5aad28bbc6d57b458935578f002c658db82ecede
[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 pthread_mutex_init(&ua_sess->lock, NULL);
829
830 /* Set default metadata channel attribute. */
831 ua_sess->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
832 ua_sess->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
833 ua_sess->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
834 ua_sess->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
835 ua_sess->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
836 ua_sess->metadata_attr.output = LTTNG_UST_MMAP;
837 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
838
839 return ua_sess;
840
841 error_free:
842 return NULL;
843 }
844
845 /*
846 * Alloc new UST app channel.
847 */
848 static
849 struct ust_app_channel *alloc_ust_app_channel(char *name,
850 struct ust_app_session *ua_sess,
851 struct lttng_ust_channel_attr *attr)
852 {
853 struct ust_app_channel *ua_chan;
854
855 /* Init most of the default value by allocating and zeroing */
856 ua_chan = zmalloc(sizeof(struct ust_app_channel));
857 if (ua_chan == NULL) {
858 PERROR("malloc");
859 goto error;
860 }
861
862 /* Setup channel name */
863 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
864 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
865
866 ua_chan->enabled = 1;
867 ua_chan->handle = -1;
868 ua_chan->session = ua_sess;
869 ua_chan->key = get_next_channel_key();
870 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
871 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
872 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
873
874 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
875 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
876
877 /* Copy attributes */
878 if (attr) {
879 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
880 ua_chan->attr.subbuf_size = attr->subbuf_size;
881 ua_chan->attr.num_subbuf = attr->num_subbuf;
882 ua_chan->attr.overwrite = attr->overwrite;
883 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
884 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
885 ua_chan->attr.output = attr->output;
886 }
887 /* By default, the channel is a per cpu channel. */
888 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
889
890 DBG3("UST app channel %s allocated", ua_chan->name);
891
892 return ua_chan;
893
894 error:
895 return NULL;
896 }
897
898 /*
899 * Allocate and initialize a UST app stream.
900 *
901 * Return newly allocated stream pointer or NULL on error.
902 */
903 struct ust_app_stream *ust_app_alloc_stream(void)
904 {
905 struct ust_app_stream *stream = NULL;
906
907 stream = zmalloc(sizeof(*stream));
908 if (stream == NULL) {
909 PERROR("zmalloc ust app stream");
910 goto error;
911 }
912
913 /* Zero could be a valid value for a handle so flag it to -1. */
914 stream->handle = -1;
915
916 error:
917 return stream;
918 }
919
920 /*
921 * Alloc new UST app event.
922 */
923 static
924 struct ust_app_event *alloc_ust_app_event(char *name,
925 struct lttng_ust_event *attr)
926 {
927 struct ust_app_event *ua_event;
928
929 /* Init most of the default value by allocating and zeroing */
930 ua_event = zmalloc(sizeof(struct ust_app_event));
931 if (ua_event == NULL) {
932 PERROR("malloc");
933 goto error;
934 }
935
936 ua_event->enabled = 1;
937 strncpy(ua_event->name, name, sizeof(ua_event->name));
938 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
939 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
940
941 /* Copy attributes */
942 if (attr) {
943 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
944 }
945
946 DBG3("UST app event %s allocated", ua_event->name);
947
948 return ua_event;
949
950 error:
951 return NULL;
952 }
953
954 /*
955 * Alloc new UST app context.
956 */
957 static
958 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
959 {
960 struct ust_app_ctx *ua_ctx;
961
962 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
963 if (ua_ctx == NULL) {
964 goto error;
965 }
966
967 CDS_INIT_LIST_HEAD(&ua_ctx->list);
968
969 if (uctx) {
970 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
971 }
972
973 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
974
975 error:
976 return ua_ctx;
977 }
978
979 /*
980 * Allocate a filter and copy the given original filter.
981 *
982 * Return allocated filter or NULL on error.
983 */
984 static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
985 struct lttng_ust_filter_bytecode *orig_f)
986 {
987 struct lttng_ust_filter_bytecode *filter = NULL;
988
989 /* Copy filter bytecode */
990 filter = zmalloc(sizeof(*filter) + orig_f->len);
991 if (!filter) {
992 PERROR("zmalloc alloc ust app filter");
993 goto error;
994 }
995
996 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
997
998 error:
999 return filter;
1000 }
1001
1002 /*
1003 * Find an ust_app using the sock and return it. RCU read side lock must be
1004 * held before calling this helper function.
1005 */
1006 struct ust_app *ust_app_find_by_sock(int sock)
1007 {
1008 struct lttng_ht_node_ulong *node;
1009 struct lttng_ht_iter iter;
1010
1011 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1012 node = lttng_ht_iter_get_node_ulong(&iter);
1013 if (node == NULL) {
1014 DBG2("UST app find by sock %d not found", sock);
1015 goto error;
1016 }
1017
1018 return caa_container_of(node, struct ust_app, sock_n);
1019
1020 error:
1021 return NULL;
1022 }
1023
1024 /*
1025 * Find an ust_app using the notify sock and return it. RCU read side lock must
1026 * be held before calling this helper function.
1027 */
1028 static struct ust_app *find_app_by_notify_sock(int sock)
1029 {
1030 struct lttng_ht_node_ulong *node;
1031 struct lttng_ht_iter iter;
1032
1033 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1034 &iter);
1035 node = lttng_ht_iter_get_node_ulong(&iter);
1036 if (node == NULL) {
1037 DBG2("UST app find by notify sock %d not found", sock);
1038 goto error;
1039 }
1040
1041 return caa_container_of(node, struct ust_app, notify_sock_n);
1042
1043 error:
1044 return NULL;
1045 }
1046
1047 /*
1048 * Lookup for an ust app event based on event name, filter bytecode and the
1049 * event loglevel.
1050 *
1051 * Return an ust_app_event object or NULL on error.
1052 */
1053 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1054 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel,
1055 const struct lttng_event_exclusion *exclusion)
1056 {
1057 struct lttng_ht_iter iter;
1058 struct lttng_ht_node_str *node;
1059 struct ust_app_event *event = NULL;
1060 struct ust_app_ht_key key;
1061
1062 assert(name);
1063 assert(ht);
1064
1065 /* Setup key for event lookup. */
1066 key.name = name;
1067 key.filter = filter;
1068 key.loglevel = loglevel;
1069 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1070 key.exclusion = (struct lttng_ust_event_exclusion *)exclusion;
1071
1072 /* Lookup using the event name as hash and a custom match fct. */
1073 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1074 ht_match_ust_app_event, &key, &iter.iter);
1075 node = lttng_ht_iter_get_node_str(&iter);
1076 if (node == NULL) {
1077 goto end;
1078 }
1079
1080 event = caa_container_of(node, struct ust_app_event, node);
1081
1082 end:
1083 return event;
1084 }
1085
1086 /*
1087 * Create the channel context on the tracer.
1088 *
1089 * Called with UST app session lock held.
1090 */
1091 static
1092 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1093 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1094 {
1095 int ret;
1096
1097 health_code_update();
1098
1099 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1100 ua_chan->obj, &ua_ctx->obj);
1101 if (ret < 0) {
1102 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1103 ERR("UST app create channel context failed for app (pid: %d) "
1104 "with ret %d", app->pid, ret);
1105 } else {
1106 /*
1107 * This is normal behavior, an application can die during the
1108 * creation process. Don't report an error so the execution can
1109 * continue normally.
1110 */
1111 ret = 0;
1112 DBG3("UST app disable event failed. Application is dead.");
1113 }
1114 goto error;
1115 }
1116
1117 ua_ctx->handle = ua_ctx->obj->handle;
1118
1119 DBG2("UST app context handle %d created successfully for channel %s",
1120 ua_ctx->handle, ua_chan->name);
1121
1122 error:
1123 health_code_update();
1124 return ret;
1125 }
1126
1127 /*
1128 * Set the filter on the tracer.
1129 */
1130 static
1131 int set_ust_event_filter(struct ust_app_event *ua_event,
1132 struct ust_app *app)
1133 {
1134 int ret;
1135
1136 health_code_update();
1137
1138 if (!ua_event->filter) {
1139 ret = 0;
1140 goto error;
1141 }
1142
1143 ret = ustctl_set_filter(app->sock, ua_event->filter,
1144 ua_event->obj);
1145 if (ret < 0) {
1146 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1147 ERR("UST app event %s filter failed for app (pid: %d) "
1148 "with ret %d", ua_event->attr.name, app->pid, ret);
1149 } else {
1150 /*
1151 * This is normal behavior, an application can die during the
1152 * creation process. Don't report an error so the execution can
1153 * continue normally.
1154 */
1155 ret = 0;
1156 DBG3("UST app filter event failed. Application is dead.");
1157 }
1158 goto error;
1159 }
1160
1161 DBG2("UST filter set successfully for event %s", ua_event->name);
1162
1163 error:
1164 health_code_update();
1165 return ret;
1166 }
1167
1168 /*
1169 * Set event exclusions on the tracer.
1170 */
1171 static
1172 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1173 struct ust_app *app)
1174 {
1175 int ret;
1176
1177 health_code_update();
1178
1179 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1180 ret = 0;
1181 goto error;
1182 }
1183
1184 ret = ustctl_set_exclusion(app->sock, ua_event->exclusion,
1185 ua_event->obj);
1186 if (ret < 0) {
1187 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1188 ERR("UST app event %s exclusions failed for app (pid: %d) "
1189 "with ret %d", ua_event->attr.name, app->pid, ret);
1190 } else {
1191 /*
1192 * This is normal behavior, an application can die during the
1193 * creation process. Don't report an error so the execution can
1194 * continue normally.
1195 */
1196 ret = 0;
1197 DBG3("UST app event exclusion failed. Application is dead.");
1198 }
1199 goto error;
1200 }
1201
1202 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1203
1204 error:
1205 health_code_update();
1206 return ret;
1207 }
1208
1209 /*
1210 * Disable the specified event on to UST tracer for the UST session.
1211 */
1212 static int disable_ust_event(struct ust_app *app,
1213 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1214 {
1215 int ret;
1216
1217 health_code_update();
1218
1219 ret = ustctl_disable(app->sock, ua_event->obj);
1220 if (ret < 0) {
1221 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1222 ERR("UST app event %s disable failed for app (pid: %d) "
1223 "and session handle %d with ret %d",
1224 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1225 } else {
1226 /*
1227 * This is normal behavior, an application can die during the
1228 * creation process. Don't report an error so the execution can
1229 * continue normally.
1230 */
1231 ret = 0;
1232 DBG3("UST app disable event failed. Application is dead.");
1233 }
1234 goto error;
1235 }
1236
1237 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1238 ua_event->attr.name, app->pid);
1239
1240 error:
1241 health_code_update();
1242 return ret;
1243 }
1244
1245 /*
1246 * Disable the specified channel on to UST tracer for the UST session.
1247 */
1248 static int disable_ust_channel(struct ust_app *app,
1249 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1250 {
1251 int ret;
1252
1253 health_code_update();
1254
1255 ret = ustctl_disable(app->sock, ua_chan->obj);
1256 if (ret < 0) {
1257 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1258 ERR("UST app channel %s disable failed for app (pid: %d) "
1259 "and session handle %d with ret %d",
1260 ua_chan->name, app->pid, ua_sess->handle, ret);
1261 } else {
1262 /*
1263 * This is normal behavior, an application can die during the
1264 * creation process. Don't report an error so the execution can
1265 * continue normally.
1266 */
1267 ret = 0;
1268 DBG3("UST app disable channel failed. Application is dead.");
1269 }
1270 goto error;
1271 }
1272
1273 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1274 ua_chan->name, app->pid);
1275
1276 error:
1277 health_code_update();
1278 return ret;
1279 }
1280
1281 /*
1282 * Enable the specified channel on to UST tracer for the UST session.
1283 */
1284 static int enable_ust_channel(struct ust_app *app,
1285 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1286 {
1287 int ret;
1288
1289 health_code_update();
1290
1291 ret = ustctl_enable(app->sock, ua_chan->obj);
1292 if (ret < 0) {
1293 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1294 ERR("UST app channel %s enable failed for app (pid: %d) "
1295 "and session handle %d with ret %d",
1296 ua_chan->name, app->pid, ua_sess->handle, ret);
1297 } else {
1298 /*
1299 * This is normal behavior, an application can die during the
1300 * creation process. Don't report an error so the execution can
1301 * continue normally.
1302 */
1303 ret = 0;
1304 DBG3("UST app enable channel failed. Application is dead.");
1305 }
1306 goto error;
1307 }
1308
1309 ua_chan->enabled = 1;
1310
1311 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1312 ua_chan->name, app->pid);
1313
1314 error:
1315 health_code_update();
1316 return ret;
1317 }
1318
1319 /*
1320 * Enable the specified event on to UST tracer for the UST session.
1321 */
1322 static int enable_ust_event(struct ust_app *app,
1323 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1324 {
1325 int ret;
1326
1327 health_code_update();
1328
1329 ret = ustctl_enable(app->sock, ua_event->obj);
1330 if (ret < 0) {
1331 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1332 ERR("UST app event %s enable failed for app (pid: %d) "
1333 "and session handle %d with ret %d",
1334 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1335 } else {
1336 /*
1337 * This is normal behavior, an application can die during the
1338 * creation process. Don't report an error so the execution can
1339 * continue normally.
1340 */
1341 ret = 0;
1342 DBG3("UST app enable event failed. Application is dead.");
1343 }
1344 goto error;
1345 }
1346
1347 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1348 ua_event->attr.name, app->pid);
1349
1350 error:
1351 health_code_update();
1352 return ret;
1353 }
1354
1355 /*
1356 * Send channel and stream buffer to application.
1357 *
1358 * Return 0 on success. On error, a negative value is returned.
1359 */
1360 static int send_channel_pid_to_ust(struct ust_app *app,
1361 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1362 {
1363 int ret;
1364 struct ust_app_stream *stream, *stmp;
1365
1366 assert(app);
1367 assert(ua_sess);
1368 assert(ua_chan);
1369
1370 health_code_update();
1371
1372 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1373 app->sock);
1374
1375 /* Send channel to the application. */
1376 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1377 if (ret < 0) {
1378 goto error;
1379 }
1380
1381 health_code_update();
1382
1383 /* Send all streams to application. */
1384 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1385 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1386 if (ret < 0) {
1387 goto error;
1388 }
1389 /* We don't need the stream anymore once sent to the tracer. */
1390 cds_list_del(&stream->list);
1391 delete_ust_app_stream(-1, stream);
1392 }
1393 /* Flag the channel that it is sent to the application. */
1394 ua_chan->is_sent = 1;
1395
1396 error:
1397 health_code_update();
1398 return ret;
1399 }
1400
1401 /*
1402 * Create the specified event onto the UST tracer for a UST session.
1403 *
1404 * Should be called with session mutex held.
