Bump version to 2.4.0-pre1
[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.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 3 elements of the key: name, filter and loglevel. */
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 /* Match. */
144 return 1;
145
146 no_match:
147 return 0;
148 }
149
150 /*
151 * Unique add of an ust app event in the given ht. This uses the custom
152 * ht_match_ust_app_event match function and the event name as hash.
153 */
154 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
155 struct ust_app_event *event)
156 {
157 struct cds_lfht_node *node_ptr;
158 struct ust_app_ht_key key;
159 struct lttng_ht *ht;
160
161 assert(ua_chan);
162 assert(ua_chan->events);
163 assert(event);
164
165 ht = ua_chan->events;
166 key.name = event->attr.name;
167 key.filter = event->filter;
168 key.loglevel = event->attr.loglevel;
169
170 node_ptr = cds_lfht_add_unique(ht->ht,
171 ht->hash_fct(event->node.key, lttng_ht_seed),
172 ht_match_ust_app_event, &key, &event->node.node);
173 assert(node_ptr == &event->node.node);
174 }
175
176 /*
177 * Close the notify socket from the given RCU head object. This MUST be called
178 * through a call_rcu().
179 */
180 static void close_notify_sock_rcu(struct rcu_head *head)
181 {
182 int ret;
183 struct ust_app_notify_sock_obj *obj =
184 caa_container_of(head, struct ust_app_notify_sock_obj, head);
185
186 /* Must have a valid fd here. */
187 assert(obj->fd >= 0);
188
189 ret = close(obj->fd);
190 if (ret) {
191 ERR("close notify sock %d RCU", obj->fd);
192 }
193 lttng_fd_put(LTTNG_FD_APPS, 1);
194
195 free(obj);
196 }
197
198 /*
199 * Return the session registry according to the buffer type of the given
200 * session.
201 *
202 * A registry per UID object MUST exists before calling this function or else
203 * it assert() if not found. RCU read side lock must be acquired.
204 */
205 static struct ust_registry_session *get_session_registry(
206 struct ust_app_session *ua_sess)
207 {
208 struct ust_registry_session *registry = NULL;
209
210 assert(ua_sess);
211
212 switch (ua_sess->buffer_type) {
213 case LTTNG_BUFFER_PER_PID:
214 {
215 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
216 if (!reg_pid) {
217 goto error;
218 }
219 registry = reg_pid->registry->reg.ust;
220 break;
221 }
222 case LTTNG_BUFFER_PER_UID:
223 {
224 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
225 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
226 if (!reg_uid) {
227 goto error;
228 }
229 registry = reg_uid->registry->reg.ust;
230 break;
231 }
232 default:
233 assert(0);
234 };
235
236 error:
237 return registry;
238 }
239
240 /*
241 * Delete ust context safely. RCU read lock must be held before calling
242 * this function.
243 */
244 static
245 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
246 {
247 int ret;
248
249 assert(ua_ctx);
250
251 if (ua_ctx->obj) {
252 ret = ustctl_release_object(sock, ua_ctx->obj);
253 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
254 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
255 sock, ua_ctx->obj->handle, ret);
256 }
257 free(ua_ctx->obj);
258 }
259 free(ua_ctx);
260 }
261
262 /*
263 * Delete ust app event safely. RCU read lock must be held before calling
264 * this function.
265 */
266 static
267 void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
268 {
269 int ret;
270
271 assert(ua_event);
272
273 free(ua_event->filter);
274
275 if (ua_event->obj != NULL) {
276 ret = ustctl_release_object(sock, ua_event->obj);
277 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
278 ERR("UST app sock %d release event obj failed with ret %d",
279 sock, ret);
280 }
281 free(ua_event->obj);
282 }
283 free(ua_event);
284 }
285
286 /*
287 * Release ust data object of the given stream.
288 *
289 * Return 0 on success or else a negative value.
290 */
291 static int release_ust_app_stream(int sock, struct ust_app_stream *stream)
292 {
293 int ret = 0;
294
295 assert(stream);
296
297 if (stream->obj) {
298 ret = ustctl_release_object(sock, stream->obj);
299 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
300 ERR("UST app sock %d release stream obj failed with ret %d",
301 sock, ret);
302 }
303 lttng_fd_put(LTTNG_FD_APPS, 2);
304 free(stream->obj);
305 }
306
307 return ret;
308 }
309
310 /*
311 * Delete ust app stream safely. RCU read lock must be held before calling
312 * this function.
313 */
314 static
315 void delete_ust_app_stream(int sock, struct ust_app_stream *stream)
316 {
317 assert(stream);
318
319 (void) release_ust_app_stream(sock, stream);
320 free(stream);
321 }
322
323 /*
324 * We need to execute ht_destroy outside of RCU read-side critical
325 * section and outside of call_rcu thread, so we postpone its execution
326 * using ht_cleanup_push. It is simpler than to change the semantic of
327 * the many callers of delete_ust_app_session().
328 */
329 static
330 void delete_ust_app_channel_rcu(struct rcu_head *head)
331 {
332 struct ust_app_channel *ua_chan =
333 caa_container_of(head, struct ust_app_channel, rcu_head);
334
335 ht_cleanup_push(ua_chan->ctx);
336 ht_cleanup_push(ua_chan->events);
337 free(ua_chan);
338 }
339
340 /*
341 * Delete ust app channel safely. RCU read lock must be held before calling
342 * this function.
343 */
344 static
345 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
346 struct ust_app *app)
347 {
348 int ret;
349 struct lttng_ht_iter iter;
350 struct ust_app_event *ua_event;
351 struct ust_app_ctx *ua_ctx;
352 struct ust_app_stream *stream, *stmp;
353 struct ust_registry_session *registry;
354
355 assert(ua_chan);
356
357 DBG3("UST app deleting channel %s", ua_chan->name);
358
359 /* Wipe stream */
360 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
361 cds_list_del(&stream->list);
362 delete_ust_app_stream(sock, stream);
363 }
364
365 /* Wipe context */
366 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
367 cds_list_del(&ua_ctx->list);
368 ret = lttng_ht_del(ua_chan->ctx, &iter);
369 assert(!ret);
370 delete_ust_app_ctx(sock, ua_ctx);
371 }
372
373 /* Wipe events */
374 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
375 node.node) {
376 ret = lttng_ht_del(ua_chan->events, &iter);
377 assert(!ret);
378 delete_ust_app_event(sock, ua_event);
379 }
380
381 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
382 /* Wipe and free registry from session registry. */
383 registry = get_session_registry(ua_chan->session);
384 if (registry) {
385 ust_registry_channel_del_free(registry, ua_chan->key);
386 }
387 }
388
389 if (ua_chan->obj != NULL) {
390 /* Remove channel from application UST object descriptor. */
391 iter.iter.node = &ua_chan->ust_objd_node.node;
392 lttng_ht_del(app->ust_objd, &iter);
393 ret = ustctl_release_object(sock, ua_chan->obj);
394 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
395 ERR("UST app sock %d release channel obj failed with ret %d",
396 sock, ret);
397 }
398 lttng_fd_put(LTTNG_FD_APPS, 1);
399 free(ua_chan->obj);
400 }
401 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
402 }
403
404 /*
405 * Push metadata to consumer socket.
406 *
407 * The socket lock MUST be acquired.
408 * The ust app session lock MUST be acquired.
409 *
410 * On success, return the len of metadata pushed or else a negative value.
411 */
412 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
413 struct consumer_socket *socket, int send_zero_data)
414 {
415 int ret;
416 char *metadata_str = NULL;
417 size_t len, offset;
418 ssize_t ret_val;
419
420 assert(registry);
421 assert(socket);
422
423 /*
424 * On a push metadata error either the consumer is dead or the metadata
425 * channel has been destroyed because its endpoint might have died (e.g:
426 * relayd). If so, the metadata closed flag is set to 1 so we deny pushing
427 * metadata again which is not valid anymore on the consumer side.
428 *
429 * The ust app session mutex locked allows us to make this check without
430 * the registry lock.
431 */
432 if (registry->metadata_closed) {
433 return -EPIPE;
434 }
435
436 pthread_mutex_lock(&registry->lock);
437
438 offset = registry->metadata_len_sent;
439 len = registry->metadata_len - registry->metadata_len_sent;
440 if (len == 0) {
441 DBG3("No metadata to push for metadata key %" PRIu64,
442 registry->metadata_key);
443 ret_val = len;
444 if (send_zero_data) {
445 DBG("No metadata to push");
446 goto push_data;
447 }
448 goto end;
449 }
450
451 /* Allocate only what we have to send. */
452 metadata_str = zmalloc(len);
453 if (!metadata_str) {
454 PERROR("zmalloc ust app metadata string");
455 ret_val = -ENOMEM;
456 goto error;
457 }
458 /* Copy what we haven't send out. */
459 memcpy(metadata_str, registry->metadata + offset, len);
460 registry->metadata_len_sent += len;
461
462 push_data:
463 pthread_mutex_unlock(&registry->lock);
464 ret = consumer_push_metadata(socket, registry->metadata_key,
465 metadata_str, len, offset);
466 if (ret < 0) {
467 ret_val = ret;
468 goto error_push;
469 }
470
471 free(metadata_str);
472 return len;
473
474 end:
475 error:
476 pthread_mutex_unlock(&registry->lock);
477 error_push:
478 free(metadata_str);
479 return ret_val;
480 }
481
482 /*
483 * For a given application and session, push metadata to consumer. The session
484 * lock MUST be acquired here before calling this.
485 * Either sock or consumer is required : if sock is NULL, the default
486 * socket to send the metadata is retrieved from consumer, if sock
487 * is not NULL we use it to send the metadata.
488 *
489 * Return 0 on success else a negative error.
490 */
491 static int push_metadata(struct ust_registry_session *registry,
492 struct consumer_output *consumer)
493 {
494 int ret_val;
495 ssize_t ret;
496 struct consumer_socket *socket;
497
498 assert(registry);
499 assert(consumer);
500
501 rcu_read_lock();
502
503 /*
504 * Means that no metadata was assigned to the session. This can happens if
505 * no start has been done previously.
506 */
507 if (!registry->metadata_key) {
508 ret_val = 0;
509 goto end_rcu_unlock;
510 }
511
512 /* Get consumer socket to use to push the metadata.*/
513 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
514 consumer);
515 if (!socket) {
516 ret_val = -1;
517 goto error_rcu_unlock;
518 }
519
520 /*
521 * TODO: Currently, we hold the socket lock around sampling of the next
522 * metadata segment to ensure we send metadata over the consumer socket in
523 * the correct order. This makes the registry lock nest inside the socket
524 * lock.
525 *
526 * Please note that this is a temporary measure: we should move this lock
527 * back into ust_consumer_push_metadata() when the consumer gets the
528 * ability to reorder the metadata it receives.
529 */
530 pthread_mutex_lock(socket->lock);
531 ret = ust_app_push_metadata(registry, socket, 0);
532 pthread_mutex_unlock(socket->lock);
533 if (ret < 0) {
534 ret_val = ret;
535 goto error_rcu_unlock;
536 }
537
538 rcu_read_unlock();
539 return 0;
540
541 error_rcu_unlock:
542 /*
543 * On error, flag the registry that the metadata is closed. We were unable
544 * to push anything and this means that either the consumer is not
545 * responding or the metadata cache has been destroyed on the consumer.
546 */
547 registry->metadata_closed = 1;
548 end_rcu_unlock:
549 rcu_read_unlock();
550 return ret_val;
551 }
552
553 /*
554 * Send to the consumer a close metadata command for the given session. Once
555 * done, the metadata channel is deleted and the session metadata pointer is
556 * nullified. The session lock MUST be acquired here unless the application is
557 * in the destroy path.
558 *
559 * Return 0 on success else a negative value.
560 */
561 static int close_metadata(struct ust_registry_session *registry,
562 struct consumer_output *consumer)
563 {
564 int ret;
565 struct consumer_socket *socket;
566
567 assert(registry);
568 assert(consumer);
569
570 rcu_read_lock();
571
572 if (!registry->metadata_key || registry->metadata_closed) {
573 ret = 0;
574 goto end;
575 }
576
577 /* Get consumer socket to use to push the metadata.*/
578 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
579 consumer);
580 if (!socket) {
581 ret = -1;
582 goto error;
583 }
584
585 ret = consumer_close_metadata(socket, registry->metadata_key);
586 if (ret < 0) {
587 goto error;
588 }
589
590 error:
591 /*
592 * Metadata closed. Even on error this means that the consumer is not
593 * responding or not found so either way a second close should NOT be emit
594 * for this registry.
595 */
596 registry->metadata_closed = 1;
597 end:
598 rcu_read_unlock();
599 return ret;
600 }
601
602 /*
603 * We need to execute ht_destroy outside of RCU read-side critical
604 * section and outside of call_rcu thread, so we postpone its execution
605 * using ht_cleanup_push. It is simpler than to change the semantic of
606 * the many callers of delete_ust_app_session().
607 */
608 static
609 void delete_ust_app_session_rcu(struct rcu_head *head)
610 {
611 struct ust_app_session *ua_sess =
612 caa_container_of(head, struct ust_app_session, rcu_head);
613
614 ht_cleanup_push(ua_sess->channels);
615 free(ua_sess);
616 }
617
618 /*
619 * Delete ust app session safely. RCU read lock must be held before calling
620 * this function.
621 */
622 static
623 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
624 struct ust_app *app)
625 {
626 int ret;
627 struct lttng_ht_iter iter;
628 struct ust_app_channel *ua_chan;
629 struct ust_registry_session *registry;
630
631 assert(ua_sess);
632
633 pthread_mutex_lock(&ua_sess->lock);
634
635 registry = get_session_registry(ua_sess);
636 if (registry && !registry->metadata_closed) {
637 /* Push metadata for application before freeing the application. */
638 (void) push_metadata(registry, ua_sess->consumer);
639
640 /*
641 * Don't ask to close metadata for global per UID buffers. Close
642 * metadata only on destroy trace session in this case. Also, the
643 * previous push metadata could have flag the metadata registry to
644 * close so don't send a close command if closed.
645 */
646 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
647 !registry->metadata_closed) {
648 /* And ask to close it for this session registry. */
649 (void) close_metadata(registry, ua_sess->consumer);
650 }
651 }
652
653 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
654 node.node) {
655 ret = lttng_ht_del(ua_sess->channels, &iter);
656 assert(!ret);
657 delete_ust_app_channel(sock, ua_chan, app);
658 }
659
660 /* In case of per PID, the registry is kept in the session. */
661 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
662 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
663 if (reg_pid) {
664 buffer_reg_pid_remove(reg_pid);
665 buffer_reg_pid_destroy(reg_pid);
666 }
667 }
668
669 if (ua_sess->handle != -1) {
670 ret = ustctl_release_handle(sock, ua_sess->handle);
671 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
672 ERR("UST app sock %d release session handle failed with ret %d",
673 sock, ret);
674 }
675 }
676 pthread_mutex_unlock(&ua_sess->lock);
677
678 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
679 }
680
681 /*
682 * Delete a traceable application structure from the global list. Never call
683 * this function outside of a call_rcu call.
684 *
685 * RCU read side lock should _NOT_ be held when calling this function.
686 */
687 static
688 void delete_ust_app(struct ust_app *app)
689 {
690 int ret, sock;
691 struct ust_app_session *ua_sess, *tmp_ua_sess;
692
693 /* Delete ust app sessions info */
694 sock = app->sock;
695 app->sock = -1;
696
697 /* Wipe sessions */
698 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
699 teardown_node) {
700 /* Free every object in the session and the session. */
701 rcu_read_lock();
702 delete_ust_app_session(sock, ua_sess, app);
703 rcu_read_unlock();
704 }
705
706 ht_cleanup_push(app->sessions);
707 ht_cleanup_push(app->ust_objd);
708
709 /*
710 * Wait until we have deleted the application from the sock hash table
711 * before closing this socket, otherwise an application could re-use the
712 * socket ID and race with the teardown, using the same hash table entry.
713 *
714 * It's OK to leave the close in call_rcu. We want it to stay unique for
715 * all RCU readers that could run concurrently with unregister app,
716 * therefore we _need_ to only close that socket after a grace period. So
717 * it should stay in this RCU callback.
718 *
719 * This close() is a very important step of the synchronization model so
720 * every modification to this function must be carefully reviewed.
721 */
722 ret = close(sock);
723 if (ret) {
724 PERROR("close");
725 }
726 lttng_fd_put(LTTNG_FD_APPS, 1);
727
728 DBG2("UST app pid %d deleted", app->pid);
729 free(app);
730 }
731
732 /*
733 * URCU intermediate call to delete an UST app.
734 */
735 static
736 void delete_ust_app_rcu(struct rcu_head *head)
737 {
738 struct lttng_ht_node_ulong *node =
739 caa_container_of(head, struct lttng_ht_node_ulong, head);
740 struct ust_app *app =
741 caa_container_of(node, struct ust_app, pid_n);
742
743 DBG3("Call RCU deleting app PID %d", app->pid);
744 delete_ust_app(app);
745 }
746
747 /*
748 * Delete the session from the application ht and delete the data structure by
749 * freeing every object inside and releasing them.
750 */
751 static void destroy_app_session(struct ust_app *app,
752 struct ust_app_session *ua_sess)
753 {
754 int ret;
755 struct lttng_ht_iter iter;
756
757 assert(app);
758 assert(ua_sess);
759
760 iter.iter.node = &ua_sess->node.node;
761 ret = lttng_ht_del(app->sessions, &iter);
762 if (ret) {
763 /* Already scheduled for teardown. */
764 goto end;
765 }
766
767 /* Once deleted, free the data structure. */
768 delete_ust_app_session(app->sock, ua_sess, app);
769
770 end:
771 return;
772 }
773
774 /*
775 * Alloc new UST app session.
