include/trace/ftrace.h

   1 /*
   2  * Stage 1 of the trace events.
   3  *
   4  * Override the macros in <trace/trace_events.h> to include the following:
   5  *
   6  * struct ftrace_raw_<call> {
   7  *      struct trace_entry              ent;
   8  *      <type>                          <item>;
   9  *      <type2>                         <item2>[<len>];
  10  *      [...]
  11  * };
  12  *
  13  * The <type> <item> is created by the __field(type, item) macro or
  14  * the __array(type2, item2, len) macro.
  15  * We simply do "type item;", and that will create the fields
  16  * in the structure.
  17  */
  18
  19 #include <linux/ftrace_event.h>
  20
  21 #undef __field
  22 #define __field(type, item)             type    item;
  23
  24 #undef __array
  25 #define __array(type, item, len)        type    item[len];
  26
  27 #undef __dynamic_array
  28 #define __dynamic_array(type, item, len) unsigned short __data_loc_##item;
  29
  30 #undef __string
  31 #define __string(item, src) __dynamic_array(char, item, -1)
  32
  33 #undef TP_STRUCT__entry
  34 #define TP_STRUCT__entry(args...) args
  35
  36 #undef TRACE_EVENT
  37 #define TRACE_EVENT(name, proto, args, tstruct, assign, print)  \
  38         struct ftrace_raw_##name {                              \
  39                 struct trace_entry      ent;                    \
  40                 tstruct                                         \
  41                 char                    __data[0];              \
  42         };                                                      \
  43         static struct ftrace_event_call event_##name
  44
  45 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
  46
  47
  48 /*
  49  * Stage 2 of the trace events.
  50  *
  51  * Include the following:
  52  *
  53  * struct ftrace_data_offsets_<call> {
  54  *      int                             <item1>;
  55  *      int                             <item2>;
  56  *      [...]
  57  * };
  58  *
  59  * The __dynamic_array() macro will create each int <item>, this is
  60  * to keep the offset of each array from the beginning of the event.
  61  */
  62
  63 #undef __field
  64 #define __field(type, item);
  65
  66 #undef __array
  67 #define __array(type, item, len)
  68
  69 #undef __dynamic_array
  70 #define __dynamic_array(type, item, len)        int item;
  71
  72 #undef __string
  73 #define __string(item, src) __dynamic_array(char, item, -1)
  74
  75 #undef TRACE_EVENT
  76 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
  77         struct ftrace_data_offsets_##call {                             \
  78                 tstruct;                                                \
  79         };
  80
  81 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
  82
  83 /*
  84  * Setup the showing format of trace point.
  85  *
  86  * int
  87  * ftrace_format_##call(struct trace_seq *s)
  88  * {
  89  *      struct ftrace_raw_##call field;
  90  *      int ret;
  91  *
  92  *      ret = trace_seq_printf(s, #type " " #item ";"
  93  *                             " offset:%u; size:%u;\n",
  94  *                             offsetof(struct ftrace_raw_##call, item),
  95  *                             sizeof(field.type));
  96  *
  97  * }
  98  */
  99
 100 #undef TP_STRUCT__entry
 101 #define TP_STRUCT__entry(args...) args
 102
 103 #undef __field
 104 #define __field(type, item)                                     \
 105         ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"      \
 106                                "offset:%u;\tsize:%u;\n",                \
 107                                (unsigned int)offsetof(typeof(field), item), \
 108                                (unsigned int)sizeof(field.item));       \
 109         if (!ret)                                                       \
 110                 return 0;
 111
 112 #undef __array
 113 #define __array(type, item, len)                                                \
 114         ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t"    \
 115                                "offset:%u;\tsize:%u;\n",                \
 116                                (unsigned int)offsetof(typeof(field), item), \
 117                                (unsigned int)sizeof(field.item));       \
 118         if (!ret)                                                       \
 119                 return 0;
 120
 121 #undef __dynamic_array
 122 #define __dynamic_array(type, item, len)                                       \
 123         ret = trace_seq_printf(s, "\tfield:__data_loc " #item ";\t"            \
 124                                "offset:%u;\tsize:%u;\n",                       \
 125                                (unsigned int)offsetof(typeof(field),           \
 126                                         __data_loc_##item),                    \
 127                                (unsigned int)sizeof(field.__data_loc_##item)); \
 128         if (!ret)                                                              \
 129                 return 0;
 130
 131 #undef __string
 132 #define __string(item, src) __dynamic_array(char, item, -1)
 133
 134 #undef __entry
 135 #define __entry REC
 136
 137 #undef __print_symbolic
 138 #undef __get_dynamic_array
 139 #undef __get_str
 140
 141 #undef TP_printk
 142 #define TP_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
 143
 144 #undef TP_fast_assign
 145 #define TP_fast_assign(args...) args
 146
 147 #undef TP_perf_assign
 148 #define TP_perf_assign(args...)
