probes/lttng-events.h

   1 /*
   2  * lttng-events.h
   3  *
   4  * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
   5  * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * Dual LGPL v2.1/GPL v2 license.
   8  */
   9
  10 #include <linux/debugfs.h>
  11 #include "lttng.h"
  12 #include "lttng-types.h"
  13 #include "../wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
  14 #include "../wrapper/ringbuffer/frontend_types.h"
  15 #include "../ltt-events.h"
  16 #include "../ltt-tracer-core.h"
  17
  18 /*
  19  * Macro declarations used for all stages.
  20  */
  21
  22 /*
  23  * DECLARE_EVENT_CLASS can be used to add a generic function
  24  * handlers for events. That is, if all events have the same
  25  * parameters and just have distinct trace points.
  26  * Each tracepoint can be defined with DEFINE_EVENT and that
  27  * will map the DECLARE_EVENT_CLASS to the tracepoint.
  28  *
  29  * TRACE_EVENT is a one to one mapping between tracepoint and template.
  30  */
  31
  32 #undef TRACE_EVENT
  33 #define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
  34         DECLARE_EVENT_CLASS(name,                              \
  35                              PARAMS(proto),                    \
  36                              PARAMS(args),                     \
  37                              PARAMS(tstruct),                  \
  38                              PARAMS(assign),                   \
  39                              PARAMS(print))                    \
  40         DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args))
  41
  42 #undef DEFINE_EVENT_PRINT
  43 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
  44         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
  45
  46 /* Callbacks are meaningless to LTTng. */
  47 #undef TRACE_EVENT_FN
  48 #define TRACE_EVENT_FN(name, proto, args, tstruct,                      \
  49                 assign, print, reg, unreg)                              \
  50         TRACE_EVENT(name, PARAMS(proto), PARAMS(args),                  \
  51                 PARAMS(tstruct), PARAMS(assign), PARAMS(print))         \
  52
  53 /*
  54  * Stage 1 of the trace events.
  55  *
  56  * Create dummy trace calls for each events, verifying that the LTTng module
  57  * TRACE_EVENT headers match the kernel arguments. Will be optimized out by the
  58  * compiler.
  59  */
  60
  61 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
  62
  63 #undef TP_PROTO
  64 #define TP_PROTO(args...) args
  65
  66 #undef TP_ARGS
  67 #define TP_ARGS(args...) args
  68
  69 #undef DEFINE_EVENT
  70 #define DEFINE_EVENT(_template, _name, _proto, _args)                   \
  71 void trace_##_name(_proto);
  72
  73 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
  74
  75 /*
  76  * Stage 2 of the trace events.
  77  *
  78  * Create event field type metadata section.
  79  * Each event produce an array of fields.
  80  */
  81
  82 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
  83
  84 /* Named field types must be defined in lttng-types.h */
  85
  86 #undef __field
  87 #define __field(_type, _item)                                   \
  88         {                                                       \
  89           .name = #_item,                                       \
  90           .type = __type_integer(_type, __BYTE_ORDER, 10, none),\
  91         },
  92
  93 #undef __field_ext
  94 #define __field_ext(_type, _item, _filter_type)         __field(_type, _item)
  95
  96 #undef __field_network
  97 #define __field_network(_type, _item)                           \
  98         {                                                       \
  99           .name = #_item,                                       \
 100           .type = __type_integer(_type, __BIG_ENDIAN, 10, none),\
 101         },
 102
 103 #undef __array_enc
 104 #define __array_enc(_type, _item, _length, _encoding)           \
 105         {                                                       \
 106           .name = #_item,                                       \
 107           .type =                                               \
 108                 {                                               \
 109                   .atype = atype_array,                         \
 110                   .u.array =                                    \
 111                         {                                       \
 112                             .length = _length,                  \
 113                             .elem_type = __type_integer(_type, __BYTE_ORDER, 10, _encoding), \
 114                         },                                      \
 115                 },                                              \
 116         },
 117
 118 #undef __array
 119 #define __array(_type, _item, _length)                          \
 120         __array_enc(_type, _item, _length, none)
