligned size by taking into account
 633  *      // the u32 field that will later store the buffer size
 634  *      __entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),
 635  *                           sizeof(u64));
 636  *      __entry_size -= sizeof(u32);
 637  *
 638  *      // Protect the non nmi buffer
 639  *      // This also protects the rcu read side
 640  *      local_irq_save(irq_flags);
 641  *      __cpu = smp_processor_id();
 642  *
 643  *      if (in_nmi())
 644  *              trace_buf = rcu_dereference_sched(perf_trace_buf_nmi);
 645  *      else
 646  *              trace_buf = rcu_dereference_sched(perf_trace_buf);
 647  *
 648  *      if (!trace_buf)
 649  *              goto end;
 650  *
 651  *      trace_buf = per_cpu_ptr(trace_buf, __cpu);
 652  *
 653  *      // Avoid recursion from perf that could mess up the buffer
 654  *      if (trace_buf->recursion++)
 655  *              goto end_recursion;
 656  *
 657  *      raw_data = trace_buf->buf;
 658  *
 659  *      // Make recursion update visible before entering perf_tp_event
 660  *      // so that we protect from perf recursions.
 661  *
 662  *      barrier();
 663  *
 664  *      //zero dead bytes from alignment to avoid stack leak to userspace:
 665  *      *(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL;
 666  *      entry = (struct ftrace_raw_<call> *)raw_data;
 667  *      ent = &entry->ent;
 668  *      tracing_generic_entry_update(ent, irq_flags, pc);
 669  *      ent->type = event_call->id;
 670  *
 671  *      <tstruct> <- do some jobs with dynamic arrays
 672  *
 673  *      <assign>  <- affect our values
 674  *
 675  *      perf_tp_event(event_call->id, __addr, __count, entry,
 676  *                   __entry_size);  <- submit them to perf counter
 677  *
 678  * }
 679  */
 680
 681 #ifdef CONFIG_PERF_EVENTS
 682
 683 #undef __entry
 684 #define __entry entry
 685
 686 #undef __get_dynamic_array
 687 #define __get_dynamic_array(field)      \
 688                 ((void *)__entry + (__entry->__data_loc_##field & 0xffff))
 689
 690 #undef __get_str
 691 #define __get_str(field) (char *)__get_dynamic_array(field)
 692
 693 #undef __perf_addr
 694 #define __perf_addr(a) __addr = (a)
 695
 696 #undef __perf_count
 697 #define __perf_count(c) __count = (c)
 698
 699 #undef DECLARE_EVENT_CLASS
 700 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 701 static notrace void                                                     \
 702 perf_trace_##call(void *__data, proto)                                  \
 703 {                                                                       \
 704         struct ftrace_event_call *event_call = __data;                  \
 705         struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
 706         struct ftrace_raw_##call *entry;                                \
 707         struct pt_regs __regs;                                          \
 708         u64 __addr = 0, __count = 1;                                    \
 709         struct hlist_head *head;                                        \
 710         int __entry_size;                                               \
 711         int __data_size;                                                \
 712         int rctx;                                                       \
 713                                                                         \
 714         perf_fetch_caller_regs(&__regs);                                \
 715                                                                         \
 716         __data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
 717         __entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
 718                              sizeof(u64));                              \
 719         __entry_size -= sizeof(u32);                                    \
 720                                                                         \
 721         if (WARN_ONCE(__entry_size > PERF_MAX_TRACE_SIZE,               \
 722                       "profile buffer not large enough"))               \
 723                 return;                                                 \
 724                                                                         \
 725         entry = (struct ftrace_raw_##call *)perf_trace_buf_prepare(     \
 726                 __entry_size, event_call->event.type, &__regs, &rctx);  \
 727         if (!entry)                                                     \
 728                 return;                                                 \
 729                                                                         \
 730         tstruct                                                         \
 731                                                                         \
 732         { assign; }                                                     \
 733                                                                         \
 734         head = this_cpu_ptr(event_call->perf_events);                   \
 735         perf_trace_buf_submit(entry, __entry_size, rctx, __addr,        \
 736                 __count, &__regs, head);                                \
 737 }
 738
 739 /*
 740  * This part is compiled out, it is only here as a build time check
 741  * to make sure that if the tracepoint handling changes, the
 742  * perf probe will fail to compile unless it too is updated.
 743  */
 744 #undef DEFINE_EVENT
 745 #define DEFINE_EVENT(template, call, proto, args)                       \
 746 static inline void perf_test_probe_##call(void)                         \
 747 {                                                                       \
 748         check_trace_callback_type_##call(perf_trace_##template);        \
 749 }
 750
 751
 752 #undef DEFINE_EVENT_PRINT
 753 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 754         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 755
 756 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 757 #endif /* CONFIG_PERF_EVENTS */
 758
 759 #undef _TRACE_PROFILE_INIT
 760