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/usterr-signal-safe.h>
  18 #include <lttng/ringbuffer-config.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 1 of tracepoint event generation.
 122  *
 123  * Create event field type metadata section.
 124  * Each event produce an array of fields.
 125  */
 126
 127 /* Reset all macros within TRACEPOINT_EVENT */
 128 #include <lttng/ust-tracepoint-event-reset.h>
 129
 130 #undef ctf_integer_ext
 131 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base) \
 132         {                                                       \
 133           .name = #_item,                                       \
 134           .type = __type_integer(_type, _byte_order, _base, none),\
 135         },
 136
 137 #undef ctf_float
 138 #define ctf_float(_type, _item, _src)                           \
 139         {                                                       \
 140           .name = #_item,                                       \
 141           .type = __type_float(_type),                          \
 142         },
 143
 144 #undef ctf_array_encoded
 145 #define ctf_array_encoded(_type, _item, _src, _length, _encoding) \
 146         {                                                       \
 147           .name = #_item,                                       \
 148           .type =                                               \
 149                 {                                               \
 150                   .atype = atype_array,                         \
 151                   .u.array =                                    \
 152                         {                                       \
 153                             .length = _length,                  \
 154                             .elem_type = __type_integer(_type, BYTE_ORDER, 10, _encoding), \
 155                         },                                      \
 156                 },                                              \
 157         },
 158
 159 #undef ctf_sequence_encoded
 160 #define ctf_sequence_encoded(_type, _item, _src,        \
 161                         _length_type, _src_length, _encoding)   \
 162         {                                                       \
 163           .name = #_item,                                       \
 164           .type =                                               \
 165                 {                                               \
 166                   .atype = atype_sequence,                      \
 167                   .u.sequence =                                 \
 168                         {                                       \
 169                             .length_type = __type_integer(_length_type, BYTE_ORDER, 10, none), \
 170                             .elem_type = __type_integer(_type, BYTE_ORDER, 10, _encoding), \
 171                         },                                      \
 172                 },                                              \
 173         },
 174
 175 #undef ctf_string
 176 #define ctf_string(_item, _src)                                 \
 177         {                                                       \
 178           .name = #_item,                                       \
 179           .type =                                               \
 180                 {                                               \
 181                   .atype = atype_string,                        \
 182                   .u.basic.string.encoding = lttng_encode_UTF8, \
 183                 },                                              \
 184         },
 185
 186 #undef TP_FIELDS
 187 #define TP_FIELDS(args...) args /* Only one used in this phase */
 188
 189 #undef TRACEPOINT_EVENT_CLASS
 190 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)                             \
 191         static const struct lttng_event_field __event_fields___##_provider##___##_name[] = { \
 192                 _fields                                                                      \
 193         };
 194
 195 #include TRACEPOINT_INCLUDE
 196
 197 /*
 198  * Stage 2 of tracepoint event generation.
 199  *
 200  * Create probe callback prototypes.
 201  */
 202
 203 /* Reset all macros within TRACEPOINT_EVENT */
 204 #include <lttng/ust-tracepoint-event-reset.h>
 205
 206 #undef TP_ARGS
 207 #define TP_ARGS(args...) args
 208
 209 #undef TRACEPOINT_EVENT_CLASS
 210 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)                \
 211 static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args));
 212
 213 #include TRACEPOINT_INCLUDE
 214
 215 /*
 216  * Stage 3 of tracepoint event generation.
 217  *
 218  * Create an array of events.
 219  */
 220
 221 /* Reset all macros within TRACEPOINT_EVENT */
 222 #include <lttng/ust-tracepoint-event-reset.h>
 223
 224 #undef TRACEPOINT_EVENT_INSTANCE
 225 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, _args)          \
 226                 {                                                              \
 227                         .fields = __event_fields___##_provider##___##_template,\
 228                         .name = #_provider ":" #_name,                         \
 229                         .probe_callback = (void *) &__event_probe__##_provider##___##_template,\
 230                         .nr_fields = _TP_ARRAY_SIZE(__event_fields___##_provider##___##_template), \
 231                 },
 232
 233 static const struct lttng_event_desc _TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)[] = {
 234 #include TRACEPOINT_INCLUDE
 235 };
 236
 237
 238 /*
 239  * Stage 4 of tracepoint event generation.
 240  *
 241  * Create a toplevel descriptor for the whole probe.
 242  */
 243
 244 /* non-const because list head will be modified when registered. */
 245 static struct lttng_probe_desc _TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER) = {
 246         .event_desc = _TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER),
 247         .nr_events = _TP_ARRAY_SIZE(_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)),
 248 };
 249
 250 /*
 251  * Stage 5 of tracepoint event generation.
