Fix: sessiond: snapshot: handle consumer return codes
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <lttng/ust-error.h>
31 #include <signal.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35
36 #include "buffer-registry.h"
37 #include "fd-limit.h"
38 #include "health-sessiond.h"
39 #include "ust-app.h"
40 #include "ust-consumer.h"
41 #include "ust-ctl.h"
42 #include "utils.h"
43 #include "session.h"
44 #include "lttng-sessiond.h"
45 #include "notification-thread-commands.h"
46 #include "rotate.h"
47
48 static
49 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51 /* Next available channel key. Access under next_channel_key_lock. */
52 static uint64_t _next_channel_key;
53 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55 /* Next available session ID. Access under next_session_id_lock. */
56 static uint64_t _next_session_id;
57 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59 /*
60 * Return the incremented value of next_channel_key.
61 */
62 static uint64_t get_next_channel_key(void)
63 {
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70 }
71
72 /*
73 * Return the atomically incremented value of next_session_id.
74 */
75 static uint64_t get_next_session_id(void)
76 {
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83 }
84
85 static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88 {
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97 }
98
99 /*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106 {
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173 no_match:
174 return 0;
175 }
176
177 /*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183 {
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202 }
203
204 /*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208 static void close_notify_sock_rcu(struct rcu_head *head)
209 {
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224 }
225
226 /*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233 static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235 {
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
254 if (!reg_uid) {
255 goto error;
256 }
257 registry = reg_uid->registry->reg.ust;
258 break;
259 }
260 default:
261 assert(0);
262 };
263
264 error:
265 return registry;
266 }
267
268 /*
269 * Delete ust context safely. RCU read lock must be held before calling
270 * this function.
271 */
272 static
273 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
274 struct ust_app *app)
275 {
276 int ret;
277
278 assert(ua_ctx);
279
280 if (ua_ctx->obj) {
281 pthread_mutex_lock(&app->sock_lock);
282 ret = ustctl_release_object(sock, ua_ctx->obj);
283 pthread_mutex_unlock(&app->sock_lock);
284 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
285 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
286 sock, ua_ctx->obj->handle, ret);
287 }
288 free(ua_ctx->obj);
289 }
290 free(ua_ctx);
291 }
292
293 /*
294 * Delete ust app event safely. RCU read lock must be held before calling
295 * this function.
296 */
297 static
298 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
299 struct ust_app *app)
300 {
301 int ret;
302
303 assert(ua_event);
304
305 free(ua_event->filter);
306 if (ua_event->exclusion != NULL)
307 free(ua_event->exclusion);
308 if (ua_event->obj != NULL) {
309 pthread_mutex_lock(&app->sock_lock);
310 ret = ustctl_release_object(sock, ua_event->obj);
311 pthread_mutex_unlock(&app->sock_lock);
312 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
313 ERR("UST app sock %d release event obj failed with ret %d",
314 sock, ret);
315 }
316 free(ua_event->obj);
317 }
318 free(ua_event);
319 }
320
321 /*
322 * Release ust data object of the given stream.
323 *
324 * Return 0 on success or else a negative value.
325 */
326 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
327 struct ust_app *app)
328 {
329 int ret = 0;
330
331 assert(stream);
332
333 if (stream->obj) {
334 pthread_mutex_lock(&app->sock_lock);
335 ret = ustctl_release_object(sock, stream->obj);
336 pthread_mutex_unlock(&app->sock_lock);
337 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
338 ERR("UST app sock %d release stream obj failed with ret %d",
339 sock, ret);
340 }
341 lttng_fd_put(LTTNG_FD_APPS, 2);
342 free(stream->obj);
343 }
344
345 return ret;
346 }
347
348 /*
349 * Delete ust app stream safely. RCU read lock must be held before calling
350 * this function.
351 */
352 static
353 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
354 struct ust_app *app)
355 {
356 assert(stream);
357
358 (void) release_ust_app_stream(sock, stream, app);
359 free(stream);
360 }
361
362 /*
363 * We need to execute ht_destroy outside of RCU read-side critical
364 * section and outside of call_rcu thread, so we postpone its execution
365 * using ht_cleanup_push. It is simpler than to change the semantic of
366 * the many callers of delete_ust_app_session().
367 */
368 static
369 void delete_ust_app_channel_rcu(struct rcu_head *head)
370 {
371 struct ust_app_channel *ua_chan =
372 caa_container_of(head, struct ust_app_channel, rcu_head);
373
374 ht_cleanup_push(ua_chan->ctx);
375 ht_cleanup_push(ua_chan->events);
376 free(ua_chan);
377 }
378
379 /*
380 * Extract the lost packet or discarded events counter when the channel is
381 * being deleted and store the value in the parent channel so we can
382 * access it from lttng list and at stop/destroy.
383 *
384 * The session list lock must be held by the caller.
385 */
386 static
387 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
388 {
389 uint64_t discarded = 0, lost = 0;
390 struct ltt_session *session;
391 struct ltt_ust_channel *uchan;
392
393 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
394 return;
395 }
396
397 rcu_read_lock();
398 session = session_find_by_id(ua_chan->session->tracing_id);
399 if (!session || !session->ust_session) {
400 /*
401 * Not finding the session is not an error because there are
402 * multiple ways the channels can be torn down.
403 *
404 * 1) The session daemon can initiate the destruction of the
405 * ust app session after receiving a destroy command or
406 * during its shutdown/teardown.
407 * 2) The application, since we are in per-pid tracing, is
408 * unregistering and tearing down its ust app session.
409 *
410 * Both paths are protected by the session list lock which
411 * ensures that the accounting of lost packets and discarded
412 * events is done exactly once. The session is then unpublished
413 * from the session list, resulting in this condition.
414 */
415 goto end;
416 }
417
418 if (ua_chan->attr.overwrite) {
419 consumer_get_lost_packets(ua_chan->session->tracing_id,
420 ua_chan->key, session->ust_session->consumer,
421 &lost);
422 } else {
423 consumer_get_discarded_events(ua_chan->session->tracing_id,
424 ua_chan->key, session->ust_session->consumer,
425 &discarded);
426 }
427 uchan = trace_ust_find_channel_by_name(
428 session->ust_session->domain_global.channels,
429 ua_chan->name);
430 if (!uchan) {
431 ERR("Missing UST channel to store discarded counters");
432 goto end;
433 }
434
435 uchan->per_pid_closed_app_discarded += discarded;
436 uchan->per_pid_closed_app_lost += lost;
437
438 end:
439 rcu_read_unlock();
440 }
441
442 /*
443 * Delete ust app channel safely. RCU read lock must be held before calling
444 * this function.
445 *
446 * The session list lock must be held by the caller.
447 */
448 static
449 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
450 struct ust_app *app)
451 {
452 int ret;
453 struct lttng_ht_iter iter;
454 struct ust_app_event *ua_event;
455 struct ust_app_ctx *ua_ctx;
456 struct ust_app_stream *stream, *stmp;
457 struct ust_registry_session *registry;
458
459 assert(ua_chan);
460
461 DBG3("UST app deleting channel %s", ua_chan->name);
462
463 /* Wipe stream */
464 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
465 cds_list_del(&stream->list);
466 delete_ust_app_stream(sock, stream, app);
467 }
468
469 /* Wipe context */
470 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
471 cds_list_del(&ua_ctx->list);
472 ret = lttng_ht_del(ua_chan->ctx, &iter);
473 assert(!ret);
474 delete_ust_app_ctx(sock, ua_ctx, app);
475 }
476
477 /* Wipe events */
478 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
479 node.node) {
480 ret = lttng_ht_del(ua_chan->events, &iter);
481 assert(!ret);
482 delete_ust_app_event(sock, ua_event, app);
483 }
484
485 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
486 /* Wipe and free registry from session registry. */
487 registry = get_session_registry(ua_chan->session);
488 if (registry) {
489 ust_registry_channel_del_free(registry, ua_chan->key,
490 sock >= 0);
491 }
492 if (sock >= 0) {
493 save_per_pid_lost_discarded_counters(ua_chan);
494 }
495 }
496
497 if (ua_chan->obj != NULL) {
498 /* Remove channel from application UST object descriptor. */
499 iter.iter.node = &ua_chan->ust_objd_node.node;
500 ret = lttng_ht_del(app->ust_objd, &iter);
501 assert(!ret);
502 pthread_mutex_lock(&app->sock_lock);
503 ret = ustctl_release_object(sock, ua_chan->obj);
504 pthread_mutex_unlock(&app->sock_lock);
505 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
506 ERR("UST app sock %d release channel obj failed with ret %d",
507 sock, ret);
508 }
509 lttng_fd_put(LTTNG_FD_APPS, 1);
510 free(ua_chan->obj);
511 }
512 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
513 }
514
515 int ust_app_register_done(struct ust_app *app)
516 {
517 int ret;
518
519 pthread_mutex_lock(&app->sock_lock);
520 ret = ustctl_register_done(app->sock);
521 pthread_mutex_unlock(&app->sock_lock);
522 return ret;
523 }
524
525 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
526 {
527 int ret, sock;
528
529 if (app) {
530 pthread_mutex_lock(&app->sock_lock);
531 sock = app->sock;
532 } else {
533 sock = -1;
534 }
535 ret = ustctl_release_object(sock, data);
536 if (app) {
537 pthread_mutex_unlock(&app->sock_lock);
538 }
539 return ret;
540 }
541
542 /*
543 * Push metadata to consumer socket.
544 *
545 * RCU read-side lock must be held to guarantee existance of socket.
546 * Must be called with the ust app session lock held.
547 * Must be called with the registry lock held.
548 *
549 * On success, return the len of metadata pushed or else a negative value.
550 * Returning a -EPIPE return value means we could not send the metadata,
551 * but it can be caused by recoverable errors (e.g. the application has
552 * terminated concurrently).
553 */
554 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
555 struct consumer_socket *socket, int send_zero_data)
556 {
557 int ret;
558 char *metadata_str = NULL;
559 size_t len, offset, new_metadata_len_sent;
560 ssize_t ret_val;
561 uint64_t metadata_key, metadata_version;
562
563 assert(registry);
564 assert(socket);
565
566 metadata_key = registry->metadata_key;
567
568 /*
569 * Means that no metadata was assigned to the session. This can
570 * happens if no start has been done previously.
