b3251c19c94ff6feb173fb387866becc799e6c03
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <lttng/ust-error.h>
31 #include <signal.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35
36 #include "buffer-registry.h"
37 #include "fd-limit.h"
38 #include "health-sessiond.h"
39 #include "ust-app.h"
40 #include "ust-consumer.h"
41 #include "ust-ctl.h"
42 #include "utils.h"
43 #include "session.h"
44 #include "lttng-sessiond.h"
45 #include "notification-thread-commands.h"
46 #include "rotate.h"
47
48 static
49 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51 /* Next available channel key. Access under next_channel_key_lock. */
52 static uint64_t _next_channel_key;
53 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55 /* Next available session ID. Access under next_session_id_lock. */
56 static uint64_t _next_session_id;
57 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59 /*
60 * Return the incremented value of next_channel_key.
61 */
62 static uint64_t get_next_channel_key(void)
63 {
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70 }
71
72 /*
73 * Return the atomically incremented value of next_session_id.
74 */
75 static uint64_t get_next_session_id(void)
76 {
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83 }
84
85 static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88 {
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97 }
98
99 /*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106 {
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173 no_match:
174 return 0;
175 }
176
177 /*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183 {
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202 }
203
204 /*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208 static void close_notify_sock_rcu(struct rcu_head *head)
209 {
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224 }
225
226 /*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233 static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235 {
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long,
254 ua_sess->real_credentials.uid);
255 if (!reg_uid) {
256 goto error;
257 }
258 registry = reg_uid->registry->reg.ust;
259 break;
260 }
261 default:
262 assert(0);
263 };
264
265 error:
266 return registry;
267 }
268
269 /*
270 * Delete ust context safely. RCU read lock must be held before calling
271 * this function.
272 */
273 static
274 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
275 struct ust_app *app)
276 {
277 int ret;
278
279 assert(ua_ctx);
280
281 if (ua_ctx->obj) {
282 pthread_mutex_lock(&app->sock_lock);
283 ret = ustctl_release_object(sock, ua_ctx->obj);
284 pthread_mutex_unlock(&app->sock_lock);
285 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
286 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
287 sock, ua_ctx->obj->handle, ret);
288 }
289 free(ua_ctx->obj);
290 }
291 free(ua_ctx);
292 }
293
294 /*
295 * Delete ust app event safely. RCU read lock must be held before calling
296 * this function.
297 */
298 static
299 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
300 struct ust_app *app)
301 {
302 int ret;
303
304 assert(ua_event);
305
306 free(ua_event->filter);
307 if (ua_event->exclusion != NULL)
308 free(ua_event->exclusion);
309 if (ua_event->obj != NULL) {
310 pthread_mutex_lock(&app->sock_lock);
311 ret = ustctl_release_object(sock, ua_event->obj);
312 pthread_mutex_unlock(&app->sock_lock);
313 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
314 ERR("UST app sock %d release event obj failed with ret %d",
315 sock, ret);
316 }
317 free(ua_event->obj);
318 }
319 free(ua_event);
320 }
321
322 /*
323 * Release ust data object of the given stream.
324 *
325 * Return 0 on success or else a negative value.
326 */
327 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
328 struct ust_app *app)
329 {
330 int ret = 0;
331
332 assert(stream);
333
334 if (stream->obj) {
335 pthread_mutex_lock(&app->sock_lock);
336 ret = ustctl_release_object(sock, stream->obj);
337 pthread_mutex_unlock(&app->sock_lock);
338 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
339 ERR("UST app sock %d release stream obj failed with ret %d",
340 sock, ret);
341 }
342 lttng_fd_put(LTTNG_FD_APPS, 2);
343 free(stream->obj);
344 }
345
346 return ret;
347 }
348
349 /*
350 * Delete ust app stream safely. RCU read lock must be held before calling
351 * this function.
352 */
353 static
354 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
355 struct ust_app *app)
356 {
357 assert(stream);
358
359 (void) release_ust_app_stream(sock, stream, app);
360 free(stream);
361 }
362
363 /*
364 * We need to execute ht_destroy outside of RCU read-side critical
365 * section and outside of call_rcu thread, so we postpone its execution
366 * using ht_cleanup_push. It is simpler than to change the semantic of
367 * the many callers of delete_ust_app_session().
368 */
369 static
370 void delete_ust_app_channel_rcu(struct rcu_head *head)
371 {
372 struct ust_app_channel *ua_chan =
373 caa_container_of(head, struct ust_app_channel, rcu_head);
374
375 ht_cleanup_push(ua_chan->ctx);
376 ht_cleanup_push(ua_chan->events);
377 free(ua_chan);
378 }
379
380 /*
381 * Extract the lost packet or discarded events counter when the channel is
382 * being deleted and store the value in the parent channel so we can
383 * access it from lttng list and at stop/destroy.
384 *
385 * The session list lock must be held by the caller.
386 */
387 static
388 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
389 {
390 uint64_t discarded = 0, lost = 0;
391 struct ltt_session *session;
392 struct ltt_ust_channel *uchan;
393
394 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
395 return;
396 }
397
398 rcu_read_lock();
399 session = session_find_by_id(ua_chan->session->tracing_id);
400 if (!session || !session->ust_session) {
401 /*
402 * Not finding the session is not an error because there are
403 * multiple ways the channels can be torn down.
404 *
405 * 1) The session daemon can initiate the destruction of the
406 * ust app session after receiving a destroy command or
407 * during its shutdown/teardown.
408 * 2) The application, since we are in per-pid tracing, is
409 * unregistering and tearing down its ust app session.
410 *
411 * Both paths are protected by the session list lock which
412 * ensures that the accounting of lost packets and discarded
413 * events is done exactly once. The session is then unpublished
414 * from the session list, resulting in this condition.
415 */
416 goto end;
417 }
418
419 if (ua_chan->attr.overwrite) {
420 consumer_get_lost_packets(ua_chan->session->tracing_id,
421 ua_chan->key, session->ust_session->consumer,
422 &lost);
423 } else {
424 consumer_get_discarded_events(ua_chan->session->tracing_id,
425 ua_chan->key, session->ust_session->consumer,
426 &discarded);
427 }
428 uchan = trace_ust_find_channel_by_name(
429 session->ust_session->domain_global.channels,
430 ua_chan->name);
431 if (!uchan) {
432 ERR("Missing UST channel to store discarded counters");
433 goto end;
434 }
435
436 uchan->per_pid_closed_app_discarded += discarded;
437 uchan->per_pid_closed_app_lost += lost;
438
439 end:
440 rcu_read_unlock();
441 if (session) {
442 session_put(session);
443 }
444 }
445
446 /*
447 * Delete ust app channel safely. RCU read lock must be held before calling
448 * this function.
449 *
450 * The session list lock must be held by the caller.
451 */
452 static
453 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
454 struct ust_app *app)
455 {
456 int ret;
457 struct lttng_ht_iter iter;
458 struct ust_app_event *ua_event;
459 struct ust_app_ctx *ua_ctx;
460 struct ust_app_stream *stream, *stmp;
461 struct ust_registry_session *registry;
462
463 assert(ua_chan);
464
465 DBG3("UST app deleting channel %s", ua_chan->name);
466
467 /* Wipe stream */
468 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
469 cds_list_del(&stream->list);
470 delete_ust_app_stream(sock, stream, app);
471 }
472
473 /* Wipe context */
474 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
475 cds_list_del(&ua_ctx->list);
476 ret = lttng_ht_del(ua_chan->ctx, &iter);
477 assert(!ret);
478 delete_ust_app_ctx(sock, ua_ctx, app);
479 }
480
481 /* Wipe events */
482 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
483 node.node) {
484 ret = lttng_ht_del(ua_chan->events, &iter);
485 assert(!ret);
486 delete_ust_app_event(sock, ua_event, app);
487 }
488
489 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
490 /* Wipe and free registry from session registry. */
491 registry = get_session_registry(ua_chan->session);
492 if (registry) {
493 ust_registry_channel_del_free(registry, ua_chan->key,
494 sock >= 0);
495 }
496 /*
497 * A negative socket can be used by the caller when
498 * cleaning-up a ua_chan in an error path. Skip the
499 * accounting in this case.
500 */
501 if (sock >= 0) {
502 save_per_pid_lost_discarded_counters(ua_chan);
503 }
504 }
505
506 if (ua_chan->obj != NULL) {
507 /* Remove channel from application UST object descriptor. */
508 iter.iter.node = &ua_chan->ust_objd_node.node;
509 ret = lttng_ht_del(app->ust_objd, &iter);
510 assert(!ret);
511 pthread_mutex_lock(&app->sock_lock);
512 ret = ustctl_release_object(sock, ua_chan->obj);
513 pthread_mutex_unlock(&app->sock_lock);
514 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
515 ERR("UST app sock %d release channel obj failed with ret %d",
516 sock, ret);
517 }
518 lttng_fd_put(LTTNG_FD_APPS, 1);
519 free(ua_chan->obj);
520 }
521 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
522 }
523
524 int ust_app_register_done(struct ust_app *app)
525 {
526 int ret;
527
528 pthread_mutex_lock(&app->sock_lock);
529 ret = ustctl_register_done(app->sock);
530 pthread_mutex_unlock(&app->sock_lock);
531 return ret;
532 }
533
534 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
535 {
536 int ret, sock;
537
538 if (app) {
539 pthread_mutex_lock(&app->sock_lock);
540 sock = app->sock;
541 } else {
542 sock = -1;
543 }
544 ret = ustctl_release_object(sock, data);
545 if (app) {
546 pthread_mutex_unlock(&app->sock_lock);
547 }
548 return ret;
549 }
550
551 /*
552 * Push metadata to consumer socket.
553 *
554 * RCU read-side lock must be held to guarantee existance of socket.
555 * Must be called with the ust app session lock held.
556 * Must be called with the registry lock held.
557 *
558 * On success, return the len of metadata pushed or else a negative value.
559 * Returning a -EPIPE return value means we could not send the metadata,
560 * but it can be caused by recoverable errors (e.g. the application has
561 * terminated concurrently).
562 */
563 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
564 struct consumer_socket *socket, int send_zero_data)
565 {
566 int ret;
567 char *metadata_str = NULL;
568 size_t len, offset, new_metadata_len_sent;
569 ssize_t ret_val;
570 uint64_t metadata_key, metadata_version;
571
572 assert(registry);
573 assert(socket);
574
575 metadata_key = registry->metadata_key;
576
577 /*
578 * Means that no metadata was assigned to the session. This can
579 * happens if no start has been done previously.
580 */
581 if (!metadata_key) {
582 return 0;
583 }
584
585 offset = registry->metadata_len_sent;
586 len = registry->metadata_len - registry->metadata_len_sent;
587 new_metadata_len_sent = registry->metadata_len;
588 metadata_version = registry->metadata_version;
589 if (len == 0) {
590 DBG3("No metadata to push for metadata key %" PRIu64,
591 registry->metadata_key);
592 ret_val = len;
593 if (send_zero_data) {
594 DBG("No metadata to push");
595 goto push_data;
596 }
597 goto end;
598 }
599
600 /* Allocate only what we have to send. */
601 metadata_str = zmalloc(len);
602 if (!metadata_str) {
603 PERROR("zmalloc ust app metadata string");
604 ret_val = -ENOMEM;
605 goto error;
606 }
607 /* Copy what we haven't sent out. */
608 memcpy(metadata_str, registry->metadata + offset, len);
609
610 push_data:
611 pthread_mutex_unlock(&registry->lock);
612 /*
613 * We need to unlock the registry while we push metadata to
614 * break a circular dependency between the consumerd metadata
615 * lock and the sessiond registry lock. Indeed, pushing metadata
616 * to the consumerd awaits that it gets pushed all the way to
617 * relayd, but doing so requires grabbing the metadata lock. If
618 * a concurrent metadata request is being performed by
619 * consumerd, this can try to grab the registry lock on the
620 * sessiond while holding the metadata lock on the consumer
621 * daemon. Those push and pull schemes are performed on two
622 * different bidirectionnal communication sockets.
623 */
624 ret = consumer_push_metadata(socket, metadata_key,
625 metadata_str, len, offset, metadata_version);
626 pthread_mutex_lock(&registry->lock);
627 if (ret < 0) {
628 /*
629 * There is an acceptable race here between the registry
630 * metadata key assignment and the creation on the
631 * consumer. The session daemon can concurrently push
632 * metadata for this registry while being created on the
633 * consumer since the metadata key of the registry is
634 * assigned *before* it is setup to avoid the consumer
635 * to ask for metadata that could possibly be not found
636 * in the session daemon.
