58308dec801f0bef53dedada426ba7bd574e51e8
[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 <signal.h>
31
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34
35 #include "buffer-registry.h"
36 #include "fd-limit.h"
37 #include "health-sessiond.h"
38 #include "ust-app.h"
39 #include "ust-consumer.h"
40 #include "lttng-ust-ctl.h"
41 #include "lttng-ust-error.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 * Do not hold the registry lock while communicating with the consumerd, because
745 * doing so causes inter-process deadlocks between consumerd and sessiond with
746 * the metadata request notification.
747 *
748 * Return 0 on success else a negative value.
749 */
750 static int close_metadata(struct ust_registry_session *registry,
751 struct consumer_output *consumer)
752 {
753 int ret;
754 struct consumer_socket *socket;
755 uint64_t metadata_key;
756 bool registry_was_already_closed;
757
758 assert(registry);
759 assert(consumer);
760
761 rcu_read_lock();
762
763 pthread_mutex_lock(&registry->lock);
764 metadata_key = registry->metadata_key;
765 registry_was_already_closed = registry->metadata_closed;
766 if (metadata_key != 0) {
767 /*
768 * Metadata closed. Even on error this means that the consumer
769 * is not responding or not found so either way a second close
770 * should NOT be emit for this registry.
771 */
772 registry->metadata_closed = 1;
773 }
774 pthread_mutex_unlock(&registry->lock);
775
776 if (metadata_key == 0 || registry_was_already_closed) {
777 ret = 0;
778 goto end;
779 }
780
781 /* Get consumer socket to use to push the metadata.*/
782 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
783 consumer);
784 if (!socket) {
785 ret = -1;
786 goto end;
787 }
788
789 ret = consumer_close_metadata(socket, metadata_key);
790 if (ret < 0) {
791 goto end;
792 }
793
794 end:
795 rcu_read_unlock();
796 return ret;
797 }
798
799 /*
800 * We need to execute ht_destroy outside of RCU read-side critical
801 * section and outside of call_rcu thread, so we postpone its execution
802 * using ht_cleanup_push. It is simpler than to change the semantic of
803 * the many callers of delete_ust_app_session().
804 */
805 static
806 void delete_ust_app_session_rcu(struct rcu_head *head)
807 {
808 struct ust_app_session *ua_sess =
809 caa_container_of(head, struct ust_app_session, rcu_head);
810
811 ht_cleanup_push(ua_sess->channels);
812 free(ua_sess);
813 }
814
815 /*
816 * Delete ust app session safely. RCU read lock must be held before calling
817 * this function.
818 *
819 * The session list lock must be held by the caller.
820 */
821 static
822 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
823 struct ust_app *app)
824 {
825 int ret;
826 struct lttng_ht_iter iter;
827 struct ust_app_channel *ua_chan;
828 struct ust_registry_session *registry;
829
830 assert(ua_sess);
831
832 pthread_mutex_lock(&ua_sess->lock);
833
834 assert(!ua_sess->deleted);
835 ua_sess->deleted = true;
836
837 registry = get_session_registry(ua_sess);
838 /* Registry can be null on error path during initialization. */
839 if (registry) {
840 /* Push metadata for application before freeing the application. */
841 (void) push_metadata(registry, ua_sess->consumer);
842
843 /*
844 * Don't ask to close metadata for global per UID buffers. Close
845 * metadata only on destroy trace session in this case. Also, the
846 * previous push metadata could have flag the metadata registry to
847 * close so don't send a close command if closed.
848 */
849 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
850 /* And ask to close it for this session registry. */
851 (void) close_metadata(registry, ua_sess->consumer);
852 }
853 }
854
855 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
856 node.node) {
857 ret = lttng_ht_del(ua_sess->channels, &iter);
858 assert(!ret);
859 delete_ust_app_channel(sock, ua_chan, app);
860 }
861
862 /* In case of per PID, the registry is kept in the session. */
863 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
864 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
865 if (reg_pid) {
866 /*
867 * Registry can be null on error path during
868 * initialization.
869 */
870 buffer_reg_pid_remove(reg_pid);
871 buffer_reg_pid_destroy(reg_pid);
872 }
873 }
874
875 if (ua_sess->handle != -1) {
876 pthread_mutex_lock(&app->sock_lock);
877 ret = ustctl_release_handle(sock, ua_sess->handle);
878 pthread_mutex_unlock(&app->sock_lock);
879 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
880 ERR("UST app sock %d release session handle failed with ret %d",
881 sock, ret);
882 }
883 /* Remove session from application UST object descriptor. */
884 iter.iter.node = &ua_sess->ust_objd_node.node;
885 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
886 assert(!ret);
887 }
888
889 pthread_mutex_unlock(&ua_sess->lock);
890
891 consumer_output_put(ua_sess->consumer);
892
893 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
894 }
895
896 /*
897 * Delete a traceable application structure from the global list. Never call
898 * this function outside of a call_rcu call.
899 *
900 * RCU read side lock should _NOT_ be held when calling this function.
901 */
902 static
903 void delete_ust_app(struct ust_app *app)
904 {
905 int ret, sock;
906 struct ust_app_session *ua_sess, *tmp_ua_sess;
907
908 /*
909 * The session list lock must be held during this function to guarantee
910 * the existence of ua_sess.
911 */
912 session_lock_list();
913 /* Delete ust app sessions info */
914 sock = app->sock;
915 app->sock = -1;
916
917 /* Wipe sessions */
918 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
919 teardown_node) {
920 /* Free every object in the session and the session. */
921 rcu_read_lock();
922 delete_ust_app_session(sock, ua_sess, app);
923 rcu_read_unlock();
924 }
925
926 ht_cleanup_push(app->sessions);
927 ht_cleanup_push(app->ust_sessions_objd);
928 ht_cleanup_push(app->ust_objd);
929
930 /*
931 * Wait until we have deleted the application from the sock hash table
932 * before closing this socket, otherwise an application could re-use the
933 * socket ID and race with the teardown, using the same hash table entry.
934 *
935 * It's OK to leave the close in call_rcu. We want it to stay unique for
936 * all RCU readers that could run concurrently with unregister app,
937 * therefore we _need_ to only close that socket after a grace period. So
938 * it should stay in this RCU callback.
939 *
940 * This close() is a very important step of the synchronization model so
941 * every modification to this function must be carefully reviewed.
942 */
943 ret = close(sock);
944 if (ret) {
945 PERROR("close");
946 }
947 lttng_fd_put(LTTNG_FD_APPS, 1);
948
949 DBG2("UST app pid %d deleted", app->pid);
950 free(app);
951 session_unlock_list();
952 }
953
954 /*
955 * URCU intermediate call to delete an UST app.
956 */
957 static
958 void delete_ust_app_rcu(struct rcu_head *head)
959 {
960 struct lttng_ht_node_ulong *node =
961 caa_container_of(head, struct lttng_ht_node_ulong, head);
962 struct ust_app *app =
963 caa_container_of(node, struct ust_app, pid_n);
964
965 DBG3("Call RCU deleting app PID %d", app->pid);
966 delete_ust_app(app);
967 }
968
969 /*
970 * Delete the session from the application ht and delete the data structure by
971 * freeing every object inside and releasing them.
972 *
973 * The session list lock must be held by the caller.
974 */
975 static void destroy_app_session(struct ust_app *app,
976 struct ust_app_session *ua_sess)
977 {
978 int ret;
979 struct lttng_ht_iter iter;
980
981 assert(app);
982 assert(ua_sess);
983
984 iter.iter.node = &ua_sess->node.node;
985 ret = lttng_ht_del(app->sessions, &iter);
986 if (ret) {
987 /* Already scheduled for teardown. */
988 goto end;
989 }
990
991 /* Once deleted, free the data structure. */
992 delete_ust_app_session(app->sock, ua_sess, app);
993
994 end:
995 return;
996 }
997
998 /*
999 * Alloc new UST app session.
1000 */
1001 static
1002 struct ust_app_session *alloc_ust_app_session(void)
1003 {
1004 struct ust_app_session *ua_sess;
1005
1006 /* Init most of the default value by allocating and zeroing */
1007 ua_sess = zmalloc(sizeof(struct ust_app_session));
1008 if (ua_sess == NULL) {
1009 PERROR("malloc");
1010 goto error_free;
1011 }
1012
1013 ua_sess->handle = -1;
1014 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1015 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1016 pthread_mutex_init(&ua_sess->lock, NULL);
1017
1018 return ua_sess;
1019
1020 error_free:
1021 return NULL;
1022 }
1023
1024 /*
1025 * Alloc new UST app channel.
1026 */
1027 static
1028 struct ust_app_channel *alloc_ust_app_channel(char *name,
1029 struct ust_app_session *ua_sess,
1030 struct lttng_ust_channel_attr *attr)
1031 {
1032 struct ust_app_channel *ua_chan;
1033
1034 /* Init most of the default value by allocating and zeroing */
1035 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1036 if (ua_chan == NULL) {
1037 PERROR("malloc");
1038 goto error;
1039 }
1040
1041 /* Setup channel name */
1042 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1043 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1044
1045 ua_chan->enabled = 1;
1046 ua_chan->handle = -1;
1047 ua_chan->session = ua_sess;
1048 ua_chan->key = get_next_channel_key();
1049 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1050 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1051 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1052
1053 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1054 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1055
1056 /* Copy attributes */
1057 if (attr) {
1058 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1059 ua_chan->attr.subbuf_size = attr->subbuf_size;
1060 ua_chan->attr.num_subbuf = attr->num_subbuf;
1061 ua_chan->attr.overwrite = attr->overwrite;
1062 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1063 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1064 ua_chan->attr.output = attr->output;
1065 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1066 }
1067 /* By default, the channel is a per cpu channel. */
1068 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1069
1070 DBG3("UST app channel %s allocated", ua_chan->name);
1071
1072 return ua_chan;
1073
1074 error:
1075 return NULL;
1076 }
1077
1078 /*
1079 * Allocate and initialize a UST app stream.
1080 *
1081 * Return newly allocated stream pointer or NULL on error.
1082 */
1083 struct ust_app_stream *ust_app_alloc_stream(void)
1084 {
1085 struct ust_app_stream *stream = NULL;
1086
1087 stream = zmalloc(sizeof(*stream));
1088 if (stream == NULL) {
1089 PERROR("zmalloc ust app stream");
1090 goto error;
1091 }
1092
1093 /* Zero could be a valid value for a handle so flag it to -1. */
1094 stream->handle = -1;
1095
1096 error:
1097 return stream;
1098 }
1099
1100 /*
1101 * Alloc new UST app event.
1102 */
1103 static
1104 struct ust_app_event *alloc_ust_app_event(char *name,
1105 struct lttng_ust_event *attr)
1106 {
1107 struct ust_app_event *ua_event;
1108
1109 /* Init most of the default value by allocating and zeroing */
1110 ua_event = zmalloc(sizeof(struct ust_app_event));
1111 if (ua_event == NULL) {
1112 PERROR("Failed to allocate ust_app_event structure");
1113 goto error;
1114 }
1115
1116 ua_event->enabled = 1;
1117 strncpy(ua_event->name, name, sizeof(ua_event->name));
1118 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1119 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1120
1121 /* Copy attributes */
1122 if (attr) {
1123 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1124 }
1125
1126 DBG3("UST app event %s allocated", ua_event->name);
1127
1128 return ua_event;
1129
1130 error:
1131 return NULL;
1132 }
1133
1134 /*
1135 * Alloc new UST app context.
1136 */
1137 static
1138 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1139 {
1140 struct ust_app_ctx *ua_ctx;
1141
1142 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1143 if (ua_ctx == NULL) {
1144 goto error;
1145 }
1146
1147 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1148
1149 if (uctx) {
1150 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1151 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1152 char *provider_name = NULL, *ctx_name = NULL;
1153
1154 provider_name = strdup(uctx->u.app_ctx.provider_name);
1155 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1156 if (!provider_name || !ctx_name) {
1157 free(provider_name);
1158 free(ctx_name);
1159 goto error;
1160 }
1161
1162 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1163 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1164 }
1165 }
1166
1167 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1168 return ua_ctx;
1169 error:
1170 free(ua_ctx);
1171 return NULL;
1172 }
1173
1174 /*
1175 * Allocate a filter and copy the given original filter.
1176 *
1177 * Return allocated filter or NULL on error.
1178 */
1179 static struct lttng_filter_bytecode *copy_filter_bytecode(
1180 struct lttng_filter_bytecode *orig_f)
1181 {
1182 struct lttng_filter_bytecode *filter = NULL;
1183
1184 /* Copy filter bytecode */
1185 filter = zmalloc(sizeof(*filter) + orig_f->len);
1186 if (!filter) {
1187 PERROR("zmalloc alloc filter bytecode");
1188 goto error;
1189 }
1190
1191 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1192
1193 error:
1194 return filter;
1195 }
1196
1197 /*
1198 * Create a liblttng-ust filter bytecode from given bytecode.
1199 *
1200 * Return allocated filter or NULL on error.
1201 */
1202 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1203 struct lttng_filter_bytecode *orig_f)
1204 {
1205 struct lttng_ust_filter_bytecode *filter = NULL;
1206
1207 /* Copy filter bytecode */
1208 filter = zmalloc(sizeof(*filter) + orig_f->len);
1209 if (!filter) {
1210 PERROR("zmalloc alloc ust filter bytecode");
1211 goto error;
1212 }
1213
1214 assert(sizeof(struct lttng_filter_bytecode) ==
1215 sizeof(struct lttng_ust_filter_bytecode));
1216 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1217 error:
1218 return filter;
1219 }
1220
1221 /*
1222 * Find an ust_app using the sock and return it. RCU read side lock must be
1223 * held before calling this helper function.
1224 */
1225 struct ust_app *ust_app_find_by_sock(int sock)
1226 {
1227 struct lttng_ht_node_ulong *node;
1228 struct lttng_ht_iter iter;
1229
1230 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1231 node = lttng_ht_iter_get_node_ulong(&iter);
1232 if (node == NULL) {
1233 DBG2("UST app find by sock %d not found", sock);
1234 goto error;
1235 }
1236
1237 return caa_container_of(node, struct ust_app, sock_n);
1238
1239 error:
1240 return NULL;
1241 }
1242
1243 /*
1244 * Find an ust_app using the notify sock and return it. RCU read side lock must
1245 * be held before calling this helper function.
1246 */
1247 static struct ust_app *find_app_by_notify_sock(int sock)
1248 {
1249 struct lttng_ht_node_ulong *node;
1250 struct lttng_ht_iter iter;
1251
1252 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1253 &iter);
1254 node = lttng_ht_iter_get_node_ulong(&iter);
1255 if (node == NULL) {
1256 DBG2("UST app find by notify sock %d not found", sock);
1257 goto error;
1258 }
1259
1260 return caa_container_of(node, struct ust_app, notify_sock_n);
1261
1262 error:
1263 return NULL;
1264 }
1265
1266 /*
1267 * Lookup for an ust app event based on event name, filter bytecode and the
1268 * event loglevel.
1269 *
1270 * Return an ust_app_event object or NULL on error.
1271 */
1272 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1273 const char *name, const struct lttng_filter_bytecode *filter,
1274 int loglevel_value,
1275 const struct lttng_event_exclusion *exclusion)
1276 {
1277 struct lttng_ht_iter iter;
1278 struct lttng_ht_node_str *node;
1279 struct ust_app_event *event = NULL;
1280 struct ust_app_ht_key key;
1281
1282 assert(name);
1283 assert(ht);
1284
1285 /* Setup key for event lookup. */
1286 key.name = name;
1287 key.filter = filter;
1288 key.loglevel_type = loglevel_value;
1289 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1290 key.exclusion = exclusion;
1291
1292 /* Lookup using the event name as hash and a custom match fct. */
1293 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1294 ht_match_ust_app_event, &key, &iter.iter);
1295 node = lttng_ht_iter_get_node_str(&iter);
1296 if (node == NULL) {
1297 goto end;
1298 }
1299
1300 event = caa_container_of(node, struct ust_app_event, node);
1301
1302 end:
1303 return event;
1304 }
1305
1306 /*
1307 * Create the channel context on the tracer.
1308 *
1309 * Called with UST app session lock held.
1310 */
1311 static
1312 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1313 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1314 {
1315 int ret;
1316
1317 health_code_update();
1318
1319 pthread_mutex_lock(&app->sock_lock);
1320 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1321 ua_chan->obj, &ua_ctx->obj);
1322 pthread_mutex_unlock(&app->sock_lock);
1323 if (ret < 0) {
1324 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1325 ERR("UST app create channel context failed for app (pid: %d) "
1326 "with ret %d", app->pid, ret);
1327 } else {
1328 /*
1329 * This is normal behavior, an application can die during the
1330 * creation process. Don't report an error so the execution can
1331 * continue normally.
1332 */
1333 ret = 0;
1334 DBG3("UST app add context failed. Application is dead.");
1335 }
1336 goto error;
1337 }
1338
1339 ua_ctx->handle = ua_ctx->obj->handle;
1340
1341 DBG2("UST app context handle %d created successfully for channel %s",
1342 ua_ctx->handle, ua_chan->name);
1343
1344 error:
1345 health_code_update();
1346 return ret;
1347 }
1348
1349 /*
1350 * Set the filter on the tracer.
1351 */
1352 static
1353 int set_ust_event_filter(struct ust_app_event *ua_event,
1354 struct ust_app *app)
1355 {
1356 int ret;
1357 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1358
1359 health_code_update();
1360
1361 if (!ua_event->filter) {
1362 ret = 0;
1363 goto error;
1364 }
1365
1366 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1367 if (!ust_bytecode) {
1368 ret = -LTTNG_ERR_NOMEM;
1369 goto error;
1370 }
1371 pthread_mutex_lock(&app->sock_lock);
1372 ret = ustctl_set_filter(app->sock, ust_bytecode,
1373 ua_event->obj);
1374 pthread_mutex_unlock(&app->sock_lock);
1375 if (ret < 0) {
1376 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1377 ERR("UST app event %s filter failed for app (pid: %d) "
1378 "with ret %d", ua_event->attr.name, app->pid, ret);
1379 } else {
1380 /*
1381 * This is normal behavior, an application can die during the
1382 * creation process. Don't report an error so the execution can
1383 * continue normally.
1384 */
1385 ret = 0;
1386 DBG3("UST app filter event failed. Application is dead.");
1387 }
1388 goto error;
1389 }
1390
1391 DBG2("UST filter set successfully for event %s", ua_event->name);
1392
1393 error:
1394 health_code_update();
1395 free(ust_bytecode);
1396 return ret;
1397 }
1398
1399 static
1400 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1401 struct lttng_event_exclusion *exclusion)
1402 {
1403 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1404 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1405 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1406
1407 ust_exclusion = zmalloc(exclusion_alloc_size);
1408 if (!ust_exclusion) {
1409 PERROR("malloc");
1410 goto end;
1411 }
1412
1413 assert(sizeof(struct lttng_event_exclusion) ==
1414 sizeof(struct lttng_ust_event_exclusion));
1415 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1416 end:
1417 return ust_exclusion;
1418 }
1419
1420 /*
1421 * Set event exclusions on the tracer.
1422 */
1423 static
1424 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1425 struct ust_app *app)
1426 {
1427 int ret;
1428 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1429
1430 health_code_update();
1431
1432 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1433 ret = 0;
1434 goto error;
1435 }
1436
1437 ust_exclusion = create_ust_exclusion_from_exclusion(
1438 ua_event->exclusion);
1439 if (!ust_exclusion) {
1440 ret = -LTTNG_ERR_NOMEM;
1441 goto error;
1442 }
1443 pthread_mutex_lock(&app->sock_lock);
1444 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1445 pthread_mutex_unlock(&app->sock_lock);
1446 if (ret < 0) {
1447 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1448 ERR("UST app event %s exclusions failed for app (pid: %d) "
1449 "with ret %d", ua_event->attr.name, app->pid, ret);
1450 } else {
1451 /*
1452 * This is normal behavior, an application can die during the
1453 * creation process. Don't report an error so the execution can
1454 * continue normally.
1455 */
1456 ret = 0;
1457 DBG3("UST app event exclusion failed. Application is dead.");
1458 }
1459 goto error;
1460 }
1461
1462 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1463
1464 error:
1465 health_code_update();
1466 free(ust_exclusion);
1467 return ret;
1468 }
1469
1470 /*
1471 * Disable the specified event on to UST tracer for the UST session.
1472 */
1473 static int disable_ust_event(struct ust_app *app,
1474 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1475 {
1476 int ret;
1477
1478 health_code_update();
1479
1480 pthread_mutex_lock(&app->sock_lock);
1481 ret = ustctl_disable(app->sock, ua_event->obj);
1482 pthread_mutex_unlock(&app->sock_lock);
1483 if (ret < 0) {
1484 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1485 ERR("UST app event %s disable failed for app (pid: %d) "
1486 "and session handle %d with ret %d",
1487 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1488 } else {
1489 /*
1490 * This is normal behavior, an application can die during the
1491 * creation process. Don't report an error so the execution can
1492 * continue normally.