1405 */
1406 static
1407 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1408 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1409 {
1410 int ret = 0;
1411
1412 health_code_update();
1413
1414 /* Create UST event on tracer */
1415 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1416 &ua_event->obj);
1417 if (ret < 0) {
1418 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1419 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1420 ua_event->attr.name, app->pid, ret);
1421 } else {
1422 /*
1423 * This is normal behavior, an application can die during the
1424 * creation process. Don't report an error so the execution can
1425 * continue normally.
1426 */
1427 ret = 0;
1428 DBG3("UST app create event failed. Application is dead.");
1429 }
1430 goto error;
1431 }
1432
1433 ua_event->handle = ua_event->obj->handle;
1434
1435 DBG2("UST app event %s created successfully for pid:%d",
1436 ua_event->attr.name, app->pid);
1437
1438 health_code_update();
1439
1440 /* Set filter if one is present. */
1441 if (ua_event->filter) {
1442 ret = set_ust_event_filter(ua_event, app);
1443 if (ret < 0) {
1444 goto error;
1445 }
1446 }
1447
1448 /* Set exclusions for the event */
1449 if (ua_event->exclusion) {
1450 ret = set_ust_event_exclusion(ua_event, app);
1451 if (ret < 0) {
1452 goto error;
1453 }
1454 }
1455
1456 /* If event not enabled, disable it on the tracer */
1457 if (ua_event->enabled == 0) {
1458 ret = disable_ust_event(app, ua_sess, ua_event);
1459 if (ret < 0) {
1460 /*
1461 * If we hit an EPERM, something is wrong with our disable call. If
1462 * we get an EEXIST, there is a problem on the tracer side since we
1463 * just created it.
1464 */
1465 switch (ret) {
1466 case -LTTNG_UST_ERR_PERM:
1467 /* Code flow problem */
1468 assert(0);
1469 case -LTTNG_UST_ERR_EXIST:
1470 /* It's OK for our use case. */
1471 ret = 0;
1472 break;
1473 default:
1474 break;
1475 }
1476 goto error;
1477 }
1478 }
1479
1480 error:
1481 health_code_update();
1482 return ret;
1483 }
1484
1485 /*
1486 * Copy data between an UST app event and a LTT event.
1487 */
1488 static void shadow_copy_event(struct ust_app_event *ua_event,
1489 struct ltt_ust_event *uevent)
1490 {
1491 size_t exclusion_alloc_size;
1492
1493 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1494 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1495
1496 ua_event->enabled = uevent->enabled;
1497
1498 /* Copy event attributes */
1499 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1500
1501 /* Copy filter bytecode */
1502 if (uevent->filter) {
1503 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1504 /* Filter might be NULL here in case of ENONEM. */
1505 }
1506
1507 /* Copy exclusion data */
1508 if (uevent->exclusion) {
1509 exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1510 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1511 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1512 if (ua_event->exclusion == NULL) {
1513 PERROR("malloc");
1514 } else {
1515 memcpy(ua_event->exclusion, uevent->exclusion,
1516 exclusion_alloc_size);
1517 }
1518 }
1519 }
1520
1521 /*
1522 * Copy data between an UST app channel and a LTT channel.
1523 */
1524 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1525 struct ltt_ust_channel *uchan)
1526 {
1527 struct lttng_ht_iter iter;
1528 struct ltt_ust_event *uevent;
1529 struct ltt_ust_context *uctx;
1530 struct ust_app_event *ua_event;
1531 struct ust_app_ctx *ua_ctx;
1532
1533 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1534
1535 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1536 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1537
1538 ua_chan->tracefile_size = uchan->tracefile_size;
1539 ua_chan->tracefile_count = uchan->tracefile_count;
1540
1541 /* Copy event attributes since the layout is different. */
1542 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1543 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1544 ua_chan->attr.overwrite = uchan->attr.overwrite;
1545 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1546 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1547 ua_chan->attr.output = uchan->attr.output;
1548 /*
1549 * Note that the attribute channel type is not set since the channel on the
1550 * tracing registry side does not have this information.
1551 */
1552
1553 ua_chan->enabled = uchan->enabled;
1554 ua_chan->tracing_channel_id = uchan->id;
1555
1556 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1557 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1558 if (ua_ctx == NULL) {
1559 continue;
1560 }
1561 lttng_ht_node_init_ulong(&ua_ctx->node,
1562 (unsigned long) ua_ctx->ctx.ctx);
1563 lttng_ht_add_unique_ulong(ua_chan->ctx, &ua_ctx->node);
1564 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1565 }
1566
1567 /* Copy all events from ltt ust channel to ust app channel */
1568 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1569 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1570 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1571 if (ua_event == NULL) {
1572 DBG2("UST event %s not found on shadow copy channel",
1573 uevent->attr.name);
1574 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1575 if (ua_event == NULL) {
1576 continue;
1577 }
1578 shadow_copy_event(ua_event, uevent);
1579 add_unique_ust_app_event(ua_chan, ua_event);
1580 }
1581 }
1582
1583 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1584 }
1585
1586 /*
1587 * Copy data between a UST app session and a regular LTT session.
1588 */
1589 static void shadow_copy_session(struct ust_app_session *ua_sess,
1590 struct ltt_ust_session *usess, struct ust_app *app)
1591 {
1592 struct lttng_ht_node_str *ua_chan_node;
1593 struct lttng_ht_iter iter;
1594 struct ltt_ust_channel *uchan;
1595 struct ust_app_channel *ua_chan;
1596 time_t rawtime;
1597 struct tm *timeinfo;
1598 char datetime[16];
1599 int ret;
1600
1601 /* Get date and time for unique app path */
1602 time(&rawtime);
1603 timeinfo = localtime(&rawtime);
1604 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1605
1606 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1607
1608 ua_sess->tracing_id = usess->id;
1609 ua_sess->id = get_next_session_id();
1610 ua_sess->uid = app->uid;
1611 ua_sess->gid = app->gid;
1612 ua_sess->euid = usess->uid;
1613 ua_sess->egid = usess->gid;
1614 ua_sess->buffer_type = usess->buffer_type;
1615 ua_sess->bits_per_long = app->bits_per_long;
1616 /* There is only one consumer object per session possible. */
1617 ua_sess->consumer = usess->consumer;
1618 ua_sess->output_traces = usess->output_traces;
1619 ua_sess->live_timer_interval = usess->live_timer_interval;
1620
1621 switch (ua_sess->buffer_type) {
1622 case LTTNG_BUFFER_PER_PID:
1623 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1624 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1625 datetime);
1626 break;
1627 case LTTNG_BUFFER_PER_UID:
1628 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1629 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1630 break;
1631 default:
1632 assert(0);
1633 goto error;
1634 }
1635 if (ret < 0) {
1636 PERROR("asprintf UST shadow copy session");
1637 assert(0);
1638 goto error;
1639 }
1640
1641 /* Iterate over all channels in global domain. */
1642 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1643 uchan, node.node) {
1644 struct lttng_ht_iter uiter;
1645
1646 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1647 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1648 if (ua_chan_node != NULL) {
1649 /* Session exist. Contiuing. */
1650 continue;
1651 }
1652
1653 DBG2("Channel %s not found on shadow session copy, creating it",
1654 uchan->name);
1655 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1656 if (ua_chan == NULL) {
1657 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1658 continue;
1659 }
1660 shadow_copy_channel(ua_chan, uchan);
1661 /*
1662 * The concept of metadata channel does not exist on the tracing
1663 * registry side of the session daemon so this can only be a per CPU
1664 * channel and not metadata.
1665 */
1666 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1667
1668 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1669 }
1670
1671 error:
1672 return;
1673 }
1674
1675 /*
1676 * Lookup sesison wrapper.
1677 */
1678 static
1679 void __lookup_session_by_app(struct ltt_ust_session *usess,
1680 struct ust_app *app, struct lttng_ht_iter *iter)
1681 {
1682 /* Get right UST app session from app */
1683 lttng_ht_lookup(app->sessions, &usess->id, iter);
1684 }
1685
1686 /*
1687 * Return ust app session from the app session hashtable using the UST session
1688 * id.
1689 */
1690 static struct ust_app_session *lookup_session_by_app(
1691 struct ltt_ust_session *usess, struct ust_app *app)
1692 {
1693 struct lttng_ht_iter iter;
1694 struct lttng_ht_node_u64 *node;
1695
1696 __lookup_session_by_app(usess, app, &iter);
1697 node = lttng_ht_iter_get_node_u64(&iter);
1698 if (node == NULL) {
1699 goto error;
1700 }
1701
1702 return caa_container_of(node, struct ust_app_session, node);
1703
1704 error:
1705 return NULL;
1706 }
1707
1708 /*
1709 * Setup buffer registry per PID for the given session and application. If none
1710 * is found, a new one is created, added to the global registry and
1711 * initialized. If regp is valid, it's set with the newly created object.
1712 *
1713 * Return 0 on success or else a negative value.
1714 */
1715 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1716 struct ust_app *app, struct buffer_reg_pid **regp)
1717 {
1718 int ret = 0;
1719 struct buffer_reg_pid *reg_pid;
1720
1721 assert(ua_sess);
1722 assert(app);
1723
1724 rcu_read_lock();
1725
1726 reg_pid = buffer_reg_pid_find(ua_sess->id);
1727 if (!reg_pid) {
1728 /*
1729 * This is the create channel path meaning that if there is NO
1730 * registry available, we have to create one for this session.
1731 */
1732 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1733 if (ret < 0) {
1734 goto error;
1735 }
1736 buffer_reg_pid_add(reg_pid);
1737 } else {
1738 goto end;
1739 }
1740
1741 /* Initialize registry. */
1742 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1743 app->bits_per_long, app->uint8_t_alignment,
1744 app->uint16_t_alignment, app->uint32_t_alignment,
1745 app->uint64_t_alignment, app->long_alignment,
1746 app->byte_order, app->version.major,
1747 app->version.minor);
1748 if (ret < 0) {
1749 goto error;
1750 }
1751
1752 DBG3("UST app buffer registry per PID created successfully");
1753
1754 end:
1755 if (regp) {
1756 *regp = reg_pid;
1757 }
1758 error:
1759 rcu_read_unlock();
1760 return ret;
1761 }
1762
1763 /*
1764 * Setup buffer registry per UID for the given session and application. If none
1765 * is found, a new one is created, added to the global registry and
1766 * initialized. If regp is valid, it's set with the newly created object.
1767 *
1768 * Return 0 on success or else a negative value.
1769 */
1770 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1771 struct ust_app *app, struct buffer_reg_uid **regp)
1772 {
1773 int ret = 0;
1774 struct buffer_reg_uid *reg_uid;
1775
1776 assert(usess);
1777 assert(app);
1778
1779 rcu_read_lock();
1780
1781 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1782 if (!reg_uid) {
1783 /*
1784 * This is the create channel path meaning that if there is NO
1785 * registry available, we have to create one for this session.
1786 */
1787 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1788 LTTNG_DOMAIN_UST, &reg_uid);
1789 if (ret < 0) {
1790 goto error;
1791 }
1792 buffer_reg_uid_add(reg_uid);
1793 } else {
1794 goto end;
1795 }
1796
1797 /* Initialize registry. */
1798 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1799 app->bits_per_long, app->uint8_t_alignment,
1800 app->uint16_t_alignment, app->uint32_t_alignment,
1801 app->uint64_t_alignment, app->long_alignment,
1802 app->byte_order, app->version.major,
1803 app->version.minor);
1804 if (ret < 0) {
1805 goto error;
1806 }
1807 /* Add node to teardown list of the session. */
1808 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1809
1810 DBG3("UST app buffer registry per UID created successfully");
1811
1812 end:
1813 if (regp) {
1814 *regp = reg_uid;
1815 }
1816 error:
1817 rcu_read_unlock();
1818 return ret;
1819 }
1820
1821 /*
1822 * Create a session on the tracer side for the given app.
1823 *
1824 * On success, ua_sess_ptr is populated with the session pointer or else left
1825 * untouched. If the session was created, is_created is set to 1. On error,
1826 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1827 * be NULL.
1828 *
1829 * Returns 0 on success or else a negative code which is either -ENOMEM or
1830 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1831 */
1832 static int create_ust_app_session(struct ltt_ust_session *usess,
1833 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1834 int *is_created)
1835 {
1836 int ret, created = 0;
1837 struct ust_app_session *ua_sess;
1838
1839 assert(usess);
1840 assert(app);
1841 assert(ua_sess_ptr);
1842
1843 health_code_update();
1844
1845 ua_sess = lookup_session_by_app(usess, app);
1846 if (ua_sess == NULL) {
1847 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1848 app->pid, usess->id);
1849 ua_sess = alloc_ust_app_session(app);
1850 if (ua_sess == NULL) {
1851 /* Only malloc can failed so something is really wrong */
1852 ret = -ENOMEM;
1853 goto error;
1854 }
1855 shadow_copy_session(ua_sess, usess, app);
1856 created = 1;
1857 }
1858
1859 switch (usess->buffer_type) {
1860 case LTTNG_BUFFER_PER_PID:
1861 /* Init local registry. */
1862 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1863 if (ret < 0) {
1864 goto error;
1865 }
1866 break;
1867 case LTTNG_BUFFER_PER_UID:
1868 /* Look for a global registry. If none exists, create one. */
1869 ret = setup_buffer_reg_uid(usess, app, NULL);
1870 if (ret < 0) {
1871 goto error;
1872 }
1873 break;
1874 default:
1875 assert(0);
1876 ret = -EINVAL;
1877 goto error;
1878 }
1879
1880 health_code_update();
1881
1882 if (ua_sess->handle == -1) {
1883 ret = ustctl_create_session(app->sock);
1884 if (ret < 0) {
1885 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1886 ERR("Creating session for app pid %d with ret %d",
1887 app->pid, ret);
1888 } else {
1889 DBG("UST app creating session failed. Application is dead");
1890 /*
1891 * This is normal behavior, an application can die during the
1892 * creation process. Don't report an error so the execution can
1893 * continue normally. This will get flagged ENOTCONN and the
1894 * caller will handle it.
1895 */
1896 ret = 0;
1897 }
1898 delete_ust_app_session(-1, ua_sess, app);
1899 if (ret != -ENOMEM) {
1900 /*
1901 * Tracer is probably gone or got an internal error so let's
1902 * behave like it will soon unregister or not usable.
1903 */
1904 ret = -ENOTCONN;
1905 }
1906 goto error;
1907 }
1908
1909 ua_sess->handle = ret;
1910
1911 /* Add ust app session to app's HT */
1912 lttng_ht_node_init_u64(&ua_sess->node,
1913 ua_sess->tracing_id);
1914 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1915
1916 DBG2("UST app session created successfully with handle %d", ret);
1917 }
1918
1919 *ua_sess_ptr = ua_sess;
1920 if (is_created) {
1921 *is_created = created;
1922 }
1923
1924 /* Everything went well. */
1925 ret = 0;
1926
1927 error:
1928 health_code_update();
1929 return ret;
1930 }
1931
1932 /*
1933 * Create a context for the channel on the tracer.
