Fix: check for lttng modules presence before testing
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
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 #include "session.h"
44 #include "lttng-sessiond.h"
45 #include "notification-thread-commands.h"
46 #include "rotate.h"
47
48 static
49 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51 /* Next available channel key. Access under next_channel_key_lock. */
52 static uint64_t _next_channel_key;
53 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55 /* Next available session ID. Access under next_session_id_lock. */
56 static uint64_t _next_session_id;
57 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59 /*
60 * Return the incremented value of next_channel_key.
61 */
62 static uint64_t get_next_channel_key(void)
63 {
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70 }
71
72 /*
73 * Return the atomically incremented value of next_session_id.
74 */
75 static uint64_t get_next_session_id(void)
76 {
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83 }
84
85 static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88 {
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97 }
98
99 /*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106 {
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173 no_match:
174 return 0;
175 }
176
177 /*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183 {
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202 }
203
204 /*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208 static void close_notify_sock_rcu(struct rcu_head *head)
209 {
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224 }
225
226 /*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233 static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235 {
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long,
254 ua_sess->real_credentials.uid);
255 if (!reg_uid) {
256 goto error;
257 }
258 registry = reg_uid->registry->reg.ust;
259 break;
260 }
261 default:
262 assert(0);
263 };
264
265 error:
266 return registry;
267 }
268
269 /*
270 * Delete ust context safely. RCU read lock must be held before calling
271 * this function.
272 */
273 static
274 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
275 struct ust_app *app)
276 {
277 int ret;
278
279 assert(ua_ctx);
280
281 if (ua_ctx->obj) {
282 pthread_mutex_lock(&app->sock_lock);
283 ret = ustctl_release_object(sock, ua_ctx->obj);
284 pthread_mutex_unlock(&app->sock_lock);
285 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
286 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
287 sock, ua_ctx->obj->handle, ret);
288 }
289 free(ua_ctx->obj);
290 }
291 free(ua_ctx);
292 }
293
294 /*
295 * Delete ust app event safely. RCU read lock must be held before calling
296 * this function.
297 */
298 static
299 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
300 struct ust_app *app)
301 {
302 int ret;
303
304 assert(ua_event);
305
306 free(ua_event->filter);
307 if (ua_event->exclusion != NULL)
308 free(ua_event->exclusion);
309 if (ua_event->obj != NULL) {
310 pthread_mutex_lock(&app->sock_lock);
311 ret = ustctl_release_object(sock, ua_event->obj);
312 pthread_mutex_unlock(&app->sock_lock);
313 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
314 ERR("UST app sock %d release event obj failed with ret %d",
315 sock, ret);
316 }
317 free(ua_event->obj);
318 }
319 free(ua_event);
320 }
321
322 /*
323 * Release ust data object of the given stream.
324 *
325 * Return 0 on success or else a negative value.
326 */
327 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
328 struct ust_app *app)
329 {
330 int ret = 0;
331
332 assert(stream);
333
334 if (stream->obj) {
335 pthread_mutex_lock(&app->sock_lock);
336 ret = ustctl_release_object(sock, stream->obj);
337 pthread_mutex_unlock(&app->sock_lock);
338 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
339 ERR("UST app sock %d release stream obj failed with ret %d",
340 sock, ret);
341 }
342 lttng_fd_put(LTTNG_FD_APPS, 2);
343 free(stream->obj);
344 }
345
346 return ret;
347 }
348
349 /*
350 * Delete ust app stream safely. RCU read lock must be held before calling
351 * this function.
352 */
353 static
354 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
355 struct ust_app *app)
356 {
357 assert(stream);
358
359 (void) release_ust_app_stream(sock, stream, app);
360 free(stream);
361 }
362
363 /*
364 * We need to execute ht_destroy outside of RCU read-side critical
365 * section and outside of call_rcu thread, so we postpone its execution
366 * using ht_cleanup_push. It is simpler than to change the semantic of
367 * the many callers of delete_ust_app_session().
368 */
369 static
370 void delete_ust_app_channel_rcu(struct rcu_head *head)
371 {
372 struct ust_app_channel *ua_chan =
373 caa_container_of(head, struct ust_app_channel, rcu_head);
374
375 ht_cleanup_push(ua_chan->ctx);
376 ht_cleanup_push(ua_chan->events);
377 free(ua_chan);
378 }
379
380 /*
381 * Extract the lost packet or discarded events counter when the channel is
382 * being deleted and store the value in the parent channel so we can
383 * access it from lttng list and at stop/destroy.
384 *
385 * The session list lock must be held by the caller.
386 */
387 static
388 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
389 {
390 uint64_t discarded = 0, lost = 0;
391 struct ltt_session *session;
392 struct ltt_ust_channel *uchan;
393
394 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
395 return;
396 }
397
398 rcu_read_lock();
399 session = session_find_by_id(ua_chan->session->tracing_id);
400 if (!session || !session->ust_session) {
401 /*
402 * Not finding the session is not an error because there are
403 * multiple ways the channels can be torn down.
404 *
405 * 1) The session daemon can initiate the destruction of the
406 * ust app session after receiving a destroy command or
407 * during its shutdown/teardown.
408 * 2) The application, since we are in per-pid tracing, is
409 * unregistering and tearing down its ust app session.
410 *
411 * Both paths are protected by the session list lock which
412 * ensures that the accounting of lost packets and discarded
413 * events is done exactly once. The session is then unpublished
414 * from the session list, resulting in this condition.
415 */
416 goto end;
417 }
418
419 if (ua_chan->attr.overwrite) {
420 consumer_get_lost_packets(ua_chan->session->tracing_id,
421 ua_chan->key, session->ust_session->consumer,
422 &lost);
423 } else {
424 consumer_get_discarded_events(ua_chan->session->tracing_id,
425 ua_chan->key, session->ust_session->consumer,
426 &discarded);
427 }
428 uchan = trace_ust_find_channel_by_name(
429 session->ust_session->domain_global.channels,
430 ua_chan->name);
431 if (!uchan) {
432 ERR("Missing UST channel to store discarded counters");
433 goto end;
434 }
435
436 uchan->per_pid_closed_app_discarded += discarded;
437 uchan->per_pid_closed_app_lost += lost;
438
439 end:
440 rcu_read_unlock();
441 if (session) {
442 session_put(session);
443 }
444 }
445
446 /*
447 * Delete ust app channel safely. RCU read lock must be held before calling
448 * this function.
449 *
450 * The session list lock must be held by the caller.
451 */
452 static
453 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
454 struct ust_app *app)
455 {
456 int ret;
457 struct lttng_ht_iter iter;
458 struct ust_app_event *ua_event;
459 struct ust_app_ctx *ua_ctx;
460 struct ust_app_stream *stream, *stmp;
461 struct ust_registry_session *registry;
462
463 assert(ua_chan);
464
465 DBG3("UST app deleting channel %s", ua_chan->name);
466
467 /* Wipe stream */
468 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
469 cds_list_del(&stream->list);
470 delete_ust_app_stream(sock, stream, app);
471 }
472
473 /* Wipe context */
474 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
475 cds_list_del(&ua_ctx->list);
476 ret = lttng_ht_del(ua_chan->ctx, &iter);
477 assert(!ret);
478 delete_ust_app_ctx(sock, ua_ctx, app);
479 }
480
481 /* Wipe events */
482 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
483 node.node) {
484 ret = lttng_ht_del(ua_chan->events, &iter);
485 assert(!ret);
486 delete_ust_app_event(sock, ua_event, app);
487 }
488
489 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
490 /* Wipe and free registry from session registry. */
491 registry = get_session_registry(ua_chan->session);
492 if (registry) {
493 ust_registry_channel_del_free(registry, ua_chan->key,
494 sock >= 0);
495 }
496 /*
497 * A negative socket can be used by the caller when
498 * cleaning-up a ua_chan in an error path. Skip the
499 * accounting in this case.
500 */
501 if (sock >= 0) {
502 save_per_pid_lost_discarded_counters(ua_chan);
503 }
504 }
505
506 if (ua_chan->obj != NULL) {
507 /* Remove channel from application UST object descriptor. */
508 iter.iter.node = &ua_chan->ust_objd_node.node;
509 ret = lttng_ht_del(app->ust_objd, &iter);
510 assert(!ret);
511 pthread_mutex_lock(&app->sock_lock);
512 ret = ustctl_release_object(sock, ua_chan->obj);
513 pthread_mutex_unlock(&app->sock_lock);
514 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
515 ERR("UST app sock %d release channel obj failed with ret %d",
516 sock, ret);
517 }
518 lttng_fd_put(LTTNG_FD_APPS, 1);
519 free(ua_chan->obj);
520 }
521 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
522 }
523
524 int ust_app_register_done(struct ust_app *app)
525 {
526 int ret;
527
528 pthread_mutex_lock(&app->sock_lock);
529 ret = ustctl_register_done(app->sock);
530 pthread_mutex_unlock(&app->sock_lock);
531 return ret;
532 }
533
534 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
535 {
536 int ret, sock;
537
538 if (app) {
539 pthread_mutex_lock(&app->sock_lock);
540 sock = app->sock;
541 } else {
542 sock = -1;
543 }
544 ret = ustctl_release_object(sock, data);
545 if (app) {
546 pthread_mutex_unlock(&app->sock_lock);
547 }
548 return ret;
549 }
550
551 /*
552 * Push metadata to consumer socket.
553 *
554 * RCU read-side lock must be held to guarantee existance of socket.
555 * Must be called with the ust app session lock held.
556 * Must be called with the registry lock held.
557 *
558 * On success, return the len of metadata pushed or else a negative value.
559 * Returning a -EPIPE return value means we could not send the metadata,
560 * but it can be caused by recoverable errors (e.g. the application has
561 * terminated concurrently).
562 */
563 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
564 struct consumer_socket *socket, int send_zero_data)
565 {
566 int ret;
567 char *metadata_str = NULL;
568 size_t len, offset, new_metadata_len_sent;
569 ssize_t ret_val;
570 uint64_t metadata_key, metadata_version;
571
572 assert(registry);
573 assert(socket);
574
575 metadata_key = registry->metadata_key;
576
577 /*
578 * Means that no metadata was assigned to the session. This can
579 * happens if no start has been done previously.
580 */
581 if (!metadata_key) {
582 return 0;
583 }
584
585 offset = registry->metadata_len_sent;
586 len = registry->metadata_len - registry->metadata_len_sent;
587 new_metadata_len_sent = registry->metadata_len;
588 metadata_version = registry->metadata_version;
589 if (len == 0) {
590 DBG3("No metadata to push for metadata key %" PRIu64,
591 registry->metadata_key);
592 ret_val = len;
593 if (send_zero_data) {
594 DBG("No metadata to push");
595 goto push_data;
596 }
597 goto end;
598 }
599
600 /* Allocate only what we have to send. */
601 metadata_str = zmalloc(len);
602 if (!metadata_str) {
603 PERROR("zmalloc ust app metadata string");
604 ret_val = -ENOMEM;
605 goto error;
606 }
607 /* Copy what we haven't sent out. */
608 memcpy(metadata_str, registry->metadata + offset, len);
609
610 push_data:
611 pthread_mutex_unlock(&registry->lock);
612 /*
613 * We need to unlock the registry while we push metadata to
614 * break a circular dependency between the consumerd metadata
615 * lock and the sessiond registry lock. Indeed, pushing metadata
616 * to the consumerd awaits that it gets pushed all the way to
617 * relayd, but doing so requires grabbing the metadata lock. If
618 * a concurrent metadata request is being performed by
619 * consumerd, this can try to grab the registry lock on the
620 * sessiond while holding the metadata lock on the consumer
621 * daemon. Those push and pull schemes are performed on two
622 * different bidirectionnal communication sockets.
623 */
624 ret = consumer_push_metadata(socket, metadata_key,
625 metadata_str, len, offset, metadata_version);
626 pthread_mutex_lock(&registry->lock);
627 if (ret < 0) {
628 /*
629 * There is an acceptable race here between the registry
630 * metadata key assignment and the creation on the
631 * consumer. The session daemon can concurrently push
632 * metadata for this registry while being created on the
633 * consumer since the metadata key of the registry is
634 * assigned *before* it is setup to avoid the consumer
635 * to ask for metadata that could possibly be not found
636 * in the session daemon.
637 *
638 * The metadata will get pushed either by the session
639 * being stopped or the consumer requesting metadata if
640 * that race is triggered.
641 */
642 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
643 ret = 0;
644 } else {
645 ERR("Error pushing metadata to consumer");
646 }
647 ret_val = ret;
648 goto error_push;
649 } else {
650 /*
651 * Metadata may have been concurrently pushed, since
652 * we're not holding the registry lock while pushing to
653 * consumer. This is handled by the fact that we send
654 * the metadata content, size, and the offset at which
655 * that metadata belongs. This may arrive out of order
656 * on the consumer side, and the consumer is able to
657 * deal with overlapping fragments. The consumer
658 * supports overlapping fragments, which must be
659 * contiguous starting from offset 0. We keep the
660 * largest metadata_len_sent value of the concurrent
661 * send.
662 */
663 registry->metadata_len_sent =
664 max_t(size_t, registry->metadata_len_sent,
665 new_metadata_len_sent);
666 }
667 free(metadata_str);
668 return len;
669
670 end:
671 error:
672 if (ret_val) {
673 /*
674 * On error, flag the registry that the metadata is
675 * closed. We were unable to push anything and this
676 * means that either the consumer is not responding or
677 * the metadata cache has been destroyed on the
678 * consumer.
679 */
680 registry->metadata_closed = 1;
681 }
682 error_push:
683 free(metadata_str);
684 return ret_val;
685 }
686
687 /*
688 * For a given application and session, push metadata to consumer.
689 * Either sock or consumer is required : if sock is NULL, the default
690 * socket to send the metadata is retrieved from consumer, if sock
691 * is not NULL we use it to send the metadata.
692 * RCU read-side lock must be held while calling this function,
693 * therefore ensuring existance of registry. It also ensures existance
694 * of socket throughout this function.
695 *
696 * Return 0 on success else a negative error.
697 * Returning a -EPIPE return value means we could not send the metadata,
698 * but it can be caused by recoverable errors (e.g. the application has
699 * terminated concurrently).
700 */
701 static int push_metadata(struct ust_registry_session *registry,
702 struct consumer_output *consumer)
703 {
704 int ret_val;
705 ssize_t ret;
706 struct consumer_socket *socket;
707
708 assert(registry);
709 assert(consumer);
710
711 pthread_mutex_lock(&registry->lock);
712 if (registry->metadata_closed) {
713 ret_val = -EPIPE;
714 goto error;
715 }
716
717 /* Get consumer socket to use to push the metadata.*/
718 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
719 consumer);
720 if (!socket) {
721 ret_val = -1;
722 goto error;
723 }
724
725 ret = ust_app_push_metadata(registry, socket, 0);
726 if (ret < 0) {
727 ret_val = ret;
728 goto error;
729 }
730 pthread_mutex_unlock(&registry->lock);
731 return 0;
732
733 error:
734 pthread_mutex_unlock(&registry->lock);
735 return ret_val;
736 }
737
738 /*
739 * Send to the consumer a close metadata command for the given session. Once
740 * done, the metadata channel is deleted and the session metadata pointer is
741 * nullified. The session lock MUST be held unless the application is
742 * in the destroy path.
743 *
744 * Return 0 on success else a negative value.
745 */
746 static int close_metadata(struct ust_registry_session *registry,
747 struct consumer_output *consumer)
748 {
749 int ret;
750 struct consumer_socket *socket;
751
752 assert(registry);
753 assert(consumer);
754
755 rcu_read_lock();
756
757 pthread_mutex_lock(&registry->lock);
758
759 if (!registry->metadata_key || registry->metadata_closed) {
760 ret = 0;
761 goto end;
762 }
763
764 /* Get consumer socket to use to push the metadata.*/
765 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
766 consumer);
767 if (!socket) {
768 ret = -1;
769 goto error;
770 }
771
772 ret = consumer_close_metadata(socket, registry->metadata_key);
773 if (ret < 0) {
774 goto error;
775 }
776
777 error:
778 /*
779 * Metadata closed. Even on error this means that the consumer is not
780 * responding or not found so either way a second close should NOT be emit
781 * for this registry.
782 */
783 registry->metadata_closed = 1;
784 end:
785 pthread_mutex_unlock(&registry->lock);
786 rcu_read_unlock();
787 return ret;
788 }
789
790 /*
791 * We need to execute ht_destroy outside of RCU read-side critical
792 * section and outside of call_rcu thread, so we postpone its execution
793 * using ht_cleanup_push. It is simpler than to change the semantic of
794 * the many callers of delete_ust_app_session().
795 */
796 static
797 void delete_ust_app_session_rcu(struct rcu_head *head)
798 {
799 struct ust_app_session *ua_sess =
800 caa_container_of(head, struct ust_app_session, rcu_head);
801
802 ht_cleanup_push(ua_sess->channels);
803 free(ua_sess);
804 }
805
806 /*
807 * Delete ust app session safely. RCU read lock must be held before calling
808 * this function.
809 *
810 * The session list lock must be held by the caller.
811 */
812 static
813 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
814 struct ust_app *app)
815 {
816 int ret;
817 struct lttng_ht_iter iter;
818 struct ust_app_channel *ua_chan;
819 struct ust_registry_session *registry;
820
821 assert(ua_sess);
822
823 pthread_mutex_lock(&ua_sess->lock);
824
825 assert(!ua_sess->deleted);
826 ua_sess->deleted = true;
827
828 registry = get_session_registry(ua_sess);
829 /* Registry can be null on error path during initialization. */
830 if (registry) {
831 /* Push metadata for application before freeing the application. */
832 (void) push_metadata(registry, ua_sess->consumer);
833
834 /*
835 * Don't ask to close metadata for global per UID buffers. Close
836 * metadata only on destroy trace session in this case. Also, the
837 * previous push metadata could have flag the metadata registry to
838 * close so don't send a close command if closed.
839 */
840 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
841 /* And ask to close it for this session registry. */
842 (void) close_metadata(registry, ua_sess->consumer);
843 }
844 }
845
846 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
847 node.node) {
848 ret = lttng_ht_del(ua_sess->channels, &iter);
849 assert(!ret);
850 delete_ust_app_channel(sock, ua_chan, app);
851 }
852
853 /* In case of per PID, the registry is kept in the session. */
854 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
855 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
856 if (reg_pid) {
857 /*
858 * Registry can be null on error path during
859 * initialization.
860 */
861 buffer_reg_pid_remove(reg_pid);
862 buffer_reg_pid_destroy(reg_pid);
863 }
864 }
865
866 if (ua_sess->handle != -1) {
867 pthread_mutex_lock(&app->sock_lock);
868 ret = ustctl_release_handle(sock, ua_sess->handle);
869 pthread_mutex_unlock(&app->sock_lock);
870 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
871 ERR("UST app sock %d release session handle failed with ret %d",
872 sock, ret);
873 }
874 /* Remove session from application UST object descriptor. */
875 iter.iter.node = &ua_sess->ust_objd_node.node;
876 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
877 assert(!ret);
878 }
879
880 pthread_mutex_unlock(&ua_sess->lock);
881
882 consumer_output_put(ua_sess->consumer);
883
884 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
885 }
886
887 /*
888 * Delete a traceable application structure from the global list. Never call
889 * this function outside of a call_rcu call.
890 *
891 * RCU read side lock should _NOT_ be held when calling this function.
892 */
893 static
894 void delete_ust_app(struct ust_app *app)
895 {
896 int ret, sock;
897 struct ust_app_session *ua_sess, *tmp_ua_sess;
898
899 /*
900 * The session list lock must be held during this function to guarantee
901 * the existence of ua_sess.
902 */
903 session_lock_list();
904 /* Delete ust app sessions info */
905 sock = app->sock;
906 app->sock = -1;
907
908 /* Wipe sessions */
909 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
910 teardown_node) {
911 /* Free every object in the session and the session. */
912 rcu_read_lock();
913 delete_ust_app_session(sock, ua_sess, app);
914 rcu_read_unlock();
915 }
916
917 ht_cleanup_push(app->sessions);
918 ht_cleanup_push(app->ust_sessions_objd);
919 ht_cleanup_push(app->ust_objd);
920
921 /*
922 * Wait until we have deleted the application from the sock hash table
923 * before closing this socket, otherwise an application could re-use the
924 * socket ID and race with the teardown, using the same hash table entry.
925 *
926 * It's OK to leave the close in call_rcu. We want it to stay unique for
927 * all RCU readers that could run concurrently with unregister app,
928 * therefore we _need_ to only close that socket after a grace period. So
929 * it should stay in this RCU callback.
930 *
931 * This close() is a very important step of the synchronization model so
932 * every modification to this function must be carefully reviewed.
933 */
934 ret = close(sock);
935 if (ret) {
936 PERROR("close");
937 }
938 lttng_fd_put(LTTNG_FD_APPS, 1);
939
940 DBG2("UST app pid %d deleted", app->pid);
941 free(app);
942 session_unlock_list();
943 }
944
945 /*
946 * URCU intermediate call to delete an UST app.
947 */
948 static
949 void delete_ust_app_rcu(struct rcu_head *head)
950 {
951 struct lttng_ht_node_ulong *node =
952 caa_container_of(head, struct lttng_ht_node_ulong, head);
953 struct ust_app *app =
954 caa_container_of(node, struct ust_app, pid_n);
955
956 DBG3("Call RCU deleting app PID %d", app->pid);
957 delete_ust_app(app);
958 }
959
960 /*
961 * Delete the session from the application ht and delete the data structure by
962 * freeing every object inside and releasing them.
963 *
964 * The session list lock must be held by the caller.
965 */
966 static void destroy_app_session(struct ust_app *app,
967 struct ust_app_session *ua_sess)
968 {
969 int ret;
970 struct lttng_ht_iter iter;
971
972 assert(app);
973 assert(ua_sess);
974
975 iter.iter.node = &ua_sess->node.node;
976 ret = lttng_ht_del(app->sessions, &iter);
977 if (ret) {
978 /* Already scheduled for teardown. */
979 goto end;
980 }
981
982 /* Once deleted, free the data structure. */
983 delete_ust_app_session(app->sock, ua_sess, app);
984
985 end:
986 return;
987 }
988
989 /*
990 * Alloc new UST app session.
