| 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 <lttng/ust-ctl.h> |
| 49 | #include <ust-comm.h> |
| 50 | #include "error.h" |
| 51 | #include "compat.h" |
| 52 | #include "lttng-ust-uuid.h" |
| 53 | |
| 54 | #include "tracepoint-internal.h" |
| 55 | #include "lttng-tracer.h" |
| 56 | #include "lttng-tracer-core.h" |
| 57 | #include "wait.h" |
| 58 | #include "../libringbuffer/shm.h" |
| 59 | #include "jhash.h" |
| 60 | |
| 61 | /* |
| 62 | * The sessions mutex is the centralized mutex across UST tracing |
| 63 | * control and probe registration. All operations within this file are |
| 64 | * called by the communication thread, under ust_lock protection. |
| 65 | */ |
| 66 | static pthread_mutex_t sessions_mutex = PTHREAD_MUTEX_INITIALIZER; |
| 67 | |
| 68 | void ust_lock(void) |
| 69 | { |
| 70 | pthread_mutex_lock(&sessions_mutex); |
| 71 | } |
| 72 | |
| 73 | void ust_unlock(void) |
| 74 | { |
| 75 | pthread_mutex_unlock(&sessions_mutex); |
| 76 | } |
| 77 | |
| 78 | static CDS_LIST_HEAD(sessions); |
| 79 | |
| 80 | static void _lttng_event_destroy(struct lttng_event *event); |
| 81 | |
| 82 | static |
| 83 | void lttng_session_lazy_sync_enablers(struct lttng_session *session); |
| 84 | static |
| 85 | void lttng_session_sync_enablers(struct lttng_session *session); |
| 86 | static |
| 87 | void lttng_enabler_destroy(struct lttng_enabler *enabler); |
| 88 | |
| 89 | /* |
| 90 | * Called with ust lock held. |
| 91 | */ |
| 92 | int lttng_session_active(void) |
| 93 | { |
| 94 | struct lttng_session *iter; |
| 95 | |
| 96 | cds_list_for_each_entry(iter, &sessions, node) { |
| 97 | if (iter->active) |
| 98 | return 1; |
| 99 | } |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | static |
| 104 | int lttng_loglevel_match(int loglevel, |
| 105 | unsigned int has_loglevel, |
| 106 | enum lttng_ust_loglevel_type req_type, |
| 107 | int req_loglevel) |
| 108 | { |
| 109 | if (req_type == LTTNG_UST_LOGLEVEL_ALL) |
| 110 | return 1; |
| 111 | if (!has_loglevel) |
| 112 | loglevel = TRACE_DEFAULT; |
| 113 | switch (req_type) { |
| 114 | case LTTNG_UST_LOGLEVEL_RANGE: |
| 115 | if (loglevel <= req_loglevel || req_loglevel == -1) |
| 116 | return 1; |
| 117 | else |
| 118 | return 0; |
| 119 | case LTTNG_UST_LOGLEVEL_SINGLE: |
| 120 | if (loglevel == req_loglevel || req_loglevel == -1) |
| 121 | return 1; |
| 122 | else |
| 123 | return 0; |
| 124 | case LTTNG_UST_LOGLEVEL_ALL: |
| 125 | default: |
| 126 | return 1; |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | void synchronize_trace(void) |
| 131 | { |
| 132 | synchronize_rcu(); |
| 133 | } |
| 134 | |
| 135 | struct lttng_session *lttng_session_create(void) |
| 136 | { |
| 137 | struct lttng_session *session; |
| 138 | int i; |
| 139 | |
| 140 | session = zmalloc(sizeof(struct lttng_session)); |
| 141 | if (!session) |
| 142 | return NULL; |
| 143 | CDS_INIT_LIST_HEAD(&session->chan_head); |
| 144 | CDS_INIT_LIST_HEAD(&session->events_head); |
| 145 | CDS_INIT_LIST_HEAD(&session->enablers_head); |
| 146 | for (i = 0; i < LTTNG_UST_EVENT_HT_SIZE; i++) |
| 147 | CDS_INIT_HLIST_HEAD(&session->events_ht.table[i]); |
| 148 | cds_list_add(&session->node, &sessions); |
| 149 | return session; |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | * Only used internally at session destruction. |
| 154 | */ |
| 155 | static |
| 156 | void _lttng_channel_unmap(struct lttng_channel *lttng_chan) |
| 157 | { |
| 158 | struct channel *chan; |
| 159 | struct lttng_ust_shm_handle *handle; |
| 160 | |
| 161 | cds_list_del(<tng_chan->node); |