776 */
777 static
778 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
779 {
780 struct ust_app_session *ua_sess;
781
782 /* Init most of the default value by allocating and zeroing */
783 ua_sess = zmalloc(sizeof(struct ust_app_session));
784 if (ua_sess == NULL) {
785 PERROR("malloc");
786 goto error_free;
787 }
788
789 ua_sess->handle = -1;
790 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
791 pthread_mutex_init(&ua_sess->lock, NULL);
792
793 return ua_sess;
794
795 error_free:
796 return NULL;
797 }
798
799 /*
800 * Alloc new UST app channel.
801 */
802 static
803 struct ust_app_channel *alloc_ust_app_channel(char *name,
804 struct ust_app_session *ua_sess,
805 struct lttng_ust_channel_attr *attr)
806 {
807 struct ust_app_channel *ua_chan;
808
809 /* Init most of the default value by allocating and zeroing */
810 ua_chan = zmalloc(sizeof(struct ust_app_channel));
811 if (ua_chan == NULL) {
812 PERROR("malloc");
813 goto error;
814 }
815
816 /* Setup channel name */
817 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
818 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
819
820 ua_chan->enabled = 1;
821 ua_chan->handle = -1;
822 ua_chan->session = ua_sess;
823 ua_chan->key = get_next_channel_key();
824 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
825 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
826 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
827
828 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
829 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
830
831 /* Copy attributes */
832 if (attr) {
833 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
834 ua_chan->attr.subbuf_size = attr->subbuf_size;
835 ua_chan->attr.num_subbuf = attr->num_subbuf;
836 ua_chan->attr.overwrite = attr->overwrite;
837 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
838 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
839 ua_chan->attr.output = attr->output;
840 }
841 /* By default, the channel is a per cpu channel. */
842 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
843
844 DBG3("UST app channel %s allocated", ua_chan->name);
845
846 return ua_chan;
847
848 error:
849 return NULL;
850 }
851
852 /*
853 * Allocate and initialize a UST app stream.
854 *
855 * Return newly allocated stream pointer or NULL on error.
856 */
857 struct ust_app_stream *ust_app_alloc_stream(void)
858 {
859 struct ust_app_stream *stream = NULL;
860
861 stream = zmalloc(sizeof(*stream));
862 if (stream == NULL) {
863 PERROR("zmalloc ust app stream");
864 goto error;
865 }
866
867 /* Zero could be a valid value for a handle so flag it to -1. */
868 stream->handle = -1;
869
870 error:
871 return stream;
872 }
873
874 /*
875 * Alloc new UST app event.
876 */
877 static
878 struct ust_app_event *alloc_ust_app_event(char *name,
879 struct lttng_ust_event *attr)
880 {
881 struct ust_app_event *ua_event;
882
883 /* Init most of the default value by allocating and zeroing */
884 ua_event = zmalloc(sizeof(struct ust_app_event));
885 if (ua_event == NULL) {
886 PERROR("malloc");
887 goto error;
888 }
889
890 ua_event->enabled = 1;
891 strncpy(ua_event->name, name, sizeof(ua_event->name));
892 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
893 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
894
895 /* Copy attributes */
896 if (attr) {
897 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
898 }
899
900 DBG3("UST app event %s allocated", ua_event->name);
901
902 return ua_event;
903
904 error:
905 return NULL;
906 }
907
908 /*
909 * Alloc new UST app context.
910 */
911 static
912 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
913 {
914 struct ust_app_ctx *ua_ctx;
915
916 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
917 if (ua_ctx == NULL) {
918 goto error;
919 }
920
921 CDS_INIT_LIST_HEAD(&ua_ctx->list);
922
923 if (uctx) {
924 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
925 }
926
927 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
928
929 error:
930 return ua_ctx;
931 }
932
933 /*
934 * Allocate a filter and copy the given original filter.
935 *
936 * Return allocated filter or NULL on error.
937 */
938 static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
939 struct lttng_ust_filter_bytecode *orig_f)
940 {
941 struct lttng_ust_filter_bytecode *filter = NULL;
942
943 /* Copy filter bytecode */
944 filter = zmalloc(sizeof(*filter) + orig_f->len);
945 if (!filter) {
946 PERROR("zmalloc alloc ust app filter");
947 goto error;
948 }
949
950 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
951
952 error:
953 return filter;
954 }
955
956 /*
957 * Find an ust_app using the sock and return it. RCU read side lock must be
958 * held before calling this helper function.
959 */
960 static
961 struct ust_app *find_app_by_sock(int sock)
962 {
963 struct lttng_ht_node_ulong *node;
964 struct lttng_ht_iter iter;
965
966 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
967 node = lttng_ht_iter_get_node_ulong(&iter);
968 if (node == NULL) {
969 DBG2("UST app find by sock %d not found", sock);
970 goto error;
971 }
972
973 return caa_container_of(node, struct ust_app, sock_n);
974
975 error:
976 return NULL;
977 }
978
979 /*
980 * Find an ust_app using the notify sock and return it. RCU read side lock must
981 * be held before calling this helper function.
982 */
983 static struct ust_app *find_app_by_notify_sock(int sock)
984 {
985 struct lttng_ht_node_ulong *node;
986 struct lttng_ht_iter iter;
987
988 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
989 &iter);
990 node = lttng_ht_iter_get_node_ulong(&iter);
991 if (node == NULL) {
992 DBG2("UST app find by notify sock %d not found", sock);
993 goto error;
994 }
995
996 return caa_container_of(node, struct ust_app, notify_sock_n);
997
998 error:
999 return NULL;
1000 }
1001
1002 /*
1003 * Lookup for an ust app event based on event name, filter bytecode and the
1004 * event loglevel.
1005 *
1006 * Return an ust_app_event object or NULL on error.
1007 */
1008 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1009 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel)
1010 {
1011 struct lttng_ht_iter iter;
1012 struct lttng_ht_node_str *node;
1013 struct ust_app_event *event = NULL;
1014 struct ust_app_ht_key key;
1015
1016 assert(name);
1017 assert(ht);
1018
1019 /* Setup key for event lookup. */
1020 key.name = name;
1021 key.filter = filter;
1022 key.loglevel = loglevel;
1023
1024 /* Lookup using the event name as hash and a custom match fct. */
1025 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1026 ht_match_ust_app_event, &key, &iter.iter);
1027 node = lttng_ht_iter_get_node_str(&iter);
1028 if (node == NULL) {
1029 goto end;
1030 }
1031
1032 event = caa_container_of(node, struct ust_app_event, node);
1033
1034 end:
1035 return event;
1036 }
1037
1038 /*
1039 * Create the channel context on the tracer.
1040 *
1041 * Called with UST app session lock held.
1042 */
1043 static
1044 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1045 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1046 {
1047 int ret;
1048
1049 health_code_update();
1050
1051 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1052 ua_chan->obj, &ua_ctx->obj);
1053 if (ret < 0) {
1054 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1055 ERR("UST app create channel context failed for app (pid: %d) "
1056 "with ret %d", app->pid, ret);
1057 } else {
1058 /*
1059 * This is normal behavior, an application can die during the
1060 * creation process. Don't report an error so the execution can
1061 * continue normally.
1062 */
1063 ret = 0;
1064 DBG3("UST app disable event failed. Application is dead.");
1065 }
1066 goto error;
1067 }
1068
1069 ua_ctx->handle = ua_ctx->obj->handle;
1070
1071 DBG2("UST app context handle %d created successfully for channel %s",
1072 ua_ctx->handle, ua_chan->name);
1073
1074 error:
1075 health_code_update();
1076 return ret;
1077 }
1078
1079 /*
1080 * Set the filter on the tracer.
1081 */
1082 static
1083 int set_ust_event_filter(struct ust_app_event *ua_event,
1084 struct ust_app *app)
1085 {
1086 int ret;
1087
1088 health_code_update();
1089
1090 if (!ua_event->filter) {
1091 ret = 0;
1092 goto error;
1093 }
1094
1095 ret = ustctl_set_filter(app->sock, ua_event->filter,
1096 ua_event->obj);
1097 if (ret < 0) {
1098 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1099 ERR("UST app event %s filter failed for app (pid: %d) "
1100 "with ret %d", ua_event->attr.name, app->pid, ret);
1101 } else {
1102 /*
1103 * This is normal behavior, an application can die during the
1104 * creation process. Don't report an error so the execution can
1105 * continue normally.
1106 */
1107 ret = 0;
1108 DBG3("UST app filter event failed. Application is dead.");
1109 }
1110 goto error;
1111 }
1112
1113 DBG2("UST filter set successfully for event %s", ua_event->name);
1114
1115 error:
1116 health_code_update();
1117 return ret;
1118 }
1119
1120 /*
1121 * Disable the specified event on to UST tracer for the UST session.
1122 */
1123 static int disable_ust_event(struct ust_app *app,
1124 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1125 {
1126 int ret;
1127
1128 health_code_update();
1129
1130 ret = ustctl_disable(app->sock, ua_event->obj);
1131 if (ret < 0) {
1132 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1133 ERR("UST app event %s disable failed for app (pid: %d) "
1134 "and session handle %d with ret %d",
1135 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1136 } else {
1137 /*
1138 * This is normal behavior, an application can die during the
1139 * creation process. Don't report an error so the execution can
1140 * continue normally.
1141 */
1142 ret = 0;
1143 DBG3("UST app disable event failed. Application is dead.");
1144 }
1145 goto error;
1146 }
1147
1148 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1149 ua_event->attr.name, app->pid);
1150
1151 error:
1152 health_code_update();
1153 return ret;
1154 }
1155
1156 /*
1157 * Disable the specified channel on to UST tracer for the UST session.
1158 */
1159 static int disable_ust_channel(struct ust_app *app,
1160 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1161 {
1162 int ret;
1163
1164 health_code_update();
1165
1166 ret = ustctl_disable(app->sock, ua_chan->obj);
1167 if (ret < 0) {
1168 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1169 ERR("UST app channel %s disable failed for app (pid: %d) "
1170 "and session handle %d with ret %d",
1171 ua_chan->name, app->pid, ua_sess->handle, ret);
1172 } else {
1173 /*
1174 * This is normal behavior, an application can die during the
1175 * creation process. Don't report an error so the execution can
1176 * continue normally.
1177 */
1178 ret = 0;
1179 DBG3("UST app disable channel failed. Application is dead.");
1180 }
1181 goto error;
1182 }
1183
1184 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1185 ua_chan->name, app->pid);
1186
1187 error:
1188 health_code_update();
1189 return ret;
1190 }
1191
1192 /*
1193 * Enable the specified channel on to UST tracer for the UST session.
1194 */
1195 static int enable_ust_channel(struct ust_app *app,
1196 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1197 {
1198 int ret;
1199
1200 health_code_update();
1201
1202 ret = ustctl_enable(app->sock, ua_chan->obj);
1203 if (ret < 0) {
1204 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1205 ERR("UST app channel %s enable failed for app (pid: %d) "
1206 "and session handle %d with ret %d",
1207 ua_chan->name, app->pid, ua_sess->handle, ret);
1208 } else {
1209 /*
1210 * This is normal behavior, an application can die during the
1211 * creation process. Don't report an error so the execution can
1212 * continue normally.
1213 */
1214 ret = 0;
1215 DBG3("UST app enable channel failed. Application is dead.");
1216 }
1217 goto error;
1218 }
1219
1220 ua_chan->enabled = 1;
1221
1222 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1223 ua_chan->name, app->pid);
1224
1225 error:
1226 health_code_update();
1227 return ret;
1228 }
1229
1230 /*
1231 * Enable the specified event on to UST tracer for the UST session.
1232 */
1233 static int enable_ust_event(struct ust_app *app,
1234 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1235 {
1236 int ret;
1237
1238 health_code_update();
1239
1240 ret = ustctl_enable(app->sock, ua_event->obj);
1241 if (ret < 0) {
1242 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1243 ERR("UST app event %s enable failed for app (pid: %d) "
1244 "and session handle %d with ret %d",
1245 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1246 } else {
1247 /*
1248 * This is normal behavior, an application can die during the
1249 * creation process. Don't report an error so the execution can
1250 * continue normally.
1251 */
1252 ret = 0;
1253 DBG3("UST app enable event failed. Application is dead.");
1254 }
1255 goto error;
1256 }
1257
1258 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1259 ua_event->attr.name, app->pid);
1260
1261 error:
1262 health_code_update();
1263 return ret;
1264 }
1265
1266 /*
1267 * Send channel and stream buffer to application.
1268 *
1269 * Return 0 on success. On error, a negative value is returned.
1270 */
1271 static int send_channel_pid_to_ust(struct ust_app *app,
1272 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1273 {
1274 int ret;
1275 struct ust_app_stream *stream, *stmp;
1276
1277 assert(app);
1278 assert(ua_sess);
1279 assert(ua_chan);
1280
1281 health_code_update();
1282
1283 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1284 app->sock);
1285
1286 /* Send channel to the application. */
1287 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1288 if (ret < 0) {
1289 goto error;
1290 }
1291
1292 health_code_update();
1293
1294 /* Send all streams to application. */
1295 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1296 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1297 if (ret < 0) {
1298 goto error;
1299 }
1300 /* We don't need the stream anymore once sent to the tracer. */
1301 cds_list_del(&stream->list);
1302 delete_ust_app_stream(-1, stream);
1303 }
1304 /* Flag the channel that it is sent to the application. */
1305 ua_chan->is_sent = 1;
1306
1307 error:
1308 health_code_update();
1309 return ret;
1310 }
1311
1312 /*
1313 * Create the specified event onto the UST tracer for a UST session.
1314 *
1315 * Should be called with session mutex held.
1316 */
1317 static
1318 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1319 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1320 {
1321 int ret = 0;
1322
1323 health_code_update();
1324
1325 /* Create UST event on tracer */
1326 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1327 &ua_event->obj);
1328 if (ret < 0) {
1329 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1330 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1331 ua_event->attr.name, app->pid, ret);
1332 } else {
1333 /*
1334 * This is normal behavior, an application can die during the
1335 * creation process. Don't report an error so the execution can
1336 * continue normally.
1337 */
1338 ret = 0;
1339 DBG3("UST app create event failed. Application is dead.");
1340 }
1341 goto error;
1342 }
1343
1344 ua_event->handle = ua_event->obj->handle;
1345
1346 DBG2("UST app event %s created successfully for pid:%d",
1347 ua_event->attr.name, app->pid);
1348
1349 health_code_update();
1350
1351 /* Set filter if one is present. */
1352 if (ua_event->filter) {
1353 ret = set_ust_event_filter(ua_event, app);
1354 if (ret < 0) {
1355 goto error;
1356 }
1357 }
1358
1359 /* If event not enabled, disable it on the tracer */
1360 if (ua_event->enabled == 0) {
1361 ret = disable_ust_event(app, ua_sess, ua_event);
1362 if (ret < 0) {
1363 /*
1364 * If we hit an EPERM, something is wrong with our disable call. If
1365 * we get an EEXIST, there is a problem on the tracer side since we
1366 * just created it.
1367 */
1368 switch (ret) {
1369 case -LTTNG_UST_ERR_PERM:
1370 /* Code flow problem */
1371 assert(0);
1372 case -LTTNG_UST_ERR_EXIST:
1373 /* It's OK for our use case. */
1374 ret = 0;
1375 break;
1376 default:
1377 break;
1378 }
1379 goto error;
1380 }
1381 }
1382
1383 error:
1384 health_code_update();
1385 return ret;
1386 }
1387
1388 /*
1389 * Copy data between an UST app event and a LTT event.
1390 */
1391 static void shadow_copy_event(struct ust_app_event *ua_event,
1392 struct ltt_ust_event *uevent)
1393 {
1394 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1395 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1396
1397 ua_event->enabled = uevent->enabled;
1398
1399 /* Copy event attributes */
1400 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1401
1402 /* Copy filter bytecode */
1403 if (uevent->filter) {
1404 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1405 /* Filter might be NULL here in case of ENONEM. */
1406 }
1407 }
1408
1409 /*
1410 * Copy data between an UST app channel and a LTT channel.
1411 */
1412 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1413 struct ltt_ust_channel *uchan)
1414 {
1415 struct lttng_ht_iter iter;
1416 struct ltt_ust_event *uevent;
1417 struct ltt_ust_context *uctx;
1418 struct ust_app_event *ua_event;
1419 struct ust_app_ctx *ua_ctx;
1420
1421 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1422
1423 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1424 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1425
1426 ua_chan->tracefile_size = uchan->tracefile_size;
1427 ua_chan->tracefile_count = uchan->tracefile_count;
1428
1429 /* Copy event attributes since the layout is different. */
1430 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1431 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1432 ua_chan->attr.overwrite = uchan->attr.overwrite;
1433 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1434 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1435 ua_chan->attr.output = uchan->attr.output;
1436 /*
1437 * Note that the attribute channel type is not set since the channel on the
1438 * tracing registry side does not have this information.