991 */
992 static
993 struct ust_app_session *alloc_ust_app_session(void)
994 {
995 struct ust_app_session *ua_sess;
996
997 /* Init most of the default value by allocating and zeroing */
998 ua_sess = zmalloc(sizeof(struct ust_app_session));
999 if (ua_sess == NULL) {
1000 PERROR("malloc");
1001 goto error_free;
1002 }
1003
1004 ua_sess->handle = -1;
1005 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1006 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1007 pthread_mutex_init(&ua_sess->lock, NULL);
1008
1009 return ua_sess;
1010
1011 error_free:
1012 return NULL;
1013 }
1014
1015 /*
1016 * Alloc new UST app channel.
1017 */
1018 static
1019 struct ust_app_channel *alloc_ust_app_channel(char *name,
1020 struct ust_app_session *ua_sess,
1021 struct lttng_ust_channel_attr *attr)
1022 {
1023 struct ust_app_channel *ua_chan;
1024
1025 /* Init most of the default value by allocating and zeroing */
1026 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1027 if (ua_chan == NULL) {
1028 PERROR("malloc");
1029 goto error;
1030 }
1031
1032 /* Setup channel name */
1033 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1034 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1035
1036 ua_chan->enabled = 1;
1037 ua_chan->handle = -1;
1038 ua_chan->session = ua_sess;
1039 ua_chan->key = get_next_channel_key();
1040 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1041 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1042 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1043
1044 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1045 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1046
1047 /* Copy attributes */
1048 if (attr) {
1049 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1050 ua_chan->attr.subbuf_size = attr->subbuf_size;
1051 ua_chan->attr.num_subbuf = attr->num_subbuf;
1052 ua_chan->attr.overwrite = attr->overwrite;
1053 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1054 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1055 ua_chan->attr.output = attr->output;
1056 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1057 }
1058 /* By default, the channel is a per cpu channel. */
1059 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1060
1061 DBG3("UST app channel %s allocated", ua_chan->name);
1062
1063 return ua_chan;
1064
1065 error:
1066 return NULL;
1067 }
1068
1069 /*
1070 * Allocate and initialize a UST app stream.
1071 *
1072 * Return newly allocated stream pointer or NULL on error.
1073 */
1074 struct ust_app_stream *ust_app_alloc_stream(void)
1075 {
1076 struct ust_app_stream *stream = NULL;
1077
1078 stream = zmalloc(sizeof(*stream));
1079 if (stream == NULL) {
1080 PERROR("zmalloc ust app stream");
1081 goto error;
1082 }
1083
1084 /* Zero could be a valid value for a handle so flag it to -1. */
1085 stream->handle = -1;
1086
1087 error:
1088 return stream;
1089 }
1090
1091 /*
1092 * Alloc new UST app event.
1093 */
1094 static
1095 struct ust_app_event *alloc_ust_app_event(char *name,
1096 struct lttng_ust_event *attr)
1097 {
1098 struct ust_app_event *ua_event;
1099
1100 /* Init most of the default value by allocating and zeroing */
1101 ua_event = zmalloc(sizeof(struct ust_app_event));
1102 if (ua_event == NULL) {
1103 PERROR("malloc");
1104 goto error;
1105 }
1106
1107 ua_event->enabled = 1;
1108 strncpy(ua_event->name, name, sizeof(ua_event->name));
1109 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1110 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1111
1112 /* Copy attributes */
1113 if (attr) {
1114 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1115 }
1116
1117 DBG3("UST app event %s allocated", ua_event->name);
1118
1119 return ua_event;
1120
1121 error:
1122 return NULL;
1123 }
1124
1125 /*
1126 * Alloc new UST app context.
1127 */
1128 static
1129 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1130 {
1131 struct ust_app_ctx *ua_ctx;
1132
1133 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1134 if (ua_ctx == NULL) {
1135 goto error;
1136 }
1137
1138 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1139
1140 if (uctx) {
1141 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1142 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1143 char *provider_name = NULL, *ctx_name = NULL;
1144
1145 provider_name = strdup(uctx->u.app_ctx.provider_name);
1146 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1147 if (!provider_name || !ctx_name) {
1148 free(provider_name);
1149 free(ctx_name);
1150 goto error;
1151 }
1152
1153 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1154 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1155 }
1156 }
1157
1158 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1159 return ua_ctx;
1160 error:
1161 free(ua_ctx);
1162 return NULL;
1163 }
1164
1165 /*
1166 * Allocate a filter and copy the given original filter.
1167 *
1168 * Return allocated filter or NULL on error.
1169 */
1170 static struct lttng_filter_bytecode *copy_filter_bytecode(
1171 struct lttng_filter_bytecode *orig_f)
1172 {
1173 struct lttng_filter_bytecode *filter = NULL;
1174
1175 /* Copy filter bytecode */
1176 filter = zmalloc(sizeof(*filter) + orig_f->len);
1177 if (!filter) {
1178 PERROR("zmalloc alloc filter bytecode");
1179 goto error;
1180 }
1181
1182 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1183
1184 error:
1185 return filter;
1186 }
1187
1188 /*
1189 * Create a liblttng-ust filter bytecode from given bytecode.
1190 *
1191 * Return allocated filter or NULL on error.
1192 */
1193 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1194 struct lttng_filter_bytecode *orig_f)
1195 {
1196 struct lttng_ust_filter_bytecode *filter = NULL;
1197
1198 /* Copy filter bytecode */
1199 filter = zmalloc(sizeof(*filter) + orig_f->len);
1200 if (!filter) {
1201 PERROR("zmalloc alloc ust filter bytecode");
1202 goto error;
1203 }
1204
1205 assert(sizeof(struct lttng_filter_bytecode) ==
1206 sizeof(struct lttng_ust_filter_bytecode));
1207 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1208 error:
1209 return filter;
1210 }
1211
1212 /*
1213 * Find an ust_app using the sock and return it. RCU read side lock must be
1214 * held before calling this helper function.
1215 */
1216 struct ust_app *ust_app_find_by_sock(int sock)
1217 {
1218 struct lttng_ht_node_ulong *node;
1219 struct lttng_ht_iter iter;
1220
1221 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1222 node = lttng_ht_iter_get_node_ulong(&iter);
1223 if (node == NULL) {
1224 DBG2("UST app find by sock %d not found", sock);
1225 goto error;
1226 }
1227
1228 return caa_container_of(node, struct ust_app, sock_n);
1229
1230 error:
1231 return NULL;
1232 }
1233
1234 /*
1235 * Find an ust_app using the notify sock and return it. RCU read side lock must
1236 * be held before calling this helper function.
1237 */
1238 static struct ust_app *find_app_by_notify_sock(int sock)
1239 {
1240 struct lttng_ht_node_ulong *node;
1241 struct lttng_ht_iter iter;
1242
1243 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1244 &iter);
1245 node = lttng_ht_iter_get_node_ulong(&iter);
1246 if (node == NULL) {
1247 DBG2("UST app find by notify sock %d not found", sock);
1248 goto error;
1249 }
1250
1251 return caa_container_of(node, struct ust_app, notify_sock_n);
1252
1253 error:
1254 return NULL;
1255 }
1256
1257 /*
1258 * Lookup for an ust app event based on event name, filter bytecode and the
1259 * event loglevel.
1260 *
1261 * Return an ust_app_event object or NULL on error.
1262 */
1263 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1264 const char *name, const struct lttng_filter_bytecode *filter,
1265 int loglevel_value,
1266 const struct lttng_event_exclusion *exclusion)
1267 {
1268 struct lttng_ht_iter iter;
1269 struct lttng_ht_node_str *node;
1270 struct ust_app_event *event = NULL;
1271 struct ust_app_ht_key key;
1272
1273 assert(name);
1274 assert(ht);
1275
1276 /* Setup key for event lookup. */
1277 key.name = name;
1278 key.filter = filter;
1279 key.loglevel_type = loglevel_value;
1280 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1281 key.exclusion = exclusion;
1282
1283 /* Lookup using the event name as hash and a custom match fct. */
1284 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1285 ht_match_ust_app_event, &key, &iter.iter);
1286 node = lttng_ht_iter_get_node_str(&iter);
1287 if (node == NULL) {
1288 goto end;
1289 }
1290
1291 event = caa_container_of(node, struct ust_app_event, node);
1292
1293 end:
1294 return event;
1295 }
1296
1297 /*
1298 * Create the channel context on the tracer.
1299 *
1300 * Called with UST app session lock held.
1301 */
1302 static
1303 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1304 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1305 {
1306 int ret;
1307
1308 health_code_update();
1309
1310 pthread_mutex_lock(&app->sock_lock);
1311 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1312 ua_chan->obj, &ua_ctx->obj);
1313 pthread_mutex_unlock(&app->sock_lock);
1314 if (ret < 0) {
1315 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1316 ERR("UST app create channel context failed for app (pid: %d) "
1317 "with ret %d", app->pid, ret);
1318 } else {
1319 /*
1320 * This is normal behavior, an application can die during the
1321 * creation process. Don't report an error so the execution can
1322 * continue normally.
1323 */
1324 ret = 0;
1325 DBG3("UST app add context failed. Application is dead.");
1326 }
1327 goto error;
1328 }
1329
1330 ua_ctx->handle = ua_ctx->obj->handle;
1331
1332 DBG2("UST app context handle %d created successfully for channel %s",
1333 ua_ctx->handle, ua_chan->name);
1334
1335 error:
1336 health_code_update();
1337 return ret;
1338 }
1339
1340 /*
1341 * Set the filter on the tracer.
1342 */
1343 static
1344 int set_ust_event_filter(struct ust_app_event *ua_event,
1345 struct ust_app *app)
1346 {
1347 int ret;
1348 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1349
1350 health_code_update();
1351
1352 if (!ua_event->filter) {
1353 ret = 0;
1354 goto error;
1355 }
1356
1357 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1358 if (!ust_bytecode) {
1359 ret = -LTTNG_ERR_NOMEM;
1360 goto error;
1361 }
1362 pthread_mutex_lock(&app->sock_lock);
1363 ret = ustctl_set_filter(app->sock, ust_bytecode,
1364 ua_event->obj);
1365 pthread_mutex_unlock(&app->sock_lock);
1366 if (ret < 0) {
1367 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1368 ERR("UST app event %s filter failed for app (pid: %d) "
1369 "with ret %d", ua_event->attr.name, app->pid, ret);
1370 } else {
1371 /*
1372 * This is normal behavior, an application can die during the
1373 * creation process. Don't report an error so the execution can
1374 * continue normally.
1375 */
1376 ret = 0;
1377 DBG3("UST app filter event failed. Application is dead.");
1378 }
1379 goto error;
1380 }
1381
1382 DBG2("UST filter set successfully for event %s", ua_event->name);
1383
1384 error:
1385 health_code_update();
1386 free(ust_bytecode);
1387 return ret;
1388 }
1389
1390 static
1391 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1392 struct lttng_event_exclusion *exclusion)
1393 {
1394 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1395 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1396 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1397
1398 ust_exclusion = zmalloc(exclusion_alloc_size);
1399 if (!ust_exclusion) {
1400 PERROR("malloc");
1401 goto end;
1402 }
1403
1404 assert(sizeof(struct lttng_event_exclusion) ==
1405 sizeof(struct lttng_ust_event_exclusion));
1406 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1407 end:
1408 return ust_exclusion;
1409 }
1410
1411 /*
1412 * Set event exclusions on the tracer.
1413 */
1414 static
1415 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1416 struct ust_app *app)
1417 {
1418 int ret;
1419 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1420
1421 health_code_update();
1422
1423 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1424 ret = 0;
1425 goto error;
1426 }
1427
1428 ust_exclusion = create_ust_exclusion_from_exclusion(
1429 ua_event->exclusion);
1430 if (!ust_exclusion) {
1431 ret = -LTTNG_ERR_NOMEM;
1432 goto error;
1433 }
1434 pthread_mutex_lock(&app->sock_lock);
1435 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1436 pthread_mutex_unlock(&app->sock_lock);
1437 if (ret < 0) {
1438 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1439 ERR("UST app event %s exclusions failed for app (pid: %d) "
1440 "with ret %d", ua_event->attr.name, app->pid, ret);
1441 } else {
1442 /*
1443 * This is normal behavior, an application can die during the
1444 * creation process. Don't report an error so the execution can
1445 * continue normally.
1446 */
1447 ret = 0;
1448 DBG3("UST app event exclusion failed. Application is dead.");
1449 }
1450 goto error;
1451 }
1452
1453 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1454
1455 error:
1456 health_code_update();
1457 free(ust_exclusion);
1458 return ret;
1459 }
1460
1461 /*
1462 * Disable the specified event on to UST tracer for the UST session.
1463 */
1464 static int disable_ust_event(struct ust_app *app,
1465 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1466 {
1467 int ret;
1468
1469 health_code_update();
1470
1471 pthread_mutex_lock(&app->sock_lock);
1472 ret = ustctl_disable(app->sock, ua_event->obj);
1473 pthread_mutex_unlock(&app->sock_lock);
1474 if (ret < 0) {
1475 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1476 ERR("UST app event %s disable failed for app (pid: %d) "
1477 "and session handle %d with ret %d",
1478 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1479 } else {
1480 /*
1481 * This is normal behavior, an application can die during the
1482 * creation process. Don't report an error so the execution can
1483 * continue normally.
1484 */
1485 ret = 0;
1486 DBG3("UST app disable event failed. Application is dead.");
1487 }
1488 goto error;
1489 }
1490
1491 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1492 ua_event->attr.name, app->pid);
1493
1494 error:
1495 health_code_update();
1496 return ret;
1497 }
1498
1499 /*
1500 * Disable the specified channel on to UST tracer for the UST session.
1501 */
1502 static int disable_ust_channel(struct ust_app *app,
1503 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1504 {
1505 int ret;
1506
1507 health_code_update();
1508
1509 pthread_mutex_lock(&app->sock_lock);
1510 ret = ustctl_disable(app->sock, ua_chan->obj);
1511 pthread_mutex_unlock(&app->sock_lock);
1512 if (ret < 0) {
1513 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1514 ERR("UST app channel %s disable failed for app (pid: %d) "
1515 "and session handle %d with ret %d",
1516 ua_chan->name, app->pid, ua_sess->handle, ret);
1517 } else {
1518 /*
1519 * This is normal behavior, an application can die during the
1520 * creation process. Don't report an error so the execution can
1521 * continue normally.
1522 */
1523 ret = 0;
1524 DBG3("UST app disable channel failed. Application is dead.");
1525 }
1526 goto error;
1527 }
1528
1529 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1530 ua_chan->name, app->pid);
1531
1532 error:
1533 health_code_update();
1534 return ret;
1535 }
1536
1537 /*
1538 * Enable the specified channel on to UST tracer for the UST session.
1539 */
1540 static int enable_ust_channel(struct ust_app *app,
1541 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1542 {
1543 int ret;
1544
1545 health_code_update();
1546
1547 pthread_mutex_lock(&app->sock_lock);
1548 ret = ustctl_enable(app->sock, ua_chan->obj);
1549 pthread_mutex_unlock(&app->sock_lock);
1550 if (ret < 0) {
1551 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1552 ERR("UST app channel %s enable failed for app (pid: %d) "
1553 "and session handle %d with ret %d",
1554 ua_chan->name, app->pid, ua_sess->handle, ret);
1555 } else {
1556 /*
1557 * This is normal behavior, an application can die during the
1558 * creation process. Don't report an error so the execution can
1559 * continue normally.
1560 */
1561 ret = 0;
1562 DBG3("UST app enable channel failed. Application is dead.");
1563 }
1564 goto error;
1565 }
1566
1567 ua_chan->enabled = 1;
1568
1569 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1570 ua_chan->name, app->pid);
1571
1572 error:
1573 health_code_update();
1574 return ret;
1575 }
1576
1577 /*
1578 * Enable the specified event on to UST tracer for the UST session.
1579 */
1580 static int enable_ust_event(struct ust_app *app,
1581 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1582 {
1583 int ret;
1584
1585 health_code_update();
1586
1587 pthread_mutex_lock(&app->sock_lock);
1588 ret = ustctl_enable(app->sock, ua_event->obj);
1589 pthread_mutex_unlock(&app->sock_lock);
1590 if (ret < 0) {
1591 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1592 ERR("UST app event %s enable failed for app (pid: %d) "
1593 "and session handle %d with ret %d",
1594 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1595 } else {
1596 /*
1597 * This is normal behavior, an application can die during the
1598 * creation process. Don't report an error so the execution can
1599 * continue normally.
1600 */
1601 ret = 0;
1602 DBG3("UST app enable event failed. Application is dead.");
1603 }
1604 goto error;
1605 }
1606
1607 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1608 ua_event->attr.name, app->pid);
1609
1610 error:
1611 health_code_update();
1612 return ret;
1613 }
1614
1615 /*
1616 * Send channel and stream buffer to application.
1617 *
1618 * Return 0 on success. On error, a negative value is returned.
1619 */
1620 static int send_channel_pid_to_ust(struct ust_app *app,
1621 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1622 {
1623 int ret;
1624 struct ust_app_stream *stream, *stmp;
1625
1626 assert(app);
1627 assert(ua_sess);
1628 assert(ua_chan);
1629
1630 health_code_update();
1631
1632 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1633 app->sock);
1634
1635 /* Send channel to the application. */
1636 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1637 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1638 ret = -ENOTCONN; /* Caused by app exiting. */
1639 goto error;
1640 } else if (ret < 0) {
1641 goto error;
1642 }
1643
1644 health_code_update();
1645
1646 /* Send all streams to application. */
1647 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1648 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1649 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1650 ret = -ENOTCONN; /* Caused by app exiting. */
1651 goto error;
1652 } else if (ret < 0) {
1653 goto error;
1654 }
1655 /* We don't need the stream anymore once sent to the tracer. */
1656 cds_list_del(&stream->list);
1657 delete_ust_app_stream(-1, stream, app);
1658 }
1659 /* Flag the channel that it is sent to the application. */
1660 ua_chan->is_sent = 1;
1661
1662 error:
1663 health_code_update();
1664 return ret;
1665 }
1666
1667 /*
1668 * Create the specified event onto the UST tracer for a UST session.
1669 *
1670 * Should be called with session mutex held.
1671 */
1672 static
1673 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1674 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1675 {
1676 int ret = 0;
1677
1678 health_code_update();
1679
1680 /* Create UST event on tracer */
1681 pthread_mutex_lock(&app->sock_lock);
1682 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1683 &ua_event->obj);
1684 pthread_mutex_unlock(&app->sock_lock);
1685 if (ret < 0) {
1686 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1687 abort();
1688 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1689 ua_event->attr.name, app->pid, ret);
1690 } else {
1691 /*
1692 * This is normal behavior, an application can die during the
1693 * creation process. Don't report an error so the execution can
1694 * continue normally.
1695 */
1696 ret = 0;
1697 DBG3("UST app create event failed. Application is dead.");
1698 }
1699 goto error;
1700 }
1701
1702 ua_event->handle = ua_event->obj->handle;
1703
1704 DBG2("UST app event %s created successfully for pid:%d",
1705 ua_event->attr.name, app->pid);
1706
1707 health_code_update();
1708
1709 /* Set filter if one is present. */
1710 if (ua_event->filter) {
1711 ret = set_ust_event_filter(ua_event, app);
1712 if (ret < 0) {
1713 goto error;
1714 }
1715 }
1716
1717 /* Set exclusions for the event */
1718 if (ua_event->exclusion) {
1719 ret = set_ust_event_exclusion(ua_event, app);
1720 if (ret < 0) {
1721 goto error;
1722 }
1723 }
1724
1725 /* If event not enabled, disable it on the tracer */
1726 if (ua_event->enabled) {
1727 /*
1728 * We now need to explicitly enable the event, since it
1729 * is now disabled at creation.
1730 */
1731 ret = enable_ust_event(app, ua_sess, ua_event);
1732 if (ret < 0) {
1733 /*
1734 * If we hit an EPERM, something is wrong with our enable call. If
1735 * we get an EEXIST, there is a problem on the tracer side since we
1736 * just created it.
1737 */
1738 switch (ret) {
1739 case -LTTNG_UST_ERR_PERM:
1740 /* Code flow problem */
1741 assert(0);
1742 case -LTTNG_UST_ERR_EXIST:
1743 /* It's OK for our use case. */
1744 ret = 0;
1745 break;
1746 default:
1747 break;
1748 }
1749 goto error;
1750 }
1751 }
1752
1753 error:
1754 health_code_update();
1755 return ret;
1756 }
1757
1758 /*
1759 * Copy data between an UST app event and a LTT event.
1760 */
1761 static void shadow_copy_event(struct ust_app_event *ua_event,
1762 struct ltt_ust_event *uevent)
1763 {
1764 size_t exclusion_alloc_size;
1765
1766 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1767 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1768
1769 ua_event->enabled = uevent->enabled;
1770
1771 /* Copy event attributes */
1772 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1773
1774 /* Copy filter bytecode */
1775 if (uevent->filter) {
1776 ua_event->filter = copy_filter_bytecode(uevent->filter);
1777 /* Filter might be NULL here in case of ENONEM. */
1778 }
1779
1780 /* Copy exclusion data */
1781 if (uevent->exclusion) {
1782 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1783 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1784 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1785 if (ua_event->exclusion == NULL) {
1786 PERROR("malloc");
1787 } else {
1788 memcpy(ua_event->exclusion, uevent->exclusion,
1789 exclusion_alloc_size);
1790 }
1791 }
1792 }
1793
1794 /*
1795 * Copy data between an UST app channel and a LTT channel.
1796 */
1797 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1798 struct ltt_ust_channel *uchan)
1799 {
1800 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1801
1802 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1803 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1804
1805 ua_chan->tracefile_size = uchan->tracefile_size;
1806 ua_chan->tracefile_count = uchan->tracefile_count;
1807
1808 /* Copy event attributes since the layout is different. */
1809 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1810 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1811 ua_chan->attr.overwrite = uchan->attr.overwrite;
1812 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1813 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1814 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1815 ua_chan->attr.output = uchan->attr.output;
1816 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1817
1818 /*
1819 * Note that the attribute channel type is not set since the channel on the
1820 * tracing registry side does not have this information.
1821 */
1822
1823 ua_chan->enabled = uchan->enabled;
1824 ua_chan->tracing_channel_id = uchan->id;
1825
1826 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1827 }
1828
1829 /*
1830 * Copy data between a UST app session and a regular LTT session.
