| 1 | /* |
| 2 | * lttng-events.c |
| 3 | * |
| 4 | * Holds LTTng per-session event registry. |
| 5 | * |
| 6 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; only |
| 11 | * version 2.1 of the License. |
| 12 | * |
| 13 | * This library is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with this library; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #define _GNU_SOURCE |
| 24 | #include <stdio.h> |
| 25 | #include <urcu/list.h> |
| 26 | #include <urcu/hlist.h> |
| 27 | #include <pthread.h> |
| 28 | #include <errno.h> |
| 29 | #include <sys/shm.h> |
| 30 | #include <sys/ipc.h> |
| 31 | #include <stdint.h> |
| 32 | #include <stddef.h> |
| 33 | #include <inttypes.h> |
| 34 | #include <time.h> |
| 35 | #include <lttng/ust-endian.h> |
| 36 | #include "clock.h" |
| 37 | |
| 38 | #include <urcu-bp.h> |
| 39 | #include <urcu/compiler.h> |
| 40 | #include <urcu/uatomic.h> |
| 41 | #include <urcu/arch.h> |
| 42 | |
| 43 | #include <lttng/tracepoint.h> |
| 44 | #include <lttng/ust-events.h> |
| 45 | |
| 46 | #include <usterr-signal-safe.h> |
| 47 | #include <helper.h> |
| 48 | #include "error.h" |
| 49 | #include "compat.h" |
| 50 | #include "lttng-ust-uuid.h" |
| 51 | |
| 52 | #include "tracepoint-internal.h" |
| 53 | #include "lttng-tracer.h" |
| 54 | #include "lttng-tracer-core.h" |
| 55 | #include "wait.h" |
| 56 | #include "../libringbuffer/shm.h" |
| 57 | #include "jhash.h" |
| 58 | |
| 59 | /* |
| 60 | * The sessions mutex is the centralized mutex across UST tracing |
| 61 | * control and probe registration. All operations within this file are |
| 62 | * called by the communication thread, under ust_lock protection. |
| 63 | */ |
| 64 | static pthread_mutex_t sessions_mutex = PTHREAD_MUTEX_INITIALIZER; |
| 65 | |
| 66 | void ust_lock(void) |
| 67 | { |
| 68 | pthread_mutex_lock(&sessions_mutex); |
| 69 | } |
| 70 | |
| 71 | void ust_unlock(void) |
| 72 | { |
| 73 | pthread_mutex_unlock(&sessions_mutex); |
| 74 | } |
| 75 | |
| 76 | static CDS_LIST_HEAD(sessions); |
| 77 | |
| 78 | static void _lttng_event_destroy(struct lttng_event *event); |
| 79 | static void _lttng_channel_destroy(struct lttng_channel *chan); |
| 80 | static int _lttng_event_unregister(struct lttng_event *event); |
| 81 | static |
| 82 | int _lttng_event_metadata_statedump(struct lttng_session *session, |
| 83 | struct lttng_channel *chan, |
| 84 | struct lttng_event *event); |
| 85 | static |
| 86 | int _lttng_session_metadata_statedump(struct lttng_session *session); |
| 87 | |
| 88 | static |
| 89 | void lttng_session_lazy_sync_enablers(struct lttng_session *session); |
| 90 | static |
| 91 | void lttng_session_sync_enablers(struct lttng_session *session); |
| 92 | static |
| 93 | void lttng_enabler_destroy(struct lttng_enabler *enabler); |
| 94 | |
| 95 | static |
| 96 | int lttng_loglevel_match(int loglevel, |
| 97 | unsigned int has_loglevel, |
| 98 | enum lttng_ust_loglevel_type req_type, |
| 99 | int req_loglevel) |
| 100 | { |
| 101 | if (req_type == LTTNG_UST_LOGLEVEL_ALL) |
| 102 | return 1; |
| 103 | if (!has_loglevel) |
| 104 | loglevel = TRACE_DEFAULT; |
| 105 | switch (req_type) { |
| 106 | case LTTNG_UST_LOGLEVEL_RANGE: |
| 107 | if (loglevel <= req_loglevel || req_loglevel == -1) |
| 108 | return 1; |
| 109 | else |
| 110 | return 0; |
| 111 | case LTTNG_UST_LOGLEVEL_SINGLE: |
| 112 | if (loglevel == req_loglevel || req_loglevel == -1) |
| 113 | return 1; |
| 114 | else |
| 115 | return 0; |
| 116 | case LTTNG_UST_LOGLEVEL_ALL: |
| 117 | default: |
| 118 | return 1; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | void synchronize_trace(void) |
| 123 | { |
| 124 | synchronize_rcu(); |
| 125 | } |
| 126 | |
| 127 | struct lttng_session *lttng_session_create(void) |
| 128 | { |
| 129 | struct lttng_session *session; |
| 130 | int ret, i; |
| 131 | |
| 132 | session = zmalloc(sizeof(struct lttng_session)); |
| 133 | if (!session) |
| 134 | return NULL; |
| 135 | CDS_INIT_LIST_HEAD(&session->chan_head); |
| 136 | CDS_INIT_LIST_HEAD(&session->events_head); |
| 137 | CDS_INIT_LIST_HEAD(&session->enablers_head); |
| 138 | for (i = 0; i < LTTNG_UST_EVENT_HT_SIZE; i++) |
| 139 | CDS_INIT_HLIST_HEAD(&session->events_ht.table[i]); |
| 140 | ret = lttng_ust_uuid_generate(session->uuid); |
| 141 | if (ret != 0) { |
| 142 | session->uuid[0] = '\0'; |
| 143 | } |
| 144 | cds_list_add(&session->node, &sessions); |
| 145 | return session; |
| 146 | } |
| 147 | |
| 148 | void lttng_session_destroy(struct lttng_session *session) |
| 149 | { |
| 150 | struct lttng_channel *chan, *tmpchan; |
| 151 | struct lttng_event *event, *tmpevent; |
| 152 | struct lttng_enabler *enabler, *tmpenabler; |
| 153 | int ret; |
| 154 | |
| 155 | CMM_ACCESS_ONCE(session->active) = 0; |
| 156 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 157 | ret = _lttng_event_unregister(event); |
| 158 | WARN_ON(ret); |
| 159 | } |
| 160 | synchronize_trace(); /* Wait for in-flight events to complete */ |
| 161 | cds_list_for_each_entry_safe(enabler, tmpenabler, |
| 162 | &session->enablers_head, node) |
| 163 | lttng_enabler_destroy(enabler); |
| 164 | cds_list_for_each_entry_safe(event, tmpevent, |
| 165 | &session->events_head, node) |
| 166 | _lttng_event_destroy(event); |
| 167 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan_head, node) |
| 168 | _lttng_channel_destroy(chan); |
| 169 | cds_list_del(&session->node); |
| 170 | free(session); |
| 171 | } |
| 172 | |
| 173 | int lttng_session_enable(struct lttng_session *session) |
| 174 | { |
| 175 | int ret = 0; |
| 176 | struct lttng_channel *chan; |
| 177 | |
| 178 | if (session->active) { |
| 179 | ret = -EBUSY; |
| 180 | goto end; |
| 181 | } |
| 182 | |
| 183 | /* We need to sync enablers with session before activation. */ |
| 184 | lttng_session_sync_enablers(session); |
| 185 | |
| 186 | /* |
| 187 | * Snapshot the number of events per channel to know the type of header |
| 188 | * we need to use. |
| 189 | */ |
| 190 | cds_list_for_each_entry(chan, &session->chan_head, node) { |
