Clean-up: silence erroneous leak warning
[lttng-tools.git] / src / bin / lttng-sessiond / event.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <urcu/list.h>
22 #include <string.h>
23
24 #include <lttng/lttng.h>
25 #include <common/error.h>
26 #include <common/sessiond-comm/sessiond-comm.h>
27 #include <common/filter.h>
28 #include <common/context.h>
29
30 #include "channel.h"
31 #include "event.h"
32 #include "kernel.h"
33 #include "lttng-sessiond.h"
34 #include "ust-ctl.h"
35 #include "ust-app.h"
36 #include "trace-kernel.h"
37 #include "trace-ust.h"
38 #include "agent.h"
39
40 /*
41 * Add unique UST event based on the event name, filter bytecode and loglevel.
42 */
43 static void add_unique_ust_event(struct lttng_ht *ht,
44 struct ltt_ust_event *event)
45 {
46 struct cds_lfht_node *node_ptr;
47 struct ltt_ust_ht_key key;
48
49 assert(ht);
50 assert(ht->ht);
51 assert(event);
52
53 key.name = event->attr.name;
54 key.filter = (struct lttng_filter_bytecode *) event->filter;
55 key.loglevel_type = event->attr.loglevel_type;
56 key.loglevel_value = event->attr.loglevel;
57 key.exclusion = event->exclusion;
58
59 node_ptr = cds_lfht_add_unique(ht->ht,
60 ht->hash_fct(event->node.key, lttng_ht_seed),
61 trace_ust_ht_match_event, &key, &event->node.node);
62 assert(node_ptr == &event->node.node);
63 }
64
65 /*
66 * Disable kernel tracepoint events for a channel from the kernel session of
67 * a specified event_name and event type.
68 * On type LTTNG_EVENT_ALL all events with event_name are disabled.
69 * If event_name is NULL all events of the specified type are disabled.
70 */
71 int event_kernel_disable_event(struct ltt_kernel_channel *kchan,
72 char *event_name, enum lttng_event_type type)
73 {
74 int ret, error = 0, found = 0;
75 struct ltt_kernel_event *kevent;
76
77 assert(kchan);
78
79 /* For each event in the kernel session */
80 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
81 if (type != LTTNG_EVENT_ALL && kevent->type != type)
82 continue;
83 if (event_name != NULL && strcmp(event_name, kevent->event->name)) {
84 continue;
85 }
86 found++;
87 ret = kernel_disable_event(kevent);
88 if (ret < 0) {
89 error = 1;
90 continue;
91 }
92 }
93 DBG("Disable kernel event: found %d events with name: %s and type: %d",
94 found, event_name ? event_name : "NULL", type);
95
96 if (event_name != NULL && !found) {
97 ret = LTTNG_ERR_NO_EVENT;
98 } else {
99 ret = error ? LTTNG_ERR_KERN_DISABLE_FAIL : LTTNG_OK;
100 }
101
102 return ret;
103 }
104
105 /*
106 * Enable kernel tracepoint event for a channel from the kernel session.
107 * We own filter_expression and filter.
108 */
109 int event_kernel_enable_event(struct ltt_kernel_channel *kchan,
110 struct lttng_event *event, char *filter_expression,
111 struct lttng_filter_bytecode *filter)
112 {
113 int ret;
114 struct ltt_kernel_event *kevent;
115
116 assert(kchan);
117 assert(event);
118
119 kevent = trace_kernel_find_event(event->name, kchan,
120 event->type, filter);
121 if (kevent == NULL) {
122 ret = kernel_create_event(event, kchan, filter_expression, filter);
123 /* We have passed ownership */
124 filter_expression = NULL;
125 filter = NULL;
126 if (ret) {
127 goto end;
128 }
129 } else if (kevent->enabled == 0) {
130 ret = kernel_enable_event(kevent);
131 if (ret < 0) {
132 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
133 goto end;
134 }
135 } else {
136 /* At this point, the event is considered enabled */
137 ret = LTTNG_ERR_KERN_EVENT_EXIST;
138 goto end;
139 }
140
141 ret = LTTNG_OK;
142 end:
143 free(filter_expression);
144 free(filter);
145 return ret;
146 }
147
148 /*
149 * ============================
150 * UST : The Ultimate Frontier!
151 * ============================
152 */
153
154 /*
155 * Enable UST tracepoint event for a channel from a UST session.
156 * We own filter_expression, filter, and exclusion.