1831 */
1832 static void shadow_copy_session(struct ust_app_session *ua_sess,
1833 struct ltt_ust_session *usess, struct ust_app *app)
1834 {
1835 struct tm *timeinfo;
1836 char datetime[16];
1837 int ret;
1838 char tmp_shm_path[PATH_MAX];
1839
1840 timeinfo = localtime(&app->registration_time);
1841 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1842
1843 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1844
1845 ua_sess->tracing_id = usess->id;
1846 ua_sess->id = get_next_session_id();
1847 ua_sess->real_credentials.uid = app->uid;
1848 ua_sess->real_credentials.gid = app->gid;
1849 ua_sess->effective_credentials.uid = usess->uid;
1850 ua_sess->effective_credentials.gid = usess->gid;
1851 ua_sess->buffer_type = usess->buffer_type;
1852 ua_sess->bits_per_long = app->bits_per_long;
1853
1854 /* There is only one consumer object per session possible. */
1855 consumer_output_get(usess->consumer);
1856 ua_sess->consumer = usess->consumer;
1857
1858 ua_sess->output_traces = usess->output_traces;
1859 ua_sess->live_timer_interval = usess->live_timer_interval;
1860 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1861 &usess->metadata_attr);
1862
1863 switch (ua_sess->buffer_type) {
1864 case LTTNG_BUFFER_PER_PID:
1865 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1866 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1867 datetime);
1868 break;
1869 case LTTNG_BUFFER_PER_UID:
1870 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1871 DEFAULT_UST_TRACE_UID_PATH,
1872 ua_sess->real_credentials.uid,
1873 app->bits_per_long);
1874 break;
1875 default:
1876 assert(0);
1877 goto error;
1878 }
1879 if (ret < 0) {
1880 PERROR("asprintf UST shadow copy session");
1881 assert(0);
1882 goto error;
1883 }
1884
1885 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1886 sizeof(ua_sess->root_shm_path));
1887 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1888 strncpy(ua_sess->shm_path, usess->shm_path,
1889 sizeof(ua_sess->shm_path));
1890 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1891 if (ua_sess->shm_path[0]) {
1892 switch (ua_sess->buffer_type) {
1893 case LTTNG_BUFFER_PER_PID:
1894 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1895 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1896 app->name, app->pid, datetime);
1897 break;
1898 case LTTNG_BUFFER_PER_UID:
1899 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1900 DEFAULT_UST_TRACE_UID_PATH,
1901 app->uid, app->bits_per_long);
1902 break;
1903 default:
1904 assert(0);
1905 goto error;
1906 }
1907 if (ret < 0) {
1908 PERROR("sprintf UST shadow copy session");
1909 assert(0);
1910 goto error;
1911 }
1912 strncat(ua_sess->shm_path, tmp_shm_path,
1913 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1914 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1915 }
1916 return;
1917
1918 error:
1919 consumer_output_put(ua_sess->consumer);
1920 }
1921
1922 /*
1923 * Lookup sesison wrapper.
1924 */
1925 static
1926 void __lookup_session_by_app(const struct ltt_ust_session *usess,
1927 struct ust_app *app, struct lttng_ht_iter *iter)
1928 {
1929 /* Get right UST app session from app */
1930 lttng_ht_lookup(app->sessions, &usess->id, iter);
1931 }
1932
1933 /*
1934 * Return ust app session from the app session hashtable using the UST session
1935 * id.
1936 */
1937 static struct ust_app_session *lookup_session_by_app(
1938 const struct ltt_ust_session *usess, struct ust_app *app)
1939 {
1940 struct lttng_ht_iter iter;
1941 struct lttng_ht_node_u64 *node;
1942
1943 __lookup_session_by_app(usess, app, &iter);
1944 node = lttng_ht_iter_get_node_u64(&iter);
1945 if (node == NULL) {
1946 goto error;
1947 }
1948
1949 return caa_container_of(node, struct ust_app_session, node);
1950
1951 error:
1952 return NULL;
1953 }
1954
1955 /*
1956 * Setup buffer registry per PID for the given session and application. If none
1957 * is found, a new one is created, added to the global registry and
1958 * initialized. If regp is valid, it's set with the newly created object.
1959 *
1960 * Return 0 on success or else a negative value.
1961 */
1962 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1963 struct ust_app *app, struct buffer_reg_pid **regp)
1964 {
1965 int ret = 0;
1966 struct buffer_reg_pid *reg_pid;
1967
1968 assert(ua_sess);
1969 assert(app);
1970
1971 rcu_read_lock();
1972
1973 reg_pid = buffer_reg_pid_find(ua_sess->id);
1974 if (!reg_pid) {
1975 /*
1976 * This is the create channel path meaning that if there is NO
1977 * registry available, we have to create one for this session.
1978 */
1979 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1980 ua_sess->root_shm_path, ua_sess->shm_path);
1981 if (ret < 0) {
1982 goto error;
1983 }
1984 } else {
1985 goto end;
1986 }
1987
1988 /* Initialize registry. */
1989 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1990 app->bits_per_long, app->uint8_t_alignment,
1991 app->uint16_t_alignment, app->uint32_t_alignment,
1992 app->uint64_t_alignment, app->long_alignment,
1993 app->byte_order, app->version.major, app->version.minor,
1994 reg_pid->root_shm_path, reg_pid->shm_path,
1995 ua_sess->effective_credentials.uid,
1996 ua_sess->effective_credentials.gid);
1997 if (ret < 0) {
1998 /*
1999 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2000 * destroy the buffer registry, because it is always expected
2001 * that if the buffer registry can be found, its ust registry is
2002 * non-NULL.
2003 */
2004 buffer_reg_pid_destroy(reg_pid);
2005 goto error;
2006 }
2007
2008 buffer_reg_pid_add(reg_pid);
2009
2010 DBG3("UST app buffer registry per PID created successfully");
2011
2012 end:
2013 if (regp) {
2014 *regp = reg_pid;
2015 }
2016 error:
2017 rcu_read_unlock();
2018 return ret;
2019 }
2020
2021 /*
2022 * Setup buffer registry per UID for the given session and application. If none
2023 * is found, a new one is created, added to the global registry and
2024 * initialized. If regp is valid, it's set with the newly created object.
2025 *
2026 * Return 0 on success or else a negative value.
2027 */
2028 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2029 struct ust_app_session *ua_sess,
2030 struct ust_app *app, struct buffer_reg_uid **regp)
2031 {
2032 int ret = 0;
2033 struct buffer_reg_uid *reg_uid;
2034
2035 assert(usess);
2036 assert(app);
2037
2038 rcu_read_lock();
2039
2040 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2041 if (!reg_uid) {
2042 /*
2043 * This is the create channel path meaning that if there is NO
2044 * registry available, we have to create one for this session.
2045 */
2046 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2047 LTTNG_DOMAIN_UST, &reg_uid,
2048 ua_sess->root_shm_path, ua_sess->shm_path);
2049 if (ret < 0) {
2050 goto error;
2051 }
2052 } else {
2053 goto end;
2054 }
2055
2056 /* Initialize registry. */
2057 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2058 app->bits_per_long, app->uint8_t_alignment,
2059 app->uint16_t_alignment, app->uint32_t_alignment,
2060 app->uint64_t_alignment, app->long_alignment,
2061 app->byte_order, app->version.major,
2062 app->version.minor, reg_uid->root_shm_path,
2063 reg_uid->shm_path, usess->uid, usess->gid);
2064 if (ret < 0) {
2065 /*
2066 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2067 * destroy the buffer registry, because it is always expected
2068 * that if the buffer registry can be found, its ust registry is
2069 * non-NULL.
2070 */
2071 buffer_reg_uid_destroy(reg_uid, NULL);
2072 goto error;
2073 }
2074 /* Add node to teardown list of the session. */
2075 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2076
2077 buffer_reg_uid_add(reg_uid);
2078
2079 DBG3("UST app buffer registry per UID created successfully");
2080 end:
2081 if (regp) {
2082 *regp = reg_uid;
2083 }
2084 error:
2085 rcu_read_unlock();
2086 return ret;
2087 }
2088
2089 /*
2090 * Create a session on the tracer side for the given app.
2091 *
2092 * On success, ua_sess_ptr is populated with the session pointer or else left
2093 * untouched. If the session was created, is_created is set to 1. On error,
2094 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2095 * be NULL.
2096 *
2097 * Returns 0 on success or else a negative code which is either -ENOMEM or
2098 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2099 */
2100 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2101 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2102 int *is_created)
2103 {
2104 int ret, created = 0;
2105 struct ust_app_session *ua_sess;
2106
2107 assert(usess);
2108 assert(app);
2109 assert(ua_sess_ptr);
2110
2111 health_code_update();
2112
2113 ua_sess = lookup_session_by_app(usess, app);
2114 if (ua_sess == NULL) {
2115 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2116 app->pid, usess->id);
2117 ua_sess = alloc_ust_app_session();
2118 if (ua_sess == NULL) {
2119 /* Only malloc can failed so something is really wrong */
2120 ret = -ENOMEM;
2121 goto error;
2122 }
2123 shadow_copy_session(ua_sess, usess, app);
2124 created = 1;
2125 }
2126
2127 switch (usess->buffer_type) {
2128 case LTTNG_BUFFER_PER_PID:
2129 /* Init local registry. */
2130 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2131 if (ret < 0) {
2132 delete_ust_app_session(-1, ua_sess, app);
2133 goto error;
2134 }
2135 break;
2136 case LTTNG_BUFFER_PER_UID:
2137 /* Look for a global registry. If none exists, create one. */
2138 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2139 if (ret < 0) {
2140 delete_ust_app_session(-1, ua_sess, app);
2141 goto error;
2142 }
2143 break;
2144 default:
2145 assert(0);
2146 ret = -EINVAL;
2147 goto error;
2148 }
2149
2150 health_code_update();
2151
2152 if (ua_sess->handle == -1) {
2153 pthread_mutex_lock(&app->sock_lock);
2154 ret = ustctl_create_session(app->sock);
2155 pthread_mutex_unlock(&app->sock_lock);
2156 if (ret < 0) {
2157 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2158 ERR("Creating session for app pid %d with ret %d",
2159 app->pid, ret);
2160 } else {
2161 DBG("UST app creating session failed. Application is dead");
2162 /*
2163 * This is normal behavior, an application can die during the
2164 * creation process. Don't report an error so the execution can
2165 * continue normally. This will get flagged ENOTCONN and the
2166 * caller will handle it.
2167 */
2168 ret = 0;
2169 }
2170 delete_ust_app_session(-1, ua_sess, app);
2171 if (ret != -ENOMEM) {
2172 /*
2173 * Tracer is probably gone or got an internal error so let's
2174 * behave like it will soon unregister or not usable.
2175 */
2176 ret = -ENOTCONN;
2177 }
2178 goto error;
2179 }
2180
2181 ua_sess->handle = ret;
2182
2183 /* Add ust app session to app's HT */
2184 lttng_ht_node_init_u64(&ua_sess->node,
2185 ua_sess->tracing_id);
2186 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2187 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2188 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2189 &ua_sess->ust_objd_node);
2190
2191 DBG2("UST app session created successfully with handle %d", ret);
2192 }
2193
2194 *ua_sess_ptr = ua_sess;
2195 if (is_created) {
2196 *is_created = created;
2197 }
2198
2199 /* Everything went well. */
2200 ret = 0;
2201
2202 error:
2203 health_code_update();
2204 return ret;
2205 }
2206
2207 /*
2208 * Match function for a hash table lookup of ust_app_ctx.
2209 *
2210 * It matches an ust app context based on the context type and, in the case
2211 * of perf counters, their name.
2212 */
2213 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2214 {
2215 struct ust_app_ctx *ctx;
2216 const struct lttng_ust_context_attr *key;
2217
2218 assert(node);
2219 assert(_key);
2220
2221 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2222 key = _key;
2223
2224 /* Context type */
2225 if (ctx->ctx.ctx != key->ctx) {
2226 goto no_match;
2227 }
2228
2229 switch(key->ctx) {
2230 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2231 if (strncmp(key->u.perf_counter.name,
2232 ctx->ctx.u.perf_counter.name,
2233 sizeof(key->u.perf_counter.name))) {
2234 goto no_match;
2235 }
2236 break;
2237 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2238 if (strcmp(key->u.app_ctx.provider_name,
2239 ctx->ctx.u.app_ctx.provider_name) ||
2240 strcmp(key->u.app_ctx.ctx_name,
2241 ctx->ctx.u.app_ctx.ctx_name)) {
2242 goto no_match;
2243 }
2244 break;
2245 default:
2246 break;
2247 }
2248
2249 /* Match. */
2250 return 1;
2251
2252 no_match:
2253 return 0;
2254 }
2255
2256 /*
2257 * Lookup for an ust app context from an lttng_ust_context.
2258 *
2259 * Must be called while holding RCU read side lock.
2260 * Return an ust_app_ctx object or NULL on error.
2261 */
2262 static
2263 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2264 struct lttng_ust_context_attr *uctx)
2265 {
2266 struct lttng_ht_iter iter;
2267 struct lttng_ht_node_ulong *node;
2268 struct ust_app_ctx *app_ctx = NULL;
2269
2270 assert(uctx);
2271 assert(ht);
2272
2273 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2274 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2275 ht_match_ust_app_ctx, uctx, &iter.iter);
2276 node = lttng_ht_iter_get_node_ulong(&iter);
2277 if (!node) {
2278 goto end;
2279 }
2280
2281 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2282
2283 end:
2284 return app_ctx;
2285 }
2286
2287 /*
2288 * Create a context for the channel on the tracer.
2289 *
2290 * Called with UST app session lock held and a RCU read side lock.
2291 */
2292 static
2293 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2294 struct lttng_ust_context_attr *uctx,
2295 struct ust_app *app)
2296 {
2297 int ret = 0;
2298 struct ust_app_ctx *ua_ctx;
2299
2300 DBG2("UST app adding context to channel %s", ua_chan->name);
2301
2302 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2303 if (ua_ctx) {
2304 ret = -EEXIST;
2305 goto error;
2306 }
2307
2308 ua_ctx = alloc_ust_app_ctx(uctx);
2309 if (ua_ctx == NULL) {
2310 /* malloc failed */
2311 ret = -ENOMEM;
2312 goto error;
2313 }
2314
2315 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2316 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2317 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2318
2319 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2320 if (ret < 0) {
2321 goto error;
2322 }
2323
2324 error:
2325 return ret;
2326 }
2327
2328 /*
2329 * Enable on the tracer side a ust app event for the session and channel.
2330 *
2331 * Called with UST app session lock held.
2332 */
2333 static
2334 int enable_ust_app_event(struct ust_app_session *ua_sess,
2335 struct ust_app_event *ua_event, struct ust_app *app)
2336 {
2337 int ret;
2338
2339 ret = enable_ust_event(app, ua_sess, ua_event);
2340 if (ret < 0) {
2341 goto error;
2342 }
2343
2344 ua_event->enabled = 1;
2345
2346 error:
2347 return ret;
2348 }
2349
2350 /*
2351 * Disable on the tracer side a ust app event for the session and channel.
2352 */
2353 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2354 struct ust_app_event *ua_event, struct ust_app *app)
2355 {
2356 int ret;
2357
2358 ret = disable_ust_event(app, ua_sess, ua_event);
2359 if (ret < 0) {
2360 goto error;
2361 }
2362
2363 ua_event->enabled = 0;
2364
2365 error:
2366 return ret;
2367 }
2368
2369 /*
2370 * Lookup ust app channel for session and disable it on the tracer side.
2371 */
2372 static
2373 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2374 struct ust_app_channel *ua_chan, struct ust_app *app)
2375 {
2376 int ret;
2377
2378 ret = disable_ust_channel(app, ua_sess, ua_chan);
2379 if (ret < 0) {
2380 goto error;
2381 }
2382
2383 ua_chan->enabled = 0;
2384
2385 error:
2386 return ret;
2387 }
2388
2389 /*
2390 * Lookup ust app channel for session and enable it on the tracer side. This
2391 * MUST be called with a RCU read side lock acquired.
2392 */
2393 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2394 struct ltt_ust_channel *uchan, struct ust_app *app)
2395 {
2396 int ret = 0;
2397 struct lttng_ht_iter iter;
2398 struct lttng_ht_node_str *ua_chan_node;
2399 struct ust_app_channel *ua_chan;
2400
2401 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2402 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2403 if (ua_chan_node == NULL) {
2404 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2405 uchan->name, ua_sess->tracing_id);
2406 goto error;
2407 }
2408
2409 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2410
2411 ret = enable_ust_channel(app, ua_sess, ua_chan);
2412 if (ret < 0) {
2413 goto error;
2414 }
2415
2416 error:
2417 return ret;
2418 }
2419
2420 /*
2421 * Ask the consumer to create a channel and get it if successful.
2422 *
2423 * Called with UST app session lock held.
2424 *
2425 * Return 0 on success or else a negative value.
2426 */
2427 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2428 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2429 int bitness, struct ust_registry_session *registry,
2430 uint64_t trace_archive_id)
2431 {
2432 int ret;
2433 unsigned int nb_fd = 0;
2434 struct consumer_socket *socket;
2435
2436 assert(usess);
2437 assert(ua_sess);
2438 assert(ua_chan);
2439 assert(registry);
2440
2441 rcu_read_lock();
2442 health_code_update();
2443
2444 /* Get the right consumer socket for the application. */
2445 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2446 if (!socket) {
2447 ret = -EINVAL;
2448 goto error;
2449 }
2450
2451 health_code_update();
2452
2453 /* Need one fd for the channel. */
2454 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2455 if (ret < 0) {
2456 ERR("Exhausted number of available FD upon create channel");
2457 goto error;
2458 }
2459
2460 /*
2461 * Ask consumer to create channel. The consumer will return the number of
2462 * stream we have to expect.
2463 */
2464 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2465 registry, usess->current_trace_chunk);
2466 if (ret < 0) {
2467 goto error_ask;
2468 }
2469
2470 /*
2471 * Compute the number of fd needed before receiving them. It must be 2 per
2472 * stream (2 being the default value here).
2473 */
2474 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2475
2476 /* Reserve the amount of file descriptor we need. */
2477 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2478 if (ret < 0) {
2479 ERR("Exhausted number of available FD upon create channel");
2480 goto error_fd_get_stream;
2481 }
2482
2483 health_code_update();
2484
2485 /*
2486 * Now get the channel from the consumer. This call wil populate the stream
2487 * list of that channel and set the ust objects.
2488 */
2489 if (usess->consumer->enabled) {
2490 ret = ust_consumer_get_channel(socket, ua_chan);
2491 if (ret < 0) {
2492 goto error_destroy;
2493 }
2494 }
2495
2496 rcu_read_unlock();
2497 return 0;
2498
2499 error_destroy:
2500 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2501 error_fd_get_stream:
2502 /*
2503 * Initiate a destroy channel on the consumer since we had an error
2504 * handling it on our side. The return value is of no importance since we
2505 * already have a ret value set by the previous error that we need to
2506 * return.
2507 */
2508 (void) ust_consumer_destroy_channel(socket, ua_chan);
2509 error_ask:
2510 lttng_fd_put(LTTNG_FD_APPS, 1);
2511 error:
2512 health_code_update();
2513 rcu_read_unlock();
2514 return ret;
2515 }
2516
2517 /*
2518 * Duplicate the ust data object of the ust app stream and save it in the
2519 * buffer registry stream.
2520 *
2521 * Return 0 on success or else a negative value.
2522 */
2523 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2524 struct ust_app_stream *stream)
2525 {
2526 int ret;
2527
2528 assert(reg_stream);
2529 assert(stream);
2530
2531 /* Reserve the amount of file descriptor we need. */
2532 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2533 if (ret < 0) {
2534 ERR("Exhausted number of available FD upon duplicate stream");
2535 goto error;
2536 }
2537
2538 /* Duplicate object for stream once the original is in the registry. */
2539 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2540 reg_stream->obj.ust);
2541 if (ret < 0) {
2542 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2543 reg_stream->obj.ust, stream->obj, ret);
2544 lttng_fd_put(LTTNG_FD_APPS, 2);
2545 goto error;
2546 }
2547 stream->handle = stream->obj->handle;
2548
2549 error:
2550 return ret;
2551 }
2552
2553 /*
2554 * Duplicate the ust data object of the ust app. channel and save it in the
2555 * buffer registry channel.
2556 *
2557 * Return 0 on success or else a negative value.
2558 */
2559 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2560 struct ust_app_channel *ua_chan)
2561 {
2562 int ret;
2563
2564 assert(reg_chan);
2565 assert(ua_chan);
2566
2567 /* Need two fds for the channel. */
2568 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2569 if (ret < 0) {
2570 ERR("Exhausted number of available FD upon duplicate channel");
2571 goto error_fd_get;
2572 }
2573
2574 /* Duplicate object for stream once the original is in the registry. */
2575 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2576 if (ret < 0) {
2577 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2578 reg_chan->obj.ust, ua_chan->obj, ret);
2579 goto error;
2580 }
2581 ua_chan->handle = ua_chan->obj->handle;
2582
2583 return 0;
2584
2585 error:
2586 lttng_fd_put(LTTNG_FD_APPS, 1);
2587 error_fd_get:
2588 return ret;
2589 }
2590
2591 /*
2592 * For a given channel buffer registry, setup all streams of the given ust
2593 * application channel.
2594 *
2595 * Return 0 on success or else a negative value.
2596 */
2597 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2598 struct ust_app_channel *ua_chan,
2599 struct ust_app *app)
2600 {
2601 int ret = 0;
2602 struct ust_app_stream *stream, *stmp;
2603
2604 assert(reg_chan);
2605 assert(ua_chan);
2606
2607 DBG2("UST app setup buffer registry stream");
2608
2609 /* Send all streams to application. */
2610 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2611 struct buffer_reg_stream *reg_stream;
2612
2613 ret = buffer_reg_stream_create(&reg_stream);
2614 if (ret < 0) {
2615 goto error;
2616 }
2617
2618 /*
2619 * Keep original pointer and nullify it in the stream so the delete
2620 * stream call does not release the object.
2621 */
2622 reg_stream->obj.ust = stream->obj;
2623 stream->obj = NULL;
2624 buffer_reg_stream_add(reg_stream, reg_chan);
2625
2626 /* We don't need the streams anymore. */
2627 cds_list_del(&stream->list);
2628 delete_ust_app_stream(-1, stream, app);
2629 }
2630
2631 error:
2632 return ret;
2633 }
2634
2635 /*
2636 * Create a buffer registry channel for the given session registry and
2637 * application channel object. If regp pointer is valid, it's set with the
2638 * created object. Important, the created object is NOT added to the session
2639 * registry hash table.
