e01d43caf024ec61f3311ad323c4d3f7254afade
[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 time_t rawtime;
1836 struct tm *timeinfo;
1837 char datetime[16];
1838 int ret;
1839 char tmp_shm_path[PATH_MAX];
1840
1841 /* Get date and time for unique app path */
1842 time(&rawtime);
1843 timeinfo = localtime(&rawtime);
1844 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1845
1846 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1847
1848 ua_sess->tracing_id = usess->id;
1849 ua_sess->id = get_next_session_id();
1850 ua_sess->real_credentials.uid = app->uid;
1851 ua_sess->real_credentials.gid = app->gid;
1852 ua_sess->effective_credentials.uid = usess->uid;
1853 ua_sess->effective_credentials.gid = usess->gid;
1854 ua_sess->buffer_type = usess->buffer_type;
1855 ua_sess->bits_per_long = app->bits_per_long;
1856
1857 /* There is only one consumer object per session possible. */
1858 consumer_output_get(usess->consumer);
1859 ua_sess->consumer = usess->consumer;
1860
1861 ua_sess->output_traces = usess->output_traces;
1862 ua_sess->live_timer_interval = usess->live_timer_interval;
1863 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1864 &usess->metadata_attr);
1865
1866 switch (ua_sess->buffer_type) {
1867 case LTTNG_BUFFER_PER_PID:
1868 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1869 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1870 datetime);
1871 break;
1872 case LTTNG_BUFFER_PER_UID:
1873 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1874 DEFAULT_UST_TRACE_UID_PATH,
1875 ua_sess->real_credentials.uid,
1876 app->bits_per_long);
1877 break;
1878 default:
1879 assert(0);
1880 goto error;
1881 }
1882 if (ret < 0) {
1883 PERROR("asprintf UST shadow copy session");
1884 assert(0);
1885 goto error;
1886 }
1887
1888 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1889 sizeof(ua_sess->root_shm_path));
1890 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1891 strncpy(ua_sess->shm_path, usess->shm_path,
1892 sizeof(ua_sess->shm_path));
1893 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1894 if (ua_sess->shm_path[0]) {
1895 switch (ua_sess->buffer_type) {
1896 case LTTNG_BUFFER_PER_PID:
1897 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1898 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1899 app->name, app->pid, datetime);
1900 break;
1901 case LTTNG_BUFFER_PER_UID:
1902 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1903 DEFAULT_UST_TRACE_UID_PATH,
1904 app->uid, app->bits_per_long);
1905 break;
1906 default:
1907 assert(0);
1908 goto error;
1909 }
1910 if (ret < 0) {
1911 PERROR("sprintf UST shadow copy session");
1912 assert(0);
1913 goto error;
1914 }
1915 strncat(ua_sess->shm_path, tmp_shm_path,
1916 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1917 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1918 }
1919 return;
1920
1921 error:
1922 consumer_output_put(ua_sess->consumer);
1923 }
1924
1925 /*
1926 * Lookup sesison wrapper.
1927 */
1928 static
1929 void __lookup_session_by_app(const struct ltt_ust_session *usess,
1930 struct ust_app *app, struct lttng_ht_iter *iter)
1931 {
1932 /* Get right UST app session from app */
1933 lttng_ht_lookup(app->sessions, &usess->id, iter);
1934 }
1935
1936 /*
1937 * Return ust app session from the app session hashtable using the UST session
1938 * id.
1939 */
1940 static struct ust_app_session *lookup_session_by_app(
1941 const struct ltt_ust_session *usess, struct ust_app *app)
1942 {
1943 struct lttng_ht_iter iter;
1944 struct lttng_ht_node_u64 *node;
1945
1946 __lookup_session_by_app(usess, app, &iter);
1947 node = lttng_ht_iter_get_node_u64(&iter);
1948 if (node == NULL) {
1949 goto error;
1950 }
1951
1952 return caa_container_of(node, struct ust_app_session, node);
1953
1954 error:
1955 return NULL;
1956 }
1957
1958 /*
1959 * Setup buffer registry per PID for the given session and application. If none
1960 * is found, a new one is created, added to the global registry and
1961 * initialized. If regp is valid, it's set with the newly created object.