| 162 | lttng_destroy_context(lttng_chan->ctx); |
| 163 | chan = lttng_chan->chan; |
| 164 | handle = lttng_chan->handle; |
| 165 | /* |
| 166 | * note: lttng_chan is private data contained within handle. It |
| 167 | * will be freed along with the handle. |
| 168 | */ |
| 169 | channel_destroy(chan, handle, 0); |
| 170 | } |
| 171 | |
| 172 | static |
| 173 | void register_event(struct lttng_event *event) |
| 174 | { |
| 175 | int ret; |
| 176 | const struct lttng_event_desc *desc; |
| 177 | |
| 178 | assert(event->registered == 0); |
| 179 | desc = event->desc; |
| 180 | ret = __tracepoint_probe_register(desc->name, |
| 181 | desc->probe_callback, |
| 182 | event, desc->signature); |
| 183 | WARN_ON_ONCE(ret); |
| 184 | if (!ret) |
| 185 | event->registered = 1; |
| 186 | } |
| 187 | |
| 188 | static |
| 189 | void unregister_event(struct lttng_event *event) |
| 190 | { |
| 191 | int ret; |
| 192 | const struct lttng_event_desc *desc; |
| 193 | |
| 194 | assert(event->registered == 1); |
| 195 | desc = event->desc; |
| 196 | ret = __tracepoint_probe_unregister(desc->name, |
| 197 | desc->probe_callback, |
| 198 | event); |
| 199 | WARN_ON_ONCE(ret); |
| 200 | if (!ret) |
| 201 | event->registered = 0; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * Only used internally at session destruction. |
| 206 | */ |
| 207 | static |
| 208 | void _lttng_event_unregister(struct lttng_event *event) |
| 209 | { |
| 210 | if (event->registered) |
| 211 | unregister_event(event); |
| 212 | } |
| 213 | |
| 214 | void lttng_session_destroy(struct lttng_session *session) |
| 215 | { |
| 216 | struct lttng_channel *chan, *tmpchan; |
| 217 | struct lttng_event *event, *tmpevent; |
| 218 | struct lttng_enabler *enabler, *tmpenabler; |
| 219 | |
| 220 | CMM_ACCESS_ONCE(session->active) = 0; |
| 221 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 222 | _lttng_event_unregister(event); |
| 223 | } |
| 224 | synchronize_trace(); /* Wait for in-flight events to complete */ |
| 225 | cds_list_for_each_entry_safe(enabler, tmpenabler, |
| 226 | &session->enablers_head, node) |
| 227 | lttng_enabler_destroy(enabler); |
| 228 | cds_list_for_each_entry_safe(event, tmpevent, |
| 229 | &session->events_head, node) |
| 230 | _lttng_event_destroy(event); |
| 231 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan_head, node) |
| 232 | _lttng_channel_unmap(chan); |
| 233 | cds_list_del(&session->node); |
| 234 | free(session); |
| 235 | } |
| 236 | |
| 237 | int lttng_session_enable(struct lttng_session *session) |
| 238 | { |
| 239 | int ret = 0; |
| 240 | struct lttng_channel *chan; |
| 241 | int notify_socket; |
| 242 | |
| 243 | if (session->active) { |
| 244 | ret = -EBUSY; |
| 245 | goto end; |
| 246 | } |
| 247 | |
| 248 | notify_socket = lttng_get_notify_socket(session->owner); |
| 249 | if (notify_socket < 0) |
| 250 | return notify_socket; |
| 251 | |
| 252 | /* Set transient enabler state to "enabled" */ |
| 253 | session->tstate = 1; |
| 254 | /* We need to sync enablers with session before activation. */ |
| 255 | lttng_session_sync_enablers(session); |
| 256 | |
| 257 | /* |
| 258 | * Snapshot the number of events per channel to know the type of header |
| 259 | * we need to use. |
| 260 | */ |
| 261 | cds_list_for_each_entry(chan, &session->chan_head, node) { |
| 262 | const struct lttng_ctx *ctx; |
| 263 | const struct lttng_ctx_field *fields = NULL; |
| 264 | size_t nr_fields = 0; |
| 265 | uint32_t chan_id; |
| 266 | |
| 267 | /* don't change it if session stop/restart */ |