1934 *
1935 * Called with UST app session lock held and a RCU read side lock.
1936 */
1937 static
1938 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
1939 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
1940 struct ust_app *app)
1941 {
1942 int ret = 0;
1943 struct lttng_ht_iter iter;
1944 struct lttng_ht_node_ulong *node;
1945 struct ust_app_ctx *ua_ctx;
1946
1947 DBG2("UST app adding context to channel %s", ua_chan->name);
1948
1949 lttng_ht_lookup(ua_chan->ctx, (void *)((unsigned long)uctx->ctx), &iter);
1950 node = lttng_ht_iter_get_node_ulong(&iter);
1951 if (node != NULL) {
1952 ret = -EEXIST;
1953 goto error;
1954 }
1955
1956 ua_ctx = alloc_ust_app_ctx(uctx);
1957 if (ua_ctx == NULL) {
1958 /* malloc failed */
1959 ret = -1;
1960 goto error;
1961 }
1962
1963 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
1964 lttng_ht_add_unique_ulong(ua_chan->ctx, &ua_ctx->node);
1965 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1966
1967 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
1968 if (ret < 0) {
1969 goto error;
1970 }
1971
1972 error:
1973 return ret;
1974 }
1975
1976 /*
1977 * Enable on the tracer side a ust app event for the session and channel.
1978 *
1979 * Called with UST app session lock held.
1980 */
1981 static
1982 int enable_ust_app_event(struct ust_app_session *ua_sess,
1983 struct ust_app_event *ua_event, struct ust_app *app)
1984 {
1985 int ret;
1986
1987 ret = enable_ust_event(app, ua_sess, ua_event);
1988 if (ret < 0) {
1989 goto error;
1990 }
1991
1992 ua_event->enabled = 1;
1993
1994 error:
1995 return ret;
1996 }
1997
1998 /*
1999 * Disable on the tracer side a ust app event for the session and channel.
2000 */
2001 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2002 struct ust_app_event *ua_event, struct ust_app *app)
2003 {
2004 int ret;
2005
2006 ret = disable_ust_event(app, ua_sess, ua_event);
2007 if (ret < 0) {
2008 goto error;
2009 }
2010
2011 ua_event->enabled = 0;
2012
2013 error:
2014 return ret;
2015 }
2016
2017 /*
2018 * Lookup ust app channel for session and disable it on the tracer side.
2019 */
2020 static
2021 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2022 struct ust_app_channel *ua_chan, struct ust_app *app)
2023 {
2024 int ret;
2025
2026 ret = disable_ust_channel(app, ua_sess, ua_chan);
2027 if (ret < 0) {
2028 goto error;
2029 }
2030
2031 ua_chan->enabled = 0;
2032
2033 error:
2034 return ret;
2035 }
2036
2037 /*
2038 * Lookup ust app channel for session and enable it on the tracer side. This
2039 * MUST be called with a RCU read side lock acquired.
2040 */
2041 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2042 struct ltt_ust_channel *uchan, struct ust_app *app)
2043 {
2044 int ret = 0;
2045 struct lttng_ht_iter iter;
2046 struct lttng_ht_node_str *ua_chan_node;
2047 struct ust_app_channel *ua_chan;
2048
2049 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2050 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2051 if (ua_chan_node == NULL) {
2052 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2053 uchan->name, ua_sess->tracing_id);
2054 goto error;
2055 }
2056
2057 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2058
2059 ret = enable_ust_channel(app, ua_sess, ua_chan);
2060 if (ret < 0) {
2061 goto error;
2062 }
2063
2064 error:
2065 return ret;
2066 }
2067
2068 /*
2069 * Ask the consumer to create a channel and get it if successful.
2070 *
2071 * Return 0 on success or else a negative value.
2072 */
2073 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2074 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2075 int bitness, struct ust_registry_session *registry)
2076 {
2077 int ret;
2078 unsigned int nb_fd = 0;
2079 struct consumer_socket *socket;
2080
2081 assert(usess);
2082 assert(ua_sess);
2083 assert(ua_chan);
2084 assert(registry);
2085
2086 rcu_read_lock();
2087 health_code_update();
2088
2089 /* Get the right consumer socket for the application. */
2090 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2091 if (!socket) {
2092 ret = -EINVAL;
2093 goto error;
2094 }
2095
2096 health_code_update();
2097
2098 /* Need one fd for the channel. */
2099 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2100 if (ret < 0) {
2101 ERR("Exhausted number of available FD upon create channel");
2102 goto error;
2103 }
2104
2105 /*
2106 * Ask consumer to create channel. The consumer will return the number of
2107 * stream we have to expect.
2108 */
2109 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2110 registry);
2111 if (ret < 0) {
2112 goto error_ask;
2113 }
2114
2115 /*
2116 * Compute the number of fd needed before receiving them. It must be 2 per
2117 * stream (2 being the default value here).
2118 */
2119 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2120
2121 /* Reserve the amount of file descriptor we need. */
2122 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2123 if (ret < 0) {
2124 ERR("Exhausted number of available FD upon create channel");
2125 goto error_fd_get_stream;
2126 }
2127
2128 health_code_update();
2129
2130 /*
2131 * Now get the channel from the consumer. This call wil populate the stream
2132 * list of that channel and set the ust objects.
2133 */
2134 if (usess->consumer->enabled) {
2135 ret = ust_consumer_get_channel(socket, ua_chan);
2136 if (ret < 0) {
2137 goto error_destroy;
2138 }
2139 }
2140
2141 rcu_read_unlock();
2142 return 0;
2143
2144 error_destroy:
2145 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2146 error_fd_get_stream:
2147 /*
2148 * Initiate a destroy channel on the consumer since we had an error
2149 * handling it on our side. The return value is of no importance since we
2150 * already have a ret value set by the previous error that we need to
2151 * return.
2152 */
2153 (void) ust_consumer_destroy_channel(socket, ua_chan);
2154 error_ask:
2155 lttng_fd_put(LTTNG_FD_APPS, 1);
2156 error:
2157 health_code_update();
2158 rcu_read_unlock();
2159 return ret;
2160 }
2161
2162 /*
2163 * Duplicate the ust data object of the ust app stream and save it in the
2164 * buffer registry stream.
2165 *
2166 * Return 0 on success or else a negative value.
2167 */
2168 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2169 struct ust_app_stream *stream)
2170 {
2171 int ret;
2172
2173 assert(reg_stream);
2174 assert(stream);
2175
2176 /* Reserve the amount of file descriptor we need. */
2177 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2178 if (ret < 0) {
2179 ERR("Exhausted number of available FD upon duplicate stream");
2180 goto error;
2181 }
2182
2183 /* Duplicate object for stream once the original is in the registry. */
2184 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2185 reg_stream->obj.ust);
2186 if (ret < 0) {
2187 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2188 reg_stream->obj.ust, stream->obj, ret);
2189 lttng_fd_put(LTTNG_FD_APPS, 2);
2190 goto error;
2191 }
2192 stream->handle = stream->obj->handle;
2193
2194 error:
2195 return ret;
2196 }
2197
2198 /*
2199 * Duplicate the ust data object of the ust app. channel and save it in the
2200 * buffer registry channel.
2201 *
2202 * Return 0 on success or else a negative value.
2203 */
2204 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2205 struct ust_app_channel *ua_chan)
2206 {
2207 int ret;
2208
2209 assert(reg_chan);
2210 assert(ua_chan);
2211
2212 /* Need two fds for the channel. */
2213 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2214 if (ret < 0) {
2215 ERR("Exhausted number of available FD upon duplicate channel");
2216 goto error_fd_get;
2217 }
2218
2219 /* Duplicate object for stream once the original is in the registry. */
2220 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2221 if (ret < 0) {
2222 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2223 reg_chan->obj.ust, ua_chan->obj, ret);
2224 goto error;
2225 }
2226 ua_chan->handle = ua_chan->obj->handle;
2227
2228 return 0;
2229
2230 error:
2231 lttng_fd_put(LTTNG_FD_APPS, 1);
2232 error_fd_get:
2233 return ret;
2234 }
2235
2236 /*
2237 * For a given channel buffer registry, setup all streams of the given ust
2238 * application channel.
2239 *
2240 * Return 0 on success or else a negative value.
2241 */
2242 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2243 struct ust_app_channel *ua_chan)
2244 {
2245 int ret = 0;
2246 struct ust_app_stream *stream, *stmp;
2247
2248 assert(reg_chan);
2249 assert(ua_chan);
2250
2251 DBG2("UST app setup buffer registry stream");
2252
2253 /* Send all streams to application. */
2254 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2255 struct buffer_reg_stream *reg_stream;
2256
2257 ret = buffer_reg_stream_create(&reg_stream);
2258 if (ret < 0) {
2259 goto error;
2260 }
2261
2262 /*
2263 * Keep original pointer and nullify it in the stream so the delete
2264 * stream call does not release the object.
2265 */
2266 reg_stream->obj.ust = stream->obj;
2267 stream->obj = NULL;
2268 buffer_reg_stream_add(reg_stream, reg_chan);
2269
2270 /* We don't need the streams anymore. */
2271 cds_list_del(&stream->list);
2272 delete_ust_app_stream(-1, stream);
2273 }
2274
2275 error:
2276 return ret;
2277 }
2278
2279 /*
2280 * Create a buffer registry channel for the given session registry and
2281 * application channel object. If regp pointer is valid, it's set with the
2282 * created object. Important, the created object is NOT added to the session
2283 * registry hash table.
2284 *
2285 * Return 0 on success else a negative value.
2286 */
2287 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2288 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2289 {
2290 int ret;
2291 struct buffer_reg_channel *reg_chan = NULL;
2292
2293 assert(reg_sess);
2294 assert(ua_chan);
2295
2296 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2297
2298 /* Create buffer registry channel. */
2299 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2300 if (ret < 0) {
2301 goto error_create;
2302 }
2303 assert(reg_chan);
2304 reg_chan->consumer_key = ua_chan->key;
2305 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2306
2307 /* Create and add a channel registry to session. */
2308 ret = ust_registry_channel_add(reg_sess->reg.ust,
2309 ua_chan->tracing_channel_id);
2310 if (ret < 0) {
2311 goto error;
2312 }
2313 buffer_reg_channel_add(reg_sess, reg_chan);
2314
2315 if (regp) {
2316 *regp = reg_chan;
2317 }
2318
2319 return 0;
2320
2321 error:
2322 /* Safe because the registry channel object was not added to any HT. */
2323 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2324 error_create:
2325 return ret;
2326 }
2327
2328 /*
2329 * Setup buffer registry channel for the given session registry and application
2330 * channel object. If regp pointer is valid, it's set with the created object.
2331 *
2332 * Return 0 on success else a negative value.
2333 */
2334 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2335 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2336 {
2337 int ret;
2338
2339 assert(reg_sess);
2340 assert(reg_chan);
2341 assert(ua_chan);
2342 assert(ua_chan->obj);
2343
2344 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2345
2346 /* Setup all streams for the registry. */
2347 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2348 if (ret < 0) {
2349 goto error;
2350 }
2351
2352 reg_chan->obj.ust = ua_chan->obj;
2353 ua_chan->obj = NULL;
2354
2355 return 0;
2356
2357 error:
2358 buffer_reg_channel_remove(reg_sess, reg_chan);
2359 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2360 return ret;
2361 }
2362
2363 /*
2364 * Send buffer registry channel to the application.
2365 *
2366 * Return 0 on success else a negative value.
2367 */
2368 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2369 struct ust_app *app, struct ust_app_session *ua_sess,
2370 struct ust_app_channel *ua_chan)
2371 {
2372 int ret;
2373 struct buffer_reg_stream *reg_stream;
2374
2375 assert(reg_chan);
2376 assert(app);
2377 assert(ua_sess);
2378 assert(ua_chan);
2379
2380 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2381
2382 ret = duplicate_channel_object(reg_chan, ua_chan);
2383 if (ret < 0) {
2384 goto error;
2385 }
2386
2387 /* Send channel to the application. */
2388 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2389 if (ret < 0) {
2390 goto error;
2391 }
2392
2393 health_code_update();
2394
2395 /* Send all streams to application. */
2396 pthread_mutex_lock(&reg_chan->stream_list_lock);
2397 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2398 struct ust_app_stream stream;
2399
2400 ret = duplicate_stream_object(reg_stream, &stream);
2401 if (ret < 0) {
2402 goto error_stream_unlock;
2403 }
2404
2405 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2406 if (ret < 0) {
2407 (void) release_ust_app_stream(-1, &stream);
2408 goto error_stream_unlock;
2409 }
2410
2411 /*
2412 * The return value is not important here. This function will output an
2413 * error if needed.
2414 */
2415 (void) release_ust_app_stream(-1, &stream);
2416 }
2417 ua_chan->is_sent = 1;
2418
2419 error_stream_unlock:
2420 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2421 error:
2422 return ret;
2423 }
2424
2425 /*
2426 * Create and send to the application the created buffers with per UID buffers.
2427 *
2428 * Return 0 on success else a negative value.
2429 */
2430 static int create_channel_per_uid(struct ust_app *app,
2431 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2432 struct ust_app_channel *ua_chan)
2433 {
2434 int ret;
2435 struct buffer_reg_uid *reg_uid;
2436 struct buffer_reg_channel *reg_chan;
2437
2438 assert(app);
2439 assert(usess);
2440 assert(ua_sess);
2441 assert(ua_chan);
2442
2443 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2444
2445 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2446 /*
2447 * The session creation handles the creation of this global registry
2448 * object. If none can be find, there is a code flow problem or a
2449 * teardown race.
2450 */
2451 assert(reg_uid);
2452
2453 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2454 reg_uid);
2455 if (!reg_chan) {
2456 /* Create the buffer registry channel object. */
2457 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2458 if (ret < 0) {
2459 goto error;
2460 }
2461 assert(reg_chan);
2462
2463 /*
2464 * Create the buffers on the consumer side. This call populates the
2465 * ust app channel object with all streams and data object.
2466 */
2467 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2468 app->bits_per_long, reg_uid->registry->reg.ust);
2469 if (ret < 0) {
2470 /*
2471 * Let's remove the previously created buffer registry channel so
2472 * it's not visible anymore in the session registry.
2473 */
2474 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2475 ua_chan->tracing_channel_id);
2476 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2477 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2478 goto error;
2479 }
2480
2481 /*
2482 * Setup the streams and add it to the session registry.
2483 */
2484 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2485 if (ret < 0) {
2486 goto error;
2487 }
2488
2489 }
2490
2491 /* Send buffers to the application. */
2492 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2493 if (ret < 0) {
2494 goto error;
2495 }
2496
2497 error:
2498 return ret;
2499 }
2500
2501 /*
2502 * Create and send to the application the created buffers with per PID buffers.
