linux/include/trace/trace_events.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Stage 1 of the trace events.
   4 *
   5 * Override the macros in the event tracepoint header <trace/events/XXX.h>
   6 * to include the following:
   7 *
   8 * struct trace_event_raw_<call> {
   9 *      struct trace_entry              ent;
  10 *      <type>                          <item>;
  11 *      <type2>                         <item2>[<len>];
  12 *      [...]
  13 * };
  14 *
  15 * The <type> <item> is created by the __field(type, item) macro or
  16 * the __array(type2, item2, len) macro.
  17 * We simply do "type item;", and that will create the fields
  18 * in the structure.
  19 */
  20
  21#include <linux/trace_events.h>
  22
  23#ifndef TRACE_SYSTEM_VAR
  24#define TRACE_SYSTEM_VAR TRACE_SYSTEM
  25#endif
  26
  27#include "stages/init.h"
  28
  29/*
  30 * DECLARE_EVENT_CLASS can be used to add a generic function
  31 * handlers for events. That is, if all events have the same
  32 * parameters and just have distinct trace points.
  33 * Each tracepoint can be defined with DEFINE_EVENT and that
  34 * will map the DECLARE_EVENT_CLASS to the tracepoint.
  35 *
  36 * TRACE_EVENT is a one to one mapping between tracepoint and template.
  37 */
  38#undef TRACE_EVENT
  39#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
  40        DECLARE_EVENT_CLASS(name,                              \
  41                             PARAMS(proto),                    \
  42                             PARAMS(args),                     \
  43                             PARAMS(tstruct),                  \
  44                             PARAMS(assign),                   \
  45                             PARAMS(print));                   \
  46        DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
  47
  48#undef TRACE_EVENT_SYSCALL
  49#define TRACE_EVENT_SYSCALL(name, proto, args, tstruct, assign, print, reg, unreg) \
  50        DECLARE_EVENT_SYSCALL_CLASS(name,                      \
  51                             PARAMS(proto),                    \
  52                             PARAMS(args),                     \
  53                             PARAMS(tstruct),                  \
  54                             PARAMS(assign),                   \
  55                             PARAMS(print));                   \
  56        DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
  57
  58#include "stages/stage1_struct_define.h"
  59
  60#undef DECLARE_EVENT_CLASS
  61#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)  \
  62        struct trace_event_raw_##name {                                 \
  63                struct trace_entry      ent;                            \
  64                tstruct                                                 \
  65                char                    __data[];                       \
  66        };                                                              \
  67                                                                        \
  68        static struct trace_event_class event_class_##name;
  69
  70#undef DECLARE_EVENT_SYSCALL_CLASS
  71#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
  72
  73#undef DEFINE_EVENT
  74#define DEFINE_EVENT(template, name, proto, args)       \
  75        static struct trace_event_call  __used          \
  76        __attribute__((__aligned__(4))) event_##name
  77
  78#undef DEFINE_EVENT_FN
  79#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)        \
  80        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
  81
  82#undef DEFINE_EVENT_PRINT
  83#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
  84        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
  85
  86/* Callbacks are meaningless to ftrace. */
  87#undef TRACE_EVENT_FN
  88#define TRACE_EVENT_FN(name, proto, args, tstruct,                      \
  89                assign, print, reg, unreg)                              \
  90        TRACE_EVENT(name, PARAMS(proto), PARAMS(args),                  \
  91                PARAMS(tstruct), PARAMS(assign), PARAMS(print))         \
  92
  93#undef TRACE_EVENT_FN_COND
  94#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct,   \
  95                assign, print, reg, unreg)                              \
  96        TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond),          \
  97                PARAMS(tstruct), PARAMS(assign), PARAMS(print))         \
  98
  99#undef TRACE_EVENT_FLAGS
 100#define TRACE_EVENT_FLAGS(name, value)                                  \
 101        __TRACE_EVENT_FLAGS(name, value)
 102
 103#undef TRACE_EVENT_PERF_PERM
 104#define TRACE_EVENT_PERF_PERM(name, expr...)                            \
 105        __TRACE_EVENT_PERF_PERM(name, expr)
 106
 107#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 108
 109/*
 110 * Stage 2 of the trace events.