| 268 | if (chan->header_type) |
| 269 | continue; |
| 270 | ctx = chan->ctx; |
| 271 | if (ctx) { |
| 272 | nr_fields = ctx->nr_fields; |
| 273 | fields = ctx->fields; |
| 274 | } |
| 275 | ret = ustcomm_register_channel(notify_socket, |
| 276 | session->objd, |
| 277 | chan->objd, |
| 278 | nr_fields, |
| 279 | fields, |
| 280 | &chan_id, |
| 281 | &chan->header_type); |
| 282 | if (ret) { |
| 283 | DBG("Error (%d) registering channel to sessiond", ret); |
| 284 | return ret; |
| 285 | } |
| 286 | if (chan_id != chan->id) { |
| 287 | DBG("Error: channel registration id (%u) does not match id assigned at creation (%u)", |
| 288 | chan_id, chan->id); |
| 289 | return -EINVAL; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | /* Set atomically the state to "active" */ |
| 294 | CMM_ACCESS_ONCE(session->active) = 1; |
| 295 | CMM_ACCESS_ONCE(session->been_active) = 1; |
| 296 | end: |
| 297 | return ret; |
| 298 | } |
| 299 | |
| 300 | int lttng_session_disable(struct lttng_session *session) |
| 301 | { |
| 302 | int ret = 0; |
| 303 | |
| 304 | if (!session->active) { |
| 305 | ret = -EBUSY; |
| 306 | goto end; |
| 307 | } |
| 308 | /* Set atomically the state to "inactive" */ |
| 309 | CMM_ACCESS_ONCE(session->active) = 0; |
| 310 | |
| 311 | /* Set transient enabler state to "disabled" */ |
| 312 | session->tstate = 0; |
| 313 | lttng_session_sync_enablers(session); |
| 314 | end: |
| 315 | return ret; |
| 316 | } |
| 317 | |
| 318 | int lttng_channel_enable(struct lttng_channel *channel) |
| 319 | { |
| 320 | int ret = 0; |
| 321 | |
| 322 | if (channel->enabled) { |
| 323 | ret = -EBUSY; |
| 324 | goto end; |
| 325 | } |
| 326 | /* Set transient enabler state to "enabled" */ |
| 327 | channel->tstate = 1; |
| 328 | lttng_session_sync_enablers(channel->session); |
| 329 | /* Set atomically the state to "enabled" */ |
| 330 | CMM_ACCESS_ONCE(channel->enabled) = 1; |
| 331 | end: |
| 332 | return ret; |
| 333 | } |
| 334 | |
| 335 | int lttng_channel_disable(struct lttng_channel *channel) |
| 336 | { |
| 337 | int ret = 0; |
| 338 | |
| 339 | if (!channel->enabled) { |
| 340 | ret = -EBUSY; |
| 341 | goto end; |
| 342 | } |
| 343 | /* Set atomically the state to "disabled" */ |
| 344 | CMM_ACCESS_ONCE(channel->enabled) = 0; |
| 345 | /* Set transient enabler state to "enabled" */ |
| 346 | channel->tstate = 0; |
| 347 | lttng_session_sync_enablers(channel->session); |
| 348 | end: |
| 349 | return ret; |
| 350 | } |
| 351 | |
| 352 | /* |
| 353 | * Supports event creation while tracing session is active. |
| 354 | */ |
| 355 | static |
| 356 | int lttng_event_create(const struct lttng_event_desc *desc, |
| 357 | struct lttng_channel *chan) |
| 358 | { |
| 359 | const char *event_name = desc->name; |
| 360 | struct lttng_event *event; |
| 361 | struct lttng_session *session = chan->session; |
| 362 | struct cds_hlist_head *head; |
| 363 | struct cds_hlist_node *node; |
| 364 | int ret = 0; |
| 365 | size_t name_len = strlen(event_name); |
| 366 | uint32_t hash; |
| 367 | int notify_socket, loglevel; |
| 368 | const char *uri; |
| 369 | |
| 370 | hash = jhash(event_name, name_len, 0); |
| 371 | head = &chan->session->events_ht.table[hash & (LTTNG_UST_EVENT_HT_SIZE - 1)]; |
| 372 | cds_hlist_for_each_entry(event, node, head, hlist) { |
| 373 | assert(event->desc); |
| 374 | if (!strncmp(event->desc->name, desc->name, |
| 375 | LTTNG_UST_SYM_NAME_LEN - 1) |
| 376 | && chan == event->chan) { |
| 377 | ret = -EEXIST; |
| 378 | goto exist; |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | notify_socket = lttng_get_notify_socket(session->owner); |
