784a49ce06f7eb61dd8afa3d8b99bfadaf33c547
[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 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <lttng/ust-error.h>
31 #include <signal.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35
36 #include "buffer-registry.h"
37 #include "fd-limit.h"
38 #include "health-sessiond.h"
39 #include "ust-app.h"
40 #include "ust-consumer.h"
41 #include "ust-ctl.h"
42 #include "utils.h"
43
44 /* Next available channel key. Access under next_channel_key_lock. */
45 static uint64_t _next_channel_key;
46 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
47
48 /* Next available session ID. Access under next_session_id_lock. */
49 static uint64_t _next_session_id;
50 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
51
52 /*
53 * Return the incremented value of next_channel_key.
54 */
55 static uint64_t get_next_channel_key(void)
56 {
57 uint64_t ret;
58
59 pthread_mutex_lock(&next_channel_key_lock);
60 ret = ++_next_channel_key;
61 pthread_mutex_unlock(&next_channel_key_lock);
62 return ret;
63 }
64
65 /*
66 * Return the atomically incremented value of next_session_id.
67 */
68 static uint64_t get_next_session_id(void)
69 {
70 uint64_t ret;
71
72 pthread_mutex_lock(&next_session_id_lock);
73 ret = ++_next_session_id;
74 pthread_mutex_unlock(&next_session_id_lock);
75 return ret;
76 }
77
78 static void copy_channel_attr_to_ustctl(
79 struct ustctl_consumer_channel_attr *attr,
80 struct lttng_ust_channel_attr *uattr)
81 {
82 /* Copy event attributes since the layout is different. */
83 attr->subbuf_size = uattr->subbuf_size;
84 attr->num_subbuf = uattr->num_subbuf;
85 attr->overwrite = uattr->overwrite;
86 attr->switch_timer_interval = uattr->switch_timer_interval;
87 attr->read_timer_interval = uattr->read_timer_interval;
88 attr->output = uattr->output;
89 }
90
91 /*
92 * Match function for the hash table lookup.
93 *
94 * It matches an ust app event based on three attributes which are the event
95 * name, the filter bytecode and the loglevel.
96 */
97 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
98 {
99 struct ust_app_event *event;
100 const struct ust_app_ht_key *key;
101
102 assert(node);
103 assert(_key);
104
105 event = caa_container_of(node, struct ust_app_event, node.node);
106 key = _key;
107
108 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
109
110 /* Event name */
111 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
112 goto no_match;
113 }
114
115 /* Event loglevel. */
116 if (event->attr.loglevel != key->loglevel) {
117 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
118 && key->loglevel == 0 && event->attr.loglevel == -1) {
119 /*
120 * Match is accepted. This is because on event creation, the
121 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
122 * -1 are accepted for this loglevel type since 0 is the one set by
123 * the API when receiving an enable event.
124 */
125 } else {
126 goto no_match;
127 }
128 }
129
130 /* One of the filters is NULL, fail. */
131 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
132 goto no_match;
133 }
134
135 if (key->filter && event->filter) {
136 /* Both filters exists, check length followed by the bytecode. */
137 if (event->filter->len != key->filter->len ||
138 memcmp(event->filter->data, key->filter->data,
139 event->filter->len) != 0) {
140 goto no_match;
141 }
142 }
143
144 /* One of the exclusions is NULL, fail. */
145 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
146 goto no_match;
147 }
148
149 if (key->exclusion && event->exclusion) {
150 /* Both exclusions exists, check count followed by the names. */
151 if (event->exclusion->count != key->exclusion->count ||
152 memcmp(event->exclusion->names, key->exclusion->names,
153 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
154 goto no_match;
155 }
156 }
157
158
159 /* Match. */
160 return 1;
161
162 no_match:
163 return 0;
164 }
165
166 /*
167 * Unique add of an ust app event in the given ht. This uses the custom
168 * ht_match_ust_app_event match function and the event name as hash.
169 */
170 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
171 struct ust_app_event *event)
172 {
173 struct cds_lfht_node *node_ptr;
174 struct ust_app_ht_key key;
175 struct lttng_ht *ht;
176
177 assert(ua_chan);
178 assert(ua_chan->events);
179 assert(event);
180
181 ht = ua_chan->events;
182 key.name = event->attr.name;
183 key.filter = event->filter;
184 key.loglevel = event->attr.loglevel;
185 key.exclusion = event->exclusion;
186
187 node_ptr = cds_lfht_add_unique(ht->ht,
188 ht->hash_fct(event->node.key, lttng_ht_seed),
189 ht_match_ust_app_event, &key, &event->node.node);
190 assert(node_ptr == &event->node.node);
191 }
192
193 /*
194 * Close the notify socket from the given RCU head object. This MUST be called
195 * through a call_rcu().
196 */
197 static void close_notify_sock_rcu(struct rcu_head *head)
198 {
199 int ret;
200 struct ust_app_notify_sock_obj *obj =
201 caa_container_of(head, struct ust_app_notify_sock_obj, head);
202
203 /* Must have a valid fd here. */
204 assert(obj->fd >= 0);
205
206 ret = close(obj->fd);
207 if (ret) {
208 ERR("close notify sock %d RCU", obj->fd);
209 }
210 lttng_fd_put(LTTNG_FD_APPS, 1);
211
212 free(obj);
213 }
214
215 /*
216 * Return the session registry according to the buffer type of the given
217 * session.
218 *
219 * A registry per UID object MUST exists before calling this function or else
220 * it assert() if not found. RCU read side lock must be acquired.
221 */
222 static struct ust_registry_session *get_session_registry(
223 struct ust_app_session *ua_sess)
224 {
225 struct ust_registry_session *registry = NULL;
226
227 assert(ua_sess);
228
229 switch (ua_sess->buffer_type) {
230 case LTTNG_BUFFER_PER_PID:
231 {
232 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
233 if (!reg_pid) {
234 goto error;
235 }
236 registry = reg_pid->registry->reg.ust;
237 break;
238 }
239 case LTTNG_BUFFER_PER_UID:
240 {
241 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
242 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
243 if (!reg_uid) {
244 goto error;
245 }
246 registry = reg_uid->registry->reg.ust;
247 break;
248 }
249 default:
250 assert(0);
251 };
252
253 error:
254 return registry;
255 }
256
257 /*
258 * Delete ust context safely. RCU read lock must be held before calling
259 * this function.
260 */
261 static
262 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
263 {
264 int ret;
265
266 assert(ua_ctx);
267
268 if (ua_ctx->obj) {
269 ret = ustctl_release_object(sock, ua_ctx->obj);
270 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
271 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
272 sock, ua_ctx->obj->handle, ret);
273 }
274 free(ua_ctx->obj);
275 }
276 free(ua_ctx);
277 }
278
279 /*
280 * Delete ust app event safely. RCU read lock must be held before calling
281 * this function.
282 */
283 static
284 void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
285 {
286 int ret;
287
288 assert(ua_event);
289
290 free(ua_event->filter);
291 if (ua_event->exclusion != NULL)
292 free(ua_event->exclusion);
293 if (ua_event->obj != NULL) {
294 ret = ustctl_release_object(sock, ua_event->obj);
295 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
296 ERR("UST app sock %d release event obj failed with ret %d",
297 sock, ret);
298 }
299 free(ua_event->obj);
300 }
301 free(ua_event);
302 }
303
304 /*
305 * Release ust data object of the given stream.
306 *
307 * Return 0 on success or else a negative value.
308 */
309 static int release_ust_app_stream(int sock, struct ust_app_stream *stream)
310 {
311 int ret = 0;
312
313 assert(stream);
314
315 if (stream->obj) {
316 ret = ustctl_release_object(sock, stream->obj);
317 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
318 ERR("UST app sock %d release stream obj failed with ret %d",
319 sock, ret);
320 }
321 lttng_fd_put(LTTNG_FD_APPS, 2);
322 free(stream->obj);
323 }
324
325 return ret;
326 }
327
328 /*
329 * Delete ust app stream safely. RCU read lock must be held before calling
330 * this function.
331 */
332 static
333 void delete_ust_app_stream(int sock, struct ust_app_stream *stream)
334 {
335 assert(stream);
336
337 (void) release_ust_app_stream(sock, stream);
338 free(stream);
339 }
340
341 /*
342 * We need to execute ht_destroy outside of RCU read-side critical
343 * section and outside of call_rcu thread, so we postpone its execution
344 * using ht_cleanup_push. It is simpler than to change the semantic of
345 * the many callers of delete_ust_app_session().
346 */
347 static
348 void delete_ust_app_channel_rcu(struct rcu_head *head)
349 {
350 struct ust_app_channel *ua_chan =
351 caa_container_of(head, struct ust_app_channel, rcu_head);
352
353 ht_cleanup_push(ua_chan->ctx);
354 ht_cleanup_push(ua_chan->events);
355 free(ua_chan);
356 }
357
358 /*
359 * Delete ust app channel safely. RCU read lock must be held before calling
360 * this function.
361 */
362 static
363 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
364 struct ust_app *app)
365 {
366 int ret;
367 struct lttng_ht_iter iter;
368 struct ust_app_event *ua_event;
369 struct ust_app_ctx *ua_ctx;
370 struct ust_app_stream *stream, *stmp;
371 struct ust_registry_session *registry;
372
373 assert(ua_chan);
374
375 DBG3("UST app deleting channel %s", ua_chan->name);
376
377 /* Wipe stream */
378 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
379 cds_list_del(&stream->list);
380 delete_ust_app_stream(sock, stream);
381 }
382
383 /* Wipe context */
384 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
385 cds_list_del(&ua_ctx->list);
386 ret = lttng_ht_del(ua_chan->ctx, &iter);
387 assert(!ret);
388 delete_ust_app_ctx(sock, ua_ctx);
389 }
390
391 /* Wipe events */
392 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
393 node.node) {
394 ret = lttng_ht_del(ua_chan->events, &iter);
395 assert(!ret);
396 delete_ust_app_event(sock, ua_event);
397 }
398
399 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
400 /* Wipe and free registry from session registry. */
401 registry = get_session_registry(ua_chan->session);
402 if (registry) {
403 ust_registry_channel_del_free(registry, ua_chan->key);
404 }
405 }
406
407 if (ua_chan->obj != NULL) {
408 /* Remove channel from application UST object descriptor. */
409 iter.iter.node = &ua_chan->ust_objd_node.node;
410 ret = lttng_ht_del(app->ust_objd, &iter);
411 assert(!ret);
412 ret = ustctl_release_object(sock, ua_chan->obj);
413 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
414 ERR("UST app sock %d release channel obj failed with ret %d",
415 sock, ret);
416 }
417 lttng_fd_put(LTTNG_FD_APPS, 1);
418 free(ua_chan->obj);
419 }
420 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
421 }
422
423 /*
424 * Push metadata to consumer socket.
425 *
426 * The socket lock MUST be acquired.
427 * The ust app session lock MUST be acquired.
428 *
429 * On success, return the len of metadata pushed or else a negative value.
430 */
431 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
432 struct consumer_socket *socket, int send_zero_data)
433 {
434 int ret;
435 char *metadata_str = NULL;
436 size_t len, offset;
437 ssize_t ret_val;
438
439 assert(registry);
440 assert(socket);
441
442 /*
443 * On a push metadata error either the consumer is dead or the metadata
444 * channel has been destroyed because its endpoint might have died (e.g:
445 * relayd). If so, the metadata closed flag is set to 1 so we deny pushing
446 * metadata again which is not valid anymore on the consumer side.
447 *
448 * The ust app session mutex locked allows us to make this check without
449 * the registry lock.
450 */
451 if (registry->metadata_closed) {
452 return -EPIPE;
453 }
454
455 pthread_mutex_lock(&registry->lock);
456
457 offset = registry->metadata_len_sent;
458 len = registry->metadata_len - registry->metadata_len_sent;
459 if (len == 0) {
460 DBG3("No metadata to push for metadata key %" PRIu64,
461 registry->metadata_key);
462 ret_val = len;
463 if (send_zero_data) {
464 DBG("No metadata to push");
465 goto push_data;
466 }
467 goto end;
468 }
469
470 /* Allocate only what we have to send. */
471 metadata_str = zmalloc(len);
472 if (!metadata_str) {
473 PERROR("zmalloc ust app metadata string");
474 ret_val = -ENOMEM;
475 goto error;
476 }
477 /* Copy what we haven't send out. */
478 memcpy(metadata_str, registry->metadata + offset, len);
479 registry->metadata_len_sent += len;
480
481 push_data:
482 pthread_mutex_unlock(&registry->lock);
483 ret = consumer_push_metadata(socket, registry->metadata_key,
484 metadata_str, len, offset);
485 if (ret < 0) {
486 /*
487 * There is an acceptable race here between the registry metadata key
488 * assignment and the creation on the consumer. The session daemon can
489 * concurrently push metadata for this registry while being created on
490 * the consumer since the metadata key of the registry is assigned
491 * *before* it is setup to avoid the consumer to ask for metadata that
492 * could possibly be not found in the session daemon.
493 *
494 * The metadata will get pushed either by the session being stopped or
495 * the consumer requesting metadata if that race is triggered.
496 */
497 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
498 ret = 0;
499 }
500
501 /* Update back the actual metadata len sent since it failed here. */
502 pthread_mutex_lock(&registry->lock);
503 registry->metadata_len_sent -= len;
504 pthread_mutex_unlock(&registry->lock);
505 ret_val = ret;
506 goto error_push;
507 }
508
509 free(metadata_str);
510 return len;
511
512 end:
513 error:
514 pthread_mutex_unlock(&registry->lock);
515 error_push:
516 free(metadata_str);
517 return ret_val;
518 }
519
520 /*
521 * For a given application and session, push metadata to consumer. The session
522 * lock MUST be acquired here before calling this.
523 * Either sock or consumer is required : if sock is NULL, the default
524 * socket to send the metadata is retrieved from consumer, if sock
525 * is not NULL we use it to send the metadata.
526 *
527 * Return 0 on success else a negative error.
528 */
529 static int push_metadata(struct ust_registry_session *registry,
530 struct consumer_output *consumer)
531 {
532 int ret_val;
533 ssize_t ret;
534 struct consumer_socket *socket;
535
536 assert(registry);
537 assert(consumer);
538
539 rcu_read_lock();
540
541 /*
542 * Means that no metadata was assigned to the session. This can happens if
543 * no start has been done previously.
544 */
545 if (!registry->metadata_key) {
546 ret_val = 0;
547 goto end_rcu_unlock;
548 }
549
550 /* Get consumer socket to use to push the metadata.*/
551 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
552 consumer);
553 if (!socket) {
554 ret_val = -1;
555 goto error_rcu_unlock;
556 }
557
558 /*
559 * TODO: Currently, we hold the socket lock around sampling of the next
560 * metadata segment to ensure we send metadata over the consumer socket in
561 * the correct order. This makes the registry lock nest inside the socket
562 * lock.
563 *
564 * Please note that this is a temporary measure: we should move this lock
565 * back into ust_consumer_push_metadata() when the consumer gets the
566 * ability to reorder the metadata it receives.
567 */
568 pthread_mutex_lock(socket->lock);
569 ret = ust_app_push_metadata(registry, socket, 0);
570 pthread_mutex_unlock(socket->lock);
571 if (ret < 0) {
572 ret_val = ret;
573 goto error_rcu_unlock;
574 }
575
576 rcu_read_unlock();
577 return 0;
578
579 error_rcu_unlock:
580 /*
581 * On error, flag the registry that the metadata is closed. We were unable
582 * to push anything and this means that either the consumer is not
583 * responding or the metadata cache has been destroyed on the consumer.
584 */
585 registry->metadata_closed = 1;
586 end_rcu_unlock:
587 rcu_read_unlock();
588 return ret_val;
589 }
590
591 /*
592 * Send to the consumer a close metadata command for the given session. Once
593 * done, the metadata channel is deleted and the session metadata pointer is
594 * nullified. The session lock MUST be acquired here unless the application is
595 * in the destroy path.
596 *
597 * Return 0 on success else a negative value.
598 */
599 static int close_metadata(struct ust_registry_session *registry,
600 struct consumer_output *consumer)
601 {
602 int ret;
603 struct consumer_socket *socket;
604
605 assert(registry);
606 assert(consumer);
607
608 rcu_read_lock();
609
610 if (!registry->metadata_key || registry->metadata_closed) {
611 ret = 0;
612 goto end;
613 }
614
615 /* Get consumer socket to use to push the metadata.*/
616 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
617 consumer);
618 if (!socket) {
619 ret = -1;
620 goto error;
621 }
622
623 ret = consumer_close_metadata(socket, registry->metadata_key);
624 if (ret < 0) {
625 goto error;
626 }
627
628 error:
629 /*
630 * Metadata closed. Even on error this means that the consumer is not
631 * responding or not found so either way a second close should NOT be emit
632 * for this registry.
633 */
634 registry->metadata_closed = 1;
635 end:
636 rcu_read_unlock();
637 return ret;
638 }
639
640 /*
641 * We need to execute ht_destroy outside of RCU read-side critical
642 * section and outside of call_rcu thread, so we postpone its execution
643 * using ht_cleanup_push. It is simpler than to change the semantic of
644 * the many callers of delete_ust_app_session().
645 */
646 static
647 void delete_ust_app_session_rcu(struct rcu_head *head)
648 {
649 struct ust_app_session *ua_sess =
650 caa_container_of(head, struct ust_app_session, rcu_head);
651
652 ht_cleanup_push(ua_sess->channels);
653 free(ua_sess);
654 }
655
656 /*
657 * Delete ust app session safely. RCU read lock must be held before calling
658 * this function.