| 191 | if (chan->header_type) |
| 192 | continue; /* don't change it if session stop/restart */ |
| 193 | if (chan->free_event_id < 31) |
| 194 | chan->header_type = 1; /* compact */ |
| 195 | else |
| 196 | chan->header_type = 2; /* large */ |
| 197 | } |
| 198 | |
| 199 | CMM_ACCESS_ONCE(session->active) = 1; |
| 200 | CMM_ACCESS_ONCE(session->been_active) = 1; |
| 201 | ret = _lttng_session_metadata_statedump(session); |
| 202 | if (ret) |
| 203 | CMM_ACCESS_ONCE(session->active) = 0; |
| 204 | end: |
| 205 | return ret; |
| 206 | } |
| 207 | |
| 208 | int lttng_session_disable(struct lttng_session *session) |
| 209 | { |
| 210 | int ret = 0; |
| 211 | |
| 212 | if (!session->active) { |
| 213 | ret = -EBUSY; |
| 214 | goto end; |
| 215 | } |
| 216 | CMM_ACCESS_ONCE(session->active) = 0; |
| 217 | end: |
| 218 | return ret; |
| 219 | } |
| 220 | |
| 221 | int lttng_channel_enable(struct lttng_channel *channel) |
| 222 | { |
| 223 | int old; |
| 224 | |
| 225 | if (channel == channel->session->metadata) |
| 226 | return -EPERM; |
| 227 | old = uatomic_xchg(&channel->enabled, 1); |
| 228 | if (old) |
| 229 | return -EEXIST; |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | int lttng_channel_disable(struct lttng_channel *channel) |
| 234 | { |
| 235 | int old; |
| 236 | |
| 237 | if (channel == channel->session->metadata) |
| 238 | return -EPERM; |
| 239 | old = uatomic_xchg(&channel->enabled, 0); |
| 240 | if (!old) |
| 241 | return -EEXIST; |
| 242 | return 0; |
| 243 | } |
| 244 | |
| 245 | int lttng_event_enable(struct lttng_event *event) |
| 246 | { |
| 247 | int old; |
| 248 | |
| 249 | if (event->chan == event->chan->session->metadata) |
| 250 | return -EPERM; |
| 251 | old = uatomic_xchg(&event->enabled, 1); |
| 252 | if (old) |
| 253 | return -EEXIST; |
| 254 | return 0; |
| 255 | } |
| 256 | |
| 257 | int lttng_event_disable(struct lttng_event *event) |
| 258 | { |
| 259 | int old; |
| 260 | |
| 261 | if (event->chan == event->chan->session->metadata) |
| 262 | return -EPERM; |
| 263 | old = uatomic_xchg(&event->enabled, 0); |
| 264 | if (!old) |
| 265 | return -EEXIST; |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | struct lttng_channel *lttng_channel_create(struct lttng_session *session, |
| 270 | const char *transport_name, |
| 271 | void *buf_addr, |
| 272 | size_t subbuf_size, size_t num_subbuf, |
| 273 | unsigned int switch_timer_interval, |
| 274 | unsigned int read_timer_interval, |
| 275 | int **shm_fd, int **wait_fd, |
| 276 | uint64_t **memory_map_size, |
| 277 | struct lttng_channel *chan_priv_init) |
| 278 | { |
| 279 | struct lttng_channel *chan = NULL; |
| 280 | struct lttng_transport *transport; |
| 281 | |
| 282 | if (session->been_active) |
| 283 | goto active; /* Refuse to add channel to active session */ |
| 284 | transport = lttng_transport_find(transport_name); |
| 285 | if (!transport) { |
| 286 | DBG("LTTng transport %s not found\n", |
| 287 | transport_name); |
| 288 | goto notransport; |
| 289 | } |
| 290 | chan_priv_init->id = session->free_chan_id++; |
| 291 | chan_priv_init->session = session; |
| 292 | /* |
| 293 | * Note: the channel creation op already writes into the packet |
| 294 | * headers. Therefore the "chan" information used as input |
| 295 | * should be already accessible. |
| 296 | */ |
| 297 | chan = transport->ops.channel_create(transport_name, buf_addr, |
| 298 | subbuf_size, num_subbuf, switch_timer_interval, |
| 299 | read_timer_interval, shm_fd, wait_fd, |
| 300 | memory_map_size, chan_priv_init); |
| 301 | if (!chan) |
| 302 | goto create_error; |
| 303 | chan->enabled = 1; |
| 304 | chan->ops = &transport->ops; |
| 305 | cds_list_add(&chan->node, &session->chan_head); |
| 306 | return chan; |
| 307 | |
| 308 | create_error: |
| 309 | notransport: |
| 310 | active: |
| 311 | return NULL; |
| 312 | } |
| 313 | |
| 314 | /* |
| 315 | * Only used internally at session destruction. |
| 316 | */ |
| 317 | static |
| 318 | void _lttng_channel_destroy(struct lttng_channel *chan) |
| 319 | { |
| 320 | cds_list_del(&chan->node); |
| 321 | lttng_destroy_context(chan->ctx); |
| 322 | chan->ops->channel_destroy(chan); |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Supports event creation while tracing session is active. |
| 327 | */ |
| 328 | static |
| 329 | int lttng_event_create(const struct lttng_event_desc *desc, |
| 330 | struct lttng_channel *chan) |
| 331 | { |
| 332 | const char *event_name = desc->name; |
| 333 | struct lttng_event *event; |
| 334 | struct cds_hlist_head *head; |
| 335 | struct cds_hlist_node *node; |
| 336 | int ret = 0; |
| 337 | size_t name_len = strlen(event_name); |
| 338 | uint32_t hash; |
| 339 | |
| 340 | if (chan->used_event_id == -1U) { |
| 341 | ret = -ENOMEM; |
| 342 | goto full; |
| 343 | } |
| 344 | hash = jhash(event_name, name_len, 0); |
| 345 | head = &chan->session->events_ht.table[hash & (LTTNG_UST_EVENT_HT_SIZE - 1)]; |
| 346 | cds_hlist_for_each_entry(event, node, head, hlist) { |
| 347 | assert(event->desc); |
| 348 | if (!strncmp(event->desc->name, |
| 349 | desc->name, |
| 350 | LTTNG_UST_SYM_NAME_LEN - 1)) { |
| 351 | ret = -EEXIST; |
| 352 | goto exist; |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | /* |
| 357 | * Check if loglevel match. Refuse to connect event if not. |
| 358 | */ |
| 359 | event = zmalloc(sizeof(struct lttng_event)); |
| 360 | if (!event) { |
| 361 | ret = -ENOMEM; |
| 362 | goto cache_error; |
| 363 | } |
| 364 | event->chan = chan; |
| 365 | |
| 366 | /* |
| 367 | * used_event_id counts the maximum number of event IDs that can |
| 368 | * register if all probes register. |
| 369 | */ |
| 370 | chan->used_event_id++; |
| 371 | event->enabled = 1; |
| 372 | CDS_INIT_LIST_HEAD(&event->bytecode_runtime_head); |
| 373 | CDS_INIT_LIST_HEAD(&event->enablers_ref_head); |
| 374 | event->desc = desc; |
| 375 | /* Populate lttng_event structure before tracepoint registration. */ |
| 376 | cmm_smp_wmb(); |
| 377 | ret = __tracepoint_probe_register(event_name, |