| 383 | if (notify_socket < 0) { |
| 384 | ret = notify_socket; |
| 385 | goto socket_error; |
| 386 | } |
| 387 | |
| 388 | /* |
| 389 | * Check if loglevel match. Refuse to connect event if not. |
| 390 | */ |
| 391 | event = zmalloc(sizeof(struct lttng_event)); |
| 392 | if (!event) { |
| 393 | ret = -ENOMEM; |
| 394 | goto cache_error; |
| 395 | } |
| 396 | event->chan = chan; |
| 397 | |
| 398 | /* Event will be enabled by enabler sync. */ |
| 399 | event->enabled = 0; |
| 400 | event->registered = 0; |
| 401 | CDS_INIT_LIST_HEAD(&event->bytecode_runtime_head); |
| 402 | CDS_INIT_LIST_HEAD(&event->enablers_ref_head); |
| 403 | event->desc = desc; |
| 404 | |
| 405 | if (desc->loglevel) |
| 406 | loglevel = *(*event->desc->loglevel); |
| 407 | else |
| 408 | loglevel = TRACE_DEFAULT; |
| 409 | if (desc->u.ext.model_emf_uri) |
| 410 | uri = *(desc->u.ext.model_emf_uri); |
| 411 | else |
| 412 | uri = NULL; |
| 413 | |
| 414 | /* Fetch event ID from sessiond */ |
| 415 | ret = ustcomm_register_event(notify_socket, |
| 416 | session->objd, |
| 417 | chan->objd, |
| 418 | event_name, |
| 419 | loglevel, |
| 420 | desc->signature, |
| 421 | desc->nr_fields, |
| 422 | desc->fields, |
| 423 | uri, |
| 424 | &event->id); |
| 425 | if (ret < 0) { |
| 426 | DBG("Error (%d) registering event to sessiond", ret); |
| 427 | goto sessiond_register_error; |
| 428 | } |
| 429 | |
| 430 | /* Populate lttng_event structure before tracepoint registration. */ |
| 431 | cmm_smp_wmb(); |
| 432 | cds_list_add(&event->node, &chan->session->events_head); |
| 433 | cds_hlist_add_head(&event->hlist, head); |
| 434 | return 0; |
| 435 | |
| 436 | sessiond_register_error: |
| 437 | free(event); |
| 438 | cache_error: |
| 439 | socket_error: |
| 440 | exist: |
| 441 | return ret; |
| 442 | } |
| 443 | |
| 444 | static |
| 445 | int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc *desc, |
| 446 | struct lttng_enabler *enabler) |
| 447 | { |
| 448 | int loglevel = 0; |
| 449 | unsigned int has_loglevel = 0; |
| 450 | |
| 451 | assert(enabler->type == LTTNG_ENABLER_WILDCARD); |
| 452 | /* Compare excluding final '*' */ |
| 453 | if (strncmp(desc->name, enabler->event_param.name, |
| 454 | strlen(enabler->event_param.name) - 1)) |
| 455 | return 0; |
| 456 | if (desc->loglevel) { |
| 457 | loglevel = *(*desc->loglevel); |
| 458 | has_loglevel = 1; |
| 459 | } |
| 460 | if (!lttng_loglevel_match(loglevel, |
| 461 | has_loglevel, |
| 462 | enabler->event_param.loglevel_type, |
| 463 | enabler->event_param.loglevel)) |
| 464 | return 0; |
| 465 | return 1; |
| 466 | } |
| 467 | |
| 468 | static |
| 469 | int lttng_desc_match_event_enabler(const struct lttng_event_desc *desc, |
| 470 | struct lttng_enabler *enabler) |
| 471 | { |
| 472 | int loglevel = 0; |
| 473 | unsigned int has_loglevel = 0; |
| 474 | |
| 475 | assert(enabler->type == LTTNG_ENABLER_EVENT); |
| 476 | if (strcmp(desc->name, enabler->event_param.name)) |
| 477 | return 0; |
| 478 | if (desc->loglevel) { |
| 479 | loglevel = *(*desc->loglevel); |
| 480 | has_loglevel = 1; |
| 481 | } |
| 482 | if (!lttng_loglevel_match(loglevel, |
| 483 | has_loglevel, |
| 484 | enabler->event_param.loglevel_type, |
| 485 | enabler->event_param.loglevel)) |
| 486 | return 0; |
| 487 | return 1; |
| 488 | } |
| 489 | |
| 490 | static |
| 491 | int lttng_desc_match_enabler(const struct lttng_event_desc *desc, |
| 492 | struct lttng_enabler *enabler) |
| 493 | { |
| 494 | struct lttng_ust_excluder_node *excluder; |
| 495 | |