 149
 150 #undef TRACE_EVENT
 151 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 152 static int                                                              \
 153 ftrace_format_##call(struct trace_seq *s)                               \
 154 {                                                                       \
 155         struct ftrace_raw_##call field __attribute__((unused));         \
 156         int ret = 0;                                                    \
 157                                                                         \
 158         tstruct;                                                        \
 159                                                                         \
 160         trace_seq_printf(s, "\nprint fmt: " print);                     \
 161                                                                         \
 162         return ret;                                                     \
 163 }
 164
 165 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 166
 167 /*
 168  * Stage 3 of the trace events.
 169  *
 170  * Override the macros in <trace/trace_events.h> to include the following:
 171  *
 172  * enum print_line_t
 173  * ftrace_raw_output_<call>(struct trace_iterator *iter, int flags)
 174  * {
 175  *      struct trace_seq *s = &iter->seq;
 176  *      struct ftrace_raw_<call> *field; <-- defined in stage 1
 177  *      struct trace_entry *entry;
 178  *      struct trace_seq *p;
 179  *      int ret;
 180  *
 181  *      entry = iter->ent;
 182  *
 183  *      if (entry->type != event_<call>.id) {
 184  *              WARN_ON_ONCE(1);
 185  *              return TRACE_TYPE_UNHANDLED;
 186  *      }
 187  *
 188  *      field = (typeof(field))entry;
 189  *
 190  *      p = get_cpu_var(ftrace_event_seq);
 191  *      trace_seq_init(p);
 192  *      ret = trace_seq_printf(s, <TP_printk> "\n");
 193  *      put_cpu();
 194  *      if (!ret)
 195  *              return TRACE_TYPE_PARTIAL_LINE;
 196  *
 197  *      return TRACE_TYPE_HANDLED;
 198  * }
 199  *
 200  * This is the method used to print the raw event to the trace
 201  * output format. Note, this is not needed if the data is read
 202  * in binary.