 252  *
 253  * Create static inline function that calculates event size.
 254  */
 255
 256 /* Reset all macros within TRACEPOINT_EVENT */
 257 #include <lttng/ust-tracepoint-event-reset.h>
 258
 259 #undef ctf_integer_ext
 260 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base)                \
 261         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 262         __event_len += sizeof(_type);
 263
 264 #undef ctf_float
 265 #define ctf_float(_type, _item, _src)                                          \
 266         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 267         __event_len += sizeof(_type);
 268
 269 #undef ctf_array_encoded
 270 #define ctf_array_encoded(_type, _item, _src, _length, _encoding)              \
 271         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 272         __event_len += sizeof(_type) * (_length);
 273
 274 #undef ctf_sequence_encoded
 275 #define ctf_sequence_encoded(_type, _item, _src, _length_type,  \
 276                         _src_length, _encoding)                 \
 277         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_length_type));   \
 278         __event_len += sizeof(_length_type);                                   \
 279         __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
 280         __dynamic_len[__dynamic_len_idx] = (_src_length);                      \
 281         __event_len += sizeof(_type) * __dynamic_len[__dynamic_len_idx];       \
 282         __dynamic_len_idx++;
 283
 284 #undef ctf_string
 285 #define ctf_string(_item, _src)                                                \
 286         __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1;
 287
 288 #undef TP_ARGS
 289 #define TP_ARGS(args...) args
 290
 291 #undef TP_FIELDS
 292 #define TP_FIELDS(args...) args
 293
 294 #undef TRACEPOINT_EVENT_CLASS
 295 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)      \
 296 static inline size_t __event_get_size__##_provider##___##_name(size_t *__dynamic_len, _TP_ARGS_DATA_PROTO(_args)) \
 297 {                                                                             \
 298         size_t __event_len = 0;                                               \
 299         unsigned int __dynamic_len_idx = 0;                                   \
 300                                                                               \
 301         if (0)                                                                \
 302                 (void) __dynamic_len_idx;       /* don't warn if unused */    \
 303         _fields                                                               \
 304         return __event_len;                                                   \
 305 }
 306
 307 #include TRACEPOINT_INCLUDE
 308
 309 /*
 310  * Stage 6 of tracepoint event generation.
 311  *
 312  * Create static inline function that calculates event payload alignment.
 313  */
 314
 315 /* Reset all macros within TRACEPOINT_EVENT */
 316 #include <lttng/ust-tracepoint-event-reset.h>
 317
 318 #undef ctf_integer_ext
 319 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base)                \
 320         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 321
 322 #undef ctf_float
 323 #define ctf_float(_type, _item, _src)                                          \
 324         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 325
 326 #undef ctf_array_encoded
 327 #define ctf_array_encoded(_type, _item, _src, _length, _encoding)              \
 328         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 329
 330 #undef ctf_sequence_encoded
 331 #define ctf_sequence_encoded(_type, _item, _src, _length_type,  \
 332                         _src_length, _encoding)                 \
 333         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_length_type));    \
 334         __event_align = _tp_max_t(size_t, __event_align, lttng_alignof(_type));
 335
 336 #undef ctf_string
 337 #define ctf_string(_item, _src)
 338
 339 #undef TP_ARGS
 340 #define TP_ARGS(args...) args
 341
 342 #undef TP_FIELDS
 343 #define TP_FIELDS(args...) args
 344
 345 #undef TRACEPOINT_EVENT_CLASS
 346 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)              \
 347 static inline                                                                 \
 348 size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 349 {                                                                             \
 350         size_t __event_align = 1;                                             \
 351         _fields                                                               \
 352         return __event_align;                                                 \
 353 }
 354
 355 #include TRACEPOINT_INCLUDE
 356
 357
 358 /*
 359  * Stage 7 of tracepoint event generation.
 360  *
 361  * Create the probe function. This function calls event size calculation
 362  * and writes event data into the buffer.