 121
 122 #undef __array_text
 123 #define __array_text(_type, _item, _length)                     \
 124         __array_enc(_type, _item, _length, UTF8)
 125
 126 #undef __dynamic_array_enc
 127 #define __dynamic_array_enc(_type, _item, _length, _encoding)   \
 128         {                                                       \
 129           .name = #_item,                                       \
 130           .type =                                               \
 131                 {                                               \
 132                   .atype = atype_sequence,                      \
 133                   .u.sequence =                                 \
 134                         {                                       \
 135                             .length_type = __type_integer(u32, __BYTE_ORDER, 10, none), \
 136                             .elem_type = __type_integer(_type, __BYTE_ORDER, 10, _encoding), \
 137                         },                                      \
 138                 },                                              \
 139         },
 140
 141 #undef __dynamic_array
 142 #define __dynamic_array(_type, _item, _length)                  \
 143         __dynamic_array_enc(_type, _item, _length, none)
 144
 145 #undef __dynamic_array_text
 146 #define __dynamic_array_text(_type, _item, _length)             \
 147         __dynamic_array_enc(_type, _item, _length, UTF8)
 148
 149 #undef __string
 150 #define __string(_item, _src)                                   \
 151         {                                                       \
 152           .name = #_item,                                       \
 153           .type =                                               \
 154                 {                                               \
 155                   .atype = atype_string,                        \
 156                   .u.basic.string.encoding = lttng_encode_UTF8, \
 157                 },                                              \
 158         },
 159
 160 #undef TP_STRUCT__entry
 161 #define TP_STRUCT__entry(args...) args  /* Only one used in this phase */
 162
 163 #undef DECLARE_EVENT_CLASS
 164 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print) \
 165         static const struct lttng_event_field __event_fields___##_name[] = { \
 166                 _tstruct                                                     \
 167         };
 168
 169 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 170
 171 #undef __type_integer
 172
 173 /*
 174  * Stage 3 of the trace events.
 175  *
 176  * Create probe callback prototypes.
 177  */
 178
 179 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 180
 181 #undef TP_PROTO
 182 #define TP_PROTO(args...) args
 183
 184 #undef DECLARE_EVENT_CLASS
 185 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
 186 static void __event_probe__##_name(void *__data, _proto);
 187
 188 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 189
 190 /*
 191  * Stage 4 of the trace events.
 192  *
 193  * Create an array of events.
 194  */
 195
 196 /* Named field types must be defined in lttng-types.h */
 197
 198 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 199
 200 #undef DEFINE_EVENT
 201 #define DEFINE_EVENT(_template, _name, _proto, _args)                          \
 202                 {                                                              \
 203                         .fields = __event_fields___##_template,                \
 204                         .name = #_name,                                        \
 205                         .probe_callback = (void *) &__event_probe__##_template,\
 206                         .nr_fields = ARRAY_SIZE(__event_fields___##_template), \
 207                         .owner = THIS_MODULE,                                  \
 208                 },
 209
 210 #define TP_ID1(_token, _system) _token##_system
 211 #define TP_ID(_token, _system)  TP_ID1(_token, _system)
 212
 213 static const struct lttng_event_desc TP_ID(__event_desc___, TRACE_SYSTEM)[] = {
 214 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 215 };
 216
 217 #undef TP_ID1
 218 #undef TP_ID
 219
 220
 221 /*
 222  * Stage 5 of the trace events.
 223  *
 224  * Create a toplevel descriptor for the whole probe.
 225  */
 226
 227 #define TP_ID1(_token, _system) _token##_system
 228 #define TP_ID(_token, _system)  TP_ID1(_token, _system)
 229
 230 /* non-const because list head will be modified when registered. */
 231 static struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
 232         .event_desc = TP_ID(__event_desc___, TRACE_SYSTEM),
 233         .nr_events = ARRAY_SIZE(TP_ID(__event_desc___, TRACE_SYSTEM)),
 234 };
 235
 236 #undef TP_ID1
 237 #undef TP_ID
 238
 239 /*
 240  * Stage 6 of the trace events.
 241  *
 242  * Create static inline function that calculates event size.