 111 *
 112 * Include the following:
 113 *
 114 * struct trace_event_data_offsets_<call> {
 115 *      u32                             <item1>;
 116 *      u32                             <item2>;
 117 *      [...]
 118 * };
 119 *
 120 * The __dynamic_array() macro will create each u32 <item>, this is
 121 * to keep the offset of each array from the beginning of the event.
 122 * The size of an array is also encoded, in the higher 16 bits of <item>.
 123 */
 124
 125#include "stages/stage2_data_offsets.h"
 126
 127#undef DECLARE_EVENT_CLASS
 128#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 129        struct trace_event_data_offsets_##call {                        \
 130                tstruct;                                                \
 131        };
 132
 133#undef DECLARE_EVENT_SYSCALL_CLASS
 134#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
 135
 136#undef DEFINE_EVENT
 137#define DEFINE_EVENT(template, name, proto, args)
 138
 139#undef DEFINE_EVENT_PRINT
 140#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
 141
 142#undef TRACE_EVENT_FLAGS
 143#define TRACE_EVENT_FLAGS(event, flag)
 144
 145#undef TRACE_EVENT_PERF_PERM
 146#define TRACE_EVENT_PERF_PERM(event, expr...)
 147
 148#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 149
 150/*
 151 * Stage 3 of the trace events.
 152 *
 153 * Override the macros in the event tracepoint header <trace/events/XXX.h>
 154 * to include the following:
 155 *
 156 * enum print_line_t
 157 * trace_raw_output_<call>(struct trace_iterator *iter, int flags)
 158 * {
 159 *      struct trace_seq *s = &iter->seq;
 160 *      struct trace_event_raw_<call> *field; <-- defined in stage 1
 161 *      struct trace_seq *p = &iter->tmp_seq;
 162 *
 163 * -------(for event)-------
 164 *
 165 *      struct trace_entry *entry;
 166 *
 167 *      entry = iter->ent;
 168 *
 169 *      if (entry->type != event_<call>->event.type) {
 170 *              WARN_ON_ONCE(1);
 171 *              return TRACE_TYPE_UNHANDLED;
 172 *      }
 173 *
 174 *      field = (typeof(field))entry;
 175 *
 176 *      trace_seq_init(p);
 177 *      return trace_output_call(iter, <call>, <TP_printk> "\n");
 178 *
 179 * ------(or, for event class)------
 180 *
 181 *      int ret;
 182 *
 183 *      field = (typeof(field))iter->ent;
 184 *
 185 *      ret = trace_raw_output_prep(iter, trace_event);
 186 *      if (ret != TRACE_TYPE_HANDLED)
 187 *              return ret;
 188 *
 189 *      trace_event_printf(iter, <TP_printk> "\n");
 190 *
 191 *      return trace_handle_return(s);
 192 * -------
 193 *  }
 194 *
 195 * This is the method used to print the raw event to the trace
 196 * output format. Note, this is not needed if the data is read
 197 * in binary.