| 496 | /* If event matches with an excluder, return 'does not match' */ |
| 497 | cds_list_for_each_entry(excluder, &enabler->excluder_head, node) { |
| 498 | int count; |
| 499 | |
| 500 | for (count = 0; count < excluder->excluder.count; count++) { |
| 501 | int found, len; |
| 502 | char *excluder_name; |
| 503 | |
| 504 | excluder_name = (char *) (excluder->excluder.names) |
| 505 | + count * LTTNG_UST_SYM_NAME_LEN; |
| 506 | len = strnlen(excluder_name, LTTNG_UST_SYM_NAME_LEN); |
| 507 | if (len > 0 && excluder_name[len - 1] == '*') { |
| 508 | found = !strncmp(desc->name, excluder_name, |
| 509 | len - 1); |
| 510 | } else { |
| 511 | found = !strncmp(desc->name, excluder_name, |
| 512 | LTTNG_UST_SYM_NAME_LEN - 1); |
| 513 | } |
| 514 | if (found) { |
| 515 | return 0; |
| 516 | } |
| 517 | } |
| 518 | } |
| 519 | switch (enabler->type) { |
| 520 | case LTTNG_ENABLER_WILDCARD: |
| 521 | return lttng_desc_match_wildcard_enabler(desc, enabler); |
| 522 | case LTTNG_ENABLER_EVENT: |
| 523 | return lttng_desc_match_event_enabler(desc, enabler); |
| 524 | default: |
| 525 | return -EINVAL; |
| 526 | } |
| 527 | } |
| 528 | |
| 529 | static |
| 530 | int lttng_event_match_enabler(struct lttng_event *event, |
| 531 | struct lttng_enabler *enabler) |
| 532 | { |
| 533 | if (lttng_desc_match_enabler(event->desc, enabler) |
| 534 | && event->chan == enabler->chan) |
| 535 | return 1; |
| 536 | else |
| 537 | return 0; |
| 538 | } |
| 539 | |
| 540 | static |
| 541 | struct lttng_enabler_ref * lttng_event_enabler_ref(struct lttng_event *event, |
| 542 | struct lttng_enabler *enabler) |
| 543 | { |
| 544 | struct lttng_enabler_ref *enabler_ref; |
| 545 | |
| 546 | cds_list_for_each_entry(enabler_ref, |
| 547 | &event->enablers_ref_head, node) { |
| 548 | if (enabler_ref->ref == enabler) |
| 549 | return enabler_ref; |
| 550 | } |
| 551 | return NULL; |
| 552 | } |
| 553 | |
| 554 | /* |
| 555 | * Create struct lttng_event if it is missing and present in the list of |
| 556 | * tracepoint probes. |
| 557 | */ |
| 558 | static |
| 559 | void lttng_create_event_if_missing(struct lttng_enabler *enabler) |
| 560 | { |
| 561 | struct lttng_session *session = enabler->chan->session; |
| 562 | struct lttng_probe_desc *probe_desc; |
| 563 | const struct lttng_event_desc *desc; |
| 564 | struct lttng_event *event; |
| 565 | int i; |
| 566 | struct cds_list_head *probe_list; |
| 567 | |
| 568 | probe_list = lttng_get_probe_list_head(); |
| 569 | /* |
| 570 | * For each probe event, if we find that a probe event matches |
| 571 | * our enabler, create an associated lttng_event if not |
| 572 | * already present. |
| 573 | */ |
| 574 | cds_list_for_each_entry(probe_desc, probe_list, head) { |
| 575 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 576 | int found = 0, ret; |
| 577 | struct cds_hlist_head *head; |
| 578 | struct cds_hlist_node *node; |
| 579 | const char *event_name; |
| 580 | size_t name_len; |
| 581 | uint32_t hash; |
| 582 | |
| 583 | desc = probe_desc->event_desc[i]; |
| 584 | if (!lttng_desc_match_enabler(desc, enabler)) |
| 585 | continue; |
| 586 | event_name = desc->name; |
| 587 | name_len = strlen(event_name); |
| 588 | |
| 589 | /* |
| 590 | * Check if already created. |
| 591 | */ |
| 592 | hash = jhash(event_name, name_len, 0); |
| 593 | head = &session->events_ht.table[hash & (LTTNG_UST_EVENT_HT_SIZE - 1)]; |
| 594 | cds_hlist_for_each_entry(event, node, head, hlist) { |
| 595 | if (event->desc == desc |
| 596 | && event->chan == enabler->chan) |
| 597 | found = 1; |
