Fix: report UST consumer channel creation error
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <errno.h>
20 #include <inttypes.h>
21 #include <pthread.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 #include <urcu/compiler.h>
29 #include <lttng/ust-error.h>
30 #include <signal.h>
31
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34
35 #include "buffer-registry.h"
36 #include "fd-limit.h"
37 #include "health-sessiond.h"
38 #include "ust-app.h"
39 #include "ust-consumer.h"
40 #include "ust-ctl.h"
41 #include "utils.h"
42
43 /* Next available channel key. Access under next_channel_key_lock. */
44 static uint64_t _next_channel_key;
45 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
46
47 /* Next available session ID. Access under next_session_id_lock. */
48 static uint64_t _next_session_id;
49 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
50
51 /*
52 * Return the incremented value of next_channel_key.
53 */
54 static uint64_t get_next_channel_key(void)
55 {
56 uint64_t ret;
57
58 pthread_mutex_lock(&next_channel_key_lock);
59 ret = ++_next_channel_key;
60 pthread_mutex_unlock(&next_channel_key_lock);
61 return ret;
62 }
63
64 /*
65 * Return the atomically incremented value of next_session_id.
66 */
67 static uint64_t get_next_session_id(void)
68 {
69 uint64_t ret;
70
71 pthread_mutex_lock(&next_session_id_lock);
72 ret = ++_next_session_id;
73 pthread_mutex_unlock(&next_session_id_lock);
74 return ret;
75 }
76
77 static void copy_channel_attr_to_ustctl(
78 struct ustctl_consumer_channel_attr *attr,
79 struct lttng_ust_channel_attr *uattr)
80 {
81 /* Copy event attributes since the layout is different. */
82 attr->subbuf_size = uattr->subbuf_size;
83 attr->num_subbuf = uattr->num_subbuf;
84 attr->overwrite = uattr->overwrite;
85 attr->switch_timer_interval = uattr->switch_timer_interval;
86 attr->read_timer_interval = uattr->read_timer_interval;
87 attr->output = uattr->output;
88 }
89
90 /*
91 * Match function for the hash table lookup.
92 *
93 * It matches an ust app event based on three attributes which are the event
94 * name, the filter bytecode and the loglevel.
95 */
96 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
97 {
98 struct ust_app_event *event;
99 const struct ust_app_ht_key *key;
100
101 assert(node);
102 assert(_key);
103
104 event = caa_container_of(node, struct ust_app_event, node.node);
105 key = _key;
106
107 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
108
109 /* Event name */
110 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
111 goto no_match;
112 }
113
114 /* Event loglevel. */
115 if (event->attr.loglevel != key->loglevel) {
116 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
117 && key->loglevel == 0 && event->attr.loglevel == -1) {
118 /*
119 * Match is accepted. This is because on event creation, the
120 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
121 * -1 are accepted for this loglevel type since 0 is the one set by
122 * the API when receiving an enable event.
123 */
124 } else {
125 goto no_match;
126 }
127 }
128
129 /* One of the filters is NULL, fail. */
130 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
131 goto no_match;
132 }
133
134 if (key->filter && event->filter) {
135 /* Both filters exists, check length followed by the bytecode. */
136 if (event->filter->len != key->filter->len ||
137 memcmp(event->filter->data, key->filter->data,
138 event->filter->len) != 0) {
139 goto no_match;
140 }
141 }
142
143 /* One of the exclusions is NULL, fail. */
144 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
145 goto no_match;
146 }
147
148 if (key->exclusion && event->exclusion) {
149 /* Both exclusions exists, check count followed by the names. */
150 if (event->exclusion->count != key->exclusion->count ||
151 memcmp(event->exclusion->names, key->exclusion->names,
152 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
153 goto no_match;
154 }
155 }
156
157
158 /* Match. */
159 return 1;
160
161 no_match:
162 return 0;
163 }
164
165 /*
166 * Unique add of an ust app event in the given ht. This uses the custom
167 * ht_match_ust_app_event match function and the event name as hash.
168 */
169 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
170 struct ust_app_event *event)
171 {
172 struct cds_lfht_node *node_ptr;
173 struct ust_app_ht_key key;
174 struct lttng_ht *ht;
175
176 assert(ua_chan);
177 assert(ua_chan->events);
178 assert(event);
179
180 ht = ua_chan->events;
181 key.name = event->attr.name;
182 key.filter = event->filter;
183 key.loglevel = event->attr.loglevel;
184 key.exclusion = event->exclusion;
185
186 node_ptr = cds_lfht_add_unique(ht->ht,
187 ht->hash_fct(event->node.key, lttng_ht_seed),
188 ht_match_ust_app_event, &key, &event->node.node);
189 assert(node_ptr == &event->node.node);
190 }
191
192 /*
193 * Close the notify socket from the given RCU head object. This MUST be called
194 * through a call_rcu().
195 */
196 static void close_notify_sock_rcu(struct rcu_head *head)
197 {
198 int ret;
199 struct ust_app_notify_sock_obj *obj =
200 caa_container_of(head, struct ust_app_notify_sock_obj, head);
201
202 /* Must have a valid fd here. */
203 assert(obj->fd >= 0);
204
205 ret = close(obj->fd);
206 if (ret) {
207 ERR("close notify sock %d RCU", obj->fd);
208 }
209 lttng_fd_put(LTTNG_FD_APPS, 1);
210
211 free(obj);
212 }
213
214 /*
215 * Return the session registry according to the buffer type of the given
216 * session.
217 *
218 * A registry per UID object MUST exists before calling this function or else
219 * it assert() if not found. RCU read side lock must be acquired.
220 */
221 static struct ust_registry_session *get_session_registry(
222 struct ust_app_session *ua_sess)
223 {
224 struct ust_registry_session *registry = NULL;
225
226 assert(ua_sess);
227
228 switch (ua_sess->buffer_type) {
229 case LTTNG_BUFFER_PER_PID:
230 {
231 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
232 if (!reg_pid) {
233 goto error;
234 }
235 registry = reg_pid->registry->reg.ust;
236 break;
237 }
238 case LTTNG_BUFFER_PER_UID:
239 {
240 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
241 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
242 if (!reg_uid) {
243 goto error;
244 }
245 registry = reg_uid->registry->reg.ust;
246 break;
247 }
248 default:
249 assert(0);
250 };
251
252 error:
253 return registry;
254 }
255
256 /*
257 * Delete ust context safely. RCU read lock must be held before calling
258 * this function.
259 */
260 static
261 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
262 {
263 int ret;
264
265 assert(ua_ctx);
266
267 if (ua_ctx->obj) {
268 ret = ustctl_release_object(sock, ua_ctx->obj);
269 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
270 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
271 sock, ua_ctx->obj->handle, ret);
272 }
273 free(ua_ctx->obj);
274 }
275 free(ua_ctx);
276 }
277
278 /*
279 * Delete ust app event safely. RCU read lock must be held before calling
280 * this function.
281 */
282 static
283 void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
284 {
285 int ret;
286
287 assert(ua_event);
288
289 free(ua_event->filter);
290 if (ua_event->exclusion != NULL)
291 free(ua_event->exclusion);
292 if (ua_event->obj != NULL) {
293 ret = ustctl_release_object(sock, ua_event->obj);
294 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
295 ERR("UST app sock %d release event obj failed with ret %d",
296 sock, ret);
297 }
298 free(ua_event->obj);
299 }
300 free(ua_event);
301 }
302
303 /*
304 * Release ust data object of the given stream.
305 *
306 * Return 0 on success or else a negative value.
307 */
308 static int release_ust_app_stream(int sock, struct ust_app_stream *stream)
309 {
310 int ret = 0;
311
312 assert(stream);
313
314 if (stream->obj) {
315 ret = ustctl_release_object(sock, stream->obj);
316 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
317 ERR("UST app sock %d release stream obj failed with ret %d",
318 sock, ret);
319 }
320 lttng_fd_put(LTTNG_FD_APPS, 2);
321 free(stream->obj);
322 }
323
324 return ret;
325 }
326
327 /*
328 * Delete ust app stream safely. RCU read lock must be held before calling
329 * this function.
330 */
331 static
332 void delete_ust_app_stream(int sock, struct ust_app_stream *stream)
333 {
334 assert(stream);
335
336 (void) release_ust_app_stream(sock, stream);
337 free(stream);
338 }
339
340 /*
341 * We need to execute ht_destroy outside of RCU read-side critical
342 * section and outside of call_rcu thread, so we postpone its execution
343 * using ht_cleanup_push. It is simpler than to change the semantic of
344 * the many callers of delete_ust_app_session().
345 */
346 static
347 void delete_ust_app_channel_rcu(struct rcu_head *head)
348 {
349 struct ust_app_channel *ua_chan =
350 caa_container_of(head, struct ust_app_channel, rcu_head);
351
352 ht_cleanup_push(ua_chan->ctx);
353 ht_cleanup_push(ua_chan->events);
354 free(ua_chan);
355 }
356
357 /*
358 * Delete ust app channel safely. RCU read lock must be held before calling
359 * this function.
360 */
361 static
362 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
363 struct ust_app *app)
364 {
365 int ret;
366 struct lttng_ht_iter iter;
367 struct ust_app_event *ua_event;
368 struct ust_app_ctx *ua_ctx;
369 struct ust_app_stream *stream, *stmp;
370 struct ust_registry_session *registry;
371
372 assert(ua_chan);
373
374 DBG3("UST app deleting channel %s", ua_chan->name);
375
376 /* Wipe stream */
377 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
378 cds_list_del(&stream->list);
379 delete_ust_app_stream(sock, stream);
380 }
381
382 /* Wipe context */
383 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
384 cds_list_del(&ua_ctx->list);
385 ret = lttng_ht_del(ua_chan->ctx, &iter);
386 assert(!ret);
387 delete_ust_app_ctx(sock, ua_ctx);
388 }
389
390 /* Wipe events */
391 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
392 node.node) {
393 ret = lttng_ht_del(ua_chan->events, &iter);
394 assert(!ret);
395 delete_ust_app_event(sock, ua_event);
396 }
397
398 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
399 /* Wipe and free registry from session registry. */
400 registry = get_session_registry(ua_chan->session);
401 if (registry) {
402 ust_registry_channel_del_free(registry, ua_chan->key);
403 }
404 }
405
406 if (ua_chan->obj != NULL) {
407 /* Remove channel from application UST object descriptor. */
408 iter.iter.node = &ua_chan->ust_objd_node.node;
409 ret = lttng_ht_del(app->ust_objd, &iter);
410 assert(!ret);
411 ret = ustctl_release_object(sock, ua_chan->obj);
412 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
413 ERR("UST app sock %d release channel obj failed with ret %d",
414 sock, ret);
415 }
416 lttng_fd_put(LTTNG_FD_APPS, 1);
417 free(ua_chan->obj);
418 }
419 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
420 }
421
422 /*
423 * Push metadata to consumer socket.
424 *
425 * The socket lock MUST be acquired.
426 * The ust app session lock MUST be acquired.
427 *
428 * On success, return the len of metadata pushed or else a negative value.
429 */
430 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
431 struct consumer_socket *socket, int send_zero_data)
432 {
433 int ret;
434 char *metadata_str = NULL;
435 size_t len, offset;
436 ssize_t ret_val;
437
438 assert(registry);
439 assert(socket);
440
441 /*
442 * On a push metadata error either the consumer is dead or the metadata
443 * channel has been destroyed because its endpoint might have died (e.g:
444 * relayd). If so, the metadata closed flag is set to 1 so we deny pushing
445 * metadata again which is not valid anymore on the consumer side.
446 *
447 * The ust app session mutex locked allows us to make this check without
448 * the registry lock.
449 */
450 if (registry->metadata_closed) {
451 return -EPIPE;
452 }
453
454 pthread_mutex_lock(&registry->lock);
455
456 offset = registry->metadata_len_sent;
457 len = registry->metadata_len - registry->metadata_len_sent;
458 if (len == 0) {
459 DBG3("No metadata to push for metadata key %" PRIu64,
460 registry->metadata_key);
461 ret_val = len;
462 if (send_zero_data) {
463 DBG("No metadata to push");
464 goto push_data;
465 }
466 goto end;
467 }
468
469 /* Allocate only what we have to send. */
470 metadata_str = zmalloc(len);
471 if (!metadata_str) {
472 PERROR("zmalloc ust app metadata string");
473 ret_val = -ENOMEM;
474 goto error;
475 }
476 /* Copy what we haven't send out. */
477 memcpy(metadata_str, registry->metadata + offset, len);
478 registry->metadata_len_sent += len;
479
480 push_data:
481 pthread_mutex_unlock(&registry->lock);
482 ret = consumer_push_metadata(socket, registry->metadata_key,
483 metadata_str, len, offset);
484 if (ret < 0) {
485 /*
486 * There is an acceptable race here between the registry metadata key
487 * assignment and the creation on the consumer. The session daemon can
488 * concurrently push metadata for this registry while being created on
489 * the consumer since the metadata key of the registry is assigned
490 * *before* it is setup to avoid the consumer to ask for metadata that
491 * could possibly be not found in the session daemon.
492 *
493 * The metadata will get pushed either by the session being stopped or
494 * the consumer requesting metadata if that race is triggered.
495 */
496 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
497 ret = 0;
498 }
499
500 /* Update back the actual metadata len sent since it failed here. */
501 pthread_mutex_lock(&registry->lock);
502 registry->metadata_len_sent -= len;
503 pthread_mutex_unlock(&registry->lock);
504 ret_val = ret;
505 goto error_push;
506 }
507
508 free(metadata_str);
509 return len;
510
511 end:
512 error:
513 pthread_mutex_unlock(&registry->lock);
514 error_push:
515 free(metadata_str);
516 return ret_val;
517 }
518
519 /*
520 * For a given application and session, push metadata to consumer. The session
521 * lock MUST be acquired here before calling this.
522 * Either sock or consumer is required : if sock is NULL, the default
523 * socket to send the metadata is retrieved from consumer, if sock
524 * is not NULL we use it to send the metadata.
525 *
526 * Return 0 on success else a negative error.
527 */
528 static int push_metadata(struct ust_registry_session *registry,
529 struct consumer_output *consumer)
530 {
531 int ret_val;
532 ssize_t ret;
533 struct consumer_socket *socket;
534
535 assert(registry);
536 assert(consumer);
537
538 rcu_read_lock();
539
540 /*
541 * Means that no metadata was assigned to the session. This can happens if
542 * no start has been done previously.
543 */
544 if (!registry->metadata_key) {
545 ret_val = 0;
546 goto end_rcu_unlock;
547 }
548
549 /* Get consumer socket to use to push the metadata.*/
550 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
551 consumer);
552 if (!socket) {
553 ret_val = -1;
554 goto error_rcu_unlock;
555 }
556
557 /*
558 * TODO: Currently, we hold the socket lock around sampling of the next
559 * metadata segment to ensure we send metadata over the consumer socket in
560 * the correct order. This makes the registry lock nest inside the socket
561 * lock.
562 *
563 * Please note that this is a temporary measure: we should move this lock
564 * back into ust_consumer_push_metadata() when the consumer gets the
565 * ability to reorder the metadata it receives.
566 */
567 pthread_mutex_lock(socket->lock);
568 ret = ust_app_push_metadata(registry, socket, 0);
569 pthread_mutex_unlock(socket->lock);
570 if (ret < 0) {
571 ret_val = ret;
572 goto error_rcu_unlock;
573 }
574
575 rcu_read_unlock();
576 return 0;
577
578 error_rcu_unlock:
579 /*
580 * On error, flag the registry that the metadata is closed. We were unable
581 * to push anything and this means that either the consumer is not
582 * responding or the metadata cache has been destroyed on the consumer.
583 */
584 registry->metadata_closed = 1;
585 end_rcu_unlock:
586 rcu_read_unlock();
587 return ret_val;
588 }
589
590 /*
591 * Send to the consumer a close metadata command for the given session. Once
592 * done, the metadata channel is deleted and the session metadata pointer is
593 * nullified. The session lock MUST be acquired here unless the application is
594 * in the destroy path.
595 *
596 * Return 0 on success else a negative value.
597 */
598 static int close_metadata(struct ust_registry_session *registry,
599 struct consumer_output *consumer)
600 {
601 int ret;
602 struct consumer_socket *socket;
603
604 assert(registry);
605 assert(consumer);
606
607 rcu_read_lock();
608
609 if (!registry->metadata_key || registry->metadata_closed) {
610 ret = 0;
611 goto end;
612 }
613
614 /* Get consumer socket to use to push the metadata.*/
615 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
616 consumer);
617 if (!socket) {
618 ret = -1;
619 goto error;
620 }
621
622 ret = consumer_close_metadata(socket, registry->metadata_key);
623 if (ret < 0) {
624 goto error;
625 }
626
627 error:
628 /*
629 * Metadata closed. Even on error this means that the consumer is not
630 * responding or not found so either way a second close should NOT be emit
631 * for this registry.
632 */
633 registry->metadata_closed = 1;
634 end:
635 rcu_read_unlock();
636 return ret;
637 }
638
639 /*
640 * We need to execute ht_destroy outside of RCU read-side critical
641 * section and outside of call_rcu thread, so we postpone its execution
642 * using ht_cleanup_push. It is simpler than to change the semantic of
643 * the many callers of delete_ust_app_session().