1439 */
1440
1441 ua_chan->enabled = uchan->enabled;
1442 ua_chan->tracing_channel_id = uchan->id;
1443
1444 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1445 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1446 if (ua_ctx == NULL) {
1447 continue;
1448 }
1449 lttng_ht_node_init_ulong(&ua_ctx->node,
1450 (unsigned long) ua_ctx->ctx.ctx);
1451 lttng_ht_add_unique_ulong(ua_chan->ctx, &ua_ctx->node);
1452 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1453 }
1454
1455 /* Copy all events from ltt ust channel to ust app channel */
1456 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1457 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1458 uevent->filter, uevent->attr.loglevel);
1459 if (ua_event == NULL) {
1460 DBG2("UST event %s not found on shadow copy channel",
1461 uevent->attr.name);
1462 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1463 if (ua_event == NULL) {
1464 continue;
1465 }
1466 shadow_copy_event(ua_event, uevent);
1467 add_unique_ust_app_event(ua_chan, ua_event);
1468 }
1469 }
1470
1471 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1472 }
1473
1474 /*
1475 * Copy data between a UST app session and a regular LTT session.
1476 */
1477 static void shadow_copy_session(struct ust_app_session *ua_sess,
1478 struct ltt_ust_session *usess, struct ust_app *app)
1479 {
1480 struct lttng_ht_node_str *ua_chan_node;
1481 struct lttng_ht_iter iter;
1482 struct ltt_ust_channel *uchan;
1483 struct ust_app_channel *ua_chan;
1484 time_t rawtime;
1485 struct tm *timeinfo;
1486 char datetime[16];
1487 int ret;
1488
1489 /* Get date and time for unique app path */
1490 time(&rawtime);
1491 timeinfo = localtime(&rawtime);
1492 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1493
1494 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1495
1496 ua_sess->tracing_id = usess->id;
1497 ua_sess->id = get_next_session_id();
1498 ua_sess->uid = app->uid;
1499 ua_sess->gid = app->gid;
1500 ua_sess->euid = usess->uid;
1501 ua_sess->egid = usess->gid;
1502 ua_sess->buffer_type = usess->buffer_type;
1503 ua_sess->bits_per_long = app->bits_per_long;
1504 /* There is only one consumer object per session possible. */
1505 ua_sess->consumer = usess->consumer;
1506 ua_sess->output_traces = usess->output_traces;
1507
1508 switch (ua_sess->buffer_type) {
1509 case LTTNG_BUFFER_PER_PID:
1510 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1511 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1512 datetime);
1513 break;
1514 case LTTNG_BUFFER_PER_UID:
1515 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1516 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1517 break;
1518 default:
1519 assert(0);
1520 goto error;
1521 }
1522 if (ret < 0) {
1523 PERROR("asprintf UST shadow copy session");
1524 assert(0);
1525 goto error;
1526 }
1527
1528 /* Iterate over all channels in global domain. */
1529 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1530 uchan, node.node) {
1531 struct lttng_ht_iter uiter;
1532
1533 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1534 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1535 if (ua_chan_node != NULL) {
1536 /* Session exist. Contiuing. */
1537 continue;
1538 }
1539
1540 DBG2("Channel %s not found on shadow session copy, creating it",
1541 uchan->name);
1542 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1543 if (ua_chan == NULL) {
1544 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1545 continue;
1546 }
1547 shadow_copy_channel(ua_chan, uchan);
1548 /*
1549 * The concept of metadata channel does not exist on the tracing
1550 * registry side of the session daemon so this can only be a per CPU
1551 * channel and not metadata.
1552 */
1553 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1554
1555 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1556 }
1557
1558 error:
1559 return;
1560 }
1561
1562 /*
1563 * Lookup sesison wrapper.
1564 */
1565 static
1566 void __lookup_session_by_app(struct ltt_ust_session *usess,
1567 struct ust_app *app, struct lttng_ht_iter *iter)
1568 {
1569 /* Get right UST app session from app */
1570 lttng_ht_lookup(app->sessions, &usess->id, iter);
1571 }
1572
1573 /*
1574 * Return ust app session from the app session hashtable using the UST session
1575 * id.
1576 */
1577 static struct ust_app_session *lookup_session_by_app(
1578 struct ltt_ust_session *usess, struct ust_app *app)
1579 {
1580 struct lttng_ht_iter iter;
1581 struct lttng_ht_node_u64 *node;
1582
1583 __lookup_session_by_app(usess, app, &iter);
1584 node = lttng_ht_iter_get_node_u64(&iter);
1585 if (node == NULL) {
1586 goto error;
1587 }
1588
1589 return caa_container_of(node, struct ust_app_session, node);
1590
1591 error:
1592 return NULL;
1593 }
1594
1595 /*
1596 * Setup buffer registry per PID for the given session and application. If none
1597 * is found, a new one is created, added to the global registry and
1598 * initialized. If regp is valid, it's set with the newly created object.
1599 *
1600 * Return 0 on success or else a negative value.
1601 */
1602 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1603 struct ust_app *app, struct buffer_reg_pid **regp)
1604 {
1605 int ret = 0;
1606 struct buffer_reg_pid *reg_pid;
1607
1608 assert(ua_sess);
1609 assert(app);
1610
1611 rcu_read_lock();
1612
1613 reg_pid = buffer_reg_pid_find(ua_sess->id);
1614 if (!reg_pid) {
1615 /*
1616 * This is the create channel path meaning that if there is NO
1617 * registry available, we have to create one for this session.
1618 */
1619 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1620 if (ret < 0) {
1621 goto error;
1622 }
1623 buffer_reg_pid_add(reg_pid);
1624 } else {
1625 goto end;
1626 }
1627
1628 /* Initialize registry. */
1629 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1630 app->bits_per_long, app->uint8_t_alignment,
1631 app->uint16_t_alignment, app->uint32_t_alignment,
1632 app->uint64_t_alignment, app->long_alignment,
1633 app->byte_order, app->version.major,
1634 app->version.minor);
1635 if (ret < 0) {
1636 goto error;
1637 }
1638
1639 DBG3("UST app buffer registry per PID created successfully");
1640
1641 end:
1642 if (regp) {
1643 *regp = reg_pid;
1644 }
1645 error:
1646 rcu_read_unlock();
1647 return ret;
1648 }
1649
1650 /*
1651 * Setup buffer registry per UID for the given session and application. If none
1652 * is found, a new one is created, added to the global registry and
1653 * initialized. If regp is valid, it's set with the newly created object.
1654 *
1655 * Return 0 on success or else a negative value.
1656 */
1657 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1658 struct ust_app *app, struct buffer_reg_uid **regp)
1659 {
1660 int ret = 0;
1661 struct buffer_reg_uid *reg_uid;
1662
1663 assert(usess);
1664 assert(app);
1665
1666 rcu_read_lock();
1667
1668 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1669 if (!reg_uid) {
1670 /*
1671 * This is the create channel path meaning that if there is NO
1672 * registry available, we have to create one for this session.
1673 */
1674 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1675 LTTNG_DOMAIN_UST, &reg_uid);
1676 if (ret < 0) {
1677 goto error;
1678 }
1679 buffer_reg_uid_add(reg_uid);
1680 } else {
1681 goto end;
1682 }
1683
1684 /* Initialize registry. */
1685 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1686 app->bits_per_long, app->uint8_t_alignment,
1687 app->uint16_t_alignment, app->uint32_t_alignment,
1688 app->uint64_t_alignment, app->long_alignment,
1689 app->byte_order, app->version.major,
1690 app->version.minor);
1691 if (ret < 0) {
1692 goto error;
1693 }
1694 /* Add node to teardown list of the session. */
1695 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1696
1697 DBG3("UST app buffer registry per UID created successfully");
1698
1699 end:
1700 if (regp) {
1701 *regp = reg_uid;
1702 }
1703 error:
1704 rcu_read_unlock();
1705 return ret;
1706 }
1707
1708 /*
1709 * Create a session on the tracer side for the given app.
1710 *
1711 * On success, ua_sess_ptr is populated with the session pointer or else left
1712 * untouched. If the session was created, is_created is set to 1. On error,
1713 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1714 * be NULL.
1715 *
1716 * Returns 0 on success or else a negative code which is either -ENOMEM or
1717 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1718 */
1719 static int create_ust_app_session(struct ltt_ust_session *usess,
1720 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1721 int *is_created)
1722 {
1723 int ret, created = 0;
1724 struct ust_app_session *ua_sess;
1725
1726 assert(usess);
1727 assert(app);
1728 assert(ua_sess_ptr);
1729
1730 health_code_update();
1731
1732 ua_sess = lookup_session_by_app(usess, app);
1733 if (ua_sess == NULL) {
1734 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1735 app->pid, usess->id);
1736 ua_sess = alloc_ust_app_session(app);
1737 if (ua_sess == NULL) {
1738 /* Only malloc can failed so something is really wrong */
1739 ret = -ENOMEM;
1740 goto error;
1741 }
1742 shadow_copy_session(ua_sess, usess, app);
1743 created = 1;
1744 }
1745
1746 switch (usess->buffer_type) {
1747 case LTTNG_BUFFER_PER_PID:
1748 /* Init local registry. */
1749 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1750 if (ret < 0) {
1751 goto error;
1752 }
1753 break;
1754 case LTTNG_BUFFER_PER_UID:
1755 /* Look for a global registry. If none exists, create one. */
1756 ret = setup_buffer_reg_uid(usess, app, NULL);
1757 if (ret < 0) {
1758 goto error;
1759 }
1760 break;
1761 default:
1762 assert(0);
1763 ret = -EINVAL;
1764 goto error;
1765 }
1766
1767 health_code_update();
1768
1769 if (ua_sess->handle == -1) {
1770 ret = ustctl_create_session(app->sock);
1771 if (ret < 0) {
1772 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1773 ERR("Creating session for app pid %d with ret %d",
1774 app->pid, ret);
1775 } else {
1776 DBG("UST app creating session failed. Application is dead");
1777 /*
1778 * This is normal behavior, an application can die during the
1779 * creation process. Don't report an error so the execution can
1780 * continue normally. This will get flagged ENOTCONN and the
1781 * caller will handle it.
1782 */
1783 ret = 0;
1784 }
1785 delete_ust_app_session(-1, ua_sess, app);
1786 if (ret != -ENOMEM) {
1787 /*
1788 * Tracer is probably gone or got an internal error so let's
1789 * behave like it will soon unregister or not usable.
1790 */
1791 ret = -ENOTCONN;
1792 }
1793 goto error;
1794 }
1795
1796 ua_sess->handle = ret;
1797
1798 /* Add ust app session to app's HT */
1799 lttng_ht_node_init_u64(&ua_sess->node,
1800 ua_sess->tracing_id);
1801 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1802
1803 DBG2("UST app session created successfully with handle %d", ret);
1804 }
1805
1806 *ua_sess_ptr = ua_sess;
1807 if (is_created) {
1808 *is_created = created;
1809 }
1810
1811 /* Everything went well. */
1812 ret = 0;
1813
1814 error:
1815 health_code_update();
1816 return ret;
1817 }
1818
1819 /*
1820 * Create a context for the channel on the tracer.
1821 *
1822 * Called with UST app session lock held and a RCU read side lock.
1823 */
1824 static
1825 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
1826 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
1827 struct ust_app *app)
1828 {
1829 int ret = 0;
1830 struct lttng_ht_iter iter;
1831 struct lttng_ht_node_ulong *node;
1832 struct ust_app_ctx *ua_ctx;
1833
1834 DBG2("UST app adding context to channel %s", ua_chan->name);
1835
1836 lttng_ht_lookup(ua_chan->ctx, (void *)((unsigned long)uctx->ctx), &iter);
1837 node = lttng_ht_iter_get_node_ulong(&iter);
1838 if (node != NULL) {
1839 ret = -EEXIST;
1840 goto error;
1841 }
1842
1843 ua_ctx = alloc_ust_app_ctx(uctx);
1844 if (ua_ctx == NULL) {
1845 /* malloc failed */
1846 ret = -1;
1847 goto error;
1848 }
1849
1850 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
1851 lttng_ht_add_unique_ulong(ua_chan->ctx, &ua_ctx->node);
1852 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1853
1854 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
1855 if (ret < 0) {
1856 goto error;
1857 }
1858
1859 error:
1860 return ret;
1861 }
1862
1863 /*
1864 * Enable on the tracer side a ust app event for the session and channel.
1865 *
1866 * Called with UST app session lock held.
1867 */
1868 static
1869 int enable_ust_app_event(struct ust_app_session *ua_sess,
1870 struct ust_app_event *ua_event, struct ust_app *app)
1871 {
1872 int ret;
1873
1874 ret = enable_ust_event(app, ua_sess, ua_event);
1875 if (ret < 0) {
1876 goto error;
1877 }
1878
1879 ua_event->enabled = 1;
1880
1881 error:
1882 return ret;
1883 }
1884
1885 /*
1886 * Disable on the tracer side a ust app event for the session and channel.
1887 */
1888 static int disable_ust_app_event(struct ust_app_session *ua_sess,
1889 struct ust_app_event *ua_event, struct ust_app *app)
1890 {
1891 int ret;
1892
1893 ret = disable_ust_event(app, ua_sess, ua_event);
1894 if (ret < 0) {
1895 goto error;
1896 }
1897
1898 ua_event->enabled = 0;
1899
1900 error:
1901 return ret;
1902 }
1903
1904 /*
1905 * Lookup ust app channel for session and disable it on the tracer side.
1906 */
1907 static
1908 int disable_ust_app_channel(struct ust_app_session *ua_sess,
1909 struct ust_app_channel *ua_chan, struct ust_app *app)
1910 {
1911 int ret;
1912
1913 ret = disable_ust_channel(app, ua_sess, ua_chan);
1914 if (ret < 0) {
1915 goto error;
1916 }
1917
1918 ua_chan->enabled = 0;
1919
1920 error:
1921 return ret;
1922 }
1923
1924 /*
1925 * Lookup ust app channel for session and enable it on the tracer side. This
1926 * MUST be called with a RCU read side lock acquired.
1927 */
1928 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
1929 struct ltt_ust_channel *uchan, struct ust_app *app)
1930 {
1931 int ret = 0;
1932 struct lttng_ht_iter iter;
1933 struct lttng_ht_node_str *ua_chan_node;
1934 struct ust_app_channel *ua_chan;
1935
1936 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
1937 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
1938 if (ua_chan_node == NULL) {
1939 DBG2("Unable to find channel %s in ust session id %" PRIu64,
1940 uchan->name, ua_sess->tracing_id);
1941 goto error;
1942 }
1943
1944 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
1945
1946 ret = enable_ust_channel(app, ua_sess, ua_chan);
1947 if (ret < 0) {
1948 goto error;
1949 }
1950
1951 error:
1952 return ret;
1953 }
1954
1955 /*
1956 * Ask the consumer to create a channel and get it if successful.
1957 *
1958 * Return 0 on success or else a negative value.
1959 */
1960 static int do_consumer_create_channel(struct ltt_ust_session *usess,
1961 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
1962 int bitness, struct ust_registry_session *registry)
1963 {
1964 int ret;
1965 unsigned int nb_fd = 0;
1966 struct consumer_socket *socket;
1967
1968 assert(usess);
1969 assert(ua_sess);
1970 assert(ua_chan);
1971 assert(registry);
1972
1973 rcu_read_lock();
1974 health_code_update();
1975
1976 /* Get the right consumer socket for the application. */
1977 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
1978 if (!socket) {
1979 ret = -EINVAL;
1980 goto error;
1981 }
1982
1983 health_code_update();
1984
1985 /* Need one fd for the channel. */
1986 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
1987 if (ret < 0) {
1988 ERR("Exhausted number of available FD upon create channel");
1989 goto error;
1990 }
1991
1992 /*
1993 * Ask consumer to create channel. The consumer will return the number of
1994 * stream we have to expect.
1995 */
1996 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
1997 registry);
1998 if (ret < 0) {
1999 goto error_ask;
2000 }
2001
2002 /*
2003 * Compute the number of fd needed before receiving them. It must be 2 per
2004 * stream (2 being the default value here).
2005 */
2006 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2007
2008 /* Reserve the amount of file descriptor we need. */
2009 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2010 if (ret < 0) {
2011 ERR("Exhausted number of available FD upon create channel");
2012 goto error_fd_get_stream;
2013 }
2014
2015 health_code_update();
2016
2017 /*
2018 * Now get the channel from the consumer. This call wil populate the stream
2019 * list of that channel and set the ust objects.
2020 */
2021 if (usess->consumer->enabled) {
2022 ret = ust_consumer_get_channel(socket, ua_chan);
2023 if (ret < 0) {
2024 goto error_destroy;
2025 }
2026 }
2027
2028 rcu_read_unlock();
2029 return 0;
2030
2031 error_destroy:
2032 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2033 error_fd_get_stream:
2034 /*
2035 * Initiate a destroy channel on the consumer since we had an error
2036 * handling it on our side. The return value is of no importance since we
2037 * already have a ret value set by the previous error that we need to
2038 * return.
2039 */
2040 (void) ust_consumer_destroy_channel(socket, ua_chan);
2041 error_ask:
2042 lttng_fd_put(LTTNG_FD_APPS, 1);
2043 error:
2044 health_code_update();
2045 rcu_read_unlock();
2046 return ret;
2047 }
2048
2049 /*
2050 * Duplicate the ust data object of the ust app stream and save it in the
2051 * buffer registry stream.
2052 *
2053 * Return 0 on success or else a negative value.