571 */
572 if (!metadata_key) {
573 return 0;
574 }
575
576 offset = registry->metadata_len_sent;
577 len = registry->metadata_len - registry->metadata_len_sent;
578 new_metadata_len_sent = registry->metadata_len;
579 metadata_version = registry->metadata_version;
580 if (len == 0) {
581 DBG3("No metadata to push for metadata key %" PRIu64,
582 registry->metadata_key);
583 ret_val = len;
584 if (send_zero_data) {
585 DBG("No metadata to push");
586 goto push_data;
587 }
588 goto end;
589 }
590
591 /* Allocate only what we have to send. */
592 metadata_str = zmalloc(len);
593 if (!metadata_str) {
594 PERROR("zmalloc ust app metadata string");
595 ret_val = -ENOMEM;
596 goto error;
597 }
598 /* Copy what we haven't sent out. */
599 memcpy(metadata_str, registry->metadata + offset, len);
600
601 push_data:
602 pthread_mutex_unlock(&registry->lock);
603 /*
604 * We need to unlock the registry while we push metadata to
605 * break a circular dependency between the consumerd metadata
606 * lock and the sessiond registry lock. Indeed, pushing metadata
607 * to the consumerd awaits that it gets pushed all the way to
608 * relayd, but doing so requires grabbing the metadata lock. If
609 * a concurrent metadata request is being performed by
610 * consumerd, this can try to grab the registry lock on the
611 * sessiond while holding the metadata lock on the consumer
612 * daemon. Those push and pull schemes are performed on two
613 * different bidirectionnal communication sockets.
614 */
615 ret = consumer_push_metadata(socket, metadata_key,
616 metadata_str, len, offset, metadata_version);
617 pthread_mutex_lock(&registry->lock);
618 if (ret < 0) {
619 /*
620 * There is an acceptable race here between the registry
621 * metadata key assignment and the creation on the
622 * consumer. The session daemon can concurrently push
623 * metadata for this registry while being created on the
624 * consumer since the metadata key of the registry is
625 * assigned *before* it is setup to avoid the consumer
626 * to ask for metadata that could possibly be not found
627 * in the session daemon.
628 *
629 * The metadata will get pushed either by the session
630 * being stopped or the consumer requesting metadata if
631 * that race is triggered.
632 */
633 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
634 ret = 0;
635 } else {
636 ERR("Error pushing metadata to consumer");
637 }
638 ret_val = ret;
639 goto error_push;
640 } else {
641 /*
642 * Metadata may have been concurrently pushed, since
643 * we're not holding the registry lock while pushing to
644 * consumer. This is handled by the fact that we send
645 * the metadata content, size, and the offset at which
646 * that metadata belongs. This may arrive out of order
647 * on the consumer side, and the consumer is able to
648 * deal with overlapping fragments. The consumer
649 * supports overlapping fragments, which must be
650 * contiguous starting from offset 0. We keep the
651 * largest metadata_len_sent value of the concurrent
652 * send.
653 */
654 registry->metadata_len_sent =
655 max_t(size_t, registry->metadata_len_sent,
656 new_metadata_len_sent);
657 }
658 free(metadata_str);
659 return len;
660
661 end:
662 error:
663 if (ret_val) {
664 /*
665 * On error, flag the registry that the metadata is
666 * closed. We were unable to push anything and this
667 * means that either the consumer is not responding or
668 * the metadata cache has been destroyed on the
669 * consumer.
670 */
671 registry->metadata_closed = 1;
672 }
673 error_push:
674 free(metadata_str);
675 return ret_val;
676 }
677
678 /*
679 * For a given application and session, push metadata to consumer.
680 * Either sock or consumer is required : if sock is NULL, the default
681 * socket to send the metadata is retrieved from consumer, if sock
682 * is not NULL we use it to send the metadata.
683 * RCU read-side lock must be held while calling this function,
684 * therefore ensuring existance of registry. It also ensures existance
685 * of socket throughout this function.
686 *
687 * Return 0 on success else a negative error.
688 * Returning a -EPIPE return value means we could not send the metadata,
689 * but it can be caused by recoverable errors (e.g. the application has
690 * terminated concurrently).
691 */
692 static int push_metadata(struct ust_registry_session *registry,
693 struct consumer_output *consumer)
694 {
695 int ret_val;
696 ssize_t ret;
697 struct consumer_socket *socket;
698
699 assert(registry);
700 assert(consumer);
701
702 pthread_mutex_lock(&registry->lock);
703 if (registry->metadata_closed) {
704 ret_val = -EPIPE;
705 goto error;
706 }
707
708 /* Get consumer socket to use to push the metadata.*/
709 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
710 consumer);
711 if (!socket) {
712 ret_val = -1;
713 goto error;
714 }
715
716 ret = ust_app_push_metadata(registry, socket, 0);
717 if (ret < 0) {
718 ret_val = ret;
719 goto error;
720 }
721 pthread_mutex_unlock(&registry->lock);
722 return 0;
723
724 error:
725 pthread_mutex_unlock(&registry->lock);
726 return ret_val;
727 }
728
729 /*
730 * Send to the consumer a close metadata command for the given session. Once
731 * done, the metadata channel is deleted and the session metadata pointer is
732 * nullified. The session lock MUST be held unless the application is
733 * in the destroy path.
734 *
735 * Return 0 on success else a negative value.
736 */
737 static int close_metadata(struct ust_registry_session *registry,
738 struct consumer_output *consumer)
739 {
740 int ret;
741 struct consumer_socket *socket;
742
743 assert(registry);
744 assert(consumer);
745
746 rcu_read_lock();
747
748 pthread_mutex_lock(&registry->lock);
749
750 if (!registry->metadata_key || registry->metadata_closed) {
751 ret = 0;
752 goto end;
753 }
754
755 /* Get consumer socket to use to push the metadata.*/
756 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
757 consumer);
758 if (!socket) {
759 ret = -1;
760 goto error;
761 }
762
763 ret = consumer_close_metadata(socket, registry->metadata_key);
764 if (ret < 0) {
765 goto error;
766 }
767
768 error:
769 /*
770 * Metadata closed. Even on error this means that the consumer is not
771 * responding or not found so either way a second close should NOT be emit
772 * for this registry.
773 */
774 registry->metadata_closed = 1;
775 end:
776 pthread_mutex_unlock(&registry->lock);
777 rcu_read_unlock();
778 return ret;
779 }
780
781 /*
782 * We need to execute ht_destroy outside of RCU read-side critical
783 * section and outside of call_rcu thread, so we postpone its execution
784 * using ht_cleanup_push. It is simpler than to change the semantic of
785 * the many callers of delete_ust_app_session().
786 */
787 static
788 void delete_ust_app_session_rcu(struct rcu_head *head)
789 {
790 struct ust_app_session *ua_sess =
791 caa_container_of(head, struct ust_app_session, rcu_head);
792
793 ht_cleanup_push(ua_sess->channels);
794 free(ua_sess);
795 }
796
797 /*
798 * Delete ust app session safely. RCU read lock must be held before calling
799 * this function.
800 *
801 * The session list lock must be held by the caller.
802 */
803 static
804 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
805 struct ust_app *app)
806 {
807 int ret;
808 struct lttng_ht_iter iter;
809 struct ust_app_channel *ua_chan;
810 struct ust_registry_session *registry;
811
812 assert(ua_sess);
813
814 pthread_mutex_lock(&ua_sess->lock);
815
816 assert(!ua_sess->deleted);
817 ua_sess->deleted = true;
818
819 registry = get_session_registry(ua_sess);
820 /* Registry can be null on error path during initialization. */
821 if (registry) {
822 /* Push metadata for application before freeing the application. */
823 (void) push_metadata(registry, ua_sess->consumer);
824
825 /*
826 * Don't ask to close metadata for global per UID buffers. Close
827 * metadata only on destroy trace session in this case. Also, the
828 * previous push metadata could have flag the metadata registry to
829 * close so don't send a close command if closed.
830 */
831 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
832 /* And ask to close it for this session registry. */
833 (void) close_metadata(registry, ua_sess->consumer);
834 }
835 }
836
837 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
838 node.node) {
839 ret = lttng_ht_del(ua_sess->channels, &iter);
840 assert(!ret);
841 delete_ust_app_channel(sock, ua_chan, app);
842 }
843
844 /* In case of per PID, the registry is kept in the session. */
845 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
846 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
847 if (reg_pid) {
848 /*
849 * Registry can be null on error path during
850 * initialization.
851 */
852 buffer_reg_pid_remove(reg_pid);
853 buffer_reg_pid_destroy(reg_pid);
854 }
855 }
856
857 if (ua_sess->handle != -1) {
858 pthread_mutex_lock(&app->sock_lock);
859 ret = ustctl_release_handle(sock, ua_sess->handle);
860 pthread_mutex_unlock(&app->sock_lock);
861 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
862 ERR("UST app sock %d release session handle failed with ret %d",
863 sock, ret);
864 }
865 /* Remove session from application UST object descriptor. */
866 iter.iter.node = &ua_sess->ust_objd_node.node;
867 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
868 assert(!ret);
869 }
870
871 pthread_mutex_unlock(&ua_sess->lock);
872
873 consumer_output_put(ua_sess->consumer);
874
875 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
876 }
877
878 /*
879 * Delete a traceable application structure from the global list. Never call
880 * this function outside of a call_rcu call.
881 *
882 * RCU read side lock should _NOT_ be held when calling this function.
883 */
884 static
885 void delete_ust_app(struct ust_app *app)
886 {
887 int ret, sock;
888 struct ust_app_session *ua_sess, *tmp_ua_sess;
889
890 /*
891 * The session list lock must be held during this function to guarantee
892 * the existence of ua_sess.
893 */
894 session_lock_list();
895 /* Delete ust app sessions info */
896 sock = app->sock;
897 app->sock = -1;
898
899 /* Wipe sessions */
900 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
901 teardown_node) {
902 /* Free every object in the session and the session. */
903 rcu_read_lock();
904 delete_ust_app_session(sock, ua_sess, app);
905 rcu_read_unlock();
906 }
907
908 ht_cleanup_push(app->sessions);
909 ht_cleanup_push(app->ust_sessions_objd);
910 ht_cleanup_push(app->ust_objd);
911
912 /*
913 * Wait until we have deleted the application from the sock hash table
914 * before closing this socket, otherwise an application could re-use the
915 * socket ID and race with the teardown, using the same hash table entry.
916 *
917 * It's OK to leave the close in call_rcu. We want it to stay unique for
918 * all RCU readers that could run concurrently with unregister app,
919 * therefore we _need_ to only close that socket after a grace period. So
920 * it should stay in this RCU callback.
921 *
922 * This close() is a very important step of the synchronization model so
923 * every modification to this function must be carefully reviewed.