644 */
645 static
646 void delete_ust_app_session_rcu(struct rcu_head *head)
647 {
648 struct ust_app_session *ua_sess =
649 caa_container_of(head, struct ust_app_session, rcu_head);
650
651 ht_cleanup_push(ua_sess->channels);
652 free(ua_sess);
653 }
654
655 /*
656 * Delete ust app session safely. RCU read lock must be held before calling
657 * this function.
658 */
659 static
660 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
661 struct ust_app *app)
662 {
663 int ret;
664 struct lttng_ht_iter iter;
665 struct ust_app_channel *ua_chan;
666 struct ust_registry_session *registry;
667
668 assert(ua_sess);
669
670 pthread_mutex_lock(&ua_sess->lock);
671
672 registry = get_session_registry(ua_sess);
673 if (registry && !registry->metadata_closed) {
674 /* Push metadata for application before freeing the application. */
675 (void) push_metadata(registry, ua_sess->consumer);
676
677 /*
678 * Don't ask to close metadata for global per UID buffers. Close
679 * metadata only on destroy trace session in this case. Also, the
680 * previous push metadata could have flag the metadata registry to
681 * close so don't send a close command if closed.
682 */
683 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
684 !registry->metadata_closed) {
685 /* And ask to close it for this session registry. */
686 (void) close_metadata(registry, ua_sess->consumer);
687 }
688 }
689
690 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
691 node.node) {
692 ret = lttng_ht_del(ua_sess->channels, &iter);
693 assert(!ret);
694 delete_ust_app_channel(sock, ua_chan, app);
695 }
696
697 /* In case of per PID, the registry is kept in the session. */
698 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
699 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
700 if (reg_pid) {
701 buffer_reg_pid_remove(reg_pid);
702 buffer_reg_pid_destroy(reg_pid);
703 }
704 }
705
706 if (ua_sess->handle != -1) {
707 ret = ustctl_release_handle(sock, ua_sess->handle);
708 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
709 ERR("UST app sock %d release session handle failed with ret %d",
710 sock, ret);
711 }
712 }
713 pthread_mutex_unlock(&ua_sess->lock);
714
715 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
716 }
717
718 /*
719 * Delete a traceable application structure from the global list. Never call
720 * this function outside of a call_rcu call.
721 *
722 * RCU read side lock should _NOT_ be held when calling this function.
723 */
724 static
725 void delete_ust_app(struct ust_app *app)
726 {
727 int ret, sock;
728 struct ust_app_session *ua_sess, *tmp_ua_sess;
729
730 /* Delete ust app sessions info */
731 sock = app->sock;
732 app->sock = -1;
733
734 /* Wipe sessions */
735 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
736 teardown_node) {
737 /* Free every object in the session and the session. */
738 rcu_read_lock();
739 delete_ust_app_session(sock, ua_sess, app);
740 rcu_read_unlock();
741 }
742
743 ht_cleanup_push(app->sessions);
744 ht_cleanup_push(app->ust_objd);
745
746 /*
747 * Wait until we have deleted the application from the sock hash table
748 * before closing this socket, otherwise an application could re-use the
749 * socket ID and race with the teardown, using the same hash table entry.
750 *
751 * It's OK to leave the close in call_rcu. We want it to stay unique for
752 * all RCU readers that could run concurrently with unregister app,
753 * therefore we _need_ to only close that socket after a grace period. So
754 * it should stay in this RCU callback.
755 *
756 * This close() is a very important step of the synchronization model so
757 * every modification to this function must be carefully reviewed.
758 */
759 ret = close(sock);
760 if (ret) {
761 PERROR("close");
762 }
763 lttng_fd_put(LTTNG_FD_APPS, 1);
764
765 DBG2("UST app pid %d deleted", app->pid);
766 free(app);
767 }
768
769 /*
770 * URCU intermediate call to delete an UST app.
771 */
772 static
773 void delete_ust_app_rcu(struct rcu_head *head)
774 {
775 struct lttng_ht_node_ulong *node =
776 caa_container_of(head, struct lttng_ht_node_ulong, head);
777 struct ust_app *app =
778 caa_container_of(node, struct ust_app, pid_n);
779
780 DBG3("Call RCU deleting app PID %d", app->pid);
781 delete_ust_app(app);
782 }
783
784 /*
785 * Delete the session from the application ht and delete the data structure by
786 * freeing every object inside and releasing them.
787 */
788 static void destroy_app_session(struct ust_app *app,
789 struct ust_app_session *ua_sess)
790 {
791 int ret;
792 struct lttng_ht_iter iter;
793
794 assert(app);
795 assert(ua_sess);
796
797 iter.iter.node = &ua_sess->node.node;
798 ret = lttng_ht_del(app->sessions, &iter);
799 if (ret) {
800 /* Already scheduled for teardown. */
801 goto end;
802 }
803
804 /* Once deleted, free the data structure. */
805 delete_ust_app_session(app->sock, ua_sess, app);
806
807 end:
808 return;
809 }
810
811 /*
812 * Alloc new UST app session.
813 */
814 static
815 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
816 {
817 struct ust_app_session *ua_sess;
818
819 /* Init most of the default value by allocating and zeroing */
820 ua_sess = zmalloc(sizeof(struct ust_app_session));
821 if (ua_sess == NULL) {
822 PERROR("malloc");
823 goto error_free;
824 }
825
826 ua_sess->handle = -1;
827 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
828 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
829 pthread_mutex_init(&ua_sess->lock, NULL);
830
831 return ua_sess;
832
833 error_free:
834 return NULL;
835 }
836
837 /*
838 * Alloc new UST app channel.
839 */
840 static
841 struct ust_app_channel *alloc_ust_app_channel(char *name,
842 struct ust_app_session *ua_sess,
843 struct lttng_ust_channel_attr *attr)
844 {
845 struct ust_app_channel *ua_chan;
846
847 /* Init most of the default value by allocating and zeroing */
848 ua_chan = zmalloc(sizeof(struct ust_app_channel));
849 if (ua_chan == NULL) {
850 PERROR("malloc");
851 goto error;
852 }
853
854 /* Setup channel name */
855 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
856 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
857
858 ua_chan->enabled = 1;
859 ua_chan->handle = -1;
860 ua_chan->session = ua_sess;
861 ua_chan->key = get_next_channel_key();
862 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
863 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
864 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
865
866 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
867 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
868
869 /* Copy attributes */
870 if (attr) {
871 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
872 ua_chan->attr.subbuf_size = attr->subbuf_size;
873 ua_chan->attr.num_subbuf = attr->num_subbuf;
874 ua_chan->attr.overwrite = attr->overwrite;
875 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
876 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
877 ua_chan->attr.output = attr->output;
878 }
879 /* By default, the channel is a per cpu channel. */
880 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
881
882 DBG3("UST app channel %s allocated", ua_chan->name);
883
884 return ua_chan;
885
886 error:
887 return NULL;
888 }
889
890 /*
891 * Allocate and initialize a UST app stream.
892 *
893 * Return newly allocated stream pointer or NULL on error.
894 */
895 struct ust_app_stream *ust_app_alloc_stream(void)
896 {
897 struct ust_app_stream *stream = NULL;
898
899 stream = zmalloc(sizeof(*stream));
900 if (stream == NULL) {
901 PERROR("zmalloc ust app stream");
902 goto error;
903 }
904
905 /* Zero could be a valid value for a handle so flag it to -1. */
906 stream->handle = -1;
907
908 error:
909 return stream;
910 }
911
912 /*
913 * Alloc new UST app event.
914 */
915 static
916 struct ust_app_event *alloc_ust_app_event(char *name,
917 struct lttng_ust_event *attr)
918 {
919 struct ust_app_event *ua_event;
920
921 /* Init most of the default value by allocating and zeroing */
922 ua_event = zmalloc(sizeof(struct ust_app_event));
923 if (ua_event == NULL) {
924 PERROR("malloc");
925 goto error;
926 }
927
928 ua_event->enabled = 1;
929 strncpy(ua_event->name, name, sizeof(ua_event->name));
930 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
931 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
932
933 /* Copy attributes */
934 if (attr) {
935 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
936 }
937
938 DBG3("UST app event %s allocated", ua_event->name);
939
940 return ua_event;
941
942 error:
943 return NULL;
944 }
945
946 /*
947 * Alloc new UST app context.
948 */
949 static
950 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
951 {
952 struct ust_app_ctx *ua_ctx;
953
954 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
955 if (ua_ctx == NULL) {
956 goto error;
957 }
958
959 CDS_INIT_LIST_HEAD(&ua_ctx->list);
960
961 if (uctx) {
962 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
963 }
964
965 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
966
967 error:
968 return ua_ctx;
969 }
970
971 /*
972 * Allocate a filter and copy the given original filter.
973 *
974 * Return allocated filter or NULL on error.
975 */
976 static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
977 struct lttng_ust_filter_bytecode *orig_f)
978 {
979 struct lttng_ust_filter_bytecode *filter = NULL;
980
981 /* Copy filter bytecode */
982 filter = zmalloc(sizeof(*filter) + orig_f->len);
983 if (!filter) {
984 PERROR("zmalloc alloc ust app filter");
985 goto error;
986 }
987
988 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
989
990 error:
991 return filter;
992 }
993
994 /*
995 * Find an ust_app using the sock and return it. RCU read side lock must be
996 * held before calling this helper function.
997 */
998 struct ust_app *ust_app_find_by_sock(int sock)
999 {
1000 struct lttng_ht_node_ulong *node;
1001 struct lttng_ht_iter iter;
1002
1003 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1004 node = lttng_ht_iter_get_node_ulong(&iter);
1005 if (node == NULL) {
1006 DBG2("UST app find by sock %d not found", sock);
1007 goto error;
1008 }
1009
1010 return caa_container_of(node, struct ust_app, sock_n);
1011
1012 error:
1013 return NULL;
1014 }
1015
1016 /*
1017 * Find an ust_app using the notify sock and return it. RCU read side lock must
1018 * be held before calling this helper function.
1019 */
1020 static struct ust_app *find_app_by_notify_sock(int sock)
1021 {
1022 struct lttng_ht_node_ulong *node;
1023 struct lttng_ht_iter iter;
1024
1025 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1026 &iter);
1027 node = lttng_ht_iter_get_node_ulong(&iter);
1028 if (node == NULL) {
1029 DBG2("UST app find by notify sock %d not found", sock);
1030 goto error;
1031 }
1032
1033 return caa_container_of(node, struct ust_app, notify_sock_n);
1034
1035 error:
1036 return NULL;
1037 }
1038
1039 /*
1040 * Lookup for an ust app event based on event name, filter bytecode and the
1041 * event loglevel.
1042 *
1043 * Return an ust_app_event object or NULL on error.
1044 */
1045 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1046 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel,
1047 const struct lttng_event_exclusion *exclusion)
1048 {
1049 struct lttng_ht_iter iter;
1050 struct lttng_ht_node_str *node;
1051 struct ust_app_event *event = NULL;
1052 struct ust_app_ht_key key;
1053
1054 assert(name);
1055 assert(ht);
1056
1057 /* Setup key for event lookup. */
1058 key.name = name;
1059 key.filter = filter;
1060 key.loglevel = loglevel;
1061 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1062 key.exclusion = (struct lttng_ust_event_exclusion *)exclusion;
1063
1064 /* Lookup using the event name as hash and a custom match fct. */
1065 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1066 ht_match_ust_app_event, &key, &iter.iter);
1067 node = lttng_ht_iter_get_node_str(&iter);
1068 if (node == NULL) {
1069 goto end;
1070 }
1071
1072 event = caa_container_of(node, struct ust_app_event, node);
1073
1074 end:
1075 return event;
1076 }
1077
1078 /*
1079 * Create the channel context on the tracer.
1080 *
1081 * Called with UST app session lock held.
1082 */
1083 static
1084 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1085 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1086 {
1087 int ret;
1088
1089 health_code_update();
1090
1091 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1092 ua_chan->obj, &ua_ctx->obj);
1093 if (ret < 0) {
1094 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1095 ERR("UST app create channel context failed for app (pid: %d) "
1096 "with ret %d", app->pid, ret);
1097 } else {
1098 /*
1099 * This is normal behavior, an application can die during the
1100 * creation process. Don't report an error so the execution can
1101 * continue normally.
1102 */
1103 ret = 0;
1104 DBG3("UST app disable event failed. Application is dead.");
1105 }
1106 goto error;
1107 }
1108
1109 ua_ctx->handle = ua_ctx->obj->handle;
1110
1111 DBG2("UST app context handle %d created successfully for channel %s",
1112 ua_ctx->handle, ua_chan->name);
1113
1114 error:
1115 health_code_update();
1116 return ret;
1117 }
1118
1119 /*
1120 * Set the filter on the tracer.
1121 */
1122 static
1123 int set_ust_event_filter(struct ust_app_event *ua_event,
1124 struct ust_app *app)
1125 {
1126 int ret;
1127
1128 health_code_update();
1129
1130 if (!ua_event->filter) {
1131 ret = 0;
1132 goto error;
1133 }
1134
1135 ret = ustctl_set_filter(app->sock, ua_event->filter,
1136 ua_event->obj);
1137 if (ret < 0) {
1138 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1139 ERR("UST app event %s filter failed for app (pid: %d) "
1140 "with ret %d", ua_event->attr.name, app->pid, ret);
1141 } else {
1142 /*
1143 * This is normal behavior, an application can die during the
1144 * creation process. Don't report an error so the execution can
1145 * continue normally.
1146 */
1147 ret = 0;
1148 DBG3("UST app filter event failed. Application is dead.");
1149 }
1150 goto error;
1151 }
1152
1153 DBG2("UST filter set successfully for event %s", ua_event->name);
1154
1155 error:
1156 health_code_update();
1157 return ret;
1158 }
1159
1160 /*
1161 * Set event exclusions on the tracer.
1162 */
1163 static
1164 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1165 struct ust_app *app)
1166 {
1167 int ret;
1168
1169 health_code_update();
1170
1171 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1172 ret = 0;
1173 goto error;
1174 }
1175
1176 ret = ustctl_set_exclusion(app->sock, ua_event->exclusion,
1177 ua_event->obj);
1178 if (ret < 0) {
1179 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1180 ERR("UST app event %s exclusions failed for app (pid: %d) "
1181 "with ret %d", ua_event->attr.name, app->pid, ret);
1182 } else {
1183 /*
1184 * This is normal behavior, an application can die during the
1185 * creation process. Don't report an error so the execution can
1186 * continue normally.
1187 */
1188 ret = 0;
1189 DBG3("UST app event exclusion failed. Application is dead.");
1190 }
1191 goto error;
1192 }
1193
1194 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1195
1196 error:
1197 health_code_update();
1198 return ret;
1199 }
1200
1201 /*
1202 * Disable the specified event on to UST tracer for the UST session.
1203 */
1204 static int disable_ust_event(struct ust_app *app,
1205 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1206 {
1207 int ret;
1208
1209 health_code_update();
1210
1211 ret = ustctl_disable(app->sock, ua_event->obj);
1212 if (ret < 0) {
1213 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1214 ERR("UST app event %s disable failed for app (pid: %d) "
1215 "and session handle %d with ret %d",
1216 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1217 } else {
1218 /*
1219 * This is normal behavior, an application can die during the
1220 * creation process. Don't report an error so the execution can
1221 * continue normally.
1222 */
1223 ret = 0;
1224 DBG3("UST app disable event failed. Application is dead.");
1225 }
1226 goto error;
1227 }
1228
1229 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1230 ua_event->attr.name, app->pid);
1231
1232 error:
1233 health_code_update();
1234 return ret;
1235 }
1236
1237 /*
1238 * Disable the specified channel on to UST tracer for the UST session.
1239 */
1240 static int disable_ust_channel(struct ust_app *app,
1241 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1242 {
1243 int ret;
1244
1245 health_code_update();
1246
1247 ret = ustctl_disable(app->sock, ua_chan->obj);
1248 if (ret < 0) {
1249 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1250 ERR("UST app channel %s disable failed for app (pid: %d) "
1251 "and session handle %d with ret %d",
1252 ua_chan->name, app->pid, ua_sess->handle, ret);
1253 } else {
1254 /*
1255 * This is normal behavior, an application can die during the
1256 * creation process. Don't report an error so the execution can
1257 * continue normally.
1258 */
1259 ret = 0;
1260 DBG3("UST app disable channel failed. Application is dead.");
1261 }
1262 goto error;
1263 }
1264
1265 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1266 ua_chan->name, app->pid);
1267
1268 error:
1269 health_code_update();
1270 return ret;
1271 }
1272
1273 /*
1274 * Enable the specified channel on to UST tracer for the UST session.
1275 */
1276 static int enable_ust_channel(struct ust_app *app,
1277 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1278 {
1279 int ret;
1280
1281 health_code_update();
1282
1283 ret = ustctl_enable(app->sock, ua_chan->obj);
1284 if (ret < 0) {
1285 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1286 ERR("UST app channel %s enable failed for app (pid: %d) "
1287 "and session handle %d with ret %d",
1288 ua_chan->name, app->pid, ua_sess->handle, ret);
1289 } else {
1290 /*
1291 * This is normal behavior, an application can die during the
1292 * creation process. Don't report an error so the execution can
1293 * continue normally.
1294 */
1295 ret = 0;
1296 DBG3("UST app enable channel failed. Application is dead.");
1297 }
1298 goto error;
1299 }
1300
1301 ua_chan->enabled = 1;
1302
1303 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1304 ua_chan->name, app->pid);
1305
1306 error:
1307 health_code_update();
1308 return ret;
1309 }
1310
1311 /*
1312 * Enable the specified event on to UST tracer for the UST session.
