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