| 378 | desc->probe_callback, |
| 379 | event, desc->signature); |
| 380 | if (ret) |
| 381 | goto register_error; |
| 382 | event->id = chan->free_event_id++; |
| 383 | ret = _lttng_event_metadata_statedump(chan->session, chan, event); |
| 384 | if (ret) |
| 385 | goto statedump_error; |
| 386 | cds_list_add(&event->node, &chan->session->events_head); |
| 387 | cds_hlist_add_head(&event->hlist, head); |
| 388 | return 0; |
| 389 | |
| 390 | statedump_error: |
| 391 | WARN_ON_ONCE(__tracepoint_probe_unregister(event_name, |
| 392 | desc->probe_callback, |
| 393 | event)); |
| 394 | register_error: |
| 395 | free(event); |
| 396 | cache_error: |
| 397 | exist: |
| 398 | full: |
| 399 | return ret; |
| 400 | } |
| 401 | |
| 402 | static |
| 403 | int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc *desc, |
| 404 | struct lttng_enabler *enabler) |
| 405 | { |
| 406 | int loglevel = 0; |
| 407 | unsigned int has_loglevel; |
| 408 | |
| 409 | assert(enabler->type == LTTNG_ENABLER_WILDCARD); |
| 410 | /* Compare excluding final '*' */ |
| 411 | if (strncmp(desc->name, enabler->event_param.name, |
| 412 | strlen(enabler->event_param.name) - 1)) |
| 413 | return 0; |
| 414 | if (desc->loglevel) { |
| 415 | loglevel = *(*desc->loglevel); |
| 416 | has_loglevel = 1; |
| 417 | } |
| 418 | if (!lttng_loglevel_match(loglevel, |
| 419 | has_loglevel, |
| 420 | enabler->event_param.loglevel_type, |
| 421 | enabler->event_param.loglevel)) |
| 422 | return 0; |
| 423 | return 1; |
| 424 | } |
| 425 | |
| 426 | static |
| 427 | int lttng_desc_match_event_enabler(const struct lttng_event_desc *desc, |
| 428 | struct lttng_enabler *enabler) |
| 429 | { |
| 430 | int loglevel = 0; |
| 431 | unsigned int has_loglevel = 0; |
| 432 | |
| 433 | assert(enabler->type == LTTNG_ENABLER_EVENT); |
| 434 | if (strcmp(desc->name, enabler->event_param.name)) |
| 435 | return 0; |
| 436 | if (desc->loglevel) { |
| 437 | loglevel = *(*desc->loglevel); |
| 438 | has_loglevel = 1; |
| 439 | } |
| 440 | if (!lttng_loglevel_match(loglevel, |
| 441 | has_loglevel, |
| 442 | enabler->event_param.loglevel_type, |
| 443 | enabler->event_param.loglevel)) |
| 444 | return 0; |
| 445 | return 1; |
| 446 | } |
| 447 | |
| 448 | static |
| 449 | int lttng_desc_match_enabler(const struct lttng_event_desc *desc, |
| 450 | struct lttng_enabler *enabler) |
| 451 | { |
| 452 | switch (enabler->type) { |
| 453 | case LTTNG_ENABLER_WILDCARD: |
| 454 | return lttng_desc_match_wildcard_enabler(desc, enabler); |
| 455 | case LTTNG_ENABLER_EVENT: |
| 456 | return lttng_desc_match_event_enabler(desc, enabler); |
| 457 | default: |
| 458 | return -EINVAL; |
| 459 | } |
| 460 | } |
| 461 | |
| 462 | static |
| 463 | int lttng_event_match_enabler(struct lttng_event *event, |
| 464 | struct lttng_enabler *enabler) |
| 465 | { |
| 466 | return lttng_desc_match_enabler(event->desc, enabler); |
| 467 | } |
| 468 | |
| 469 | static |
| 470 | struct lttng_enabler_ref * lttng_event_enabler_ref(struct lttng_event *event, |
| 471 | struct lttng_enabler *enabler) |
| 472 | { |
| 473 | struct lttng_enabler_ref *enabler_ref; |
| 474 | |
| 475 | cds_list_for_each_entry(enabler_ref, |
| 476 | &event->enablers_ref_head, node) { |
| 477 | if (enabler_ref->ref == enabler) |
| 478 | return enabler_ref; |
| 479 | } |
| 480 | return NULL; |
| 481 | } |
| 482 | |
| 483 | /* |
| 484 | * Create struct lttng_event if it is missing and present in the list of |
| 485 | * tracepoint probes. |
| 486 | */ |
| 487 | static |
| 488 | void lttng_create_event_if_missing(struct lttng_enabler *enabler) |
| 489 | { |
| 490 | struct lttng_session *session = enabler->chan->session; |
| 491 | struct lttng_probe_desc *probe_desc; |
| 492 | const struct lttng_event_desc *desc; |
| 493 | struct lttng_event *event; |
| 494 | int i; |
| 495 | struct cds_list_head *probe_list; |
| 496 | |
| 497 | probe_list = lttng_get_probe_list_head(); |
| 498 | /* |
| 499 | * For each probe event, if we find that a probe event matches |
| 500 | * our enabler, create an associated lttng_event if not |
| 501 | * already present. |
| 502 | */ |
| 503 | cds_list_for_each_entry(probe_desc, probe_list, head) { |
| 504 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 505 | int found = 0, ret; |
| 506 | struct cds_hlist_head *head; |
| 507 | struct cds_hlist_node *node; |
| 508 | const char *event_name; |
| 509 | size_t name_len; |
| 510 | uint32_t hash; |
| 511 | |
| 512 | desc = probe_desc->event_desc[i]; |
| 513 | if (!lttng_desc_match_enabler(desc, enabler)) |
| 514 | continue; |
| 515 | event_name = desc->name; |
| 516 | name_len = strlen(event_name); |
| 517 | |
| 518 | /* |
| 519 | * Check if already created. |
| 520 | */ |
| 521 | hash = jhash(event_name, name_len, 0); |
| 522 | head = &session->events_ht.table[hash & (LTTNG_UST_EVENT_HT_SIZE - 1)]; |
| 523 | cds_hlist_for_each_entry(event, node, head, hlist) { |
| 524 | if (event->desc == desc) |
| 525 | found = 1; |
| 526 | } |
| 527 | if (found) |
| 528 | continue; |
| 529 | |
| 530 | /* |
| 531 | * We need to create an event for this |
| 532 | * event probe. |
| 533 | */ |
| 534 | ret = lttng_event_create(probe_desc->event_desc[i], |
| 535 | enabler->chan); |
| 536 | if (ret) { |
| 537 | DBG("Unable to create event %s\n", |
| 538 | probe_desc->event_desc[i]->name); |
| 539 | } |
| 540 | } |
| 541 | } |
| 542 | } |
| 543 | |
| 544 | /* |
| 545 | * Create events associated with an enabler (if not already present), |
| 546 | * and add backward reference from the event to the enabler. |
| 547 | */ |
| 548 | static |
| 549 | int lttng_enabler_ref_events(struct lttng_enabler *enabler) |
| 550 | { |
| 551 | struct lttng_session *session = enabler->chan->session; |
| 552 | struct lttng_event *event; |
| 553 | |
| 554 | /* First ensure that probe events are created for this enabler. */ |
| 555 | lttng_create_event_if_missing(enabler); |
| 556 | |
| 557 | /* For each event matching enabler in session event list. */ |
| 558 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 559 | struct lttng_enabler_ref *enabler_ref; |