1493 */
1494 ret = 0;
1495 DBG3("UST app disable event failed. Application is dead.");
1496 }
1497 goto error;
1498 }
1499
1500 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1501 ua_event->attr.name, app->pid);
1502
1503 error:
1504 health_code_update();
1505 return ret;
1506 }
1507
1508 /*
1509 * Disable the specified channel on to UST tracer for the UST session.
1510 */
1511 static int disable_ust_channel(struct ust_app *app,
1512 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1513 {
1514 int ret;
1515
1516 health_code_update();
1517
1518 pthread_mutex_lock(&app->sock_lock);
1519 ret = ustctl_disable(app->sock, ua_chan->obj);
1520 pthread_mutex_unlock(&app->sock_lock);
1521 if (ret < 0) {
1522 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1523 ERR("UST app channel %s disable failed for app (pid: %d) "
1524 "and session handle %d with ret %d",
1525 ua_chan->name, app->pid, ua_sess->handle, ret);
1526 } else {
1527 /*
1528 * This is normal behavior, an application can die during the
1529 * creation process. Don't report an error so the execution can
1530 * continue normally.
1531 */
1532 ret = 0;
1533 DBG3("UST app disable channel failed. Application is dead.");
1534 }
1535 goto error;
1536 }
1537
1538 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1539 ua_chan->name, app->pid);
1540
1541 error:
1542 health_code_update();
1543 return ret;
1544 }
1545
1546 /*
1547 * Enable the specified channel on to UST tracer for the UST session.
1548 */
1549 static int enable_ust_channel(struct ust_app *app,
1550 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1551 {
1552 int ret;
1553
1554 health_code_update();
1555
1556 pthread_mutex_lock(&app->sock_lock);
1557 ret = ustctl_enable(app->sock, ua_chan->obj);
1558 pthread_mutex_unlock(&app->sock_lock);
1559 if (ret < 0) {
1560 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1561 ERR("UST app channel %s enable failed for app (pid: %d) "
1562 "and session handle %d with ret %d",
1563 ua_chan->name, app->pid, ua_sess->handle, ret);
1564 } else {
1565 /*
1566 * This is normal behavior, an application can die during the
1567 * creation process. Don't report an error so the execution can
1568 * continue normally.
1569 */
1570 ret = 0;
1571 DBG3("UST app enable channel failed. Application is dead.");
1572 }
1573 goto error;
1574 }
1575
1576 ua_chan->enabled = 1;
1577
1578 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1579 ua_chan->name, app->pid);
1580
1581 error:
1582 health_code_update();
1583 return ret;
1584 }
1585
1586 /*
1587 * Enable the specified event on to UST tracer for the UST session.
1588 */
1589 static int enable_ust_event(struct ust_app *app,
1590 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1591 {
1592 int ret;
1593
1594 health_code_update();
1595
1596 pthread_mutex_lock(&app->sock_lock);
1597 ret = ustctl_enable(app->sock, ua_event->obj);
1598 pthread_mutex_unlock(&app->sock_lock);
1599 if (ret < 0) {
1600 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1601 ERR("UST app event %s enable failed for app (pid: %d) "
1602 "and session handle %d with ret %d",
1603 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1604 } else {
1605 /*
1606 * This is normal behavior, an application can die during the
1607 * creation process. Don't report an error so the execution can
1608 * continue normally.
1609 */
1610 ret = 0;
1611 DBG3("UST app enable event failed. Application is dead.");
1612 }
1613 goto error;
1614 }
1615
1616 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1617 ua_event->attr.name, app->pid);
1618
1619 error:
1620 health_code_update();
1621 return ret;
1622 }
1623
1624 /*
1625 * Send channel and stream buffer to application.
1626 *
1627 * Return 0 on success. On error, a negative value is returned.
1628 */
1629 static int send_channel_pid_to_ust(struct ust_app *app,
1630 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1631 {
1632 int ret;
1633 struct ust_app_stream *stream, *stmp;
1634
1635 assert(app);
1636 assert(ua_sess);
1637 assert(ua_chan);
1638
1639 health_code_update();
1640
1641 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1642 app->sock);
1643
1644 /* Send channel to the application. */
1645 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1646 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1647 ret = -ENOTCONN; /* Caused by app exiting. */
1648 goto error;
1649 } else if (ret < 0) {
1650 goto error;
1651 }
1652
1653 health_code_update();
1654
1655 /* Send all streams to application. */
1656 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1657 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1658 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1659 ret = -ENOTCONN; /* Caused by app exiting. */
1660 goto error;
1661 } else if (ret < 0) {
1662 goto error;
1663 }
1664 /* We don't need the stream anymore once sent to the tracer. */
1665 cds_list_del(&stream->list);
1666 delete_ust_app_stream(-1, stream, app);
1667 }
1668 /* Flag the channel that it is sent to the application. */
1669 ua_chan->is_sent = 1;
1670
1671 error:
1672 health_code_update();
1673 return ret;
1674 }
1675
1676 /*
1677 * Create the specified event onto the UST tracer for a UST session.
1678 *
1679 * Should be called with session mutex held.
1680 */
1681 static
1682 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1683 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1684 {
1685 int ret = 0;
1686
1687 health_code_update();
1688
1689 /* Create UST event on tracer */
1690 pthread_mutex_lock(&app->sock_lock);
1691 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1692 &ua_event->obj);
1693 pthread_mutex_unlock(&app->sock_lock);
1694 if (ret < 0) {
1695 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1696 abort();
1697 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1698 ua_event->attr.name, app->pid, ret);
1699 } else {
1700 /*
1701 * This is normal behavior, an application can die during the
1702 * creation process. Don't report an error so the execution can
1703 * continue normally.
1704 */
1705 ret = 0;
1706 DBG3("UST app create event failed. Application is dead.");
1707 }
1708 goto error;
1709 }
1710
1711 ua_event->handle = ua_event->obj->handle;
1712
1713 DBG2("UST app event %s created successfully for pid:%d",
1714 ua_event->attr.name, app->pid);
1715
1716 health_code_update();
1717
1718 /* Set filter if one is present. */
1719 if (ua_event->filter) {
1720 ret = set_ust_event_filter(ua_event, app);
1721 if (ret < 0) {
1722 goto error;
1723 }
1724 }
1725
1726 /* Set exclusions for the event */
1727 if (ua_event->exclusion) {
1728 ret = set_ust_event_exclusion(ua_event, app);
1729 if (ret < 0) {
1730 goto error;
1731 }
1732 }
1733
1734 /* If event not enabled, disable it on the tracer */
1735 if (ua_event->enabled) {
1736 /*
1737 * We now need to explicitly enable the event, since it
1738 * is now disabled at creation.
1739 */
1740 ret = enable_ust_event(app, ua_sess, ua_event);
1741 if (ret < 0) {
1742 /*
1743 * If we hit an EPERM, something is wrong with our enable call. If
1744 * we get an EEXIST, there is a problem on the tracer side since we
1745 * just created it.
1746 */
1747 switch (ret) {
1748 case -LTTNG_UST_ERR_PERM:
1749 /* Code flow problem */
1750 assert(0);
1751 case -LTTNG_UST_ERR_EXIST:
1752 /* It's OK for our use case. */
1753 ret = 0;
1754 break;
1755 default:
1756 break;
1757 }
1758 goto error;
1759 }
1760 }
1761
1762 error:
1763 health_code_update();
1764 return ret;
1765 }
1766
1767 /*
1768 * Copy data between an UST app event and a LTT event.
1769 */
1770 static void shadow_copy_event(struct ust_app_event *ua_event,
1771 struct ltt_ust_event *uevent)
1772 {
1773 size_t exclusion_alloc_size;
1774
1775 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1776 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1777
1778 ua_event->enabled = uevent->enabled;
1779
1780 /* Copy event attributes */
1781 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1782
1783 /* Copy filter bytecode */
1784 if (uevent->filter) {
1785 ua_event->filter = copy_filter_bytecode(uevent->filter);
1786 /* Filter might be NULL here in case of ENONEM. */
1787 }
1788
1789 /* Copy exclusion data */
1790 if (uevent->exclusion) {
1791 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1792 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1793 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1794 if (ua_event->exclusion == NULL) {
1795 PERROR("malloc");
1796 } else {
1797 memcpy(ua_event->exclusion, uevent->exclusion,
1798 exclusion_alloc_size);
1799 }
1800 }
1801 }
1802
1803 /*
1804 * Copy data between an UST app channel and a LTT channel.
1805 */
1806 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1807 struct ltt_ust_channel *uchan)
1808 {
1809 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1810
1811 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1812 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1813
1814 ua_chan->tracefile_size = uchan->tracefile_size;
1815 ua_chan->tracefile_count = uchan->tracefile_count;
1816
1817 /* Copy event attributes since the layout is different. */
1818 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1819 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1820 ua_chan->attr.overwrite = uchan->attr.overwrite;
1821 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1822 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1823 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1824 ua_chan->attr.output = uchan->attr.output;
1825 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1826
1827 /*
1828 * Note that the attribute channel type is not set since the channel on the
1829 * tracing registry side does not have this information.
1830 */
1831
1832 ua_chan->enabled = uchan->enabled;
1833 ua_chan->tracing_channel_id = uchan->id;
1834
1835 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1836 }
1837
1838 /*
1839 * Copy data between a UST app session and a regular LTT session.
1840 */
1841 static void shadow_copy_session(struct ust_app_session *ua_sess,
1842 struct ltt_ust_session *usess, struct ust_app *app)
1843 {
1844 struct tm *timeinfo;
1845 char datetime[16];
1846 int ret;
1847 char tmp_shm_path[PATH_MAX];
1848
1849 timeinfo = localtime(&app->registration_time);
1850 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1851
1852 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1853
1854 ua_sess->tracing_id = usess->id;
1855 ua_sess->id = get_next_session_id();
1856 ua_sess->real_credentials.uid = app->uid;
1857 ua_sess->real_credentials.gid = app->gid;
1858 ua_sess->effective_credentials.uid = usess->uid;
1859 ua_sess->effective_credentials.gid = usess->gid;
1860 ua_sess->buffer_type = usess->buffer_type;
1861 ua_sess->bits_per_long = app->bits_per_long;
1862
1863 /* There is only one consumer object per session possible. */
1864 consumer_output_get(usess->consumer);
1865 ua_sess->consumer = usess->consumer;
1866
1867 ua_sess->output_traces = usess->output_traces;
1868 ua_sess->live_timer_interval = usess->live_timer_interval;
1869 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1870 &usess->metadata_attr);
1871
1872 switch (ua_sess->buffer_type) {
1873 case LTTNG_BUFFER_PER_PID:
1874 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1875 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1876 datetime);
1877 break;
1878 case LTTNG_BUFFER_PER_UID:
1879 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1880 DEFAULT_UST_TRACE_UID_PATH,
1881 ua_sess->real_credentials.uid,
1882 app->bits_per_long);
1883 break;
1884 default:
1885 assert(0);
1886 goto error;
1887 }
1888 if (ret < 0) {
1889 PERROR("asprintf UST shadow copy session");
1890 assert(0);
1891 goto error;
1892 }
1893
1894 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1895 sizeof(ua_sess->root_shm_path));
1896 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1897 strncpy(ua_sess->shm_path, usess->shm_path,
1898 sizeof(ua_sess->shm_path));
1899 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1900 if (ua_sess->shm_path[0]) {
1901 switch (ua_sess->buffer_type) {
1902 case LTTNG_BUFFER_PER_PID:
1903 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1904 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1905 app->name, app->pid, datetime);
1906 break;
1907 case LTTNG_BUFFER_PER_UID:
1908 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1909 DEFAULT_UST_TRACE_UID_PATH,
1910 app->uid, app->bits_per_long);
1911 break;
1912 default:
1913 assert(0);
1914 goto error;
1915 }
1916 if (ret < 0) {
1917 PERROR("sprintf UST shadow copy session");
1918 assert(0);
1919 goto error;
1920 }
1921 strncat(ua_sess->shm_path, tmp_shm_path,
1922 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1923 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1924 }
1925 return;
1926
1927 error:
1928 consumer_output_put(ua_sess->consumer);
1929 }
1930
1931 /*
1932 * Lookup sesison wrapper.
1933 */
1934 static
1935 void __lookup_session_by_app(const struct ltt_ust_session *usess,
1936 struct ust_app *app, struct lttng_ht_iter *iter)
1937 {
1938 /* Get right UST app session from app */
1939 lttng_ht_lookup(app->sessions, &usess->id, iter);
1940 }
1941
1942 /*
1943 * Return ust app session from the app session hashtable using the UST session
1944 * id.
1945 */
1946 static struct ust_app_session *lookup_session_by_app(
1947 const struct ltt_ust_session *usess, struct ust_app *app)
1948 {
1949 struct lttng_ht_iter iter;
1950 struct lttng_ht_node_u64 *node;
1951
1952 __lookup_session_by_app(usess, app, &iter);
1953 node = lttng_ht_iter_get_node_u64(&iter);
1954 if (node == NULL) {
1955 goto error;
1956 }
1957
1958 return caa_container_of(node, struct ust_app_session, node);
1959
1960 error:
1961 return NULL;
1962 }
1963
1964 /*
1965 * Setup buffer registry per PID for the given session and application. If none
1966 * is found, a new one is created, added to the global registry and
1967 * initialized. If regp is valid, it's set with the newly created object.
1968 *
1969 * Return 0 on success or else a negative value.
1970 */
1971 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1972 struct ust_app *app, struct buffer_reg_pid **regp)
1973 {
1974 int ret = 0;
1975 struct buffer_reg_pid *reg_pid;
1976
1977 assert(ua_sess);
1978 assert(app);
1979
1980 rcu_read_lock();
1981
1982 reg_pid = buffer_reg_pid_find(ua_sess->id);
1983 if (!reg_pid) {
1984 /*
1985 * This is the create channel path meaning that if there is NO
1986 * registry available, we have to create one for this session.
1987 */
1988 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1989 ua_sess->root_shm_path, ua_sess->shm_path);
1990 if (ret < 0) {
1991 goto error;
1992 }
1993 } else {
1994 goto end;
1995 }
1996
1997 /* Initialize registry. */
1998 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1999 app->bits_per_long, app->uint8_t_alignment,
2000 app->uint16_t_alignment, app->uint32_t_alignment,
2001 app->uint64_t_alignment, app->long_alignment,
2002 app->byte_order, app->version.major, app->version.minor,
2003 reg_pid->root_shm_path, reg_pid->shm_path,
2004 ua_sess->effective_credentials.uid,
2005 ua_sess->effective_credentials.gid, ua_sess->tracing_id,
2006 app->uid);
2007 if (ret < 0) {
2008 /*
2009 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2010 * destroy the buffer registry, because it is always expected
2011 * that if the buffer registry can be found, its ust registry is
2012 * non-NULL.
2013 */
2014 buffer_reg_pid_destroy(reg_pid);
2015 goto error;
2016 }
2017
2018 buffer_reg_pid_add(reg_pid);
2019
2020 DBG3("UST app buffer registry per PID created successfully");
2021
2022 end:
2023 if (regp) {
2024 *regp = reg_pid;
2025 }
2026 error:
2027 rcu_read_unlock();
2028 return ret;
2029 }
2030
2031 /*
2032 * Setup buffer registry per UID for the given session and application. If none
2033 * is found, a new one is created, added to the global registry and
2034 * initialized. If regp is valid, it's set with the newly created object.
2035 *
2036 * Return 0 on success or else a negative value.
2037 */
2038 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2039 struct ust_app_session *ua_sess,
2040 struct ust_app *app, struct buffer_reg_uid **regp)
2041 {
2042 int ret = 0;
2043 struct buffer_reg_uid *reg_uid;
2044
2045 assert(usess);
2046 assert(app);
2047
2048 rcu_read_lock();
2049
2050 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2051 if (!reg_uid) {
2052 /*
2053 * This is the create channel path meaning that if there is NO
2054 * registry available, we have to create one for this session.
2055 */
2056 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2057 LTTNG_DOMAIN_UST, &reg_uid,
2058 ua_sess->root_shm_path, ua_sess->shm_path);
2059 if (ret < 0) {
2060 goto error;
2061 }
2062 } else {
2063 goto end;
2064 }
2065
2066 /* Initialize registry. */
2067 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2068 app->bits_per_long, app->uint8_t_alignment,
2069 app->uint16_t_alignment, app->uint32_t_alignment,
2070 app->uint64_t_alignment, app->long_alignment,
2071 app->byte_order, app->version.major,
2072 app->version.minor, reg_uid->root_shm_path,
2073 reg_uid->shm_path, usess->uid, usess->gid,
2074 ua_sess->tracing_id, app->uid);
2075 if (ret < 0) {
2076 /*
2077 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2078 * destroy the buffer registry, because it is always expected
2079 * that if the buffer registry can be found, its ust registry is
2080 * non-NULL.
2081 */
2082 buffer_reg_uid_destroy(reg_uid, NULL);
2083 goto error;
2084 }
2085 /* Add node to teardown list of the session. */
2086 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2087
2088 buffer_reg_uid_add(reg_uid);
2089
2090 DBG3("UST app buffer registry per UID created successfully");
2091 end:
2092 if (regp) {
2093 *regp = reg_uid;
2094 }
2095 error:
2096 rcu_read_unlock();
2097 return ret;
2098 }
2099
2100 /*
2101 * Create a session on the tracer side for the given app.
2102 *
2103 * On success, ua_sess_ptr is populated with the session pointer or else left
2104 * untouched. If the session was created, is_created is set to 1. On error,
2105 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2106 * be NULL.
2107 *
2108 * Returns 0 on success or else a negative code which is either -ENOMEM or
2109 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2110 */
2111 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2112 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2113 int *is_created)
2114 {
2115 int ret, created = 0;
2116 struct ust_app_session *ua_sess;
2117
2118 assert(usess);
2119 assert(app);
2120 assert(ua_sess_ptr);
2121
2122 health_code_update();
2123
2124 ua_sess = lookup_session_by_app(usess, app);
2125 if (ua_sess == NULL) {
2126 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2127 app->pid, usess->id);
2128 ua_sess = alloc_ust_app_session();
2129 if (ua_sess == NULL) {
2130 /* Only malloc can failed so something is really wrong */
2131 ret = -ENOMEM;
2132 goto error;
2133 }
2134 shadow_copy_session(ua_sess, usess, app);
2135 created = 1;
2136 }
2137
2138 switch (usess->buffer_type) {
2139 case LTTNG_BUFFER_PER_PID:
2140 /* Init local registry. */
2141 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2142 if (ret < 0) {
2143 delete_ust_app_session(-1, ua_sess, app);
2144 goto error;
2145 }
2146 break;
2147 case LTTNG_BUFFER_PER_UID:
2148 /* Look for a global registry. If none exists, create one. */
2149 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2150 if (ret < 0) {
2151 delete_ust_app_session(-1, ua_sess, app);
2152 goto error;
2153 }
2154 break;
2155 default:
2156 assert(0);
2157 ret = -EINVAL;
2158 goto error;
2159 }
2160
2161 health_code_update();
2162
2163 if (ua_sess->handle == -1) {
2164 pthread_mutex_lock(&app->sock_lock);
2165 ret = ustctl_create_session(app->sock);
2166 pthread_mutex_unlock(&app->sock_lock);
2167 if (ret < 0) {
2168 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2169 ERR("Creating session for app pid %d with ret %d",
2170 app->pid, ret);
2171 } else {
2172 DBG("UST app creating session failed. Application is dead");
2173 /*
2174 * This is normal behavior, an application can die during the
2175 * creation process. Don't report an error so the execution can
2176 * continue normally. This will get flagged ENOTCONN and the
2177 * caller will handle it.
2178 */
2179 ret = 0;
2180 }
2181 delete_ust_app_session(-1, ua_sess, app);
2182 if (ret != -ENOMEM) {
2183 /*
2184 * Tracer is probably gone or got an internal error so let's
2185 * behave like it will soon unregister or not usable.
2186 */
2187 ret = -ENOTCONN;
2188 }
2189 goto error;
2190 }
2191
2192 ua_sess->handle = ret;
2193
2194 /* Add ust app session to app's HT */
2195 lttng_ht_node_init_u64(&ua_sess->node,
2196 ua_sess->tracing_id);
2197 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2198 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2199 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2200 &ua_sess->ust_objd_node);
2201
2202 DBG2("UST app session created successfully with handle %d", ret);
2203 }
2204
2205 *ua_sess_ptr = ua_sess;
2206 if (is_created) {
2207 *is_created = created;
2208 }
2209
2210 /* Everything went well. */
2211 ret = 0;
2212
2213 error:
2214 health_code_update();
2215 return ret;
2216 }
2217
2218 /*
2219 * Match function for a hash table lookup of ust_app_ctx.