 198 */
 199
 200#include "stages/stage3_trace_output.h"
 201
 202#undef DECLARE_EVENT_CLASS
 203#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 204static notrace enum print_line_t                                        \
 205trace_raw_output_##call(struct trace_iterator *iter, int flags,         \
 206                        struct trace_event *trace_event)                \
 207{                                                                       \
 208        struct trace_seq *s = &iter->seq;                               \
 209        struct trace_seq __maybe_unused *p = &iter->tmp_seq;            \
 210        struct trace_event_raw_##call *field;                           \
 211        int ret;                                                        \
 212                                                                        \
 213        field = (typeof(field))iter->ent;                               \
 214                                                                        \
 215        ret = trace_raw_output_prep(iter, trace_event);                 \
 216        if (ret != TRACE_TYPE_HANDLED)                                  \
 217                return ret;                                             \
 218                                                                        \
 219        trace_event_printf(iter, print);                                \
 220                                                                        \
 221        return trace_handle_return(s);                                  \
 222}                                                                       \
 223static struct trace_event_functions trace_event_type_funcs_##call = {   \
 224        .trace                  = trace_raw_output_##call,              \
 225};
 226
 227#undef DECLARE_EVENT_SYSCALL_CLASS
 228#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
 229
 230#undef DEFINE_EVENT_PRINT
 231#define DEFINE_EVENT_PRINT(template, call, proto, args, print)          \
 232static notrace enum print_line_t                                        \
 233trace_raw_output_##call(struct trace_iterator *iter, int flags,         \
 234                         struct trace_event *event)                     \
 235{                                                                       \
 236        struct trace_event_raw_##template *field;                       \
 237        struct trace_entry *entry;                                      \
 238        struct trace_seq *p = &iter->tmp_seq;                           \
 239                                                                        \
 240        entry = iter->ent;                                              \
 241                                                                        \
 242        if (entry->type != event_##call.event.type) {                   \
 243                WARN_ON_ONCE(1);                                        \
 244                return TRACE_TYPE_UNHANDLED;                            \
 245        }                                                               \
 246                                                                        \
 247        field = (typeof(field))entry;                                   \
 248                                                                        \
 249        trace_seq_init(p);                                              \
 250        return trace_output_call(iter, #call, print);                   \
 251}                                                                       \
 252static struct trace_event_functions trace_event_type_funcs_##call = {   \
 253        .trace                  = trace_raw_output_##call,              \
 254};
 255
 256#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 257
 258#include "stages/stage4_event_fields.h"
 259
 260#undef DECLARE_EVENT_CLASS
 261#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)    \
 262static struct trace_event_fields trace_event_fields_##call[] = {        \
 263        tstruct                                                         \
 264        {} };
 265
 266#undef DECLARE_EVENT_SYSCALL_CLASS
 267#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
 268
 269#undef DEFINE_EVENT_PRINT
 270#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
 271
 272#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 273
 274#include "stages/stage5_get_offsets.h"
 275
 276#undef DECLARE_EVENT_CLASS
 277#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 278static inline notrace int trace_event_get_offsets_##call(               \
 279        struct trace_event_data_offsets_##call *__data_offsets, proto)  \
 280{                                                                       \
 281        int __data_size = 0;                                            \
 282        int __maybe_unused __item_length;                               \
 283        struct trace_event_raw_##call __maybe_unused *entry;            \
 284                                                                        \
 285        tstruct;                                                        \
 286                                                                        \
 287        return __data_size;                                             \
 288}
 289
 290#undef DECLARE_EVENT_SYSCALL_CLASS
 291#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
 292
 293#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 294
 295/*
 296 * Stage 4 of the trace events.
 297 *
 298 * Override the macros in the event tracepoint header <trace/events/XXX.h>
 299 * to include the following:
 300 *
 301 * For those macros defined with TRACE_EVENT:
 302 *
 303 * static struct trace_event_call event_<call>;
 304 *
 305 * static void trace_event_raw_event_<call>(void *__data, proto)
 306 * {
 307 *      struct trace_event_file *trace_file = __data;
 308 *      struct trace_event_call *event_call = trace_file->event_call;
 309 *      struct trace_event_data_offsets_<call> __maybe_unused __data_offsets;
 310 *      unsigned long eflags = trace_file->flags;
 311 *      enum event_trigger_type __tt = ETT_NONE;
 312 *      struct ring_buffer_event *event;
 313 *      struct trace_event_raw_<call> *entry; <-- defined in stage 1
 314 *      struct trace_buffer *buffer;
 315 *      unsigned long irq_flags;
 316 *      int __data_size;
 317 *      int pc;
 318 *
 319 *      if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
 320 *              if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
 321 *                      event_triggers_call(trace_file, NULL);
 322 *              if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
 323 *                      return;
 324 *      }
 325 *
 326 *      local_save_flags(irq_flags);
 327 *      pc = preempt_count();
 328 *
 329 *      __data_size = trace_event_get_offsets_<call>(&__data_offsets, args);
 330 *
 331 *      event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 332 *                                event_<call>->event.type,
 333 *                                sizeof(*entry) + __data_size,
 334 *                                irq_flags, pc);
 335 *      if (!event)
 336 *              return;
 337 *      entry   = ring_buffer_event_data(event);
 338 *
 339 *      { <assign>; }  <-- Here we assign the entries by the __field and
 340 *                         __array macros.
