11b588f77f675aef1a60d9a3c265cec76f2fb4bf
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <errno.h>
20 #include <inttypes.h>
21 #include <pthread.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 #include <urcu/compiler.h>
29 #include <lttng/ust-error.h>
30 #include <signal.h>
31
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34
35 #include "buffer-registry.h"
36 #include "fd-limit.h"
37 #include "health-sessiond.h"
38 #include "ust-app.h"
39 #include "ust-consumer.h"
40 #include "ust-ctl.h"
41 #include "utils.h"
42
43 /* Next available channel key. Access under next_channel_key_lock. */
44 static uint64_t _next_channel_key;
45 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
46
47 /* Next available session ID. Access under next_session_id_lock. */
48 static uint64_t _next_session_id;
49 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
50
51 /*
52 * Return the incremented value of next_channel_key.
53 */
54 static uint64_t get_next_channel_key(void)
55 {
56 uint64_t ret;
57
58 pthread_mutex_lock(&next_channel_key_lock);
59 ret = ++_next_channel_key;
60 pthread_mutex_unlock(&next_channel_key_lock);
61 return ret;
62 }
63
64 /*
65 * Return the atomically incremented value of next_session_id.
66 */
67 static uint64_t get_next_session_id(void)
68 {
69 uint64_t ret;
70
71 pthread_mutex_lock(&next_session_id_lock);
72 ret = ++_next_session_id;
73 pthread_mutex_unlock(&next_session_id_lock);
74 return ret;
75 }
76
77 static void copy_channel_attr_to_ustctl(
78 struct ustctl_consumer_channel_attr *attr,
79 struct lttng_ust_channel_attr *uattr)
80 {
81 /* Copy event attributes since the layout is different. */
82 attr->subbuf_size = uattr->subbuf_size;
83 attr->num_subbuf = uattr->num_subbuf;
84 attr->overwrite = uattr->overwrite;
85 attr->switch_timer_interval = uattr->switch_timer_interval;
86 attr->read_timer_interval = uattr->read_timer_interval;
87 attr->output = uattr->output;
88 }
89
90 /*
91 * Match function for the hash table lookup.
92 *
93 * It matches an ust app event based on three attributes which are the event
94 * name, the filter bytecode and the loglevel.
95 */
96 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
97 {
98 struct ust_app_event *event;
99 const struct ust_app_ht_key *key;
100
101 assert(node);
102 assert(_key);
103
104 event = caa_container_of(node, struct ust_app_event, node.node);
105 key = _key;
106
107 /* Match the 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 struct ust_app *ust_app_find_by_sock(int sock)
961 {
962 struct lttng_ht_node_ulong *node;
963 struct lttng_ht_iter iter;
964
965 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
966 node = lttng_ht_iter_get_node_ulong(&iter);
967 if (node == NULL) {
968 DBG2("UST app find by sock %d not found", sock);
969 goto error;
970 }
971
972 return caa_container_of(node, struct ust_app, sock_n);
973
974 error:
975 return NULL;
976 }
977
978 /*
979 * Find an ust_app using the notify sock and return it. RCU read side lock must
980 * be held before calling this helper function.
981 */
982 static struct ust_app *find_app_by_notify_sock(int sock)
983 {
984 struct lttng_ht_node_ulong *node;
985 struct lttng_ht_iter iter;
986
987 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
988 &iter);
989 node = lttng_ht_iter_get_node_ulong(&iter);
990 if (node == NULL) {
991 DBG2("UST app find by notify sock %d not found", sock);
992 goto error;
993 }
994
995 return caa_container_of(node, struct ust_app, notify_sock_n);
996
997 error:
998 return NULL;
999 }
1000
1001 /*
1002 * Lookup for an ust app event based on event name, filter bytecode and the
1003 * event loglevel.
1004 *
1005 * Return an ust_app_event object or NULL on error.
1006 */
1007 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1008 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel)
1009 {
1010 struct lttng_ht_iter iter;
1011 struct lttng_ht_node_str *node;
1012 struct ust_app_event *event = NULL;
1013 struct ust_app_ht_key key;
1014
1015 assert(name);
1016 assert(ht);
1017
1018 /* Setup key for event lookup. */
1019 key.name = name;
1020 key.filter = filter;
1021 key.loglevel = loglevel;
1022
1023 /* Lookup using the event name as hash and a custom match fct. */
1024 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1025 ht_match_ust_app_event, &key, &iter.iter);
1026 node = lttng_ht_iter_get_node_str(&iter);
1027 if (node == NULL) {
1028 goto end;
1029 }
1030
1031 event = caa_container_of(node, struct ust_app_event, node);
1032
1033 end:
1034 return event;
1035 }
1036
1037 /*
1038 * Create the channel context on the tracer.