2220 *
2221 * It matches an ust app context based on the context type and, in the case
2222 * of perf counters, their name.
2223 */
2224 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2225 {
2226 struct ust_app_ctx *ctx;
2227 const struct lttng_ust_context_attr *key;
2228
2229 assert(node);
2230 assert(_key);
2231
2232 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2233 key = _key;
2234
2235 /* Context type */
2236 if (ctx->ctx.ctx != key->ctx) {
2237 goto no_match;
2238 }
2239
2240 switch(key->ctx) {
2241 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2242 if (strncmp(key->u.perf_counter.name,
2243 ctx->ctx.u.perf_counter.name,
2244 sizeof(key->u.perf_counter.name))) {
2245 goto no_match;
2246 }
2247 break;
2248 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2249 if (strcmp(key->u.app_ctx.provider_name,
2250 ctx->ctx.u.app_ctx.provider_name) ||
2251 strcmp(key->u.app_ctx.ctx_name,
2252 ctx->ctx.u.app_ctx.ctx_name)) {
2253 goto no_match;
2254 }
2255 break;
2256 default:
2257 break;
2258 }
2259
2260 /* Match. */
2261 return 1;
2262
2263 no_match:
2264 return 0;
2265 }
2266
2267 /*
2268 * Lookup for an ust app context from an lttng_ust_context.
2269 *
2270 * Must be called while holding RCU read side lock.
2271 * Return an ust_app_ctx object or NULL on error.
2272 */
2273 static
2274 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2275 struct lttng_ust_context_attr *uctx)
2276 {
2277 struct lttng_ht_iter iter;
2278 struct lttng_ht_node_ulong *node;
2279 struct ust_app_ctx *app_ctx = NULL;
2280
2281 assert(uctx);
2282 assert(ht);
2283
2284 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2285 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2286 ht_match_ust_app_ctx, uctx, &iter.iter);
2287 node = lttng_ht_iter_get_node_ulong(&iter);
2288 if (!node) {
2289 goto end;
2290 }
2291
2292 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2293
2294 end:
2295 return app_ctx;
2296 }
2297
2298 /*
2299 * Create a context for the channel on the tracer.
2300 *
2301 * Called with UST app session lock held and a RCU read side lock.
2302 */
2303 static
2304 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2305 struct lttng_ust_context_attr *uctx,
2306 struct ust_app *app)
2307 {
2308 int ret = 0;
2309 struct ust_app_ctx *ua_ctx;
2310
2311 DBG2("UST app adding context to channel %s", ua_chan->name);
2312
2313 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2314 if (ua_ctx) {
2315 ret = -EEXIST;
2316 goto error;
2317 }
2318
2319 ua_ctx = alloc_ust_app_ctx(uctx);
2320 if (ua_ctx == NULL) {
2321 /* malloc failed */
2322 ret = -ENOMEM;
2323 goto error;
2324 }
2325
2326 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2327 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2328 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2329
2330 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2331 if (ret < 0) {
2332 goto error;
2333 }
2334
2335 error:
2336 return ret;
2337 }
2338
2339 /*
2340 * Enable on the tracer side a ust app event for the session and channel.
2341 *
2342 * Called with UST app session lock held.
2343 */
2344 static
2345 int enable_ust_app_event(struct ust_app_session *ua_sess,
2346 struct ust_app_event *ua_event, struct ust_app *app)
2347 {
2348 int ret;
2349
2350 ret = enable_ust_event(app, ua_sess, ua_event);
2351 if (ret < 0) {
2352 goto error;
2353 }
2354
2355 ua_event->enabled = 1;
2356
2357 error:
2358 return ret;
2359 }
2360
2361 /*
2362 * Disable on the tracer side a ust app event for the session and channel.
2363 */
2364 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2365 struct ust_app_event *ua_event, struct ust_app *app)
2366 {
2367 int ret;
2368
2369 ret = disable_ust_event(app, ua_sess, ua_event);
2370 if (ret < 0) {
2371 goto error;
2372 }
2373
2374 ua_event->enabled = 0;
2375
2376 error:
2377 return ret;
2378 }
2379
2380 /*
2381 * Lookup ust app channel for session and disable it on the tracer side.
2382 */
2383 static
2384 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2385 struct ust_app_channel *ua_chan, struct ust_app *app)
2386 {
2387 int ret;
2388
2389 ret = disable_ust_channel(app, ua_sess, ua_chan);
2390 if (ret < 0) {
2391 goto error;
2392 }
2393
2394 ua_chan->enabled = 0;
2395
2396 error:
2397 return ret;
2398 }
2399
2400 /*
2401 * Lookup ust app channel for session and enable it on the tracer side. This
2402 * MUST be called with a RCU read side lock acquired.
2403 */
2404 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2405 struct ltt_ust_channel *uchan, struct ust_app *app)
2406 {
2407 int ret = 0;
2408 struct lttng_ht_iter iter;
2409 struct lttng_ht_node_str *ua_chan_node;
2410 struct ust_app_channel *ua_chan;
2411
2412 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2413 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2414 if (ua_chan_node == NULL) {
2415 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2416 uchan->name, ua_sess->tracing_id);
2417 goto error;
2418 }
2419
2420 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2421
2422 ret = enable_ust_channel(app, ua_sess, ua_chan);
2423 if (ret < 0) {
2424 goto error;
2425 }
2426
2427 error:
2428 return ret;
2429 }
2430
2431 /*
2432 * Ask the consumer to create a channel and get it if successful.
2433 *
2434 * Called with UST app session lock held.
2435 *
2436 * Return 0 on success or else a negative value.
2437 */
2438 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2439 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2440 int bitness, struct ust_registry_session *registry,
2441 uint64_t trace_archive_id)
2442 {
2443 int ret;
2444 unsigned int nb_fd = 0;
2445 struct consumer_socket *socket;
2446
2447 assert(usess);
2448 assert(ua_sess);
2449 assert(ua_chan);
2450 assert(registry);
2451
2452 rcu_read_lock();
2453 health_code_update();
2454
2455 /* Get the right consumer socket for the application. */
2456 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2457 if (!socket) {
2458 ret = -EINVAL;
2459 goto error;
2460 }
2461
2462 health_code_update();
2463
2464 /* Need one fd for the channel. */
2465 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2466 if (ret < 0) {
2467 ERR("Exhausted number of available FD upon create channel");
2468 goto error;
2469 }
2470
2471 /*
2472 * Ask consumer to create channel. The consumer will return the number of
2473 * stream we have to expect.
2474 */
2475 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2476 registry, usess->current_trace_chunk);
2477 if (ret < 0) {
2478 goto error_ask;
2479 }
2480
2481 /*
2482 * Compute the number of fd needed before receiving them. It must be 2 per
2483 * stream (2 being the default value here).
2484 */
2485 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2486
2487 /* Reserve the amount of file descriptor we need. */
2488 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2489 if (ret < 0) {
2490 ERR("Exhausted number of available FD upon create channel");
2491 goto error_fd_get_stream;
2492 }
2493
2494 health_code_update();
2495
2496 /*
2497 * Now get the channel from the consumer. This call wil populate the stream
2498 * list of that channel and set the ust objects.
2499 */
2500 if (usess->consumer->enabled) {
2501 ret = ust_consumer_get_channel(socket, ua_chan);
2502 if (ret < 0) {
2503 goto error_destroy;
2504 }
2505 }
2506
2507 rcu_read_unlock();
2508 return 0;
2509
2510 error_destroy:
2511 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2512 error_fd_get_stream:
2513 /*
2514 * Initiate a destroy channel on the consumer since we had an error
2515 * handling it on our side. The return value is of no importance since we
2516 * already have a ret value set by the previous error that we need to
2517 * return.
2518 */
2519 (void) ust_consumer_destroy_channel(socket, ua_chan);
2520 error_ask:
2521 lttng_fd_put(LTTNG_FD_APPS, 1);
2522 error:
2523 health_code_update();
2524 rcu_read_unlock();
2525 return ret;
2526 }
2527
2528 /*
2529 * Duplicate the ust data object of the ust app stream and save it in the
2530 * buffer registry stream.
2531 *
2532 * Return 0 on success or else a negative value.
2533 */
2534 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2535 struct ust_app_stream *stream)
2536 {
2537 int ret;
2538
2539 assert(reg_stream);
2540 assert(stream);
2541
2542 /* Reserve the amount of file descriptor we need. */
2543 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2544 if (ret < 0) {
2545 ERR("Exhausted number of available FD upon duplicate stream");
2546 goto error;
2547 }
2548
2549 /* Duplicate object for stream once the original is in the registry. */
2550 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2551 reg_stream->obj.ust);
2552 if (ret < 0) {
2553 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2554 reg_stream->obj.ust, stream->obj, ret);
2555 lttng_fd_put(LTTNG_FD_APPS, 2);
2556 goto error;
2557 }
2558 stream->handle = stream->obj->handle;
2559
2560 error:
2561 return ret;
2562 }
2563
2564 /*
2565 * Duplicate the ust data object of the ust app. channel and save it in the
2566 * buffer registry channel.
2567 *
2568 * Return 0 on success or else a negative value.
2569 */
2570 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2571 struct ust_app_channel *ua_chan)
2572 {
2573 int ret;
2574
2575 assert(reg_chan);
2576 assert(ua_chan);
2577
2578 /* Need two fds for the channel. */
2579 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2580 if (ret < 0) {
2581 ERR("Exhausted number of available FD upon duplicate channel");
2582 goto error_fd_get;
2583 }
2584
2585 /* Duplicate object for stream once the original is in the registry. */
2586 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2587 if (ret < 0) {
2588 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2589 reg_chan->obj.ust, ua_chan->obj, ret);
2590 goto error;
2591 }
2592 ua_chan->handle = ua_chan->obj->handle;
2593
2594 return 0;
2595
2596 error:
2597 lttng_fd_put(LTTNG_FD_APPS, 1);
2598 error_fd_get:
2599 return ret;
2600 }
2601
2602 /*
2603 * For a given channel buffer registry, setup all streams of the given ust
2604 * application channel.
2605 *
2606 * Return 0 on success or else a negative value.
2607 */
2608 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2609 struct ust_app_channel *ua_chan,
2610 struct ust_app *app)
2611 {
2612 int ret = 0;
2613 struct ust_app_stream *stream, *stmp;
2614
2615 assert(reg_chan);
2616 assert(ua_chan);
2617
2618 DBG2("UST app setup buffer registry stream");
2619
2620 /* Send all streams to application. */
2621 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2622 struct buffer_reg_stream *reg_stream;
2623
2624 ret = buffer_reg_stream_create(&reg_stream);
2625 if (ret < 0) {
2626 goto error;
2627 }
2628
2629 /*
2630 * Keep original pointer and nullify it in the stream so the delete
2631 * stream call does not release the object.
2632 */
2633 reg_stream->obj.ust = stream->obj;
2634 stream->obj = NULL;
2635 buffer_reg_stream_add(reg_stream, reg_chan);
2636
2637 /* We don't need the streams anymore. */
2638 cds_list_del(&stream->list);
2639 delete_ust_app_stream(-1, stream, app);
2640 }
2641
2642 error:
2643 return ret;
2644 }
2645
2646 /*
2647 * Create a buffer registry channel for the given session registry and
2648 * application channel object. If regp pointer is valid, it's set with the
2649 * created object. Important, the created object is NOT added to the session
2650 * registry hash table.
2651 *
2652 * Return 0 on success else a negative value.
2653 */
2654 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2655 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2656 {
2657 int ret;
2658 struct buffer_reg_channel *reg_chan = NULL;
2659
2660 assert(reg_sess);
2661 assert(ua_chan);
2662
2663 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2664
2665 /* Create buffer registry channel. */
2666 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2667 if (ret < 0) {
2668 goto error_create;
2669 }
2670 assert(reg_chan);
2671 reg_chan->consumer_key = ua_chan->key;
2672 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2673 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2674
2675 /* Create and add a channel registry to session. */
2676 ret = ust_registry_channel_add(reg_sess->reg.ust,
2677 ua_chan->tracing_channel_id);
2678 if (ret < 0) {
2679 goto error;
2680 }
2681 buffer_reg_channel_add(reg_sess, reg_chan);
2682
2683 if (regp) {
2684 *regp = reg_chan;
2685 }
2686
2687 return 0;
2688
2689 error:
2690 /* Safe because the registry channel object was not added to any HT. */
2691 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2692 error_create:
2693 return ret;
2694 }
2695
2696 /*
2697 * Setup buffer registry channel for the given session registry and application
2698 * channel object. If regp pointer is valid, it's set with the created object.
2699 *
2700 * Return 0 on success else a negative value.
2701 */
2702 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2703 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2704 struct ust_app *app)
2705 {
2706 int ret;
2707
2708 assert(reg_sess);
2709 assert(reg_chan);
2710 assert(ua_chan);
2711 assert(ua_chan->obj);
2712
2713 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2714
2715 /* Setup all streams for the registry. */
2716 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2717 if (ret < 0) {
2718 goto error;
2719 }
2720
2721 reg_chan->obj.ust = ua_chan->obj;
2722 ua_chan->obj = NULL;
2723
2724 return 0;
2725
2726 error:
2727 buffer_reg_channel_remove(reg_sess, reg_chan);
2728 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2729 return ret;
2730 }
2731
2732 /*
2733 * Send buffer registry channel to the application.
2734 *
2735 * Return 0 on success else a negative value.
2736 */
2737 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2738 struct ust_app *app, struct ust_app_session *ua_sess,
2739 struct ust_app_channel *ua_chan)
2740 {
2741 int ret;
2742 struct buffer_reg_stream *reg_stream;
2743
2744 assert(reg_chan);
2745 assert(app);
2746 assert(ua_sess);
2747 assert(ua_chan);
2748
2749 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2750
2751 ret = duplicate_channel_object(reg_chan, ua_chan);
2752 if (ret < 0) {
2753 goto error;
2754 }
2755
2756 /* Send channel to the application. */
2757 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2758 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2759 ret = -ENOTCONN; /* Caused by app exiting. */
2760 goto error;
2761 } else if (ret < 0) {
2762 goto error;
2763 }
2764
2765 health_code_update();
2766
2767 /* Send all streams to application. */
2768 pthread_mutex_lock(&reg_chan->stream_list_lock);
2769 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2770 struct ust_app_stream stream;
2771
2772 ret = duplicate_stream_object(reg_stream, &stream);
2773 if (ret < 0) {
2774 goto error_stream_unlock;
2775 }
2776
2777 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2778 if (ret < 0) {
2779 (void) release_ust_app_stream(-1, &stream, app);
2780 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2781 ret = -ENOTCONN; /* Caused by app exiting. */
2782 }
2783 goto error_stream_unlock;
2784 }
2785
2786 /*
2787 * The return value is not important here. This function will output an
2788 * error if needed.
2789 */
2790 (void) release_ust_app_stream(-1, &stream, app);
2791 }
2792 ua_chan->is_sent = 1;
2793
2794 error_stream_unlock:
2795 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2796 error:
2797 return ret;
2798 }
2799
2800 /*
2801 * Create and send to the application the created buffers with per UID buffers.
2802 *
2803 * This MUST be called with a RCU read side lock acquired.
2804 * The session list lock and the session's lock must be acquired.
2805 *
2806 * Return 0 on success else a negative value.
2807 */
2808 static int create_channel_per_uid(struct ust_app *app,
2809 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2810 struct ust_app_channel *ua_chan)
2811 {
2812 int ret;
2813 struct buffer_reg_uid *reg_uid;
2814 struct buffer_reg_channel *reg_chan;
2815 struct ltt_session *session = NULL;
2816 enum lttng_error_code notification_ret;
2817 struct ust_registry_channel *chan_reg;
2818
2819 assert(app);
2820 assert(usess);
2821 assert(ua_sess);
2822 assert(ua_chan);
2823
2824 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2825
2826 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2827 /*
2828 * The session creation handles the creation of this global registry
2829 * object. If none can be find, there is a code flow problem or a
2830 * teardown race.
2831 */
2832 assert(reg_uid);
2833
2834 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2835 reg_uid);
2836 if (reg_chan) {
2837 goto send_channel;
2838 }
2839
2840 /* Create the buffer registry channel object. */
2841 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2842 if (ret < 0) {
2843 ERR("Error creating the UST channel \"%s\" registry instance",
2844 ua_chan->name);
2845 goto error;
2846 }
2847
2848 session = session_find_by_id(ua_sess->tracing_id);
2849 assert(session);
2850 assert(pthread_mutex_trylock(&session->lock));
2851 assert(session_trylock_list());
2852
2853 /*
2854 * Create the buffers on the consumer side. This call populates the
2855 * ust app channel object with all streams and data object.
2856 */
2857 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2858 app->bits_per_long, reg_uid->registry->reg.ust,
2859 session->most_recent_chunk_id.value);
2860 if (ret < 0) {
2861 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2862 ua_chan->name);
2863
2864 /*
2865 * Let's remove the previously created buffer registry channel so
2866 * it's not visible anymore in the session registry.
2867 */
2868 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2869 ua_chan->tracing_channel_id, false);
2870 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2871 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2872 goto error;
2873 }
2874
2875 /*
2876 * Setup the streams and add it to the session registry.
2877 */
2878 ret = setup_buffer_reg_channel(reg_uid->registry,
2879 ua_chan, reg_chan, app);
2880 if (ret < 0) {
2881 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2882 goto error;
2883 }
2884
2885 /* Notify the notification subsystem of the channel's creation. */
2886 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2887 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2888 ua_chan->tracing_channel_id);
2889 assert(chan_reg);
2890 chan_reg->consumer_key = ua_chan->key;
2891 chan_reg = NULL;
2892 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2893
2894 notification_ret = notification_thread_command_add_channel(
2895 notification_thread_handle, session->name,
2896 ua_sess->effective_credentials.uid,
2897 ua_sess->effective_credentials.gid, ua_chan->name,
2898 ua_chan->key, LTTNG_DOMAIN_UST,
2899 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2900 if (notification_ret != LTTNG_OK) {
2901 ret = - (int) notification_ret;
2902 ERR("Failed to add channel to notification thread");
2903 goto error;
2904 }
2905
2906 send_channel:
2907 /* Send buffers to the application. */
2908 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2909 if (ret < 0) {
2910 if (ret != -ENOTCONN) {
2911 ERR("Error sending channel to application");
2912 }
2913 goto error;
2914 }
2915
2916 error:
2917 if (session) {
2918 session_put(session);
2919 }
2920 return ret;
2921 }
2922
2923 /*
2924 * Create and send to the application the created buffers with per PID buffers.
2925 *
2926 * Called with UST app session lock held.
2927 * The session list lock and the session's lock must be acquired.
2928 *
2929 * Return 0 on success else a negative value.
2930 */
2931 static int create_channel_per_pid(struct ust_app *app,
2932 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2933 struct ust_app_channel *ua_chan)
2934 {
2935 int ret;
2936 struct ust_registry_session *registry;
2937 enum lttng_error_code cmd_ret;
2938 struct ltt_session *session = NULL;
2939 uint64_t chan_reg_key;
2940 struct ust_registry_channel *chan_reg;
2941
2942 assert(app);
2943 assert(usess);
2944 assert(ua_sess);
2945 assert(ua_chan);
2946
2947 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2948
2949 rcu_read_lock();
2950
2951 registry = get_session_registry(ua_sess);
2952 /* The UST app session lock is held, registry shall not be null. */
2953 assert(registry);
2954
2955 /* Create and add a new channel registry to session. */
2956 ret = ust_registry_channel_add(registry, ua_chan->key);
2957 if (ret < 0) {
2958 ERR("Error creating the UST channel \"%s\" registry instance",
2959 ua_chan->name);
2960 goto error;
2961 }
2962
2963 session = session_find_by_id(ua_sess->tracing_id);
2964 assert(session);
2965
2966 assert(pthread_mutex_trylock(&session->lock));
2967 assert(session_trylock_list());
2968
2969 /* Create and get channel on the consumer side. */
2970 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2971 app->bits_per_long, registry,
2972 session->most_recent_chunk_id.value);
2973 if (ret < 0) {
2974 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2975 ua_chan->name);
2976 goto error_remove_from_registry;
2977 }
2978
2979 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2980 if (ret < 0) {
2981 if (ret != -ENOTCONN) {
2982 ERR("Error sending channel to application");
2983 }
2984 goto error_remove_from_registry;
2985 }
2986
2987 chan_reg_key = ua_chan->key;
2988 pthread_mutex_lock(&registry->lock);
2989 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2990 assert(chan_reg);
2991 chan_reg->consumer_key = ua_chan->key;
2992 pthread_mutex_unlock(&registry->lock);
2993
2994 cmd_ret = notification_thread_command_add_channel(
2995 notification_thread_handle, session->name,
2996 ua_sess->effective_credentials.uid,
2997 ua_sess->effective_credentials.gid, ua_chan->name,
2998 ua_chan->key, LTTNG_DOMAIN_UST,
2999 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
3000 if (cmd_ret != LTTNG_OK) {
3001 ret = - (int) cmd_ret;
3002 ERR("Failed to add channel to notification thread");
3003 goto error_remove_from_registry;
3004 }
3005
3006 error_remove_from_registry:
3007 if (ret) {
3008 ust_registry_channel_del_free(registry, ua_chan->key, false);
3009 }
3010 error:
3011 rcu_read_unlock();
3012 if (session) {
3013 session_put(session);
3014 }
3015 return ret;
3016 }
3017
3018 /*
3019 * From an already allocated ust app channel, create the channel buffers if
3020 * needed and send them to the application. This MUST be called with a RCU read
3021 * side lock acquired.