 203  */
 204
 205 #undef __entry
 206 #define __entry field
 207
 208 #undef TP_printk
 209 #define TP_printk(fmt, args...) fmt "\n", args
 210
 211 #undef __get_dynamic_array
 212 #define __get_dynamic_array(field)      \
 213                 ((void *)__entry + __entry->__data_loc_##field)
 214
 215 #undef __get_str
 216 #define __get_str(field) (char *)__get_dynamic_array(field)
 217
 218 #undef __print_flags
 219 #define __print_flags(flag, delim, flag_array...)                       \
 220         ({                                                              \
 221                 static const struct trace_print_flags flags[] =         \
 222                         { flag_array, { -1, NULL }};                    \
 223                 ftrace_print_flags_seq(p, delim, flag, flags);          \
 224         })
 225
 226 #undef __print_symbolic
 227 #define __print_symbolic(value, symbol_array...)                        \
 228         ({                                                              \
 229                 static const struct trace_print_flags symbols[] =       \
 230                         { symbol_array, { -1, NULL }};                  \
 231                 ftrace_print_symbols_seq(p, value, symbols);            \
 232         })
 233
 234 #undef TRACE_EVENT
 235 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 236 enum print_line_t                                                       \
 237 ftrace_raw_output_##call(struct trace_iterator *iter, int flags)        \
 238 {                                                                       \
 239         struct trace_seq *s = &iter->seq;                               \
 240         struct ftrace_raw_##call *field;                                \
 241         struct trace_entry *entry;                                      \
 242         struct trace_seq *p;                                            \
 243         int ret;                                                        \
 244                                                                         \
 245         entry = iter->ent;                                              \
 246                                                                         \
 247         if (entry->type != event_##call.id) {                           \
 248                 WARN_ON_ONCE(1);                                        \
 249                 return TRACE_TYPE_UNHANDLED;                            \
 250         }                                                               \
 251                                                                         \
 252         field = (typeof(field))entry;                                   \
 253                                                                         \
 254         p = &get_cpu_var(ftrace_event_seq);                             \
 255         trace_seq_init(p);                                              \
 256         ret = trace_seq_printf(s, #call ": " print);                    \
 257         put_cpu();                                                      \
 258         if (!ret)                                                       \
 259                 return TRACE_TYPE_PARTIAL_LINE;                         \
 260                                                                         \
 261         return TRACE_TYPE_HANDLED;                                      \
 262 }
 263
 264 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 265
 266 #undef __field
 267 #define __field(type, item)                                             \
 268         ret = trace_define_field(event_call, #type, #item,              \
 269                                  offsetof(typeof(field), item),         \
 270                                  sizeof(field.item), is_signed_type(type));     \
 271         if (ret)                                                        \
 272                 return ret;
 273
 274 #undef __array
 275 #define __array(type, item, len)                                        \
 276         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 277         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 278                                  offsetof(typeof(field), item),         \
 279                                  sizeof(field.item), 0);                \
 280         if (ret)                                                        \
 281                 return ret;
 282
 283 #undef __dynamic_array
 284 #define __dynamic_array(type, item, len)                                       \
 285         ret = trace_define_field(event_call, "__data_loc" "[" #type "]", #item,\
 286                                 offsetof(typeof(field), __data_loc_##item),    \
 287                                  sizeof(field.__data_loc_##item), 0);
 288
 289 #undef __string
 290 #define __string(item, src) __dynamic_array(char, item, -1)
 291
 292 #undef TRACE_EVENT
 293 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 294 int                                                                     \
 295 ftrace_define_fields_##call(void)                                       \
 296 {                                                                       \
 297         struct ftrace_raw_##call field;                                 \
 298         struct ftrace_event_call *event_call = &event_##call;           \
 299         int ret;                                                        \
 300                                                                         \
 301         __common_field(int, type, 1);                                   \
 302         __common_field(unsigned char, flags, 0);                        \
 303         __common_field(unsigned char, preempt_count, 0);                \
 304         __common_field(int, pid, 1);                                    \
 305         __common_field(int, tgid, 1);                                   \
 306                                                                         \
 307         tstruct;                                                        \
 308                                                                         \
 309         return ret;                                                     \
 310 }
 311
 312 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 313
 314 /*
 315  * remember the offset of each array from the beginning of the event.
 316  */
 317
 318 #undef __entry
 319 #define __entry entry
 320
 321 #undef __field
 322 #define __field(type, item)
 323
 324 #undef __array
 325 #define __array(type, item, len)
 326
 327 #undef __dynamic_array
 328 #define __dynamic_array(type, item, len)                                \
 329         __data_offsets->item = __data_size +                            \
 330                                offsetof(typeof(*entry), __data);        \
 331         __data_size += (len) * sizeof(type);
 332
 333 #undef __string
 334 #define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)       \
 335
 336 #undef TRACE_EVENT
 337 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 338 static inline int ftrace_get_offsets_##call(                            \
 339         struct ftrace_data_offsets_##call *__data_offsets, proto)       \
 340 {                                                                       \
 341         int __data_size = 0;                                            \
 342         struct ftrace_raw_##call __maybe_unused *entry;                 \
 343                                                                         \
 344         tstruct;                                                        \
 345                                                                         \
 346         return __data_size;                                             \
 347 }
 348
 349 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 350
 351 #ifdef CONFIG_EVENT_PROFILE
 352
 353 /*
 354  * Generate the functions needed for tracepoint perf_counter support.