| 598 | } |
| 599 | if (found) |
| 600 | continue; |
| 601 | |
| 602 | /* |
| 603 | * We need to create an event for this |
| 604 | * event probe. |
| 605 | */ |
| 606 | ret = lttng_event_create(probe_desc->event_desc[i], |
| 607 | enabler->chan); |
| 608 | if (ret) { |
| 609 | DBG("Unable to create event %s, error %d\n", |
| 610 | probe_desc->event_desc[i]->name, ret); |
| 611 | } |
| 612 | } |
| 613 | } |
| 614 | } |
| 615 | |
| 616 | /* |
| 617 | * Create events associated with an enabler (if not already present), |
| 618 | * and add backward reference from the event to the enabler. |
| 619 | */ |
| 620 | static |
| 621 | int lttng_enabler_ref_events(struct lttng_enabler *enabler) |
| 622 | { |
| 623 | struct lttng_session *session = enabler->chan->session; |
| 624 | struct lttng_event *event; |
| 625 | |
| 626 | /* First ensure that probe events are created for this enabler. */ |
| 627 | lttng_create_event_if_missing(enabler); |
| 628 | |
| 629 | /* For each event matching enabler in session event list. */ |
| 630 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 631 | struct lttng_enabler_ref *enabler_ref; |
| 632 | |
| 633 | if (!lttng_event_match_enabler(event, enabler)) |
| 634 | continue; |
| 635 | |
| 636 | enabler_ref = lttng_event_enabler_ref(event, enabler); |
| 637 | if (!enabler_ref) { |
| 638 | /* |
| 639 | * If no backward ref, create it. |
| 640 | * Add backward ref from event to enabler. |
| 641 | */ |
| 642 | enabler_ref = zmalloc(sizeof(*enabler_ref)); |
| 643 | if (!enabler_ref) |
| 644 | return -ENOMEM; |
| 645 | enabler_ref->ref = enabler; |
| 646 | cds_list_add(&enabler_ref->node, |
| 647 | &event->enablers_ref_head); |
| 648 | } |
| 649 | |
| 650 | /* |
| 651 | * Link filter bytecodes if not linked yet. |
| 652 | */ |
| 653 | lttng_enabler_event_link_bytecode(event, enabler); |
| 654 | |
| 655 | /* TODO: merge event context. */ |
| 656 | } |
| 657 | return 0; |
| 658 | } |
| 659 | |
| 660 | /* |
| 661 | * Called at library load: connect the probe on all enablers matching |
| 662 | * this event. |
| 663 | * Called with session mutex held. |
| 664 | */ |
| 665 | int lttng_fix_pending_events(void) |
| 666 | { |
| 667 | struct lttng_session *session; |
| 668 | |
| 669 | cds_list_for_each_entry(session, &sessions, node) { |
| 670 | lttng_session_lazy_sync_enablers(session); |
| 671 | } |
| 672 | return 0; |
| 673 | } |
| 674 | |
| 675 | /* |
| 676 | * Only used internally at session destruction. |
| 677 | */ |
| 678 | static |
| 679 | void _lttng_event_destroy(struct lttng_event *event) |
| 680 | { |
| 681 | struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref; |
| 682 | |
| 683 | cds_list_del(&event->node); |
| 684 | lttng_destroy_context(event->ctx); |
| 685 | lttng_free_event_filter_runtime(event); |
| 686 | /* Free event enabler refs */ |
| 687 | cds_list_for_each_entry_safe(enabler_ref, tmp_enabler_ref, |
| 688 | &event->enablers_ref_head, node) |
| 689 | free(enabler_ref); |
| 690 | free(event); |
| 691 | } |
| 692 | |
| 693 | void lttng_ust_events_exit(void) |
| 694 | { |
| 695 | struct lttng_session *session, *tmpsession; |
| 696 | |
| 697 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, node) |
| 698 | lttng_session_destroy(session); |
| 699 | } |
| 700 | |
| 701 | /* |
| 702 | * Enabler management. |
| 703 | */ |
| 704 | struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type, |
| 705 | struct lttng_ust_event *event_param, |
| 706 | struct lttng_channel *chan) |
| 707 | { |
| 708 | struct lttng_enabler *enabler; |
| 709 | |