1313 */
1314 static int enable_ust_event(struct ust_app *app,
1315 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1316 {
1317 int ret;
1318
1319 health_code_update();
1320
1321 ret = ustctl_enable(app->sock, ua_event->obj);
1322 if (ret < 0) {
1323 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1324 ERR("UST app event %s enable failed for app (pid: %d) "
1325 "and session handle %d with ret %d",
1326 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1327 } else {
1328 /*
1329 * This is normal behavior, an application can die during the
1330 * creation process. Don't report an error so the execution can
1331 * continue normally.
1332 */
1333 ret = 0;
1334 DBG3("UST app enable event failed. Application is dead.");
1335 }
1336 goto error;
1337 }
1338
1339 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1340 ua_event->attr.name, app->pid);
1341
1342 error:
1343 health_code_update();
1344 return ret;
1345 }
1346
1347 /*
1348 * Send channel and stream buffer to application.
1349 *
1350 * Return 0 on success. On error, a negative value is returned.
1351 */
1352 static int send_channel_pid_to_ust(struct ust_app *app,
1353 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1354 {
1355 int ret;
1356 struct ust_app_stream *stream, *stmp;
1357
1358 assert(app);
1359 assert(ua_sess);
1360 assert(ua_chan);
1361
1362 health_code_update();
1363
1364 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1365 app->sock);
1366
1367 /* Send channel to the application. */
1368 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1369 if (ret < 0) {
1370 goto error;
1371 }
1372
1373 health_code_update();
1374
1375 /* Send all streams to application. */
1376 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1377 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1378 if (ret < 0) {
1379 goto error;
1380 }
1381 /* We don't need the stream anymore once sent to the tracer. */
1382 cds_list_del(&stream->list);
1383 delete_ust_app_stream(-1, stream);
1384 }
1385 /* Flag the channel that it is sent to the application. */
1386 ua_chan->is_sent = 1;
1387
1388 error:
1389 health_code_update();
1390 return ret;
1391 }
1392
1393 /*
1394 * Create the specified event onto the UST tracer for a UST session.
1395 *
1396 * Should be called with session mutex held.
1397 */
1398 static
1399 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1400 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1401 {
1402 int ret = 0;
1403
1404 health_code_update();
1405
1406 /* Create UST event on tracer */
1407 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1408 &ua_event->obj);
1409 if (ret < 0) {
1410 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1411 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1412 ua_event->attr.name, app->pid, ret);
1413 } else {
1414 /*
1415 * This is normal behavior, an application can die during the
1416 * creation process. Don't report an error so the execution can
1417 * continue normally.
1418 */
1419 ret = 0;
1420 DBG3("UST app create event failed. Application is dead.");
1421 }
1422 goto error;
1423 }
1424
1425 ua_event->handle = ua_event->obj->handle;
1426
1427 DBG2("UST app event %s created successfully for pid:%d",
1428 ua_event->attr.name, app->pid);
1429
1430 health_code_update();
1431
1432 /* Set filter if one is present. */
1433 if (ua_event->filter) {
1434 ret = set_ust_event_filter(ua_event, app);
1435 if (ret < 0) {
1436 goto error;
1437 }
1438 }
1439
1440 /* Set exclusions for the event */
1441 if (ua_event->exclusion) {
1442 ret = set_ust_event_exclusion(ua_event, app);
1443 if (ret < 0) {
1444 goto error;
1445 }
1446 }
1447
1448 /* If event not enabled, disable it on the tracer */
1449 if (ua_event->enabled == 0) {
1450 ret = disable_ust_event(app, ua_sess, ua_event);
1451 if (ret < 0) {
1452 /*
1453 * If we hit an EPERM, something is wrong with our disable call. If
1454 * we get an EEXIST, there is a problem on the tracer side since we
1455 * just created it.
1456 */
1457 switch (ret) {
1458 case -LTTNG_UST_ERR_PERM:
1459 /* Code flow problem */
1460 assert(0);
1461 case -LTTNG_UST_ERR_EXIST:
1462 /* It's OK for our use case. */
1463 ret = 0;
1464 break;
1465 default:
1466 break;
1467 }
1468 goto error;
1469 }
1470 }
1471
1472 error:
1473 health_code_update();
1474 return ret;
1475 }
1476
1477 /*
1478 * Copy data between an UST app event and a LTT event.
1479 */
1480 static void shadow_copy_event(struct ust_app_event *ua_event,
1481 struct ltt_ust_event *uevent)
1482 {
1483 size_t exclusion_alloc_size;
1484
1485 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1486 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1487
1488 ua_event->enabled = uevent->enabled;
1489
1490 /* Copy event attributes */
1491 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1492
1493 /* Copy filter bytecode */
1494 if (uevent->filter) {
1495 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1496 /* Filter might be NULL here in case of ENONEM. */
1497 }
1498
1499 /* Copy exclusion data */
1500 if (uevent->exclusion) {
1501 exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1502 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1503 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1504 if (ua_event->exclusion == NULL) {
1505 PERROR("malloc");
1506 } else {
1507 memcpy(ua_event->exclusion, uevent->exclusion,
1508 exclusion_alloc_size);
1509 }
1510 }
1511 }
1512
1513 /*
1514 * Copy data between an UST app channel and a LTT channel.
1515 */
1516 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1517 struct ltt_ust_channel *uchan)
1518 {
1519 struct lttng_ht_iter iter;
1520 struct ltt_ust_event *uevent;
1521 struct ltt_ust_context *uctx;
1522 struct ust_app_event *ua_event;
1523 struct ust_app_ctx *ua_ctx;
1524
1525 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1526
1527 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1528 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1529
1530 ua_chan->tracefile_size = uchan->tracefile_size;
1531 ua_chan->tracefile_count = uchan->tracefile_count;
1532
1533 /* Copy event attributes since the layout is different. */
1534 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1535 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1536 ua_chan->attr.overwrite = uchan->attr.overwrite;
1537 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1538 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1539 ua_chan->attr.output = uchan->attr.output;
1540 /*
1541 * Note that the attribute channel type is not set since the channel on the
1542 * tracing registry side does not have this information.
1543 */
1544
1545 ua_chan->enabled = uchan->enabled;
1546 ua_chan->tracing_channel_id = uchan->id;
1547
1548 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1549 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1550 if (ua_ctx == NULL) {
1551 continue;
1552 }
1553 lttng_ht_node_init_ulong(&ua_ctx->node,
1554 (unsigned long) ua_ctx->ctx.ctx);
1555 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1556 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1557 }
1558
1559 /* Copy all events from ltt ust channel to ust app channel */
1560 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1561 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1562 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1563 if (ua_event == NULL) {
1564 DBG2("UST event %s not found on shadow copy channel",
1565 uevent->attr.name);
1566 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1567 if (ua_event == NULL) {
1568 continue;
1569 }
1570 shadow_copy_event(ua_event, uevent);
1571 add_unique_ust_app_event(ua_chan, ua_event);
1572 }
1573 }
1574
1575 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1576 }
1577
1578 /*
1579 * Copy data between a UST app session and a regular LTT session.
1580 */
1581 static void shadow_copy_session(struct ust_app_session *ua_sess,
1582 struct ltt_ust_session *usess, struct ust_app *app)
1583 {
1584 struct lttng_ht_node_str *ua_chan_node;
1585 struct lttng_ht_iter iter;
1586 struct ltt_ust_channel *uchan;
1587 struct ust_app_channel *ua_chan;
1588 time_t rawtime;
1589 struct tm *timeinfo;
1590 char datetime[16];
1591 int ret;
1592
1593 /* Get date and time for unique app path */
1594 time(&rawtime);
1595 timeinfo = localtime(&rawtime);
1596 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1597
1598 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1599
1600 ua_sess->tracing_id = usess->id;
1601 ua_sess->id = get_next_session_id();
1602 ua_sess->uid = app->uid;
1603 ua_sess->gid = app->gid;
1604 ua_sess->euid = usess->uid;
1605 ua_sess->egid = usess->gid;
1606 ua_sess->buffer_type = usess->buffer_type;
1607 ua_sess->bits_per_long = app->bits_per_long;
1608 /* There is only one consumer object per session possible. */
1609 ua_sess->consumer = usess->consumer;
1610 ua_sess->output_traces = usess->output_traces;
1611 ua_sess->live_timer_interval = usess->live_timer_interval;
1612 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1613 &usess->metadata_attr);
1614
1615 switch (ua_sess->buffer_type) {
1616 case LTTNG_BUFFER_PER_PID:
1617 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1618 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1619 datetime);
1620 break;
1621 case LTTNG_BUFFER_PER_UID:
1622 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1623 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1624 break;
1625 default:
1626 assert(0);
1627 goto error;
1628 }
1629 if (ret < 0) {
1630 PERROR("asprintf UST shadow copy session");
1631 assert(0);
1632 goto error;
1633 }
1634
1635 /* Iterate over all channels in global domain. */
1636 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1637 uchan, node.node) {
1638 struct lttng_ht_iter uiter;
1639
1640 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1641 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1642 if (ua_chan_node != NULL) {
1643 /* Session exist. Contiuing. */
1644 continue;
1645 }
1646
1647 DBG2("Channel %s not found on shadow session copy, creating it",
1648 uchan->name);
1649 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1650 if (ua_chan == NULL) {
1651 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1652 continue;
1653 }
1654 shadow_copy_channel(ua_chan, uchan);
1655 /*
1656 * The concept of metadata channel does not exist on the tracing
1657 * registry side of the session daemon so this can only be a per CPU
1658 * channel and not metadata.
1659 */
1660 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1661
1662 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1663 }
1664
1665 error:
1666 return;
1667 }
1668
1669 /*
1670 * Lookup sesison wrapper.
1671 */
1672 static
1673 void __lookup_session_by_app(struct ltt_ust_session *usess,
1674 struct ust_app *app, struct lttng_ht_iter *iter)
1675 {
1676 /* Get right UST app session from app */
1677 lttng_ht_lookup(app->sessions, &usess->id, iter);
1678 }
1679
1680 /*
1681 * Return ust app session from the app session hashtable using the UST session
1682 * id.
1683 */
1684 static struct ust_app_session *lookup_session_by_app(
1685 struct ltt_ust_session *usess, struct ust_app *app)
1686 {
1687 struct lttng_ht_iter iter;
1688 struct lttng_ht_node_u64 *node;
1689
1690 __lookup_session_by_app(usess, app, &iter);
1691 node = lttng_ht_iter_get_node_u64(&iter);
1692 if (node == NULL) {
1693 goto error;
1694 }
1695
1696 return caa_container_of(node, struct ust_app_session, node);
1697
1698 error:
1699 return NULL;
1700 }
1701
1702 /*
1703 * Setup buffer registry per PID for the given session and application. If none
1704 * is found, a new one is created, added to the global registry and
1705 * initialized. If regp is valid, it's set with the newly created object.
1706 *
1707 * Return 0 on success or else a negative value.
1708 */
1709 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1710 struct ust_app *app, struct buffer_reg_pid **regp)
1711 {
1712 int ret = 0;
1713 struct buffer_reg_pid *reg_pid;
1714
1715 assert(ua_sess);
1716 assert(app);
1717
1718 rcu_read_lock();
1719
1720 reg_pid = buffer_reg_pid_find(ua_sess->id);
1721 if (!reg_pid) {
1722 /*
1723 * This is the create channel path meaning that if there is NO
1724 * registry available, we have to create one for this session.
1725 */
1726 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1727 if (ret < 0) {
1728 goto error;
1729 }
1730 buffer_reg_pid_add(reg_pid);
1731 } else {
1732 goto end;
1733 }
1734
1735 /* Initialize registry. */
1736 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1737 app->bits_per_long, app->uint8_t_alignment,
1738 app->uint16_t_alignment, app->uint32_t_alignment,
1739 app->uint64_t_alignment, app->long_alignment,
1740 app->byte_order, app->version.major,
1741 app->version.minor);
1742 if (ret < 0) {
1743 goto error;
1744 }
1745
1746 DBG3("UST app buffer registry per PID created successfully");
1747
1748 end:
1749 if (regp) {
1750 *regp = reg_pid;
1751 }
1752 error:
1753 rcu_read_unlock();
1754 return ret;
1755 }
1756
1757 /*
1758 * Setup buffer registry per UID for the given session and application. If none
1759 * is found, a new one is created, added to the global registry and
1760 * initialized. If regp is valid, it's set with the newly created object.
1761 *
1762 * Return 0 on success or else a negative value.
1763 */
1764 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1765 struct ust_app *app, struct buffer_reg_uid **regp)
1766 {
1767 int ret = 0;
1768 struct buffer_reg_uid *reg_uid;
1769
1770 assert(usess);
1771 assert(app);
1772
1773 rcu_read_lock();
1774
1775 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1776 if (!reg_uid) {
1777 /*
1778 * This is the create channel path meaning that if there is NO
1779 * registry available, we have to create one for this session.
1780 */
1781 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1782 LTTNG_DOMAIN_UST, &reg_uid);
1783 if (ret < 0) {
1784 goto error;
1785 }
1786 buffer_reg_uid_add(reg_uid);
1787 } else {
1788 goto end;
1789 }
1790
1791 /* Initialize registry. */
1792 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1793 app->bits_per_long, app->uint8_t_alignment,
1794 app->uint16_t_alignment, app->uint32_t_alignment,
1795 app->uint64_t_alignment, app->long_alignment,
1796 app->byte_order, app->version.major,
1797 app->version.minor);
1798 if (ret < 0) {
1799 goto error;
1800 }
1801 /* Add node to teardown list of the session. */
1802 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1803
1804 DBG3("UST app buffer registry per UID created successfully");
1805
1806 end:
1807 if (regp) {
1808 *regp = reg_uid;
1809 }
1810 error:
1811 rcu_read_unlock();
1812 return ret;
1813 }
1814
1815 /*
1816 * Create a session on the tracer side for the given app.
1817 *
1818 * On success, ua_sess_ptr is populated with the session pointer or else left
1819 * untouched. If the session was created, is_created is set to 1. On error,
1820 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1821 * be NULL.
1822 *
1823 * Returns 0 on success or else a negative code which is either -ENOMEM or
1824 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1825 */
1826 static int create_ust_app_session(struct ltt_ust_session *usess,
1827 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1828 int *is_created)
1829 {
1830 int ret, created = 0;
1831 struct ust_app_session *ua_sess;
1832
1833 assert(usess);
1834 assert(app);
1835 assert(ua_sess_ptr);
1836
1837 health_code_update();
1838
1839 ua_sess = lookup_session_by_app(usess, app);
1840 if (ua_sess == NULL) {
1841 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1842 app->pid, usess->id);
1843 ua_sess = alloc_ust_app_session(app);
1844 if (ua_sess == NULL) {
1845 /* Only malloc can failed so something is really wrong */
1846 ret = -ENOMEM;
1847 goto error;
1848 }
1849 shadow_copy_session(ua_sess, usess, app);
1850 created = 1;
1851 }
1852
1853 switch (usess->buffer_type) {
1854 case LTTNG_BUFFER_PER_PID:
1855 /* Init local registry. */
1856 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1857 if (ret < 0) {
1858 goto error;
1859 }
1860 break;
1861 case LTTNG_BUFFER_PER_UID:
1862 /* Look for a global registry. If none exists, create one. */
1863 ret = setup_buffer_reg_uid(usess, app, NULL);
1864 if (ret < 0) {
1865 goto error;
1866 }
1867 break;
1868 default:
1869 assert(0);
1870 ret = -EINVAL;
1871 goto error;
1872 }
1873
1874 health_code_update();
1875
1876 if (ua_sess->handle == -1) {
1877 ret = ustctl_create_session(app->sock);
1878 if (ret < 0) {
1879 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1880 ERR("Creating session for app pid %d with ret %d",
1881 app->pid, ret);
1882 } else {
1883 DBG("UST app creating session failed. Application is dead");
1884 /*
1885 * This is normal behavior, an application can die during the
1886 * creation process. Don't report an error so the execution can
1887 * continue normally. This will get flagged ENOTCONN and the
1888 * caller will handle it.
1889 */
1890 ret = 0;
1891 }
1892 delete_ust_app_session(-1, ua_sess, app);
1893 if (ret != -ENOMEM) {
1894 /*
1895 * Tracer is probably gone or got an internal error so let's
1896 * behave like it will soon unregister or not usable.
1897 */
1898 ret = -ENOTCONN;
1899 }
1900 goto error;
1901 }
1902
1903 ua_sess->handle = ret;
1904
1905 /* Add ust app session to app's HT */
1906 lttng_ht_node_init_u64(&ua_sess->node,
1907 ua_sess->tracing_id);
1908 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1909
1910 DBG2("UST app session created successfully with handle %d", ret);
1911 }
1912
1913 *ua_sess_ptr = ua_sess;
1914 if (is_created) {
1915 *is_created = created;
1916 }
1917
1918 /* Everything went well. */
1919 ret = 0;
1920
1921 error:
1922 health_code_update();
1923 return ret;
1924 }
1925
1926 /*
1927 * Create a context for the channel on the tracer.
1928 *
1929 * Called with UST app session lock held and a RCU read side lock.