157 */
158 int event_ust_enable_tracepoint(struct ltt_ust_session *usess,
159 struct ltt_ust_channel *uchan, struct lttng_event *event,
160 char *filter_expression,
161 struct lttng_filter_bytecode *filter,
162 struct lttng_event_exclusion *exclusion,
163 bool internal_event)
164 {
165 int ret = LTTNG_OK, to_create = 0;
166 struct ltt_ust_event *uevent;
167
168 assert(usess);
169 assert(uchan);
170 assert(event);
171
172 rcu_read_lock();
173
174 uevent = trace_ust_find_event(uchan->events, event->name, filter,
175 event->loglevel_type, event->loglevel, exclusion);
176 if (!uevent) {
177 ret = trace_ust_create_event(event, filter_expression,
178 filter, exclusion, internal_event, &uevent);
179 /* We have passed ownership */
180 filter_expression = NULL;
181 filter = NULL;
182 exclusion = NULL;
183 if (ret != LTTNG_OK) {
184 goto error;
185 }
186
187 /* Valid to set it after the goto error since uevent is still NULL */
188 to_create = 1;
189 }
190
191 if (uevent->enabled) {
192 /* It's already enabled so everything is OK */
193 assert(!to_create);
194 ret = LTTNG_ERR_UST_EVENT_ENABLED;
195 goto end;
196 }
197
198 uevent->enabled = 1;
199 if (to_create) {
200 /* Add ltt ust event to channel */
201 add_unique_ust_event(uchan->events, uevent);
202 }
203
204 if (!usess->active) {
205 goto end;
206 }
207
208 if (to_create) {
209 /* Create event on all UST registered apps for session */
210 ret = ust_app_create_event_glb(usess, uchan, uevent);
211 } else {
212 /* Enable event on all UST registered apps for session */
213 ret = ust_app_enable_event_glb(usess, uchan, uevent);
214 }
215
216 if (ret < 0) {
217 if (ret == -LTTNG_UST_ERR_EXIST) {
218 ret = LTTNG_ERR_UST_EVENT_EXIST;
219 goto end;
220 } else {
221 ret = LTTNG_ERR_UST_ENABLE_FAIL;
222 goto error;
223 }
224 }
225
226 DBG("Event UST %s %s in channel %s", uevent->attr.name,
227 to_create ? "created" : "enabled", uchan->name);
228
229 ret = LTTNG_OK;
230
231 end:
232 rcu_read_unlock();
233 free(filter_expression);
234 free(filter);
235 free(exclusion);
236 return ret;
237
238 error:
239 /*
240 * Only destroy event on creation time (not enabling time) because if the
241 * event is found in the channel (to_create == 0), it means that at some
242 * point the enable_event worked and it's thus valid to keep it alive.
243 * Destroying it also implies that we also destroy it's shadow copy to sync
244 * everyone up.
245 */
246 if (to_create) {
247 /* In this code path, the uevent was not added to the hash table */
248 trace_ust_destroy_event(uevent);
249 }
250 rcu_read_unlock();
251 free(filter_expression);
252 free(filter);
253 free(exclusion);
254 return ret;
255 }
256
257 /*
258 * Disable UST tracepoint of a channel from a UST session.
259 */
260 int event_ust_disable_tracepoint(struct ltt_ust_session *usess,
261 struct ltt_ust_channel *uchan, char *event_name)
262 {
263 int ret;
264 struct ltt_ust_event *uevent;
265 struct lttng_ht_node_str *node;
266 struct lttng_ht_iter iter;
267 struct lttng_ht *ht;
268
269 assert(usess);
270 assert(uchan);
271 assert(event_name);
272
273 ht = uchan->events;
274
275 rcu_read_lock();
276
277 /*
278 * We use a custom lookup since we need the iterator for the next_duplicate
279 * call in the do while loop below.
280 */
281 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) event_name, lttng_ht_seed),
282 trace_ust_ht_match_event_by_name, event_name, &iter.iter);
283 node = lttng_ht_iter_get_node_str(&iter);
284 if (node == NULL) {
285 DBG2("Trace UST event NOT found by name %s", event_name);
286 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
287 goto error;
288 }
289
290 do {
291 uevent = caa_container_of(node, struct ltt_ust_event, node);
292 assert(uevent);
293
294 if (uevent->enabled == 0) {
295 /* It's already disabled so everything is OK */
296 goto next;
297 }
298 uevent->enabled = 0;
299 DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
300 uchan->name);
301
302 if (!usess->active) {
303 goto next;
304 }
305 ret = ust_app_disable_event_glb(usess, uchan, uevent);
306 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
307 ret = LTTNG_ERR_UST_DISABLE_FAIL;
308 goto error;
309 }
310 next:
311 /* Get next duplicate event by name. */
312 cds_lfht_next_duplicate(ht->ht, trace_ust_ht_match_event_by_name,
313 event_name, &iter.iter);
314 node = lttng_ht_iter_get_node_str(&iter);
315 } while (node);
316
317 ret = LTTNG_OK;
318
319 error:
320 rcu_read_unlock();
321 return ret;
322 }
323
324 /*
325 * Disable all UST tracepoints for a channel from a UST session.