659 */
660 static
661 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
662 struct ust_app *app)
663 {
664 int ret;
665 struct lttng_ht_iter iter;
666 struct ust_app_channel *ua_chan;
667 struct ust_registry_session *registry;
668
669 assert(ua_sess);
670
671 pthread_mutex_lock(&ua_sess->lock);
672
673 registry = get_session_registry(ua_sess);
674 if (registry && !registry->metadata_closed) {
675 /* Push metadata for application before freeing the application. */
676 (void) push_metadata(registry, ua_sess->consumer);
677
678 /*
679 * Don't ask to close metadata for global per UID buffers. Close
680 * metadata only on destroy trace session in this case. Also, the
681 * previous push metadata could have flag the metadata registry to
682 * close so don't send a close command if closed.
683 */
684 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
685 !registry->metadata_closed) {
686 /* And ask to close it for this session registry. */
687 (void) close_metadata(registry, ua_sess->consumer);
688 }
689 }
690
691 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
692 node.node) {
693 ret = lttng_ht_del(ua_sess->channels, &iter);
694 assert(!ret);
695 delete_ust_app_channel(sock, ua_chan, app);
696 }
697
698 /* In case of per PID, the registry is kept in the session. */
699 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
700 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
701 if (reg_pid) {
702 buffer_reg_pid_remove(reg_pid);
703 buffer_reg_pid_destroy(reg_pid);
704 }
705 }
706
707 if (ua_sess->handle != -1) {
708 ret = ustctl_release_handle(sock, ua_sess->handle);
709 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
710 ERR("UST app sock %d release session handle failed with ret %d",
711 sock, ret);
712 }
713 }
714 pthread_mutex_unlock(&ua_sess->lock);
715
716 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
717 }
718
719 /*
720 * Delete a traceable application structure from the global list. Never call
721 * this function outside of a call_rcu call.
722 *
723 * RCU read side lock should _NOT_ be held when calling this function.
724 */
725 static
726 void delete_ust_app(struct ust_app *app)
727 {
728 int ret, sock;
729 struct ust_app_session *ua_sess, *tmp_ua_sess;
730
731 /* Delete ust app sessions info */
732 sock = app->sock;
733 app->sock = -1;
734
735 /* Wipe sessions */
736 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
737 teardown_node) {
738 /* Free every object in the session and the session. */
739 rcu_read_lock();
740 delete_ust_app_session(sock, ua_sess, app);
741 rcu_read_unlock();
742 }
743
744 ht_cleanup_push(app->sessions);
745 ht_cleanup_push(app->ust_objd);
746
747 /*
748 * Wait until we have deleted the application from the sock hash table
749 * before closing this socket, otherwise an application could re-use the
750 * socket ID and race with the teardown, using the same hash table entry.
751 *
752 * It's OK to leave the close in call_rcu. We want it to stay unique for
753 * all RCU readers that could run concurrently with unregister app,
754 * therefore we _need_ to only close that socket after a grace period. So
755 * it should stay in this RCU callback.
756 *
757 * This close() is a very important step of the synchronization model so
758 * every modification to this function must be carefully reviewed.
759 */
760 ret = close(sock);
761 if (ret) {
762 PERROR("close");
763 }
764 lttng_fd_put(LTTNG_FD_APPS, 1);
765
766 DBG2("UST app pid %d deleted", app->pid);
767 free(app);
768 }
769
770 /*
771 * URCU intermediate call to delete an UST app.
772 */
773 static
774 void delete_ust_app_rcu(struct rcu_head *head)
775 {
776 struct lttng_ht_node_ulong *node =
777 caa_container_of(head, struct lttng_ht_node_ulong, head);
778 struct ust_app *app =
779 caa_container_of(node, struct ust_app, pid_n);
780
781 DBG3("Call RCU deleting app PID %d", app->pid);
782 delete_ust_app(app);
783 }
784
785 /*
786 * Delete the session from the application ht and delete the data structure by
787 * freeing every object inside and releasing them.
788 */
789 static void destroy_app_session(struct ust_app *app,
790 struct ust_app_session *ua_sess)
791 {
792 int ret;
793 struct lttng_ht_iter iter;
794
795 assert(app);
796 assert(ua_sess);
797
798 iter.iter.node = &ua_sess->node.node;
799 ret = lttng_ht_del(app->sessions, &iter);
800 if (ret) {
801 /* Already scheduled for teardown. */
802 goto end;
803 }
804
805 /* Once deleted, free the data structure. */
806 delete_ust_app_session(app->sock, ua_sess, app);
807
808 end:
809 return;
810 }
811
812 /*
813 * Alloc new UST app session.
814 */
815 static
816 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
817 {
818 struct ust_app_session *ua_sess;
819
820 /* Init most of the default value by allocating and zeroing */
821 ua_sess = zmalloc(sizeof(struct ust_app_session));
822 if (ua_sess == NULL) {
823 PERROR("malloc");
824 goto error_free;
825 }
826
827 ua_sess->handle = -1;
828 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
829 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
830 pthread_mutex_init(&ua_sess->lock, NULL);
831
832 return ua_sess;
833
834 error_free:
835 return NULL;
836 }
837
838 /*
839 * Alloc new UST app channel.
840 */
841 static
842 struct ust_app_channel *alloc_ust_app_channel(char *name,
843 struct ust_app_session *ua_sess,
844 struct lttng_ust_channel_attr *attr)
845 {
846 struct ust_app_channel *ua_chan;
847
848 /* Init most of the default value by allocating and zeroing */
849 ua_chan = zmalloc(sizeof(struct ust_app_channel));
850 if (ua_chan == NULL) {
851 PERROR("malloc");
852 goto error;
853 }
854
855 /* Setup channel name */
856 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
857 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
858
859 ua_chan->enabled = 1;
860 ua_chan->handle = -1;
861 ua_chan->session = ua_sess;
862 ua_chan->key = get_next_channel_key();
863 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
864 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
865 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
866
867 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
868 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
869
870 /* Copy attributes */
871 if (attr) {
872 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
873 ua_chan->attr.subbuf_size = attr->subbuf_size;
874 ua_chan->attr.num_subbuf = attr->num_subbuf;
875 ua_chan->attr.overwrite = attr->overwrite;
876 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
877 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
878 ua_chan->attr.output = attr->output;
879 }
880 /* By default, the channel is a per cpu channel. */
881 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
882
883 DBG3("UST app channel %s allocated", ua_chan->name);
884
885 return ua_chan;
886
887 error:
888 return NULL;
889 }
890
891 /*
892 * Allocate and initialize a UST app stream.
893 *
894 * Return newly allocated stream pointer or NULL on error.
895 */
896 struct ust_app_stream *ust_app_alloc_stream(void)
897 {
898 struct ust_app_stream *stream = NULL;
899
900 stream = zmalloc(sizeof(*stream));
901 if (stream == NULL) {
902 PERROR("zmalloc ust app stream");
903 goto error;
904 }
905
906 /* Zero could be a valid value for a handle so flag it to -1. */
907 stream->handle = -1;
908
909 error:
910 return stream;
911 }
912
913 /*
914 * Alloc new UST app event.
915 */
916 static
917 struct ust_app_event *alloc_ust_app_event(char *name,
918 struct lttng_ust_event *attr)
919 {
920 struct ust_app_event *ua_event;
921
922 /* Init most of the default value by allocating and zeroing */
923 ua_event = zmalloc(sizeof(struct ust_app_event));
924 if (ua_event == NULL) {
925 PERROR("malloc");
926 goto error;
927 }
928
929 ua_event->enabled = 1;
930 strncpy(ua_event->name, name, sizeof(ua_event->name));
931 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
932 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
933
934 /* Copy attributes */
935 if (attr) {
936 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
937 }
938
939 DBG3("UST app event %s allocated", ua_event->name);
940
941 return ua_event;
942
943 error:
944 return NULL;
945 }
946
947 /*
948 * Alloc new UST app context.
949 */
950 static
951 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
952 {
953 struct ust_app_ctx *ua_ctx;
954
955 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
956 if (ua_ctx == NULL) {
957 goto error;
958 }
959
960 CDS_INIT_LIST_HEAD(&ua_ctx->list);
961
962 if (uctx) {
963 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
964 }
965
966 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
967
968 error:
969 return ua_ctx;
970 }
971
972 /*
973 * Allocate a filter and copy the given original filter.
974 *
975 * Return allocated filter or NULL on error.
976 */
977 static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
978 struct lttng_ust_filter_bytecode *orig_f)
979 {
980 struct lttng_ust_filter_bytecode *filter = NULL;
981
982 /* Copy filter bytecode */
983 filter = zmalloc(sizeof(*filter) + orig_f->len);
984 if (!filter) {
985 PERROR("zmalloc alloc ust app filter");
986 goto error;
987 }
988
989 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
990
991 error:
992 return filter;
993 }
994
995 /*
996 * Find an ust_app using the sock and return it. RCU read side lock must be
997 * held before calling this helper function.
998 */
999 struct ust_app *ust_app_find_by_sock(int sock)
1000 {
1001 struct lttng_ht_node_ulong *node;
1002 struct lttng_ht_iter iter;
1003
1004 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1005 node = lttng_ht_iter_get_node_ulong(&iter);
1006 if (node == NULL) {
1007 DBG2("UST app find by sock %d not found", sock);
1008 goto error;
1009 }
1010
1011 return caa_container_of(node, struct ust_app, sock_n);
1012
1013 error:
1014 return NULL;
1015 }
1016
1017 /*
1018 * Find an ust_app using the notify sock and return it. RCU read side lock must
1019 * be held before calling this helper function.
1020 */
1021 static struct ust_app *find_app_by_notify_sock(int sock)
1022 {
1023 struct lttng_ht_node_ulong *node;
1024 struct lttng_ht_iter iter;
1025
1026 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1027 &iter);
1028 node = lttng_ht_iter_get_node_ulong(&iter);
1029 if (node == NULL) {
1030 DBG2("UST app find by notify sock %d not found", sock);
1031 goto error;
1032 }
1033
1034 return caa_container_of(node, struct ust_app, notify_sock_n);
1035
1036 error:
1037 return NULL;
1038 }
1039
1040 /*
1041 * Lookup for an ust app event based on event name, filter bytecode and the
1042 * event loglevel.
1043 *
1044 * Return an ust_app_event object or NULL on error.
1045 */
1046 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1047 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel,
1048 const struct lttng_event_exclusion *exclusion)
1049 {
1050 struct lttng_ht_iter iter;
1051 struct lttng_ht_node_str *node;
1052 struct ust_app_event *event = NULL;
1053 struct ust_app_ht_key key;
1054
1055 assert(name);
1056 assert(ht);
1057
1058 /* Setup key for event lookup. */
1059 key.name = name;
1060 key.filter = filter;
1061 key.loglevel = loglevel;
1062 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1063 key.exclusion = (struct lttng_ust_event_exclusion *)exclusion;
1064
1065 /* Lookup using the event name as hash and a custom match fct. */
1066 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1067 ht_match_ust_app_event, &key, &iter.iter);
1068 node = lttng_ht_iter_get_node_str(&iter);
1069 if (node == NULL) {
1070 goto end;
1071 }
1072
1073 event = caa_container_of(node, struct ust_app_event, node);
1074
1075 end:
1076 return event;
1077 }
1078
1079 /*
1080 * Create the channel context on the tracer.
1081 *
1082 * Called with UST app session lock held.
1083 */
1084 static
1085 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1086 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1087 {
1088 int ret;
1089
1090 health_code_update();
1091
1092 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1093 ua_chan->obj, &ua_ctx->obj);
1094 if (ret < 0) {
1095 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1096 ERR("UST app create channel context failed for app (pid: %d) "
1097 "with ret %d", app->pid, ret);
1098 } else {
1099 /*
1100 * This is normal behavior, an application can die during the
1101 * creation process. Don't report an error so the execution can
1102 * continue normally.
1103 */
1104 ret = 0;
1105 DBG3("UST app disable event failed. Application is dead.");
1106 }
1107 goto error;
1108 }
1109
1110 ua_ctx->handle = ua_ctx->obj->handle;
1111
1112 DBG2("UST app context handle %d created successfully for channel %s",
1113 ua_ctx->handle, ua_chan->name);
1114
1115 error:
1116 health_code_update();
1117 return ret;
1118 }
1119
1120 /*
1121 * Set the filter on the tracer.
1122 */
1123 static
1124 int set_ust_event_filter(struct ust_app_event *ua_event,
1125 struct ust_app *app)
1126 {
1127 int ret;
1128
1129 health_code_update();
1130
1131 if (!ua_event->filter) {
1132 ret = 0;
1133 goto error;
1134 }
1135
1136 ret = ustctl_set_filter(app->sock, ua_event->filter,
1137 ua_event->obj);
1138 if (ret < 0) {
1139 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1140 ERR("UST app event %s filter failed for app (pid: %d) "
1141 "with ret %d", ua_event->attr.name, app->pid, ret);
1142 } else {
1143 /*
1144 * This is normal behavior, an application can die during the
1145 * creation process. Don't report an error so the execution can
1146 * continue normally.
1147 */
1148 ret = 0;
1149 DBG3("UST app filter event failed. Application is dead.");
1150 }
1151 goto error;
1152 }
1153
1154 DBG2("UST filter set successfully for event %s", ua_event->name);
1155
1156 error:
1157 health_code_update();
1158 return ret;
1159 }
1160
1161 /*
1162 * Set event exclusions on the tracer.
1163 */
1164 static
1165 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1166 struct ust_app *app)
1167 {
1168 int ret;
1169
1170 health_code_update();
1171
1172 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1173 ret = 0;
1174 goto error;
1175 }
1176
1177 ret = ustctl_set_exclusion(app->sock, ua_event->exclusion,
1178 ua_event->obj);
1179 if (ret < 0) {
1180 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1181 ERR("UST app event %s exclusions failed for app (pid: %d) "
1182 "with ret %d", ua_event->attr.name, app->pid, ret);
1183 } else {
1184 /*
1185 * This is normal behavior, an application can die during the
1186 * creation process. Don't report an error so the execution can
1187 * continue normally.
1188 */
1189 ret = 0;
1190 DBG3("UST app event exclusion failed. Application is dead.");
1191 }
1192 goto error;
1193 }
1194
1195 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1196
1197 error:
1198 health_code_update();
1199 return ret;
1200 }
1201
1202 /*
1203 * Disable the specified event on to UST tracer for the UST session.
1204 */
1205 static int disable_ust_event(struct ust_app *app,
1206 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1207 {
1208 int ret;
1209
1210 health_code_update();
1211
1212 ret = ustctl_disable(app->sock, ua_event->obj);
1213 if (ret < 0) {
1214 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1215 ERR("UST app event %s disable failed for app (pid: %d) "
1216 "and session handle %d with ret %d",
1217 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1218 } else {
1219 /*
1220 * This is normal behavior, an application can die during the
1221 * creation process. Don't report an error so the execution can
1222 * continue normally.
1223 */
1224 ret = 0;
1225 DBG3("UST app disable event failed. Application is dead.");
1226 }
1227 goto error;
1228 }
1229
1230 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1231 ua_event->attr.name, app->pid);
1232
1233 error:
1234 health_code_update();
1235 return ret;
1236 }
1237
1238 /*
1239 * Disable the specified channel on to UST tracer for the UST session.
1240 */
1241 static int disable_ust_channel(struct ust_app *app,
1242 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1243 {
1244 int ret;
1245
1246 health_code_update();
1247
1248 ret = ustctl_disable(app->sock, ua_chan->obj);
1249 if (ret < 0) {
1250 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1251 ERR("UST app channel %s disable failed for app (pid: %d) "
1252 "and session handle %d with ret %d",
1253 ua_chan->name, app->pid, ua_sess->handle, ret);
1254 } else {
1255 /*
1256 * This is normal behavior, an application can die during the
1257 * creation process. Don't report an error so the execution can
1258 * continue normally.
1259 */
1260 ret = 0;
1261 DBG3("UST app disable channel failed. Application is dead.");
1262 }
1263 goto error;
1264 }
1265
1266 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1267 ua_chan->name, app->pid);
1268
1269 error:
1270 health_code_update();
1271 return ret;
1272 }
1273
1274 /*
1275 * Enable the specified channel on to UST tracer for the UST session.
1276 */
1277 static int enable_ust_channel(struct ust_app *app,
1278 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1279 {
1280 int ret;
1281
1282 health_code_update();
1283
1284 ret = ustctl_enable(app->sock, ua_chan->obj);
1285 if (ret < 0) {
1286 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1287 ERR("UST app channel %s enable failed for app (pid: %d) "
1288 "and session handle %d with ret %d",
1289 ua_chan->name, app->pid, ua_sess->handle, ret);
1290 } else {
1291 /*
1292 * This is normal behavior, an application can die during the
1293 * creation process. Don't report an error so the execution can
1294 * continue normally.
1295 */
1296 ret = 0;
1297 DBG3("UST app enable channel failed. Application is dead.");
1298 }
1299 goto error;
1300 }
1301
1302 ua_chan->enabled = 1;
1303
1304 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1305 ua_chan->name, app->pid);
1306
1307 error:
1308 health_code_update();
1309 return ret;
1310 }
1311
1312 /*
1313 * Enable the specified event on to UST tracer for the UST session.
1314 */
1315 static int enable_ust_event(struct ust_app *app,
1316 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1317 {
1318 int ret;
1319
1320 health_code_update();
1321
1322 ret = ustctl_enable(app->sock, ua_event->obj);
1323 if (ret < 0) {
1324 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1325 ERR("UST app event %s enable failed for app (pid: %d) "
1326 "and session handle %d with ret %d",
1327 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1328 } else {
1329 /*
1330 * This is normal behavior, an application can die during the
1331 * creation process. Don't report an error so the execution can
1332 * continue normally.