3022 *
3023 * Called with UST app session lock held.
3024 *
3025 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3026 * the application exited concurrently.
3027 */
3028 static int ust_app_channel_send(struct ust_app *app,
3029 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3030 struct ust_app_channel *ua_chan)
3031 {
3032 int ret;
3033
3034 assert(app);
3035 assert(usess);
3036 assert(usess->active);
3037 assert(ua_sess);
3038 assert(ua_chan);
3039
3040 /* Handle buffer type before sending the channel to the application. */
3041 switch (usess->buffer_type) {
3042 case LTTNG_BUFFER_PER_UID:
3043 {
3044 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3045 if (ret < 0) {
3046 goto error;
3047 }
3048 break;
3049 }
3050 case LTTNG_BUFFER_PER_PID:
3051 {
3052 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3053 if (ret < 0) {
3054 goto error;
3055 }
3056 break;
3057 }
3058 default:
3059 assert(0);
3060 ret = -EINVAL;
3061 goto error;
3062 }
3063
3064 /* Initialize ust objd object using the received handle and add it. */
3065 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3066 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3067
3068 /* If channel is not enabled, disable it on the tracer */
3069 if (!ua_chan->enabled) {
3070 ret = disable_ust_channel(app, ua_sess, ua_chan);
3071 if (ret < 0) {
3072 goto error;
3073 }
3074 }
3075
3076 error:
3077 return ret;
3078 }
3079
3080 /*
3081 * Create UST app channel and return it through ua_chanp if not NULL.
3082 *
3083 * Called with UST app session lock and RCU read-side lock held.
3084 *
3085 * Return 0 on success or else a negative value.
3086 */
3087 static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3088 struct ltt_ust_channel *uchan,
3089 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3090 struct ust_app_channel **ua_chanp)
3091 {
3092 int ret = 0;
3093 struct lttng_ht_iter iter;
3094 struct lttng_ht_node_str *ua_chan_node;
3095 struct ust_app_channel *ua_chan;
3096
3097 /* Lookup channel in the ust app session */
3098 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3099 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3100 if (ua_chan_node != NULL) {
3101 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3102 goto end;
3103 }
3104
3105 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3106 if (ua_chan == NULL) {
3107 /* Only malloc can fail here */
3108 ret = -ENOMEM;
3109 goto error;
3110 }
3111 shadow_copy_channel(ua_chan, uchan);
3112
3113 /* Set channel type. */
3114 ua_chan->attr.type = type;
3115
3116 /* Only add the channel if successful on the tracer side. */
3117 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3118 end:
3119 if (ua_chanp) {
3120 *ua_chanp = ua_chan;
3121 }
3122
3123 /* Everything went well. */
3124 return 0;
3125
3126 error:
3127 return ret;
3128 }
3129
3130 /*
3131 * Create UST app event and create it on the tracer side.
3132 *
3133 * Called with ust app session mutex held.
3134 */
3135 static
3136 int create_ust_app_event(struct ust_app_session *ua_sess,
3137 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3138 struct ust_app *app)
3139 {
3140 int ret = 0;
3141 struct ust_app_event *ua_event;
3142
3143 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3144 if (ua_event == NULL) {
3145 /* Only failure mode of alloc_ust_app_event(). */
3146 ret = -ENOMEM;
3147 goto end;
3148 }
3149 shadow_copy_event(ua_event, uevent);
3150
3151 /* Create it on the tracer side */
3152 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3153 if (ret < 0) {
3154 /*
3155 * Not found previously means that it does not exist on the
3156 * tracer. If the application reports that the event existed,
3157 * it means there is a bug in the sessiond or lttng-ust
3158 * (or corruption, etc.)
3159 */
3160 if (ret == -LTTNG_UST_ERR_EXIST) {
3161 ERR("Tracer for application reported that an event being created already existed: "
3162 "event_name = \"%s\", pid = %d, ppid = %d, uid = %d, gid = %d",
3163 uevent->attr.name,
3164 app->pid, app->ppid, app->uid,
3165 app->gid);
3166 }
3167 goto error;
3168 }
3169
3170 add_unique_ust_app_event(ua_chan, ua_event);
3171
3172 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3173 app->pid);
3174
3175 end:
3176 return ret;
3177
3178 error:
3179 /* Valid. Calling here is already in a read side lock */
3180 delete_ust_app_event(-1, ua_event, app);
3181 return ret;
3182 }
3183
3184 /*
3185 * Create UST metadata and open it on the tracer side.
3186 *
3187 * Called with UST app session lock held and RCU read side lock.
3188 */
3189 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3190 struct ust_app *app, struct consumer_output *consumer)
3191 {
3192 int ret = 0;
3193 struct ust_app_channel *metadata;
3194 struct consumer_socket *socket;
3195 struct ust_registry_session *registry;
3196 struct ltt_session *session = NULL;
3197
3198 assert(ua_sess);
3199 assert(app);
3200 assert(consumer);
3201
3202 registry = get_session_registry(ua_sess);
3203 /* The UST app session is held registry shall not be null. */
3204 assert(registry);
3205
3206 pthread_mutex_lock(&registry->lock);
3207
3208 /* Metadata already exists for this registry or it was closed previously */
3209 if (registry->metadata_key || registry->metadata_closed) {
3210 ret = 0;
3211 goto error;
3212 }
3213
3214 /* Allocate UST metadata */
3215 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3216 if (!metadata) {
3217 /* malloc() failed */
3218 ret = -ENOMEM;
3219 goto error;
3220 }
3221
3222 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3223
3224 /* Need one fd for the channel. */
3225 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3226 if (ret < 0) {
3227 ERR("Exhausted number of available FD upon create metadata");
3228 goto error;
3229 }
3230
3231 /* Get the right consumer socket for the application. */
3232 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3233 if (!socket) {
3234 ret = -EINVAL;
3235 goto error_consumer;
3236 }
3237
3238 /*
3239 * Keep metadata key so we can identify it on the consumer side. Assign it
3240 * to the registry *before* we ask the consumer so we avoid the race of the
3241 * consumer requesting the metadata and the ask_channel call on our side
3242 * did not returned yet.
3243 */
3244 registry->metadata_key = metadata->key;
3245
3246 session = session_find_by_id(ua_sess->tracing_id);
3247 assert(session);
3248
3249 assert(pthread_mutex_trylock(&session->lock));
3250 assert(session_trylock_list());
3251
3252 /*
3253 * Ask the metadata channel creation to the consumer. The metadata object
3254 * will be created by the consumer and kept their. However, the stream is
3255 * never added or monitored until we do a first push metadata to the
3256 * consumer.
3257 */
3258 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3259 registry, session->current_trace_chunk);
3260 if (ret < 0) {
3261 /* Nullify the metadata key so we don't try to close it later on. */
3262 registry->metadata_key = 0;
3263 goto error_consumer;
3264 }
3265
3266 /*
3267 * The setup command will make the metadata stream be sent to the relayd,
3268 * if applicable, and the thread managing the metadatas. This is important
3269 * because after this point, if an error occurs, the only way the stream
3270 * can be deleted is to be monitored in the consumer.
3271 */
3272 ret = consumer_setup_metadata(socket, metadata->key);
3273 if (ret < 0) {
3274 /* Nullify the metadata key so we don't try to close it later on. */
3275 registry->metadata_key = 0;
3276 goto error_consumer;
3277 }
3278
3279 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3280 metadata->key, app->pid);
3281
3282 error_consumer:
3283 lttng_fd_put(LTTNG_FD_APPS, 1);
3284 delete_ust_app_channel(-1, metadata, app);
3285 error:
3286 pthread_mutex_unlock(&registry->lock);
3287 if (session) {
3288 session_put(session);
3289 }
3290 return ret;
3291 }
3292
3293 /*
3294 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3295 * acquired before calling this function.
3296 */
3297 struct ust_app *ust_app_find_by_pid(pid_t pid)
3298 {
3299 struct ust_app *app = NULL;
3300 struct lttng_ht_node_ulong *node;
3301 struct lttng_ht_iter iter;
3302
3303 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3304 node = lttng_ht_iter_get_node_ulong(&iter);
3305 if (node == NULL) {
3306 DBG2("UST app no found with pid %d", pid);
3307 goto error;
3308 }
3309
3310 DBG2("Found UST app by pid %d", pid);
3311
3312 app = caa_container_of(node, struct ust_app, pid_n);
3313
3314 error:
3315 return app;
3316 }
3317
3318 /*
3319 * Allocate and init an UST app object using the registration information and
3320 * the command socket. This is called when the command socket connects to the
3321 * session daemon.
3322 *
3323 * The object is returned on success or else NULL.
3324 */
3325 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3326 {
3327 struct ust_app *lta = NULL;
3328
3329 assert(msg);
3330 assert(sock >= 0);
3331
3332 DBG3("UST app creating application for socket %d", sock);
3333
3334 if ((msg->bits_per_long == 64 &&
3335 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3336 || (msg->bits_per_long == 32 &&
3337 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3338 ERR("Registration failed: application \"%s\" (pid: %d) has "
3339 "%d-bit long, but no consumerd for this size is available.\n",
3340 msg->name, msg->pid, msg->bits_per_long);
3341 goto error;
3342 }
3343
3344 lta = zmalloc(sizeof(struct ust_app));
3345 if (lta == NULL) {
3346 PERROR("malloc");
3347 goto error;
3348 }
3349
3350 lta->ppid = msg->ppid;
3351 lta->uid = msg->uid;
3352 lta->gid = msg->gid;
3353
3354 lta->bits_per_long = msg->bits_per_long;
3355 lta->uint8_t_alignment = msg->uint8_t_alignment;
3356 lta->uint16_t_alignment = msg->uint16_t_alignment;
3357 lta->uint32_t_alignment = msg->uint32_t_alignment;
3358 lta->uint64_t_alignment = msg->uint64_t_alignment;
3359 lta->long_alignment = msg->long_alignment;
3360 lta->byte_order = msg->byte_order;
3361
3362 lta->v_major = msg->major;
3363 lta->v_minor = msg->minor;
3364 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3365 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3366 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3367 lta->notify_sock = -1;
3368
3369 /* Copy name and make sure it's NULL terminated. */
3370 strncpy(lta->name, msg->name, sizeof(lta->name));
3371 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3372
3373 /*
3374 * Before this can be called, when receiving the registration information,
3375 * the application compatibility is checked. So, at this point, the
3376 * application can work with this session daemon.
3377 */
3378 lta->compatible = 1;
3379
3380 lta->pid = msg->pid;
3381 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3382 lta->sock = sock;
3383 pthread_mutex_init(&lta->sock_lock, NULL);
3384 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3385
3386 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3387 error:
3388 return lta;
3389 }
3390
3391 /*
3392 * For a given application object, add it to every hash table.
3393 */
3394 void ust_app_add(struct ust_app *app)
3395 {
3396 assert(app);
3397 assert(app->notify_sock >= 0);
3398
3399 app->registration_time = time(NULL);
3400
3401 rcu_read_lock();
3402
3403 /*
3404 * On a re-registration, we want to kick out the previous registration of
3405 * that pid
3406 */
3407 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3408
3409 /*
3410 * The socket _should_ be unique until _we_ call close. So, a add_unique
3411 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3412 * already in the table.
3413 */
3414 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3415
3416 /* Add application to the notify socket hash table. */
3417 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3418 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3419
3420 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3421 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3422 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3423 app->v_minor);
3424
3425 rcu_read_unlock();
3426 }
3427
3428 /*
3429 * Set the application version into the object.
3430 *
3431 * Return 0 on success else a negative value either an errno code or a
3432 * LTTng-UST error code.
3433 */
3434 int ust_app_version(struct ust_app *app)
3435 {
3436 int ret;
3437
3438 assert(app);
3439
3440 pthread_mutex_lock(&app->sock_lock);
3441 ret = ustctl_tracer_version(app->sock, &app->version);
3442 pthread_mutex_unlock(&app->sock_lock);
3443 if (ret < 0) {
3444 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3445 ERR("UST app %d version failed with ret %d", app->sock, ret);
3446 } else {
3447 DBG3("UST app %d version failed. Application is dead", app->sock);
3448 }
3449 }
3450
3451 return ret;
3452 }
3453
3454 /*
3455 * Unregister app by removing it from the global traceable app list and freeing
3456 * the data struct.
3457 *
3458 * The socket is already closed at this point so no close to sock.
3459 */
3460 void ust_app_unregister(int sock)
3461 {
3462 struct ust_app *lta;
3463 struct lttng_ht_node_ulong *node;
3464 struct lttng_ht_iter ust_app_sock_iter;
3465 struct lttng_ht_iter iter;
3466 struct ust_app_session *ua_sess;
3467 int ret;
3468
3469 rcu_read_lock();
3470
3471 /* Get the node reference for a call_rcu */
3472 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3473 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3474 assert(node);
3475
3476 lta = caa_container_of(node, struct ust_app, sock_n);
3477 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3478
3479 /*
3480 * For per-PID buffers, perform "push metadata" and flush all
3481 * application streams before removing app from hash tables,
3482 * ensuring proper behavior of data_pending check.
3483 * Remove sessions so they are not visible during deletion.
3484 */
3485 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3486 node.node) {
3487 struct ust_registry_session *registry;
3488
3489 ret = lttng_ht_del(lta->sessions, &iter);
3490 if (ret) {
3491 /* The session was already removed so scheduled for teardown. */
3492 continue;
3493 }
3494
3495 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3496 (void) ust_app_flush_app_session(lta, ua_sess);
3497 }
3498
3499 /*
3500 * Add session to list for teardown. This is safe since at this point we
3501 * are the only one using this list.
3502 */
3503 pthread_mutex_lock(&ua_sess->lock);
3504
3505 if (ua_sess->deleted) {
3506 pthread_mutex_unlock(&ua_sess->lock);
3507 continue;
3508 }
3509
3510 /*
3511 * Normally, this is done in the delete session process which is
3512 * executed in the call rcu below. However, upon registration we can't
3513 * afford to wait for the grace period before pushing data or else the
3514 * data pending feature can race between the unregistration and stop
3515 * command where the data pending command is sent *before* the grace
3516 * period ended.
3517 *
3518 * The close metadata below nullifies the metadata pointer in the
3519 * session so the delete session will NOT push/close a second time.
3520 */
3521 registry = get_session_registry(ua_sess);
3522 if (registry) {
3523 /* Push metadata for application before freeing the application. */
3524 (void) push_metadata(registry, ua_sess->consumer);
3525
3526 /*
3527 * Don't ask to close metadata for global per UID buffers. Close
3528 * metadata only on destroy trace session in this case. Also, the
3529 * previous push metadata could have flag the metadata registry to
3530 * close so don't send a close command if closed.
3531 */
3532 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3533 /* And ask to close it for this session registry. */
3534 (void) close_metadata(registry, ua_sess->consumer);
3535 }
3536 }
3537 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3538
3539 pthread_mutex_unlock(&ua_sess->lock);
3540 }
3541
3542 /* Remove application from PID hash table */
3543 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3544 assert(!ret);
3545
3546 /*
3547 * Remove application from notify hash table. The thread handling the
3548 * notify socket could have deleted the node so ignore on error because
3549 * either way it's valid. The close of that socket is handled by the
3550 * apps_notify_thread.
3551 */
3552 iter.iter.node = &lta->notify_sock_n.node;
3553 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3554
3555 /*
3556 * Ignore return value since the node might have been removed before by an
3557 * add replace during app registration because the PID can be reassigned by
3558 * the OS.
3559 */
3560 iter.iter.node = &lta->pid_n.node;
3561 ret = lttng_ht_del(ust_app_ht, &iter);
3562 if (ret) {
3563 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3564 lta->pid);
3565 }
3566
3567 /* Free memory */
3568 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3569
3570 rcu_read_unlock();
3571 return;
3572 }
3573
3574 /*
3575 * Fill events array with all events name of all registered apps.
3576 */
3577 int ust_app_list_events(struct lttng_event **events)
3578 {
3579 int ret, handle;
3580 size_t nbmem, count = 0;
3581 struct lttng_ht_iter iter;
3582 struct ust_app *app;
3583 struct lttng_event *tmp_event;
3584
3585 nbmem = UST_APP_EVENT_LIST_SIZE;
3586 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3587 if (tmp_event == NULL) {
3588 PERROR("zmalloc ust app events");
3589 ret = -ENOMEM;
3590 goto error;
3591 }
3592
3593 rcu_read_lock();
3594
3595 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3596 struct lttng_ust_tracepoint_iter uiter;
3597
3598 health_code_update();
3599
3600 if (!app->compatible) {
3601 /*
3602 * TODO: In time, we should notice the caller of this error by
3603 * telling him that this is a version error.
3604 */
3605 continue;
3606 }
3607 pthread_mutex_lock(&app->sock_lock);
3608 handle = ustctl_tracepoint_list(app->sock);
3609 if (handle < 0) {
3610 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3611 ERR("UST app list events getting handle failed for app pid %d",
3612 app->pid);
3613 }
3614 pthread_mutex_unlock(&app->sock_lock);
3615 continue;
3616 }
3617
3618 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3619 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3620 /* Handle ustctl error. */
3621 if (ret < 0) {
3622 int release_ret;
3623
3624 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3625 ERR("UST app tp list get failed for app %d with ret %d",
3626 app->sock, ret);
3627 } else {
3628 DBG3("UST app tp list get failed. Application is dead");
3629 /*
3630 * This is normal behavior, an application can die during the
3631 * creation process. Don't report an error so the execution can
3632 * continue normally. Continue normal execution.
3633 */
3634 break;
3635 }
3636 free(tmp_event);
3637 release_ret = ustctl_release_handle(app->sock, handle);
3638 if (release_ret < 0 &&
3639 release_ret != -LTTNG_UST_ERR_EXITING &&
3640 release_ret != -EPIPE) {
3641 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3642 }
3643 pthread_mutex_unlock(&app->sock_lock);
3644 goto rcu_error;
3645 }
3646
3647 health_code_update();
3648 if (count >= nbmem) {
3649 /* In case the realloc fails, we free the memory */
3650 struct lttng_event *new_tmp_event;
3651 size_t new_nbmem;
3652
3653 new_nbmem = nbmem << 1;
3654 DBG2("Reallocating event list from %zu to %zu entries",
3655 nbmem, new_nbmem);
3656 new_tmp_event = realloc(tmp_event,
3657 new_nbmem * sizeof(struct lttng_event));
3658 if (new_tmp_event == NULL) {
3659 int release_ret;
3660
3661 PERROR("realloc ust app events");
3662 free(tmp_event);
3663 ret = -ENOMEM;
3664 release_ret = ustctl_release_handle(app->sock, handle);
3665 if (release_ret < 0 &&
3666 release_ret != -LTTNG_UST_ERR_EXITING &&
3667 release_ret != -EPIPE) {
3668 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3669 }
3670 pthread_mutex_unlock(&app->sock_lock);
3671 goto rcu_error;
3672 }
3673 /* Zero the new memory */
3674 memset(new_tmp_event + nbmem, 0,
3675 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3676 nbmem = new_nbmem;
3677 tmp_event = new_tmp_event;
3678 }
3679 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3680 tmp_event[count].loglevel = uiter.loglevel;
3681 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3682 tmp_event[count].pid = app->pid;
3683 tmp_event[count].enabled = -1;
3684 count++;
3685 }
3686 ret = ustctl_release_handle(app->sock, handle);
3687 pthread_mutex_unlock(&app->sock_lock);
3688 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3689 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3690 }
3691 }
3692
3693 ret = count;
3694 *events = tmp_event;
3695
3696 DBG2("UST app list events done (%zu events)", count);
3697
3698 rcu_error:
3699 rcu_read_unlock();
3700 error:
3701 health_code_update();
3702 return ret;
3703 }
3704
3705 /*
3706 * Fill events array with all events name of all registered apps.