1039 *
1040 * Called with UST app session lock held.
1041 */
1042 static
1043 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1044 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1045 {
1046 int ret;
1047
1048 health_code_update();
1049
1050 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1051 ua_chan->obj, &ua_ctx->obj);
1052 if (ret < 0) {
1053 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1054 ERR("UST app create channel context failed for app (pid: %d) "
1055 "with ret %d", app->pid, ret);
1056 } else {
1057 /*
1058 * This is normal behavior, an application can die during the
1059 * creation process. Don't report an error so the execution can
1060 * continue normally.
1061 */
1062 ret = 0;
1063 DBG3("UST app disable event failed. Application is dead.");
1064 }
1065 goto error;
1066 }
1067
1068 ua_ctx->handle = ua_ctx->obj->handle;
1069
1070 DBG2("UST app context handle %d created successfully for channel %s",
1071 ua_ctx->handle, ua_chan->name);
1072
1073 error:
1074 health_code_update();
1075 return ret;
1076 }
1077
1078 /*
1079 * Set the filter on the tracer.
1080 */
1081 static
1082 int set_ust_event_filter(struct ust_app_event *ua_event,
1083 struct ust_app *app)
1084 {
1085 int ret;
1086
1087 health_code_update();
1088
1089 if (!ua_event->filter) {
1090 ret = 0;
1091 goto error;
1092 }
1093
1094 ret = ustctl_set_filter(app->sock, ua_event->filter,
1095 ua_event->obj);
1096 if (ret < 0) {
1097 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1098 ERR("UST app event %s filter failed for app (pid: %d) "
1099 "with ret %d", ua_event->attr.name, app->pid, ret);
1100 } else {
1101 /*
1102 * This is normal behavior, an application can die during the
1103 * creation process. Don't report an error so the execution can
1104 * continue normally.
1105 */
1106 ret = 0;
1107 DBG3("UST app filter event failed. Application is dead.");
1108 }
1109 goto error;
1110 }
1111
1112 DBG2("UST filter set successfully for event %s", ua_event->name);
1113
1114 error:
1115 health_code_update();
1116 return ret;
1117 }
1118
1119 /*
1120 * Disable the specified event on to UST tracer for the UST session.
1121 */
1122 static int disable_ust_event(struct ust_app *app,
1123 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1124 {
1125 int ret;
1126
1127 health_code_update();
1128
1129 ret = ustctl_disable(app->sock, ua_event->obj);
1130 if (ret < 0) {
1131 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1132 ERR("UST app event %s disable failed for app (pid: %d) "
1133 "and session handle %d with ret %d",
1134 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1135 } else {
1136 /*
1137 * This is normal behavior, an application can die during the
1138 * creation process. Don't report an error so the execution can
1139 * continue normally.
1140 */
1141 ret = 0;
1142 DBG3("UST app disable event failed. Application is dead.");
1143 }
1144 goto error;
1145 }
1146
1147 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1148 ua_event->attr.name, app->pid);
1149
1150 error:
1151 health_code_update();
1152 return ret;
1153 }
1154
1155 /*
1156 * Disable the specified channel on to UST tracer for the UST session.
1157 */
1158 static int disable_ust_channel(struct ust_app *app,
1159 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1160 {
1161 int ret;
1162
1163 health_code_update();
1164
1165 ret = ustctl_disable(app->sock, ua_chan->obj);
1166 if (ret < 0) {
1167 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1168 ERR("UST app channel %s disable failed for app (pid: %d) "
1169 "and session handle %d with ret %d",
1170 ua_chan->name, app->pid, ua_sess->handle, ret);
1171 } else {
1172 /*
1173 * This is normal behavior, an application can die during the
1174 * creation process. Don't report an error so the execution can
1175 * continue normally.
1176 */
1177 ret = 0;
1178 DBG3("UST app disable channel failed. Application is dead.");
1179 }
1180 goto error;
1181 }
1182
1183 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1184 ua_chan->name, app->pid);
1185
1186 error:
1187 health_code_update();
1188 return ret;
1189 }
1190
1191 /*
1192 * Enable the specified channel on to UST tracer for the UST session.
