| 1 | /* |
| 2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "action-executor.h" |
| 9 | #include "cmd.h" |
| 10 | #include "health-sessiond.h" |
| 11 | #include "lttng-sessiond.h" |
| 12 | #include "notification-thread-internal.h" |
| 13 | #include "session.h" |
| 14 | #include "thread.h" |
| 15 | #include <common/dynamic-array.h> |
| 16 | #include <common/macros.h> |
| 17 | #include <common/optional.h> |
| 18 | #include <lttng/action/action-internal.h> |
| 19 | #include <lttng/action/group-internal.h> |
| 20 | #include <lttng/action/group.h> |
| 21 | #include <lttng/action/notify-internal.h> |
| 22 | #include <lttng/action/notify.h> |
| 23 | #include <lttng/action/rotate-session.h> |
| 24 | #include <lttng/action/snapshot-session.h> |
| 25 | #include <lttng/action/start-session.h> |
| 26 | #include <lttng/action/stop-session.h> |
| 27 | #include <lttng/condition/evaluation.h> |
| 28 | #include <lttng/condition/on-event-internal.h> |
| 29 | #include <lttng/lttng-error.h> |
| 30 | #include <lttng/trigger/trigger-internal.h> |
| 31 | #include <pthread.h> |
| 32 | #include <stdbool.h> |
| 33 | #include <stddef.h> |
| 34 | #include <urcu/list.h> |
| 35 | |
| 36 | #define THREAD_NAME "Action Executor" |
| 37 | #define MAX_QUEUED_WORK_COUNT 8192 |
| 38 | |
| 39 | /* |
| 40 | * A work item is composed of a dynamic array of sub-items which |
| 41 | * represent a flattened, and augmented, version of a trigger's actions. |
| 42 | * |
| 43 | * We cannot rely solely on the trigger's actions since each action can have an |
| 44 | * execution context we need to comply with. |
| 45 | * |
| 46 | * The notion of execution context is required since for some actions the |
| 47 | * associated object are referenced by name and not by id. This can lead to |
| 48 | * a number of ambiguities when executing an action work item. |
| 49 | * |
| 50 | * For example, let's take a simple trigger such as: |
| 51 | * - condition: ust event a |
| 52 | * - action: start session S |
| 53 | * |
| 54 | * At time T, session S exists. |
| 55 | * At T + 1, the event A is hit. |
| 56 | * At T + 2, the tracer event notification is received and the work item is |
| 57 | * queued. Here session S have an id of 1. |
| 58 | * At T + 3, the session S is destroyed and a new session S is created, with a |
| 59 | * resulting id of 200. |
| 60 | * At T +4, the work item is popped from the queue and begin execution and will |
| 61 | * start session S with an id of 200 instead of the session S id 1 that was |
| 62 | * present at the queuing phase. |
| 63 | * |
| 64 | * The context to be respected is the one when the work item is queued. If the |
| 65 | * execution context is not the same at the moment of execution, we skip the |
| 66 | * execution of that sub-item. |
| 67 | * |
| 68 | * It is the same policy in regards to the validity of the associated |
| 69 | * trigger object at the moment of execution, if the trigger is found to be |
| 70 | * unregistered, the execution is skipped. |
| 71 | */ |
| 72 | |
| 73 | struct action_work_item { |
| 74 | uint64_t id; |
| 75 | |
| 76 | /* |
| 77 | * The actions to be executed with their respective execution context. |
| 78 | * See struct `action_work_subitem`. |
| 79 | */ |
| 80 | struct lttng_dynamic_array *subitems; |
| 81 | |
| 82 | /* Execution context data */ |
| 83 | struct lttng_trigger *trigger; |
| 84 | struct lttng_evaluation *evaluation; |
| 85 | struct notification_client_list *client_list; |
| 86 | LTTNG_OPTIONAL(struct lttng_credentials) object_creds; |
| 87 | struct cds_list_head list_node; |
| 88 | }; |
| 89 | |
| 90 | struct action_work_subitem { |
| 91 | struct lttng_action *action; |
| 92 | struct { |
| 93 | /* Used by actions targeting a session. */ |
| 94 | LTTNG_OPTIONAL(uint64_t) session_id; |
| 95 | } context; |
| 96 | }; |
| 97 | |
| 98 | struct action_executor { |
| 99 | struct lttng_thread *thread; |
| 100 | struct notification_thread_handle *notification_thread_handle; |
| 101 | struct { |
| 102 | uint64_t pending_count; |
| 103 | struct cds_list_head list; |
| 104 | pthread_cond_t cond; |
| 105 | pthread_mutex_t lock; |
| 106 | } work; |
| 107 | bool should_quit; |
| 108 | uint64_t next_work_item_id; |
| 109 | }; |
| 110 | |
| 111 | /* |
| 112 | * Only return non-zero on a fatal error that should shut down the action |
| 113 | * executor. |
| 114 | */ |
| 115 | typedef int (*action_executor_handler)(struct action_executor *executor, |
| 116 | const struct action_work_item *, |
| 117 | struct action_work_subitem *item); |
| 118 | |
| 119 | static int action_executor_notify_handler(struct action_executor *executor, |
| 120 | const struct action_work_item *, |
| 121 | struct action_work_subitem *); |
| 122 | static int action_executor_start_session_handler( |
| 123 | struct action_executor *executor, |
| 124 | const struct action_work_item *, |
| 125 | struct action_work_subitem *); |
| 126 | static int action_executor_stop_session_handler( |
| 127 | struct action_executor *executor, |
| 128 | const struct action_work_item *, |
| 129 | struct action_work_subitem *); |
| 130 | static int action_executor_rotate_session_handler( |
| 131 | struct action_executor *executor, |
| 132 | const struct action_work_item *, |
| 133 | struct action_work_subitem *); |
| 134 | static int action_executor_snapshot_session_handler( |