924 */
925 ret = close(sock);
926 if (ret) {
927 PERROR("close");
928 }
929 lttng_fd_put(LTTNG_FD_APPS, 1);
930
931 DBG2("UST app pid %d deleted", app->pid);
932 free(app);
933 session_unlock_list();
934 }
935
936 /*
937 * URCU intermediate call to delete an UST app.
938 */
939 static
940 void delete_ust_app_rcu(struct rcu_head *head)
941 {
942 struct lttng_ht_node_ulong *node =
943 caa_container_of(head, struct lttng_ht_node_ulong, head);
944 struct ust_app *app =
945 caa_container_of(node, struct ust_app, pid_n);
946
947 DBG3("Call RCU deleting app PID %d", app->pid);
948 delete_ust_app(app);
949 }
950
951 /*
952 * Delete the session from the application ht and delete the data structure by
953 * freeing every object inside and releasing them.
954 *
955 * The session list lock must be held by the caller.
956 */
957 static void destroy_app_session(struct ust_app *app,
958 struct ust_app_session *ua_sess)
959 {
960 int ret;
961 struct lttng_ht_iter iter;
962
963 assert(app);
964 assert(ua_sess);
965
966 iter.iter.node = &ua_sess->node.node;
967 ret = lttng_ht_del(app->sessions, &iter);
968 if (ret) {
969 /* Already scheduled for teardown. */
970 goto end;
971 }
972
973 /* Once deleted, free the data structure. */
974 delete_ust_app_session(app->sock, ua_sess, app);
975
976 end:
977 return;
978 }
979
980 /*
981 * Alloc new UST app session.
982 */
983 static
984 struct ust_app_session *alloc_ust_app_session(void)
985 {
986 struct ust_app_session *ua_sess;
987
988 /* Init most of the default value by allocating and zeroing */
989 ua_sess = zmalloc(sizeof(struct ust_app_session));
990 if (ua_sess == NULL) {
991 PERROR("malloc");
992 goto error_free;
993 }
994
995 ua_sess->handle = -1;
996 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
997 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
998 pthread_mutex_init(&ua_sess->lock, NULL);
999
1000 return ua_sess;
1001
1002 error_free:
1003 return NULL;
1004 }
1005
1006 /*
1007 * Alloc new UST app channel.
1008 */
1009 static
1010 struct ust_app_channel *alloc_ust_app_channel(char *name,
1011 struct ust_app_session *ua_sess,
1012 struct lttng_ust_channel_attr *attr)
1013 {
1014 struct ust_app_channel *ua_chan;
1015
1016 /* Init most of the default value by allocating and zeroing */
1017 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1018 if (ua_chan == NULL) {
1019 PERROR("malloc");
1020 goto error;
1021 }
1022
1023 /* Setup channel name */
1024 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1025 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1026
1027 ua_chan->enabled = 1;
1028 ua_chan->handle = -1;
1029 ua_chan->session = ua_sess;
1030 ua_chan->key = get_next_channel_key();
1031 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1032 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1033 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1034
1035 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1036 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1037
1038 /* Copy attributes */
1039 if (attr) {
1040 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1041 ua_chan->attr.subbuf_size = attr->subbuf_size;
1042 ua_chan->attr.num_subbuf = attr->num_subbuf;
1043 ua_chan->attr.overwrite = attr->overwrite;
1044 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1045 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1046 ua_chan->attr.output = attr->output;
1047 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1048 }
1049 /* By default, the channel is a per cpu channel. */
1050 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1051
1052 DBG3("UST app channel %s allocated", ua_chan->name);
1053
1054 return ua_chan;
1055
1056 error:
1057 return NULL;
1058 }
1059
1060 /*
1061 * Allocate and initialize a UST app stream.
1062 *
1063 * Return newly allocated stream pointer or NULL on error.
1064 */
1065 struct ust_app_stream *ust_app_alloc_stream(void)
1066 {
1067 struct ust_app_stream *stream = NULL;
1068
1069 stream = zmalloc(sizeof(*stream));
1070 if (stream == NULL) {
1071 PERROR("zmalloc ust app stream");
1072 goto error;
1073 }
1074
1075 /* Zero could be a valid value for a handle so flag it to -1. */
1076 stream->handle = -1;
1077
1078 error:
1079 return stream;
1080 }
1081
1082 /*
1083 * Alloc new UST app event.
1084 */
1085 static
1086 struct ust_app_event *alloc_ust_app_event(char *name,
1087 struct lttng_ust_event *attr)
1088 {
1089 struct ust_app_event *ua_event;
1090
1091 /* Init most of the default value by allocating and zeroing */
1092 ua_event = zmalloc(sizeof(struct ust_app_event));
1093 if (ua_event == NULL) {
1094 PERROR("malloc");
1095 goto error;
1096 }
1097
1098 ua_event->enabled = 1;
1099 strncpy(ua_event->name, name, sizeof(ua_event->name));
1100 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1101 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1102
1103 /* Copy attributes */
1104 if (attr) {
1105 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1106 }
1107
1108 DBG3("UST app event %s allocated", ua_event->name);
1109
1110 return ua_event;
1111
1112 error:
1113 return NULL;
1114 }
1115
1116 /*
1117 * Alloc new UST app context.
1118 */
1119 static
1120 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1121 {
1122 struct ust_app_ctx *ua_ctx;
1123
1124 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1125 if (ua_ctx == NULL) {
1126 goto error;
1127 }
1128
1129 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1130
1131 if (uctx) {
1132 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1133 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1134 char *provider_name = NULL, *ctx_name = NULL;
1135
1136 provider_name = strdup(uctx->u.app_ctx.provider_name);
1137 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1138 if (!provider_name || !ctx_name) {
1139 free(provider_name);
1140 free(ctx_name);
1141 goto error;
1142 }
1143
1144 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1145 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1146 }
1147 }
1148
1149 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1150 return ua_ctx;
1151 error:
1152 free(ua_ctx);
1153 return NULL;
1154 }
1155
1156 /*
1157 * Allocate a filter and copy the given original filter.
1158 *
1159 * Return allocated filter or NULL on error.
1160 */
1161 static struct lttng_filter_bytecode *copy_filter_bytecode(
1162 struct lttng_filter_bytecode *orig_f)
1163 {
1164 struct lttng_filter_bytecode *filter = NULL;
1165
1166 /* Copy filter bytecode */
1167 filter = zmalloc(sizeof(*filter) + orig_f->len);
1168 if (!filter) {
1169 PERROR("zmalloc alloc filter bytecode");
1170 goto error;
1171 }
1172
1173 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1174
1175 error:
1176 return filter;
1177 }
1178
1179 /*
1180 * Create a liblttng-ust filter bytecode from given bytecode.
1181 *
1182 * Return allocated filter or NULL on error.
1183 */
1184 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1185 struct lttng_filter_bytecode *orig_f)
1186 {
1187 struct lttng_ust_filter_bytecode *filter = NULL;
1188
1189 /* Copy filter bytecode */
1190 filter = zmalloc(sizeof(*filter) + orig_f->len);
1191 if (!filter) {
1192 PERROR("zmalloc alloc ust filter bytecode");
1193 goto error;
1194 }
1195
1196 assert(sizeof(struct lttng_filter_bytecode) ==
1197 sizeof(struct lttng_ust_filter_bytecode));
1198 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1199 error:
1200 return filter;
1201 }
1202
1203 /*
1204 * Find an ust_app using the sock and return it. RCU read side lock must be
1205 * held before calling this helper function.
1206 */
1207 struct ust_app *ust_app_find_by_sock(int sock)
1208 {
1209 struct lttng_ht_node_ulong *node;
1210 struct lttng_ht_iter iter;
1211
1212 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1213 node = lttng_ht_iter_get_node_ulong(&iter);
1214 if (node == NULL) {
1215 DBG2("UST app find by sock %d not found", sock);
1216 goto error;
1217 }
1218
1219 return caa_container_of(node, struct ust_app, sock_n);
1220
1221 error:
1222 return NULL;
1223 }
1224
1225 /*
1226 * Find an ust_app using the notify sock and return it. RCU read side lock must
1227 * be held before calling this helper function.
1228 */
1229 static struct ust_app *find_app_by_notify_sock(int sock)
1230 {
1231 struct lttng_ht_node_ulong *node;
1232 struct lttng_ht_iter iter;
1233
1234 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1235 &iter);
1236 node = lttng_ht_iter_get_node_ulong(&iter);
1237 if (node == NULL) {
1238 DBG2("UST app find by notify sock %d not found", sock);
1239 goto error;
1240 }
1241
1242 return caa_container_of(node, struct ust_app, notify_sock_n);
1243
1244 error:
1245 return NULL;
1246 }
1247
1248 /*
1249 * Lookup for an ust app event based on event name, filter bytecode and the
1250 * event loglevel.
1251 *
1252 * Return an ust_app_event object or NULL on error.
1253 */
1254 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1255 char *name, struct lttng_filter_bytecode *filter,
1256 int loglevel_value,
1257 const struct lttng_event_exclusion *exclusion)
1258 {
1259 struct lttng_ht_iter iter;
1260 struct lttng_ht_node_str *node;
1261 struct ust_app_event *event = NULL;
1262 struct ust_app_ht_key key;
1263
1264 assert(name);
1265 assert(ht);
1266
1267 /* Setup key for event lookup. */
1268 key.name = name;
1269 key.filter = filter;
1270 key.loglevel_type = loglevel_value;
1271 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1272 key.exclusion = exclusion;
1273
1274 /* Lookup using the event name as hash and a custom match fct. */
1275 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1276 ht_match_ust_app_event, &key, &iter.iter);
1277 node = lttng_ht_iter_get_node_str(&iter);
1278 if (node == NULL) {
1279 goto end;
1280 }
1281
1282 event = caa_container_of(node, struct ust_app_event, node);
1283
1284 end:
1285 return event;
1286 }
1287
1288 /*
1289 * Create the channel context on the tracer.
1290 *
1291 * Called with UST app session lock held.
1292 */
1293 static
1294 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1295 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1296 {
1297 int ret;
1298
1299 health_code_update();
1300
1301 pthread_mutex_lock(&app->sock_lock);
1302 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1303 ua_chan->obj, &ua_ctx->obj);
1304 pthread_mutex_unlock(&app->sock_lock);
1305 if (ret < 0) {
1306 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1307 ERR("UST app create channel context failed for app (pid: %d) "
1308 "with ret %d", app->pid, ret);
1309 } else {
1310 /*
1311 * This is normal behavior, an application can die during the
1312 * creation process. Don't report an error so the execution can
1313 * continue normally.
