probes/lttng-events.h

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