include/lttng/ust-tracepoint-event.h

   1 /*
   2  * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3  *
   4  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   5  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   6  *
   7  * Permission is hereby granted to use or copy this program
   8  * for any purpose,  provided the above notices are retained on all copies.
   9  * Permission to modify the code and to distribute modified code is granted,
  10  * provided the above notices are retained, and a notice that the code was
  11  * modified is included with the above copyright notice.
  12  */
  13
  14 #include <stdio.h>
  15 #include <urcu/compiler.h>
  16 #include <lttng/ust-events.h>
  17 #include <lttng/ringbuffer-config.h>
  18 #include <string.h>
  19
  20 /*
  21  * Macro declarations used for all stages.
  22  */
  23
  24 #undef ctf_integer
  25 #define ctf_integer(_type, _item, _src)                         \
  26         ctf_integer_ext(_type, _item, _src, BYTE_ORDER, 10)
  27
  28 #undef ctf_integer_hex
  29 #define ctf_integer_hex(_type, _item, _src)                     \
  30         ctf_integer_ext(_type, _item, _src, BYTE_ORDER, 16)
  31
  32 #undef ctf_integer_network
  33 #define ctf_integer_network(_type, _item, _src)                 \
  34         ctf_integer_ext(_type, _item, _src, BIG_ENDIAN, 10)
  35
  36 #undef ctf_integer_network_hex
  37 #define ctf_integer_network_hex(_type, _item, _src)             \
  38         ctf_integer_ext(_type, _item, _src, BIG_ENDIAN, 16)
  39
  40 /* ctf_float is redefined at each step */
  41
  42 #undef ctf_array
  43 #define ctf_array(_type, _item, _src, _length)                  \
  44         ctf_array_encoded(_type, _item, _src, _length, none)
  45
  46 #undef ctf_array_text
  47 #define ctf_array_text(_type, _item, _src, _length)             \
  48         ctf_array_encoded(_type, _item, _src, _length, UTF8)
  49
  50 #undef ctf_sequence
  51 #define ctf_sequence(_type, _item, _src, _length_type, _src_length)     \
  52         ctf_sequence_encoded(_type, _item, _src,                        \
  53                         _length_type, _src_length, none)
  54
  55 #undef ctf_sequence_text
  56 #define ctf_sequence_text(_type, _item, _src, _length_type, _src_length) \
  57         ctf_sequence_encoded(_type, _item, _src,                         \
  58                         _length_type, _src_length, UTF8)
  59
  60 /* ctf_string is redefined at each step */
  61
  62 /*
  63  * TRACEPOINT_EVENT_CLASS declares a class of tracepoints receiving the
  64  * same arguments and having the same field layout.
  65  *
  66  * TRACEPOINT_EVENT_INSTANCE declares an instance of a tracepoint, with
  67  * its own provider and name. It refers to a class (template).
  68  *
  69  * TRACEPOINT_EVENT declared both a class and an instance and does a
  70  * direct mapping from the instance to the class.
  71  */
  72
  73 #undef TRACEPOINT_EVENT
  74 #define TRACEPOINT_EVENT(_provider, _name, _args, _fields)      \
  75         TRACEPOINT_EVENT_CLASS(_provider, _name,                \
  76                          _TP_PARAMS(_args),                     \
  77                          _TP_PARAMS(_fields))                   \
  78         TRACEPOINT_EVENT_INSTANCE(_provider, _name, _name,      \
  79                          _TP_PARAMS(args))
  80
  81 /* Helpers */
  82 #define _TP_ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  83
  84 #define _tp_max_t(type, x, y)                           \
  85         ({                                              \
  86                 type __max1 = (x);                      \
  87                 type __max2 = (y);                      \
  88                 __max1 > __max2 ? __max1: __max2;       \
  89         })
  90
  91 /*
  92  * Stage 0 of tracepoint event generation.
  93  *
  94  * Check that each TRACEPOINT_EVENT provider argument match the
  95  * TRACEPOINT_PROVIDER by creating dummy callbacks.