1962 *
1963 * Return 0 on success or else a negative value.
1964 */
1965 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1966 struct ust_app *app, struct buffer_reg_pid **regp)
1967 {
1968 int ret = 0;
1969 struct buffer_reg_pid *reg_pid;
1970
1971 assert(ua_sess);
1972 assert(app);
1973
1974 rcu_read_lock();
1975
1976 reg_pid = buffer_reg_pid_find(ua_sess->id);
1977 if (!reg_pid) {
1978 /*
1979 * This is the create channel path meaning that if there is NO
1980 * registry available, we have to create one for this session.
1981 */
1982 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1983 ua_sess->root_shm_path, ua_sess->shm_path);
1984 if (ret < 0) {
1985 goto error;
1986 }
1987 } else {
1988 goto end;
1989 }
1990
1991 /* Initialize registry. */
1992 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1993 app->bits_per_long, app->uint8_t_alignment,
1994 app->uint16_t_alignment, app->uint32_t_alignment,
1995 app->uint64_t_alignment, app->long_alignment,
1996 app->byte_order, app->version.major, app->version.minor,
1997 reg_pid->root_shm_path, reg_pid->shm_path,
1998 ua_sess->effective_credentials.uid,
1999 ua_sess->effective_credentials.gid);
2000 if (ret < 0) {
2001 /*
2002 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2003 * destroy the buffer registry, because it is always expected
2004 * that if the buffer registry can be found, its ust registry is
2005 * non-NULL.
2006 */
2007 buffer_reg_pid_destroy(reg_pid);
2008 goto error;
2009 }
2010
2011 buffer_reg_pid_add(reg_pid);
2012
2013 DBG3("UST app buffer registry per PID created successfully");
2014
2015 end:
2016 if (regp) {
2017 *regp = reg_pid;
2018 }
2019 error:
2020 rcu_read_unlock();
2021 return ret;
2022 }
2023
2024 /*
2025 * Setup buffer registry per UID for the given session and application. If none
2026 * is found, a new one is created, added to the global registry and
2027 * initialized. If regp is valid, it's set with the newly created object.
2028 *
2029 * Return 0 on success or else a negative value.
2030 */
2031 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2032 struct ust_app_session *ua_sess,
2033 struct ust_app *app, struct buffer_reg_uid **regp)
2034 {
2035 int ret = 0;
2036 struct buffer_reg_uid *reg_uid;
2037
2038 assert(usess);
2039 assert(app);
2040
2041 rcu_read_lock();
2042
2043 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2044 if (!reg_uid) {
2045 /*
2046 * This is the create channel path meaning that if there is NO
2047 * registry available, we have to create one for this session.
2048 */
2049 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2050 LTTNG_DOMAIN_UST, &reg_uid,
2051 ua_sess->root_shm_path, ua_sess->shm_path);
2052 if (ret < 0) {
2053 goto error;
2054 }
2055 } else {
2056 goto end;
2057 }
2058
2059 /* Initialize registry. */
2060 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2061 app->bits_per_long, app->uint8_t_alignment,
2062 app->uint16_t_alignment, app->uint32_t_alignment,
2063 app->uint64_t_alignment, app->long_alignment,
2064 app->byte_order, app->version.major,
2065 app->version.minor, reg_uid->root_shm_path,
2066 reg_uid->shm_path, usess->uid, usess->gid);
2067 if (ret < 0) {
2068 /*
2069 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2070 * destroy the buffer registry, because it is always expected
2071 * that if the buffer registry can be found, its ust registry is
2072 * non-NULL.
2073 */
2074 buffer_reg_uid_destroy(reg_uid, NULL);
2075 goto error;
2076 }
2077 /* Add node to teardown list of the session. */
2078 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2079
2080 buffer_reg_uid_add(reg_uid);
2081
2082 DBG3("UST app buffer registry per UID created successfully");
2083 end:
2084 if (regp) {
2085 *regp = reg_uid;
2086 }
2087 error:
2088 rcu_read_unlock();
2089 return ret;
2090 }
2091
2092 /*
2093 * Create a session on the tracer side for the given app.
