b0b37bed777a4eb5b537b0739c14115b5e3020a2
[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 ret = LTTNG_ERR_UST_EVENT_ENABLED;
194 goto end;
195 }
196
197 uevent->enabled = 1;
198 if (to_create) {
199 /* Add ltt ust event to channel */
200 add_unique_ust_event(uchan->events, uevent);
201 }
202
203 if (!usess->active) {
204 goto end;
205 }
206
207 if (to_create) {
208 /* Create event on all UST registered apps for session */
209 ret = ust_app_create_event_glb(usess, uchan, uevent);
210 } else {
211 /* Enable event on all UST registered apps for session */
212 ret = ust_app_enable_event_glb(usess, uchan, uevent);
213 }
214
215 if (ret < 0) {
216 if (ret == -LTTNG_UST_ERR_EXIST) {
217 ret = LTTNG_ERR_UST_EVENT_EXIST;
218 goto end;
219 } else {
220 ret = LTTNG_ERR_UST_ENABLE_FAIL;
221 goto error;
222 }
223 }
224
225 DBG("Event UST %s %s in channel %s", uevent->attr.name,
226 to_create ? "created" : "enabled", uchan->name);
227
228 ret = LTTNG_OK;
229
230 end:
231 rcu_read_unlock();
232 free(filter_expression);
233 free(filter);
234 free(exclusion);
235 return ret;
236
237 error:
238 /*
239 * Only destroy event on creation time (not enabling time) because if the
240 * event is found in the channel (to_create == 0), it means that at some
241 * point the enable_event worked and it's thus valid to keep it alive.
242 * Destroying it also implies that we also destroy it's shadow copy to sync
243 * everyone up.
244 */
245 if (to_create) {
246 /* In this code path, the uevent was not added to the hash table */
247 trace_ust_destroy_event(uevent);
248 }
249 rcu_read_unlock();
250 free(filter_expression);
251 free(filter);
252 free(exclusion);
253 return ret;
254 }
255
256 /*
257 * Disable UST tracepoint of a channel from a UST session.
258 */
259 int event_ust_disable_tracepoint(struct ltt_ust_session *usess,
260 struct ltt_ust_channel *uchan, char *event_name)
261 {
262 int ret;
263 struct ltt_ust_event *uevent;
264 struct lttng_ht_node_str *node;
265 struct lttng_ht_iter iter;
266 struct lttng_ht *ht;
267
268 assert(usess);
269 assert(uchan);
270 assert(event_name);
271
272 ht = uchan->events;
273
274 rcu_read_lock();
275
276 /*
277 * We use a custom lookup since we need the iterator for the next_duplicate
278 * call in the do while loop below.
279 */
280 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) event_name, lttng_ht_seed),
281 trace_ust_ht_match_event_by_name, event_name, &iter.iter);
282 node = lttng_ht_iter_get_node_str(&iter);
283 if (node == NULL) {
284 DBG2("Trace UST event NOT found by name %s", event_name);
285 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
286 goto error;
287 }
288
289 do {
290 uevent = caa_container_of(node, struct ltt_ust_event, node);
291 assert(uevent);
292
293 if (uevent->enabled == 0) {
294 /* It's already disabled so everything is OK */
295 goto next;
296 }
297 uevent->enabled = 0;
298 DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
299 uchan->name);
300
301 if (!usess->active) {
302 goto next;
303 }
304 ret = ust_app_disable_event_glb(usess, uchan, uevent);
305 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
306 ret = LTTNG_ERR_UST_DISABLE_FAIL;
307 goto error;
308 }
309 next:
310 /* Get next duplicate event by name. */
311 cds_lfht_next_duplicate(ht->ht, trace_ust_ht_match_event_by_name,
312 event_name, &iter.iter);
313 node = lttng_ht_iter_get_node_str(&iter);
314 } while (node);
315
316 ret = LTTNG_OK;
317
318 error:
319 rcu_read_unlock();
320 return ret;
321 }
322
323 /*
324 * Disable all UST tracepoints for a channel from a UST session.