| 135 | struct action_executor *executor, |
| 136 | const struct action_work_item *, |
| 137 | struct action_work_subitem *); |
| 138 | static int action_executor_group_handler(struct action_executor *executor, |
| 139 | const struct action_work_item *, |
| 140 | struct action_work_subitem *); |
| 141 | static int action_executor_generic_handler(struct action_executor *executor, |
| 142 | const struct action_work_item *, |
| 143 | struct action_work_subitem *); |
| 144 | |
| 145 | static const action_executor_handler action_executors[] = { |
| 146 | [LTTNG_ACTION_TYPE_NOTIFY] = action_executor_notify_handler, |
| 147 | [LTTNG_ACTION_TYPE_START_SESSION] = action_executor_start_session_handler, |
| 148 | [LTTNG_ACTION_TYPE_STOP_SESSION] = action_executor_stop_session_handler, |
| 149 | [LTTNG_ACTION_TYPE_ROTATE_SESSION] = action_executor_rotate_session_handler, |
| 150 | [LTTNG_ACTION_TYPE_SNAPSHOT_SESSION] = action_executor_snapshot_session_handler, |
| 151 | [LTTNG_ACTION_TYPE_GROUP] = action_executor_group_handler, |
| 152 | }; |
| 153 | |
| 154 | /* Forward declaration */ |
| 155 | static int add_action_to_subitem_array(struct lttng_action *action, |
| 156 | struct lttng_dynamic_array *subitems); |
| 157 | |
| 158 | static int populate_subitem_array_from_trigger(struct lttng_trigger *trigger, |
| 159 | struct lttng_dynamic_array *subitems); |
| 160 | |
| 161 | static void action_work_subitem_destructor(void *element) |
| 162 | { |
| 163 | struct action_work_subitem *subitem = element; |
| 164 | |
| 165 | lttng_action_put(subitem->action); |
| 166 | } |
| 167 | |
| 168 | static const char *get_action_name(const struct lttng_action *action) |
| 169 | { |
| 170 | const enum lttng_action_type action_type = lttng_action_get_type(action); |
| 171 | |
| 172 | assert(action_type != LTTNG_ACTION_TYPE_UNKNOWN); |
| 173 | |
| 174 | return lttng_action_type_string(action_type); |
| 175 | } |
| 176 | |
| 177 | /* Check if this trigger allowed to interect with a given session. */ |
| 178 | static bool is_trigger_allowed_for_session(const struct lttng_trigger *trigger, |
| 179 | struct ltt_session *session) |
| 180 | { |
| 181 | bool is_allowed = false; |
| 182 | const struct lttng_credentials session_creds = { |
| 183 | .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid), |
| 184 | .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid), |
| 185 | }; |
| 186 | /* Can never be NULL. */ |
| 187 | const struct lttng_credentials *trigger_creds = |
| 188 | lttng_trigger_get_credentials(trigger); |
| 189 | |
| 190 | is_allowed = (lttng_credentials_is_equal_uid(trigger_creds, &session_creds)) || |
| 191 | (lttng_credentials_get_uid(trigger_creds) == 0); |
| 192 | if (!is_allowed) { |
| 193 | WARN("Trigger is not allowed to interact with session `%s`: session uid = %ld, session gid = %ld, trigger uid = %ld", |
| 194 | session->name, |
| 195 | (long int) session->uid, |
| 196 | (long int) session->gid, |
| 197 | (long int) lttng_credentials_get_uid(trigger_creds)); |
| 198 | } |
| 199 | |
| 200 | return is_allowed; |
| 201 | } |
| 202 | |
| 203 | static const char *get_trigger_name(const struct lttng_trigger *trigger) |
| 204 | { |
| 205 | const char *trigger_name; |
| 206 | enum lttng_trigger_status trigger_status; |
| 207 | |
| 208 | trigger_status = lttng_trigger_get_name(trigger, &trigger_name); |
| 209 | assert(trigger_status == LTTNG_TRIGGER_STATUS_OK); |
| 210 | |
| 211 | return trigger_name; |
| 212 | } |
| 213 | |
| 214 | static int client_handle_transmission_status( |
| 215 | struct notification_client *client, |
| 216 | enum client_transmission_status status, |
| 217 | void *user_data) |
| 218 | { |
| 219 | int ret = 0; |
| 220 | struct action_executor *executor = user_data; |
| 221 | bool update_communication = true; |
| 222 | |
| 223 | switch (status) { |
| 224 | case CLIENT_TRANSMISSION_STATUS_COMPLETE: |
| 225 | DBG("Successfully sent full notification to client, client_id = %" PRIu64, |
| 226 | client->id); |
| 227 | update_communication = false; |
| 228 | break; |
| 229 | case CLIENT_TRANSMISSION_STATUS_QUEUED: |
| 230 | DBG("Queued notification in client outgoing buffer, client_id = %" PRIu64, |
| 231 | client->id); |
| 232 | break; |
| 233 | case CLIENT_TRANSMISSION_STATUS_FAIL: |
| 234 | DBG("Communication error occurred while sending notification to client, client_id = %" PRIu64, |
| 235 | client->id); |
| 236 | break; |
| 237 | default: |
| 238 | ERR("Fatal error encoutered while sending notification to client, client_id = %" PRIu64, |
| 239 | client->id); |
| 240 | ret = -1; |
| 241 | goto end; |
| 242 | } |
| 243 | |
| 244 | if (!update_communication) { |
| 245 | goto end; |
| 246 | } |
| 247 | |
| 248 | /* Safe to read client's id without locking as it is immutable. */ |
| 249 | ret = notification_thread_client_communication_update( |
| 250 | executor->notification_thread_handle, client->id, |
| 251 | status); |
| 252 | end: |
| 253 | return ret; |
| 254 | } |
| 255 | |
| 256 | static int action_executor_notify_handler(struct action_executor *executor, |
| 257 | const struct action_work_item *work_item, |
| 258 | struct action_work_subitem *item) |
| 259 | { |
| 260 | return notification_client_list_send_evaluation(work_item->client_list, |
| 261 | work_item->trigger, |
| 262 | work_item->evaluation, |
| 263 | work_item->object_creds.is_set ? |