 355  *
 356  * static void ftrace_profile_<call>(proto)
 357  * {
 358  *      extern void perf_tpcounter_event(int, u64, u64);
 359  *      u64 __addr = 0, __count = 1;
 360  *
 361  *      <assign>   <-- here we expand the TP_perf_assign() macro
 362  *
 363  *      perf_tpcounter_event(event_<call>.id, __addr, __count);
 364  * }
 365  *
 366  * static int ftrace_profile_enable_<call>(struct ftrace_event_call *event_call)
 367  * {
 368  *      int ret = 0;
 369  *
 370  *      if (!atomic_inc_return(&event_call->profile_count))
 371  *              ret = register_trace_<call>(ftrace_profile_<call>);
 372  *
 373  *      return ret;
 374  * }
 375  *
 376  * static void ftrace_profile_disable_<call>(struct ftrace_event_call *event_call)
 377  * {
 378  *      if (atomic_add_negative(-1, &event->call->profile_count))
 379  *              unregister_trace_<call>(ftrace_profile_<call>);
 380  * }
 381  *
 382  */
 383
 384 #undef TP_fast_assign
 385 #define TP_fast_assign(args...)
 386
 387 #undef TP_perf_assign
 388 #define TP_perf_assign(args...) args
 389
 390 #undef __perf_addr
 391 #define __perf_addr(a) __addr = (a)
 392
 393 #undef __perf_count
 394 #define __perf_count(c) __count = (c)
 395
 396 #undef TRACE_EVENT
 397 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 398                                                                         \
 399 static void ftrace_profile_##call(proto)                                \
 400 {                                                                       \
 401         extern void perf_tpcounter_event(int, u64, u64);                \
 402         u64 __addr = 0, __count = 1;                                    \
 403         { assign; }                                                     \
 404         perf_tpcounter_event(event_##call.id, __addr, __count);         \
 405 }                                                                       \
 406                                                                         \
 407 static int ftrace_profile_enable_##call(struct ftrace_event_call *event_call) \
 408 {                                                                       \
 409         int ret = 0;                                                    \
 410                                                                         \
 411         if (!atomic_inc_return(&event_call->profile_count))             \
 412                 ret = register_trace_##call(ftrace_profile_##call);     \
 413                                                                         \
 414         return ret;                                                     \
 415 }                                                                       \
 416                                                                         \
 417 static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\
 418 {                                                                       \
 419         if (atomic_add_negative(-1, &event_call->profile_count))        \
 420                 unregister_trace_##call(ftrace_profile_##call);         \
 421 }
 422
 423 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 424
 425 #undef TP_fast_assign
 426 #define TP_fast_assign(args...) args
 427
 428 #undef TP_perf_assign
 429 #define TP_perf_assign(args...)
 430
 431 #endif
 432
 433 /*
 434  * Stage 4 of the trace events.