1930 */
1931 static
1932 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
1933 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
1934 struct ust_app *app)
1935 {
1936 int ret = 0;
1937 struct lttng_ht_iter iter;
1938 struct lttng_ht_node_ulong *node;
1939 struct ust_app_ctx *ua_ctx;
1940
1941 DBG2("UST app adding context to channel %s", ua_chan->name);
1942
1943 lttng_ht_lookup(ua_chan->ctx, (void *)((unsigned long)uctx->ctx), &iter);
1944 node = lttng_ht_iter_get_node_ulong(&iter);
1945 if (node != NULL) {
1946 ret = -EEXIST;
1947 goto error;
1948 }
1949
1950 ua_ctx = alloc_ust_app_ctx(uctx);
1951 if (ua_ctx == NULL) {
1952 /* malloc failed */
1953 ret = -1;
1954 goto error;
1955 }
1956
1957 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
1958 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1959 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1960
1961 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
1962 if (ret < 0) {
1963 goto error;
1964 }
1965
1966 error:
1967 return ret;
1968 }
1969
1970 /*
1971 * Enable on the tracer side a ust app event for the session and channel.
1972 *
1973 * Called with UST app session lock held.
1974 */
1975 static
1976 int enable_ust_app_event(struct ust_app_session *ua_sess,
1977 struct ust_app_event *ua_event, struct ust_app *app)
1978 {
1979 int ret;
1980
1981 ret = enable_ust_event(app, ua_sess, ua_event);
1982 if (ret < 0) {
1983 goto error;
1984 }
1985
1986 ua_event->enabled = 1;
1987
1988 error:
1989 return ret;
1990 }
1991
1992 /*
1993 * Disable on the tracer side a ust app event for the session and channel.
1994 */
1995 static int disable_ust_app_event(struct ust_app_session *ua_sess,
1996 struct ust_app_event *ua_event, struct ust_app *app)
1997 {
1998 int ret;
1999
2000 ret = disable_ust_event(app, ua_sess, ua_event);
2001 if (ret < 0) {
2002 goto error;
2003 }
2004
2005 ua_event->enabled = 0;
2006
2007 error:
2008 return ret;
2009 }
2010
2011 /*
2012 * Lookup ust app channel for session and disable it on the tracer side.
2013 */
2014 static
2015 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2016 struct ust_app_channel *ua_chan, struct ust_app *app)
2017 {
2018 int ret;
2019
2020 ret = disable_ust_channel(app, ua_sess, ua_chan);
2021 if (ret < 0) {
2022 goto error;
2023 }
2024
2025 ua_chan->enabled = 0;
2026
2027 error:
2028 return ret;
2029 }
2030
2031 /*
2032 * Lookup ust app channel for session and enable it on the tracer side. This
2033 * MUST be called with a RCU read side lock acquired.
2034 */
2035 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2036 struct ltt_ust_channel *uchan, struct ust_app *app)
2037 {
2038 int ret = 0;
2039 struct lttng_ht_iter iter;
2040 struct lttng_ht_node_str *ua_chan_node;
2041 struct ust_app_channel *ua_chan;
2042
2043 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2044 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2045 if (ua_chan_node == NULL) {
2046 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2047 uchan->name, ua_sess->tracing_id);
2048 goto error;
2049 }
2050
2051 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2052
2053 ret = enable_ust_channel(app, ua_sess, ua_chan);
2054 if (ret < 0) {
2055 goto error;
2056 }
2057
2058 error:
2059 return ret;
2060 }
2061
2062 /*
2063 * Ask the consumer to create a channel and get it if successful.
2064 *
2065 * Return 0 on success or else a negative value.
2066 */
2067 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2068 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2069 int bitness, struct ust_registry_session *registry)
2070 {
2071 int ret;
2072 unsigned int nb_fd = 0;
2073 struct consumer_socket *socket;
2074
2075 assert(usess);
2076 assert(ua_sess);
2077 assert(ua_chan);
2078 assert(registry);
2079
2080 rcu_read_lock();
2081 health_code_update();
2082
2083 /* Get the right consumer socket for the application. */
2084 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2085 if (!socket) {
2086 ret = -EINVAL;
2087 goto error;
2088 }
2089
2090 health_code_update();
2091
2092 /* Need one fd for the channel. */
2093 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2094 if (ret < 0) {
2095 ERR("Exhausted number of available FD upon create channel");
2096 goto error;
2097 }
2098
2099 /*
2100 * Ask consumer to create channel. The consumer will return the number of
2101 * stream we have to expect.
2102 */
2103 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2104 registry);
2105 if (ret < 0) {
2106 goto error_ask;
2107 }
2108
2109 /*
2110 * Compute the number of fd needed before receiving them. It must be 2 per
2111 * stream (2 being the default value here).
2112 */
2113 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2114
2115 /* Reserve the amount of file descriptor we need. */
2116 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2117 if (ret < 0) {
2118 ERR("Exhausted number of available FD upon create channel");
2119 goto error_fd_get_stream;
2120 }
2121
2122 health_code_update();
2123
2124 /*
2125 * Now get the channel from the consumer. This call wil populate the stream
2126 * list of that channel and set the ust objects.
2127 */
2128 if (usess->consumer->enabled) {
2129 ret = ust_consumer_get_channel(socket, ua_chan);
2130 if (ret < 0) {
2131 goto error_destroy;
2132 }
2133 }
2134
2135 rcu_read_unlock();
2136 return 0;
2137
2138 error_destroy:
2139 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2140 error_fd_get_stream:
2141 /*
2142 * Initiate a destroy channel on the consumer since we had an error
2143 * handling it on our side. The return value is of no importance since we
2144 * already have a ret value set by the previous error that we need to
2145 * return.
2146 */
2147 (void) ust_consumer_destroy_channel(socket, ua_chan);
2148 error_ask:
2149 lttng_fd_put(LTTNG_FD_APPS, 1);
2150 error:
2151 health_code_update();
2152 rcu_read_unlock();
2153 return ret;
2154 }
2155
2156 /*
2157 * Duplicate the ust data object of the ust app stream and save it in the
2158 * buffer registry stream.
2159 *
2160 * Return 0 on success or else a negative value.
2161 */
2162 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2163 struct ust_app_stream *stream)
2164 {
2165 int ret;
2166
2167 assert(reg_stream);
2168 assert(stream);
2169
2170 /* Reserve the amount of file descriptor we need. */
2171 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2172 if (ret < 0) {
2173 ERR("Exhausted number of available FD upon duplicate stream");
2174 goto error;
2175 }
2176
2177 /* Duplicate object for stream once the original is in the registry. */
2178 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2179 reg_stream->obj.ust);
2180 if (ret < 0) {
2181 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2182 reg_stream->obj.ust, stream->obj, ret);
2183 lttng_fd_put(LTTNG_FD_APPS, 2);
2184 goto error;
2185 }
2186 stream->handle = stream->obj->handle;
2187
2188 error:
2189 return ret;
2190 }
2191
2192 /*
2193 * Duplicate the ust data object of the ust app. channel and save it in the
2194 * buffer registry channel.
2195 *
2196 * Return 0 on success or else a negative value.
2197 */
2198 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2199 struct ust_app_channel *ua_chan)
2200 {
2201 int ret;
2202
2203 assert(reg_chan);
2204 assert(ua_chan);
2205
2206 /* Need two fds for the channel. */
2207 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2208 if (ret < 0) {
2209 ERR("Exhausted number of available FD upon duplicate channel");
2210 goto error_fd_get;
2211 }
2212
2213 /* Duplicate object for stream once the original is in the registry. */
2214 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2215 if (ret < 0) {
2216 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2217 reg_chan->obj.ust, ua_chan->obj, ret);
2218 goto error;
2219 }
2220 ua_chan->handle = ua_chan->obj->handle;
2221
2222 return 0;
2223
2224 error:
2225 lttng_fd_put(LTTNG_FD_APPS, 1);
2226 error_fd_get:
2227 return ret;
2228 }
2229
2230 /*
2231 * For a given channel buffer registry, setup all streams of the given ust
2232 * application channel.
2233 *
2234 * Return 0 on success or else a negative value.
2235 */
2236 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2237 struct ust_app_channel *ua_chan)
2238 {
2239 int ret = 0;
2240 struct ust_app_stream *stream, *stmp;
2241
2242 assert(reg_chan);
2243 assert(ua_chan);
2244
2245 DBG2("UST app setup buffer registry stream");
2246
2247 /* Send all streams to application. */
2248 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2249 struct buffer_reg_stream *reg_stream;
2250
2251 ret = buffer_reg_stream_create(&reg_stream);
2252 if (ret < 0) {
2253 goto error;
2254 }
2255
2256 /*
2257 * Keep original pointer and nullify it in the stream so the delete
2258 * stream call does not release the object.
2259 */
2260 reg_stream->obj.ust = stream->obj;
2261 stream->obj = NULL;
2262 buffer_reg_stream_add(reg_stream, reg_chan);
2263
2264 /* We don't need the streams anymore. */
2265 cds_list_del(&stream->list);
2266 delete_ust_app_stream(-1, stream);
2267 }
2268
2269 error:
2270 return ret;
2271 }
2272
2273 /*
2274 * Create a buffer registry channel for the given session registry and
2275 * application channel object. If regp pointer is valid, it's set with the
2276 * created object. Important, the created object is NOT added to the session
2277 * registry hash table.
2278 *
2279 * Return 0 on success else a negative value.
2280 */
2281 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2282 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2283 {
2284 int ret;
2285 struct buffer_reg_channel *reg_chan = NULL;
2286
2287 assert(reg_sess);
2288 assert(ua_chan);
2289
2290 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2291
2292 /* Create buffer registry channel. */
2293 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2294 if (ret < 0) {
2295 goto error_create;
2296 }
2297 assert(reg_chan);
2298 reg_chan->consumer_key = ua_chan->key;
2299 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2300
2301 /* Create and add a channel registry to session. */
2302 ret = ust_registry_channel_add(reg_sess->reg.ust,
2303 ua_chan->tracing_channel_id);
2304 if (ret < 0) {
2305 goto error;
2306 }
2307 buffer_reg_channel_add(reg_sess, reg_chan);
2308
2309 if (regp) {
2310 *regp = reg_chan;
2311 }
2312
2313 return 0;
2314
2315 error:
2316 /* Safe because the registry channel object was not added to any HT. */
2317 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2318 error_create:
2319 return ret;
2320 }
2321
2322 /*
2323 * Setup buffer registry channel for the given session registry and application
2324 * channel object. If regp pointer is valid, it's set with the created object.
2325 *
2326 * Return 0 on success else a negative value.
2327 */
2328 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2329 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2330 {
2331 int ret;
2332
2333 assert(reg_sess);
2334 assert(reg_chan);
2335 assert(ua_chan);
2336 assert(ua_chan->obj);
2337
2338 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2339
2340 /* Setup all streams for the registry. */
2341 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2342 if (ret < 0) {
2343 goto error;
2344 }
2345
2346 reg_chan->obj.ust = ua_chan->obj;
2347 ua_chan->obj = NULL;
2348
2349 return 0;
2350
2351 error:
2352 buffer_reg_channel_remove(reg_sess, reg_chan);
2353 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2354 return ret;
2355 }
2356
2357 /*
2358 * Send buffer registry channel to the application.
2359 *
2360 * Return 0 on success else a negative value.
2361 */
2362 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2363 struct ust_app *app, struct ust_app_session *ua_sess,
2364 struct ust_app_channel *ua_chan)
2365 {
2366 int ret;
2367 struct buffer_reg_stream *reg_stream;
2368
2369 assert(reg_chan);
2370 assert(app);
2371 assert(ua_sess);
2372 assert(ua_chan);
2373
2374 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2375
2376 ret = duplicate_channel_object(reg_chan, ua_chan);
2377 if (ret < 0) {
2378 goto error;
2379 }
2380
2381 /* Send channel to the application. */
2382 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2383 if (ret < 0) {
2384 goto error;
2385 }
2386
2387 health_code_update();
2388
2389 /* Send all streams to application. */
2390 pthread_mutex_lock(&reg_chan->stream_list_lock);
2391 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2392 struct ust_app_stream stream;
2393
2394 ret = duplicate_stream_object(reg_stream, &stream);
2395 if (ret < 0) {
2396 goto error_stream_unlock;
2397 }
2398
2399 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2400 if (ret < 0) {
2401 (void) release_ust_app_stream(-1, &stream);
2402 goto error_stream_unlock;
2403 }
2404
2405 /*
2406 * The return value is not important here. This function will output an
2407 * error if needed.
2408 */
2409 (void) release_ust_app_stream(-1, &stream);
2410 }
2411 ua_chan->is_sent = 1;
2412
2413 error_stream_unlock:
2414 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2415 error:
2416 return ret;
2417 }
2418
2419 /*
2420 * Create and send to the application the created buffers with per UID buffers.
2421 *
2422 * Return 0 on success else a negative value.
2423 */
2424 static int create_channel_per_uid(struct ust_app *app,
2425 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2426 struct ust_app_channel *ua_chan)
2427 {
2428 int ret;
2429 struct buffer_reg_uid *reg_uid;
2430 struct buffer_reg_channel *reg_chan;
2431
2432 assert(app);
2433 assert(usess);
2434 assert(ua_sess);
2435 assert(ua_chan);
2436
2437 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2438
2439 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2440 /*
2441 * The session creation handles the creation of this global registry
2442 * object. If none can be find, there is a code flow problem or a
2443 * teardown race.
2444 */
2445 assert(reg_uid);
2446
2447 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2448 reg_uid);
2449 if (!reg_chan) {
2450 /* Create the buffer registry channel object. */
2451 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2452 if (ret < 0) {
2453 ERR("Error creating the UST channel \"%s\" registry instance",
2454 ua_chan->name);
2455 goto error;
2456 }
2457 assert(reg_chan);
2458
2459 /*
2460 * Create the buffers on the consumer side. This call populates the
2461 * ust app channel object with all streams and data object.
2462 */
2463 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2464 app->bits_per_long, reg_uid->registry->reg.ust);
2465 if (ret < 0) {
2466 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2467 ua_chan->name);
2468
2469 /*
2470 * Let's remove the previously created buffer registry channel so
2471 * it's not visible anymore in the session registry.
2472 */
2473 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2474 ua_chan->tracing_channel_id);
2475 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2476 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2477 goto error;
2478 }
2479
2480 /*
2481 * Setup the streams and add it to the session registry.
2482 */
2483 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2484 if (ret < 0) {
2485 ERR("Error setting up UST channel \"%s\"",
2486 ua_chan->name);
2487 goto error;
2488 }
2489
2490 }
2491
2492 /* Send buffers to the application. */
2493 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2494 if (ret < 0) {
2495 /*
2496 * Don't report error to the console, since it may be
2497 * caused by application concurrently exiting.
2498 */
2499 goto error;
2500 }
2501
2502 error:
2503 return ret;
2504 }
2505
2506 /*
2507 * Create and send to the application the created buffers with per PID buffers.
2508 *
2509 * Return 0 on success else a negative value.
2510 */
2511 static int create_channel_per_pid(struct ust_app *app,
2512 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2513 struct ust_app_channel *ua_chan)
2514 {
2515 int ret;
2516 struct ust_registry_session *registry;
2517
2518 assert(app);
2519 assert(usess);
2520 assert(ua_sess);
2521 assert(ua_chan);
2522
2523 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2524
2525 rcu_read_lock();
2526
2527 registry = get_session_registry(ua_sess);
2528 assert(registry);
2529
2530 /* Create and add a new channel registry to session. */
2531 ret = ust_registry_channel_add(registry, ua_chan->key);
2532 if (ret < 0) {
2533 ERR("Error creating the UST channel \"%s\" registry instance",
2534 ua_chan->name);
2535 goto error;
2536 }
2537
2538 /* Create and get channel on the consumer side. */
2539 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2540 app->bits_per_long, registry);
2541 if (ret < 0) {
2542 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2543 ua_chan->name);
2544 goto error;
2545 }
2546
2547 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2548 if (ret < 0) {
2549 /*
2550 * Don't report error to the console, since it may be
2551 * caused by application concurrently exiting.
2552 */
2553 goto error;
2554 }
2555
2556 error:
2557 rcu_read_unlock();
2558 return ret;
2559 }
2560
2561 /*
2562 * From an already allocated ust app channel, create the channel buffers if
2563 * need and send it to the application. This MUST be called with a RCU read
2564 * side lock acquired.
2565 *
2566 * Return 0 on success or else a negative value.
2567 */
2568 static int do_create_channel(struct ust_app *app,
2569 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2570 struct ust_app_channel *ua_chan)
2571 {
2572 int ret;
2573
2574 assert(app);
2575 assert(usess);
2576 assert(ua_sess);
2577 assert(ua_chan);
2578
2579 /* Handle buffer type before sending the channel to the application. */
2580 switch (usess->buffer_type) {
2581 case LTTNG_BUFFER_PER_UID:
2582 {
2583 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2584 if (ret < 0) {
2585 goto error;
2586 }
2587 break;
2588 }
2589 case LTTNG_BUFFER_PER_PID:
2590 {
2591 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2592 if (ret < 0) {
2593 goto error;
2594 }
2595 break;
2596 }
2597 default:
2598 assert(0);
2599 ret = -EINVAL;
2600 goto error;
2601 }
2602
2603 /* Initialize ust objd object using the received handle and add it. */
2604 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2605 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2606
2607 /* If channel is not enabled, disable it on the tracer */
2608 if (!ua_chan->enabled) {
2609 ret = disable_ust_channel(app, ua_sess, ua_chan);
2610 if (ret < 0) {
2611 goto error;
2612 }
2613 }
2614
2615 error:
2616 return ret;
2617 }
2618
2619 /*
2620 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2621 * newly created channel if not NULL.
2622 *
2623 * Called with UST app session lock and RCU read-side lock held.