637 *
638 * The metadata will get pushed either by the session
639 * being stopped or the consumer requesting metadata if
640 * that race is triggered.
641 */
642 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
643 ret = 0;
644 } else {
645 ERR("Error pushing metadata to consumer");
646 }
647 ret_val = ret;
648 goto error_push;
649 } else {
650 /*
651 * Metadata may have been concurrently pushed, since
652 * we're not holding the registry lock while pushing to
653 * consumer. This is handled by the fact that we send
654 * the metadata content, size, and the offset at which
655 * that metadata belongs. This may arrive out of order
656 * on the consumer side, and the consumer is able to
657 * deal with overlapping fragments. The consumer
658 * supports overlapping fragments, which must be
659 * contiguous starting from offset 0. We keep the
660 * largest metadata_len_sent value of the concurrent
661 * send.
662 */
663 registry->metadata_len_sent =
664 max_t(size_t, registry->metadata_len_sent,
665 new_metadata_len_sent);
666 }
667 free(metadata_str);
668 return len;
669
670 end:
671 error:
672 if (ret_val) {
673 /*
674 * On error, flag the registry that the metadata is
675 * closed. We were unable to push anything and this
676 * means that either the consumer is not responding or
677 * the metadata cache has been destroyed on the
678 * consumer.
679 */
680 registry->metadata_closed = 1;
681 }
682 error_push:
683 free(metadata_str);
684 return ret_val;
685 }
686
687 /*
688 * For a given application and session, push metadata to consumer.
689 * Either sock or consumer is required : if sock is NULL, the default
690 * socket to send the metadata is retrieved from consumer, if sock
691 * is not NULL we use it to send the metadata.
692 * RCU read-side lock must be held while calling this function,
693 * therefore ensuring existance of registry. It also ensures existance
694 * of socket throughout this function.
695 *
696 * Return 0 on success else a negative error.
697 * Returning a -EPIPE return value means we could not send the metadata,
698 * but it can be caused by recoverable errors (e.g. the application has
699 * terminated concurrently).
700 */
701 static int push_metadata(struct ust_registry_session *registry,
702 struct consumer_output *consumer)
703 {
704 int ret_val;
705 ssize_t ret;
706 struct consumer_socket *socket;
707
708 assert(registry);
709 assert(consumer);
710
711 pthread_mutex_lock(&registry->lock);
712 if (registry->metadata_closed) {
713 ret_val = -EPIPE;
714 goto error;
715 }
716
717 /* Get consumer socket to use to push the metadata.*/
718 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
719 consumer);
720 if (!socket) {
721 ret_val = -1;
722 goto error;
723 }
724
725 ret = ust_app_push_metadata(registry, socket, 0);
726 if (ret < 0) {
727 ret_val = ret;
728 goto error;
729 }
730 pthread_mutex_unlock(&registry->lock);
731 return 0;
732
733 error:
734 pthread_mutex_unlock(&registry->lock);
735 return ret_val;
736 }
737
738 /*
739 * Send to the consumer a close metadata command for the given session. Once
740 * done, the metadata channel is deleted and the session metadata pointer is
741 * nullified. The session lock MUST be held unless the application is
742 * in the destroy path.
743 *
744 * Return 0 on success else a negative value.
745 */
746 static int close_metadata(struct ust_registry_session *registry,
747 struct consumer_output *consumer)
748 {
749 int ret;
750 struct consumer_socket *socket;
751
752 assert(registry);
753 assert(consumer);
754
755 rcu_read_lock();
756
757 pthread_mutex_lock(&registry->lock);
758
759 if (!registry->metadata_key || registry->metadata_closed) {
760 ret = 0;
761 goto end;
762 }
763
764 /* Get consumer socket to use to push the metadata.*/
765 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
766 consumer);
767 if (!socket) {
768 ret = -1;
769 goto error;
770 }
771
772 ret = consumer_close_metadata(socket, registry->metadata_key);
773 if (ret < 0) {
774 goto error;
775 }
776
777 error:
778 /*
779 * Metadata closed. Even on error this means that the consumer is not
780 * responding or not found so either way a second close should NOT be emit
781 * for this registry.
782 */
783 registry->metadata_closed = 1;
784 end:
785 pthread_mutex_unlock(&registry->lock);
786 rcu_read_unlock();
787 return ret;
788 }
789
790 /*
791 * We need to execute ht_destroy outside of RCU read-side critical
792 * section and outside of call_rcu thread, so we postpone its execution
793 * using ht_cleanup_push. It is simpler than to change the semantic of
794 * the many callers of delete_ust_app_session().
795 */
796 static
797 void delete_ust_app_session_rcu(struct rcu_head *head)
798 {
799 struct ust_app_session *ua_sess =
800 caa_container_of(head, struct ust_app_session, rcu_head);
801
802 ht_cleanup_push(ua_sess->channels);
803 free(ua_sess);
804 }
805
806 /*
807 * Delete ust app session safely. RCU read lock must be held before calling
808 * this function.
809 *
810 * The session list lock must be held by the caller.
811 */
812 static
813 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
814 struct ust_app *app)
815 {
816 int ret;
817 struct lttng_ht_iter iter;
818 struct ust_app_channel *ua_chan;
819 struct ust_registry_session *registry;
820
821 assert(ua_sess);
822
823 pthread_mutex_lock(&ua_sess->lock);
824
825 assert(!ua_sess->deleted);
826 ua_sess->deleted = true;
827
828 registry = get_session_registry(ua_sess);
829 /* Registry can be null on error path during initialization. */
830 if (registry) {
831 /* Push metadata for application before freeing the application. */
832 (void) push_metadata(registry, ua_sess->consumer);
833
834 /*
835 * Don't ask to close metadata for global per UID buffers. Close
836 * metadata only on destroy trace session in this case. Also, the
837 * previous push metadata could have flag the metadata registry to
838 * close so don't send a close command if closed.
839 */
840 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
841 /* And ask to close it for this session registry. */
842 (void) close_metadata(registry, ua_sess->consumer);
843 }
844 }
845
846 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
847 node.node) {
848 ret = lttng_ht_del(ua_sess->channels, &iter);
849 assert(!ret);
850 delete_ust_app_channel(sock, ua_chan, app);
851 }
852
853 /* In case of per PID, the registry is kept in the session. */
854 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
855 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
856 if (reg_pid) {
857 /*
858 * Registry can be null on error path during
859 * initialization.
860 */
861 buffer_reg_pid_remove(reg_pid);
862 buffer_reg_pid_destroy(reg_pid);
863 }
864 }
865
866 if (ua_sess->handle != -1) {
867 pthread_mutex_lock(&app->sock_lock);
868 ret = ustctl_release_handle(sock, ua_sess->handle);
869 pthread_mutex_unlock(&app->sock_lock);
870 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
871 ERR("UST app sock %d release session handle failed with ret %d",
872 sock, ret);
873 }
874 /* Remove session from application UST object descriptor. */
875 iter.iter.node = &ua_sess->ust_objd_node.node;
876 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
877 assert(!ret);
878 }
879
880 pthread_mutex_unlock(&ua_sess->lock);
881
882 consumer_output_put(ua_sess->consumer);
883
884 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
885 }
886
887 /*
888 * Delete a traceable application structure from the global list. Never call
889 * this function outside of a call_rcu call.
890 *
891 * RCU read side lock should _NOT_ be held when calling this function.
892 */
893 static
894 void delete_ust_app(struct ust_app *app)
895 {
896 int ret, sock;
897 struct ust_app_session *ua_sess, *tmp_ua_sess;
898
899 /*
900 * The session list lock must be held during this function to guarantee
901 * the existence of ua_sess.
902 */
903 session_lock_list();
904 /* Delete ust app sessions info */
905 sock = app->sock;
906 app->sock = -1;
907
908 /* Wipe sessions */
909 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
910 teardown_node) {
911 /* Free every object in the session and the session. */
912 rcu_read_lock();
913 delete_ust_app_session(sock, ua_sess, app);
914 rcu_read_unlock();
915 }
916
917 ht_cleanup_push(app->sessions);
918 ht_cleanup_push(app->ust_sessions_objd);
919 ht_cleanup_push(app->ust_objd);
920
921 /*
922 * Wait until we have deleted the application from the sock hash table
923 * before closing this socket, otherwise an application could re-use the
924 * socket ID and race with the teardown, using the same hash table entry.
925 *
926 * It's OK to leave the close in call_rcu. We want it to stay unique for
927 * all RCU readers that could run concurrently with unregister app,
928 * therefore we _need_ to only close that socket after a grace period. So
929 * it should stay in this RCU callback.
930 *
931 * This close() is a very important step of the synchronization model so
932 * every modification to this function must be carefully reviewed.
933 */
934 ret = close(sock);
935 if (ret) {
936 PERROR("close");
937 }
938 lttng_fd_put(LTTNG_FD_APPS, 1);
939
940 DBG2("UST app pid %d deleted", app->pid);
941 free(app);
942 session_unlock_list();
943 }
944
945 /*
946 * URCU intermediate call to delete an UST app.
947 */
948 static
949 void delete_ust_app_rcu(struct rcu_head *head)
950 {
951 struct lttng_ht_node_ulong *node =
952 caa_container_of(head, struct lttng_ht_node_ulong, head);
953 struct ust_app *app =
954 caa_container_of(node, struct ust_app, pid_n);
955
956 DBG3("Call RCU deleting app PID %d", app->pid);
957 delete_ust_app(app);
958 }
959
960 /*
961 * Delete the session from the application ht and delete the data structure by
962 * freeing every object inside and releasing them.
963 *
964 * The session list lock must be held by the caller.
965 */
966 static void destroy_app_session(struct ust_app *app,
967 struct ust_app_session *ua_sess)
968 {
969 int ret;
970 struct lttng_ht_iter iter;
971
972 assert(app);
973 assert(ua_sess);
974
975 iter.iter.node = &ua_sess->node.node;
976 ret = lttng_ht_del(app->sessions, &iter);
977 if (ret) {
978 /* Already scheduled for teardown. */
979 goto end;
980 }
981
982 /* Once deleted, free the data structure. */
983 delete_ust_app_session(app->sock, ua_sess, app);
984
985 end:
986 return;
987 }
988
989 /*
990 * Alloc new UST app session.
991 */
992 static
993 struct ust_app_session *alloc_ust_app_session(void)
994 {
995 struct ust_app_session *ua_sess;
996
997 /* Init most of the default value by allocating and zeroing */
998 ua_sess = zmalloc(sizeof(struct ust_app_session));
999 if (ua_sess == NULL) {
1000 PERROR("malloc");
1001 goto error_free;
1002 }
1003
1004 ua_sess->handle = -1;
1005 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1006 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1007 pthread_mutex_init(&ua_sess->lock, NULL);
1008
1009 return ua_sess;
1010
1011 error_free:
1012 return NULL;
1013 }
1014
1015 /*
1016 * Alloc new UST app channel.
1017 */
1018 static
1019 struct ust_app_channel *alloc_ust_app_channel(char *name,
1020 struct ust_app_session *ua_sess,
1021 struct lttng_ust_channel_attr *attr)
1022 {
1023 struct ust_app_channel *ua_chan;
1024
1025 /* Init most of the default value by allocating and zeroing */
1026 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1027 if (ua_chan == NULL) {
1028 PERROR("malloc");
1029 goto error;
1030 }
1031
1032 /* Setup channel name */
1033 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1034 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1035
1036 ua_chan->enabled = 1;
1037 ua_chan->handle = -1;
1038 ua_chan->session = ua_sess;
1039 ua_chan->key = get_next_channel_key();
1040 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1041 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1042 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1043
1044 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1045 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1046
1047 /* Copy attributes */
1048 if (attr) {
1049 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1050 ua_chan->attr.subbuf_size = attr->subbuf_size;
1051 ua_chan->attr.num_subbuf = attr->num_subbuf;
1052 ua_chan->attr.overwrite = attr->overwrite;
1053 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1054 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1055 ua_chan->attr.output = attr->output;
1056 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1057 }
1058 /* By default, the channel is a per cpu channel. */
1059 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1060
1061 DBG3("UST app channel %s allocated", ua_chan->name);
1062
1063 return ua_chan;
1064
1065 error:
1066 return NULL;
1067 }
1068
1069 /*
1070 * Allocate and initialize a UST app stream.