 243  */
 244
 245 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 246
 247 /* Named field types must be defined in lttng-types.h */
 248
 249 #undef __field
 250 #define __field(_type, _item)                                                  \
 251         __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(_type)); \
 252         __event_len += sizeof(_type);
 253
 254 #undef __field_ext
 255 #define __field_ext(_type, _item, _filter_type) __field(_type, _item)
 256
 257 #undef __array
 258 #define __array(_type, _item, _length)                                         \
 259         __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(_type)); \
 260         __event_len += sizeof(_type) * (_length);
 261
 262 #undef __array_text
 263 #define __array_text(_type, _item, _length)                                    \
 264         __array(_type, _item, _length)
 265
 266 #undef __dynamic_array
 267 #define __dynamic_array(_type, _item, _length)                                 \
 268         __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(u32));   \
 269         __event_len += sizeof(u32);                                            \
 270         __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(_type)); \
 271         __dynamic_len[__dynamic_len_idx] = (_length);                          \
 272         __event_len += sizeof(_type) * __dynamic_len[__dynamic_len_idx];       \
 273         __dynamic_len_idx++;
 274
 275 #undef __dynamic_array_text
 276 #define __dynamic_array_text(_type, _item, _length)                            \
 277         __dynamic_array(_type, _item, _length)
 278
 279 #undef __string
 280 #define __string(_item, _src)                                                  \
 281         __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1;
 282
 283 #undef TP_PROTO
 284 #define TP_PROTO(args...) args
 285
 286 #undef TP_STRUCT__entry
 287 #define TP_STRUCT__entry(args...) args
 288
 289 #undef DECLARE_EVENT_CLASS
 290 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
 291 static inline size_t __event_get_size__##_name(size_t *__dynamic_len, _proto) \
 292 {                                                                             \
 293         size_t __event_len = 0;                                               \
 294         unsigned int __dynamic_len_idx = 0;                                   \
 295                                                                               \
 296         if (0)                                                                \
 297                 (void) __dynamic_len_idx;       /* don't warn if unused */    \
 298         _tstruct                                                              \
 299         return __event_len;                                                   \
 300 }
 301
 302 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 303
 304 /*
 305  * Stage 7 of the trace events.
 306  *
 307  * Create static inline function that calculates event payload alignment.
 308  */
 309
 310 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 311
 312 /* Named field types must be defined in lttng-types.h */
 313
 314 #undef __field
 315 #define __field(_type, _item)                                             \
 316         __event_align = max_t(size_t, __event_align, ltt_alignof(_type));
 317
 318 #undef __field_ext
 319 #define __field_ext(_type, _item, _filter_type) __field(_type, _item)
 320
 321 #undef __array
 322 #define __array(_type, _item, _length)                                    \
 323         __event_align = max_t(size_t, __event_align, ltt_alignof(_type));
 324
 325 #undef __array_text
 326 #define __array_text(_type, _item, _length)                               \
 327         __array(_type, _item, _length)
 328
 329 #undef __dynamic_array
 330 #define __dynamic_array(_type, _item, _length)                            \
 331         __event_align = max_t(size_t, __event_align, ltt_alignof(u32));   \
 332         __event_align = max_t(size_t, __event_align, ltt_alignof(_type));
 333
 334 #undef __dynamic_array_text
 335 #define __dynamic_array_text(_type, _item, _length)                       \
 336         __dynamic_array(_type, _item, _length)
 337
 338 #undef __string
 339 #define __string(_item, _src)
 340
 341 #undef TP_PROTO
 342 #define TP_PROTO(args...) args
 343
 344 #undef TP_STRUCT__entry
 345 #define TP_STRUCT__entry(args...) args
 346
 347 #undef DECLARE_EVENT_CLASS
 348 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
 349 static inline size_t __event_get_align__##_name(_proto)                       \
 350 {                                                                             \
 351         size_t __event_align = 1;                                             \
 352         _tstruct                                                              \
 353         return __event_align;                                                 \
 354 }
 355
 356 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 357
 358
 359 /*
 360  * Stage 8 of the trace events.
 361  *
 362  * Create structure declaration that allows the "assign" macros to access the
 363  * field types.