| 264 | &(work_item->object_creds.value) : |
| 265 | NULL, |
| 266 | client_handle_transmission_status, executor); |
| 267 | } |
| 268 | |
| 269 | static int action_executor_start_session_handler( |
| 270 | struct action_executor *executor, |
| 271 | const struct action_work_item *work_item, |
| 272 | struct action_work_subitem *item) |
| 273 | { |
| 274 | int ret = 0; |
| 275 | const char *session_name; |
| 276 | enum lttng_action_status action_status; |
| 277 | struct ltt_session *session; |
| 278 | enum lttng_error_code cmd_ret; |
| 279 | struct lttng_action *action = item->action; |
| 280 | |
| 281 | action_status = lttng_action_start_session_get_session_name( |
| 282 | action, &session_name); |
| 283 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 284 | ERR("Failed to get session name from `%s` action", |
| 285 | get_action_name(action)); |
| 286 | ret = -1; |
| 287 | goto end; |
| 288 | } |
| 289 | |
| 290 | /* |
| 291 | * Validate if at the moment of the action was queued the session |
| 292 | * existed. If not skip the action altogether. |
| 293 | */ |
| 294 | if (!item->context.session_id.is_set) { |
| 295 | DBG("Session `%s` was not present at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 296 | session_name, get_action_name(action), |
| 297 | get_trigger_name(work_item->trigger)); |
| 298 | lttng_action_increase_execution_failure_count(action); |
| 299 | ret = 0; |
| 300 | goto end; |
| 301 | } |
| 302 | |
| 303 | session_lock_list(); |
| 304 | session = session_find_by_name(session_name); |
| 305 | if (!session) { |
| 306 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 307 | session_name, get_action_name(action), |
| 308 | get_trigger_name(work_item->trigger)); |
| 309 | goto error_unlock_list; |
| 310 | } |
| 311 | |
| 312 | /* |
| 313 | * Check if the session id is the same as when the work item was |
| 314 | * enqueued. |
| 315 | */ |
| 316 | if (session->id != LTTNG_OPTIONAL_GET(item->context.session_id)) { |
| 317 | DBG("Session id for session `%s` (id: %" PRIu64 |
| 318 | " is not the same that was sampled (id: %" PRIu64 |
| 319 | " at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 320 | session_name, session->id, |
| 321 | LTTNG_OPTIONAL_GET(item->context.session_id), |
| 322 | get_action_name(action), |
| 323 | get_trigger_name(work_item->trigger)); |
| 324 | ret = 0; |
| 325 | goto error_unlock_list; |
| 326 | } |
| 327 | |
| 328 | session_lock(session); |
| 329 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 330 | goto error_dispose_session; |
| 331 | } |
| 332 | |
| 333 | cmd_ret = cmd_start_trace(session); |
| 334 | switch (cmd_ret) { |
| 335 | case LTTNG_OK: |
| 336 | DBG("Successfully started session `%s` on behalf of trigger `%s`", |
| 337 | session_name, get_trigger_name(work_item->trigger)); |
| 338 | break; |
| 339 | case LTTNG_ERR_TRACE_ALREADY_STARTED: |
| 340 | DBG("Attempted to start session `%s` on behalf of trigger `%s` but it was already started", |
| 341 | session_name, get_trigger_name(work_item->trigger)); |
| 342 | break; |
| 343 | default: |
| 344 | WARN("Failed to start session `%s` on behalf of trigger `%s`: %s", |
| 345 | session_name, get_trigger_name(work_item->trigger), |
| 346 | lttng_strerror(-cmd_ret)); |
| 347 | lttng_action_increase_execution_failure_count(action); |
| 348 | break; |
| 349 | } |
| 350 | |
| 351 | error_dispose_session: |
| 352 | session_unlock(session); |
| 353 | session_put(session); |
| 354 | error_unlock_list: |
| 355 | session_unlock_list(); |
| 356 | end: |
| 357 | return ret; |
| 358 | } |
| 359 | |
| 360 | static int action_executor_stop_session_handler( |
| 361 | struct action_executor *executor, |
| 362 | const struct action_work_item *work_item, |
| 363 | struct action_work_subitem *item) |
| 364 | { |
| 365 | int ret = 0; |
| 366 | const char *session_name; |
| 367 | enum lttng_action_status action_status; |
| 368 | struct ltt_session *session; |
| 369 | enum lttng_error_code cmd_ret; |
| 370 | struct lttng_action *action = item->action; |
| 371 | |
| 372 | action_status = lttng_action_stop_session_get_session_name( |
| 373 | action, &session_name); |
| 374 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 375 | ERR("Failed to get session name from `%s` action", |
| 376 | get_action_name(action)); |
| 377 | ret = -1; |
| 378 | goto end; |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * Validate if, at the moment the action was queued, the target session |
| 383 | * existed. If not, skip the action altogether. |
| 384 | */ |
| 385 | if (!item->context.session_id.is_set) { |
| 386 | DBG("Session `%s` was not present at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 387 | session_name, get_action_name(action), |
| 388 | get_trigger_name(work_item->trigger)); |
| 389 | lttng_action_increase_execution_failure_count(action); |
| 390 | ret = 0; |
| 391 | goto end; |
| 392 | } |
| 393 | |
| 394 | session_lock_list(); |
| 395 | session = session_find_by_name(session_name); |
| 396 | if (!session) { |
| 397 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 398 | session_name, get_action_name(action), |
| 399 | get_trigger_name(work_item->trigger)); |
| 400 | lttng_action_increase_execution_failure_count(action); |
| 401 | goto error_unlock_list; |
| 402 | } |
| 403 | |
| 404 | /* |