1071 *
1072 * Return newly allocated stream pointer or NULL on error.
1073 */
1074 struct ust_app_stream *ust_app_alloc_stream(void)
1075 {
1076 struct ust_app_stream *stream = NULL;
1077
1078 stream = zmalloc(sizeof(*stream));
1079 if (stream == NULL) {
1080 PERROR("zmalloc ust app stream");
1081 goto error;
1082 }
1083
1084 /* Zero could be a valid value for a handle so flag it to -1. */
1085 stream->handle = -1;
1086
1087 error:
1088 return stream;
1089 }
1090
1091 /*
1092 * Alloc new UST app event.
1093 */
1094 static
1095 struct ust_app_event *alloc_ust_app_event(char *name,
1096 struct lttng_ust_event *attr)
1097 {
1098 struct ust_app_event *ua_event;
1099
1100 /* Init most of the default value by allocating and zeroing */
1101 ua_event = zmalloc(sizeof(struct ust_app_event));
1102 if (ua_event == NULL) {
1103 PERROR("malloc");
1104 goto error;
1105 }
1106
1107 ua_event->enabled = 1;
1108 strncpy(ua_event->name, name, sizeof(ua_event->name));
1109 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1110 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1111
1112 /* Copy attributes */
1113 if (attr) {
1114 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1115 }
1116
1117 DBG3("UST app event %s allocated", ua_event->name);
1118
1119 return ua_event;
1120
1121 error:
1122 return NULL;
1123 }
1124
1125 /*
1126 * Alloc new UST app context.
1127 */
1128 static
1129 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1130 {
1131 struct ust_app_ctx *ua_ctx;
1132
1133 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1134 if (ua_ctx == NULL) {
1135 goto error;
1136 }
1137
1138 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1139
1140 if (uctx) {
1141 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1142 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1143 char *provider_name = NULL, *ctx_name = NULL;
1144
1145 provider_name = strdup(uctx->u.app_ctx.provider_name);
1146 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1147 if (!provider_name || !ctx_name) {
1148 free(provider_name);
1149 free(ctx_name);
1150 goto error;
1151 }
1152
1153 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1154 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1155 }
1156 }
1157
1158 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1159 return ua_ctx;
1160 error:
1161 free(ua_ctx);
1162 return NULL;
1163 }
1164
1165 /*
1166 * Allocate a filter and copy the given original filter.
1167 *
1168 * Return allocated filter or NULL on error.
1169 */
1170 static struct lttng_filter_bytecode *copy_filter_bytecode(
1171 struct lttng_filter_bytecode *orig_f)
1172 {
1173 struct lttng_filter_bytecode *filter = NULL;
1174
1175 /* Copy filter bytecode */
1176 filter = zmalloc(sizeof(*filter) + orig_f->len);
1177 if (!filter) {
1178 PERROR("zmalloc alloc filter bytecode");
1179 goto error;
1180 }
1181
1182 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1183
1184 error:
1185 return filter;
1186 }
1187
1188 /*
1189 * Create a liblttng-ust filter bytecode from given bytecode.
1190 *
1191 * Return allocated filter or NULL on error.
1192 */
1193 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1194 struct lttng_filter_bytecode *orig_f)
1195 {
1196 struct lttng_ust_filter_bytecode *filter = NULL;
1197
1198 /* Copy filter bytecode */
1199 filter = zmalloc(sizeof(*filter) + orig_f->len);
1200 if (!filter) {
1201 PERROR("zmalloc alloc ust filter bytecode");
1202 goto error;
1203 }
1204
1205 assert(sizeof(struct lttng_filter_bytecode) ==
1206 sizeof(struct lttng_ust_filter_bytecode));
1207 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1208 error:
1209 return filter;
1210 }
1211
1212 /*
1213 * Find an ust_app using the sock and return it. RCU read side lock must be
1214 * held before calling this helper function.
1215 */
1216 struct ust_app *ust_app_find_by_sock(int sock)
1217 {
1218 struct lttng_ht_node_ulong *node;
1219 struct lttng_ht_iter iter;
1220
1221 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1222 node = lttng_ht_iter_get_node_ulong(&iter);
1223 if (node == NULL) {
1224 DBG2("UST app find by sock %d not found", sock);
1225 goto error;
1226 }
1227
1228 return caa_container_of(node, struct ust_app, sock_n);
1229
1230 error:
1231 return NULL;
1232 }
1233
1234 /*
1235 * Find an ust_app using the notify sock and return it. RCU read side lock must
1236 * be held before calling this helper function.
1237 */
1238 static struct ust_app *find_app_by_notify_sock(int sock)
1239 {
1240 struct lttng_ht_node_ulong *node;
1241 struct lttng_ht_iter iter;
1242
1243 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1244 &iter);
1245 node = lttng_ht_iter_get_node_ulong(&iter);
1246 if (node == NULL) {
1247 DBG2("UST app find by notify sock %d not found", sock);
1248 goto error;
1249 }
1250
1251 return caa_container_of(node, struct ust_app, notify_sock_n);
1252
1253 error:
1254 return NULL;
1255 }
1256
1257 /*
1258 * Lookup for an ust app event based on event name, filter bytecode and the
1259 * event loglevel.
1260 *
1261 * Return an ust_app_event object or NULL on error.
1262 */
1263 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1264 const char *name, const struct lttng_filter_bytecode *filter,
1265 int loglevel_value,
1266 const struct lttng_event_exclusion *exclusion)
1267 {
1268 struct lttng_ht_iter iter;
1269 struct lttng_ht_node_str *node;
1270 struct ust_app_event *event = NULL;
1271 struct ust_app_ht_key key;
1272
1273 assert(name);
1274 assert(ht);
1275
1276 /* Setup key for event lookup. */
1277 key.name = name;
1278 key.filter = filter;
1279 key.loglevel_type = loglevel_value;
1280 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1281 key.exclusion = exclusion;
1282
1283 /* Lookup using the event name as hash and a custom match fct. */
1284 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1285 ht_match_ust_app_event, &key, &iter.iter);
1286 node = lttng_ht_iter_get_node_str(&iter);
1287 if (node == NULL) {
1288 goto end;
1289 }
1290
1291 event = caa_container_of(node, struct ust_app_event, node);
1292
1293 end:
1294 return event;
1295 }
1296
1297 /*
1298 * Create the channel context on the tracer.
1299 *
1300 * Called with UST app session lock held.
1301 */
1302 static
1303 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1304 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1305 {
1306 int ret;
1307
1308 health_code_update();
1309
1310 pthread_mutex_lock(&app->sock_lock);
1311 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1312 ua_chan->obj, &ua_ctx->obj);
1313 pthread_mutex_unlock(&app->sock_lock);
1314 if (ret < 0) {
1315 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1316 ERR("UST app create channel context failed for app (pid: %d) "
1317 "with ret %d", app->pid, ret);
1318 } else {
1319 /*
1320 * This is normal behavior, an application can die during the
1321 * creation process. Don't report an error so the execution can
1322 * continue normally.
1323 */
1324 ret = 0;
1325 DBG3("UST app add context failed. Application is dead.");
1326 }
1327 goto error;
1328 }
1329
1330 ua_ctx->handle = ua_ctx->obj->handle;
1331
1332 DBG2("UST app context handle %d created successfully for channel %s",
1333 ua_ctx->handle, ua_chan->name);
1334
1335 error:
1336 health_code_update();
1337 return ret;
1338 }
1339
1340 /*
1341 * Set the filter on the tracer.
1342 */
1343 static
1344 int set_ust_event_filter(struct ust_app_event *ua_event,
1345 struct ust_app *app)
1346 {
1347 int ret;
1348 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1349
1350 health_code_update();
1351
1352 if (!ua_event->filter) {
1353 ret = 0;
1354 goto error;
1355 }
1356
1357 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1358 if (!ust_bytecode) {
1359 ret = -LTTNG_ERR_NOMEM;
1360 goto error;
1361 }
1362 pthread_mutex_lock(&app->sock_lock);
1363 ret = ustctl_set_filter(app->sock, ust_bytecode,
1364 ua_event->obj);
1365 pthread_mutex_unlock(&app->sock_lock);
1366 if (ret < 0) {
1367 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1368 ERR("UST app event %s filter failed for app (pid: %d) "
1369 "with ret %d", ua_event->attr.name, app->pid, ret);
1370 } else {
1371 /*
1372 * This is normal behavior, an application can die during the
1373 * creation process. Don't report an error so the execution can
1374 * continue normally.
1375 */
1376 ret = 0;
1377 DBG3("UST app filter event failed. Application is dead.");
1378 }
1379 goto error;
1380 }
1381
1382 DBG2("UST filter set successfully for event %s", ua_event->name);
1383
1384 error:
1385 health_code_update();
1386 free(ust_bytecode);
1387 return ret;
1388 }
1389
1390 static
1391 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1392 struct lttng_event_exclusion *exclusion)
1393 {
1394 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1395 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1396 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1397
1398 ust_exclusion = zmalloc(exclusion_alloc_size);
1399 if (!ust_exclusion) {
1400 PERROR("malloc");
1401 goto end;
1402 }
1403
1404 assert(sizeof(struct lttng_event_exclusion) ==
1405 sizeof(struct lttng_ust_event_exclusion));
1406 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1407 end:
1408 return ust_exclusion;
1409 }
1410
1411 /*
1412 * Set event exclusions on the tracer.
1413 */
1414 static
1415 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1416 struct ust_app *app)
1417 {
1418 int ret;
1419 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1420
1421 health_code_update();
1422
1423 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1424 ret = 0;
1425 goto error;
1426 }
1427
1428 ust_exclusion = create_ust_exclusion_from_exclusion(
1429 ua_event->exclusion);
1430 if (!ust_exclusion) {
1431 ret = -LTTNG_ERR_NOMEM;
1432 goto error;
1433 }
1434 pthread_mutex_lock(&app->sock_lock);
1435 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1436 pthread_mutex_unlock(&app->sock_lock);
1437 if (ret < 0) {
1438 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1439 ERR("UST app event %s exclusions failed for app (pid: %d) "
1440 "with ret %d", ua_event->attr.name, app->pid, ret);
1441 } else {
1442 /*
1443 * This is normal behavior, an application can die during the
1444 * creation process. Don't report an error so the execution can
1445 * continue normally.
1446 */
1447 ret = 0;
1448 DBG3("UST app event exclusion failed. Application is dead.");
1449 }
1450 goto error;
1451 }
1452
1453 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1454
1455 error:
1456 health_code_update();
1457 free(ust_exclusion);
1458 return ret;
1459 }
1460
1461 /*
1462 * Disable the specified event on to UST tracer for the UST session.
1463 */
1464 static int disable_ust_event(struct ust_app *app,
1465 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1466 {
1467 int ret;
1468
1469 health_code_update();
1470
1471 pthread_mutex_lock(&app->sock_lock);
1472 ret = ustctl_disable(app->sock, ua_event->obj);
1473 pthread_mutex_unlock(&app->sock_lock);
1474 if (ret < 0) {
1475 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1476 ERR("UST app event %s disable failed for app (pid: %d) "
1477 "and session handle %d with ret %d",
1478 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1479 } else {
1480 /*
1481 * This is normal behavior, an application can die during the
1482 * creation process. Don't report an error so the execution can
1483 * continue normally.
1484 */
1485 ret = 0;
1486 DBG3("UST app disable event failed. Application is dead.");
1487 }
1488 goto error;
1489 }
1490
1491 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1492 ua_event->attr.name, app->pid);
1493
1494 error:
1495 health_code_update();
1496 return ret;
1497 }
1498
1499 /*
1500 * Disable the specified channel on to UST tracer for the UST session.
1501 */
1502 static int disable_ust_channel(struct ust_app *app,
1503 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1504 {
1505 int ret;
1506
1507 health_code_update();
1508
1509 pthread_mutex_lock(&app->sock_lock);
1510 ret = ustctl_disable(app->sock, ua_chan->obj);
1511 pthread_mutex_unlock(&app->sock_lock);
1512 if (ret < 0) {
1513 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1514 ERR("UST app channel %s disable failed for app (pid: %d) "
1515 "and session handle %d with ret %d",
1516 ua_chan->name, app->pid, ua_sess->handle, ret);
1517 } else {
1518 /*
1519 * This is normal behavior, an application can die during the
1520 * creation process. Don't report an error so the execution can
1521 * continue normally.