1333 */
1334 ret = 0;
1335 DBG3("UST app enable event failed. Application is dead.");
1336 }
1337 goto error;
1338 }
1339
1340 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1341 ua_event->attr.name, app->pid);
1342
1343 error:
1344 health_code_update();
1345 return ret;
1346 }
1347
1348 /*
1349 * Send channel and stream buffer to application.
1350 *
1351 * Return 0 on success. On error, a negative value is returned.
1352 */
1353 static int send_channel_pid_to_ust(struct ust_app *app,
1354 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1355 {
1356 int ret;
1357 struct ust_app_stream *stream, *stmp;
1358
1359 assert(app);
1360 assert(ua_sess);
1361 assert(ua_chan);
1362
1363 health_code_update();
1364
1365 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1366 app->sock);
1367
1368 /* Send channel to the application. */
1369 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1370 if (ret < 0) {
1371 goto error;
1372 }
1373
1374 health_code_update();
1375
1376 /* Send all streams to application. */
1377 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1378 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1379 if (ret < 0) {
1380 goto error;
1381 }
1382 /* We don't need the stream anymore once sent to the tracer. */
1383 cds_list_del(&stream->list);
1384 delete_ust_app_stream(-1, stream);
1385 }
1386 /* Flag the channel that it is sent to the application. */
1387 ua_chan->is_sent = 1;
1388
1389 error:
1390 health_code_update();
1391 return ret;
1392 }
1393
1394 /*
1395 * Create the specified event onto the UST tracer for a UST session.
1396 *
1397 * Should be called with session mutex held.
1398 */
1399 static
1400 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1401 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1402 {
1403 int ret = 0;
1404
1405 health_code_update();
1406
1407 /* Create UST event on tracer */
1408 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1409 &ua_event->obj);
1410 if (ret < 0) {
1411 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1412 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1413 ua_event->attr.name, app->pid, ret);
1414 } else {
1415 /*
1416 * This is normal behavior, an application can die during the
1417 * creation process. Don't report an error so the execution can
1418 * continue normally.
1419 */
1420 ret = 0;
1421 DBG3("UST app create event failed. Application is dead.");
1422 }
1423 goto error;
1424 }
1425
1426 ua_event->handle = ua_event->obj->handle;
1427
1428 DBG2("UST app event %s created successfully for pid:%d",
1429 ua_event->attr.name, app->pid);
1430
1431 health_code_update();
1432
1433 /* Set filter if one is present. */
1434 if (ua_event->filter) {
1435 ret = set_ust_event_filter(ua_event, app);
1436 if (ret < 0) {
1437 goto error;
1438 }
1439 }
1440
1441 /* Set exclusions for the event */
1442 if (ua_event->exclusion) {
1443 ret = set_ust_event_exclusion(ua_event, app);
1444 if (ret < 0) {
1445 goto error;
1446 }
1447 }
1448
1449 /* If event not enabled, disable it on the tracer */
1450 if (ua_event->enabled) {
1451 /*
1452 * We now need to explicitly enable the event, since it
1453 * is now disabled at creation.
1454 */
1455 ret = enable_ust_event(app, ua_sess, ua_event);
1456 if (ret < 0) {
1457 /*
1458 * If we hit an EPERM, something is wrong with our enable call. If
1459 * we get an EEXIST, there is a problem on the tracer side since we
1460 * just created it.
1461 */
1462 switch (ret) {
1463 case -LTTNG_UST_ERR_PERM:
1464 /* Code flow problem */
1465 assert(0);
1466 case -LTTNG_UST_ERR_EXIST:
1467 /* It's OK for our use case. */
1468 ret = 0;
1469 break;
1470 default:
1471 break;
1472 }
1473 goto error;
1474 }
1475 }
1476
1477 error:
1478 health_code_update();
1479 return ret;
1480 }
1481
1482 /*
1483 * Copy data between an UST app event and a LTT event.
1484 */
1485 static void shadow_copy_event(struct ust_app_event *ua_event,
1486 struct ltt_ust_event *uevent)
1487 {
1488 size_t exclusion_alloc_size;
1489
1490 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1491 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1492
1493 ua_event->enabled = uevent->enabled;
1494
1495 /* Copy event attributes */
1496 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1497
1498 /* Copy filter bytecode */
1499 if (uevent->filter) {
1500 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1501 /* Filter might be NULL here in case of ENONEM. */
1502 }
1503
1504 /* Copy exclusion data */
1505 if (uevent->exclusion) {
1506 exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1507 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1508 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1509 if (ua_event->exclusion == NULL) {
1510 PERROR("malloc");
1511 } else {
1512 memcpy(ua_event->exclusion, uevent->exclusion,
1513 exclusion_alloc_size);
1514 }
1515 }
1516 }
1517
1518 /*
1519 * Copy data between an UST app channel and a LTT channel.
1520 */
1521 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1522 struct ltt_ust_channel *uchan)
1523 {
1524 struct lttng_ht_iter iter;
1525 struct ltt_ust_event *uevent;
1526 struct ltt_ust_context *uctx;
1527 struct ust_app_event *ua_event;
1528 struct ust_app_ctx *ua_ctx;
1529
1530 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1531
1532 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1533 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1534
1535 ua_chan->tracefile_size = uchan->tracefile_size;
1536 ua_chan->tracefile_count = uchan->tracefile_count;
1537
1538 /* Copy event attributes since the layout is different. */
1539 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1540 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1541 ua_chan->attr.overwrite = uchan->attr.overwrite;
1542 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1543 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1544 ua_chan->attr.output = uchan->attr.output;
1545 /*
1546 * Note that the attribute channel type is not set since the channel on the
1547 * tracing registry side does not have this information.
1548 */
1549
1550 ua_chan->enabled = uchan->enabled;
1551 ua_chan->tracing_channel_id = uchan->id;
1552
1553 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1554 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1555 if (ua_ctx == NULL) {
1556 continue;
1557 }
1558 lttng_ht_node_init_ulong(&ua_ctx->node,
1559 (unsigned long) ua_ctx->ctx.ctx);
1560 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1561 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1562 }
1563
1564 /* Copy all events from ltt ust channel to ust app channel */
1565 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1566 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1567 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1568 if (ua_event == NULL) {
1569 DBG2("UST event %s not found on shadow copy channel",
1570 uevent->attr.name);
1571 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1572 if (ua_event == NULL) {
1573 continue;
1574 }
1575 shadow_copy_event(ua_event, uevent);
1576 add_unique_ust_app_event(ua_chan, ua_event);
1577 }
1578 }
1579
1580 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1581 }
1582
1583 /*
1584 * Copy data between a UST app session and a regular LTT session.
1585 */
1586 static void shadow_copy_session(struct ust_app_session *ua_sess,
1587 struct ltt_ust_session *usess, struct ust_app *app)
1588 {
1589 struct lttng_ht_node_str *ua_chan_node;
1590 struct lttng_ht_iter iter;
1591 struct ltt_ust_channel *uchan;
1592 struct ust_app_channel *ua_chan;
1593 time_t rawtime;
1594 struct tm *timeinfo;
1595 char datetime[16];
1596 int ret;
1597
1598 /* Get date and time for unique app path */
1599 time(&rawtime);
1600 timeinfo = localtime(&rawtime);
1601 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1602
1603 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1604
1605 ua_sess->tracing_id = usess->id;
1606 ua_sess->id = get_next_session_id();
1607 ua_sess->uid = app->uid;
1608 ua_sess->gid = app->gid;
1609 ua_sess->euid = usess->uid;
1610 ua_sess->egid = usess->gid;
1611 ua_sess->buffer_type = usess->buffer_type;
1612 ua_sess->bits_per_long = app->bits_per_long;
1613 /* There is only one consumer object per session possible. */
1614 ua_sess->consumer = usess->consumer;
1615 ua_sess->output_traces = usess->output_traces;
1616 ua_sess->live_timer_interval = usess->live_timer_interval;
1617 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1618 &usess->metadata_attr);
1619
1620 switch (ua_sess->buffer_type) {
1621 case LTTNG_BUFFER_PER_PID:
1622 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1623 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1624 datetime);
1625 break;
1626 case LTTNG_BUFFER_PER_UID:
1627 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1628 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1629 break;
1630 default:
1631 assert(0);
1632 goto error;
1633 }
1634 if (ret < 0) {
1635 PERROR("asprintf UST shadow copy session");
1636 assert(0);
1637 goto error;
1638 }
1639
1640 /* Iterate over all channels in global domain. */
1641 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1642 uchan, node.node) {
1643 struct lttng_ht_iter uiter;
1644
1645 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1646 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1647 if (ua_chan_node != NULL) {
1648 /* Session exist. Contiuing. */
1649 continue;
1650 }
1651
1652 DBG2("Channel %s not found on shadow session copy, creating it",
1653 uchan->name);
1654 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1655 if (ua_chan == NULL) {
1656 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1657 continue;
1658 }
1659 shadow_copy_channel(ua_chan, uchan);
1660 /*
1661 * The concept of metadata channel does not exist on the tracing
1662 * registry side of the session daemon so this can only be a per CPU
1663 * channel and not metadata.
1664 */
1665 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1666
1667 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1668 }
1669
1670 error:
1671 return;
1672 }
1673
1674 /*
1675 * Lookup sesison wrapper.
1676 */
1677 static
1678 void __lookup_session_by_app(struct ltt_ust_session *usess,
1679 struct ust_app *app, struct lttng_ht_iter *iter)
1680 {
1681 /* Get right UST app session from app */
1682 lttng_ht_lookup(app->sessions, &usess->id, iter);
1683 }
1684
1685 /*
1686 * Return ust app session from the app session hashtable using the UST session
1687 * id.
1688 */
1689 static struct ust_app_session *lookup_session_by_app(
1690 struct ltt_ust_session *usess, struct ust_app *app)
1691 {
1692 struct lttng_ht_iter iter;
1693 struct lttng_ht_node_u64 *node;
1694
1695 __lookup_session_by_app(usess, app, &iter);
1696 node = lttng_ht_iter_get_node_u64(&iter);
1697 if (node == NULL) {
1698 goto error;
1699 }
1700
1701 return caa_container_of(node, struct ust_app_session, node);
1702
1703 error:
1704 return NULL;
1705 }
1706
1707 /*
1708 * Setup buffer registry per PID for the given session and application. If none
1709 * is found, a new one is created, added to the global registry and
1710 * initialized. If regp is valid, it's set with the newly created object.
1711 *
1712 * Return 0 on success or else a negative value.
1713 */
1714 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1715 struct ust_app *app, struct buffer_reg_pid **regp)
1716 {
1717 int ret = 0;
1718 struct buffer_reg_pid *reg_pid;
1719
1720 assert(ua_sess);
1721 assert(app);
1722
1723 rcu_read_lock();
1724
1725 reg_pid = buffer_reg_pid_find(ua_sess->id);
1726 if (!reg_pid) {
1727 /*
1728 * This is the create channel path meaning that if there is NO
1729 * registry available, we have to create one for this session.
1730 */
1731 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1732 if (ret < 0) {
1733 goto error;
1734 }
1735 buffer_reg_pid_add(reg_pid);
1736 } else {
1737 goto end;
1738 }
1739
1740 /* Initialize registry. */
1741 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1742 app->bits_per_long, app->uint8_t_alignment,
1743 app->uint16_t_alignment, app->uint32_t_alignment,
1744 app->uint64_t_alignment, app->long_alignment,
1745 app->byte_order, app->version.major,
1746 app->version.minor);
1747 if (ret < 0) {
1748 goto error;
1749 }
1750
1751 DBG3("UST app buffer registry per PID created successfully");
1752
1753 end:
1754 if (regp) {
1755 *regp = reg_pid;
1756 }
1757 error:
1758 rcu_read_unlock();
1759 return ret;
1760 }
1761
1762 /*
1763 * Setup buffer registry per UID for the given session and application. If none
1764 * is found, a new one is created, added to the global registry and
1765 * initialized. If regp is valid, it's set with the newly created object.
1766 *
1767 * Return 0 on success or else a negative value.
1768 */
1769 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1770 struct ust_app *app, struct buffer_reg_uid **regp)
1771 {
1772 int ret = 0;
1773 struct buffer_reg_uid *reg_uid;
1774
1775 assert(usess);
1776 assert(app);
1777
1778 rcu_read_lock();
1779
1780 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1781 if (!reg_uid) {
1782 /*
1783 * This is the create channel path meaning that if there is NO
1784 * registry available, we have to create one for this session.
1785 */
1786 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1787 LTTNG_DOMAIN_UST, &reg_uid);
1788 if (ret < 0) {
1789 goto error;
1790 }
1791 buffer_reg_uid_add(reg_uid);
1792 } else {
1793 goto end;
1794 }
1795
1796 /* Initialize registry. */
1797 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1798 app->bits_per_long, app->uint8_t_alignment,
1799 app->uint16_t_alignment, app->uint32_t_alignment,
1800 app->uint64_t_alignment, app->long_alignment,
1801 app->byte_order, app->version.major,
1802 app->version.minor);
1803 if (ret < 0) {
1804 goto error;
1805 }
1806 /* Add node to teardown list of the session. */
1807 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1808
1809 DBG3("UST app buffer registry per UID created successfully");
1810
1811 end:
1812 if (regp) {
1813 *regp = reg_uid;
1814 }
1815 error:
1816 rcu_read_unlock();
1817 return ret;
1818 }
1819
1820 /*
1821 * Create a session on the tracer side for the given app.
1822 *
1823 * On success, ua_sess_ptr is populated with the session pointer or else left
1824 * untouched. If the session was created, is_created is set to 1. On error,
1825 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1826 * be NULL.
1827 *
1828 * Returns 0 on success or else a negative code which is either -ENOMEM or
1829 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1830 */
1831 static int create_ust_app_session(struct ltt_ust_session *usess,
1832 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1833 int *is_created)
1834 {
1835 int ret, created = 0;
1836 struct ust_app_session *ua_sess;
1837
1838 assert(usess);
1839 assert(app);
1840 assert(ua_sess_ptr);
1841
1842 health_code_update();
1843
1844 ua_sess = lookup_session_by_app(usess, app);
1845 if (ua_sess == NULL) {
1846 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1847 app->pid, usess->id);
1848 ua_sess = alloc_ust_app_session(app);
1849 if (ua_sess == NULL) {
1850 /* Only malloc can failed so something is really wrong */
1851 ret = -ENOMEM;
1852 goto error;
1853 }
1854 shadow_copy_session(ua_sess, usess, app);
1855 created = 1;
1856 }
1857
1858 switch (usess->buffer_type) {
1859 case LTTNG_BUFFER_PER_PID:
1860 /* Init local registry. */
1861 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1862 if (ret < 0) {
1863 goto error;
1864 }
1865 break;
1866 case LTTNG_BUFFER_PER_UID:
1867 /* Look for a global registry. If none exists, create one. */
1868 ret = setup_buffer_reg_uid(usess, app, NULL);
1869 if (ret < 0) {
1870 goto error;
1871 }
1872 break;
1873 default:
1874 assert(0);
1875 ret = -EINVAL;
1876 goto error;
1877 }
1878
1879 health_code_update();
1880
1881 if (ua_sess->handle == -1) {
1882 ret = ustctl_create_session(app->sock);
1883 if (ret < 0) {
1884 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1885 ERR("Creating session for app pid %d with ret %d",
1886 app->pid, ret);
1887 } else {
1888 DBG("UST app creating session failed. Application is dead");
1889 /*
1890 * This is normal behavior, an application can die during the
1891 * creation process. Don't report an error so the execution can
1892 * continue normally. This will get flagged ENOTCONN and the
1893 * caller will handle it.
1894 */
1895 ret = 0;
1896 }
1897 delete_ust_app_session(-1, ua_sess, app);
1898 if (ret != -ENOMEM) {
1899 /*
1900 * Tracer is probably gone or got an internal error so let's
1901 * behave like it will soon unregister or not usable.
1902 */
1903 ret = -ENOTCONN;
1904 }
1905 goto error;
1906 }
1907
1908 ua_sess->handle = ret;
1909
1910 /* Add ust app session to app's HT */
1911 lttng_ht_node_init_u64(&ua_sess->node,
1912 ua_sess->tracing_id);
1913 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1914
1915 DBG2("UST app session created successfully with handle %d", ret);
1916 }
1917
1918 *ua_sess_ptr = ua_sess;
1919 if (is_created) {
1920 *is_created = created;
1921 }
1922
1923 /* Everything went well. */
1924 ret = 0;
1925
1926 error:
1927 health_code_update();
1928 return ret;
1929 }
1930
1931 /*
1932 * Match function for a hash table lookup of ust_app_ctx.
1933 *
1934 * It matches an ust app context based on the context type and, in the case
1935 * of perf counters, their name.
1936 */
1937 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
1938 {
1939 struct ust_app_ctx *ctx;
1940 const struct lttng_ust_context *key;
1941
1942 assert(node);
1943 assert(_key);
1944
1945 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
1946 key = _key;
1947
1948 /* Context type */
1949 if (ctx->ctx.ctx != key->ctx) {
1950 goto no_match;
1951 }
1952
1953 /* Check the name in the case of perf thread counters. */
1954 if (key->ctx == LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER) {
1955 if (strncmp(key->u.perf_counter.name,
1956 ctx->ctx.u.perf_counter.name,
1957 sizeof(key->u.perf_counter.name))) {
1958 goto no_match;
1959 }
1960 }
1961
1962 /* Match. */
1963 return 1;
1964
1965 no_match:
1966 return 0;
1967 }
1968
1969 /*
1970 * Lookup for an ust app context from an lttng_ust_context.