2503 *
2504 * Return 0 on success else a negative value.
2505 */
2506 static int create_channel_per_pid(struct ust_app *app,
2507 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2508 struct ust_app_channel *ua_chan)
2509 {
2510 int ret;
2511 struct ust_registry_session *registry;
2512
2513 assert(app);
2514 assert(usess);
2515 assert(ua_sess);
2516 assert(ua_chan);
2517
2518 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2519
2520 rcu_read_lock();
2521
2522 registry = get_session_registry(ua_sess);
2523 assert(registry);
2524
2525 /* Create and add a new channel registry to session. */
2526 ret = ust_registry_channel_add(registry, ua_chan->key);
2527 if (ret < 0) {
2528 goto error;
2529 }
2530
2531 /* Create and get channel on the consumer side. */
2532 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2533 app->bits_per_long, registry);
2534 if (ret < 0) {
2535 goto error;
2536 }
2537
2538 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2539 if (ret < 0) {
2540 goto error;
2541 }
2542
2543 error:
2544 rcu_read_unlock();
2545 return ret;
2546 }
2547
2548 /*
2549 * From an already allocated ust app channel, create the channel buffers if
2550 * need and send it to the application. This MUST be called with a RCU read
2551 * side lock acquired.
2552 *
2553 * Return 0 on success or else a negative value.
2554 */
2555 static int do_create_channel(struct ust_app *app,
2556 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2557 struct ust_app_channel *ua_chan)
2558 {
2559 int ret;
2560
2561 assert(app);
2562 assert(usess);
2563 assert(ua_sess);
2564 assert(ua_chan);
2565
2566 /* Handle buffer type before sending the channel to the application. */
2567 switch (usess->buffer_type) {
2568 case LTTNG_BUFFER_PER_UID:
2569 {
2570 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2571 if (ret < 0) {
2572 goto error;
2573 }
2574 break;
2575 }
2576 case LTTNG_BUFFER_PER_PID:
2577 {
2578 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2579 if (ret < 0) {
2580 goto error;
2581 }
2582 break;
2583 }
2584 default:
2585 assert(0);
2586 ret = -EINVAL;
2587 goto error;
2588 }
2589
2590 /* Initialize ust objd object using the received handle and add it. */
2591 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2592 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2593
2594 /* If channel is not enabled, disable it on the tracer */
2595 if (!ua_chan->enabled) {
2596 ret = disable_ust_channel(app, ua_sess, ua_chan);
2597 if (ret < 0) {
2598 goto error;
2599 }
2600 }
2601
2602 error:
2603 return ret;
2604 }
2605
2606 /*
2607 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2608 * newly created channel if not NULL.
2609 *
2610 * Called with UST app session lock and RCU read-side lock held.
2611 *
2612 * Return 0 on success or else a negative value.
2613 */
2614 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2615 struct ltt_ust_channel *uchan, struct ust_app *app,
2616 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2617 struct ust_app_channel **ua_chanp)
2618 {
2619 int ret = 0;
2620 struct lttng_ht_iter iter;
2621 struct lttng_ht_node_str *ua_chan_node;
2622 struct ust_app_channel *ua_chan;
2623
2624 /* Lookup channel in the ust app session */
2625 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2626 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2627 if (ua_chan_node != NULL) {
2628 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2629 goto end;
2630 }
2631
2632 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2633 if (ua_chan == NULL) {
2634 /* Only malloc can fail here */
2635 ret = -ENOMEM;
2636 goto error_alloc;
2637 }
2638 shadow_copy_channel(ua_chan, uchan);
2639
2640 /* Set channel type. */
2641 ua_chan->attr.type = type;
2642
2643 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2644 if (ret < 0) {
2645 goto error;
2646 }
2647
2648 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2649 app->pid);
2650
2651 /* Only add the channel if successful on the tracer side. */
2652 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2653
2654 end:
2655 if (ua_chanp) {
2656 *ua_chanp = ua_chan;
2657 }
2658
2659 /* Everything went well. */
2660 return 0;
2661
2662 error:
2663 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2664 error_alloc:
2665 return ret;
2666 }
2667
2668 /*
2669 * Create UST app event and create it on the tracer side.
2670 *
2671 * Called with ust app session mutex held.
2672 */
2673 static
2674 int create_ust_app_event(struct ust_app_session *ua_sess,
2675 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2676 struct ust_app *app)
2677 {
2678 int ret = 0;
2679 struct ust_app_event *ua_event;
2680
2681 /* Get event node */
2682 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2683 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
2684 if (ua_event != NULL) {
2685 ret = -EEXIST;
2686 goto end;
2687 }
2688
2689 /* Does not exist so create one */
2690 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2691 if (ua_event == NULL) {
2692 /* Only malloc can failed so something is really wrong */
2693 ret = -ENOMEM;
2694 goto end;
2695 }
2696 shadow_copy_event(ua_event, uevent);
2697
2698 /* Create it on the tracer side */
2699 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2700 if (ret < 0) {
2701 /* Not found previously means that it does not exist on the tracer */
2702 assert(ret != -LTTNG_UST_ERR_EXIST);
2703 goto error;
2704 }
2705
2706 add_unique_ust_app_event(ua_chan, ua_event);
2707
2708 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2709 app->pid);
2710
2711 end:
2712 return ret;
2713
2714 error:
2715 /* Valid. Calling here is already in a read side lock */
2716 delete_ust_app_event(-1, ua_event);
2717 return ret;
2718 }
2719
2720 /*
2721 * Create UST metadata and open it on the tracer side.
2722 *
2723 * Called with UST app session lock held and RCU read side lock.
2724 */
2725 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2726 struct ust_app *app, struct consumer_output *consumer)
2727 {
2728 int ret = 0;
2729 struct ust_app_channel *metadata;
2730 struct consumer_socket *socket;
2731 struct ust_registry_session *registry;
2732
2733 assert(ua_sess);
2734 assert(app);
2735 assert(consumer);
2736
2737 registry = get_session_registry(ua_sess);
2738 assert(registry);
2739
2740 /* Metadata already exists for this registry or it was closed previously */
2741 if (registry->metadata_key || registry->metadata_closed) {
2742 ret = 0;
2743 goto error;
2744 }
2745
2746 /* Allocate UST metadata */
2747 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2748 if (!metadata) {
2749 /* malloc() failed */
2750 ret = -ENOMEM;
2751 goto error;
2752 }
2753
2754 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
2755
2756 /* Need one fd for the channel. */
2757 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2758 if (ret < 0) {
2759 ERR("Exhausted number of available FD upon create metadata");
2760 goto error;
2761 }
2762
2763 /* Get the right consumer socket for the application. */
2764 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2765 if (!socket) {
2766 ret = -EINVAL;
2767 goto error_consumer;
2768 }
2769
2770 /*
2771 * Keep metadata key so we can identify it on the consumer side. Assign it
2772 * to the registry *before* we ask the consumer so we avoid the race of the
2773 * consumer requesting the metadata and the ask_channel call on our side
2774 * did not returned yet.
2775 */
2776 registry->metadata_key = metadata->key;
2777
2778 /*
2779 * Ask the metadata channel creation to the consumer. The metadata object
2780 * will be created by the consumer and kept their. However, the stream is
2781 * never added or monitored until we do a first push metadata to the
2782 * consumer.
2783 */
2784 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2785 registry);
2786 if (ret < 0) {
2787 /* Nullify the metadata key so we don't try to close it later on. */
2788 registry->metadata_key = 0;
2789 goto error_consumer;
2790 }
2791
2792 /*
2793 * The setup command will make the metadata stream be sent to the relayd,
2794 * if applicable, and the thread managing the metadatas. This is important
2795 * because after this point, if an error occurs, the only way the stream
2796 * can be deleted is to be monitored in the consumer.
2797 */
2798 ret = consumer_setup_metadata(socket, metadata->key);
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 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2806 metadata->key, app->pid);
2807
2808 error_consumer:
2809 lttng_fd_put(LTTNG_FD_APPS, 1);
2810 delete_ust_app_channel(-1, metadata, app);
2811 error:
2812 return ret;
2813 }
2814
2815 /*
2816 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2817 * acquired before calling this function.
2818 */
2819 struct ust_app *ust_app_find_by_pid(pid_t pid)
2820 {
2821 struct ust_app *app = NULL;
2822 struct lttng_ht_node_ulong *node;
2823 struct lttng_ht_iter iter;
2824
2825 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2826 node = lttng_ht_iter_get_node_ulong(&iter);
2827 if (node == NULL) {
2828 DBG2("UST app no found with pid %d", pid);
2829 goto error;
2830 }
2831
2832 DBG2("Found UST app by pid %d", pid);
2833
2834 app = caa_container_of(node, struct ust_app, pid_n);
2835
2836 error:
2837 return app;
2838 }
2839
2840 /*
2841 * Allocate and init an UST app object using the registration information and
2842 * the command socket. This is called when the command socket connects to the
2843 * session daemon.
2844 *
2845 * The object is returned on success or else NULL.
2846 */
2847 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2848 {
2849 struct ust_app *lta = NULL;
2850
2851 assert(msg);
2852 assert(sock >= 0);
2853
2854 DBG3("UST app creating application for socket %d", sock);
2855
2856 if ((msg->bits_per_long == 64 &&
2857 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2858 || (msg->bits_per_long == 32 &&
2859 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2860 ERR("Registration failed: application \"%s\" (pid: %d) has "
2861 "%d-bit long, but no consumerd for this size is available.\n",
2862 msg->name, msg->pid, msg->bits_per_long);
2863 goto error;
2864 }
2865
2866 lta = zmalloc(sizeof(struct ust_app));
2867 if (lta == NULL) {
2868 PERROR("malloc");
2869 goto error;
2870 }
2871
2872 lta->ppid = msg->ppid;
2873 lta->uid = msg->uid;
2874 lta->gid = msg->gid;
2875
2876 lta->bits_per_long = msg->bits_per_long;
2877 lta->uint8_t_alignment = msg->uint8_t_alignment;
2878 lta->uint16_t_alignment = msg->uint16_t_alignment;
2879 lta->uint32_t_alignment = msg->uint32_t_alignment;
2880 lta->uint64_t_alignment = msg->uint64_t_alignment;
2881 lta->long_alignment = msg->long_alignment;
2882 lta->byte_order = msg->byte_order;
2883
2884 lta->v_major = msg->major;
2885 lta->v_minor = msg->minor;
2886 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2887 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2888 lta->notify_sock = -1;
2889
2890 /* Copy name and make sure it's NULL terminated. */
2891 strncpy(lta->name, msg->name, sizeof(lta->name));
2892 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2893
2894 /*
2895 * Before this can be called, when receiving the registration information,
2896 * the application compatibility is checked. So, at this point, the
2897 * application can work with this session daemon.
2898 */
2899 lta->compatible = 1;
2900
2901 lta->pid = msg->pid;
2902 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
2903 lta->sock = sock;
2904 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
2905
2906 CDS_INIT_LIST_HEAD(&lta->teardown_head);
2907
2908 error:
2909 return lta;
2910 }
2911
2912 /*
2913 * For a given application object, add it to every hash table.
2914 */
2915 void ust_app_add(struct ust_app *app)
2916 {
2917 assert(app);
2918 assert(app->notify_sock >= 0);
2919
2920 rcu_read_lock();
2921
2922 /*
2923 * On a re-registration, we want to kick out the previous registration of
2924 * that pid
2925 */
2926 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
2927
2928 /*
2929 * The socket _should_ be unique until _we_ call close. So, a add_unique
2930 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
2931 * already in the table.
2932 */
2933 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
2934
2935 /* Add application to the notify socket hash table. */
2936 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
2937 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
2938
2939 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
2940 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
2941 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
2942 app->v_minor);
2943
2944 rcu_read_unlock();
2945 }
2946
2947 /*
2948 * Set the application version into the object.
2949 *
2950 * Return 0 on success else a negative value either an errno code or a
2951 * LTTng-UST error code.
2952 */
2953 int ust_app_version(struct ust_app *app)
2954 {
2955 int ret;
2956
2957 assert(app);
2958
2959 ret = ustctl_tracer_version(app->sock, &app->version);
2960 if (ret < 0) {
2961 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
2962 ERR("UST app %d verson failed with ret %d", app->sock, ret);
2963 } else {
2964 DBG3("UST app %d verion failed. Application is dead", app->sock);
2965 }
2966 }
2967
2968 return ret;
2969 }
2970
2971 /*
2972 * Unregister app by removing it from the global traceable app list and freeing
2973 * the data struct.
2974 *
2975 * The socket is already closed at this point so no close to sock.
2976 */
2977 void ust_app_unregister(int sock)
2978 {
2979 struct ust_app *lta;
2980 struct lttng_ht_node_ulong *node;
2981 struct lttng_ht_iter iter;
2982 struct ust_app_session *ua_sess;
2983 int ret;
2984
2985 rcu_read_lock();
2986
2987 /* Get the node reference for a call_rcu */
2988 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
2989 node = lttng_ht_iter_get_node_ulong(&iter);
2990 assert(node);
2991
2992 lta = caa_container_of(node, struct ust_app, sock_n);
2993 DBG("PID %d unregistering with sock %d", lta->pid, sock);
2994
2995 /* Remove application from PID hash table */
2996 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
2997 assert(!ret);
2998
2999 /*
3000 * Remove application from notify hash table. The thread handling the
3001 * notify socket could have deleted the node so ignore on error because
3002 * either way it's valid. The close of that socket is handled by the other
3003 * thread.
3004 */
3005 iter.iter.node = &lta->notify_sock_n.node;
3006 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3007
3008 /*
3009 * Ignore return value since the node might have been removed before by an
3010 * add replace during app registration because the PID can be reassigned by
3011 * the OS.
3012 */
3013 iter.iter.node = &lta->pid_n.node;
3014 ret = lttng_ht_del(ust_app_ht, &iter);
3015 if (ret) {
3016 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3017 lta->pid);
3018 }
3019
3020 /* Remove sessions so they are not visible during deletion.*/
3021 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3022 node.node) {
3023 struct ust_registry_session *registry;
3024
3025 ret = lttng_ht_del(lta->sessions, &iter);
3026 if (ret) {
3027 /* The session was already removed so scheduled for teardown. */
3028 continue;
3029 }
3030
3031 /*
3032 * Add session to list for teardown. This is safe since at this point we
3033 * are the only one using this list.
3034 */
3035 pthread_mutex_lock(&ua_sess->lock);
3036
3037 /*
3038 * Normally, this is done in the delete session process which is
3039 * executed in the call rcu below. However, upon registration we can't
3040 * afford to wait for the grace period before pushing data or else the
3041 * data pending feature can race between the unregistration and stop
3042 * command where the data pending command is sent *before* the grace
3043 * period ended.