1522 */
1523 ret = 0;
1524 DBG3("UST app disable channel failed. Application is dead.");
1525 }
1526 goto error;
1527 }
1528
1529 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1530 ua_chan->name, app->pid);
1531
1532 error:
1533 health_code_update();
1534 return ret;
1535 }
1536
1537 /*
1538 * Enable the specified channel on to UST tracer for the UST session.
1539 */
1540 static int enable_ust_channel(struct ust_app *app,
1541 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1542 {
1543 int ret;
1544
1545 health_code_update();
1546
1547 pthread_mutex_lock(&app->sock_lock);
1548 ret = ustctl_enable(app->sock, ua_chan->obj);
1549 pthread_mutex_unlock(&app->sock_lock);
1550 if (ret < 0) {
1551 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1552 ERR("UST app channel %s enable failed for app (pid: %d) "
1553 "and session handle %d with ret %d",
1554 ua_chan->name, app->pid, ua_sess->handle, ret);
1555 } else {
1556 /*
1557 * This is normal behavior, an application can die during the
1558 * creation process. Don't report an error so the execution can
1559 * continue normally.
1560 */
1561 ret = 0;
1562 DBG3("UST app enable channel failed. Application is dead.");
1563 }
1564 goto error;
1565 }
1566
1567 ua_chan->enabled = 1;
1568
1569 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1570 ua_chan->name, app->pid);
1571
1572 error:
1573 health_code_update();
1574 return ret;
1575 }
1576
1577 /*
1578 * Enable the specified event on to UST tracer for the UST session.
1579 */
1580 static int enable_ust_event(struct ust_app *app,
1581 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1582 {
1583 int ret;
1584
1585 health_code_update();
1586
1587 pthread_mutex_lock(&app->sock_lock);
1588 ret = ustctl_enable(app->sock, ua_event->obj);
1589 pthread_mutex_unlock(&app->sock_lock);
1590 if (ret < 0) {
1591 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1592 ERR("UST app event %s enable failed for app (pid: %d) "
1593 "and session handle %d with ret %d",
1594 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1595 } else {
1596 /*
1597 * This is normal behavior, an application can die during the
1598 * creation process. Don't report an error so the execution can
1599 * continue normally.
1600 */
1601 ret = 0;
1602 DBG3("UST app enable event failed. Application is dead.");
1603 }
1604 goto error;
1605 }
1606
1607 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1608 ua_event->attr.name, app->pid);
1609
1610 error:
1611 health_code_update();
1612 return ret;
1613 }
1614
1615 /*
1616 * Send channel and stream buffer to application.
1617 *
1618 * Return 0 on success. On error, a negative value is returned.
1619 */
1620 static int send_channel_pid_to_ust(struct ust_app *app,
1621 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1622 {
1623 int ret;
1624 struct ust_app_stream *stream, *stmp;
1625
1626 assert(app);
1627 assert(ua_sess);
1628 assert(ua_chan);
1629
1630 health_code_update();
1631
1632 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1633 app->sock);
1634
1635 /* Send channel to the application. */
1636 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1637 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1638 ret = -ENOTCONN; /* Caused by app exiting. */
1639 goto error;
1640 } else if (ret < 0) {
1641 goto error;
1642 }
1643
1644 health_code_update();
1645
1646 /* Send all streams to application. */
1647 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1648 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1649 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1650 ret = -ENOTCONN; /* Caused by app exiting. */
1651 goto error;
1652 } else if (ret < 0) {
1653 goto error;
1654 }
1655 /* We don't need the stream anymore once sent to the tracer. */
1656 cds_list_del(&stream->list);
1657 delete_ust_app_stream(-1, stream, app);
1658 }
1659 /* Flag the channel that it is sent to the application. */
1660 ua_chan->is_sent = 1;
1661
1662 error:
1663 health_code_update();
1664 return ret;
1665 }
1666
1667 /*
1668 * Create the specified event onto the UST tracer for a UST session.
1669 *
1670 * Should be called with session mutex held.
1671 */
1672 static
1673 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1674 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1675 {
1676 int ret = 0;
1677
1678 health_code_update();
1679
1680 /* Create UST event on tracer */
1681 pthread_mutex_lock(&app->sock_lock);
1682 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1683 &ua_event->obj);
1684 pthread_mutex_unlock(&app->sock_lock);
1685 if (ret < 0) {
1686 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1687 abort();
1688 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1689 ua_event->attr.name, app->pid, ret);
1690 } else {
1691 /*
1692 * This is normal behavior, an application can die during the
1693 * creation process. Don't report an error so the execution can
1694 * continue normally.
1695 */
1696 ret = 0;
1697 DBG3("UST app create event failed. Application is dead.");
1698 }
1699 goto error;
1700 }
1701
1702 ua_event->handle = ua_event->obj->handle;
1703
1704 DBG2("UST app event %s created successfully for pid:%d",
1705 ua_event->attr.name, app->pid);
1706
1707 health_code_update();
1708
1709 /* Set filter if one is present. */
1710 if (ua_event->filter) {
1711 ret = set_ust_event_filter(ua_event, app);
1712 if (ret < 0) {
1713 goto error;
1714 }
1715 }
1716
1717 /* Set exclusions for the event */
1718 if (ua_event->exclusion) {
1719 ret = set_ust_event_exclusion(ua_event, app);
1720 if (ret < 0) {
1721 goto error;
1722 }
1723 }
1724
1725 /* If event not enabled, disable it on the tracer */
1726 if (ua_event->enabled) {
1727 /*
1728 * We now need to explicitly enable the event, since it
1729 * is now disabled at creation.
1730 */
1731 ret = enable_ust_event(app, ua_sess, ua_event);
1732 if (ret < 0) {
1733 /*
1734 * If we hit an EPERM, something is wrong with our enable call. If
1735 * we get an EEXIST, there is a problem on the tracer side since we
1736 * just created it.
1737 */
1738 switch (ret) {
1739 case -LTTNG_UST_ERR_PERM:
1740 /* Code flow problem */
1741 assert(0);
1742 case -LTTNG_UST_ERR_EXIST:
1743 /* It's OK for our use case. */
1744 ret = 0;
1745 break;
1746 default:
1747 break;
1748 }
1749 goto error;
1750 }
1751 }
1752
1753 error:
1754 health_code_update();
1755 return ret;
1756 }
1757
1758 /*
1759 * Copy data between an UST app event and a LTT event.
1760 */
1761 static void shadow_copy_event(struct ust_app_event *ua_event,
1762 struct ltt_ust_event *uevent)
1763 {
1764 size_t exclusion_alloc_size;
1765
1766 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1767 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1768
1769 ua_event->enabled = uevent->enabled;
1770
1771 /* Copy event attributes */
1772 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1773
1774 /* Copy filter bytecode */
1775 if (uevent->filter) {
1776 ua_event->filter = copy_filter_bytecode(uevent->filter);
1777 /* Filter might be NULL here in case of ENONEM. */
1778 }
1779
1780 /* Copy exclusion data */
1781 if (uevent->exclusion) {
1782 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1783 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1784 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1785 if (ua_event->exclusion == NULL) {
1786 PERROR("malloc");
1787 } else {
1788 memcpy(ua_event->exclusion, uevent->exclusion,
1789 exclusion_alloc_size);
1790 }
1791 }
1792 }
1793
1794 /*
1795 * Copy data between an UST app channel and a LTT channel.
1796 */
1797 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1798 struct ltt_ust_channel *uchan)
1799 {
1800 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1801
1802 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1803 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1804
1805 ua_chan->tracefile_size = uchan->tracefile_size;
1806 ua_chan->tracefile_count = uchan->tracefile_count;
1807
1808 /* Copy event attributes since the layout is different. */
1809 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1810 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1811 ua_chan->attr.overwrite = uchan->attr.overwrite;
1812 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1813 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1814 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1815 ua_chan->attr.output = uchan->attr.output;
1816 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1817
1818 /*
1819 * Note that the attribute channel type is not set since the channel on the
1820 * tracing registry side does not have this information.
1821 */
1822
1823 ua_chan->enabled = uchan->enabled;
1824 ua_chan->tracing_channel_id = uchan->id;
1825
1826 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1827 }
1828
1829 /*
1830 * Copy data between a UST app session and a regular LTT session.
1831 */
1832 static void shadow_copy_session(struct ust_app_session *ua_sess,
1833 struct ltt_ust_session *usess, struct ust_app *app)
1834 {
1835 struct tm *timeinfo;
1836 char datetime[16];
1837 int ret;
1838 char tmp_shm_path[PATH_MAX];
1839
1840 timeinfo = localtime(&app->registration_time);
1841 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1842
1843 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1844
1845 ua_sess->tracing_id = usess->id;
1846 ua_sess->id = get_next_session_id();
1847 ua_sess->real_credentials.uid = app->uid;
1848 ua_sess->real_credentials.gid = app->gid;
1849 ua_sess->effective_credentials.uid = usess->uid;
1850 ua_sess->effective_credentials.gid = usess->gid;
1851 ua_sess->buffer_type = usess->buffer_type;
1852 ua_sess->bits_per_long = app->bits_per_long;
1853
1854 /* There is only one consumer object per session possible. */
1855 consumer_output_get(usess->consumer);
1856 ua_sess->consumer = usess->consumer;
1857
1858 ua_sess->output_traces = usess->output_traces;
1859 ua_sess->live_timer_interval = usess->live_timer_interval;
1860 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1861 &usess->metadata_attr);
1862
1863 switch (ua_sess->buffer_type) {
1864 case LTTNG_BUFFER_PER_PID:
1865 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1866 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1867 datetime);
1868 break;
1869 case LTTNG_BUFFER_PER_UID:
1870 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1871 DEFAULT_UST_TRACE_UID_PATH,
1872 ua_sess->real_credentials.uid,
1873 app->bits_per_long);
1874 break;
1875 default:
1876 assert(0);
1877 goto error;
1878 }
1879 if (ret < 0) {
1880 PERROR("asprintf UST shadow copy session");
1881 assert(0);
1882 goto error;
1883 }
1884
1885 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1886 sizeof(ua_sess->root_shm_path));
1887 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1888 strncpy(ua_sess->shm_path, usess->shm_path,
1889 sizeof(ua_sess->shm_path));
1890 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1891 if (ua_sess->shm_path[0]) {
1892 switch (ua_sess->buffer_type) {
1893 case LTTNG_BUFFER_PER_PID:
1894 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1895 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1896 app->name, app->pid, datetime);
1897 break;
1898 case LTTNG_BUFFER_PER_UID:
1899 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1900 DEFAULT_UST_TRACE_UID_PATH,
1901 app->uid, app->bits_per_long);
1902 break;
1903 default:
1904 assert(0);
1905 goto error;
1906 }
1907 if (ret < 0) {
1908 PERROR("sprintf UST shadow copy session");
1909 assert(0);
1910 goto error;
1911 }
1912 strncat(ua_sess->shm_path, tmp_shm_path,
1913 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1914 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1915 }
1916 return;
1917
1918 error:
1919 consumer_output_put(ua_sess->consumer);
1920 }
1921
1922 /*
1923 * Lookup sesison wrapper.
1924 */
1925 static
1926 void __lookup_session_by_app(const struct ltt_ust_session *usess,
1927 struct ust_app *app, struct lttng_ht_iter *iter)
1928 {
1929 /* Get right UST app session from app */
1930 lttng_ht_lookup(app->sessions, &usess->id, iter);
1931 }
1932
1933 /*
1934 * Return ust app session from the app session hashtable using the UST session
1935 * id.
1936 */
1937 static struct ust_app_session *lookup_session_by_app(
1938 const struct ltt_ust_session *usess, struct ust_app *app)
1939 {
1940 struct lttng_ht_iter iter;
1941 struct lttng_ht_node_u64 *node;
1942
1943 __lookup_session_by_app(usess, app, &iter);
1944 node = lttng_ht_iter_get_node_u64(&iter);
1945 if (node == NULL) {
1946 goto error;
1947 }
1948
1949 return caa_container_of(node, struct ust_app_session, node);
1950
1951 error:
1952 return NULL;
1953 }
1954
1955 /*
1956 * Setup buffer registry per PID for the given session and application. If none
1957 * is found, a new one is created, added to the global registry and
1958 * initialized. If regp is valid, it's set with the newly created object.
1959 *
1960 * Return 0 on success or else a negative value.