2054 */
2055 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2056 struct ust_app_stream *stream)
2057 {
2058 int ret;
2059
2060 assert(reg_stream);
2061 assert(stream);
2062
2063 /* Reserve the amount of file descriptor we need. */
2064 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2065 if (ret < 0) {
2066 ERR("Exhausted number of available FD upon duplicate stream");
2067 goto error;
2068 }
2069
2070 /* Duplicate object for stream once the original is in the registry. */
2071 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2072 reg_stream->obj.ust);
2073 if (ret < 0) {
2074 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2075 reg_stream->obj.ust, stream->obj, ret);
2076 lttng_fd_put(LTTNG_FD_APPS, 2);
2077 goto error;
2078 }
2079 stream->handle = stream->obj->handle;
2080
2081 error:
2082 return ret;
2083 }
2084
2085 /*
2086 * Duplicate the ust data object of the ust app. channel and save it in the
2087 * buffer registry channel.
2088 *
2089 * Return 0 on success or else a negative value.
2090 */
2091 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2092 struct ust_app_channel *ua_chan)
2093 {
2094 int ret;
2095
2096 assert(reg_chan);
2097 assert(ua_chan);
2098
2099 /* Need two fds for the channel. */
2100 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2101 if (ret < 0) {
2102 ERR("Exhausted number of available FD upon duplicate channel");
2103 goto error_fd_get;
2104 }
2105
2106 /* Duplicate object for stream once the original is in the registry. */
2107 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2108 if (ret < 0) {
2109 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2110 reg_chan->obj.ust, ua_chan->obj, ret);
2111 goto error;
2112 }
2113 ua_chan->handle = ua_chan->obj->handle;
2114
2115 return 0;
2116
2117 error:
2118 lttng_fd_put(LTTNG_FD_APPS, 1);
2119 error_fd_get:
2120 return ret;
2121 }
2122
2123 /*
2124 * For a given channel buffer registry, setup all streams of the given ust
2125 * application channel.
2126 *
2127 * Return 0 on success or else a negative value.
2128 */
2129 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2130 struct ust_app_channel *ua_chan)
2131 {
2132 int ret = 0;
2133 struct ust_app_stream *stream, *stmp;
2134
2135 assert(reg_chan);
2136 assert(ua_chan);
2137
2138 DBG2("UST app setup buffer registry stream");
2139
2140 /* Send all streams to application. */
2141 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2142 struct buffer_reg_stream *reg_stream;
2143
2144 ret = buffer_reg_stream_create(&reg_stream);
2145 if (ret < 0) {
2146 goto error;
2147 }
2148
2149 /*
2150 * Keep original pointer and nullify it in the stream so the delete
2151 * stream call does not release the object.
2152 */
2153 reg_stream->obj.ust = stream->obj;
2154 stream->obj = NULL;
2155 buffer_reg_stream_add(reg_stream, reg_chan);
2156
2157 /* We don't need the streams anymore. */
2158 cds_list_del(&stream->list);
2159 delete_ust_app_stream(-1, stream);
2160 }
2161
2162 error:
2163 return ret;
2164 }
2165
2166 /*
2167 * Create a buffer registry channel for the given session registry and
2168 * application channel object. If regp pointer is valid, it's set with the
2169 * created object. Important, the created object is NOT added to the session
2170 * registry hash table.
2171 *
2172 * Return 0 on success else a negative value.
2173 */
2174 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2175 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2176 {
2177 int ret;
2178 struct buffer_reg_channel *reg_chan = NULL;
2179
2180 assert(reg_sess);
2181 assert(ua_chan);
2182
2183 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2184
2185 /* Create buffer registry channel. */
2186 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2187 if (ret < 0) {
2188 goto error_create;
2189 }
2190 assert(reg_chan);
2191 reg_chan->consumer_key = ua_chan->key;
2192 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2193
2194 /* Create and add a channel registry to session. */
2195 ret = ust_registry_channel_add(reg_sess->reg.ust,
2196 ua_chan->tracing_channel_id);
2197 if (ret < 0) {
2198 goto error;
2199 }
2200 buffer_reg_channel_add(reg_sess, reg_chan);
2201
2202 if (regp) {
2203 *regp = reg_chan;
2204 }
2205
2206 return 0;
2207
2208 error:
2209 /* Safe because the registry channel object was not added to any HT. */
2210 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2211 error_create:
2212 return ret;
2213 }
2214
2215 /*
2216 * Setup buffer registry channel for the given session registry and application
2217 * channel object. If regp pointer is valid, it's set with the created object.
2218 *
2219 * Return 0 on success else a negative value.
2220 */
2221 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2222 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2223 {
2224 int ret;
2225
2226 assert(reg_sess);
2227 assert(reg_chan);
2228 assert(ua_chan);
2229 assert(ua_chan->obj);
2230
2231 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2232
2233 /* Setup all streams for the registry. */
2234 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2235 if (ret < 0) {
2236 goto error;
2237 }
2238
2239 reg_chan->obj.ust = ua_chan->obj;
2240 ua_chan->obj = NULL;
2241
2242 return 0;
2243
2244 error:
2245 buffer_reg_channel_remove(reg_sess, reg_chan);
2246 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2247 return ret;
2248 }
2249
2250 /*
2251 * Send buffer registry channel to the application.
2252 *
2253 * Return 0 on success else a negative value.
2254 */
2255 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2256 struct ust_app *app, struct ust_app_session *ua_sess,
2257 struct ust_app_channel *ua_chan)
2258 {
2259 int ret;
2260 struct buffer_reg_stream *reg_stream;
2261
2262 assert(reg_chan);
2263 assert(app);
2264 assert(ua_sess);
2265 assert(ua_chan);
2266
2267 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2268
2269 ret = duplicate_channel_object(reg_chan, ua_chan);
2270 if (ret < 0) {
2271 goto error;
2272 }
2273
2274 /* Send channel to the application. */
2275 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2276 if (ret < 0) {
2277 goto error;
2278 }
2279
2280 health_code_update();
2281
2282 /* Send all streams to application. */
2283 pthread_mutex_lock(&reg_chan->stream_list_lock);
2284 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2285 struct ust_app_stream stream;
2286
2287 ret = duplicate_stream_object(reg_stream, &stream);
2288 if (ret < 0) {
2289 goto error_stream_unlock;
2290 }
2291
2292 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2293 if (ret < 0) {
2294 (void) release_ust_app_stream(-1, &stream);
2295 goto error_stream_unlock;
2296 }
2297
2298 /*
2299 * The return value is not important here. This function will output an
2300 * error if needed.
2301 */
2302 (void) release_ust_app_stream(-1, &stream);
2303 }
2304 ua_chan->is_sent = 1;
2305
2306 error_stream_unlock:
2307 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2308 error:
2309 return ret;
2310 }
2311
2312 /*
2313 * Create and send to the application the created buffers with per UID buffers.
2314 *
2315 * Return 0 on success else a negative value.
2316 */
2317 static int create_channel_per_uid(struct ust_app *app,
2318 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2319 struct ust_app_channel *ua_chan)
2320 {
2321 int ret;
2322 struct buffer_reg_uid *reg_uid;
2323 struct buffer_reg_channel *reg_chan;
2324
2325 assert(app);
2326 assert(usess);
2327 assert(ua_sess);
2328 assert(ua_chan);
2329
2330 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2331
2332 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2333 /*
2334 * The session creation handles the creation of this global registry
2335 * object. If none can be find, there is a code flow problem or a
2336 * teardown race.
2337 */
2338 assert(reg_uid);
2339
2340 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2341 reg_uid);
2342 if (!reg_chan) {
2343 /* Create the buffer registry channel object. */
2344 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2345 if (ret < 0) {
2346 goto error;
2347 }
2348 assert(reg_chan);
2349
2350 /*
2351 * Create the buffers on the consumer side. This call populates the
2352 * ust app channel object with all streams and data object.
2353 */
2354 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2355 app->bits_per_long, reg_uid->registry->reg.ust);
2356 if (ret < 0) {
2357 /*
2358 * Let's remove the previously created buffer registry channel so
2359 * it's not visible anymore in the session registry.
2360 */
2361 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2362 ua_chan->tracing_channel_id);
2363 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2364 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2365 goto error;
2366 }
2367
2368 /*
2369 * Setup the streams and add it to the session registry.
2370 */
2371 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2372 if (ret < 0) {
2373 goto error;
2374 }
2375
2376 }
2377
2378 /* Send buffers to the application. */
2379 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2380 if (ret < 0) {
2381 goto error;
2382 }
2383
2384 error:
2385 return ret;
2386 }
2387
2388 /*
2389 * Create and send to the application the created buffers with per PID buffers.
2390 *
2391 * Return 0 on success else a negative value.
2392 */
2393 static int create_channel_per_pid(struct ust_app *app,
2394 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2395 struct ust_app_channel *ua_chan)
2396 {
2397 int ret;
2398 struct ust_registry_session *registry;
2399
2400 assert(app);
2401 assert(usess);
2402 assert(ua_sess);
2403 assert(ua_chan);
2404
2405 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2406
2407 rcu_read_lock();
2408
2409 registry = get_session_registry(ua_sess);
2410 assert(registry);
2411
2412 /* Create and add a new channel registry to session. */
2413 ret = ust_registry_channel_add(registry, ua_chan->key);
2414 if (ret < 0) {
2415 goto error;
2416 }
2417
2418 /* Create and get channel on the consumer side. */
2419 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2420 app->bits_per_long, registry);
2421 if (ret < 0) {
2422 goto error;
2423 }
2424
2425 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2426 if (ret < 0) {
2427 goto error;
2428 }
2429
2430 error:
2431 rcu_read_unlock();
2432 return ret;
2433 }
2434
2435 /*
2436 * From an already allocated ust app channel, create the channel buffers if
2437 * need and send it to the application. This MUST be called with a RCU read
2438 * side lock acquired.
2439 *
2440 * Return 0 on success or else a negative value.
2441 */
2442 static int do_create_channel(struct ust_app *app,
2443 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2444 struct ust_app_channel *ua_chan)
2445 {
2446 int ret;
2447
2448 assert(app);
2449 assert(usess);
2450 assert(ua_sess);
2451 assert(ua_chan);
2452
2453 /* Handle buffer type before sending the channel to the application. */
2454 switch (usess->buffer_type) {
2455 case LTTNG_BUFFER_PER_UID:
2456 {
2457 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2458 if (ret < 0) {
2459 goto error;
2460 }
2461 break;
2462 }
2463 case LTTNG_BUFFER_PER_PID:
2464 {
2465 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2466 if (ret < 0) {
2467 goto error;
2468 }
2469 break;
2470 }
2471 default:
2472 assert(0);
2473 ret = -EINVAL;
2474 goto error;
2475 }
2476
2477 /* Initialize ust objd object using the received handle and add it. */
2478 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2479 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2480
2481 /* If channel is not enabled, disable it on the tracer */
2482 if (!ua_chan->enabled) {
2483 ret = disable_ust_channel(app, ua_sess, ua_chan);
2484 if (ret < 0) {
2485 goto error;
2486 }
2487 }
2488
2489 error:
2490 return ret;
2491 }
2492
2493 /*
2494 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2495 * newly created channel if not NULL.
2496 *
2497 * Called with UST app session lock and RCU read-side lock held.
2498 *
2499 * Return 0 on success or else a negative value.
2500 */
2501 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2502 struct ltt_ust_channel *uchan, struct ust_app *app,
2503 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2504 struct ust_app_channel **ua_chanp)
2505 {
2506 int ret = 0;
2507 struct lttng_ht_iter iter;
2508 struct lttng_ht_node_str *ua_chan_node;
2509 struct ust_app_channel *ua_chan;
2510
2511 /* Lookup channel in the ust app session */
2512 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2513 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2514 if (ua_chan_node != NULL) {
2515 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2516 goto end;
2517 }
2518
2519 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2520 if (ua_chan == NULL) {
2521 /* Only malloc can fail here */
2522 ret = -ENOMEM;
2523 goto error_alloc;
2524 }
2525 shadow_copy_channel(ua_chan, uchan);
2526
2527 /* Set channel type. */
2528 ua_chan->attr.type = type;
2529
2530 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2531 if (ret < 0) {
2532 goto error;
2533 }
2534
2535 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2536 app->pid);
2537
2538 /* Only add the channel if successful on the tracer side. */
2539 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2540
2541 end:
2542 if (ua_chanp) {
2543 *ua_chanp = ua_chan;
2544 }
2545
2546 /* Everything went well. */
2547 return 0;
2548
2549 error:
2550 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2551 error_alloc:
2552 return ret;
2553 }
2554
2555 /*
2556 * Create UST app event and create it on the tracer side.
2557 *
2558 * Called with ust app session mutex held.
2559 */
2560 static
2561 int create_ust_app_event(struct ust_app_session *ua_sess,
2562 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2563 struct ust_app *app)
2564 {
2565 int ret = 0;
2566 struct ust_app_event *ua_event;
2567
2568 /* Get event node */
2569 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2570 uevent->filter, uevent->attr.loglevel);
2571 if (ua_event != NULL) {
2572 ret = -EEXIST;
2573 goto end;
2574 }
2575
2576 /* Does not exist so create one */
2577 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2578 if (ua_event == NULL) {
2579 /* Only malloc can failed so something is really wrong */
2580 ret = -ENOMEM;
2581 goto end;
2582 }
2583 shadow_copy_event(ua_event, uevent);
2584
2585 /* Create it on the tracer side */
2586 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2587 if (ret < 0) {
2588 /* Not found previously means that it does not exist on the tracer */
2589 assert(ret != -LTTNG_UST_ERR_EXIST);
2590 goto error;
2591 }
2592
2593 add_unique_ust_app_event(ua_chan, ua_event);
2594
2595 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2596 app->pid);
2597
2598 end:
2599 return ret;
2600
2601 error:
2602 /* Valid. Calling here is already in a read side lock */
2603 delete_ust_app_event(-1, ua_event);
2604 return ret;
2605 }
2606
2607 /*
2608 * Create UST metadata and open it on the tracer side.
2609 *
2610 * Called with UST app session lock held and RCU read side lock.
2611 */
2612 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2613 struct ust_app *app, struct consumer_output *consumer,
2614 struct ustctl_consumer_channel_attr *attr)
2615 {
2616 int ret = 0;
2617 struct ust_app_channel *metadata;
2618 struct consumer_socket *socket;
2619 struct ust_registry_session *registry;
2620
2621 assert(ua_sess);
2622 assert(app);
2623 assert(consumer);
2624
2625 registry = get_session_registry(ua_sess);
2626 assert(registry);
2627
2628 /* Metadata already exists for this registry or it was closed previously */
2629 if (registry->metadata_key || registry->metadata_closed) {
2630 ret = 0;
2631 goto error;
2632 }
2633
2634 /* Allocate UST metadata */
2635 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2636 if (!metadata) {
2637 /* malloc() failed */
2638 ret = -ENOMEM;
2639 goto error;
2640 }
2641
2642 if (!attr) {
2643 /* Set default attributes for metadata. */
2644 metadata->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
2645 metadata->attr.subbuf_size = default_get_metadata_subbuf_size();
2646 metadata->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
2647 metadata->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
2648 metadata->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
2649 metadata->attr.output = LTTNG_UST_MMAP;
2650 metadata->attr.type = LTTNG_UST_CHAN_METADATA;
2651 } else {
2652 memcpy(&metadata->attr, attr, sizeof(metadata->attr));
2653 metadata->attr.output = LTTNG_UST_MMAP;
2654 metadata->attr.type = LTTNG_UST_CHAN_METADATA;
2655 }
2656
2657 /* Need one fd for the channel. */
2658 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2659 if (ret < 0) {
2660 ERR("Exhausted number of available FD upon create metadata");
2661 goto error;
2662 }
2663
2664 /* Get the right consumer socket for the application. */
2665 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2666 if (!socket) {
2667 ret = -EINVAL;
2668 goto error_consumer;
2669 }
2670
2671 /*
2672 * Keep metadata key so we can identify it on the consumer side. Assign it
2673 * to the registry *before* we ask the consumer so we avoid the race of the
2674 * consumer requesting the metadata and the ask_channel call on our side
2675 * did not returned yet.
2676 */
2677 registry->metadata_key = metadata->key;
2678
2679 /*
2680 * Ask the metadata channel creation to the consumer. The metadata object
2681 * will be created by the consumer and kept their. However, the stream is
2682 * never added or monitored until we do a first push metadata to the
2683 * consumer.
2684 */
2685 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2686 registry);
2687 if (ret < 0) {
2688 /* Nullify the metadata key so we don't try to close it later on. */
2689 registry->metadata_key = 0;
2690 goto error_consumer;
2691 }
2692
2693 /*
2694 * The setup command will make the metadata stream be sent to the relayd,
2695 * if applicable, and the thread managing the metadatas. This is important
2696 * because after this point, if an error occurs, the only way the stream
2697 * can be deleted is to be monitored in the consumer.
2698 */
2699 ret = consumer_setup_metadata(socket, metadata->key);
2700 if (ret < 0) {
2701 /* Nullify the metadata key so we don't try to close it later on. */
2702 registry->metadata_key = 0;
2703 goto error_consumer;
2704 }
2705
2706 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2707 metadata->key, app->pid);
2708
2709 error_consumer:
2710 lttng_fd_put(LTTNG_FD_APPS, 1);
2711 delete_ust_app_channel(-1, metadata, app);
2712 error:
2713 return ret;
2714 }
2715
2716 /*
2717 * Return pointer to traceable apps list.
2718 */
2719 struct lttng_ht *ust_app_get_ht(void)
2720 {
2721 return ust_app_ht;
2722 }
2723
2724 /*
2725 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2726 * acquired before calling this function.