  96  */
  97
  98 /* Reset all macros within TRACEPOINT_EVENT */
  99 #include <lttng/ust-tracepoint-event-reset.h>
 100
 101 static inline
 102 void _TP_COMBINE_TOKENS(__tracepoint_provider_mismatch_, TRACEPOINT_PROVIDER)(void)
 103 {
 104 }
 105
 106 #undef TRACEPOINT_EVENT_CLASS
 107 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)        \
 108         __tracepoint_provider_mismatch_##_provider();
 109
 110 #undef TRACEPOINT_EVENT_INSTANCE
 111 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, _args)   \
 112         __tracepoint_provider_mismatch_##_provider();
 113
 114 static __attribute__((unused))
 115 void _TP_COMBINE_TOKENS(__tracepoint_provider_check_, TRACEPOINT_PROVIDER)(void)
 116 {
 117 #include TRACEPOINT_INCLUDE
 118 }
 119
 120 /*
 121  * Stage 0.1 of tracepoint event generation.
 122  *
 123  * Check that each TRACEPOINT_EVENT provider:name does not exceed the
 124  * tracepoint name length limit.
 125  */
 126
 127 /* Reset all macros within TRACEPOINT_EVENT */
 128 #include <lttng/ust-tracepoint-event-reset.h>
 129
 130 #undef TRACEPOINT_EVENT_INSTANCE
 131 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, _args)   \
 132 static const char                                                       \
 133         __tp_name_len_check##_provider##___##_name[LTTNG_UST_SYM_NAME_LEN] \
 134         __attribute__((unused)) =                                       \
 135                 #_provider ":" #_name;
 136
 137 #include TRACEPOINT_INCLUDE
 138
 139 /*
 140  * Stage 1 of tracepoint event generation.
 141  *
 142  * Create event field type metadata section.
 143  * Each event produce an array of fields.
 144  */
 145
 146 /* Reset all macros within TRACEPOINT_EVENT */
 147 #include <lttng/ust-tracepoint-event-reset.h>
 148
 149 #undef ctf_integer_ext
 150 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base) \
 151         {                                                       \
 152           .name = #_item,                                       \
 153           .type = __type_integer(_type, _byte_order, _base, none),\
 154         },
 155
 156 #undef ctf_float
 157 #define ctf_float(_type, _item, _src)                           \
 158         {                                                       \
 159           .name = #_item,                                       \
 160           .type = __type_float(_type),                          \
 161         },
 162
 163 #undef ctf_array_encoded
 164 #define ctf_array_encoded(_type, _item, _src, _length, _encoding) \
 165         {                                                       \
 166           .name = #_item,                                       \
 167           .type =                                               \
 168                 {                                               \
 169                   .atype = atype_array,                         \
 170                   .u.array =                                    \
 171                         {                                       \
 172                             .length = _length,                  \
 173                             .elem_type = __type_integer(_type, BYTE_ORDER, 10, _encoding), \
 174                         },                                      \
 175                 },                                              \
 176         },
 177
 178 #undef ctf_sequence_encoded
 179 #define ctf_sequence_encoded(_type, _item, _src,        \
 180                         _length_type, _src_length, _encoding)   \
 181         {                                                       \
 182           .name = #_item,                                       \
 183           .type =                                               \
 184                 {                                               \
 185                   .atype = atype_sequence,                      \
 186                   .u.sequence =                                 \
 187                         {                                       \
 188                             .length_type = __type_integer(_length_type, BYTE_ORDER, 10, none), \
 189                             .elem_type = __type_integer(_type, BYTE_ORDER, 10, _encoding), \
 190                         },                                      \
 191                 },                                              \
 192         },
 193
 194 #undef ctf_string
 195 #define ctf_string(_item, _src)                                 \
 196         {                                                       \
 197           .name = #_item,                                       \
 198           .type =                                               \
 199                 {                                               \
 200                   .atype = atype_string,                        \
 201                   .u.basic.string.encoding = lttng_encode_UTF8, \
 202                 },                                              \
 203         },
 204
 205 #undef TP_FIELDS
 206 #define TP_FIELDS(args...) args /* Only one used in this phase */
 207
 208 #undef TRACEPOINT_EVENT_CLASS
 209 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)                             \
 210         static const struct lttng_event_field __event_fields___##_provider##___##_name[] = { \
 211                 _fields                                                                      \
 212         };
 213
 214 #include TRACEPOINT_INCLUDE
 215
 216 /*
 217  * Stage 2 of tracepoint event generation.
 218  *
 219  * Create probe callback prototypes.