 435  *
 436  * Override the macros in <trace/trace_events.h> to include the following:
 437  *
 438  * static void ftrace_event_<call>(proto)
 439  * {
 440  *      event_trace_printk(_RET_IP_, "<call>: " <fmt>);
 441  * }
 442  *
 443  * static int ftrace_reg_event_<call>(void)
 444  * {
 445  *      int ret;
 446  *
 447  *      ret = register_trace_<call>(ftrace_event_<call>);
 448  *      if (!ret)
 449  *              pr_info("event trace: Could not activate trace point "
 450  *                      "probe to  <call>");
 451  *      return ret;
 452  * }
 453  *
 454  * static void ftrace_unreg_event_<call>(void)
 455  * {
 456  *      unregister_trace_<call>(ftrace_event_<call>);
 457  * }
 458  *
 459  *
 460  * For those macros defined with TRACE_EVENT:
 461  *
 462  * static struct ftrace_event_call event_<call>;
 463  *
 464  * static void ftrace_raw_event_<call>(proto)
 465  * {
 466  *      struct ring_buffer_event *event;
 467  *      struct ftrace_raw_<call> *entry; <-- defined in stage 1
 468  *      unsigned long irq_flags;
 469  *      int pc;
 470  *
 471  *      local_save_flags(irq_flags);
 472  *      pc = preempt_count();
 473  *
 474  *      event = trace_current_buffer_lock_reserve(event_<call>.id,
 475  *                                sizeof(struct ftrace_raw_<call>),
 476  *                                irq_flags, pc);
 477  *      if (!event)
 478  *              return;
 479  *      entry   = ring_buffer_event_data(event);
 480  *
 481  *      <assign>;  <-- Here we assign the entries by the __field and
 482  *                      __array macros.
 483  *
 484  *      trace_current_buffer_unlock_commit(event, irq_flags, pc);
 485  * }
 486  *
 487  * static int ftrace_raw_reg_event_<call>(void)
 488  * {
 489  *      int ret;
 490  *
 491  *      ret = register_trace_<call>(ftrace_raw_event_<call>);
 492  *      if (!ret)
 493  *              pr_info("event trace: Could not activate trace point "
 494  *                      "probe to <call>");
 495  *      return ret;
 496  * }
 497  *
 498  * static void ftrace_unreg_event_<call>(void)
 499  * {
 500  *      unregister_trace_<call>(ftrace_raw_event_<call>);
 501  * }
 502  *
 503  * static struct trace_event ftrace_event_type_<call> = {
 504  *      .trace                  = ftrace_raw_output_<call>, <-- stage 2
 505  * };
 506  *
 507  * static int ftrace_raw_init_event_<call>(void)
 508  * {
 509  *      int id;
 510  *
 511  *      id = register_ftrace_event(&ftrace_event_type_<call>);
 512  *      if (!id)
 513  *              return -ENODEV;
 514  *      event_<call>.id = id;
 515  *      return 0;
 516  * }
 517  *
 518  * static struct ftrace_event_call __used
 519  * __attribute__((__aligned__(4)))
 520  * __attribute__((section("_ftrace_events"))) event_<call> = {
 521  *      .name                   = "<call>",
 522  *      .system                 = "<system>",
 523  *      .raw_init               = ftrace_raw_init_event_<call>,
 524  *      .regfunc                = ftrace_reg_event_<call>,
 525  *      .unregfunc              = ftrace_unreg_event_<call>,
 526  *      .show_format            = ftrace_format_<call>,
 527  * }
 528  *
 529  */
 530
 531 #undef TP_FMT
 532 #define TP_FMT(fmt, args...)    fmt "\n", ##args
 533
 534 #ifdef CONFIG_EVENT_PROFILE
 535
 536 #define _TRACE_PROFILE_INIT(call)                                       \
 537         .profile_count = ATOMIC_INIT(-1),                               \
 538         .profile_enable = ftrace_profile_enable_##call,                 \
 539         .profile_disable = ftrace_profile_disable_##call,
 540
 541 #else
 542 #define _TRACE_PROFILE_INIT(call)
 543 #endif
 544
 545 #undef __entry
 546 #define __entry entry
 547
 548 #undef __field
 549 #define __field(type, item)
 550
 551 #undef __array
 552 #define __array(type, item, len)
 553
 554 #undef __dynamic_array
 555 #define __dynamic_array(type, item, len)                                \
 556         __entry->__data_loc_##item = __data_offsets.item;
 557
 558 #undef __string
 559 #define __string(item, src) __dynamic_array(char, item, -1)             \
 560
 561 #undef __assign_str
 562 #define __assign_str(dst, src)                                          \
 563         strcpy(__get_str(dst), src);
 564
 565 #undef TRACE_EVENT
 566 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 567                                                                         \
 568 static struct ftrace_event_call event_##call;                           \
 569                                                                         \
 570 static void ftrace_raw_event_##call(proto)                              \
 571 {                                                                       \
 572         struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
 573         struct ftrace_event_call *event_call = &event_##call;           \
 574         struct ring_buffer_event *event;                                \
 575         struct ftrace_raw_##call *entry;                                \
 576         unsigned long irq_flags;                                        \
 577         int __data_size;                                                \
 578         int pc;                                                         \
 579                                                                         \