2094 *
2095 * On success, ua_sess_ptr is populated with the session pointer or else left
2096 * untouched. If the session was created, is_created is set to 1. On error,
2097 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2098 * be NULL.
2099 *
2100 * Returns 0 on success or else a negative code which is either -ENOMEM or
2101 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2102 */
2103 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2104 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2105 int *is_created)
2106 {
2107 int ret, created = 0;
2108 struct ust_app_session *ua_sess;
2109
2110 assert(usess);
2111 assert(app);
2112 assert(ua_sess_ptr);
2113
2114 health_code_update();
2115
2116 ua_sess = lookup_session_by_app(usess, app);
2117 if (ua_sess == NULL) {
2118 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2119 app->pid, usess->id);
2120 ua_sess = alloc_ust_app_session();
2121 if (ua_sess == NULL) {
2122 /* Only malloc can failed so something is really wrong */
2123 ret = -ENOMEM;
2124 goto error;
2125 }
2126 shadow_copy_session(ua_sess, usess, app);
2127 created = 1;
2128 }
2129
2130 switch (usess->buffer_type) {
2131 case LTTNG_BUFFER_PER_PID:
2132 /* Init local registry. */
2133 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2134 if (ret < 0) {
2135 delete_ust_app_session(-1, ua_sess, app);
2136 goto error;
2137 }
2138 break;
2139 case LTTNG_BUFFER_PER_UID:
2140 /* Look for a global registry. If none exists, create one. */
2141 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2142 if (ret < 0) {
2143 delete_ust_app_session(-1, ua_sess, app);
2144 goto error;
2145 }
2146 break;
2147 default:
2148 assert(0);
2149 ret = -EINVAL;
2150 goto error;
2151 }
2152
2153 health_code_update();
2154
2155 if (ua_sess->handle == -1) {
2156 pthread_mutex_lock(&app->sock_lock);
2157 ret = ustctl_create_session(app->sock);
2158 pthread_mutex_unlock(&app->sock_lock);
2159 if (ret < 0) {
2160 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2161 ERR("Creating session for app pid %d with ret %d",
2162 app->pid, ret);
2163 } else {
2164 DBG("UST app creating session failed. Application is dead");
2165 /*
2166 * This is normal behavior, an application can die during the
2167 * creation process. Don't report an error so the execution can
2168 * continue normally. This will get flagged ENOTCONN and the
2169 * caller will handle it.
2170 */
2171 ret = 0;
2172 }
2173 delete_ust_app_session(-1, ua_sess, app);
2174 if (ret != -ENOMEM) {
2175 /*
2176 * Tracer is probably gone or got an internal error so let's
2177 * behave like it will soon unregister or not usable.
2178 */
2179 ret = -ENOTCONN;
2180 }
2181 goto error;
2182 }
2183
2184 ua_sess->handle = ret;
2185
2186 /* Add ust app session to app's HT */
2187 lttng_ht_node_init_u64(&ua_sess->node,
2188 ua_sess->tracing_id);
2189 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2190 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2191 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2192 &ua_sess->ust_objd_node);
2193
2194 DBG2("UST app session created successfully with handle %d", ret);
2195 }
2196
2197 *ua_sess_ptr = ua_sess;
2198 if (is_created) {
2199 *is_created = created;
2200 }
2201
2202 /* Everything went well. */
2203 ret = 0;
2204
2205 error:
2206 health_code_update();
2207 return ret;
2208 }
2209
2210 /*
2211 * Match function for a hash table lookup of ust_app_ctx.
2212 *
2213 * It matches an ust app context based on the context type and, in the case
2214 * of perf counters, their name.