| 405 | * Check if the session id is the same as when the work item was |
| 406 | * enqueued |
| 407 | */ |
| 408 | if (session->id != LTTNG_OPTIONAL_GET(item->context.session_id)) { |
| 409 | DBG("Session id for session `%s` (id: %" PRIu64 |
| 410 | " is not the same that was sampled (id: %" PRIu64 |
| 411 | " at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 412 | session_name, session->id, |
| 413 | LTTNG_OPTIONAL_GET(item->context.session_id), |
| 414 | get_action_name(action), |
| 415 | get_trigger_name(work_item->trigger)); |
| 416 | ret = 0; |
| 417 | goto error_unlock_list; |
| 418 | } |
| 419 | |
| 420 | session_lock(session); |
| 421 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 422 | goto error_dispose_session; |
| 423 | } |
| 424 | |
| 425 | cmd_ret = cmd_stop_trace(session); |
| 426 | switch (cmd_ret) { |
| 427 | case LTTNG_OK: |
| 428 | DBG("Successfully stopped session `%s` on behalf of trigger `%s`", |
| 429 | session_name, get_trigger_name(work_item->trigger)); |
| 430 | break; |
| 431 | case LTTNG_ERR_TRACE_ALREADY_STOPPED: |
| 432 | DBG("Attempted to stop session `%s` on behalf of trigger `%s` but it was already stopped", |
| 433 | session_name, get_trigger_name(work_item->trigger)); |
| 434 | break; |
| 435 | default: |
| 436 | WARN("Failed to stop session `%s` on behalf of trigger `%s`: %s", |
| 437 | session_name, get_trigger_name(work_item->trigger), |
| 438 | lttng_strerror(-cmd_ret)); |
| 439 | lttng_action_increase_execution_failure_count(action); |
| 440 | break; |
| 441 | } |
| 442 | |
| 443 | error_dispose_session: |
| 444 | session_unlock(session); |
| 445 | session_put(session); |
| 446 | error_unlock_list: |
| 447 | session_unlock_list(); |
| 448 | end: |
| 449 | return ret; |
| 450 | } |
| 451 | |
| 452 | static int action_executor_rotate_session_handler( |
| 453 | struct action_executor *executor, |
| 454 | const struct action_work_item *work_item, |
| 455 | struct action_work_subitem *item) |
| 456 | { |
| 457 | int ret = 0; |
| 458 | const char *session_name; |
| 459 | enum lttng_action_status action_status; |
| 460 | struct ltt_session *session; |
| 461 | enum lttng_error_code cmd_ret; |
| 462 | struct lttng_action *action = item->action; |
| 463 | |
| 464 | action_status = lttng_action_rotate_session_get_session_name( |
| 465 | action, &session_name); |
| 466 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 467 | ERR("Failed to get session name from `%s` action", |
| 468 | get_action_name(action)); |
| 469 | ret = -1; |
| 470 | goto end; |
| 471 | } |
| 472 | |
| 473 | /* |
| 474 | * Validate if, at the moment the action was queued, the target session |
| 475 | * existed. If not, skip the action altogether. |
| 476 | */ |
| 477 | if (!item->context.session_id.is_set) { |
| 478 | DBG("Session `%s` was not present at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 479 | session_name, get_action_name(action), |
| 480 | get_trigger_name(work_item->trigger)); |
| 481 | lttng_action_increase_execution_failure_count(action); |
| 482 | ret = 0; |
| 483 | goto end; |
| 484 | } |
| 485 | |
| 486 | session_lock_list(); |
| 487 | session = session_find_by_name(session_name); |
| 488 | if (!session) { |
| 489 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 490 | session_name, get_action_name(action), |
| 491 | get_trigger_name(work_item->trigger)); |
| 492 | lttng_action_increase_execution_failure_count(action); |
| 493 | goto error_unlock_list; |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | * Check if the session id is the same as when the work item was |
| 498 | * enqueued. |
| 499 | */ |
| 500 | if (session->id != LTTNG_OPTIONAL_GET(item->context.session_id)) { |
| 501 | DBG("Session id for session `%s` (id: %" PRIu64 |
| 502 | " is not the same that was sampled (id: %" PRIu64 |
| 503 | " at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 504 | session_name, session->id, |
| 505 | LTTNG_OPTIONAL_GET(item->context.session_id), |
| 506 | get_action_name(action), |
| 507 | get_trigger_name(work_item->trigger)); |
| 508 | ret = 0; |
| 509 | goto error_unlock_list; |
| 510 | } |
| 511 | |
| 512 | session_lock(session); |
| 513 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 514 | goto error_dispose_session; |
| 515 | } |
| 516 | |
| 517 | cmd_ret = cmd_rotate_session(session, NULL, false, |
| 518 | LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED); |
| 519 | switch (cmd_ret) { |
| 520 | case LTTNG_OK: |
| 521 | DBG("Successfully started rotation of session `%s` on behalf of trigger `%s`", |
| 522 | session_name, get_trigger_name(work_item->trigger)); |
| 523 | break; |
| 524 | case LTTNG_ERR_ROTATION_PENDING: |
| 525 | DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation is already ongoing", |
| 526 | session_name, get_trigger_name(work_item->trigger)); |
| 527 | lttng_action_increase_execution_failure_count(action); |
| 528 | break; |
| 529 | case LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP: |
| 530 | case LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR: |
| 531 | DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation has already been completed since the last stop or clear", |
| 532 | session_name, get_trigger_name(work_item->trigger)); |
| 533 | break; |
| 534 | default: |
| 535 | WARN("Failed to start a rotation of session `%s` on behalf of trigger `%s`: %s", |