1314 */
1315 ret = 0;
1316 DBG3("UST app disable event failed. Application is dead.");
1317 }
1318 goto error;
1319 }
1320
1321 ua_ctx->handle = ua_ctx->obj->handle;
1322
1323 DBG2("UST app context handle %d created successfully for channel %s",
1324 ua_ctx->handle, ua_chan->name);
1325
1326 error:
1327 health_code_update();
1328 return ret;
1329 }
1330
1331 /*
1332 * Set the filter on the tracer.
1333 */
1334 static
1335 int set_ust_event_filter(struct ust_app_event *ua_event,
1336 struct ust_app *app)
1337 {
1338 int ret;
1339 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1340
1341 health_code_update();
1342
1343 if (!ua_event->filter) {
1344 ret = 0;
1345 goto error;
1346 }
1347
1348 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1349 if (!ust_bytecode) {
1350 ret = -LTTNG_ERR_NOMEM;
1351 goto error;
1352 }
1353 pthread_mutex_lock(&app->sock_lock);
1354 ret = ustctl_set_filter(app->sock, ust_bytecode,
1355 ua_event->obj);
1356 pthread_mutex_unlock(&app->sock_lock);
1357 if (ret < 0) {
1358 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1359 ERR("UST app event %s filter failed for app (pid: %d) "
1360 "with ret %d", ua_event->attr.name, app->pid, ret);
1361 } else {
1362 /*
1363 * This is normal behavior, an application can die during the
1364 * creation process. Don't report an error so the execution can
1365 * continue normally.
1366 */
1367 ret = 0;
1368 DBG3("UST app filter event failed. Application is dead.");
1369 }
1370 goto error;
1371 }
1372
1373 DBG2("UST filter set successfully for event %s", ua_event->name);
1374
1375 error:
1376 health_code_update();
1377 free(ust_bytecode);
1378 return ret;
1379 }
1380
1381 static
1382 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1383 struct lttng_event_exclusion *exclusion)
1384 {
1385 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1386 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1387 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1388
1389 ust_exclusion = zmalloc(exclusion_alloc_size);
1390 if (!ust_exclusion) {
1391 PERROR("malloc");
1392 goto end;
1393 }
1394
1395 assert(sizeof(struct lttng_event_exclusion) ==
1396 sizeof(struct lttng_ust_event_exclusion));
1397 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1398 end:
1399 return ust_exclusion;
1400 }
1401
1402 /*
1403 * Set event exclusions on the tracer.
1404 */
1405 static
1406 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1407 struct ust_app *app)
1408 {
1409 int ret;
1410 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1411
1412 health_code_update();
1413
1414 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1415 ret = 0;
1416 goto error;
1417 }
1418
1419 ust_exclusion = create_ust_exclusion_from_exclusion(
1420 ua_event->exclusion);
1421 if (!ust_exclusion) {
1422 ret = -LTTNG_ERR_NOMEM;
1423 goto error;
1424 }
1425 pthread_mutex_lock(&app->sock_lock);
1426 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1427 pthread_mutex_unlock(&app->sock_lock);
1428 if (ret < 0) {
1429 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1430 ERR("UST app event %s exclusions failed for app (pid: %d) "
1431 "with ret %d", ua_event->attr.name, app->pid, ret);
1432 } else {
1433 /*
1434 * This is normal behavior, an application can die during the
1435 * creation process. Don't report an error so the execution can
1436 * continue normally.
1437 */
1438 ret = 0;
1439 DBG3("UST app event exclusion failed. Application is dead.");
1440 }
1441 goto error;
1442 }
1443
1444 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1445
1446 error:
1447 health_code_update();
1448 free(ust_exclusion);
1449 return ret;
1450 }
1451
1452 /*
1453 * Disable the specified event on to UST tracer for the UST session.
1454 */
1455 static int disable_ust_event(struct ust_app *app,
1456 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1457 {
1458 int ret;
1459
1460 health_code_update();
1461
1462 pthread_mutex_lock(&app->sock_lock);
1463 ret = ustctl_disable(app->sock, ua_event->obj);
1464 pthread_mutex_unlock(&app->sock_lock);
1465 if (ret < 0) {
1466 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1467 ERR("UST app event %s disable failed for app (pid: %d) "
1468 "and session handle %d with ret %d",
1469 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1470 } else {
1471 /*
1472 * This is normal behavior, an application can die during the
1473 * creation process. Don't report an error so the execution can
1474 * continue normally.
1475 */
1476 ret = 0;
1477 DBG3("UST app disable event failed. Application is dead.");
1478 }
1479 goto error;
1480 }
1481
1482 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1483 ua_event->attr.name, app->pid);
1484
1485 error:
1486 health_code_update();
1487 return ret;
1488 }
1489
1490 /*
1491 * Disable the specified channel on to UST tracer for the UST session.
1492 */
1493 static int disable_ust_channel(struct ust_app *app,
1494 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1495 {
1496 int ret;
1497
1498 health_code_update();
1499
1500 pthread_mutex_lock(&app->sock_lock);
1501 ret = ustctl_disable(app->sock, ua_chan->obj);
1502 pthread_mutex_unlock(&app->sock_lock);
1503 if (ret < 0) {
1504 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1505 ERR("UST app channel %s disable failed for app (pid: %d) "
1506 "and session handle %d with ret %d",
1507 ua_chan->name, app->pid, ua_sess->handle, ret);
1508 } else {
1509 /*
1510 * This is normal behavior, an application can die during the
1511 * creation process. Don't report an error so the execution can
1512 * continue normally.
1513 */
1514 ret = 0;
1515 DBG3("UST app disable channel failed. Application is dead.");
1516 }
1517 goto error;
1518 }
1519
1520 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1521 ua_chan->name, app->pid);
1522
1523 error:
1524 health_code_update();
1525 return ret;
1526 }
1527
1528 /*
1529 * Enable the specified channel on to UST tracer for the UST session.
1530 */
1531 static int enable_ust_channel(struct ust_app *app,
1532 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1533 {
1534 int ret;
1535
1536 health_code_update();
1537
1538 pthread_mutex_lock(&app->sock_lock);
1539 ret = ustctl_enable(app->sock, ua_chan->obj);
1540 pthread_mutex_unlock(&app->sock_lock);
1541 if (ret < 0) {
1542 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1543 ERR("UST app channel %s enable failed for app (pid: %d) "
1544 "and session handle %d with ret %d",
1545 ua_chan->name, app->pid, ua_sess->handle, ret);
1546 } else {
1547 /*
1548 * This is normal behavior, an application can die during the
1549 * creation process. Don't report an error so the execution can
1550 * continue normally.
1551 */
1552 ret = 0;
1553 DBG3("UST app enable channel failed. Application is dead.");
1554 }
1555 goto error;
1556 }
1557
1558 ua_chan->enabled = 1;
1559
1560 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1561 ua_chan->name, app->pid);
1562
1563 error:
1564 health_code_update();
1565 return ret;
1566 }
1567
1568 /*
1569 * Enable the specified event on to UST tracer for the UST session.
1570 */
1571 static int enable_ust_event(struct ust_app *app,
1572 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1573 {
1574 int ret;
1575
1576 health_code_update();
1577
1578 pthread_mutex_lock(&app->sock_lock);
1579 ret = ustctl_enable(app->sock, ua_event->obj);
1580 pthread_mutex_unlock(&app->sock_lock);
1581 if (ret < 0) {
1582 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1583 ERR("UST app event %s enable failed for app (pid: %d) "
1584 "and session handle %d with ret %d",
1585 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1586 } else {
1587 /*
1588 * This is normal behavior, an application can die during the
1589 * creation process. Don't report an error so the execution can
1590 * continue normally.
1591 */
1592 ret = 0;
1593 DBG3("UST app enable event failed. Application is dead.");
1594 }
1595 goto error;
1596 }
1597
1598 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1599 ua_event->attr.name, app->pid);
1600
1601 error:
1602 health_code_update();
1603 return ret;
1604 }
1605
1606 /*
1607 * Send channel and stream buffer to application.
1608 *
1609 * Return 0 on success. On error, a negative value is returned.
1610 */
1611 static int send_channel_pid_to_ust(struct ust_app *app,
1612 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1613 {
1614 int ret;
1615 struct ust_app_stream *stream, *stmp;
1616
1617 assert(app);
1618 assert(ua_sess);
1619 assert(ua_chan);
1620
1621 health_code_update();
1622
1623 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1624 app->sock);
1625
1626 /* Send channel to the application. */
1627 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1628 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1629 ret = -ENOTCONN; /* Caused by app exiting. */
1630 goto error;
1631 } else if (ret < 0) {
1632 goto error;
1633 }
1634
1635 health_code_update();
1636
1637 /* Send all streams to application. */
1638 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1639 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1640 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1641 ret = -ENOTCONN; /* Caused by app exiting. */
1642 goto error;
1643 } else if (ret < 0) {
1644 goto error;
1645 }
1646 /* We don't need the stream anymore once sent to the tracer. */
1647 cds_list_del(&stream->list);
1648 delete_ust_app_stream(-1, stream, app);
1649 }
1650 /* Flag the channel that it is sent to the application. */
1651 ua_chan->is_sent = 1;
1652
1653 error:
1654 health_code_update();
1655 return ret;
1656 }
1657
1658 /*
1659 * Create the specified event onto the UST tracer for a UST session.
1660 *
1661 * Should be called with session mutex held.
1662 */
1663 static
1664 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1665 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1666 {
1667 int ret = 0;
1668
1669 health_code_update();
1670
1671 /* Create UST event on tracer */
1672 pthread_mutex_lock(&app->sock_lock);
1673 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1674 &ua_event->obj);
1675 pthread_mutex_unlock(&app->sock_lock);
1676 if (ret < 0) {
1677 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1678 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1679 ua_event->attr.name, app->pid, ret);
1680 } else {
1681 /*
1682 * This is normal behavior, an application can die during the
1683 * creation process. Don't report an error so the execution can
1684 * continue normally.
1685 */
1686 ret = 0;
1687 DBG3("UST app create event failed. Application is dead.");
1688 }
1689 goto error;
1690 }
1691
1692 ua_event->handle = ua_event->obj->handle;
1693
1694 DBG2("UST app event %s created successfully for pid:%d",
1695 ua_event->attr.name, app->pid);
1696
1697 health_code_update();
1698
1699 /* Set filter if one is present. */
1700 if (ua_event->filter) {
1701 ret = set_ust_event_filter(ua_event, app);
1702 if (ret < 0) {
1703 goto error;
1704 }
1705 }
1706
1707 /* Set exclusions for the event */
1708 if (ua_event->exclusion) {
1709 ret = set_ust_event_exclusion(ua_event, app);
1710 if (ret < 0) {
1711 goto error;
1712 }
1713 }
1714
1715 /* If event not enabled, disable it on the tracer */
1716 if (ua_event->enabled) {
1717 /*
1718 * We now need to explicitly enable the event, since it
1719 * is now disabled at creation.