2215 */
2216 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2217 {
2218 struct ust_app_ctx *ctx;
2219 const struct lttng_ust_context_attr *key;
2220
2221 assert(node);
2222 assert(_key);
2223
2224 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2225 key = _key;
2226
2227 /* Context type */
2228 if (ctx->ctx.ctx != key->ctx) {
2229 goto no_match;
2230 }
2231
2232 switch(key->ctx) {
2233 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2234 if (strncmp(key->u.perf_counter.name,
2235 ctx->ctx.u.perf_counter.name,
2236 sizeof(key->u.perf_counter.name))) {
2237 goto no_match;
2238 }
2239 break;
2240 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2241 if (strcmp(key->u.app_ctx.provider_name,
2242 ctx->ctx.u.app_ctx.provider_name) ||
2243 strcmp(key->u.app_ctx.ctx_name,
2244 ctx->ctx.u.app_ctx.ctx_name)) {
2245 goto no_match;
2246 }
2247 break;
2248 default:
2249 break;
2250 }
2251
2252 /* Match. */
2253 return 1;
2254
2255 no_match:
2256 return 0;
2257 }
2258
2259 /*
2260 * Lookup for an ust app context from an lttng_ust_context.
2261 *
2262 * Must be called while holding RCU read side lock.
2263 * Return an ust_app_ctx object or NULL on error.
2264 */
2265 static
2266 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2267 struct lttng_ust_context_attr *uctx)
2268 {
2269 struct lttng_ht_iter iter;
2270 struct lttng_ht_node_ulong *node;
2271 struct ust_app_ctx *app_ctx = NULL;
2272
2273 assert(uctx);
2274 assert(ht);
2275
2276 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2277 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2278 ht_match_ust_app_ctx, uctx, &iter.iter);
2279 node = lttng_ht_iter_get_node_ulong(&iter);
2280 if (!node) {
2281 goto end;
2282 }
2283
2284 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2285
2286 end:
2287 return app_ctx;
2288 }
2289
2290 /*
2291 * Create a context for the channel on the tracer.
2292 *
2293 * Called with UST app session lock held and a RCU read side lock.
2294 */
2295 static
2296 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2297 struct lttng_ust_context_attr *uctx,
2298 struct ust_app *app)
2299 {
2300 int ret = 0;
2301 struct ust_app_ctx *ua_ctx;
2302
2303 DBG2("UST app adding context to channel %s", ua_chan->name);
2304
2305 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2306 if (ua_ctx) {
2307 ret = -EEXIST;
2308 goto error;
2309 }
2310
2311 ua_ctx = alloc_ust_app_ctx(uctx);
2312 if (ua_ctx == NULL) {
2313 /* malloc failed */
2314 ret = -ENOMEM;
2315 goto error;
2316 }
2317
2318 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2319 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2320 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2321
2322 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2323 if (ret < 0) {
2324 goto error;
2325 }
2326
2327 error:
2328 return ret;
2329 }
2330
2331 /*
2332 * Enable on the tracer side a ust app event for the session and channel.
2333 *
2334 * Called with UST app session lock held.
2335 */
2336 static
2337 int enable_ust_app_event(struct ust_app_session *ua_sess,
2338 struct ust_app_event *ua_event, struct ust_app *app)
2339 {
2340 int ret;
2341
2342 ret = enable_ust_event(app, ua_sess, ua_event);
2343 if (ret < 0) {
2344 goto error;
2345 }
2346
2347 ua_event->enabled = 1;
2348
2349 error:
2350 return ret;
2351 }
2352
2353 /*
2354 * Disable on the tracer side a ust app event for the session and channel.
2355 */
2356 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2357 struct ust_app_event *ua_event, struct ust_app *app)
2358 {
2359 int ret;
2360
2361 ret = disable_ust_event(app, ua_sess, ua_event);
2362 if (ret < 0) {
2363 goto error;
2364 }
2365
2366 ua_event->enabled = 0;
2367
2368 error:
2369 return ret;
2370 }
2371
2372 /*
2373 * Lookup ust app channel for session and disable it on the tracer side.
