Fix: ust-app: per-PID app unregister vs tracing stop races
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
... / ...
CommitLineData
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
44static
45int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
46
47/* Next available channel key. Access under next_channel_key_lock. */
48static uint64_t _next_channel_key;
49static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
50
51/* Next available session ID. Access under next_session_id_lock. */
52static uint64_t _next_session_id;
53static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
54
55/*
56 * Return the incremented value of next_channel_key.
57 */
58static uint64_t get_next_channel_key(void)
59{
60 uint64_t ret;
61
62 pthread_mutex_lock(&next_channel_key_lock);
63 ret = ++_next_channel_key;
64 pthread_mutex_unlock(&next_channel_key_lock);
65 return ret;
66}
67
68/*
69 * Return the atomically incremented value of next_session_id.
70 */
71static uint64_t get_next_session_id(void)
72{
73 uint64_t ret;
74
75 pthread_mutex_lock(&next_session_id_lock);
76 ret = ++_next_session_id;
77 pthread_mutex_unlock(&next_session_id_lock);
78 return ret;
79}
80
81static void copy_channel_attr_to_ustctl(
82 struct ustctl_consumer_channel_attr *attr,
83 struct lttng_ust_channel_attr *uattr)
84{
85 /* Copy event attributes since the layout is different. */
86 attr->subbuf_size = uattr->subbuf_size;
87 attr->num_subbuf = uattr->num_subbuf;
88 attr->overwrite = uattr->overwrite;
89 attr->switch_timer_interval = uattr->switch_timer_interval;
90 attr->read_timer_interval = uattr->read_timer_interval;
91 attr->output = uattr->output;
92}
93
94/*
95 * Match function for the hash table lookup.
96 *
97 * It matches an ust app event based on three attributes which are the event
98 * name, the filter bytecode and the loglevel.
99 */
100static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
101{
102 struct ust_app_event *event;
103 const struct ust_app_ht_key *key;
104
105 assert(node);
106 assert(_key);
107
108 event = caa_container_of(node, struct ust_app_event, node.node);
109 key = _key;
110
111 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
112
113 /* Event name */
114 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
115 goto no_match;
116 }
117
118 /* Event loglevel. */
119 if (event->attr.loglevel != key->loglevel) {
120 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
121 && key->loglevel == 0 && event->attr.loglevel == -1) {
122 /*
123 * Match is accepted. This is because on event creation, the
124 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
125 * -1 are accepted for this loglevel type since 0 is the one set by
126 * the API when receiving an enable event.
127 */
128 } else {
129 goto no_match;
130 }
131 }
132
133 /* One of the filters is NULL, fail. */
134 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
135 goto no_match;
136 }
137
138 if (key->filter && event->filter) {
139 /* Both filters exists, check length followed by the bytecode. */
140 if (event->filter->len != key->filter->len ||
141 memcmp(event->filter->data, key->filter->data,
142 event->filter->len) != 0) {
143 goto no_match;
144 }
145 }
146
147 /* One of the exclusions is NULL, fail. */
148 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
149 goto no_match;
150 }
151
152 if (key->exclusion && event->exclusion) {
153 /* Both exclusions exists, check count followed by the names. */
154 if (event->exclusion->count != key->exclusion->count ||
155 memcmp(event->exclusion->names, key->exclusion->names,
156 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
157 goto no_match;
158 }
159 }
160
161
162 /* Match. */
163 return 1;
164
165no_match:
166 return 0;
167}
168
169/*
170 * Unique add of an ust app event in the given ht. This uses the custom
171 * ht_match_ust_app_event match function and the event name as hash.
172 */
173static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
174 struct ust_app_event *event)
175{
176 struct cds_lfht_node *node_ptr;
177 struct ust_app_ht_key key;
178 struct lttng_ht *ht;
179
180 assert(ua_chan);
181 assert(ua_chan->events);
182 assert(event);
183
184 ht = ua_chan->events;
185 key.name = event->attr.name;
186 key.filter = event->filter;
187 key.loglevel = event->attr.loglevel;
188 key.exclusion = event->exclusion;
189
190 node_ptr = cds_lfht_add_unique(ht->ht,
191 ht->hash_fct(event->node.key, lttng_ht_seed),
192 ht_match_ust_app_event, &key, &event->node.node);
193 assert(node_ptr == &event->node.node);
194}
195
196/*
197 * Close the notify socket from the given RCU head object. This MUST be called
198 * through a call_rcu().
199 */
200static void close_notify_sock_rcu(struct rcu_head *head)
201{
202 int ret;
203 struct ust_app_notify_sock_obj *obj =
204 caa_container_of(head, struct ust_app_notify_sock_obj, head);
205
206 /* Must have a valid fd here. */
207 assert(obj->fd >= 0);
208
209 ret = close(obj->fd);
210 if (ret) {
211 ERR("close notify sock %d RCU", obj->fd);
212 }
213 lttng_fd_put(LTTNG_FD_APPS, 1);
214
215 free(obj);
216}
217
218/*
219 * Return the session registry according to the buffer type of the given
220 * session.
221 *
222 * A registry per UID object MUST exists before calling this function or else
223 * it assert() if not found. RCU read side lock must be acquired.
224 */
225static struct ust_registry_session *get_session_registry(
226 struct ust_app_session *ua_sess)
227{
228 struct ust_registry_session *registry = NULL;
229
230 assert(ua_sess);
231
232 switch (ua_sess->buffer_type) {
233 case LTTNG_BUFFER_PER_PID:
234 {
235 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
236 if (!reg_pid) {
237 goto error;
238 }
239 registry = reg_pid->registry->reg.ust;
240 break;
241 }
242 case LTTNG_BUFFER_PER_UID:
243 {
244 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
245 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
246 if (!reg_uid) {
247 goto error;
248 }
249 registry = reg_uid->registry->reg.ust;
250 break;
251 }
252 default:
253 assert(0);
254 };
255
256error:
257 return registry;
258}
259
260/*
261 * Delete ust context safely. RCU read lock must be held before calling
262 * this function.
263 */
264static
265void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
266{
267 int ret;
268
269 assert(ua_ctx);
270
271 if (ua_ctx->obj) {
272 ret = ustctl_release_object(sock, ua_ctx->obj);
273 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
274 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
275 sock, ua_ctx->obj->handle, ret);
276 }
277 free(ua_ctx->obj);
278 }
279 free(ua_ctx);
280}
281
282/*
283 * Delete ust app event safely. RCU read lock must be held before calling
284 * this function.
285 */
286static
287void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
288{
289 int ret;
290
291 assert(ua_event);
292
293 free(ua_event->filter);
294 if (ua_event->exclusion != NULL)
295 free(ua_event->exclusion);
296 if (ua_event->obj != NULL) {
297 ret = ustctl_release_object(sock, ua_event->obj);
298 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
299 ERR("UST app sock %d release event obj failed with ret %d",
300 sock, ret);
301 }
302 free(ua_event->obj);
303 }
304 free(ua_event);
305}
306
307/*
308 * Release ust data object of the given stream.
309 *
310 * Return 0 on success or else a negative value.
311 */
312static int release_ust_app_stream(int sock, struct ust_app_stream *stream)
313{
314 int ret = 0;
315
316 assert(stream);
317
318 if (stream->obj) {
319 ret = ustctl_release_object(sock, stream->obj);
320 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
321 ERR("UST app sock %d release stream obj failed with ret %d",
322 sock, ret);
323 }
324 lttng_fd_put(LTTNG_FD_APPS, 2);
325 free(stream->obj);
326 }
327
328 return ret;
329}
330
331/*
332 * Delete ust app stream safely. RCU read lock must be held before calling
333 * this function.
334 */
335static
336void delete_ust_app_stream(int sock, struct ust_app_stream *stream)
337{
338 assert(stream);
339
340 (void) release_ust_app_stream(sock, stream);
341 free(stream);
342}
343
344/*
345 * We need to execute ht_destroy outside of RCU read-side critical
346 * section and outside of call_rcu thread, so we postpone its execution
347 * using ht_cleanup_push. It is simpler than to change the semantic of
348 * the many callers of delete_ust_app_session().
349 */
350static
351void delete_ust_app_channel_rcu(struct rcu_head *head)
352{
353 struct ust_app_channel *ua_chan =
354 caa_container_of(head, struct ust_app_channel, rcu_head);
355
356 ht_cleanup_push(ua_chan->ctx);
357 ht_cleanup_push(ua_chan->events);
358 free(ua_chan);
359}
360
361/*
362 * Delete ust app channel safely. RCU read lock must be held before calling
363 * this function.
364 */
365static
366void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
367 struct ust_app *app)
368{
369 int ret;
370 struct lttng_ht_iter iter;
371 struct ust_app_event *ua_event;
372 struct ust_app_ctx *ua_ctx;
373 struct ust_app_stream *stream, *stmp;
374 struct ust_registry_session *registry;
375
376 assert(ua_chan);
377
378 DBG3("UST app deleting channel %s", ua_chan->name);
379
380 /* Wipe stream */
381 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
382 cds_list_del(&stream->list);
383 delete_ust_app_stream(sock, stream);
384 }
385
386 /* Wipe context */
387 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
388 cds_list_del(&ua_ctx->list);
389 ret = lttng_ht_del(ua_chan->ctx, &iter);
390 assert(!ret);
391 delete_ust_app_ctx(sock, ua_ctx);
392 }
393
394 /* Wipe events */
395 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
396 node.node) {
397 ret = lttng_ht_del(ua_chan->events, &iter);
398 assert(!ret);
399 delete_ust_app_event(sock, ua_event);
400 }
401
402 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
403 /* Wipe and free registry from session registry. */
404 registry = get_session_registry(ua_chan->session);
405 if (registry) {
406 ust_registry_channel_del_free(registry, ua_chan->key);
407 }
408 }
409
410 if (ua_chan->obj != NULL) {
411 /* Remove channel from application UST object descriptor. */
412 iter.iter.node = &ua_chan->ust_objd_node.node;
413 ret = lttng_ht_del(app->ust_objd, &iter);
414 assert(!ret);
415 ret = ustctl_release_object(sock, ua_chan->obj);
416 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
417 ERR("UST app sock %d release channel obj failed with ret %d",
418 sock, ret);
419 }
420 lttng_fd_put(LTTNG_FD_APPS, 1);
421 free(ua_chan->obj);
422 }
423 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
424}
425
426/*
427 * Push metadata to consumer socket.
428 *
429 * The socket lock MUST be acquired.
430 * The ust app session lock MUST be acquired.
431 *
432 * On success, return the len of metadata pushed or else a negative value.
433 */
434ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
435 struct consumer_socket *socket, int send_zero_data)
436{
437 int ret;
438 char *metadata_str = NULL;
439 size_t len, offset;
440 ssize_t ret_val;
441
442 assert(registry);
443 assert(socket);
444
445 /*
446 * On a push metadata error either the consumer is dead or the metadata
447 * channel has been destroyed because its endpoint might have died (e.g:
448 * relayd). If so, the metadata closed flag is set to 1 so we deny pushing
449 * metadata again which is not valid anymore on the consumer side.
450 *
451 * The ust app session mutex locked allows us to make this check without
452 * the registry lock.
453 */
454 if (registry->metadata_closed) {
455 return -EPIPE;
456 }
457
458 pthread_mutex_lock(&registry->lock);
459
460 offset = registry->metadata_len_sent;
461 len = registry->metadata_len - registry->metadata_len_sent;
462 if (len == 0) {
463 DBG3("No metadata to push for metadata key %" PRIu64,
464 registry->metadata_key);
465 ret_val = len;
466 if (send_zero_data) {
467 DBG("No metadata to push");
468 goto push_data;
469 }
470 goto end;
471 }
472
473 /* Allocate only what we have to send. */
474 metadata_str = zmalloc(len);
475 if (!metadata_str) {
476 PERROR("zmalloc ust app metadata string");
477 ret_val = -ENOMEM;
478 goto error;
479 }
480 /* Copy what we haven't send out. */
481 memcpy(metadata_str, registry->metadata + offset, len);
482 registry->metadata_len_sent += len;
483
484push_data:
485 pthread_mutex_unlock(&registry->lock);
486 ret = consumer_push_metadata(socket, registry->metadata_key,
487 metadata_str, len, offset);
488 if (ret < 0) {
489 /*
490 * There is an acceptable race here between the registry metadata key
491 * assignment and the creation on the consumer. The session daemon can
492 * concurrently push metadata for this registry while being created on
493 * the consumer since the metadata key of the registry is assigned
494 * *before* it is setup to avoid the consumer to ask for metadata that
495 * could possibly be not found in the session daemon.
496 *
497 * The metadata will get pushed either by the session being stopped or
498 * the consumer requesting metadata if that race is triggered.
499 */
500 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
501 ret = 0;
502 }
503
504 /* Update back the actual metadata len sent since it failed here. */
505 pthread_mutex_lock(&registry->lock);
506 registry->metadata_len_sent -= len;
507 pthread_mutex_unlock(&registry->lock);
508 ret_val = ret;
509 goto error_push;
510 }
511
512 free(metadata_str);
513 return len;
514
515end:
516error:
517 pthread_mutex_unlock(&registry->lock);
518error_push:
519 free(metadata_str);
520 return ret_val;
521}
522
523/*
524 * For a given application and session, push metadata to consumer. The session
525 * lock MUST be acquired here before calling this.
526 * Either sock or consumer is required : if sock is NULL, the default
527 * socket to send the metadata is retrieved from consumer, if sock
528 * is not NULL we use it to send the metadata.
529 *
530 * Return 0 on success else a negative error.
531 */
532static int push_metadata(struct ust_registry_session *registry,
533 struct consumer_output *consumer)
534{
535 int ret_val;
536 ssize_t ret;
537 struct consumer_socket *socket;
538
539 assert(registry);
540 assert(consumer);
541
542 rcu_read_lock();
543
544 /*
545 * Means that no metadata was assigned to the session. This can happens if
546 * no start has been done previously.
547 */
548 if (!registry->metadata_key) {
549 ret_val = 0;
550 goto end_rcu_unlock;
551 }
552
553 /* Get consumer socket to use to push the metadata.*/
554 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
555 consumer);
556 if (!socket) {
557 ret_val = -1;
558 goto error_rcu_unlock;
559 }
560
561 /*
562 * TODO: Currently, we hold the socket lock around sampling of the next
563 * metadata segment to ensure we send metadata over the consumer socket in
564 * the correct order. This makes the registry lock nest inside the socket
565 * lock.
566 *
567 * Please note that this is a temporary measure: we should move this lock
568 * back into ust_consumer_push_metadata() when the consumer gets the
569 * ability to reorder the metadata it receives.
570 */
571 pthread_mutex_lock(socket->lock);
572 ret = ust_app_push_metadata(registry, socket, 0);
573 pthread_mutex_unlock(socket->lock);
574 if (ret < 0) {
575 ret_val = ret;
576 goto error_rcu_unlock;
577 }
578
579 rcu_read_unlock();
580 return 0;
581
582error_rcu_unlock:
583 /*
584 * On error, flag the registry that the metadata is closed. We were unable
585 * to push anything and this means that either the consumer is not
586 * responding or the metadata cache has been destroyed on the consumer.
587 */
588 registry->metadata_closed = 1;
589end_rcu_unlock:
590 rcu_read_unlock();
591 return ret_val;
592}
593
594/*
595 * Send to the consumer a close metadata command for the given session. Once
596 * done, the metadata channel is deleted and the session metadata pointer is
597 * nullified. The session lock MUST be acquired here unless the application is
598 * in the destroy path.
599 *
600 * Return 0 on success else a negative value.
601 */
602static int close_metadata(struct ust_registry_session *registry,
603 struct consumer_output *consumer)
604{
605 int ret;
606 struct consumer_socket *socket;
607
608 assert(registry);
609 assert(consumer);
610
611 rcu_read_lock();
612
613 if (!registry->metadata_key || registry->metadata_closed) {
614 ret = 0;
615 goto end;
616 }
617
618 /* Get consumer socket to use to push the metadata.*/
619 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
620 consumer);
621 if (!socket) {
622 ret = -1;
623 goto error;
624 }
625
626 ret = consumer_close_metadata(socket, registry->metadata_key);
627 if (ret < 0) {
628 goto error;
629 }
630
631error:
632 /*
633 * Metadata closed. Even on error this means that the consumer is not
634 * responding or not found so either way a second close should NOT be emit
635 * for this registry.
636 */
637 registry->metadata_closed = 1;
638end:
639 rcu_read_unlock();
640 return ret;
641}
642
643/*
644 * We need to execute ht_destroy outside of RCU read-side critical
645 * section and outside of call_rcu thread, so we postpone its execution
646 * using ht_cleanup_push. It is simpler than to change the semantic of
647 * the many callers of delete_ust_app_session().
648 */
649static
650void delete_ust_app_session_rcu(struct rcu_head *head)
651{
652 struct ust_app_session *ua_sess =
653 caa_container_of(head, struct ust_app_session, rcu_head);
654
655 ht_cleanup_push(ua_sess->channels);
656 free(ua_sess);
657}
658
659/*
660 * Delete ust app session safely. RCU read lock must be held before calling
661 * this function.
662 */
663static
664void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
665 struct ust_app *app)
666{
667 int ret;
668 struct lttng_ht_iter iter;
669 struct ust_app_channel *ua_chan;
670 struct ust_registry_session *registry;
671
672 assert(ua_sess);
673
674 pthread_mutex_lock(&ua_sess->lock);
675
676 registry = get_session_registry(ua_sess);
677 if (registry && !registry->metadata_closed) {
678 /* Push metadata for application before freeing the application. */
679 (void) push_metadata(registry, ua_sess->consumer);
680
681 /*
682 * Don't ask to close metadata for global per UID buffers. Close
683 * metadata only on destroy trace session in this case. Also, the
684 * previous push metadata could have flag the metadata registry to
685 * close so don't send a close command if closed.