2727 */
2728 struct ust_app *ust_app_find_by_pid(pid_t pid)
2729 {
2730 struct ust_app *app = NULL;
2731 struct lttng_ht_node_ulong *node;
2732 struct lttng_ht_iter iter;
2733
2734 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2735 node = lttng_ht_iter_get_node_ulong(&iter);
2736 if (node == NULL) {
2737 DBG2("UST app no found with pid %d", pid);
2738 goto error;
2739 }
2740
2741 DBG2("Found UST app by pid %d", pid);
2742
2743 app = caa_container_of(node, struct ust_app, pid_n);
2744
2745 error:
2746 return app;
2747 }
2748
2749 /*
2750 * Allocate and init an UST app object using the registration information and
2751 * the command socket. This is called when the command socket connects to the
2752 * session daemon.
2753 *
2754 * The object is returned on success or else NULL.
2755 */
2756 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2757 {
2758 struct ust_app *lta = NULL;
2759
2760 assert(msg);
2761 assert(sock >= 0);
2762
2763 DBG3("UST app creating application for socket %d", sock);
2764
2765 if ((msg->bits_per_long == 64 &&
2766 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2767 || (msg->bits_per_long == 32 &&
2768 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2769 ERR("Registration failed: application \"%s\" (pid: %d) has "
2770 "%d-bit long, but no consumerd for this size is available.\n",
2771 msg->name, msg->pid, msg->bits_per_long);
2772 goto error;
2773 }
2774
2775 lta = zmalloc(sizeof(struct ust_app));
2776 if (lta == NULL) {
2777 PERROR("malloc");
2778 goto error;
2779 }
2780
2781 lta->ppid = msg->ppid;
2782 lta->uid = msg->uid;
2783 lta->gid = msg->gid;
2784
2785 lta->bits_per_long = msg->bits_per_long;
2786 lta->uint8_t_alignment = msg->uint8_t_alignment;
2787 lta->uint16_t_alignment = msg->uint16_t_alignment;
2788 lta->uint32_t_alignment = msg->uint32_t_alignment;
2789 lta->uint64_t_alignment = msg->uint64_t_alignment;
2790 lta->long_alignment = msg->long_alignment;
2791 lta->byte_order = msg->byte_order;
2792
2793 lta->v_major = msg->major;
2794 lta->v_minor = msg->minor;
2795 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2796 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2797 lta->notify_sock = -1;
2798
2799 /* Copy name and make sure it's NULL terminated. */
2800 strncpy(lta->name, msg->name, sizeof(lta->name));
2801 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2802
2803 /*
2804 * Before this can be called, when receiving the registration information,
2805 * the application compatibility is checked. So, at this point, the
2806 * application can work with this session daemon.
2807 */
2808 lta->compatible = 1;
2809
2810 lta->pid = msg->pid;
2811 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
2812 lta->sock = sock;
2813 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
2814
2815 CDS_INIT_LIST_HEAD(&lta->teardown_head);
2816
2817 error:
2818 return lta;
2819 }
2820
2821 /*
2822 * For a given application object, add it to every hash table.
2823 */
2824 void ust_app_add(struct ust_app *app)
2825 {
2826 assert(app);
2827 assert(app->notify_sock >= 0);
2828
2829 rcu_read_lock();
2830
2831 /*
2832 * On a re-registration, we want to kick out the previous registration of
2833 * that pid
2834 */
2835 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
2836
2837 /*
2838 * The socket _should_ be unique until _we_ call close. So, a add_unique
2839 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
2840 * already in the table.
2841 */
2842 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
2843
2844 /* Add application to the notify socket hash table. */
2845 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
2846 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
2847
2848 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
2849 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
2850 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
2851 app->v_minor);
2852
2853 rcu_read_unlock();
2854 }
2855
2856 /*
2857 * Set the application version into the object.
2858 *
2859 * Return 0 on success else a negative value either an errno code or a
2860 * LTTng-UST error code.
2861 */
2862 int ust_app_version(struct ust_app *app)
2863 {
2864 int ret;
2865
2866 assert(app);
2867
2868 ret = ustctl_tracer_version(app->sock, &app->version);
2869 if (ret < 0) {
2870 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
2871 ERR("UST app %d verson failed with ret %d", app->sock, ret);
2872 } else {
2873 DBG3("UST app %d verion failed. Application is dead", app->sock);
2874 }
2875 }
2876
2877 return ret;
2878 }
2879
2880 /*
2881 * Unregister app by removing it from the global traceable app list and freeing
2882 * the data struct.
2883 *
2884 * The socket is already closed at this point so no close to sock.
2885 */
2886 void ust_app_unregister(int sock)
2887 {
2888 struct ust_app *lta;
2889 struct lttng_ht_node_ulong *node;
2890 struct lttng_ht_iter iter;
2891 struct ust_app_session *ua_sess;
2892 int ret;
2893
2894 rcu_read_lock();
2895
2896 /* Get the node reference for a call_rcu */
2897 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
2898 node = lttng_ht_iter_get_node_ulong(&iter);
2899 assert(node);
2900
2901 lta = caa_container_of(node, struct ust_app, sock_n);
2902 DBG("PID %d unregistering with sock %d", lta->pid, sock);
2903
2904 /* Remove application from PID hash table */
2905 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
2906 assert(!ret);
2907
2908 /*
2909 * Remove application from notify hash table. The thread handling the
2910 * notify socket could have deleted the node so ignore on error because
2911 * either way it's valid. The close of that socket is handled by the other
2912 * thread.
2913 */
2914 iter.iter.node = &lta->notify_sock_n.node;
2915 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
2916
2917 /*
2918 * Ignore return value since the node might have been removed before by an
2919 * add replace during app registration because the PID can be reassigned by
2920 * the OS.
2921 */
2922 iter.iter.node = &lta->pid_n.node;
2923 ret = lttng_ht_del(ust_app_ht, &iter);
2924 if (ret) {
2925 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
2926 lta->pid);
2927 }
2928
2929 /* Remove sessions so they are not visible during deletion.*/
2930 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
2931 node.node) {
2932 struct ust_registry_session *registry;
2933
2934 ret = lttng_ht_del(lta->sessions, &iter);
2935 if (ret) {
2936 /* The session was already removed so scheduled for teardown. */
2937 continue;
2938 }
2939
2940 /*
2941 * Add session to list for teardown. This is safe since at this point we
2942 * are the only one using this list.
2943 */
2944 pthread_mutex_lock(&ua_sess->lock);
2945
2946 /*
2947 * Normally, this is done in the delete session process which is
2948 * executed in the call rcu below. However, upon registration we can't
2949 * afford to wait for the grace period before pushing data or else the
2950 * data pending feature can race between the unregistration and stop
2951 * command where the data pending command is sent *before* the grace
2952 * period ended.
2953 *
2954 * The close metadata below nullifies the metadata pointer in the
2955 * session so the delete session will NOT push/close a second time.
2956 */
2957 registry = get_session_registry(ua_sess);
2958 if (registry && !registry->metadata_closed) {
2959 /* Push metadata for application before freeing the application. */
2960 (void) push_metadata(registry, ua_sess->consumer);
2961
2962 /*
2963 * Don't ask to close metadata for global per UID buffers. Close
2964 * metadata only on destroy trace session in this case. Also, the
2965 * previous push metadata could have flag the metadata registry to
2966 * close so don't send a close command if closed.
2967 */
2968 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
2969 !registry->metadata_closed) {
2970 /* And ask to close it for this session registry. */
2971 (void) close_metadata(registry, ua_sess->consumer);
2972 }
2973 }
2974
2975 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
2976 pthread_mutex_unlock(&ua_sess->lock);
2977 }
2978
2979 /* Free memory */
2980 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
2981
2982 rcu_read_unlock();
2983 return;
2984 }
2985
2986 /*
2987 * Return traceable_app_count
2988 */
2989 unsigned long ust_app_list_count(void)
2990 {
2991 unsigned long count;
2992
2993 rcu_read_lock();
2994 count = lttng_ht_get_count(ust_app_ht);
2995 rcu_read_unlock();
2996
2997 return count;
2998 }
2999
3000 /*
3001 * Fill events array with all events name of all registered apps.
3002 */
3003 int ust_app_list_events(struct lttng_event **events)
3004 {
3005 int ret, handle;
3006 size_t nbmem, count = 0;
3007 struct lttng_ht_iter iter;
3008 struct ust_app *app;
3009 struct lttng_event *tmp_event;
3010
3011 nbmem = UST_APP_EVENT_LIST_SIZE;
3012 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3013 if (tmp_event == NULL) {
3014 PERROR("zmalloc ust app events");
3015 ret = -ENOMEM;
3016 goto error;
3017 }
3018
3019 rcu_read_lock();
3020
3021 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3022 struct lttng_ust_tracepoint_iter uiter;
3023
3024 health_code_update();
3025
3026 if (!app->compatible) {
3027 /*
3028 * TODO: In time, we should notice the caller of this error by
3029 * telling him that this is a version error.
3030 */
3031 continue;
3032 }
3033 handle = ustctl_tracepoint_list(app->sock);
3034 if (handle < 0) {
3035 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3036 ERR("UST app list events getting handle failed for app pid %d",
3037 app->pid);
3038 }
3039 continue;
3040 }
3041
3042 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3043 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3044 /* Handle ustctl error. */
3045 if (ret < 0) {
3046 free(tmp_event);
3047 if (ret != -LTTNG_UST_ERR_EXITING || ret != -EPIPE) {
3048 ERR("UST app tp list get failed for app %d with ret %d",
3049 app->sock, ret);
3050 } else {
3051 DBG3("UST app tp list get failed. Application is dead");
3052 /*
3053 * This is normal behavior, an application can die during the
3054 * creation process. Don't report an error so the execution can
3055 * continue normally. Continue normal execution.
3056 */
3057 break;
3058 }
3059 goto rcu_error;
3060 }
3061
3062 health_code_update();
3063 if (count >= nbmem) {
3064 /* In case the realloc fails, we free the memory */
3065 void *ptr;
3066
3067 DBG2("Reallocating event list from %zu to %zu entries", nbmem,
3068 2 * nbmem);
3069 nbmem *= 2;
3070 ptr = realloc(tmp_event, nbmem * sizeof(struct lttng_event));
3071 if (ptr == NULL) {
3072 PERROR("realloc ust app events");
3073 free(tmp_event);
3074 ret = -ENOMEM;
3075 goto rcu_error;
3076 }
3077 tmp_event = ptr;
3078 }
3079 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3080 tmp_event[count].loglevel = uiter.loglevel;
3081 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3082 tmp_event[count].pid = app->pid;
3083 tmp_event[count].enabled = -1;
3084 count++;
3085 }
3086 }
3087
3088 ret = count;
3089 *events = tmp_event;
3090
3091 DBG2("UST app list events done (%zu events)", count);
3092
3093 rcu_error:
3094 rcu_read_unlock();
3095 error:
3096 health_code_update();
3097 return ret;
3098 }
3099
3100 /*
3101 * Fill events array with all events name of all registered apps.
3102 */
3103 int ust_app_list_event_fields(struct lttng_event_field **fields)
3104 {
3105 int ret, handle;
3106 size_t nbmem, count = 0;
3107 struct lttng_ht_iter iter;
3108 struct ust_app *app;
3109 struct lttng_event_field *tmp_event;
3110
3111 nbmem = UST_APP_EVENT_LIST_SIZE;
3112 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3113 if (tmp_event == NULL) {
3114 PERROR("zmalloc ust app event fields");
3115 ret = -ENOMEM;
3116 goto error;
3117 }
3118
3119 rcu_read_lock();
3120
3121 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3122 struct lttng_ust_field_iter uiter;
3123
3124 health_code_update();
3125
3126 if (!app->compatible) {
3127 /*
3128 * TODO: In time, we should notice the caller of this error by
3129 * telling him that this is a version error.
3130 */
3131 continue;
3132 }
3133 handle = ustctl_tracepoint_field_list(app->sock);
3134 if (handle < 0) {
3135 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3136 ERR("UST app list field getting handle failed for app pid %d",
3137 app->pid);
3138 }
3139 continue;
3140 }
3141
3142 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3143 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3144 /* Handle ustctl error. */
3145 if (ret < 0) {
3146 free(tmp_event);
3147 if (ret != -LTTNG_UST_ERR_EXITING || ret != -EPIPE) {
3148 ERR("UST app tp list field failed for app %d with ret %d",
3149 app->sock, ret);
3150 } else {
3151 DBG3("UST app tp list field failed. Application is dead");
3152 /*
3153 * This is normal behavior, an application can die during the
3154 * creation process. Don't report an error so the execution can
3155 * continue normally.
3156 */
3157 break;
3158 }
3159 goto rcu_error;
3160 }
3161
3162 health_code_update();
3163 if (count >= nbmem) {
3164 /* In case the realloc fails, we free the memory */
3165 void *ptr;
3166
3167 DBG2("Reallocating event field list from %zu to %zu entries", nbmem,
3168 2 * nbmem);
3169 nbmem *= 2;
3170 ptr = realloc(tmp_event, nbmem * sizeof(struct lttng_event_field));
3171 if (ptr == NULL) {
3172 PERROR("realloc ust app event fields");
3173 free(tmp_event);
3174 ret = -ENOMEM;
3175 goto rcu_error;
3176 }
3177 tmp_event = ptr;
3178 }
3179
3180 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3181 tmp_event[count].type = uiter.type;
3182 tmp_event[count].nowrite = uiter.nowrite;
3183
3184 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3185 tmp_event[count].event.loglevel = uiter.loglevel;
3186 tmp_event[count].event.type = LTTNG_UST_TRACEPOINT;
3187 tmp_event[count].event.pid = app->pid;
3188 tmp_event[count].event.enabled = -1;
3189 count++;
3190 }
3191 }
3192
3193 ret = count;
3194 *fields = tmp_event;
3195
3196 DBG2("UST app list event fields done (%zu events)", count);
3197
3198 rcu_error:
3199 rcu_read_unlock();
3200 error:
3201 health_code_update();
3202 return ret;
3203 }
3204
3205 /*
3206 * Free and clean all traceable apps of the global list.
3207 *
3208 * Should _NOT_ be called with RCU read-side lock held.
3209 */
3210 void ust_app_clean_list(void)
3211 {
3212 int ret;
3213 struct ust_app *app;
3214 struct lttng_ht_iter iter;
3215
3216 DBG2("UST app cleaning registered apps hash table");
3217
3218 rcu_read_lock();
3219
3220 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3221 ret = lttng_ht_del(ust_app_ht, &iter);
3222 assert(!ret);
3223 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3224 }
3225
3226 /* Cleanup socket hash table */
3227 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3228 sock_n.node) {
3229 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3230 assert(!ret);
3231 }
3232
3233 /* Cleanup notify socket hash table */
3234 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3235 notify_sock_n.node) {
3236 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3237 assert(!ret);
3238 }
3239 rcu_read_unlock();
3240
3241 /* Destroy is done only when the ht is empty */
3242 ht_cleanup_push(ust_app_ht);
3243 ht_cleanup_push(ust_app_ht_by_sock);
3244 ht_cleanup_push(ust_app_ht_by_notify_sock);
3245 }
3246
3247 /*
3248 * Init UST app hash table.
3249 */
3250 void ust_app_ht_alloc(void)
3251 {
3252 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3253 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3254 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3255 }
3256
3257 /*
3258 * For a specific UST session, disable the channel for all registered apps.
3259 */
3260 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3261 struct ltt_ust_channel *uchan)
3262 {
3263 int ret = 0;
3264 struct lttng_ht_iter iter;
3265 struct lttng_ht_node_str *ua_chan_node;
3266 struct ust_app *app;
3267 struct ust_app_session *ua_sess;
3268 struct ust_app_channel *ua_chan;
3269
3270 if (usess == NULL || uchan == NULL) {
3271 ERR("Disabling UST global channel with NULL values");
3272 ret = -1;
3273 goto error;
3274 }
3275
3276 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3277 uchan->name, usess->id);
3278
3279 rcu_read_lock();
3280
3281 /* For every registered applications */
3282 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3283 struct lttng_ht_iter uiter;
3284 if (!app->compatible) {
3285 /*
3286 * TODO: In time, we should notice the caller of this error by
3287 * telling him that this is a version error.
3288 */
3289 continue;
3290 }
3291 ua_sess = lookup_session_by_app(usess, app);
3292 if (ua_sess == NULL) {
3293 continue;
3294 }
3295
3296 /* Get channel */
3297 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3298 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3299 /* If the session if found for the app, the channel must be there */
3300 assert(ua_chan_node);
3301
3302 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3303 /* The channel must not be already disabled */
3304 assert(ua_chan->enabled == 1);
3305
3306 /* Disable channel onto application */
3307 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3308 if (ret < 0) {
3309 /* XXX: We might want to report this error at some point... */
3310 continue;
3311 }
3312 }
3313
3314 rcu_read_unlock();
3315
3316 error:
3317 return ret;
3318 }
3319
3320 /*
3321 * For a specific UST session, enable the channel for all registered apps.
3322 */
3323 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3324 struct ltt_ust_channel *uchan)
3325 {
3326 int ret = 0;
3327 struct lttng_ht_iter iter;
3328 struct ust_app *app;
3329 struct ust_app_session *ua_sess;
3330
3331 if (usess == NULL || uchan == NULL) {
3332 ERR("Adding UST global channel to NULL values");
3333 ret = -1;
3334 goto error;
3335 }
3336
3337 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3338 uchan->name, usess->id);
3339
3340 rcu_read_lock();
3341
3342 /* For every registered applications */
3343 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3344 if (!app->compatible) {
3345 /*
3346 * TODO: In time, we should notice the caller of this error by
3347 * telling him that this is a version error.
