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 TRACE_EVENT
 148 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 149 static int                                                              \
 150 ftrace_format_##call(struct trace_seq *s)                               \
 151 {                                                                       \
 152         struct ftrace_raw_##call field __attribute__((unused));         \
 153         int ret = 0;                                                    \
 154                                                                         \
 155         tstruct;                                                        \
 156                                                                         \
 157         trace_seq_printf(s, "\nprint fmt: " print);                     \
 158                                                                         \
 159         return ret;                                                     \
 160 }
 161
 162 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 163
 164 /*
 165  * Stage 3 of the trace events.
 166  *
 167  * Override the macros in <trace/trace_events.h> to include the following:
 168  *
 169  * enum print_line_t
 170  * ftrace_raw_output_<call>(struct trace_iterator *iter, int flags)
 171  * {
 172  *      struct trace_seq *s = &iter->seq;
 173  *      struct ftrace_raw_<call> *field; <-- defined in stage 1
 174  *      struct trace_entry *entry;
 175  *      struct trace_seq *p;
 176  *      int ret;
 177  *
 178  *      entry = iter->ent;
 179  *
 180  *      if (entry->type != event_<call>.id) {
 181  *              WARN_ON_ONCE(1);
 182  *              return TRACE_TYPE_UNHANDLED;
 183  *      }
 184  *
 185  *      field = (typeof(field))entry;
 186  *
 187  *      p = get_cpu_var(ftrace_event_seq);
 188  *      trace_seq_init(p);
 189  *      ret = trace_seq_printf(s, <TP_printk> "\n");
 190  *      put_cpu();
 191  *      if (!ret)
 192  *              return TRACE_TYPE_PARTIAL_LINE;
 193  *
 194  *      return TRACE_TYPE_HANDLED;
 195  * }
 196  *
 197  * This is the method used to print the raw event to the trace
 198  * output format. Note, this is not needed if the data is read
 199  * in binary.
 200  */
 201
 202 #undef __entry
 203 #define __entry field
 204
 205 #undef TP_printk
 206 #define TP_printk(fmt, args...) fmt "\n", args
 207
 208 #undef __get_dynamic_array
 209 #define __get_dynamic_array(field)      \
 210                 ((void *)__entry + __entry->__data_loc_##field)
 211
 212 #undef __get_str
 213 #define __get_str(field) (char *)__get_dynamic_array(field)
 214
 215 #undef __print_flags
 216 #define __print_flags(flag, delim, flag_array...)                       \
 217         ({                                                              \
 218                 static const struct trace_print_flags flags[] =         \
 219                         { flag_array, { -1, NULL }};                    \
 220                 ftrace_print_flags_seq(p, delim, flag, flags);          \
 221         })
 222
 223 #undef __print_symbolic
 224 #define __print_symbolic(value, symbol_array...)                        \
 225         ({                                                              \
 226                 static const struct trace_print_flags symbols[] =       \
 227                         { symbol_array, { -1, NULL }};                  \
 228                 ftrace_print_symbols_seq(p, value, symbols);            \
 229         })
 230
 231 #undef TRACE_EVENT
 232 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 233 enum print_line_t                                                       \
 234 ftrace_raw_output_##call(struct trace_iterator *iter, int flags)        \
 235 {                                                                       \
 236         struct trace_seq *s = &iter->seq;                               \
 237         struct ftrace_raw_##call *field;                                \
 238         struct trace_entry *entry;                                      \
 239         struct trace_seq *p;                                            \
 240         int ret;                                                        \
 241                                                                         \
 242         entry = iter->ent;                                              \
 243                                                                         \
 244         if (entry->type != event_##call.id) {                           \
 245                 WARN_ON_ONCE(1);                                        \
 246                 return TRACE_TYPE_UNHANDLED;                            \
 247         }                                                               \
 248                                                                         \
 249         field = (typeof(field))entry;                                   \
 250                                                                         \
 251         p = &get_cpu_var(ftrace_event_seq);                             \
 252         trace_seq_init(p);                                              \
 253         ret = trace_seq_printf(s, #call ": " print);                    \
 254         put_cpu();                                                      \
 255         if (!ret)                                                       \
 256                 return TRACE_TYPE_PARTIAL_LINE;                         \
 257                                                                         \
 258         return TRACE_TYPE_HANDLED;                                      \
 259 }
 260
 261 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 262
 263 #undef __field
 264 #define __field(type, item)                                             \
 265         ret = trace_define_field(event_call, #type, #item,              \