2624 *
2625 * Return 0 on success or else a negative value.
2626 */
2627 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2628 struct ltt_ust_channel *uchan, struct ust_app *app,
2629 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2630 struct ust_app_channel **ua_chanp)
2631 {
2632 int ret = 0;
2633 struct lttng_ht_iter iter;
2634 struct lttng_ht_node_str *ua_chan_node;
2635 struct ust_app_channel *ua_chan;
2636
2637 /* Lookup channel in the ust app session */
2638 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2639 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2640 if (ua_chan_node != NULL) {
2641 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2642 goto end;
2643 }
2644
2645 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2646 if (ua_chan == NULL) {
2647 /* Only malloc can fail here */
2648 ret = -ENOMEM;
2649 goto error_alloc;
2650 }
2651 shadow_copy_channel(ua_chan, uchan);
2652
2653 /* Set channel type. */
2654 ua_chan->attr.type = type;
2655
2656 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2657 if (ret < 0) {
2658 goto error;
2659 }
2660
2661 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2662 app->pid);
2663
2664 /* Only add the channel if successful on the tracer side. */
2665 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2666
2667 end:
2668 if (ua_chanp) {
2669 *ua_chanp = ua_chan;
2670 }
2671
2672 /* Everything went well. */
2673 return 0;
2674
2675 error:
2676 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2677 error_alloc:
2678 return ret;
2679 }
2680
2681 /*
2682 * Create UST app event and create it on the tracer side.
2683 *
2684 * Called with ust app session mutex held.
2685 */
2686 static
2687 int create_ust_app_event(struct ust_app_session *ua_sess,
2688 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2689 struct ust_app *app)
2690 {
2691 int ret = 0;
2692 struct ust_app_event *ua_event;
2693
2694 /* Get event node */
2695 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2696 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
2697 if (ua_event != NULL) {
2698 ret = -EEXIST;
2699 goto end;
2700 }
2701
2702 /* Does not exist so create one */
2703 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2704 if (ua_event == NULL) {
2705 /* Only malloc can failed so something is really wrong */
2706 ret = -ENOMEM;
2707 goto end;
2708 }
2709 shadow_copy_event(ua_event, uevent);
2710
2711 /* Create it on the tracer side */
2712 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2713 if (ret < 0) {
2714 /* Not found previously means that it does not exist on the tracer */
2715 assert(ret != -LTTNG_UST_ERR_EXIST);
2716 goto error;
2717 }
2718
2719 add_unique_ust_app_event(ua_chan, ua_event);
2720
2721 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2722 app->pid);
2723
2724 end:
2725 return ret;
2726
2727 error:
2728 /* Valid. Calling here is already in a read side lock */
2729 delete_ust_app_event(-1, ua_event);
2730 return ret;
2731 }
2732
2733 /*
2734 * Create UST metadata and open it on the tracer side.
2735 *
2736 * Called with UST app session lock held and RCU read side lock.
2737 */
2738 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2739 struct ust_app *app, struct consumer_output *consumer)
2740 {
2741 int ret = 0;
2742 struct ust_app_channel *metadata;
2743 struct consumer_socket *socket;
2744 struct ust_registry_session *registry;
2745
2746 assert(ua_sess);
2747 assert(app);
2748 assert(consumer);
2749
2750 registry = get_session_registry(ua_sess);
2751 assert(registry);
2752
2753 /* Metadata already exists for this registry or it was closed previously */
2754 if (registry->metadata_key || registry->metadata_closed) {
2755 ret = 0;
2756 goto error;
2757 }
2758
2759 /* Allocate UST metadata */
2760 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2761 if (!metadata) {
2762 /* malloc() failed */
2763 ret = -ENOMEM;
2764 goto error;
2765 }
2766
2767 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
2768
2769 /* Need one fd for the channel. */
2770 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2771 if (ret < 0) {
2772 ERR("Exhausted number of available FD upon create metadata");
2773 goto error;
2774 }
2775
2776 /* Get the right consumer socket for the application. */
2777 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2778 if (!socket) {
2779 ret = -EINVAL;
2780 goto error_consumer;
2781 }
2782
2783 /*
2784 * Keep metadata key so we can identify it on the consumer side. Assign it
2785 * to the registry *before* we ask the consumer so we avoid the race of the
2786 * consumer requesting the metadata and the ask_channel call on our side
2787 * did not returned yet.
2788 */
2789 registry->metadata_key = metadata->key;
2790
2791 /*
2792 * Ask the metadata channel creation to the consumer. The metadata object
2793 * will be created by the consumer and kept their. However, the stream is
2794 * never added or monitored until we do a first push metadata to the
2795 * consumer.
2796 */
2797 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2798 registry);
2799 if (ret < 0) {
2800 /* Nullify the metadata key so we don't try to close it later on. */
2801 registry->metadata_key = 0;
2802 goto error_consumer;
2803 }
2804
2805 /*
2806 * The setup command will make the metadata stream be sent to the relayd,
2807 * if applicable, and the thread managing the metadatas. This is important
2808 * because after this point, if an error occurs, the only way the stream
2809 * can be deleted is to be monitored in the consumer.
2810 */
2811 ret = consumer_setup_metadata(socket, metadata->key);
2812 if (ret < 0) {
2813 /* Nullify the metadata key so we don't try to close it later on. */
2814 registry->metadata_key = 0;
2815 goto error_consumer;
2816 }
2817
2818 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2819 metadata->key, app->pid);
2820
2821 error_consumer:
2822 lttng_fd_put(LTTNG_FD_APPS, 1);
2823 delete_ust_app_channel(-1, metadata, app);
2824 error:
2825 return ret;
2826 }
2827
2828 /*
2829 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2830 * acquired before calling this function.
2831 */
2832 struct ust_app *ust_app_find_by_pid(pid_t pid)
2833 {
2834 struct ust_app *app = NULL;
2835 struct lttng_ht_node_ulong *node;
2836 struct lttng_ht_iter iter;
2837
2838 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2839 node = lttng_ht_iter_get_node_ulong(&iter);
2840 if (node == NULL) {
2841 DBG2("UST app no found with pid %d", pid);
2842 goto error;
2843 }
2844
2845 DBG2("Found UST app by pid %d", pid);
2846
2847 app = caa_container_of(node, struct ust_app, pid_n);
2848
2849 error:
2850 return app;
2851 }
2852
2853 /*
2854 * Allocate and init an UST app object using the registration information and
2855 * the command socket. This is called when the command socket connects to the
2856 * session daemon.
2857 *
2858 * The object is returned on success or else NULL.
2859 */
2860 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2861 {
2862 struct ust_app *lta = NULL;
2863
2864 assert(msg);
2865 assert(sock >= 0);
2866
2867 DBG3("UST app creating application for socket %d", sock);
2868
2869 if ((msg->bits_per_long == 64 &&
2870 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2871 || (msg->bits_per_long == 32 &&
2872 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2873 ERR("Registration failed: application \"%s\" (pid: %d) has "
2874 "%d-bit long, but no consumerd for this size is available.\n",
2875 msg->name, msg->pid, msg->bits_per_long);
2876 goto error;
2877 }
2878
2879 lta = zmalloc(sizeof(struct ust_app));
2880 if (lta == NULL) {
2881 PERROR("malloc");
2882 goto error;
2883 }
2884
2885 lta->ppid = msg->ppid;
2886 lta->uid = msg->uid;
2887 lta->gid = msg->gid;
2888
2889 lta->bits_per_long = msg->bits_per_long;
2890 lta->uint8_t_alignment = msg->uint8_t_alignment;
2891 lta->uint16_t_alignment = msg->uint16_t_alignment;
2892 lta->uint32_t_alignment = msg->uint32_t_alignment;
2893 lta->uint64_t_alignment = msg->uint64_t_alignment;
2894 lta->long_alignment = msg->long_alignment;
2895 lta->byte_order = msg->byte_order;
2896
2897 lta->v_major = msg->major;
2898 lta->v_minor = msg->minor;
2899 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2900 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2901 lta->notify_sock = -1;
2902
2903 /* Copy name and make sure it's NULL terminated. */
2904 strncpy(lta->name, msg->name, sizeof(lta->name));
2905 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2906
2907 /*
2908 * Before this can be called, when receiving the registration information,
2909 * the application compatibility is checked. So, at this point, the
2910 * application can work with this session daemon.
2911 */
2912 lta->compatible = 1;
2913
2914 lta->pid = msg->pid;
2915 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
2916 lta->sock = sock;
2917 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
2918
2919 CDS_INIT_LIST_HEAD(&lta->teardown_head);
2920
2921 error:
2922 return lta;
2923 }
2924
2925 /*
2926 * For a given application object, add it to every hash table.
2927 */
2928 void ust_app_add(struct ust_app *app)
2929 {
2930 assert(app);
2931 assert(app->notify_sock >= 0);
2932
2933 rcu_read_lock();
2934
2935 /*
2936 * On a re-registration, we want to kick out the previous registration of
2937 * that pid
2938 */
2939 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
2940
2941 /*
2942 * The socket _should_ be unique until _we_ call close. So, a add_unique
2943 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
2944 * already in the table.
2945 */
2946 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
2947
2948 /* Add application to the notify socket hash table. */
2949 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
2950 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
2951
2952 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
2953 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
2954 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
2955 app->v_minor);
2956
2957 rcu_read_unlock();
2958 }
2959
2960 /*
2961 * Set the application version into the object.
2962 *
2963 * Return 0 on success else a negative value either an errno code or a
2964 * LTTng-UST error code.
2965 */
2966 int ust_app_version(struct ust_app *app)
2967 {
2968 int ret;
2969
2970 assert(app);
2971
2972 ret = ustctl_tracer_version(app->sock, &app->version);
2973 if (ret < 0) {
2974 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
2975 ERR("UST app %d version failed with ret %d", app->sock, ret);
2976 } else {
2977 DBG3("UST app %d version failed. Application is dead", app->sock);
2978 }
2979 }
2980
2981 return ret;
2982 }
2983
2984 /*
2985 * Unregister app by removing it from the global traceable app list and freeing
2986 * the data struct.
2987 *
2988 * The socket is already closed at this point so no close to sock.
2989 */
2990 void ust_app_unregister(int sock)
2991 {
2992 struct ust_app *lta;
2993 struct lttng_ht_node_ulong *node;
2994 struct lttng_ht_iter iter;
2995 struct ust_app_session *ua_sess;
2996 int ret;
2997
2998 rcu_read_lock();
2999
3000 /* Get the node reference for a call_rcu */
3001 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
3002 node = lttng_ht_iter_get_node_ulong(&iter);
3003 assert(node);
3004
3005 lta = caa_container_of(node, struct ust_app, sock_n);
3006 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3007
3008 /* Remove application from PID hash table */
3009 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3010 assert(!ret);
3011
3012 /*
3013 * Remove application from notify hash table. The thread handling the
3014 * notify socket could have deleted the node so ignore on error because
3015 * either way it's valid. The close of that socket is handled by the other
3016 * thread.
3017 */
3018 iter.iter.node = &lta->notify_sock_n.node;
3019 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3020
3021 /*
3022 * Ignore return value since the node might have been removed before by an
3023 * add replace during app registration because the PID can be reassigned by
3024 * the OS.
3025 */
3026 iter.iter.node = &lta->pid_n.node;
3027 ret = lttng_ht_del(ust_app_ht, &iter);
3028 if (ret) {
3029 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3030 lta->pid);
3031 }
3032
3033 /* Remove sessions so they are not visible during deletion.*/
3034 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3035 node.node) {
3036 struct ust_registry_session *registry;
3037
3038 ret = lttng_ht_del(lta->sessions, &iter);
3039 if (ret) {
3040 /* The session was already removed so scheduled for teardown. */
3041 continue;
3042 }
3043
3044 /*
3045 * Add session to list for teardown. This is safe since at this point we
3046 * are the only one using this list.
3047 */
3048 pthread_mutex_lock(&ua_sess->lock);
3049
3050 /*
3051 * Normally, this is done in the delete session process which is
3052 * executed in the call rcu below. However, upon registration we can't
3053 * afford to wait for the grace period before pushing data or else the
3054 * data pending feature can race between the unregistration and stop
3055 * command where the data pending command is sent *before* the grace
3056 * period ended.
3057 *
3058 * The close metadata below nullifies the metadata pointer in the
3059 * session so the delete session will NOT push/close a second time.
3060 */
3061 registry = get_session_registry(ua_sess);
3062 if (registry && !registry->metadata_closed) {
3063 /* Push metadata for application before freeing the application. */
3064 (void) push_metadata(registry, ua_sess->consumer);
3065
3066 /*
3067 * Don't ask to close metadata for global per UID buffers. Close
3068 * metadata only on destroy trace session in this case. Also, the
3069 * previous push metadata could have flag the metadata registry to
3070 * close so don't send a close command if closed.
3071 */
3072 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
3073 !registry->metadata_closed) {
3074 /* And ask to close it for this session registry. */
3075 (void) close_metadata(registry, ua_sess->consumer);
3076 }
3077 }
3078
3079 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3080 pthread_mutex_unlock(&ua_sess->lock);
3081 }
3082
3083 /* Free memory */
3084 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3085
3086 rcu_read_unlock();
3087 return;
3088 }
3089
3090 /*
3091 * Fill events array with all events name of all registered apps.
3092 */
3093 int ust_app_list_events(struct lttng_event **events)
3094 {
3095 int ret, handle;
3096 size_t nbmem, count = 0;
3097 struct lttng_ht_iter iter;
3098 struct ust_app *app;
3099 struct lttng_event *tmp_event;
3100
3101 nbmem = UST_APP_EVENT_LIST_SIZE;
3102 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3103 if (tmp_event == NULL) {
3104 PERROR("zmalloc ust app events");
3105 ret = -ENOMEM;
3106 goto error;
3107 }
3108
3109 rcu_read_lock();
3110
3111 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3112 struct lttng_ust_tracepoint_iter uiter;
3113
3114 health_code_update();
3115
3116 if (!app->compatible) {
3117 /*
3118 * TODO: In time, we should notice the caller of this error by
3119 * telling him that this is a version error.
3120 */
3121 continue;
3122 }
3123 handle = ustctl_tracepoint_list(app->sock);
3124 if (handle < 0) {
3125 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3126 ERR("UST app list events getting handle failed for app pid %d",
3127 app->pid);
3128 }
3129 continue;
3130 }
3131
3132 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3133 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3134 /* Handle ustctl error. */
3135 if (ret < 0) {
3136 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3137 ERR("UST app tp list get failed for app %d with ret %d",
3138 app->sock, ret);
3139 } else {
3140 DBG3("UST app tp list get failed. Application is dead");
3141 /*
3142 * This is normal behavior, an application can die during the
3143 * creation process. Don't report an error so the execution can
3144 * continue normally. Continue normal execution.
3145 */
3146 break;
3147 }
3148 free(tmp_event);
3149 goto rcu_error;
3150 }
3151
3152 health_code_update();
3153 if (count >= nbmem) {
3154 /* In case the realloc fails, we free the memory */
3155 struct lttng_event *new_tmp_event;
3156 size_t new_nbmem;
3157
3158 new_nbmem = nbmem << 1;
3159 DBG2("Reallocating event list from %zu to %zu entries",
3160 nbmem, new_nbmem);
3161 new_tmp_event = realloc(tmp_event,
3162 new_nbmem * sizeof(struct lttng_event));
3163 if (new_tmp_event == NULL) {
3164 PERROR("realloc ust app events");
3165 free(tmp_event);
3166 ret = -ENOMEM;
3167 goto rcu_error;
3168 }
3169 /* Zero the new memory */
3170 memset(new_tmp_event + nbmem, 0,
3171 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3172 nbmem = new_nbmem;
3173 tmp_event = new_tmp_event;
3174 }
3175 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3176 tmp_event[count].loglevel = uiter.loglevel;
3177 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3178 tmp_event[count].pid = app->pid;
3179 tmp_event[count].enabled = -1;
3180 count++;
3181 }
3182 }
3183
3184 ret = count;
3185 *events = tmp_event;
3186
3187 DBG2("UST app list events done (%zu events)", count);
3188
3189 rcu_error:
3190 rcu_read_unlock();
3191 error:
3192 health_code_update();
3193 return ret;
3194 }
3195
3196 /*
3197 * Fill events array with all events name of all registered apps.
3198 */
3199 int ust_app_list_event_fields(struct lttng_event_field **fields)
3200 {
3201 int ret, handle;
3202 size_t nbmem, count = 0;
3203 struct lttng_ht_iter iter;
3204 struct ust_app *app;
3205 struct lttng_event_field *tmp_event;
3206
3207 nbmem = UST_APP_EVENT_LIST_SIZE;
3208 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3209 if (tmp_event == NULL) {
3210 PERROR("zmalloc ust app event fields");
3211 ret = -ENOMEM;
3212 goto error;
3213 }
3214
3215 rcu_read_lock();
3216
3217 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3218 struct lttng_ust_field_iter uiter;
3219
3220 health_code_update();
3221
3222 if (!app->compatible) {
3223 /*
3224 * TODO: In time, we should notice the caller of this error by
3225 * telling him that this is a version error.