3348 */
3349 continue;
3350 }
3351 ua_sess = lookup_session_by_app(usess, app);
3352 if (ua_sess == NULL) {
3353 continue;
3354 }
3355
3356 /* Enable channel onto application */
3357 ret = enable_ust_app_channel(ua_sess, uchan, app);
3358 if (ret < 0) {
3359 /* XXX: We might want to report this error at some point... */
3360 continue;
3361 }
3362 }
3363
3364 rcu_read_unlock();
3365
3366 error:
3367 return ret;
3368 }
3369
3370 /*
3371 * Disable an event in a channel and for a specific session.
3372 */
3373 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3374 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3375 {
3376 int ret = 0;
3377 struct lttng_ht_iter iter, uiter;
3378 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
3379 struct ust_app *app;
3380 struct ust_app_session *ua_sess;
3381 struct ust_app_channel *ua_chan;
3382 struct ust_app_event *ua_event;
3383
3384 DBG("UST app disabling event %s for all apps in channel "
3385 "%s for session id %" PRIu64,
3386 uevent->attr.name, uchan->name, usess->id);
3387
3388 rcu_read_lock();
3389
3390 /* For all registered applications */
3391 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3392 if (!app->compatible) {
3393 /*
3394 * TODO: In time, we should notice the caller of this error by
3395 * telling him that this is a version error.
3396 */
3397 continue;
3398 }
3399 ua_sess = lookup_session_by_app(usess, app);
3400 if (ua_sess == NULL) {
3401 /* Next app */
3402 continue;
3403 }
3404
3405 /* Lookup channel in the ust app session */
3406 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3407 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3408 if (ua_chan_node == NULL) {
3409 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3410 "Skipping", uchan->name, usess->id, app->pid);
3411 continue;
3412 }
3413 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3414
3415 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
3416 ua_event_node = lttng_ht_iter_get_node_str(&uiter);
3417 if (ua_event_node == NULL) {
3418 DBG2("Event %s not found in channel %s for app pid %d."
3419 "Skipping", uevent->attr.name, uchan->name, app->pid);
3420 continue;
3421 }
3422 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
3423
3424 ret = disable_ust_app_event(ua_sess, ua_event, app);
3425 if (ret < 0) {
3426 /* XXX: Report error someday... */
3427 continue;
3428 }
3429 }
3430
3431 rcu_read_unlock();
3432
3433 return ret;
3434 }
3435
3436 /*
3437 * For a specific UST session and UST channel, the event for all
3438 * registered apps.
3439 */
3440 int ust_app_disable_all_event_glb(struct ltt_ust_session *usess,
3441 struct ltt_ust_channel *uchan)
3442 {
3443 int ret = 0;
3444 struct lttng_ht_iter iter, uiter;
3445 struct lttng_ht_node_str *ua_chan_node;
3446 struct ust_app *app;
3447 struct ust_app_session *ua_sess;
3448 struct ust_app_channel *ua_chan;
3449 struct ust_app_event *ua_event;
3450
3451 DBG("UST app disabling all event for all apps in channel "
3452 "%s for session id %" PRIu64, uchan->name, usess->id);
3453
3454 rcu_read_lock();
3455
3456 /* For all registered applications */
3457 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3458 if (!app->compatible) {
3459 /*
3460 * TODO: In time, we should notice the caller of this error by
3461 * telling him that this is a version error.
3462 */
3463 continue;
3464 }
3465 ua_sess = lookup_session_by_app(usess, app);
3466 if (!ua_sess) {
3467 /* The application has problem or is probably dead. */
3468 continue;
3469 }
3470
3471 /* Lookup channel in the ust app session */
3472 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3473 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3474 /* If the channel is not found, there is a code flow error */
3475 assert(ua_chan_node);
3476
3477 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3478
3479 /* Disable each events of channel */
3480 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
3481 node.node) {
3482 ret = disable_ust_app_event(ua_sess, ua_event, app);
3483 if (ret < 0) {
3484 /* XXX: Report error someday... */
3485 continue;
3486 }
3487 }
3488 }
3489
3490 rcu_read_unlock();
3491
3492 return ret;
3493 }
3494
3495 /*
3496 * For a specific UST session, create the channel for all registered apps.
3497 */
3498 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3499 struct ltt_ust_channel *uchan)
3500 {
3501 int ret = 0, created;
3502 struct lttng_ht_iter iter;
3503 struct ust_app *app;
3504 struct ust_app_session *ua_sess = NULL;
3505
3506 /* Very wrong code flow */
3507 assert(usess);
3508 assert(uchan);
3509
3510 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3511 uchan->name, usess->id);
3512
3513 rcu_read_lock();
3514
3515 /* For every registered applications */
3516 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3517 if (!app->compatible) {
3518 /*
3519 * TODO: In time, we should notice the caller of this error by
3520 * telling him that this is a version error.
3521 */
3522 continue;
3523 }
3524 /*
3525 * Create session on the tracer side and add it to app session HT. Note
3526 * that if session exist, it will simply return a pointer to the ust
3527 * app session.
3528 */
3529 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3530 if (ret < 0) {
3531 switch (ret) {
3532 case -ENOTCONN:
3533 /*
3534 * The application's socket is not valid. Either a bad socket
3535 * or a timeout on it. We can't inform the caller that for a
3536 * specific app, the session failed so lets continue here.
3537 */
3538 continue;
3539 case -ENOMEM:
3540 default:
3541 goto error_rcu_unlock;
3542 }
3543 }
3544 assert(ua_sess);
3545
3546 pthread_mutex_lock(&ua_sess->lock);
3547 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
3548 sizeof(uchan->name))) {
3549 struct ustctl_consumer_channel_attr attr;
3550 copy_channel_attr_to_ustctl(&attr, &uchan->attr);
3551 ret = create_ust_app_metadata(ua_sess, app, usess->consumer,
3552 &attr);
3553 } else {
3554 /* Create channel onto application. We don't need the chan ref. */
3555 ret = create_ust_app_channel(ua_sess, uchan, app,
3556 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
3557 }
3558 pthread_mutex_unlock(&ua_sess->lock);
3559 if (ret < 0) {
3560 if (ret == -ENOMEM) {
3561 /* No more memory is a fatal error. Stop right now. */
3562 goto error_rcu_unlock;
3563 }
3564 /* Cleanup the created session if it's the case. */
3565 if (created) {
3566 destroy_app_session(app, ua_sess);
3567 }
3568 }
3569 }
3570
3571 error_rcu_unlock:
3572 rcu_read_unlock();
3573 return ret;
3574 }
3575
3576 /*
3577 * Enable event for a specific session and channel on the tracer.
3578 */
3579 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
3580 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3581 {
3582 int ret = 0;
3583 struct lttng_ht_iter iter, uiter;
3584 struct lttng_ht_node_str *ua_chan_node;
3585 struct ust_app *app;
3586 struct ust_app_session *ua_sess;
3587 struct ust_app_channel *ua_chan;
3588 struct ust_app_event *ua_event;
3589
3590 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
3591 uevent->attr.name, usess->id);
3592
3593 /*
3594 * NOTE: At this point, this function is called only if the session and
3595 * channel passed are already created for all apps. and enabled on the
3596 * tracer also.
3597 */
3598
3599 rcu_read_lock();
3600
3601 /* For all registered applications */
3602 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3603 if (!app->compatible) {
3604 /*
3605 * TODO: In time, we should notice the caller of this error by
3606 * telling him that this is a version error.
3607 */
3608 continue;
3609 }
3610 ua_sess = lookup_session_by_app(usess, app);
3611 if (!ua_sess) {
3612 /* The application has problem or is probably dead. */
3613 continue;
3614 }
3615
3616 pthread_mutex_lock(&ua_sess->lock);
3617
3618 /* Lookup channel in the ust app session */
3619 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3620 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3621 /* If the channel is not found, there is a code flow error */
3622 assert(ua_chan_node);
3623
3624 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3625
3626 /* Get event node */
3627 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3628 uevent->filter, uevent->attr.loglevel);
3629 if (ua_event == NULL) {
3630 DBG3("UST app enable event %s not found for app PID %d."
3631 "Skipping app", uevent->attr.name, app->pid);
3632 goto next_app;
3633 }
3634
3635 ret = enable_ust_app_event(ua_sess, ua_event, app);
3636 if (ret < 0) {
3637 pthread_mutex_unlock(&ua_sess->lock);
3638 goto error;
3639 }
3640 next_app:
3641 pthread_mutex_unlock(&ua_sess->lock);
3642 }
3643
3644 error:
3645 rcu_read_unlock();
3646 return ret;
3647 }
3648
3649 /*
3650 * For a specific existing UST session and UST channel, creates the event for
3651 * all registered apps.
3652 */
3653 int ust_app_create_event_glb(struct ltt_ust_session *usess,
3654 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3655 {
3656 int ret = 0;
3657 struct lttng_ht_iter iter, uiter;
3658 struct lttng_ht_node_str *ua_chan_node;
3659 struct ust_app *app;
3660 struct ust_app_session *ua_sess;
3661 struct ust_app_channel *ua_chan;
3662
3663 DBG("UST app creating event %s for all apps for session id %" PRIu64,
3664 uevent->attr.name, usess->id);
3665
3666 rcu_read_lock();
3667
3668 /* For all registered applications */
3669 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3670 if (!app->compatible) {
3671 /*
3672 * TODO: In time, we should notice the caller of this error by
3673 * telling him that this is a version error.
3674 */
3675 continue;
3676 }
3677 ua_sess = lookup_session_by_app(usess, app);
3678 if (!ua_sess) {
3679 /* The application has problem or is probably dead. */
3680 continue;
3681 }
3682
3683 pthread_mutex_lock(&ua_sess->lock);
3684 /* Lookup channel in the ust app session */
3685 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3686 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3687 /* If the channel is not found, there is a code flow error */
3688 assert(ua_chan_node);
3689
3690 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3691
3692 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
3693 pthread_mutex_unlock(&ua_sess->lock);
3694 if (ret < 0) {
3695 if (ret != -LTTNG_UST_ERR_EXIST) {
3696 /* Possible value at this point: -ENOMEM. If so, we stop! */
3697 break;
3698 }
3699 DBG2("UST app event %s already exist on app PID %d",
3700 uevent->attr.name, app->pid);
3701 continue;
3702 }
3703 }
3704
3705 rcu_read_unlock();
3706
3707 return ret;
3708 }
3709
3710 /*
3711 * Start tracing for a specific UST session and app.
3712 */
3713 static
3714 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
3715 {
3716 int ret = 0;
3717 struct ust_app_session *ua_sess;
3718
3719 DBG("Starting tracing for ust app pid %d", app->pid);
3720
3721 rcu_read_lock();
3722
3723 if (!app->compatible) {
3724 goto end;
3725 }
3726
3727 ua_sess = lookup_session_by_app(usess, app);
3728 if (ua_sess == NULL) {
3729 /* The session is in teardown process. Ignore and continue. */
3730 goto end;
3731 }
3732
3733 pthread_mutex_lock(&ua_sess->lock);
3734
3735 /* Upon restart, we skip the setup, already done */
3736 if (ua_sess->started) {
3737 goto skip_setup;
3738 }
3739
3740 /* Create directories if consumer is LOCAL and has a path defined. */
3741 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
3742 strlen(usess->consumer->dst.trace_path) > 0) {
3743 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
3744 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
3745 if (ret < 0) {
3746 if (ret != -EEXIST) {
3747 ERR("Trace directory creation error");
3748 goto error_unlock;
3749 }
3750 }
3751 }
3752
3753 /*
3754 * Create the metadata for the application. This returns gracefully if a
3755 * metadata was already set for the session.
3756 */
3757 ret = create_ust_app_metadata(ua_sess, app, usess->consumer, NULL);
3758 if (ret < 0) {
3759 goto error_unlock;
3760 }
3761
3762 health_code_update();
3763
3764 skip_setup:
3765 /* This start the UST tracing */
3766 ret = ustctl_start_session(app->sock, ua_sess->handle);
3767 if (ret < 0) {
3768 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3769 ERR("Error starting tracing for app pid: %d (ret: %d)",
3770 app->pid, ret);
3771 } else {
3772 DBG("UST app start session failed. Application is dead.");
3773 /*
3774 * This is normal behavior, an application can die during the
3775 * creation process. Don't report an error so the execution can
3776 * continue normally.
3777 */
3778 pthread_mutex_unlock(&ua_sess->lock);
3779 goto end;
3780 }
3781 goto error_unlock;
3782 }
3783
3784 /* Indicate that the session has been started once */
3785 ua_sess->started = 1;
3786
3787 pthread_mutex_unlock(&ua_sess->lock);
3788
3789 health_code_update();
3790
3791 /* Quiescent wait after starting trace */
3792 ret = ustctl_wait_quiescent(app->sock);
3793 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3794 ERR("UST app wait quiescent failed for app pid %d ret %d",
3795 app->pid, ret);
3796 }
3797
3798 end:
3799 rcu_read_unlock();
3800 health_code_update();
3801 return 0;
3802
3803 error_unlock:
3804 pthread_mutex_unlock(&ua_sess->lock);
3805 rcu_read_unlock();
3806 health_code_update();
3807 return -1;
3808 }
3809
3810 /*
3811 * Stop tracing for a specific UST session and app.
3812 */
3813 static
3814 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
3815 {
3816 int ret = 0;
3817 struct ust_app_session *ua_sess;
3818 struct ust_registry_session *registry;
3819
3820 DBG("Stopping tracing for ust app pid %d", app->pid);
3821
3822 rcu_read_lock();
3823
3824 if (!app->compatible) {
3825 goto end_no_session;
3826 }
3827
3828 ua_sess = lookup_session_by_app(usess, app);
3829 if (ua_sess == NULL) {
3830 goto end_no_session;
3831 }
3832
3833 pthread_mutex_lock(&ua_sess->lock);
3834
3835 /*
3836 * If started = 0, it means that stop trace has been called for a session
3837 * that was never started. It's possible since we can have a fail start
3838 * from either the application manager thread or the command thread. Simply
3839 * indicate that this is a stop error.
3840 */
3841 if (!ua_sess->started) {
3842 goto error_rcu_unlock;
3843 }
3844
3845 health_code_update();
3846
3847 /* This inhibits UST tracing */
3848 ret = ustctl_stop_session(app->sock, ua_sess->handle);
3849 if (ret < 0) {
3850 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3851 ERR("Error stopping tracing for app pid: %d (ret: %d)",
3852 app->pid, ret);
3853 } else {
3854 DBG("UST app stop session failed. Application is dead.");
3855 /*
3856 * This is normal behavior, an application can die during the
3857 * creation process. Don't report an error so the execution can
3858 * continue normally.
3859 */
3860 goto end_unlock;
3861 }
3862 goto error_rcu_unlock;
3863 }
3864
3865 health_code_update();
3866
3867 /* Quiescent wait after stopping trace */
3868 ret = ustctl_wait_quiescent(app->sock);
3869 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3870 ERR("UST app wait quiescent failed for app pid %d ret %d",
3871 app->pid, ret);
3872 }
3873
3874 health_code_update();
3875
3876 registry = get_session_registry(ua_sess);
3877 assert(registry);
3878
3879 if (!registry->metadata_closed) {
3880 /* Push metadata for application before freeing the application. */
3881 (void) push_metadata(registry, ua_sess->consumer);
3882 }
3883
3884 end_unlock:
3885 pthread_mutex_unlock(&ua_sess->lock);
3886 end_no_session:
3887 rcu_read_unlock();
3888 health_code_update();
3889 return 0;
3890
3891 error_rcu_unlock:
3892 pthread_mutex_unlock(&ua_sess->lock);
3893 rcu_read_unlock();
3894 health_code_update();
3895 return -1;
3896 }
3897
3898 /*
3899 * Flush buffers for a specific UST session and app.
3900 */
3901 static
3902 int ust_app_flush_trace(struct ltt_ust_session *usess, struct ust_app *app)
3903 {
3904 int ret = 0;
3905 struct lttng_ht_iter iter;
3906 struct ust_app_session *ua_sess;
3907 struct ust_app_channel *ua_chan;
3908
3909 DBG("Flushing buffers for ust app pid %d", app->pid);
3910
3911 rcu_read_lock();
3912
3913 if (!app->compatible) {
3914 goto end_no_session;
3915 }
3916
3917 ua_sess = lookup_session_by_app(usess, app);
3918 if (ua_sess == NULL) {
3919 goto end_no_session;
3920 }
3921
3922 pthread_mutex_lock(&ua_sess->lock);
3923
3924 health_code_update();
3925
3926 /* Flushing buffers */
3927 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
3928 node.node) {
3929 health_code_update();
3930 assert(ua_chan->is_sent);
3931 ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
3932 if (ret < 0) {
3933 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3934 ERR("UST app PID %d channel %s flush failed with ret %d",
3935 app->pid, ua_chan->name, ret);
3936 } else {
3937 DBG3("UST app failed to flush %s. Application is dead.",
3938 ua_chan->name);
3939 /*
3940 * This is normal behavior, an application can die during the
3941 * creation process. Don't report an error so the execution can
3942 * continue normally.