| 710 | enabler = zmalloc(sizeof(*enabler)); |
| 711 | if (!enabler) |
| 712 | return NULL; |
| 713 | enabler->type = type; |
| 714 | CDS_INIT_LIST_HEAD(&enabler->filter_bytecode_head); |
| 715 | CDS_INIT_LIST_HEAD(&enabler->excluder_head); |
| 716 | memcpy(&enabler->event_param, event_param, |
| 717 | sizeof(enabler->event_param)); |
| 718 | enabler->chan = chan; |
| 719 | /* ctx left NULL */ |
| 720 | enabler->enabled = 1; |
| 721 | cds_list_add(&enabler->node, &enabler->chan->session->enablers_head); |
| 722 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 723 | return enabler; |
| 724 | } |
| 725 | |
| 726 | int lttng_enabler_enable(struct lttng_enabler *enabler) |
| 727 | { |
| 728 | enabler->enabled = 1; |
| 729 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 730 | return 0; |
| 731 | } |
| 732 | |
| 733 | int lttng_enabler_disable(struct lttng_enabler *enabler) |
| 734 | { |
| 735 | enabler->enabled = 0; |
| 736 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 737 | return 0; |
| 738 | } |
| 739 | |
| 740 | int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler, |
| 741 | struct lttng_ust_filter_bytecode_node *bytecode) |
| 742 | { |
| 743 | bytecode->enabler = enabler; |
| 744 | cds_list_add_tail(&bytecode->node, &enabler->filter_bytecode_head); |
| 745 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 746 | return 0; |
| 747 | } |
| 748 | |
| 749 | int lttng_enabler_attach_exclusion(struct lttng_enabler *enabler, |
| 750 | struct lttng_ust_excluder_node *excluder) |
| 751 | { |
| 752 | excluder->enabler = enabler; |
| 753 | cds_list_add_tail(&excluder->node, &enabler->excluder_head); |
| 754 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 755 | return 0; |
| 756 | } |
| 757 | |
| 758 | int lttng_attach_context(struct lttng_ust_context *context_param, |
| 759 | struct lttng_ctx **ctx, struct lttng_session *session) |
| 760 | { |
| 761 | /* |
| 762 | * We cannot attach a context after trace has been started for a |
| 763 | * session because the metadata does not allow expressing this |
| 764 | * information outside of the original channel scope. |
| 765 | */ |
| 766 | if (session->been_active) |
| 767 | return -EPERM; |
| 768 | |
| 769 | switch (context_param->ctx) { |
| 770 | case LTTNG_UST_CONTEXT_PTHREAD_ID: |
| 771 | return lttng_add_pthread_id_to_ctx(ctx); |
| 772 | case LTTNG_UST_CONTEXT_VTID: |
| 773 | return lttng_add_vtid_to_ctx(ctx); |
| 774 | case LTTNG_UST_CONTEXT_VPID: |
| 775 | return lttng_add_vpid_to_ctx(ctx); |
| 776 | case LTTNG_UST_CONTEXT_PROCNAME: |
| 777 | return lttng_add_procname_to_ctx(ctx); |
| 778 | case LTTNG_UST_CONTEXT_IP: |
| 779 | return lttng_add_ip_to_ctx(ctx); |
| 780 | default: |
| 781 | return -EINVAL; |
| 782 | } |
| 783 | } |
| 784 | |
| 785 | int lttng_enabler_attach_context(struct lttng_enabler *enabler, |
| 786 | struct lttng_ust_context *context_param) |
| 787 | { |
| 788 | #if 0 // disabled for now. |
| 789 | struct lttng_session *session = enabler->chan->session; |
| 790 | int ret; |
| 791 | |
| 792 | ret = lttng_attach_context(context_param, &enabler->ctx, |
| 793 | session); |
| 794 | if (ret) |
| 795 | return ret; |
| 796 | lttng_session_lazy_sync_enablers(enabler->chan->session); |
| 797 | #endif |
| 798 | return -ENOSYS; |
| 799 | } |
| 800 | |
| 801 | static |
| 802 | void lttng_enabler_destroy(struct lttng_enabler *enabler) |
| 803 | { |
| 804 | struct lttng_ust_filter_bytecode_node *filter_node, *tmp_filter_node; |
| 805 | struct lttng_ust_excluder_node *excluder_node, *tmp_excluder_node; |
| 806 | |