3707 */
3708 int ust_app_list_event_fields(struct lttng_event_field **fields)
3709 {
3710 int ret, handle;
3711 size_t nbmem, count = 0;
3712 struct lttng_ht_iter iter;
3713 struct ust_app *app;
3714 struct lttng_event_field *tmp_event;
3715
3716 nbmem = UST_APP_EVENT_LIST_SIZE;
3717 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3718 if (tmp_event == NULL) {
3719 PERROR("zmalloc ust app event fields");
3720 ret = -ENOMEM;
3721 goto error;
3722 }
3723
3724 rcu_read_lock();
3725
3726 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3727 struct lttng_ust_field_iter uiter;
3728
3729 health_code_update();
3730
3731 if (!app->compatible) {
3732 /*
3733 * TODO: In time, we should notice the caller of this error by
3734 * telling him that this is a version error.
3735 */
3736 continue;
3737 }
3738 pthread_mutex_lock(&app->sock_lock);
3739 handle = ustctl_tracepoint_field_list(app->sock);
3740 if (handle < 0) {
3741 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3742 ERR("UST app list field getting handle failed for app pid %d",
3743 app->pid);
3744 }
3745 pthread_mutex_unlock(&app->sock_lock);
3746 continue;
3747 }
3748
3749 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3750 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3751 /* Handle ustctl error. */
3752 if (ret < 0) {
3753 int release_ret;
3754
3755 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3756 ERR("UST app tp list field failed for app %d with ret %d",
3757 app->sock, ret);
3758 } else {
3759 DBG3("UST app tp list field failed. Application is dead");
3760 /*
3761 * This is normal behavior, an application can die during the
3762 * creation process. Don't report an error so the execution can
3763 * continue normally. Reset list and count for next app.
3764 */
3765 break;
3766 }
3767 free(tmp_event);
3768 release_ret = ustctl_release_handle(app->sock, handle);
3769 pthread_mutex_unlock(&app->sock_lock);
3770 if (release_ret < 0 &&
3771 release_ret != -LTTNG_UST_ERR_EXITING &&
3772 release_ret != -EPIPE) {
3773 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3774 }
3775 goto rcu_error;
3776 }
3777
3778 health_code_update();
3779 if (count >= nbmem) {
3780 /* In case the realloc fails, we free the memory */
3781 struct lttng_event_field *new_tmp_event;
3782 size_t new_nbmem;
3783
3784 new_nbmem = nbmem << 1;
3785 DBG2("Reallocating event field list from %zu to %zu entries",
3786 nbmem, new_nbmem);
3787 new_tmp_event = realloc(tmp_event,
3788 new_nbmem * sizeof(struct lttng_event_field));
3789 if (new_tmp_event == NULL) {
3790 int release_ret;
3791
3792 PERROR("realloc ust app event fields");
3793 free(tmp_event);
3794 ret = -ENOMEM;
3795 release_ret = ustctl_release_handle(app->sock, handle);
3796 pthread_mutex_unlock(&app->sock_lock);
3797 if (release_ret &&
3798 release_ret != -LTTNG_UST_ERR_EXITING &&
3799 release_ret != -EPIPE) {
3800 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3801 }
3802 goto rcu_error;
3803 }
3804 /* Zero the new memory */
3805 memset(new_tmp_event + nbmem, 0,
3806 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3807 nbmem = new_nbmem;
3808 tmp_event = new_tmp_event;
3809 }
3810
3811 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3812 /* Mapping between these enums matches 1 to 1. */
3813 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3814 tmp_event[count].nowrite = uiter.nowrite;
3815
3816 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3817 tmp_event[count].event.loglevel = uiter.loglevel;
3818 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3819 tmp_event[count].event.pid = app->pid;
3820 tmp_event[count].event.enabled = -1;
3821 count++;
3822 }
3823 ret = ustctl_release_handle(app->sock, handle);
3824 pthread_mutex_unlock(&app->sock_lock);
3825 if (ret < 0 &&
3826 ret != -LTTNG_UST_ERR_EXITING &&
3827 ret != -EPIPE) {
3828 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3829 }
3830 }
3831
3832 ret = count;
3833 *fields = tmp_event;
3834
3835 DBG2("UST app list event fields done (%zu events)", count);
3836
3837 rcu_error:
3838 rcu_read_unlock();
3839 error:
3840 health_code_update();
3841 return ret;
3842 }
3843
3844 /*
3845 * Free and clean all traceable apps of the global list.
3846 *
3847 * Should _NOT_ be called with RCU read-side lock held.
3848 */
3849 void ust_app_clean_list(void)
3850 {
3851 int ret;
3852 struct ust_app *app;
3853 struct lttng_ht_iter iter;
3854
3855 DBG2("UST app cleaning registered apps hash table");
3856
3857 rcu_read_lock();
3858
3859 /* Cleanup notify socket hash table */
3860 if (ust_app_ht_by_notify_sock) {
3861 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3862 notify_sock_n.node) {
3863 struct cds_lfht_node *node;
3864 struct ust_app *app;
3865
3866 node = cds_lfht_iter_get_node(&iter.iter);
3867 if (!node) {
3868 continue;
3869 }
3870
3871 app = container_of(node, struct ust_app,
3872 notify_sock_n.node);
3873 ust_app_notify_sock_unregister(app->notify_sock);
3874 }
3875 }
3876
3877 if (ust_app_ht) {
3878 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3879 ret = lttng_ht_del(ust_app_ht, &iter);
3880 assert(!ret);
3881 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3882 }
3883 }
3884
3885 /* Cleanup socket hash table */
3886 if (ust_app_ht_by_sock) {
3887 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3888 sock_n.node) {
3889 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3890 assert(!ret);
3891 }
3892 }
3893
3894 rcu_read_unlock();
3895
3896 /* Destroy is done only when the ht is empty */
3897 if (ust_app_ht) {
3898 ht_cleanup_push(ust_app_ht);
3899 }
3900 if (ust_app_ht_by_sock) {
3901 ht_cleanup_push(ust_app_ht_by_sock);
3902 }
3903 if (ust_app_ht_by_notify_sock) {
3904 ht_cleanup_push(ust_app_ht_by_notify_sock);
3905 }
3906 }
3907
3908 /*
3909 * Init UST app hash table.
3910 */
3911 int ust_app_ht_alloc(void)
3912 {
3913 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3914 if (!ust_app_ht) {
3915 return -1;
3916 }
3917 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3918 if (!ust_app_ht_by_sock) {
3919 return -1;
3920 }
3921 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3922 if (!ust_app_ht_by_notify_sock) {
3923 return -1;
3924 }
3925 return 0;
3926 }
3927
3928 /*
3929 * For a specific UST session, disable the channel for all registered apps.
3930 */
3931 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3932 struct ltt_ust_channel *uchan)
3933 {
3934 int ret = 0;
3935 struct lttng_ht_iter iter;
3936 struct lttng_ht_node_str *ua_chan_node;
3937 struct ust_app *app;
3938 struct ust_app_session *ua_sess;
3939 struct ust_app_channel *ua_chan;
3940
3941 assert(usess->active);
3942 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3943 uchan->name, usess->id);
3944
3945 rcu_read_lock();
3946
3947 /* For every registered applications */
3948 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3949 struct lttng_ht_iter uiter;
3950 if (!app->compatible) {
3951 /*
3952 * TODO: In time, we should notice the caller of this error by
3953 * telling him that this is a version error.
3954 */
3955 continue;
3956 }
3957 ua_sess = lookup_session_by_app(usess, app);
3958 if (ua_sess == NULL) {
3959 continue;
3960 }
3961
3962 /* Get channel */
3963 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3964 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3965 /* If the session if found for the app, the channel must be there */
3966 assert(ua_chan_node);
3967
3968 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3969 /* The channel must not be already disabled */
3970 assert(ua_chan->enabled == 1);
3971
3972 /* Disable channel onto application */
3973 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3974 if (ret < 0) {
3975 /* XXX: We might want to report this error at some point... */
3976 continue;
3977 }
3978 }
3979
3980 rcu_read_unlock();
3981 return ret;
3982 }
3983
3984 /*
3985 * For a specific UST session, enable the channel for all registered apps.
3986 */
3987 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3988 struct ltt_ust_channel *uchan)
3989 {
3990 int ret = 0;
3991 struct lttng_ht_iter iter;
3992 struct ust_app *app;
3993 struct ust_app_session *ua_sess;
3994
3995 assert(usess->active);
3996 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3997 uchan->name, usess->id);
3998
3999 rcu_read_lock();
4000
4001 /* For every registered applications */
4002 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4003 if (!app->compatible) {
4004 /*
4005 * TODO: In time, we should notice the caller of this error by
4006 * telling him that this is a version error.
4007 */
4008 continue;
4009 }
4010 ua_sess = lookup_session_by_app(usess, app);
4011 if (ua_sess == NULL) {
4012 continue;
4013 }
4014
4015 /* Enable channel onto application */
4016 ret = enable_ust_app_channel(ua_sess, uchan, app);
4017 if (ret < 0) {
4018 /* XXX: We might want to report this error at some point... */
4019 continue;
4020 }
4021 }
4022
4023 rcu_read_unlock();
4024 return ret;
4025 }
4026
4027 /*
4028 * Disable an event in a channel and for a specific session.
4029 */
4030 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
4031 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4032 {
4033 int ret = 0;
4034 struct lttng_ht_iter iter, uiter;
4035 struct lttng_ht_node_str *ua_chan_node;
4036 struct ust_app *app;
4037 struct ust_app_session *ua_sess;
4038 struct ust_app_channel *ua_chan;
4039 struct ust_app_event *ua_event;
4040
4041 assert(usess->active);
4042 DBG("UST app disabling event %s for all apps in channel "
4043 "%s for session id %" PRIu64,
4044 uevent->attr.name, uchan->name, usess->id);
4045
4046 rcu_read_lock();
4047
4048 /* For all registered applications */
4049 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4050 if (!app->compatible) {
4051 /*
4052 * TODO: In time, we should notice the caller of this error by
4053 * telling him that this is a version error.
4054 */
4055 continue;
4056 }
4057 ua_sess = lookup_session_by_app(usess, app);
4058 if (ua_sess == NULL) {
4059 /* Next app */
4060 continue;
4061 }
4062
4063 /* Lookup channel in the ust app session */
4064 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4065 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4066 if (ua_chan_node == NULL) {
4067 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
4068 "Skipping", uchan->name, usess->id, app->pid);
4069 continue;
4070 }
4071 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4072
4073 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4074 uevent->filter, uevent->attr.loglevel,
4075 uevent->exclusion);
4076 if (ua_event == NULL) {
4077 DBG2("Event %s not found in channel %s for app pid %d."
4078 "Skipping", uevent->attr.name, uchan->name, app->pid);
4079 continue;
4080 }
4081
4082 ret = disable_ust_app_event(ua_sess, ua_event, app);
4083 if (ret < 0) {
4084 /* XXX: Report error someday... */
4085 continue;
4086 }
4087 }
4088
4089 rcu_read_unlock();
4090 return ret;
4091 }
4092
4093 /* The ua_sess lock must be held by the caller. */
4094 static
4095 int ust_app_channel_create(struct ltt_ust_session *usess,
4096 struct ust_app_session *ua_sess,
4097 struct ltt_ust_channel *uchan, struct ust_app *app,
4098 struct ust_app_channel **_ua_chan)
4099 {
4100 int ret = 0;
4101 struct ust_app_channel *ua_chan = NULL;
4102
4103 assert(ua_sess);
4104 ASSERT_LOCKED(ua_sess->lock);
4105
4106 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
4107 sizeof(uchan->name))) {
4108 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
4109 &uchan->attr);
4110 ret = 0;
4111 } else {
4112 struct ltt_ust_context *uctx = NULL;
4113
4114 /*
4115 * Create channel onto application and synchronize its
4116 * configuration.
4117 */
4118 ret = ust_app_channel_allocate(ua_sess, uchan,
4119 LTTNG_UST_CHAN_PER_CPU, usess,
4120 &ua_chan);
4121 if (ret == 0) {
4122 ret = ust_app_channel_send(app, usess,
4123 ua_sess, ua_chan);
4124 } else {
4125 goto end;
4126 }
4127
4128 /* Add contexts. */
4129 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
4130 ret = create_ust_app_channel_context(ua_chan,
4131 &uctx->ctx, app);
4132 if (ret) {
4133 goto end;
4134 }
4135 }
4136 }
4137 if (ret < 0) {
4138 switch (ret) {
4139 case -ENOTCONN:
4140 /*
4141 * The application's socket is not valid. Either a bad socket
4142 * or a timeout on it. We can't inform the caller that for a
4143 * specific app, the session failed so lets continue here.
4144 */
4145 ret = 0; /* Not an error. */
4146 break;
4147 case -ENOMEM:
4148 default:
4149 break;
4150 }
4151 }
4152 end:
4153 if (ret == 0 && _ua_chan) {
4154 /*
4155 * Only return the application's channel on success. Note
4156 * that the channel can still be part of the application's
4157 * channel hashtable on error.
4158 */
4159 *_ua_chan = ua_chan;
4160 }
4161 return ret;
4162 }
4163
4164 /*
4165 * For a specific UST session, create the channel for all registered apps.
4166 */
4167 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
4168 struct ltt_ust_channel *uchan)
4169 {
4170 int ret = 0;
4171 struct cds_lfht_iter iter;
4172 struct ust_app *app;
4173
4174 assert(usess);
4175 assert(usess->active);
4176 assert(uchan);
4177
4178 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
4179 uchan->name, usess->id);
4180
4181 rcu_read_lock();
4182 /* For every registered applications */
4183 cds_lfht_for_each_entry(ust_app_ht->ht, &iter, app, pid_n.node) {
4184 struct ust_app_session *ua_sess;
4185 int session_was_created = 0;
4186
4187 if (!app->compatible ||
4188 !trace_ust_pid_tracker_lookup(usess, app->pid)) {
4189 goto error_rcu_unlock;
4190 }
4191
4192 /*
4193 * Create session on the tracer side and add it to app session HT. Note
4194 * that if session exist, it will simply return a pointer to the ust
4195 * app session.
4196 */
4197 ret = find_or_create_ust_app_session(usess, app, &ua_sess,
4198 &session_was_created);
4199 if (ret < 0) {
4200 switch (ret) {
4201 case -ENOTCONN:
4202 /*
4203 * The application's socket is not valid. Either a bad
4204 * socket or a timeout on it. We can't inform the caller
4205 * that for a specific app, the session failed so lets
4206 * continue here; it is not an error.
4207 */
4208 ret = 0;
4209 goto error_rcu_unlock;
4210 case -ENOMEM:
4211 default:
4212 goto error_rcu_unlock;
4213 }
4214 }
4215
4216 if (ua_sess->deleted) {
4217 continue;
4218 }
4219 ret = ust_app_channel_create(usess, ua_sess, uchan, app, NULL);
4220 if (ret) {
4221 if (session_was_created) {
4222 destroy_app_session(app, ua_sess);
4223 }
4224 /* Continue to the next application. */
4225 }
4226 }
4227
4228 error_rcu_unlock:
4229 rcu_read_unlock();
4230 return ret;
4231 }
4232
4233 /*
4234 * Enable event for a specific session and channel on the tracer.
4235 */
4236 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
4237 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4238 {
4239 int ret = 0;
4240 struct lttng_ht_iter iter, uiter;
4241 struct lttng_ht_node_str *ua_chan_node;
4242 struct ust_app *app;
4243 struct ust_app_session *ua_sess;
4244 struct ust_app_channel *ua_chan;
4245 struct ust_app_event *ua_event;
4246
4247 assert(usess->active);
4248 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
4249 uevent->attr.name, usess->id);
4250
4251 /*
4252 * NOTE: At this point, this function is called only if the session and
4253 * channel passed are already created for all apps. and enabled on the
4254 * tracer also.
4255 */
4256
4257 rcu_read_lock();
4258
4259 /* For all registered applications */
4260 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4261 if (!app->compatible) {
4262 /*
4263 * TODO: In time, we should notice the caller of this error by
4264 * telling him that this is a version error.
4265 */
4266 continue;
4267 }
4268 ua_sess = lookup_session_by_app(usess, app);
4269 if (!ua_sess) {
4270 /* The application has problem or is probably dead. */
4271 continue;
4272 }
4273
4274 pthread_mutex_lock(&ua_sess->lock);
4275
4276 if (ua_sess->deleted) {
4277 pthread_mutex_unlock(&ua_sess->lock);
4278 continue;
4279 }
4280
4281 /* Lookup channel in the ust app session */
4282 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4283 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4284 /*
4285 * It is possible that the channel cannot be found is
4286 * the channel/event creation occurs concurrently with
4287 * an application exit.
4288 */
4289 if (!ua_chan_node) {
4290 pthread_mutex_unlock(&ua_sess->lock);
4291 continue;
4292 }
4293
4294 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4295
4296 /* Get event node */
4297 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4298 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4299 if (ua_event == NULL) {
4300 DBG3("UST app enable event %s not found for app PID %d."
4301 "Skipping app", uevent->attr.name, app->pid);
4302 goto next_app;
4303 }
4304
4305 ret = enable_ust_app_event(ua_sess, ua_event, app);
4306 if (ret < 0) {
4307 pthread_mutex_unlock(&ua_sess->lock);
4308 goto error;
4309 }
4310 next_app:
4311 pthread_mutex_unlock(&ua_sess->lock);
4312 }
4313
4314 error:
4315 rcu_read_unlock();
4316 return ret;
4317 }
4318
4319 /*
4320 * For a specific existing UST session and UST channel, creates the event for
4321 * all registered apps.
4322 */
4323 int ust_app_create_event_glb(struct ltt_ust_session *usess,
4324 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4325 {
4326 int ret = 0;
4327 struct lttng_ht_iter iter, uiter;
4328 struct lttng_ht_node_str *ua_chan_node;
4329 struct ust_app *app;
4330 struct ust_app_session *ua_sess;
4331 struct ust_app_channel *ua_chan;
4332
4333 assert(usess->active);
4334 DBG("UST app creating event %s for all apps for session id %" PRIu64,
4335 uevent->attr.name, usess->id);
4336
4337 rcu_read_lock();
4338
4339 /* For all registered applications */
4340 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4341 if (!app->compatible) {
4342 /*
4343 * TODO: In time, we should notice the caller of this error by
4344 * telling him that this is a version error.
4345 */
4346 continue;
4347 }
4348 ua_sess = lookup_session_by_app(usess, app);
4349 if (!ua_sess) {
4350 /* The application has problem or is probably dead. */
4351 continue;
4352 }
4353
4354 pthread_mutex_lock(&ua_sess->lock);
4355
4356 if (ua_sess->deleted) {
4357 pthread_mutex_unlock(&ua_sess->lock);
4358 continue;
4359 }
4360
4361 /* Lookup channel in the ust app session */
4362 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4363 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4364 /* If the channel is not found, there is a code flow error */
4365 assert(ua_chan_node);
4366
4367 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4368
4369 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4370 pthread_mutex_unlock(&ua_sess->lock);
4371 if (ret < 0) {
4372 if (ret != -LTTNG_UST_ERR_EXIST) {
4373 /* Possible value at this point: -ENOMEM. If so, we stop! */
4374 break;
4375 }
4376 DBG2("UST app event %s already exist on app PID %d",
4377 uevent->attr.name, app->pid);
4378 continue;
4379 }
4380 }
4381
4382 rcu_read_unlock();
4383 return ret;
4384 }
4385
4386 /*
4387 * Start tracing for a specific UST session and app.
4388 *
4389 * Called with UST app session lock held.
4390 *
4391 */
4392 static
4393 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
4394 {
4395 int ret = 0;
4396 struct ust_app_session *ua_sess;
4397
4398 DBG("Starting tracing for ust app pid %d", app->pid);
4399
4400 rcu_read_lock();
4401
4402 if (!app->compatible) {
4403 goto end;
4404 }
4405
4406 ua_sess = lookup_session_by_app(usess, app);
4407 if (ua_sess == NULL) {
4408 /* The session is in teardown process. Ignore and continue. */
4409 goto end;
4410 }
4411
4412 pthread_mutex_lock(&ua_sess->lock);
4413
4414 if (ua_sess->deleted) {
4415 pthread_mutex_unlock(&ua_sess->lock);
4416 goto end;
4417 }
4418
4419 /* Upon restart, we skip the setup, already done */
4420 if (ua_sess->started) {
4421 goto skip_setup;
4422 }
4423
4424 /*
4425 * Create the metadata for the application. This returns gracefully if a
4426 * metadata was already set for the session.