1720 */
1721 ret = enable_ust_event(app, ua_sess, ua_event);
1722 if (ret < 0) {
1723 /*
1724 * If we hit an EPERM, something is wrong with our enable call. If
1725 * we get an EEXIST, there is a problem on the tracer side since we
1726 * just created it.
1727 */
1728 switch (ret) {
1729 case -LTTNG_UST_ERR_PERM:
1730 /* Code flow problem */
1731 assert(0);
1732 case -LTTNG_UST_ERR_EXIST:
1733 /* It's OK for our use case. */
1734 ret = 0;
1735 break;
1736 default:
1737 break;
1738 }
1739 goto error;
1740 }
1741 }
1742
1743 error:
1744 health_code_update();
1745 return ret;
1746 }
1747
1748 /*
1749 * Copy data between an UST app event and a LTT event.
1750 */
1751 static void shadow_copy_event(struct ust_app_event *ua_event,
1752 struct ltt_ust_event *uevent)
1753 {
1754 size_t exclusion_alloc_size;
1755
1756 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1757 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1758
1759 ua_event->enabled = uevent->enabled;
1760
1761 /* Copy event attributes */
1762 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1763
1764 /* Copy filter bytecode */
1765 if (uevent->filter) {
1766 ua_event->filter = copy_filter_bytecode(uevent->filter);
1767 /* Filter might be NULL here in case of ENONEM. */
1768 }
1769
1770 /* Copy exclusion data */
1771 if (uevent->exclusion) {
1772 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1773 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1774 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1775 if (ua_event->exclusion == NULL) {
1776 PERROR("malloc");
1777 } else {
1778 memcpy(ua_event->exclusion, uevent->exclusion,
1779 exclusion_alloc_size);
1780 }
1781 }
1782 }
1783
1784 /*
1785 * Copy data between an UST app channel and a LTT channel.
1786 */
1787 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1788 struct ltt_ust_channel *uchan)
1789 {
1790 struct lttng_ht_iter iter;
1791 struct ltt_ust_event *uevent;
1792 struct ltt_ust_context *uctx;
1793 struct ust_app_event *ua_event;
1794
1795 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1796
1797 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1798 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1799
1800 ua_chan->tracefile_size = uchan->tracefile_size;
1801 ua_chan->tracefile_count = uchan->tracefile_count;
1802
1803 /* Copy event attributes since the layout is different. */
1804 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1805 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1806 ua_chan->attr.overwrite = uchan->attr.overwrite;
1807 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1808 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1809 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1810 ua_chan->attr.output = uchan->attr.output;
1811 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1812
1813 /*
1814 * Note that the attribute channel type is not set since the channel on the
1815 * tracing registry side does not have this information.
1816 */
1817
1818 ua_chan->enabled = uchan->enabled;
1819 ua_chan->tracing_channel_id = uchan->id;
1820
1821 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1822 struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1823
1824 if (ua_ctx == NULL) {
1825 continue;
1826 }
1827 lttng_ht_node_init_ulong(&ua_ctx->node,
1828 (unsigned long) ua_ctx->ctx.ctx);
1829 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1830 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1831 }
1832
1833 /* Copy all events from ltt ust channel to ust app channel */
1834 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1835 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1836 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1837 if (ua_event == NULL) {
1838 DBG2("UST event %s not found on shadow copy channel",
1839 uevent->attr.name);
1840 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1841 if (ua_event == NULL) {
1842 continue;
1843 }
1844 shadow_copy_event(ua_event, uevent);
1845 add_unique_ust_app_event(ua_chan, ua_event);
1846 }
1847 }
1848
1849 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1850 }
1851
1852 /*
1853 * Copy data between a UST app session and a regular LTT session.
1854 */
1855 static void shadow_copy_session(struct ust_app_session *ua_sess,
1856 struct ltt_ust_session *usess, struct ust_app *app)
1857 {
1858 struct lttng_ht_node_str *ua_chan_node;
1859 struct lttng_ht_iter iter;
1860 struct ltt_ust_channel *uchan;
1861 struct ust_app_channel *ua_chan;
1862 time_t rawtime;
1863 struct tm *timeinfo;
1864 char datetime[16];
1865 int ret;
1866 char tmp_shm_path[PATH_MAX];
1867
1868 /* Get date and time for unique app path */
1869 time(&rawtime);
1870 timeinfo = localtime(&rawtime);
1871 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1872
1873 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1874
1875 ua_sess->tracing_id = usess->id;
1876 ua_sess->id = get_next_session_id();
1877 ua_sess->uid = app->uid;
1878 ua_sess->gid = app->gid;
1879 ua_sess->euid = usess->uid;
1880 ua_sess->egid = usess->gid;
1881 ua_sess->buffer_type = usess->buffer_type;
1882 ua_sess->bits_per_long = app->bits_per_long;
1883
1884 /* There is only one consumer object per session possible. */
1885 consumer_output_get(usess->consumer);
1886 ua_sess->consumer = usess->consumer;
1887
1888 ua_sess->output_traces = usess->output_traces;
1889 ua_sess->live_timer_interval = usess->live_timer_interval;
1890 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1891 &usess->metadata_attr);
1892
1893 switch (ua_sess->buffer_type) {
1894 case LTTNG_BUFFER_PER_PID:
1895 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1896 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1897 datetime);
1898 break;
1899 case LTTNG_BUFFER_PER_UID:
1900 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1901 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1902 break;
1903 default:
1904 assert(0);
1905 goto error;
1906 }
1907 if (ret < 0) {
1908 PERROR("asprintf UST shadow copy session");
1909 assert(0);
1910 goto error;
1911 }
1912
1913 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1914 sizeof(ua_sess->root_shm_path));
1915 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1916 strncpy(ua_sess->shm_path, usess->shm_path,
1917 sizeof(ua_sess->shm_path));
1918 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1919 if (ua_sess->shm_path[0]) {
1920 switch (ua_sess->buffer_type) {
1921 case LTTNG_BUFFER_PER_PID:
1922 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1923 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1924 app->name, app->pid, datetime);
1925 break;
1926 case LTTNG_BUFFER_PER_UID:
1927 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1928 DEFAULT_UST_TRACE_UID_PATH,
1929 app->uid, app->bits_per_long);
1930 break;
1931 default:
1932 assert(0);
1933 goto error;
1934 }
1935 if (ret < 0) {
1936 PERROR("sprintf UST shadow copy session");
1937 assert(0);
1938 goto error;
1939 }
1940 strncat(ua_sess->shm_path, tmp_shm_path,
1941 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1942 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1943 }
1944
1945 /* Iterate over all channels in global domain. */
1946 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1947 uchan, node.node) {
1948 struct lttng_ht_iter uiter;
1949
1950 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1951 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1952 if (ua_chan_node != NULL) {
1953 /* Session exist. Contiuing. */
1954 continue;
1955 }
1956
1957 DBG2("Channel %s not found on shadow session copy, creating it",
1958 uchan->name);
1959 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess,
1960 &uchan->attr);
1961 if (ua_chan == NULL) {
1962 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1963 continue;
1964 }
1965 shadow_copy_channel(ua_chan, uchan);
1966 /*
1967 * The concept of metadata channel does not exist on the tracing
1968 * registry side of the session daemon so this can only be a per CPU
1969 * channel and not metadata.
1970 */
1971 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1972
1973 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1974 }
1975 return;
1976
1977 error:
1978 consumer_output_put(ua_sess->consumer);
1979 }
1980
1981 /*
1982 * Lookup sesison wrapper.
1983 */
1984 static
1985 void __lookup_session_by_app(struct ltt_ust_session *usess,
1986 struct ust_app *app, struct lttng_ht_iter *iter)
1987 {
1988 /* Get right UST app session from app */
1989 lttng_ht_lookup(app->sessions, &usess->id, iter);
1990 }
1991
1992 /*
1993 * Return ust app session from the app session hashtable using the UST session
1994 * id.
1995 */
1996 static struct ust_app_session *lookup_session_by_app(
1997 struct ltt_ust_session *usess, struct ust_app *app)
1998 {
1999 struct lttng_ht_iter iter;
2000 struct lttng_ht_node_u64 *node;
2001
2002 __lookup_session_by_app(usess, app, &iter);
2003 node = lttng_ht_iter_get_node_u64(&iter);
2004 if (node == NULL) {
2005 goto error;
2006 }
2007
2008 return caa_container_of(node, struct ust_app_session, node);
2009
2010 error:
2011 return NULL;
2012 }
2013
2014 /*
2015 * Setup buffer registry per PID for the given session and application. If none
2016 * is found, a new one is created, added to the global registry and
2017 * initialized. If regp is valid, it's set with the newly created object.
2018 *
2019 * Return 0 on success or else a negative value.
2020 */
2021 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
2022 struct ust_app *app, struct buffer_reg_pid **regp)
2023 {
2024 int ret = 0;
2025 struct buffer_reg_pid *reg_pid;
2026
2027 assert(ua_sess);
2028 assert(app);
2029
2030 rcu_read_lock();
2031
2032 reg_pid = buffer_reg_pid_find(ua_sess->id);
2033 if (!reg_pid) {
2034 /*
2035 * This is the create channel path meaning that if there is NO
2036 * registry available, we have to create one for this session.
2037 */
2038 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
2039 ua_sess->root_shm_path, ua_sess->shm_path);
2040 if (ret < 0) {
2041 goto error;
2042 }
2043 } else {
2044 goto end;
2045 }
2046
2047 /* Initialize registry. */
2048 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
2049 app->bits_per_long, app->uint8_t_alignment,
2050 app->uint16_t_alignment, app->uint32_t_alignment,
2051 app->uint64_t_alignment, app->long_alignment,
2052 app->byte_order, app->version.major,
2053 app->version.minor, reg_pid->root_shm_path,
2054 reg_pid->shm_path,
2055 ua_sess->euid, ua_sess->egid);
2056 if (ret < 0) {
2057 /*
2058 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2059 * destroy the buffer registry, because it is always expected
2060 * that if the buffer registry can be found, its ust registry is
2061 * non-NULL.