3044 *
3045 * The close metadata below nullifies the metadata pointer in the
3046 * session so the delete session will NOT push/close a second time.
3047 */
3048 registry = get_session_registry(ua_sess);
3049 if (registry && !registry->metadata_closed) {
3050 /* Push metadata for application before freeing the application. */
3051 (void) push_metadata(registry, ua_sess->consumer);
3052
3053 /*
3054 * Don't ask to close metadata for global per UID buffers. Close
3055 * metadata only on destroy trace session in this case. Also, the
3056 * previous push metadata could have flag the metadata registry to
3057 * close so don't send a close command if closed.
3058 */
3059 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
3060 !registry->metadata_closed) {
3061 /* And ask to close it for this session registry. */
3062 (void) close_metadata(registry, ua_sess->consumer);
3063 }
3064 }
3065
3066 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3067 pthread_mutex_unlock(&ua_sess->lock);
3068 }
3069
3070 /* Free memory */
3071 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3072
3073 rcu_read_unlock();
3074 return;
3075 }
3076
3077 /*
3078 * Fill events array with all events name of all registered apps.
3079 */
3080 int ust_app_list_events(struct lttng_event **events)
3081 {
3082 int ret, handle;
3083 size_t nbmem, count = 0;
3084 struct lttng_ht_iter iter;
3085 struct ust_app *app;
3086 struct lttng_event *tmp_event;
3087
3088 nbmem = UST_APP_EVENT_LIST_SIZE;
3089 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3090 if (tmp_event == NULL) {
3091 PERROR("zmalloc ust app events");
3092 ret = -ENOMEM;
3093 goto error;
3094 }
3095
3096 rcu_read_lock();
3097
3098 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3099 struct lttng_ust_tracepoint_iter uiter;
3100
3101 health_code_update();
3102
3103 if (!app->compatible) {
3104 /*
3105 * TODO: In time, we should notice the caller of this error by
3106 * telling him that this is a version error.
3107 */
3108 continue;
3109 }
3110 handle = ustctl_tracepoint_list(app->sock);
3111 if (handle < 0) {
3112 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3113 ERR("UST app list events getting handle failed for app pid %d",
3114 app->pid);
3115 }
3116 continue;
3117 }
3118
3119 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3120 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3121 /* Handle ustctl error. */
3122 if (ret < 0) {
3123 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3124 ERR("UST app tp list get failed for app %d with ret %d",
3125 app->sock, ret);
3126 } else {
3127 DBG3("UST app tp list get failed. Application is dead");
3128 /*
3129 * This is normal behavior, an application can die during the
3130 * creation process. Don't report an error so the execution can
3131 * continue normally. Continue normal execution.
3132 */
3133 break;
3134 }
3135 free(tmp_event);
3136 goto rcu_error;
3137 }
3138
3139 health_code_update();
3140 if (count >= nbmem) {
3141 /* In case the realloc fails, we free the memory */
3142 struct lttng_event *new_tmp_event;
3143 size_t new_nbmem;
3144
3145 new_nbmem = nbmem << 1;
3146 DBG2("Reallocating event list from %zu to %zu entries",
3147 nbmem, new_nbmem);
3148 new_tmp_event = realloc(tmp_event,
3149 new_nbmem * sizeof(struct lttng_event));
3150 if (new_tmp_event == NULL) {
3151 PERROR("realloc ust app events");
3152 free(tmp_event);
3153 ret = -ENOMEM;
3154 goto rcu_error;
3155 }
3156 /* Zero the new memory */
3157 memset(new_tmp_event + nbmem, 0,
3158 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3159 nbmem = new_nbmem;
3160 tmp_event = new_tmp_event;
3161 }
3162 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3163 tmp_event[count].loglevel = uiter.loglevel;
3164 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3165 tmp_event[count].pid = app->pid;
3166 tmp_event[count].enabled = -1;
3167 count++;
3168 }
3169 }
3170
3171 ret = count;
3172 *events = tmp_event;
3173
3174 DBG2("UST app list events done (%zu events)", count);
3175
3176 rcu_error:
3177 rcu_read_unlock();
3178 error:
3179 health_code_update();
3180 return ret;
3181 }
3182
3183 /*
3184 * Fill events array with all events name of all registered apps.
3185 */
3186 int ust_app_list_event_fields(struct lttng_event_field **fields)
3187 {
3188 int ret, handle;
3189 size_t nbmem, count = 0;
3190 struct lttng_ht_iter iter;
3191 struct ust_app *app;
3192 struct lttng_event_field *tmp_event;
3193
3194 nbmem = UST_APP_EVENT_LIST_SIZE;
3195 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3196 if (tmp_event == NULL) {
3197 PERROR("zmalloc ust app event fields");
3198 ret = -ENOMEM;
3199 goto error;
3200 }
3201
3202 rcu_read_lock();
3203
3204 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3205 struct lttng_ust_field_iter uiter;
3206
3207 health_code_update();
3208
3209 if (!app->compatible) {
3210 /*
3211 * TODO: In time, we should notice the caller of this error by
3212 * telling him that this is a version error.
3213 */
3214 continue;
3215 }
3216 handle = ustctl_tracepoint_field_list(app->sock);
3217 if (handle < 0) {
3218 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3219 ERR("UST app list field getting handle failed for app pid %d",
3220 app->pid);
3221 }
3222 continue;
3223 }
3224
3225 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3226 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3227 /* Handle ustctl error. */
3228 if (ret < 0) {
3229 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3230 ERR("UST app tp list field failed for app %d with ret %d",
3231 app->sock, ret);
3232 } else {
3233 DBG3("UST app tp list field failed. Application is dead");
3234 /*
3235 * This is normal behavior, an application can die during the
3236 * creation process. Don't report an error so the execution can
3237 * continue normally. Reset list and count for next app.
3238 */
3239 break;
3240 }
3241 free(tmp_event);
3242 goto rcu_error;
3243 }
3244
3245 health_code_update();
3246 if (count >= nbmem) {
3247 /* In case the realloc fails, we free the memory */
3248 struct lttng_event_field *new_tmp_event;
3249 size_t new_nbmem;
3250
3251 new_nbmem = nbmem << 1;
3252 DBG2("Reallocating event field list from %zu to %zu entries",
3253 nbmem, new_nbmem);
3254 new_tmp_event = realloc(tmp_event,
3255 new_nbmem * sizeof(struct lttng_event_field));
3256 if (new_tmp_event == NULL) {
3257 PERROR("realloc ust app event fields");
3258 free(tmp_event);
3259 ret = -ENOMEM;
3260 goto rcu_error;
3261 }
3262 /* Zero the new memory */
3263 memset(new_tmp_event + nbmem, 0,
3264 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3265 nbmem = new_nbmem;
3266 tmp_event = new_tmp_event;
3267 }
3268
3269 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3270 /* Mapping between these enums matches 1 to 1. */
3271 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3272 tmp_event[count].nowrite = uiter.nowrite;
3273
3274 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3275 tmp_event[count].event.loglevel = uiter.loglevel;
3276 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3277 tmp_event[count].event.pid = app->pid;
3278 tmp_event[count].event.enabled = -1;
3279 count++;
3280 }
3281 }
3282
3283 ret = count;
3284 *fields = tmp_event;
3285
3286 DBG2("UST app list event fields done (%zu events)", count);
3287
3288 rcu_error:
3289 rcu_read_unlock();
3290 error:
3291 health_code_update();
3292 return ret;
3293 }
3294
3295 /*
3296 * Free and clean all traceable apps of the global list.
3297 *
3298 * Should _NOT_ be called with RCU read-side lock held.
3299 */
3300 void ust_app_clean_list(void)
3301 {
3302 int ret;
3303 struct ust_app *app;
3304 struct lttng_ht_iter iter;
3305
3306 DBG2("UST app cleaning registered apps hash table");
3307
3308 rcu_read_lock();
3309
3310 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3311 ret = lttng_ht_del(ust_app_ht, &iter);
3312 assert(!ret);
3313 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3314 }
3315
3316 /* Cleanup socket hash table */
3317 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3318 sock_n.node) {
3319 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3320 assert(!ret);
3321 }
3322
3323 /* Cleanup notify socket hash table */
3324 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3325 notify_sock_n.node) {
3326 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3327 assert(!ret);
3328 }
3329 rcu_read_unlock();
3330
3331 /* Destroy is done only when the ht is empty */
3332 ht_cleanup_push(ust_app_ht);
3333 ht_cleanup_push(ust_app_ht_by_sock);
3334 ht_cleanup_push(ust_app_ht_by_notify_sock);
3335 }
3336
3337 /*
3338 * Init UST app hash table.
3339 */
3340 void ust_app_ht_alloc(void)
3341 {
3342 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3343 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3344 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3345 }
3346
3347 /*
3348 * For a specific UST session, disable the channel for all registered apps.
3349 */
3350 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3351 struct ltt_ust_channel *uchan)
3352 {
3353 int ret = 0;
3354 struct lttng_ht_iter iter;
3355 struct lttng_ht_node_str *ua_chan_node;
3356 struct ust_app *app;
3357 struct ust_app_session *ua_sess;
3358 struct ust_app_channel *ua_chan;
3359
3360 if (usess == NULL || uchan == NULL) {
3361 ERR("Disabling UST global channel with NULL values");
3362 ret = -1;
3363 goto error;
3364 }
3365
3366 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3367 uchan->name, usess->id);
3368
3369 rcu_read_lock();
3370
3371 /* For every registered applications */
3372 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3373 struct lttng_ht_iter uiter;
3374 if (!app->compatible) {
3375 /*
3376 * TODO: In time, we should notice the caller of this error by
3377 * telling him that this is a version error.
3378 */
3379 continue;
3380 }
3381 ua_sess = lookup_session_by_app(usess, app);
3382 if (ua_sess == NULL) {
3383 continue;
3384 }
3385
3386 /* Get channel */
3387 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3388 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3389 /* If the session if found for the app, the channel must be there */
3390 assert(ua_chan_node);
3391
3392 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3393 /* The channel must not be already disabled */
3394 assert(ua_chan->enabled == 1);
3395
3396 /* Disable channel onto application */
3397 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3398 if (ret < 0) {
3399 /* XXX: We might want to report this error at some point... */
3400 continue;
3401 }
3402 }
3403
3404 rcu_read_unlock();
3405
3406 error:
3407 return ret;
3408 }
3409
3410 /*
3411 * For a specific UST session, enable the channel for all registered apps.
3412 */
3413 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3414 struct ltt_ust_channel *uchan)
3415 {
3416 int ret = 0;
3417 struct lttng_ht_iter iter;
3418 struct ust_app *app;
3419 struct ust_app_session *ua_sess;
3420
3421 if (usess == NULL || uchan == NULL) {
3422 ERR("Adding UST global channel to NULL values");
3423 ret = -1;
3424 goto error;
3425 }
3426
3427 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3428 uchan->name, usess->id);
3429
3430 rcu_read_lock();
3431
3432 /* For every registered applications */
3433 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3434 if (!app->compatible) {
3435 /*
3436 * TODO: In time, we should notice the caller of this error by
3437 * telling him that this is a version error.
3438 */
3439 continue;
3440 }
3441 ua_sess = lookup_session_by_app(usess, app);
3442 if (ua_sess == NULL) {
3443 continue;
3444 }
3445
3446 /* Enable channel onto application */
3447 ret = enable_ust_app_channel(ua_sess, uchan, app);
3448 if (ret < 0) {
3449 /* XXX: We might want to report this error at some point... */
3450 continue;
3451 }
3452 }
3453
3454 rcu_read_unlock();
3455
3456 error:
3457 return ret;
3458 }
3459
3460 /*
3461 * Disable an event in a channel and for a specific session.
3462 */
3463 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3464 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3465 {
3466 int ret = 0;
3467 struct lttng_ht_iter iter, uiter;
3468 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
3469 struct ust_app *app;
3470 struct ust_app_session *ua_sess;
3471 struct ust_app_channel *ua_chan;
3472 struct ust_app_event *ua_event;
3473
3474 DBG("UST app disabling event %s for all apps in channel "
3475 "%s for session id %" PRIu64,
3476 uevent->attr.name, uchan->name, usess->id);
3477
3478 rcu_read_lock();
3479
3480 /* For all registered applications */
3481 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3482 if (!app->compatible) {
3483 /*
3484 * TODO: In time, we should notice the caller of this error by
3485 * telling him that this is a version error.
3486 */
3487 continue;
3488 }
3489 ua_sess = lookup_session_by_app(usess, app);
3490 if (ua_sess == NULL) {
3491 /* Next app */
3492 continue;
3493 }
3494
3495 /* Lookup channel in the ust app session */
3496 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3497 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3498 if (ua_chan_node == NULL) {
3499 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3500 "Skipping", uchan->name, usess->id, app->pid);
3501 continue;
3502 }
3503 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3504
3505 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
3506 ua_event_node = lttng_ht_iter_get_node_str(&uiter);
3507 if (ua_event_node == NULL) {
3508 DBG2("Event %s not found in channel %s for app pid %d."
3509 "Skipping", uevent->attr.name, uchan->name, app->pid);
3510 continue;
3511 }
3512 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
3513
3514 ret = disable_ust_app_event(ua_sess, ua_event, app);
3515 if (ret < 0) {
3516 /* XXX: Report error someday... */
3517 continue;
3518 }
3519 }
3520
3521 rcu_read_unlock();
3522
3523 return ret;
3524 }
3525
3526 /*
3527 * For a specific UST session, create the channel for all registered apps.
3528 */
3529 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3530 struct ltt_ust_channel *uchan)
3531 {
3532 int ret = 0, created;
3533 struct lttng_ht_iter iter;
3534 struct ust_app *app;
3535 struct ust_app_session *ua_sess = NULL;
3536
3537 /* Very wrong code flow */
3538 assert(usess);
3539 assert(uchan);
3540
3541 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3542 uchan->name, usess->id);
3543
3544 rcu_read_lock();
3545
3546 /* For every registered applications */
3547 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3548 if (!app->compatible) {
3549 /*
3550 * TODO: In time, we should notice the caller of this error by
3551 * telling him that this is a version error.
3552 */
3553 continue;
3554 }
3555 /*
3556 * Create session on the tracer side and add it to app session HT. Note
3557 * that if session exist, it will simply return a pointer to the ust
3558 * app session.
3559 */
3560 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3561 if (ret < 0) {
3562 switch (ret) {
3563 case -ENOTCONN:
3564 /*
3565 * The application's socket is not valid. Either a bad socket
3566 * or a timeout on it. We can't inform the caller that for a
3567 * specific app, the session failed so lets continue here.