686 */
687 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
688 !registry->metadata_closed) {
689 /* And ask to close it for this session registry. */
690 (void) close_metadata(registry, ua_sess->consumer);
691 }
692 }
693
694 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
695 node.node) {
696 ret = lttng_ht_del(ua_sess->channels, &iter);
697 assert(!ret);
698 delete_ust_app_channel(sock, ua_chan, app);
699 }
700
701 /* In case of per PID, the registry is kept in the session. */
702 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
703 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
704 if (reg_pid) {
705 buffer_reg_pid_remove(reg_pid);
706 buffer_reg_pid_destroy(reg_pid);
707 }
708 }
709
710 if (ua_sess->handle != -1) {
711 ret = ustctl_release_handle(sock, ua_sess->handle);
712 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
713 ERR("UST app sock %d release session handle failed with ret %d",
714 sock, ret);
715 }
716 }
717 pthread_mutex_unlock(&ua_sess->lock);
718
719 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
720}
721
722/*
723 * Delete a traceable application structure from the global list. Never call
724 * this function outside of a call_rcu call.
725 *
726 * RCU read side lock should _NOT_ be held when calling this function.
727 */
728static
729void delete_ust_app(struct ust_app *app)
730{
731 int ret, sock;
732 struct ust_app_session *ua_sess, *tmp_ua_sess;
733
734 /* Delete ust app sessions info */
735 sock = app->sock;
736 app->sock = -1;
737
738 /* Wipe sessions */
739 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
740 teardown_node) {
741 /* Free every object in the session and the session. */
742 rcu_read_lock();
743 delete_ust_app_session(sock, ua_sess, app);
744 rcu_read_unlock();
745 }
746
747 ht_cleanup_push(app->sessions);
748 ht_cleanup_push(app->ust_objd);
749
750 /*
751 * Wait until we have deleted the application from the sock hash table
752 * before closing this socket, otherwise an application could re-use the
753 * socket ID and race with the teardown, using the same hash table entry.
754 *
755 * It's OK to leave the close in call_rcu. We want it to stay unique for
756 * all RCU readers that could run concurrently with unregister app,
757 * therefore we _need_ to only close that socket after a grace period. So
758 * it should stay in this RCU callback.
759 *
760 * This close() is a very important step of the synchronization model so
761 * every modification to this function must be carefully reviewed.
762 */
763 ret = close(sock);
764 if (ret) {
765 PERROR("close");
766 }
767 lttng_fd_put(LTTNG_FD_APPS, 1);
768
769 DBG2("UST app pid %d deleted", app->pid);
770 free(app);
771}
772
773/*
774 * URCU intermediate call to delete an UST app.
775 */
776static
777void delete_ust_app_rcu(struct rcu_head *head)
778{
779 struct lttng_ht_node_ulong *node =
780 caa_container_of(head, struct lttng_ht_node_ulong, head);
781 struct ust_app *app =
782 caa_container_of(node, struct ust_app, pid_n);
783
784 DBG3("Call RCU deleting app PID %d", app->pid);
785 delete_ust_app(app);
786}
787
788/*
789 * Delete the session from the application ht and delete the data structure by
790 * freeing every object inside and releasing them.
791 */
792static void destroy_app_session(struct ust_app *app,
793 struct ust_app_session *ua_sess)
794{
795 int ret;
796 struct lttng_ht_iter iter;
797
798 assert(app);
799 assert(ua_sess);
800
801 iter.iter.node = &ua_sess->node.node;
802 ret = lttng_ht_del(app->sessions, &iter);
803 if (ret) {
804 /* Already scheduled for teardown. */
805 goto end;
806 }
807
808 /* Once deleted, free the data structure. */
809 delete_ust_app_session(app->sock, ua_sess, app);
810
811end:
812 return;
813}
814
815/*
816 * Alloc new UST app session.
817 */
818static
819struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
820{
821 struct ust_app_session *ua_sess;
822
823 /* Init most of the default value by allocating and zeroing */
824 ua_sess = zmalloc(sizeof(struct ust_app_session));
825 if (ua_sess == NULL) {
826 PERROR("malloc");
827 goto error_free;
828 }
829
830 ua_sess->handle = -1;
831 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
832 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
833 pthread_mutex_init(&ua_sess->lock, NULL);
834
835 return ua_sess;
836
837error_free:
838 return NULL;
839}
840
841/*
842 * Alloc new UST app channel.
843 */
844static
845struct ust_app_channel *alloc_ust_app_channel(char *name,
846 struct ust_app_session *ua_sess,
847 struct lttng_ust_channel_attr *attr)
848{
849 struct ust_app_channel *ua_chan;
850
851 /* Init most of the default value by allocating and zeroing */
852 ua_chan = zmalloc(sizeof(struct ust_app_channel));
853 if (ua_chan == NULL) {
854 PERROR("malloc");
855 goto error;
856 }
857
858 /* Setup channel name */
859 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
860 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
861
862 ua_chan->enabled = 1;
863 ua_chan->handle = -1;
864 ua_chan->session = ua_sess;
865 ua_chan->key = get_next_channel_key();
866 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
867 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
868 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
869
870 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
871 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
872
873 /* Copy attributes */
874 if (attr) {
875 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
876 ua_chan->attr.subbuf_size = attr->subbuf_size;
877 ua_chan->attr.num_subbuf = attr->num_subbuf;
878 ua_chan->attr.overwrite = attr->overwrite;
879 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
880 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
881 ua_chan->attr.output = attr->output;
882 }
883 /* By default, the channel is a per cpu channel. */
884 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
885
886 DBG3("UST app channel %s allocated", ua_chan->name);
887
888 return ua_chan;
889
890error:
891 return NULL;
892}
893
894/*
895 * Allocate and initialize a UST app stream.
896 *
897 * Return newly allocated stream pointer or NULL on error.
898 */
899struct ust_app_stream *ust_app_alloc_stream(void)
900{
901 struct ust_app_stream *stream = NULL;
902
903 stream = zmalloc(sizeof(*stream));
904 if (stream == NULL) {
905 PERROR("zmalloc ust app stream");
906 goto error;
907 }
908
909 /* Zero could be a valid value for a handle so flag it to -1. */
910 stream->handle = -1;
911
912error:
913 return stream;
914}
915
916/*
917 * Alloc new UST app event.
918 */
919static
920struct ust_app_event *alloc_ust_app_event(char *name,
921 struct lttng_ust_event *attr)
922{
923 struct ust_app_event *ua_event;
924
925 /* Init most of the default value by allocating and zeroing */
926 ua_event = zmalloc(sizeof(struct ust_app_event));
927 if (ua_event == NULL) {
928 PERROR("malloc");
929 goto error;
930 }
931
932 ua_event->enabled = 1;
933 strncpy(ua_event->name, name, sizeof(ua_event->name));
934 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
935 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
936
937 /* Copy attributes */
938 if (attr) {
939 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
940 }
941
942 DBG3("UST app event %s allocated", ua_event->name);
943
944 return ua_event;
945
946error:
947 return NULL;
948}
949
950/*
951 * Alloc new UST app context.
952 */
953static
954struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
955{
956 struct ust_app_ctx *ua_ctx;
957
958 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
959 if (ua_ctx == NULL) {
960 goto error;
961 }
962
963 CDS_INIT_LIST_HEAD(&ua_ctx->list);
964
965 if (uctx) {
966 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
967 }
968
969 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
970
971error:
972 return ua_ctx;
973}
974
975/*
976 * Allocate a filter and copy the given original filter.
977 *
978 * Return allocated filter or NULL on error.
979 */
980static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
981 struct lttng_ust_filter_bytecode *orig_f)
982{
983 struct lttng_ust_filter_bytecode *filter = NULL;
984
985 /* Copy filter bytecode */
986 filter = zmalloc(sizeof(*filter) + orig_f->len);
987 if (!filter) {
988 PERROR("zmalloc alloc ust app filter");
989 goto error;
990 }
991
992 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
993
994error:
995 return filter;
996}
997
998/*
999 * Find an ust_app using the sock and return it. RCU read side lock must be
1000 * held before calling this helper function.
1001 */
1002struct ust_app *ust_app_find_by_sock(int sock)
1003{
1004 struct lttng_ht_node_ulong *node;
1005 struct lttng_ht_iter iter;
1006
1007 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1008 node = lttng_ht_iter_get_node_ulong(&iter);
1009 if (node == NULL) {
1010 DBG2("UST app find by sock %d not found", sock);
1011 goto error;
1012 }
1013
1014 return caa_container_of(node, struct ust_app, sock_n);
1015
1016error:
1017 return NULL;
1018}
1019
1020/*
1021 * Find an ust_app using the notify sock and return it. RCU read side lock must
1022 * be held before calling this helper function.
1023 */
1024static struct ust_app *find_app_by_notify_sock(int sock)
1025{
1026 struct lttng_ht_node_ulong *node;
1027 struct lttng_ht_iter iter;
1028
1029 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1030 &iter);
1031 node = lttng_ht_iter_get_node_ulong(&iter);
1032 if (node == NULL) {
1033 DBG2("UST app find by notify sock %d not found", sock);
1034 goto error;
1035 }
1036
1037 return caa_container_of(node, struct ust_app, notify_sock_n);
1038
1039error:
1040 return NULL;
1041}
1042
1043/*
1044 * Lookup for an ust app event based on event name, filter bytecode and the
1045 * event loglevel.
1046 *
1047 * Return an ust_app_event object or NULL on error.
1048 */
1049static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1050 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel,
1051 const struct lttng_event_exclusion *exclusion)
1052{
1053 struct lttng_ht_iter iter;
1054 struct lttng_ht_node_str *node;
1055 struct ust_app_event *event = NULL;
1056 struct ust_app_ht_key key;
1057
1058 assert(name);
1059 assert(ht);
1060
1061 /* Setup key for event lookup. */
1062 key.name = name;
1063 key.filter = filter;
1064 key.loglevel = loglevel;
1065 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1066 key.exclusion = (struct lttng_ust_event_exclusion *)exclusion;
1067
1068 /* Lookup using the event name as hash and a custom match fct. */
1069 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1070 ht_match_ust_app_event, &key, &iter.iter);
1071 node = lttng_ht_iter_get_node_str(&iter);
1072 if (node == NULL) {
1073 goto end;
1074 }
1075
1076 event = caa_container_of(node, struct ust_app_event, node);
1077
1078end:
1079 return event;
1080}
1081
1082/*
1083 * Create the channel context on the tracer.
1084 *
1085 * Called with UST app session lock held.
1086 */
1087static
1088int create_ust_channel_context(struct ust_app_channel *ua_chan,
1089 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1090{
1091 int ret;
1092
1093 health_code_update();
1094
1095 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1096 ua_chan->obj, &ua_ctx->obj);
1097 if (ret < 0) {
1098 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1099 ERR("UST app create channel context failed for app (pid: %d) "
1100 "with ret %d", app->pid, ret);
1101 } else {
1102 /*
1103 * This is normal behavior, an application can die during the
1104 * creation process. Don't report an error so the execution can
1105 * continue normally.
1106 */
1107 ret = 0;
1108 DBG3("UST app disable event failed. Application is dead.");
1109 }
1110 goto error;
1111 }
1112
1113 ua_ctx->handle = ua_ctx->obj->handle;
1114
1115 DBG2("UST app context handle %d created successfully for channel %s",
1116 ua_ctx->handle, ua_chan->name);
1117
1118error:
1119 health_code_update();
1120 return ret;
1121}
1122
1123/*
1124 * Set the filter on the tracer.
1125 */
1126static
1127int set_ust_event_filter(struct ust_app_event *ua_event,
1128 struct ust_app *app)
1129{
1130 int ret;
1131
1132 health_code_update();
1133
1134 if (!ua_event->filter) {
1135 ret = 0;
1136 goto error;
1137 }
1138
1139 ret = ustctl_set_filter(app->sock, ua_event->filter,
1140 ua_event->obj);
1141 if (ret < 0) {
1142 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1143 ERR("UST app event %s filter failed for app (pid: %d) "
1144 "with ret %d", ua_event->attr.name, app->pid, ret);
1145 } else {
1146 /*
1147 * This is normal behavior, an application can die during the
1148 * creation process. Don't report an error so the execution can
1149 * continue normally.
1150 */
1151 ret = 0;
1152 DBG3("UST app filter event failed. Application is dead.");
1153 }
1154 goto error;
1155 }
1156
1157 DBG2("UST filter set successfully for event %s", ua_event->name);
1158
1159error:
1160 health_code_update();
1161 return ret;
1162}
1163
1164/*
1165 * Set event exclusions on the tracer.
1166 */
1167static
1168int set_ust_event_exclusion(struct ust_app_event *ua_event,
1169 struct ust_app *app)
1170{
1171 int ret;
1172
1173 health_code_update();
1174
1175 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1176 ret = 0;
1177 goto error;
1178 }
1179
1180 ret = ustctl_set_exclusion(app->sock, ua_event->exclusion,
1181 ua_event->obj);
1182 if (ret < 0) {
1183 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1184 ERR("UST app event %s exclusions failed for app (pid: %d) "
1185 "with ret %d", ua_event->attr.name, app->pid, ret);
1186 } else {
1187 /*
1188 * This is normal behavior, an application can die during the
1189 * creation process. Don't report an error so the execution can
1190 * continue normally.
1191 */
1192 ret = 0;
1193 DBG3("UST app event exclusion failed. Application is dead.");
1194 }
1195 goto error;
1196 }
1197
1198 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1199
1200error:
1201 health_code_update();
1202 return ret;
1203}
1204
1205/*
1206 * Disable the specified event on to UST tracer for the UST session.
1207 */
1208static int disable_ust_event(struct ust_app *app,
1209 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1210{
1211 int ret;
1212
1213 health_code_update();
1214
1215 ret = ustctl_disable(app->sock, ua_event->obj);
1216 if (ret < 0) {
1217 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1218 ERR("UST app event %s disable failed for app (pid: %d) "
1219 "and session handle %d with ret %d",
1220 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1221 } else {
1222 /*
1223 * This is normal behavior, an application can die during the
1224 * creation process. Don't report an error so the execution can
1225 * continue normally.
1226 */
1227 ret = 0;
1228 DBG3("UST app disable event failed. Application is dead.");
1229 }
1230 goto error;
1231 }
1232
1233 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1234 ua_event->attr.name, app->pid);
1235
1236error:
1237 health_code_update();
1238 return ret;
1239}
1240
1241/*
1242 * Disable the specified channel on to UST tracer for the UST session.
1243 */
1244static int disable_ust_channel(struct ust_app *app,
1245 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1246{
1247 int ret;
1248
1249 health_code_update();
1250
1251 ret = ustctl_disable(app->sock, ua_chan->obj);
1252 if (ret < 0) {
1253 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1254 ERR("UST app channel %s disable failed for app (pid: %d) "
1255 "and session handle %d with ret %d",
1256 ua_chan->name, app->pid, ua_sess->handle, ret);
1257 } else {
1258 /*
1259 * This is normal behavior, an application can die during the
1260 * creation process. Don't report an error so the execution can
1261 * continue normally.
1262 */
1263 ret = 0;
1264 DBG3("UST app disable channel failed. Application is dead.");
1265 }
1266 goto error;
1267 }
1268
1269 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1270 ua_chan->name, app->pid);
1271
1272error:
1273 health_code_update();
1274 return ret;
1275}
1276
1277/*
1278 * Enable the specified channel on to UST tracer for the UST session.
1279 */
1280static int enable_ust_channel(struct ust_app *app,
1281 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1282{
1283 int ret;
1284
1285 health_code_update();
1286
1287 ret = ustctl_enable(app->sock, ua_chan->obj);
1288 if (ret < 0) {
1289 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1290 ERR("UST app channel %s enable failed for app (pid: %d) "
1291 "and session handle %d with ret %d",
1292 ua_chan->name, app->pid, ua_sess->handle, ret);
1293 } else {
1294 /*
1295 * This is normal behavior, an application can die during the
1296 * creation process. Don't report an error so the execution can
1297 * continue normally.
1298 */
1299 ret = 0;
1300 DBG3("UST app enable channel failed. Application is dead.");
1301 }
1302 goto error;
1303 }
1304
1305 ua_chan->enabled = 1;
1306
1307 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1308 ua_chan->name, app->pid);
1309
1310error:
1311 health_code_update();
1312 return ret;
1313}
1314
1315/*
1316 * Enable the specified event on to UST tracer for the UST session.
1317 */
1318static int enable_ust_event(struct ust_app *app,
1319 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1320{
1321 int ret;
1322
1323 health_code_update();
1324
1325 ret = ustctl_enable(app->sock, ua_event->obj);
1326 if (ret < 0) {
1327 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1328 ERR("UST app event %s enable failed for app (pid: %d) "
1329 "and session handle %d with ret %d",
1330 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1331 } else {
1332 /*
1333 * This is normal behavior, an application can die during the
1334 * creation process. Don't report an error so the execution can
1335 * continue normally.
1336 */
1337 ret = 0;
1338 DBG3("UST app enable event failed. Application is dead.");
1339 }
1340 goto error;
1341 }
1342
1343 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1344 ua_event->attr.name, app->pid);
1345
1346error:
1347 health_code_update();
1348 return ret;
1349}
1350
1351/*
1352 * Send channel and stream buffer to application.
1353 *
1354 * Return 0 on success. On error, a negative value is returned.