| 560 | |
| 561 | if (!lttng_event_match_enabler(event, enabler)) |
| 562 | continue; |
| 563 | |
| 564 | enabler_ref = lttng_event_enabler_ref(event, enabler); |
| 565 | if (!enabler_ref) { |
| 566 | /* |
| 567 | * If no backward ref, create it. |
| 568 | * Add backward ref from event to enabler. |
| 569 | */ |
| 570 | enabler_ref = zmalloc(sizeof(*enabler_ref)); |
| 571 | if (!enabler_ref) |
| 572 | return -ENOMEM; |
| 573 | enabler_ref->ref = enabler; |
| 574 | cds_list_add(&enabler_ref->node, |
| 575 | &event->enablers_ref_head); |
| 576 | } |
| 577 | |
| 578 | /* |
| 579 | * Link filter bytecodes if not linked yet. |
| 580 | */ |
| 581 | lttng_enabler_event_link_bytecode(event, enabler); |
| 582 | |
| 583 | /* TODO: merge event context. */ |
| 584 | } |
| 585 | return 0; |
| 586 | } |
| 587 | |
| 588 | /* |
| 589 | * Called at library load: connect the probe on all enablers matching |
| 590 | * this event. |
| 591 | * called with session mutex held. |
| 592 | * TODO: currently, for each desc added, we iterate on all event desc |
| 593 | * (inefficient). We should create specific code that only target the |
| 594 | * added desc. |
| 595 | */ |
| 596 | int lttng_fix_pending_event_desc(const struct lttng_event_desc *desc) |
| 597 | { |
| 598 | struct lttng_session *session; |
| 599 | |
| 600 | cds_list_for_each_entry(session, &sessions, node) { |
| 601 | lttng_session_lazy_sync_enablers(session); |
| 602 | } |
| 603 | return 0; |
| 604 | } |
| 605 | |
| 606 | /* |
| 607 | * Only used internally at session destruction. |
| 608 | */ |
| 609 | int _lttng_event_unregister(struct lttng_event *event) |
| 610 | { |
| 611 | return __tracepoint_probe_unregister(event->desc->name, |
| 612 | event->desc->probe_callback, |
| 613 | event); |
| 614 | } |
| 615 | |
| 616 | /* |
| 617 | * Only used internally at session destruction. |
| 618 | */ |
| 619 | static |
| 620 | void _lttng_event_destroy(struct lttng_event *event) |
| 621 | { |
| 622 | struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref; |
| 623 | |
| 624 | cds_list_del(&event->node); |
| 625 | lttng_destroy_context(event->ctx); |
| 626 | lttng_free_event_filter_runtime(event); |
| 627 | /* Free event enabler refs */ |
| 628 | cds_list_for_each_entry_safe(enabler_ref, tmp_enabler_ref, |
| 629 | &event->enablers_ref_head, node) |
| 630 | free(enabler_ref); |
| 631 | free(event); |
| 632 | } |
| 633 | |
| 634 | /* |
| 635 | * We have exclusive access to our metadata buffer (protected by the |
| 636 | * ust_lock), so we can do racy operations such as looking for |
| 637 | * remaining space left in packet and write, since mutual exclusion |
| 638 | * protects us from concurrent writes. |
| 639 | */ |
| 640 | int lttng_metadata_printf(struct lttng_session *session, |
| 641 | const char *fmt, ...) |
| 642 | { |
| 643 | struct lttng_ust_lib_ring_buffer_ctx ctx; |
| 644 | struct lttng_channel *chan = session->metadata; |
| 645 | char *str = NULL; |
| 646 | int ret = 0, waitret; |
| 647 | size_t len, reserve_len, pos; |
| 648 | va_list ap; |
| 649 | |
| 650 | WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active)); |
| 651 | |
| 652 | va_start(ap, fmt); |
| 653 | ret = vasprintf(&str, fmt, ap); |
| 654 | va_end(ap); |
| 655 | if (ret < 0) |
| 656 | return -ENOMEM; |
| 657 | |
| 658 | len = strlen(str); |
| 659 | pos = 0; |
| 660 | |
| 661 | for (pos = 0; pos < len; pos += reserve_len) { |
| 662 | reserve_len = min_t(size_t, |
| 663 | chan->ops->packet_avail_size(chan->chan, chan->handle), |
| 664 | len - pos); |
| 665 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, |
| 666 | sizeof(char), -1, chan->handle); |
| 667 | /* |
| 668 | * We don't care about metadata buffer's records lost |
| 669 | * count, because we always retry here. Report error if |
| 670 | * we need to bail out after timeout or being |
| 671 | * interrupted. |
| 672 | */ |
| 673 | waitret = wait_cond_interruptible_timeout( |
| 674 | ({ |
| 675 | ret = chan->ops->event_reserve(&ctx, 0); |
| 676 | ret != -ENOBUFS || !ret; |
| 677 | }), |
| 678 | LTTNG_METADATA_TIMEOUT_MSEC); |
| 679 | if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) { |
| 680 | DBG("LTTng: Failure to write metadata to buffers (%s)\n", |
| 681 | waitret == -EINTR ? "interrupted" : |
| 682 | (ret == -ENOBUFS ? "timeout" : "I/O error")); |
| 683 | if (waitret == -EINTR) |
| 684 | ret = waitret; |
| 685 | goto end; |
| 686 | } |
| 687 | chan->ops->event_write(&ctx, &str[pos], reserve_len); |
| 688 | chan->ops->event_commit(&ctx); |
| 689 | } |
| 690 | end: |
| 691 | free(str); |
| 692 | return ret; |
| 693 | } |
| 694 | |
| 695 | static |
| 696 | int _lttng_field_statedump(struct lttng_session *session, |
| 697 | const struct lttng_event_field *field) |
| 698 | { |
| 699 | int ret = 0; |
| 700 | |
| 701 | if (field->nowrite) |
| 702 | return 0; |
| 703 | |
| 704 | switch (field->type.atype) { |
| 705 | case atype_integer: |
| 706 | ret = lttng_metadata_printf(session, |
| 707 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n", |
| 708 | field->type.u.basic.integer.size, |
| 709 | field->type.u.basic.integer.alignment, |
| 710 | field->type.u.basic.integer.signedness, |
| 711 | (field->type.u.basic.integer.encoding == lttng_encode_none) |
| 712 | ? "none" |
| 713 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) |
| 714 | ? "UTF8" |
| 715 | : "ASCII", |
| 716 | field->type.u.basic.integer.base, |
| 717 | #if (BYTE_ORDER == BIG_ENDIAN) |
| 718 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
| 719 | #else |
| 720 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
| 721 | #endif |
| 722 | field->name); |
| 723 | break; |
| 724 | case atype_float: |
| 725 | ret = lttng_metadata_printf(session, |
| 726 | " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n", |
| 727 | field->type.u.basic._float.exp_dig, |
| 728 | field->type.u.basic._float.mant_dig, |
| 729 | field->type.u.basic._float.alignment, |
| 730 | #if (BYTE_ORDER == BIG_ENDIAN) |
| 731 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