 266                                  offsetof(typeof(field), item),         \
 267                                  sizeof(field.item), is_signed_type(type));     \
 268         if (ret)                                                        \
 269                 return ret;
 270
 271 #undef __array
 272 #define __array(type, item, len)                                        \
 273         BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
 274         ret = trace_define_field(event_call, #type "[" #len "]", #item, \
 275                                  offsetof(typeof(field), item),         \
 276                                  sizeof(field.item), 0);                \
 277         if (ret)                                                        \
 278                 return ret;
 279
 280 #undef __dynamic_array
 281 #define __dynamic_array(type, item, len)                                       \
 282         ret = trace_define_field(event_call, "__data_loc" "[" #type "]", #item,\
 283                                 offsetof(typeof(field), __data_loc_##item),    \
 284                                  sizeof(field.__data_loc_##item), 0);
 285
 286 #undef __string
 287 #define __string(item, src) __dynamic_array(char, item, -1)
 288
 289 #undef TRACE_EVENT
 290 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 291 int                                                                     \
 292 ftrace_define_fields_##call(void)                                       \
 293 {                                                                       \
 294         struct ftrace_raw_##call field;                                 \
 295         struct ftrace_event_call *event_call = &event_##call;           \
 296         int ret;                                                        \
 297                                                                         \
 298         __common_field(int, type, 1);                                   \
 299         __common_field(unsigned char, flags, 0);                        \
 300         __common_field(unsigned char, preempt_count, 0);                \
 301         __common_field(int, pid, 1);                                    \
 302         __common_field(int, tgid, 1);                                   \
 303                                                                         \
 304         tstruct;                                                        \
 305                                                                         \
 306         return ret;                                                     \
 307 }
 308
 309 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 310
 311 /*
 312  * remember the offset of each array from the beginning of the event.
 313  */
 314
 315 #undef __entry
 316 #define __entry entry
 317
 318 #undef __field
 319 #define __field(type, item)
 320
 321 #undef __array
 322 #define __array(type, item, len)
 323
 324 #undef __dynamic_array
 325 #define __dynamic_array(type, item, len)                                \
 326         __data_offsets->item = __data_size +                            \
 327                                offsetof(typeof(*entry), __data);        \
 328         __data_size += (len) * sizeof(type);
 329
 330 #undef __string
 331 #define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)       \
 332
 333 #undef TRACE_EVENT
 334 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 335 static inline int ftrace_get_offsets_##call(                            \
 336         struct ftrace_data_offsets_##call *__data_offsets, proto)       \
 337 {                                                                       \
 338         int __data_size = 0;                                            \
 339         struct ftrace_raw_##call __maybe_unused *entry;                 \
 340                                                                         \
 341         tstruct;                                                        \
 342                                                                         \
 343         return __data_size;                                             \
 344 }
 345
 346 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 347
 348 /*
 349  * Stage 4 of the trace events.
 350  *
 351  * Override the macros in <trace/trace_events.h> to include the following:
 352  *
 353  * static void ftrace_event_<call>(proto)
 354  * {
 355  *      event_trace_printk(_RET_IP_, "<call>: " <fmt>);
 356  * }
 357  *
 358  * static int ftrace_reg_event_<call>(void)
 359  * {
 360  *      int ret;
 361  *
 362  *      ret = register_trace_<call>(ftrace_event_<call>);
 363  *      if (!ret)
 364  *              pr_info("event trace: Could not activate trace point "
 365  *                      "probe to  <call>");
 366  *      return ret;
 367  * }
 368  *
 369  * static void ftrace_unreg_event_<call>(void)
 370  * {
 371  *      unregister_trace_<call>(ftrace_event_<call>);
 372  * }
 373  *
 374  *
 375  * For those macros defined with TRACE_EVENT:
 376  *
 377  * static struct ftrace_event_call event_<call>;
 378  *
 379  * static void ftrace_raw_event_<call>(proto)
 380  * {
 381  *      struct ring_buffer_event *event;
 382  *      struct ftrace_raw_<call> *entry; <-- defined in stage 1
 383  *      unsigned long irq_flags;
 384  *      int pc;
 385  *
 386  *      local_save_flags(irq_flags);
 387  *      pc = preempt_count();
 388  *
 389  *      event = trace_current_buffer_lock_reserve(event_<call>.id,
 390  *                                sizeof(struct ftrace_raw_<call>),
 391  *                                irq_flags, pc);
 392  *      if (!event)
 393  *              return;
 394  *      entry   = ring_buffer_event_data(event);
 395  *
 396  *      <assign>;  <-- Here we assign the entries by the __field and
 397  *                      __array macros.