 363  */
 364
 365 /* Reset all macros within TRACEPOINT_EVENT */
 366 #include <lttng/ust-tracepoint-event-reset.h>
 367
 368 #undef ctf_integer_ext
 369 #define ctf_integer_ext(_type, _item, _src, _byte_order, _base)         \
 370         {                                                               \
 371                 _type __tmp = (_src);                                   \
 372                 lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__tmp));\
 373                 __chan->ops->event_write(&__ctx, &__tmp, sizeof(__tmp));\
 374         }
 375
 376 #undef ctf_float
 377 #define ctf_float(_type, _item, _src)                                   \
 378         {                                                               \
 379                 _type __tmp = (_src);                                   \
 380                 lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__tmp));\
 381                 __chan->ops->event_write(&__ctx, &__tmp, sizeof(__tmp));\
 382         }
 383
 384 #undef ctf_array_encoded
 385 #define ctf_array_encoded(_type, _item, _src, _length, _encoding)       \
 386         lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_type));        \
 387         __chan->ops->event_write(&__ctx, _src, sizeof(_type) * (_length));
 388
 389 #undef ctf_sequence_encoded
 390 #define ctf_sequence_encoded(_type, _item, _src, _length_type,          \
 391                         _src_length, _encoding)                 \
 392         {                                                               \
 393                 _length_type __tmpl = __dynamic_len[__dynamic_len_idx]; \
 394                 lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_length_type));\
 395                 __chan->ops->event_write(&__ctx, &__tmpl, sizeof(_length_type));\
 396         }                                                               \
 397         lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_type));        \
 398         __chan->ops->event_write(&__ctx, _src,                          \
 399                 sizeof(_type) * __get_dynamic_len(dest));
 400
 401 #undef ctf_string
 402 #define ctf_string(_item, _src)                                         \
 403         lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(*(_src)));      \
 404         __chan->ops->event_write(&__ctx, _src, __get_dynamic_len(dest));
 405
 406 /* Beware: this get len actually consumes the len value */
 407 #undef __get_dynamic_len
 408 #define __get_dynamic_len(field)        __dynamic_len[__dynamic_len_idx++]
 409
 410 #undef TP_ARGS
 411 #define TP_ARGS(args...) args
 412
 413 #undef TP_FIELDS
 414 #define TP_FIELDS(args...) args
 415
 416 #undef TRACEPOINT_EVENT_CLASS
 417 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)              \
 418 static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))\
 419 {                                                                             \
 420         struct ltt_event *__event = __tp_data;                                \
 421         struct ltt_channel *__chan = __event->chan;                           \
 422         struct lttng_ust_lib_ring_buffer_ctx __ctx;                           \
 423         size_t __event_len, __event_align;                                    \
 424         size_t __dynamic_len_idx = 0;                                         \
 425         size_t __dynamic_len[_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name)];       \
 426         int __ret;                                                            \
 427                                                                               \
 428         if (0)                                                                \
 429                 (void) __dynamic_len_idx;       /* don't warn if unused */    \
 430         if (caa_unlikely(!CMM_ACCESS_ONCE(__chan->session->active)))          \
 431                 return;                                                       \
 432         if (caa_unlikely(!CMM_ACCESS_ONCE(__chan->enabled)))                  \
 433                 return;                                                       \
 434         if (caa_unlikely(!CMM_ACCESS_ONCE(__event->enabled)))                 \
 435                 return;                                                       \
 436         __event_len = __event_get_size__##_provider##___##_name(__dynamic_len,\
 437                  _TP_ARGS_DATA_VAR(_args));                                   \
 438         __event_align = __event_get_align__##_provider##___##_name(_TP_ARGS_VAR(_args)); \
 439         lib_ring_buffer_ctx_init(&__ctx, __chan->chan, __event, __event_len,  \
 440                                  __event_align, -1, __chan->handle);          \
 441         __ret = __chan->ops->event_reserve(&__ctx, __event->id);              \
 442         if (__ret < 0)                                                        \
 443                 return;                                                       \
 444         _fields                                                               \
 445         __chan->ops->event_commit(&__ctx);                                    \
 446 }
 447
 448 #include TRACEPOINT_INCLUDE
 449
 450 #undef __get_dynamic_len
 451
 452 /*
 453  * Stage 8 of tracepoint event generation.
 454  *
 455  * Register/unregister probes at module load/unload.
 456  */
 457
 458 /* Reset all macros within TRACEPOINT_EVENT */
 459 #include <lttng/ust-tracepoint-event-reset.h>
 460
 461 static void __attribute__((constructor))
 462 _TP_COMBINE_TOKENS(__lttng_events_init__, TRACEPOINT_PROVIDER)(void)
 463 {
 464         int ret;
 465
 466         ret = ltt_probe_register(&_TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER));
 467         assert(!ret);
 468 }
 469
 470 static void __attribute__((destructor))
 471 _TP_COMBINE_TOKENS(__lttng_events_exit__, TRACEPOINT_PROVIDER)(void)
 472 {
 473         ltt_probe_unregister(&_TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER));
 474 }