1971 *
1972 * Return an ust_app_ctx object or NULL on error.
1973 */
1974 static
1975 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
1976 struct lttng_ust_context *uctx)
1977 {
1978 struct lttng_ht_iter iter;
1979 struct lttng_ht_node_ulong *node;
1980 struct ust_app_ctx *app_ctx = NULL;
1981
1982 assert(uctx);
1983 assert(ht);
1984
1985 /* Lookup using the lttng_ust_context_type and a custom match fct. */
1986 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
1987 ht_match_ust_app_ctx, uctx, &iter.iter);
1988 node = lttng_ht_iter_get_node_ulong(&iter);
1989 if (!node) {
1990 goto end;
1991 }
1992
1993 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
1994
1995 end:
1996 return app_ctx;
1997 }
1998
1999 /*
2000 * Create a context for the channel on the tracer.
2001 *
2002 * Called with UST app session lock held and a RCU read side lock.
2003 */
2004 static
2005 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
2006 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
2007 struct ust_app *app)
2008 {
2009 int ret = 0;
2010 struct ust_app_ctx *ua_ctx;
2011
2012 DBG2("UST app adding context to channel %s", ua_chan->name);
2013
2014 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2015 if (ua_ctx) {
2016 ret = -EEXIST;
2017 goto error;
2018 }
2019
2020 ua_ctx = alloc_ust_app_ctx(uctx);
2021 if (ua_ctx == NULL) {
2022 /* malloc failed */
2023 ret = -1;
2024 goto error;
2025 }
2026
2027 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2028 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2029 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2030
2031 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2032 if (ret < 0) {
2033 goto error;
2034 }
2035
2036 error:
2037 return ret;
2038 }
2039
2040 /*
2041 * Enable on the tracer side a ust app event for the session and channel.
2042 *
2043 * Called with UST app session lock held.
2044 */
2045 static
2046 int enable_ust_app_event(struct ust_app_session *ua_sess,
2047 struct ust_app_event *ua_event, struct ust_app *app)
2048 {
2049 int ret;
2050
2051 ret = enable_ust_event(app, ua_sess, ua_event);
2052 if (ret < 0) {
2053 goto error;
2054 }
2055
2056 ua_event->enabled = 1;
2057
2058 error:
2059 return ret;
2060 }
2061
2062 /*
2063 * Disable on the tracer side a ust app event for the session and channel.
2064 */
2065 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2066 struct ust_app_event *ua_event, struct ust_app *app)
2067 {
2068 int ret;
2069
2070 ret = disable_ust_event(app, ua_sess, ua_event);
2071 if (ret < 0) {
2072 goto error;
2073 }
2074
2075 ua_event->enabled = 0;
2076
2077 error:
2078 return ret;
2079 }
2080
2081 /*
2082 * Lookup ust app channel for session and disable it on the tracer side.
2083 */
2084 static
2085 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2086 struct ust_app_channel *ua_chan, struct ust_app *app)
2087 {
2088 int ret;
2089
2090 ret = disable_ust_channel(app, ua_sess, ua_chan);
2091 if (ret < 0) {
2092 goto error;
2093 }
2094
2095 ua_chan->enabled = 0;
2096
2097 error:
2098 return ret;
2099 }
2100
2101 /*
2102 * Lookup ust app channel for session and enable it on the tracer side. This
2103 * MUST be called with a RCU read side lock acquired.
2104 */
2105 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2106 struct ltt_ust_channel *uchan, struct ust_app *app)
2107 {
2108 int ret = 0;
2109 struct lttng_ht_iter iter;
2110 struct lttng_ht_node_str *ua_chan_node;
2111 struct ust_app_channel *ua_chan;
2112
2113 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2114 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2115 if (ua_chan_node == NULL) {
2116 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2117 uchan->name, ua_sess->tracing_id);
2118 goto error;
2119 }
2120
2121 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2122
2123 ret = enable_ust_channel(app, ua_sess, ua_chan);
2124 if (ret < 0) {
2125 goto error;
2126 }
2127
2128 error:
2129 return ret;
2130 }
2131
2132 /*
2133 * Ask the consumer to create a channel and get it if successful.
2134 *
2135 * Return 0 on success or else a negative value.
2136 */
2137 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2138 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2139 int bitness, struct ust_registry_session *registry)
2140 {
2141 int ret;
2142 unsigned int nb_fd = 0;
2143 struct consumer_socket *socket;
2144
2145 assert(usess);
2146 assert(ua_sess);
2147 assert(ua_chan);
2148 assert(registry);
2149
2150 rcu_read_lock();
2151 health_code_update();
2152
2153 /* Get the right consumer socket for the application. */
2154 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2155 if (!socket) {
2156 ret = -EINVAL;
2157 goto error;
2158 }
2159
2160 health_code_update();
2161
2162 /* Need one fd for the channel. */
2163 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2164 if (ret < 0) {
2165 ERR("Exhausted number of available FD upon create channel");
2166 goto error;
2167 }
2168
2169 /*
2170 * Ask consumer to create channel. The consumer will return the number of
2171 * stream we have to expect.
2172 */
2173 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2174 registry);
2175 if (ret < 0) {
2176 goto error_ask;
2177 }
2178
2179 /*
2180 * Compute the number of fd needed before receiving them. It must be 2 per
2181 * stream (2 being the default value here).
2182 */
2183 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2184
2185 /* Reserve the amount of file descriptor we need. */
2186 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2187 if (ret < 0) {
2188 ERR("Exhausted number of available FD upon create channel");
2189 goto error_fd_get_stream;
2190 }
2191
2192 health_code_update();
2193
2194 /*
2195 * Now get the channel from the consumer. This call wil populate the stream
2196 * list of that channel and set the ust objects.
2197 */
2198 if (usess->consumer->enabled) {
2199 ret = ust_consumer_get_channel(socket, ua_chan);
2200 if (ret < 0) {
2201 goto error_destroy;
2202 }
2203 }
2204
2205 rcu_read_unlock();
2206 return 0;
2207
2208 error_destroy:
2209 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2210 error_fd_get_stream:
2211 /*
2212 * Initiate a destroy channel on the consumer since we had an error
2213 * handling it on our side. The return value is of no importance since we
2214 * already have a ret value set by the previous error that we need to
2215 * return.
2216 */
2217 (void) ust_consumer_destroy_channel(socket, ua_chan);
2218 error_ask:
2219 lttng_fd_put(LTTNG_FD_APPS, 1);
2220 error:
2221 health_code_update();
2222 rcu_read_unlock();
2223 return ret;
2224 }
2225
2226 /*
2227 * Duplicate the ust data object of the ust app stream and save it in the
2228 * buffer registry stream.
2229 *
2230 * Return 0 on success or else a negative value.
2231 */
2232 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2233 struct ust_app_stream *stream)
2234 {
2235 int ret;
2236
2237 assert(reg_stream);
2238 assert(stream);
2239
2240 /* Reserve the amount of file descriptor we need. */
2241 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2242 if (ret < 0) {
2243 ERR("Exhausted number of available FD upon duplicate stream");
2244 goto error;
2245 }
2246
2247 /* Duplicate object for stream once the original is in the registry. */
2248 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2249 reg_stream->obj.ust);
2250 if (ret < 0) {
2251 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2252 reg_stream->obj.ust, stream->obj, ret);
2253 lttng_fd_put(LTTNG_FD_APPS, 2);
2254 goto error;
2255 }
2256 stream->handle = stream->obj->handle;
2257
2258 error:
2259 return ret;
2260 }
2261
2262 /*
2263 * Duplicate the ust data object of the ust app. channel and save it in the
2264 * buffer registry channel.
2265 *
2266 * Return 0 on success or else a negative value.
2267 */
2268 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2269 struct ust_app_channel *ua_chan)
2270 {
2271 int ret;
2272
2273 assert(reg_chan);
2274 assert(ua_chan);
2275
2276 /* Need two fds for the channel. */
2277 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2278 if (ret < 0) {
2279 ERR("Exhausted number of available FD upon duplicate channel");
2280 goto error_fd_get;
2281 }
2282
2283 /* Duplicate object for stream once the original is in the registry. */
2284 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2285 if (ret < 0) {
2286 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2287 reg_chan->obj.ust, ua_chan->obj, ret);
2288 goto error;
2289 }
2290 ua_chan->handle = ua_chan->obj->handle;
2291
2292 return 0;
2293
2294 error:
2295 lttng_fd_put(LTTNG_FD_APPS, 1);
2296 error_fd_get:
2297 return ret;
2298 }
2299
2300 /*
2301 * For a given channel buffer registry, setup all streams of the given ust
2302 * application channel.
2303 *
2304 * Return 0 on success or else a negative value.
2305 */
2306 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2307 struct ust_app_channel *ua_chan)
2308 {
2309 int ret = 0;
2310 struct ust_app_stream *stream, *stmp;
2311
2312 assert(reg_chan);
2313 assert(ua_chan);
2314
2315 DBG2("UST app setup buffer registry stream");
2316
2317 /* Send all streams to application. */
2318 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2319 struct buffer_reg_stream *reg_stream;
2320
2321 ret = buffer_reg_stream_create(&reg_stream);
2322 if (ret < 0) {
2323 goto error;
2324 }
2325
2326 /*
2327 * Keep original pointer and nullify it in the stream so the delete
2328 * stream call does not release the object.
2329 */
2330 reg_stream->obj.ust = stream->obj;
2331 stream->obj = NULL;
2332 buffer_reg_stream_add(reg_stream, reg_chan);
2333
2334 /* We don't need the streams anymore. */
2335 cds_list_del(&stream->list);
2336 delete_ust_app_stream(-1, stream);
2337 }
2338
2339 error:
2340 return ret;
2341 }
2342
2343 /*
2344 * Create a buffer registry channel for the given session registry and
2345 * application channel object. If regp pointer is valid, it's set with the
2346 * created object. Important, the created object is NOT added to the session
2347 * registry hash table.
2348 *
2349 * Return 0 on success else a negative value.
2350 */
2351 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2352 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2353 {
2354 int ret;
2355 struct buffer_reg_channel *reg_chan = NULL;
2356
2357 assert(reg_sess);
2358 assert(ua_chan);
2359
2360 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2361
2362 /* Create buffer registry channel. */
2363 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2364 if (ret < 0) {
2365 goto error_create;
2366 }
2367 assert(reg_chan);
2368 reg_chan->consumer_key = ua_chan->key;
2369 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2370
2371 /* Create and add a channel registry to session. */
2372 ret = ust_registry_channel_add(reg_sess->reg.ust,
2373 ua_chan->tracing_channel_id);
2374 if (ret < 0) {
2375 goto error;
2376 }
2377 buffer_reg_channel_add(reg_sess, reg_chan);
2378
2379 if (regp) {
2380 *regp = reg_chan;
2381 }
2382
2383 return 0;
2384
2385 error:
2386 /* Safe because the registry channel object was not added to any HT. */
2387 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2388 error_create:
2389 return ret;
2390 }
2391
2392 /*
2393 * Setup buffer registry channel for the given session registry and application
2394 * channel object. If regp pointer is valid, it's set with the created object.
2395 *
2396 * Return 0 on success else a negative value.
2397 */
2398 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2399 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2400 {
2401 int ret;
2402
2403 assert(reg_sess);
2404 assert(reg_chan);
2405 assert(ua_chan);
2406 assert(ua_chan->obj);
2407
2408 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2409
2410 /* Setup all streams for the registry. */
2411 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2412 if (ret < 0) {
2413 goto error;
2414 }
2415
2416 reg_chan->obj.ust = ua_chan->obj;
2417 ua_chan->obj = NULL;
2418
2419 return 0;
2420
2421 error:
2422 buffer_reg_channel_remove(reg_sess, reg_chan);
2423 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2424 return ret;
2425 }
2426
2427 /*
2428 * Send buffer registry channel to the application.
2429 *
2430 * Return 0 on success else a negative value.
2431 */
2432 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2433 struct ust_app *app, struct ust_app_session *ua_sess,
2434 struct ust_app_channel *ua_chan)
2435 {
2436 int ret;
2437 struct buffer_reg_stream *reg_stream;
2438
2439 assert(reg_chan);
2440 assert(app);
2441 assert(ua_sess);
2442 assert(ua_chan);
2443
2444 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2445
2446 ret = duplicate_channel_object(reg_chan, ua_chan);
2447 if (ret < 0) {
2448 goto error;
2449 }
2450
2451 /* Send channel to the application. */
2452 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2453 if (ret < 0) {
2454 goto error;
2455 }
2456
2457 health_code_update();
2458
2459 /* Send all streams to application. */
2460 pthread_mutex_lock(&reg_chan->stream_list_lock);
2461 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2462 struct ust_app_stream stream;
2463
2464 ret = duplicate_stream_object(reg_stream, &stream);
2465 if (ret < 0) {
2466 goto error_stream_unlock;
2467 }
2468
2469 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2470 if (ret < 0) {
2471 (void) release_ust_app_stream(-1, &stream);
2472 goto error_stream_unlock;
2473 }
2474
2475 /*
2476 * The return value is not important here. This function will output an
2477 * error if needed.
2478 */
2479 (void) release_ust_app_stream(-1, &stream);
2480 }
2481 ua_chan->is_sent = 1;
2482
2483 error_stream_unlock:
2484 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2485 error:
2486 return ret;
2487 }
2488
2489 /*
2490 * Create and send to the application the created buffers with per UID buffers.
2491 *
2492 * Return 0 on success else a negative value.
2493 */
2494 static int create_channel_per_uid(struct ust_app *app,
2495 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2496 struct ust_app_channel *ua_chan)
2497 {
2498 int ret;
2499 struct buffer_reg_uid *reg_uid;
2500 struct buffer_reg_channel *reg_chan;
2501
2502 assert(app);
2503 assert(usess);
2504 assert(ua_sess);
2505 assert(ua_chan);
2506
2507 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2508
2509 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2510 /*
2511 * The session creation handles the creation of this global registry
2512 * object. If none can be find, there is a code flow problem or a
2513 * teardown race.
2514 */
2515 assert(reg_uid);
2516
2517 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2518 reg_uid);
2519 if (!reg_chan) {
2520 /* Create the buffer registry channel object. */
2521 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2522 if (ret < 0) {
2523 ERR("Error creating the UST channel \"%s\" registry instance",
2524 ua_chan->name);
2525 goto error;
2526 }
2527 assert(reg_chan);
2528
2529 /*
2530 * Create the buffers on the consumer side. This call populates the
2531 * ust app channel object with all streams and data object.
2532 */
2533 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2534 app->bits_per_long, reg_uid->registry->reg.ust);
2535 if (ret < 0) {
2536 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2537 ua_chan->name);
2538
2539 /*
2540 * Let's remove the previously created buffer registry channel so
2541 * it's not visible anymore in the session registry.
2542 */
2543 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2544 ua_chan->tracing_channel_id);
2545 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2546 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2547 goto error;
2548 }
2549
2550 /*
2551 * Setup the streams and add it to the session registry.
2552 */
2553 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2554 if (ret < 0) {
2555 ERR("Error setting up UST channel \"%s\"",
2556 ua_chan->name);
2557 goto error;
2558 }
2559
2560 }
2561
2562 /* Send buffers to the application. */
2563 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2564 if (ret < 0) {
2565 /*
2566 * Don't report error to the console, since it may be
2567 * caused by application concurrently exiting.
2568 */
2569 goto error;
2570 }
2571
2572 error:
2573 return ret;
2574 }
2575
2576 /*
2577 * Create and send to the application the created buffers with per PID buffers.
2578 *
2579 * Return 0 on success else a negative value.
2580 */
2581 static int create_channel_per_pid(struct ust_app *app,
2582 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2583 struct ust_app_channel *ua_chan)
2584 {
2585 int ret;
2586 struct ust_registry_session *registry;
2587
2588 assert(app);
2589 assert(usess);
2590 assert(ua_sess);
2591 assert(ua_chan);
2592
2593 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2594
2595 rcu_read_lock();
2596
2597 registry = get_session_registry(ua_sess);
2598 assert(registry);
2599
2600 /* Create and add a new channel registry to session. */
2601 ret = ust_registry_channel_add(registry, ua_chan->key);
2602 if (ret < 0) {
2603 ERR("Error creating the UST channel \"%s\" registry instance",
2604 ua_chan->name);
2605 goto error;
2606 }
2607
2608 /* Create and get channel on the consumer side. */
2609 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2610 app->bits_per_long, registry);
2611 if (ret < 0) {
2612 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2613 ua_chan->name);
2614 goto error;
2615 }
2616
2617 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2618 if (ret < 0) {
2619 /*
2620 * Don't report error to the console, since it may be
2621 * caused by application concurrently exiting.
2622 */
2623 goto error;
2624 }
2625
2626 error:
2627 rcu_read_unlock();
2628 return ret;
2629 }
2630
2631 /*
2632 * From an already allocated ust app channel, create the channel buffers if
2633 * need and send it to the application. This MUST be called with a RCU read
2634 * side lock acquired.
2635 *
2636 * Return 0 on success or else a negative value.