1961 */
1962 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1963 struct ust_app *app, struct buffer_reg_pid **regp)
1964 {
1965 int ret = 0;
1966 struct buffer_reg_pid *reg_pid;
1967
1968 assert(ua_sess);
1969 assert(app);
1970
1971 rcu_read_lock();
1972
1973 reg_pid = buffer_reg_pid_find(ua_sess->id);
1974 if (!reg_pid) {
1975 /*
1976 * This is the create channel path meaning that if there is NO
1977 * registry available, we have to create one for this session.
1978 */
1979 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1980 ua_sess->root_shm_path, ua_sess->shm_path);
1981 if (ret < 0) {
1982 goto error;
1983 }
1984 } else {
1985 goto end;
1986 }
1987
1988 /* Initialize registry. */
1989 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1990 app->bits_per_long, app->uint8_t_alignment,
1991 app->uint16_t_alignment, app->uint32_t_alignment,
1992 app->uint64_t_alignment, app->long_alignment,
1993 app->byte_order, app->version.major, app->version.minor,
1994 reg_pid->root_shm_path, reg_pid->shm_path,
1995 ua_sess->effective_credentials.uid,
1996 ua_sess->effective_credentials.gid, ua_sess->tracing_id,
1997 app->uid);
1998 if (ret < 0) {
1999 /*
2000 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2001 * destroy the buffer registry, because it is always expected
2002 * that if the buffer registry can be found, its ust registry is
2003 * non-NULL.
2004 */
2005 buffer_reg_pid_destroy(reg_pid);
2006 goto error;
2007 }
2008
2009 buffer_reg_pid_add(reg_pid);
2010
2011 DBG3("UST app buffer registry per PID created successfully");
2012
2013 end:
2014 if (regp) {
2015 *regp = reg_pid;
2016 }
2017 error:
2018 rcu_read_unlock();
2019 return ret;
2020 }
2021
2022 /*
2023 * Setup buffer registry per UID for the given session and application. If none
2024 * is found, a new one is created, added to the global registry and
2025 * initialized. If regp is valid, it's set with the newly created object.
2026 *
2027 * Return 0 on success or else a negative value.
2028 */
2029 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2030 struct ust_app_session *ua_sess,
2031 struct ust_app *app, struct buffer_reg_uid **regp)
2032 {
2033 int ret = 0;
2034 struct buffer_reg_uid *reg_uid;
2035
2036 assert(usess);
2037 assert(app);
2038
2039 rcu_read_lock();
2040
2041 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2042 if (!reg_uid) {
2043 /*
2044 * This is the create channel path meaning that if there is NO
2045 * registry available, we have to create one for this session.
2046 */
2047 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2048 LTTNG_DOMAIN_UST, &reg_uid,
2049 ua_sess->root_shm_path, ua_sess->shm_path);
2050 if (ret < 0) {
2051 goto error;
2052 }
2053 } else {
2054 goto end;
2055 }
2056
2057 /* Initialize registry. */
2058 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2059 app->bits_per_long, app->uint8_t_alignment,
2060 app->uint16_t_alignment, app->uint32_t_alignment,
2061 app->uint64_t_alignment, app->long_alignment,
2062 app->byte_order, app->version.major,
2063 app->version.minor, reg_uid->root_shm_path,
2064 reg_uid->shm_path, usess->uid, usess->gid,
2065 ua_sess->tracing_id, app->uid);
2066 if (ret < 0) {
2067 /*
2068 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2069 * destroy the buffer registry, because it is always expected
2070 * that if the buffer registry can be found, its ust registry is
2071 * non-NULL.
2072 */
2073 buffer_reg_uid_destroy(reg_uid, NULL);
2074 goto error;
2075 }
2076 /* Add node to teardown list of the session. */
2077 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2078
2079 buffer_reg_uid_add(reg_uid);
2080
2081 DBG3("UST app buffer registry per UID created successfully");
2082 end:
2083 if (regp) {
2084 *regp = reg_uid;
2085 }
2086 error:
2087 rcu_read_unlock();
2088 return ret;
2089 }
2090
2091 /*
2092 * Create a session on the tracer side for the given app.
2093 *
2094 * On success, ua_sess_ptr is populated with the session pointer or else left
2095 * untouched. If the session was created, is_created is set to 1. On error,
2096 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2097 * be NULL.
2098 *
2099 * Returns 0 on success or else a negative code which is either -ENOMEM or
2100 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2101 */
2102 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2103 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2104 int *is_created)
2105 {
2106 int ret, created = 0;
2107 struct ust_app_session *ua_sess;
2108
2109 assert(usess);
2110 assert(app);
2111 assert(ua_sess_ptr);
2112
2113 health_code_update();
2114
2115 ua_sess = lookup_session_by_app(usess, app);
2116 if (ua_sess == NULL) {
2117 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2118 app->pid, usess->id);
2119 ua_sess = alloc_ust_app_session();
2120 if (ua_sess == NULL) {
2121 /* Only malloc can failed so something is really wrong */
2122 ret = -ENOMEM;
2123 goto error;
2124 }
2125 shadow_copy_session(ua_sess, usess, app);
2126 created = 1;
2127 }
2128
2129 switch (usess->buffer_type) {
2130 case LTTNG_BUFFER_PER_PID:
2131 /* Init local registry. */
2132 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2133 if (ret < 0) {
2134 delete_ust_app_session(-1, ua_sess, app);
2135 goto error;
2136 }
2137 break;
2138 case LTTNG_BUFFER_PER_UID:
2139 /* Look for a global registry. If none exists, create one. */
2140 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2141 if (ret < 0) {
2142 delete_ust_app_session(-1, ua_sess, app);
2143 goto error;
2144 }
2145 break;
2146 default:
2147 assert(0);
2148 ret = -EINVAL;
2149 goto error;
2150 }
2151
2152 health_code_update();
2153
2154 if (ua_sess->handle == -1) {
2155 pthread_mutex_lock(&app->sock_lock);
2156 ret = ustctl_create_session(app->sock);
2157 pthread_mutex_unlock(&app->sock_lock);
2158 if (ret < 0) {
2159 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2160 ERR("Creating session for app pid %d with ret %d",
2161 app->pid, ret);
2162 } else {
2163 DBG("UST app creating session failed. Application is dead");
2164 /*
2165 * This is normal behavior, an application can die during the
2166 * creation process. Don't report an error so the execution can
2167 * continue normally. This will get flagged ENOTCONN and the
2168 * caller will handle it.
2169 */
2170 ret = 0;
2171 }
2172 delete_ust_app_session(-1, ua_sess, app);
2173 if (ret != -ENOMEM) {
2174 /*
2175 * Tracer is probably gone or got an internal error so let's
2176 * behave like it will soon unregister or not usable.
2177 */
2178 ret = -ENOTCONN;
2179 }
2180 goto error;
2181 }
2182
2183 ua_sess->handle = ret;
2184
2185 /* Add ust app session to app's HT */
2186 lttng_ht_node_init_u64(&ua_sess->node,
2187 ua_sess->tracing_id);
2188 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2189 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2190 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2191 &ua_sess->ust_objd_node);
2192
2193 DBG2("UST app session created successfully with handle %d", ret);
2194 }
2195
2196 *ua_sess_ptr = ua_sess;
2197 if (is_created) {
2198 *is_created = created;
2199 }
2200
2201 /* Everything went well. */
2202 ret = 0;
2203
2204 error:
2205 health_code_update();
2206 return ret;
2207 }
2208
2209 /*
2210 * Match function for a hash table lookup of ust_app_ctx.
2211 *
2212 * It matches an ust app context based on the context type and, in the case
2213 * of perf counters, their name.
2214 */
2215 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2216 {
2217 struct ust_app_ctx *ctx;
2218 const struct lttng_ust_context_attr *key;
2219
2220 assert(node);
2221 assert(_key);
2222
2223 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2224 key = _key;
2225
2226 /* Context type */
2227 if (ctx->ctx.ctx != key->ctx) {
2228 goto no_match;
2229 }
2230
2231 switch(key->ctx) {
2232 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2233 if (strncmp(key->u.perf_counter.name,
2234 ctx->ctx.u.perf_counter.name,
2235 sizeof(key->u.perf_counter.name))) {
2236 goto no_match;
2237 }
2238 break;
2239 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2240 if (strcmp(key->u.app_ctx.provider_name,
2241 ctx->ctx.u.app_ctx.provider_name) ||
2242 strcmp(key->u.app_ctx.ctx_name,
2243 ctx->ctx.u.app_ctx.ctx_name)) {
2244 goto no_match;
2245 }
2246 break;
2247 default:
2248 break;
2249 }
2250
2251 /* Match. */
2252 return 1;
2253
2254 no_match:
2255 return 0;
2256 }
2257
2258 /*
2259 * Lookup for an ust app context from an lttng_ust_context.
2260 *
2261 * Must be called while holding RCU read side lock.
2262 * Return an ust_app_ctx object or NULL on error.
2263 */
2264 static
2265 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2266 struct lttng_ust_context_attr *uctx)
2267 {
2268 struct lttng_ht_iter iter;
2269 struct lttng_ht_node_ulong *node;
2270 struct ust_app_ctx *app_ctx = NULL;
2271
2272 assert(uctx);
2273 assert(ht);
2274
2275 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2276 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2277 ht_match_ust_app_ctx, uctx, &iter.iter);
2278 node = lttng_ht_iter_get_node_ulong(&iter);
2279 if (!node) {
2280 goto end;
2281 }
2282
2283 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2284
2285 end:
2286 return app_ctx;
2287 }
2288
2289 /*
2290 * Create a context for the channel on the tracer.
2291 *
2292 * Called with UST app session lock held and a RCU read side lock.
2293 */
2294 static
2295 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2296 struct lttng_ust_context_attr *uctx,
2297 struct ust_app *app)
2298 {
2299 int ret = 0;
2300 struct ust_app_ctx *ua_ctx;
2301
2302 DBG2("UST app adding context to channel %s", ua_chan->name);
2303
2304 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2305 if (ua_ctx) {
2306 ret = -EEXIST;
2307 goto error;
2308 }
2309
2310 ua_ctx = alloc_ust_app_ctx(uctx);
2311 if (ua_ctx == NULL) {
2312 /* malloc failed */
2313 ret = -ENOMEM;
2314 goto error;
2315 }
2316
2317 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2318 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2319 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2320
2321 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2322 if (ret < 0) {
2323 goto error;
2324 }
2325
2326 error:
2327 return ret;
2328 }
2329
2330 /*
2331 * Enable on the tracer side a ust app event for the session and channel.
2332 *
2333 * Called with UST app session lock held.
2334 */
2335 static
2336 int enable_ust_app_event(struct ust_app_session *ua_sess,
2337 struct ust_app_event *ua_event, struct ust_app *app)
2338 {
2339 int ret;
2340
2341 ret = enable_ust_event(app, ua_sess, ua_event);
2342 if (ret < 0) {
2343 goto error;
2344 }
2345
2346 ua_event->enabled = 1;
2347
2348 error:
2349 return ret;
2350 }
2351
2352 /*
2353 * Disable on the tracer side a ust app event for the session and channel.
2354 */
2355 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2356 struct ust_app_event *ua_event, struct ust_app *app)
2357 {
2358 int ret;
2359
2360 ret = disable_ust_event(app, ua_sess, ua_event);
2361 if (ret < 0) {
2362 goto error;
2363 }
2364
2365 ua_event->enabled = 0;
2366
2367 error:
2368 return ret;
2369 }
2370
2371 /*
2372 * Lookup ust app channel for session and disable it on the tracer side.
2373 */
2374 static
2375 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2376 struct ust_app_channel *ua_chan, struct ust_app *app)
2377 {
2378 int ret;
2379
2380 ret = disable_ust_channel(app, ua_sess, ua_chan);
2381 if (ret < 0) {
2382 goto error;
2383 }
2384
2385 ua_chan->enabled = 0;
2386
2387 error:
2388 return ret;
2389 }
2390
2391 /*
2392 * Lookup ust app channel for session and enable it on the tracer side. This
2393 * MUST be called with a RCU read side lock acquired.
2394 */
2395 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2396 struct ltt_ust_channel *uchan, struct ust_app *app)
2397 {
2398 int ret = 0;
2399 struct lttng_ht_iter iter;
2400 struct lttng_ht_node_str *ua_chan_node;
2401 struct ust_app_channel *ua_chan;
2402
2403 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2404 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2405 if (ua_chan_node == NULL) {
2406 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2407 uchan->name, ua_sess->tracing_id);
2408 goto error;
2409 }
2410
2411 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2412
2413 ret = enable_ust_channel(app, ua_sess, ua_chan);
2414 if (ret < 0) {
2415 goto error;
2416 }
2417
2418 error:
2419 return ret;
2420 }
2421
2422 /*
2423 * Ask the consumer to create a channel and get it if successful.