 220  */
 221
 222 /* Reset all macros within TRACEPOINT_EVENT */
 223 #include <lttng/ust-tracepoint-event-reset.h>
 224
 225 #undef TP_ARGS
 226 #define TP_ARGS(args...) args
 227
 228 #undef TRACEPOINT_EVENT_CLASS
 229 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)                \
 230 static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args));
 231
 232 #include TRACEPOINT_INCLUDE
 233
 234 /*
 235  * Stage 3 of tracepoint event generation.
 236  *
 237  * Create static inline function that calculates event size.
 238  */
 239
 240 /* Reset all macros within TRACEPOINT_EVENT */
 241 #include <lttng/ust-tracepoint-event-reset.h>
 242
 243 #undef ctf_integer_ext
 244 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base)                \
 245         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 246         __event_len += sizeof(_type);
 247
 248 #undef ctf_float
 249 #define ctf_float(_type, _item, _src)                                          \
 250         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 251         __event_len += sizeof(_type);
 252
 253 #undef ctf_array_encoded
 254 #define ctf_array_encoded(_type, _item, _src, _length, _encoding)              \
 255         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 256         __event_len += sizeof(_type) * (_length);
 257
 258 #undef ctf_sequence_encoded
 259 #define ctf_sequence_encoded(_type, _item, _src, _length_type,  \
 260                         _src_length, _encoding)                 \
 261         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_length_type));   \
 262         __event_len += sizeof(_length_type);                                   \
 263         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 264         __dynamic_len[__dynamic_len_idx] = (_src_length);                      \
 265         __event_len += sizeof(_type) * __dynamic_len[__dynamic_len_idx];       \
 266         __dynamic_len_idx++;
 267
 268 #undef ctf_string
 269 #define ctf_string(_item, _src)                                                \
 270         __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1;
 271
 272 #undef TP_ARGS
 273 #define TP_ARGS(args...) args
 274
 275 #undef TP_FIELDS
 276 #define TP_FIELDS(args...) args
 277
 278 #undef TRACEPOINT_EVENT_CLASS
 279 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)      \
 280 static inline size_t __event_get_size__##_provider##___##_name(size_t *__dynamic_len, _TP_ARGS_DATA_PROTO(_args)) \
 281 {                                                                             \
 282         size_t __event_len = 0;                                               \
 283         unsigned int __dynamic_len_idx = 0;                                   \
 284                                                                               \
 285         if (0)                                                                \
 286                 (void) __dynamic_len_idx;       /* don't warn if unused */    \
 287         _fields                                                               \
 288         return __event_len;                                                   \
 289 }
 290
 291 #include TRACEPOINT_INCLUDE
 292
 293 /*
 294  * Stage 4 of tracepoint event generation.
 295  *
 296  * Create static inline function that calculates event payload alignment.
 297  */
 298
 299 /* Reset all macros within TRACEPOINT_EVENT */
 300 #include <lttng/ust-tracepoint-event-reset.h>
 301
 302 #undef ctf_integer_ext
 303 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base)                \
 304         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 305
 306 #undef ctf_float
 307 #define ctf_float(_type, _item, _src)                                          \
 308         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 309
 310 #undef ctf_array_encoded
 311 #define ctf_array_encoded(_type, _item, _src, _length, _encoding)              \
 312         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 313
 314 #undef ctf_sequence_encoded
 315 #define ctf_sequence_encoded(_type, _item, _src, _length_type,  \
 316                         _src_length, _encoding)                 \
 317         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_length_type));    \
 318         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 319
 320 #undef ctf_string
 321 #define ctf_string(_item, _src)
 322
 323 #undef TP_ARGS
 324 #define TP_ARGS(args...) args
 325
 326 #undef TP_FIELDS
 327 #define TP_FIELDS(args...) args
 328
 329 #undef TRACEPOINT_EVENT_CLASS
 330 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)              \
 331 static inline                                                                 \
 332 size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 333 {                                                                             \
 334         size_t __event_align = 1;                                             \
 335         _fields                                                               \
 336         return __event_align;                                                 \
 337 }
 338
 339 #include TRACEPOINT_INCLUDE
 340
 341
 342 /*
 343  * Stage 5 of tracepoint event generation.