2640 *
2641 * Return 0 on success else a negative value.
2642 */
2643 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2644 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2645 {
2646 int ret;
2647 struct buffer_reg_channel *reg_chan = NULL;
2648
2649 assert(reg_sess);
2650 assert(ua_chan);
2651
2652 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2653
2654 /* Create buffer registry channel. */
2655 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2656 if (ret < 0) {
2657 goto error_create;
2658 }
2659 assert(reg_chan);
2660 reg_chan->consumer_key = ua_chan->key;
2661 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2662 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2663
2664 /* Create and add a channel registry to session. */
2665 ret = ust_registry_channel_add(reg_sess->reg.ust,
2666 ua_chan->tracing_channel_id);
2667 if (ret < 0) {
2668 goto error;
2669 }
2670 buffer_reg_channel_add(reg_sess, reg_chan);
2671
2672 if (regp) {
2673 *regp = reg_chan;
2674 }
2675
2676 return 0;
2677
2678 error:
2679 /* Safe because the registry channel object was not added to any HT. */
2680 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2681 error_create:
2682 return ret;
2683 }
2684
2685 /*
2686 * Setup buffer registry channel for the given session registry and application
2687 * channel object. If regp pointer is valid, it's set with the created object.
2688 *
2689 * Return 0 on success else a negative value.
2690 */
2691 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2692 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2693 struct ust_app *app)
2694 {
2695 int ret;
2696
2697 assert(reg_sess);
2698 assert(reg_chan);
2699 assert(ua_chan);
2700 assert(ua_chan->obj);
2701
2702 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2703
2704 /* Setup all streams for the registry. */
2705 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2706 if (ret < 0) {
2707 goto error;
2708 }
2709
2710 reg_chan->obj.ust = ua_chan->obj;
2711 ua_chan->obj = NULL;
2712
2713 return 0;
2714
2715 error:
2716 buffer_reg_channel_remove(reg_sess, reg_chan);
2717 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2718 return ret;
2719 }
2720
2721 /*
2722 * Send buffer registry channel to the application.
2723 *
2724 * Return 0 on success else a negative value.
2725 */
2726 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2727 struct ust_app *app, struct ust_app_session *ua_sess,
2728 struct ust_app_channel *ua_chan)
2729 {
2730 int ret;
2731 struct buffer_reg_stream *reg_stream;
2732
2733 assert(reg_chan);
2734 assert(app);
2735 assert(ua_sess);
2736 assert(ua_chan);
2737
2738 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2739
2740 ret = duplicate_channel_object(reg_chan, ua_chan);
2741 if (ret < 0) {
2742 goto error;
2743 }
2744
2745 /* Send channel to the application. */
2746 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2747 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2748 ret = -ENOTCONN; /* Caused by app exiting. */
2749 goto error;
2750 } else if (ret < 0) {
2751 goto error;
2752 }
2753
2754 health_code_update();
2755
2756 /* Send all streams to application. */
2757 pthread_mutex_lock(&reg_chan->stream_list_lock);
2758 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2759 struct ust_app_stream stream;
2760
2761 ret = duplicate_stream_object(reg_stream, &stream);
2762 if (ret < 0) {
2763 goto error_stream_unlock;
2764 }
2765
2766 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2767 if (ret < 0) {
2768 (void) release_ust_app_stream(-1, &stream, app);
2769 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2770 ret = -ENOTCONN; /* Caused by app exiting. */
2771 }
2772 goto error_stream_unlock;
2773 }
2774
2775 /*
2776 * The return value is not important here. This function will output an
2777 * error if needed.
2778 */
2779 (void) release_ust_app_stream(-1, &stream, app);
2780 }
2781 ua_chan->is_sent = 1;
2782
2783 error_stream_unlock:
2784 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2785 error:
2786 return ret;
2787 }
2788
2789 /*
2790 * Create and send to the application the created buffers with per UID buffers.
2791 *
2792 * This MUST be called with a RCU read side lock acquired.
2793 * The session list lock and the session's lock must be acquired.
2794 *
2795 * Return 0 on success else a negative value.
2796 */
2797 static int create_channel_per_uid(struct ust_app *app,
2798 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2799 struct ust_app_channel *ua_chan)
2800 {
2801 int ret;
2802 struct buffer_reg_uid *reg_uid;
2803 struct buffer_reg_channel *reg_chan;
2804 struct ltt_session *session = NULL;
2805 enum lttng_error_code notification_ret;
2806 struct ust_registry_channel *chan_reg;
2807
2808 assert(app);
2809 assert(usess);
2810 assert(ua_sess);
2811 assert(ua_chan);
2812
2813 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2814
2815 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2816 /*
2817 * The session creation handles the creation of this global registry
2818 * object. If none can be find, there is a code flow problem or a
2819 * teardown race.
2820 */
2821 assert(reg_uid);
2822
2823 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2824 reg_uid);
2825 if (reg_chan) {
2826 goto send_channel;
2827 }
2828
2829 /* Create the buffer registry channel object. */
2830 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2831 if (ret < 0) {
2832 ERR("Error creating the UST channel \"%s\" registry instance",
2833 ua_chan->name);
2834 goto error;
2835 }
2836
2837 session = session_find_by_id(ua_sess->tracing_id);
2838 assert(session);
2839 assert(pthread_mutex_trylock(&session->lock));
2840 assert(session_trylock_list());
2841
2842 /*
2843 * Create the buffers on the consumer side. This call populates the
2844 * ust app channel object with all streams and data object.
2845 */
2846 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2847 app->bits_per_long, reg_uid->registry->reg.ust,
2848 session->most_recent_chunk_id.value);
2849 if (ret < 0) {
2850 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2851 ua_chan->name);
2852
2853 /*
2854 * Let's remove the previously created buffer registry channel so
2855 * it's not visible anymore in the session registry.
2856 */
2857 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2858 ua_chan->tracing_channel_id, false);
2859 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2860 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2861 goto error;
2862 }
2863
2864 /*
2865 * Setup the streams and add it to the session registry.
2866 */
2867 ret = setup_buffer_reg_channel(reg_uid->registry,
2868 ua_chan, reg_chan, app);
2869 if (ret < 0) {
2870 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2871 goto error;
2872 }
2873
2874 /* Notify the notification subsystem of the channel's creation. */
2875 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2876 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2877 ua_chan->tracing_channel_id);
2878 assert(chan_reg);
2879 chan_reg->consumer_key = ua_chan->key;
2880 chan_reg = NULL;
2881 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2882
2883 notification_ret = notification_thread_command_add_channel(
2884 notification_thread_handle, session->name,
2885 ua_sess->effective_credentials.uid,
2886 ua_sess->effective_credentials.gid, ua_chan->name,
2887 ua_chan->key, LTTNG_DOMAIN_UST,
2888 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2889 if (notification_ret != LTTNG_OK) {
2890 ret = - (int) notification_ret;
2891 ERR("Failed to add channel to notification thread");
2892 goto error;
2893 }
2894
2895 send_channel:
2896 /* Send buffers to the application. */
2897 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2898 if (ret < 0) {
2899 if (ret != -ENOTCONN) {
2900 ERR("Error sending channel to application");
2901 }
2902 goto error;
2903 }
2904
2905 error:
2906 if (session) {
2907 session_put(session);
2908 }
2909 return ret;
2910 }
2911
2912 /*
2913 * Create and send to the application the created buffers with per PID buffers.
2914 *
2915 * Called with UST app session lock held.
2916 * The session list lock and the session's lock must be acquired.
2917 *
2918 * Return 0 on success else a negative value.
2919 */
2920 static int create_channel_per_pid(struct ust_app *app,
2921 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2922 struct ust_app_channel *ua_chan)
2923 {
2924 int ret;
2925 struct ust_registry_session *registry;
2926 enum lttng_error_code cmd_ret;
2927 struct ltt_session *session = NULL;
2928 uint64_t chan_reg_key;
2929 struct ust_registry_channel *chan_reg;
2930
2931 assert(app);
2932 assert(usess);
2933 assert(ua_sess);
2934 assert(ua_chan);
2935
2936 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2937
2938 rcu_read_lock();
2939
2940 registry = get_session_registry(ua_sess);
2941 /* The UST app session lock is held, registry shall not be null. */
2942 assert(registry);
2943
2944 /* Create and add a new channel registry to session. */
2945 ret = ust_registry_channel_add(registry, ua_chan->key);
2946 if (ret < 0) {
2947 ERR("Error creating the UST channel \"%s\" registry instance",
2948 ua_chan->name);
2949 goto error;
2950 }
2951
2952 session = session_find_by_id(ua_sess->tracing_id);
2953 assert(session);
2954
2955 assert(pthread_mutex_trylock(&session->lock));
2956 assert(session_trylock_list());
2957
2958 /* Create and get channel on the consumer side. */
2959 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2960 app->bits_per_long, registry,
2961 session->most_recent_chunk_id.value);
2962 if (ret < 0) {
2963 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2964 ua_chan->name);
2965 goto error_remove_from_registry;
2966 }
2967
2968 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2969 if (ret < 0) {
2970 if (ret != -ENOTCONN) {
2971 ERR("Error sending channel to application");
2972 }
2973 goto error_remove_from_registry;
2974 }
2975
2976 chan_reg_key = ua_chan->key;
2977 pthread_mutex_lock(&registry->lock);
2978 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2979 assert(chan_reg);
2980 chan_reg->consumer_key = ua_chan->key;
2981 pthread_mutex_unlock(&registry->lock);
2982
2983 cmd_ret = notification_thread_command_add_channel(
2984 notification_thread_handle, session->name,
2985 ua_sess->effective_credentials.uid,
2986 ua_sess->effective_credentials.gid, ua_chan->name,
2987 ua_chan->key, LTTNG_DOMAIN_UST,
2988 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2989 if (cmd_ret != LTTNG_OK) {
2990 ret = - (int) cmd_ret;
2991 ERR("Failed to add channel to notification thread");
2992 goto error_remove_from_registry;
2993 }
2994
2995 error_remove_from_registry:
2996 if (ret) {
2997 ust_registry_channel_del_free(registry, ua_chan->key, false);
2998 }
2999 error:
3000 rcu_read_unlock();
3001 if (session) {
3002 session_put(session);
3003 }
3004 return ret;
3005 }
3006
3007 /*
3008 * From an already allocated ust app channel, create the channel buffers if
3009 * needed and send them to the application. This MUST be called with a RCU read
3010 * side lock acquired.
3011 *
3012 * Called with UST app session lock held.
3013 *
3014 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3015 * the application exited concurrently.
3016 */
3017 static int ust_app_channel_send(struct ust_app *app,
3018 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3019 struct ust_app_channel *ua_chan)
3020 {
3021 int ret;
3022
3023 assert(app);
3024 assert(usess);
3025 assert(usess->active);
3026 assert(ua_sess);
3027 assert(ua_chan);
3028
3029 /* Handle buffer type before sending the channel to the application. */
3030 switch (usess->buffer_type) {
3031 case LTTNG_BUFFER_PER_UID:
3032 {
3033 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3034 if (ret < 0) {
3035 goto error;
3036 }
3037 break;
3038 }
3039 case LTTNG_BUFFER_PER_PID:
3040 {
3041 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3042 if (ret < 0) {
3043 goto error;
3044 }
3045 break;
3046 }
3047 default:
3048 assert(0);
3049 ret = -EINVAL;
3050 goto error;
3051 }
3052
3053 /* Initialize ust objd object using the received handle and add it. */
3054 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3055 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3056
3057 /* If channel is not enabled, disable it on the tracer */
3058 if (!ua_chan->enabled) {
3059 ret = disable_ust_channel(app, ua_sess, ua_chan);
3060 if (ret < 0) {
3061 goto error;
3062 }
3063 }
3064
3065 error:
3066 return ret;
3067 }
3068
3069 /*
3070 * Create UST app channel and return it through ua_chanp if not NULL.
3071 *
3072 * Called with UST app session lock and RCU read-side lock held.
3073 *
3074 * Return 0 on success or else a negative value.
3075 */
3076 static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3077 struct ltt_ust_channel *uchan,
3078 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3079 struct ust_app_channel **ua_chanp)
3080 {
3081 int ret = 0;
3082 struct lttng_ht_iter iter;
3083 struct lttng_ht_node_str *ua_chan_node;
3084 struct ust_app_channel *ua_chan;
3085
3086 /* Lookup channel in the ust app session */
3087 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3088 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3089 if (ua_chan_node != NULL) {
3090 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3091 goto end;
3092 }
3093
3094 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3095 if (ua_chan == NULL) {
3096 /* Only malloc can fail here */
3097 ret = -ENOMEM;
3098 goto error;
3099 }
3100 shadow_copy_channel(ua_chan, uchan);
3101
3102 /* Set channel type. */
3103 ua_chan->attr.type = type;
3104
3105 /* Only add the channel if successful on the tracer side. */
3106 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3107 end:
3108 if (ua_chanp) {
3109 *ua_chanp = ua_chan;
3110 }
3111
3112 /* Everything went well. */
3113 return 0;
3114
3115 error:
3116 return ret;
3117 }
3118
3119 /*
3120 * Create UST app event and create it on the tracer side.
3121 *
3122 * Called with ust app session mutex held.
3123 */
3124 static
3125 int create_ust_app_event(struct ust_app_session *ua_sess,
3126 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3127 struct ust_app *app)
3128 {
3129 int ret = 0;
3130 struct ust_app_event *ua_event;
3131
3132 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3133 if (ua_event == NULL) {
3134 /* Only malloc can failed so something is really wrong */
3135 ret = -ENOMEM;
3136 goto end;
3137 }
3138 shadow_copy_event(ua_event, uevent);
3139
3140 /* Create it on the tracer side */
3141 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3142 if (ret < 0) {
3143 /* Not found previously means that it does not exist on the tracer */
3144 assert(ret != -LTTNG_UST_ERR_EXIST);
3145 goto error;
3146 }
3147
3148 add_unique_ust_app_event(ua_chan, ua_event);
3149
3150 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3151 app->pid);
3152
3153 end:
3154 return ret;
3155
3156 error:
3157 /* Valid. Calling here is already in a read side lock */
3158 delete_ust_app_event(-1, ua_event, app);
3159 return ret;
3160 }
3161
3162 /*
3163 * Create UST metadata and open it on the tracer side.
3164 *
3165 * Called with UST app session lock held and RCU read side lock.
3166 */
3167 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3168 struct ust_app *app, struct consumer_output *consumer)
3169 {
3170 int ret = 0;
3171 struct ust_app_channel *metadata;
3172 struct consumer_socket *socket;
3173 struct ust_registry_session *registry;
3174 struct ltt_session *session = NULL;
3175
3176 assert(ua_sess);
3177 assert(app);
3178 assert(consumer);
3179
3180 registry = get_session_registry(ua_sess);
3181 /* The UST app session is held registry shall not be null. */
3182 assert(registry);
3183
3184 pthread_mutex_lock(&registry->lock);
3185
3186 /* Metadata already exists for this registry or it was closed previously */
3187 if (registry->metadata_key || registry->metadata_closed) {
3188 ret = 0;
3189 goto error;
3190 }
3191
3192 /* Allocate UST metadata */
3193 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3194 if (!metadata) {
3195 /* malloc() failed */
3196 ret = -ENOMEM;
3197 goto error;
3198 }
3199
3200 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3201
3202 /* Need one fd for the channel. */
3203 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3204 if (ret < 0) {
3205 ERR("Exhausted number of available FD upon create metadata");
3206 goto error;
3207 }
3208
3209 /* Get the right consumer socket for the application. */
3210 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3211 if (!socket) {
3212 ret = -EINVAL;
3213 goto error_consumer;
3214 }
3215
3216 /*
3217 * Keep metadata key so we can identify it on the consumer side. Assign it
3218 * to the registry *before* we ask the consumer so we avoid the race of the
3219 * consumer requesting the metadata and the ask_channel call on our side
3220 * did not returned yet.
3221 */
3222 registry->metadata_key = metadata->key;
3223
3224 session = session_find_by_id(ua_sess->tracing_id);
3225 assert(session);
3226
3227 assert(pthread_mutex_trylock(&session->lock));
3228 assert(session_trylock_list());
3229
3230 /*
3231 * Ask the metadata channel creation to the consumer. The metadata object
3232 * will be created by the consumer and kept their. However, the stream is
3233 * never added or monitored until we do a first push metadata to the
3234 * consumer.
3235 */
3236 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3237 registry, session->current_trace_chunk);
3238 if (ret < 0) {
3239 /* Nullify the metadata key so we don't try to close it later on. */
3240 registry->metadata_key = 0;
3241 goto error_consumer;
3242 }
3243
3244 /*
3245 * The setup command will make the metadata stream be sent to the relayd,
3246 * if applicable, and the thread managing the metadatas. This is important
3247 * because after this point, if an error occurs, the only way the stream
3248 * can be deleted is to be monitored in the consumer.
3249 */
3250 ret = consumer_setup_metadata(socket, metadata->key);
3251 if (ret < 0) {
3252 /* Nullify the metadata key so we don't try to close it later on. */
3253 registry->metadata_key = 0;
3254 goto error_consumer;
3255 }
3256
3257 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3258 metadata->key, app->pid);
3259
3260 error_consumer:
3261 lttng_fd_put(LTTNG_FD_APPS, 1);
3262 delete_ust_app_channel(-1, metadata, app);
3263 error:
3264 pthread_mutex_unlock(&registry->lock);
3265 if (session) {
3266 session_put(session);
3267 }
3268 return ret;
3269 }
3270
3271 /*
3272 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3273 * acquired before calling this function.
3274 */
3275 struct ust_app *ust_app_find_by_pid(pid_t pid)
3276 {
3277 struct ust_app *app = NULL;
3278 struct lttng_ht_node_ulong *node;
3279 struct lttng_ht_iter iter;
3280
3281 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3282 node = lttng_ht_iter_get_node_ulong(&iter);
3283 if (node == NULL) {
3284 DBG2("UST app no found with pid %d", pid);
3285 goto error;
3286 }
3287
3288 DBG2("Found UST app by pid %d", pid);
3289
3290 app = caa_container_of(node, struct ust_app, pid_n);
3291
3292 error:
3293 return app;
3294 }
3295
3296 /*
3297 * Allocate and init an UST app object using the registration information and
3298 * the command socket. This is called when the command socket connects to the
3299 * session daemon.
3300 *
3301 * The object is returned on success or else NULL.
3302 */
3303 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3304 {
3305 struct ust_app *lta = NULL;
3306
3307 assert(msg);
3308 assert(sock >= 0);
3309
3310 DBG3("UST app creating application for socket %d", sock);
3311
3312 if ((msg->bits_per_long == 64 &&
3313 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3314 || (msg->bits_per_long == 32 &&
3315 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3316 ERR("Registration failed: application \"%s\" (pid: %d) has "
3317 "%d-bit long, but no consumerd for this size is available.\n",
3318 msg->name, msg->pid, msg->bits_per_long);
3319 goto error;
3320 }
3321
3322 lta = zmalloc(sizeof(struct ust_app));
3323 if (lta == NULL) {
3324 PERROR("malloc");
3325 goto error;
3326 }
3327
3328 lta->ppid = msg->ppid;
3329 lta->uid = msg->uid;
3330 lta->gid = msg->gid;
3331
3332 lta->bits_per_long = msg->bits_per_long;
3333 lta->uint8_t_alignment = msg->uint8_t_alignment;
3334 lta->uint16_t_alignment = msg->uint16_t_alignment;
3335 lta->uint32_t_alignment = msg->uint32_t_alignment;
3336 lta->uint64_t_alignment = msg->uint64_t_alignment;
3337 lta->long_alignment = msg->long_alignment;
3338 lta->byte_order = msg->byte_order;
3339
3340 lta->v_major = msg->major;
3341 lta->v_minor = msg->minor;
3342 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3343 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3344 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3345 lta->notify_sock = -1;
3346
3347 /* Copy name and make sure it's NULL terminated. */
3348 strncpy(lta->name, msg->name, sizeof(lta->name));
3349 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3350
3351 /*
3352 * Before this can be called, when receiving the registration information,
3353 * the application compatibility is checked. So, at this point, the
3354 * application can work with this session daemon.
3355 */
3356 lta->compatible = 1;
3357
3358 lta->pid = msg->pid;
3359 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3360 lta->sock = sock;
3361 pthread_mutex_init(&lta->sock_lock, NULL);
3362 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3363
3364 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3365 error:
3366 return lta;
3367 }
3368
3369 /*
3370 * For a given application object, add it to every hash table.
3371 */
3372 void ust_app_add(struct ust_app *app)
3373 {
3374 assert(app);
3375 assert(app->notify_sock >= 0);
3376
3377 app->registration_time = time(NULL);
3378
3379 rcu_read_lock();
3380
3381 /*
3382 * On a re-registration, we want to kick out the previous registration of
3383 * that pid
3384 */
3385 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3386
3387 /*
3388 * The socket _should_ be unique until _we_ call close. So, a add_unique
3389 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3390 * already in the table.
3391 */
3392 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3393
3394 /* Add application to the notify socket hash table. */
3395 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3396 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3397
3398 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3399 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3400 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3401 app->v_minor);
3402
3403 rcu_read_unlock();
3404 }
3405
3406 /*
3407 * Set the application version into the object.
3408 *
3409 * Return 0 on success else a negative value either an errno code or a
3410 * LTTng-UST error code.
3411 */
3412 int ust_app_version(struct ust_app *app)
3413 {
3414 int ret;
3415
3416 assert(app);
3417
3418 pthread_mutex_lock(&app->sock_lock);
3419 ret = ustctl_tracer_version(app->sock, &app->version);
3420 pthread_mutex_unlock(&app->sock_lock);
3421 if (ret < 0) {
3422 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3423 ERR("UST app %d version failed with ret %d", app->sock, ret);
3424 } else {
3425 DBG3("UST app %d version failed. Application is dead", app->sock);
3426 }
3427 }
3428
3429 return ret;
3430 }
3431
3432 /*
3433 * Unregister app by removing it from the global traceable app list and freeing
3434 * the data struct.
3435 *
3436 * The socket is already closed at this point so no close to sock.