4427 */
4428 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
4429 if (ret < 0) {
4430 goto error_unlock;
4431 }
4432
4433 health_code_update();
4434
4435 skip_setup:
4436 /* This starts the UST tracing */
4437 pthread_mutex_lock(&app->sock_lock);
4438 ret = ustctl_start_session(app->sock, ua_sess->handle);
4439 pthread_mutex_unlock(&app->sock_lock);
4440 if (ret < 0) {
4441 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4442 ERR("Error starting tracing for app pid: %d (ret: %d)",
4443 app->pid, ret);
4444 } else {
4445 DBG("UST app start session failed. Application is dead.");
4446 /*
4447 * This is normal behavior, an application can die during the
4448 * creation process. Don't report an error so the execution can
4449 * continue normally.
4450 */
4451 pthread_mutex_unlock(&ua_sess->lock);
4452 goto end;
4453 }
4454 goto error_unlock;
4455 }
4456
4457 /* Indicate that the session has been started once */
4458 ua_sess->started = 1;
4459
4460 pthread_mutex_unlock(&ua_sess->lock);
4461
4462 health_code_update();
4463
4464 /* Quiescent wait after starting trace */
4465 pthread_mutex_lock(&app->sock_lock);
4466 ret = ustctl_wait_quiescent(app->sock);
4467 pthread_mutex_unlock(&app->sock_lock);
4468 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4469 ERR("UST app wait quiescent failed for app pid %d ret %d",
4470 app->pid, ret);
4471 }
4472
4473 end:
4474 rcu_read_unlock();
4475 health_code_update();
4476 return 0;
4477
4478 error_unlock:
4479 pthread_mutex_unlock(&ua_sess->lock);
4480 rcu_read_unlock();
4481 health_code_update();
4482 return -1;
4483 }
4484
4485 /*
4486 * Stop tracing for a specific UST session and app.
4487 */
4488 static
4489 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
4490 {
4491 int ret = 0;
4492 struct ust_app_session *ua_sess;
4493 struct ust_registry_session *registry;
4494
4495 DBG("Stopping tracing for ust app pid %d", app->pid);
4496
4497 rcu_read_lock();
4498
4499 if (!app->compatible) {
4500 goto end_no_session;
4501 }
4502
4503 ua_sess = lookup_session_by_app(usess, app);
4504 if (ua_sess == NULL) {
4505 goto end_no_session;
4506 }
4507
4508 pthread_mutex_lock(&ua_sess->lock);
4509
4510 if (ua_sess->deleted) {
4511 pthread_mutex_unlock(&ua_sess->lock);
4512 goto end_no_session;
4513 }
4514
4515 /*
4516 * If started = 0, it means that stop trace has been called for a session
4517 * that was never started. It's possible since we can have a fail start
4518 * from either the application manager thread or the command thread. Simply
4519 * indicate that this is a stop error.
4520 */
4521 if (!ua_sess->started) {
4522 goto error_rcu_unlock;
4523 }
4524
4525 health_code_update();
4526
4527 /* This inhibits UST tracing */
4528 pthread_mutex_lock(&app->sock_lock);
4529 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4530 pthread_mutex_unlock(&app->sock_lock);
4531 if (ret < 0) {
4532 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4533 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4534 app->pid, ret);
4535 } else {
4536 DBG("UST app stop session failed. Application is dead.");
4537 /*
4538 * This is normal behavior, an application can die during the
4539 * creation process. Don't report an error so the execution can
4540 * continue normally.
4541 */
4542 goto end_unlock;
4543 }
4544 goto error_rcu_unlock;
4545 }
4546
4547 health_code_update();
4548
4549 /* Quiescent wait after stopping trace */
4550 pthread_mutex_lock(&app->sock_lock);
4551 ret = ustctl_wait_quiescent(app->sock);
4552 pthread_mutex_unlock(&app->sock_lock);
4553 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4554 ERR("UST app wait quiescent failed for app pid %d ret %d",
4555 app->pid, ret);
4556 }
4557
4558 health_code_update();
4559
4560 registry = get_session_registry(ua_sess);
4561
4562 /* The UST app session is held registry shall not be null. */
4563 assert(registry);
4564
4565 /* Push metadata for application before freeing the application. */
4566 (void) push_metadata(registry, ua_sess->consumer);
4567
4568 end_unlock:
4569 pthread_mutex_unlock(&ua_sess->lock);
4570 end_no_session:
4571 rcu_read_unlock();
4572 health_code_update();
4573 return 0;
4574
4575 error_rcu_unlock:
4576 pthread_mutex_unlock(&ua_sess->lock);
4577 rcu_read_unlock();
4578 health_code_update();
4579 return -1;
4580 }
4581
4582 static
4583 int ust_app_flush_app_session(struct ust_app *app,
4584 struct ust_app_session *ua_sess)
4585 {
4586 int ret, retval = 0;
4587 struct lttng_ht_iter iter;
4588 struct ust_app_channel *ua_chan;
4589 struct consumer_socket *socket;
4590
4591 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4592
4593 rcu_read_lock();
4594
4595 if (!app->compatible) {
4596 goto end_not_compatible;
4597 }
4598
4599 pthread_mutex_lock(&ua_sess->lock);
4600
4601 if (ua_sess->deleted) {
4602 goto end_deleted;
4603 }
4604
4605 health_code_update();
4606
4607 /* Flushing buffers */
4608 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4609 ua_sess->consumer);
4610
4611 /* Flush buffers and push metadata. */
4612 switch (ua_sess->buffer_type) {
4613 case LTTNG_BUFFER_PER_PID:
4614 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4615 node.node) {
4616 health_code_update();
4617 ret = consumer_flush_channel(socket, ua_chan->key);
4618 if (ret) {
4619 ERR("Error flushing consumer channel");
4620 retval = -1;
4621 continue;
4622 }
4623 }
4624 break;
4625 case LTTNG_BUFFER_PER_UID:
4626 default:
4627 assert(0);
4628 break;
4629 }
4630
4631 health_code_update();
4632
4633 end_deleted:
4634 pthread_mutex_unlock(&ua_sess->lock);
4635
4636 end_not_compatible:
4637 rcu_read_unlock();
4638 health_code_update();
4639 return retval;
4640 }
4641
4642 /*
4643 * Flush buffers for all applications for a specific UST session.
4644 * Called with UST session lock held.
4645 */
4646 static
4647 int ust_app_flush_session(struct ltt_ust_session *usess)
4648
4649 {
4650 int ret = 0;
4651
4652 DBG("Flushing session buffers for all ust apps");
4653
4654 rcu_read_lock();
4655
4656 /* Flush buffers and push metadata. */
4657 switch (usess->buffer_type) {
4658 case LTTNG_BUFFER_PER_UID:
4659 {
4660 struct buffer_reg_uid *reg;
4661 struct lttng_ht_iter iter;
4662
4663 /* Flush all per UID buffers associated to that session. */
4664 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4665 struct ust_registry_session *ust_session_reg;
4666 struct buffer_reg_channel *reg_chan;
4667 struct consumer_socket *socket;
4668
4669 /* Get consumer socket to use to push the metadata.*/
4670 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4671 usess->consumer);
4672 if (!socket) {
4673 /* Ignore request if no consumer is found for the session. */
4674 continue;
4675 }
4676
4677 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4678 reg_chan, node.node) {
4679 /*
4680 * The following call will print error values so the return
4681 * code is of little importance because whatever happens, we
4682 * have to try them all.
4683 */
4684 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4685 }
4686
4687 ust_session_reg = reg->registry->reg.ust;
4688 /* Push metadata. */
4689 (void) push_metadata(ust_session_reg, usess->consumer);
4690 }
4691 break;
4692 }
4693 case LTTNG_BUFFER_PER_PID:
4694 {
4695 struct ust_app_session *ua_sess;
4696 struct lttng_ht_iter iter;
4697 struct ust_app *app;
4698
4699 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4700 ua_sess = lookup_session_by_app(usess, app);
4701 if (ua_sess == NULL) {
4702 continue;
4703 }
4704 (void) ust_app_flush_app_session(app, ua_sess);
4705 }
4706 break;
4707 }
4708 default:
4709 ret = -1;
4710 assert(0);
4711 break;
4712 }
4713
4714 rcu_read_unlock();
4715 health_code_update();
4716 return ret;
4717 }
4718
4719 static
4720 int ust_app_clear_quiescent_app_session(struct ust_app *app,
4721 struct ust_app_session *ua_sess)
4722 {
4723 int ret = 0;
4724 struct lttng_ht_iter iter;
4725 struct ust_app_channel *ua_chan;
4726 struct consumer_socket *socket;
4727
4728 DBG("Clearing stream quiescent state for ust app pid %d", app->pid);
4729
4730 rcu_read_lock();
4731
4732 if (!app->compatible) {
4733 goto end_not_compatible;
4734 }
4735
4736 pthread_mutex_lock(&ua_sess->lock);
4737
4738 if (ua_sess->deleted) {
4739 goto end_unlock;
4740 }
4741
4742 health_code_update();
4743
4744 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4745 ua_sess->consumer);
4746 if (!socket) {
4747 ERR("Failed to find consumer (%" PRIu32 ") socket",
4748 app->bits_per_long);
4749 ret = -1;
4750 goto end_unlock;
4751 }
4752
4753 /* Clear quiescent state. */
4754 switch (ua_sess->buffer_type) {
4755 case LTTNG_BUFFER_PER_PID:
4756 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter,
4757 ua_chan, node.node) {
4758 health_code_update();
4759 ret = consumer_clear_quiescent_channel(socket,
4760 ua_chan->key);
4761 if (ret) {
4762 ERR("Error clearing quiescent state for consumer channel");
4763 ret = -1;
4764 continue;
4765 }
4766 }
4767 break;
4768 case LTTNG_BUFFER_PER_UID:
4769 default:
4770 assert(0);
4771 ret = -1;
4772 break;
4773 }
4774
4775 health_code_update();
4776
4777 end_unlock:
4778 pthread_mutex_unlock(&ua_sess->lock);
4779
4780 end_not_compatible:
4781 rcu_read_unlock();
4782 health_code_update();
4783 return ret;
4784 }
4785
4786 /*
4787 * Clear quiescent state in each stream for all applications for a
4788 * specific UST session.
4789 * Called with UST session lock held.
4790 */
4791 static
4792 int ust_app_clear_quiescent_session(struct ltt_ust_session *usess)
4793
4794 {
4795 int ret = 0;
4796
4797 DBG("Clearing stream quiescent state for all ust apps");
4798
4799 rcu_read_lock();
4800
4801 switch (usess->buffer_type) {
4802 case LTTNG_BUFFER_PER_UID:
4803 {
4804 struct lttng_ht_iter iter;
4805 struct buffer_reg_uid *reg;
4806
4807 /*
4808 * Clear quiescent for all per UID buffers associated to
4809 * that session.
4810 */
4811 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4812 struct consumer_socket *socket;
4813 struct buffer_reg_channel *reg_chan;
4814
4815 /* Get associated consumer socket.*/
4816 socket = consumer_find_socket_by_bitness(
4817 reg->bits_per_long, usess->consumer);
4818 if (!socket) {
4819 /*
4820 * Ignore request if no consumer is found for
4821 * the session.
4822 */
4823 continue;
4824 }
4825
4826 cds_lfht_for_each_entry(reg->registry->channels->ht,
4827 &iter.iter, reg_chan, node.node) {
4828 /*
4829 * The following call will print error values so
4830 * the return code is of little importance
4831 * because whatever happens, we have to try them
4832 * all.
4833 */
4834 (void) consumer_clear_quiescent_channel(socket,
4835 reg_chan->consumer_key);
4836 }
4837 }
4838 break;
4839 }
4840 case LTTNG_BUFFER_PER_PID:
4841 {
4842 struct ust_app_session *ua_sess;
4843 struct lttng_ht_iter iter;
4844 struct ust_app *app;
4845
4846 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
4847 pid_n.node) {
4848 ua_sess = lookup_session_by_app(usess, app);
4849 if (ua_sess == NULL) {
4850 continue;
4851 }
4852 (void) ust_app_clear_quiescent_app_session(app,
4853 ua_sess);
4854 }
4855 break;
4856 }
4857 default:
4858 ret = -1;
4859 assert(0);
4860 break;
4861 }
4862
4863 rcu_read_unlock();
4864 health_code_update();
4865 return ret;
4866 }
4867
4868 /*
4869 * Destroy a specific UST session in apps.
4870 */
4871 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4872 {
4873 int ret;
4874 struct ust_app_session *ua_sess;
4875 struct lttng_ht_iter iter;
4876 struct lttng_ht_node_u64 *node;
4877
4878 DBG("Destroy tracing for ust app pid %d", app->pid);
4879
4880 rcu_read_lock();
4881
4882 if (!app->compatible) {
4883 goto end;
4884 }
4885
4886 __lookup_session_by_app(usess, app, &iter);
4887 node = lttng_ht_iter_get_node_u64(&iter);
4888 if (node == NULL) {
4889 /* Session is being or is deleted. */
4890 goto end;
4891 }
4892 ua_sess = caa_container_of(node, struct ust_app_session, node);
4893
4894 health_code_update();
4895 destroy_app_session(app, ua_sess);
4896
4897 health_code_update();
4898
4899 /* Quiescent wait after stopping trace */
4900 pthread_mutex_lock(&app->sock_lock);
4901 ret = ustctl_wait_quiescent(app->sock);
4902 pthread_mutex_unlock(&app->sock_lock);
4903 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4904 ERR("UST app wait quiescent failed for app pid %d ret %d",
4905 app->pid, ret);
4906 }
4907 end:
4908 rcu_read_unlock();
4909 health_code_update();
4910 return 0;
4911 }
4912
4913 /*
4914 * Start tracing for the UST session.
4915 */
4916 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4917 {
4918 struct lttng_ht_iter iter;
4919 struct ust_app *app;
4920
4921 DBG("Starting all UST traces");
4922
4923 /*
4924 * Even though the start trace might fail, flag this session active so
4925 * other application coming in are started by default.
4926 */
4927 usess->active = 1;
4928
4929 rcu_read_lock();
4930
4931 /*
4932 * In a start-stop-start use-case, we need to clear the quiescent state
4933 * of each channel set by the prior stop command, thus ensuring that a
4934 * following stop or destroy is sure to grab a timestamp_end near those
4935 * operations, even if the packet is empty.
4936 */
4937 (void) ust_app_clear_quiescent_session(usess);
4938
4939 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4940 ust_app_global_update(usess, app);
4941 }
4942
4943 rcu_read_unlock();
4944
4945 return 0;
4946 }
4947
4948 /*
4949 * Start tracing for the UST session.
4950 * Called with UST session lock held.
4951 */
4952 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4953 {
4954 int ret = 0;
4955 struct lttng_ht_iter iter;
4956 struct ust_app *app;
4957
4958 DBG("Stopping all UST traces");
4959
4960 /*
4961 * Even though the stop trace might fail, flag this session inactive so
4962 * other application coming in are not started by default.
4963 */
4964 usess->active = 0;
4965
4966 rcu_read_lock();
4967
4968 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4969 ret = ust_app_stop_trace(usess, app);
4970 if (ret < 0) {
4971 /* Continue to next apps even on error */
4972 continue;
4973 }
4974 }
4975
4976 (void) ust_app_flush_session(usess);
4977
4978 rcu_read_unlock();
4979
4980 return 0;
4981 }
4982
4983 /*
4984 * Destroy app UST session.
4985 */
4986 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4987 {
4988 int ret = 0;
4989 struct lttng_ht_iter iter;
4990 struct ust_app *app;
4991
4992 DBG("Destroy all UST traces");
4993
4994 rcu_read_lock();
4995
4996 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4997 ret = destroy_trace(usess, app);
4998 if (ret < 0) {
4999 /* Continue to next apps even on error */
5000 continue;
5001 }
5002 }
5003
5004 rcu_read_unlock();
5005
5006 return 0;
5007 }
5008
5009 /* The ua_sess lock must be held by the caller. */
5010 static
5011 int find_or_create_ust_app_channel(
5012 struct ltt_ust_session *usess,
5013 struct ust_app_session *ua_sess,
5014 struct ust_app *app,
5015 struct ltt_ust_channel *uchan,
5016 struct ust_app_channel **ua_chan)
5017 {
5018 int ret = 0;
5019 struct lttng_ht_iter iter;
5020 struct lttng_ht_node_str *ua_chan_node;
5021
5022 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &iter);
5023 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
5024 if (ua_chan_node) {
5025 *ua_chan = caa_container_of(ua_chan_node,
5026 struct ust_app_channel, node);
5027 goto end;
5028 }
5029
5030 ret = ust_app_channel_create(usess, ua_sess, uchan, app, ua_chan);
5031 if (ret) {
5032 goto end;
5033 }
5034 end:
5035 return ret;
5036 }
5037
5038 static
5039 int ust_app_channel_synchronize_event(struct ust_app_channel *ua_chan,
5040 struct ltt_ust_event *uevent, struct ust_app_session *ua_sess,
5041 struct ust_app *app)
5042 {
5043 int ret = 0;
5044 struct ust_app_event *ua_event = NULL;
5045
5046 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
5047 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
5048 if (!ua_event) {
5049 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
5050 if (ret < 0) {
5051 goto end;
5052 }
5053 } else {
5054 if (ua_event->enabled != uevent->enabled) {
5055 ret = uevent->enabled ?
5056 enable_ust_app_event(ua_sess, ua_event, app) :
5057 disable_ust_app_event(ua_sess, ua_event, app);
5058 }
5059 }
5060
5061 end:
5062 return ret;
5063 }
5064
5065 /*
5066 * The caller must ensure that the application is compatible and is tracked
5067 * by the PID tracker.
5068 */
5069 static
5070 void ust_app_synchronize(struct ltt_ust_session *usess,
5071 struct ust_app *app)
5072 {
5073 int ret = 0;
5074 struct cds_lfht_iter uchan_iter;
5075 struct ltt_ust_channel *uchan;
5076 struct ust_app_session *ua_sess = NULL;
5077
5078 /*
5079 * The application's configuration should only be synchronized for
5080 * active sessions.
5081 */
5082 assert(usess->active);
5083
5084 ret = find_or_create_ust_app_session(usess, app, &ua_sess, NULL);
5085 if (ret < 0) {
5086 /* Tracer is probably gone or ENOMEM. */
5087 goto error;
5088 }
5089 assert(ua_sess);
5090
5091 pthread_mutex_lock(&ua_sess->lock);
5092 if (ua_sess->deleted) {
5093 pthread_mutex_unlock(&ua_sess->lock);
5094 goto end;
5095 }
5096
5097 rcu_read_lock();
5098 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &uchan_iter,
5099 uchan, node.node) {
5100 struct ust_app_channel *ua_chan;
5101 struct cds_lfht_iter uevent_iter;
5102 struct ltt_ust_event *uevent;
5103
5104 /*
5105 * Search for a matching ust_app_channel. If none is found,
5106 * create it. Creating the channel will cause the ua_chan
5107 * structure to be allocated, the channel buffers to be
5108 * allocated (if necessary) and sent to the application, and
5109 * all enabled contexts will be added to the channel.
5110 */
5111 ret = find_or_create_ust_app_channel(usess, ua_sess,
5112 app, uchan, &ua_chan);
5113 if (ret) {
5114 /* Tracer is probably gone or ENOMEM. */
5115 goto error_unlock;
5116 }
5117
5118 if (!ua_chan) {
5119 /* ua_chan will be NULL for the metadata channel */
5120 continue;
5121 }
5122
5123 cds_lfht_for_each_entry(uchan->events->ht, &uevent_iter, uevent,
5124 node.node) {
5125 ret = ust_app_channel_synchronize_event(ua_chan,
5126 uevent, ua_sess, app);
5127 if (ret) {
5128 goto error_unlock;
5129 }
5130 }
5131
5132 if (ua_chan->enabled != uchan->enabled) {
5133 ret = uchan->enabled ?
5134 enable_ust_app_channel(ua_sess, uchan, app) :
5135 disable_ust_app_channel(ua_sess, ua_chan, app);
5136 if (ret) {
5137 goto error_unlock;
5138 }
5139 }
5140 }
5141 rcu_read_unlock();
5142
5143 end:
5144 pthread_mutex_unlock(&ua_sess->lock);
5145 /* Everything went well at this point. */
5146 return;
5147
5148 error_unlock:
5149 rcu_read_unlock();
5150 pthread_mutex_unlock(&ua_sess->lock);
5151 error:
5152 if (ua_sess) {
5153 destroy_app_session(app, ua_sess);
5154 }
5155 return;
5156 }
5157
5158 static
5159 void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
5160 {
5161 struct ust_app_session *ua_sess;
5162
5163 ua_sess = lookup_session_by_app(usess, app);
5164 if (ua_sess == NULL) {
5165 return;
5166 }
5167 destroy_app_session(app, ua_sess);
5168 }
5169
5170 /*
5171 * Add channels/events from UST global domain to registered apps at sock.