2637 */
2638 static int do_create_channel(struct ust_app *app,
2639 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2640 struct ust_app_channel *ua_chan)
2641 {
2642 int ret;
2643
2644 assert(app);
2645 assert(usess);
2646 assert(ua_sess);
2647 assert(ua_chan);
2648
2649 /* Handle buffer type before sending the channel to the application. */
2650 switch (usess->buffer_type) {
2651 case LTTNG_BUFFER_PER_UID:
2652 {
2653 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2654 if (ret < 0) {
2655 goto error;
2656 }
2657 break;
2658 }
2659 case LTTNG_BUFFER_PER_PID:
2660 {
2661 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2662 if (ret < 0) {
2663 goto error;
2664 }
2665 break;
2666 }
2667 default:
2668 assert(0);
2669 ret = -EINVAL;
2670 goto error;
2671 }
2672
2673 /* Initialize ust objd object using the received handle and add it. */
2674 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2675 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2676
2677 /* If channel is not enabled, disable it on the tracer */
2678 if (!ua_chan->enabled) {
2679 ret = disable_ust_channel(app, ua_sess, ua_chan);
2680 if (ret < 0) {
2681 goto error;
2682 }
2683 }
2684
2685 error:
2686 return ret;
2687 }
2688
2689 /*
2690 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2691 * newly created channel if not NULL.
2692 *
2693 * Called with UST app session lock and RCU read-side lock held.
2694 *
2695 * Return 0 on success or else a negative value.
2696 */
2697 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2698 struct ltt_ust_channel *uchan, struct ust_app *app,
2699 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2700 struct ust_app_channel **ua_chanp)
2701 {
2702 int ret = 0;
2703 struct lttng_ht_iter iter;
2704 struct lttng_ht_node_str *ua_chan_node;
2705 struct ust_app_channel *ua_chan;
2706
2707 /* Lookup channel in the ust app session */
2708 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2709 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2710 if (ua_chan_node != NULL) {
2711 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2712 goto end;
2713 }
2714
2715 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2716 if (ua_chan == NULL) {
2717 /* Only malloc can fail here */
2718 ret = -ENOMEM;
2719 goto error_alloc;
2720 }
2721 shadow_copy_channel(ua_chan, uchan);
2722
2723 /* Set channel type. */
2724 ua_chan->attr.type = type;
2725
2726 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2727 if (ret < 0) {
2728 goto error;
2729 }
2730
2731 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2732 app->pid);
2733
2734 /* Only add the channel if successful on the tracer side. */
2735 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2736
2737 end:
2738 if (ua_chanp) {
2739 *ua_chanp = ua_chan;
2740 }
2741
2742 /* Everything went well. */
2743 return 0;
2744
2745 error:
2746 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2747 error_alloc:
2748 return ret;
2749 }
2750
2751 /*
2752 * Create UST app event and create it on the tracer side.
2753 *
2754 * Called with ust app session mutex held.
2755 */
2756 static
2757 int create_ust_app_event(struct ust_app_session *ua_sess,
2758 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2759 struct ust_app *app)
2760 {
2761 int ret = 0;
2762 struct ust_app_event *ua_event;
2763
2764 /* Get event node */
2765 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2766 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
2767 if (ua_event != NULL) {
2768 ret = -EEXIST;
2769 goto end;
2770 }
2771
2772 /* Does not exist so create one */
2773 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2774 if (ua_event == NULL) {
2775 /* Only malloc can failed so something is really wrong */
2776 ret = -ENOMEM;
2777 goto end;
2778 }
2779 shadow_copy_event(ua_event, uevent);
2780
2781 /* Create it on the tracer side */
2782 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2783 if (ret < 0) {
2784 /* Not found previously means that it does not exist on the tracer */
2785 assert(ret != -LTTNG_UST_ERR_EXIST);
2786 goto error;
2787 }
2788
2789 add_unique_ust_app_event(ua_chan, ua_event);
2790
2791 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2792 app->pid);
2793
2794 end:
2795 return ret;
2796
2797 error:
2798 /* Valid. Calling here is already in a read side lock */
2799 delete_ust_app_event(-1, ua_event);
2800 return ret;
2801 }
2802
2803 /*
2804 * Create UST metadata and open it on the tracer side.
2805 *
2806 * Called with UST app session lock held and RCU read side lock.
2807 */
2808 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2809 struct ust_app *app, struct consumer_output *consumer)
2810 {
2811 int ret = 0;
2812 struct ust_app_channel *metadata;
2813 struct consumer_socket *socket;
2814 struct ust_registry_session *registry;
2815
2816 assert(ua_sess);
2817 assert(app);
2818 assert(consumer);
2819
2820 registry = get_session_registry(ua_sess);
2821 assert(registry);
2822
2823 /* Metadata already exists for this registry or it was closed previously */
2824 if (registry->metadata_key || registry->metadata_closed) {
2825 ret = 0;
2826 goto error;
2827 }
2828
2829 /* Allocate UST metadata */
2830 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2831 if (!metadata) {
2832 /* malloc() failed */
2833 ret = -ENOMEM;
2834 goto error;
2835 }
2836
2837 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
2838
2839 /* Need one fd for the channel. */
2840 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2841 if (ret < 0) {
2842 ERR("Exhausted number of available FD upon create metadata");
2843 goto error;
2844 }
2845
2846 /* Get the right consumer socket for the application. */
2847 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2848 if (!socket) {
2849 ret = -EINVAL;
2850 goto error_consumer;
2851 }
2852
2853 /*
2854 * Keep metadata key so we can identify it on the consumer side. Assign it
2855 * to the registry *before* we ask the consumer so we avoid the race of the
2856 * consumer requesting the metadata and the ask_channel call on our side
2857 * did not returned yet.
2858 */
2859 registry->metadata_key = metadata->key;
2860
2861 /*
2862 * Ask the metadata channel creation to the consumer. The metadata object
2863 * will be created by the consumer and kept their. However, the stream is
2864 * never added or monitored until we do a first push metadata to the
2865 * consumer.
2866 */
2867 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2868 registry);
2869 if (ret < 0) {
2870 /* Nullify the metadata key so we don't try to close it later on. */
2871 registry->metadata_key = 0;
2872 goto error_consumer;
2873 }
2874
2875 /*
2876 * The setup command will make the metadata stream be sent to the relayd,
2877 * if applicable, and the thread managing the metadatas. This is important
2878 * because after this point, if an error occurs, the only way the stream
2879 * can be deleted is to be monitored in the consumer.
2880 */
2881 ret = consumer_setup_metadata(socket, metadata->key);
2882 if (ret < 0) {
2883 /* Nullify the metadata key so we don't try to close it later on. */
2884 registry->metadata_key = 0;
2885 goto error_consumer;
2886 }
2887
2888 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2889 metadata->key, app->pid);
2890
2891 error_consumer:
2892 lttng_fd_put(LTTNG_FD_APPS, 1);
2893 delete_ust_app_channel(-1, metadata, app);
2894 error:
2895 return ret;
2896 }
2897
2898 /*
2899 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2900 * acquired before calling this function.
2901 */
2902 struct ust_app *ust_app_find_by_pid(pid_t pid)
2903 {
2904 struct ust_app *app = NULL;
2905 struct lttng_ht_node_ulong *node;
2906 struct lttng_ht_iter iter;
2907
2908 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2909 node = lttng_ht_iter_get_node_ulong(&iter);
2910 if (node == NULL) {
2911 DBG2("UST app no found with pid %d", pid);
2912 goto error;
2913 }
2914
2915 DBG2("Found UST app by pid %d", pid);
2916
2917 app = caa_container_of(node, struct ust_app, pid_n);
2918
2919 error:
2920 return app;
2921 }
2922
2923 /*
2924 * Allocate and init an UST app object using the registration information and
2925 * the command socket. This is called when the command socket connects to the
2926 * session daemon.
2927 *
2928 * The object is returned on success or else NULL.
2929 */
2930 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2931 {
2932 struct ust_app *lta = NULL;
2933
2934 assert(msg);
2935 assert(sock >= 0);
2936
2937 DBG3("UST app creating application for socket %d", sock);
2938
2939 if ((msg->bits_per_long == 64 &&
2940 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2941 || (msg->bits_per_long == 32 &&
2942 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2943 ERR("Registration failed: application \"%s\" (pid: %d) has "
2944 "%d-bit long, but no consumerd for this size is available.\n",
2945 msg->name, msg->pid, msg->bits_per_long);
2946 goto error;
2947 }
2948
2949 lta = zmalloc(sizeof(struct ust_app));
2950 if (lta == NULL) {
2951 PERROR("malloc");
2952 goto error;
2953 }
2954
2955 lta->ppid = msg->ppid;
2956 lta->uid = msg->uid;
2957 lta->gid = msg->gid;
2958
2959 lta->bits_per_long = msg->bits_per_long;
2960 lta->uint8_t_alignment = msg->uint8_t_alignment;
2961 lta->uint16_t_alignment = msg->uint16_t_alignment;
2962 lta->uint32_t_alignment = msg->uint32_t_alignment;
2963 lta->uint64_t_alignment = msg->uint64_t_alignment;
2964 lta->long_alignment = msg->long_alignment;
2965 lta->byte_order = msg->byte_order;
2966
2967 lta->v_major = msg->major;
2968 lta->v_minor = msg->minor;
2969 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2970 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2971 lta->notify_sock = -1;
2972
2973 /* Copy name and make sure it's NULL terminated. */
2974 strncpy(lta->name, msg->name, sizeof(lta->name));
2975 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2976
2977 /*
2978 * Before this can be called, when receiving the registration information,
2979 * the application compatibility is checked. So, at this point, the
2980 * application can work with this session daemon.
2981 */
2982 lta->compatible = 1;
2983
2984 lta->pid = msg->pid;
2985 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
2986 lta->sock = sock;
2987 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
2988
2989 CDS_INIT_LIST_HEAD(&lta->teardown_head);
2990
2991 error:
2992 return lta;
2993 }
2994
2995 /*
2996 * For a given application object, add it to every hash table.
2997 */
2998 void ust_app_add(struct ust_app *app)
2999 {
3000 assert(app);
3001 assert(app->notify_sock >= 0);
3002
3003 rcu_read_lock();
3004
3005 /*
3006 * On a re-registration, we want to kick out the previous registration of
3007 * that pid
3008 */
3009 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3010
3011 /*
3012 * The socket _should_ be unique until _we_ call close. So, a add_unique
3013 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3014 * already in the table.
3015 */
3016 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3017
3018 /* Add application to the notify socket hash table. */
3019 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3020 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3021
3022 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3023 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3024 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3025 app->v_minor);
3026
3027 rcu_read_unlock();
3028 }
3029
3030 /*
3031 * Set the application version into the object.
3032 *
3033 * Return 0 on success else a negative value either an errno code or a
3034 * LTTng-UST error code.
3035 */
3036 int ust_app_version(struct ust_app *app)
3037 {
3038 int ret;
3039
3040 assert(app);
3041
3042 ret = ustctl_tracer_version(app->sock, &app->version);
3043 if (ret < 0) {
3044 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3045 ERR("UST app %d version failed with ret %d", app->sock, ret);
3046 } else {
3047 DBG3("UST app %d version failed. Application is dead", app->sock);
3048 }
3049 }
3050
3051 return ret;
3052 }
3053
3054 /*
3055 * Unregister app by removing it from the global traceable app list and freeing
3056 * the data struct.
3057 *
3058 * The socket is already closed at this point so no close to sock.
3059 */
3060 void ust_app_unregister(int sock)
3061 {
3062 struct ust_app *lta;
3063 struct lttng_ht_node_ulong *node;
3064 struct lttng_ht_iter iter;
3065 struct ust_app_session *ua_sess;
3066 int ret;
3067
3068 rcu_read_lock();
3069
3070 /* Get the node reference for a call_rcu */
3071 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
3072 node = lttng_ht_iter_get_node_ulong(&iter);
3073 assert(node);
3074
3075 lta = caa_container_of(node, struct ust_app, sock_n);
3076 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3077
3078 /* Remove application from PID hash table */
3079 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3080 assert(!ret);
3081
3082 /*
3083 * Remove application from notify hash table. The thread handling the
3084 * notify socket could have deleted the node so ignore on error because
3085 * either way it's valid. The close of that socket is handled by the other
3086 * thread.
3087 */
3088 iter.iter.node = &lta->notify_sock_n.node;
3089 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3090
3091 /*
3092 * Ignore return value since the node might have been removed before by an
3093 * add replace during app registration because the PID can be reassigned by
3094 * the OS.
3095 */
3096 iter.iter.node = &lta->pid_n.node;
3097 ret = lttng_ht_del(ust_app_ht, &iter);
3098 if (ret) {
3099 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3100 lta->pid);
3101 }
3102
3103 /* Remove sessions so they are not visible during deletion.*/
3104 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3105 node.node) {
3106 struct ust_registry_session *registry;
3107
3108 ret = lttng_ht_del(lta->sessions, &iter);
3109 if (ret) {
3110 /* The session was already removed so scheduled for teardown. */
3111 continue;
3112 }
3113
3114 /*
3115 * Add session to list for teardown. This is safe since at this point we
3116 * are the only one using this list.
3117 */
3118 pthread_mutex_lock(&ua_sess->lock);
3119
3120 /*
3121 * Normally, this is done in the delete session process which is
3122 * executed in the call rcu below. However, upon registration we can't
3123 * afford to wait for the grace period before pushing data or else the
3124 * data pending feature can race between the unregistration and stop
3125 * command where the data pending command is sent *before* the grace
3126 * period ended.
3127 *
3128 * The close metadata below nullifies the metadata pointer in the
3129 * session so the delete session will NOT push/close a second time.
3130 */
3131 registry = get_session_registry(ua_sess);
3132 if (registry && !registry->metadata_closed) {
3133 /* Push metadata for application before freeing the application. */
3134 (void) push_metadata(registry, ua_sess->consumer);
3135
3136 /*
3137 * Don't ask to close metadata for global per UID buffers. Close
3138 * metadata only on destroy trace session in this case. Also, the
3139 * previous push metadata could have flag the metadata registry to
3140 * close so don't send a close command if closed.
3141 */
3142 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
3143 !registry->metadata_closed) {
3144 /* And ask to close it for this session registry. */
3145 (void) close_metadata(registry, ua_sess->consumer);
3146 }
3147 }
3148
3149 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3150 pthread_mutex_unlock(&ua_sess->lock);
3151 }
3152
3153 /* Free memory */
3154 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3155
3156 rcu_read_unlock();
3157 return;
3158 }
3159
3160 /*
3161 * Fill events array with all events name of all registered apps.
3162 */
3163 int ust_app_list_events(struct lttng_event **events)
3164 {
3165 int ret, handle;
3166 size_t nbmem, count = 0;
3167 struct lttng_ht_iter iter;
3168 struct ust_app *app;
3169 struct lttng_event *tmp_event;
3170
3171 nbmem = UST_APP_EVENT_LIST_SIZE;
3172 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3173 if (tmp_event == NULL) {
3174 PERROR("zmalloc ust app events");
3175 ret = -ENOMEM;
3176 goto error;
3177 }
3178
3179 rcu_read_lock();
3180
3181 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3182 struct lttng_ust_tracepoint_iter uiter;
3183
3184 health_code_update();
3185
3186 if (!app->compatible) {
3187 /*
3188 * TODO: In time, we should notice the caller of this error by
3189 * telling him that this is a version error.
3190 */
3191 continue;
3192 }
3193 handle = ustctl_tracepoint_list(app->sock);
3194 if (handle < 0) {
3195 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3196 ERR("UST app list events getting handle failed for app pid %d",
3197 app->pid);
3198 }
3199 continue;
3200 }
3201
3202 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3203 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3204 /* Handle ustctl error. */
3205 if (ret < 0) {
3206 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3207 ERR("UST app tp list get failed for app %d with ret %d",
3208 app->sock, ret);
3209 } else {
3210 DBG3("UST app tp list get failed. Application is dead");
3211 /*
3212 * This is normal behavior, an application can die during the
3213 * creation process. Don't report an error so the execution can
3214 * continue normally. Continue normal execution.
3215 */
3216 break;
3217 }
3218 free(tmp_event);
3219 goto rcu_error;
3220 }
3221
3222 health_code_update();
3223 if (count >= nbmem) {
3224 /* In case the realloc fails, we free the memory */
3225 struct lttng_event *new_tmp_event;
3226 size_t new_nbmem;
3227
3228 new_nbmem = nbmem << 1;
3229 DBG2("Reallocating event list from %zu to %zu entries",
3230 nbmem, new_nbmem);
3231 new_tmp_event = realloc(tmp_event,
3232 new_nbmem * sizeof(struct lttng_event));
3233 if (new_tmp_event == NULL) {
3234 PERROR("realloc ust app events");
3235 free(tmp_event);
3236 ret = -ENOMEM;
3237 goto rcu_error;
3238 }
3239 /* Zero the new memory */
3240 memset(new_tmp_event + nbmem, 0,
3241 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3242 nbmem = new_nbmem;
3243 tmp_event = new_tmp_event;
3244 }
3245 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3246 tmp_event[count].loglevel = uiter.loglevel;
3247 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3248 tmp_event[count].pid = app->pid;
3249 tmp_event[count].enabled = -1;
3250 count++;
3251 }
3252 }
3253
3254 ret = count;
3255 *events = tmp_event;
3256
3257 DBG2("UST app list events done (%zu events)", count);
3258
3259 rcu_error:
3260 rcu_read_unlock();
3261 error:
3262 health_code_update();
3263 return ret;
3264 }
3265
3266 /*
3267 * Fill events array with all events name of all registered apps.
3268 */
3269 int ust_app_list_event_fields(struct lttng_event_field **fields)
3270 {
3271 int ret, handle;
3272 size_t nbmem, count = 0;
3273 struct lttng_ht_iter iter;
3274 struct ust_app *app;
3275 struct lttng_event_field *tmp_event;
3276
3277 nbmem = UST_APP_EVENT_LIST_SIZE;
3278 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3279 if (tmp_event == NULL) {
3280 PERROR("zmalloc ust app event fields");
3281 ret = -ENOMEM;
3282 goto error;
3283 }
3284
3285 rcu_read_lock();
3286
3287 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3288 struct lttng_ust_field_iter uiter;
3289
3290 health_code_update();
3291
3292 if (!app->compatible) {
3293 /*
3294 * TODO: In time, we should notice the caller of this error by
3295 * telling him that this is a version error.