1355 */
1356static int send_channel_pid_to_ust(struct ust_app *app,
1357 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1358{
1359 int ret;
1360 struct ust_app_stream *stream, *stmp;
1361
1362 assert(app);
1363 assert(ua_sess);
1364 assert(ua_chan);
1365
1366 health_code_update();
1367
1368 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1369 app->sock);
1370
1371 /* Send channel to the application. */
1372 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1373 if (ret < 0) {
1374 goto error;
1375 }
1376
1377 health_code_update();
1378
1379 /* Send all streams to application. */
1380 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1381 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1382 if (ret < 0) {
1383 goto error;
1384 }
1385 /* We don't need the stream anymore once sent to the tracer. */
1386 cds_list_del(&stream->list);
1387 delete_ust_app_stream(-1, stream);
1388 }
1389 /* Flag the channel that it is sent to the application. */
1390 ua_chan->is_sent = 1;
1391
1392error:
1393 health_code_update();
1394 return ret;
1395}
1396
1397/*
1398 * Create the specified event onto the UST tracer for a UST session.
1399 *
1400 * Should be called with session mutex held.
1401 */
1402static
1403int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1404 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1405{
1406 int ret = 0;
1407
1408 health_code_update();
1409
1410 /* Create UST event on tracer */
1411 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1412 &ua_event->obj);
1413 if (ret < 0) {
1414 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1415 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1416 ua_event->attr.name, app->pid, ret);
1417 } else {
1418 /*
1419 * This is normal behavior, an application can die during the
1420 * creation process. Don't report an error so the execution can
1421 * continue normally.
1422 */
1423 ret = 0;
1424 DBG3("UST app create event failed. Application is dead.");
1425 }
1426 goto error;
1427 }
1428
1429 ua_event->handle = ua_event->obj->handle;
1430
1431 DBG2("UST app event %s created successfully for pid:%d",
1432 ua_event->attr.name, app->pid);
1433
1434 health_code_update();
1435
1436 /* Set filter if one is present. */
1437 if (ua_event->filter) {
1438 ret = set_ust_event_filter(ua_event, app);
1439 if (ret < 0) {
1440 goto error;
1441 }
1442 }
1443
1444 /* Set exclusions for the event */
1445 if (ua_event->exclusion) {
1446 ret = set_ust_event_exclusion(ua_event, app);
1447 if (ret < 0) {
1448 goto error;
1449 }
1450 }
1451
1452 /* If event not enabled, disable it on the tracer */
1453 if (ua_event->enabled) {
1454 /*
1455 * We now need to explicitly enable the event, since it
1456 * is now disabled at creation.
1457 */
1458 ret = enable_ust_event(app, ua_sess, ua_event);
1459 if (ret < 0) {
1460 /*
1461 * If we hit an EPERM, something is wrong with our enable call. If
1462 * we get an EEXIST, there is a problem on the tracer side since we
1463 * just created it.
1464 */
1465 switch (ret) {
1466 case -LTTNG_UST_ERR_PERM:
1467 /* Code flow problem */
1468 assert(0);
1469 case -LTTNG_UST_ERR_EXIST:
1470 /* It's OK for our use case. */
1471 ret = 0;
1472 break;
1473 default:
1474 break;
1475 }
1476 goto error;
1477 }
1478 }
1479
1480error:
1481 health_code_update();
1482 return ret;
1483}
1484
1485/*
1486 * Copy data between an UST app event and a LTT event.
1487 */
1488static void shadow_copy_event(struct ust_app_event *ua_event,
1489 struct ltt_ust_event *uevent)
1490{
1491 size_t exclusion_alloc_size;
1492
1493 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1494 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1495
1496 ua_event->enabled = uevent->enabled;
1497
1498 /* Copy event attributes */
1499 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1500
1501 /* Copy filter bytecode */
1502 if (uevent->filter) {
1503 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1504 /* Filter might be NULL here in case of ENONEM. */
1505 }
1506
1507 /* Copy exclusion data */
1508 if (uevent->exclusion) {
1509 exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1510 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1511 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1512 if (ua_event->exclusion == NULL) {
1513 PERROR("malloc");
1514 } else {
1515 memcpy(ua_event->exclusion, uevent->exclusion,
1516 exclusion_alloc_size);
1517 }
1518 }
1519}
1520
1521/*
1522 * Copy data between an UST app channel and a LTT channel.
1523 */
1524static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1525 struct ltt_ust_channel *uchan)
1526{
1527 struct lttng_ht_iter iter;
1528 struct ltt_ust_event *uevent;
1529 struct ltt_ust_context *uctx;
1530 struct ust_app_event *ua_event;
1531 struct ust_app_ctx *ua_ctx;
1532
1533 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1534
1535 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1536 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1537
1538 ua_chan->tracefile_size = uchan->tracefile_size;
1539 ua_chan->tracefile_count = uchan->tracefile_count;
1540
1541 /* Copy event attributes since the layout is different. */
1542 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1543 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1544 ua_chan->attr.overwrite = uchan->attr.overwrite;
1545 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1546 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1547 ua_chan->attr.output = uchan->attr.output;
1548 /*
1549 * Note that the attribute channel type is not set since the channel on the
1550 * tracing registry side does not have this information.
1551 */
1552
1553 ua_chan->enabled = uchan->enabled;
1554 ua_chan->tracing_channel_id = uchan->id;
1555
1556 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1557 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1558 if (ua_ctx == NULL) {
1559 continue;
1560 }
1561 lttng_ht_node_init_ulong(&ua_ctx->node,
1562 (unsigned long) ua_ctx->ctx.ctx);
1563 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1564 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1565 }
1566
1567 /* Copy all events from ltt ust channel to ust app channel */
1568 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1569 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1570 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1571 if (ua_event == NULL) {
1572 DBG2("UST event %s not found on shadow copy channel",
1573 uevent->attr.name);
1574 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1575 if (ua_event == NULL) {
1576 continue;
1577 }
1578 shadow_copy_event(ua_event, uevent);
1579 add_unique_ust_app_event(ua_chan, ua_event);
1580 }
1581 }
1582
1583 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1584}
1585
1586/*
1587 * Copy data between a UST app session and a regular LTT session.
1588 */
1589static void shadow_copy_session(struct ust_app_session *ua_sess,
1590 struct ltt_ust_session *usess, struct ust_app *app)
1591{
1592 struct lttng_ht_node_str *ua_chan_node;
1593 struct lttng_ht_iter iter;
1594 struct ltt_ust_channel *uchan;
1595 struct ust_app_channel *ua_chan;
1596 time_t rawtime;
1597 struct tm *timeinfo;
1598 char datetime[16];
1599 int ret;
1600
1601 /* Get date and time for unique app path */
1602 time(&rawtime);
1603 timeinfo = localtime(&rawtime);
1604 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1605
1606 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1607
1608 ua_sess->tracing_id = usess->id;
1609 ua_sess->id = get_next_session_id();
1610 ua_sess->uid = app->uid;
1611 ua_sess->gid = app->gid;
1612 ua_sess->euid = usess->uid;
1613 ua_sess->egid = usess->gid;
1614 ua_sess->buffer_type = usess->buffer_type;
1615 ua_sess->bits_per_long = app->bits_per_long;
1616 /* There is only one consumer object per session possible. */
1617 ua_sess->consumer = usess->consumer;
1618 ua_sess->output_traces = usess->output_traces;
1619 ua_sess->live_timer_interval = usess->live_timer_interval;
1620 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1621 &usess->metadata_attr);
1622
1623 switch (ua_sess->buffer_type) {
1624 case LTTNG_BUFFER_PER_PID:
1625 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1626 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1627 datetime);
1628 break;
1629 case LTTNG_BUFFER_PER_UID:
1630 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1631 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1632 break;
1633 default:
1634 assert(0);
1635 goto error;
1636 }
1637 if (ret < 0) {
1638 PERROR("asprintf UST shadow copy session");
1639 assert(0);
1640 goto error;
1641 }
1642
1643 /* Iterate over all channels in global domain. */
1644 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1645 uchan, node.node) {
1646 struct lttng_ht_iter uiter;
1647
1648 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1649 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1650 if (ua_chan_node != NULL) {
1651 /* Session exist. Contiuing. */
1652 continue;
1653 }
1654
1655 DBG2("Channel %s not found on shadow session copy, creating it",
1656 uchan->name);
1657 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1658 if (ua_chan == NULL) {
1659 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1660 continue;
1661 }
1662 shadow_copy_channel(ua_chan, uchan);
1663 /*
1664 * The concept of metadata channel does not exist on the tracing
1665 * registry side of the session daemon so this can only be a per CPU
1666 * channel and not metadata.
1667 */
1668 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1669
1670 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1671 }
1672
1673error:
1674 return;
1675}
1676
1677/*
1678 * Lookup sesison wrapper.
1679 */
1680static
1681void __lookup_session_by_app(struct ltt_ust_session *usess,
1682 struct ust_app *app, struct lttng_ht_iter *iter)
1683{
1684 /* Get right UST app session from app */
1685 lttng_ht_lookup(app->sessions, &usess->id, iter);
1686}
1687
1688/*
1689 * Return ust app session from the app session hashtable using the UST session
1690 * id.
1691 */
1692static struct ust_app_session *lookup_session_by_app(
1693 struct ltt_ust_session *usess, struct ust_app *app)
1694{
1695 struct lttng_ht_iter iter;
1696 struct lttng_ht_node_u64 *node;
1697
1698 __lookup_session_by_app(usess, app, &iter);
1699 node = lttng_ht_iter_get_node_u64(&iter);
1700 if (node == NULL) {
1701 goto error;
1702 }
1703
1704 return caa_container_of(node, struct ust_app_session, node);
1705
1706error:
1707 return NULL;
1708}
1709
1710/*
1711 * Setup buffer registry per PID for the given session and application. If none
1712 * is found, a new one is created, added to the global registry and
1713 * initialized. If regp is valid, it's set with the newly created object.
1714 *
1715 * Return 0 on success or else a negative value.
1716 */
1717static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1718 struct ust_app *app, struct buffer_reg_pid **regp)
1719{
1720 int ret = 0;
1721 struct buffer_reg_pid *reg_pid;
1722
1723 assert(ua_sess);
1724 assert(app);
1725
1726 rcu_read_lock();
1727
1728 reg_pid = buffer_reg_pid_find(ua_sess->id);
1729 if (!reg_pid) {
1730 /*
1731 * This is the create channel path meaning that if there is NO
1732 * registry available, we have to create one for this session.
1733 */
1734 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1735 if (ret < 0) {
1736 goto error;
1737 }
1738 } else {
1739 goto end;
1740 }
1741
1742 /* Initialize registry. */
1743 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1744 app->bits_per_long, app->uint8_t_alignment,
1745 app->uint16_t_alignment, app->uint32_t_alignment,
1746 app->uint64_t_alignment, app->long_alignment,
1747 app->byte_order, app->version.major,
1748 app->version.minor);
1749 if (ret < 0) {
1750 /*
1751 * reg_pid->registry->reg.ust is NULL upon error, so we need to
1752 * destroy the buffer registry, because it is always expected
1753 * that if the buffer registry can be found, its ust registry is
1754 * non-NULL.
1755 */
1756 buffer_reg_pid_destroy(reg_pid);
1757 goto error;
1758 }
1759
1760 buffer_reg_pid_add(reg_pid);
1761
1762 DBG3("UST app buffer registry per PID created successfully");
1763
1764end:
1765 if (regp) {
1766 *regp = reg_pid;
1767 }
1768error:
1769 rcu_read_unlock();
1770 return ret;
1771}
1772
1773/*
1774 * Setup buffer registry per UID for the given session and application. If none
1775 * is found, a new one is created, added to the global registry and
1776 * initialized. If regp is valid, it's set with the newly created object.
1777 *
1778 * Return 0 on success or else a negative value.
1779 */
1780static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1781 struct ust_app *app, struct buffer_reg_uid **regp)
1782{
1783 int ret = 0;
1784 struct buffer_reg_uid *reg_uid;
1785
1786 assert(usess);
1787 assert(app);
1788
1789 rcu_read_lock();
1790
1791 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1792 if (!reg_uid) {
1793 /*
1794 * This is the create channel path meaning that if there is NO
1795 * registry available, we have to create one for this session.
1796 */
1797 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1798 LTTNG_DOMAIN_UST, &reg_uid);
1799 if (ret < 0) {
1800 goto error;
1801 }
1802 } else {
1803 goto end;
1804 }
1805
1806 /* Initialize registry. */
1807 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1808 app->bits_per_long, app->uint8_t_alignment,
1809 app->uint16_t_alignment, app->uint32_t_alignment,
1810 app->uint64_t_alignment, app->long_alignment,
1811 app->byte_order, app->version.major,
1812 app->version.minor);
1813 if (ret < 0) {
1814 /*
1815 * reg_uid->registry->reg.ust is NULL upon error, so we need to
1816 * destroy the buffer registry, because it is always expected
1817 * that if the buffer registry can be found, its ust registry is
1818 * non-NULL.
1819 */
1820 buffer_reg_uid_destroy(reg_uid, NULL);
1821 goto error;
1822 }
1823 /* Add node to teardown list of the session. */
1824 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1825
1826 buffer_reg_uid_add(reg_uid);
1827
1828 DBG3("UST app buffer registry per UID created successfully");
1829end:
1830 if (regp) {
1831 *regp = reg_uid;
1832 }
1833error:
1834 rcu_read_unlock();
1835 return ret;
1836}
1837
1838/*
1839 * Create a session on the tracer side for the given app.
1840 *
1841 * On success, ua_sess_ptr is populated with the session pointer or else left
1842 * untouched. If the session was created, is_created is set to 1. On error,
1843 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1844 * be NULL.
1845 *
1846 * Returns 0 on success or else a negative code which is either -ENOMEM or
1847 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1848 */
1849static int create_ust_app_session(struct ltt_ust_session *usess,
1850 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1851 int *is_created)
1852{
1853 int ret, created = 0;
1854 struct ust_app_session *ua_sess;
1855
1856 assert(usess);
1857 assert(app);
1858 assert(ua_sess_ptr);
1859
1860 health_code_update();
1861
1862 ua_sess = lookup_session_by_app(usess, app);
1863 if (ua_sess == NULL) {
1864 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1865 app->pid, usess->id);
1866 ua_sess = alloc_ust_app_session(app);
1867 if (ua_sess == NULL) {
1868 /* Only malloc can failed so something is really wrong */
1869 ret = -ENOMEM;
1870 goto error;
1871 }
1872 shadow_copy_session(ua_sess, usess, app);
1873 created = 1;
1874 }
1875
1876 switch (usess->buffer_type) {
1877 case LTTNG_BUFFER_PER_PID:
1878 /* Init local registry. */
1879 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1880 if (ret < 0) {
1881 delete_ust_app_session(-1, ua_sess, app);
1882 goto error;
1883 }
1884 break;
1885 case LTTNG_BUFFER_PER_UID:
1886 /* Look for a global registry. If none exists, create one. */
1887 ret = setup_buffer_reg_uid(usess, app, NULL);
1888 if (ret < 0) {
1889 delete_ust_app_session(-1, ua_sess, app);
1890 goto error;
1891 }
1892 break;
1893 default:
1894 assert(0);
1895 ret = -EINVAL;
1896 goto error;
1897 }
1898
1899 health_code_update();
1900
1901 if (ua_sess->handle == -1) {
1902 ret = ustctl_create_session(app->sock);
1903 if (ret < 0) {
1904 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1905 ERR("Creating session for app pid %d with ret %d",
1906 app->pid, ret);
1907 } else {
1908 DBG("UST app creating session failed. Application is dead");
1909 /*
1910 * This is normal behavior, an application can die during the
1911 * creation process. Don't report an error so the execution can
1912 * continue normally. This will get flagged ENOTCONN and the
1913 * caller will handle it.
1914 */
1915 ret = 0;
1916 }
1917 delete_ust_app_session(-1, ua_sess, app);
1918 if (ret != -ENOMEM) {
1919 /*
1920 * Tracer is probably gone or got an internal error so let's
1921 * behave like it will soon unregister or not usable.
1922 */
1923 ret = -ENOTCONN;
1924 }
1925 goto error;
1926 }
1927
1928 ua_sess->handle = ret;
1929
1930 /* Add ust app session to app's HT */
1931 lttng_ht_node_init_u64(&ua_sess->node,
1932 ua_sess->tracing_id);
1933 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1934
1935 DBG2("UST app session created successfully with handle %d", ret);
1936 }
1937
1938 *ua_sess_ptr = ua_sess;
1939 if (is_created) {
1940 *is_created = created;
1941 }
1942
1943 /* Everything went well. */
1944 ret = 0;
1945
1946error:
1947 health_code_update();
1948 return ret;
1949}
1950
1951/*
1952 * Match function for a hash table lookup of ust_app_ctx.
1953 *
1954 * It matches an ust app context based on the context type and, in the case
1955 * of perf counters, their name.
1956 */
1957static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
1958{
1959 struct ust_app_ctx *ctx;
1960 const struct lttng_ust_context *key;
1961
1962 assert(node);
1963 assert(_key);
1964
1965 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
1966 key = _key;
1967
1968 /* Context type */
1969 if (ctx->ctx.ctx != key->ctx) {
1970 goto no_match;
1971 }
1972
1973 /* Check the name in the case of perf thread counters. */
1974 if (key->ctx == LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER) {
1975 if (strncmp(key->u.perf_counter.name,
1976 ctx->ctx.u.perf_counter.name,
1977 sizeof(key->u.perf_counter.name))) {
1978 goto no_match;
1979 }
1980 }
1981
1982 /* Match. */
1983 return 1;
1984
1985no_match:
1986 return 0;
1987}
1988
1989/*
1990 * Lookup for an ust app context from an lttng_ust_context.
1991 *
1992 * Must be called while holding RCU read side lock.
1993 * Return an ust_app_ctx object or NULL on error.