| 732 | #else |
| 733 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
| 734 | #endif |
| 735 | field->name); |
| 736 | break; |
| 737 | case atype_enum: |
| 738 | ret = lttng_metadata_printf(session, |
| 739 | " %s %s;\n", |
| 740 | field->type.u.basic.enumeration.name, |
| 741 | field->name); |
| 742 | break; |
| 743 | case atype_array: |
| 744 | { |
| 745 | const struct lttng_basic_type *elem_type; |
| 746 | |
| 747 | elem_type = &field->type.u.array.elem_type; |
| 748 | ret = lttng_metadata_printf(session, |
| 749 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n", |
| 750 | elem_type->u.basic.integer.size, |
| 751 | elem_type->u.basic.integer.alignment, |
| 752 | elem_type->u.basic.integer.signedness, |
| 753 | (elem_type->u.basic.integer.encoding == lttng_encode_none) |
| 754 | ? "none" |
| 755 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) |
| 756 | ? "UTF8" |
| 757 | : "ASCII", |
| 758 | elem_type->u.basic.integer.base, |
| 759 | #if (BYTE_ORDER == BIG_ENDIAN) |
| 760 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
| 761 | #else |
| 762 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
| 763 | #endif |
| 764 | field->name, field->type.u.array.length); |
| 765 | break; |
| 766 | } |
| 767 | case atype_sequence: |
| 768 | { |
| 769 | const struct lttng_basic_type *elem_type; |
| 770 | const struct lttng_basic_type *length_type; |
| 771 | |
| 772 | elem_type = &field->type.u.sequence.elem_type; |
| 773 | length_type = &field->type.u.sequence.length_type; |
| 774 | ret = lttng_metadata_printf(session, |
| 775 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", |
| 776 | length_type->u.basic.integer.size, |
| 777 | (unsigned int) length_type->u.basic.integer.alignment, |
| 778 | length_type->u.basic.integer.signedness, |
| 779 | (length_type->u.basic.integer.encoding == lttng_encode_none) |
| 780 | ? "none" |
| 781 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) |
| 782 | ? "UTF8" |
| 783 | : "ASCII"), |
| 784 | length_type->u.basic.integer.base, |
| 785 | #if (BYTE_ORDER == BIG_ENDIAN) |
| 786 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
| 787 | #else |
| 788 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
| 789 | #endif |
| 790 | field->name); |
| 791 | if (ret) |
| 792 | return ret; |
| 793 | |
| 794 | ret = lttng_metadata_printf(session, |
| 795 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n", |
| 796 | elem_type->u.basic.integer.size, |
| 797 | (unsigned int) elem_type->u.basic.integer.alignment, |
| 798 | elem_type->u.basic.integer.signedness, |
| 799 | (elem_type->u.basic.integer.encoding == lttng_encode_none) |
| 800 | ? "none" |
| 801 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) |
| 802 | ? "UTF8" |
| 803 | : "ASCII"), |
| 804 | elem_type->u.basic.integer.base, |
| 805 | #if (BYTE_ORDER == BIG_ENDIAN) |
| 806 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
| 807 | #else |
| 808 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
| 809 | #endif |
| 810 | field->name, |
| 811 | field->name); |
| 812 | break; |
| 813 | } |
| 814 | |
| 815 | case atype_string: |
| 816 | /* Default encoding is UTF8 */ |
| 817 | ret = lttng_metadata_printf(session, |
| 818 | " string%s _%s;\n", |
| 819 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? |
| 820 | " { encoding = ASCII; }" : "", |
| 821 | field->name); |
| 822 | break; |
| 823 | default: |
| 824 | WARN_ON_ONCE(1); |
| 825 | return -EINVAL; |
| 826 | } |
| 827 | return ret; |
| 828 | } |
| 829 | |
| 830 | static |
| 831 | int _lttng_context_metadata_statedump(struct lttng_session *session, |
| 832 | struct lttng_ctx *ctx) |
| 833 | { |
| 834 | int ret = 0; |
| 835 | int i; |
| 836 | |
| 837 | if (!ctx) |
| 838 | return 0; |
| 839 | for (i = 0; i < ctx->nr_fields; i++) { |
| 840 | const struct lttng_ctx_field *field = &ctx->fields[i]; |
| 841 | |
| 842 | ret = _lttng_field_statedump(session, &field->event_field); |
| 843 | if (ret) |
| 844 | return ret; |
| 845 | } |
| 846 | return ret; |
| 847 | } |
| 848 | |
| 849 | static |
| 850 | int _lttng_fields_metadata_statedump(struct lttng_session *session, |
| 851 | struct lttng_event *event) |
| 852 | { |
| 853 | const struct lttng_event_desc *desc = event->desc; |
| 854 | int ret = 0; |
| 855 | int i; |
| 856 | |
| 857 | for (i = 0; i < desc->nr_fields; i++) { |
| 858 | const struct lttng_event_field *field = &desc->fields[i]; |
| 859 | |
| 860 | ret = _lttng_field_statedump(session, field); |
| 861 | if (ret) |
| 862 | return ret; |
| 863 | } |
| 864 | return ret; |
| 865 | } |
| 866 | |
| 867 | static |
| 868 | int _lttng_event_metadata_statedump(struct lttng_session *session, |
| 869 | struct lttng_channel *chan, |
| 870 | struct lttng_event *event) |
| 871 | { |
| 872 | int ret = 0; |
| 873 | int loglevel = TRACE_DEFAULT; |
| 874 | |
| 875 | if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
| 876 | return 0; |
| 877 | if (chan == session->metadata) |
| 878 | return 0; |
| 879 | /* |
| 880 | * Don't print events for which probe load is pending. |
| 881 | */ |
| 882 | if (!event->desc) |
| 883 | return 0; |
| 884 | |
| 885 | ret = lttng_metadata_printf(session, |
| 886 | "event {\n" |
| 887 | " name = \"%s\";\n" |
| 888 | " id = %u;\n" |
| 889 | " stream_id = %u;\n", |
| 890 | event->desc->name, |
| 891 | event->id, |
| 892 | event->chan->id); |
| 893 | if (ret) |
| 894 | goto end; |
| 895 | |
| 896 | if (event->desc->loglevel) |
| 897 | loglevel = *(*event->desc->loglevel); |
| 898 | |
| 899 | ret = lttng_metadata_printf(session, |
| 900 | " loglevel = %d;\n", |
| 901 | loglevel); |
| 902 | if (ret) |
| 903 | goto end; |
| 904 | |
| 905 | if (event->desc->u.ext.model_emf_uri) { |
| 906 | ret = lttng_metadata_printf(session, |
| 907 | " model.emf.uri = \"%s\";\n", |
| 908 | *(event->desc->u.ext.model_emf_uri)); |
| 909 | if (ret) |
| 910 | goto end; |
| 911 | } |
| 912 | |
| 913 | if (event->ctx) { |
| 914 | ret = lttng_metadata_printf(session, |
| 915 | " context := struct {\n"); |
| 916 | if (ret) |