3296 */
3297 continue;
3298 }
3299 handle = ustctl_tracepoint_field_list(app->sock);
3300 if (handle < 0) {
3301 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3302 ERR("UST app list field getting handle failed for app pid %d",
3303 app->pid);
3304 }
3305 continue;
3306 }
3307
3308 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3309 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3310 /* Handle ustctl error. */
3311 if (ret < 0) {
3312 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3313 ERR("UST app tp list field failed for app %d with ret %d",
3314 app->sock, ret);
3315 } else {
3316 DBG3("UST app tp list field failed. Application is dead");
3317 /*
3318 * This is normal behavior, an application can die during the
3319 * creation process. Don't report an error so the execution can
3320 * continue normally. Reset list and count for next app.
3321 */
3322 break;
3323 }
3324 free(tmp_event);
3325 goto rcu_error;
3326 }
3327
3328 health_code_update();
3329 if (count >= nbmem) {
3330 /* In case the realloc fails, we free the memory */
3331 struct lttng_event_field *new_tmp_event;
3332 size_t new_nbmem;
3333
3334 new_nbmem = nbmem << 1;
3335 DBG2("Reallocating event field list from %zu to %zu entries",
3336 nbmem, new_nbmem);
3337 new_tmp_event = realloc(tmp_event,
3338 new_nbmem * sizeof(struct lttng_event_field));
3339 if (new_tmp_event == NULL) {
3340 PERROR("realloc ust app event fields");
3341 free(tmp_event);
3342 ret = -ENOMEM;
3343 goto rcu_error;
3344 }
3345 /* Zero the new memory */
3346 memset(new_tmp_event + nbmem, 0,
3347 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3348 nbmem = new_nbmem;
3349 tmp_event = new_tmp_event;
3350 }
3351
3352 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3353 /* Mapping between these enums matches 1 to 1. */
3354 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3355 tmp_event[count].nowrite = uiter.nowrite;
3356
3357 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3358 tmp_event[count].event.loglevel = uiter.loglevel;
3359 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3360 tmp_event[count].event.pid = app->pid;
3361 tmp_event[count].event.enabled = -1;
3362 count++;
3363 }
3364 }
3365
3366 ret = count;
3367 *fields = tmp_event;
3368
3369 DBG2("UST app list event fields done (%zu events)", count);
3370
3371 rcu_error:
3372 rcu_read_unlock();
3373 error:
3374 health_code_update();
3375 return ret;
3376 }
3377
3378 /*
3379 * Free and clean all traceable apps of the global list.
3380 *
3381 * Should _NOT_ be called with RCU read-side lock held.
3382 */
3383 void ust_app_clean_list(void)
3384 {
3385 int ret;
3386 struct ust_app *app;
3387 struct lttng_ht_iter iter;
3388
3389 DBG2("UST app cleaning registered apps hash table");
3390
3391 rcu_read_lock();
3392
3393 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3394 ret = lttng_ht_del(ust_app_ht, &iter);
3395 assert(!ret);
3396 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3397 }
3398
3399 /* Cleanup socket hash table */
3400 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3401 sock_n.node) {
3402 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3403 assert(!ret);
3404 }
3405
3406 /* Cleanup notify socket hash table */
3407 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3408 notify_sock_n.node) {
3409 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3410 assert(!ret);
3411 }
3412 rcu_read_unlock();
3413
3414 /* Destroy is done only when the ht is empty */
3415 ht_cleanup_push(ust_app_ht);
3416 ht_cleanup_push(ust_app_ht_by_sock);
3417 ht_cleanup_push(ust_app_ht_by_notify_sock);
3418 }
3419
3420 /*
3421 * Init UST app hash table.
3422 */
3423 void ust_app_ht_alloc(void)
3424 {
3425 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3426 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3427 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3428 }
3429
3430 /*
3431 * For a specific UST session, disable the channel for all registered apps.
3432 */
3433 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3434 struct ltt_ust_channel *uchan)
3435 {
3436 int ret = 0;
3437 struct lttng_ht_iter iter;
3438 struct lttng_ht_node_str *ua_chan_node;
3439 struct ust_app *app;
3440 struct ust_app_session *ua_sess;
3441 struct ust_app_channel *ua_chan;
3442
3443 if (usess == NULL || uchan == NULL) {
3444 ERR("Disabling UST global channel with NULL values");
3445 ret = -1;
3446 goto error;
3447 }
3448
3449 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3450 uchan->name, usess->id);
3451
3452 rcu_read_lock();
3453
3454 /* For every registered applications */
3455 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3456 struct lttng_ht_iter uiter;
3457 if (!app->compatible) {
3458 /*
3459 * TODO: In time, we should notice the caller of this error by
3460 * telling him that this is a version error.
3461 */
3462 continue;
3463 }
3464 ua_sess = lookup_session_by_app(usess, app);
3465 if (ua_sess == NULL) {
3466 continue;
3467 }
3468
3469 /* Get channel */
3470 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3471 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3472 /* If the session if found for the app, the channel must be there */
3473 assert(ua_chan_node);
3474
3475 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3476 /* The channel must not be already disabled */
3477 assert(ua_chan->enabled == 1);
3478
3479 /* Disable channel onto application */
3480 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3481 if (ret < 0) {
3482 /* XXX: We might want to report this error at some point... */
3483 continue;
3484 }
3485 }
3486
3487 rcu_read_unlock();
3488
3489 error:
3490 return ret;
3491 }
3492
3493 /*
3494 * For a specific UST session, enable the channel for all registered apps.
3495 */
3496 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3497 struct ltt_ust_channel *uchan)
3498 {
3499 int ret = 0;
3500 struct lttng_ht_iter iter;
3501 struct ust_app *app;
3502 struct ust_app_session *ua_sess;
3503
3504 if (usess == NULL || uchan == NULL) {
3505 ERR("Adding UST global channel to NULL values");
3506 ret = -1;
3507 goto error;
3508 }
3509
3510 DBG2("UST app enabling channel %s to global 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 ua_sess = lookup_session_by_app(usess, app);
3525 if (ua_sess == NULL) {
3526 continue;
3527 }
3528
3529 /* Enable channel onto application */
3530 ret = enable_ust_app_channel(ua_sess, uchan, app);
3531 if (ret < 0) {
3532 /* XXX: We might want to report this error at some point... */
3533 continue;
3534 }
3535 }
3536
3537 rcu_read_unlock();
3538
3539 error:
3540 return ret;
3541 }
3542
3543 /*
3544 * Disable an event in a channel and for a specific session.
3545 */
3546 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3547 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3548 {
3549 int ret = 0;
3550 struct lttng_ht_iter iter, uiter;
3551 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
3552 struct ust_app *app;
3553 struct ust_app_session *ua_sess;
3554 struct ust_app_channel *ua_chan;
3555 struct ust_app_event *ua_event;
3556
3557 DBG("UST app disabling event %s for all apps in channel "
3558 "%s for session id %" PRIu64,
3559 uevent->attr.name, uchan->name, usess->id);
3560
3561 rcu_read_lock();
3562
3563 /* For all registered applications */
3564 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3565 if (!app->compatible) {
3566 /*
3567 * TODO: In time, we should notice the caller of this error by
3568 * telling him that this is a version error.
3569 */
3570 continue;
3571 }
3572 ua_sess = lookup_session_by_app(usess, app);
3573 if (ua_sess == NULL) {
3574 /* Next app */
3575 continue;
3576 }
3577
3578 /* Lookup channel in the ust app session */
3579 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3580 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3581 if (ua_chan_node == NULL) {
3582 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3583 "Skipping", uchan->name, usess->id, app->pid);
3584 continue;
3585 }
3586 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3587
3588 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
3589 ua_event_node = lttng_ht_iter_get_node_str(&uiter);
3590 if (ua_event_node == NULL) {
3591 DBG2("Event %s not found in channel %s for app pid %d."
3592 "Skipping", uevent->attr.name, uchan->name, app->pid);
3593 continue;
3594 }
3595 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
3596
3597 ret = disable_ust_app_event(ua_sess, ua_event, app);
3598 if (ret < 0) {
3599 /* XXX: Report error someday... */
3600 continue;
3601 }
3602 }
3603
3604 rcu_read_unlock();
3605
3606 return ret;
3607 }
3608
3609 /*
3610 * For a specific UST session, create the channel for all registered apps.
3611 */
3612 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3613 struct ltt_ust_channel *uchan)
3614 {
3615 int ret = 0, created;
3616 struct lttng_ht_iter iter;
3617 struct ust_app *app;
3618 struct ust_app_session *ua_sess = NULL;
3619
3620 /* Very wrong code flow */
3621 assert(usess);
3622 assert(uchan);
3623
3624 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3625 uchan->name, usess->id);
3626
3627 rcu_read_lock();
3628
3629 /* For every registered applications */
3630 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3631 if (!app->compatible) {
3632 /*
3633 * TODO: In time, we should notice the caller of this error by
3634 * telling him that this is a version error.
3635 */
3636 continue;
3637 }
3638 /*
3639 * Create session on the tracer side and add it to app session HT. Note
3640 * that if session exist, it will simply return a pointer to the ust
3641 * app session.
3642 */
3643 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3644 if (ret < 0) {
3645 switch (ret) {
3646 case -ENOTCONN:
3647 /*
3648 * The application's socket is not valid. Either a bad socket
3649 * or a timeout on it. We can't inform the caller that for a
3650 * specific app, the session failed so lets continue here.
3651 */
3652 continue;
3653 case -ENOMEM:
3654 default:
3655 goto error_rcu_unlock;
3656 }
3657 }
3658 assert(ua_sess);
3659
3660 pthread_mutex_lock(&ua_sess->lock);
3661 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
3662 sizeof(uchan->name))) {
3663 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
3664 ret = 0;
3665 } else {
3666 /* Create channel onto application. We don't need the chan ref. */
3667 ret = create_ust_app_channel(ua_sess, uchan, app,
3668 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
3669 }
3670 pthread_mutex_unlock(&ua_sess->lock);
3671 if (ret < 0) {
3672 if (ret == -ENOMEM) {
3673 /* No more memory is a fatal error. Stop right now. */
3674 goto error_rcu_unlock;
3675 }
3676 /* Cleanup the created session if it's the case. */
3677 if (created) {
3678 destroy_app_session(app, ua_sess);
3679 }
3680 }
3681 }
3682
3683 error_rcu_unlock:
3684 rcu_read_unlock();
3685 return ret;
3686 }
3687
3688 /*
3689 * Enable event for a specific session and channel on the tracer.
3690 */
3691 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
3692 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3693 {
3694 int ret = 0;
3695 struct lttng_ht_iter iter, uiter;
3696 struct lttng_ht_node_str *ua_chan_node;
3697 struct ust_app *app;
3698 struct ust_app_session *ua_sess;
3699 struct ust_app_channel *ua_chan;
3700 struct ust_app_event *ua_event;
3701
3702 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
3703 uevent->attr.name, usess->id);
3704
3705 /*
3706 * NOTE: At this point, this function is called only if the session and
3707 * channel passed are already created for all apps. and enabled on the
3708 * tracer also.
3709 */
3710
3711 rcu_read_lock();
3712
3713 /* For all registered applications */
3714 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3715 if (!app->compatible) {
3716 /*
3717 * TODO: In time, we should notice the caller of this error by
3718 * telling him that this is a version error.
3719 */
3720 continue;
3721 }
3722 ua_sess = lookup_session_by_app(usess, app);
3723 if (!ua_sess) {
3724 /* The application has problem or is probably dead. */
3725 continue;
3726 }
3727
3728 pthread_mutex_lock(&ua_sess->lock);
3729
3730 /* Lookup channel in the ust app session */
3731 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3732 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3733 /* If the channel is not found, there is a code flow error */
3734 assert(ua_chan_node);
3735
3736 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3737
3738 /* Get event node */
3739 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3740 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3741 if (ua_event == NULL) {
3742 DBG3("UST app enable event %s not found for app PID %d."
3743 "Skipping app", uevent->attr.name, app->pid);
3744 goto next_app;
3745 }
3746
3747 ret = enable_ust_app_event(ua_sess, ua_event, app);
3748 if (ret < 0) {
3749 pthread_mutex_unlock(&ua_sess->lock);
3750 goto error;
3751 }
3752 next_app:
3753 pthread_mutex_unlock(&ua_sess->lock);
3754 }
3755
3756 error:
3757 rcu_read_unlock();
3758 return ret;
3759 }
3760
3761 /*
3762 * For a specific existing UST session and UST channel, creates the event for
3763 * all registered apps.
3764 */
3765 int ust_app_create_event_glb(struct ltt_ust_session *usess,
3766 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3767 {
3768 int ret = 0;
3769 struct lttng_ht_iter iter, uiter;
3770 struct lttng_ht_node_str *ua_chan_node;
3771 struct ust_app *app;
3772 struct ust_app_session *ua_sess;
3773 struct ust_app_channel *ua_chan;
3774
3775 DBG("UST app creating event %s for all apps for session id %" PRIu64,
3776 uevent->attr.name, usess->id);
3777
3778 rcu_read_lock();
3779
3780 /* For all registered applications */
3781 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3782 if (!app->compatible) {
3783 /*
3784 * TODO: In time, we should notice the caller of this error by
3785 * telling him that this is a version error.
3786 */
3787 continue;
3788 }
3789 ua_sess = lookup_session_by_app(usess, app);
3790 if (!ua_sess) {
3791 /* The application has problem or is probably dead. */
3792 continue;
3793 }
3794
3795 pthread_mutex_lock(&ua_sess->lock);
3796 /* Lookup channel in the ust app session */
3797 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3798 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3799 /* If the channel is not found, there is a code flow error */
3800 assert(ua_chan_node);
3801
3802 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3803
3804 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
3805 pthread_mutex_unlock(&ua_sess->lock);
3806 if (ret < 0) {
3807 if (ret != -LTTNG_UST_ERR_EXIST) {
3808 /* Possible value at this point: -ENOMEM. If so, we stop! */
3809 break;
3810 }
3811 DBG2("UST app event %s already exist on app PID %d",
3812 uevent->attr.name, app->pid);
3813 continue;
3814 }
3815 }
3816
3817 rcu_read_unlock();
3818
3819 return ret;
3820 }
3821
3822 /*
3823 * Start tracing for a specific UST session and app.
3824 */
3825 static
3826 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
3827 {
3828 int ret = 0;
3829 struct ust_app_session *ua_sess;
3830
3831 DBG("Starting tracing for ust app pid %d", app->pid);
3832
3833 rcu_read_lock();
3834
3835 if (!app->compatible) {
3836 goto end;
3837 }
3838
3839 ua_sess = lookup_session_by_app(usess, app);
3840 if (ua_sess == NULL) {
3841 /* The session is in teardown process. Ignore and continue. */
3842 goto end;
3843 }
3844
3845 pthread_mutex_lock(&ua_sess->lock);
3846
3847 /* Upon restart, we skip the setup, already done */
3848 if (ua_sess->started) {
3849 goto skip_setup;
3850 }
3851
3852 /* Create directories if consumer is LOCAL and has a path defined. */
3853 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
3854 strlen(usess->consumer->dst.trace_path) > 0) {
3855 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
3856 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
3857 if (ret < 0) {
3858 if (ret != -EEXIST) {
3859 ERR("Trace directory creation error");
3860 goto error_unlock;
3861 }
3862 }
3863 }
3864
3865 /*
3866 * Create the metadata for the application. This returns gracefully if a
3867 * metadata was already set for the session.
3868 */
3869 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
3870 if (ret < 0) {
3871 goto error_unlock;
3872 }
3873
3874 health_code_update();
3875
3876 skip_setup:
3877 /* This start the UST tracing */
3878 ret = ustctl_start_session(app->sock, ua_sess->handle);
3879 if (ret < 0) {
3880 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3881 ERR("Error starting tracing for app pid: %d (ret: %d)",
3882 app->pid, ret);
3883 } else {
3884 DBG("UST app start session failed. Application is dead.");
3885 /*
3886 * This is normal behavior, an application can die during the
3887 * creation process. Don't report an error so the execution can
3888 * continue normally.
3889 */
3890 pthread_mutex_unlock(&ua_sess->lock);
3891 goto end;
3892 }
3893 goto error_unlock;
3894 }
3895
3896 /* Indicate that the session has been started once */
3897 ua_sess->started = 1;
3898
3899 pthread_mutex_unlock(&ua_sess->lock);
3900
3901 health_code_update();
3902
3903 /* Quiescent wait after starting trace */
3904 ret = ustctl_wait_quiescent(app->sock);
3905 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3906 ERR("UST app wait quiescent failed for app pid %d ret %d",
3907 app->pid, ret);
3908 }
3909
3910 end:
3911 rcu_read_unlock();
3912 health_code_update();
3913 return 0;
3914
3915 error_unlock:
3916 pthread_mutex_unlock(&ua_sess->lock);
3917 rcu_read_unlock();
3918 health_code_update();
3919 return -1;
3920 }
3921
3922 /*
3923 * Stop tracing for a specific UST session and app.