2062 */
2063 buffer_reg_pid_destroy(reg_pid);
2064 goto error;
2065 }
2066
2067 buffer_reg_pid_add(reg_pid);
2068
2069 DBG3("UST app buffer registry per PID created successfully");
2070
2071 end:
2072 if (regp) {
2073 *regp = reg_pid;
2074 }
2075 error:
2076 rcu_read_unlock();
2077 return ret;
2078 }
2079
2080 /*
2081 * Setup buffer registry per UID for the given session and application. If none
2082 * is found, a new one is created, added to the global registry and
2083 * initialized. If regp is valid, it's set with the newly created object.
2084 *
2085 * Return 0 on success or else a negative value.
2086 */
2087 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2088 struct ust_app_session *ua_sess,
2089 struct ust_app *app, struct buffer_reg_uid **regp)
2090 {
2091 int ret = 0;
2092 struct buffer_reg_uid *reg_uid;
2093
2094 assert(usess);
2095 assert(app);
2096
2097 rcu_read_lock();
2098
2099 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2100 if (!reg_uid) {
2101 /*
2102 * This is the create channel path meaning that if there is NO
2103 * registry available, we have to create one for this session.
2104 */
2105 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2106 LTTNG_DOMAIN_UST, &reg_uid,
2107 ua_sess->root_shm_path, ua_sess->shm_path);
2108 if (ret < 0) {
2109 goto error;
2110 }
2111 } else {
2112 goto end;
2113 }
2114
2115 /* Initialize registry. */
2116 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2117 app->bits_per_long, app->uint8_t_alignment,
2118 app->uint16_t_alignment, app->uint32_t_alignment,
2119 app->uint64_t_alignment, app->long_alignment,
2120 app->byte_order, app->version.major,
2121 app->version.minor, reg_uid->root_shm_path,
2122 reg_uid->shm_path, usess->uid, usess->gid);
2123 if (ret < 0) {
2124 /*
2125 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2126 * destroy the buffer registry, because it is always expected
2127 * that if the buffer registry can be found, its ust registry is
2128 * non-NULL.
2129 */
2130 buffer_reg_uid_destroy(reg_uid, NULL);
2131 goto error;
2132 }
2133 /* Add node to teardown list of the session. */
2134 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2135
2136 buffer_reg_uid_add(reg_uid);
2137
2138 DBG3("UST app buffer registry per UID created successfully");
2139 end:
2140 if (regp) {
2141 *regp = reg_uid;
2142 }
2143 error:
2144 rcu_read_unlock();
2145 return ret;
2146 }
2147
2148 /*
2149 * Create a session on the tracer side for the given app.
2150 *
2151 * On success, ua_sess_ptr is populated with the session pointer or else left
2152 * untouched. If the session was created, is_created is set to 1. On error,
2153 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2154 * be NULL.
2155 *
2156 * Returns 0 on success or else a negative code which is either -ENOMEM or
2157 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2158 */
2159 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2160 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2161 int *is_created)
2162 {
2163 int ret, created = 0;
2164 struct ust_app_session *ua_sess;
2165
2166 assert(usess);
2167 assert(app);
2168 assert(ua_sess_ptr);
2169
2170 health_code_update();
2171
2172 ua_sess = lookup_session_by_app(usess, app);
2173 if (ua_sess == NULL) {
2174 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2175 app->pid, usess->id);
2176 ua_sess = alloc_ust_app_session();
2177 if (ua_sess == NULL) {
2178 /* Only malloc can failed so something is really wrong */
2179 ret = -ENOMEM;
2180 goto error;
2181 }
2182 shadow_copy_session(ua_sess, usess, app);
2183 created = 1;
2184 }
2185
2186 switch (usess->buffer_type) {
2187 case LTTNG_BUFFER_PER_PID:
2188 /* Init local registry. */
2189 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2190 if (ret < 0) {
2191 delete_ust_app_session(-1, ua_sess, app);
2192 goto error;
2193 }
2194 break;
2195 case LTTNG_BUFFER_PER_UID:
2196 /* Look for a global registry. If none exists, create one. */
2197 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2198 if (ret < 0) {
2199 delete_ust_app_session(-1, ua_sess, app);
2200 goto error;
2201 }
2202 break;
2203 default:
2204 assert(0);
2205 ret = -EINVAL;
2206 goto error;
2207 }
2208
2209 health_code_update();
2210
2211 if (ua_sess->handle == -1) {
2212 pthread_mutex_lock(&app->sock_lock);
2213 ret = ustctl_create_session(app->sock);
2214 pthread_mutex_unlock(&app->sock_lock);
2215 if (ret < 0) {
2216 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2217 ERR("Creating session for app pid %d with ret %d",
2218 app->pid, ret);
2219 } else {
2220 DBG("UST app creating session failed. Application is dead");
2221 /*
2222 * This is normal behavior, an application can die during the
2223 * creation process. Don't report an error so the execution can
2224 * continue normally. This will get flagged ENOTCONN and the
2225 * caller will handle it.
2226 */
2227 ret = 0;
2228 }
2229 delete_ust_app_session(-1, ua_sess, app);
2230 if (ret != -ENOMEM) {
2231 /*
2232 * Tracer is probably gone or got an internal error so let's
2233 * behave like it will soon unregister or not usable.
2234 */
2235 ret = -ENOTCONN;
2236 }
2237 goto error;
2238 }
2239
2240 ua_sess->handle = ret;
2241
2242 /* Add ust app session to app's HT */
2243 lttng_ht_node_init_u64(&ua_sess->node,
2244 ua_sess->tracing_id);
2245 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2246 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2247 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2248 &ua_sess->ust_objd_node);
2249
2250 DBG2("UST app session created successfully with handle %d", ret);
2251 }
2252
2253 *ua_sess_ptr = ua_sess;
2254 if (is_created) {
2255 *is_created = created;
2256 }
2257
2258 /* Everything went well. */
2259 ret = 0;
2260
2261 error:
2262 health_code_update();
2263 return ret;
2264 }
2265
2266 /*
2267 * Match function for a hash table lookup of ust_app_ctx.
2268 *
2269 * It matches an ust app context based on the context type and, in the case
2270 * of perf counters, their name.
2271 */
2272 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2273 {
2274 struct ust_app_ctx *ctx;
2275 const struct lttng_ust_context_attr *key;
2276
2277 assert(node);
2278 assert(_key);
2279
2280 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2281 key = _key;
2282
2283 /* Context type */
2284 if (ctx->ctx.ctx != key->ctx) {
2285 goto no_match;
2286 }
2287
2288 switch(key->ctx) {
2289 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2290 if (strncmp(key->u.perf_counter.name,
2291 ctx->ctx.u.perf_counter.name,
2292 sizeof(key->u.perf_counter.name))) {
2293 goto no_match;
2294 }
2295 break;
2296 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2297 if (strcmp(key->u.app_ctx.provider_name,
2298 ctx->ctx.u.app_ctx.provider_name) ||
2299 strcmp(key->u.app_ctx.ctx_name,
2300 ctx->ctx.u.app_ctx.ctx_name)) {
2301 goto no_match;
2302 }
2303 break;
2304 default:
2305 break;
2306 }
2307
2308 /* Match. */
2309 return 1;
2310
2311 no_match:
2312 return 0;
2313 }
2314
2315 /*
2316 * Lookup for an ust app context from an lttng_ust_context.
2317 *
2318 * Must be called while holding RCU read side lock.
2319 * Return an ust_app_ctx object or NULL on error.
2320 */
2321 static
2322 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2323 struct lttng_ust_context_attr *uctx)
2324 {
2325 struct lttng_ht_iter iter;
2326 struct lttng_ht_node_ulong *node;
2327 struct ust_app_ctx *app_ctx = NULL;
2328
2329 assert(uctx);
2330 assert(ht);
2331
2332 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2333 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2334 ht_match_ust_app_ctx, uctx, &iter.iter);
2335 node = lttng_ht_iter_get_node_ulong(&iter);
2336 if (!node) {
2337 goto end;
2338 }
2339
2340 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2341
2342 end:
2343 return app_ctx;
2344 }
2345
2346 /*
2347 * Create a context for the channel on the tracer.
2348 *
2349 * Called with UST app session lock held and a RCU read side lock.
2350 */
2351 static
2352 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2353 struct lttng_ust_context_attr *uctx,
2354 struct ust_app *app)
2355 {
2356 int ret = 0;
2357 struct ust_app_ctx *ua_ctx;
2358
2359 DBG2("UST app adding context to channel %s", ua_chan->name);
2360
2361 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2362 if (ua_ctx) {
2363 ret = -EEXIST;
2364 goto error;
2365 }
2366
2367 ua_ctx = alloc_ust_app_ctx(uctx);
2368 if (ua_ctx == NULL) {
2369 /* malloc failed */
2370 ret = -ENOMEM;
2371 goto error;
2372 }
2373
2374 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2375 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2376 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2377
2378 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2379 if (ret < 0) {
2380 goto error;
2381 }
2382
2383 error:
2384 return ret;
2385 }
2386
2387 /*
2388 * Enable on the tracer side a ust app event for the session and channel.
2389 *
2390 * Called with UST app session lock held.
2391 */
2392 static
2393 int enable_ust_app_event(struct ust_app_session *ua_sess,
2394 struct ust_app_event *ua_event, struct ust_app *app)
2395 {
2396 int ret;
2397
2398 ret = enable_ust_event(app, ua_sess, ua_event);
2399 if (ret < 0) {
2400 goto error;
2401 }
2402
2403 ua_event->enabled = 1;
2404
2405 error:
2406 return ret;
2407 }
2408
2409 /*
2410 * Disable on the tracer side a ust app event for the session and channel.
2411 */
2412 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2413 struct ust_app_event *ua_event, struct ust_app *app)
2414 {
2415 int ret;
2416
2417 ret = disable_ust_event(app, ua_sess, ua_event);
2418 if (ret < 0) {
2419 goto error;
2420 }
2421
2422 ua_event->enabled = 0;
2423
2424 error:
2425 return ret;
2426 }
2427
2428 /*
2429 * Lookup ust app channel for session and disable it on the tracer side.
2430 */
2431 static
2432 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2433 struct ust_app_channel *ua_chan, struct ust_app *app)
2434 {
2435 int ret;
2436
2437 ret = disable_ust_channel(app, ua_sess, ua_chan);
2438 if (ret < 0) {
2439 goto error;
2440 }
2441
2442 ua_chan->enabled = 0;
2443
2444 error:
2445 return ret;
2446 }
2447
2448 /*
2449 * Lookup ust app channel for session and enable it on the tracer side. This
2450 * MUST be called with a RCU read side lock acquired.