3226 */
3227 continue;
3228 }
3229 handle = ustctl_tracepoint_field_list(app->sock);
3230 if (handle < 0) {
3231 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3232 ERR("UST app list field getting handle failed for app pid %d",
3233 app->pid);
3234 }
3235 continue;
3236 }
3237
3238 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3239 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3240 /* Handle ustctl error. */
3241 if (ret < 0) {
3242 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3243 ERR("UST app tp list field failed for app %d with ret %d",
3244 app->sock, ret);
3245 } else {
3246 DBG3("UST app tp list field failed. Application is dead");
3247 /*
3248 * This is normal behavior, an application can die during the
3249 * creation process. Don't report an error so the execution can
3250 * continue normally. Reset list and count for next app.
3251 */
3252 break;
3253 }
3254 free(tmp_event);
3255 goto rcu_error;
3256 }
3257
3258 health_code_update();
3259 if (count >= nbmem) {
3260 /* In case the realloc fails, we free the memory */
3261 struct lttng_event_field *new_tmp_event;
3262 size_t new_nbmem;
3263
3264 new_nbmem = nbmem << 1;
3265 DBG2("Reallocating event field list from %zu to %zu entries",
3266 nbmem, new_nbmem);
3267 new_tmp_event = realloc(tmp_event,
3268 new_nbmem * sizeof(struct lttng_event_field));
3269 if (new_tmp_event == NULL) {
3270 PERROR("realloc ust app event fields");
3271 free(tmp_event);
3272 ret = -ENOMEM;
3273 goto rcu_error;
3274 }
3275 /* Zero the new memory */
3276 memset(new_tmp_event + nbmem, 0,
3277 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3278 nbmem = new_nbmem;
3279 tmp_event = new_tmp_event;
3280 }
3281
3282 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3283 /* Mapping between these enums matches 1 to 1. */
3284 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3285 tmp_event[count].nowrite = uiter.nowrite;
3286
3287 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3288 tmp_event[count].event.loglevel = uiter.loglevel;
3289 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3290 tmp_event[count].event.pid = app->pid;
3291 tmp_event[count].event.enabled = -1;
3292 count++;
3293 }
3294 }
3295
3296 ret = count;
3297 *fields = tmp_event;
3298
3299 DBG2("UST app list event fields done (%zu events)", count);
3300
3301 rcu_error:
3302 rcu_read_unlock();
3303 error:
3304 health_code_update();
3305 return ret;
3306 }
3307
3308 /*
3309 * Free and clean all traceable apps of the global list.
3310 *
3311 * Should _NOT_ be called with RCU read-side lock held.
3312 */
3313 void ust_app_clean_list(void)
3314 {
3315 int ret;
3316 struct ust_app *app;
3317 struct lttng_ht_iter iter;
3318
3319 DBG2("UST app cleaning registered apps hash table");
3320
3321 rcu_read_lock();
3322
3323 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3324 ret = lttng_ht_del(ust_app_ht, &iter);
3325 assert(!ret);
3326 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3327 }
3328
3329 /* Cleanup socket hash table */
3330 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3331 sock_n.node) {
3332 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3333 assert(!ret);
3334 }
3335
3336 /* Cleanup notify socket hash table */
3337 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3338 notify_sock_n.node) {
3339 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3340 assert(!ret);
3341 }
3342 rcu_read_unlock();
3343
3344 /* Destroy is done only when the ht is empty */
3345 ht_cleanup_push(ust_app_ht);
3346 ht_cleanup_push(ust_app_ht_by_sock);
3347 ht_cleanup_push(ust_app_ht_by_notify_sock);
3348 }
3349
3350 /*
3351 * Init UST app hash table.
3352 */
3353 void ust_app_ht_alloc(void)
3354 {
3355 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3356 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3357 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3358 }
3359
3360 /*
3361 * For a specific UST session, disable the channel for all registered apps.
3362 */
3363 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3364 struct ltt_ust_channel *uchan)
3365 {
3366 int ret = 0;
3367 struct lttng_ht_iter iter;
3368 struct lttng_ht_node_str *ua_chan_node;
3369 struct ust_app *app;
3370 struct ust_app_session *ua_sess;
3371 struct ust_app_channel *ua_chan;
3372
3373 if (usess == NULL || uchan == NULL) {
3374 ERR("Disabling UST global channel with NULL values");
3375 ret = -1;
3376 goto error;
3377 }
3378
3379 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3380 uchan->name, usess->id);
3381
3382 rcu_read_lock();
3383
3384 /* For every registered applications */
3385 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3386 struct lttng_ht_iter uiter;
3387 if (!app->compatible) {
3388 /*
3389 * TODO: In time, we should notice the caller of this error by
3390 * telling him that this is a version error.
3391 */
3392 continue;
3393 }
3394 ua_sess = lookup_session_by_app(usess, app);
3395 if (ua_sess == NULL) {
3396 continue;
3397 }
3398
3399 /* Get channel */
3400 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3401 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3402 /* If the session if found for the app, the channel must be there */
3403 assert(ua_chan_node);
3404
3405 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3406 /* The channel must not be already disabled */
3407 assert(ua_chan->enabled == 1);
3408
3409 /* Disable channel onto application */
3410 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3411 if (ret < 0) {
3412 /* XXX: We might want to report this error at some point... */
3413 continue;
3414 }
3415 }
3416
3417 rcu_read_unlock();
3418
3419 error:
3420 return ret;
3421 }
3422
3423 /*
3424 * For a specific UST session, enable the channel for all registered apps.
3425 */
3426 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3427 struct ltt_ust_channel *uchan)
3428 {
3429 int ret = 0;
3430 struct lttng_ht_iter iter;
3431 struct ust_app *app;
3432 struct ust_app_session *ua_sess;
3433
3434 if (usess == NULL || uchan == NULL) {
3435 ERR("Adding UST global channel to NULL values");
3436 ret = -1;
3437 goto error;
3438 }
3439
3440 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3441 uchan->name, usess->id);
3442
3443 rcu_read_lock();
3444
3445 /* For every registered applications */
3446 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3447 if (!app->compatible) {
3448 /*
3449 * TODO: In time, we should notice the caller of this error by
3450 * telling him that this is a version error.
3451 */
3452 continue;
3453 }
3454 ua_sess = lookup_session_by_app(usess, app);
3455 if (ua_sess == NULL) {
3456 continue;
3457 }
3458
3459 /* Enable channel onto application */
3460 ret = enable_ust_app_channel(ua_sess, uchan, app);
3461 if (ret < 0) {
3462 /* XXX: We might want to report this error at some point... */
3463 continue;
3464 }
3465 }
3466
3467 rcu_read_unlock();
3468
3469 error:
3470 return ret;
3471 }
3472
3473 /*
3474 * Disable an event in a channel and for a specific session.
3475 */
3476 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3477 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3478 {
3479 int ret = 0;
3480 struct lttng_ht_iter iter, uiter;
3481 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
3482 struct ust_app *app;
3483 struct ust_app_session *ua_sess;
3484 struct ust_app_channel *ua_chan;
3485 struct ust_app_event *ua_event;
3486
3487 DBG("UST app disabling event %s for all apps in channel "
3488 "%s for session id %" PRIu64,
3489 uevent->attr.name, uchan->name, usess->id);
3490
3491 rcu_read_lock();
3492
3493 /* For all registered applications */
3494 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3495 if (!app->compatible) {
3496 /*
3497 * TODO: In time, we should notice the caller of this error by
3498 * telling him that this is a version error.
3499 */
3500 continue;
3501 }
3502 ua_sess = lookup_session_by_app(usess, app);
3503 if (ua_sess == NULL) {
3504 /* Next app */
3505 continue;
3506 }
3507
3508 /* Lookup channel in the ust app session */
3509 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3510 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3511 if (ua_chan_node == NULL) {
3512 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3513 "Skipping", uchan->name, usess->id, app->pid);
3514 continue;
3515 }
3516 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3517
3518 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
3519 ua_event_node = lttng_ht_iter_get_node_str(&uiter);
3520 if (ua_event_node == NULL) {
3521 DBG2("Event %s not found in channel %s for app pid %d."
3522 "Skipping", uevent->attr.name, uchan->name, app->pid);
3523 continue;
3524 }
3525 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
3526
3527 ret = disable_ust_app_event(ua_sess, ua_event, app);
3528 if (ret < 0) {
3529 /* XXX: Report error someday... */
3530 continue;
3531 }
3532 }
3533
3534 rcu_read_unlock();
3535
3536 return ret;
3537 }
3538
3539 /*
3540 * For a specific UST session, create the channel for all registered apps.
3541 */
3542 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3543 struct ltt_ust_channel *uchan)
3544 {
3545 int ret = 0, created;
3546 struct lttng_ht_iter iter;
3547 struct ust_app *app;
3548 struct ust_app_session *ua_sess = NULL;
3549
3550 /* Very wrong code flow */
3551 assert(usess);
3552 assert(uchan);
3553
3554 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3555 uchan->name, usess->id);
3556
3557 rcu_read_lock();
3558
3559 /* For every registered applications */
3560 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3561 if (!app->compatible) {
3562 /*
3563 * TODO: In time, we should notice the caller of this error by
3564 * telling him that this is a version error.
3565 */
3566 continue;
3567 }
3568 /*
3569 * Create session on the tracer side and add it to app session HT. Note
3570 * that if session exist, it will simply return a pointer to the ust
3571 * app session.
3572 */
3573 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3574 if (ret < 0) {
3575 switch (ret) {
3576 case -ENOTCONN:
3577 /*
3578 * The application's socket is not valid. Either a bad socket
3579 * or a timeout on it. We can't inform the caller that for a
3580 * specific app, the session failed so lets continue here.
3581 */
3582 continue;
3583 case -ENOMEM:
3584 default:
3585 goto error_rcu_unlock;
3586 }
3587 }
3588 assert(ua_sess);
3589
3590 pthread_mutex_lock(&ua_sess->lock);
3591 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
3592 sizeof(uchan->name))) {
3593 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
3594 ret = 0;
3595 } else {
3596 /* Create channel onto application. We don't need the chan ref. */
3597 ret = create_ust_app_channel(ua_sess, uchan, app,
3598 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
3599 }
3600 pthread_mutex_unlock(&ua_sess->lock);
3601 if (ret < 0) {
3602 if (ret == -ENOMEM) {
3603 /* No more memory is a fatal error. Stop right now. */
3604 goto error_rcu_unlock;
3605 }
3606 /* Cleanup the created session if it's the case. */
3607 if (created) {
3608 destroy_app_session(app, ua_sess);
3609 }
3610 }
3611 }
3612
3613 error_rcu_unlock:
3614 rcu_read_unlock();
3615 return ret;
3616 }
3617
3618 /*
3619 * Enable event for a specific session and channel on the tracer.
3620 */
3621 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
3622 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3623 {
3624 int ret = 0;
3625 struct lttng_ht_iter iter, uiter;
3626 struct lttng_ht_node_str *ua_chan_node;
3627 struct ust_app *app;
3628 struct ust_app_session *ua_sess;
3629 struct ust_app_channel *ua_chan;
3630 struct ust_app_event *ua_event;
3631
3632 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
3633 uevent->attr.name, usess->id);
3634
3635 /*
3636 * NOTE: At this point, this function is called only if the session and
3637 * channel passed are already created for all apps. and enabled on the
3638 * tracer also.
3639 */
3640
3641 rcu_read_lock();
3642
3643 /* For all registered applications */
3644 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3645 if (!app->compatible) {
3646 /*
3647 * TODO: In time, we should notice the caller of this error by
3648 * telling him that this is a version error.
3649 */
3650 continue;
3651 }
3652 ua_sess = lookup_session_by_app(usess, app);
3653 if (!ua_sess) {
3654 /* The application has problem or is probably dead. */
3655 continue;
3656 }
3657
3658 pthread_mutex_lock(&ua_sess->lock);
3659
3660 /* Lookup channel in the ust app session */
3661 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3662 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3663 /* If the channel is not found, there is a code flow error */
3664 assert(ua_chan_node);
3665
3666 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3667
3668 /* Get event node */
3669 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3670 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3671 if (ua_event == NULL) {
3672 DBG3("UST app enable event %s not found for app PID %d."
3673 "Skipping app", uevent->attr.name, app->pid);
3674 goto next_app;
3675 }
3676
3677 ret = enable_ust_app_event(ua_sess, ua_event, app);
3678 if (ret < 0) {
3679 pthread_mutex_unlock(&ua_sess->lock);
3680 goto error;
3681 }
3682 next_app:
3683 pthread_mutex_unlock(&ua_sess->lock);
3684 }
3685
3686 error:
3687 rcu_read_unlock();
3688 return ret;
3689 }
3690
3691 /*
3692 * For a specific existing UST session and UST channel, creates the event for
3693 * all registered apps.
3694 */
3695 int ust_app_create_event_glb(struct ltt_ust_session *usess,
3696 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3697 {
3698 int ret = 0;
3699 struct lttng_ht_iter iter, uiter;
3700 struct lttng_ht_node_str *ua_chan_node;
3701 struct ust_app *app;
3702 struct ust_app_session *ua_sess;
3703 struct ust_app_channel *ua_chan;
3704
3705 DBG("UST app creating event %s for all apps for session id %" PRIu64,
3706 uevent->attr.name, usess->id);
3707
3708 rcu_read_lock();
3709
3710 /* For all registered applications */
3711 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3712 if (!app->compatible) {
3713 /*
3714 * TODO: In time, we should notice the caller of this error by
3715 * telling him that this is a version error.
3716 */
3717 continue;
3718 }
3719 ua_sess = lookup_session_by_app(usess, app);
3720 if (!ua_sess) {
3721 /* The application has problem or is probably dead. */
3722 continue;
3723 }
3724
3725 pthread_mutex_lock(&ua_sess->lock);
3726 /* Lookup channel in the ust app session */
3727 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3728 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3729 /* If the channel is not found, there is a code flow error */
3730 assert(ua_chan_node);
3731
3732 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3733
3734 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
3735 pthread_mutex_unlock(&ua_sess->lock);
3736 if (ret < 0) {
3737 if (ret != -LTTNG_UST_ERR_EXIST) {
3738 /* Possible value at this point: -ENOMEM. If so, we stop! */
3739 break;
3740 }
3741 DBG2("UST app event %s already exist on app PID %d",
3742 uevent->attr.name, app->pid);
3743 continue;
3744 }
3745 }
3746
3747 rcu_read_unlock();
3748
3749 return ret;
3750 }
3751
3752 /*
3753 * Start tracing for a specific UST session and app.
3754 */
3755 static
3756 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
3757 {
3758 int ret = 0;
3759 struct ust_app_session *ua_sess;
3760
3761 DBG("Starting tracing for ust app pid %d", app->pid);
3762
3763 rcu_read_lock();
3764
3765 if (!app->compatible) {
3766 goto end;
3767 }
3768
3769 ua_sess = lookup_session_by_app(usess, app);
3770 if (ua_sess == NULL) {
3771 /* The session is in teardown process. Ignore and continue. */
3772 goto end;
3773 }
3774
3775 pthread_mutex_lock(&ua_sess->lock);
3776
3777 /* Upon restart, we skip the setup, already done */
3778 if (ua_sess->started) {
3779 goto skip_setup;
3780 }
3781
3782 /* Create directories if consumer is LOCAL and has a path defined. */
3783 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
3784 strlen(usess->consumer->dst.trace_path) > 0) {
3785 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
3786 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
3787 if (ret < 0) {
3788 if (ret != -EEXIST) {
3789 ERR("Trace directory creation error");
3790 goto error_unlock;
3791 }
3792 }
3793 }
3794
3795 /*
3796 * Create the metadata for the application. This returns gracefully if a
3797 * metadata was already set for the session.
3798 */
3799 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
3800 if (ret < 0) {
3801 goto error_unlock;
3802 }
3803
3804 health_code_update();
3805
3806 skip_setup:
3807 /* This start the UST tracing */
3808 ret = ustctl_start_session(app->sock, ua_sess->handle);
3809 if (ret < 0) {
3810 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3811 ERR("Error starting tracing for app pid: %d (ret: %d)",
3812 app->pid, ret);
3813 } else {
3814 DBG("UST app start session failed. Application is dead.");
3815 /*
3816 * This is normal behavior, an application can die during the
3817 * creation process. Don't report an error so the execution can
3818 * continue normally.
3819 */
3820 pthread_mutex_unlock(&ua_sess->lock);
3821 goto end;
3822 }
3823 goto error_unlock;
3824 }
3825
3826 /* Indicate that the session has been started once */
3827 ua_sess->started = 1;
3828
3829 pthread_mutex_unlock(&ua_sess->lock);
3830
3831 health_code_update();
3832
3833 /* Quiescent wait after starting trace */
3834 ret = ustctl_wait_quiescent(app->sock);
3835 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3836 ERR("UST app wait quiescent failed for app pid %d ret %d",
3837 app->pid, ret);
3838 }
3839
3840 end:
3841 rcu_read_unlock();
3842 health_code_update();
3843 return 0;
3844
3845 error_unlock:
3846 pthread_mutex_unlock(&ua_sess->lock);
3847 rcu_read_unlock();
3848 health_code_update();
3849 return -1;
3850 }
3851
3852 /*
3853 * Stop tracing for a specific UST session and app.
3854 */
3855 static
3856 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
3857 {
3858 int ret = 0;
3859 struct ust_app_session *ua_sess;
3860 struct ust_registry_session *registry;
3861
3862 DBG("Stopping tracing for ust app pid %d", app->pid);
3863
3864 rcu_read_lock();
3865
3866 if (!app->compatible) {
3867 goto end_no_session;
3868 }
3869
3870 ua_sess = lookup_session_by_app(usess, app);
3871 if (ua_sess == NULL) {
3872 goto end_no_session;
3873 }
3874
3875 pthread_mutex_lock(&ua_sess->lock);
3876
3877 /*
3878 * If started = 0, it means that stop trace has been called for a session
3879 * that was never started. It's possible since we can have a fail start
3880 * from either the application manager thread or the command thread. Simply
3881 * indicate that this is a stop error.