2424 *
2425 * Called with UST app session lock held.
2426 *
2427 * Return 0 on success or else a negative value.
2428 */
2429 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2430 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2431 int bitness, struct ust_registry_session *registry,
2432 uint64_t trace_archive_id)
2433 {
2434 int ret;
2435 unsigned int nb_fd = 0;
2436 struct consumer_socket *socket;
2437
2438 assert(usess);
2439 assert(ua_sess);
2440 assert(ua_chan);
2441 assert(registry);
2442
2443 rcu_read_lock();
2444 health_code_update();
2445
2446 /* Get the right consumer socket for the application. */
2447 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2448 if (!socket) {
2449 ret = -EINVAL;
2450 goto error;
2451 }
2452
2453 health_code_update();
2454
2455 /* Need one fd for the channel. */
2456 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2457 if (ret < 0) {
2458 ERR("Exhausted number of available FD upon create channel");
2459 goto error;
2460 }
2461
2462 /*
2463 * Ask consumer to create channel. The consumer will return the number of
2464 * stream we have to expect.
2465 */
2466 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2467 registry, usess->current_trace_chunk);
2468 if (ret < 0) {
2469 goto error_ask;
2470 }
2471
2472 /*
2473 * Compute the number of fd needed before receiving them. It must be 2 per
2474 * stream (2 being the default value here).
2475 */
2476 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2477
2478 /* Reserve the amount of file descriptor we need. */
2479 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2480 if (ret < 0) {
2481 ERR("Exhausted number of available FD upon create channel");
2482 goto error_fd_get_stream;
2483 }
2484
2485 health_code_update();
2486
2487 /*
2488 * Now get the channel from the consumer. This call wil populate the stream
2489 * list of that channel and set the ust objects.
2490 */
2491 if (usess->consumer->enabled) {
2492 ret = ust_consumer_get_channel(socket, ua_chan);
2493 if (ret < 0) {
2494 goto error_destroy;
2495 }
2496 }
2497
2498 rcu_read_unlock();
2499 return 0;
2500
2501 error_destroy:
2502 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2503 error_fd_get_stream:
2504 /*
2505 * Initiate a destroy channel on the consumer since we had an error
2506 * handling it on our side. The return value is of no importance since we
2507 * already have a ret value set by the previous error that we need to
2508 * return.
2509 */
2510 (void) ust_consumer_destroy_channel(socket, ua_chan);
2511 error_ask:
2512 lttng_fd_put(LTTNG_FD_APPS, 1);
2513 error:
2514 health_code_update();
2515 rcu_read_unlock();
2516 return ret;
2517 }
2518
2519 /*
2520 * Duplicate the ust data object of the ust app stream and save it in the
2521 * buffer registry stream.
2522 *
2523 * Return 0 on success or else a negative value.
2524 */
2525 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2526 struct ust_app_stream *stream)
2527 {
2528 int ret;
2529
2530 assert(reg_stream);
2531 assert(stream);
2532
2533 /* Reserve the amount of file descriptor we need. */
2534 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2535 if (ret < 0) {
2536 ERR("Exhausted number of available FD upon duplicate stream");
2537 goto error;
2538 }
2539
2540 /* Duplicate object for stream once the original is in the registry. */
2541 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2542 reg_stream->obj.ust);
2543 if (ret < 0) {
2544 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2545 reg_stream->obj.ust, stream->obj, ret);
2546 lttng_fd_put(LTTNG_FD_APPS, 2);
2547 goto error;
2548 }
2549 stream->handle = stream->obj->handle;
2550
2551 error:
2552 return ret;
2553 }
2554
2555 /*
2556 * Duplicate the ust data object of the ust app. channel and save it in the
2557 * buffer registry channel.
2558 *
2559 * Return 0 on success or else a negative value.
2560 */
2561 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2562 struct ust_app_channel *ua_chan)
2563 {
2564 int ret;
2565
2566 assert(reg_chan);
2567 assert(ua_chan);
2568
2569 /* Need two fds for the channel. */
2570 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2571 if (ret < 0) {
2572 ERR("Exhausted number of available FD upon duplicate channel");
2573 goto error_fd_get;
2574 }
2575
2576 /* Duplicate object for stream once the original is in the registry. */
2577 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2578 if (ret < 0) {
2579 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2580 reg_chan->obj.ust, ua_chan->obj, ret);
2581 goto error;
2582 }
2583 ua_chan->handle = ua_chan->obj->handle;
2584
2585 return 0;
2586
2587 error:
2588 lttng_fd_put(LTTNG_FD_APPS, 1);
2589 error_fd_get:
2590 return ret;
2591 }
2592
2593 /*
2594 * For a given channel buffer registry, setup all streams of the given ust
2595 * application channel.
2596 *
2597 * Return 0 on success or else a negative value.
2598 */
2599 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2600 struct ust_app_channel *ua_chan,
2601 struct ust_app *app)
2602 {
2603 int ret = 0;
2604 struct ust_app_stream *stream, *stmp;
2605
2606 assert(reg_chan);
2607 assert(ua_chan);
2608
2609 DBG2("UST app setup buffer registry stream");
2610
2611 /* Send all streams to application. */
2612 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2613 struct buffer_reg_stream *reg_stream;
2614
2615 ret = buffer_reg_stream_create(&reg_stream);
2616 if (ret < 0) {
2617 goto error;
2618 }
2619
2620 /*
2621 * Keep original pointer and nullify it in the stream so the delete
2622 * stream call does not release the object.
2623 */
2624 reg_stream->obj.ust = stream->obj;
2625 stream->obj = NULL;
2626 buffer_reg_stream_add(reg_stream, reg_chan);
2627
2628 /* We don't need the streams anymore. */
2629 cds_list_del(&stream->list);
2630 delete_ust_app_stream(-1, stream, app);
2631 }
2632
2633 error:
2634 return ret;
2635 }
2636
2637 /*
2638 * Create a buffer registry channel for the given session registry and
2639 * application channel object. If regp pointer is valid, it's set with the
2640 * created object. Important, the created object is NOT added to the session
2641 * registry hash table.
2642 *
2643 * Return 0 on success else a negative value.
2644 */
2645 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2646 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2647 {
2648 int ret;
2649 struct buffer_reg_channel *reg_chan = NULL;
2650
2651 assert(reg_sess);
2652 assert(ua_chan);
2653
2654 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2655
2656 /* Create buffer registry channel. */
2657 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2658 if (ret < 0) {
2659 goto error_create;
2660 }
2661 assert(reg_chan);
2662 reg_chan->consumer_key = ua_chan->key;
2663 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2664 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2665
2666 /* Create and add a channel registry to session. */
2667 ret = ust_registry_channel_add(reg_sess->reg.ust,
2668 ua_chan->tracing_channel_id);
2669 if (ret < 0) {
2670 goto error;
2671 }
2672 buffer_reg_channel_add(reg_sess, reg_chan);
2673
2674 if (regp) {
2675 *regp = reg_chan;
2676 }
2677
2678 return 0;
2679
2680 error:
2681 /* Safe because the registry channel object was not added to any HT. */
2682 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2683 error_create:
2684 return ret;
2685 }
2686
2687 /*
2688 * Setup buffer registry channel for the given session registry and application
2689 * channel object. If regp pointer is valid, it's set with the created object.
2690 *
2691 * Return 0 on success else a negative value.
2692 */
2693 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2694 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2695 struct ust_app *app)
2696 {
2697 int ret;
2698
2699 assert(reg_sess);
2700 assert(reg_chan);
2701 assert(ua_chan);
2702 assert(ua_chan->obj);
2703
2704 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2705
2706 /* Setup all streams for the registry. */
2707 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2708 if (ret < 0) {
2709 goto error;
2710 }
2711
2712 reg_chan->obj.ust = ua_chan->obj;
2713 ua_chan->obj = NULL;
2714
2715 return 0;
2716
2717 error:
2718 buffer_reg_channel_remove(reg_sess, reg_chan);
2719 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2720 return ret;
2721 }
2722
2723 /*
2724 * Send buffer registry channel to the application.
2725 *
2726 * Return 0 on success else a negative value.
2727 */
2728 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2729 struct ust_app *app, struct ust_app_session *ua_sess,
2730 struct ust_app_channel *ua_chan)
2731 {
2732 int ret;
2733 struct buffer_reg_stream *reg_stream;
2734
2735 assert(reg_chan);
2736 assert(app);
2737 assert(ua_sess);
2738 assert(ua_chan);
2739
2740 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2741
2742 ret = duplicate_channel_object(reg_chan, ua_chan);
2743 if (ret < 0) {
2744 goto error;
2745 }
2746
2747 /* Send channel to the application. */
2748 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2749 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2750 ret = -ENOTCONN; /* Caused by app exiting. */
2751 goto error;
2752 } else if (ret < 0) {
2753 goto error;
2754 }
2755
2756 health_code_update();
2757
2758 /* Send all streams to application. */
2759 pthread_mutex_lock(&reg_chan->stream_list_lock);
2760 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2761 struct ust_app_stream stream;
2762
2763 ret = duplicate_stream_object(reg_stream, &stream);
2764 if (ret < 0) {
2765 goto error_stream_unlock;
2766 }
2767
2768 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2769 if (ret < 0) {
2770 (void) release_ust_app_stream(-1, &stream, app);
2771 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2772 ret = -ENOTCONN; /* Caused by app exiting. */
2773 }
2774 goto error_stream_unlock;
2775 }
2776
2777 /*
2778 * The return value is not important here. This function will output an
2779 * error if needed.
2780 */
2781 (void) release_ust_app_stream(-1, &stream, app);
2782 }
2783 ua_chan->is_sent = 1;
2784
2785 error_stream_unlock:
2786 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2787 error:
2788 return ret;
2789 }
2790
2791 /*
2792 * Create and send to the application the created buffers with per UID buffers.
2793 *
2794 * This MUST be called with a RCU read side lock acquired.
2795 * The session list lock and the session's lock must be acquired.
2796 *
2797 * Return 0 on success else a negative value.
2798 */
2799 static int create_channel_per_uid(struct ust_app *app,
2800 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2801 struct ust_app_channel *ua_chan)
2802 {
2803 int ret;
2804 struct buffer_reg_uid *reg_uid;
2805 struct buffer_reg_channel *reg_chan;
2806 struct ltt_session *session = NULL;
2807 enum lttng_error_code notification_ret;
2808 struct ust_registry_channel *chan_reg;
2809
2810 assert(app);
2811 assert(usess);
2812 assert(ua_sess);
2813 assert(ua_chan);
2814
2815 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2816
2817 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2818 /*
2819 * The session creation handles the creation of this global registry
2820 * object. If none can be find, there is a code flow problem or a
2821 * teardown race.
2822 */
2823 assert(reg_uid);
2824
2825 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2826 reg_uid);
2827 if (reg_chan) {
2828 goto send_channel;
2829 }
2830
2831 /* Create the buffer registry channel object. */
2832 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2833 if (ret < 0) {
2834 ERR("Error creating the UST channel \"%s\" registry instance",
2835 ua_chan->name);
2836 goto error;
2837 }
2838
2839 session = session_find_by_id(ua_sess->tracing_id);
2840 assert(session);
2841 assert(pthread_mutex_trylock(&session->lock));
2842 assert(session_trylock_list());
2843
2844 /*
2845 * Create the buffers on the consumer side. This call populates the
2846 * ust app channel object with all streams and data object.
2847 */
2848 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2849 app->bits_per_long, reg_uid->registry->reg.ust,
2850 session->most_recent_chunk_id.value);
2851 if (ret < 0) {
2852 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2853 ua_chan->name);
2854
2855 /*
2856 * Let's remove the previously created buffer registry channel so
2857 * it's not visible anymore in the session registry.
2858 */
2859 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2860 ua_chan->tracing_channel_id, false);
2861 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2862 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2863 goto error;
2864 }
2865
2866 /*
2867 * Setup the streams and add it to the session registry.