 398  *
 399  *      trace_current_buffer_unlock_commit(event, irq_flags, pc);
 400  * }
 401  *
 402  * static int ftrace_raw_reg_event_<call>(void)
 403  * {
 404  *      int ret;
 405  *
 406  *      ret = register_trace_<call>(ftrace_raw_event_<call>);
 407  *      if (!ret)
 408  *              pr_info("event trace: Could not activate trace point "
 409  *                      "probe to <call>");
 410  *      return ret;
 411  * }
 412  *
 413  * static void ftrace_unreg_event_<call>(void)
 414  * {
 415  *      unregister_trace_<call>(ftrace_raw_event_<call>);
 416  * }
 417  *
 418  * static struct trace_event ftrace_event_type_<call> = {
 419  *      .trace                  = ftrace_raw_output_<call>, <-- stage 2
 420  * };
 421  *
 422  * static int ftrace_raw_init_event_<call>(void)
 423  * {
 424  *      int id;
 425  *
 426  *      id = register_ftrace_event(&ftrace_event_type_<call>);
 427  *      if (!id)
 428  *              return -ENODEV;
 429  *      event_<call>.id = id;
 430  *      return 0;
 431  * }
 432  *
 433  * static struct ftrace_event_call __used
 434  * __attribute__((__aligned__(4)))
 435  * __attribute__((section("_ftrace_events"))) event_<call> = {
 436  *      .name                   = "<call>",
 437  *      .system                 = "<system>",
 438  *      .raw_init               = ftrace_raw_init_event_<call>,
 439  *      .regfunc                = ftrace_reg_event_<call>,
 440  *      .unregfunc              = ftrace_unreg_event_<call>,
 441  *      .show_format            = ftrace_format_<call>,
 442  * }
 443  *
 444  */
 445
 446 #undef TP_FMT
 447 #define TP_FMT(fmt, args...)    fmt "\n", ##args
 448
 449 #ifdef CONFIG_EVENT_PROFILE
 450 #define _TRACE_PROFILE(call, proto, args)                               \
 451 static void ftrace_profile_##call(proto)                                \
 452 {                                                                       \
 453         extern void perf_tpcounter_event(int);                          \
 454         perf_tpcounter_event(event_##call.id);                          \
 455 }                                                                       \
 456                                                                         \
 457 static int ftrace_profile_enable_##call(struct ftrace_event_call *event_call) \
 458 {                                                                       \
 459         int ret = 0;                                                    \
 460                                                                         \
 461         if (!atomic_inc_return(&event_call->profile_count))             \
 462                 ret = register_trace_##call(ftrace_profile_##call);     \
 463                                                                         \
 464         return ret;                                                     \
 465 }                                                                       \
 466                                                                         \
 467 static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\
 468 {                                                                       \
 469         if (atomic_add_negative(-1, &event_call->profile_count))        \
 470                 unregister_trace_##call(ftrace_profile_##call);         \
 471 }
 472
 473 #define _TRACE_PROFILE_INIT(call)                                       \
 474         .profile_count = ATOMIC_INIT(-1),                               \
 475         .profile_enable = ftrace_profile_enable_##call,                 \
 476         .profile_disable = ftrace_profile_disable_##call,
 477
 478 #else
 479 #define _TRACE_PROFILE(call, proto, args)
 480 #define _TRACE_PROFILE_INIT(call)
 481 #endif
 482
 483 #undef __entry
 484 #define __entry entry
 485
 486 #undef __field
 487 #define __field(type, item)
 488
 489 #undef __array
 490 #define __array(type, item, len)
 491
 492 #undef __dynamic_array
 493 #define __dynamic_array(type, item, len)                                \
 494         __entry->__data_loc_##item = __data_offsets.item;
 495
 496 #undef __string
 497 #define __string(item, src) __dynamic_array(char, item, -1)             \
 498
 499 #undef __assign_str
 500 #define __assign_str(dst, src)                                          \
 501         strcpy(__get_str(dst), src);
 502
 503 #undef TRACE_EVENT
 504 #define TRACE_EVENT(call, proto, args, tstruct, assign, print)          \
 505 _TRACE_PROFILE(call, PARAMS(proto), PARAMS(args))                       \
 506                                                                         \
 507 static struct ftrace_event_call event_##call;                           \
 508                                                                         \
 509 static void ftrace_raw_event_##call(proto)                              \
 510 {                                                                       \
 511         struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
 512         struct ftrace_event_call *event_call = &event_##call;           \
 513         struct ring_buffer_event *event;                                \
 514         struct ftrace_raw_##call *entry;                                \
 515         unsigned long irq_flags;                                        \
 516         int __data_size;                                                \