 341 *
 342 *      if (eflags & EVENT_FILE_FL_TRIGGER_COND)
 343 *              __tt = event_triggers_call(trace_file, entry);
 344 *
 345 *      if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT,
 346 *                   &trace_file->flags))
 347 *              ring_buffer_discard_commit(buffer, event);
 348 *      else if (!filter_check_discard(trace_file, entry, buffer, event))
 349 *              trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
 350 *
 351 *      if (__tt)
 352 *              event_triggers_post_call(trace_file, __tt);
 353 * }
 354 *
 355 * static struct trace_event ftrace_event_type_<call> = {
 356 *      .trace                  = trace_raw_output_<call>, <-- stage 2
 357 * };
 358 *
 359 * static char print_fmt_<call>[] = <TP_printk>;
 360 *
 361 * static struct trace_event_class __used event_class_<template> = {
 362 *      .system                 = "<system>",
 363 *      .fields_array           = trace_event_fields_<call>,
 364 *      .fields                 = LIST_HEAD_INIT(event_class_##call.fields),
 365 *      .raw_init               = trace_event_raw_init,
 366 *      .probe                  = trace_event_raw_event_##call,
 367 *      .reg                    = trace_event_reg,
 368 * };
 369 *
 370 * static struct trace_event_call event_<call> = {
 371 *      .class                  = event_class_<template>,
 372 *      {
 373 *              .tp                     = &__tracepoint_<call>,
 374 *      },
 375 *      .event                  = &ftrace_event_type_<call>,
 376 *      .print_fmt              = print_fmt_<call>,
 377 *      .flags                  = TRACE_EVENT_FL_TRACEPOINT,
 378 * };
 379 * // its only safe to use pointers when doing linker tricks to
 380 * // create an array.
 381 * static struct trace_event_call __used
 382 * __section("_ftrace_events") *__event_<call> = &event_<call>;
 383 *
 384 */
 385
 386#ifdef CONFIG_PERF_EVENTS
 387
 388#define _TRACE_PERF_PROTO(call, proto)                                  \
 389        static notrace void                                             \
 390        perf_trace_##call(void *__data, proto);
 391
 392#define _TRACE_PERF_INIT(call)                                          \
 393        .perf_probe             = perf_trace_##call,
 394
 395#else
 396#define _TRACE_PERF_PROTO(call, proto)
 397#define _TRACE_PERF_INIT(call)
 398#endif /* CONFIG_PERF_EVENTS */
 399
 400#include "stages/stage6_event_callback.h"
 401
 402
 403#undef __DECLARE_EVENT_CLASS
 404#define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
 405static notrace void                                                     \
 406do_trace_event_raw_event_##call(void *__data, proto)                    \
 407{                                                                       \
 408        struct trace_event_file *trace_file = __data;                   \
 409        struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
 410        struct trace_event_buffer fbuffer;                              \
 411        struct trace_event_raw_##call *entry;                           \
 412        int __data_size;                                                \
 413                                                                        \
 414        if (trace_trigger_soft_disabled(trace_file))                    \
 415                return;                                                 \
 416                                                                        \
 417        __data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
 418                                                                        \
 419        entry = trace_event_buffer_reserve(&fbuffer, trace_file,        \
 420                                 sizeof(*entry) + __data_size);         \
 421                                                                        \
 422        if (!entry)                                                     \
 423                return;                                                 \
 424                                                                        \
 425        tstruct                                                         \
 426                                                                        \
 427        { assign; }                                                     \
 428                                                                        \
 429        trace_event_buffer_commit(&fbuffer);                            \
 430}
 431
 432#undef DECLARE_EVENT_CLASS
 433#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 434__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
 435                      PARAMS(assign), PARAMS(print))                    \
 436static notrace void                                                     \
 437trace_event_raw_event_##call(void *__data, proto)                       \
 438{                                                                       \
 439        do_trace_event_raw_event_##call(__data, args);                  \
 440}
 441
 442#undef DECLARE_EVENT_SYSCALL_CLASS
 443#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
 444__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
 445                      PARAMS(assign), PARAMS(print))                    \
 446static notrace void                                                     \
 447trace_event_raw_event_##call(void *__data, proto)                       \
 448{                                                                       \
 449        might_fault();                                                  \
 450        preempt_disable_notrace();                                      \
 451        do_trace_event_raw_event_##call(__data, args);                  \
 452        preempt_enable_notrace();                                       \
 453}
 454
 455/*
 456 * The ftrace_test_probe is compiled out, it is only here as a build time check
 457 * to make sure that if the tracepoint handling changes, the ftrace probe will
 458 * fail to compile unless it too is updated.