3437 */
3438 void ust_app_unregister(int sock)
3439 {
3440 struct ust_app *lta;
3441 struct lttng_ht_node_ulong *node;
3442 struct lttng_ht_iter ust_app_sock_iter;
3443 struct lttng_ht_iter iter;
3444 struct ust_app_session *ua_sess;
3445 int ret;
3446
3447 rcu_read_lock();
3448
3449 /* Get the node reference for a call_rcu */
3450 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3451 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3452 assert(node);
3453
3454 lta = caa_container_of(node, struct ust_app, sock_n);
3455 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3456
3457 /*
3458 * For per-PID buffers, perform "push metadata" and flush all
3459 * application streams before removing app from hash tables,
3460 * ensuring proper behavior of data_pending check.
3461 * Remove sessions so they are not visible during deletion.
3462 */
3463 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3464 node.node) {
3465 struct ust_registry_session *registry;
3466
3467 ret = lttng_ht_del(lta->sessions, &iter);
3468 if (ret) {
3469 /* The session was already removed so scheduled for teardown. */
3470 continue;
3471 }
3472
3473 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3474 (void) ust_app_flush_app_session(lta, ua_sess);
3475 }
3476
3477 /*
3478 * Add session to list for teardown. This is safe since at this point we
3479 * are the only one using this list.
3480 */
3481 pthread_mutex_lock(&ua_sess->lock);
3482
3483 if (ua_sess->deleted) {
3484 pthread_mutex_unlock(&ua_sess->lock);
3485 continue;
3486 }
3487
3488 /*
3489 * Normally, this is done in the delete session process which is
3490 * executed in the call rcu below. However, upon registration we can't
3491 * afford to wait for the grace period before pushing data or else the
3492 * data pending feature can race between the unregistration and stop
3493 * command where the data pending command is sent *before* the grace
3494 * period ended.
3495 *
3496 * The close metadata below nullifies the metadata pointer in the
3497 * session so the delete session will NOT push/close a second time.
3498 */
3499 registry = get_session_registry(ua_sess);
3500 if (registry) {
3501 /* Push metadata for application before freeing the application. */
3502 (void) push_metadata(registry, ua_sess->consumer);
3503
3504 /*
3505 * Don't ask to close metadata for global per UID buffers. Close
3506 * metadata only on destroy trace session in this case. Also, the
3507 * previous push metadata could have flag the metadata registry to
3508 * close so don't send a close command if closed.
3509 */
3510 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3511 /* And ask to close it for this session registry. */
3512 (void) close_metadata(registry, ua_sess->consumer);
3513 }
3514 }
3515 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3516
3517 pthread_mutex_unlock(&ua_sess->lock);
3518 }
3519
3520 /* Remove application from PID hash table */
3521 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3522 assert(!ret);
3523
3524 /*
3525 * Remove application from notify hash table. The thread handling the
3526 * notify socket could have deleted the node so ignore on error because
3527 * either way it's valid. The close of that socket is handled by the
3528 * apps_notify_thread.
3529 */
3530 iter.iter.node = &lta->notify_sock_n.node;
3531 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3532
3533 /*
3534 * Ignore return value since the node might have been removed before by an
3535 * add replace during app registration because the PID can be reassigned by
3536 * the OS.
3537 */
3538 iter.iter.node = &lta->pid_n.node;
3539 ret = lttng_ht_del(ust_app_ht, &iter);
3540 if (ret) {
3541 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3542 lta->pid);
3543 }
3544
3545 /* Free memory */
3546 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3547
3548 rcu_read_unlock();
3549 return;
3550 }
3551
3552 /*
3553 * Fill events array with all events name of all registered apps.
3554 */
3555 int ust_app_list_events(struct lttng_event **events)
3556 {
3557 int ret, handle;
3558 size_t nbmem, count = 0;
3559 struct lttng_ht_iter iter;
3560 struct ust_app *app;
3561 struct lttng_event *tmp_event;
3562
3563 nbmem = UST_APP_EVENT_LIST_SIZE;
3564 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3565 if (tmp_event == NULL) {
3566 PERROR("zmalloc ust app events");
3567 ret = -ENOMEM;
3568 goto error;
3569 }
3570
3571 rcu_read_lock();
3572
3573 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3574 struct lttng_ust_tracepoint_iter uiter;
3575
3576 health_code_update();
3577
3578 if (!app->compatible) {
3579 /*
3580 * TODO: In time, we should notice the caller of this error by
3581 * telling him that this is a version error.
3582 */
3583 continue;
3584 }
3585 pthread_mutex_lock(&app->sock_lock);
3586 handle = ustctl_tracepoint_list(app->sock);
3587 if (handle < 0) {
3588 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3589 ERR("UST app list events getting handle failed for app pid %d",
3590 app->pid);
3591 }
3592 pthread_mutex_unlock(&app->sock_lock);
3593 continue;
3594 }
3595
3596 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3597 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3598 /* Handle ustctl error. */
3599 if (ret < 0) {
3600 int release_ret;
3601
3602 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3603 ERR("UST app tp list get failed for app %d with ret %d",
3604 app->sock, ret);
3605 } else {
3606 DBG3("UST app tp list get failed. Application is dead");
3607 /*
3608 * This is normal behavior, an application can die during the
3609 * creation process. Don't report an error so the execution can
3610 * continue normally. Continue normal execution.
3611 */
3612 break;
3613 }
3614 free(tmp_event);
3615 release_ret = ustctl_release_handle(app->sock, handle);
3616 if (release_ret < 0 &&
3617 release_ret != -LTTNG_UST_ERR_EXITING &&
3618 release_ret != -EPIPE) {
3619 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3620 }
3621 pthread_mutex_unlock(&app->sock_lock);
3622 goto rcu_error;
3623 }
3624
3625 health_code_update();
3626 if (count >= nbmem) {
3627 /* In case the realloc fails, we free the memory */
3628 struct lttng_event *new_tmp_event;
3629 size_t new_nbmem;
3630
3631 new_nbmem = nbmem << 1;
3632 DBG2("Reallocating event list from %zu to %zu entries",
3633 nbmem, new_nbmem);
3634 new_tmp_event = realloc(tmp_event,
3635 new_nbmem * sizeof(struct lttng_event));
3636 if (new_tmp_event == NULL) {
3637 int release_ret;
3638
3639 PERROR("realloc ust app events");
3640 free(tmp_event);
3641 ret = -ENOMEM;
3642 release_ret = ustctl_release_handle(app->sock, handle);
3643 if (release_ret < 0 &&
3644 release_ret != -LTTNG_UST_ERR_EXITING &&
3645 release_ret != -EPIPE) {
3646 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3647 }
3648 pthread_mutex_unlock(&app->sock_lock);
3649 goto rcu_error;
3650 }
3651 /* Zero the new memory */
3652 memset(new_tmp_event + nbmem, 0,
3653 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3654 nbmem = new_nbmem;
3655 tmp_event = new_tmp_event;
3656 }
3657 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3658 tmp_event[count].loglevel = uiter.loglevel;
3659 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3660 tmp_event[count].pid = app->pid;
3661 tmp_event[count].enabled = -1;
3662 count++;
3663 }
3664 ret = ustctl_release_handle(app->sock, handle);
3665 pthread_mutex_unlock(&app->sock_lock);
3666 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3667 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3668 }
3669 }
3670
3671 ret = count;
3672 *events = tmp_event;
3673
3674 DBG2("UST app list events done (%zu events)", count);
3675
3676 rcu_error:
3677 rcu_read_unlock();
3678 error:
3679 health_code_update();
3680 return ret;
3681 }
3682
3683 /*
3684 * Fill events array with all events name of all registered apps.
3685 */
3686 int ust_app_list_event_fields(struct lttng_event_field **fields)
3687 {
3688 int ret, handle;
3689 size_t nbmem, count = 0;
3690 struct lttng_ht_iter iter;
3691 struct ust_app *app;
3692 struct lttng_event_field *tmp_event;
3693
3694 nbmem = UST_APP_EVENT_LIST_SIZE;
3695 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3696 if (tmp_event == NULL) {
3697 PERROR("zmalloc ust app event fields");
3698 ret = -ENOMEM;
3699 goto error;
3700 }
3701
3702 rcu_read_lock();
3703
3704 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3705 struct lttng_ust_field_iter uiter;
3706
3707 health_code_update();
3708
3709 if (!app->compatible) {
3710 /*
3711 * TODO: In time, we should notice the caller of this error by
3712 * telling him that this is a version error.
3713 */
3714 continue;
3715 }
3716 pthread_mutex_lock(&app->sock_lock);
3717 handle = ustctl_tracepoint_field_list(app->sock);
3718 if (handle < 0) {
3719 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3720 ERR("UST app list field getting handle failed for app pid %d",
3721 app->pid);
3722 }
3723 pthread_mutex_unlock(&app->sock_lock);
3724 continue;
3725 }
3726
3727 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3728 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3729 /* Handle ustctl error. */
3730 if (ret < 0) {
3731 int release_ret;
3732
3733 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3734 ERR("UST app tp list field failed for app %d with ret %d",
3735 app->sock, ret);
3736 } else {
3737 DBG3("UST app tp list field failed. Application is dead");
3738 /*
3739 * This is normal behavior, an application can die during the
3740 * creation process. Don't report an error so the execution can
3741 * continue normally. Reset list and count for next app.
3742 */
3743 break;
3744 }
3745 free(tmp_event);
3746 release_ret = ustctl_release_handle(app->sock, handle);
3747 pthread_mutex_unlock(&app->sock_lock);
3748 if (release_ret < 0 &&
3749 release_ret != -LTTNG_UST_ERR_EXITING &&
3750 release_ret != -EPIPE) {
3751 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3752 }
3753 goto rcu_error;
3754 }
3755
3756 health_code_update();
3757 if (count >= nbmem) {
3758 /* In case the realloc fails, we free the memory */
3759 struct lttng_event_field *new_tmp_event;
3760 size_t new_nbmem;
3761
3762 new_nbmem = nbmem << 1;
3763 DBG2("Reallocating event field list from %zu to %zu entries",
3764 nbmem, new_nbmem);
3765 new_tmp_event = realloc(tmp_event,
3766 new_nbmem * sizeof(struct lttng_event_field));
3767 if (new_tmp_event == NULL) {
3768 int release_ret;
3769
3770 PERROR("realloc ust app event fields");
3771 free(tmp_event);
3772 ret = -ENOMEM;
3773 release_ret = ustctl_release_handle(app->sock, handle);
3774 pthread_mutex_unlock(&app->sock_lock);
3775 if (release_ret &&
3776 release_ret != -LTTNG_UST_ERR_EXITING &&
3777 release_ret != -EPIPE) {
3778 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3779 }
3780 goto rcu_error;
3781 }
3782 /* Zero the new memory */
3783 memset(new_tmp_event + nbmem, 0,
3784 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3785 nbmem = new_nbmem;
3786 tmp_event = new_tmp_event;
3787 }
3788
3789 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3790 /* Mapping between these enums matches 1 to 1. */
3791 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3792 tmp_event[count].nowrite = uiter.nowrite;
3793
3794 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3795 tmp_event[count].event.loglevel = uiter.loglevel;
3796 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3797 tmp_event[count].event.pid = app->pid;
3798 tmp_event[count].event.enabled = -1;
3799 count++;
3800 }
3801 ret = ustctl_release_handle(app->sock, handle);
3802 pthread_mutex_unlock(&app->sock_lock);
3803 if (ret < 0 &&
3804 ret != -LTTNG_UST_ERR_EXITING &&
3805 ret != -EPIPE) {
3806 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3807 }
3808 }
3809
3810 ret = count;
3811 *fields = tmp_event;
3812
3813 DBG2("UST app list event fields done (%zu events)", count);
3814
3815 rcu_error:
3816 rcu_read_unlock();
3817 error:
3818 health_code_update();
3819 return ret;
3820 }
3821
3822 /*
3823 * Free and clean all traceable apps of the global list.
3824 *
3825 * Should _NOT_ be called with RCU read-side lock held.
3826 */
3827 void ust_app_clean_list(void)
3828 {
3829 int ret;
3830 struct ust_app *app;
3831 struct lttng_ht_iter iter;
3832
3833 DBG2("UST app cleaning registered apps hash table");
3834
3835 rcu_read_lock();
3836
3837 /* Cleanup notify socket hash table */
3838 if (ust_app_ht_by_notify_sock) {
3839 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3840 notify_sock_n.node) {
3841 struct cds_lfht_node *node;
3842 struct ust_app *app;
3843
3844 node = cds_lfht_iter_get_node(&iter.iter);
3845 if (!node) {
3846 continue;
3847 }
3848
3849 app = container_of(node, struct ust_app,
3850 notify_sock_n.node);
3851 ust_app_notify_sock_unregister(app->notify_sock);
3852 }
3853 }
3854
3855 if (ust_app_ht) {
3856 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3857 ret = lttng_ht_del(ust_app_ht, &iter);
3858 assert(!ret);
3859 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3860 }
3861 }
3862
3863 /* Cleanup socket hash table */
3864 if (ust_app_ht_by_sock) {
3865 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3866 sock_n.node) {
3867 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3868 assert(!ret);
3869 }
3870 }
3871
3872 rcu_read_unlock();
3873
3874 /* Destroy is done only when the ht is empty */
3875 if (ust_app_ht) {
3876 ht_cleanup_push(ust_app_ht);
3877 }
3878 if (ust_app_ht_by_sock) {
3879 ht_cleanup_push(ust_app_ht_by_sock);
3880 }
3881 if (ust_app_ht_by_notify_sock) {
3882 ht_cleanup_push(ust_app_ht_by_notify_sock);
3883 }
3884 }
3885
3886 /*
3887 * Init UST app hash table.
3888 */
3889 int ust_app_ht_alloc(void)
3890 {
3891 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3892 if (!ust_app_ht) {
3893 return -1;
3894 }
3895 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3896 if (!ust_app_ht_by_sock) {
3897 return -1;
3898 }
3899 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3900 if (!ust_app_ht_by_notify_sock) {
3901 return -1;
3902 }
3903 return 0;
3904 }
3905
3906 /*
3907 * For a specific UST session, disable the channel for all registered apps.
3908 */
3909 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3910 struct ltt_ust_channel *uchan)
3911 {
3912 int ret = 0;
3913 struct lttng_ht_iter iter;
3914 struct lttng_ht_node_str *ua_chan_node;
3915 struct ust_app *app;
3916 struct ust_app_session *ua_sess;
3917 struct ust_app_channel *ua_chan;
3918
3919 assert(usess->active);
3920 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3921 uchan->name, usess->id);
3922
3923 rcu_read_lock();
3924
3925 /* For every registered applications */
3926 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3927 struct lttng_ht_iter uiter;
3928 if (!app->compatible) {
3929 /*
3930 * TODO: In time, we should notice the caller of this error by
3931 * telling him that this is a version error.
3932 */
3933 continue;
3934 }
3935 ua_sess = lookup_session_by_app(usess, app);
3936 if (ua_sess == NULL) {
3937 continue;
3938 }
3939
3940 /* Get channel */
3941 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3942 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3943 /* If the session if found for the app, the channel must be there */
3944 assert(ua_chan_node);
3945
3946 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3947 /* The channel must not be already disabled */
3948 assert(ua_chan->enabled == 1);
3949
3950 /* Disable channel onto application */
3951 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3952 if (ret < 0) {
3953 /* XXX: We might want to report this error at some point... */
3954 continue;
3955 }
3956 }
3957
3958 rcu_read_unlock();
3959 return ret;
3960 }
3961
3962 /*
3963 * For a specific UST session, enable the channel for all registered apps.
3964 */
3965 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3966 struct ltt_ust_channel *uchan)
3967 {
3968 int ret = 0;
3969 struct lttng_ht_iter iter;
3970 struct ust_app *app;
3971 struct ust_app_session *ua_sess;
3972
3973 assert(usess->active);
3974 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3975 uchan->name, usess->id);
3976
3977 rcu_read_lock();
3978
3979 /* For every registered applications */
3980 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3981 if (!app->compatible) {
3982 /*
3983 * TODO: In time, we should notice the caller of this error by
3984 * telling him that this is a version error.
3985 */
3986 continue;
3987 }
3988 ua_sess = lookup_session_by_app(usess, app);
3989 if (ua_sess == NULL) {
3990 continue;
3991 }
3992
3993 /* Enable channel onto application */
3994 ret = enable_ust_app_channel(ua_sess, uchan, app);
3995 if (ret < 0) {
3996 /* XXX: We might want to report this error at some point... */
3997 continue;
3998 }
3999 }
4000
4001 rcu_read_unlock();
4002 return ret;
4003 }
4004
4005 /*
4006 * Disable an event in a channel and for a specific session.
4007 */
4008 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
4009 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4010 {
4011 int ret = 0;
4012 struct lttng_ht_iter iter, uiter;
4013 struct lttng_ht_node_str *ua_chan_node;
4014 struct ust_app *app;
4015 struct ust_app_session *ua_sess;
4016 struct ust_app_channel *ua_chan;
4017 struct ust_app_event *ua_event;
4018
4019 assert(usess->active);
4020 DBG("UST app disabling event %s for all apps in channel "
4021 "%s for session id %" PRIu64,
4022 uevent->attr.name, uchan->name, usess->id);
4023
4024 rcu_read_lock();
4025
4026 /* For all registered applications */
4027 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4028 if (!app->compatible) {
4029 /*
4030 * TODO: In time, we should notice the caller of this error by
4031 * telling him that this is a version error.
4032 */
4033 continue;
4034 }
4035 ua_sess = lookup_session_by_app(usess, app);
4036 if (ua_sess == NULL) {
4037 /* Next app */
4038 continue;
4039 }
4040
4041 /* Lookup channel in the ust app session */
4042 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4043 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4044 if (ua_chan_node == NULL) {
4045 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
4046 "Skipping", uchan->name, usess->id, app->pid);
4047 continue;
4048 }
4049 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4050
4051 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4052 uevent->filter, uevent->attr.loglevel,
4053 uevent->exclusion);
4054 if (ua_event == NULL) {
4055 DBG2("Event %s not found in channel %s for app pid %d."
4056 "Skipping", uevent->attr.name, uchan->name, app->pid);
4057 continue;
4058 }
4059
4060 ret = disable_ust_app_event(ua_sess, ua_event, app);
4061 if (ret < 0) {
4062 /* XXX: Report error someday... */
4063 continue;
4064 }
4065 }
4066
4067 rcu_read_unlock();
4068 return ret;
4069 }
4070
4071 /* The ua_sess lock must be held by the caller. */
4072 static
4073 int ust_app_channel_create(struct ltt_ust_session *usess,
4074 struct ust_app_session *ua_sess,
4075 struct ltt_ust_channel *uchan, struct ust_app *app,
4076 struct ust_app_channel **_ua_chan)
4077 {
4078 int ret = 0;
4079 struct ust_app_channel *ua_chan = NULL;
4080
4081 assert(ua_sess);
4082 ASSERT_LOCKED(ua_sess->lock);
4083
4084 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
4085 sizeof(uchan->name))) {
4086 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
4087 &uchan->attr);
4088 ret = 0;
4089 } else {
4090 struct ltt_ust_context *uctx = NULL;
4091
4092 /*
4093 * Create channel onto application and synchronize its
4094 * configuration.
4095 */
4096 ret = ust_app_channel_allocate(ua_sess, uchan,
4097 LTTNG_UST_CHAN_PER_CPU, usess,
4098 &ua_chan);
4099 if (ret == 0) {
4100 ret = ust_app_channel_send(app, usess,
4101 ua_sess, ua_chan);
4102 } else {
4103 goto end;
4104 }
4105
4106 /* Add contexts. */
4107 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
4108 ret = create_ust_app_channel_context(ua_chan,
4109 &uctx->ctx, app);
4110 if (ret) {
4111 goto end;
4112 }
4113 }
4114 }
4115 if (ret < 0) {
4116 switch (ret) {
4117 case -ENOTCONN:
4118 /*
4119 * The application's socket is not valid. Either a bad socket
4120 * or a timeout on it. We can't inform the caller that for a
4121 * specific app, the session failed so lets continue here.
4122 */
4123 ret = 0; /* Not an error. */
4124 break;
4125 case -ENOMEM:
4126 default:
4127 break;
4128 }
4129 }
4130 end:
4131 if (ret == 0 && _ua_chan) {
4132 /*
4133 * Only return the application's channel on success. Note
4134 * that the channel can still be part of the application's
4135 * channel hashtable on error.
4136 */
4137 *_ua_chan = ua_chan;
4138 }
4139 return ret;
4140 }
4141
4142 /*
4143 * For a specific UST session, create the channel for all registered apps.
4144 */
4145 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
4146 struct ltt_ust_channel *uchan)
4147 {
4148 int ret = 0;
4149 struct cds_lfht_iter iter;
4150 struct ust_app *app;
4151
4152 assert(usess);
4153 assert(usess->active);
4154 assert(uchan);
4155
4156 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
4157 uchan->name, usess->id);
4158
4159 rcu_read_lock();
4160 /* For every registered applications */
4161 cds_lfht_for_each_entry(ust_app_ht->ht, &iter, app, pid_n.node) {
4162 struct ust_app_session *ua_sess;
4163 int session_was_created = 0;
4164
4165 if (!app->compatible ||
4166 !trace_ust_pid_tracker_lookup(usess, app->pid)) {
4167 goto error_rcu_unlock;
4168 }
4169
4170 /*
4171 * Create session on the tracer side and add it to app session HT. Note
4172 * that if session exist, it will simply return a pointer to the ust
4173 * app session.
4174 */
4175 ret = find_or_create_ust_app_session(usess, app, &ua_sess,
4176 &session_was_created);
4177 if (ret < 0) {
4178 switch (ret) {
4179 case -ENOTCONN:
4180 /*
4181 * The application's socket is not valid. Either a bad
4182 * socket or a timeout on it. We can't inform the caller
4183 * that for a specific app, the session failed so lets
4184 * continue here; it is not an error.
4185 */
4186 ret = 0;
4187 goto error_rcu_unlock;
4188 case -ENOMEM:
4189 default:
4190 goto error_rcu_unlock;
4191 }
4192 }
4193
4194 if (ua_sess->deleted) {
4195 continue;
4196 }
4197 ret = ust_app_channel_create(usess, ua_sess, uchan, app, NULL);
4198 if (ret) {
4199 if (session_was_created) {
4200 destroy_app_session(app, ua_sess);
4201 }
4202 goto error_rcu_unlock;
4203 }
4204 }
4205
4206 error_rcu_unlock:
4207 rcu_read_unlock();
4208 return ret;
4209 }
4210
4211 /*
4212 * Enable event for a specific session and channel on the tracer.