2451 */
2452 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2453 struct ltt_ust_channel *uchan, struct ust_app *app)
2454 {
2455 int ret = 0;
2456 struct lttng_ht_iter iter;
2457 struct lttng_ht_node_str *ua_chan_node;
2458 struct ust_app_channel *ua_chan;
2459
2460 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2461 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2462 if (ua_chan_node == NULL) {
2463 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2464 uchan->name, ua_sess->tracing_id);
2465 goto error;
2466 }
2467
2468 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2469
2470 ret = enable_ust_channel(app, ua_sess, ua_chan);
2471 if (ret < 0) {
2472 goto error;
2473 }
2474
2475 error:
2476 return ret;
2477 }
2478
2479 /*
2480 * Ask the consumer to create a channel and get it if successful.
2481 *
2482 * Called with UST app session lock held.
2483 *
2484 * Return 0 on success or else a negative value.
2485 */
2486 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2487 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2488 int bitness, struct ust_registry_session *registry,
2489 uint64_t trace_archive_id)
2490 {
2491 int ret;
2492 unsigned int nb_fd = 0;
2493 struct consumer_socket *socket;
2494
2495 assert(usess);
2496 assert(ua_sess);
2497 assert(ua_chan);
2498 assert(registry);
2499
2500 rcu_read_lock();
2501 health_code_update();
2502
2503 /* Get the right consumer socket for the application. */
2504 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2505 if (!socket) {
2506 ret = -EINVAL;
2507 goto error;
2508 }
2509
2510 health_code_update();
2511
2512 /* Need one fd for the channel. */
2513 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2514 if (ret < 0) {
2515 ERR("Exhausted number of available FD upon create channel");
2516 goto error;
2517 }
2518
2519 /*
2520 * Ask consumer to create channel. The consumer will return the number of
2521 * stream we have to expect.
2522 */
2523 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2524 registry, trace_archive_id);
2525 if (ret < 0) {
2526 goto error_ask;
2527 }
2528
2529 /*
2530 * Compute the number of fd needed before receiving them. It must be 2 per
2531 * stream (2 being the default value here).
2532 */
2533 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2534
2535 /* Reserve the amount of file descriptor we need. */
2536 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2537 if (ret < 0) {
2538 ERR("Exhausted number of available FD upon create channel");
2539 goto error_fd_get_stream;
2540 }
2541
2542 health_code_update();
2543
2544 /*
2545 * Now get the channel from the consumer. This call wil populate the stream
2546 * list of that channel and set the ust objects.
2547 */
2548 if (usess->consumer->enabled) {
2549 ret = ust_consumer_get_channel(socket, ua_chan);
2550 if (ret < 0) {
2551 goto error_destroy;
2552 }
2553 }
2554
2555 rcu_read_unlock();
2556 return 0;
2557
2558 error_destroy:
2559 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2560 error_fd_get_stream:
2561 /*
2562 * Initiate a destroy channel on the consumer since we had an error
2563 * handling it on our side. The return value is of no importance since we
2564 * already have a ret value set by the previous error that we need to
2565 * return.
2566 */
2567 (void) ust_consumer_destroy_channel(socket, ua_chan);
2568 error_ask:
2569 lttng_fd_put(LTTNG_FD_APPS, 1);
2570 error:
2571 health_code_update();
2572 rcu_read_unlock();
2573 return ret;
2574 }
2575
2576 /*
2577 * Duplicate the ust data object of the ust app stream and save it in the
2578 * buffer registry stream.
2579 *
2580 * Return 0 on success or else a negative value.
2581 */
2582 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2583 struct ust_app_stream *stream)
2584 {
2585 int ret;
2586
2587 assert(reg_stream);
2588 assert(stream);
2589
2590 /* Reserve the amount of file descriptor we need. */
2591 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2592 if (ret < 0) {
2593 ERR("Exhausted number of available FD upon duplicate stream");
2594 goto error;
2595 }
2596
2597 /* Duplicate object for stream once the original is in the registry. */
2598 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2599 reg_stream->obj.ust);
2600 if (ret < 0) {
2601 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2602 reg_stream->obj.ust, stream->obj, ret);
2603 lttng_fd_put(LTTNG_FD_APPS, 2);
2604 goto error;
2605 }
2606 stream->handle = stream->obj->handle;
2607
2608 error:
2609 return ret;
2610 }
2611
2612 /*
2613 * Duplicate the ust data object of the ust app. channel and save it in the
2614 * buffer registry channel.
2615 *
2616 * Return 0 on success or else a negative value.
2617 */
2618 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2619 struct ust_app_channel *ua_chan)
2620 {
2621 int ret;
2622
2623 assert(reg_chan);
2624 assert(ua_chan);
2625
2626 /* Need two fds for the channel. */
2627 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2628 if (ret < 0) {
2629 ERR("Exhausted number of available FD upon duplicate channel");
2630 goto error_fd_get;
2631 }
2632
2633 /* Duplicate object for stream once the original is in the registry. */
2634 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2635 if (ret < 0) {
2636 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2637 reg_chan->obj.ust, ua_chan->obj, ret);
2638 goto error;
2639 }
2640 ua_chan->handle = ua_chan->obj->handle;
2641
2642 return 0;
2643
2644 error:
2645 lttng_fd_put(LTTNG_FD_APPS, 1);
2646 error_fd_get:
2647 return ret;
2648 }
2649
2650 /*
2651 * For a given channel buffer registry, setup all streams of the given ust
2652 * application channel.
2653 *
2654 * Return 0 on success or else a negative value.
2655 */
2656 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2657 struct ust_app_channel *ua_chan,
2658 struct ust_app *app)
2659 {
2660 int ret = 0;
2661 struct ust_app_stream *stream, *stmp;
2662
2663 assert(reg_chan);
2664 assert(ua_chan);
2665
2666 DBG2("UST app setup buffer registry stream");
2667
2668 /* Send all streams to application. */
2669 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2670 struct buffer_reg_stream *reg_stream;
2671
2672 ret = buffer_reg_stream_create(&reg_stream);
2673 if (ret < 0) {
2674 goto error;
2675 }
2676
2677 /*
2678 * Keep original pointer and nullify it in the stream so the delete
2679 * stream call does not release the object.
2680 */
2681 reg_stream->obj.ust = stream->obj;
2682 stream->obj = NULL;
2683 buffer_reg_stream_add(reg_stream, reg_chan);
2684
2685 /* We don't need the streams anymore. */
2686 cds_list_del(&stream->list);
2687 delete_ust_app_stream(-1, stream, app);
2688 }
2689
2690 error:
2691 return ret;
2692 }
2693
2694 /*
2695 * Create a buffer registry channel for the given session registry and
2696 * application channel object. If regp pointer is valid, it's set with the
2697 * created object. Important, the created object is NOT added to the session
2698 * registry hash table.
2699 *
2700 * Return 0 on success else a negative value.
2701 */
2702 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2703 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2704 {
2705 int ret;
2706 struct buffer_reg_channel *reg_chan = NULL;
2707
2708 assert(reg_sess);
2709 assert(ua_chan);
2710
2711 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2712
2713 /* Create buffer registry channel. */
2714 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2715 if (ret < 0) {
2716 goto error_create;
2717 }
2718 assert(reg_chan);
2719 reg_chan->consumer_key = ua_chan->key;
2720 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2721 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2722
2723 /* Create and add a channel registry to session. */
2724 ret = ust_registry_channel_add(reg_sess->reg.ust,
2725 ua_chan->tracing_channel_id);
2726 if (ret < 0) {
2727 goto error;
2728 }
2729 buffer_reg_channel_add(reg_sess, reg_chan);
2730
2731 if (regp) {
2732 *regp = reg_chan;
2733 }
2734
2735 return 0;
2736
2737 error:
2738 /* Safe because the registry channel object was not added to any HT. */
2739 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2740 error_create:
2741 return ret;
2742 }
2743
2744 /*
2745 * Setup buffer registry channel for the given session registry and application
2746 * channel object. If regp pointer is valid, it's set with the created object.
2747 *
2748 * Return 0 on success else a negative value.
2749 */
2750 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2751 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2752 struct ust_app *app)
2753 {
2754 int ret;
2755
2756 assert(reg_sess);
2757 assert(reg_chan);
2758 assert(ua_chan);
2759 assert(ua_chan->obj);
2760
2761 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2762
2763 /* Setup all streams for the registry. */
2764 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2765 if (ret < 0) {
2766 goto error;
2767 }
2768
2769 reg_chan->obj.ust = ua_chan->obj;
2770 ua_chan->obj = NULL;
2771
2772 return 0;
2773
2774 error:
2775 buffer_reg_channel_remove(reg_sess, reg_chan);
2776 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2777 return ret;
2778 }
2779
2780 /*
2781 * Send buffer registry channel to the application.
2782 *
2783 * Return 0 on success else a negative value.
2784 */
2785 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2786 struct ust_app *app, struct ust_app_session *ua_sess,
2787 struct ust_app_channel *ua_chan)
2788 {
2789 int ret;
2790 struct buffer_reg_stream *reg_stream;
2791
2792 assert(reg_chan);
2793 assert(app);
2794 assert(ua_sess);
2795 assert(ua_chan);
2796
2797 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2798
2799 ret = duplicate_channel_object(reg_chan, ua_chan);
2800 if (ret < 0) {
2801 goto error;
2802 }
2803
2804 /* Send channel to the application. */
2805 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2806 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2807 ret = -ENOTCONN; /* Caused by app exiting. */
2808 goto error;
2809 } else if (ret < 0) {
2810 goto error;
2811 }
2812
2813 health_code_update();
2814
2815 /* Send all streams to application. */
2816 pthread_mutex_lock(&reg_chan->stream_list_lock);
2817 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2818 struct ust_app_stream stream;
2819
2820 ret = duplicate_stream_object(reg_stream, &stream);
2821 if (ret < 0) {
2822 goto error_stream_unlock;
2823 }
2824
2825 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2826 if (ret < 0) {
2827 (void) release_ust_app_stream(-1, &stream, app);
2828 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2829 ret = -ENOTCONN; /* Caused by app exiting. */
2830 }
2831 goto error_stream_unlock;
2832 }
2833
2834 /*
2835 * The return value is not important here. This function will output an
2836 * error if needed.
2837 */
2838 (void) release_ust_app_stream(-1, &stream, app);
2839 }
2840 ua_chan->is_sent = 1;
2841
2842 error_stream_unlock:
2843 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2844 error:
2845 return ret;
2846 }
2847
2848 /*
2849 * Create and send to the application the created buffers with per UID buffers.
2850 *
2851 * This MUST be called with a RCU read side lock acquired.