 580         local_save_flags(irq_flags);                                    \
 581         pc = preempt_count();                                           \
 582                                                                         \
 583         __data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
 584                                                                         \
 585         event = trace_current_buffer_lock_reserve(event_##call.id,      \
 586                                  sizeof(*entry) + __data_size,          \
 587                                  irq_flags, pc);                        \
 588         if (!event)                                                     \
 589                 return;                                                 \
 590         entry   = ring_buffer_event_data(event);                        \
 591                                                                         \
 592                                                                         \
 593         tstruct                                                         \
 594                                                                         \
 595         { assign; }                                                     \
 596                                                                         \
 597         if (!filter_current_check_discard(event_call, entry, event))    \
 598                 trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
 599 }                                                                       \
 600                                                                         \
 601 static int ftrace_raw_reg_event_##call(void)                            \
 602 {                                                                       \
 603         int ret;                                                        \
 604                                                                         \
 605         ret = register_trace_##call(ftrace_raw_event_##call);           \
 606         if (ret)                                                        \
 607                 pr_info("event trace: Could not activate trace point "  \
 608                         "probe to " #call "\n");                        \
 609         return ret;                                                     \
 610 }                                                                       \
 611                                                                         \
 612 static void ftrace_raw_unreg_event_##call(void)                         \
 613 {                                                                       \
 614         unregister_trace_##call(ftrace_raw_event_##call);               \
 615 }                                                                       \
 616                                                                         \
 617 static struct trace_event ftrace_event_type_##call = {                  \
 618         .trace                  = ftrace_raw_output_##call,             \
 619 };                                                                      \
 620                                                                         \
 621 static int ftrace_raw_init_event_##call(void)                           \
 622 {                                                                       \
 623         int id;                                                         \
 624                                                                         \
 625         id = register_ftrace_event(&ftrace_event_type_##call);          \
 626         if (!id)                                                        \
 627                 return -ENODEV;                                         \
 628         event_##call.id = id;                                           \
 629         INIT_LIST_HEAD(&event_##call.fields);                           \
 630         init_preds(&event_##call);                                      \
 631         return 0;                                                       \
 632 }                                                                       \
 633                                                                         \
 634 static struct ftrace_event_call __used                                  \
 635 __attribute__((__aligned__(4)))                                         \
 636 __attribute__((section("_ftrace_events"))) event_##call = {             \
 637         .name                   = #call,                                \
 638         .system                 = __stringify(TRACE_SYSTEM),            \
 639         .event                  = &ftrace_event_type_##call,            \
 640         .raw_init               = ftrace_raw_init_event_##call,         \
 641         .regfunc                = ftrace_raw_reg_event_##call,          \
 642         .unregfunc              = ftrace_raw_unreg_event_##call,        \
 643         .show_format            = ftrace_format_##call,                 \
 644         .define_fields          = ftrace_define_fields_##call,          \
 645         _TRACE_PROFILE_INIT(call)                                       \
 646 }
 647
 648 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 649
 650 #undef _TRACE_PROFILE_INIT
 651