3943 */
3944 }
3945 /* Continuing flushing all buffers */
3946 continue;
3947 }
3948 }
3949
3950 health_code_update();
3951
3952 pthread_mutex_unlock(&ua_sess->lock);
3953 end_no_session:
3954 rcu_read_unlock();
3955 health_code_update();
3956 return 0;
3957 }
3958
3959 /*
3960 * Destroy a specific UST session in apps.
3961 */
3962 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
3963 {
3964 int ret;
3965 struct ust_app_session *ua_sess;
3966 struct lttng_ht_iter iter;
3967 struct lttng_ht_node_u64 *node;
3968
3969 DBG("Destroy tracing for ust app pid %d", app->pid);
3970
3971 rcu_read_lock();
3972
3973 if (!app->compatible) {
3974 goto end;
3975 }
3976
3977 __lookup_session_by_app(usess, app, &iter);
3978 node = lttng_ht_iter_get_node_u64(&iter);
3979 if (node == NULL) {
3980 /* Session is being or is deleted. */
3981 goto end;
3982 }
3983 ua_sess = caa_container_of(node, struct ust_app_session, node);
3984
3985 health_code_update();
3986 destroy_app_session(app, ua_sess);
3987
3988 health_code_update();
3989
3990 /* Quiescent wait after stopping trace */
3991 ret = ustctl_wait_quiescent(app->sock);
3992 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3993 ERR("UST app wait quiescent failed for app pid %d ret %d",
3994 app->pid, ret);
3995 }
3996 end:
3997 rcu_read_unlock();
3998 health_code_update();
3999 return 0;
4000 }
4001
4002 /*
4003 * Start tracing for the UST session.
4004 */
4005 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4006 {
4007 int ret = 0;
4008 struct lttng_ht_iter iter;
4009 struct ust_app *app;
4010
4011 DBG("Starting all UST traces");
4012
4013 rcu_read_lock();
4014
4015 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4016 ret = ust_app_start_trace(usess, app);
4017 if (ret < 0) {
4018 /* Continue to next apps even on error */
4019 continue;
4020 }
4021 }
4022
4023 rcu_read_unlock();
4024
4025 return 0;
4026 }
4027
4028 /*
4029 * Start tracing for the UST session.
4030 */
4031 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4032 {
4033 int ret = 0;
4034 struct lttng_ht_iter iter;
4035 struct ust_app *app;
4036
4037 DBG("Stopping all UST traces");
4038
4039 rcu_read_lock();
4040
4041 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4042 ret = ust_app_stop_trace(usess, app);
4043 if (ret < 0) {
4044 /* Continue to next apps even on error */
4045 continue;
4046 }
4047 }
4048
4049 /* Flush buffers and push metadata (for UID buffers). */
4050 switch (usess->buffer_type) {
4051 case LTTNG_BUFFER_PER_UID:
4052 {
4053 struct buffer_reg_uid *reg;
4054
4055 /* Flush all per UID buffers associated to that session. */
4056 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4057 struct ust_registry_session *ust_session_reg;
4058 struct buffer_reg_channel *reg_chan;
4059 struct consumer_socket *socket;
4060
4061 /* Get consumer socket to use to push the metadata.*/
4062 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4063 usess->consumer);
4064 if (!socket) {
4065 /* Ignore request if no consumer is found for the session. */
4066 continue;
4067 }
4068
4069 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4070 reg_chan, node.node) {
4071 /*
4072 * The following call will print error values so the return
4073 * code is of little importance because whatever happens, we
4074 * have to try them all.
4075 */
4076 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4077 }
4078
4079 ust_session_reg = reg->registry->reg.ust;
4080 if (!ust_session_reg->metadata_closed) {
4081 /* Push metadata. */
4082 (void) push_metadata(ust_session_reg, usess->consumer);
4083 }
4084 }
4085
4086 break;
4087 }
4088 case LTTNG_BUFFER_PER_PID:
4089 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4090 ret = ust_app_flush_trace(usess, app);
4091 if (ret < 0) {
4092 /* Continue to next apps even on error */
4093 continue;
4094 }
4095 }
4096 break;
4097 default:
4098 assert(0);
4099 break;
4100 }
4101
4102 rcu_read_unlock();
4103
4104 return 0;
4105 }
4106
4107 /*
4108 * Destroy app UST session.
4109 */
4110 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4111 {
4112 int ret = 0;
4113 struct lttng_ht_iter iter;
4114 struct ust_app *app;
4115
4116 DBG("Destroy all UST traces");
4117
4118 rcu_read_lock();
4119
4120 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4121 ret = destroy_trace(usess, app);
4122 if (ret < 0) {
4123 /* Continue to next apps even on error */
4124 continue;
4125 }
4126 }
4127
4128 rcu_read_unlock();
4129
4130 return 0;
4131 }
4132
4133 /*
4134 * Add channels/events from UST global domain to registered apps at sock.
4135 */
4136 void ust_app_global_update(struct ltt_ust_session *usess, int sock)
4137 {
4138 int ret = 0;
4139 struct lttng_ht_iter iter, uiter;
4140 struct ust_app *app;
4141 struct ust_app_session *ua_sess = NULL;
4142 struct ust_app_channel *ua_chan;
4143 struct ust_app_event *ua_event;
4144 struct ust_app_ctx *ua_ctx;
4145
4146 assert(usess);
4147 assert(sock >= 0);
4148
4149 DBG2("UST app global update for app sock %d for session id %" PRIu64, sock,
4150 usess->id);
4151
4152 rcu_read_lock();
4153
4154 app = find_app_by_sock(sock);
4155 if (app == NULL) {
4156 /*
4157 * Application can be unregistered before so this is possible hence
4158 * simply stopping the update.
4159 */
4160 DBG3("UST app update failed to find app sock %d", sock);
4161 goto error;
4162 }
4163
4164 if (!app->compatible) {
4165 goto error;
4166 }
4167
4168 ret = create_ust_app_session(usess, app, &ua_sess, NULL);
4169 if (ret < 0) {
4170 /* Tracer is probably gone or ENOMEM. */
4171 goto error;
4172 }
4173 assert(ua_sess);
4174
4175 pthread_mutex_lock(&ua_sess->lock);
4176
4177 /*
4178 * We can iterate safely here over all UST app session since the create ust
4179 * app session above made a shadow copy of the UST global domain from the
4180 * ltt ust session.
4181 */
4182 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4183 node.node) {
4184 /*
4185 * For a metadata channel, handle it differently.
4186 */
4187 if (!strncmp(ua_chan->name, DEFAULT_METADATA_NAME,
4188 sizeof(ua_chan->name))) {
4189 ret = create_ust_app_metadata(ua_sess, app, usess->consumer,
4190 &ua_chan->attr);
4191 if (ret < 0) {
4192 goto error_unlock;
4193 }
4194 /* Remove it from the hash table and continue!. */
4195 ret = lttng_ht_del(ua_sess->channels, &iter);
4196 assert(!ret);
4197 delete_ust_app_channel(-1, ua_chan, app);
4198 continue;
4199 } else {
4200 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4201 if (ret < 0) {
4202 /*
4203 * Stop everything. On error, the application failed, no more
4204 * file descriptor are available or ENOMEM so stopping here is
4205 * the only thing we can do for now.
4206 */
4207 goto error_unlock;
4208 }
4209 }
4210
4211 /*
4212 * Add context using the list so they are enabled in the same order the
4213 * user added them.
4214 */
4215 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4216 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4217 if (ret < 0) {
4218 goto error_unlock;
4219 }
4220 }
4221
4222
4223 /* For each events */
4224 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4225 node.node) {
4226 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4227 if (ret < 0) {
4228 goto error_unlock;
4229 }
4230 }
4231 }
4232
4233 pthread_mutex_unlock(&ua_sess->lock);
4234
4235 if (usess->start_trace) {
4236 ret = ust_app_start_trace(usess, app);
4237 if (ret < 0) {
4238 goto error;
4239 }
4240
4241 DBG2("UST trace started for app pid %d", app->pid);
4242 }
4243
4244 /* Everything went well at this point. */
4245 rcu_read_unlock();
4246 return;
4247
4248 error_unlock:
4249 pthread_mutex_unlock(&ua_sess->lock);
4250 error:
4251 if (ua_sess) {
4252 destroy_app_session(app, ua_sess);
4253 }
4254 rcu_read_unlock();
4255 return;
4256 }
4257
4258 /*
4259 * Add context to a specific channel for global UST domain.
4260 */
4261 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4262 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4263 {
4264 int ret = 0;
4265 struct lttng_ht_node_str *ua_chan_node;
4266 struct lttng_ht_iter iter, uiter;
4267 struct ust_app_channel *ua_chan = NULL;
4268 struct ust_app_session *ua_sess;
4269 struct ust_app *app;
4270
4271 rcu_read_lock();
4272
4273 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4274 if (!app->compatible) {
4275 /*
4276 * TODO: In time, we should notice the caller of this error by
4277 * telling him that this is a version error.
4278 */
4279 continue;
4280 }
4281 ua_sess = lookup_session_by_app(usess, app);
4282 if (ua_sess == NULL) {
4283 continue;
4284 }
4285
4286 pthread_mutex_lock(&ua_sess->lock);
4287 /* Lookup channel in the ust app session */
4288 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4289 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4290 if (ua_chan_node == NULL) {
4291 goto next_app;
4292 }
4293 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4294 node);
4295 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4296 if (ret < 0) {
4297 goto next_app;
4298 }
4299 next_app:
4300 pthread_mutex_unlock(&ua_sess->lock);
4301 }
4302
4303 rcu_read_unlock();
4304 return ret;
4305 }
4306
4307 /*
4308 * Enable event for a channel from a UST session for a specific PID.
4309 */
4310 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4311 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4312 {
4313 int ret = 0;
4314 struct lttng_ht_iter iter;
4315 struct lttng_ht_node_str *ua_chan_node;
4316 struct ust_app *app;
4317 struct ust_app_session *ua_sess;
4318 struct ust_app_channel *ua_chan;
4319 struct ust_app_event *ua_event;
4320
4321 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4322
4323 rcu_read_lock();
4324
4325 app = ust_app_find_by_pid(pid);
4326 if (app == NULL) {
4327 ERR("UST app enable event per PID %d not found", pid);
4328 ret = -1;
4329 goto end;
4330 }
4331
4332 if (!app->compatible) {
4333 ret = 0;
4334 goto end;
4335 }
4336
4337 ua_sess = lookup_session_by_app(usess, app);
4338 if (!ua_sess) {
4339 /* The application has problem or is probably dead. */
4340 ret = 0;
4341 goto end;
4342 }
4343
4344 pthread_mutex_lock(&ua_sess->lock);
4345 /* Lookup channel in the ust app session */
4346 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4347 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4348 /* If the channel is not found, there is a code flow error */
4349 assert(ua_chan_node);
4350
4351 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4352
4353 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4354 uevent->filter, uevent->attr.loglevel);
4355 if (ua_event == NULL) {
4356 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4357 if (ret < 0) {
4358 goto end_unlock;
4359 }
4360 } else {
4361 ret = enable_ust_app_event(ua_sess, ua_event, app);
4362 if (ret < 0) {
4363 goto end_unlock;
4364 }
4365 }
4366
4367 end_unlock:
4368 pthread_mutex_unlock(&ua_sess->lock);
4369 end:
4370 rcu_read_unlock();
4371 return ret;
4372 }
4373
4374 /*
4375 * Disable event for a channel from a UST session for a specific PID.
4376 */
4377 int ust_app_disable_event_pid(struct ltt_ust_session *usess,
4378 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4379 {
4380 int ret = 0;
4381 struct lttng_ht_iter iter;
4382 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
4383 struct ust_app *app;
4384 struct ust_app_session *ua_sess;
4385 struct ust_app_channel *ua_chan;
4386 struct ust_app_event *ua_event;
4387
4388 DBG("UST app disabling event %s for PID %d", uevent->attr.name, pid);
4389
4390 rcu_read_lock();
4391
4392 app = ust_app_find_by_pid(pid);
4393 if (app == NULL) {
4394 ERR("UST app disable event per PID %d not found", pid);
4395 ret = -1;
4396 goto error;
4397 }
4398
4399 if (!app->compatible) {
4400 ret = 0;
4401 goto error;
4402 }
4403
4404 ua_sess = lookup_session_by_app(usess, app);
4405 if (!ua_sess) {
4406 /* The application has problem or is probably dead. */
4407 goto error;
4408 }
4409
4410 /* Lookup channel in the ust app session */
4411 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4412 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4413 if (ua_chan_node == NULL) {
4414 /* Channel does not exist, skip disabling */
4415 goto error;
4416 }
4417 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4418
4419 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &iter);
4420 ua_event_node = lttng_ht_iter_get_node_str(&iter);
4421 if (ua_event_node == NULL) {
4422 /* Event does not exist, skip disabling */
4423 goto error;
4424 }
4425 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
4426
4427 ret = disable_ust_app_event(ua_sess, ua_event, app);
4428 if (ret < 0) {
4429 goto error;
4430 }
4431
4432 error:
4433 rcu_read_unlock();
4434 return ret;
4435 }
4436
4437 /*
4438 * Calibrate registered applications.
4439 */
4440 int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4441 {
4442 int ret = 0;
4443 struct lttng_ht_iter iter;
4444 struct ust_app *app;
4445
4446 rcu_read_lock();
4447
4448 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4449 if (!app->compatible) {
4450 /*
4451 * TODO: In time, we should notice the caller of this error by
4452 * telling him that this is a version error.
4453 */
4454 continue;
4455 }
4456
4457 health_code_update();
4458
4459 ret = ustctl_calibrate(app->sock, calibrate);
4460 if (ret < 0) {
4461 switch (ret) {
4462 case -ENOSYS:
4463 /* Means that it's not implemented on the tracer side. */
4464 ret = 0;
4465 break;
4466 default:
4467 DBG2("Calibrate app PID %d returned with error %d",
4468 app->pid, ret);
4469 break;
4470 }
4471 }
4472 }
4473
4474 DBG("UST app global domain calibration finished");
4475
4476 rcu_read_unlock();
4477
4478 health_code_update();
4479
4480 return ret;
4481 }
4482
4483 /*
4484 * Receive registration and populate the given msg structure.
4485 *
4486 * On success return 0 else a negative value returned by the ustctl call.
4487 */
4488 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4489 {
4490 int ret;
4491 uint32_t pid, ppid, uid, gid;
4492
4493 assert(msg);
4494
4495 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4496 &pid, &ppid, &uid, &gid,
4497 &msg->bits_per_long,
4498 &msg->uint8_t_alignment,
4499 &msg->uint16_t_alignment,
4500 &msg->uint32_t_alignment,
4501 &msg->uint64_t_alignment,
4502 &msg->long_alignment,
4503 &msg->byte_order,
4504 msg->name);
4505 if (ret < 0) {
4506 switch (-ret) {
4507 case EPIPE:
4508 case ECONNRESET:
4509 case LTTNG_UST_ERR_EXITING:
4510 DBG3("UST app recv reg message failed. Application died");
4511 break;
4512 case LTTNG_UST_ERR_UNSUP_MAJOR:
4513 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4514 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
4515 LTTNG_UST_ABI_MINOR_VERSION);
4516 break;
4517 default:
4518 ERR("UST app recv reg message failed with ret %d", ret);
4519 break;
4520 }
4521 goto error;
4522 }
4523 msg->pid = (pid_t) pid;
4524 msg->ppid = (pid_t) ppid;
4525 msg->uid = (uid_t) uid;
4526 msg->gid = (gid_t) gid;
4527
4528 error:
4529 return ret;
4530 }
4531
4532 /*
4533 * Return a ust app channel object using the application object and the channel
4534 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4535 * lock MUST be acquired before calling this function.
4536 */
4537 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
4538 int objd)
4539 {
4540 struct lttng_ht_node_ulong *node;
4541 struct lttng_ht_iter iter;
4542 struct ust_app_channel *ua_chan = NULL;
4543
4544 assert(app);
4545
4546 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
4547 node = lttng_ht_iter_get_node_ulong(&iter);
4548 if (node == NULL) {
4549 DBG2("UST app channel find by objd %d not found", objd);
4550 goto error;
4551 }
4552
4553 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
4554
4555 error:
4556 return ua_chan;
4557 }
4558
4559 /*
4560 * Reply to a register channel notification from an application on the notify
4561 * socket. The channel metadata is also created.
4562 *
4563 * The session UST registry lock is acquired in this function.
4564 *
4565 * On success 0 is returned else a negative value.