1994 */
1995static
1996struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
1997 struct lttng_ust_context *uctx)
1998{
1999 struct lttng_ht_iter iter;
2000 struct lttng_ht_node_ulong *node;
2001 struct ust_app_ctx *app_ctx = NULL;
2002
2003 assert(uctx);
2004 assert(ht);
2005
2006 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2007 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2008 ht_match_ust_app_ctx, uctx, &iter.iter);
2009 node = lttng_ht_iter_get_node_ulong(&iter);
2010 if (!node) {
2011 goto end;
2012 }
2013
2014 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2015
2016end:
2017 return app_ctx;
2018}
2019
2020/*
2021 * Create a context for the channel on the tracer.
2022 *
2023 * Called with UST app session lock held and a RCU read side lock.
2024 */
2025static
2026int create_ust_app_channel_context(struct ust_app_session *ua_sess,
2027 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
2028 struct ust_app *app)
2029{
2030 int ret = 0;
2031 struct ust_app_ctx *ua_ctx;
2032
2033 DBG2("UST app adding context to channel %s", ua_chan->name);
2034
2035 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2036 if (ua_ctx) {
2037 ret = -EEXIST;
2038 goto error;
2039 }
2040
2041 ua_ctx = alloc_ust_app_ctx(uctx);
2042 if (ua_ctx == NULL) {
2043 /* malloc failed */
2044 ret = -1;
2045 goto error;
2046 }
2047
2048 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2049 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2050 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2051
2052 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2053 if (ret < 0) {
2054 goto error;
2055 }
2056
2057error:
2058 return ret;
2059}
2060
2061/*
2062 * Enable on the tracer side a ust app event for the session and channel.
2063 *
2064 * Called with UST app session lock held.
2065 */
2066static
2067int enable_ust_app_event(struct ust_app_session *ua_sess,
2068 struct ust_app_event *ua_event, struct ust_app *app)
2069{
2070 int ret;
2071
2072 ret = enable_ust_event(app, ua_sess, ua_event);
2073 if (ret < 0) {
2074 goto error;
2075 }
2076
2077 ua_event->enabled = 1;
2078
2079error:
2080 return ret;
2081}
2082
2083/*
2084 * Disable on the tracer side a ust app event for the session and channel.
2085 */
2086static int disable_ust_app_event(struct ust_app_session *ua_sess,
2087 struct ust_app_event *ua_event, struct ust_app *app)
2088{
2089 int ret;
2090
2091 ret = disable_ust_event(app, ua_sess, ua_event);
2092 if (ret < 0) {
2093 goto error;
2094 }
2095
2096 ua_event->enabled = 0;
2097
2098error:
2099 return ret;
2100}
2101
2102/*
2103 * Lookup ust app channel for session and disable it on the tracer side.
2104 */
2105static
2106int disable_ust_app_channel(struct ust_app_session *ua_sess,
2107 struct ust_app_channel *ua_chan, struct ust_app *app)
2108{
2109 int ret;
2110
2111 ret = disable_ust_channel(app, ua_sess, ua_chan);
2112 if (ret < 0) {
2113 goto error;
2114 }
2115
2116 ua_chan->enabled = 0;
2117
2118error:
2119 return ret;
2120}
2121
2122/*
2123 * Lookup ust app channel for session and enable it on the tracer side. This
2124 * MUST be called with a RCU read side lock acquired.
2125 */
2126static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2127 struct ltt_ust_channel *uchan, struct ust_app *app)
2128{
2129 int ret = 0;
2130 struct lttng_ht_iter iter;
2131 struct lttng_ht_node_str *ua_chan_node;
2132 struct ust_app_channel *ua_chan;
2133
2134 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2135 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2136 if (ua_chan_node == NULL) {
2137 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2138 uchan->name, ua_sess->tracing_id);
2139 goto error;
2140 }
2141
2142 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2143
2144 ret = enable_ust_channel(app, ua_sess, ua_chan);
2145 if (ret < 0) {
2146 goto error;
2147 }
2148
2149error:
2150 return ret;
2151}
2152
2153/*
2154 * Ask the consumer to create a channel and get it if successful.
2155 *
2156 * Return 0 on success or else a negative value.
2157 */
2158static int do_consumer_create_channel(struct ltt_ust_session *usess,
2159 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2160 int bitness, struct ust_registry_session *registry)
2161{
2162 int ret;
2163 unsigned int nb_fd = 0;
2164 struct consumer_socket *socket;
2165
2166 assert(usess);
2167 assert(ua_sess);
2168 assert(ua_chan);
2169 assert(registry);
2170
2171 rcu_read_lock();
2172 health_code_update();
2173
2174 /* Get the right consumer socket for the application. */
2175 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2176 if (!socket) {
2177 ret = -EINVAL;
2178 goto error;
2179 }
2180
2181 health_code_update();
2182
2183 /* Need one fd for the channel. */
2184 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2185 if (ret < 0) {
2186 ERR("Exhausted number of available FD upon create channel");
2187 goto error;
2188 }
2189
2190 /*
2191 * Ask consumer to create channel. The consumer will return the number of
2192 * stream we have to expect.
2193 */
2194 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2195 registry);
2196 if (ret < 0) {
2197 goto error_ask;
2198 }
2199
2200 /*
2201 * Compute the number of fd needed before receiving them. It must be 2 per
2202 * stream (2 being the default value here).
2203 */
2204 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2205
2206 /* Reserve the amount of file descriptor we need. */
2207 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2208 if (ret < 0) {
2209 ERR("Exhausted number of available FD upon create channel");
2210 goto error_fd_get_stream;
2211 }
2212
2213 health_code_update();
2214
2215 /*
2216 * Now get the channel from the consumer. This call wil populate the stream
2217 * list of that channel and set the ust objects.
2218 */
2219 if (usess->consumer->enabled) {
2220 ret = ust_consumer_get_channel(socket, ua_chan);
2221 if (ret < 0) {
2222 goto error_destroy;
2223 }
2224 }
2225
2226 rcu_read_unlock();
2227 return 0;
2228
2229error_destroy:
2230 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2231error_fd_get_stream:
2232 /*
2233 * Initiate a destroy channel on the consumer since we had an error
2234 * handling it on our side. The return value is of no importance since we
2235 * already have a ret value set by the previous error that we need to
2236 * return.
2237 */
2238 (void) ust_consumer_destroy_channel(socket, ua_chan);
2239error_ask:
2240 lttng_fd_put(LTTNG_FD_APPS, 1);
2241error:
2242 health_code_update();
2243 rcu_read_unlock();
2244 return ret;
2245}
2246
2247/*
2248 * Duplicate the ust data object of the ust app stream and save it in the
2249 * buffer registry stream.
2250 *
2251 * Return 0 on success or else a negative value.
2252 */
2253static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2254 struct ust_app_stream *stream)
2255{
2256 int ret;
2257
2258 assert(reg_stream);
2259 assert(stream);
2260
2261 /* Reserve the amount of file descriptor we need. */
2262 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2263 if (ret < 0) {
2264 ERR("Exhausted number of available FD upon duplicate stream");
2265 goto error;
2266 }
2267
2268 /* Duplicate object for stream once the original is in the registry. */
2269 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2270 reg_stream->obj.ust);
2271 if (ret < 0) {
2272 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2273 reg_stream->obj.ust, stream->obj, ret);
2274 lttng_fd_put(LTTNG_FD_APPS, 2);
2275 goto error;
2276 }
2277 stream->handle = stream->obj->handle;
2278
2279error:
2280 return ret;
2281}
2282
2283/*
2284 * Duplicate the ust data object of the ust app. channel and save it in the
2285 * buffer registry channel.
2286 *
2287 * Return 0 on success or else a negative value.
2288 */
2289static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2290 struct ust_app_channel *ua_chan)
2291{
2292 int ret;
2293
2294 assert(reg_chan);
2295 assert(ua_chan);
2296
2297 /* Need two fds for the channel. */
2298 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2299 if (ret < 0) {
2300 ERR("Exhausted number of available FD upon duplicate channel");
2301 goto error_fd_get;
2302 }
2303
2304 /* Duplicate object for stream once the original is in the registry. */
2305 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2306 if (ret < 0) {
2307 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2308 reg_chan->obj.ust, ua_chan->obj, ret);
2309 goto error;
2310 }
2311 ua_chan->handle = ua_chan->obj->handle;
2312
2313 return 0;
2314
2315error:
2316 lttng_fd_put(LTTNG_FD_APPS, 1);
2317error_fd_get:
2318 return ret;
2319}
2320
2321/*
2322 * For a given channel buffer registry, setup all streams of the given ust
2323 * application channel.
2324 *
2325 * Return 0 on success or else a negative value.
2326 */
2327static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2328 struct ust_app_channel *ua_chan)
2329{
2330 int ret = 0;
2331 struct ust_app_stream *stream, *stmp;
2332
2333 assert(reg_chan);
2334 assert(ua_chan);
2335
2336 DBG2("UST app setup buffer registry stream");
2337
2338 /* Send all streams to application. */
2339 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2340 struct buffer_reg_stream *reg_stream;
2341
2342 ret = buffer_reg_stream_create(&reg_stream);
2343 if (ret < 0) {
2344 goto error;
2345 }
2346
2347 /*
2348 * Keep original pointer and nullify it in the stream so the delete
2349 * stream call does not release the object.
2350 */
2351 reg_stream->obj.ust = stream->obj;
2352 stream->obj = NULL;
2353 buffer_reg_stream_add(reg_stream, reg_chan);
2354
2355 /* We don't need the streams anymore. */
2356 cds_list_del(&stream->list);
2357 delete_ust_app_stream(-1, stream);
2358 }
2359
2360error:
2361 return ret;
2362}
2363
2364/*
2365 * Create a buffer registry channel for the given session registry and
2366 * application channel object. If regp pointer is valid, it's set with the
2367 * created object. Important, the created object is NOT added to the session
2368 * registry hash table.
2369 *
2370 * Return 0 on success else a negative value.
2371 */
2372static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2373 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2374{
2375 int ret;
2376 struct buffer_reg_channel *reg_chan = NULL;
2377
2378 assert(reg_sess);
2379 assert(ua_chan);
2380
2381 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2382
2383 /* Create buffer registry channel. */
2384 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2385 if (ret < 0) {
2386 goto error_create;
2387 }
2388 assert(reg_chan);
2389 reg_chan->consumer_key = ua_chan->key;
2390 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2391
2392 /* Create and add a channel registry to session. */
2393 ret = ust_registry_channel_add(reg_sess->reg.ust,
2394 ua_chan->tracing_channel_id);
2395 if (ret < 0) {
2396 goto error;
2397 }
2398 buffer_reg_channel_add(reg_sess, reg_chan);
2399
2400 if (regp) {
2401 *regp = reg_chan;
2402 }
2403
2404 return 0;
2405
2406error:
2407 /* Safe because the registry channel object was not added to any HT. */
2408 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2409error_create:
2410 return ret;
2411}
2412
2413/*
2414 * Setup buffer registry channel for the given session registry and application
2415 * channel object. If regp pointer is valid, it's set with the created object.
2416 *
2417 * Return 0 on success else a negative value.
2418 */
2419static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2420 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2421{
2422 int ret;
2423
2424 assert(reg_sess);
2425 assert(reg_chan);
2426 assert(ua_chan);
2427 assert(ua_chan->obj);
2428
2429 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2430
2431 /* Setup all streams for the registry. */
2432 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2433 if (ret < 0) {
2434 goto error;
2435 }
2436
2437 reg_chan->obj.ust = ua_chan->obj;
2438 ua_chan->obj = NULL;
2439
2440 return 0;
2441
2442error:
2443 buffer_reg_channel_remove(reg_sess, reg_chan);
2444 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2445 return ret;
2446}
2447
2448/*
2449 * Send buffer registry channel to the application.
2450 *
2451 * Return 0 on success else a negative value.
2452 */
2453static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2454 struct ust_app *app, struct ust_app_session *ua_sess,
2455 struct ust_app_channel *ua_chan)
2456{
2457 int ret;
2458 struct buffer_reg_stream *reg_stream;
2459
2460 assert(reg_chan);
2461 assert(app);
2462 assert(ua_sess);
2463 assert(ua_chan);
2464
2465 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2466
2467 ret = duplicate_channel_object(reg_chan, ua_chan);
2468 if (ret < 0) {
2469 goto error;
2470 }
2471
2472 /* Send channel to the application. */
2473 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2474 if (ret < 0) {
2475 goto error;
2476 }
2477
2478 health_code_update();
2479
2480 /* Send all streams to application. */
2481 pthread_mutex_lock(&reg_chan->stream_list_lock);
2482 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2483 struct ust_app_stream stream;
2484
2485 ret = duplicate_stream_object(reg_stream, &stream);
2486 if (ret < 0) {
2487 goto error_stream_unlock;
2488 }
2489
2490 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2491 if (ret < 0) {
2492 (void) release_ust_app_stream(-1, &stream);
2493 goto error_stream_unlock;
2494 }
2495
2496 /*
2497 * The return value is not important here. This function will output an
2498 * error if needed.
2499 */
2500 (void) release_ust_app_stream(-1, &stream);
2501 }
2502 ua_chan->is_sent = 1;
2503
2504error_stream_unlock:
2505 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2506error:
2507 return ret;
2508}
2509
2510/*
2511 * Create and send to the application the created buffers with per UID buffers.
2512 *
2513 * Return 0 on success else a negative value.
2514 */
2515static int create_channel_per_uid(struct ust_app *app,
2516 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2517 struct ust_app_channel *ua_chan)
2518{
2519 int ret;
2520 struct buffer_reg_uid *reg_uid;
2521 struct buffer_reg_channel *reg_chan;
2522
2523 assert(app);
2524 assert(usess);
2525 assert(ua_sess);
2526 assert(ua_chan);
2527
2528 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2529
2530 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2531 /*
2532 * The session creation handles the creation of this global registry
2533 * object. If none can be find, there is a code flow problem or a
2534 * teardown race.
2535 */
2536 assert(reg_uid);
2537
2538 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2539 reg_uid);
2540 if (!reg_chan) {
2541 /* Create the buffer registry channel object. */
2542 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2543 if (ret < 0) {
2544 ERR("Error creating the UST channel \"%s\" registry instance",
2545 ua_chan->name);
2546 goto error;
2547 }
2548 assert(reg_chan);
2549
2550 /*
2551 * Create the buffers on the consumer side. This call populates the
2552 * ust app channel object with all streams and data object.
2553 */
2554 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2555 app->bits_per_long, reg_uid->registry->reg.ust);
2556 if (ret < 0) {
2557 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2558 ua_chan->name);
2559
2560 /*
2561 * Let's remove the previously created buffer registry channel so
2562 * it's not visible anymore in the session registry.
2563 */
2564 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2565 ua_chan->tracing_channel_id);
2566 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2567 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2568 goto error;
2569 }
2570
2571 /*
2572 * Setup the streams and add it to the session registry.
2573 */
2574 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2575 if (ret < 0) {
2576 ERR("Error setting up UST channel \"%s\"",
2577 ua_chan->name);
2578 goto error;
2579 }
2580
2581 }
2582
2583 /* Send buffers to the application. */
2584 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2585 if (ret < 0) {
2586 /*
2587 * Don't report error to the console, since it may be
2588 * caused by application concurrently exiting.
2589 */
2590 goto error;
2591 }
2592
2593error:
2594 return ret;
2595}
2596
2597/*
2598 * Create and send to the application the created buffers with per PID buffers.
2599 *
2600 * Return 0 on success else a negative value.
2601 */
2602static int create_channel_per_pid(struct ust_app *app,
2603 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2604 struct ust_app_channel *ua_chan)
2605{
2606 int ret;
2607 struct ust_registry_session *registry;
2608
2609 assert(app);
2610 assert(usess);
2611 assert(ua_sess);
2612 assert(ua_chan);
2613
2614 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2615
2616 rcu_read_lock();
2617
2618 registry = get_session_registry(ua_sess);
2619 assert(registry);
2620
2621 /* Create and add a new channel registry to session. */
2622 ret = ust_registry_channel_add(registry, ua_chan->key);
2623 if (ret < 0) {
2624 ERR("Error creating the UST channel \"%s\" registry instance",
2625 ua_chan->name);
2626 goto error;
2627 }
2628
2629 /* Create and get channel on the consumer side. */
2630 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2631 app->bits_per_long, registry);
2632 if (ret < 0) {
2633 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2634 ua_chan->name);
2635 goto error;
2636 }
2637
2638 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2639 if (ret < 0) {
2640 /*
2641 * Don't report error to the console, since it may be
2642 * caused by application concurrently exiting.
2643 */
2644 goto error;
2645 }
2646
2647error:
2648 rcu_read_unlock();
2649 return ret;
2650}
2651
2652/*
2653 * From an already allocated ust app channel, create the channel buffers if
2654 * need and send it to the application. This MUST be called with a RCU read
2655 * side lock acquired.
2656 *
2657 * Return 0 on success or else a negative value.
2658 */
2659static int do_create_channel(struct ust_app *app,
2660 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2661 struct ust_app_channel *ua_chan)
2662{
2663 int ret;
2664
2665 assert(app);
2666 assert(usess);
2667 assert(ua_sess);
2668 assert(ua_chan);
2669
2670 /* Handle buffer type before sending the channel to the application. */
2671 switch (usess->buffer_type) {
2672 case LTTNG_BUFFER_PER_UID:
2673 {
2674 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2675 if (ret < 0) {
2676 goto error;
2677 }
2678 break;
2679 }
2680 case LTTNG_BUFFER_PER_PID:
2681 {
2682 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2683 if (ret < 0) {
2684 goto error;
2685 }
2686 break;
2687 }
2688 default:
2689 assert(0);
2690 ret = -EINVAL;
2691 goto error;
2692 }
2693
2694 /* Initialize ust objd object using the received handle and add it. */
2695 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2696 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2697
2698 /* If channel is not enabled, disable it on the tracer */
2699 if (!ua_chan->enabled) {
2700 ret = disable_ust_channel(app, ua_sess, ua_chan);
2701 if (ret < 0) {
2702 goto error;
2703 }
2704 }
2705
2706error:
2707 return ret;
2708}
2709
2710/*
2711 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2712 * newly created channel if not NULL.