| 536 | session_name, get_trigger_name(work_item->trigger), |
| 537 | lttng_strerror(-cmd_ret)); |
| 538 | lttng_action_increase_execution_failure_count(action); |
| 539 | break; |
| 540 | } |
| 541 | |
| 542 | error_dispose_session: |
| 543 | session_unlock(session); |
| 544 | session_put(session); |
| 545 | error_unlock_list: |
| 546 | session_unlock_list(); |
| 547 | end: |
| 548 | return ret; |
| 549 | } |
| 550 | |
| 551 | static int action_executor_snapshot_session_handler( |
| 552 | struct action_executor *executor, |
| 553 | const struct action_work_item *work_item, |
| 554 | struct action_work_subitem *item) |
| 555 | { |
| 556 | int ret = 0; |
| 557 | const char *session_name; |
| 558 | enum lttng_action_status action_status; |
| 559 | struct ltt_session *session; |
| 560 | const struct lttng_snapshot_output default_snapshot_output = { |
| 561 | .max_size = UINT64_MAX, |
| 562 | }; |
| 563 | const struct lttng_snapshot_output *snapshot_output = |
| 564 | &default_snapshot_output; |
| 565 | enum lttng_error_code cmd_ret; |
| 566 | struct lttng_action *action = item->action; |
| 567 | |
| 568 | /* |
| 569 | * Validate if, at the moment the action was queued, the target session |
| 570 | * existed. If not, skip the action altogether. |
| 571 | */ |
| 572 | if (!item->context.session_id.is_set) { |
| 573 | DBG("Session was not present at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 574 | get_action_name(action), |
| 575 | get_trigger_name(work_item->trigger)); |
| 576 | lttng_action_increase_execution_failure_count(action); |
| 577 | ret = 0; |
| 578 | goto end; |
| 579 | } |
| 580 | |
| 581 | action_status = lttng_action_snapshot_session_get_session_name( |
| 582 | action, &session_name); |
| 583 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 584 | ERR("Failed to get session name from `%s` action", |
| 585 | get_action_name(action)); |
| 586 | ret = -1; |
| 587 | goto end; |
| 588 | } |
| 589 | |
| 590 | action_status = lttng_action_snapshot_session_get_output( |
| 591 | action, &snapshot_output); |
| 592 | if (action_status != LTTNG_ACTION_STATUS_OK && |
| 593 | action_status != LTTNG_ACTION_STATUS_UNSET) { |
| 594 | ERR("Failed to get output from `%s` action", |
| 595 | get_action_name(action)); |
| 596 | ret = -1; |
| 597 | goto end; |
| 598 | } |
| 599 | |
| 600 | session_lock_list(); |
| 601 | session = session_find_by_name(session_name); |
| 602 | if (!session) { |
| 603 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 604 | session_name, get_action_name(action), |
| 605 | get_trigger_name(work_item->trigger)); |
| 606 | lttng_action_increase_execution_failure_count(action); |
| 607 | goto error_unlock_list; |
| 608 | } |
| 609 | |
| 610 | /* |
| 611 | * Check if the session id is the same as when the work item was |
| 612 | * enqueued. |
| 613 | */ |
| 614 | if (session->id != LTTNG_OPTIONAL_GET(item->context.session_id)) { |
| 615 | DBG("Session id for session `%s` (id: %" PRIu64 |
| 616 | " is not the same that was sampled (id: %" PRIu64 |
| 617 | " at the moment the work item was enqueued for %s` action of trigger `%s`", |
| 618 | session_name, session->id, |
| 619 | LTTNG_OPTIONAL_GET(item->context.session_id), |
| 620 | get_action_name(action), |
| 621 | get_trigger_name(work_item->trigger)); |
| 622 | ret = 0; |
| 623 | goto error_unlock_list; |
| 624 | } |
| 625 | |
| 626 | session_lock(session); |
| 627 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 628 | goto error_dispose_session; |
| 629 | } |
| 630 | |
| 631 | cmd_ret = cmd_snapshot_record(session, snapshot_output, 0); |
| 632 | switch (cmd_ret) { |
| 633 | case LTTNG_OK: |
| 634 | DBG("Successfully recorded snapshot of session `%s` on behalf of trigger `%s`", |
| 635 | session_name, get_trigger_name(work_item->trigger)); |
| 636 | break; |
| 637 | default: |
| 638 | WARN("Failed to record snapshot of session `%s` on behalf of trigger `%s`: %s", |
| 639 | session_name, get_trigger_name(work_item->trigger), |
| 640 | lttng_strerror(-cmd_ret)); |
| 641 | lttng_action_increase_execution_failure_count(action); |
| 642 | break; |
| 643 | } |
| 644 | |
| 645 | error_dispose_session: |
| 646 | session_unlock(session); |
| 647 | session_put(session); |
| 648 | error_unlock_list: |
| 649 | session_unlock_list(); |
| 650 | end: |
| 651 | return ret; |
| 652 | } |
| 653 | |
| 654 | static int action_executor_group_handler(struct action_executor *executor, |
| 655 | const struct action_work_item *work_item, |
| 656 | struct action_work_subitem *item) |
| 657 | { |
| 658 | ERR("Execution of a group action by the action executor should never occur"); |
| 659 | abort(); |
| 660 | } |
| 661 | |
| 662 | static int action_executor_generic_handler(struct action_executor *executor, |
| 663 | const struct action_work_item *work_item, |
| 664 | struct action_work_subitem *item) |
| 665 | { |
| 666 | int ret; |
| 667 | struct lttng_action *action = item->action; |
| 668 | const enum lttng_action_type action_type = lttng_action_get_type(action); |
| 669 | |
| 670 | assert(action_type != LTTNG_ACTION_TYPE_UNKNOWN); |
| 671 | |
| 672 | lttng_action_increase_execution_request_count(action); |
| 673 | if (!lttng_action_should_execute(action)) { |
| 674 | DBG("Policy prevented execution of action `%s` of trigger `%s` action work item %" PRIu64, |