4566 */
4567 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
4568 size_t nr_fields, struct ustctl_field *fields)
4569 {
4570 int ret, ret_code = 0;
4571 uint32_t chan_id, reg_count;
4572 uint64_t chan_reg_key;
4573 enum ustctl_channel_header type;
4574 struct ust_app *app;
4575 struct ust_app_channel *ua_chan;
4576 struct ust_app_session *ua_sess;
4577 struct ust_registry_session *registry;
4578 struct ust_registry_channel *chan_reg;
4579
4580 rcu_read_lock();
4581
4582 /* Lookup application. If not found, there is a code flow error. */
4583 app = find_app_by_notify_sock(sock);
4584 if (!app) {
4585 DBG("Application socket %d is being teardown. Abort event notify",
4586 sock);
4587 ret = 0;
4588 free(fields);
4589 goto error_rcu_unlock;
4590 }
4591
4592 /* Lookup channel by UST object descriptor. */
4593 ua_chan = find_channel_by_objd(app, cobjd);
4594 if (!ua_chan) {
4595 DBG("Application channel is being teardown. Abort event notify");
4596 ret = 0;
4597 free(fields);
4598 goto error_rcu_unlock;
4599 }
4600
4601 assert(ua_chan->session);
4602 ua_sess = ua_chan->session;
4603
4604 /* Get right session registry depending on the session buffer type. */
4605 registry = get_session_registry(ua_sess);
4606 assert(registry);
4607
4608 /* Depending on the buffer type, a different channel key is used. */
4609 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4610 chan_reg_key = ua_chan->tracing_channel_id;
4611 } else {
4612 chan_reg_key = ua_chan->key;
4613 }
4614
4615 pthread_mutex_lock(&registry->lock);
4616
4617 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
4618 assert(chan_reg);
4619
4620 if (!chan_reg->register_done) {
4621 reg_count = ust_registry_get_event_count(chan_reg);
4622 if (reg_count < 31) {
4623 type = USTCTL_CHANNEL_HEADER_COMPACT;
4624 } else {
4625 type = USTCTL_CHANNEL_HEADER_LARGE;
4626 }
4627
4628 chan_reg->nr_ctx_fields = nr_fields;
4629 chan_reg->ctx_fields = fields;
4630 chan_reg->header_type = type;
4631 } else {
4632 /* Get current already assigned values. */
4633 type = chan_reg->header_type;
4634 free(fields);
4635 /* Set to NULL so the error path does not do a double free. */
4636 fields = NULL;
4637 }
4638 /* Channel id is set during the object creation. */
4639 chan_id = chan_reg->chan_id;
4640
4641 /* Append to metadata */
4642 if (!chan_reg->metadata_dumped) {
4643 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
4644 if (ret_code) {
4645 ERR("Error appending channel metadata (errno = %d)", ret_code);
4646 goto reply;
4647 }
4648 }
4649
4650 reply:
4651 DBG3("UST app replying to register channel key %" PRIu64
4652 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
4653 ret_code);
4654
4655 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
4656 if (ret < 0) {
4657 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4658 ERR("UST app reply channel failed with ret %d", ret);
4659 } else {
4660 DBG3("UST app reply channel failed. Application died");
4661 }
4662 goto error;
4663 }
4664
4665 /* This channel registry registration is completed. */
4666 chan_reg->register_done = 1;
4667
4668 error:
4669 pthread_mutex_unlock(&registry->lock);
4670 error_rcu_unlock:
4671 rcu_read_unlock();
4672 if (ret) {
4673 free(fields);
4674 }
4675 return ret;
4676 }
4677
4678 /*
4679 * Add event to the UST channel registry. When the event is added to the
4680 * registry, the metadata is also created. Once done, this replies to the
4681 * application with the appropriate error code.
4682 *
4683 * The session UST registry lock is acquired in the function.
4684 *
4685 * On success 0 is returned else a negative value.
4686 */
4687 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
4688 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
4689 char *model_emf_uri)
4690 {
4691 int ret, ret_code;
4692 uint32_t event_id = 0;
4693 uint64_t chan_reg_key;
4694 struct ust_app *app;
4695 struct ust_app_channel *ua_chan;
4696 struct ust_app_session *ua_sess;
4697 struct ust_registry_session *registry;
4698
4699 rcu_read_lock();
4700
4701 /* Lookup application. If not found, there is a code flow error. */
4702 app = find_app_by_notify_sock(sock);
4703 if (!app) {
4704 DBG("Application socket %d is being teardown. Abort event notify",
4705 sock);
4706 ret = 0;
4707 free(sig);
4708 free(fields);
4709 free(model_emf_uri);
4710 goto error_rcu_unlock;
4711 }
4712
4713 /* Lookup channel by UST object descriptor. */
4714 ua_chan = find_channel_by_objd(app, cobjd);
4715 if (!ua_chan) {
4716 DBG("Application channel is being teardown. Abort event notify");
4717 ret = 0;
4718 free(sig);
4719 free(fields);
4720 free(model_emf_uri);
4721 goto error_rcu_unlock;
4722 }
4723
4724 assert(ua_chan->session);
4725 ua_sess = ua_chan->session;
4726
4727 registry = get_session_registry(ua_sess);
4728 assert(registry);
4729
4730 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4731 chan_reg_key = ua_chan->tracing_channel_id;
4732 } else {
4733 chan_reg_key = ua_chan->key;
4734 }
4735
4736 pthread_mutex_lock(&registry->lock);
4737
4738 /*
4739 * From this point on, this call acquires the ownership of the sig, fields
4740 * and model_emf_uri meaning any free are done inside it if needed. These
4741 * three variables MUST NOT be read/write after this.
4742 */
4743 ret_code = ust_registry_create_event(registry, chan_reg_key,
4744 sobjd, cobjd, name, sig, nr_fields, fields, loglevel,
4745 model_emf_uri, ua_sess->buffer_type, &event_id,
4746 app);
4747
4748 /*
4749 * The return value is returned to ustctl so in case of an error, the
4750 * application can be notified. In case of an error, it's important not to
4751 * return a negative error or else the application will get closed.
4752 */
4753 ret = ustctl_reply_register_event(sock, event_id, ret_code);
4754 if (ret < 0) {
4755 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4756 ERR("UST app reply event failed with ret %d", ret);
4757 } else {
4758 DBG3("UST app reply event failed. Application died");
4759 }
4760 /*
4761 * No need to wipe the create event since the application socket will
4762 * get close on error hence cleaning up everything by itself.
4763 */
4764 goto error;
4765 }
4766
4767 DBG3("UST registry event %s with id %" PRId32 " added successfully",
4768 name, event_id);
4769
4770 error:
4771 pthread_mutex_unlock(&registry->lock);
4772 error_rcu_unlock:
4773 rcu_read_unlock();
4774 return ret;
4775 }
4776
4777 /*
4778 * Handle application notification through the given notify socket.
4779 *
4780 * Return 0 on success or else a negative value.
4781 */
4782 int ust_app_recv_notify(int sock)
4783 {
4784 int ret;
4785 enum ustctl_notify_cmd cmd;
4786
4787 DBG3("UST app receiving notify from sock %d", sock);
4788
4789 ret = ustctl_recv_notify(sock, &cmd);
4790 if (ret < 0) {
4791 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4792 ERR("UST app recv notify failed with ret %d", ret);
4793 } else {
4794 DBG3("UST app recv notify failed. Application died");
4795 }
4796 goto error;
4797 }
4798
4799 switch (cmd) {
4800 case USTCTL_NOTIFY_CMD_EVENT:
4801 {
4802 int sobjd, cobjd, loglevel;
4803 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
4804 size_t nr_fields;
4805 struct ustctl_field *fields;
4806
4807 DBG2("UST app ustctl register event received");
4808
4809 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name, &loglevel,
4810 &sig, &nr_fields, &fields, &model_emf_uri);
4811 if (ret < 0) {
4812 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4813 ERR("UST app recv event failed with ret %d", ret);
4814 } else {
4815 DBG3("UST app recv event failed. Application died");
4816 }
4817 goto error;
4818 }
4819
4820 /*
4821 * Add event to the UST registry coming from the notify socket. This
4822 * call will free if needed the sig, fields and model_emf_uri. This
4823 * code path loses the ownsership of these variables and transfer them
4824 * to the this function.
4825 */
4826 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
4827 fields, loglevel, model_emf_uri);
4828 if (ret < 0) {
4829 goto error;
4830 }
4831
4832 break;
4833 }
4834 case USTCTL_NOTIFY_CMD_CHANNEL:
4835 {
4836 int sobjd, cobjd;
4837 size_t nr_fields;
4838 struct ustctl_field *fields;
4839
4840 DBG2("UST app ustctl register channel received");
4841
4842 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
4843 &fields);
4844 if (ret < 0) {
4845 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4846 ERR("UST app recv channel failed with ret %d", ret);
4847 } else {
4848 DBG3("UST app recv channel failed. Application died");
4849 }
4850 goto error;
4851 }
4852
4853 /*
4854 * The fields ownership are transfered to this function call meaning
4855 * that if needed it will be freed. After this, it's invalid to access
4856 * fields or clean it up.
4857 */
4858 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
4859 fields);
4860 if (ret < 0) {
4861 goto error;
4862 }
4863
4864 break;
4865 }
4866 default:
4867 /* Should NEVER happen. */
4868 assert(0);
4869 }
4870
4871 error:
4872 return ret;
4873 }
4874
4875 /*
4876 * Once the notify socket hangs up, this is called. First, it tries to find the
4877 * corresponding application. On failure, the call_rcu to close the socket is
4878 * executed. If an application is found, it tries to delete it from the notify
4879 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4880 *
4881 * Note that an object needs to be allocated here so on ENOMEM failure, the
4882 * call RCU is not done but the rest of the cleanup is.
4883 */
4884 void ust_app_notify_sock_unregister(int sock)
4885 {
4886 int err_enomem = 0;
4887 struct lttng_ht_iter iter;
4888 struct ust_app *app;
4889 struct ust_app_notify_sock_obj *obj;
4890
4891 assert(sock >= 0);
4892
4893 rcu_read_lock();
4894
4895 obj = zmalloc(sizeof(*obj));
4896 if (!obj) {
4897 /*
4898 * An ENOMEM is kind of uncool. If this strikes we continue the
4899 * procedure but the call_rcu will not be called. In this case, we
4900 * accept the fd leak rather than possibly creating an unsynchronized
4901 * state between threads.
4902 *
4903 * TODO: The notify object should be created once the notify socket is
4904 * registered and stored independantely from the ust app object. The
4905 * tricky part is to synchronize the teardown of the application and
4906 * this notify object. Let's keep that in mind so we can avoid this
4907 * kind of shenanigans with ENOMEM in the teardown path.
4908 */
4909 err_enomem = 1;
4910 } else {
4911 obj->fd = sock;
4912 }
4913
4914 DBG("UST app notify socket unregister %d", sock);
4915
4916 /*
4917 * Lookup application by notify socket. If this fails, this means that the
4918 * hash table delete has already been done by the application
4919 * unregistration process so we can safely close the notify socket in a
4920 * call RCU.
4921 */
4922 app = find_app_by_notify_sock(sock);
4923 if (!app) {
4924 goto close_socket;
4925 }
4926
4927 iter.iter.node = &app->notify_sock_n.node;
4928
4929 /*
4930 * Whatever happens here either we fail or succeed, in both cases we have
4931 * to close the socket after a grace period to continue to the call RCU
4932 * here. If the deletion is successful, the application is not visible
4933 * anymore by other threads and is it fails it means that it was already
4934 * deleted from the hash table so either way we just have to close the
4935 * socket.
4936 */
4937 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
4938
4939 close_socket:
4940 rcu_read_unlock();
4941
4942 /*
4943 * Close socket after a grace period to avoid for the socket to be reused
4944 * before the application object is freed creating potential race between
4945 * threads trying to add unique in the global hash table.
4946 */
4947 if (!err_enomem) {
4948 call_rcu(&obj->head, close_notify_sock_rcu);
4949 }
4950 }
4951
4952 /*
4953 * Destroy a ust app data structure and free its memory.
4954 */
4955 void ust_app_destroy(struct ust_app *app)
4956 {
4957 if (!app) {
4958 return;
4959 }
4960
4961 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
4962 }
4963
4964 /*
4965 * Take a snapshot for a given UST session. The snapshot is sent to the given
4966 * output.
4967 *
4968 * Return 0 on success or else a negative value.
4969 */
4970 int ust_app_snapshot_record(struct ltt_ust_session *usess,
4971 struct snapshot_output *output, int wait, unsigned int nb_streams)
4972 {
4973 int ret = 0;
4974 struct lttng_ht_iter iter;
4975 struct ust_app *app;
4976 char pathname[PATH_MAX];
4977 uint64_t max_stream_size = 0;
4978
4979 assert(usess);
4980 assert(output);
4981
4982 rcu_read_lock();
4983
4984 /*
4985 * Compute the maximum size of a single stream if a max size is asked by
4986 * the caller.
4987 */
4988 if (output->max_size > 0 && nb_streams > 0) {
4989 max_stream_size = output->max_size / nb_streams;
4990 }
4991
4992 switch (usess->buffer_type) {
4993 case LTTNG_BUFFER_PER_UID:
4994 {
4995 struct buffer_reg_uid *reg;
4996
4997 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4998 struct buffer_reg_channel *reg_chan;
4999 struct consumer_socket *socket;
5000
5001 /* Get consumer socket to use to push the metadata.*/
5002 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5003 usess->consumer);
5004 if (!socket) {
5005 ret = -EINVAL;
5006 goto error;
5007 }
5008
5009 memset(pathname, 0, sizeof(pathname));
5010 ret = snprintf(pathname, sizeof(pathname),
5011 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
5012 reg->uid, reg->bits_per_long);
5013 if (ret < 0) {
5014 PERROR("snprintf snapshot path");
5015 goto error;
5016 }
5017
5018 /* Add the UST default trace dir to path. */
5019 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5020 reg_chan, node.node) {
5021
5022 /*
5023 * Make sure the maximum stream size is not lower than the
5024 * subbuffer size or else it's an error since we won't be able to
5025 * snapshot anything.
5026 */
5027 if (max_stream_size &&
5028 reg_chan->subbuf_size > max_stream_size) {
5029 ret = -EINVAL;
5030 DBG3("UST app snapshot record maximum stream size %" PRIu64
5031 " is smaller than subbuffer size of %zu",
5032 max_stream_size, reg_chan->subbuf_size);
5033 goto error;
5034 }
5035 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key, output, 0,
5036 usess->uid, usess->gid, pathname, wait,
5037 max_stream_size);
5038 if (ret < 0) {
5039 goto error;
5040 }
5041 }
5042 ret = consumer_snapshot_channel(socket, reg->registry->reg.ust->metadata_key, output,
5043 1, usess->uid, usess->gid, pathname, wait,
5044 max_stream_size);
5045 if (ret < 0) {
5046 goto error;
5047 }
5048 }
5049 break;
5050 }
5051 case LTTNG_BUFFER_PER_PID:
5052 {
5053 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5054 struct consumer_socket *socket;
5055 struct lttng_ht_iter chan_iter;
5056 struct ust_app_channel *ua_chan;
5057 struct ust_app_session *ua_sess;
5058 struct ust_registry_session *registry;
5059
5060 ua_sess = lookup_session_by_app(usess, app);
5061 if (!ua_sess) {
5062 /* Session not associated with this app. */
5063 continue;
5064 }
5065
5066 /* Get the right consumer socket for the application. */
5067 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5068 output->consumer);
5069 if (!socket) {
5070 ret = -EINVAL;
5071 goto error;
5072 }
5073
5074 /* Add the UST default trace dir to path. */
5075 memset(pathname, 0, sizeof(pathname));
5076 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
5077 ua_sess->path);
5078 if (ret < 0) {
5079 PERROR("snprintf snapshot path");
5080 goto error;
5081 }
5082
5083 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5084 ua_chan, node.node) {
5085 /*
5086 * Make sure the maximum stream size is not lower than the
5087 * subbuffer size or else it's an error since we won't be able to
5088 * snapshot anything.
5089 */
5090 if (max_stream_size &&
5091 ua_chan->attr.subbuf_size > max_stream_size) {
5092 ret = -EINVAL;
5093 DBG3("UST app snapshot record maximum stream size %" PRIu64
5094 " is smaller than subbuffer size of %" PRIu64,
5095 max_stream_size, ua_chan->attr.subbuf_size);
5096 goto error;
5097 }
5098
5099 ret = consumer_snapshot_channel(socket, ua_chan->key, output, 0,
5100 ua_sess->euid, ua_sess->egid, pathname, wait,
5101 max_stream_size);
5102 if (ret < 0) {
5103 goto error;
5104 }
5105 }
5106
5107 registry = get_session_registry(ua_sess);
5108 assert(registry);
5109 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5110 1, ua_sess->euid, ua_sess->egid, pathname, wait,
5111 max_stream_size);
5112 if (ret < 0) {
5113 goto error;
5114 }
5115 }
5116 break;
5117 }
5118 default:
5119 assert(0);
5120 break;
5121 }
5122
5123 error:
5124 rcu_read_unlock();
5125 return ret;
5126 }
5127
5128 /*
5129 * Return the number of streams for a UST session.
5130 */
5131 unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
5132 {
5133 unsigned int ret = 0;
5134 struct ust_app *app;
5135 struct lttng_ht_iter iter;
5136
5137 assert(usess);
5138
5139 switch (usess->buffer_type) {
5140 case LTTNG_BUFFER_PER_UID:
5141 {
5142 struct buffer_reg_uid *reg;
5143
5144 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5145 struct buffer_reg_channel *reg_chan;
5146
5147 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5148 reg_chan, node.node) {
5149 ret += reg_chan->stream_count;
5150 }
5151 }
5152 break;
5153 }
5154 case LTTNG_BUFFER_PER_PID:
5155 {
5156 rcu_read_lock();
5157 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5158 struct ust_app_channel *ua_chan;
5159 struct ust_app_session *ua_sess;
5160 struct lttng_ht_iter chan_iter;
5161
5162 ua_sess = lookup_session_by_app(usess, app);
5163 if (!ua_sess) {
5164 /* Session not associated with this app. */
5165 continue;
5166 }
5167
5168 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5169 ua_chan, node.node) {
5170 ret += ua_chan->streams.count;
5171 }
5172 }
5173 rcu_read_unlock();
5174 break;
5175 }
5176 default:
5177 assert(0);
5178 break;
5179 }
5180
5181 return ret;
5182 }
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