| 917 | goto end; |
| 918 | } |
| 919 | ret = _lttng_context_metadata_statedump(session, event->ctx); |
| 920 | if (ret) |
| 921 | goto end; |
| 922 | if (event->ctx) { |
| 923 | ret = lttng_metadata_printf(session, |
| 924 | " };\n"); |
| 925 | if (ret) |
| 926 | goto end; |
| 927 | } |
| 928 | |
| 929 | ret = lttng_metadata_printf(session, |
| 930 | " fields := struct {\n" |
| 931 | ); |
| 932 | if (ret) |
| 933 | goto end; |
| 934 | |
| 935 | ret = _lttng_fields_metadata_statedump(session, event); |
| 936 | if (ret) |
| 937 | goto end; |
| 938 | |
| 939 | /* |
| 940 | * LTTng space reservation can only reserve multiples of the |
| 941 | * byte size. |
| 942 | */ |
| 943 | ret = lttng_metadata_printf(session, |
| 944 | " };\n" |
| 945 | "};\n\n"); |
| 946 | if (ret) |
| 947 | goto end; |
| 948 | |
| 949 | event->metadata_dumped = 1; |
| 950 | end: |
| 951 | return ret; |
| 952 | |
| 953 | } |
| 954 | |
| 955 | static |
| 956 | int _lttng_channel_metadata_statedump(struct lttng_session *session, |
| 957 | struct lttng_channel *chan) |
| 958 | { |
| 959 | int ret = 0; |
| 960 | |
| 961 | if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
| 962 | return 0; |
| 963 | if (chan == session->metadata) |
| 964 | return 0; |
| 965 | |
| 966 | WARN_ON_ONCE(!chan->header_type); |
| 967 | ret = lttng_metadata_printf(session, |
| 968 | "stream {\n" |
| 969 | " id = %u;\n" |
| 970 | " event.header := %s;\n" |
| 971 | " packet.context := struct packet_context;\n", |
| 972 | chan->id, |
| 973 | chan->header_type == 1 ? "struct event_header_compact" : |
| 974 | "struct event_header_large"); |
| 975 | if (ret) |
| 976 | goto end; |
| 977 | |
| 978 | if (chan->ctx) { |
| 979 | ret = lttng_metadata_printf(session, |
| 980 | " event.context := struct {\n"); |
| 981 | if (ret) |
| 982 | goto end; |
| 983 | } |
| 984 | ret = _lttng_context_metadata_statedump(session, chan->ctx); |
| 985 | if (ret) |
| 986 | goto end; |
| 987 | if (chan->ctx) { |
| 988 | ret = lttng_metadata_printf(session, |
| 989 | " };\n"); |
| 990 | if (ret) |
| 991 | goto end; |
| 992 | } |
| 993 | |
| 994 | ret = lttng_metadata_printf(session, |
| 995 | "};\n\n"); |
| 996 | |
| 997 | chan->metadata_dumped = 1; |
| 998 | end: |
| 999 | return ret; |
| 1000 | } |
| 1001 | |
| 1002 | static |
| 1003 | int _lttng_stream_packet_context_declare(struct lttng_session *session) |
| 1004 | { |
| 1005 | return lttng_metadata_printf(session, |
| 1006 | "struct packet_context {\n" |
| 1007 | " uint64_clock_monotonic_t timestamp_begin;\n" |
| 1008 | " uint64_clock_monotonic_t timestamp_end;\n" |
| 1009 | " uint64_t content_size;\n" |
| 1010 | " uint64_t packet_size;\n" |
| 1011 | " unsigned long events_discarded;\n" |
| 1012 | " uint32_t cpu_id;\n" |
| 1013 | "};\n\n" |
| 1014 | ); |
| 1015 | } |
| 1016 | |
| 1017 | /* |
| 1018 | * Compact header: |
| 1019 | * id: range: 0 - 30. |
| 1020 | * id 31 is reserved to indicate an extended header. |
| 1021 | * |
| 1022 | * Large header: |
| 1023 | * id: range: 0 - 65534. |
| 1024 | * id 65535 is reserved to indicate an extended header. |
| 1025 | */ |
| 1026 | static |
| 1027 | int _lttng_event_header_declare(struct lttng_session *session) |
| 1028 | { |
| 1029 | return lttng_metadata_printf(session, |
| 1030 | "struct event_header_compact {\n" |
| 1031 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" |
| 1032 | " variant <id> {\n" |
| 1033 | " struct {\n" |
| 1034 | " uint27_clock_monotonic_t timestamp;\n" |
| 1035 | " } compact;\n" |
| 1036 | " struct {\n" |
| 1037 | " uint32_t id;\n" |
| 1038 | " uint64_clock_monotonic_t timestamp;\n" |
| 1039 | " } extended;\n" |
| 1040 | " } v;\n" |
| 1041 | "} align(%u);\n" |
| 1042 | "\n" |
| 1043 | "struct event_header_large {\n" |
| 1044 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" |
| 1045 | " variant <id> {\n" |
| 1046 | " struct {\n" |
| 1047 | " uint32_clock_monotonic_t timestamp;\n" |
| 1048 | " } compact;\n" |
| 1049 | " struct {\n" |
| 1050 | " uint32_t id;\n" |
| 1051 | " uint64_clock_monotonic_t timestamp;\n" |
| 1052 | " } extended;\n" |
| 1053 | " } v;\n" |
| 1054 | "} align(%u);\n\n", |
| 1055 | lttng_alignof(uint32_t) * CHAR_BIT, |
| 1056 | lttng_alignof(uint16_t) * CHAR_BIT |
| 1057 | ); |
| 1058 | } |
| 1059 | |
| 1060 | /* |
| 1061 | * Approximation of NTP time of day to clock monotonic correlation, |
| 1062 | * taken at start of trace. |
| 1063 | * Yes, this is only an approximation. Yes, we can (and will) do better |
| 1064 | * in future versions. |
| 1065 | */ |
| 1066 | static |
| 1067 | uint64_t measure_clock_offset(void) |
| 1068 | { |
| 1069 | uint64_t offset, monotonic[2], realtime; |
| 1070 | struct timespec rts = { 0, 0 }; |
| 1071 | int ret; |
| 1072 | |
| 1073 | monotonic[0] = trace_clock_read64(); |
| 1074 | ret = clock_gettime(CLOCK_REALTIME, &rts); |
| 1075 | if (ret < 0) |
| 1076 | return 0; |
| 1077 | monotonic[1] = trace_clock_read64(); |
| 1078 | offset = (monotonic[0] + monotonic[1]) >> 1; |
| 1079 | realtime = (uint64_t) rts.tv_sec * 1000000000ULL; |
| 1080 | realtime += rts.tv_nsec; |
| 1081 | offset = realtime - offset; |
| 1082 | return offset; |
| 1083 | } |
| 1084 | |
| 1085 | /* |
| 1086 | * Output metadata into this session's metadata buffers. |
| 1087 | */ |
| 1088 | static |
| 1089 | int _lttng_session_metadata_statedump(struct lttng_session *session) |
| 1090 | { |
| 1091 | unsigned char *uuid_c = session->uuid; |
| 1092 | char uuid_s[LTTNG_UST_UUID_STR_LEN], |
| 1093 | clock_uuid_s[LTTNG_UST_UUID_STR_LEN]; |
| 1094 | struct lttng_channel *chan; |
| 1095 | struct lttng_event *event; |
| 1096 | int ret = 0; |
| 1097 | char procname[LTTNG_UST_PROCNAME_LEN] = ""; |
| 1098 | char hostname[HOST_NAME_MAX]; |
| 1099 | |
| 1100 | if (!CMM_ACCESS_ONCE(session->active)) |
| 1101 | return 0; |
| 1102 | if (session->metadata_dumped) |
| 1103 | goto skip_session; |
| 1104 | if (!session->metadata) { |
| 1105 | DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
| 1106 | return -EPERM; |
| 1107 | } |
| 1108 | |