325 */
326 int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess,
327 struct ltt_ust_channel *uchan)
328 {
329 int ret, i, size, error = 0;
330 struct lttng_ht_iter iter;
331 struct ltt_ust_event *uevent = NULL;
332 struct lttng_event *events = NULL;
333
334 assert(usess);
335 assert(uchan);
336
337 rcu_read_lock();
338
339 /* Disabling existing events */
340 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent,
341 node.node) {
342 if (uevent->enabled == 1) {
343 ret = event_ust_disable_tracepoint(usess, uchan,
344 uevent->attr.name);
345 if (ret < 0) {
346 error = LTTNG_ERR_UST_DISABLE_FAIL;
347 continue;
348 }
349 }
350 }
351
352 /* Get all UST available events */
353 size = ust_app_list_events(&events);
354 if (size < 0) {
355 ret = LTTNG_ERR_UST_LIST_FAIL;
356 goto error;
357 }
358
359 for (i = 0; i < size; i++) {
360 ret = event_ust_disable_tracepoint(usess, uchan,
361 events[i].name);
362 if (ret < 0) {
363 /* Continue to disable the rest... */
364 error = LTTNG_ERR_UST_DISABLE_FAIL;
365 continue;
366 }
367 }
368
369 ret = error ? error : LTTNG_OK;
370 error:
371 rcu_read_unlock();
372 free(events);
373 return ret;
374 }
375
376 /*
377 * Enable all agent event for a given UST session.
378 *
379 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
380 */
381 int event_agent_enable_all(struct ltt_ust_session *usess,
382 struct agent *agt, struct lttng_event *event,
383 struct lttng_filter_bytecode *filter ,char *filter_expression)
384 {
385 int ret;
386 struct agent_event *aevent;
387 struct lttng_ht_iter iter;
388
389 assert(usess);
390
391 DBG("Event agent enabling ALL events for session %" PRIu64, usess->id);
392
393 /* Enable event on agent application through TCP socket. */
394 ret = event_agent_enable(usess, agt, event, filter, filter_expression);
395 if (ret != LTTNG_OK) {
396 goto error;
397 }
398
399 /* Flag every event that they are now enabled. */
400 rcu_read_lock();
401 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
402 node.node) {
403 aevent->enabled = 1;
404 }
405 rcu_read_unlock();
406
407 ret = LTTNG_OK;
408
409 error:
410 return ret;
411 }
412
413 /*
414 * Check if this event's filter requires the activation of application contexts
415 * and enable them in the agent.
416 * TODO: bytecode iterator does not support non-legacy application
417 * contexts yet. Not an issue for now, since they are not generated by
418 * the lttng-ctl library.
419 */
420 static int add_filter_app_ctx(struct lttng_filter_bytecode *bytecode,
421 const char *filter_expression, struct agent *agt)
422 {
423 int ret = LTTNG_OK;
424 char *provider_name = NULL, *ctx_name = NULL;
425 struct bytecode_symbol_iterator *it =
426 bytecode_symbol_iterator_create(bytecode);
427
428 if (!it) {
429 ret = LTTNG_ERR_NOMEM;
430 goto end;
431 }
432
433 do {
434 struct lttng_event_context ctx;
435 const char *symbol_name =
436 bytecode_symbol_iterator_get_name(it);
437
438 if (parse_application_context(symbol_name, &provider_name,
439 &ctx_name)) {
440 /* Not an application context. */
441 continue;
442 }
443
444 ctx.ctx = LTTNG_EVENT_CONTEXT_APP_CONTEXT;
445 ctx.u.app_ctx.provider_name = provider_name;
446 ctx.u.app_ctx.ctx_name = ctx_name;
447
448 /* Recognized an application context. */
449 DBG("Enabling event with filter expression \"%s\" requires enabling the %s:%s application context.",
450 filter_expression, provider_name, ctx_name);
451
452 ret = agent_add_context(&ctx, agt);
453 if (ret != LTTNG_OK) {
454 ERR("Failed to add application context %s:%s.",
455 provider_name, ctx_name);
456 goto end;
457 }
458
459 ret = agent_enable_context(&ctx, agt->domain);
460 if (ret != LTTNG_OK) {
461 ERR("Failed to enable application context %s:%s.",
462 provider_name, ctx_name);
463 goto end;
464 }
465
466 free(provider_name);
467 free(ctx_name);
468 provider_name = ctx_name = NULL;
469 } while (bytecode_symbol_iterator_next(it) == 0);
470 end:
471 free(provider_name);
472 free(ctx_name);
473 bytecode_symbol_iterator_destroy(it);
474 return ret;
475 }
476
477 /*
478 * Enable a single agent event for a given UST session.