5172 *
5173 * Called with session lock held.
5174 * Called with RCU read-side lock held.
5175 */
5176 void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
5177 {
5178 assert(usess);
5179 assert(usess->active);
5180
5181 DBG2("UST app global update for app sock %d for session id %" PRIu64,
5182 app->sock, usess->id);
5183
5184 if (!app->compatible) {
5185 return;
5186 }
5187 if (trace_ust_pid_tracker_lookup(usess, app->pid)) {
5188 /*
5189 * Synchronize the application's internal tracing configuration
5190 * and start tracing.
5191 */
5192 ust_app_synchronize(usess, app);
5193 ust_app_start_trace(usess, app);
5194 } else {
5195 ust_app_global_destroy(usess, app);
5196 }
5197 }
5198
5199 /*
5200 * Called with session lock held.
5201 */
5202 void ust_app_global_update_all(struct ltt_ust_session *usess)
5203 {
5204 struct lttng_ht_iter iter;
5205 struct ust_app *app;
5206
5207 rcu_read_lock();
5208 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5209 ust_app_global_update(usess, app);
5210 }
5211 rcu_read_unlock();
5212 }
5213
5214 /*
5215 * Add context to a specific channel for global UST domain.
5216 */
5217 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
5218 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
5219 {
5220 int ret = 0;
5221 struct lttng_ht_node_str *ua_chan_node;
5222 struct lttng_ht_iter iter, uiter;
5223 struct ust_app_channel *ua_chan = NULL;
5224 struct ust_app_session *ua_sess;
5225 struct ust_app *app;
5226
5227 assert(usess->active);
5228
5229 rcu_read_lock();
5230 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5231 if (!app->compatible) {
5232 /*
5233 * TODO: In time, we should notice the caller of this error by
5234 * telling him that this is a version error.
5235 */
5236 continue;
5237 }
5238 ua_sess = lookup_session_by_app(usess, app);
5239 if (ua_sess == NULL) {
5240 continue;
5241 }
5242
5243 pthread_mutex_lock(&ua_sess->lock);
5244
5245 if (ua_sess->deleted) {
5246 pthread_mutex_unlock(&ua_sess->lock);
5247 continue;
5248 }
5249
5250 /* Lookup channel in the ust app session */
5251 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
5252 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
5253 if (ua_chan_node == NULL) {
5254 goto next_app;
5255 }
5256 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
5257 node);
5258 ret = create_ust_app_channel_context(ua_chan, &uctx->ctx, app);
5259 if (ret < 0) {
5260 goto next_app;
5261 }
5262 next_app:
5263 pthread_mutex_unlock(&ua_sess->lock);
5264 }
5265
5266 rcu_read_unlock();
5267 return ret;
5268 }
5269
5270 /*
5271 * Receive registration and populate the given msg structure.
5272 *
5273 * On success return 0 else a negative value returned by the ustctl call.
5274 */
5275 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
5276 {
5277 int ret;
5278 uint32_t pid, ppid, uid, gid;
5279
5280 assert(msg);
5281
5282 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
5283 &pid, &ppid, &uid, &gid,
5284 &msg->bits_per_long,
5285 &msg->uint8_t_alignment,
5286 &msg->uint16_t_alignment,
5287 &msg->uint32_t_alignment,
5288 &msg->uint64_t_alignment,
5289 &msg->long_alignment,
5290 &msg->byte_order,
5291 msg->name);
5292 if (ret < 0) {
5293 switch (-ret) {
5294 case EPIPE:
5295 case ECONNRESET:
5296 case LTTNG_UST_ERR_EXITING:
5297 DBG3("UST app recv reg message failed. Application died");
5298 break;
5299 case LTTNG_UST_ERR_UNSUP_MAJOR:
5300 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
5301 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
5302 LTTNG_UST_ABI_MINOR_VERSION);
5303 break;
5304 default:
5305 ERR("UST app recv reg message failed with ret %d", ret);
5306 break;
5307 }
5308 goto error;
5309 }
5310 msg->pid = (pid_t) pid;
5311 msg->ppid = (pid_t) ppid;
5312 msg->uid = (uid_t) uid;
5313 msg->gid = (gid_t) gid;
5314
5315 error:
5316 return ret;
5317 }
5318
5319 /*
5320 * Return a ust app session object using the application object and the
5321 * session object descriptor has a key. If not found, NULL is returned.
5322 * A RCU read side lock MUST be acquired when calling this function.
5323 */
5324 static struct ust_app_session *find_session_by_objd(struct ust_app *app,
5325 int objd)
5326 {
5327 struct lttng_ht_node_ulong *node;
5328 struct lttng_ht_iter iter;
5329 struct ust_app_session *ua_sess = NULL;
5330
5331 assert(app);
5332
5333 lttng_ht_lookup(app->ust_sessions_objd, (void *)((unsigned long) objd), &iter);
5334 node = lttng_ht_iter_get_node_ulong(&iter);
5335 if (node == NULL) {
5336 DBG2("UST app session find by objd %d not found", objd);
5337 goto error;
5338 }
5339
5340 ua_sess = caa_container_of(node, struct ust_app_session, ust_objd_node);
5341
5342 error:
5343 return ua_sess;
5344 }
5345
5346 /*
5347 * Return a ust app channel object using the application object and the channel
5348 * object descriptor has a key. If not found, NULL is returned. A RCU read side
5349 * lock MUST be acquired before calling this function.
5350 */
5351 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
5352 int objd)
5353 {
5354 struct lttng_ht_node_ulong *node;
5355 struct lttng_ht_iter iter;
5356 struct ust_app_channel *ua_chan = NULL;
5357
5358 assert(app);
5359
5360 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
5361 node = lttng_ht_iter_get_node_ulong(&iter);
5362 if (node == NULL) {
5363 DBG2("UST app channel find by objd %d not found", objd);
5364 goto error;
5365 }
5366
5367 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
5368
5369 error:
5370 return ua_chan;
5371 }
5372
5373 /*
5374 * Reply to a register channel notification from an application on the notify
5375 * socket. The channel metadata is also created.
5376 *
5377 * The session UST registry lock is acquired in this function.
5378 *
5379 * On success 0 is returned else a negative value.
5380 */
5381 static int reply_ust_register_channel(int sock, int cobjd,
5382 size_t nr_fields, struct ustctl_field *fields)
5383 {
5384 int ret, ret_code = 0;
5385 uint32_t chan_id;
5386 uint64_t chan_reg_key;
5387 enum ustctl_channel_header type;
5388 struct ust_app *app;
5389 struct ust_app_channel *ua_chan;
5390 struct ust_app_session *ua_sess;
5391 struct ust_registry_session *registry;
5392 struct ust_registry_channel *chan_reg;
5393
5394 rcu_read_lock();
5395
5396 /* Lookup application. If not found, there is a code flow error. */
5397 app = find_app_by_notify_sock(sock);
5398 if (!app) {
5399 DBG("Application socket %d is being torn down. Abort event notify",
5400 sock);
5401 ret = 0;
5402 goto error_rcu_unlock;
5403 }
5404
5405 /* Lookup channel by UST object descriptor. */
5406 ua_chan = find_channel_by_objd(app, cobjd);
5407 if (!ua_chan) {
5408 DBG("Application channel is being torn down. Abort event notify");
5409 ret = 0;
5410 goto error_rcu_unlock;
5411 }
5412
5413 assert(ua_chan->session);
5414 ua_sess = ua_chan->session;
5415
5416 /* Get right session registry depending on the session buffer type. */
5417 registry = get_session_registry(ua_sess);
5418 if (!registry) {
5419 DBG("Application session is being torn down. Abort event notify");
5420 ret = 0;
5421 goto error_rcu_unlock;
5422 };
5423
5424 /* Depending on the buffer type, a different channel key is used. */
5425 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5426 chan_reg_key = ua_chan->tracing_channel_id;
5427 } else {
5428 chan_reg_key = ua_chan->key;
5429 }
5430
5431 pthread_mutex_lock(&registry->lock);
5432
5433 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
5434 assert(chan_reg);
5435
5436 if (!chan_reg->register_done) {
5437 /*
5438 * TODO: eventually use the registry event count for
5439 * this channel to better guess header type for per-pid
5440 * buffers.
5441 */
5442 type = USTCTL_CHANNEL_HEADER_LARGE;
5443 chan_reg->nr_ctx_fields = nr_fields;
5444 chan_reg->ctx_fields = fields;
5445 fields = NULL;
5446 chan_reg->header_type = type;
5447 } else {
5448 /* Get current already assigned values. */
5449 type = chan_reg->header_type;
5450 }
5451 /* Channel id is set during the object creation. */
5452 chan_id = chan_reg->chan_id;
5453
5454 /* Append to metadata */
5455 if (!chan_reg->metadata_dumped) {
5456 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
5457 if (ret_code) {
5458 ERR("Error appending channel metadata (errno = %d)", ret_code);
5459 goto reply;
5460 }
5461 }
5462
5463 reply:
5464 DBG3("UST app replying to register channel key %" PRIu64
5465 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
5466 ret_code);
5467
5468 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
5469 if (ret < 0) {
5470 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5471 ERR("UST app reply channel failed with ret %d", ret);
5472 } else {
5473 DBG3("UST app reply channel failed. Application died");
5474 }
5475 goto error;
5476 }
5477
5478 /* This channel registry registration is completed. */
5479 chan_reg->register_done = 1;
5480
5481 error:
5482 pthread_mutex_unlock(&registry->lock);
5483 error_rcu_unlock:
5484 rcu_read_unlock();
5485 free(fields);
5486 return ret;
5487 }
5488
5489 /*
5490 * Add event to the UST channel registry. When the event is added to the
5491 * registry, the metadata is also created. Once done, this replies to the
5492 * application with the appropriate error code.
5493 *
5494 * The session UST registry lock is acquired in the function.
5495 *
5496 * On success 0 is returned else a negative value.
5497 */
5498 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
5499 char *sig, size_t nr_fields, struct ustctl_field *fields,
5500 int loglevel_value, char *model_emf_uri)
5501 {
5502 int ret, ret_code;
5503 uint32_t event_id = 0;
5504 uint64_t chan_reg_key;
5505 struct ust_app *app;
5506 struct ust_app_channel *ua_chan;
5507 struct ust_app_session *ua_sess;
5508 struct ust_registry_session *registry;
5509
5510 rcu_read_lock();
5511
5512 /* Lookup application. If not found, there is a code flow error. */
5513 app = find_app_by_notify_sock(sock);
5514 if (!app) {
5515 DBG("Application socket %d is being torn down. Abort event notify",
5516 sock);
5517 ret = 0;
5518 goto error_rcu_unlock;
5519 }
5520
5521 /* Lookup channel by UST object descriptor. */
5522 ua_chan = find_channel_by_objd(app, cobjd);
5523 if (!ua_chan) {
5524 DBG("Application channel is being torn down. Abort event notify");
5525 ret = 0;
5526 goto error_rcu_unlock;
5527 }
5528
5529 assert(ua_chan->session);
5530 ua_sess = ua_chan->session;
5531
5532 registry = get_session_registry(ua_sess);
5533 if (!registry) {
5534 DBG("Application session is being torn down. Abort event notify");
5535 ret = 0;
5536 goto error_rcu_unlock;
5537 }
5538
5539 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5540 chan_reg_key = ua_chan->tracing_channel_id;
5541 } else {
5542 chan_reg_key = ua_chan->key;
5543 }
5544
5545 pthread_mutex_lock(&registry->lock);
5546
5547 /*
5548 * From this point on, this call acquires the ownership of the sig, fields
5549 * and model_emf_uri meaning any free are done inside it if needed. These
5550 * three variables MUST NOT be read/write after this.
5551 */
5552 ret_code = ust_registry_create_event(registry, chan_reg_key,
5553 sobjd, cobjd, name, sig, nr_fields, fields,
5554 loglevel_value, model_emf_uri, ua_sess->buffer_type,
5555 &event_id, app);
5556 sig = NULL;
5557 fields = NULL;
5558 model_emf_uri = NULL;
5559
5560 /*
5561 * The return value is returned to ustctl so in case of an error, the
5562 * application can be notified. In case of an error, it's important not to
5563 * return a negative error or else the application will get closed.
5564 */
5565 ret = ustctl_reply_register_event(sock, event_id, ret_code);
5566 if (ret < 0) {
5567 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5568 ERR("UST app reply event failed with ret %d", ret);
5569 } else {
5570 DBG3("UST app reply event failed. Application died");
5571 }
5572 /*
5573 * No need to wipe the create event since the application socket will
5574 * get close on error hence cleaning up everything by itself.
5575 */
5576 goto error;
5577 }
5578
5579 DBG3("UST registry event %s with id %" PRId32 " added successfully",
5580 name, event_id);
5581
5582 error:
5583 pthread_mutex_unlock(&registry->lock);
5584 error_rcu_unlock:
5585 rcu_read_unlock();
5586 free(sig);
5587 free(fields);
5588 free(model_emf_uri);
5589 return ret;
5590 }
5591
5592 /*
5593 * Add enum to the UST session registry. Once done, this replies to the
5594 * application with the appropriate error code.
5595 *
5596 * The session UST registry lock is acquired within this function.
5597 *
5598 * On success 0 is returned else a negative value.
5599 */
5600 static int add_enum_ust_registry(int sock, int sobjd, char *name,
5601 struct ustctl_enum_entry *entries, size_t nr_entries)
5602 {
5603 int ret = 0, ret_code;
5604 struct ust_app *app;
5605 struct ust_app_session *ua_sess;
5606 struct ust_registry_session *registry;
5607 uint64_t enum_id = -1ULL;
5608
5609 rcu_read_lock();
5610
5611 /* Lookup application. If not found, there is a code flow error. */
5612 app = find_app_by_notify_sock(sock);
5613 if (!app) {
5614 /* Return an error since this is not an error */
5615 DBG("Application socket %d is being torn down. Aborting enum registration",
5616 sock);
5617 free(entries);
5618 goto error_rcu_unlock;
5619 }
5620
5621 /* Lookup session by UST object descriptor. */
5622 ua_sess = find_session_by_objd(app, sobjd);
5623 if (!ua_sess) {
5624 /* Return an error since this is not an error */
5625 DBG("Application session is being torn down (session not found). Aborting enum registration.");
5626 free(entries);
5627 goto error_rcu_unlock;
5628 }
5629
5630 registry = get_session_registry(ua_sess);
5631 if (!registry) {
5632 DBG("Application session is being torn down (registry not found). Aborting enum registration.");
5633 free(entries);
5634 goto error_rcu_unlock;
5635 }
5636
5637 pthread_mutex_lock(&registry->lock);
5638
5639 /*
5640 * From this point on, the callee acquires the ownership of
5641 * entries. The variable entries MUST NOT be read/written after
5642 * call.
5643 */
5644 ret_code = ust_registry_create_or_find_enum(registry, sobjd, name,
5645 entries, nr_entries, &enum_id);
5646 entries = NULL;
5647
5648 /*
5649 * The return value is returned to ustctl so in case of an error, the
5650 * application can be notified. In case of an error, it's important not to
5651 * return a negative error or else the application will get closed.
5652 */
5653 ret = ustctl_reply_register_enum(sock, enum_id, ret_code);
5654 if (ret < 0) {
5655 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5656 ERR("UST app reply enum failed with ret %d", ret);
5657 } else {
5658 DBG3("UST app reply enum failed. Application died");
5659 }
5660 /*
5661 * No need to wipe the create enum since the application socket will
5662 * get close on error hence cleaning up everything by itself.
5663 */
5664 goto error;
5665 }
5666
5667 DBG3("UST registry enum %s added successfully or already found", name);
5668
5669 error:
5670 pthread_mutex_unlock(&registry->lock);
5671 error_rcu_unlock:
5672 rcu_read_unlock();
5673 return ret;
5674 }
5675
5676 /*
5677 * Handle application notification through the given notify socket.
5678 *
5679 * Return 0 on success or else a negative value.
5680 */
5681 int ust_app_recv_notify(int sock)
5682 {
5683 int ret;
5684 enum ustctl_notify_cmd cmd;
5685
5686 DBG3("UST app receiving notify from sock %d", sock);
5687
5688 ret = ustctl_recv_notify(sock, &cmd);
5689 if (ret < 0) {
5690 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5691 ERR("UST app recv notify failed with ret %d", ret);
5692 } else {
5693 DBG3("UST app recv notify failed. Application died");
5694 }
5695 goto error;
5696 }
5697
5698 switch (cmd) {
5699 case USTCTL_NOTIFY_CMD_EVENT:
5700 {
5701 int sobjd, cobjd, loglevel_value;
5702 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
5703 size_t nr_fields;
5704 struct ustctl_field *fields;
5705
5706 DBG2("UST app ustctl register event received");
5707
5708 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
5709 &loglevel_value, &sig, &nr_fields, &fields,
5710 &model_emf_uri);
5711 if (ret < 0) {
5712 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5713 ERR("UST app recv event failed with ret %d", ret);
5714 } else {
5715 DBG3("UST app recv event failed. Application died");
5716 }
5717 goto error;
5718 }
5719
5720 /*
5721 * Add event to the UST registry coming from the notify socket. This
5722 * call will free if needed the sig, fields and model_emf_uri. This
5723 * code path loses the ownsership of these variables and transfer them
5724 * to the this function.
5725 */
5726 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
5727 fields, loglevel_value, model_emf_uri);
5728 if (ret < 0) {
5729 goto error;
5730 }
5731
5732 break;
5733 }
5734 case USTCTL_NOTIFY_CMD_CHANNEL:
5735 {
5736 int sobjd, cobjd;
5737 size_t nr_fields;
5738 struct ustctl_field *fields;
5739
5740 DBG2("UST app ustctl register channel received");
5741
5742 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
5743 &fields);
5744 if (ret < 0) {
5745 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5746 ERR("UST app recv channel failed with ret %d", ret);
5747 } else {
5748 DBG3("UST app recv channel failed. Application died");
5749 }
5750 goto error;
5751 }
5752
5753 /*
5754 * The fields ownership are transfered to this function call meaning
5755 * that if needed it will be freed. After this, it's invalid to access
5756 * fields or clean it up.
5757 */
5758 ret = reply_ust_register_channel(sock, cobjd, nr_fields,
5759 fields);
5760 if (ret < 0) {
5761 goto error;
5762 }
5763
5764 break;
5765 }
5766 case USTCTL_NOTIFY_CMD_ENUM:
5767 {
5768 int sobjd;
5769 char name[LTTNG_UST_SYM_NAME_LEN];
5770 size_t nr_entries;
5771 struct ustctl_enum_entry *entries;
5772
5773 DBG2("UST app ustctl register enum received");
5774
5775 ret = ustctl_recv_register_enum(sock, &sobjd, name,
5776 &entries, &nr_entries);
5777 if (ret < 0) {
5778 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5779 ERR("UST app recv enum failed with ret %d", ret);
5780 } else {
5781 DBG3("UST app recv enum failed. Application died");
5782 }
5783 goto error;
5784 }
5785
5786 /* Callee assumes ownership of entries */
5787 ret = add_enum_ust_registry(sock, sobjd, name,
5788 entries, nr_entries);
5789 if (ret < 0) {
5790 goto error;
5791 }
5792
5793 break;
5794 }
5795 default:
5796 /* Should NEVER happen. */
5797 assert(0);
5798 }
5799
5800 error:
5801 return ret;
5802 }
5803
5804 /*
5805 * Once the notify socket hangs up, this is called. First, it tries to find the
5806 * corresponding application. On failure, the call_rcu to close the socket is
5807 * executed. If an application is found, it tries to delete it from the notify
5808 * socket hash table. Whathever the result, it proceeds to the call_rcu.
5809 *
5810 * Note that an object needs to be allocated here so on ENOMEM failure, the
5811 * call RCU is not done but the rest of the cleanup is.
5812 */
5813 void ust_app_notify_sock_unregister(int sock)
5814 {
5815 int err_enomem = 0;
5816 struct lttng_ht_iter iter;
5817 struct ust_app *app;
5818 struct ust_app_notify_sock_obj *obj;
5819
5820 assert(sock >= 0);
5821
5822 rcu_read_lock();
5823
5824 obj = zmalloc(sizeof(*obj));
5825 if (!obj) {
5826 /*
5827 * An ENOMEM is kind of uncool. If this strikes we continue the
5828 * procedure but the call_rcu will not be called. In this case, we
5829 * accept the fd leak rather than possibly creating an unsynchronized
5830 * state between threads.