4213 */
4214 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
4215 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4216 {
4217 int ret = 0;
4218 struct lttng_ht_iter iter, uiter;
4219 struct lttng_ht_node_str *ua_chan_node;
4220 struct ust_app *app;
4221 struct ust_app_session *ua_sess;
4222 struct ust_app_channel *ua_chan;
4223 struct ust_app_event *ua_event;
4224
4225 assert(usess->active);
4226 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
4227 uevent->attr.name, usess->id);
4228
4229 /*
4230 * NOTE: At this point, this function is called only if the session and
4231 * channel passed are already created for all apps. and enabled on the
4232 * tracer also.
4233 */
4234
4235 rcu_read_lock();
4236
4237 /* For all registered applications */
4238 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4239 if (!app->compatible) {
4240 /*
4241 * TODO: In time, we should notice the caller of this error by
4242 * telling him that this is a version error.
4243 */
4244 continue;
4245 }
4246 ua_sess = lookup_session_by_app(usess, app);
4247 if (!ua_sess) {
4248 /* The application has problem or is probably dead. */
4249 continue;
4250 }
4251
4252 pthread_mutex_lock(&ua_sess->lock);
4253
4254 if (ua_sess->deleted) {
4255 pthread_mutex_unlock(&ua_sess->lock);
4256 continue;
4257 }
4258
4259 /* Lookup channel in the ust app session */
4260 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4261 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4262 /*
4263 * It is possible that the channel cannot be found is
4264 * the channel/event creation occurs concurrently with
4265 * an application exit.
4266 */
4267 if (!ua_chan_node) {
4268 pthread_mutex_unlock(&ua_sess->lock);
4269 continue;
4270 }
4271
4272 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4273
4274 /* Get event node */
4275 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4276 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4277 if (ua_event == NULL) {
4278 DBG3("UST app enable event %s not found for app PID %d."
4279 "Skipping app", uevent->attr.name, app->pid);
4280 goto next_app;
4281 }
4282
4283 ret = enable_ust_app_event(ua_sess, ua_event, app);
4284 if (ret < 0) {
4285 pthread_mutex_unlock(&ua_sess->lock);
4286 goto error;
4287 }
4288 next_app:
4289 pthread_mutex_unlock(&ua_sess->lock);
4290 }
4291
4292 error:
4293 rcu_read_unlock();
4294 return ret;
4295 }
4296
4297 /*
4298 * For a specific existing UST session and UST channel, creates the event for
4299 * all registered apps.
4300 */
4301 int ust_app_create_event_glb(struct ltt_ust_session *usess,
4302 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4303 {
4304 int ret = 0;
4305 struct lttng_ht_iter iter, uiter;
4306 struct lttng_ht_node_str *ua_chan_node;
4307 struct ust_app *app;
4308 struct ust_app_session *ua_sess;
4309 struct ust_app_channel *ua_chan;
4310
4311 assert(usess->active);
4312 DBG("UST app creating event %s for all apps for session id %" PRIu64,
4313 uevent->attr.name, usess->id);
4314
4315 rcu_read_lock();
4316
4317 /* For all registered applications */
4318 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4319 if (!app->compatible) {
4320 /*
4321 * TODO: In time, we should notice the caller of this error by
4322 * telling him that this is a version error.
4323 */
4324 continue;
4325 }
4326 ua_sess = lookup_session_by_app(usess, app);
4327 if (!ua_sess) {
4328 /* The application has problem or is probably dead. */
4329 continue;
4330 }
4331
4332 pthread_mutex_lock(&ua_sess->lock);
4333
4334 if (ua_sess->deleted) {
4335 pthread_mutex_unlock(&ua_sess->lock);
4336 continue;
4337 }
4338
4339 /* Lookup channel in the ust app session */
4340 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4341 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4342 /* If the channel is not found, there is a code flow error */
4343 assert(ua_chan_node);
4344
4345 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4346
4347 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4348 pthread_mutex_unlock(&ua_sess->lock);
4349 if (ret < 0) {
4350 if (ret != -LTTNG_UST_ERR_EXIST) {
4351 /* Possible value at this point: -ENOMEM. If so, we stop! */
4352 break;
4353 }
4354 DBG2("UST app event %s already exist on app PID %d",
4355 uevent->attr.name, app->pid);
4356 continue;
4357 }
4358 }
4359
4360 rcu_read_unlock();
4361 return ret;
4362 }
4363
4364 /*
4365 * Start tracing for a specific UST session and app.
4366 *
4367 * Called with UST app session lock held.
4368 *
4369 */
4370 static
4371 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
4372 {
4373 int ret = 0;
4374 struct ust_app_session *ua_sess;
4375
4376 DBG("Starting tracing for ust app pid %d", app->pid);
4377
4378 rcu_read_lock();
4379
4380 if (!app->compatible) {
4381 goto end;
4382 }
4383
4384 ua_sess = lookup_session_by_app(usess, app);
4385 if (ua_sess == NULL) {
4386 /* The session is in teardown process. Ignore and continue. */
4387 goto end;
4388 }
4389
4390 pthread_mutex_lock(&ua_sess->lock);
4391
4392 if (ua_sess->deleted) {
4393 pthread_mutex_unlock(&ua_sess->lock);
4394 goto end;
4395 }
4396
4397 /* Upon restart, we skip the setup, already done */
4398 if (ua_sess->started) {
4399 goto skip_setup;
4400 }
4401
4402 /*
4403 * Create the metadata for the application. This returns gracefully if a
4404 * metadata was already set for the session.
4405 */
4406 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
4407 if (ret < 0) {
4408 goto error_unlock;
4409 }
4410
4411 health_code_update();
4412
4413 skip_setup:
4414 /* This start the UST tracing */
4415 pthread_mutex_lock(&app->sock_lock);
4416 ret = ustctl_start_session(app->sock, ua_sess->handle);
4417 pthread_mutex_unlock(&app->sock_lock);
4418 if (ret < 0) {
4419 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4420 ERR("Error starting tracing for app pid: %d (ret: %d)",
4421 app->pid, ret);
4422 } else {
4423 DBG("UST app start session failed. Application is dead.");
4424 /*
4425 * This is normal behavior, an application can die during the
4426 * creation process. Don't report an error so the execution can
4427 * continue normally.
4428 */
4429 pthread_mutex_unlock(&ua_sess->lock);
4430 goto end;
4431 }
4432 goto error_unlock;
4433 }
4434
4435 /* Indicate that the session has been started once */
4436 ua_sess->started = 1;
4437
4438 pthread_mutex_unlock(&ua_sess->lock);
4439
4440 health_code_update();
4441
4442 /* Quiescent wait after starting trace */
4443 pthread_mutex_lock(&app->sock_lock);
4444 ret = ustctl_wait_quiescent(app->sock);
4445 pthread_mutex_unlock(&app->sock_lock);
4446 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4447 ERR("UST app wait quiescent failed for app pid %d ret %d",
4448 app->pid, ret);
4449 }
4450
4451 end:
4452 rcu_read_unlock();
4453 health_code_update();
4454 return 0;
4455
4456 error_unlock:
4457 pthread_mutex_unlock(&ua_sess->lock);
4458 rcu_read_unlock();
4459 health_code_update();
4460 return -1;
4461 }
4462
4463 /*
4464 * Stop tracing for a specific UST session and app.
4465 */
4466 static
4467 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
4468 {
4469 int ret = 0;
4470 struct ust_app_session *ua_sess;
4471 struct ust_registry_session *registry;
4472
4473 DBG("Stopping tracing for ust app pid %d", app->pid);
4474
4475 rcu_read_lock();
4476
4477 if (!app->compatible) {
4478 goto end_no_session;
4479 }
4480
4481 ua_sess = lookup_session_by_app(usess, app);
4482 if (ua_sess == NULL) {
4483 goto end_no_session;
4484 }
4485
4486 pthread_mutex_lock(&ua_sess->lock);
4487
4488 if (ua_sess->deleted) {
4489 pthread_mutex_unlock(&ua_sess->lock);
4490 goto end_no_session;
4491 }
4492
4493 /*
4494 * If started = 0, it means that stop trace has been called for a session
4495 * that was never started. It's possible since we can have a fail start
4496 * from either the application manager thread or the command thread. Simply
4497 * indicate that this is a stop error.
4498 */
4499 if (!ua_sess->started) {
4500 goto error_rcu_unlock;
4501 }
4502
4503 health_code_update();
4504
4505 /* This inhibits UST tracing */
4506 pthread_mutex_lock(&app->sock_lock);
4507 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4508 pthread_mutex_unlock(&app->sock_lock);
4509 if (ret < 0) {
4510 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4511 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4512 app->pid, ret);
4513 } else {
4514 DBG("UST app stop session failed. Application is dead.");
4515 /*
4516 * This is normal behavior, an application can die during the
4517 * creation process. Don't report an error so the execution can
4518 * continue normally.
4519 */
4520 goto end_unlock;
4521 }
4522 goto error_rcu_unlock;
4523 }
4524
4525 health_code_update();
4526
4527 /* Quiescent wait after stopping trace */
4528 pthread_mutex_lock(&app->sock_lock);
4529 ret = ustctl_wait_quiescent(app->sock);
4530 pthread_mutex_unlock(&app->sock_lock);
4531 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4532 ERR("UST app wait quiescent failed for app pid %d ret %d",
4533 app->pid, ret);
4534 }
4535
4536 health_code_update();
4537
4538 registry = get_session_registry(ua_sess);
4539
4540 /* The UST app session is held registry shall not be null. */
4541 assert(registry);
4542
4543 /* Push metadata for application before freeing the application. */
4544 (void) push_metadata(registry, ua_sess->consumer);
4545
4546 end_unlock:
4547 pthread_mutex_unlock(&ua_sess->lock);
4548 end_no_session:
4549 rcu_read_unlock();
4550 health_code_update();
4551 return 0;
4552
4553 error_rcu_unlock:
4554 pthread_mutex_unlock(&ua_sess->lock);
4555 rcu_read_unlock();
4556 health_code_update();
4557 return -1;
4558 }
4559
4560 static
4561 int ust_app_flush_app_session(struct ust_app *app,
4562 struct ust_app_session *ua_sess)
4563 {
4564 int ret, retval = 0;
4565 struct lttng_ht_iter iter;
4566 struct ust_app_channel *ua_chan;
4567 struct consumer_socket *socket;
4568
4569 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4570
4571 rcu_read_lock();
4572
4573 if (!app->compatible) {
4574 goto end_not_compatible;
4575 }
4576
4577 pthread_mutex_lock(&ua_sess->lock);
4578
4579 if (ua_sess->deleted) {
4580 goto end_deleted;
4581 }
4582
4583 health_code_update();
4584
4585 /* Flushing buffers */
4586 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4587 ua_sess->consumer);
4588
4589 /* Flush buffers and push metadata. */
4590 switch (ua_sess->buffer_type) {
4591 case LTTNG_BUFFER_PER_PID:
4592 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4593 node.node) {
4594 health_code_update();
4595 ret = consumer_flush_channel(socket, ua_chan->key);
4596 if (ret) {
4597 ERR("Error flushing consumer channel");
4598 retval = -1;
4599 continue;
4600 }
4601 }
4602 break;
4603 case LTTNG_BUFFER_PER_UID:
4604 default:
4605 assert(0);
4606 break;
4607 }
4608
4609 health_code_update();
4610
4611 end_deleted:
4612 pthread_mutex_unlock(&ua_sess->lock);
4613
4614 end_not_compatible:
4615 rcu_read_unlock();
4616 health_code_update();
4617 return retval;
4618 }
4619
4620 /*
4621 * Flush buffers for all applications for a specific UST session.
4622 * Called with UST session lock held.
4623 */
4624 static
4625 int ust_app_flush_session(struct ltt_ust_session *usess)
4626
4627 {
4628 int ret = 0;
4629
4630 DBG("Flushing session buffers for all ust apps");
4631
4632 rcu_read_lock();
4633
4634 /* Flush buffers and push metadata. */
4635 switch (usess->buffer_type) {
4636 case LTTNG_BUFFER_PER_UID:
4637 {
4638 struct buffer_reg_uid *reg;
4639 struct lttng_ht_iter iter;
4640
4641 /* Flush all per UID buffers associated to that session. */
4642 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4643 struct ust_registry_session *ust_session_reg;
4644 struct buffer_reg_channel *reg_chan;
4645 struct consumer_socket *socket;
4646
4647 /* Get consumer socket to use to push the metadata.*/
4648 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4649 usess->consumer);
4650 if (!socket) {
4651 /* Ignore request if no consumer is found for the session. */
4652 continue;
4653 }
4654
4655 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4656 reg_chan, node.node) {
4657 /*
4658 * The following call will print error values so the return
4659 * code is of little importance because whatever happens, we
4660 * have to try them all.
4661 */
4662 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4663 }
4664
4665 ust_session_reg = reg->registry->reg.ust;
4666 /* Push metadata. */
4667 (void) push_metadata(ust_session_reg, usess->consumer);
4668 }
4669 break;
4670 }
4671 case LTTNG_BUFFER_PER_PID:
4672 {
4673 struct ust_app_session *ua_sess;
4674 struct lttng_ht_iter iter;
4675 struct ust_app *app;
4676
4677 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4678 ua_sess = lookup_session_by_app(usess, app);
4679 if (ua_sess == NULL) {
4680 continue;
4681 }
4682 (void) ust_app_flush_app_session(app, ua_sess);
4683 }
4684 break;
4685 }
4686 default:
4687 ret = -1;
4688 assert(0);
4689 break;
4690 }
4691
4692 rcu_read_unlock();
4693 health_code_update();
4694 return ret;
4695 }
4696
4697 static
4698 int ust_app_clear_quiescent_app_session(struct ust_app *app,
4699 struct ust_app_session *ua_sess)
4700 {
4701 int ret = 0;
4702 struct lttng_ht_iter iter;
4703 struct ust_app_channel *ua_chan;
4704 struct consumer_socket *socket;
4705
4706 DBG("Clearing stream quiescent state for ust app pid %d", app->pid);
4707
4708 rcu_read_lock();
4709
4710 if (!app->compatible) {
4711 goto end_not_compatible;
4712 }
4713
4714 pthread_mutex_lock(&ua_sess->lock);
4715
4716 if (ua_sess->deleted) {
4717 goto end_unlock;
4718 }
4719
4720 health_code_update();
4721
4722 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4723 ua_sess->consumer);
4724 if (!socket) {
4725 ERR("Failed to find consumer (%" PRIu32 ") socket",
4726 app->bits_per_long);
4727 ret = -1;
4728 goto end_unlock;
4729 }
4730
4731 /* Clear quiescent state. */
4732 switch (ua_sess->buffer_type) {
4733 case LTTNG_BUFFER_PER_PID:
4734 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter,
4735 ua_chan, node.node) {
4736 health_code_update();
4737 ret = consumer_clear_quiescent_channel(socket,
4738 ua_chan->key);
4739 if (ret) {
4740 ERR("Error clearing quiescent state for consumer channel");
4741 ret = -1;
4742 continue;
4743 }
4744 }
4745 break;
4746 case LTTNG_BUFFER_PER_UID:
4747 default:
4748 assert(0);
4749 ret = -1;
4750 break;
4751 }
4752
4753 health_code_update();
4754
4755 end_unlock:
4756 pthread_mutex_unlock(&ua_sess->lock);
4757
4758 end_not_compatible:
4759 rcu_read_unlock();
4760 health_code_update();
4761 return ret;
4762 }
4763
4764 /*
4765 * Clear quiescent state in each stream for all applications for a
4766 * specific UST session.
4767 * Called with UST session lock held.
4768 */
4769 static
4770 int ust_app_clear_quiescent_session(struct ltt_ust_session *usess)
4771
4772 {
4773 int ret = 0;
4774
4775 DBG("Clearing stream quiescent state for all ust apps");
4776
4777 rcu_read_lock();
4778
4779 switch (usess->buffer_type) {
4780 case LTTNG_BUFFER_PER_UID:
4781 {
4782 struct lttng_ht_iter iter;
4783 struct buffer_reg_uid *reg;
4784
4785 /*
4786 * Clear quiescent for all per UID buffers associated to
4787 * that session.
4788 */
4789 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4790 struct consumer_socket *socket;
4791 struct buffer_reg_channel *reg_chan;
4792
4793 /* Get associated consumer socket.*/
4794 socket = consumer_find_socket_by_bitness(
4795 reg->bits_per_long, usess->consumer);
4796 if (!socket) {
4797 /*
4798 * Ignore request if no consumer is found for
4799 * the session.
4800 */
4801 continue;
4802 }
4803
4804 cds_lfht_for_each_entry(reg->registry->channels->ht,
4805 &iter.iter, reg_chan, node.node) {
4806 /*
4807 * The following call will print error values so
4808 * the return code is of little importance
4809 * because whatever happens, we have to try them
4810 * all.
4811 */
4812 (void) consumer_clear_quiescent_channel(socket,
4813 reg_chan->consumer_key);
4814 }
4815 }
4816 break;
4817 }
4818 case LTTNG_BUFFER_PER_PID:
4819 {
4820 struct ust_app_session *ua_sess;
4821 struct lttng_ht_iter iter;
4822 struct ust_app *app;
4823
4824 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
4825 pid_n.node) {
4826 ua_sess = lookup_session_by_app(usess, app);
4827 if (ua_sess == NULL) {
4828 continue;
4829 }
4830 (void) ust_app_clear_quiescent_app_session(app,
4831 ua_sess);
4832 }
4833 break;
4834 }
4835 default:
4836 ret = -1;
4837 assert(0);
4838 break;
4839 }
4840
4841 rcu_read_unlock();
4842 health_code_update();
4843 return ret;
4844 }
4845
4846 /*
4847 * Destroy a specific UST session in apps.
4848 */
4849 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4850 {
4851 int ret;
4852 struct ust_app_session *ua_sess;
4853 struct lttng_ht_iter iter;
4854 struct lttng_ht_node_u64 *node;
4855
4856 DBG("Destroy tracing for ust app pid %d", app->pid);
4857
4858 rcu_read_lock();
4859
4860 if (!app->compatible) {
4861 goto end;
4862 }
4863
4864 __lookup_session_by_app(usess, app, &iter);
4865 node = lttng_ht_iter_get_node_u64(&iter);
4866 if (node == NULL) {
4867 /* Session is being or is deleted. */
4868 goto end;
4869 }
4870 ua_sess = caa_container_of(node, struct ust_app_session, node);
4871
4872 health_code_update();
4873 destroy_app_session(app, ua_sess);
4874
4875 health_code_update();
4876
4877 /* Quiescent wait after stopping trace */
4878 pthread_mutex_lock(&app->sock_lock);
4879 ret = ustctl_wait_quiescent(app->sock);
4880 pthread_mutex_unlock(&app->sock_lock);
4881 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4882 ERR("UST app wait quiescent failed for app pid %d ret %d",
4883 app->pid, ret);
4884 }
4885 end:
4886 rcu_read_unlock();
4887 health_code_update();
4888 return 0;
4889 }
4890
4891 /*
4892 * Start tracing for the UST session.
4893 */
4894 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4895 {
4896 struct lttng_ht_iter iter;
4897 struct ust_app *app;
4898
4899 DBG("Starting all UST traces");
4900
4901 /*
4902 * Even though the start trace might fail, flag this session active so
4903 * other application coming in are started by default.
4904 */
4905 usess->active = 1;
4906
4907 rcu_read_lock();
4908
4909 /*
4910 * In a start-stop-start use-case, we need to clear the quiescent state
4911 * of each channel set by the prior stop command, thus ensuring that a
4912 * following stop or destroy is sure to grab a timestamp_end near those
4913 * operations, even if the packet is empty.
4914 */
4915 (void) ust_app_clear_quiescent_session(usess);
4916
4917 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4918 ust_app_global_update(usess, app);
4919 }
4920
4921 rcu_read_unlock();
4922
4923 return 0;
4924 }
4925
4926 /*
4927 * Start tracing for the UST session.
4928 * Called with UST session lock held.
4929 */
4930 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4931 {
4932 int ret = 0;
4933 struct lttng_ht_iter iter;
4934 struct ust_app *app;
4935
4936 DBG("Stopping all UST traces");
4937
4938 /*
4939 * Even though the stop trace might fail, flag this session inactive so
4940 * other application coming in are not started by default.
4941 */
4942 usess->active = 0;
4943
4944 rcu_read_lock();
4945
4946 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4947 ret = ust_app_stop_trace(usess, app);
4948 if (ret < 0) {
4949 /* Continue to next apps even on error */
4950 continue;
4951 }
4952 }
4953
4954 (void) ust_app_flush_session(usess);
4955
4956 rcu_read_unlock();
4957
4958 return 0;
4959 }
4960
4961 /*
4962 * Destroy app UST session.
4963 */
4964 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4965 {
4966 int ret = 0;
4967 struct lttng_ht_iter iter;
4968 struct ust_app *app;
4969
4970 DBG("Destroy all UST traces");
4971
4972 rcu_read_lock();
4973
4974 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4975 ret = destroy_trace(usess, app);
4976 if (ret < 0) {
4977 /* Continue to next apps even on error */
4978 continue;
4979 }
4980 }
4981
4982 rcu_read_unlock();
4983
4984 return 0;
4985 }
4986
4987 /* The ua_sess lock must be held by the caller. */
4988 static
4989 int find_or_create_ust_app_channel(
4990 struct ltt_ust_session *usess,
4991 struct ust_app_session *ua_sess,
4992 struct ust_app *app,
4993 struct ltt_ust_channel *uchan,
4994 struct ust_app_channel **ua_chan)
4995 {
4996 int ret = 0;
4997 struct lttng_ht_iter iter;
4998 struct lttng_ht_node_str *ua_chan_node;
4999
5000 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &iter);
5001 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
5002 if (ua_chan_node) {
5003 *ua_chan = caa_container_of(ua_chan_node,
5004 struct ust_app_channel, node);
5005 goto end;
5006 }
5007
5008 ret = ust_app_channel_create(usess, ua_sess, uchan, app, ua_chan);
5009 if (ret) {
5010 goto end;
5011 }
5012 end:
5013 return ret;
5014 }
5015
5016 static
5017 int ust_app_channel_synchronize_event(struct ust_app_channel *ua_chan,
5018 struct ltt_ust_event *uevent, struct ust_app_session *ua_sess,
5019 struct ust_app *app)
5020 {
5021 int ret = 0;
5022 struct ust_app_event *ua_event = NULL;
5023
5024 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
5025 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
5026 if (!ua_event) {
5027 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
5028 if (ret < 0) {
5029 goto end;
5030 }
5031 } else {
5032 if (ua_event->enabled != uevent->enabled) {
5033 ret = uevent->enabled ?