1193 */
1194 static int enable_ust_channel(struct ust_app *app,
1195 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1196 {
1197 int ret;
1198
1199 health_code_update();
1200
1201 ret = ustctl_enable(app->sock, ua_chan->obj);
1202 if (ret < 0) {
1203 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1204 ERR("UST app channel %s enable failed for app (pid: %d) "
1205 "and session handle %d with ret %d",
1206 ua_chan->name, app->pid, ua_sess->handle, ret);
1207 } else {
1208 /*
1209 * This is normal behavior, an application can die during the
1210 * creation process. Don't report an error so the execution can
1211 * continue normally.
1212 */
1213 ret = 0;
1214 DBG3("UST app enable channel failed. Application is dead.");
1215 }
1216 goto error;
1217 }
1218
1219 ua_chan->enabled = 1;
1220
1221 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1222 ua_chan->name, app->pid);
1223
1224 error:
1225 health_code_update();
1226 return ret;
1227 }
1228
1229 /*
1230 * Enable the specified event on to UST tracer for the UST session.
1231 */
1232 static int enable_ust_event(struct ust_app *app,
1233 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1234 {
1235 int ret;
1236
1237 health_code_update();
1238
1239 ret = ustctl_enable(app->sock, ua_event->obj);
1240 if (ret < 0) {
1241 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1242 ERR("UST app event %s enable failed for app (pid: %d) "
1243 "and session handle %d with ret %d",
1244 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1245 } else {
1246 /*
1247 * This is normal behavior, an application can die during the
1248 * creation process. Don't report an error so the execution can
1249 * continue normally.
1250 */
1251 ret = 0;
1252 DBG3("UST app enable event failed. Application is dead.");
1253 }
1254 goto error;
1255 }
1256
1257 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1258 ua_event->attr.name, app->pid);
1259
1260 error:
1261 health_code_update();
1262 return ret;
1263 }
1264
1265 /*
1266 * Send channel and stream buffer to application.
1267 *
1268 * Return 0 on success. On error, a negative value is returned.
1269 */
1270 static int send_channel_pid_to_ust(struct ust_app *app,
1271 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1272 {
1273 int ret;
1274 struct ust_app_stream *stream, *stmp;
1275
1276 assert(app);
1277 assert(ua_sess);
1278 assert(ua_chan);
1279
1280 health_code_update();
1281
1282 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1283 app->sock);
1284
1285 /* Send channel to the application. */
1286 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1287 if (ret < 0) {
1288 goto error;
1289 }
1290
1291 health_code_update();
1292
1293 /* Send all streams to application. */
1294 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1295 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1296 if (ret < 0) {
1297 goto error;
1298 }
1299 /* We don't need the stream anymore once sent to the tracer. */
1300 cds_list_del(&stream->list);
1301 delete_ust_app_stream(-1, stream);
1302 }
1303 /* Flag the channel that it is sent to the application. */
1304 ua_chan->is_sent = 1;
1305
1306 error:
1307 health_code_update();
1308 return ret;
1309 }
1310
1311 /*
1312 * Create the specified event onto the UST tracer for a UST session.
1313 *
1314 * Should be called with session mutex held.
1315 */
1316 static
1317 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1318 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1319 {
1320 int ret = 0;
1321
1322 health_code_update();
1323
1324 /* Create UST event on tracer */
1325 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1326 &ua_event->obj);
1327 if (ret < 0) {
1328 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1329 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1330 ua_event->attr.name, app->pid, ret);
1331 } else {
1332 /*
1333 * This is normal behavior, an application can die during the
1334 * creation process. Don't report an error so the execution can
1335 * continue normally.
1336 */
1337 ret = 0;
1338 DBG3("UST app create event failed. Application is dead.");
1339 }
1340 goto error;
1341 }
1342
1343 ua_event->handle = ua_event->obj->handle;
1344
1345 DBG2("UST app event %s created successfully for pid:%d",
1346 ua_event->attr.name, app->pid);
1347
1348 health_code_update();
1349
1350 /* Set filter if one is present. */
1351 if (ua_event->filter) {
1352 ret = set_ust_event_filter(ua_event, app);
1353 if (ret < 0) {
1354 goto error;
1355 }
1356 }
1357
1358 /* If event not enabled, disable it on the tracer */
1359 if (ua_event->enabled == 0) {
1360 ret = disable_ust_event(app, ua_sess, ua_event);
1361 if (ret < 0) {
1362 /*
1363 * If we hit an EPERM, something is wrong with our disable call. If
1364 * we get an EEXIST, there is a problem on the tracer side since we
1365 * just created it.