| 1109 | snprintf(uuid_s, sizeof(uuid_s), |
| 1110 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", |
| 1111 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], |
| 1112 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], |
| 1113 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], |
| 1114 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); |
| 1115 | |
| 1116 | ret = lttng_metadata_printf(session, |
| 1117 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
| 1118 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" |
| 1119 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" |
| 1120 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" |
| 1121 | "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n" |
| 1122 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" |
| 1123 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" |
| 1124 | "\n" |
| 1125 | "trace {\n" |
| 1126 | " major = %u;\n" |
| 1127 | " minor = %u;\n" |
| 1128 | " uuid = \"%s\";\n" |
| 1129 | " byte_order = %s;\n" |
| 1130 | " packet.header := struct {\n" |
| 1131 | " uint32_t magic;\n" |
| 1132 | " uint8_t uuid[16];\n" |
| 1133 | " uint32_t stream_id;\n" |
| 1134 | " };\n" |
| 1135 | "};\n\n", |
| 1136 | lttng_alignof(uint8_t) * CHAR_BIT, |
| 1137 | lttng_alignof(uint16_t) * CHAR_BIT, |
| 1138 | lttng_alignof(uint32_t) * CHAR_BIT, |
| 1139 | lttng_alignof(uint64_t) * CHAR_BIT, |
| 1140 | sizeof(unsigned long) * CHAR_BIT, |
| 1141 | lttng_alignof(unsigned long) * CHAR_BIT, |
| 1142 | CTF_SPEC_MAJOR, |
| 1143 | CTF_SPEC_MINOR, |
| 1144 | uuid_s, |
| 1145 | #if (BYTE_ORDER == BIG_ENDIAN) |
| 1146 | "be" |
| 1147 | #else |
| 1148 | "le" |
| 1149 | #endif |
| 1150 | ); |
| 1151 | if (ret) |
| 1152 | goto end; |
| 1153 | |
| 1154 | /* ignore error, just use empty string if error. */ |
| 1155 | hostname[0] = '\0'; |
| 1156 | ret = gethostname(hostname, sizeof(hostname)); |
| 1157 | if (ret && errno == ENAMETOOLONG) |
| 1158 | hostname[HOST_NAME_MAX - 1] = '\0'; |
| 1159 | lttng_ust_getprocname(procname); |
| 1160 | procname[LTTNG_UST_PROCNAME_LEN - 1] = '\0'; |
| 1161 | ret = lttng_metadata_printf(session, |
| 1162 | "env {\n" |
| 1163 | " hostname = \"%s\";\n" |
| 1164 | " vpid = %d;\n" |
| 1165 | " procname = \"%s\";\n" |
| 1166 | " domain = \"ust\";\n" |
| 1167 | " tracer_name = \"lttng-ust\";\n" |
| 1168 | " tracer_major = %u;\n" |
| 1169 | " tracer_minor = %u;\n" |
| 1170 | " tracer_patchlevel = %u;\n" |
| 1171 | "};\n\n", |
| 1172 | hostname, |
| 1173 | (int) getpid(), |
| 1174 | procname, |
| 1175 | LTTNG_UST_MAJOR_VERSION, |
| 1176 | LTTNG_UST_MINOR_VERSION, |
| 1177 | LTTNG_UST_PATCHLEVEL_VERSION |
| 1178 | ); |
| 1179 | if (ret) |
| 1180 | goto end; |
| 1181 | |
| 1182 | ret = lttng_metadata_printf(session, |
| 1183 | "clock {\n" |
| 1184 | " name = %s;\n", |
| 1185 | "monotonic" |
| 1186 | ); |
| 1187 | if (ret) |
| 1188 | goto end; |
| 1189 | |
| 1190 | if (!trace_clock_uuid(clock_uuid_s)) { |
| 1191 | ret = lttng_metadata_printf(session, |
| 1192 | " uuid = \"%s\";\n", |
| 1193 | clock_uuid_s |
| 1194 | ); |
| 1195 | if (ret) |
| 1196 | goto end; |
| 1197 | } |
| 1198 | |
| 1199 | ret = lttng_metadata_printf(session, |
| 1200 | " description = \"Monotonic Clock\";\n" |
| 1201 | " freq = %" PRIu64 "; /* Frequency, in Hz */\n" |
| 1202 | " /* clock value offset from Epoch is: offset * (1/freq) */\n" |
| 1203 | " offset = %" PRIu64 ";\n" |
| 1204 | "};\n\n", |
| 1205 | trace_clock_freq(), |
| 1206 | measure_clock_offset() |
| 1207 | ); |
| 1208 | if (ret) |
| 1209 | goto end; |
| 1210 | |
| 1211 | ret = lttng_metadata_printf(session, |
| 1212 | "typealias integer {\n" |
| 1213 | " size = 27; align = 1; signed = false;\n" |
| 1214 | " map = clock.monotonic.value;\n" |
| 1215 | "} := uint27_clock_monotonic_t;\n" |
| 1216 | "\n" |
| 1217 | "typealias integer {\n" |
| 1218 | " size = 32; align = %u; signed = false;\n" |
| 1219 | " map = clock.monotonic.value;\n" |
| 1220 | "} := uint32_clock_monotonic_t;\n" |
| 1221 | "\n" |
| 1222 | "typealias integer {\n" |
| 1223 | " size = 64; align = %u; signed = false;\n" |
| 1224 | " map = clock.monotonic.value;\n" |
| 1225 | "} := uint64_clock_monotonic_t;\n\n", |
| 1226 | lttng_alignof(uint32_t) * CHAR_BIT, |
| 1227 | lttng_alignof(uint64_t) * CHAR_BIT |
| 1228 | ); |
| 1229 | if (ret) |
| 1230 | goto end; |
| 1231 | |
| 1232 | ret = _lttng_stream_packet_context_declare(session); |
| 1233 | if (ret) |
| 1234 | goto end; |
| 1235 | |
| 1236 | ret = _lttng_event_header_declare(session); |
| 1237 | if (ret) |
| 1238 | goto end; |
| 1239 | |
| 1240 | skip_session: |
| 1241 | cds_list_for_each_entry(chan, &session->chan_head, node) { |
| 1242 | ret = _lttng_channel_metadata_statedump(session, chan); |
| 1243 | if (ret) |
| 1244 | goto end; |
| 1245 | } |
| 1246 | |
| 1247 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 1248 | ret = _lttng_event_metadata_statedump(session, event->chan, event); |
| 1249 | if (ret) |
| 1250 | goto end; |
| 1251 | } |
| 1252 | session->metadata_dumped = 1; |
| 1253 | end: |
| 1254 | return ret; |
| 1255 | } |
| 1256 | |
| 1257 | void lttng_ust_events_exit(void) |
| 1258 | { |
| 1259 | struct lttng_session *session, *tmpsession; |
| 1260 | |
| 1261 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, node) |
| 1262 | lttng_session_destroy(session); |
| 1263 | } |
| 1264 | |
| 1265 | /* |
| 1266 | * Enabler management. |
| 1267 | */ |
| 1268 | struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type, |
| 1269 | struct lttng_ust_event *event_param, |
| 1270 | struct lttng_channel *chan) |
| 1271 | { |
| 1272 | struct lttng_enabler *enabler; |
| 1273 | |
| 1274 | enabler = zmalloc(sizeof(*enabler)); |
| 1275 | if (!enabler) |
| 1276 | return NULL; |
| 1277 | enabler->type = type; |
| 1278 | CDS_INIT_LIST_HEAD(&enabler->filter_bytecode_head); |
| 1279 | memcpy(&enabler->event_param, event_param, |
| 1280 | sizeof(enabler->event_param)); |
| 1281 | enabler->chan = chan; |
| 1282 | /* ctx left NULL */ |
| 1283 | enabler->enabled = 1; |