2713 *
2714 * Called with UST app session lock and RCU read-side lock held.
2715 *
2716 * Return 0 on success or else a negative value.
2717 */
2718static int create_ust_app_channel(struct ust_app_session *ua_sess,
2719 struct ltt_ust_channel *uchan, struct ust_app *app,
2720 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2721 struct ust_app_channel **ua_chanp)
2722{
2723 int ret = 0;
2724 struct lttng_ht_iter iter;
2725 struct lttng_ht_node_str *ua_chan_node;
2726 struct ust_app_channel *ua_chan;
2727
2728 /* Lookup channel in the ust app session */
2729 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2730 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2731 if (ua_chan_node != NULL) {
2732 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2733 goto end;
2734 }
2735
2736 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2737 if (ua_chan == NULL) {
2738 /* Only malloc can fail here */
2739 ret = -ENOMEM;
2740 goto error_alloc;
2741 }
2742 shadow_copy_channel(ua_chan, uchan);
2743
2744 /* Set channel type. */
2745 ua_chan->attr.type = type;
2746
2747 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2748 if (ret < 0) {
2749 goto error;
2750 }
2751
2752 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2753 app->pid);
2754
2755 /* Only add the channel if successful on the tracer side. */
2756 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2757
2758end:
2759 if (ua_chanp) {
2760 *ua_chanp = ua_chan;
2761 }
2762
2763 /* Everything went well. */
2764 return 0;
2765
2766error:
2767 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2768error_alloc:
2769 return ret;
2770}
2771
2772/*
2773 * Create UST app event and create it on the tracer side.
2774 *
2775 * Called with ust app session mutex held.
2776 */
2777static
2778int create_ust_app_event(struct ust_app_session *ua_sess,
2779 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2780 struct ust_app *app)
2781{
2782 int ret = 0;
2783 struct ust_app_event *ua_event;
2784
2785 /* Get event node */
2786 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2787 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
2788 if (ua_event != NULL) {
2789 ret = -EEXIST;
2790 goto end;
2791 }
2792
2793 /* Does not exist so create one */
2794 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2795 if (ua_event == NULL) {
2796 /* Only malloc can failed so something is really wrong */
2797 ret = -ENOMEM;
2798 goto end;
2799 }
2800 shadow_copy_event(ua_event, uevent);
2801
2802 /* Create it on the tracer side */
2803 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2804 if (ret < 0) {
2805 /* Not found previously means that it does not exist on the tracer */
2806 assert(ret != -LTTNG_UST_ERR_EXIST);
2807 goto error;
2808 }
2809
2810 add_unique_ust_app_event(ua_chan, ua_event);
2811
2812 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2813 app->pid);
2814
2815end:
2816 return ret;
2817
2818error:
2819 /* Valid. Calling here is already in a read side lock */
2820 delete_ust_app_event(-1, ua_event);
2821 return ret;
2822}
2823
2824/*
2825 * Create UST metadata and open it on the tracer side.
2826 *
2827 * Called with UST app session lock held and RCU read side lock.
2828 */
2829static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2830 struct ust_app *app, struct consumer_output *consumer)
2831{
2832 int ret = 0;
2833 struct ust_app_channel *metadata;
2834 struct consumer_socket *socket;
2835 struct ust_registry_session *registry;
2836
2837 assert(ua_sess);
2838 assert(app);
2839 assert(consumer);
2840
2841 registry = get_session_registry(ua_sess);
2842 assert(registry);
2843
2844 /* Metadata already exists for this registry or it was closed previously */
2845 if (registry->metadata_key || registry->metadata_closed) {
2846 ret = 0;
2847 goto error;
2848 }
2849
2850 /* Allocate UST metadata */
2851 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2852 if (!metadata) {
2853 /* malloc() failed */
2854 ret = -ENOMEM;
2855 goto error;
2856 }
2857
2858 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
2859
2860 /* Need one fd for the channel. */
2861 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2862 if (ret < 0) {
2863 ERR("Exhausted number of available FD upon create metadata");
2864 goto error;
2865 }
2866
2867 /* Get the right consumer socket for the application. */
2868 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2869 if (!socket) {
2870 ret = -EINVAL;
2871 goto error_consumer;
2872 }
2873
2874 /*
2875 * Keep metadata key so we can identify it on the consumer side. Assign it
2876 * to the registry *before* we ask the consumer so we avoid the race of the
2877 * consumer requesting the metadata and the ask_channel call on our side
2878 * did not returned yet.
2879 */
2880 registry->metadata_key = metadata->key;
2881
2882 /*
2883 * Ask the metadata channel creation to the consumer. The metadata object
2884 * will be created by the consumer and kept their. However, the stream is
2885 * never added or monitored until we do a first push metadata to the
2886 * consumer.
2887 */
2888 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2889 registry);
2890 if (ret < 0) {
2891 /* Nullify the metadata key so we don't try to close it later on. */
2892 registry->metadata_key = 0;
2893 goto error_consumer;
2894 }
2895
2896 /*
2897 * The setup command will make the metadata stream be sent to the relayd,
2898 * if applicable, and the thread managing the metadatas. This is important
2899 * because after this point, if an error occurs, the only way the stream
2900 * can be deleted is to be monitored in the consumer.
2901 */
2902 ret = consumer_setup_metadata(socket, metadata->key);
2903 if (ret < 0) {
2904 /* Nullify the metadata key so we don't try to close it later on. */
2905 registry->metadata_key = 0;
2906 goto error_consumer;
2907 }
2908
2909 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2910 metadata->key, app->pid);
2911
2912error_consumer:
2913 lttng_fd_put(LTTNG_FD_APPS, 1);
2914 delete_ust_app_channel(-1, metadata, app);
2915error:
2916 return ret;
2917}
2918
2919/*
2920 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2921 * acquired before calling this function.
2922 */
2923struct ust_app *ust_app_find_by_pid(pid_t pid)
2924{
2925 struct ust_app *app = NULL;
2926 struct lttng_ht_node_ulong *node;
2927 struct lttng_ht_iter iter;
2928
2929 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2930 node = lttng_ht_iter_get_node_ulong(&iter);
2931 if (node == NULL) {
2932 DBG2("UST app no found with pid %d", pid);
2933 goto error;
2934 }
2935
2936 DBG2("Found UST app by pid %d", pid);
2937
2938 app = caa_container_of(node, struct ust_app, pid_n);
2939
2940error:
2941 return app;
2942}
2943
2944/*
2945 * Allocate and init an UST app object using the registration information and
2946 * the command socket. This is called when the command socket connects to the
2947 * session daemon.
2948 *
2949 * The object is returned on success or else NULL.
2950 */
2951struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2952{
2953 struct ust_app *lta = NULL;
2954
2955 assert(msg);
2956 assert(sock >= 0);
2957
2958 DBG3("UST app creating application for socket %d", sock);
2959
2960 if ((msg->bits_per_long == 64 &&
2961 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2962 || (msg->bits_per_long == 32 &&
2963 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2964 ERR("Registration failed: application \"%s\" (pid: %d) has "
2965 "%d-bit long, but no consumerd for this size is available.\n",
2966 msg->name, msg->pid, msg->bits_per_long);
2967 goto error;
2968 }
2969
2970 lta = zmalloc(sizeof(struct ust_app));
2971 if (lta == NULL) {
2972 PERROR("malloc");
2973 goto error;
2974 }
2975
2976 lta->ppid = msg->ppid;
2977 lta->uid = msg->uid;
2978 lta->gid = msg->gid;
2979
2980 lta->bits_per_long = msg->bits_per_long;
2981 lta->uint8_t_alignment = msg->uint8_t_alignment;
2982 lta->uint16_t_alignment = msg->uint16_t_alignment;
2983 lta->uint32_t_alignment = msg->uint32_t_alignment;
2984 lta->uint64_t_alignment = msg->uint64_t_alignment;
2985 lta->long_alignment = msg->long_alignment;
2986 lta->byte_order = msg->byte_order;
2987
2988 lta->v_major = msg->major;
2989 lta->v_minor = msg->minor;
2990 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2991 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2992 lta->notify_sock = -1;
2993
2994 /* Copy name and make sure it's NULL terminated. */
2995 strncpy(lta->name, msg->name, sizeof(lta->name));
2996 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2997
2998 /*
2999 * Before this can be called, when receiving the registration information,
3000 * the application compatibility is checked. So, at this point, the
3001 * application can work with this session daemon.
3002 */
3003 lta->compatible = 1;
3004
3005 lta->pid = msg->pid;
3006 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3007 lta->sock = sock;
3008 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3009
3010 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3011
3012error:
3013 return lta;
3014}
3015
3016/*
3017 * For a given application object, add it to every hash table.
3018 */
3019void ust_app_add(struct ust_app *app)
3020{
3021 assert(app);
3022 assert(app->notify_sock >= 0);
3023
3024 rcu_read_lock();
3025
3026 /*
3027 * On a re-registration, we want to kick out the previous registration of
3028 * that pid
3029 */
3030 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3031
3032 /*
3033 * The socket _should_ be unique until _we_ call close. So, a add_unique
3034 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3035 * already in the table.
3036 */
3037 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3038
3039 /* Add application to the notify socket hash table. */
3040 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3041 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3042
3043 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3044 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3045 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3046 app->v_minor);
3047
3048 rcu_read_unlock();
3049}
3050
3051/*
3052 * Set the application version into the object.
3053 *
3054 * Return 0 on success else a negative value either an errno code or a
3055 * LTTng-UST error code.
3056 */
3057int ust_app_version(struct ust_app *app)
3058{
3059 int ret;
3060
3061 assert(app);
3062
3063 ret = ustctl_tracer_version(app->sock, &app->version);
3064 if (ret < 0) {
3065 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3066 ERR("UST app %d version failed with ret %d", app->sock, ret);
3067 } else {
3068 DBG3("UST app %d version failed. Application is dead", app->sock);
3069 }
3070 }
3071
3072 return ret;
3073}
3074
3075/*
3076 * Unregister app by removing it from the global traceable app list and freeing
3077 * the data struct.
3078 *
3079 * The socket is already closed at this point so no close to sock.
3080 */
3081void ust_app_unregister(int sock)
3082{
3083 struct ust_app *lta;
3084 struct lttng_ht_node_ulong *node;
3085 struct lttng_ht_iter ust_app_sock_iter;
3086 struct lttng_ht_iter iter;
3087 struct ust_app_session *ua_sess;
3088 int ret;
3089
3090 rcu_read_lock();
3091
3092 /* Get the node reference for a call_rcu */
3093 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3094 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3095 assert(node);
3096
3097 lta = caa_container_of(node, struct ust_app, sock_n);
3098 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3099
3100 /*
3101 * Perform "push metadata" and flush all application streams
3102 * before removing app from hash tables, ensuring proper
3103 * behavior of data_pending check.
3104 * Remove sessions so they are not visible during deletion.
3105 */
3106 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3107 node.node) {
3108 struct ust_registry_session *registry;
3109
3110 ret = lttng_ht_del(lta->sessions, &iter);
3111 if (ret) {
3112 /* The session was already removed so scheduled for teardown. */
3113 continue;
3114 }
3115
3116 (void) ust_app_flush_app_session(lta, ua_sess);
3117
3118 /*
3119 * Add session to list for teardown. This is safe since at this point we
3120 * are the only one using this list.
3121 */
3122 pthread_mutex_lock(&ua_sess->lock);
3123
3124 /*
3125 * Normally, this is done in the delete session process which is
3126 * executed in the call rcu below. However, upon registration we can't
3127 * afford to wait for the grace period before pushing data or else the
3128 * data pending feature can race between the unregistration and stop
3129 * command where the data pending command is sent *before* the grace
3130 * period ended.
3131 *
3132 * The close metadata below nullifies the metadata pointer in the
3133 * session so the delete session will NOT push/close a second time.
3134 */
3135 registry = get_session_registry(ua_sess);
3136 if (registry && !registry->metadata_closed) {
3137 /* Push metadata for application before freeing the application. */
3138 (void) push_metadata(registry, ua_sess->consumer);
3139
3140 /*
3141 * Don't ask to close metadata for global per UID buffers. Close
3142 * metadata only on destroy trace session in this case. Also, the
3143 * previous push metadata could have flag the metadata registry to
3144 * close so don't send a close command if closed.
3145 */
3146 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
3147 !registry->metadata_closed) {
3148 /* And ask to close it for this session registry. */
3149 (void) close_metadata(registry, ua_sess->consumer);
3150 }
3151 }
3152 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3153
3154 pthread_mutex_unlock(&ua_sess->lock);
3155 }
3156
3157 /* Remove application from PID hash table */
3158 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3159 assert(!ret);
3160
3161 /*
3162 * Remove application from notify hash table. The thread handling the
3163 * notify socket could have deleted the node so ignore on error because
3164 * either way it's valid. The close of that socket is handled by the other
3165 * thread.
3166 */
3167 iter.iter.node = &lta->notify_sock_n.node;
3168 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3169
3170 /*
3171 * Ignore return value since the node might have been removed before by an
3172 * add replace during app registration because the PID can be reassigned by
3173 * the OS.
3174 */
3175 iter.iter.node = &lta->pid_n.node;
3176 ret = lttng_ht_del(ust_app_ht, &iter);
3177 if (ret) {
3178 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3179 lta->pid);
3180 }
3181
3182 /* Free memory */
3183 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3184
3185 rcu_read_unlock();
3186 return;
3187}
3188
3189/*
3190 * Fill events array with all events name of all registered apps.
3191 */
3192int ust_app_list_events(struct lttng_event **events)
3193{
3194 int ret, handle;
3195 size_t nbmem, count = 0;
3196 struct lttng_ht_iter iter;
3197 struct ust_app *app;
3198 struct lttng_event *tmp_event;
3199
3200 nbmem = UST_APP_EVENT_LIST_SIZE;
3201 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3202 if (tmp_event == NULL) {
3203 PERROR("zmalloc ust app events");
3204 ret = -ENOMEM;
3205 goto error;
3206 }
3207
3208 rcu_read_lock();
3209
3210 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3211 struct lttng_ust_tracepoint_iter uiter;
3212
3213 health_code_update();
3214
3215 if (!app->compatible) {
3216 /*
3217 * TODO: In time, we should notice the caller of this error by
3218 * telling him that this is a version error.
3219 */
3220 continue;
3221 }
3222 handle = ustctl_tracepoint_list(app->sock);
3223 if (handle < 0) {
3224 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3225 ERR("UST app list events getting handle failed for app pid %d",
3226 app->pid);
3227 }
3228 continue;
3229 }
3230
3231 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3232 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3233 /* Handle ustctl error. */
3234 if (ret < 0) {
3235 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3236 ERR("UST app tp list get failed for app %d with ret %d",
3237 app->sock, ret);
3238 } else {
3239 DBG3("UST app tp list get failed. Application is dead");
3240 /*
3241 * This is normal behavior, an application can die during the
3242 * creation process. Don't report an error so the execution can
3243 * continue normally. Continue normal execution.
3244 */
3245 break;
3246 }
3247 free(tmp_event);
3248 goto rcu_error;
3249 }
3250
3251 health_code_update();
3252 if (count >= nbmem) {
3253 /* In case the realloc fails, we free the memory */
3254 struct lttng_event *new_tmp_event;
3255 size_t new_nbmem;
3256
3257 new_nbmem = nbmem << 1;
3258 DBG2("Reallocating event list from %zu to %zu entries",
3259 nbmem, new_nbmem);
3260 new_tmp_event = realloc(tmp_event,
3261 new_nbmem * sizeof(struct lttng_event));
3262 if (new_tmp_event == NULL) {
3263 PERROR("realloc ust app events");
3264 free(tmp_event);
3265 ret = -ENOMEM;
3266 goto rcu_error;
3267 }
3268 /* Zero the new memory */
3269 memset(new_tmp_event + nbmem, 0,
3270 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3271 nbmem = new_nbmem;
3272 tmp_event = new_tmp_event;
3273 }
3274 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3275 tmp_event[count].loglevel = uiter.loglevel;
3276 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3277 tmp_event[count].pid = app->pid;
3278 tmp_event[count].enabled = -1;
3279 count++;
3280 }
3281 }
3282
3283 ret = count;
3284 *events = tmp_event;
3285
3286 DBG2("UST app list events done (%zu events)", count);
3287
3288rcu_error:
3289 rcu_read_unlock();
3290error:
3291 health_code_update();
3292 return ret;
3293}
3294
3295/*
3296 * Fill events array with all events name of all registered apps.
3297 */
3298int ust_app_list_event_fields(struct lttng_event_field **fields)
3299{
3300 int ret, handle;
3301 size_t nbmem, count = 0;
3302 struct lttng_ht_iter iter;
3303 struct ust_app *app;
3304 struct lttng_event_field *tmp_event;
3305
3306 nbmem = UST_APP_EVENT_LIST_SIZE;
3307 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3308 if (tmp_event == NULL) {
3309 PERROR("zmalloc ust app event fields");
3310 ret = -ENOMEM;
3311 goto error;
3312 }
3313
3314 rcu_read_lock();
3315
3316 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3317 struct lttng_ust_field_iter uiter;
3318
3319 health_code_update();
3320
3321 if (!app->compatible) {
3322 /*
3323 * TODO: In time, we should notice the caller of this error by
3324 * telling him that this is a version error.