 364  */
 365
 366 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 367
 368 /* Named field types must be defined in lttng-types.h */
 369
 370 #undef __field
 371 #define __field(_type, _item)   _type   _item;
 372
 373 #undef __field_ext
 374 #define __field_ext(_type, _item, _filter_type) __field(_type, _item)
 375
 376 #undef __array
 377 #define __array(_type, _item, _length)  _type   _item;
 378
 379 #undef __array_text
 380 #define __array_text(_type, _item, _length)                               \
 381         __array(_type, _item, _length)
 382
 383 #undef __dynamic_array
 384 #define __dynamic_array(_type, _item, _length)  _type   _item;
 385
 386 #undef __dynamic_array_text
 387 #define __dynamic_array_text(_type, _item, _length)                       \
 388         __dynamic_array(_type, _item, _length)
 389
 390 #undef __string
 391 #define __string(_item, _src)   char _item;
 392
 393 #undef TP_STRUCT__entry
 394 #define TP_STRUCT__entry(args...) args
 395
 396 #undef DECLARE_EVENT_CLASS
 397 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
 398 struct __event_typemap__##_name {                                             \
 399         _tstruct                                                              \
 400 };
 401
 402 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 403
 404
 405 /*
 406  * Stage 9 of the trace events.
 407  *
 408  * Create the probe function : call even size calculation and write event data
 409  * into the buffer.
 410  *
 411  * We use both the field and assignment macros to write the fields in the order
 412  * defined in the field declaration. The field declarations control the
 413  * execution order, jumping to the appropriate assignment block.
 414  */
 415
 416 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 417
 418 #undef __field
 419 #define __field(_type, _item)                                           \
 420         goto __assign_##_item;                                          \
 421 __end_field_##_item:
 422
 423 #undef __field_ext
 424 #define __field_ext(_type, _item, _filter_type) __field(_type, _item)
 425
 426 #undef __array
 427 #define __array(_type, _item, _length)                                  \
 428         goto __assign_##_item;                                          \
 429 __end_field_##_item:
 430
 431 #undef __array_text
 432 #define __array_text(_type, _item, _length)                             \
 433         __array(_type, _item, _length)
 434
 435 #undef __dynamic_array
 436 #define __dynamic_array(_type, _item, _length)                          \
 437         goto __assign_##_item##_1;                                      \
 438 __end_field_##_item##_1:                                                \
 439         goto __assign_##_item##_2;                                      \
 440 __end_field_##_item##_2:
 441
 442 #undef __dynamic_array_text
 443 #define __dynamic_array_text(_type, _item, _length)                     \
 444         __dynamic_array(_type, _item, _length)
 445
 446 #undef __string
 447 #define __string(_item, _src)                                           \
 448         goto __assign_##_item;                                          \
 449 __end_field_##_item:
 450
 451 /*
 452  * Macros mapping tp_assign() to "=", tp_memcpy() to memcpy() and tp_strcpy() to
 453  * strcpy().
 454  */
 455 #undef tp_assign
 456 #define tp_assign(dest, src)                                            \
 457 __assign_##dest:                                                        \
 458         {                                                               \
 459                 __typeof__(__typemap.dest) __tmp = (src);               \
 460                 lib_ring_buffer_align_ctx(&ctx, ltt_alignof(__tmp));    \
 461                 __chan->ops->event_write(&ctx, &__tmp, sizeof(__tmp));  \
 462         }                                                               \
 463         goto __end_field_##dest;
 464
 465 #undef tp_memcpy
 466 #define tp_memcpy(dest, src, len)                                       \
 467 __assign_##dest:                                                        \
 468         if (0)                                                          \
 469                 (void) __typemap.dest;                                  \
 470         lib_ring_buffer_align_ctx(&ctx, ltt_alignof(__typemap.dest));   \
 471         __chan->ops->event_write(&ctx, src, len);                       \
 472         goto __end_field_##dest;
 473
 474 #undef tp_memcpy_dyn
 475 #define tp_memcpy_dyn(dest, src)                                        \
 476 __assign_##dest##_1:                                                    \
 477         {                                                               \
 478                 u32 __tmpl = __dynamic_len[__dynamic_len_idx];          \
 479                 lib_ring_buffer_align_ctx(&ctx, ltt_alignof(u32));      \
 480                 __chan->ops->event_write(&ctx, &__tmpl, sizeof(u32));   \
 481         }                                                               \