 344  *
 345  * Create the probe function. This function calls event size calculation
 346  * and writes event data into the buffer.
 347  */
 348
 349 /* Reset all macros within TRACEPOINT_EVENT */
 350 #include <lttng/ust-tracepoint-event-reset.h>
 351
 352 #undef ctf_integer_ext
 353 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base)         \
 354         {                                                               \
 355                 _type __tmp = (_src);                                   \
 356                 lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__tmp));\
 357                 __chan->ops->event_write(&__ctx, &__tmp, sizeof(__tmp));\
 358         }
 359
 360 #undef ctf_float
 361 #define ctf_float(_type, _item, _src)                                   \
 362         {                                                               \
 363                 _type __tmp = (_src);                                   \
 364                 lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__tmp));\
 365                 __chan->ops->event_write(&__ctx, &__tmp, sizeof(__tmp));\
 366         }
 367
 368 #undef ctf_array_encoded
 369 #define ctf_array_encoded(_type, _item, _src, _length, _encoding)       \
 370         lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_type));        \
 371         __chan->ops->event_write(&__ctx, _src, sizeof(_type) * (_length));
 372
 373 #undef ctf_sequence_encoded
 374 #define ctf_sequence_encoded(_type, _item, _src, _length_type,          \
 375                         _src_length, _encoding)                 \
 376         {                                                               \
 377                 _length_type __tmpl = __dynamic_len[__dynamic_len_idx]; \
 378                 lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_length_type));\
 379                 __chan->ops->event_write(&__ctx, &__tmpl, sizeof(_length_type));\
 380         }                                                               \
 381         lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_type));        \
 382         __chan->ops->event_write(&__ctx, _src,                          \
 383                 sizeof(_type) * __get_dynamic_len(dest));
 384
 385 #undef ctf_string
 386 #define ctf_string(_item, _src)                                         \
 387         lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(*(_src)));      \
 388         __chan->ops->event_write(&__ctx, _src, __get_dynamic_len(dest));
 389
 390 /* Beware: this get len actually consumes the len value */
 391 #undef __get_dynamic_len
 392 #define __get_dynamic_len(field)        __dynamic_len[__dynamic_len_idx++]
 393
 394 #undef TP_ARGS
 395 #define TP_ARGS(args...) args
 396
 397 #undef TP_FIELDS
 398 #define TP_FIELDS(args...) args
 399
 400 #undef TRACEPOINT_EVENT_CLASS
 401 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)              \
 402 static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))\
 403 {                                                                             \
 404         struct ltt_event *__event = __tp_data;                                \
 405         struct ltt_channel *__chan = __event->chan;                           \
 406         struct lttng_ust_lib_ring_buffer_ctx __ctx;                           \
 407         size_t __event_len, __event_align;                                    \
 408         size_t __dynamic_len_idx = 0;                                         \
 409         size_t __dynamic_len[_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name)];       \
 410         int __ret;                                                            \
 411                                                                               \
 412         if (0)                                                                \
 413                 (void) __dynamic_len_idx;       /* don't warn if unused */    \
 414         if (caa_unlikely(!CMM_ACCESS_ONCE(__chan->session->active)))          \
 415                 return;                                                       \
 416         if (caa_unlikely(!CMM_ACCESS_ONCE(__chan->enabled)))                  \
 417                 return;                                                       \
 418         if (caa_unlikely(!CMM_ACCESS_ONCE(__event->enabled)))                 \
 419                 return;                                                       \
 420         __event_len = __event_get_size__##_provider##___##_name(__dynamic_len,\
 421                  _TP_ARGS_DATA_VAR(_args));                                   \
 422         __event_align = __event_get_align__##_provider##___##_name(_TP_ARGS_VAR(_args)); \
 423         lib_ring_buffer_ctx_init(&__ctx, __chan->chan, __event, __event_len,  \
 424                                  __event_align, -1, __chan->handle);          \
 425         __ret = __chan->ops->event_reserve(&__ctx, __event->id);              \
 426         if (__ret < 0)                                                        \
 427                 return;                                                       \
 428         _fields                                                               \
 429         __chan->ops->event_commit(&__ctx);                                    \
 430 }
 431
 432 #include TRACEPOINT_INCLUDE
 433
 434 #undef __get_dynamic_len
 435
 436 /*
 437  * Stage 6 of tracepoint event generation.