2374 */
2375 static
2376 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2377 struct ust_app_channel *ua_chan, struct ust_app *app)
2378 {
2379 int ret;
2380
2381 ret = disable_ust_channel(app, ua_sess, ua_chan);
2382 if (ret < 0) {
2383 goto error;
2384 }
2385
2386 ua_chan->enabled = 0;
2387
2388 error:
2389 return ret;
2390 }
2391
2392 /*
2393 * Lookup ust app channel for session and enable it on the tracer side. This
2394 * MUST be called with a RCU read side lock acquired.
2395 */
2396 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2397 struct ltt_ust_channel *uchan, struct ust_app *app)
2398 {
2399 int ret = 0;
2400 struct lttng_ht_iter iter;
2401 struct lttng_ht_node_str *ua_chan_node;
2402 struct ust_app_channel *ua_chan;
2403
2404 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2405 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2406 if (ua_chan_node == NULL) {
2407 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2408 uchan->name, ua_sess->tracing_id);
2409 goto error;
2410 }
2411
2412 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2413
2414 ret = enable_ust_channel(app, ua_sess, ua_chan);
2415 if (ret < 0) {
2416 goto error;
2417 }
2418
2419 error:
2420 return ret;
2421 }
2422
2423 /*
2424 * Ask the consumer to create a channel and get it if successful.
2425 *
2426 * Called with UST app session lock held.
2427 *
2428 * Return 0 on success or else a negative value.
2429 */
2430 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2431 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2432 int bitness, struct ust_registry_session *registry,
2433 uint64_t trace_archive_id)
2434 {
2435 int ret;
2436 unsigned int nb_fd = 0;
2437 struct consumer_socket *socket;
2438
2439 assert(usess);
2440 assert(ua_sess);
2441 assert(ua_chan);
2442 assert(registry);
2443
2444 rcu_read_lock();
2445 health_code_update();
2446
2447 /* Get the right consumer socket for the application. */
2448 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2449 if (!socket) {
2450 ret = -EINVAL;
2451 goto error;
2452 }
2453
2454 health_code_update();
2455
2456 /* Need one fd for the channel. */
2457 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2458 if (ret < 0) {
2459 ERR("Exhausted number of available FD upon create channel");
2460 goto error;
2461 }
2462
2463 /*
2464 * Ask consumer to create channel. The consumer will return the number of
2465 * stream we have to expect.
2466 */
2467 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2468 registry, usess->current_trace_chunk);
2469 if (ret < 0) {
2470 goto error_ask;
2471 }
2472
2473 /*
2474 * Compute the number of fd needed before receiving them. It must be 2 per
2475 * stream (2 being the default value here).
2476 */
2477 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2478
2479 /* Reserve the amount of file descriptor we need. */
2480 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2481 if (ret < 0) {
2482 ERR("Exhausted number of available FD upon create channel");
2483 goto error_fd_get_stream;
2484 }
2485
2486 health_code_update();
2487
2488 /*
2489 * Now get the channel from the consumer. This call wil populate the stream
2490 * list of that channel and set the ust objects.
2491 */
2492 if (usess->consumer->enabled) {
2493 ret = ust_consumer_get_channel(socket, ua_chan);
2494 if (ret < 0) {
2495 goto error_destroy;
2496 }
2497 }
2498
2499 rcu_read_unlock();
2500 return 0;
2501
2502 error_destroy:
2503 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2504 error_fd_get_stream:
2505 /*
2506 * Initiate a destroy channel on the consumer since we had an error
2507 * handling it on our side. The return value is of no importance since we
2508 * already have a ret value set by the previous error that we need to
2509 * return.
2510 */
2511 (void) ust_consumer_destroy_channel(socket, ua_chan);
2512 error_ask:
2513 lttng_fd_put(LTTNG_FD_APPS, 1);
2514 error:
2515 health_code_update();
2516 rcu_read_unlock();
2517 return ret;
2518 }
2519
2520 /*
2521 * Duplicate the ust data object of the ust app stream and save it in the
2522 * buffer registry stream.