326 */
327 int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess,
328 struct ltt_ust_channel *uchan)
329 {
330 int ret, i, size, error = 0;
331 struct lttng_ht_iter iter;
332 struct ltt_ust_event *uevent = NULL;
333 struct lttng_event *events = NULL;
334
335 assert(usess);
336 assert(uchan);
337
338 rcu_read_lock();
339
340 /* Disabling existing events */
341 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent,
342 node.node) {
343 if (uevent->enabled == 1) {
344 ret = event_ust_disable_tracepoint(usess, uchan,
345 uevent->attr.name);
346 if (ret < 0) {
347 error = LTTNG_ERR_UST_DISABLE_FAIL;
348 continue;
349 }
350 }
351 }
352
353 /* Get all UST available events */
354 size = ust_app_list_events(&events);
355 if (size < 0) {
356 ret = LTTNG_ERR_UST_LIST_FAIL;
357 goto error;
358 }
359
360 for (i = 0; i < size; i++) {
361 ret = event_ust_disable_tracepoint(usess, uchan,
362 events[i].name);
363 if (ret < 0) {
364 /* Continue to disable the rest... */
365 error = LTTNG_ERR_UST_DISABLE_FAIL;
366 continue;
367 }
368 }
369
370 ret = error ? error : LTTNG_OK;
371 error:
372 rcu_read_unlock();
373 free(events);
374 return ret;
375 }
376
377 /*
378 * Enable all agent event for a given UST session.
379 *
380 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
381 */
382 int event_agent_enable_all(struct ltt_ust_session *usess,
383 struct agent *agt, struct lttng_event *event,
384 struct lttng_filter_bytecode *filter ,char *filter_expression)
385 {
386 int ret;
387 struct agent_event *aevent;
388 struct lttng_ht_iter iter;
389
390 assert(usess);
391
392 DBG("Event agent enabling ALL events for session %" PRIu64, usess->id);
393
394 /* Enable event on agent application through TCP socket. */
395 ret = event_agent_enable(usess, agt, event, filter, filter_expression);
396 if (ret != LTTNG_OK) {
397 goto error;
398 }
399
400 /* Flag every event that they are now enabled. */
401 rcu_read_lock();
402 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
403 node.node) {
404 aevent->enabled = 1;
405 }
406 rcu_read_unlock();
407
408 ret = LTTNG_OK;
409
410 error:
411 return ret;
412 }
413
414 /*
415 * Check if this event's filter requires the activation of application contexts
416 * and enable them in the agent.
417 * TODO: bytecode iterator does not support non-legacy application
418 * contexts yet. Not an issue for now, since they are not generated by
419 * the lttng-ctl library.
420 */
421 static int add_filter_app_ctx(struct lttng_filter_bytecode *bytecode,
422 const char *filter_expression, struct agent *agt)
423 {
424 int ret = LTTNG_OK;
425 char *provider_name = NULL, *ctx_name = NULL;
426 struct bytecode_symbol_iterator *it =
427 bytecode_symbol_iterator_create(bytecode);
428
429 if (!it) {
430 ret = LTTNG_ERR_NOMEM;
431 goto end;
432 }
433
434 do {
435 struct lttng_event_context ctx;
436 const char *symbol_name =
437 bytecode_symbol_iterator_get_name(it);
438
439 if (parse_application_context(symbol_name, &provider_name,
440 &ctx_name)) {
441 /* Not an application context. */
442 continue;
443 }
444
445 ctx.ctx = LTTNG_EVENT_CONTEXT_APP_CONTEXT;
446 ctx.u.app_ctx.provider_name = provider_name;
447 ctx.u.app_ctx.ctx_name = ctx_name;
448
449 /* Recognized an application context. */
450 DBG("Enabling event with filter expression \"%s\" requires enabling the %s:%s application context.",
451 filter_expression, provider_name, ctx_name);
452
453 ret = agent_add_context(&ctx, agt);
454 if (ret != LTTNG_OK) {
455 ERR("Failed to add application context %s:%s.",
456 provider_name, ctx_name);
457 goto end;
458 }
459
460 ret = agent_enable_context(&ctx, agt->domain);
461 if (ret != LTTNG_OK) {
462 ERR("Failed to enable application context %s:%s.",
463 provider_name, ctx_name);
464 goto end;
465 }
466
467 free(provider_name);
468 free(ctx_name);
469 provider_name = ctx_name = NULL;
470 } while (bytecode_symbol_iterator_next(it) == 0);
471 end:
472 free(provider_name);
473 free(ctx_name);
474 bytecode_symbol_iterator_destroy(it);
475 return ret;
476 }
477
478 /*
479 * Enable a single agent event for a given UST session.