479 *
480 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
481 */
482 int event_agent_enable(struct ltt_ust_session *usess,
483 struct agent *agt, struct lttng_event *event,
484 struct lttng_filter_bytecode *filter,
485 char *filter_expression)
486 {
487 int ret, created = 0;
488 struct agent_event *aevent;
489
490 assert(usess);
491 assert(event);
492 assert(agt);
493
494 DBG("Event agent enabling %s for session %" PRIu64 " with loglevel type %d "
495 ", loglevel %d and filter \"%s\"", event->name,
496 usess->id, event->loglevel_type, event->loglevel,
497 filter_expression ? filter_expression : "NULL");
498
499 aevent = agent_find_event(event->name, event->loglevel_type,
500 event->loglevel, filter_expression, agt);
501 if (!aevent) {
502 aevent = agent_create_event(event->name, event->loglevel_type,
503 event->loglevel, filter,
504 filter_expression);
505 if (!aevent) {
506 ret = LTTNG_ERR_NOMEM;
507 goto error;
508 }
509 filter = NULL;
510 filter_expression = NULL;
511 created = 1;
512 }
513
514 if (created && filter) {
515 ret = add_filter_app_ctx(filter, filter_expression, agt);
516 if (ret != LTTNG_OK) {
517 goto error;
518 }
519 }
520
521 /* Already enabled? */
522 if (aevent->enabled) {
523 ret = LTTNG_OK;
524 goto end;
525 }
526
527 ret = agent_enable_event(aevent, agt->domain);
528 if (ret != LTTNG_OK) {
529 goto error;
530 }
531
532 /* If the event was created prior to the enable, add it to the domain. */
533 if (created) {
534 agent_add_event(aevent, agt);
535 }
536
537 ret = LTTNG_OK;
538 goto end;
539
540 error:
541 if (created) {
542 agent_destroy_event(aevent);
543 }
544 end:
545 free(filter);
546 free(filter_expression);
547 return ret;
548 }
549
550 /*
551 * Return the default event name associated with the provided UST domain. Return
552 * NULL on error.
553 */
554 const char *event_get_default_agent_ust_name(enum lttng_domain_type domain)
555 {
556 const char *default_event_name = NULL;
557
558 switch (domain) {
559 case LTTNG_DOMAIN_LOG4J:
560 default_event_name = DEFAULT_LOG4J_EVENT_NAME;
561 break;
562 case LTTNG_DOMAIN_JUL:
563 default_event_name = DEFAULT_JUL_EVENT_NAME;
564 break;
565 case LTTNG_DOMAIN_PYTHON:
566 default_event_name = DEFAULT_PYTHON_EVENT_NAME;
567 break;
568 default:
569 assert(0);
570 }
571
572 return default_event_name;
573 }
574
575 /*
576 * Disable a given agent event for a given UST session.
577 *
578 * Must be called with the RCU read lock held.
579 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
580 */
581 static int event_agent_disable_one(struct ltt_ust_session *usess,
582 struct agent *agt, struct agent_event *aevent)
583 {
584 int ret;
585 struct ltt_ust_event *uevent = NULL;
586 struct ltt_ust_channel *uchan = NULL;
587 const char *ust_event_name, *ust_channel_name;
588
589 assert(agt);
590 assert(usess);
591 assert(aevent);
592
593 DBG("Event agent disabling %s (loglevel type %d, loglevel value %d) for session %" PRIu64,
594 aevent->name, aevent->loglevel_type, aevent->loglevel_value,
595 usess->id);
596
597 /* Already disabled? */
598 if (!aevent->enabled) {
599 goto end;
600 }
601
602 if (agt->domain == LTTNG_DOMAIN_JUL) {
603 ust_channel_name = DEFAULT_JUL_CHANNEL_NAME;
604 } else if (agt->domain == LTTNG_DOMAIN_LOG4J) {
605 ust_channel_name = DEFAULT_LOG4J_CHANNEL_NAME;
606 } else if (agt->domain == LTTNG_DOMAIN_PYTHON) {
607 ust_channel_name = DEFAULT_PYTHON_CHANNEL_NAME;
608 } else {
609 ret = LTTNG_ERR_INVALID;
610 goto error;
611 }
612
613 /*
614 * Disable it on the UST side. First get the channel reference then find
615 * the event and finally disable it.