| 1284 | cds_list_add(&enabler->node, &enabler->chan->session->enablers_head); |
| 1285 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 1286 | return enabler; |
| 1287 | } |
| 1288 | |
| 1289 | int lttng_enabler_enable(struct lttng_enabler *enabler) |
| 1290 | { |
| 1291 | enabler->enabled = 1; |
| 1292 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 1293 | return 0; |
| 1294 | } |
| 1295 | |
| 1296 | int lttng_enabler_disable(struct lttng_enabler *enabler) |
| 1297 | { |
| 1298 | if (enabler->chan == enabler->chan->session->metadata) |
| 1299 | return -EPERM; |
| 1300 | enabler->enabled = 0; |
| 1301 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 1302 | return 0; |
| 1303 | } |
| 1304 | |
| 1305 | int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler, |
| 1306 | struct lttng_ust_filter_bytecode_node *bytecode) |
| 1307 | { |
| 1308 | bytecode->enabler = enabler; |
| 1309 | cds_list_add_tail(&bytecode->node, &enabler->filter_bytecode_head); |
| 1310 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 1311 | return 0; |
| 1312 | } |
| 1313 | |
| 1314 | int lttng_attach_context(struct lttng_ust_context *context_param, |
| 1315 | struct lttng_ctx **ctx, struct lttng_session *session) |
| 1316 | { |
| 1317 | /* |
| 1318 | * We cannot attach a context after trace has been started for a |
| 1319 | * session because the metadata does not allow expressing this |
| 1320 | * information outside of the original channel scope. |
| 1321 | */ |
| 1322 | if (session->been_active) |
| 1323 | return -EPERM; |
| 1324 | |
| 1325 | switch (context_param->ctx) { |
| 1326 | case LTTNG_UST_CONTEXT_PTHREAD_ID: |
| 1327 | return lttng_add_pthread_id_to_ctx(ctx); |
| 1328 | case LTTNG_UST_CONTEXT_VTID: |
| 1329 | return lttng_add_vtid_to_ctx(ctx); |
| 1330 | case LTTNG_UST_CONTEXT_VPID: |
| 1331 | return lttng_add_vpid_to_ctx(ctx); |
| 1332 | case LTTNG_UST_CONTEXT_PROCNAME: |
| 1333 | return lttng_add_procname_to_ctx(ctx); |
| 1334 | default: |
| 1335 | return -EINVAL; |
| 1336 | } |
| 1337 | } |
| 1338 | |
| 1339 | int lttng_enabler_attach_context(struct lttng_enabler *enabler, |
| 1340 | struct lttng_ust_context *context_param) |
| 1341 | { |
| 1342 | #if 0 // disabled for now. |
| 1343 | struct lttng_session *session = enabler->chan->session; |
| 1344 | int ret; |
| 1345 | |
| 1346 | ret = lttng_attach_context(context_param, &enabler->ctx, |
| 1347 | session); |
| 1348 | if (ret) |
| 1349 | return ret; |
| 1350 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 1351 | #endif |
| 1352 | return -ENOSYS; |
| 1353 | } |
| 1354 | |
| 1355 | static |
| 1356 | void lttng_enabler_destroy(struct lttng_enabler *enabler) |
| 1357 | { |
| 1358 | struct lttng_ust_filter_bytecode_node *filter_node, *tmp_filter_node; |
| 1359 | |
| 1360 | /* Destroy filter bytecode */ |
| 1361 | cds_list_for_each_entry_safe(filter_node, tmp_filter_node, |
| 1362 | &enabler->filter_bytecode_head, node) { |
| 1363 | free(filter_node); |
| 1364 | } |
| 1365 | |
| 1366 | /* Destroy contexts */ |
| 1367 | lttng_destroy_context(enabler->ctx); |
| 1368 | |
| 1369 | cds_list_del(&enabler->node); |
| 1370 | free(enabler); |
| 1371 | } |
| 1372 | |
| 1373 | /* |
| 1374 | * lttng_session_sync_enablers should be called just before starting a |
| 1375 | * session. |
| 1376 | */ |
| 1377 | static |
| 1378 | void lttng_session_sync_enablers(struct lttng_session *session) |
| 1379 | { |
| 1380 | struct lttng_enabler *enabler; |
| 1381 | struct lttng_event *event; |
| 1382 | |
| 1383 | cds_list_for_each_entry(enabler, &session->enablers_head, node) |
| 1384 | lttng_enabler_ref_events(enabler); |
| 1385 | /* |
| 1386 | * For each event, if at least one of its enablers is enabled, |
| 1387 | * we enable the event, else we disable it. |
| 1388 | */ |
| 1389 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 1390 | struct lttng_enabler_ref *enabler_ref; |
| 1391 | struct lttng_bytecode_runtime *runtime; |
| 1392 | int enabled = 0, has_enablers_without_bytecode = 0; |
| 1393 | |
| 1394 | /* Enable events */ |
| 1395 | cds_list_for_each_entry(enabler_ref, |
| 1396 | &event->enablers_ref_head, node) { |
| 1397 | if (enabler_ref->ref->enabled) { |
| 1398 | enabled = 1; |
| 1399 | break; |
| 1400 | } |
| 1401 | } |
| 1402 | event->enabled = enabled; |
| 1403 | |
| 1404 | /* Check if has enablers without bytecode enabled */ |
| 1405 | cds_list_for_each_entry(enabler_ref, |
| 1406 | &event->enablers_ref_head, node) { |
| 1407 | if (enabler_ref->ref->enabled |
| 1408 | && cds_list_empty(&enabler_ref->ref->filter_bytecode_head)) { |
| 1409 | has_enablers_without_bytecode = 1; |
| 1410 | break; |
| 1411 | } |
| 1412 | } |
| 1413 | event->has_enablers_without_bytecode = |
| 1414 | has_enablers_without_bytecode; |
| 1415 | |
| 1416 | /* Enable filters */ |
| 1417 | cds_list_for_each_entry(runtime, |
| 1418 | &event->bytecode_runtime_head, node) { |
| 1419 | lttng_filter_sync_state(runtime); |
| 1420 | } |
| 1421 | } |
| 1422 | } |
| 1423 | |
| 1424 | /* |
| 1425 | * Apply enablers to session events, adding events to session if need |
| 1426 | * be. It is required after each modification applied to an active |
| 1427 | * session, and right before session "start". |
| 1428 | * "lazy" sync means we only sync if required. |
| 1429 | */ |
| 1430 | static |
| 1431 | void lttng_session_lazy_sync_enablers(struct lttng_session *session) |
| 1432 | { |
| 1433 | /* We can skip if session is not active */ |
| 1434 | if (!session->active) |
| 1435 | return; |
| 1436 | lttng_session_sync_enablers(session); |
| 1437 | } |
| 1438 | |
| 1439 | /* |
| 1440 | * Take the TLS "fault" in libuuid if dlopen'd, which can take the |
| 1441 | * dynamic linker mutex, outside of the UST lock, since the UST lock is |
| 1442 | * taken in constructors, which are called with dynamic linker mutex |
| 1443 | * held. |
| 1444 | */ |
| 1445 | void lttng_fixup_event_tls(void) |
| 1446 | { |
| 1447 | unsigned char uuid[LTTNG_UST_UUID_STR_LEN]; |
| 1448 | |
| 1449 | (void) lttng_ust_uuid_generate(uuid); |
| 1450 | } |