480 *
481 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
482 */
483 int event_agent_enable(struct ltt_ust_session *usess,
484 struct agent *agt, struct lttng_event *event,
485 struct lttng_filter_bytecode *filter,
486 char *filter_expression)
487 {
488 int ret, created = 0;
489 struct agent_event *aevent;
490
491 assert(usess);
492 assert(event);
493 assert(agt);
494
495 DBG("Event agent enabling %s for session %" PRIu64 " with loglevel type %d "
496 ", loglevel %d and filter \"%s\"", event->name,
497 usess->id, event->loglevel_type, event->loglevel,
498 filter_expression ? filter_expression : "NULL");
499
500 aevent = agent_find_event(event->name, event->loglevel_type,
501 event->loglevel, filter_expression, agt);
502 if (!aevent) {
503 aevent = agent_create_event(event->name, event->loglevel_type,
504 event->loglevel, filter,
505 filter_expression);
506 if (!aevent) {
507 ret = LTTNG_ERR_NOMEM;
508 goto error;
509 }
510 filter = NULL;
511 filter_expression = NULL;
512 created = 1;
513 }
514
515 if (created && filter) {
516 ret = add_filter_app_ctx(filter, filter_expression, agt);
517 if (ret != LTTNG_OK) {
518 goto error;
519 }
520 }
521
522 /* Already enabled? */
523 if (aevent->enabled) {
524 ret = LTTNG_OK;
525 goto end;
526 }
527
528 ret = agent_enable_event(aevent, agt->domain);
529 if (ret != LTTNG_OK) {
530 goto error;
531 }
532
533 /* If the event was created prior to the enable, add it to the domain. */
534 if (created) {
535 agent_add_event(aevent, agt);
536 }
537
538 ret = LTTNG_OK;
539 goto end;
540
541 error:
542 if (created) {
543 agent_destroy_event(aevent);
544 }
545 end:
546 free(filter);
547 free(filter_expression);
548 return ret;
549 }
550
551 /*
552 * Return the default event name associated with the provided UST domain. Return
553 * NULL on error.
554 */
555 const char *event_get_default_agent_ust_name(enum lttng_domain_type domain)
556 {
557 const char *default_event_name = NULL;
558
559 switch (domain) {
560 case LTTNG_DOMAIN_LOG4J:
561 default_event_name = DEFAULT_LOG4J_EVENT_NAME;
562 break;
563 case LTTNG_DOMAIN_JUL:
564 default_event_name = DEFAULT_JUL_EVENT_NAME;
565 break;
566 case LTTNG_DOMAIN_PYTHON:
567 default_event_name = DEFAULT_PYTHON_EVENT_NAME;
568 break;
569 default:
570 assert(0);
571 }
572
573 return default_event_name;
574 }
575
576 /*
577 * Disable a given agent event for a given UST session.
578 *
579 * Must be called with the RCU read lock held.
580 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
581 */
582 static int event_agent_disable_one(struct ltt_ust_session *usess,
583 struct agent *agt, struct agent_event *aevent)
584 {
585 int ret;
586 struct ltt_ust_event *uevent = NULL;
587 struct ltt_ust_channel *uchan = NULL;
588 const char *ust_event_name, *ust_channel_name;
589
590 assert(agt);
591 assert(usess);
592 assert(aevent);
593
594 DBG("Event agent disabling %s (loglevel type %d, loglevel value %d) for session %" PRIu64,
595 aevent->name, aevent->loglevel_type, aevent->loglevel_value,
596 usess->id);
597
598 /* Already disabled? */
599 if (!aevent->enabled) {
600 goto end;
601 }
602
603 if (agt->domain == LTTNG_DOMAIN_JUL) {
604 ust_channel_name = DEFAULT_JUL_CHANNEL_NAME;
605 } else if (agt->domain == LTTNG_DOMAIN_LOG4J) {
606 ust_channel_name = DEFAULT_LOG4J_CHANNEL_NAME;
607 } else if (agt->domain == LTTNG_DOMAIN_PYTHON) {
608 ust_channel_name = DEFAULT_PYTHON_CHANNEL_NAME;
609 } else {
610 ret = LTTNG_ERR_INVALID;
611 goto error;
612 }
613
614 /*
615 * Disable it on the UST side. First get the channel reference then find
616 * the event and finally disable it.