3924 */
3925 static
3926 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
3927 {
3928 int ret = 0;
3929 struct ust_app_session *ua_sess;
3930 struct ust_registry_session *registry;
3931
3932 DBG("Stopping tracing for ust app pid %d", app->pid);
3933
3934 rcu_read_lock();
3935
3936 if (!app->compatible) {
3937 goto end_no_session;
3938 }
3939
3940 ua_sess = lookup_session_by_app(usess, app);
3941 if (ua_sess == NULL) {
3942 goto end_no_session;
3943 }
3944
3945 pthread_mutex_lock(&ua_sess->lock);
3946
3947 /*
3948 * If started = 0, it means that stop trace has been called for a session
3949 * that was never started. It's possible since we can have a fail start
3950 * from either the application manager thread or the command thread. Simply
3951 * indicate that this is a stop error.
3952 */
3953 if (!ua_sess->started) {
3954 goto error_rcu_unlock;
3955 }
3956
3957 health_code_update();
3958
3959 /* This inhibits UST tracing */
3960 ret = ustctl_stop_session(app->sock, ua_sess->handle);
3961 if (ret < 0) {
3962 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3963 ERR("Error stopping tracing for app pid: %d (ret: %d)",
3964 app->pid, ret);
3965 } else {
3966 DBG("UST app stop session failed. Application is dead.");
3967 /*
3968 * This is normal behavior, an application can die during the
3969 * creation process. Don't report an error so the execution can
3970 * continue normally.
3971 */
3972 goto end_unlock;
3973 }
3974 goto error_rcu_unlock;
3975 }
3976
3977 health_code_update();
3978
3979 /* Quiescent wait after stopping trace */
3980 ret = ustctl_wait_quiescent(app->sock);
3981 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3982 ERR("UST app wait quiescent failed for app pid %d ret %d",
3983 app->pid, ret);
3984 }
3985
3986 health_code_update();
3987
3988 registry = get_session_registry(ua_sess);
3989 assert(registry);
3990
3991 if (!registry->metadata_closed) {
3992 /* Push metadata for application before freeing the application. */
3993 (void) push_metadata(registry, ua_sess->consumer);
3994 }
3995
3996 end_unlock:
3997 pthread_mutex_unlock(&ua_sess->lock);
3998 end_no_session:
3999 rcu_read_unlock();
4000 health_code_update();
4001 return 0;
4002
4003 error_rcu_unlock:
4004 pthread_mutex_unlock(&ua_sess->lock);
4005 rcu_read_unlock();
4006 health_code_update();
4007 return -1;
4008 }
4009
4010 /*
4011 * Flush buffers for a specific UST session and app.
4012 */
4013 static
4014 int ust_app_flush_trace(struct ltt_ust_session *usess, struct ust_app *app)
4015 {
4016 int ret = 0;
4017 struct lttng_ht_iter iter;
4018 struct ust_app_session *ua_sess;
4019 struct ust_app_channel *ua_chan;
4020
4021 DBG("Flushing buffers for ust app pid %d", app->pid);
4022
4023 rcu_read_lock();
4024
4025 if (!app->compatible) {
4026 goto end_no_session;
4027 }
4028
4029 ua_sess = lookup_session_by_app(usess, app);
4030 if (ua_sess == NULL) {
4031 goto end_no_session;
4032 }
4033
4034 pthread_mutex_lock(&ua_sess->lock);
4035
4036 health_code_update();
4037
4038 /* Flushing buffers */
4039 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4040 node.node) {
4041 health_code_update();
4042 assert(ua_chan->is_sent);
4043 ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
4044 if (ret < 0) {
4045 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4046 ERR("UST app PID %d channel %s flush failed with ret %d",
4047 app->pid, ua_chan->name, ret);
4048 } else {
4049 DBG3("UST app failed to flush %s. Application is dead.",
4050 ua_chan->name);
4051 /*
4052 * This is normal behavior, an application can die during the
4053 * creation process. Don't report an error so the execution can
4054 * continue normally.
4055 */
4056 }
4057 /* Continuing flushing all buffers */
4058 continue;
4059 }
4060 }
4061
4062 health_code_update();
4063
4064 pthread_mutex_unlock(&ua_sess->lock);
4065 end_no_session:
4066 rcu_read_unlock();
4067 health_code_update();
4068 return 0;
4069 }
4070
4071 /*
4072 * Destroy a specific UST session in apps.
4073 */
4074 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4075 {
4076 int ret;
4077 struct ust_app_session *ua_sess;
4078 struct lttng_ht_iter iter;
4079 struct lttng_ht_node_u64 *node;
4080
4081 DBG("Destroy tracing for ust app pid %d", app->pid);
4082
4083 rcu_read_lock();
4084
4085 if (!app->compatible) {
4086 goto end;
4087 }
4088
4089 __lookup_session_by_app(usess, app, &iter);
4090 node = lttng_ht_iter_get_node_u64(&iter);
4091 if (node == NULL) {
4092 /* Session is being or is deleted. */
4093 goto end;
4094 }
4095 ua_sess = caa_container_of(node, struct ust_app_session, node);
4096
4097 health_code_update();
4098 destroy_app_session(app, ua_sess);
4099
4100 health_code_update();
4101
4102 /* Quiescent wait after stopping trace */
4103 ret = ustctl_wait_quiescent(app->sock);
4104 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4105 ERR("UST app wait quiescent failed for app pid %d ret %d",
4106 app->pid, ret);
4107 }
4108 end:
4109 rcu_read_unlock();
4110 health_code_update();
4111 return 0;
4112 }
4113
4114 /*
4115 * Start tracing for the UST session.
4116 */
4117 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4118 {
4119 int ret = 0;
4120 struct lttng_ht_iter iter;
4121 struct ust_app *app;
4122
4123 DBG("Starting all UST traces");
4124
4125 rcu_read_lock();
4126
4127 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4128 ret = ust_app_start_trace(usess, app);
4129 if (ret < 0) {
4130 /* Continue to next apps even on error */
4131 continue;
4132 }
4133 }
4134
4135 rcu_read_unlock();
4136
4137 return 0;
4138 }
4139
4140 /*
4141 * Start tracing for the UST session.
4142 */
4143 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4144 {
4145 int ret = 0;
4146 struct lttng_ht_iter iter;
4147 struct ust_app *app;
4148
4149 DBG("Stopping all UST traces");
4150
4151 rcu_read_lock();
4152
4153 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4154 ret = ust_app_stop_trace(usess, app);
4155 if (ret < 0) {
4156 /* Continue to next apps even on error */
4157 continue;
4158 }
4159 }
4160
4161 /* Flush buffers and push metadata (for UID buffers). */
4162 switch (usess->buffer_type) {
4163 case LTTNG_BUFFER_PER_UID:
4164 {
4165 struct buffer_reg_uid *reg;
4166
4167 /* Flush all per UID buffers associated to that session. */
4168 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4169 struct ust_registry_session *ust_session_reg;
4170 struct buffer_reg_channel *reg_chan;
4171 struct consumer_socket *socket;
4172
4173 /* Get consumer socket to use to push the metadata.*/
4174 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4175 usess->consumer);
4176 if (!socket) {
4177 /* Ignore request if no consumer is found for the session. */
4178 continue;
4179 }
4180
4181 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4182 reg_chan, node.node) {
4183 /*
4184 * The following call will print error values so the return
4185 * code is of little importance because whatever happens, we
4186 * have to try them all.
4187 */
4188 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4189 }
4190
4191 ust_session_reg = reg->registry->reg.ust;
4192 if (!ust_session_reg->metadata_closed) {
4193 /* Push metadata. */
4194 (void) push_metadata(ust_session_reg, usess->consumer);
4195 }
4196 }
4197
4198 break;
4199 }
4200 case LTTNG_BUFFER_PER_PID:
4201 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4202 ret = ust_app_flush_trace(usess, app);
4203 if (ret < 0) {
4204 /* Continue to next apps even on error */
4205 continue;
4206 }
4207 }
4208 break;
4209 default:
4210 assert(0);
4211 break;
4212 }
4213
4214 rcu_read_unlock();
4215
4216 return 0;
4217 }
4218
4219 /*
4220 * Destroy app UST session.
4221 */
4222 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4223 {
4224 int ret = 0;
4225 struct lttng_ht_iter iter;
4226 struct ust_app *app;
4227
4228 DBG("Destroy all UST traces");
4229
4230 rcu_read_lock();
4231
4232 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4233 ret = destroy_trace(usess, app);
4234 if (ret < 0) {
4235 /* Continue to next apps even on error */
4236 continue;
4237 }
4238 }
4239
4240 rcu_read_unlock();
4241
4242 return 0;
4243 }
4244
4245 /*
4246 * Add channels/events from UST global domain to registered apps at sock.
4247 */
4248 void ust_app_global_update(struct ltt_ust_session *usess, int sock)
4249 {
4250 int ret = 0;
4251 struct lttng_ht_iter iter, uiter;
4252 struct ust_app *app;
4253 struct ust_app_session *ua_sess = NULL;
4254 struct ust_app_channel *ua_chan;
4255 struct ust_app_event *ua_event;
4256 struct ust_app_ctx *ua_ctx;
4257
4258 assert(usess);
4259 assert(sock >= 0);
4260
4261 DBG2("UST app global update for app sock %d for session id %" PRIu64, sock,
4262 usess->id);
4263
4264 rcu_read_lock();
4265
4266 app = ust_app_find_by_sock(sock);
4267 if (app == NULL) {
4268 /*
4269 * Application can be unregistered before so this is possible hence
4270 * simply stopping the update.
4271 */
4272 DBG3("UST app update failed to find app sock %d", sock);
4273 goto error;
4274 }
4275
4276 if (!app->compatible) {
4277 goto error;
4278 }
4279
4280 ret = create_ust_app_session(usess, app, &ua_sess, NULL);
4281 if (ret < 0) {
4282 /* Tracer is probably gone or ENOMEM. */
4283 goto error;
4284 }
4285 assert(ua_sess);
4286
4287 pthread_mutex_lock(&ua_sess->lock);
4288
4289 /*
4290 * We can iterate safely here over all UST app session since the create ust
4291 * app session above made a shadow copy of the UST global domain from the
4292 * ltt ust session.
4293 */
4294 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4295 node.node) {
4296 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4297 if (ret < 0) {
4298 /*
4299 * Stop everything. On error, the application failed, no more
4300 * file descriptor are available or ENOMEM so stopping here is
4301 * the only thing we can do for now.
4302 */
4303 goto error_unlock;
4304 }
4305
4306 /*
4307 * Add context using the list so they are enabled in the same order the
4308 * user added them.
4309 */
4310 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4311 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4312 if (ret < 0) {
4313 goto error_unlock;
4314 }
4315 }
4316
4317
4318 /* For each events */
4319 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4320 node.node) {
4321 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4322 if (ret < 0) {
4323 goto error_unlock;
4324 }
4325 }
4326 }
4327
4328 pthread_mutex_unlock(&ua_sess->lock);
4329
4330 if (usess->active) {
4331 ret = ust_app_start_trace(usess, app);
4332 if (ret < 0) {
4333 goto error;
4334 }
4335
4336 DBG2("UST trace started for app pid %d", app->pid);
4337 }
4338
4339 /* Everything went well at this point. */
4340 rcu_read_unlock();
4341 return;
4342
4343 error_unlock:
4344 pthread_mutex_unlock(&ua_sess->lock);
4345 error:
4346 if (ua_sess) {
4347 destroy_app_session(app, ua_sess);
4348 }
4349 rcu_read_unlock();
4350 return;
4351 }
4352
4353 /*
4354 * Add context to a specific channel for global UST domain.
4355 */
4356 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4357 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4358 {
4359 int ret = 0;
4360 struct lttng_ht_node_str *ua_chan_node;
4361 struct lttng_ht_iter iter, uiter;
4362 struct ust_app_channel *ua_chan = NULL;
4363 struct ust_app_session *ua_sess;
4364 struct ust_app *app;
4365
4366 rcu_read_lock();
4367
4368 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4369 if (!app->compatible) {
4370 /*
4371 * TODO: In time, we should notice the caller of this error by
4372 * telling him that this is a version error.
4373 */
4374 continue;
4375 }
4376 ua_sess = lookup_session_by_app(usess, app);
4377 if (ua_sess == NULL) {
4378 continue;
4379 }
4380
4381 pthread_mutex_lock(&ua_sess->lock);
4382 /* Lookup channel in the ust app session */
4383 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4384 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4385 if (ua_chan_node == NULL) {
4386 goto next_app;
4387 }
4388 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4389 node);
4390 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4391 if (ret < 0) {
4392 goto next_app;
4393 }
4394 next_app:
4395 pthread_mutex_unlock(&ua_sess->lock);
4396 }
4397
4398 rcu_read_unlock();
4399 return ret;
4400 }
4401
4402 /*
4403 * Enable event for a channel from a UST session for a specific PID.
4404 */
4405 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4406 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4407 {
4408 int ret = 0;
4409 struct lttng_ht_iter iter;
4410 struct lttng_ht_node_str *ua_chan_node;
4411 struct ust_app *app;
4412 struct ust_app_session *ua_sess;
4413 struct ust_app_channel *ua_chan;
4414 struct ust_app_event *ua_event;
4415
4416 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4417
4418 rcu_read_lock();
4419
4420 app = ust_app_find_by_pid(pid);
4421 if (app == NULL) {
4422 ERR("UST app enable event per PID %d not found", pid);
4423 ret = -1;
4424 goto end;
4425 }
4426
4427 if (!app->compatible) {
4428 ret = 0;
4429 goto end;
4430 }
4431
4432 ua_sess = lookup_session_by_app(usess, app);
4433 if (!ua_sess) {
4434 /* The application has problem or is probably dead. */
4435 ret = 0;
4436 goto end;
4437 }
4438
4439 pthread_mutex_lock(&ua_sess->lock);
4440 /* Lookup channel in the ust app session */
4441 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4442 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4443 /* If the channel is not found, there is a code flow error */
4444 assert(ua_chan_node);
4445
4446 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4447
4448 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4449 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4450 if (ua_event == NULL) {
4451 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4452 if (ret < 0) {
4453 goto end_unlock;
4454 }
4455 } else {
4456 ret = enable_ust_app_event(ua_sess, ua_event, app);
4457 if (ret < 0) {
4458 goto end_unlock;
4459 }
4460 }
4461
4462 end_unlock:
4463 pthread_mutex_unlock(&ua_sess->lock);
4464 end:
4465 rcu_read_unlock();
4466 return ret;
4467 }
4468
4469 /*
4470 * Calibrate registered applications.
4471 */
4472 int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4473 {
4474 int ret = 0;
4475 struct lttng_ht_iter iter;
4476 struct ust_app *app;
4477
4478 rcu_read_lock();
4479
4480 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4481 if (!app->compatible) {
4482 /*
4483 * TODO: In time, we should notice the caller of this error by
4484 * telling him that this is a version error.
4485 */
4486 continue;
4487 }
4488
4489 health_code_update();
4490
4491 ret = ustctl_calibrate(app->sock, calibrate);
4492 if (ret < 0) {
4493 switch (ret) {
4494 case -ENOSYS:
4495 /* Means that it's not implemented on the tracer side. */
4496 ret = 0;
4497 break;
4498 default:
4499 DBG2("Calibrate app PID %d returned with error %d",
4500 app->pid, ret);
4501 break;
4502 }
4503 }
4504 }
4505
4506 DBG("UST app global domain calibration finished");
4507
4508 rcu_read_unlock();
4509
4510 health_code_update();
4511
4512 return ret;
4513 }
4514
4515 /*
4516 * Receive registration and populate the given msg structure.
4517 *
4518 * On success return 0 else a negative value returned by the ustctl call.
4519 */
4520 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4521 {
4522 int ret;
4523 uint32_t pid, ppid, uid, gid;
4524
4525 assert(msg);
4526
4527 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4528 &pid, &ppid, &uid, &gid,
4529 &msg->bits_per_long,
4530 &msg->uint8_t_alignment,
4531 &msg->uint16_t_alignment,
4532 &msg->uint32_t_alignment,
4533 &msg->uint64_t_alignment,
4534 &msg->long_alignment,
4535 &msg->byte_order,
4536 msg->name);
4537 if (ret < 0) {
4538 switch (-ret) {
4539 case EPIPE:
4540 case ECONNRESET:
4541 case LTTNG_UST_ERR_EXITING:
4542 DBG3("UST app recv reg message failed. Application died");
4543 break;
4544 case LTTNG_UST_ERR_UNSUP_MAJOR:
4545 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4546 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
4547 LTTNG_UST_ABI_MINOR_VERSION);
4548 break;
4549 default:
4550 ERR("UST app recv reg message failed with ret %d", ret);
4551 break;
4552 }
4553 goto error;
4554 }
4555 msg->pid = (pid_t) pid;
4556 msg->ppid = (pid_t) ppid;
4557 msg->uid = (uid_t) uid;
4558 msg->gid = (gid_t) gid;
4559
4560 error:
4561 return ret;
4562 }
4563
4564 /*
4565 * Return a ust app channel object using the application object and the channel
4566 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4567 * lock MUST be acquired before calling this function.
4568 */
4569 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
4570 int objd)
4571 {
4572 struct lttng_ht_node_ulong *node;
4573 struct lttng_ht_iter iter;
4574 struct ust_app_channel *ua_chan = NULL;
4575
4576 assert(app);
4577
4578 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
4579 node = lttng_ht_iter_get_node_ulong(&iter);
4580 if (node == NULL) {
4581 DBG2("UST app channel find by objd %d not found", objd);
4582 goto error;
4583 }
4584
4585 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
4586
4587 error:
4588 return ua_chan;
4589 }
4590
4591 /*
4592 * Reply to a register channel notification from an application on the notify
4593 * socket. The channel metadata is also created.
4594 *
4595 * The session UST registry lock is acquired in this function.
