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