 459 */
 460
 461#undef DEFINE_EVENT
 462#define DEFINE_EVENT(template, call, proto, args)                       \
 463static inline void ftrace_test_probe_##call(void)                       \
 464{                                                                       \
 465        check_trace_callback_type_##call(trace_event_raw_event_##template); \
 466}
 467
 468#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 469
 470#undef __DECLARE_EVENT_CLASS
 471
 472#include "stages/stage7_class_define.h"
 473
 474#undef DECLARE_EVENT_CLASS
 475#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
 476_TRACE_PERF_PROTO(call, PARAMS(proto));                                 \
 477static char print_fmt_##call[] = print;                                 \
 478static struct trace_event_class __used __refdata event_class_##call = { \
 479        .system                 = TRACE_SYSTEM_STRING,                  \
 480        .fields_array           = trace_event_fields_##call,            \
 481        .fields                 = LIST_HEAD_INIT(event_class_##call.fields),\
 482        .raw_init               = trace_event_raw_init,                 \
 483        .probe                  = trace_event_raw_event_##call,         \
 484        .reg                    = trace_event_reg,                      \
 485        _TRACE_PERF_INIT(call)                                          \
 486};
 487
 488#undef DECLARE_EVENT_SYSCALL_CLASS
 489#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
 490
 491#undef DEFINE_EVENT
 492#define DEFINE_EVENT(template, call, proto, args)                       \
 493                                                                        \
 494static struct trace_event_call __used event_##call = {                  \
 495        .class                  = &event_class_##template,              \
 496        {                                                               \
 497                .tp                     = &__tracepoint_##call,         \
 498        },                                                              \
 499        .event.funcs            = &trace_event_type_funcs_##template,   \
 500        .print_fmt              = print_fmt_##template,                 \
 501        .flags                  = TRACE_EVENT_FL_TRACEPOINT,            \
 502};                                                                      \
 503static struct trace_event_call __used                                   \
 504__section("_ftrace_events") *__event_##call = &event_##call
 505
 506#undef DEFINE_EVENT_PRINT
 507#define DEFINE_EVENT_PRINT(template, call, proto, args, print)          \
 508                                                                        \
 509static char print_fmt_##call[] = print;                                 \
 510                                                                        \
 511static struct trace_event_call __used event_##call = {                  \
 512        .class                  = &event_class_##template,              \
 513        {                                                               \
 514                .tp                     = &__tracepoint_##call,         \
 515        },                                                              \
 516        .event.funcs            = &trace_event_type_funcs_##call,       \
 517        .print_fmt              = print_fmt_##call,                     \
 518        .flags                  = TRACE_EVENT_FL_TRACEPOINT,            \
 519};                                                                      \
 520static struct trace_event_call __used                                   \
 521__section("_ftrace_events") *__event_##call = &event_##call
 522
 523#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 524