616 */
617 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
618 (char *) ust_channel_name);
619 if (!uchan) {
620 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
621 goto error;
622 }
623
624 ust_event_name = event_get_default_agent_ust_name(agt->domain);
625 if (!ust_event_name) {
626 ret = LTTNG_ERR_FATAL;
627 goto error;
628 }
629
630 /*
631 * Agent UST event has its loglevel type forced to
632 * LTTNG_UST_LOGLEVEL_ALL. The actual loglevel type/value filtering
633 * happens thanks to an UST filter. The following -1 is actually
634 * ignored since the type is LTTNG_UST_LOGLEVEL_ALL.
635 */
636 uevent = trace_ust_find_event(uchan->events, (char *) ust_event_name,
637 aevent->filter, LTTNG_UST_LOGLEVEL_ALL, -1, NULL);
638 /* If the agent event exists, it must be available on the UST side. */
639 assert(uevent);
640
641 if (usess->active) {
642 ret = ust_app_disable_event_glb(usess, uchan, uevent);
643 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
644 ret = LTTNG_ERR_UST_DISABLE_FAIL;
645 goto error;
646 }
647 }
648
649 /*
650 * Flag event that it's disabled so the shadow copy on the ust app side
651 * will disable it if an application shows up.
652 */
653 uevent->enabled = 0;
654
655 ret = agent_disable_event(aevent, agt->domain);
656 if (ret != LTTNG_OK) {
657 goto error;
658 }
659
660 end:
661 return LTTNG_OK;
662
663 error:
664 return ret;
665 }
666
667 /*
668 * Disable all agent events matching a given name for a given UST session.
669 *
670 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
671 */
672 int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
673 char *event_name)
674 {
675 int ret = LTTNG_OK;
676 struct agent_event *aevent;
677 struct lttng_ht_iter iter;
678 struct lttng_ht_node_str *node;
679
680 assert(agt);
681 assert(usess);
682 assert(event_name);
683
684 DBG("Event agent disabling %s (all loglevels) for session %" PRIu64, event_name, usess->id);
685
686 rcu_read_lock();
687 agent_find_events_by_name(event_name, agt, &iter);
688 node = lttng_ht_iter_get_node_str(&iter);
689
690 if (node == NULL) {
691 DBG2("Event agent NOT found by name %s", event_name);
692 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
693 goto end;
694 }
695
696 do {
697 aevent = caa_container_of(node, struct agent_event, node);
698 ret = event_agent_disable_one(usess, agt, aevent);
699
700 if (ret != LTTNG_OK) {
701 goto end;
702 }
703
704 /* Get next duplicate agent event by name. */
705 agent_event_next_duplicate(event_name, agt, &iter);
706 node = lttng_ht_iter_get_node_str(&iter);
707 } while (node);
708 end:
709 rcu_read_unlock();
710 return ret;
711 }
712 /*
713 * Disable all agent event for a given UST session.
714 *
715 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
716 */
717 int event_agent_disable_all(struct ltt_ust_session *usess,
718 struct agent *agt)
719 {
720 int ret;
721 struct agent_event *aevent;
722 struct lttng_ht_iter iter;
723
724 assert(agt);
725 assert(usess);
726
727 /*
728 * Disable event on agent application. Continue to disable all other events
729 * if the * event is not found.
730 */
731 ret = event_agent_disable(usess, agt, "*");
732 if (ret != LTTNG_OK && ret != LTTNG_ERR_UST_EVENT_NOT_FOUND) {
733 goto error;
734 }
735
736 /* Disable every event. */
737 rcu_read_lock();
738 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
739 node.node) {
740 if (!aevent->enabled) {
741 continue;
742 }
743
744 ret = event_agent_disable(usess, agt, aevent->name);
745 if (ret != LTTNG_OK) {
746 goto error_unlock;
747 }
748 }
749 ret = LTTNG_OK;
750
751 error_unlock:
752 rcu_read_unlock();
753 error:
754 return ret;
755 }
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