3325 */
3326 continue;
3327 }
3328 handle = ustctl_tracepoint_field_list(app->sock);
3329 if (handle < 0) {
3330 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3331 ERR("UST app list field getting handle failed for app pid %d",
3332 app->pid);
3333 }
3334 continue;
3335 }
3336
3337 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3338 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3339 /* Handle ustctl error. */
3340 if (ret < 0) {
3341 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3342 ERR("UST app tp list field failed for app %d with ret %d",
3343 app->sock, ret);
3344 } else {
3345 DBG3("UST app tp list field failed. Application is dead");
3346 /*
3347 * This is normal behavior, an application can die during the
3348 * creation process. Don't report an error so the execution can
3349 * continue normally. Reset list and count for next app.
3350 */
3351 break;
3352 }
3353 free(tmp_event);
3354 goto rcu_error;
3355 }
3356
3357 health_code_update();
3358 if (count >= nbmem) {
3359 /* In case the realloc fails, we free the memory */
3360 struct lttng_event_field *new_tmp_event;
3361 size_t new_nbmem;
3362
3363 new_nbmem = nbmem << 1;
3364 DBG2("Reallocating event field list from %zu to %zu entries",
3365 nbmem, new_nbmem);
3366 new_tmp_event = realloc(tmp_event,
3367 new_nbmem * sizeof(struct lttng_event_field));
3368 if (new_tmp_event == NULL) {
3369 PERROR("realloc ust app event fields");
3370 free(tmp_event);
3371 ret = -ENOMEM;
3372 goto rcu_error;
3373 }
3374 /* Zero the new memory */
3375 memset(new_tmp_event + nbmem, 0,
3376 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3377 nbmem = new_nbmem;
3378 tmp_event = new_tmp_event;
3379 }
3380
3381 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3382 /* Mapping between these enums matches 1 to 1. */
3383 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3384 tmp_event[count].nowrite = uiter.nowrite;
3385
3386 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3387 tmp_event[count].event.loglevel = uiter.loglevel;
3388 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3389 tmp_event[count].event.pid = app->pid;
3390 tmp_event[count].event.enabled = -1;
3391 count++;
3392 }
3393 }
3394
3395 ret = count;
3396 *fields = tmp_event;
3397
3398 DBG2("UST app list event fields done (%zu events)", count);
3399
3400rcu_error:
3401 rcu_read_unlock();
3402error:
3403 health_code_update();
3404 return ret;
3405}
3406
3407/*
3408 * Free and clean all traceable apps of the global list.
3409 *
3410 * Should _NOT_ be called with RCU read-side lock held.
3411 */
3412void ust_app_clean_list(void)
3413{
3414 int ret;
3415 struct ust_app *app;
3416 struct lttng_ht_iter iter;
3417
3418 DBG2("UST app cleaning registered apps hash table");
3419
3420 rcu_read_lock();
3421
3422 if (ust_app_ht) {
3423 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3424 ret = lttng_ht_del(ust_app_ht, &iter);
3425 assert(!ret);
3426 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3427 }
3428 }
3429
3430 /* Cleanup socket hash table */
3431 if (ust_app_ht_by_sock) {
3432 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3433 sock_n.node) {
3434 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3435 assert(!ret);
3436 }
3437 }
3438
3439 /* Cleanup notify socket hash table */
3440 if (ust_app_ht_by_notify_sock) {
3441 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3442 notify_sock_n.node) {
3443 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3444 assert(!ret);
3445 }
3446 }
3447 rcu_read_unlock();
3448
3449 /* Destroy is done only when the ht is empty */
3450 if (ust_app_ht) {
3451 ht_cleanup_push(ust_app_ht);
3452 }
3453 if (ust_app_ht_by_sock) {
3454 ht_cleanup_push(ust_app_ht_by_sock);
3455 }
3456 if (ust_app_ht_by_notify_sock) {
3457 ht_cleanup_push(ust_app_ht_by_notify_sock);
3458 }
3459}
3460
3461/*
3462 * Init UST app hash table.
3463 */
3464int ust_app_ht_alloc(void)
3465{
3466 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3467 if (!ust_app_ht) {
3468 return -1;
3469 }
3470 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3471 if (!ust_app_ht_by_sock) {
3472 return -1;
3473 }
3474 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3475 if (!ust_app_ht_by_notify_sock) {
3476 return -1;
3477 }
3478 return 0;
3479}
3480
3481/*
3482 * For a specific UST session, disable the channel for all registered apps.
3483 */
3484int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3485 struct ltt_ust_channel *uchan)
3486{
3487 int ret = 0;
3488 struct lttng_ht_iter iter;
3489 struct lttng_ht_node_str *ua_chan_node;
3490 struct ust_app *app;
3491 struct ust_app_session *ua_sess;
3492 struct ust_app_channel *ua_chan;
3493
3494 if (usess == NULL || uchan == NULL) {
3495 ERR("Disabling UST global channel with NULL values");
3496 ret = -1;
3497 goto error;
3498 }
3499
3500 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3501 uchan->name, usess->id);
3502
3503 rcu_read_lock();
3504
3505 /* For every registered applications */
3506 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3507 struct lttng_ht_iter uiter;
3508 if (!app->compatible) {
3509 /*
3510 * TODO: In time, we should notice the caller of this error by
3511 * telling him that this is a version error.
3512 */
3513 continue;
3514 }
3515 ua_sess = lookup_session_by_app(usess, app);
3516 if (ua_sess == NULL) {
3517 continue;
3518 }
3519
3520 /* Get channel */
3521 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3522 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3523 /* If the session if found for the app, the channel must be there */
3524 assert(ua_chan_node);
3525
3526 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3527 /* The channel must not be already disabled */
3528 assert(ua_chan->enabled == 1);
3529
3530 /* Disable channel onto application */
3531 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3532 if (ret < 0) {
3533 /* XXX: We might want to report this error at some point... */
3534 continue;
3535 }
3536 }
3537
3538 rcu_read_unlock();
3539
3540error:
3541 return ret;
3542}
3543
3544/*
3545 * For a specific UST session, enable the channel for all registered apps.
3546 */
3547int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3548 struct ltt_ust_channel *uchan)
3549{
3550 int ret = 0;
3551 struct lttng_ht_iter iter;
3552 struct ust_app *app;
3553 struct ust_app_session *ua_sess;
3554
3555 if (usess == NULL || uchan == NULL) {
3556 ERR("Adding UST global channel to NULL values");
3557 ret = -1;
3558 goto error;
3559 }
3560
3561 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3562 uchan->name, usess->id);
3563
3564 rcu_read_lock();
3565
3566 /* For every registered applications */
3567 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3568 if (!app->compatible) {
3569 /*
3570 * TODO: In time, we should notice the caller of this error by
3571 * telling him that this is a version error.
3572 */
3573 continue;
3574 }
3575 ua_sess = lookup_session_by_app(usess, app);
3576 if (ua_sess == NULL) {
3577 continue;
3578 }
3579
3580 /* Enable channel onto application */
3581 ret = enable_ust_app_channel(ua_sess, uchan, app);
3582 if (ret < 0) {
3583 /* XXX: We might want to report this error at some point... */
3584 continue;
3585 }
3586 }
3587
3588 rcu_read_unlock();
3589
3590error:
3591 return ret;
3592}
3593
3594/*
3595 * Disable an event in a channel and for a specific session.
3596 */
3597int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3598 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3599{
3600 int ret = 0;
3601 struct lttng_ht_iter iter, uiter;
3602 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
3603 struct ust_app *app;
3604 struct ust_app_session *ua_sess;
3605 struct ust_app_channel *ua_chan;
3606 struct ust_app_event *ua_event;
3607
3608 DBG("UST app disabling event %s for all apps in channel "
3609 "%s for session id %" PRIu64,
3610 uevent->attr.name, uchan->name, usess->id);
3611
3612 rcu_read_lock();
3613
3614 /* For all registered applications */
3615 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3616 if (!app->compatible) {
3617 /*
3618 * TODO: In time, we should notice the caller of this error by
3619 * telling him that this is a version error.
3620 */
3621 continue;
3622 }
3623 ua_sess = lookup_session_by_app(usess, app);
3624 if (ua_sess == NULL) {
3625 /* Next app */
3626 continue;
3627 }
3628
3629 /* Lookup channel in the ust app session */
3630 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3631 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3632 if (ua_chan_node == NULL) {
3633 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3634 "Skipping", uchan->name, usess->id, app->pid);
3635 continue;
3636 }
3637 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3638
3639 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
3640 ua_event_node = lttng_ht_iter_get_node_str(&uiter);
3641 if (ua_event_node == NULL) {
3642 DBG2("Event %s not found in channel %s for app pid %d."
3643 "Skipping", uevent->attr.name, uchan->name, app->pid);
3644 continue;
3645 }
3646 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
3647
3648 ret = disable_ust_app_event(ua_sess, ua_event, app);
3649 if (ret < 0) {
3650 /* XXX: Report error someday... */
3651 continue;
3652 }
3653 }
3654
3655 rcu_read_unlock();
3656
3657 return ret;
3658}
3659
3660/*
3661 * For a specific UST session, create the channel for all registered apps.
3662 */
3663int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3664 struct ltt_ust_channel *uchan)
3665{
3666 int ret = 0, created;
3667 struct lttng_ht_iter iter;
3668 struct ust_app *app;
3669 struct ust_app_session *ua_sess = NULL;
3670
3671 /* Very wrong code flow */
3672 assert(usess);
3673 assert(uchan);
3674
3675 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3676 uchan->name, usess->id);
3677
3678 rcu_read_lock();
3679
3680 /* For every registered applications */
3681 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3682 if (!app->compatible) {
3683 /*
3684 * TODO: In time, we should notice the caller of this error by
3685 * telling him that this is a version error.
3686 */
3687 continue;
3688 }
3689 /*
3690 * Create session on the tracer side and add it to app session HT. Note
3691 * that if session exist, it will simply return a pointer to the ust
3692 * app session.
3693 */
3694 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3695 if (ret < 0) {
3696 switch (ret) {
3697 case -ENOTCONN:
3698 /*
3699 * The application's socket is not valid. Either a bad socket
3700 * or a timeout on it. We can't inform the caller that for a
3701 * specific app, the session failed so lets continue here.
3702 */
3703 continue;
3704 case -ENOMEM:
3705 default:
3706 goto error_rcu_unlock;
3707 }
3708 }
3709 assert(ua_sess);
3710
3711 pthread_mutex_lock(&ua_sess->lock);
3712 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
3713 sizeof(uchan->name))) {
3714 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
3715 ret = 0;
3716 } else {
3717 /* Create channel onto application. We don't need the chan ref. */
3718 ret = create_ust_app_channel(ua_sess, uchan, app,
3719 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
3720 }
3721 pthread_mutex_unlock(&ua_sess->lock);
3722 if (ret < 0) {
3723 if (ret == -ENOMEM) {
3724 /* No more memory is a fatal error. Stop right now. */
3725 goto error_rcu_unlock;
3726 }
3727 /* Cleanup the created session if it's the case. */
3728 if (created) {
3729 destroy_app_session(app, ua_sess);
3730 }
3731 }
3732 }
3733
3734error_rcu_unlock:
3735 rcu_read_unlock();
3736 return ret;
3737}
3738
3739/*
3740 * Enable event for a specific session and channel on the tracer.
3741 */
3742int ust_app_enable_event_glb(struct ltt_ust_session *usess,
3743 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3744{
3745 int ret = 0;
3746 struct lttng_ht_iter iter, uiter;
3747 struct lttng_ht_node_str *ua_chan_node;
3748 struct ust_app *app;
3749 struct ust_app_session *ua_sess;
3750 struct ust_app_channel *ua_chan;
3751 struct ust_app_event *ua_event;
3752
3753 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
3754 uevent->attr.name, usess->id);
3755
3756 /*
3757 * NOTE: At this point, this function is called only if the session and
3758 * channel passed are already created for all apps. and enabled on the
3759 * tracer also.
3760 */
3761
3762 rcu_read_lock();
3763
3764 /* For all registered applications */
3765 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3766 if (!app->compatible) {
3767 /*
3768 * TODO: In time, we should notice the caller of this error by
3769 * telling him that this is a version error.
3770 */
3771 continue;
3772 }
3773 ua_sess = lookup_session_by_app(usess, app);
3774 if (!ua_sess) {
3775 /* The application has problem or is probably dead. */
3776 continue;
3777 }
3778
3779 pthread_mutex_lock(&ua_sess->lock);
3780
3781 /* Lookup channel in the ust app session */
3782 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3783 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3784 /* If the channel is not found, there is a code flow error */
3785 assert(ua_chan_node);
3786
3787 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3788
3789 /* Get event node */
3790 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3791 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3792 if (ua_event == NULL) {
3793 DBG3("UST app enable event %s not found for app PID %d."
3794 "Skipping app", uevent->attr.name, app->pid);
3795 goto next_app;
3796 }
3797
3798 ret = enable_ust_app_event(ua_sess, ua_event, app);
3799 if (ret < 0) {
3800 pthread_mutex_unlock(&ua_sess->lock);
3801 goto error;
3802 }
3803 next_app:
3804 pthread_mutex_unlock(&ua_sess->lock);
3805 }
3806
3807error:
3808 rcu_read_unlock();
3809 return ret;
3810}
3811
3812/*
3813 * For a specific existing UST session and UST channel, creates the event for
3814 * all registered apps.
3815 */
3816int ust_app_create_event_glb(struct ltt_ust_session *usess,
3817 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3818{
3819 int ret = 0;
3820 struct lttng_ht_iter iter, uiter;
3821 struct lttng_ht_node_str *ua_chan_node;
3822 struct ust_app *app;
3823 struct ust_app_session *ua_sess;
3824 struct ust_app_channel *ua_chan;
3825
3826 DBG("UST app creating event %s for all apps for session id %" PRIu64,
3827 uevent->attr.name, usess->id);
3828
3829 rcu_read_lock();
3830
3831 /* For all registered applications */
3832 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3833 if (!app->compatible) {
3834 /*
3835 * TODO: In time, we should notice the caller of this error by
3836 * telling him that this is a version error.
3837 */
3838 continue;
3839 }
3840 ua_sess = lookup_session_by_app(usess, app);
3841 if (!ua_sess) {
3842 /* The application has problem or is probably dead. */
3843 continue;
3844 }
3845
3846 pthread_mutex_lock(&ua_sess->lock);
3847 /* Lookup channel in the ust app session */
3848 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3849 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3850 /* If the channel is not found, there is a code flow error */
3851 assert(ua_chan_node);
3852
3853 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3854
3855 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
3856 pthread_mutex_unlock(&ua_sess->lock);
3857 if (ret < 0) {
3858 if (ret != -LTTNG_UST_ERR_EXIST) {
3859 /* Possible value at this point: -ENOMEM. If so, we stop! */
3860 break;
3861 }
3862 DBG2("UST app event %s already exist on app PID %d",
3863 uevent->attr.name, app->pid);
3864 continue;
3865 }
3866 }
3867
3868 rcu_read_unlock();
3869
3870 return ret;
3871}
3872
3873/*
3874 * Start tracing for a specific UST session and app.
3875 */
3876static
3877int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
3878{
3879 int ret = 0;
3880 struct ust_app_session *ua_sess;
3881
3882 DBG("Starting tracing for ust app pid %d", app->pid);
3883
3884 rcu_read_lock();
3885
3886 if (!app->compatible) {
3887 goto end;
3888 }
3889
3890 ua_sess = lookup_session_by_app(usess, app);
3891 if (ua_sess == NULL) {
3892 /* The session is in teardown process. Ignore and continue. */
3893 goto end;
3894 }
3895
3896 pthread_mutex_lock(&ua_sess->lock);
3897
3898 /* Upon restart, we skip the setup, already done */
3899 if (ua_sess->started) {
3900 goto skip_setup;
3901 }
3902
3903 /* Create directories if consumer is LOCAL and has a path defined. */
3904 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
3905 strlen(usess->consumer->dst.trace_path) > 0) {
3906 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
3907 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
3908 if (ret < 0) {
3909 if (ret != -EEXIST) {
3910 ERR("Trace directory creation error");
3911 goto error_unlock;
3912 }
3913 }
3914 }
3915
3916 /*
3917 * Create the metadata for the application. This returns gracefully if a
3918 * metadata was already set for the session.
3919 */
3920 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
3921 if (ret < 0) {
3922 goto error_unlock;
3923 }
3924
3925 health_code_update();
3926
3927skip_setup:
3928 /* This start the UST tracing */
3929 ret = ustctl_start_session(app->sock, ua_sess->handle);
3930 if (ret < 0) {
3931 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3932 ERR("Error starting tracing for app pid: %d (ret: %d)",
3933 app->pid, ret);
3934 } else {
3935 DBG("UST app start session failed. Application is dead.");
3936 /*
3937 * This is normal behavior, an application can die during the
3938 * creation process. Don't report an error so the execution can
3939 * continue normally.
3940 */
3941 pthread_mutex_unlock(&ua_sess->lock);
3942 goto end;
3943 }
3944 goto error_unlock;
3945 }
3946
3947 /* Indicate that the session has been started once */
3948 ua_sess->started = 1;
3949
3950 pthread_mutex_unlock(&ua_sess->lock);
3951
3952 health_code_update();
3953
3954 /* Quiescent wait after starting trace */
3955 ret = ustctl_wait_quiescent(app->sock);
3956 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3957 ERR("UST app wait quiescent failed for app pid %d ret %d",
3958 app->pid, ret);
3959 }
3960
3961end:
3962 rcu_read_unlock();
3963 health_code_update();
3964 return 0;
3965
3966error_unlock:
3967 pthread_mutex_unlock(&ua_sess->lock);
3968 rcu_read_unlock();
3969 health_code_update();
3970 return -1;
3971}
3972
3973/*
3974 * Stop tracing for a specific UST session and app.