3568 */
3569 continue;
3570 case -ENOMEM:
3571 default:
3572 goto error_rcu_unlock;
3573 }
3574 }
3575 assert(ua_sess);
3576
3577 pthread_mutex_lock(&ua_sess->lock);
3578 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
3579 sizeof(uchan->name))) {
3580 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
3581 ret = 0;
3582 } else {
3583 /* Create channel onto application. We don't need the chan ref. */
3584 ret = create_ust_app_channel(ua_sess, uchan, app,
3585 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
3586 }
3587 pthread_mutex_unlock(&ua_sess->lock);
3588 if (ret < 0) {
3589 if (ret == -ENOMEM) {
3590 /* No more memory is a fatal error. Stop right now. */
3591 goto error_rcu_unlock;
3592 }
3593 /* Cleanup the created session if it's the case. */
3594 if (created) {
3595 destroy_app_session(app, ua_sess);
3596 }
3597 }
3598 }
3599
3600 error_rcu_unlock:
3601 rcu_read_unlock();
3602 return ret;
3603 }
3604
3605 /*
3606 * Enable event for a specific session and channel on the tracer.
3607 */
3608 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
3609 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3610 {
3611 int ret = 0;
3612 struct lttng_ht_iter iter, uiter;
3613 struct lttng_ht_node_str *ua_chan_node;
3614 struct ust_app *app;
3615 struct ust_app_session *ua_sess;
3616 struct ust_app_channel *ua_chan;
3617 struct ust_app_event *ua_event;
3618
3619 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
3620 uevent->attr.name, usess->id);
3621
3622 /*
3623 * NOTE: At this point, this function is called only if the session and
3624 * channel passed are already created for all apps. and enabled on the
3625 * tracer also.
3626 */
3627
3628 rcu_read_lock();
3629
3630 /* For all registered applications */
3631 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3632 if (!app->compatible) {
3633 /*
3634 * TODO: In time, we should notice the caller of this error by
3635 * telling him that this is a version error.
3636 */
3637 continue;
3638 }
3639 ua_sess = lookup_session_by_app(usess, app);
3640 if (!ua_sess) {
3641 /* The application has problem or is probably dead. */
3642 continue;
3643 }
3644
3645 pthread_mutex_lock(&ua_sess->lock);
3646
3647 /* Lookup channel in the ust app session */
3648 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3649 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3650 /* If the channel is not found, there is a code flow error */
3651 assert(ua_chan_node);
3652
3653 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3654
3655 /* Get event node */
3656 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3657 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3658 if (ua_event == NULL) {
3659 DBG3("UST app enable event %s not found for app PID %d."
3660 "Skipping app", uevent->attr.name, app->pid);
3661 goto next_app;
3662 }
3663
3664 ret = enable_ust_app_event(ua_sess, ua_event, app);
3665 if (ret < 0) {
3666 pthread_mutex_unlock(&ua_sess->lock);
3667 goto error;
3668 }
3669 next_app:
3670 pthread_mutex_unlock(&ua_sess->lock);
3671 }
3672
3673 error:
3674 rcu_read_unlock();
3675 return ret;
3676 }
3677
3678 /*
3679 * For a specific existing UST session and UST channel, creates the event for
3680 * all registered apps.
3681 */
3682 int ust_app_create_event_glb(struct ltt_ust_session *usess,
3683 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3684 {
3685 int ret = 0;
3686 struct lttng_ht_iter iter, uiter;
3687 struct lttng_ht_node_str *ua_chan_node;
3688 struct ust_app *app;
3689 struct ust_app_session *ua_sess;
3690 struct ust_app_channel *ua_chan;
3691
3692 DBG("UST app creating event %s for all apps for session id %" PRIu64,
3693 uevent->attr.name, usess->id);
3694
3695 rcu_read_lock();
3696
3697 /* For all registered applications */
3698 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3699 if (!app->compatible) {
3700 /*
3701 * TODO: In time, we should notice the caller of this error by
3702 * telling him that this is a version error.
3703 */
3704 continue;
3705 }
3706 ua_sess = lookup_session_by_app(usess, app);
3707 if (!ua_sess) {
3708 /* The application has problem or is probably dead. */
3709 continue;
3710 }
3711
3712 pthread_mutex_lock(&ua_sess->lock);
3713 /* Lookup channel in the ust app session */
3714 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3715 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3716 /* If the channel is not found, there is a code flow error */
3717 assert(ua_chan_node);
3718
3719 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3720
3721 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
3722 pthread_mutex_unlock(&ua_sess->lock);
3723 if (ret < 0) {
3724 if (ret != -LTTNG_UST_ERR_EXIST) {
3725 /* Possible value at this point: -ENOMEM. If so, we stop! */
3726 break;
3727 }
3728 DBG2("UST app event %s already exist on app PID %d",
3729 uevent->attr.name, app->pid);
3730 continue;
3731 }
3732 }
3733
3734 rcu_read_unlock();
3735
3736 return ret;
3737 }
3738
3739 /*
3740 * Start tracing for a specific UST session and app.
3741 */
3742 static
3743 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
3744 {
3745 int ret = 0;
3746 struct ust_app_session *ua_sess;
3747
3748 DBG("Starting tracing for ust app pid %d", app->pid);
3749
3750 rcu_read_lock();
3751
3752 if (!app->compatible) {
3753 goto end;
3754 }
3755
3756 ua_sess = lookup_session_by_app(usess, app);
3757 if (ua_sess == NULL) {
3758 /* The session is in teardown process. Ignore and continue. */
3759 goto end;
3760 }
3761
3762 pthread_mutex_lock(&ua_sess->lock);
3763
3764 /* Upon restart, we skip the setup, already done */
3765 if (ua_sess->started) {
3766 goto skip_setup;
3767 }
3768
3769 /* Create directories if consumer is LOCAL and has a path defined. */
3770 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
3771 strlen(usess->consumer->dst.trace_path) > 0) {
3772 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
3773 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
3774 if (ret < 0) {
3775 if (ret != -EEXIST) {
3776 ERR("Trace directory creation error");
3777 goto error_unlock;
3778 }
3779 }
3780 }
3781
3782 /*
3783 * Create the metadata for the application. This returns gracefully if a
3784 * metadata was already set for the session.
3785 */
3786 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
3787 if (ret < 0) {
3788 goto error_unlock;
3789 }
3790
3791 health_code_update();
3792
3793 skip_setup:
3794 /* This start the UST tracing */
3795 ret = ustctl_start_session(app->sock, ua_sess->handle);
3796 if (ret < 0) {
3797 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3798 ERR("Error starting tracing for app pid: %d (ret: %d)",
3799 app->pid, ret);
3800 } else {
3801 DBG("UST app start session failed. Application is dead.");
3802 /*
3803 * This is normal behavior, an application can die during the
3804 * creation process. Don't report an error so the execution can
3805 * continue normally.
3806 */
3807 pthread_mutex_unlock(&ua_sess->lock);
3808 goto end;
3809 }
3810 goto error_unlock;
3811 }
3812
3813 /* Indicate that the session has been started once */
3814 ua_sess->started = 1;
3815
3816 pthread_mutex_unlock(&ua_sess->lock);
3817
3818 health_code_update();
3819
3820 /* Quiescent wait after starting trace */
3821 ret = ustctl_wait_quiescent(app->sock);
3822 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3823 ERR("UST app wait quiescent failed for app pid %d ret %d",
3824 app->pid, ret);
3825 }
3826
3827 end:
3828 rcu_read_unlock();
3829 health_code_update();
3830 return 0;
3831
3832 error_unlock:
3833 pthread_mutex_unlock(&ua_sess->lock);
3834 rcu_read_unlock();
3835 health_code_update();
3836 return -1;
3837 }
3838
3839 /*
3840 * Stop tracing for a specific UST session and app.
3841 */
3842 static
3843 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
3844 {
3845 int ret = 0;
3846 struct ust_app_session *ua_sess;
3847 struct ust_registry_session *registry;
3848
3849 DBG("Stopping tracing for ust app pid %d", app->pid);
3850
3851 rcu_read_lock();
3852
3853 if (!app->compatible) {
3854 goto end_no_session;
3855 }
3856
3857 ua_sess = lookup_session_by_app(usess, app);
3858 if (ua_sess == NULL) {
3859 goto end_no_session;
3860 }
3861
3862 pthread_mutex_lock(&ua_sess->lock);
3863
3864 /*
3865 * If started = 0, it means that stop trace has been called for a session
3866 * that was never started. It's possible since we can have a fail start
3867 * from either the application manager thread or the command thread. Simply
3868 * indicate that this is a stop error.
3869 */
3870 if (!ua_sess->started) {
3871 goto error_rcu_unlock;
3872 }
3873
3874 health_code_update();
3875
3876 /* This inhibits UST tracing */
3877 ret = ustctl_stop_session(app->sock, ua_sess->handle);
3878 if (ret < 0) {
3879 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3880 ERR("Error stopping tracing for app pid: %d (ret: %d)",
3881 app->pid, ret);
3882 } else {
3883 DBG("UST app stop session failed. Application is dead.");
3884 /*
3885 * This is normal behavior, an application can die during the
3886 * creation process. Don't report an error so the execution can
3887 * continue normally.
3888 */
3889 goto end_unlock;
3890 }
3891 goto error_rcu_unlock;
3892 }
3893
3894 health_code_update();
3895
3896 /* Quiescent wait after stopping trace */
3897 ret = ustctl_wait_quiescent(app->sock);
3898 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3899 ERR("UST app wait quiescent failed for app pid %d ret %d",
3900 app->pid, ret);
3901 }
3902
3903 health_code_update();
3904
3905 registry = get_session_registry(ua_sess);
3906 assert(registry);
3907
3908 if (!registry->metadata_closed) {
3909 /* Push metadata for application before freeing the application. */
3910 (void) push_metadata(registry, ua_sess->consumer);
3911 }
3912
3913 end_unlock:
3914 pthread_mutex_unlock(&ua_sess->lock);
3915 end_no_session:
3916 rcu_read_unlock();
3917 health_code_update();
3918 return 0;
3919
3920 error_rcu_unlock:
3921 pthread_mutex_unlock(&ua_sess->lock);
3922 rcu_read_unlock();
3923 health_code_update();
3924 return -1;
3925 }
3926
3927 /*
3928 * Flush buffers for a specific UST session and app.
3929 */
3930 static
3931 int ust_app_flush_trace(struct ltt_ust_session *usess, struct ust_app *app)
3932 {
3933 int ret = 0;
3934 struct lttng_ht_iter iter;
3935 struct ust_app_session *ua_sess;
3936 struct ust_app_channel *ua_chan;
3937
3938 DBG("Flushing buffers for ust app pid %d", app->pid);
3939
3940 rcu_read_lock();
3941
3942 if (!app->compatible) {
3943 goto end_no_session;
3944 }
3945
3946 ua_sess = lookup_session_by_app(usess, app);
3947 if (ua_sess == NULL) {
3948 goto end_no_session;
3949 }
3950
3951 pthread_mutex_lock(&ua_sess->lock);
3952
3953 health_code_update();
3954
3955 /* Flushing buffers */
3956 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
3957 node.node) {
3958 health_code_update();
3959 assert(ua_chan->is_sent);
3960 ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
3961 if (ret < 0) {
3962 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3963 ERR("UST app PID %d channel %s flush failed with ret %d",
3964 app->pid, ua_chan->name, ret);
3965 } else {
3966 DBG3("UST app failed to flush %s. Application is dead.",
3967 ua_chan->name);
3968 /*
3969 * This is normal behavior, an application can die during the
3970 * creation process. Don't report an error so the execution can
3971 * continue normally.
3972 */
3973 }
3974 /* Continuing flushing all buffers */
3975 continue;
3976 }
3977 }
3978
3979 health_code_update();
3980
3981 pthread_mutex_unlock(&ua_sess->lock);
3982 end_no_session:
3983 rcu_read_unlock();
3984 health_code_update();
3985 return 0;
3986 }
3987
3988 /*
3989 * Destroy a specific UST session in apps.
3990 */
3991 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
3992 {
3993 int ret;
3994 struct ust_app_session *ua_sess;
3995 struct lttng_ht_iter iter;
3996 struct lttng_ht_node_u64 *node;
3997
3998 DBG("Destroy tracing for ust app pid %d", app->pid);
3999
4000 rcu_read_lock();
4001
4002 if (!app->compatible) {
4003 goto end;
4004 }
4005
4006 __lookup_session_by_app(usess, app, &iter);
4007 node = lttng_ht_iter_get_node_u64(&iter);
4008 if (node == NULL) {
4009 /* Session is being or is deleted. */
4010 goto end;
4011 }
4012 ua_sess = caa_container_of(node, struct ust_app_session, node);
4013
4014 health_code_update();
4015 destroy_app_session(app, ua_sess);
4016
4017 health_code_update();
4018
4019 /* Quiescent wait after stopping trace */
4020 ret = ustctl_wait_quiescent(app->sock);
4021 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4022 ERR("UST app wait quiescent failed for app pid %d ret %d",
4023 app->pid, ret);
4024 }
4025 end:
4026 rcu_read_unlock();
4027 health_code_update();
4028 return 0;
4029 }
4030
4031 /*
4032 * Start tracing for the UST session.
4033 */
4034 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4035 {
4036 int ret = 0;
4037 struct lttng_ht_iter iter;
4038 struct ust_app *app;
4039
4040 DBG("Starting all UST traces");
4041
4042 rcu_read_lock();
4043
4044 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4045 ret = ust_app_start_trace(usess, app);
4046 if (ret < 0) {
4047 /* Continue to next apps even on error */
4048 continue;
4049 }
4050 }
4051
4052 rcu_read_unlock();
4053
4054 return 0;
4055 }
4056
4057 /*
4058 * Start tracing for the UST session.
4059 */
4060 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4061 {
4062 int ret = 0;
4063 struct lttng_ht_iter iter;
4064 struct ust_app *app;
4065
4066 DBG("Stopping all UST traces");
4067
4068 rcu_read_lock();
4069
4070 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4071 ret = ust_app_stop_trace(usess, app);
4072 if (ret < 0) {
4073 /* Continue to next apps even on error */
4074 continue;
4075 }
4076 }
4077
4078 /* Flush buffers and push metadata (for UID buffers). */
4079 switch (usess->buffer_type) {
4080 case LTTNG_BUFFER_PER_UID:
4081 {
4082 struct buffer_reg_uid *reg;
4083
4084 /* Flush all per UID buffers associated to that session. */
4085 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4086 struct ust_registry_session *ust_session_reg;
4087 struct buffer_reg_channel *reg_chan;
4088 struct consumer_socket *socket;
4089
4090 /* Get consumer socket to use to push the metadata.*/
4091 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4092 usess->consumer);
4093 if (!socket) {
4094 /* Ignore request if no consumer is found for the session. */
4095 continue;
4096 }
4097
4098 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4099 reg_chan, node.node) {
4100 /*
4101 * The following call will print error values so the return
4102 * code is of little importance because whatever happens, we
4103 * have to try them all.