3882 */
3883 if (!ua_sess->started) {
3884 goto error_rcu_unlock;
3885 }
3886
3887 health_code_update();
3888
3889 /* This inhibits UST tracing */
3890 ret = ustctl_stop_session(app->sock, ua_sess->handle);
3891 if (ret < 0) {
3892 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3893 ERR("Error stopping tracing for app pid: %d (ret: %d)",
3894 app->pid, ret);
3895 } else {
3896 DBG("UST app stop session failed. Application is dead.");
3897 /*
3898 * This is normal behavior, an application can die during the
3899 * creation process. Don't report an error so the execution can
3900 * continue normally.
3901 */
3902 goto end_unlock;
3903 }
3904 goto error_rcu_unlock;
3905 }
3906
3907 health_code_update();
3908
3909 /* Quiescent wait after stopping trace */
3910 ret = ustctl_wait_quiescent(app->sock);
3911 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3912 ERR("UST app wait quiescent failed for app pid %d ret %d",
3913 app->pid, ret);
3914 }
3915
3916 health_code_update();
3917
3918 registry = get_session_registry(ua_sess);
3919 assert(registry);
3920
3921 if (!registry->metadata_closed) {
3922 /* Push metadata for application before freeing the application. */
3923 (void) push_metadata(registry, ua_sess->consumer);
3924 }
3925
3926 end_unlock:
3927 pthread_mutex_unlock(&ua_sess->lock);
3928 end_no_session:
3929 rcu_read_unlock();
3930 health_code_update();
3931 return 0;
3932
3933 error_rcu_unlock:
3934 pthread_mutex_unlock(&ua_sess->lock);
3935 rcu_read_unlock();
3936 health_code_update();
3937 return -1;
3938 }
3939
3940 /*
3941 * Flush buffers for a specific UST session and app.
3942 */
3943 static
3944 int ust_app_flush_trace(struct ltt_ust_session *usess, struct ust_app *app)
3945 {
3946 int ret = 0;
3947 struct lttng_ht_iter iter;
3948 struct ust_app_session *ua_sess;
3949 struct ust_app_channel *ua_chan;
3950
3951 DBG("Flushing buffers for ust app pid %d", app->pid);
3952
3953 rcu_read_lock();
3954
3955 if (!app->compatible) {
3956 goto end_no_session;
3957 }
3958
3959 ua_sess = lookup_session_by_app(usess, app);
3960 if (ua_sess == NULL) {
3961 goto end_no_session;
3962 }
3963
3964 pthread_mutex_lock(&ua_sess->lock);
3965
3966 health_code_update();
3967
3968 /* Flushing buffers */
3969 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
3970 node.node) {
3971 health_code_update();
3972 assert(ua_chan->is_sent);
3973 ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
3974 if (ret < 0) {
3975 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3976 ERR("UST app PID %d channel %s flush failed with ret %d",
3977 app->pid, ua_chan->name, ret);
3978 } else {
3979 DBG3("UST app failed to flush %s. Application is dead.",
3980 ua_chan->name);
3981 /*
3982 * This is normal behavior, an application can die during the
3983 * creation process. Don't report an error so the execution can
3984 * continue normally.
3985 */
3986 }
3987 /* Continuing flushing all buffers */
3988 continue;
3989 }
3990 }
3991
3992 health_code_update();
3993
3994 pthread_mutex_unlock(&ua_sess->lock);
3995 end_no_session:
3996 rcu_read_unlock();
3997 health_code_update();
3998 return 0;
3999 }
4000
4001 /*
4002 * Destroy a specific UST session in apps.
4003 */
4004 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4005 {
4006 int ret;
4007 struct ust_app_session *ua_sess;
4008 struct lttng_ht_iter iter;
4009 struct lttng_ht_node_u64 *node;
4010
4011 DBG("Destroy tracing for ust app pid %d", app->pid);
4012
4013 rcu_read_lock();
4014
4015 if (!app->compatible) {
4016 goto end;
4017 }
4018
4019 __lookup_session_by_app(usess, app, &iter);
4020 node = lttng_ht_iter_get_node_u64(&iter);
4021 if (node == NULL) {
4022 /* Session is being or is deleted. */
4023 goto end;
4024 }
4025 ua_sess = caa_container_of(node, struct ust_app_session, node);
4026
4027 health_code_update();
4028 destroy_app_session(app, ua_sess);
4029
4030 health_code_update();
4031
4032 /* Quiescent wait after stopping trace */
4033 ret = ustctl_wait_quiescent(app->sock);
4034 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4035 ERR("UST app wait quiescent failed for app pid %d ret %d",
4036 app->pid, ret);
4037 }
4038 end:
4039 rcu_read_unlock();
4040 health_code_update();
4041 return 0;
4042 }
4043
4044 /*
4045 * Start tracing for the UST session.
4046 */
4047 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4048 {
4049 int ret = 0;
4050 struct lttng_ht_iter iter;
4051 struct ust_app *app;
4052
4053 DBG("Starting all UST traces");
4054
4055 rcu_read_lock();
4056
4057 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4058 ret = ust_app_start_trace(usess, app);
4059 if (ret < 0) {
4060 /* Continue to next apps even on error */
4061 continue;
4062 }
4063 }
4064
4065 rcu_read_unlock();
4066
4067 return 0;
4068 }
4069
4070 /*
4071 * Start tracing for the UST session.
4072 */
4073 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4074 {
4075 int ret = 0;
4076 struct lttng_ht_iter iter;
4077 struct ust_app *app;
4078
4079 DBG("Stopping all UST traces");
4080
4081 rcu_read_lock();
4082
4083 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4084 ret = ust_app_stop_trace(usess, app);
4085 if (ret < 0) {
4086 /* Continue to next apps even on error */
4087 continue;
4088 }
4089 }
4090
4091 /* Flush buffers and push metadata (for UID buffers). */
4092 switch (usess->buffer_type) {
4093 case LTTNG_BUFFER_PER_UID:
4094 {
4095 struct buffer_reg_uid *reg;
4096
4097 /* Flush all per UID buffers associated to that session. */
4098 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4099 struct ust_registry_session *ust_session_reg;
4100 struct buffer_reg_channel *reg_chan;
4101 struct consumer_socket *socket;
4102
4103 /* Get consumer socket to use to push the metadata.*/
4104 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4105 usess->consumer);
4106 if (!socket) {
4107 /* Ignore request if no consumer is found for the session. */
4108 continue;
4109 }
4110
4111 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4112 reg_chan, node.node) {
4113 /*
4114 * The following call will print error values so the return
4115 * code is of little importance because whatever happens, we
4116 * have to try them all.
4117 */
4118 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4119 }
4120
4121 ust_session_reg = reg->registry->reg.ust;
4122 if (!ust_session_reg->metadata_closed) {
4123 /* Push metadata. */
4124 (void) push_metadata(ust_session_reg, usess->consumer);
4125 }
4126 }
4127
4128 break;
4129 }
4130 case LTTNG_BUFFER_PER_PID:
4131 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4132 ret = ust_app_flush_trace(usess, app);
4133 if (ret < 0) {
4134 /* Continue to next apps even on error */
4135 continue;
4136 }
4137 }
4138 break;
4139 default:
4140 assert(0);
4141 break;
4142 }
4143
4144 rcu_read_unlock();
4145
4146 return 0;
4147 }
4148
4149 /*
4150 * Destroy app UST session.
4151 */
4152 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4153 {
4154 int ret = 0;
4155 struct lttng_ht_iter iter;
4156 struct ust_app *app;
4157
4158 DBG("Destroy all UST traces");
4159
4160 rcu_read_lock();
4161
4162 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4163 ret = destroy_trace(usess, app);
4164 if (ret < 0) {
4165 /* Continue to next apps even on error */
4166 continue;
4167 }
4168 }
4169
4170 rcu_read_unlock();
4171
4172 return 0;
4173 }
4174
4175 /*
4176 * Add channels/events from UST global domain to registered apps at sock.
4177 */
4178 void ust_app_global_update(struct ltt_ust_session *usess, int sock)
4179 {
4180 int ret = 0;
4181 struct lttng_ht_iter iter, uiter;
4182 struct ust_app *app;
4183 struct ust_app_session *ua_sess = NULL;
4184 struct ust_app_channel *ua_chan;
4185 struct ust_app_event *ua_event;
4186 struct ust_app_ctx *ua_ctx;
4187
4188 assert(usess);
4189 assert(sock >= 0);
4190
4191 DBG2("UST app global update for app sock %d for session id %" PRIu64, sock,
4192 usess->id);
4193
4194 rcu_read_lock();
4195
4196 app = ust_app_find_by_sock(sock);
4197 if (app == NULL) {
4198 /*
4199 * Application can be unregistered before so this is possible hence
4200 * simply stopping the update.
4201 */
4202 DBG3("UST app update failed to find app sock %d", sock);
4203 goto error;
4204 }
4205
4206 if (!app->compatible) {
4207 goto error;
4208 }
4209
4210 ret = create_ust_app_session(usess, app, &ua_sess, NULL);
4211 if (ret < 0) {
4212 /* Tracer is probably gone or ENOMEM. */
4213 goto error;
4214 }
4215 assert(ua_sess);
4216
4217 pthread_mutex_lock(&ua_sess->lock);
4218
4219 /*
4220 * We can iterate safely here over all UST app session since the create ust
4221 * app session above made a shadow copy of the UST global domain from the
4222 * ltt ust session.
4223 */
4224 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4225 node.node) {
4226 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4227 if (ret < 0) {
4228 /*
4229 * Stop everything. On error, the application failed, no more
4230 * file descriptor are available or ENOMEM so stopping here is
4231 * the only thing we can do for now.
4232 */
4233 goto error_unlock;
4234 }
4235
4236 /*
4237 * Add context using the list so they are enabled in the same order the
4238 * user added them.
4239 */
4240 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4241 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4242 if (ret < 0) {
4243 goto error_unlock;
4244 }
4245 }
4246
4247
4248 /* For each events */
4249 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4250 node.node) {
4251 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4252 if (ret < 0) {
4253 goto error_unlock;
4254 }
4255 }
4256 }
4257
4258 pthread_mutex_unlock(&ua_sess->lock);
4259
4260 if (usess->active) {
4261 ret = ust_app_start_trace(usess, app);
4262 if (ret < 0) {
4263 goto error;
4264 }
4265
4266 DBG2("UST trace started for app pid %d", app->pid);
4267 }
4268
4269 /* Everything went well at this point. */
4270 rcu_read_unlock();
4271 return;
4272
4273 error_unlock:
4274 pthread_mutex_unlock(&ua_sess->lock);
4275 error:
4276 if (ua_sess) {
4277 destroy_app_session(app, ua_sess);
4278 }
4279 rcu_read_unlock();
4280 return;
4281 }
4282
4283 /*
4284 * Add context to a specific channel for global UST domain.
4285 */
4286 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4287 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4288 {
4289 int ret = 0;
4290 struct lttng_ht_node_str *ua_chan_node;
4291 struct lttng_ht_iter iter, uiter;
4292 struct ust_app_channel *ua_chan = NULL;
4293 struct ust_app_session *ua_sess;
4294 struct ust_app *app;
4295
4296 rcu_read_lock();
4297
4298 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4299 if (!app->compatible) {
4300 /*
4301 * TODO: In time, we should notice the caller of this error by
4302 * telling him that this is a version error.
4303 */
4304 continue;
4305 }
4306 ua_sess = lookup_session_by_app(usess, app);
4307 if (ua_sess == NULL) {
4308 continue;
4309 }
4310
4311 pthread_mutex_lock(&ua_sess->lock);
4312 /* Lookup channel in the ust app session */
4313 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4314 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4315 if (ua_chan_node == NULL) {
4316 goto next_app;
4317 }
4318 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4319 node);
4320 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4321 if (ret < 0) {
4322 goto next_app;
4323 }
4324 next_app:
4325 pthread_mutex_unlock(&ua_sess->lock);
4326 }
4327
4328 rcu_read_unlock();
4329 return ret;
4330 }
4331
4332 /*
4333 * Enable event for a channel from a UST session for a specific PID.
4334 */
4335 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4336 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4337 {
4338 int ret = 0;
4339 struct lttng_ht_iter iter;
4340 struct lttng_ht_node_str *ua_chan_node;
4341 struct ust_app *app;
4342 struct ust_app_session *ua_sess;
4343 struct ust_app_channel *ua_chan;
4344 struct ust_app_event *ua_event;
4345
4346 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4347
4348 rcu_read_lock();
4349
4350 app = ust_app_find_by_pid(pid);
4351 if (app == NULL) {
4352 ERR("UST app enable event per PID %d not found", pid);
4353 ret = -1;
4354 goto end;
4355 }
4356
4357 if (!app->compatible) {
4358 ret = 0;
4359 goto end;
4360 }
4361
4362 ua_sess = lookup_session_by_app(usess, app);
4363 if (!ua_sess) {
4364 /* The application has problem or is probably dead. */
4365 ret = 0;
4366 goto end;
4367 }
4368
4369 pthread_mutex_lock(&ua_sess->lock);
4370 /* Lookup channel in the ust app session */
4371 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4372 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4373 /* If the channel is not found, there is a code flow error */
4374 assert(ua_chan_node);
4375
4376 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4377
4378 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4379 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4380 if (ua_event == NULL) {
4381 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4382 if (ret < 0) {
4383 goto end_unlock;
4384 }
4385 } else {
4386 ret = enable_ust_app_event(ua_sess, ua_event, app);
4387 if (ret < 0) {
4388 goto end_unlock;
4389 }
4390 }
4391
4392 end_unlock:
4393 pthread_mutex_unlock(&ua_sess->lock);
4394 end:
4395 rcu_read_unlock();
4396 return ret;
4397 }
4398
4399 /*
4400 * Calibrate registered applications.
4401 */
4402 int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4403 {
4404 int ret = 0;
4405 struct lttng_ht_iter iter;
4406 struct ust_app *app;
4407
4408 rcu_read_lock();
4409
4410 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4411 if (!app->compatible) {
4412 /*
4413 * TODO: In time, we should notice the caller of this error by
4414 * telling him that this is a version error.
4415 */
4416 continue;
4417 }
4418
4419 health_code_update();
4420
4421 ret = ustctl_calibrate(app->sock, calibrate);
4422 if (ret < 0) {
4423 switch (ret) {
4424 case -ENOSYS:
4425 /* Means that it's not implemented on the tracer side. */
4426 ret = 0;
4427 break;
4428 default:
4429 DBG2("Calibrate app PID %d returned with error %d",
4430 app->pid, ret);
4431 break;
4432 }
4433 }
4434 }
4435
4436 DBG("UST app global domain calibration finished");
4437
4438 rcu_read_unlock();
4439
4440 health_code_update();
4441
4442 return ret;
4443 }
4444
4445 /*
4446 * Receive registration and populate the given msg structure.
4447 *
4448 * On success return 0 else a negative value returned by the ustctl call.
4449 */
4450 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4451 {
4452 int ret;
4453 uint32_t pid, ppid, uid, gid;
4454
4455 assert(msg);
4456
4457 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4458 &pid, &ppid, &uid, &gid,
4459 &msg->bits_per_long,
4460 &msg->uint8_t_alignment,
4461 &msg->uint16_t_alignment,
4462 &msg->uint32_t_alignment,
4463 &msg->uint64_t_alignment,
4464 &msg->long_alignment,
4465 &msg->byte_order,
4466 msg->name);
4467 if (ret < 0) {
4468 switch (-ret) {
4469 case EPIPE:
4470 case ECONNRESET:
4471 case LTTNG_UST_ERR_EXITING:
4472 DBG3("UST app recv reg message failed. Application died");
4473 break;
4474 case LTTNG_UST_ERR_UNSUP_MAJOR:
4475 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4476 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
4477 LTTNG_UST_ABI_MINOR_VERSION);
4478 break;
4479 default:
4480 ERR("UST app recv reg message failed with ret %d", ret);
4481 break;
4482 }
4483 goto error;
4484 }
4485 msg->pid = (pid_t) pid;
4486 msg->ppid = (pid_t) ppid;
4487 msg->uid = (uid_t) uid;
4488 msg->gid = (gid_t) gid;
4489
4490 error:
4491 return ret;
4492 }
4493
4494 /*
4495 * Return a ust app channel object using the application object and the channel
4496 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4497 * lock MUST be acquired before calling this function.
4498 */
4499 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
4500 int objd)
4501 {
4502 struct lttng_ht_node_ulong *node;
4503 struct lttng_ht_iter iter;
4504 struct ust_app_channel *ua_chan = NULL;
4505
4506 assert(app);
4507
4508 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
4509 node = lttng_ht_iter_get_node_ulong(&iter);
4510 if (node == NULL) {
4511 DBG2("UST app channel find by objd %d not found", objd);
4512 goto error;
4513 }
4514
4515 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
4516
4517 error:
4518 return ua_chan;
4519 }
4520
4521 /*
4522 * Reply to a register channel notification from an application on the notify
4523 * socket. The channel metadata is also created.
4524 *
4525 * The session UST registry lock is acquired in this function.
4526 *
4527 * On success 0 is returned else a negative value.