| 807 | /* Destroy filter bytecode */ |
| 808 | cds_list_for_each_entry_safe(filter_node, tmp_filter_node, |
| 809 | &enabler->filter_bytecode_head, node) { |
| 810 | free(filter_node); |
| 811 | } |
| 812 | |
| 813 | /* Destroy excluders */ |
| 814 | cds_list_for_each_entry_safe(excluder_node, tmp_excluder_node, |
| 815 | &enabler->excluder_head, node) { |
| 816 | free(excluder_node); |
| 817 | } |
| 818 | |
| 819 | /* Destroy contexts */ |
| 820 | lttng_destroy_context(enabler->ctx); |
| 821 | |
| 822 | cds_list_del(&enabler->node); |
| 823 | free(enabler); |
| 824 | } |
| 825 | |
| 826 | /* |
| 827 | * lttng_session_sync_enablers should be called just before starting a |
| 828 | * session. |
| 829 | */ |
| 830 | static |
| 831 | void lttng_session_sync_enablers(struct lttng_session *session) |
| 832 | { |
| 833 | struct lttng_enabler *enabler; |
| 834 | struct lttng_event *event; |
| 835 | |
| 836 | cds_list_for_each_entry(enabler, &session->enablers_head, node) |
| 837 | lttng_enabler_ref_events(enabler); |
| 838 | /* |
| 839 | * For each event, if at least one of its enablers is enabled, |
| 840 | * and its channel and session transient states are enabled, we |
| 841 | * enable the event, else we disable it. |
| 842 | */ |
| 843 | cds_list_for_each_entry(event, &session->events_head, node) { |
| 844 | struct lttng_enabler_ref *enabler_ref; |
| 845 | struct lttng_bytecode_runtime *runtime; |
| 846 | int enabled = 0, has_enablers_without_bytecode = 0; |
| 847 | |
| 848 | /* Enable events */ |
| 849 | cds_list_for_each_entry(enabler_ref, |
| 850 | &event->enablers_ref_head, node) { |
| 851 | if (enabler_ref->ref->enabled) { |
| 852 | enabled = 1; |
| 853 | break; |
| 854 | } |
| 855 | } |
| 856 | /* |
| 857 | * Enabled state is based on union of enablers, with |
| 858 | * intesection of session and channel transient enable |
| 859 | * states. |
| 860 | */ |
| 861 | enabled = enabled && session->tstate && event->chan->tstate; |
| 862 | |
| 863 | CMM_STORE_SHARED(event->enabled, enabled); |
| 864 | /* |
| 865 | * Sync tracepoint registration with event enabled |
| 866 | * state. |
| 867 | */ |
| 868 | if (enabled) { |
| 869 | if (!event->registered) |
| 870 | register_event(event); |
| 871 | } else { |
| 872 | if (event->registered) |
| 873 | unregister_event(event); |
| 874 | } |
| 875 | |
| 876 | /* Check if has enablers without bytecode enabled */ |
| 877 | cds_list_for_each_entry(enabler_ref, |
| 878 | &event->enablers_ref_head, node) { |
| 879 | if (enabler_ref->ref->enabled |
| 880 | && cds_list_empty(&enabler_ref->ref->filter_bytecode_head)) { |
| 881 | has_enablers_without_bytecode = 1; |
| 882 | break; |
| 883 | } |
| 884 | } |
| 885 | event->has_enablers_without_bytecode = |
| 886 | has_enablers_without_bytecode; |
| 887 | |
| 888 | /* Enable filters */ |
| 889 | cds_list_for_each_entry(runtime, |
| 890 | &event->bytecode_runtime_head, node) { |
| 891 | lttng_filter_sync_state(runtime); |
| 892 | } |
| 893 | } |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * Apply enablers to session events, adding events to session if need |
| 898 | * be. It is required after each modification applied to an active |
| 899 | * session, and right before session "start". |
| 900 | * "lazy" sync means we only sync if required. |
| 901 | */ |
| 902 | static |
| 903 | void lttng_session_lazy_sync_enablers(struct lttng_session *session) |
| 904 | { |
| 905 | /* We can skip if session is not active */ |
| 906 | if (!session->active) |
| 907 | return; |
| 908 | lttng_session_sync_enablers(session); |
| 909 | } |