2868 */
2869 ret = setup_buffer_reg_channel(reg_uid->registry,
2870 ua_chan, reg_chan, app);
2871 if (ret < 0) {
2872 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2873 goto error;
2874 }
2875
2876 /* Notify the notification subsystem of the channel's creation. */
2877 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2878 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2879 ua_chan->tracing_channel_id);
2880 assert(chan_reg);
2881 chan_reg->consumer_key = ua_chan->key;
2882 chan_reg = NULL;
2883 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2884
2885 notification_ret = notification_thread_command_add_channel(
2886 notification_thread_handle, session->name,
2887 ua_sess->effective_credentials.uid,
2888 ua_sess->effective_credentials.gid, ua_chan->name,
2889 ua_chan->key, LTTNG_DOMAIN_UST,
2890 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2891 if (notification_ret != LTTNG_OK) {
2892 ret = - (int) notification_ret;
2893 ERR("Failed to add channel to notification thread");
2894 goto error;
2895 }
2896
2897 send_channel:
2898 /* Send buffers to the application. */
2899 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2900 if (ret < 0) {
2901 if (ret != -ENOTCONN) {
2902 ERR("Error sending channel to application");
2903 }
2904 goto error;
2905 }
2906
2907 error:
2908 if (session) {
2909 session_put(session);
2910 }
2911 return ret;
2912 }
2913
2914 /*
2915 * Create and send to the application the created buffers with per PID buffers.
2916 *
2917 * Called with UST app session lock held.
2918 * The session list lock and the session's lock must be acquired.
2919 *
2920 * Return 0 on success else a negative value.
2921 */
2922 static int create_channel_per_pid(struct ust_app *app,
2923 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2924 struct ust_app_channel *ua_chan)
2925 {
2926 int ret;
2927 struct ust_registry_session *registry;
2928 enum lttng_error_code cmd_ret;
2929 struct ltt_session *session = NULL;
2930 uint64_t chan_reg_key;
2931 struct ust_registry_channel *chan_reg;
2932
2933 assert(app);
2934 assert(usess);
2935 assert(ua_sess);
2936 assert(ua_chan);
2937
2938 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2939
2940 rcu_read_lock();
2941
2942 registry = get_session_registry(ua_sess);
2943 /* The UST app session lock is held, registry shall not be null. */
2944 assert(registry);
2945
2946 /* Create and add a new channel registry to session. */
2947 ret = ust_registry_channel_add(registry, ua_chan->key);
2948 if (ret < 0) {
2949 ERR("Error creating the UST channel \"%s\" registry instance",
2950 ua_chan->name);
2951 goto error;
2952 }
2953
2954 session = session_find_by_id(ua_sess->tracing_id);
2955 assert(session);
2956
2957 assert(pthread_mutex_trylock(&session->lock));
2958 assert(session_trylock_list());
2959
2960 /* Create and get channel on the consumer side. */
2961 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2962 app->bits_per_long, registry,
2963 session->most_recent_chunk_id.value);
2964 if (ret < 0) {
2965 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2966 ua_chan->name);
2967 goto error_remove_from_registry;
2968 }
2969
2970 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2971 if (ret < 0) {
2972 if (ret != -ENOTCONN) {
2973 ERR("Error sending channel to application");
2974 }
2975 goto error_remove_from_registry;
2976 }
2977
2978 chan_reg_key = ua_chan->key;
2979 pthread_mutex_lock(&registry->lock);
2980 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2981 assert(chan_reg);
2982 chan_reg->consumer_key = ua_chan->key;
2983 pthread_mutex_unlock(&registry->lock);
2984
2985 cmd_ret = notification_thread_command_add_channel(
2986 notification_thread_handle, session->name,
2987 ua_sess->effective_credentials.uid,
2988 ua_sess->effective_credentials.gid, ua_chan->name,
2989 ua_chan->key, LTTNG_DOMAIN_UST,
2990 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2991 if (cmd_ret != LTTNG_OK) {
2992 ret = - (int) cmd_ret;
2993 ERR("Failed to add channel to notification thread");
2994 goto error_remove_from_registry;
2995 }
2996
2997 error_remove_from_registry:
2998 if (ret) {
2999 ust_registry_channel_del_free(registry, ua_chan->key, false);
3000 }
3001 error:
3002 rcu_read_unlock();
3003 if (session) {
3004 session_put(session);
3005 }
3006 return ret;
3007 }
3008
3009 /*
3010 * From an already allocated ust app channel, create the channel buffers if
3011 * needed and send them to the application. This MUST be called with a RCU read
3012 * side lock acquired.
3013 *
3014 * Called with UST app session lock held.
3015 *
3016 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3017 * the application exited concurrently.
3018 */
3019 static int ust_app_channel_send(struct ust_app *app,
3020 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3021 struct ust_app_channel *ua_chan)
3022 {
3023 int ret;
3024
3025 assert(app);
3026 assert(usess);
3027 assert(usess->active);
3028 assert(ua_sess);
3029 assert(ua_chan);
3030
3031 /* Handle buffer type before sending the channel to the application. */
3032 switch (usess->buffer_type) {
3033 case LTTNG_BUFFER_PER_UID:
3034 {
3035 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3036 if (ret < 0) {
3037 goto error;
3038 }
3039 break;
3040 }
3041 case LTTNG_BUFFER_PER_PID:
3042 {
3043 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3044 if (ret < 0) {
3045 goto error;
3046 }
3047 break;
3048 }
3049 default:
3050 assert(0);
3051 ret = -EINVAL;
3052 goto error;
3053 }
3054
3055 /* Initialize ust objd object using the received handle and add it. */
3056 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3057 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3058
3059 /* If channel is not enabled, disable it on the tracer */
3060 if (!ua_chan->enabled) {
3061 ret = disable_ust_channel(app, ua_sess, ua_chan);
3062 if (ret < 0) {
3063 goto error;
3064 }
3065 }
3066
3067 error:
3068 return ret;
3069 }
3070
3071 /*
3072 * Create UST app channel and return it through ua_chanp if not NULL.
3073 *
3074 * Called with UST app session lock and RCU read-side lock held.
3075 *
3076 * Return 0 on success or else a negative value.
3077 */
3078 static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3079 struct ltt_ust_channel *uchan,
3080 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3081 struct ust_app_channel **ua_chanp)
3082 {
3083 int ret = 0;
3084 struct lttng_ht_iter iter;
3085 struct lttng_ht_node_str *ua_chan_node;
3086 struct ust_app_channel *ua_chan;
3087
3088 /* Lookup channel in the ust app session */
3089 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3090 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3091 if (ua_chan_node != NULL) {
3092 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3093 goto end;
3094 }
3095
3096 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3097 if (ua_chan == NULL) {
3098 /* Only malloc can fail here */
3099 ret = -ENOMEM;
3100 goto error;
3101 }
3102 shadow_copy_channel(ua_chan, uchan);
3103
3104 /* Set channel type. */
3105 ua_chan->attr.type = type;
3106
3107 /* Only add the channel if successful on the tracer side. */
3108 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3109 end:
3110 if (ua_chanp) {
3111 *ua_chanp = ua_chan;
3112 }
3113
3114 /* Everything went well. */
3115 return 0;
3116
3117 error:
3118 return ret;
3119 }
3120
3121 /*
3122 * Create UST app event and create it on the tracer side.
3123 *
3124 * Called with ust app session mutex held.
3125 */
3126 static
3127 int create_ust_app_event(struct ust_app_session *ua_sess,
3128 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3129 struct ust_app *app)
3130 {
3131 int ret = 0;
3132 struct ust_app_event *ua_event;
3133
3134 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3135 if (ua_event == NULL) {
3136 /* Only malloc can failed so something is really wrong */
3137 ret = -ENOMEM;
3138 goto end;
3139 }
3140 shadow_copy_event(ua_event, uevent);
3141
3142 /* Create it on the tracer side */
3143 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3144 if (ret < 0) {
3145 /*
3146 * Not found previously means that it does not exist on the
3147 * tracer. If the application reports that the event existed,
3148 * it means there is a bug in the sessiond or lttng-ust
3149 * (or corruption, etc.)
3150 */
3151 if (ret == -LTTNG_UST_ERR_EXIST) {
3152 ERR("Tracer for application reported that an event being created already existed: "
3153 "event_name = \"%s\", pid = %d, ppid = %d, uid = %d, gid = %d",
3154 uevent->attr.name,
3155 app->pid, app->ppid, app->uid,
3156 app->gid);
3157 }
3158 goto error;
3159 }
3160
3161 add_unique_ust_app_event(ua_chan, ua_event);
3162
3163 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3164 app->pid);
3165
3166 end:
3167 return ret;
3168
3169 error:
3170 /* Valid. Calling here is already in a read side lock */
3171 delete_ust_app_event(-1, ua_event, app);
3172 return ret;
3173 }
3174
3175 /*
3176 * Create UST metadata and open it on the tracer side.
3177 *
3178 * Called with UST app session lock held and RCU read side lock.
3179 */
3180 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3181 struct ust_app *app, struct consumer_output *consumer)
3182 {
3183 int ret = 0;
3184 struct ust_app_channel *metadata;
3185 struct consumer_socket *socket;
3186 struct ust_registry_session *registry;
3187 struct ltt_session *session = NULL;
3188
3189 assert(ua_sess);
3190 assert(app);
3191 assert(consumer);
3192
3193 registry = get_session_registry(ua_sess);
3194 /* The UST app session is held registry shall not be null. */
3195 assert(registry);
3196
3197 pthread_mutex_lock(&registry->lock);
3198
3199 /* Metadata already exists for this registry or it was closed previously */
3200 if (registry->metadata_key || registry->metadata_closed) {
3201 ret = 0;
3202 goto error;
3203 }
3204
3205 /* Allocate UST metadata */
3206 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3207 if (!metadata) {
3208 /* malloc() failed */
3209 ret = -ENOMEM;
3210 goto error;
3211 }
3212
3213 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3214
3215 /* Need one fd for the channel. */
3216 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3217 if (ret < 0) {
3218 ERR("Exhausted number of available FD upon create metadata");
3219 goto error;
3220 }
3221
3222 /* Get the right consumer socket for the application. */
3223 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3224 if (!socket) {
3225 ret = -EINVAL;
3226 goto error_consumer;
3227 }
3228
3229 /*
3230 * Keep metadata key so we can identify it on the consumer side. Assign it
3231 * to the registry *before* we ask the consumer so we avoid the race of the
3232 * consumer requesting the metadata and the ask_channel call on our side
3233 * did not returned yet.
3234 */
3235 registry->metadata_key = metadata->key;
3236
3237 session = session_find_by_id(ua_sess->tracing_id);
3238 assert(session);
3239
3240 assert(pthread_mutex_trylock(&session->lock));
3241 assert(session_trylock_list());
3242
3243 /*
3244 * Ask the metadata channel creation to the consumer. The metadata object
3245 * will be created by the consumer and kept their. However, the stream is
3246 * never added or monitored until we do a first push metadata to the
3247 * consumer.
3248 */
3249 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3250 registry, session->current_trace_chunk);
3251 if (ret < 0) {
3252 /* Nullify the metadata key so we don't try to close it later on. */
3253 registry->metadata_key = 0;
3254 goto error_consumer;
3255 }
3256
3257 /*
3258 * The setup command will make the metadata stream be sent to the relayd,
3259 * if applicable, and the thread managing the metadatas. This is important
3260 * because after this point, if an error occurs, the only way the stream
3261 * can be deleted is to be monitored in the consumer.
3262 */
3263 ret = consumer_setup_metadata(socket, metadata->key);
3264 if (ret < 0) {
3265 /* Nullify the metadata key so we don't try to close it later on. */
3266 registry->metadata_key = 0;
3267 goto error_consumer;
3268 }
3269
3270 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3271 metadata->key, app->pid);
3272
3273 error_consumer:
3274 lttng_fd_put(LTTNG_FD_APPS, 1);
3275 delete_ust_app_channel(-1, metadata, app);
3276 error:
3277 pthread_mutex_unlock(&registry->lock);
3278 if (session) {
3279 session_put(session);
3280 }
3281 return ret;
3282 }
3283
3284 /*
3285 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3286 * acquired before calling this function.
3287 */
3288 struct ust_app *ust_app_find_by_pid(pid_t pid)
3289 {
3290 struct ust_app *app = NULL;
3291 struct lttng_ht_node_ulong *node;
3292 struct lttng_ht_iter iter;
3293
3294 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3295 node = lttng_ht_iter_get_node_ulong(&iter);
3296 if (node == NULL) {
3297 DBG2("UST app no found with pid %d", pid);
3298 goto error;
3299 }
3300
3301 DBG2("Found UST app by pid %d", pid);
3302
3303 app = caa_container_of(node, struct ust_app, pid_n);
3304
3305 error:
3306 return app;
3307 }
3308
3309 /*
3310 * Allocate and init an UST app object using the registration information and
3311 * the command socket. This is called when the command socket connects to the
3312 * session daemon.