4104 */
4105 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4106 }
4107
4108 ust_session_reg = reg->registry->reg.ust;
4109 if (!ust_session_reg->metadata_closed) {
4110 /* Push metadata. */
4111 (void) push_metadata(ust_session_reg, usess->consumer);
4112 }
4113 }
4114
4115 break;
4116 }
4117 case LTTNG_BUFFER_PER_PID:
4118 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4119 ret = ust_app_flush_trace(usess, app);
4120 if (ret < 0) {
4121 /* Continue to next apps even on error */
4122 continue;
4123 }
4124 }
4125 break;
4126 default:
4127 assert(0);
4128 break;
4129 }
4130
4131 rcu_read_unlock();
4132
4133 return 0;
4134 }
4135
4136 /*
4137 * Destroy app UST session.
4138 */
4139 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4140 {
4141 int ret = 0;
4142 struct lttng_ht_iter iter;
4143 struct ust_app *app;
4144
4145 DBG("Destroy all UST traces");
4146
4147 rcu_read_lock();
4148
4149 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4150 ret = destroy_trace(usess, app);
4151 if (ret < 0) {
4152 /* Continue to next apps even on error */
4153 continue;
4154 }
4155 }
4156
4157 rcu_read_unlock();
4158
4159 return 0;
4160 }
4161
4162 /*
4163 * Add channels/events from UST global domain to registered apps at sock.
4164 */
4165 void ust_app_global_update(struct ltt_ust_session *usess, int sock)
4166 {
4167 int ret = 0;
4168 struct lttng_ht_iter iter, uiter;
4169 struct ust_app *app;
4170 struct ust_app_session *ua_sess = NULL;
4171 struct ust_app_channel *ua_chan;
4172 struct ust_app_event *ua_event;
4173 struct ust_app_ctx *ua_ctx;
4174
4175 assert(usess);
4176 assert(sock >= 0);
4177
4178 DBG2("UST app global update for app sock %d for session id %" PRIu64, sock,
4179 usess->id);
4180
4181 rcu_read_lock();
4182
4183 app = ust_app_find_by_sock(sock);
4184 if (app == NULL) {
4185 /*
4186 * Application can be unregistered before so this is possible hence
4187 * simply stopping the update.
4188 */
4189 DBG3("UST app update failed to find app sock %d", sock);
4190 goto error;
4191 }
4192
4193 if (!app->compatible) {
4194 goto error;
4195 }
4196
4197 ret = create_ust_app_session(usess, app, &ua_sess, NULL);
4198 if (ret < 0) {
4199 /* Tracer is probably gone or ENOMEM. */
4200 goto error;
4201 }
4202 assert(ua_sess);
4203
4204 pthread_mutex_lock(&ua_sess->lock);
4205
4206 /*
4207 * We can iterate safely here over all UST app session since the create ust
4208 * app session above made a shadow copy of the UST global domain from the
4209 * ltt ust session.
4210 */
4211 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4212 node.node) {
4213 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4214 if (ret < 0) {
4215 /*
4216 * Stop everything. On error, the application failed, no more
4217 * file descriptor are available or ENOMEM so stopping here is
4218 * the only thing we can do for now.
4219 */
4220 goto error_unlock;
4221 }
4222
4223 /*
4224 * Add context using the list so they are enabled in the same order the
4225 * user added them.
4226 */
4227 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4228 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4229 if (ret < 0) {
4230 goto error_unlock;
4231 }
4232 }
4233
4234
4235 /* For each events */
4236 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4237 node.node) {
4238 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4239 if (ret < 0) {
4240 goto error_unlock;
4241 }
4242 }
4243 }
4244
4245 pthread_mutex_unlock(&ua_sess->lock);
4246
4247 if (usess->start_trace) {
4248 ret = ust_app_start_trace(usess, app);
4249 if (ret < 0) {
4250 goto error;
4251 }
4252
4253 DBG2("UST trace started for app pid %d", app->pid);
4254 }
4255
4256 /* Everything went well at this point. */
4257 rcu_read_unlock();
4258 return;
4259
4260 error_unlock:
4261 pthread_mutex_unlock(&ua_sess->lock);
4262 error:
4263 if (ua_sess) {
4264 destroy_app_session(app, ua_sess);
4265 }
4266 rcu_read_unlock();
4267 return;
4268 }
4269
4270 /*
4271 * Add context to a specific channel for global UST domain.
4272 */
4273 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4274 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4275 {
4276 int ret = 0;
4277 struct lttng_ht_node_str *ua_chan_node;
4278 struct lttng_ht_iter iter, uiter;
4279 struct ust_app_channel *ua_chan = NULL;
4280 struct ust_app_session *ua_sess;
4281 struct ust_app *app;
4282
4283 rcu_read_lock();
4284
4285 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4286 if (!app->compatible) {
4287 /*
4288 * TODO: In time, we should notice the caller of this error by
4289 * telling him that this is a version error.
4290 */
4291 continue;
4292 }
4293 ua_sess = lookup_session_by_app(usess, app);
4294 if (ua_sess == NULL) {
4295 continue;
4296 }
4297
4298 pthread_mutex_lock(&ua_sess->lock);
4299 /* Lookup channel in the ust app session */
4300 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4301 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4302 if (ua_chan_node == NULL) {
4303 goto next_app;
4304 }
4305 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4306 node);
4307 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4308 if (ret < 0) {
4309 goto next_app;
4310 }
4311 next_app:
4312 pthread_mutex_unlock(&ua_sess->lock);
4313 }
4314
4315 rcu_read_unlock();
4316 return ret;
4317 }
4318
4319 /*
4320 * Enable event for a channel from a UST session for a specific PID.
4321 */
4322 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4323 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4324 {
4325 int ret = 0;
4326 struct lttng_ht_iter iter;
4327 struct lttng_ht_node_str *ua_chan_node;
4328 struct ust_app *app;
4329 struct ust_app_session *ua_sess;
4330 struct ust_app_channel *ua_chan;
4331 struct ust_app_event *ua_event;
4332
4333 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4334
4335 rcu_read_lock();
4336
4337 app = ust_app_find_by_pid(pid);
4338 if (app == NULL) {
4339 ERR("UST app enable event per PID %d not found", pid);
4340 ret = -1;
4341 goto end;
4342 }
4343
4344 if (!app->compatible) {
4345 ret = 0;
4346 goto end;
4347 }
4348
4349 ua_sess = lookup_session_by_app(usess, app);
4350 if (!ua_sess) {
4351 /* The application has problem or is probably dead. */
4352 ret = 0;
4353 goto end;
4354 }
4355
4356 pthread_mutex_lock(&ua_sess->lock);
4357 /* Lookup channel in the ust app session */
4358 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4359 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4360 /* If the channel is not found, there is a code flow error */
4361 assert(ua_chan_node);
4362
4363 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4364
4365 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4366 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4367 if (ua_event == NULL) {
4368 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4369 if (ret < 0) {
4370 goto end_unlock;
4371 }
4372 } else {
4373 ret = enable_ust_app_event(ua_sess, ua_event, app);
4374 if (ret < 0) {
4375 goto end_unlock;
4376 }
4377 }
4378
4379 end_unlock:
4380 pthread_mutex_unlock(&ua_sess->lock);
4381 end:
4382 rcu_read_unlock();
4383 return ret;
4384 }
4385
4386 /*
4387 * Calibrate registered applications.
4388 */
4389 int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4390 {
4391 int ret = 0;
4392 struct lttng_ht_iter iter;
4393 struct ust_app *app;
4394
4395 rcu_read_lock();
4396
4397 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4398 if (!app->compatible) {
4399 /*
4400 * TODO: In time, we should notice the caller of this error by
4401 * telling him that this is a version error.
4402 */
4403 continue;
4404 }
4405
4406 health_code_update();
4407
4408 ret = ustctl_calibrate(app->sock, calibrate);
4409 if (ret < 0) {
4410 switch (ret) {
4411 case -ENOSYS:
4412 /* Means that it's not implemented on the tracer side. */
4413 ret = 0;
4414 break;
4415 default:
4416 DBG2("Calibrate app PID %d returned with error %d",
4417 app->pid, ret);
4418 break;
4419 }
4420 }
4421 }
4422
4423 DBG("UST app global domain calibration finished");
4424
4425 rcu_read_unlock();
4426
4427 health_code_update();
4428
4429 return ret;
4430 }
4431
4432 /*
4433 * Receive registration and populate the given msg structure.
4434 *
4435 * On success return 0 else a negative value returned by the ustctl call.
4436 */
4437 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4438 {
4439 int ret;
4440 uint32_t pid, ppid, uid, gid;
4441
4442 assert(msg);
4443
4444 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4445 &pid, &ppid, &uid, &gid,
4446 &msg->bits_per_long,
4447 &msg->uint8_t_alignment,
4448 &msg->uint16_t_alignment,
4449 &msg->uint32_t_alignment,
4450 &msg->uint64_t_alignment,
4451 &msg->long_alignment,
4452 &msg->byte_order,
4453 msg->name);
4454 if (ret < 0) {
4455 switch (-ret) {
4456 case EPIPE:
4457 case ECONNRESET:
4458 case LTTNG_UST_ERR_EXITING:
4459 DBG3("UST app recv reg message failed. Application died");
4460 break;
4461 case LTTNG_UST_ERR_UNSUP_MAJOR:
4462 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4463 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
4464 LTTNG_UST_ABI_MINOR_VERSION);
4465 break;
4466 default:
4467 ERR("UST app recv reg message failed with ret %d", ret);
4468 break;
4469 }
4470 goto error;
4471 }
4472 msg->pid = (pid_t) pid;
4473 msg->ppid = (pid_t) ppid;
4474 msg->uid = (uid_t) uid;
4475 msg->gid = (gid_t) gid;
4476
4477 error:
4478 return ret;
4479 }
4480
4481 /*
4482 * Return a ust app channel object using the application object and the channel
4483 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4484 * lock MUST be acquired before calling this function.
4485 */
4486 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
4487 int objd)
4488 {
4489 struct lttng_ht_node_ulong *node;
4490 struct lttng_ht_iter iter;
4491 struct ust_app_channel *ua_chan = NULL;
4492
4493 assert(app);
4494
4495 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
4496 node = lttng_ht_iter_get_node_ulong(&iter);
4497 if (node == NULL) {
4498 DBG2("UST app channel find by objd %d not found", objd);
4499 goto error;
4500 }
4501
4502 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
4503
4504 error:
4505 return ua_chan;
4506 }
4507
4508 /*
4509 * Reply to a register channel notification from an application on the notify
4510 * socket. The channel metadata is also created.
4511 *
4512 * The session UST registry lock is acquired in this function.
4513 *
4514 * On success 0 is returned else a negative value.
4515 */
4516 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
4517 size_t nr_fields, struct ustctl_field *fields)
4518 {
4519 int ret, ret_code = 0;
4520 uint32_t chan_id, reg_count;
4521 uint64_t chan_reg_key;
4522 enum ustctl_channel_header type;
4523 struct ust_app *app;
4524 struct ust_app_channel *ua_chan;
4525 struct ust_app_session *ua_sess;
4526 struct ust_registry_session *registry;
4527 struct ust_registry_channel *chan_reg;
4528
4529 rcu_read_lock();
4530
4531 /* Lookup application. If not found, there is a code flow error. */
4532 app = find_app_by_notify_sock(sock);
4533 if (!app) {
4534 DBG("Application socket %d is being teardown. Abort event notify",
4535 sock);
4536 ret = 0;
4537 free(fields);
4538 goto error_rcu_unlock;
4539 }
4540
4541 /* Lookup channel by UST object descriptor. */
4542 ua_chan = find_channel_by_objd(app, cobjd);
4543 if (!ua_chan) {
4544 DBG("Application channel is being teardown. Abort event notify");
4545 ret = 0;
4546 free(fields);
4547 goto error_rcu_unlock;
4548 }
4549
4550 assert(ua_chan->session);
4551 ua_sess = ua_chan->session;
4552
4553 /* Get right session registry depending on the session buffer type. */
4554 registry = get_session_registry(ua_sess);
4555 assert(registry);
4556
4557 /* Depending on the buffer type, a different channel key is used. */
4558 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4559 chan_reg_key = ua_chan->tracing_channel_id;
4560 } else {
4561 chan_reg_key = ua_chan->key;
4562 }
4563
4564 pthread_mutex_lock(&registry->lock);
4565
4566 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
4567 assert(chan_reg);
4568
4569 if (!chan_reg->register_done) {
4570 reg_count = ust_registry_get_event_count(chan_reg);
4571 if (reg_count < 31) {
4572 type = USTCTL_CHANNEL_HEADER_COMPACT;
4573 } else {
4574 type = USTCTL_CHANNEL_HEADER_LARGE;
4575 }
4576
4577 chan_reg->nr_ctx_fields = nr_fields;
4578 chan_reg->ctx_fields = fields;
4579 chan_reg->header_type = type;
4580 } else {
4581 /* Get current already assigned values. */
4582 type = chan_reg->header_type;
4583 free(fields);
4584 /* Set to NULL so the error path does not do a double free. */
4585 fields = NULL;
4586 }
4587 /* Channel id is set during the object creation. */
4588 chan_id = chan_reg->chan_id;
4589
4590 /* Append to metadata */
4591 if (!chan_reg->metadata_dumped) {
4592 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
4593 if (ret_code) {
4594 ERR("Error appending channel metadata (errno = %d)", ret_code);
4595 goto reply;
4596 }
4597 }
4598
4599 reply:
4600 DBG3("UST app replying to register channel key %" PRIu64
4601 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
4602 ret_code);
4603
4604 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
4605 if (ret < 0) {
4606 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4607 ERR("UST app reply channel failed with ret %d", ret);
4608 } else {
4609 DBG3("UST app reply channel failed. Application died");
4610 }
4611 goto error;
4612 }
4613
4614 /* This channel registry registration is completed. */
4615 chan_reg->register_done = 1;
4616
4617 error:
4618 pthread_mutex_unlock(&registry->lock);
4619 error_rcu_unlock:
4620 rcu_read_unlock();
4621 if (ret) {
4622 free(fields);
4623 }
4624 return ret;
4625 }
4626
4627 /*
4628 * Add event to the UST channel registry. When the event is added to the
4629 * registry, the metadata is also created. Once done, this replies to the
4630 * application with the appropriate error code.
4631 *
4632 * The session UST registry lock is acquired in the function.
4633 *
4634 * On success 0 is returned else a negative value.