2852 * The session list lock and the session's lock must be acquired.
2853 *
2854 * Return 0 on success else a negative value.
2855 */
2856 static int create_channel_per_uid(struct ust_app *app,
2857 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2858 struct ust_app_channel *ua_chan)
2859 {
2860 int ret;
2861 struct buffer_reg_uid *reg_uid;
2862 struct buffer_reg_channel *reg_chan;
2863 struct ltt_session *session;
2864 enum lttng_error_code notification_ret;
2865 struct ust_registry_channel *chan_reg;
2866
2867 assert(app);
2868 assert(usess);
2869 assert(ua_sess);
2870 assert(ua_chan);
2871
2872 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2873
2874 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2875 /*
2876 * The session creation handles the creation of this global registry
2877 * object. If none can be find, there is a code flow problem or a
2878 * teardown race.
2879 */
2880 assert(reg_uid);
2881
2882 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2883 reg_uid);
2884 if (reg_chan) {
2885 goto send_channel;
2886 }
2887
2888 /* Create the buffer registry channel object. */
2889 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2890 if (ret < 0) {
2891 ERR("Error creating the UST channel \"%s\" registry instance",
2892 ua_chan->name);
2893 goto error;
2894 }
2895
2896 session = session_find_by_id(ua_sess->tracing_id);
2897 assert(session);
2898 assert(pthread_mutex_trylock(&session->lock));
2899 assert(session_trylock_list());
2900
2901 /*
2902 * Create the buffers on the consumer side. This call populates the
2903 * ust app channel object with all streams and data object.
2904 */
2905 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2906 app->bits_per_long, reg_uid->registry->reg.ust,
2907 session->current_archive_id);
2908 if (ret < 0) {
2909 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2910 ua_chan->name);
2911
2912 /*
2913 * Let's remove the previously created buffer registry channel so
2914 * it's not visible anymore in the session registry.
2915 */
2916 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2917 ua_chan->tracing_channel_id, false);
2918 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2919 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2920 goto error;
2921 }
2922
2923 /*
2924 * Setup the streams and add it to the session registry.
2925 */
2926 ret = setup_buffer_reg_channel(reg_uid->registry,
2927 ua_chan, reg_chan, app);
2928 if (ret < 0) {
2929 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2930 goto error;
2931 }
2932
2933 /* Notify the notification subsystem of the channel's creation. */
2934 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2935 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2936 ua_chan->tracing_channel_id);
2937 assert(chan_reg);
2938 chan_reg->consumer_key = ua_chan->key;
2939 chan_reg = NULL;
2940 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2941
2942 notification_ret = notification_thread_command_add_channel(
2943 notification_thread_handle, session->name,
2944 ua_sess->euid, ua_sess->egid,
2945 ua_chan->name,
2946 ua_chan->key,
2947 LTTNG_DOMAIN_UST,
2948 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2949 if (notification_ret != LTTNG_OK) {
2950 ret = - (int) notification_ret;
2951 ERR("Failed to add channel to notification thread");
2952 goto error;
2953 }
2954
2955 send_channel:
2956 /* Send buffers to the application. */
2957 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2958 if (ret < 0) {
2959 if (ret != -ENOTCONN) {
2960 ERR("Error sending channel to application");
2961 }
2962 goto error;
2963 }
2964
2965 error:
2966 return ret;
2967 }
2968
2969 /*
2970 * Create and send to the application the created buffers with per PID buffers.
2971 *
2972 * Called with UST app session lock held.
2973 * The session list lock and the session's lock must be acquired.
2974 *
2975 * Return 0 on success else a negative value.
2976 */
2977 static int create_channel_per_pid(struct ust_app *app,
2978 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2979 struct ust_app_channel *ua_chan)
2980 {
2981 int ret;
2982 struct ust_registry_session *registry;
2983 enum lttng_error_code cmd_ret;
2984 struct ltt_session *session;
2985 uint64_t chan_reg_key;
2986 struct ust_registry_channel *chan_reg;
2987
2988 assert(app);
2989 assert(usess);
2990 assert(ua_sess);
2991 assert(ua_chan);
2992
2993 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2994
2995 rcu_read_lock();
2996
2997 registry = get_session_registry(ua_sess);
2998 /* The UST app session lock is held, registry shall not be null. */
2999 assert(registry);
3000
3001 /* Create and add a new channel registry to session. */
3002 ret = ust_registry_channel_add(registry, ua_chan->key);
3003 if (ret < 0) {
3004 ERR("Error creating the UST channel \"%s\" registry instance",
3005 ua_chan->name);
3006 goto error;
3007 }
3008
3009 session = session_find_by_id(ua_sess->tracing_id);
3010 assert(session);
3011
3012 assert(pthread_mutex_trylock(&session->lock));
3013 assert(session_trylock_list());
3014
3015 /* Create and get channel on the consumer side. */
3016 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
3017 app->bits_per_long, registry,
3018 session->current_archive_id);
3019 if (ret < 0) {
3020 ERR("Error creating UST channel \"%s\" on the consumer daemon",
3021 ua_chan->name);
3022 goto error_remove_from_registry;
3023 }
3024
3025 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
3026 if (ret < 0) {
3027 if (ret != -ENOTCONN) {
3028 ERR("Error sending channel to application");
3029 }
3030 goto error_remove_from_registry;
3031 }
3032
3033 chan_reg_key = ua_chan->key;
3034 pthread_mutex_lock(&registry->lock);
3035 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
3036 assert(chan_reg);
3037 chan_reg->consumer_key = ua_chan->key;
3038 pthread_mutex_unlock(&registry->lock);
3039
3040 cmd_ret = notification_thread_command_add_channel(
3041 notification_thread_handle, session->name,
3042 ua_sess->euid, ua_sess->egid,
3043 ua_chan->name,
3044 ua_chan->key,
3045 LTTNG_DOMAIN_UST,
3046 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
3047 if (cmd_ret != LTTNG_OK) {
3048 ret = - (int) cmd_ret;
3049 ERR("Failed to add channel to notification thread");
3050 goto error_remove_from_registry;
3051 }
3052
3053 error_remove_from_registry:
3054 if (ret) {
3055 ust_registry_channel_del_free(registry, ua_chan->key, false);
3056 }
3057 error:
3058 rcu_read_unlock();
3059 return ret;
3060 }
3061
3062 /*
3063 * From an already allocated ust app channel, create the channel buffers if
3064 * need and send it to the application. This MUST be called with a RCU read
3065 * side lock acquired.
3066 *
3067 * Called with UST app session lock held.
3068 *
3069 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3070 * the application exited concurrently.
3071 */
3072 static int do_create_channel(struct ust_app *app,
3073 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3074 struct ust_app_channel *ua_chan)
3075 {
3076 int ret;
3077
3078 assert(app);
3079 assert(usess);
3080 assert(ua_sess);
3081 assert(ua_chan);
3082
3083 /* Handle buffer type before sending the channel to the application. */
3084 switch (usess->buffer_type) {
3085 case LTTNG_BUFFER_PER_UID:
3086 {
3087 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3088 if (ret < 0) {
3089 goto error;
3090 }
3091 break;
3092 }
3093 case LTTNG_BUFFER_PER_PID:
3094 {
3095 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3096 if (ret < 0) {
3097 goto error;
3098 }
3099 break;
3100 }
3101 default:
3102 assert(0);
3103 ret = -EINVAL;
3104 goto error;
3105 }
3106
3107 /* Initialize ust objd object using the received handle and add it. */
3108 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3109 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3110
3111 /* If channel is not enabled, disable it on the tracer */
3112 if (!ua_chan->enabled) {
3113 ret = disable_ust_channel(app, ua_sess, ua_chan);
3114 if (ret < 0) {
3115 goto error;
3116 }
3117 }
3118
3119 error:
3120 return ret;
3121 }
3122
3123 /*
3124 * Create UST app channel and create it on the tracer. Set ua_chanp of the
3125 * newly created channel if not NULL.
3126 *
3127 * Called with UST app session lock and RCU read-side lock held.
3128 *
3129 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3130 * the application exited concurrently.
3131 */
3132 static int create_ust_app_channel(struct ust_app_session *ua_sess,
3133 struct ltt_ust_channel *uchan, struct ust_app *app,
3134 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3135 struct ust_app_channel **ua_chanp)
3136 {
3137 int ret = 0;
3138 struct lttng_ht_iter iter;
3139 struct lttng_ht_node_str *ua_chan_node;
3140 struct ust_app_channel *ua_chan;
3141
3142 /* Lookup channel in the ust app session */
3143 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3144 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3145 if (ua_chan_node != NULL) {
3146 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3147 goto end;
3148 }
3149
3150 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3151 if (ua_chan == NULL) {
3152 /* Only malloc can fail here */
3153 ret = -ENOMEM;
3154 goto error_alloc;
3155 }
3156 shadow_copy_channel(ua_chan, uchan);
3157
3158 /* Set channel type. */
3159 ua_chan->attr.type = type;
3160
3161 ret = do_create_channel(app, usess, ua_sess, ua_chan);
3162 if (ret < 0) {
3163 goto error;
3164 }
3165
3166 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
3167 app->pid);
3168
3169 /* Only add the channel if successful on the tracer side. */
3170 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3171 end:
3172 if (ua_chanp) {
3173 *ua_chanp = ua_chan;
3174 }
3175
3176 /* Everything went well. */
3177 return 0;
3178
3179 error:
3180 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
3181 error_alloc:
3182 return ret;
3183 }
3184
3185 /*
3186 * Create UST app event and create it on the tracer side.
3187 *
3188 * Called with ust app session mutex held.
3189 */
3190 static
3191 int create_ust_app_event(struct ust_app_session *ua_sess,
3192 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3193 struct ust_app *app)
3194 {
3195 int ret = 0;
3196 struct ust_app_event *ua_event;
3197
3198 /* Get event node */
3199 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3200 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3201 if (ua_event != NULL) {
3202 ret = -EEXIST;
3203 goto end;
3204 }
3205
3206 /* Does not exist so create one */
3207 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3208 if (ua_event == NULL) {
3209 /* Only malloc can failed so something is really wrong */
3210 ret = -ENOMEM;
3211 goto end;
3212 }
3213 shadow_copy_event(ua_event, uevent);
3214
3215 /* Create it on the tracer side */
3216 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3217 if (ret < 0) {
3218 /* Not found previously means that it does not exist on the tracer */
3219 assert(ret != -LTTNG_UST_ERR_EXIST);
3220 goto error;
3221 }
3222
3223 add_unique_ust_app_event(ua_chan, ua_event);
3224