 438  *
 439  * Tracepoint loglevel mapping definition generation. We generate a
 440  * symbol for each mapping for a provider/event to ensure at most a 1 to
 441  * 1 mapping between events and loglevels. If the symbol is repeated,
 442  * the compiler will complain.
 443  */
 444
 445 /* Reset all macros within TRACEPOINT_EVENT */
 446 #include <lttng/ust-tracepoint-event-reset.h>
 447
 448 #undef TRACEPOINT_LOGLEVEL
 449 #define TRACEPOINT_LOGLEVEL(__provider, __name, __loglevel)                \
 450 static const int _loglevel_value___##__provider##___##__name = __loglevel; \
 451 static const int *_loglevel___##__provider##___##__name =                  \
 452                 &_loglevel_value___##__provider##___##__name;
 453
 454 #include TRACEPOINT_INCLUDE
 455
 456 /*
 457  * Stage 7.1 of tracepoint event generation.
 458  *
 459  * Create events description structures. We use a weakref because
 460  * loglevels are optional. If not declared, the event will point to the
 461  * a loglevel that contains NULL.
 462  */
 463
 464 /* Reset all macros within TRACEPOINT_EVENT */
 465 #include <lttng/ust-tracepoint-event-reset.h>
 466
 467 #undef TRACEPOINT_EVENT_INSTANCE
 468 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, _args)          \
 469 static const int *                                                             \
 470         __ref_loglevel___##_provider##___##_name                               \
 471         __attribute__((weakref ("_loglevel___" #_provider "___" #_name)));     \
 472 const struct lttng_event_desc __event_desc___##_provider##_##_name = {         \
 473         .fields = __event_fields___##_provider##___##_template,                \
 474         .name = #_provider ":" #_name,                                         \
 475         .probe_callback = (void *) &__event_probe__##_provider##___##_template,\
 476         .nr_fields = _TP_ARRAY_SIZE(__event_fields___##_provider##___##_template), \
 477         .loglevel = &__ref_loglevel___##_provider##___##_name,                 \
 478 };
 479
 480 #include TRACEPOINT_INCLUDE
 481
 482 /*
 483  * Stage 7.2 of tracepoint event generation.
 484  *
 485  * Create array of events.
 486  */
 487
 488 /* Reset all macros within TRACEPOINT_EVENT */
 489 #include <lttng/ust-tracepoint-event-reset.h>
 490
 491 #undef TRACEPOINT_EVENT_INSTANCE
 492 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, _args)          \
 493         &__event_desc___##_provider##_##_name,
 494
 495 static const struct lttng_event_desc *_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)[] = {
 496 #include TRACEPOINT_INCLUDE
 497 };
 498
 499
 500 /*
 501  * Stage 8 of tracepoint event generation.
 502  *
 503  * Create a toplevel descriptor for the whole probe.
 504  */
 505
 506 /* non-const because list head will be modified when registered. */
 507 static struct lttng_probe_desc _TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER) = {
 508         .provider = __tp_stringify(TRACEPOINT_PROVIDER),
 509         .event_desc = _TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER),
 510         .nr_events = _TP_ARRAY_SIZE(_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)),
 511 };
 512
 513 /*
 514  * Stage 9 of tracepoint event generation.
 515  *
 516  * Register/unregister probes at module load/unload.
 517  *
 518  * Generate the constructor as an externally visible symbol for use when
 519  * linking the probe statically.
 520  */
 521
 522 /* Reset all macros within TRACEPOINT_EVENT */
 523 #include <lttng/ust-tracepoint-event-reset.h>
 524 static void __attribute__((constructor))
 525 _TP_COMBINE_TOKENS(__lttng_events_init__, TRACEPOINT_PROVIDER)(void)
 526 {
 527         int ret;
 528
 529         ret = ltt_probe_register(&_TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER));
 530         assert(!ret);
 531 }
 532
 533 static void __attribute__((destructor))
 534 _TP_COMBINE_TOKENS(__lttng_events_exit__, TRACEPOINT_PROVIDER)(void)
 535 {
 536         ltt_probe_unregister(&_TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER));
 537 }
 538
 539 int _TP_COMBINE_TOKENS(__tracepoint_provider_, TRACEPOINT_PROVIDER);