4635 */
4636 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
4637 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
4638 char *model_emf_uri)
4639 {
4640 int ret, ret_code;
4641 uint32_t event_id = 0;
4642 uint64_t chan_reg_key;
4643 struct ust_app *app;
4644 struct ust_app_channel *ua_chan;
4645 struct ust_app_session *ua_sess;
4646 struct ust_registry_session *registry;
4647
4648 rcu_read_lock();
4649
4650 /* Lookup application. If not found, there is a code flow error. */
4651 app = find_app_by_notify_sock(sock);
4652 if (!app) {
4653 DBG("Application socket %d is being teardown. Abort event notify",
4654 sock);
4655 ret = 0;
4656 free(sig);
4657 free(fields);
4658 free(model_emf_uri);
4659 goto error_rcu_unlock;
4660 }
4661
4662 /* Lookup channel by UST object descriptor. */
4663 ua_chan = find_channel_by_objd(app, cobjd);
4664 if (!ua_chan) {
4665 DBG("Application channel is being teardown. Abort event notify");
4666 ret = 0;
4667 free(sig);
4668 free(fields);
4669 free(model_emf_uri);
4670 goto error_rcu_unlock;
4671 }
4672
4673 assert(ua_chan->session);
4674 ua_sess = ua_chan->session;
4675
4676 registry = get_session_registry(ua_sess);
4677 assert(registry);
4678
4679 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4680 chan_reg_key = ua_chan->tracing_channel_id;
4681 } else {
4682 chan_reg_key = ua_chan->key;
4683 }
4684
4685 pthread_mutex_lock(&registry->lock);
4686
4687 /*
4688 * From this point on, this call acquires the ownership of the sig, fields
4689 * and model_emf_uri meaning any free are done inside it if needed. These
4690 * three variables MUST NOT be read/write after this.
4691 */
4692 ret_code = ust_registry_create_event(registry, chan_reg_key,
4693 sobjd, cobjd, name, sig, nr_fields, fields, loglevel,
4694 model_emf_uri, ua_sess->buffer_type, &event_id,
4695 app);
4696
4697 /*
4698 * The return value is returned to ustctl so in case of an error, the
4699 * application can be notified. In case of an error, it's important not to
4700 * return a negative error or else the application will get closed.
4701 */
4702 ret = ustctl_reply_register_event(sock, event_id, ret_code);
4703 if (ret < 0) {
4704 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4705 ERR("UST app reply event failed with ret %d", ret);
4706 } else {
4707 DBG3("UST app reply event failed. Application died");
4708 }
4709 /*
4710 * No need to wipe the create event since the application socket will
4711 * get close on error hence cleaning up everything by itself.
4712 */
4713 goto error;
4714 }
4715
4716 DBG3("UST registry event %s with id %" PRId32 " added successfully",
4717 name, event_id);
4718
4719 error:
4720 pthread_mutex_unlock(&registry->lock);
4721 error_rcu_unlock:
4722 rcu_read_unlock();
4723 return ret;
4724 }
4725
4726 /*
4727 * Handle application notification through the given notify socket.
4728 *
4729 * Return 0 on success or else a negative value.
4730 */
4731 int ust_app_recv_notify(int sock)
4732 {
4733 int ret;
4734 enum ustctl_notify_cmd cmd;
4735
4736 DBG3("UST app receiving notify from sock %d", sock);
4737
4738 ret = ustctl_recv_notify(sock, &cmd);
4739 if (ret < 0) {
4740 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4741 ERR("UST app recv notify failed with ret %d", ret);
4742 } else {
4743 DBG3("UST app recv notify failed. Application died");
4744 }
4745 goto error;
4746 }
4747
4748 switch (cmd) {
4749 case USTCTL_NOTIFY_CMD_EVENT:
4750 {
4751 int sobjd, cobjd, loglevel;
4752 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
4753 size_t nr_fields;
4754 struct ustctl_field *fields;
4755
4756 DBG2("UST app ustctl register event received");
4757
4758 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name, &loglevel,
4759 &sig, &nr_fields, &fields, &model_emf_uri);
4760 if (ret < 0) {
4761 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4762 ERR("UST app recv event failed with ret %d", ret);
4763 } else {
4764 DBG3("UST app recv event failed. Application died");
4765 }
4766 goto error;
4767 }
4768
4769 /*
4770 * Add event to the UST registry coming from the notify socket. This
4771 * call will free if needed the sig, fields and model_emf_uri. This
4772 * code path loses the ownsership of these variables and transfer them
4773 * to the this function.
4774 */
4775 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
4776 fields, loglevel, model_emf_uri);
4777 if (ret < 0) {
4778 goto error;
4779 }
4780
4781 break;
4782 }
4783 case USTCTL_NOTIFY_CMD_CHANNEL:
4784 {
4785 int sobjd, cobjd;
4786 size_t nr_fields;
4787 struct ustctl_field *fields;
4788
4789 DBG2("UST app ustctl register channel received");
4790
4791 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
4792 &fields);
4793 if (ret < 0) {
4794 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4795 ERR("UST app recv channel failed with ret %d", ret);
4796 } else {
4797 DBG3("UST app recv channel failed. Application died");
4798 }
4799 goto error;
4800 }
4801
4802 /*
4803 * The fields ownership are transfered to this function call meaning
4804 * that if needed it will be freed. After this, it's invalid to access
4805 * fields or clean it up.
4806 */
4807 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
4808 fields);
4809 if (ret < 0) {
4810 goto error;
4811 }
4812
4813 break;
4814 }
4815 default:
4816 /* Should NEVER happen. */
4817 assert(0);
4818 }
4819
4820 error:
4821 return ret;
4822 }
4823
4824 /*
4825 * Once the notify socket hangs up, this is called. First, it tries to find the
4826 * corresponding application. On failure, the call_rcu to close the socket is
4827 * executed. If an application is found, it tries to delete it from the notify
4828 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4829 *
4830 * Note that an object needs to be allocated here so on ENOMEM failure, the
4831 * call RCU is not done but the rest of the cleanup is.
4832 */
4833 void ust_app_notify_sock_unregister(int sock)
4834 {
4835 int err_enomem = 0;
4836 struct lttng_ht_iter iter;
4837 struct ust_app *app;
4838 struct ust_app_notify_sock_obj *obj;
4839
4840 assert(sock >= 0);
4841
4842 rcu_read_lock();
4843
4844 obj = zmalloc(sizeof(*obj));
4845 if (!obj) {
4846 /*
4847 * An ENOMEM is kind of uncool. If this strikes we continue the
4848 * procedure but the call_rcu will not be called. In this case, we
4849 * accept the fd leak rather than possibly creating an unsynchronized
4850 * state between threads.
4851 *
4852 * TODO: The notify object should be created once the notify socket is
4853 * registered and stored independantely from the ust app object. The
4854 * tricky part is to synchronize the teardown of the application and
4855 * this notify object. Let's keep that in mind so we can avoid this
4856 * kind of shenanigans with ENOMEM in the teardown path.
4857 */
4858 err_enomem = 1;
4859 } else {
4860 obj->fd = sock;
4861 }
4862
4863 DBG("UST app notify socket unregister %d", sock);
4864
4865 /*
4866 * Lookup application by notify socket. If this fails, this means that the
4867 * hash table delete has already been done by the application
4868 * unregistration process so we can safely close the notify socket in a
4869 * call RCU.
4870 */
4871 app = find_app_by_notify_sock(sock);
4872 if (!app) {
4873 goto close_socket;
4874 }
4875
4876 iter.iter.node = &app->notify_sock_n.node;
4877
4878 /*
4879 * Whatever happens here either we fail or succeed, in both cases we have
4880 * to close the socket after a grace period to continue to the call RCU
4881 * here. If the deletion is successful, the application is not visible
4882 * anymore by other threads and is it fails it means that it was already
4883 * deleted from the hash table so either way we just have to close the
4884 * socket.
4885 */
4886 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
4887
4888 close_socket:
4889 rcu_read_unlock();
4890
4891 /*
4892 * Close socket after a grace period to avoid for the socket to be reused
4893 * before the application object is freed creating potential race between
4894 * threads trying to add unique in the global hash table.
4895 */
4896 if (!err_enomem) {
4897 call_rcu(&obj->head, close_notify_sock_rcu);
4898 }
4899 }
4900
4901 /*
4902 * Destroy a ust app data structure and free its memory.
4903 */
4904 void ust_app_destroy(struct ust_app *app)
4905 {
4906 if (!app) {
4907 return;
4908 }
4909
4910 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
4911 }
4912
4913 /*
4914 * Take a snapshot for a given UST session. The snapshot is sent to the given
4915 * output.
4916 *
4917 * Return 0 on success or else a negative value.
4918 */
4919 int ust_app_snapshot_record(struct ltt_ust_session *usess,
4920 struct snapshot_output *output, int wait, unsigned int nb_streams)
4921 {
4922 int ret = 0;
4923 unsigned int snapshot_done = 0;
4924 struct lttng_ht_iter iter;
4925 struct ust_app *app;
4926 char pathname[PATH_MAX];
4927 uint64_t max_stream_size = 0;
4928
4929 assert(usess);
4930 assert(output);
4931
4932 rcu_read_lock();
4933
4934 /*
4935 * Compute the maximum size of a single stream if a max size is asked by
4936 * the caller.
4937 */
4938 if (output->max_size > 0 && nb_streams > 0) {
4939 max_stream_size = output->max_size / nb_streams;
4940 }
4941
4942 switch (usess->buffer_type) {
4943 case LTTNG_BUFFER_PER_UID:
4944 {
4945 struct buffer_reg_uid *reg;
4946
4947 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4948 struct buffer_reg_channel *reg_chan;
4949 struct consumer_socket *socket;
4950
4951 /* Get consumer socket to use to push the metadata.*/
4952 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4953 usess->consumer);
4954 if (!socket) {
4955 ret = -EINVAL;
4956 goto error;
4957 }
4958
4959 memset(pathname, 0, sizeof(pathname));
4960 ret = snprintf(pathname, sizeof(pathname),
4961 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
4962 reg->uid, reg->bits_per_long);
4963 if (ret < 0) {
4964 PERROR("snprintf snapshot path");
4965 goto error;
4966 }
4967
4968 /* Add the UST default trace dir to path. */
4969 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4970 reg_chan, node.node) {
4971
4972 /*
4973 * Make sure the maximum stream size is not lower than the
4974 * subbuffer size or else it's an error since we won't be able to
4975 * snapshot anything.
4976 */
4977 if (max_stream_size &&
4978 reg_chan->subbuf_size > max_stream_size) {
4979 ret = -EINVAL;
4980 DBG3("UST app snapshot record maximum stream size %" PRIu64
4981 " is smaller than subbuffer size of %zu",
4982 max_stream_size, reg_chan->subbuf_size);
4983 goto error;
4984 }
4985 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key, output, 0,
4986 usess->uid, usess->gid, pathname, wait,
4987 max_stream_size);
4988 if (ret < 0) {
4989 goto error;
4990 }
4991 }
4992 ret = consumer_snapshot_channel(socket, reg->registry->reg.ust->metadata_key, output,
4993 1, usess->uid, usess->gid, pathname, wait,
4994 max_stream_size);
4995 if (ret < 0) {
4996 goto error;
4997 }
4998 snapshot_done = 1;
4999 }
5000 break;
5001 }
5002 case LTTNG_BUFFER_PER_PID:
5003 {
5004 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5005 struct consumer_socket *socket;
5006 struct lttng_ht_iter chan_iter;
5007 struct ust_app_channel *ua_chan;
5008 struct ust_app_session *ua_sess;
5009 struct ust_registry_session *registry;
5010
5011 ua_sess = lookup_session_by_app(usess, app);
5012 if (!ua_sess) {
5013 /* Session not associated with this app. */
5014 continue;
5015 }
5016
5017 /* Get the right consumer socket for the application. */
5018 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5019 output->consumer);
5020 if (!socket) {
5021 ret = -EINVAL;
5022 goto error;
5023 }
5024
5025 /* Add the UST default trace dir to path. */
5026 memset(pathname, 0, sizeof(pathname));
5027 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
5028 ua_sess->path);
5029 if (ret < 0) {
5030 PERROR("snprintf snapshot path");
5031 goto error;
5032 }
5033
5034 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5035 ua_chan, node.node) {
5036 /*
5037 * Make sure the maximum stream size is not lower than the
5038 * subbuffer size or else it's an error since we won't be able to
5039 * snapshot anything.
5040 */
5041 if (max_stream_size &&
5042 ua_chan->attr.subbuf_size > max_stream_size) {
5043 ret = -EINVAL;
5044 DBG3("UST app snapshot record maximum stream size %" PRIu64
5045 " is smaller than subbuffer size of %" PRIu64,
5046 max_stream_size, ua_chan->attr.subbuf_size);
5047 goto error;
5048 }
5049
5050 ret = consumer_snapshot_channel(socket, ua_chan->key, output, 0,
5051 ua_sess->euid, ua_sess->egid, pathname, wait,
5052 max_stream_size);
5053 if (ret < 0) {
5054 goto error;
5055 }
5056 }
5057
5058 registry = get_session_registry(ua_sess);
5059 assert(registry);
5060 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5061 1, ua_sess->euid, ua_sess->egid, pathname, wait,
5062 max_stream_size);
5063 if (ret < 0) {
5064 goto error;
5065 }
5066 snapshot_done = 1;
5067 }
5068 break;
5069 }
5070 default:
5071 assert(0);
5072 break;
5073 }
5074
5075 if (!snapshot_done) {
5076 /*
5077 * If no snapshot was made and we are not in the error path, this means
5078 * that there are no buffers thus no (prior) application to snapshot
5079 * data from so we have simply NO data.
5080 */
5081 ret = -ENODATA;
5082 }
5083
5084 error:
5085 rcu_read_unlock();
5086 return ret;
5087 }
5088
5089 /*
5090 * Return the number of streams for a UST session.
5091 */
5092 unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
5093 {
5094 unsigned int ret = 0;
5095 struct ust_app *app;
5096 struct lttng_ht_iter iter;
5097
5098 assert(usess);
5099
5100 switch (usess->buffer_type) {
5101 case LTTNG_BUFFER_PER_UID:
5102 {
5103 struct buffer_reg_uid *reg;
5104
5105 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5106 struct buffer_reg_channel *reg_chan;
5107
5108 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5109 reg_chan, node.node) {
5110 ret += reg_chan->stream_count;
5111 }
5112 }
5113 break;
5114 }
5115 case LTTNG_BUFFER_PER_PID:
5116 {
5117 rcu_read_lock();
5118 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5119 struct ust_app_channel *ua_chan;
5120 struct ust_app_session *ua_sess;
5121 struct lttng_ht_iter chan_iter;
5122
5123 ua_sess = lookup_session_by_app(usess, app);
5124 if (!ua_sess) {
5125 /* Session not associated with this app. */
5126 continue;
5127 }
5128
5129 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5130 ua_chan, node.node) {
5131 ret += ua_chan->streams.count;
5132 }
5133 }
5134 rcu_read_unlock();
5135 break;
5136 }
5137 default:
5138 assert(0);
5139 break;
5140 }
5141
5142 return ret;
5143 }
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