3975 */
3976static
3977int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
3978{
3979 int ret = 0;
3980 struct ust_app_session *ua_sess;
3981 struct ust_registry_session *registry;
3982
3983 DBG("Stopping tracing for ust app pid %d", app->pid);
3984
3985 rcu_read_lock();
3986
3987 if (!app->compatible) {
3988 goto end_no_session;
3989 }
3990
3991 ua_sess = lookup_session_by_app(usess, app);
3992 if (ua_sess == NULL) {
3993 goto end_no_session;
3994 }
3995
3996 pthread_mutex_lock(&ua_sess->lock);
3997
3998 /*
3999 * If started = 0, it means that stop trace has been called for a session
4000 * that was never started. It's possible since we can have a fail start
4001 * from either the application manager thread or the command thread. Simply
4002 * indicate that this is a stop error.
4003 */
4004 if (!ua_sess->started) {
4005 goto error_rcu_unlock;
4006 }
4007
4008 health_code_update();
4009
4010 /* This inhibits UST tracing */
4011 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4012 if (ret < 0) {
4013 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4014 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4015 app->pid, ret);
4016 } else {
4017 DBG("UST app stop session failed. Application is dead.");
4018 /*
4019 * This is normal behavior, an application can die during the
4020 * creation process. Don't report an error so the execution can
4021 * continue normally.
4022 */
4023 goto end_unlock;
4024 }
4025 goto error_rcu_unlock;
4026 }
4027
4028 health_code_update();
4029
4030 /* Quiescent wait after stopping trace */
4031 ret = ustctl_wait_quiescent(app->sock);
4032 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4033 ERR("UST app wait quiescent failed for app pid %d ret %d",
4034 app->pid, ret);
4035 }
4036
4037 health_code_update();
4038
4039 registry = get_session_registry(ua_sess);
4040 assert(registry);
4041
4042 if (!registry->metadata_closed) {
4043 /* Push metadata for application before freeing the application. */
4044 (void) push_metadata(registry, ua_sess->consumer);
4045 }
4046
4047end_unlock:
4048 pthread_mutex_unlock(&ua_sess->lock);
4049end_no_session:
4050 rcu_read_unlock();
4051 health_code_update();
4052 return 0;
4053
4054error_rcu_unlock:
4055 pthread_mutex_unlock(&ua_sess->lock);
4056 rcu_read_unlock();
4057 health_code_update();
4058 return -1;
4059}
4060
4061static
4062int ust_app_flush_app_session(struct ust_app *app,
4063 struct ust_app_session *ua_sess)
4064{
4065 int ret, retval = 0;
4066 struct lttng_ht_iter iter;
4067 struct ust_app_channel *ua_chan;
4068 struct consumer_socket *socket;
4069
4070 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4071
4072 rcu_read_lock();
4073
4074 if (!app->compatible) {
4075 goto end_not_compatible;
4076 }
4077
4078 pthread_mutex_lock(&ua_sess->lock);
4079
4080 health_code_update();
4081
4082 /* Flushing buffers */
4083 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4084 ua_sess->consumer);
4085 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4086 node.node) {
4087 health_code_update();
4088 assert(ua_chan->is_sent);
4089 ret = consumer_flush_channel(socket, ua_chan->key);
4090 if (ret) {
4091 ERR("Error flushing consumer channel");
4092 retval = -1;
4093 continue;
4094 }
4095 }
4096
4097 health_code_update();
4098
4099 pthread_mutex_unlock(&ua_sess->lock);
4100end_not_compatible:
4101 rcu_read_unlock();
4102 health_code_update();
4103 return retval;
4104}
4105
4106/*
4107 * Flush buffers for a specific UST session and app.
4108 */
4109static
4110int ust_app_flush_session(struct ust_app *app, struct ltt_ust_session *usess)
4111
4112{
4113 int ret;
4114 struct ust_app_session *ua_sess;
4115
4116 DBG("Flushing session buffers for ust app pid %d", app->pid);
4117
4118 rcu_read_lock();
4119
4120 ua_sess = lookup_session_by_app(usess, app);
4121 if (ua_sess == NULL) {
4122 ret = -1;
4123 goto end_no_session;
4124 }
4125 ret = ust_app_flush_app_session(app, ua_sess);
4126
4127end_no_session:
4128 rcu_read_unlock();
4129 health_code_update();
4130 return ret;
4131}
4132
4133/*
4134 * Destroy a specific UST session in apps.
4135 */
4136static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4137{
4138 int ret;
4139 struct ust_app_session *ua_sess;
4140 struct lttng_ht_iter iter;
4141 struct lttng_ht_node_u64 *node;
4142
4143 DBG("Destroy tracing for ust app pid %d", app->pid);
4144
4145 rcu_read_lock();
4146
4147 if (!app->compatible) {
4148 goto end;
4149 }
4150
4151 __lookup_session_by_app(usess, app, &iter);
4152 node = lttng_ht_iter_get_node_u64(&iter);
4153 if (node == NULL) {
4154 /* Session is being or is deleted. */
4155 goto end;
4156 }
4157 ua_sess = caa_container_of(node, struct ust_app_session, node);
4158
4159 health_code_update();
4160 destroy_app_session(app, ua_sess);
4161
4162 health_code_update();
4163
4164 /* Quiescent wait after stopping trace */
4165 ret = ustctl_wait_quiescent(app->sock);
4166 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4167 ERR("UST app wait quiescent failed for app pid %d ret %d",
4168 app->pid, ret);
4169 }
4170end:
4171 rcu_read_unlock();
4172 health_code_update();
4173 return 0;
4174}
4175
4176/*
4177 * Start tracing for the UST session.
4178 */
4179int ust_app_start_trace_all(struct ltt_ust_session *usess)
4180{
4181 int ret = 0;
4182 struct lttng_ht_iter iter;
4183 struct ust_app *app;
4184
4185 DBG("Starting all UST traces");
4186
4187 rcu_read_lock();
4188
4189 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4190 ret = ust_app_start_trace(usess, app);
4191 if (ret < 0) {
4192 /* Continue to next apps even on error */
4193 continue;
4194 }
4195 }
4196
4197 rcu_read_unlock();
4198
4199 return 0;
4200}
4201
4202/*
4203 * Start tracing for the UST session.
4204 */
4205int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4206{
4207 int ret = 0;
4208 struct lttng_ht_iter iter;
4209 struct ust_app *app;
4210
4211 DBG("Stopping all UST traces");
4212
4213 rcu_read_lock();
4214
4215 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4216 ret = ust_app_stop_trace(usess, app);
4217 if (ret < 0) {
4218 /* Continue to next apps even on error */
4219 continue;
4220 }
4221 }
4222
4223 /* Flush buffers and push metadata (for UID buffers). */
4224 switch (usess->buffer_type) {
4225 case LTTNG_BUFFER_PER_UID:
4226 {
4227 struct buffer_reg_uid *reg;
4228
4229 /* Flush all per UID buffers associated to that session. */
4230 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4231 struct ust_registry_session *ust_session_reg;
4232 struct buffer_reg_channel *reg_chan;
4233 struct consumer_socket *socket;
4234
4235 /* Get consumer socket to use to push the metadata.*/
4236 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4237 usess->consumer);
4238 if (!socket) {
4239 /* Ignore request if no consumer is found for the session. */
4240 continue;
4241 }
4242
4243 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4244 reg_chan, node.node) {
4245 /*
4246 * The following call will print error values so the return
4247 * code is of little importance because whatever happens, we
4248 * have to try them all.
4249 */
4250 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4251 }
4252
4253 ust_session_reg = reg->registry->reg.ust;
4254 if (!ust_session_reg->metadata_closed) {
4255 /* Push metadata. */
4256 (void) push_metadata(ust_session_reg, usess->consumer);
4257 }
4258 }
4259
4260 break;
4261 }
4262 case LTTNG_BUFFER_PER_PID:
4263 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4264 ret = ust_app_flush_session(app, usess);
4265 if (ret < 0) {
4266 /* Continue to next apps even on error */
4267 continue;
4268 }
4269 }
4270 break;
4271 default:
4272 assert(0);
4273 break;
4274 }
4275
4276 rcu_read_unlock();
4277
4278 return 0;
4279}
4280
4281/*
4282 * Destroy app UST session.
4283 */
4284int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4285{
4286 int ret = 0;
4287 struct lttng_ht_iter iter;
4288 struct ust_app *app;
4289
4290 DBG("Destroy all UST traces");
4291
4292 rcu_read_lock();
4293
4294 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4295 ret = destroy_trace(usess, app);
4296 if (ret < 0) {
4297 /* Continue to next apps even on error */
4298 continue;
4299 }
4300 }
4301
4302 rcu_read_unlock();
4303
4304 return 0;
4305}
4306
4307/*
4308 * Add channels/events from UST global domain to registered apps at sock.
4309 */
4310void ust_app_global_update(struct ltt_ust_session *usess, int sock)
4311{
4312 int ret = 0;
4313 struct lttng_ht_iter iter, uiter;
4314 struct ust_app *app;
4315 struct ust_app_session *ua_sess = NULL;
4316 struct ust_app_channel *ua_chan;
4317 struct ust_app_event *ua_event;
4318 struct ust_app_ctx *ua_ctx;
4319
4320 assert(usess);
4321 assert(sock >= 0);
4322
4323 DBG2("UST app global update for app sock %d for session id %" PRIu64, sock,
4324 usess->id);
4325
4326 rcu_read_lock();
4327
4328 app = ust_app_find_by_sock(sock);
4329 if (app == NULL) {
4330 /*
4331 * Application can be unregistered before so this is possible hence
4332 * simply stopping the update.
4333 */
4334 DBG3("UST app update failed to find app sock %d", sock);
4335 goto error;
4336 }
4337
4338 if (!app->compatible) {
4339 goto error;
4340 }
4341
4342 ret = create_ust_app_session(usess, app, &ua_sess, NULL);
4343 if (ret < 0) {
4344 /* Tracer is probably gone or ENOMEM. */
4345 goto error;
4346 }
4347 assert(ua_sess);
4348
4349 pthread_mutex_lock(&ua_sess->lock);
4350
4351 /*
4352 * We can iterate safely here over all UST app session since the create ust
4353 * app session above made a shadow copy of the UST global domain from the
4354 * ltt ust session.
4355 */
4356 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4357 node.node) {
4358 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4359 if (ret < 0) {
4360 /*
4361 * Stop everything. On error, the application failed, no more
4362 * file descriptor are available or ENOMEM so stopping here is
4363 * the only thing we can do for now.
4364 */
4365 goto error_unlock;
4366 }
4367
4368 /*
4369 * Add context using the list so they are enabled in the same order the
4370 * user added them.
4371 */
4372 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4373 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4374 if (ret < 0) {
4375 goto error_unlock;
4376 }
4377 }
4378
4379
4380 /* For each events */
4381 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4382 node.node) {
4383 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4384 if (ret < 0) {
4385 goto error_unlock;
4386 }
4387 }
4388 }
4389
4390 pthread_mutex_unlock(&ua_sess->lock);
4391
4392 if (usess->active) {
4393 ret = ust_app_start_trace(usess, app);
4394 if (ret < 0) {
4395 goto error;
4396 }
4397
4398 DBG2("UST trace started for app pid %d", app->pid);
4399 }
4400
4401 /* Everything went well at this point. */
4402 rcu_read_unlock();
4403 return;
4404
4405error_unlock:
4406 pthread_mutex_unlock(&ua_sess->lock);
4407error:
4408 if (ua_sess) {
4409 destroy_app_session(app, ua_sess);
4410 }
4411 rcu_read_unlock();
4412 return;
4413}
4414
4415/*
4416 * Add context to a specific channel for global UST domain.
4417 */
4418int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4419 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4420{
4421 int ret = 0;
4422 struct lttng_ht_node_str *ua_chan_node;
4423 struct lttng_ht_iter iter, uiter;
4424 struct ust_app_channel *ua_chan = NULL;
4425 struct ust_app_session *ua_sess;
4426 struct ust_app *app;
4427
4428 rcu_read_lock();
4429
4430 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4431 if (!app->compatible) {
4432 /*
4433 * TODO: In time, we should notice the caller of this error by
4434 * telling him that this is a version error.
4435 */
4436 continue;
4437 }
4438 ua_sess = lookup_session_by_app(usess, app);
4439 if (ua_sess == NULL) {
4440 continue;
4441 }
4442
4443 pthread_mutex_lock(&ua_sess->lock);
4444 /* Lookup channel in the ust app session */
4445 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4446 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4447 if (ua_chan_node == NULL) {
4448 goto next_app;
4449 }
4450 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4451 node);
4452 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4453 if (ret < 0) {
4454 goto next_app;
4455 }
4456 next_app:
4457 pthread_mutex_unlock(&ua_sess->lock);
4458 }
4459
4460 rcu_read_unlock();
4461 return ret;
4462}
4463
4464/*
4465 * Enable event for a channel from a UST session for a specific PID.
4466 */
4467int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4468 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4469{
4470 int ret = 0;
4471 struct lttng_ht_iter iter;
4472 struct lttng_ht_node_str *ua_chan_node;
4473 struct ust_app *app;
4474 struct ust_app_session *ua_sess;
4475 struct ust_app_channel *ua_chan;
4476 struct ust_app_event *ua_event;
4477
4478 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4479
4480 rcu_read_lock();
4481
4482 app = ust_app_find_by_pid(pid);
4483 if (app == NULL) {
4484 ERR("UST app enable event per PID %d not found", pid);
4485 ret = -1;
4486 goto end;
4487 }
4488
4489 if (!app->compatible) {
4490 ret = 0;
4491 goto end;
4492 }
4493
4494 ua_sess = lookup_session_by_app(usess, app);
4495 if (!ua_sess) {
4496 /* The application has problem or is probably dead. */
4497 ret = 0;
4498 goto end;
4499 }
4500
4501 pthread_mutex_lock(&ua_sess->lock);
4502 /* Lookup channel in the ust app session */
4503 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4504 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4505 /* If the channel is not found, there is a code flow error */
4506 assert(ua_chan_node);
4507
4508 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4509
4510 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4511 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4512 if (ua_event == NULL) {
4513 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4514 if (ret < 0) {
4515 goto end_unlock;
4516 }
4517 } else {
4518 ret = enable_ust_app_event(ua_sess, ua_event, app);
4519 if (ret < 0) {
4520 goto end_unlock;
4521 }
4522 }
4523
4524end_unlock:
4525 pthread_mutex_unlock(&ua_sess->lock);
4526end:
4527 rcu_read_unlock();
4528 return ret;
4529}
4530
4531/*
4532 * Calibrate registered applications.
4533 */
4534int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4535{
4536 int ret = 0;
4537 struct lttng_ht_iter iter;
4538 struct ust_app *app;
4539
4540 rcu_read_lock();
4541
4542 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4543 if (!app->compatible) {
4544 /*
4545 * TODO: In time, we should notice the caller of this error by
4546 * telling him that this is a version error.
4547 */
4548 continue;
4549 }
4550
4551 health_code_update();
4552
4553 ret = ustctl_calibrate(app->sock, calibrate);
4554 if (ret < 0) {
4555 switch (ret) {
4556 case -ENOSYS:
4557 /* Means that it's not implemented on the tracer side. */
4558 ret = 0;
4559 break;
4560 default:
4561 DBG2("Calibrate app PID %d returned with error %d",
4562 app->pid, ret);
4563 break;
4564 }
4565 }
4566 }
4567
4568 DBG("UST app global domain calibration finished");
4569
4570 rcu_read_unlock();
4571
4572 health_code_update();
4573
4574 return ret;
4575}
4576
4577/*
4578 * Receive registration and populate the given msg structure.
4579 *
4580 * On success return 0 else a negative value returned by the ustctl call.
4581 */
4582int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4583{
4584 int ret;
4585 uint32_t pid, ppid, uid, gid;
4586
4587 assert(msg);
4588
4589 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4590 &pid, &ppid, &uid, &gid,
4591 &msg->bits_per_long,
4592 &msg->uint8_t_alignment,
4593 &msg->uint16_t_alignment,
4594 &msg->uint32_t_alignment,
4595 &msg->uint64_t_alignment,
4596 &msg->long_alignment,
4597 &msg->byte_order,
4598 msg->name);
4599 if (ret < 0) {
4600 switch (-ret) {
4601 case EPIPE:
4602 case ECONNRESET:
4603 case LTTNG_UST_ERR_EXITING:
4604 DBG3("UST app recv reg message failed. Application died");
4605 break;
4606 case LTTNG_UST_ERR_UNSUP_MAJOR:
4607 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4608 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
4609 LTTNG_UST_ABI_MINOR_VERSION);
4610 break;
4611 default:
4612 ERR("UST app recv reg message failed with ret %d", ret);
4613 break;
4614 }
4615 goto error;
4616 }
4617 msg->pid = (pid_t) pid;
4618 msg->ppid = (pid_t) ppid;
4619 msg->uid = (uid_t) uid;
4620 msg->gid = (gid_t) gid;
4621
4622error:
4623 return ret;
4624}
4625
4626/*
4627 * Return a ust app channel object using the application object and the channel
4628 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4629 * lock MUST be acquired before calling this function.
4630 */
4631static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
4632 int objd)
4633{
4634 struct lttng_ht_node_ulong *node;
4635 struct lttng_ht_iter iter;
4636 struct ust_app_channel *ua_chan = NULL;
4637
4638 assert(app);
4639
4640 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
4641 node = lttng_ht_iter_get_node_ulong(&iter);
4642 if (node == NULL) {
4643 DBG2("UST app channel find by objd %d not found", objd);
4644 goto error;
4645 }
4646
4647 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
4648
4649error:
4650 return ua_chan;
4651}
4652
4653/*
4654 * Reply to a register channel notification from an application on the notify
4655 * socket. The channel metadata is also created.