| 675 | get_action_name(action), |
| 676 | get_trigger_name(work_item->trigger), |
| 677 | work_item->id); |
| 678 | ret = 0; |
| 679 | goto end; |
| 680 | } |
| 681 | |
| 682 | lttng_action_increase_execution_count(action); |
| 683 | DBG("Executing action `%s` of trigger `%s` action work item %" PRIu64, |
| 684 | get_action_name(action), |
| 685 | get_trigger_name(work_item->trigger), |
| 686 | work_item->id); |
| 687 | ret = action_executors[action_type](executor, work_item, item); |
| 688 | end: |
| 689 | return ret; |
| 690 | } |
| 691 | |
| 692 | static int action_work_item_execute(struct action_executor *executor, |
| 693 | struct action_work_item *work_item) |
| 694 | { |
| 695 | int ret; |
| 696 | size_t count, i; |
| 697 | |
| 698 | DBG("Starting execution of action work item %" PRIu64 " of trigger `%s`", |
| 699 | work_item->id, get_trigger_name(work_item->trigger)); |
| 700 | |
| 701 | count = lttng_dynamic_array_get_count(work_item->subitems); |
| 702 | for (i = 0; i < count; i++) { |
| 703 | struct action_work_subitem *item; |
| 704 | |
| 705 | item = lttng_dynamic_array_get_element(work_item->subitems, i); |
| 706 | ret = action_executor_generic_handler( |
| 707 | executor, work_item, item); |
| 708 | if (ret) { |
| 709 | goto end; |
| 710 | } |
| 711 | } |
| 712 | end: |
| 713 | DBG("Completed execution of action work item %" PRIu64 " of trigger `%s`", |
| 714 | work_item->id, get_trigger_name(work_item->trigger)); |
| 715 | return ret; |
| 716 | } |
| 717 | |
| 718 | static void action_work_item_destroy(struct action_work_item *work_item) |
| 719 | { |
| 720 | lttng_trigger_put(work_item->trigger); |
| 721 | lttng_evaluation_destroy(work_item->evaluation); |
| 722 | notification_client_list_put(work_item->client_list); |
| 723 | lttng_dynamic_array_reset(work_item->subitems); |
| 724 | free(work_item); |
| 725 | } |
| 726 | |
| 727 | static void *action_executor_thread(void *_data) |
| 728 | { |
| 729 | struct action_executor *executor = _data; |
| 730 | |
| 731 | assert(executor); |
| 732 | |
| 733 | health_register(the_health_sessiond, |
| 734 | HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR); |
| 735 | |
| 736 | rcu_register_thread(); |
| 737 | rcu_thread_online(); |
| 738 | |
| 739 | DBG("Entering work execution loop"); |
| 740 | pthread_mutex_lock(&executor->work.lock); |
| 741 | while (!executor->should_quit) { |
| 742 | int ret; |
| 743 | struct action_work_item *work_item; |
| 744 | |
| 745 | health_code_update(); |
| 746 | if (executor->work.pending_count == 0) { |
| 747 | health_poll_entry(); |
| 748 | DBG("No work items enqueued, entering wait"); |
| 749 | pthread_cond_wait(&executor->work.cond, |
| 750 | &executor->work.lock); |
| 751 | DBG("Woke-up from wait"); |
| 752 | health_poll_exit(); |
| 753 | continue; |
| 754 | } |
| 755 | |
| 756 | /* Pop item from front of the list with work lock held. */ |
| 757 | work_item = cds_list_first_entry(&executor->work.list, |
| 758 | struct action_work_item, list_node); |
| 759 | cds_list_del(&work_item->list_node); |
| 760 | executor->work.pending_count--; |
| 761 | |
| 762 | /* |
| 763 | * Work can be performed without holding the work lock, |
| 764 | * allowing new items to be queued. |
| 765 | */ |
| 766 | pthread_mutex_unlock(&executor->work.lock); |
| 767 | |
| 768 | /* Execute item only if a trigger is registered. */ |
| 769 | lttng_trigger_lock(work_item->trigger); |
| 770 | if (!lttng_trigger_is_registered(work_item->trigger)) { |
| 771 | const char *trigger_name = NULL; |
| 772 | uid_t trigger_owner_uid; |
| 773 | enum lttng_trigger_status trigger_status; |
| 774 | |
| 775 | trigger_status = lttng_trigger_get_name( |
| 776 | work_item->trigger, &trigger_name); |
| 777 | switch (trigger_status) { |
| 778 | case LTTNG_TRIGGER_STATUS_OK: |
| 779 | break; |
| 780 | case LTTNG_TRIGGER_STATUS_UNSET: |
| 781 | trigger_name = "(unset)"; |
| 782 | break; |
| 783 | default: |
| 784 | abort(); |
| 785 | } |
| 786 | |
| 787 | trigger_status = lttng_trigger_get_owner_uid( |
| 788 | work_item->trigger, &trigger_owner_uid); |
| 789 | assert(trigger_status == LTTNG_TRIGGER_STATUS_OK); |
| 790 | |
| 791 | DBG("Work item skipped since the associated trigger is no longer registered: work item id = %" PRIu64 ", trigger name = '%s', trigger owner uid = %d", |
| 792 | work_item->id, trigger_name, |
| 793 | (int) trigger_owner_uid); |
| 794 | ret = 0; |
| 795 | goto skip_execute; |
| 796 | } |
| 797 | |
| 798 | ret = action_work_item_execute(executor, work_item); |
| 799 | |
| 800 | skip_execute: |
| 801 | lttng_trigger_unlock(work_item->trigger); |
| 802 | action_work_item_destroy(work_item); |
| 803 | if (ret) { |
| 804 | /* Fatal error. */ |
| 805 | break; |
| 806 | } |
| 807 | |
| 808 | health_code_update(); |
| 809 | pthread_mutex_lock(&executor->work.lock); |
| 810 | } |
| 811 | |
| 812 | if (executor->should_quit) { |
| 813 | pthread_mutex_unlock(&executor->work.lock); |
| 814 | } |
| 815 | DBG("Left work execution loop"); |
| 816 | |
| 817 | health_code_update(); |
| 818 | |
| 819 | rcu_thread_offline(); |
| 820 | rcu_unregister_thread(); |
| 821 | health_unregister(the_health_sessiond); |
| 822 | |
| 823 | return NULL; |
| 824 | } |
| 825 | |
| 826 | static bool shutdown_action_executor_thread(void *_data) |
| 827 | { |
| 828 | struct action_executor *executor = _data; |
| 829 | |