617 */
618 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
619 (char *) ust_channel_name);
620 if (!uchan) {
621 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
622 goto error;
623 }
624
625 ust_event_name = event_get_default_agent_ust_name(agt->domain);
626 if (!ust_event_name) {
627 ret = LTTNG_ERR_FATAL;
628 goto error;
629 }
630
631 /*
632 * Agent UST event has its loglevel type forced to
633 * LTTNG_UST_LOGLEVEL_ALL. The actual loglevel type/value filtering
634 * happens thanks to an UST filter. The following -1 is actually
635 * ignored since the type is LTTNG_UST_LOGLEVEL_ALL.
636 */
637 uevent = trace_ust_find_event(uchan->events, (char *) ust_event_name,
638 aevent->filter, LTTNG_UST_LOGLEVEL_ALL, -1, NULL);
639 /* If the agent event exists, it must be available on the UST side. */
640 assert(uevent);
641
642 if (usess->active) {
643 ret = ust_app_disable_event_glb(usess, uchan, uevent);
644 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
645 ret = LTTNG_ERR_UST_DISABLE_FAIL;
646 goto error;
647 }
648 }
649
650 /*
651 * Flag event that it's disabled so the shadow copy on the ust app side
652 * will disable it if an application shows up.
653 */
654 uevent->enabled = 0;
655
656 ret = agent_disable_event(aevent, agt->domain);
657 if (ret != LTTNG_OK) {
658 goto error;
659 }
660
661 end:
662 return LTTNG_OK;
663
664 error:
665 return ret;
666 }
667
668 /*
669 * Disable all agent events matching a given name for a given UST session.
670 *
671 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
672 */
673 int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
674 char *event_name)
675 {
676 int ret = LTTNG_OK;
677 struct agent_event *aevent;
678 struct lttng_ht_iter iter;
679 struct lttng_ht_node_str *node;
680
681 assert(agt);
682 assert(usess);
683 assert(event_name);
684
685 DBG("Event agent disabling %s (all loglevels) for session %" PRIu64, event_name, usess->id);
686
687 rcu_read_lock();
688 agent_find_events_by_name(event_name, agt, &iter);
689 node = lttng_ht_iter_get_node_str(&iter);
690
691 if (node == NULL) {
692 DBG2("Event agent NOT found by name %s", event_name);
693 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
694 goto end;
695 }
696
697 do {
698 aevent = caa_container_of(node, struct agent_event, node);
699 ret = event_agent_disable_one(usess, agt, aevent);
700
701 if (ret != LTTNG_OK) {
702 goto end;
703 }
704
705 /* Get next duplicate agent event by name. */
706 agent_event_next_duplicate(event_name, agt, &iter);
707 node = lttng_ht_iter_get_node_str(&iter);
708 } while (node);
709 end:
710 rcu_read_unlock();
711 return ret;
712 }
713 /*
714 * Disable all agent event for a given UST session.
715 *
716 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
717 */
718 int event_agent_disable_all(struct ltt_ust_session *usess,
719 struct agent *agt)
720 {
721 int ret;
722 struct agent_event *aevent;
723 struct lttng_ht_iter iter;
724
725 assert(agt);
726 assert(usess);
727
728 /*
729 * Disable event on agent application. Continue to disable all other events
730 * if the * event is not found.
731 */
732 ret = event_agent_disable(usess, agt, "*");
733 if (ret != LTTNG_OK && ret != LTTNG_ERR_UST_EVENT_NOT_FOUND) {
734 goto error;
735 }
736
737 /* Disable every event. */
738 rcu_read_lock();
739 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
740 node.node) {
741 if (!aevent->enabled) {
742 continue;
743 }
744
745 ret = event_agent_disable(usess, agt, aevent->name);
746 if (ret != LTTNG_OK) {
747 goto error_unlock;
748 }
749 }
750 ret = LTTNG_OK;
751
752 error_unlock:
753 rcu_read_unlock();
754 error:
755 return ret;
756 }
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