4596 *
4597 * On success 0 is returned else a negative value.
4598 */
4599 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
4600 size_t nr_fields, struct ustctl_field *fields)
4601 {
4602 int ret, ret_code = 0;
4603 uint32_t chan_id, reg_count;
4604 uint64_t chan_reg_key;
4605 enum ustctl_channel_header type;
4606 struct ust_app *app;
4607 struct ust_app_channel *ua_chan;
4608 struct ust_app_session *ua_sess;
4609 struct ust_registry_session *registry;
4610 struct ust_registry_channel *chan_reg;
4611
4612 rcu_read_lock();
4613
4614 /* Lookup application. If not found, there is a code flow error. */
4615 app = find_app_by_notify_sock(sock);
4616 if (!app) {
4617 DBG("Application socket %d is being teardown. Abort event notify",
4618 sock);
4619 ret = 0;
4620 free(fields);
4621 goto error_rcu_unlock;
4622 }
4623
4624 /* Lookup channel by UST object descriptor. */
4625 ua_chan = find_channel_by_objd(app, cobjd);
4626 if (!ua_chan) {
4627 DBG("Application channel is being teardown. Abort event notify");
4628 ret = 0;
4629 free(fields);
4630 goto error_rcu_unlock;
4631 }
4632
4633 assert(ua_chan->session);
4634 ua_sess = ua_chan->session;
4635
4636 /* Get right session registry depending on the session buffer type. */
4637 registry = get_session_registry(ua_sess);
4638 assert(registry);
4639
4640 /* Depending on the buffer type, a different channel key is used. */
4641 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4642 chan_reg_key = ua_chan->tracing_channel_id;
4643 } else {
4644 chan_reg_key = ua_chan->key;
4645 }
4646
4647 pthread_mutex_lock(&registry->lock);
4648
4649 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
4650 assert(chan_reg);
4651
4652 if (!chan_reg->register_done) {
4653 reg_count = ust_registry_get_event_count(chan_reg);
4654 if (reg_count < 31) {
4655 type = USTCTL_CHANNEL_HEADER_COMPACT;
4656 } else {
4657 type = USTCTL_CHANNEL_HEADER_LARGE;
4658 }
4659
4660 chan_reg->nr_ctx_fields = nr_fields;
4661 chan_reg->ctx_fields = fields;
4662 chan_reg->header_type = type;
4663 } else {
4664 /* Get current already assigned values. */
4665 type = chan_reg->header_type;
4666 free(fields);
4667 /* Set to NULL so the error path does not do a double free. */
4668 fields = NULL;
4669 }
4670 /* Channel id is set during the object creation. */
4671 chan_id = chan_reg->chan_id;
4672
4673 /* Append to metadata */
4674 if (!chan_reg->metadata_dumped) {
4675 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
4676 if (ret_code) {
4677 ERR("Error appending channel metadata (errno = %d)", ret_code);
4678 goto reply;
4679 }
4680 }
4681
4682 reply:
4683 DBG3("UST app replying to register channel key %" PRIu64
4684 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
4685 ret_code);
4686
4687 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
4688 if (ret < 0) {
4689 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4690 ERR("UST app reply channel failed with ret %d", ret);
4691 } else {
4692 DBG3("UST app reply channel failed. Application died");
4693 }
4694 goto error;
4695 }
4696
4697 /* This channel registry registration is completed. */
4698 chan_reg->register_done = 1;
4699
4700 error:
4701 pthread_mutex_unlock(&registry->lock);
4702 error_rcu_unlock:
4703 rcu_read_unlock();
4704 if (ret) {
4705 free(fields);
4706 }
4707 return ret;
4708 }
4709
4710 /*
4711 * Add event to the UST channel registry. When the event is added to the
4712 * registry, the metadata is also created. Once done, this replies to the
4713 * application with the appropriate error code.
4714 *
4715 * The session UST registry lock is acquired in the function.
4716 *
4717 * On success 0 is returned else a negative value.
4718 */
4719 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
4720 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
4721 char *model_emf_uri)
4722 {
4723 int ret, ret_code;
4724 uint32_t event_id = 0;
4725 uint64_t chan_reg_key;
4726 struct ust_app *app;
4727 struct ust_app_channel *ua_chan;
4728 struct ust_app_session *ua_sess;
4729 struct ust_registry_session *registry;
4730
4731 rcu_read_lock();
4732
4733 /* Lookup application. If not found, there is a code flow error. */
4734 app = find_app_by_notify_sock(sock);
4735 if (!app) {
4736 DBG("Application socket %d is being teardown. Abort event notify",
4737 sock);
4738 ret = 0;
4739 free(sig);
4740 free(fields);
4741 free(model_emf_uri);
4742 goto error_rcu_unlock;
4743 }
4744
4745 /* Lookup channel by UST object descriptor. */
4746 ua_chan = find_channel_by_objd(app, cobjd);
4747 if (!ua_chan) {
4748 DBG("Application channel is being teardown. Abort event notify");
4749 ret = 0;
4750 free(sig);
4751 free(fields);
4752 free(model_emf_uri);
4753 goto error_rcu_unlock;
4754 }
4755
4756 assert(ua_chan->session);
4757 ua_sess = ua_chan->session;
4758
4759 registry = get_session_registry(ua_sess);
4760 assert(registry);
4761
4762 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4763 chan_reg_key = ua_chan->tracing_channel_id;
4764 } else {
4765 chan_reg_key = ua_chan->key;
4766 }
4767
4768 pthread_mutex_lock(&registry->lock);
4769
4770 /*
4771 * From this point on, this call acquires the ownership of the sig, fields
4772 * and model_emf_uri meaning any free are done inside it if needed. These
4773 * three variables MUST NOT be read/write after this.
4774 */
4775 ret_code = ust_registry_create_event(registry, chan_reg_key,
4776 sobjd, cobjd, name, sig, nr_fields, fields, loglevel,
4777 model_emf_uri, ua_sess->buffer_type, &event_id,
4778 app);
4779
4780 /*
4781 * The return value is returned to ustctl so in case of an error, the
4782 * application can be notified. In case of an error, it's important not to
4783 * return a negative error or else the application will get closed.
4784 */
4785 ret = ustctl_reply_register_event(sock, event_id, ret_code);
4786 if (ret < 0) {
4787 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4788 ERR("UST app reply event failed with ret %d", ret);
4789 } else {
4790 DBG3("UST app reply event failed. Application died");
4791 }
4792 /*
4793 * No need to wipe the create event since the application socket will
4794 * get close on error hence cleaning up everything by itself.
4795 */
4796 goto error;
4797 }
4798
4799 DBG3("UST registry event %s with id %" PRId32 " added successfully",
4800 name, event_id);
4801
4802 error:
4803 pthread_mutex_unlock(&registry->lock);
4804 error_rcu_unlock:
4805 rcu_read_unlock();
4806 return ret;
4807 }
4808
4809 /*
4810 * Handle application notification through the given notify socket.
4811 *
4812 * Return 0 on success or else a negative value.
4813 */
4814 int ust_app_recv_notify(int sock)
4815 {
4816 int ret;
4817 enum ustctl_notify_cmd cmd;
4818
4819 DBG3("UST app receiving notify from sock %d", sock);
4820
4821 ret = ustctl_recv_notify(sock, &cmd);
4822 if (ret < 0) {
4823 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4824 ERR("UST app recv notify failed with ret %d", ret);
4825 } else {
4826 DBG3("UST app recv notify failed. Application died");
4827 }
4828 goto error;
4829 }
4830
4831 switch (cmd) {
4832 case USTCTL_NOTIFY_CMD_EVENT:
4833 {
4834 int sobjd, cobjd, loglevel;
4835 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
4836 size_t nr_fields;
4837 struct ustctl_field *fields;
4838
4839 DBG2("UST app ustctl register event received");
4840
4841 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name, &loglevel,
4842 &sig, &nr_fields, &fields, &model_emf_uri);
4843 if (ret < 0) {
4844 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4845 ERR("UST app recv event failed with ret %d", ret);
4846 } else {
4847 DBG3("UST app recv event failed. Application died");
4848 }
4849 goto error;
4850 }
4851
4852 /*
4853 * Add event to the UST registry coming from the notify socket. This
4854 * call will free if needed the sig, fields and model_emf_uri. This
4855 * code path loses the ownsership of these variables and transfer them
4856 * to the this function.
4857 */
4858 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
4859 fields, loglevel, model_emf_uri);
4860 if (ret < 0) {
4861 goto error;
4862 }
4863
4864 break;
4865 }
4866 case USTCTL_NOTIFY_CMD_CHANNEL:
4867 {
4868 int sobjd, cobjd;
4869 size_t nr_fields;
4870 struct ustctl_field *fields;
4871
4872 DBG2("UST app ustctl register channel received");
4873
4874 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
4875 &fields);
4876 if (ret < 0) {
4877 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4878 ERR("UST app recv channel failed with ret %d", ret);
4879 } else {
4880 DBG3("UST app recv channel failed. Application died");
4881 }
4882 goto error;
4883 }
4884
4885 /*
4886 * The fields ownership are transfered to this function call meaning
4887 * that if needed it will be freed. After this, it's invalid to access
4888 * fields or clean it up.
4889 */
4890 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
4891 fields);
4892 if (ret < 0) {
4893 goto error;
4894 }
4895
4896 break;
4897 }
4898 default:
4899 /* Should NEVER happen. */
4900 assert(0);
4901 }
4902
4903 error:
4904 return ret;
4905 }
4906
4907 /*
4908 * Once the notify socket hangs up, this is called. First, it tries to find the
4909 * corresponding application. On failure, the call_rcu to close the socket is
4910 * executed. If an application is found, it tries to delete it from the notify
4911 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4912 *
4913 * Note that an object needs to be allocated here so on ENOMEM failure, the
4914 * call RCU is not done but the rest of the cleanup is.
4915 */
4916 void ust_app_notify_sock_unregister(int sock)
4917 {
4918 int err_enomem = 0;
4919 struct lttng_ht_iter iter;
4920 struct ust_app *app;
4921 struct ust_app_notify_sock_obj *obj;
4922
4923 assert(sock >= 0);
4924
4925 rcu_read_lock();
4926
4927 obj = zmalloc(sizeof(*obj));
4928 if (!obj) {
4929 /*
4930 * An ENOMEM is kind of uncool. If this strikes we continue the
4931 * procedure but the call_rcu will not be called. In this case, we
4932 * accept the fd leak rather than possibly creating an unsynchronized
4933 * state between threads.
4934 *
4935 * TODO: The notify object should be created once the notify socket is
4936 * registered and stored independantely from the ust app object. The
4937 * tricky part is to synchronize the teardown of the application and
4938 * this notify object. Let's keep that in mind so we can avoid this
4939 * kind of shenanigans with ENOMEM in the teardown path.
4940 */
4941 err_enomem = 1;
4942 } else {
4943 obj->fd = sock;
4944 }
4945
4946 DBG("UST app notify socket unregister %d", sock);
4947
4948 /*
4949 * Lookup application by notify socket. If this fails, this means that the
4950 * hash table delete has already been done by the application
4951 * unregistration process so we can safely close the notify socket in a
4952 * call RCU.
4953 */
4954 app = find_app_by_notify_sock(sock);
4955 if (!app) {
4956 goto close_socket;
4957 }
4958
4959 iter.iter.node = &app->notify_sock_n.node;
4960
4961 /*
4962 * Whatever happens here either we fail or succeed, in both cases we have
4963 * to close the socket after a grace period to continue to the call RCU
4964 * here. If the deletion is successful, the application is not visible
4965 * anymore by other threads and is it fails it means that it was already
4966 * deleted from the hash table so either way we just have to close the
4967 * socket.
4968 */
4969 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
4970
4971 close_socket:
4972 rcu_read_unlock();
4973
4974 /*
4975 * Close socket after a grace period to avoid for the socket to be reused
4976 * before the application object is freed creating potential race between
4977 * threads trying to add unique in the global hash table.
4978 */
4979 if (!err_enomem) {
4980 call_rcu(&obj->head, close_notify_sock_rcu);
4981 }
4982 }
4983
4984 /*
4985 * Destroy a ust app data structure and free its memory.
4986 */
4987 void ust_app_destroy(struct ust_app *app)
4988 {
4989 if (!app) {
4990 return;
4991 }
4992
4993 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
4994 }
4995
4996 /*
4997 * Take a snapshot for a given UST session. The snapshot is sent to the given
4998 * output.
4999 *
5000 * Return 0 on success or else a negative value.
5001 */
5002 int ust_app_snapshot_record(struct ltt_ust_session *usess,
5003 struct snapshot_output *output, int wait, uint64_t max_stream_size)
5004 {
5005 int ret = 0;
5006 unsigned int snapshot_done = 0;
5007 struct lttng_ht_iter iter;
5008 struct ust_app *app;
5009 char pathname[PATH_MAX];
5010
5011 assert(usess);
5012 assert(output);
5013
5014 rcu_read_lock();
5015
5016 switch (usess->buffer_type) {
5017 case LTTNG_BUFFER_PER_UID:
5018 {
5019 struct buffer_reg_uid *reg;
5020
5021 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5022 struct buffer_reg_channel *reg_chan;
5023 struct consumer_socket *socket;
5024
5025 /* Get consumer socket to use to push the metadata.*/
5026 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5027 usess->consumer);
5028 if (!socket) {
5029 ret = -EINVAL;
5030 goto error;
5031 }
5032
5033 memset(pathname, 0, sizeof(pathname));
5034 ret = snprintf(pathname, sizeof(pathname),
5035 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
5036 reg->uid, reg->bits_per_long);
5037 if (ret < 0) {
5038 PERROR("snprintf snapshot path");
5039 goto error;
5040 }
5041
5042 /* Add the UST default trace dir to path. */
5043 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5044 reg_chan, node.node) {
5045 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key,
5046 output, 0, usess->uid, usess->gid, pathname, wait,
5047 max_stream_size);
5048 if (ret < 0) {
5049 goto error;
5050 }
5051 }
5052 ret = consumer_snapshot_channel(socket,
5053 reg->registry->reg.ust->metadata_key, output, 1,
5054 usess->uid, usess->gid, pathname, wait, max_stream_size);
5055 if (ret < 0) {
5056 goto error;
5057 }
5058 snapshot_done = 1;
5059 }
5060 break;
5061 }
5062 case LTTNG_BUFFER_PER_PID:
5063 {
5064 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5065 struct consumer_socket *socket;
5066 struct lttng_ht_iter chan_iter;
5067 struct ust_app_channel *ua_chan;
5068 struct ust_app_session *ua_sess;
5069 struct ust_registry_session *registry;
5070
5071 ua_sess = lookup_session_by_app(usess, app);
5072 if (!ua_sess) {
5073 /* Session not associated with this app. */
5074 continue;
5075 }
5076
5077 /* Get the right consumer socket for the application. */
5078 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5079 output->consumer);
5080 if (!socket) {
5081 ret = -EINVAL;
5082 goto error;
5083 }
5084
5085 /* Add the UST default trace dir to path. */
5086 memset(pathname, 0, sizeof(pathname));
5087 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
5088 ua_sess->path);
5089 if (ret < 0) {
5090 PERROR("snprintf snapshot path");
5091 goto error;
5092 }
5093
5094 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5095 ua_chan, node.node) {
5096 ret = consumer_snapshot_channel(socket, ua_chan->key, output,
5097 0, ua_sess->euid, ua_sess->egid, pathname, wait,
5098 max_stream_size);
5099 if (ret < 0) {
5100 goto error;
5101 }
5102 }
5103
5104 registry = get_session_registry(ua_sess);
5105 assert(registry);
5106 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5107 1, ua_sess->euid, ua_sess->egid, pathname, wait,
5108 max_stream_size);
5109 if (ret < 0) {
5110 goto error;
5111 }
5112 snapshot_done = 1;
5113 }
5114 break;
5115 }
5116 default:
5117 assert(0);
5118 break;
5119 }
5120
5121 if (!snapshot_done) {
5122 /*
5123 * If no snapshot was made and we are not in the error path, this means
5124 * that there are no buffers thus no (prior) application to snapshot
5125 * data from so we have simply NO data.
5126 */
5127 ret = -ENODATA;
5128 }
5129
5130 error:
5131 rcu_read_unlock();
5132 return ret;
5133 }
5134
5135 /*
5136 * Return the number of streams for a UST session.
5137 */
5138 unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
5139 {
5140 unsigned int ret = 0;
5141 struct ust_app *app;
5142 struct lttng_ht_iter iter;
5143
5144 assert(usess);
5145
5146 switch (usess->buffer_type) {
5147 case LTTNG_BUFFER_PER_UID:
5148 {
5149 struct buffer_reg_uid *reg;
5150
5151 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5152 struct buffer_reg_channel *reg_chan;
5153
5154 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5155 reg_chan, node.node) {
5156 ret += reg_chan->stream_count;
5157 }
5158 }
5159 break;
5160 }
5161 case LTTNG_BUFFER_PER_PID:
5162 {
5163 rcu_read_lock();
5164 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5165 struct ust_app_channel *ua_chan;
5166 struct ust_app_session *ua_sess;
5167 struct lttng_ht_iter chan_iter;
5168
5169 ua_sess = lookup_session_by_app(usess, app);
5170 if (!ua_sess) {
5171 /* Session not associated with this app. */
5172 continue;
5173 }
5174
5175 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5176 ua_chan, node.node) {
5177 ret += ua_chan->streams.count;
5178 }
5179 }
5180 rcu_read_unlock();
5181 break;
5182 }
5183 default:
5184 assert(0);
5185 break;
5186 }
5187
5188 return ret;
5189 }
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