 482         goto __end_field_##dest##_1;                                    \
 483 __assign_##dest##_2:                                                    \
 484         lib_ring_buffer_align_ctx(&ctx, ltt_alignof(__typemap.dest));   \
 485         __chan->ops->event_write(&ctx, src,                             \
 486                 sizeof(__typemap.dest) * __get_dynamic_array_len(dest));\
 487         goto __end_field_##dest##_2;
 488
 489 #undef tp_strcpy
 490 #define tp_strcpy(dest, src)                                            \
 491         tp_memcpy(dest, src, __get_dynamic_array_len(dest))
 492
 493 /* Named field types must be defined in lttng-types.h */
 494
 495 #undef __get_str
 496 #define __get_str(field)                field
 497
 498 #undef __get_dynamic_array
 499 #define __get_dynamic_array(field)      field
 500
 501 /* Beware: this get len actually consumes the len value */
 502 #undef __get_dynamic_array_len
 503 #define __get_dynamic_array_len(field)  __dynamic_len[__dynamic_len_idx++]
 504
 505 #undef TP_PROTO
 506 #define TP_PROTO(args...) args
 507
 508 #undef TP_ARGS
 509 #define TP_ARGS(args...) args
 510
 511 #undef TP_STRUCT__entry
 512 #define TP_STRUCT__entry(args...) args
 513
 514 #undef TP_fast_assign
 515 #define TP_fast_assign(args...) args
 516
 517 #undef DECLARE_EVENT_CLASS
 518 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
 519 static void __event_probe__##_name(void *__data, _proto)                      \
 520 {                                                                             \
 521         struct ltt_event *__event = __data;                                   \
 522         struct ltt_channel *__chan = __event->chan;                           \
 523         struct lib_ring_buffer_ctx ctx;                                       \
 524         size_t __event_len, __event_align;                                    \
 525         size_t __dynamic_len_idx = 0;                                         \
 526         size_t __dynamic_len[ARRAY_SIZE(__event_fields___##_name)];           \
 527         struct __event_typemap__##_name __typemap;                            \
 528         int __ret;                                                            \
 529                                                                               \
 530         if (0)                                                                \
 531                 (void) __dynamic_len_idx;       /* don't warn if unused */    \
 532         if (!ACCESS_ONCE(__chan->session->active))                            \
 533                 return;                                                       \
 534         __event_len = __event_get_size__##_name(__dynamic_len, _args);        \
 535         __event_align = __event_get_align__##_name(_args);                    \
 536         lib_ring_buffer_ctx_init(&ctx, __chan->chan, __event, __event_len,    \
 537                                  __event_align, -1);                          \
 538         __ret = __chan->ops->event_reserve(&ctx, __event->id);                \
 539         if (__ret < 0)                                                        \
 540                 return;                                                       \
 541         /* Control code (field ordering) */                                   \
 542         _tstruct                                                              \
 543         __chan->ops->event_commit(&ctx);                                      \
 544         return;                                                               \
 545         /* Copy code, steered by control code */                              \
 546         _assign                                                               \
 547 }
 548
 549 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 550
 551 /*
 552  * Stage 10 of the trace events.
 553  *
 554  * Register/unregister probes at module load/unload.
 555  */
 556
 557 #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
 558
 559 #define TP_ID1(_token, _system) _token##_system
 560 #define TP_ID(_token, _system)  TP_ID1(_token, _system)
 561 #define module_init_eval1(_token, _system)      module_init(_token##_system)
 562 #define module_init_eval(_token, _system)       module_init_eval1(_token, _system)
 563 #define module_exit_eval1(_token, _system)      module_exit(_token##_system)
 564 #define module_exit_eval(_token, _system)       module_exit_eval1(_token, _system)
 565
 566 static int TP_ID(__lttng_events_init__, TRACE_SYSTEM)(void)
 567 {
 568         wrapper_vmalloc_sync_all();
 569         return ltt_probe_register(&TP_ID(__probe_desc___, TRACE_SYSTEM));
 570 }
 571
 572 module_init_eval(__lttng_events_init__, TRACE_SYSTEM);
 573
 574 static void TP_ID(__lttng_events_exit__, TRACE_SYSTEM)(void)
 575 {
 576         ltt_probe_unregister(&TP_ID(__probe_desc___, TRACE_SYSTEM));
 577 }
 578
 579 module_exit_eval(__lttng_events_exit__, TRACE_SYSTEM);
 580
 581 #undef module_init_eval
 582 #undef module_exit_eval
 583 #undef TP_ID1
 584 #undef TP_ID