1366 */
1367 switch (ret) {
1368 case -LTTNG_UST_ERR_PERM:
1369 /* Code flow problem */
1370 assert(0);
1371 case -LTTNG_UST_ERR_EXIST:
1372 /* It's OK for our use case. */
1373 ret = 0;
1374 break;
1375 default:
1376 break;
1377 }
1378 goto error;
1379 }
1380 }
1381
1382 error:
1383 health_code_update();
1384 return ret;
1385 }
1386
1387 /*
1388 * Copy data between an UST app event and a LTT event.
1389 */
1390 static void shadow_copy_event(struct ust_app_event *ua_event,
1391 struct ltt_ust_event *uevent)
1392 {
1393 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1394 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1395
1396 ua_event->enabled = uevent->enabled;
1397
1398 /* Copy event attributes */
1399 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1400
1401 /* Copy filter bytecode */
1402 if (uevent->filter) {
1403 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1404 /* Filter might be NULL here in case of ENONEM. */
1405 }
1406 }
1407
1408 /*
1409 * Copy data between an UST app channel and a LTT channel.
1410 */
1411 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1412 struct ltt_ust_channel *uchan)
1413 {
1414 struct lttng_ht_iter iter;
1415 struct ltt_ust_event *uevent;
1416 struct ltt_ust_context *uctx;
1417 struct ust_app_event *ua_event;
1418 struct ust_app_ctx *ua_ctx;
1419
1420 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1421
1422 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1423 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1424
1425 ua_chan->tracefile_size = uchan->tracefile_size;
1426 ua_chan->tracefile_count = uchan->tracefile_count;
1427
1428 /* Copy event attributes since the layout is different. */
1429 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1430 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1431 ua_chan->attr.overwrite = uchan->attr.overwrite;
1432 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1433 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1434 ua_chan->attr.output = uchan->attr.output;
1435 /*
1436 * Note that the attribute channel type is not set since the channel on the
1437 * tracing registry side does not have this information.
1438 */
1439
1440 ua_chan->enabled = uchan->enabled;
1441 ua_chan->tracing_channel_id = uchan->id;
1442
1443 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1444 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1445 if (ua_ctx == NULL) {
1446 continue;
1447 }
1448 lttng_ht_node_init_ulong(&ua_ctx->node,
1449 (unsigned long) ua_ctx->ctx.ctx);
1450 lttng_ht_add_unique_ulong(ua_chan->ctx, &ua_ctx->node);
1451 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1452 }
1453
1454 /* Copy all events from ltt ust channel to ust app channel */
1455 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1456 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1457 uevent->filter, uevent->attr.loglevel);
1458 if (ua_event == NULL) {
1459 DBG2("UST event %s not found on shadow copy channel",
1460 uevent->attr.name);
1461 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1462 if (ua_event == NULL) {
1463 continue;
1464 }
1465 shadow_copy_event(ua_event, uevent);
1466 add_unique_ust_app_event(ua_chan, ua_event);
1467 }
1468 }
1469
1470 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1471 }
1472
1473 /*
1474 * Copy data between a UST app session and a regular LTT session.
1475 */
1476 static void shadow_copy_session(struct ust_app_session *ua_sess,
1477 struct ltt_ust_session *usess, struct ust_app *app)
1478 {
1479 struct lttng_ht_node_str *ua_chan_node;
1480 struct lttng_ht_iter iter;
1481 struct ltt_ust_channel *uchan;
1482 struct ust_app_channel *ua_chan;
1483 time_t rawtime;
1484 struct tm *timeinfo;
1485 char datetime[16];
1486 int ret;
1487
1488 /* Get date and time for unique app path */
1489 time(&rawtime);
1490 timeinfo = localtime(&rawtime);
1491 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1492
1493 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1494
1495 ua_sess->tracing_id = usess->id;
1496 ua_sess->id = get_next_session_id();
1497 ua_sess->uid = app->uid;
1498 ua_sess->gid = app->gid;
1499 ua_sess->euid = usess->uid;
1500 ua_sess->egid = usess->gid;
1501 ua_sess->buffer_type = usess->buffer_type;
1502 ua_sess->bits_per_long = app->bits_per_long;
1503 /* There is only one consumer object per session possible. */
1504 ua_sess->consumer = usess->consumer;
1505 ua_sess->output_traces = usess->output_traces;
1506 ua_sess->live_timer_interval = usess->live_timer_interval;
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 /*