4656 *
4657 * The session UST registry lock is acquired in this function.
4658 *
4659 * On success 0 is returned else a negative value.
4660 */
4661static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
4662 size_t nr_fields, struct ustctl_field *fields)
4663{
4664 int ret, ret_code = 0;
4665 uint32_t chan_id, reg_count;
4666 uint64_t chan_reg_key;
4667 enum ustctl_channel_header type;
4668 struct ust_app *app;
4669 struct ust_app_channel *ua_chan;
4670 struct ust_app_session *ua_sess;
4671 struct ust_registry_session *registry;
4672 struct ust_registry_channel *chan_reg;
4673
4674 rcu_read_lock();
4675
4676 /* Lookup application. If not found, there is a code flow error. */
4677 app = find_app_by_notify_sock(sock);
4678 if (!app) {
4679 DBG("Application socket %d is being teardown. Abort event notify",
4680 sock);
4681 ret = 0;
4682 free(fields);
4683 goto error_rcu_unlock;
4684 }
4685
4686 /* Lookup channel by UST object descriptor. */
4687 ua_chan = find_channel_by_objd(app, cobjd);
4688 if (!ua_chan) {
4689 DBG("Application channel is being teardown. Abort event notify");
4690 ret = 0;
4691 free(fields);
4692 goto error_rcu_unlock;
4693 }
4694
4695 assert(ua_chan->session);
4696 ua_sess = ua_chan->session;
4697
4698 /* Get right session registry depending on the session buffer type. */
4699 registry = get_session_registry(ua_sess);
4700 assert(registry);
4701
4702 /* Depending on the buffer type, a different channel key is used. */
4703 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4704 chan_reg_key = ua_chan->tracing_channel_id;
4705 } else {
4706 chan_reg_key = ua_chan->key;
4707 }
4708
4709 pthread_mutex_lock(&registry->lock);
4710
4711 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
4712 assert(chan_reg);
4713
4714 if (!chan_reg->register_done) {
4715 reg_count = ust_registry_get_event_count(chan_reg);
4716 if (reg_count < 31) {
4717 type = USTCTL_CHANNEL_HEADER_COMPACT;
4718 } else {
4719 type = USTCTL_CHANNEL_HEADER_LARGE;
4720 }
4721
4722 chan_reg->nr_ctx_fields = nr_fields;
4723 chan_reg->ctx_fields = fields;
4724 chan_reg->header_type = type;
4725 } else {
4726 /* Get current already assigned values. */
4727 type = chan_reg->header_type;
4728 free(fields);
4729 /* Set to NULL so the error path does not do a double free. */
4730 fields = NULL;
4731 }
4732 /* Channel id is set during the object creation. */
4733 chan_id = chan_reg->chan_id;
4734
4735 /* Append to metadata */
4736 if (!chan_reg->metadata_dumped) {
4737 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
4738 if (ret_code) {
4739 ERR("Error appending channel metadata (errno = %d)", ret_code);
4740 goto reply;
4741 }
4742 }
4743
4744reply:
4745 DBG3("UST app replying to register channel key %" PRIu64
4746 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
4747 ret_code);
4748
4749 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
4750 if (ret < 0) {
4751 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4752 ERR("UST app reply channel failed with ret %d", ret);
4753 } else {
4754 DBG3("UST app reply channel failed. Application died");
4755 }
4756 goto error;
4757 }
4758
4759 /* This channel registry registration is completed. */
4760 chan_reg->register_done = 1;
4761
4762error:
4763 pthread_mutex_unlock(&registry->lock);
4764error_rcu_unlock:
4765 rcu_read_unlock();
4766 if (ret) {
4767 free(fields);
4768 }
4769 return ret;
4770}
4771
4772/*
4773 * Add event to the UST channel registry. When the event is added to the
4774 * registry, the metadata is also created. Once done, this replies to the
4775 * application with the appropriate error code.
4776 *
4777 * The session UST registry lock is acquired in the function.
4778 *
4779 * On success 0 is returned else a negative value.
4780 */
4781static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
4782 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
4783 char *model_emf_uri)
4784{
4785 int ret, ret_code;
4786 uint32_t event_id = 0;
4787 uint64_t chan_reg_key;
4788 struct ust_app *app;
4789 struct ust_app_channel *ua_chan;
4790 struct ust_app_session *ua_sess;
4791 struct ust_registry_session *registry;
4792
4793 rcu_read_lock();
4794
4795 /* Lookup application. If not found, there is a code flow error. */
4796 app = find_app_by_notify_sock(sock);
4797 if (!app) {
4798 DBG("Application socket %d is being teardown. Abort event notify",
4799 sock);
4800 ret = 0;
4801 free(sig);
4802 free(fields);
4803 free(model_emf_uri);
4804 goto error_rcu_unlock;
4805 }
4806
4807 /* Lookup channel by UST object descriptor. */
4808 ua_chan = find_channel_by_objd(app, cobjd);
4809 if (!ua_chan) {
4810 DBG("Application channel is being teardown. Abort event notify");
4811 ret = 0;
4812 free(sig);
4813 free(fields);
4814 free(model_emf_uri);
4815 goto error_rcu_unlock;
4816 }
4817
4818 assert(ua_chan->session);
4819 ua_sess = ua_chan->session;
4820
4821 registry = get_session_registry(ua_sess);
4822 assert(registry);
4823
4824 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4825 chan_reg_key = ua_chan->tracing_channel_id;
4826 } else {
4827 chan_reg_key = ua_chan->key;
4828 }
4829
4830 pthread_mutex_lock(&registry->lock);
4831
4832 /*
4833 * From this point on, this call acquires the ownership of the sig, fields
4834 * and model_emf_uri meaning any free are done inside it if needed. These
4835 * three variables MUST NOT be read/write after this.
4836 */
4837 ret_code = ust_registry_create_event(registry, chan_reg_key,
4838 sobjd, cobjd, name, sig, nr_fields, fields, loglevel,
4839 model_emf_uri, ua_sess->buffer_type, &event_id,
4840 app);
4841
4842 /*
4843 * The return value is returned to ustctl so in case of an error, the
4844 * application can be notified. In case of an error, it's important not to
4845 * return a negative error or else the application will get closed.
4846 */
4847 ret = ustctl_reply_register_event(sock, event_id, ret_code);
4848 if (ret < 0) {
4849 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4850 ERR("UST app reply event failed with ret %d", ret);
4851 } else {
4852 DBG3("UST app reply event failed. Application died");
4853 }
4854 /*
4855 * No need to wipe the create event since the application socket will
4856 * get close on error hence cleaning up everything by itself.
4857 */
4858 goto error;
4859 }
4860
4861 DBG3("UST registry event %s with id %" PRId32 " added successfully",
4862 name, event_id);
4863
4864error:
4865 pthread_mutex_unlock(&registry->lock);
4866error_rcu_unlock:
4867 rcu_read_unlock();
4868 return ret;
4869}
4870
4871/*
4872 * Handle application notification through the given notify socket.
4873 *
4874 * Return 0 on success or else a negative value.
4875 */
4876int ust_app_recv_notify(int sock)
4877{
4878 int ret;
4879 enum ustctl_notify_cmd cmd;
4880
4881 DBG3("UST app receiving notify from sock %d", sock);
4882
4883 ret = ustctl_recv_notify(sock, &cmd);
4884 if (ret < 0) {
4885 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4886 ERR("UST app recv notify failed with ret %d", ret);
4887 } else {
4888 DBG3("UST app recv notify failed. Application died");
4889 }
4890 goto error;
4891 }
4892
4893 switch (cmd) {
4894 case USTCTL_NOTIFY_CMD_EVENT:
4895 {
4896 int sobjd, cobjd, loglevel;
4897 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
4898 size_t nr_fields;
4899 struct ustctl_field *fields;
4900
4901 DBG2("UST app ustctl register event received");
4902
4903 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name, &loglevel,
4904 &sig, &nr_fields, &fields, &model_emf_uri);
4905 if (ret < 0) {
4906 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4907 ERR("UST app recv event failed with ret %d", ret);
4908 } else {
4909 DBG3("UST app recv event failed. Application died");
4910 }
4911 goto error;
4912 }
4913
4914 /*
4915 * Add event to the UST registry coming from the notify socket. This
4916 * call will free if needed the sig, fields and model_emf_uri. This
4917 * code path loses the ownsership of these variables and transfer them
4918 * to the this function.
4919 */
4920 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
4921 fields, loglevel, model_emf_uri);
4922 if (ret < 0) {
4923 goto error;
4924 }
4925
4926 break;
4927 }
4928 case USTCTL_NOTIFY_CMD_CHANNEL:
4929 {
4930 int sobjd, cobjd;
4931 size_t nr_fields;
4932 struct ustctl_field *fields;
4933
4934 DBG2("UST app ustctl register channel received");
4935
4936 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
4937 &fields);
4938 if (ret < 0) {
4939 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4940 ERR("UST app recv channel failed with ret %d", ret);
4941 } else {
4942 DBG3("UST app recv channel failed. Application died");
4943 }
4944 goto error;
4945 }
4946
4947 /*
4948 * The fields ownership are transfered to this function call meaning
4949 * that if needed it will be freed. After this, it's invalid to access
4950 * fields or clean it up.
4951 */
4952 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
4953 fields);
4954 if (ret < 0) {
4955 goto error;
4956 }
4957
4958 break;
4959 }
4960 default:
4961 /* Should NEVER happen. */
4962 assert(0);
4963 }
4964
4965error:
4966 return ret;
4967}
4968
4969/*
4970 * Once the notify socket hangs up, this is called. First, it tries to find the
4971 * corresponding application. On failure, the call_rcu to close the socket is
4972 * executed. If an application is found, it tries to delete it from the notify
4973 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4974 *
4975 * Note that an object needs to be allocated here so on ENOMEM failure, the
4976 * call RCU is not done but the rest of the cleanup is.
4977 */
4978void ust_app_notify_sock_unregister(int sock)
4979{
4980 int err_enomem = 0;
4981 struct lttng_ht_iter iter;
4982 struct ust_app *app;
4983 struct ust_app_notify_sock_obj *obj;
4984
4985 assert(sock >= 0);
4986
4987 rcu_read_lock();
4988
4989 obj = zmalloc(sizeof(*obj));
4990 if (!obj) {
4991 /*
4992 * An ENOMEM is kind of uncool. If this strikes we continue the
4993 * procedure but the call_rcu will not be called. In this case, we
4994 * accept the fd leak rather than possibly creating an unsynchronized
4995 * state between threads.
4996 *
4997 * TODO: The notify object should be created once the notify socket is
4998 * registered and stored independantely from the ust app object. The
4999 * tricky part is to synchronize the teardown of the application and
5000 * this notify object. Let's keep that in mind so we can avoid this
5001 * kind of shenanigans with ENOMEM in the teardown path.
5002 */
5003 err_enomem = 1;
5004 } else {
5005 obj->fd = sock;
5006 }
5007
5008 DBG("UST app notify socket unregister %d", sock);
5009
5010 /*
5011 * Lookup application by notify socket. If this fails, this means that the
5012 * hash table delete has already been done by the application
5013 * unregistration process so we can safely close the notify socket in a
5014 * call RCU.
5015 */
5016 app = find_app_by_notify_sock(sock);
5017 if (!app) {
5018 goto close_socket;
5019 }
5020
5021 iter.iter.node = &app->notify_sock_n.node;
5022
5023 /*
5024 * Whatever happens here either we fail or succeed, in both cases we have
5025 * to close the socket after a grace period to continue to the call RCU
5026 * here. If the deletion is successful, the application is not visible
5027 * anymore by other threads and is it fails it means that it was already
5028 * deleted from the hash table so either way we just have to close the
5029 * socket.
5030 */
5031 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5032
5033close_socket:
5034 rcu_read_unlock();
5035
5036 /*
5037 * Close socket after a grace period to avoid for the socket to be reused
5038 * before the application object is freed creating potential race between
5039 * threads trying to add unique in the global hash table.
5040 */
5041 if (!err_enomem) {
5042 call_rcu(&obj->head, close_notify_sock_rcu);
5043 }
5044}
5045
5046/*
5047 * Destroy a ust app data structure and free its memory.
5048 */
5049void ust_app_destroy(struct ust_app *app)
5050{
5051 if (!app) {
5052 return;
5053 }
5054
5055 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5056}
5057
5058/*
5059 * Take a snapshot for a given UST session. The snapshot is sent to the given
5060 * output.
5061 *
5062 * Return 0 on success or else a negative value.
5063 */
5064int ust_app_snapshot_record(struct ltt_ust_session *usess,
5065 struct snapshot_output *output, int wait, uint64_t max_stream_size)
5066{
5067 int ret = 0;
5068 unsigned int snapshot_done = 0;
5069 struct lttng_ht_iter iter;
5070 struct ust_app *app;
5071 char pathname[PATH_MAX];
5072
5073 assert(usess);
5074 assert(output);
5075
5076 rcu_read_lock();
5077
5078 switch (usess->buffer_type) {
5079 case LTTNG_BUFFER_PER_UID:
5080 {
5081 struct buffer_reg_uid *reg;
5082
5083 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5084 struct buffer_reg_channel *reg_chan;
5085 struct consumer_socket *socket;
5086
5087 /* Get consumer socket to use to push the metadata.*/
5088 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5089 usess->consumer);
5090 if (!socket) {
5091 ret = -EINVAL;
5092 goto error;
5093 }
5094
5095 memset(pathname, 0, sizeof(pathname));
5096 ret = snprintf(pathname, sizeof(pathname),
5097 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
5098 reg->uid, reg->bits_per_long);
5099 if (ret < 0) {
5100 PERROR("snprintf snapshot path");
5101 goto error;
5102 }
5103
5104 /* Add the UST default trace dir to path. */
5105 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5106 reg_chan, node.node) {
5107 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key,
5108 output, 0, usess->uid, usess->gid, pathname, wait,
5109 max_stream_size);
5110 if (ret < 0) {
5111 goto error;
5112 }
5113 }
5114 ret = consumer_snapshot_channel(socket,
5115 reg->registry->reg.ust->metadata_key, output, 1,
5116 usess->uid, usess->gid, pathname, wait, max_stream_size);
5117 if (ret < 0) {
5118 goto error;
5119 }
5120 snapshot_done = 1;
5121 }
5122 break;
5123 }
5124 case LTTNG_BUFFER_PER_PID:
5125 {
5126 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5127 struct consumer_socket *socket;
5128 struct lttng_ht_iter chan_iter;
5129 struct ust_app_channel *ua_chan;
5130 struct ust_app_session *ua_sess;
5131 struct ust_registry_session *registry;
5132
5133 ua_sess = lookup_session_by_app(usess, app);
5134 if (!ua_sess) {
5135 /* Session not associated with this app. */
5136 continue;
5137 }
5138
5139 /* Get the right consumer socket for the application. */
5140 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5141 output->consumer);
5142 if (!socket) {
5143 ret = -EINVAL;
5144 goto error;
5145 }
5146
5147 /* Add the UST default trace dir to path. */
5148 memset(pathname, 0, sizeof(pathname));
5149 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
5150 ua_sess->path);
5151 if (ret < 0) {
5152 PERROR("snprintf snapshot path");
5153 goto error;
5154 }
5155
5156 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5157 ua_chan, node.node) {
5158 ret = consumer_snapshot_channel(socket, ua_chan->key, output,
5159 0, ua_sess->euid, ua_sess->egid, pathname, wait,
5160 max_stream_size);
5161 if (ret < 0) {
5162 goto error;
5163 }
5164 }
5165
5166 registry = get_session_registry(ua_sess);
5167 assert(registry);
5168 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5169 1, ua_sess->euid, ua_sess->egid, pathname, wait,
5170 max_stream_size);
5171 if (ret < 0) {
5172 goto error;
5173 }
5174 snapshot_done = 1;
5175 }
5176 break;
5177 }
5178 default:
5179 assert(0);
5180 break;
5181 }
5182
5183 if (!snapshot_done) {
5184 /*
5185 * If no snapshot was made and we are not in the error path, this means
5186 * that there are no buffers thus no (prior) application to snapshot
5187 * data from so we have simply NO data.
5188 */
5189 ret = -ENODATA;
5190 }
5191
5192error:
5193 rcu_read_unlock();
5194 return ret;
5195}
5196
5197/*
5198 * Return the number of streams for a UST session.
5199 */
5200unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
5201{
5202 unsigned int ret = 0;
5203 struct ust_app *app;
5204 struct lttng_ht_iter iter;
5205
5206 assert(usess);
5207
5208 switch (usess->buffer_type) {
5209 case LTTNG_BUFFER_PER_UID:
5210 {
5211 struct buffer_reg_uid *reg;
5212
5213 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5214 struct buffer_reg_channel *reg_chan;
5215
5216 rcu_read_lock();
5217 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5218 reg_chan, node.node) {
5219 ret += reg_chan->stream_count;
5220 }
5221 rcu_read_unlock();
5222 }
5223 break;
5224 }
5225 case LTTNG_BUFFER_PER_PID:
5226 {
5227 rcu_read_lock();
5228 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5229 struct ust_app_channel *ua_chan;
5230 struct ust_app_session *ua_sess;
5231 struct lttng_ht_iter chan_iter;
5232
5233 ua_sess = lookup_session_by_app(usess, app);
5234 if (!ua_sess) {
5235 /* Session not associated with this app. */
5236 continue;
5237 }
5238
5239 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5240 ua_chan, node.node) {
5241 ret += ua_chan->streams.count;
5242 }
5243 }
5244 rcu_read_unlock();
5245 break;
5246 }
5247 default:
5248 assert(0);
5249 break;
5250 }
5251
5252 return ret;
5253}
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