| 830 | pthread_mutex_lock(&executor->work.lock); |
| 831 | executor->should_quit = true; |
| 832 | pthread_cond_signal(&executor->work.cond); |
| 833 | pthread_mutex_unlock(&executor->work.lock); |
| 834 | return true; |
| 835 | } |
| 836 | |
| 837 | static void clean_up_action_executor_thread(void *_data) |
| 838 | { |
| 839 | struct action_executor *executor = _data; |
| 840 | |
| 841 | assert(cds_list_empty(&executor->work.list)); |
| 842 | |
| 843 | pthread_mutex_destroy(&executor->work.lock); |
| 844 | pthread_cond_destroy(&executor->work.cond); |
| 845 | free(executor); |
| 846 | } |
| 847 | |
| 848 | struct action_executor *action_executor_create( |
| 849 | struct notification_thread_handle *handle) |
| 850 | { |
| 851 | struct action_executor *executor = zmalloc(sizeof(*executor)); |
| 852 | |
| 853 | if (!executor) { |
| 854 | goto end; |
| 855 | } |
| 856 | |
| 857 | CDS_INIT_LIST_HEAD(&executor->work.list); |
| 858 | pthread_cond_init(&executor->work.cond, NULL); |
| 859 | pthread_mutex_init(&executor->work.lock, NULL); |
| 860 | executor->notification_thread_handle = handle; |
| 861 | |
| 862 | executor->thread = lttng_thread_create(THREAD_NAME, |
| 863 | action_executor_thread, shutdown_action_executor_thread, |
| 864 | clean_up_action_executor_thread, executor); |
| 865 | end: |
| 866 | return executor; |
| 867 | } |
| 868 | |
| 869 | void action_executor_destroy(struct action_executor *executor) |
| 870 | { |
| 871 | struct action_work_item *work_item, *tmp; |
| 872 | |
| 873 | /* TODO Wait for work list to drain? */ |
| 874 | lttng_thread_shutdown(executor->thread); |
| 875 | pthread_mutex_lock(&executor->work.lock); |
| 876 | if (executor->work.pending_count != 0) { |
| 877 | WARN("%" PRIu64 |
| 878 | " trigger action%s still queued for execution and will be discarded", |
| 879 | executor->work.pending_count, |
| 880 | executor->work.pending_count == 1 ? " is" : |
| 881 | "s are"); |
| 882 | } |
| 883 | |
| 884 | cds_list_for_each_entry_safe ( |
| 885 | work_item, tmp, &executor->work.list, list_node) { |
| 886 | WARN("Discarding action work item %" PRIu64 |
| 887 | " associated to trigger `%s`", |
| 888 | work_item->id, get_trigger_name(work_item->trigger)); |
| 889 | cds_list_del(&work_item->list_node); |
| 890 | action_work_item_destroy(work_item); |
| 891 | } |
| 892 | pthread_mutex_unlock(&executor->work.lock); |
| 893 | lttng_thread_put(executor->thread); |
| 894 | } |
| 895 | |
| 896 | /* RCU read-lock must be held by the caller. */ |
| 897 | enum action_executor_status action_executor_enqueue_trigger( |
| 898 | struct action_executor *executor, |
| 899 | struct lttng_trigger *trigger, |
| 900 | struct lttng_evaluation *evaluation, |
| 901 | const struct lttng_credentials *object_creds, |
| 902 | struct notification_client_list *client_list) |
| 903 | { |
| 904 | int ret; |
| 905 | enum action_executor_status executor_status = ACTION_EXECUTOR_STATUS_OK; |
| 906 | const uint64_t work_item_id = executor->next_work_item_id++; |
| 907 | struct action_work_item *work_item; |
| 908 | bool signal = false; |
| 909 | struct lttng_dynamic_array *subitems = NULL; |
| 910 | |
| 911 | assert(trigger); |
| 912 | |
| 913 | /* Build the array of action work subitems for the passed trigger. */ |
| 914 | subitems = zmalloc(sizeof(*subitems)); |
| 915 | if (!subitems) { |
| 916 | PERROR("Failed to allocate action executor subitems array: trigger name = `%s`", |
| 917 | get_trigger_name(trigger)); |
| 918 | executor_status = ACTION_EXECUTOR_STATUS_ERROR; |
| 919 | goto error_unlock; |
| 920 | } |
| 921 | |
| 922 | lttng_dynamic_array_init(subitems, sizeof(struct action_work_subitem), |
| 923 | action_work_subitem_destructor); |
| 924 | |
| 925 | ret = populate_subitem_array_from_trigger(trigger, subitems); |
| 926 | if (ret) { |
| 927 | ERR("Failed to populate work item sub items on behalf of trigger: trigger name = `%s`", |
| 928 | get_trigger_name(trigger)); |
| 929 | executor_status = ACTION_EXECUTOR_STATUS_ERROR; |
| 930 | goto error_unlock; |
| 931 | } |
| 932 | |
| 933 | pthread_mutex_lock(&executor->work.lock); |
| 934 | /* Check for queue overflow. */ |
| 935 | if (executor->work.pending_count >= MAX_QUEUED_WORK_COUNT) { |
| 936 | /* Most likely spammy, remove if it is the case. */ |
| 937 | DBG("Refusing to enqueue action for trigger (overflow): trigger name = `%s`, work item id = %" PRIu64, |
| 938 | get_trigger_name(trigger), work_item_id); |
| 939 | executor_status = ACTION_EXECUTOR_STATUS_OVERFLOW; |
| 940 | goto error_unlock; |
| 941 | } |
| 942 | |
| 943 | work_item = zmalloc(sizeof(*work_item)); |
| 944 | if (!work_item) { |
| 945 | PERROR("Failed to allocate action executor work item: trigger name = '%s'", |
| 946 | get_trigger_name(trigger)); |
| 947 | executor_status = ACTION_EXECUTOR_STATUS_ERROR; |
| 948 | goto error_unlock; |
| 949 | } |
| 950 | |
| 951 | lttng_trigger_get(trigger); |
| 952 | if (client_list) { |
| 953 | const bool reference_acquired = |
| 954 | notification_client_list_get(client_list); |
| 955 | |
| 956 | assert(reference_acquired); |
| 957 | } |
| 958 | |
| 959 | *work_item = (typeof(*work_item)){ |
| 960 | .id = work_item_id, |
| 961 | /* Ownership transferred to the work item. */ |
| 962 | .subitems = subitems, |
| 963 | .trigger = trigger, |
| 964 | /* Ownership transferred to the work item. */ |