5831 *
5832 * TODO: The notify object should be created once the notify socket is
5833 * registered and stored independantely from the ust app object. The
5834 * tricky part is to synchronize the teardown of the application and
5835 * this notify object. Let's keep that in mind so we can avoid this
5836 * kind of shenanigans with ENOMEM in the teardown path.
5837 */
5838 err_enomem = 1;
5839 } else {
5840 obj->fd = sock;
5841 }
5842
5843 DBG("UST app notify socket unregister %d", sock);
5844
5845 /*
5846 * Lookup application by notify socket. If this fails, this means that the
5847 * hash table delete has already been done by the application
5848 * unregistration process so we can safely close the notify socket in a
5849 * call RCU.
5850 */
5851 app = find_app_by_notify_sock(sock);
5852 if (!app) {
5853 goto close_socket;
5854 }
5855
5856 iter.iter.node = &app->notify_sock_n.node;
5857
5858 /*
5859 * Whatever happens here either we fail or succeed, in both cases we have
5860 * to close the socket after a grace period to continue to the call RCU
5861 * here. If the deletion is successful, the application is not visible
5862 * anymore by other threads and is it fails it means that it was already
5863 * deleted from the hash table so either way we just have to close the
5864 * socket.
5865 */
5866 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5867
5868 close_socket:
5869 rcu_read_unlock();
5870
5871 /*
5872 * Close socket after a grace period to avoid for the socket to be reused
5873 * before the application object is freed creating potential race between
5874 * threads trying to add unique in the global hash table.
5875 */
5876 if (!err_enomem) {
5877 call_rcu(&obj->head, close_notify_sock_rcu);
5878 }
5879 }
5880
5881 /*
5882 * Destroy a ust app data structure and free its memory.
5883 */
5884 void ust_app_destroy(struct ust_app *app)
5885 {
5886 if (!app) {
5887 return;
5888 }
5889
5890 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5891 }
5892
5893 /*
5894 * Take a snapshot for a given UST session. The snapshot is sent to the given
5895 * output.
5896 *
5897 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
5898 */
5899 enum lttng_error_code ust_app_snapshot_record(
5900 const struct ltt_ust_session *usess,
5901 const struct consumer_output *output, int wait,
5902 uint64_t nb_packets_per_stream)
5903 {
5904 int ret = 0;
5905 enum lttng_error_code status = LTTNG_OK;
5906 struct lttng_ht_iter iter;
5907 struct ust_app *app;
5908 char *trace_path = NULL;
5909
5910 assert(usess);
5911 assert(output);
5912
5913 rcu_read_lock();
5914
5915 switch (usess->buffer_type) {
5916 case LTTNG_BUFFER_PER_UID:
5917 {
5918 struct buffer_reg_uid *reg;
5919
5920 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5921 struct buffer_reg_channel *reg_chan;
5922 struct consumer_socket *socket;
5923 char pathname[PATH_MAX];
5924
5925 if (!reg->registry->reg.ust->metadata_key) {
5926 /* Skip since no metadata is present */
5927 continue;
5928 }
5929
5930 /* Get consumer socket to use to push the metadata.*/
5931 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5932 usess->consumer);
5933 if (!socket) {
5934 status = LTTNG_ERR_INVALID;
5935 goto error;
5936 }
5937
5938 memset(pathname, 0, sizeof(pathname));
5939 /*
5940 * DEFAULT_UST_TRACE_UID_PATH already contains a path
5941 * separator.
5942 */
5943 ret = snprintf(pathname, sizeof(pathname),
5944 DEFAULT_UST_TRACE_DIR DEFAULT_UST_TRACE_UID_PATH,
5945 reg->uid, reg->bits_per_long);
5946 if (ret < 0) {
5947 PERROR("snprintf snapshot path");
5948 status = LTTNG_ERR_INVALID;
5949 goto error;
5950 }
5951 /* Free path allowed on previous iteration. */
5952 free(trace_path);
5953 trace_path = setup_channel_trace_path(usess->consumer, pathname);
5954 if (!trace_path) {
5955 status = LTTNG_ERR_INVALID;
5956 goto error;
5957 }
5958 /* Add the UST default trace dir to path. */
5959 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5960 reg_chan, node.node) {
5961 status = consumer_snapshot_channel(socket,
5962 reg_chan->consumer_key,
5963 output, 0, usess->uid,
5964 usess->gid, trace_path, wait,
5965 nb_packets_per_stream);
5966 if (status != LTTNG_OK) {
5967 goto error;
5968 }
5969 }
5970 status = consumer_snapshot_channel(socket,
5971 reg->registry->reg.ust->metadata_key, output, 1,
5972 usess->uid, usess->gid, trace_path, wait, 0);
5973 if (status != LTTNG_OK) {
5974 goto error;
5975 }
5976 }
5977 break;
5978 }
5979 case LTTNG_BUFFER_PER_PID:
5980 {
5981 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5982 struct consumer_socket *socket;
5983 struct lttng_ht_iter chan_iter;
5984 struct ust_app_channel *ua_chan;
5985 struct ust_app_session *ua_sess;
5986 struct ust_registry_session *registry;
5987 char pathname[PATH_MAX];
5988
5989 ua_sess = lookup_session_by_app(usess, app);
5990 if (!ua_sess) {
5991 /* Session not associated with this app. */
5992 continue;
5993 }
5994
5995 /* Get the right consumer socket for the application. */
5996 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5997 output);
5998 if (!socket) {
5999 status = LTTNG_ERR_INVALID;
6000 goto error;
6001 }
6002
6003 /* Add the UST default trace dir to path. */
6004 memset(pathname, 0, sizeof(pathname));
6005 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "%s",
6006 ua_sess->path);
6007 if (ret < 0) {
6008 status = LTTNG_ERR_INVALID;
6009 PERROR("snprintf snapshot path");
6010 goto error;
6011 }
6012 /* Free path allowed on previous iteration. */
6013 free(trace_path);
6014 trace_path = setup_channel_trace_path(usess->consumer, pathname);
6015 if (!trace_path) {
6016 status = LTTNG_ERR_INVALID;
6017 goto error;
6018 }
6019 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6020 ua_chan, node.node) {
6021 status = consumer_snapshot_channel(socket,
6022 ua_chan->key, output, 0,
6023 ua_sess->effective_credentials
6024 .uid,
6025 ua_sess->effective_credentials
6026 .gid,
6027 trace_path, wait,
6028 nb_packets_per_stream);
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
6039 registry = get_session_registry(ua_sess);
6040 if (!registry) {
6041 DBG("Application session is being torn down. Skip application.");
6042 continue;
6043 }
6044 status = consumer_snapshot_channel(socket,
6045 registry->metadata_key, output, 1,
6046 ua_sess->effective_credentials.uid,
6047 ua_sess->effective_credentials.gid,
6048 trace_path, wait, 0);
6049 switch (status) {
6050 case LTTNG_OK:
6051 break;
6052 case LTTNG_ERR_CHAN_NOT_FOUND:
6053 continue;
6054 default:
6055 goto error;
6056 }
6057 }
6058 break;
6059 }
6060 default:
6061 assert(0);
6062 break;
6063 }
6064
6065 error:
6066 free(trace_path);
6067 rcu_read_unlock();
6068 return status;
6069 }
6070
6071 /*
6072 * Return the size taken by one more packet per stream.
6073 */
6074 uint64_t ust_app_get_size_one_more_packet_per_stream(
6075 const struct ltt_ust_session *usess, uint64_t cur_nr_packets)
6076 {
6077 uint64_t tot_size = 0;
6078 struct ust_app *app;
6079 struct lttng_ht_iter iter;
6080
6081 assert(usess);
6082
6083 switch (usess->buffer_type) {
6084 case LTTNG_BUFFER_PER_UID:
6085 {
6086 struct buffer_reg_uid *reg;
6087
6088 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6089 struct buffer_reg_channel *reg_chan;
6090
6091 rcu_read_lock();
6092 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6093 reg_chan, node.node) {
6094 if (cur_nr_packets >= reg_chan->num_subbuf) {
6095 /*
6096 * Don't take channel into account if we
6097 * already grab all its packets.
6098 */
6099 continue;
6100 }
6101 tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
6102 }
6103 rcu_read_unlock();
6104 }
6105 break;
6106 }
6107 case LTTNG_BUFFER_PER_PID:
6108 {
6109 rcu_read_lock();
6110 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6111 struct ust_app_channel *ua_chan;
6112 struct ust_app_session *ua_sess;
6113 struct lttng_ht_iter chan_iter;
6114
6115 ua_sess = lookup_session_by_app(usess, app);
6116 if (!ua_sess) {
6117 /* Session not associated with this app. */
6118 continue;
6119 }
6120
6121 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6122 ua_chan, node.node) {
6123 if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
6124 /*
6125 * Don't take channel into account if we
6126 * already grab all its packets.
6127 */
6128 continue;
6129 }
6130 tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
6131 }
6132 }
6133 rcu_read_unlock();
6134 break;
6135 }
6136 default:
6137 assert(0);
6138 break;
6139 }
6140
6141 return tot_size;
6142 }
6143
6144 int ust_app_uid_get_channel_runtime_stats(uint64_t ust_session_id,
6145 struct cds_list_head *buffer_reg_uid_list,
6146 struct consumer_output *consumer, uint64_t uchan_id,
6147 int overwrite, uint64_t *discarded, uint64_t *lost)
6148 {
6149 int ret;
6150 uint64_t consumer_chan_key;
6151
6152 *discarded = 0;
6153 *lost = 0;
6154
6155 ret = buffer_reg_uid_consumer_channel_key(
6156 buffer_reg_uid_list, uchan_id, &consumer_chan_key);
6157 if (ret < 0) {
6158 /* Not found */
6159 ret = 0;
6160 goto end;
6161 }
6162
6163 if (overwrite) {
6164 ret = consumer_get_lost_packets(ust_session_id,
6165 consumer_chan_key, consumer, lost);
6166 } else {
6167 ret = consumer_get_discarded_events(ust_session_id,
6168 consumer_chan_key, consumer, discarded);
6169 }
6170
6171 end:
6172 return ret;
6173 }
6174
6175 int ust_app_pid_get_channel_runtime_stats(struct ltt_ust_session *usess,
6176 struct ltt_ust_channel *uchan,
6177 struct consumer_output *consumer, int overwrite,
6178 uint64_t *discarded, uint64_t *lost)
6179 {
6180 int ret = 0;
6181 struct lttng_ht_iter iter;
6182 struct lttng_ht_node_str *ua_chan_node;
6183 struct ust_app *app;
6184 struct ust_app_session *ua_sess;
6185 struct ust_app_channel *ua_chan;
6186
6187 *discarded = 0;
6188 *lost = 0;
6189
6190 rcu_read_lock();
6191 /*
6192 * Iterate over every registered applications. Sum counters for
6193 * all applications containing requested session and channel.
6194 */
6195 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6196 struct lttng_ht_iter uiter;
6197
6198 ua_sess = lookup_session_by_app(usess, app);
6199 if (ua_sess == NULL) {
6200 continue;
6201 }
6202
6203 /* Get channel */
6204 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &uiter);
6205 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
6206 /* If the session is found for the app, the channel must be there */
6207 assert(ua_chan_node);
6208
6209 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
6210
6211 if (overwrite) {
6212 uint64_t _lost;
6213
6214 ret = consumer_get_lost_packets(usess->id, ua_chan->key,
6215 consumer, &_lost);
6216 if (ret < 0) {
6217 break;
6218 }
6219 (*lost) += _lost;
6220 } else {
6221 uint64_t _discarded;
6222
6223 ret = consumer_get_discarded_events(usess->id,
6224 ua_chan->key, consumer, &_discarded);
6225 if (ret < 0) {
6226 break;
6227 }
6228 (*discarded) += _discarded;
6229 }
6230 }
6231
6232 rcu_read_unlock();
6233 return ret;
6234 }
6235
6236 static
6237 int ust_app_regenerate_statedump(struct ltt_ust_session *usess,
6238 struct ust_app *app)
6239 {
6240 int ret = 0;
6241 struct ust_app_session *ua_sess;
6242
6243 DBG("Regenerating the metadata for ust app pid %d", app->pid);
6244
6245 rcu_read_lock();
6246
6247 ua_sess = lookup_session_by_app(usess, app);
6248 if (ua_sess == NULL) {
6249 /* The session is in teardown process. Ignore and continue. */
6250 goto end;
6251 }
6252
6253 pthread_mutex_lock(&ua_sess->lock);
6254
6255 if (ua_sess->deleted) {
6256 goto end_unlock;
6257 }
6258
6259 pthread_mutex_lock(&app->sock_lock);
6260 ret = ustctl_regenerate_statedump(app->sock, ua_sess->handle);
6261 pthread_mutex_unlock(&app->sock_lock);
6262
6263 end_unlock:
6264 pthread_mutex_unlock(&ua_sess->lock);
6265
6266 end:
6267 rcu_read_unlock();
6268 health_code_update();
6269 return ret;
6270 }
6271
6272 /*
6273 * Regenerate the statedump for each app in the session.
6274 */
6275 int ust_app_regenerate_statedump_all(struct ltt_ust_session *usess)
6276 {
6277 int ret = 0;
6278 struct lttng_ht_iter iter;
6279 struct ust_app *app;
6280
6281 DBG("Regenerating the metadata for all UST apps");
6282
6283 rcu_read_lock();
6284
6285 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6286 if (!app->compatible) {
6287 continue;
6288 }
6289
6290 ret = ust_app_regenerate_statedump(usess, app);
6291 if (ret < 0) {
6292 /* Continue to the next app even on error */
6293 continue;
6294 }
6295 }
6296
6297 rcu_read_unlock();
6298
6299 return 0;
6300 }
6301
6302 /*
6303 * Rotate all the channels of a session.
6304 *
6305 * Return LTTNG_OK on success or else an LTTng error code.
6306 */
6307 enum lttng_error_code ust_app_rotate_session(struct ltt_session *session)
6308 {
6309 int ret;
6310 enum lttng_error_code cmd_ret = LTTNG_OK;
6311 struct lttng_ht_iter iter;
6312 struct ust_app *app;
6313 struct ltt_ust_session *usess = session->ust_session;
6314
6315 assert(usess);
6316
6317 rcu_read_lock();
6318
6319 switch (usess->buffer_type) {
6320 case LTTNG_BUFFER_PER_UID:
6321 {
6322 struct buffer_reg_uid *reg;
6323
6324 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6325 struct buffer_reg_channel *reg_chan;
6326 struct consumer_socket *socket;
6327
6328 /* Get consumer socket to use to push the metadata.*/
6329 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
6330 usess->consumer);
6331 if (!socket) {
6332 cmd_ret = LTTNG_ERR_INVALID;
6333 goto error;
6334 }
6335
6336 /* Rotate the data channels. */
6337 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6338 reg_chan, node.node) {
6339 ret = consumer_rotate_channel(socket,
6340 reg_chan->consumer_key,
6341 usess->uid, usess->gid,
6342 usess->consumer,
6343 /* is_metadata_channel */ false);
6344 if (ret < 0) {
6345 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6346 goto error;
6347 }
6348 }
6349
6350 (void) push_metadata(reg->registry->reg.ust, usess->consumer);
6351
6352 ret = consumer_rotate_channel(socket,
6353 reg->registry->reg.ust->metadata_key,
6354 usess->uid, usess->gid,
6355 usess->consumer,
6356 /* is_metadata_channel */ true);
6357 if (ret < 0) {
6358 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6359 goto error;
6360 }
6361 }
6362 break;
6363 }
6364 case LTTNG_BUFFER_PER_PID:
6365 {
6366 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6367 struct consumer_socket *socket;
6368 struct lttng_ht_iter chan_iter;
6369 struct ust_app_channel *ua_chan;
6370 struct ust_app_session *ua_sess;
6371 struct ust_registry_session *registry;
6372
6373 ua_sess = lookup_session_by_app(usess, app);
6374 if (!ua_sess) {
6375 /* Session not associated with this app. */
6376 continue;
6377 }
6378
6379 /* Get the right consumer socket for the application. */
6380 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6381 usess->consumer);
6382 if (!socket) {
6383 cmd_ret = LTTNG_ERR_INVALID;
6384 goto error;
6385 }
6386
6387 registry = get_session_registry(ua_sess);
6388 if (!registry) {
6389 DBG("Application session is being torn down. Skip application.");
6390 continue;
6391 }
6392
6393 /* Rotate the data channels. */
6394 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6395 ua_chan, node.node) {
6396 ret = consumer_rotate_channel(socket,
6397 ua_chan->key,
6398 ua_sess->effective_credentials
6399 .uid,
6400 ua_sess->effective_credentials
6401 .gid,
6402 ua_sess->consumer,
6403 /* is_metadata_channel */ false);
6404 if (ret < 0) {
6405 /* Per-PID buffer and application going away. */
6406 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6407 continue;
6408 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6409 goto error;
6410 }
6411 }
6412
6413 /* Rotate the metadata channel. */
6414 (void) push_metadata(registry, usess->consumer);
6415 ret = consumer_rotate_channel(socket,
6416 registry->metadata_key,
6417 ua_sess->effective_credentials.uid,
6418 ua_sess->effective_credentials.gid,
6419 ua_sess->consumer,
6420 /* is_metadata_channel */ true);
6421 if (ret < 0) {
6422 /* Per-PID buffer and application going away. */
6423 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6424 continue;
6425 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6426 goto error;
6427 }
6428 }
6429 break;
6430 }
6431 default:
6432 assert(0);
6433 break;
6434 }
6435
6436 cmd_ret = LTTNG_OK;
6437
6438 error:
6439 rcu_read_unlock();
6440 return cmd_ret;
6441 }
6442
6443 enum lttng_error_code ust_app_create_channel_subdirectories(
6444 const struct ltt_ust_session *usess)
6445 {
6446 enum lttng_error_code ret = LTTNG_OK;
6447 struct lttng_ht_iter iter;
6448 enum lttng_trace_chunk_status chunk_status;
6449 char *pathname_index;
6450 int fmt_ret;
6451
6452 assert(usess->current_trace_chunk);
6453 rcu_read_lock();
6454
6455 switch (usess->buffer_type) {
6456 case LTTNG_BUFFER_PER_UID:
6457 {
6458 struct buffer_reg_uid *reg;
6459
6460 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6461 fmt_ret = asprintf(&pathname_index,
6462 DEFAULT_UST_TRACE_DIR DEFAULT_UST_TRACE_UID_PATH "/" DEFAULT_INDEX_DIR,
6463 reg->uid, reg->bits_per_long);
6464 if (fmt_ret < 0) {
6465 ERR("Failed to format channel index directory");
6466 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6467 goto error;
6468 }
6469
6470 /*
6471 * Create the index subdirectory which will take care
6472 * of implicitly creating the channel's path.
6473 */
6474 chunk_status = lttng_trace_chunk_create_subdirectory(
6475 usess->current_trace_chunk,
6476 pathname_index);
6477 free(pathname_index);
6478 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6479 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6480 goto error;
6481 }
6482 }
6483 break;
6484 }
6485 case LTTNG_BUFFER_PER_PID:
6486 {
6487 struct ust_app *app;
6488
6489 /*
6490 * Create the toplevel ust/ directory in case no apps are running.
6491 */
6492 chunk_status = lttng_trace_chunk_create_subdirectory(
6493 usess->current_trace_chunk,
6494 DEFAULT_UST_TRACE_DIR);
6495 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6496 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6497 goto error;
6498 }
6499
6500 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
6501 pid_n.node) {
6502 struct ust_app_session *ua_sess;
6503 struct ust_registry_session *registry;
6504
6505 ua_sess = lookup_session_by_app(usess, app);
6506 if (!ua_sess) {
6507 /* Session not associated with this app. */
6508 continue;
6509 }
6510
6511 registry = get_session_registry(ua_sess);
6512 if (!registry) {
6513 DBG("Application session is being torn down. Skip application.");
6514 continue;
6515 }
6516
6517 fmt_ret = asprintf(&pathname_index,
6518 DEFAULT_UST_TRACE_DIR "%s/" DEFAULT_INDEX_DIR,
6519 ua_sess->path);
6520 if (fmt_ret < 0) {
6521 ERR("Failed to format channel index directory");
6522 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6523 goto error;
6524 }
6525 /*
6526 * Create the index subdirectory which will take care
6527 * of implicitly creating the channel's path.
6528 */
6529 chunk_status = lttng_trace_chunk_create_subdirectory(
6530 usess->current_trace_chunk,
6531 pathname_index);
6532 free(pathname_index);
6533 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6534 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6535 goto error;
6536 }
6537 }
6538 break;
6539 }
6540 default:
6541 abort();
6542 }
6543
6544 ret = LTTNG_OK;
6545 error:
6546 rcu_read_unlock();
6547 return ret;
6548 }
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