3313 *
3314 * The object is returned on success or else NULL.
3315 */
3316 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3317 {
3318 struct ust_app *lta = NULL;
3319
3320 assert(msg);
3321 assert(sock >= 0);
3322
3323 DBG3("UST app creating application for socket %d", sock);
3324
3325 if ((msg->bits_per_long == 64 &&
3326 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3327 || (msg->bits_per_long == 32 &&
3328 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3329 ERR("Registration failed: application \"%s\" (pid: %d) has "
3330 "%d-bit long, but no consumerd for this size is available.\n",
3331 msg->name, msg->pid, msg->bits_per_long);
3332 goto error;
3333 }
3334
3335 lta = zmalloc(sizeof(struct ust_app));
3336 if (lta == NULL) {
3337 PERROR("malloc");
3338 goto error;
3339 }
3340
3341 lta->ppid = msg->ppid;
3342 lta->uid = msg->uid;
3343 lta->gid = msg->gid;
3344
3345 lta->bits_per_long = msg->bits_per_long;
3346 lta->uint8_t_alignment = msg->uint8_t_alignment;
3347 lta->uint16_t_alignment = msg->uint16_t_alignment;
3348 lta->uint32_t_alignment = msg->uint32_t_alignment;
3349 lta->uint64_t_alignment = msg->uint64_t_alignment;
3350 lta->long_alignment = msg->long_alignment;
3351 lta->byte_order = msg->byte_order;
3352
3353 lta->v_major = msg->major;
3354 lta->v_minor = msg->minor;
3355 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3356 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3357 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3358 lta->notify_sock = -1;
3359
3360 /* Copy name and make sure it's NULL terminated. */
3361 strncpy(lta->name, msg->name, sizeof(lta->name));
3362 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3363
3364 /*
3365 * Before this can be called, when receiving the registration information,
3366 * the application compatibility is checked. So, at this point, the
3367 * application can work with this session daemon.
3368 */
3369 lta->compatible = 1;
3370
3371 lta->pid = msg->pid;
3372 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3373 lta->sock = sock;
3374 pthread_mutex_init(&lta->sock_lock, NULL);
3375 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3376
3377 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3378 error:
3379 return lta;
3380 }
3381
3382 /*
3383 * For a given application object, add it to every hash table.
3384 */
3385 void ust_app_add(struct ust_app *app)
3386 {
3387 assert(app);
3388 assert(app->notify_sock >= 0);
3389
3390 app->registration_time = time(NULL);
3391
3392 rcu_read_lock();
3393
3394 /*
3395 * On a re-registration, we want to kick out the previous registration of
3396 * that pid
3397 */
3398 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3399
3400 /*
3401 * The socket _should_ be unique until _we_ call close. So, a add_unique
3402 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3403 * already in the table.
3404 */
3405 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3406
3407 /* Add application to the notify socket hash table. */
3408 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3409 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3410
3411 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3412 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3413 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3414 app->v_minor);
3415
3416 rcu_read_unlock();
3417 }
3418
3419 /*
3420 * Set the application version into the object.
3421 *
3422 * Return 0 on success else a negative value either an errno code or a
3423 * LTTng-UST error code.
3424 */
3425 int ust_app_version(struct ust_app *app)
3426 {
3427 int ret;
3428
3429 assert(app);
3430
3431 pthread_mutex_lock(&app->sock_lock);
3432 ret = ustctl_tracer_version(app->sock, &app->version);
3433 pthread_mutex_unlock(&app->sock_lock);
3434 if (ret < 0) {
3435 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3436 ERR("UST app %d version failed with ret %d", app->sock, ret);
3437 } else {
3438 DBG3("UST app %d version failed. Application is dead", app->sock);
3439 }
3440 }
3441
3442 return ret;
3443 }
3444
3445 /*
3446 * Unregister app by removing it from the global traceable app list and freeing
3447 * the data struct.
3448 *
3449 * The socket is already closed at this point so no close to sock.
3450 */
3451 void ust_app_unregister(int sock)
3452 {
3453 struct ust_app *lta;
3454 struct lttng_ht_node_ulong *node;
3455 struct lttng_ht_iter ust_app_sock_iter;
3456 struct lttng_ht_iter iter;
3457 struct ust_app_session *ua_sess;
3458 int ret;
3459
3460 rcu_read_lock();
3461
3462 /* Get the node reference for a call_rcu */
3463 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3464 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3465 assert(node);
3466
3467 lta = caa_container_of(node, struct ust_app, sock_n);
3468 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3469
3470 /*
3471 * For per-PID buffers, perform "push metadata" and flush all
3472 * application streams before removing app from hash tables,
3473 * ensuring proper behavior of data_pending check.
3474 * Remove sessions so they are not visible during deletion.
3475 */
3476 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3477 node.node) {
3478 struct ust_registry_session *registry;
3479
3480 ret = lttng_ht_del(lta->sessions, &iter);
3481 if (ret) {
3482 /* The session was already removed so scheduled for teardown. */
3483 continue;
3484 }
3485
3486 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3487 (void) ust_app_flush_app_session(lta, ua_sess);
3488 }
3489
3490 /*
3491 * Add session to list for teardown. This is safe since at this point we
3492 * are the only one using this list.
3493 */
3494 pthread_mutex_lock(&ua_sess->lock);
3495
3496 if (ua_sess->deleted) {
3497 pthread_mutex_unlock(&ua_sess->lock);
3498 continue;
3499 }
3500
3501 /*
3502 * Normally, this is done in the delete session process which is
3503 * executed in the call rcu below. However, upon registration we can't
3504 * afford to wait for the grace period before pushing data or else the
3505 * data pending feature can race between the unregistration and stop
3506 * command where the data pending command is sent *before* the grace
3507 * period ended.
3508 *
3509 * The close metadata below nullifies the metadata pointer in the
3510 * session so the delete session will NOT push/close a second time.
3511 */
3512 registry = get_session_registry(ua_sess);
3513 if (registry) {
3514 /* Push metadata for application before freeing the application. */
3515 (void) push_metadata(registry, ua_sess->consumer);
3516
3517 /*
3518 * Don't ask to close metadata for global per UID buffers. Close
3519 * metadata only on destroy trace session in this case. Also, the
3520 * previous push metadata could have flag the metadata registry to
3521 * close so don't send a close command if closed.
3522 */
3523 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3524 /* And ask to close it for this session registry. */
3525 (void) close_metadata(registry, ua_sess->consumer);
3526 }
3527 }
3528 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3529
3530 pthread_mutex_unlock(&ua_sess->lock);
3531 }
3532
3533 /* Remove application from PID hash table */
3534 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3535 assert(!ret);
3536
3537 /*
3538 * Remove application from notify hash table. The thread handling the
3539 * notify socket could have deleted the node so ignore on error because
3540 * either way it's valid. The close of that socket is handled by the
3541 * apps_notify_thread.
3542 */
3543 iter.iter.node = &lta->notify_sock_n.node;
3544 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3545
3546 /*
3547 * Ignore return value since the node might have been removed before by an
3548 * add replace during app registration because the PID can be reassigned by
3549 * the OS.
3550 */
3551 iter.iter.node = &lta->pid_n.node;
3552 ret = lttng_ht_del(ust_app_ht, &iter);
3553 if (ret) {
3554 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3555 lta->pid);
3556 }
3557
3558 /* Free memory */
3559 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3560
3561 rcu_read_unlock();
3562 return;
3563 }
3564
3565 /*
3566 * Fill events array with all events name of all registered apps.
3567 */
3568 int ust_app_list_events(struct lttng_event **events)
3569 {
3570 int ret, handle;
3571 size_t nbmem, count = 0;
3572 struct lttng_ht_iter iter;
3573 struct ust_app *app;
3574 struct lttng_event *tmp_event;
3575
3576 nbmem = UST_APP_EVENT_LIST_SIZE;
3577 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3578 if (tmp_event == NULL) {
3579 PERROR("zmalloc ust app events");
3580 ret = -ENOMEM;
3581 goto error;
3582 }
3583
3584 rcu_read_lock();
3585
3586 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3587 struct lttng_ust_tracepoint_iter uiter;
3588
3589 health_code_update();
3590
3591 if (!app->compatible) {
3592 /*
3593 * TODO: In time, we should notice the caller of this error by
3594 * telling him that this is a version error.
3595 */
3596 continue;
3597 }
3598 pthread_mutex_lock(&app->sock_lock);
3599 handle = ustctl_tracepoint_list(app->sock);
3600 if (handle < 0) {
3601 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3602 ERR("UST app list events getting handle failed for app pid %d",
3603 app->pid);
3604 }
3605 pthread_mutex_unlock(&app->sock_lock);
3606 continue;
3607 }
3608
3609 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3610 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3611 /* Handle ustctl error. */
3612 if (ret < 0) {
3613 int release_ret;
3614
3615 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3616 ERR("UST app tp list get failed for app %d with ret %d",
3617 app->sock, ret);
3618 } else {
3619 DBG3("UST app tp list get failed. Application is dead");
3620 /*
3621 * This is normal behavior, an application can die during the
3622 * creation process. Don't report an error so the execution can
3623 * continue normally. Continue normal execution.
3624 */
3625 break;
3626 }
3627 free(tmp_event);
3628 release_ret = ustctl_release_handle(app->sock, handle);
3629 if (release_ret < 0 &&
3630 release_ret != -LTTNG_UST_ERR_EXITING &&
3631 release_ret != -EPIPE) {
3632 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3633 }
3634 pthread_mutex_unlock(&app->sock_lock);
3635 goto rcu_error;
3636 }
3637
3638 health_code_update();
3639 if (count >= nbmem) {
3640 /* In case the realloc fails, we free the memory */
3641 struct lttng_event *new_tmp_event;
3642 size_t new_nbmem;
3643
3644 new_nbmem = nbmem << 1;
3645 DBG2("Reallocating event list from %zu to %zu entries",
3646 nbmem, new_nbmem);
3647 new_tmp_event = realloc(tmp_event,
3648 new_nbmem * sizeof(struct lttng_event));
3649 if (new_tmp_event == NULL) {
3650 int release_ret;
3651
3652 PERROR("realloc ust app events");
3653 free(tmp_event);
3654 ret = -ENOMEM;
3655 release_ret = ustctl_release_handle(app->sock, handle);
3656 if (release_ret < 0 &&
3657 release_ret != -LTTNG_UST_ERR_EXITING &&
3658 release_ret != -EPIPE) {
3659 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3660 }
3661 pthread_mutex_unlock(&app->sock_lock);
3662 goto rcu_error;
3663 }
3664 /* Zero the new memory */
3665 memset(new_tmp_event + nbmem, 0,
3666 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3667 nbmem = new_nbmem;
3668 tmp_event = new_tmp_event;
3669 }
3670 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3671 tmp_event[count].loglevel = uiter.loglevel;
3672 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3673 tmp_event[count].pid = app->pid;
3674 tmp_event[count].enabled = -1;
3675 count++;
3676 }
3677 ret = ustctl_release_handle(app->sock, handle);
3678 pthread_mutex_unlock(&app->sock_lock);
3679 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3680 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3681 }
3682 }
3683
3684 ret = count;
3685 *events = tmp_event;
3686
3687 DBG2("UST app list events done (%zu events)", count);
3688
3689 rcu_error:
3690 rcu_read_unlock();
3691 error:
3692 health_code_update();
3693 return ret;
3694 }
3695
3696 /*
3697 * Fill events array with all events name of all registered apps.
3698 */
3699 int ust_app_list_event_fields(struct lttng_event_field **fields)
3700 {
3701 int ret, handle;
3702 size_t nbmem, count = 0;
3703 struct lttng_ht_iter iter;
3704 struct ust_app *app;
3705 struct lttng_event_field *tmp_event;
3706
3707 nbmem = UST_APP_EVENT_LIST_SIZE;
3708 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3709 if (tmp_event == NULL) {
3710 PERROR("zmalloc ust app event fields");
3711 ret = -ENOMEM;
3712 goto error;
3713 }
3714
3715 rcu_read_lock();
3716
3717 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3718 struct lttng_ust_field_iter uiter;
3719
3720 health_code_update();
3721
3722 if (!app->compatible) {
3723 /*
3724 * TODO: In time, we should notice the caller of this error by
3725 * telling him that this is a version error.
3726 */
3727