5034 enable_ust_app_event(ua_sess, ua_event, app) :
5035 disable_ust_app_event(ua_sess, ua_event, app);
5036 }
5037 }
5038
5039 end:
5040 return ret;
5041 }
5042
5043 /*
5044 * The caller must ensure that the application is compatible and is tracked
5045 * by the PID tracker.
5046 */
5047 static
5048 void ust_app_synchronize(struct ltt_ust_session *usess,
5049 struct ust_app *app)
5050 {
5051 int ret = 0;
5052 struct cds_lfht_iter uchan_iter;
5053 struct ltt_ust_channel *uchan;
5054 struct ust_app_session *ua_sess = NULL;
5055
5056 /*
5057 * The application's configuration should only be synchronized for
5058 * active sessions.
5059 */
5060 assert(usess->active);
5061
5062 ret = find_or_create_ust_app_session(usess, app, &ua_sess, NULL);
5063 if (ret < 0) {
5064 /* Tracer is probably gone or ENOMEM. */
5065 goto error;
5066 }
5067 assert(ua_sess);
5068
5069 pthread_mutex_lock(&ua_sess->lock);
5070 if (ua_sess->deleted) {
5071 pthread_mutex_unlock(&ua_sess->lock);
5072 goto end;
5073 }
5074
5075 rcu_read_lock();
5076 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &uchan_iter,
5077 uchan, node.node) {
5078 struct ust_app_channel *ua_chan;
5079 struct cds_lfht_iter uevent_iter;
5080 struct ltt_ust_event *uevent;
5081
5082 /*
5083 * Search for a matching ust_app_channel. If none is found,
5084 * create it. Creating the channel will cause the ua_chan
5085 * structure to be allocated, the channel buffers to be
5086 * allocated (if necessary) and sent to the application, and
5087 * all enabled contexts will be added to the channel.
5088 */
5089 ret = find_or_create_ust_app_channel(usess, ua_sess,
5090 app, uchan, &ua_chan);
5091 if (ret) {
5092 /* Tracer is probably gone or ENOMEM. */
5093 goto error_unlock;
5094 }
5095
5096 if (!ua_chan) {
5097 /* ua_chan will be NULL for the metadata channel */
5098 continue;
5099 }
5100
5101 cds_lfht_for_each_entry(uchan->events->ht, &uevent_iter, uevent,
5102 node.node) {
5103 ret = ust_app_channel_synchronize_event(ua_chan,
5104 uevent, ua_sess, app);
5105 if (ret) {
5106 goto error_unlock;
5107 }
5108 }
5109
5110 if (ua_chan->enabled != uchan->enabled) {
5111 ret = uchan->enabled ?
5112 enable_ust_app_channel(ua_sess, uchan, app) :
5113 disable_ust_app_channel(ua_sess, ua_chan, app);
5114 if (ret) {
5115 goto error_unlock;
5116 }
5117 }
5118 }
5119 rcu_read_unlock();
5120
5121 end:
5122 pthread_mutex_unlock(&ua_sess->lock);
5123 /* Everything went well at this point. */
5124 return;
5125
5126 error_unlock:
5127 rcu_read_unlock();
5128 pthread_mutex_unlock(&ua_sess->lock);
5129 error:
5130 if (ua_sess) {
5131 destroy_app_session(app, ua_sess);
5132 }
5133 return;
5134 }
5135
5136 static
5137 void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
5138 {
5139 struct ust_app_session *ua_sess;
5140
5141 ua_sess = lookup_session_by_app(usess, app);
5142 if (ua_sess == NULL) {
5143 return;
5144 }
5145 destroy_app_session(app, ua_sess);
5146 }
5147
5148 /*
5149 * Add channels/events from UST global domain to registered apps at sock.
5150 *
5151 * Called with session lock held.
5152 * Called with RCU read-side lock held.
5153 */
5154 void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
5155 {
5156 assert(usess);
5157 assert(usess->active);
5158
5159 DBG2("UST app global update for app sock %d for session id %" PRIu64,
5160 app->sock, usess->id);
5161
5162 if (!app->compatible) {
5163 return;
5164 }
5165 if (trace_ust_pid_tracker_lookup(usess, app->pid)) {
5166 /*
5167 * Synchronize the application's internal tracing configuration
5168 * and start tracing.
5169 */
5170 ust_app_synchronize(usess, app);
5171 ust_app_start_trace(usess, app);
5172 } else {
5173 ust_app_global_destroy(usess, app);
5174 }
5175 }
5176
5177 /*
5178 * Called with session lock held.
5179 */
5180 void ust_app_global_update_all(struct ltt_ust_session *usess)
5181 {
5182 struct lttng_ht_iter iter;
5183 struct ust_app *app;
5184
5185 rcu_read_lock();
5186 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5187 ust_app_global_update(usess, app);
5188 }
5189 rcu_read_unlock();
5190 }
5191
5192 /*
5193 * Add context to a specific channel for global UST domain.
5194 */
5195 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
5196 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
5197 {
5198 int ret = 0;
5199 struct lttng_ht_node_str *ua_chan_node;
5200 struct lttng_ht_iter iter, uiter;
5201 struct ust_app_channel *ua_chan = NULL;
5202 struct ust_app_session *ua_sess;
5203 struct ust_app *app;
5204
5205 assert(usess->active);
5206
5207 rcu_read_lock();
5208 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5209 if (!app->compatible) {
5210 /*
5211 * TODO: In time, we should notice the caller of this error by
5212 * telling him that this is a version error.
5213 */
5214 continue;
5215 }
5216 ua_sess = lookup_session_by_app(usess, app);
5217 if (ua_sess == NULL) {
5218 continue;
5219 }
5220
5221 pthread_mutex_lock(&ua_sess->lock);
5222
5223 if (ua_sess->deleted) {
5224 pthread_mutex_unlock(&ua_sess->lock);
5225 continue;
5226 }
5227
5228 /* Lookup channel in the ust app session */
5229 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
5230 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
5231 if (ua_chan_node == NULL) {
5232 goto next_app;
5233 }
5234 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
5235 node);
5236 ret = create_ust_app_channel_context(ua_chan, &uctx->ctx, app);
5237 if (ret < 0) {
5238 goto next_app;
5239 }
5240 next_app:
5241 pthread_mutex_unlock(&ua_sess->lock);
5242 }
5243
5244 rcu_read_unlock();
5245 return ret;
5246 }
5247
5248 /*
5249 * Receive registration and populate the given msg structure.
5250 *
5251 * On success return 0 else a negative value returned by the ustctl call.
5252 */
5253 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
5254 {
5255 int ret;
5256 uint32_t pid, ppid, uid, gid;
5257
5258 assert(msg);
5259
5260 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
5261 &pid, &ppid, &uid, &gid,
5262 &msg->bits_per_long,
5263 &msg->uint8_t_alignment,
5264 &msg->uint16_t_alignment,
5265 &msg->uint32_t_alignment,
5266 &msg->uint64_t_alignment,
5267 &msg->long_alignment,
5268 &msg->byte_order,
5269 msg->name);
5270 if (ret < 0) {
5271 switch (-ret) {
5272 case EPIPE:
5273 case ECONNRESET:
5274 case LTTNG_UST_ERR_EXITING:
5275 DBG3("UST app recv reg message failed. Application died");
5276 break;
5277 case LTTNG_UST_ERR_UNSUP_MAJOR:
5278 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
5279 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
5280 LTTNG_UST_ABI_MINOR_VERSION);
5281 break;
5282 default:
5283 ERR("UST app recv reg message failed with ret %d", ret);
5284 break;
5285 }
5286 goto error;
5287 }
5288 msg->pid = (pid_t) pid;
5289 msg->ppid = (pid_t) ppid;
5290 msg->uid = (uid_t) uid;
5291 msg->gid = (gid_t) gid;
5292
5293 error:
5294 return ret;
5295 }
5296
5297 /*
5298 * Return a ust app session object using the application object and the
5299 * session object descriptor has a key. If not found, NULL is returned.
5300 * A RCU read side lock MUST be acquired when calling this function.
5301 */
5302 static struct ust_app_session *find_session_by_objd(struct ust_app *app,
5303 int objd)
5304 {
5305 struct lttng_ht_node_ulong *node;
5306 struct lttng_ht_iter iter;
5307 struct ust_app_session *ua_sess = NULL;
5308
5309 assert(app);
5310
5311 lttng_ht_lookup(app->ust_sessions_objd, (void *)((unsigned long) objd), &iter);
5312 node = lttng_ht_iter_get_node_ulong(&iter);
5313 if (node == NULL) {
5314 DBG2("UST app session find by objd %d not found", objd);
5315 goto error;
5316 }
5317
5318 ua_sess = caa_container_of(node, struct ust_app_session, ust_objd_node);
5319
5320 error:
5321 return ua_sess;
5322 }
5323
5324 /*
5325 * Return a ust app channel object using the application object and the channel
5326 * object descriptor has a key. If not found, NULL is returned. A RCU read side
5327 * lock MUST be acquired before calling this function.
5328 */
5329 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
5330 int objd)
5331 {
5332 struct lttng_ht_node_ulong *node;
5333 struct lttng_ht_iter iter;
5334 struct ust_app_channel *ua_chan = NULL;
5335
5336 assert(app);
5337
5338 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
5339 node = lttng_ht_iter_get_node_ulong(&iter);
5340 if (node == NULL) {
5341 DBG2("UST app channel find by objd %d not found", objd);
5342 goto error;
5343 }
5344
5345 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
5346
5347 error:
5348 return ua_chan;
5349 }
5350
5351 /*
5352 * Reply to a register channel notification from an application on the notify
5353 * socket. The channel metadata is also created.
5354 *
5355 * The session UST registry lock is acquired in this function.
5356 *
5357 * On success 0 is returned else a negative value.
5358 */
5359 static int reply_ust_register_channel(int sock, int cobjd,
5360 size_t nr_fields, struct ustctl_field *fields)
5361 {
5362 int ret, ret_code = 0;
5363 uint32_t chan_id;
5364 uint64_t chan_reg_key;
5365 enum ustctl_channel_header type;
5366 struct ust_app *app;
5367 struct ust_app_channel *ua_chan;
5368 struct ust_app_session *ua_sess;
5369 struct ust_registry_session *registry;
5370 struct ust_registry_channel *chan_reg;
5371
5372 rcu_read_lock();
5373
5374 /* Lookup application. If not found, there is a code flow error. */
5375 app = find_app_by_notify_sock(sock);
5376 if (!app) {
5377 DBG("Application socket %d is being torn down. Abort event notify",
5378 sock);
5379 ret = 0;
5380 goto error_rcu_unlock;
5381 }
5382
5383 /* Lookup channel by UST object descriptor. */
5384 ua_chan = find_channel_by_objd(app, cobjd);
5385 if (!ua_chan) {
5386 DBG("Application channel is being torn down. Abort event notify");
5387 ret = 0;
5388 goto error_rcu_unlock;
5389 }
5390
5391 assert(ua_chan->session);
5392 ua_sess = ua_chan->session;
5393
5394 /* Get right session registry depending on the session buffer type. */
5395 registry = get_session_registry(ua_sess);
5396 if (!registry) {
5397 DBG("Application session is being torn down. Abort event notify");
5398 ret = 0;
5399 goto error_rcu_unlock;
5400 };
5401
5402 /* Depending on the buffer type, a different channel key is used. */
5403 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5404 chan_reg_key = ua_chan->tracing_channel_id;
5405 } else {
5406 chan_reg_key = ua_chan->key;
5407 }
5408
5409 pthread_mutex_lock(&registry->lock);
5410
5411 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
5412 assert(chan_reg);
5413
5414 if (!chan_reg->register_done) {
5415 /*
5416 * TODO: eventually use the registry event count for
5417 * this channel to better guess header type for per-pid
5418 * buffers.
5419 */
5420 type = USTCTL_CHANNEL_HEADER_LARGE;
5421 chan_reg->nr_ctx_fields = nr_fields;
5422 chan_reg->ctx_fields = fields;
5423 fields = NULL;
5424 chan_reg->header_type = type;
5425 } else {
5426 /* Get current already assigned values. */
5427 type = chan_reg->header_type;
5428 }
5429 /* Channel id is set during the object creation. */
5430 chan_id = chan_reg->chan_id;
5431
5432 /* Append to metadata */
5433 if (!chan_reg->metadata_dumped) {
5434 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
5435 if (ret_code) {
5436 ERR("Error appending channel metadata (errno = %d)", ret_code);
5437 goto reply;
5438 }
5439 }
5440
5441 reply:
5442 DBG3("UST app replying to register channel key %" PRIu64
5443 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
5444 ret_code);
5445
5446 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
5447 if (ret < 0) {
5448 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5449 ERR("UST app reply channel failed with ret %d", ret);
5450 } else {
5451 DBG3("UST app reply channel failed. Application died");
5452 }
5453 goto error;
5454 }
5455
5456 /* This channel registry registration is completed. */
5457 chan_reg->register_done = 1;
5458
5459 error:
5460 pthread_mutex_unlock(&registry->lock);
5461 error_rcu_unlock:
5462 rcu_read_unlock();
5463 free(fields);
5464 return ret;
5465 }
5466
5467 /*
5468 * Add event to the UST channel registry. When the event is added to the
5469 * registry, the metadata is also created. Once done, this replies to the
5470 * application with the appropriate error code.
5471 *
5472 * The session UST registry lock is acquired in the function.
5473 *
5474 * On success 0 is returned else a negative value.
5475 */
5476 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
5477 char *sig, size_t nr_fields, struct ustctl_field *fields,
5478 int loglevel_value, char *model_emf_uri)
5479 {
5480 int ret, ret_code;
5481 uint32_t event_id = 0;
5482 uint64_t chan_reg_key;
5483 struct ust_app *app;
5484 struct ust_app_channel *ua_chan;
5485 struct ust_app_session *ua_sess;
5486 struct ust_registry_session *registry;
5487
5488 rcu_read_lock();
5489
5490 /* Lookup application. If not found, there is a code flow error. */
5491 app = find_app_by_notify_sock(sock);
5492 if (!app) {
5493 DBG("Application socket %d is being torn down. Abort event notify",
5494 sock);
5495 ret = 0;
5496 goto error_rcu_unlock;
5497 }
5498
5499 /* Lookup channel by UST object descriptor. */
5500 ua_chan = find_channel_by_objd(app, cobjd);
5501 if (!ua_chan) {
5502 DBG("Application channel is being torn down. Abort event notify");
5503 ret = 0;
5504 goto error_rcu_unlock;
5505 }
5506
5507 assert(ua_chan->session);
5508 ua_sess = ua_chan->session;
5509
5510 registry = get_session_registry(ua_sess);
5511 if (!registry) {
5512 DBG("Application session is being torn down. Abort event notify");
5513 ret = 0;
5514 goto error_rcu_unlock;
5515 }
5516
5517 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5518 chan_reg_key = ua_chan->tracing_channel_id;
5519 } else {
5520 chan_reg_key = ua_chan->key;
5521 }
5522
5523 pthread_mutex_lock(&registry->lock);
5524
5525 /*
5526 * From this point on, this call acquires the ownership of the sig, fields
5527 * and model_emf_uri meaning any free are done inside it if needed. These
5528 * three variables MUST NOT be read/write after this.
5529 */
5530 ret_code = ust_registry_create_event(registry, chan_reg_key,
5531 sobjd, cobjd, name, sig, nr_fields, fields,
5532 loglevel_value, model_emf_uri, ua_sess->buffer_type,
5533 &event_id, app);
5534 sig = NULL;
5535 fields = NULL;
5536 model_emf_uri = NULL;
5537
5538 /*
5539 * The return value is returned to ustctl so in case of an error, the
5540 * application can be notified. In case of an error, it's important not to
5541 * return a negative error or else the application will get closed.
5542 */
5543 ret = ustctl_reply_register_event(sock, event_id, ret_code);
5544 if (ret < 0) {
5545 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5546 ERR("UST app reply event failed with ret %d", ret);
5547 } else {
5548 DBG3("UST app reply event failed. Application died");
5549 }
5550 /*
5551 * No need to wipe the create event since the application socket will
5552 * get close on error hence cleaning up everything by itself.
5553 */
5554 goto error;
5555 }
5556
5557 DBG3("UST registry event %s with id %" PRId32 " added successfully",
5558 name, event_id);
5559
5560 error:
5561 pthread_mutex_unlock(&registry->lock);
5562 error_rcu_unlock:
5563 rcu_read_unlock();
5564 free(sig);
5565 free(fields);
5566 free(model_emf_uri);
5567 return ret;
5568 }
5569
5570 /*
5571 * Add enum to the UST session registry. Once done, this replies to the
5572 * application with the appropriate error code.
5573 *
5574 * The session UST registry lock is acquired within this function.
5575 *
5576 * On success 0 is returned else a negative value.
5577 */
5578 static int add_enum_ust_registry(int sock, int sobjd, char *name,
5579 struct ustctl_enum_entry *entries, size_t nr_entries)
5580 {
5581 int ret = 0, ret_code;
5582 struct ust_app *app;
5583 struct ust_app_session *ua_sess;
5584 struct ust_registry_session *registry;
5585 uint64_t enum_id = -1ULL;
5586
5587 rcu_read_lock();
5588
5589 /* Lookup application. If not found, there is a code flow error. */
5590 app = find_app_by_notify_sock(sock);
5591 if (!app) {
5592 /* Return an error since this is not an error */
5593 DBG("Application socket %d is being torn down. Aborting enum registration",
5594 sock);
5595 free(entries);
5596 goto error_rcu_unlock;
5597 }
5598
5599 /* Lookup session by UST object descriptor. */
5600 ua_sess = find_session_by_objd(app, sobjd);
5601 if (!ua_sess) {
5602 /* Return an error since this is not an error */
5603 DBG("Application session is being torn down (session not found). Aborting enum registration.");
5604 free(entries);
5605 goto error_rcu_unlock;
5606 }
5607
5608 registry = get_session_registry(ua_sess);
5609 if (!registry) {
5610 DBG("Application session is being torn down (registry not found). Aborting enum registration.");
5611 free(entries);
5612 goto error_rcu_unlock;
5613 }
5614
5615 pthread_mutex_lock(&registry->lock);
5616
5617 /*
5618 * From this point on, the callee acquires the ownership of
5619 * entries. The variable entries MUST NOT be read/written after
5620 * call.
5621 */
5622 ret_code = ust_registry_create_or_find_enum(registry, sobjd, name,
5623 entries, nr_entries, &enum_id);
5624 entries = NULL;
5625
5626 /*
5627 * The return value is returned to ustctl so in case of an error, the
5628 * application can be notified. In case of an error, it's important not to
5629 * return a negative error or else the application will get closed.
5630 */
5631 ret = ustctl_reply_register_enum(sock, enum_id, ret_code);
5632 if (ret < 0) {
5633 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5634 ERR("UST app reply enum failed with ret %d", ret);
5635 } else {
5636 DBG3("UST app reply enum failed. Application died");
5637 }
5638 /*
5639 * No need to wipe the create enum since the application socket will
5640 * get close on error hence cleaning up everything by itself.
5641 */
5642 goto error;
5643 }
5644
5645 DBG3("UST registry enum %s added successfully or already found", name);
5646
5647 error:
5648 pthread_mutex_unlock(&registry->lock);
5649 error_rcu_unlock:
5650 rcu_read_unlock();
5651 return ret;
5652 }
5653
5654 /*
5655 * Handle application notification through the given notify socket.
5656 *
5657 * Return 0 on success or else a negative value.
5658 */
5659 int ust_app_recv_notify(int sock)
5660 {
5661 int ret;
5662 enum ustctl_notify_cmd cmd;
5663
5664 DBG3("UST app receiving notify from sock %d", sock);
5665
5666 ret = ustctl_recv_notify(sock, &cmd);
5667 if (ret < 0) {
5668 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5669 ERR("UST app recv notify failed with ret %d", ret);
5670 } else {
5671 DBG3("UST app recv notify failed. Application died");
5672 }
5673 goto error;
5674 }
5675
5676 switch (cmd) {
5677 case USTCTL_NOTIFY_CMD_EVENT:
5678 {
5679 int sobjd, cobjd, loglevel_value;
5680 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
5681 size_t nr_fields;
5682 struct ustctl_field *fields;
5683
5684 DBG2("UST app ustctl register event received");
5685
5686 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
5687 &loglevel_value, &sig, &nr_fields, &fields,
5688 &model_emf_uri);
5689 if (ret < 0) {
5690 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5691 ERR("UST app recv event failed with ret %d", ret);
5692 } else {
5693 DBG3("UST app recv event failed. Application died");
5694 }
5695 goto error;
5696 }
5697
5698 /*
5699 * Add event to the UST registry coming from the notify socket. This
5700 * call will free if needed the sig, fields and model_emf_uri. This
5701 * code path loses the ownsership of these variables and transfer them
5702 * to the this function.
5703 */
5704 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
5705 fields, loglevel_value, model_emf_uri);
5706 if (ret < 0) {
5707 goto error;
5708 }
5709
5710 break;
5711 }
5712 case USTCTL_NOTIFY_CMD_CHANNEL:
5713 {
5714 int sobjd, cobjd;
5715 size_t nr_fields;
5716 struct ustctl_field *fields;
5717
5718 DBG2("UST app ustctl register channel received");
5719
5720 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
5721 &fields);
5722 if (ret < 0) {
5723 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5724 ERR("UST app recv channel failed with ret %d", ret);
5725 } else {
5726 DBG3("UST app recv channel failed. Application died");
5727 }
5728 goto error;
5729 }
5730
5731 /*
5732 * The fields ownership are transfered to this function call meaning
5733 * that if needed it will be freed. After this, it's invalid to access
5734 * fields or clean it up.