4528 */
4529 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
4530 size_t nr_fields, struct ustctl_field *fields)
4531 {
4532 int ret, ret_code = 0;
4533 uint32_t chan_id, reg_count;
4534 uint64_t chan_reg_key;
4535 enum ustctl_channel_header type;
4536 struct ust_app *app;
4537 struct ust_app_channel *ua_chan;
4538 struct ust_app_session *ua_sess;
4539 struct ust_registry_session *registry;
4540 struct ust_registry_channel *chan_reg;
4541
4542 rcu_read_lock();
4543
4544 /* Lookup application. If not found, there is a code flow error. */
4545 app = find_app_by_notify_sock(sock);
4546 if (!app) {
4547 DBG("Application socket %d is being teardown. Abort event notify",
4548 sock);
4549 ret = 0;
4550 free(fields);
4551 goto error_rcu_unlock;
4552 }
4553
4554 /* Lookup channel by UST object descriptor. */
4555 ua_chan = find_channel_by_objd(app, cobjd);
4556 if (!ua_chan) {
4557 DBG("Application channel is being teardown. Abort event notify");
4558 ret = 0;
4559 free(fields);
4560 goto error_rcu_unlock;
4561 }
4562
4563 assert(ua_chan->session);
4564 ua_sess = ua_chan->session;
4565
4566 /* Get right session registry depending on the session buffer type. */
4567 registry = get_session_registry(ua_sess);
4568 assert(registry);
4569
4570 /* Depending on the buffer type, a different channel key is used. */
4571 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4572 chan_reg_key = ua_chan->tracing_channel_id;
4573 } else {
4574 chan_reg_key = ua_chan->key;
4575 }
4576
4577 pthread_mutex_lock(&registry->lock);
4578
4579 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
4580 assert(chan_reg);
4581
4582 if (!chan_reg->register_done) {
4583 reg_count = ust_registry_get_event_count(chan_reg);
4584 if (reg_count < 31) {
4585 type = USTCTL_CHANNEL_HEADER_COMPACT;
4586 } else {
4587 type = USTCTL_CHANNEL_HEADER_LARGE;
4588 }
4589
4590 chan_reg->nr_ctx_fields = nr_fields;
4591 chan_reg->ctx_fields = fields;
4592 chan_reg->header_type = type;
4593 } else {
4594 /* Get current already assigned values. */
4595 type = chan_reg->header_type;
4596 free(fields);
4597 /* Set to NULL so the error path does not do a double free. */
4598 fields = NULL;
4599 }
4600 /* Channel id is set during the object creation. */
4601 chan_id = chan_reg->chan_id;
4602
4603 /* Append to metadata */
4604 if (!chan_reg->metadata_dumped) {
4605 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
4606 if (ret_code) {
4607 ERR("Error appending channel metadata (errno = %d)", ret_code);
4608 goto reply;
4609 }
4610 }
4611
4612 reply:
4613 DBG3("UST app replying to register channel key %" PRIu64
4614 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
4615 ret_code);
4616
4617 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
4618 if (ret < 0) {
4619 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4620 ERR("UST app reply channel failed with ret %d", ret);
4621 } else {
4622 DBG3("UST app reply channel failed. Application died");
4623 }
4624 goto error;
4625 }
4626
4627 /* This channel registry registration is completed. */
4628 chan_reg->register_done = 1;
4629
4630 error:
4631 pthread_mutex_unlock(&registry->lock);
4632 error_rcu_unlock:
4633 rcu_read_unlock();
4634 if (ret) {
4635 free(fields);
4636 }
4637 return ret;
4638 }
4639
4640 /*
4641 * Add event to the UST channel registry. When the event is added to the
4642 * registry, the metadata is also created. Once done, this replies to the
4643 * application with the appropriate error code.
4644 *
4645 * The session UST registry lock is acquired in the function.
4646 *
4647 * On success 0 is returned else a negative value.
4648 */
4649 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
4650 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
4651 char *model_emf_uri)
4652 {
4653 int ret, ret_code;
4654 uint32_t event_id = 0;
4655 uint64_t chan_reg_key;
4656 struct ust_app *app;
4657 struct ust_app_channel *ua_chan;
4658 struct ust_app_session *ua_sess;
4659 struct ust_registry_session *registry;
4660
4661 rcu_read_lock();
4662
4663 /* Lookup application. If not found, there is a code flow error. */
4664 app = find_app_by_notify_sock(sock);
4665 if (!app) {
4666 DBG("Application socket %d is being teardown. Abort event notify",
4667 sock);
4668 ret = 0;
4669 free(sig);
4670 free(fields);
4671 free(model_emf_uri);
4672 goto error_rcu_unlock;
4673 }
4674
4675 /* Lookup channel by UST object descriptor. */
4676 ua_chan = find_channel_by_objd(app, cobjd);
4677 if (!ua_chan) {
4678 DBG("Application channel is being teardown. Abort event notify");
4679 ret = 0;
4680 free(sig);
4681 free(fields);
4682 free(model_emf_uri);
4683 goto error_rcu_unlock;
4684 }
4685
4686 assert(ua_chan->session);
4687 ua_sess = ua_chan->session;
4688
4689 registry = get_session_registry(ua_sess);
4690 assert(registry);
4691
4692 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4693 chan_reg_key = ua_chan->tracing_channel_id;
4694 } else {
4695 chan_reg_key = ua_chan->key;
4696 }
4697
4698 pthread_mutex_lock(&registry->lock);
4699
4700 /*
4701 * From this point on, this call acquires the ownership of the sig, fields
4702 * and model_emf_uri meaning any free are done inside it if needed. These
4703 * three variables MUST NOT be read/write after this.
4704 */
4705 ret_code = ust_registry_create_event(registry, chan_reg_key,
4706 sobjd, cobjd, name, sig, nr_fields, fields, loglevel,
4707 model_emf_uri, ua_sess->buffer_type, &event_id,
4708 app);
4709
4710 /*
4711 * The return value is returned to ustctl so in case of an error, the
4712 * application can be notified. In case of an error, it's important not to
4713 * return a negative error or else the application will get closed.
4714 */
4715 ret = ustctl_reply_register_event(sock, event_id, ret_code);
4716 if (ret < 0) {
4717 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4718 ERR("UST app reply event failed with ret %d", ret);
4719 } else {
4720 DBG3("UST app reply event failed. Application died");
4721 }
4722 /*
4723 * No need to wipe the create event since the application socket will
4724 * get close on error hence cleaning up everything by itself.
4725 */
4726 goto error;
4727 }
4728
4729 DBG3("UST registry event %s with id %" PRId32 " added successfully",
4730 name, event_id);
4731
4732 error:
4733 pthread_mutex_unlock(&registry->lock);
4734 error_rcu_unlock:
4735 rcu_read_unlock();
4736 return ret;
4737 }
4738
4739 /*
4740 * Handle application notification through the given notify socket.
4741 *
4742 * Return 0 on success or else a negative value.
4743 */
4744 int ust_app_recv_notify(int sock)
4745 {
4746 int ret;
4747 enum ustctl_notify_cmd cmd;
4748
4749 DBG3("UST app receiving notify from sock %d", sock);
4750
4751 ret = ustctl_recv_notify(sock, &cmd);
4752 if (ret < 0) {
4753 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4754 ERR("UST app recv notify failed with ret %d", ret);
4755 } else {
4756 DBG3("UST app recv notify failed. Application died");
4757 }
4758 goto error;
4759 }
4760
4761 switch (cmd) {
4762 case USTCTL_NOTIFY_CMD_EVENT:
4763 {
4764 int sobjd, cobjd, loglevel;
4765 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
4766 size_t nr_fields;
4767 struct ustctl_field *fields;
4768
4769 DBG2("UST app ustctl register event received");
4770
4771 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name, &loglevel,
4772 &sig, &nr_fields, &fields, &model_emf_uri);
4773 if (ret < 0) {
4774 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4775 ERR("UST app recv event failed with ret %d", ret);
4776 } else {
4777 DBG3("UST app recv event failed. Application died");
4778 }
4779 goto error;
4780 }
4781
4782 /*
4783 * Add event to the UST registry coming from the notify socket. This
4784 * call will free if needed the sig, fields and model_emf_uri. This
4785 * code path loses the ownsership of these variables and transfer them
4786 * to the this function.
4787 */
4788 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
4789 fields, loglevel, model_emf_uri);
4790 if (ret < 0) {
4791 goto error;
4792 }
4793
4794 break;
4795 }
4796 case USTCTL_NOTIFY_CMD_CHANNEL:
4797 {
4798 int sobjd, cobjd;
4799 size_t nr_fields;
4800 struct ustctl_field *fields;
4801
4802 DBG2("UST app ustctl register channel received");
4803
4804 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
4805 &fields);
4806 if (ret < 0) {
4807 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4808 ERR("UST app recv channel failed with ret %d", ret);
4809 } else {
4810 DBG3("UST app recv channel failed. Application died");
4811 }
4812 goto error;
4813 }
4814
4815 /*
4816 * The fields ownership are transfered to this function call meaning
4817 * that if needed it will be freed. After this, it's invalid to access
4818 * fields or clean it up.
4819 */
4820 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
4821 fields);
4822 if (ret < 0) {
4823 goto error;
4824 }
4825
4826 break;
4827 }
4828 default:
4829 /* Should NEVER happen. */
4830 assert(0);
4831 }
4832
4833 error:
4834 return ret;
4835 }
4836
4837 /*
4838 * Once the notify socket hangs up, this is called. First, it tries to find the
4839 * corresponding application. On failure, the call_rcu to close the socket is
4840 * executed. If an application is found, it tries to delete it from the notify
4841 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4842 *
4843 * Note that an object needs to be allocated here so on ENOMEM failure, the
4844 * call RCU is not done but the rest of the cleanup is.
4845 */
4846 void ust_app_notify_sock_unregister(int sock)
4847 {
4848 int err_enomem = 0;
4849 struct lttng_ht_iter iter;
4850 struct ust_app *app;
4851 struct ust_app_notify_sock_obj *obj;
4852
4853 assert(sock >= 0);
4854
4855 rcu_read_lock();
4856
4857 obj = zmalloc(sizeof(*obj));
4858 if (!obj) {
4859 /*
4860 * An ENOMEM is kind of uncool. If this strikes we continue the
4861 * procedure but the call_rcu will not be called. In this case, we
4862 * accept the fd leak rather than possibly creating an unsynchronized
4863 * state between threads.
4864 *
4865 * TODO: The notify object should be created once the notify socket is
4866 * registered and stored independantely from the ust app object. The
4867 * tricky part is to synchronize the teardown of the application and
4868 * this notify object. Let's keep that in mind so we can avoid this
4869 * kind of shenanigans with ENOMEM in the teardown path.
4870 */
4871 err_enomem = 1;
4872 } else {
4873 obj->fd = sock;
4874 }
4875
4876 DBG("UST app notify socket unregister %d", sock);
4877
4878 /*
4879 * Lookup application by notify socket. If this fails, this means that the
4880 * hash table delete has already been done by the application
4881 * unregistration process so we can safely close the notify socket in a
4882 * call RCU.
4883 */
4884 app = find_app_by_notify_sock(sock);
4885 if (!app) {
4886 goto close_socket;
4887 }
4888
4889 iter.iter.node = &app->notify_sock_n.node;
4890
4891 /*
4892 * Whatever happens here either we fail or succeed, in both cases we have
4893 * to close the socket after a grace period to continue to the call RCU
4894 * here. If the deletion is successful, the application is not visible
4895 * anymore by other threads and is it fails it means that it was already
4896 * deleted from the hash table so either way we just have to close the
4897 * socket.
4898 */
4899 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
4900
4901 close_socket:
4902 rcu_read_unlock();
4903
4904 /*
4905 * Close socket after a grace period to avoid for the socket to be reused
4906 * before the application object is freed creating potential race between
4907 * threads trying to add unique in the global hash table.
4908 */
4909 if (!err_enomem) {
4910 call_rcu(&obj->head, close_notify_sock_rcu);
4911 }
4912 }
4913
4914 /*
4915 * Destroy a ust app data structure and free its memory.
4916 */
4917 void ust_app_destroy(struct ust_app *app)
4918 {
4919 if (!app) {
4920 return;
4921 }
4922
4923 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
4924 }
4925
4926 /*
4927 * Take a snapshot for a given UST session. The snapshot is sent to the given
4928 * output.
4929 *
4930 * Return 0 on success or else a negative value.
4931 */
4932 int ust_app_snapshot_record(struct ltt_ust_session *usess,
4933 struct snapshot_output *output, int wait, uint64_t max_stream_size)
4934 {
4935 int ret = 0;
4936 unsigned int snapshot_done = 0;
4937 struct lttng_ht_iter iter;
4938 struct ust_app *app;
4939 char pathname[PATH_MAX];
4940
4941 assert(usess);
4942 assert(output);
4943
4944 rcu_read_lock();
4945
4946 switch (usess->buffer_type) {
4947 case LTTNG_BUFFER_PER_UID:
4948 {
4949 struct buffer_reg_uid *reg;
4950
4951 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4952 struct buffer_reg_channel *reg_chan;
4953 struct consumer_socket *socket;
4954
4955 /* Get consumer socket to use to push the metadata.*/
4956 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4957 usess->consumer);
4958 if (!socket) {
4959 ret = -EINVAL;
4960 goto error;
4961 }
4962
4963 memset(pathname, 0, sizeof(pathname));
4964 ret = snprintf(pathname, sizeof(pathname),
4965 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
4966 reg->uid, reg->bits_per_long);
4967 if (ret < 0) {
4968 PERROR("snprintf snapshot path");
4969 goto error;
4970 }
4971
4972 /* Add the UST default trace dir to path. */
4973 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4974 reg_chan, node.node) {
4975 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key,
4976 output, 0, usess->uid, usess->gid, pathname, wait,
4977 max_stream_size);
4978 if (ret < 0) {
4979 goto error;
4980 }
4981 }
4982 ret = consumer_snapshot_channel(socket,
4983 reg->registry->reg.ust->metadata_key, output, 1,
4984 usess->uid, usess->gid, pathname, wait, max_stream_size);
4985 if (ret < 0) {
4986 goto error;
4987 }
4988 snapshot_done = 1;
4989 }
4990 break;
4991 }
4992 case LTTNG_BUFFER_PER_PID:
4993 {
4994 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4995 struct consumer_socket *socket;
4996 struct lttng_ht_iter chan_iter;
4997 struct ust_app_channel *ua_chan;
4998 struct ust_app_session *ua_sess;
4999 struct ust_registry_session *registry;
5000
5001 ua_sess = lookup_session_by_app(usess, app);
5002 if (!ua_sess) {
5003 /* Session not associated with this app. */
5004 continue;
5005 }
5006
5007 /* Get the right consumer socket for the application. */
5008 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5009 output->consumer);
5010 if (!socket) {
5011 ret = -EINVAL;
5012 goto error;
5013 }
5014
5015 /* Add the UST default trace dir to path. */
5016 memset(pathname, 0, sizeof(pathname));
5017 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
5018 ua_sess->path);
5019 if (ret < 0) {
5020 PERROR("snprintf snapshot path");
5021 goto error;
5022 }
5023
5024 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5025 ua_chan, node.node) {
5026 ret = consumer_snapshot_channel(socket, ua_chan->key, output,
5027 0, ua_sess->euid, ua_sess->egid, pathname, wait,
5028 max_stream_size);
5029 if (ret < 0) {
5030 goto error;
5031 }
5032 }
5033
5034 registry = get_session_registry(ua_sess);
5035 assert(registry);
5036 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5037 1, ua_sess->euid, ua_sess->egid, pathname, wait,
5038 max_stream_size);
5039 if (ret < 0) {
5040 goto error;
5041 }
5042 snapshot_done = 1;
5043 }
5044 break;
5045 }
5046 default:
5047 assert(0);
5048 break;
5049 }
5050
5051 if (!snapshot_done) {
5052 /*
5053 * If no snapshot was made and we are not in the error path, this means
5054 * that there are no buffers thus no (prior) application to snapshot
5055 * data from so we have simply NO data.
5056 */
5057 ret = -ENODATA;
5058 }
5059
5060 error:
5061 rcu_read_unlock();
5062 return ret;
5063 }
5064
5065 /*
5066 * Return the number of streams for a UST session.
5067 */
5068 unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
5069 {
5070 unsigned int ret = 0;
5071 struct ust_app *app;
5072 struct lttng_ht_iter iter;
5073
5074 assert(usess);
5075
5076 switch (usess->buffer_type) {
5077 case LTTNG_BUFFER_PER_UID:
5078 {
5079 struct buffer_reg_uid *reg;
5080
5081 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5082 struct buffer_reg_channel *reg_chan;
5083
5084 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5085 reg_chan, node.node) {
5086 ret += reg_chan->stream_count;
5087 }
5088 }
5089 break;
5090 }
5091 case LTTNG_BUFFER_PER_PID:
5092 {
5093 rcu_read_lock();
5094 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5095 struct ust_app_channel *ua_chan;
5096 struct ust_app_session *ua_sess;
5097 struct lttng_ht_iter chan_iter;
5098
5099 ua_sess = lookup_session_by_app(usess, app);
5100 if (!ua_sess) {
5101 /* Session not associated with this app. */
5102 continue;
5103 }
5104
5105 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5106 ua_chan, node.node) {
5107 ret += ua_chan->streams.count;
5108 }
5109 }
5110 rcu_read_unlock();
5111 break;
5112 }
5113 default:
5114 assert(0);
5115 break;
5116 }
5117
5118 return ret;
5119 }
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