| 965 | .evaluation = evaluation, |
| 966 | .object_creds = { |
| 967 | .is_set = !!object_creds, |
| 968 | .value = object_creds ? *object_creds : |
| 969 | (typeof(work_item->object_creds.value)) {}, |
| 970 | }, |
| 971 | .client_list = client_list, |
| 972 | .list_node = CDS_LIST_HEAD_INIT(work_item->list_node), |
| 973 | }; |
| 974 | |
| 975 | evaluation = NULL; |
| 976 | subitems = NULL; |
| 977 | cds_list_add_tail(&work_item->list_node, &executor->work.list); |
| 978 | executor->work.pending_count++; |
| 979 | DBG("Enqueued action for trigger: trigger name = `%s`, work item id = %" PRIu64, |
| 980 | get_trigger_name(trigger), work_item_id); |
| 981 | signal = true; |
| 982 | |
| 983 | error_unlock: |
| 984 | if (signal) { |
| 985 | pthread_cond_signal(&executor->work.cond); |
| 986 | } |
| 987 | pthread_mutex_unlock(&executor->work.lock); |
| 988 | |
| 989 | lttng_evaluation_destroy(evaluation); |
| 990 | if (subitems) { |
| 991 | lttng_dynamic_array_reset(subitems); |
| 992 | free(subitems); |
| 993 | } |
| 994 | return executor_status; |
| 995 | } |
| 996 | |
| 997 | static int add_action_to_subitem_array(struct lttng_action *action, |
| 998 | struct lttng_dynamic_array *subitems) |
| 999 | { |
| 1000 | int ret; |
| 1001 | enum lttng_action_type type = lttng_action_get_type(action); |
| 1002 | const char *session_name = NULL; |
| 1003 | enum lttng_action_status status; |
| 1004 | struct action_work_subitem subitem = { |
| 1005 | .action = NULL, |
| 1006 | .context = { |
| 1007 | .session_id = LTTNG_OPTIONAL_INIT_UNSET, |
| 1008 | }, |
| 1009 | }; |
| 1010 | |
| 1011 | assert(action); |
| 1012 | assert(subitems); |
| 1013 | |
| 1014 | if (type == LTTNG_ACTION_TYPE_GROUP) { |
| 1015 | unsigned int count, i; |
| 1016 | |
| 1017 | status = lttng_action_group_get_count(action, &count); |
| 1018 | assert(status == LTTNG_ACTION_STATUS_OK); |
| 1019 | |
| 1020 | for (i = 0; i < count; i++) { |
| 1021 | struct lttng_action *inner_action = NULL; |
| 1022 | |
| 1023 | inner_action = lttng_action_group_borrow_mutable_at_index( |
| 1024 | action, i); |
| 1025 | assert(inner_action); |
| 1026 | ret = add_action_to_subitem_array( |
| 1027 | inner_action, subitems); |
| 1028 | if (ret) { |
| 1029 | goto end; |
| 1030 | } |
| 1031 | } |
| 1032 | |
| 1033 | /* |
| 1034 | * Go directly to the end since there is no need to add the |
| 1035 | * group action by itself to the subitems array. |
| 1036 | */ |
| 1037 | goto end; |
| 1038 | } |
| 1039 | |
| 1040 | /* Gather execution context. */ |
| 1041 | switch (type) { |
| 1042 | case LTTNG_ACTION_TYPE_NOTIFY: |
| 1043 | break; |
| 1044 | case LTTNG_ACTION_TYPE_START_SESSION: |
| 1045 | status = lttng_action_start_session_get_session_name( |
| 1046 | action, &session_name); |
| 1047 | assert(status == LTTNG_ACTION_STATUS_OK); |
| 1048 | break; |
| 1049 | case LTTNG_ACTION_TYPE_STOP_SESSION: |
| 1050 | status = lttng_action_stop_session_get_session_name( |
| 1051 | action, &session_name); |
| 1052 | assert(status == LTTNG_ACTION_STATUS_OK); |
| 1053 | break; |
| 1054 | case LTTNG_ACTION_TYPE_ROTATE_SESSION: |
| 1055 | status = lttng_action_rotate_session_get_session_name( |
| 1056 | action, &session_name); |
| 1057 | assert(status == LTTNG_ACTION_STATUS_OK); |
| 1058 | break; |
| 1059 | case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION: |
| 1060 | status = lttng_action_snapshot_session_get_session_name( |
| 1061 | action, &session_name); |
| 1062 | assert(status == LTTNG_ACTION_STATUS_OK); |
| 1063 | break; |
| 1064 | case LTTNG_ACTION_TYPE_GROUP: |
| 1065 | case LTTNG_ACTION_TYPE_UNKNOWN: |
| 1066 | /* Fallthrough */ |
| 1067 | default: |
| 1068 | abort(); |
| 1069 | break; |
| 1070 | } |
| 1071 | |
| 1072 | /* |
| 1073 | * Fetch the session execution context info as needed. |
| 1074 | * Note that we could decide to not add an action for which we know the |
| 1075 | * execution will not happen (i.e no session exists for that name). For |
| 1076 | * now we leave the decision to skip to the action executor for sake of |
| 1077 | * simplicity and consistency. |
| 1078 | */ |
| 1079 | if (session_name != NULL) { |
| 1080 | struct ltt_session *session = NULL; |
| 1081 | |
| 1082 | session_lock_list(); |
| 1083 | session = session_find_by_name(session_name); |
| 1084 | if (session) { |
| 1085 | LTTNG_OPTIONAL_SET(&subitem.context.session_id, |
| 1086 | session->id); |
| 1087 | session_put(session); |
| 1088 | } |
| 1089 | |
| 1090 | session_unlock_list(); |
| 1091 | } |
| 1092 | |
| 1093 | /* Get a reference to the action. */ |
| 1094 | lttng_action_get(action); |
| 1095 | subitem.action = action; |
| 1096 | |
| 1097 | ret = lttng_dynamic_array_add_element(subitems, &subitem); |
| 1098 | if (ret) { |
| 1099 | ERR("Failed to add work subitem to the subitem array"); |
| 1100 | lttng_action_put(action); |
| 1101 | ret = -1; |
| 1102 | goto end; |
| 1103 | } |
| 1104 | |
| 1105 | end: |
| 1106 | return ret; |
| 1107 | } |
| 1108 | |
| 1109 | static int populate_subitem_array_from_trigger(struct lttng_trigger *trigger, |
| 1110 | struct lttng_dynamic_array *subitems) |
| 1111 | { |
| 1112 | struct lttng_action *action; |
| 1113 | |
| 1114 | action = lttng_trigger_get_action(trigger); |
| 1115 | assert(action); |
| 1116 | |
| 1117 | return add_action_to_subitem_array(action, subitems); |
| 1118 | } |