5735 */
5736 ret = reply_ust_register_channel(sock, cobjd, nr_fields,
5737 fields);
5738 if (ret < 0) {
5739 goto error;
5740 }
5741
5742 break;
5743 }
5744 case USTCTL_NOTIFY_CMD_ENUM:
5745 {
5746 int sobjd;
5747 char name[LTTNG_UST_SYM_NAME_LEN];
5748 size_t nr_entries;
5749 struct ustctl_enum_entry *entries;
5750
5751 DBG2("UST app ustctl register enum received");
5752
5753 ret = ustctl_recv_register_enum(sock, &sobjd, name,
5754 &entries, &nr_entries);
5755 if (ret < 0) {
5756 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5757 ERR("UST app recv enum failed with ret %d", ret);
5758 } else {
5759 DBG3("UST app recv enum failed. Application died");
5760 }
5761 goto error;
5762 }
5763
5764 /* Callee assumes ownership of entries */
5765 ret = add_enum_ust_registry(sock, sobjd, name,
5766 entries, nr_entries);
5767 if (ret < 0) {
5768 goto error;
5769 }
5770
5771 break;
5772 }
5773 default:
5774 /* Should NEVER happen. */
5775 assert(0);
5776 }
5777
5778 error:
5779 return ret;
5780 }
5781
5782 /*
5783 * Once the notify socket hangs up, this is called. First, it tries to find the
5784 * corresponding application. On failure, the call_rcu to close the socket is
5785 * executed. If an application is found, it tries to delete it from the notify
5786 * socket hash table. Whathever the result, it proceeds to the call_rcu.
5787 *
5788 * Note that an object needs to be allocated here so on ENOMEM failure, the
5789 * call RCU is not done but the rest of the cleanup is.
5790 */
5791 void ust_app_notify_sock_unregister(int sock)
5792 {
5793 int err_enomem = 0;
5794 struct lttng_ht_iter iter;
5795 struct ust_app *app;
5796 struct ust_app_notify_sock_obj *obj;
5797
5798 assert(sock >= 0);
5799
5800 rcu_read_lock();
5801
5802 obj = zmalloc(sizeof(*obj));
5803 if (!obj) {
5804 /*
5805 * An ENOMEM is kind of uncool. If this strikes we continue the
5806 * procedure but the call_rcu will not be called. In this case, we
5807 * accept the fd leak rather than possibly creating an unsynchronized
5808 * state between threads.
5809 *
5810 * TODO: The notify object should be created once the notify socket is
5811 * registered and stored independantely from the ust app object. The
5812 * tricky part is to synchronize the teardown of the application and
5813 * this notify object. Let's keep that in mind so we can avoid this
5814 * kind of shenanigans with ENOMEM in the teardown path.
5815 */
5816 err_enomem = 1;
5817 } else {
5818 obj->fd = sock;
5819 }
5820
5821 DBG("UST app notify socket unregister %d", sock);
5822
5823 /*
5824 * Lookup application by notify socket. If this fails, this means that the
5825 * hash table delete has already been done by the application
5826 * unregistration process so we can safely close the notify socket in a
5827 * call RCU.
5828 */
5829 app = find_app_by_notify_sock(sock);
5830 if (!app) {
5831 goto close_socket;
5832 }
5833
5834 iter.iter.node = &app->notify_sock_n.node;
5835
5836 /*
5837 * Whatever happens here either we fail or succeed, in both cases we have
5838 * to close the socket after a grace period to continue to the call RCU
5839 * here. If the deletion is successful, the application is not visible
5840 * anymore by other threads and is it fails it means that it was already
5841 * deleted from the hash table so either way we just have to close the
5842 * socket.
5843 */
5844 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5845
5846 close_socket:
5847 rcu_read_unlock();
5848
5849 /*
5850 * Close socket after a grace period to avoid for the socket to be reused
5851 * before the application object is freed creating potential race between
5852 * threads trying to add unique in the global hash table.
5853 */
5854 if (!err_enomem) {
5855 call_rcu(&obj->head, close_notify_sock_rcu);
5856 }
5857 }
5858
5859 /*
5860 * Destroy a ust app data structure and free its memory.
5861 */
5862 void ust_app_destroy(struct ust_app *app)
5863 {
5864 if (!app) {
5865 return;
5866 }
5867
5868 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5869 }
5870
5871 /*
5872 * Take a snapshot for a given UST session. The snapshot is sent to the given
5873 * output.
5874 *
5875 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
5876 */
5877 enum lttng_error_code ust_app_snapshot_record(
5878 const struct ltt_ust_session *usess,
5879 const struct consumer_output *output, int wait,
5880 uint64_t nb_packets_per_stream)
5881 {
5882 int ret = 0;
5883 enum lttng_error_code status = LTTNG_OK;
5884 struct lttng_ht_iter iter;
5885 struct ust_app *app;
5886
5887 assert(usess);
5888 assert(output);
5889
5890 rcu_read_lock();
5891
5892 switch (usess->buffer_type) {
5893 case LTTNG_BUFFER_PER_UID:
5894 {
5895 struct buffer_reg_uid *reg;
5896
5897 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5898 struct buffer_reg_channel *reg_chan;
5899 struct consumer_socket *socket;
5900 char *trace_path = NULL;
5901 char pathname[PATH_MAX];
5902
5903 if (!reg->registry->reg.ust->metadata_key) {
5904 /* Skip since no metadata is present */
5905 continue;
5906 }
5907
5908 /* Get consumer socket to use to push the metadata.*/
5909 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5910 usess->consumer);
5911 if (!socket) {
5912 status = LTTNG_ERR_INVALID;
5913 goto error;
5914 }
5915
5916 memset(pathname, 0, sizeof(pathname));
5917 /*
5918 * DEFAULT_UST_TRACE_UID_PATH already contains a path
5919 * separator.
5920 */
5921 ret = snprintf(pathname, sizeof(pathname),
5922 DEFAULT_UST_TRACE_DIR DEFAULT_UST_TRACE_UID_PATH,
5923 reg->uid, reg->bits_per_long);
5924 if (ret < 0) {
5925 PERROR("snprintf snapshot path");
5926 status = LTTNG_ERR_INVALID;
5927 goto error;
5928 }
5929 trace_path = setup_channel_trace_path(usess->consumer, pathname);
5930 if (!trace_path) {
5931 status = LTTNG_ERR_INVALID;
5932 goto error;
5933 }
5934 /* Add the UST default trace dir to path. */
5935 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5936 reg_chan, node.node) {
5937 status = consumer_snapshot_channel(socket,
5938 reg_chan->consumer_key,
5939 output, 0, usess->uid,
5940 usess->gid, trace_path, wait,
5941 nb_packets_per_stream);
5942 if (status != LTTNG_OK) {
5943 free(trace_path);
5944 goto error;
5945 }
5946 }
5947 status = consumer_snapshot_channel(socket,
5948 reg->registry->reg.ust->metadata_key, output, 1,
5949 usess->uid, usess->gid, trace_path, wait, 0);
5950 free(trace_path);
5951 if (status != LTTNG_OK) {
5952 goto error;
5953 }
5954 }
5955 break;
5956 }
5957 case LTTNG_BUFFER_PER_PID:
5958 {
5959 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5960 struct consumer_socket *socket;
5961 struct lttng_ht_iter chan_iter;
5962 struct ust_app_channel *ua_chan;
5963 struct ust_app_session *ua_sess;
5964 struct ust_registry_session *registry;
5965 char *trace_path = NULL;
5966 char pathname[PATH_MAX];
5967
5968 ua_sess = lookup_session_by_app(usess, app);
5969 if (!ua_sess) {
5970 /* Session not associated with this app. */
5971 continue;
5972 }
5973
5974 /* Get the right consumer socket for the application. */
5975 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5976 output);
5977 if (!socket) {
5978 status = LTTNG_ERR_INVALID;
5979 goto error;
5980 }
5981
5982 /* Add the UST default trace dir to path. */
5983 memset(pathname, 0, sizeof(pathname));
5984 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "%s",
5985 ua_sess->path);
5986 if (ret < 0) {
5987 status = LTTNG_ERR_INVALID;
5988 PERROR("snprintf snapshot path");
5989 goto error;
5990 }
5991 trace_path = setup_channel_trace_path(usess->consumer, pathname);
5992 if (!trace_path) {
5993 status = LTTNG_ERR_INVALID;
5994 goto error;
5995 }
5996 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5997 ua_chan, node.node) {
5998 status = consumer_snapshot_channel(socket,
5999 ua_chan->key, output, 0,
6000 ua_sess->effective_credentials
6001 .uid,
6002 ua_sess->effective_credentials
6003 .gid,
6004 trace_path, wait,
6005 nb_packets_per_stream);
6006 switch (status) {
6007 case LTTNG_OK:
6008 break;
6009 case LTTNG_ERR_CHAN_NOT_FOUND:
6010 free(trace_path);
6011 continue;
6012 default:
6013 free(trace_path);
6014 goto error;
6015 }
6016 }
6017
6018 registry = get_session_registry(ua_sess);
6019 if (!registry) {
6020 DBG("Application session is being torn down. Skip application.");
6021 continue;
6022 }
6023 status = consumer_snapshot_channel(socket,
6024 registry->metadata_key, output, 1,
6025 ua_sess->effective_credentials.uid,
6026 ua_sess->effective_credentials.gid,
6027 trace_path, wait, 0);
6028 free(trace_path);
6029 switch (status) {
6030 case LTTNG_OK:
6031 break;
6032 case LTTNG_ERR_CHAN_NOT_FOUND:
6033 continue;
6034 default:
6035 goto error;
6036 }
6037 }
6038 break;
6039 }
6040 default:
6041 assert(0);
6042 break;
6043 }
6044
6045 error:
6046 rcu_read_unlock();
6047 return status;
6048 }
6049
6050 /*
6051 * Return the size taken by one more packet per stream.
6052 */
6053 uint64_t ust_app_get_size_one_more_packet_per_stream(
6054 const struct ltt_ust_session *usess, uint64_t cur_nr_packets)
6055 {
6056 uint64_t tot_size = 0;
6057 struct ust_app *app;
6058 struct lttng_ht_iter iter;
6059
6060 assert(usess);
6061
6062 switch (usess->buffer_type) {
6063 case LTTNG_BUFFER_PER_UID:
6064 {
6065 struct buffer_reg_uid *reg;
6066
6067 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6068 struct buffer_reg_channel *reg_chan;
6069
6070 rcu_read_lock();
6071 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6072 reg_chan, node.node) {
6073 if (cur_nr_packets >= reg_chan->num_subbuf) {
6074 /*
6075 * Don't take channel into account if we
6076 * already grab all its packets.
6077 */
6078 continue;
6079 }
6080 tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
6081 }
6082 rcu_read_unlock();
6083 }
6084 break;
6085 }
6086 case LTTNG_BUFFER_PER_PID:
6087 {
6088 rcu_read_lock();
6089 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6090 struct ust_app_channel *ua_chan;
6091 struct ust_app_session *ua_sess;
6092 struct lttng_ht_iter chan_iter;
6093
6094 ua_sess = lookup_session_by_app(usess, app);
6095 if (!ua_sess) {
6096 /* Session not associated with this app. */
6097 continue;
6098 }
6099
6100 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6101 ua_chan, node.node) {
6102 if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
6103 /*
6104 * Don't take channel into account if we
6105 * already grab all its packets.
6106 */
6107 continue;
6108 }
6109 tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
6110 }
6111 }
6112 rcu_read_unlock();
6113 break;
6114 }
6115 default:
6116 assert(0);
6117 break;
6118 }
6119
6120 return tot_size;
6121 }
6122
6123 int ust_app_uid_get_channel_runtime_stats(uint64_t ust_session_id,
6124 struct cds_list_head *buffer_reg_uid_list,
6125 struct consumer_output *consumer, uint64_t uchan_id,
6126 int overwrite, uint64_t *discarded, uint64_t *lost)
6127 {
6128 int ret;
6129 uint64_t consumer_chan_key;
6130
6131 *discarded = 0;
6132 *lost = 0;
6133
6134 ret = buffer_reg_uid_consumer_channel_key(
6135 buffer_reg_uid_list, uchan_id, &consumer_chan_key);
6136 if (ret < 0) {
6137 /* Not found */
6138 ret = 0;
6139 goto end;
6140 }
6141
6142 if (overwrite) {
6143 ret = consumer_get_lost_packets(ust_session_id,
6144 consumer_chan_key, consumer, lost);
6145 } else {
6146 ret = consumer_get_discarded_events(ust_session_id,
6147 consumer_chan_key, consumer, discarded);
6148 }
6149
6150 end:
6151 return ret;
6152 }
6153
6154 int ust_app_pid_get_channel_runtime_stats(struct ltt_ust_session *usess,
6155 struct ltt_ust_channel *uchan,
6156 struct consumer_output *consumer, int overwrite,
6157 uint64_t *discarded, uint64_t *lost)
6158 {
6159 int ret = 0;
6160 struct lttng_ht_iter iter;
6161 struct lttng_ht_node_str *ua_chan_node;
6162 struct ust_app *app;
6163 struct ust_app_session *ua_sess;
6164 struct ust_app_channel *ua_chan;
6165
6166 *discarded = 0;
6167 *lost = 0;
6168
6169 rcu_read_lock();
6170 /*
6171 * Iterate over every registered applications. Sum counters for
6172 * all applications containing requested session and channel.
6173 */
6174 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6175 struct lttng_ht_iter uiter;
6176
6177 ua_sess = lookup_session_by_app(usess, app);
6178 if (ua_sess == NULL) {
6179 continue;
6180 }
6181
6182 /* Get channel */
6183 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &uiter);
6184 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
6185 /* If the session is found for the app, the channel must be there */
6186 assert(ua_chan_node);
6187
6188 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
6189
6190 if (overwrite) {
6191 uint64_t _lost;
6192
6193 ret = consumer_get_lost_packets(usess->id, ua_chan->key,
6194 consumer, &_lost);
6195 if (ret < 0) {
6196 break;
6197 }
6198 (*lost) += _lost;
6199 } else {
6200 uint64_t _discarded;
6201
6202 ret = consumer_get_discarded_events(usess->id,
6203 ua_chan->key, consumer, &_discarded);
6204 if (ret < 0) {
6205 break;
6206 }
6207 (*discarded) += _discarded;
6208 }
6209 }
6210
6211 rcu_read_unlock();
6212 return ret;
6213 }
6214
6215 static
6216 int ust_app_regenerate_statedump(struct ltt_ust_session *usess,
6217 struct ust_app *app)
6218 {
6219 int ret = 0;
6220 struct ust_app_session *ua_sess;
6221
6222 DBG("Regenerating the metadata for ust app pid %d", app->pid);
6223
6224 rcu_read_lock();
6225
6226 ua_sess = lookup_session_by_app(usess, app);
6227 if (ua_sess == NULL) {
6228 /* The session is in teardown process. Ignore and continue. */
6229 goto end;
6230 }
6231
6232 pthread_mutex_lock(&ua_sess->lock);
6233
6234 if (ua_sess->deleted) {
6235 goto end_unlock;
6236 }
6237
6238 pthread_mutex_lock(&app->sock_lock);
6239 ret = ustctl_regenerate_statedump(app->sock, ua_sess->handle);
6240 pthread_mutex_unlock(&app->sock_lock);
6241
6242 end_unlock:
6243 pthread_mutex_unlock(&ua_sess->lock);
6244
6245 end:
6246 rcu_read_unlock();
6247 health_code_update();
6248 return ret;
6249 }
6250
6251 /*
6252 * Regenerate the statedump for each app in the session.
6253 */
6254 int ust_app_regenerate_statedump_all(struct ltt_ust_session *usess)
6255 {
6256 int ret = 0;
6257 struct lttng_ht_iter iter;
6258 struct ust_app *app;
6259
6260 DBG("Regenerating the metadata for all UST apps");
6261
6262 rcu_read_lock();
6263
6264 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6265 if (!app->compatible) {
6266 continue;
6267 }
6268
6269 ret = ust_app_regenerate_statedump(usess, app);
6270 if (ret < 0) {
6271 /* Continue to the next app even on error */
6272 continue;
6273 }
6274 }
6275
6276 rcu_read_unlock();
6277
6278 return 0;
6279 }
6280
6281 /*
6282 * Rotate all the channels of a session.
6283 *
6284 * Return LTTNG_OK on success or else an LTTng error code.
6285 */
6286 enum lttng_error_code ust_app_rotate_session(struct ltt_session *session)
6287 {
6288 int ret;
6289 enum lttng_error_code cmd_ret = LTTNG_OK;
6290 struct lttng_ht_iter iter;
6291 struct ust_app *app;
6292 struct ltt_ust_session *usess = session->ust_session;
6293
6294 assert(usess);
6295
6296 rcu_read_lock();
6297
6298 switch (usess->buffer_type) {
6299 case LTTNG_BUFFER_PER_UID:
6300 {
6301 struct buffer_reg_uid *reg;
6302
6303 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6304 struct buffer_reg_channel *reg_chan;
6305 struct consumer_socket *socket;
6306
6307 /* Get consumer socket to use to push the metadata.*/
6308 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
6309 usess->consumer);
6310 if (!socket) {
6311 cmd_ret = LTTNG_ERR_INVALID;
6312 goto error;
6313 }
6314
6315 /* Rotate the data channels. */
6316 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6317 reg_chan, node.node) {
6318 ret = consumer_rotate_channel(socket,
6319 reg_chan->consumer_key,
6320 usess->uid, usess->gid,
6321 usess->consumer,
6322 /* is_metadata_channel */ false);
6323 if (ret < 0) {
6324 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6325 goto error;
6326 }
6327 }
6328
6329 (void) push_metadata(reg->registry->reg.ust, usess->consumer);
6330
6331 ret = consumer_rotate_channel(socket,
6332 reg->registry->reg.ust->metadata_key,
6333 usess->uid, usess->gid,
6334 usess->consumer,
6335 /* is_metadata_channel */ true);
6336 if (ret < 0) {
6337 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6338 goto error;
6339 }
6340 }
6341 break;
6342 }
6343 case LTTNG_BUFFER_PER_PID:
6344 {
6345 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6346 struct consumer_socket *socket;
6347 struct lttng_ht_iter chan_iter;
6348 struct ust_app_channel *ua_chan;
6349 struct ust_app_session *ua_sess;
6350 struct ust_registry_session *registry;
6351
6352 ua_sess = lookup_session_by_app(usess, app);
6353 if (!ua_sess) {
6354 /* Session not associated with this app. */
6355 continue;
6356 }
6357
6358 /* Get the right consumer socket for the application. */
6359 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6360 usess->consumer);
6361 if (!socket) {
6362 cmd_ret = LTTNG_ERR_INVALID;
6363 goto error;
6364 }
6365
6366 registry = get_session_registry(ua_sess);
6367 if (!registry) {
6368 DBG("Application session is being torn down. Skip application.");
6369 continue;
6370 }
6371
6372 /* Rotate the data channels. */
6373 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6374 ua_chan, node.node) {
6375 ret = consumer_rotate_channel(socket,
6376 ua_chan->key,
6377 ua_sess->effective_credentials
6378 .uid,
6379 ua_sess->effective_credentials
6380 .gid,
6381 ua_sess->consumer,
6382 /* is_metadata_channel */ false);
6383 if (ret < 0) {
6384 /* Per-PID buffer and application going away. */
6385 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6386 continue;
6387 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6388 goto error;
6389 }
6390 }
6391
6392 /* Rotate the metadata channel. */
6393 (void) push_metadata(registry, usess->consumer);
6394 ret = consumer_rotate_channel(socket,
6395 registry->metadata_key,
6396 ua_sess->effective_credentials.uid,
6397 ua_sess->effective_credentials.gid,
6398 ua_sess->consumer,
6399 /* is_metadata_channel */ true);
6400 if (ret < 0) {
6401 /* Per-PID buffer and application going away. */
6402 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6403 continue;
6404 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6405 goto error;
6406 }
6407 }
6408 break;
6409 }
6410 default:
6411 assert(0);
6412 break;
6413 }
6414
6415 cmd_ret = LTTNG_OK;
6416
6417 error:
6418 rcu_read_unlock();
6419 return cmd_ret;
6420 }
6421
6422 enum lttng_error_code ust_app_create_channel_subdirectories(
6423 const struct ltt_ust_session *usess)
6424 {
6425 enum lttng_error_code ret = LTTNG_OK;
6426 struct lttng_ht_iter iter;
6427 enum lttng_trace_chunk_status chunk_status;
6428 char *pathname_index;
6429 int fmt_ret;
6430
6431 assert(usess->current_trace_chunk);
6432 rcu_read_lock();
6433
6434 switch (usess->buffer_type) {
6435 case LTTNG_BUFFER_PER_UID:
6436 {
6437 struct buffer_reg_uid *reg;
6438
6439 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6440 fmt_ret = asprintf(&pathname_index,
6441 DEFAULT_UST_TRACE_DIR DEFAULT_UST_TRACE_UID_PATH "/" DEFAULT_INDEX_DIR,
6442 reg->uid, reg->bits_per_long);
6443 if (fmt_ret < 0) {
6444 ERR("Failed to format channel index directory");
6445 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6446 goto error;
6447 }
6448
6449 /*
6450 * Create the index subdirectory which will take care
6451 * of implicitly creating the channel's path.
6452 */
6453 chunk_status = lttng_trace_chunk_create_subdirectory(
6454 usess->current_trace_chunk,
6455 pathname_index);
6456 free(pathname_index);
6457 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6458 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6459 goto error;
6460 }
6461 }
6462 break;
6463 }
6464 case LTTNG_BUFFER_PER_PID:
6465 {
6466 struct ust_app *app;
6467
6468 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
6469 pid_n.node) {
6470 struct ust_app_session *ua_sess;
6471 struct ust_registry_session *registry;
6472
6473 ua_sess = lookup_session_by_app(usess, app);
6474 if (!ua_sess) {
6475 /* Session not associated with this app. */
6476 continue;
6477 }
6478
6479 registry = get_session_registry(ua_sess);
6480 if (!registry) {
6481 DBG("Application session is being torn down. Skip application.");
6482 continue;
6483 }
6484
6485 fmt_ret = asprintf(&pathname_index,
6486 DEFAULT_UST_TRACE_DIR "%s/" DEFAULT_INDEX_DIR,
6487 ua_sess->path);
6488 if (fmt_ret < 0) {
6489 ERR("Failed to format channel index directory");
6490 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6491 goto error;
6492 }
6493 /*
6494 * Create the index subdirectory which will take care
6495 * of implicitly creating the channel's path.
6496 */
6497 chunk_status = lttng_trace_chunk_create_subdirectory(
6498 usess->current_trace_chunk,
6499 pathname_index);
6500 free(pathname_index);
6501 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6502 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6503 goto error;
6504 }
6505 }
6506 break;
6507 }
6508 default:
6509 abort();
6510 }
6511
6512 ret = LTTNG_OK;
6513 error:
6514 rcu_read_unlock();
6515 return ret;
6516 }
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