 517         int pc;                                                         \
 518                                                                         \
 519         local_save_flags(irq_flags);                                    \
 520         pc = preempt_count();                                           \
 521                                                                         \
 522         __data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
 523                                                                         \
 524         event = trace_current_buffer_lock_reserve(event_##call.id,      \
 525                                  sizeof(*entry) + __data_size,          \
 526                                  irq_flags, pc);                        \
 527         if (!event)                                                     \
 528                 return;                                                 \
 529         entry   = ring_buffer_event_data(event);                        \
 530                                                                         \
 531                                                                         \
 532         tstruct                                                         \
 533                                                                         \
 534         { assign; }                                                     \
 535                                                                         \
 536         if (!filter_current_check_discard(event_call, entry, event))    \
 537                 trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
 538 }                                                                       \
 539                                                                         \
 540 static int ftrace_raw_reg_event_##call(void)                            \
 541 {                                                                       \
 542         int ret;                                                        \
 543                                                                         \
 544         ret = register_trace_##call(ftrace_raw_event_##call);           \
 545         if (ret)                                                        \
 546                 pr_info("event trace: Could not activate trace point "  \
 547                         "probe to " #call "\n");                        \
 548         return ret;                                                     \
 549 }                                                                       \
 550                                                                         \
 551 static void ftrace_raw_unreg_event_##call(void)                         \
 552 {                                                                       \
 553         unregister_trace_##call(ftrace_raw_event_##call);               \
 554 }                                                                       \
 555                                                                         \
 556 static struct trace_event ftrace_event_type_##call = {                  \
 557         .trace                  = ftrace_raw_output_##call,             \
 558 };                                                                      \
 559                                                                         \
 560 static int ftrace_raw_init_event_##call(void)                           \
 561 {                                                                       \
 562         int id;                                                         \
 563                                                                         \
 564         id = register_ftrace_event(&ftrace_event_type_##call);          \
 565         if (!id)                                                        \
 566                 return -ENODEV;                                         \
 567         event_##call.id = id;                                           \
 568         INIT_LIST_HEAD(&event_##call.fields);                           \
 569         init_preds(&event_##call);                                      \
 570         return 0;                                                       \
 571 }                                                                       \
 572                                                                         \
 573 static struct ftrace_event_call __used                                  \
 574 __attribute__((__aligned__(4)))                                         \
 575 __attribute__((section("_ftrace_events"))) event_##call = {             \
 576         .name                   = #call,                                \
 577         .system                 = __stringify(TRACE_SYSTEM),            \
 578         .event                  = &ftrace_event_type_##call,            \
 579         .raw_init               = ftrace_raw_init_event_##call,         \
 580         .regfunc                = ftrace_raw_reg_event_##call,          \
 581         .unregfunc              = ftrace_raw_unreg_event_##call,        \
 582         .show_format            = ftrace_format_##call,                 \
 583         .define_fields          = ftrace_define_fields_##call,          \
 584         _TRACE_PROFILE_INIT(call)                                       \
 585 }
 586
 587 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 588
 589 #undef _TRACE_PROFILE
 590 #undef _TRACE_PROFILE_INIT
 591