2523 *
2524 * Return 0 on success or else a negative value.
2525 */
2526 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2527 struct ust_app_stream *stream)
2528 {
2529 int ret;
2530
2531 assert(reg_stream);
2532 assert(stream);
2533
2534 /* Reserve the amount of file descriptor we need. */
2535 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2536 if (ret < 0) {
2537 ERR("Exhausted number of available FD upon duplicate stream");
2538 goto error;
2539 }
2540
2541 /* Duplicate object for stream once the original is in the registry. */
2542 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2543 reg_stream->obj.ust);
2544 if (ret < 0) {
2545 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2546 reg_stream->obj.ust, stream->obj, ret);
2547 lttng_fd_put(LTTNG_FD_APPS, 2);
2548 goto error;
2549 }
2550 stream->handle = stream->obj->handle;
2551
2552 error:
2553 return ret;
2554 }
2555
2556 /*
2557 * Duplicate the ust data object of the ust app. channel and save it in the
2558 * buffer registry channel.
2559 *
2560 * Return 0 on success or else a negative value.
2561 */
2562 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2563 struct ust_app_channel *ua_chan)
2564 {
2565 int ret;
2566
2567 assert(reg_chan);
2568 assert(ua_chan);
2569
2570 /* Need two fds for the channel. */
2571 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2572 if (ret < 0) {
2573 ERR("Exhausted number of available FD upon duplicate channel");
2574 goto error_fd_get;
2575 }
2576
2577 /* Duplicate object for stream once the original is in the registry. */
2578 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2579 if (ret < 0) {
2580 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2581 reg_chan->obj.ust, ua_chan->obj, ret);
2582 goto error;
2583 }
2584 ua_chan->handle = ua_chan->obj->handle;
2585
2586 return 0;
2587
2588 error:
2589 lttng_fd_put(LTTNG_FD_APPS, 1);
2590 error_fd_get:
2591 return ret;
2592 }
2593
2594 /*
2595 * For a given channel buffer registry, setup all streams of the given ust
2596 * application channel.
2597 *
2598 * Return 0 on success or else a negative value.
2599 */
2600 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2601 struct ust_app_channel *ua_chan,
2602 struct ust_app *app)
2603 {
2604 int ret = 0;
2605 struct ust_app_stream *stream, *stmp;
2606
2607 assert(reg_chan);
2608 assert(ua_chan);
2609
2610 DBG2("UST app setup buffer registry stream");
2611
2612 /* Send all streams to application. */
2613 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2614 struct buffer_reg_stream *reg_stream;
2615
2616 ret = buffer_reg_stream_create(&reg_stream);
2617 if (ret < 0) {
2618 goto error;
2619 }
2620
2621 /*
2622 * Keep original pointer and nullify it in the stream so the delete
2623 * stream call does not release the object.
2624 */
2625 reg_stream->obj.ust = stream->obj;
2626 stream->obj = NULL;
2627 buffer_reg_stream_add(reg_stream, reg_chan);
2628
2629 /* We don't need the streams anymore. */
2630 cds_list_del(&stream->list);
2631 delete_ust_app_stream(-1, stream, app);
2632 }
2633
2634 error:
2635 return ret;
2636 }
2637
2638 /*
2639 * Create a buffer registry channel for the given session registry and
2640 * application channel object. If regp pointer is valid, it's set with the
2641 * created object. Important, the created object is NOT added to the session
2642 * registry hash table.
2643 *
2644 * Return 0 on success else a negative value.
2645 */
2646 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2647 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2648 {
2649 int ret;
2650 struct buffer_reg_channel *reg_chan = NULL;
2651
2652 assert(reg_sess);
2653 assert(ua_chan);
2654
2655 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2656
2657 /* Create buffer registry channel. */
2658 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2659 if (ret < 0) {
2660 goto error_create;
2661 }
2662 assert(reg_chan);
2663 reg_chan->consumer_key = ua_chan->key;
2664 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2665 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2666
2667 /* Create and add a channel registry to session. */
2668 ret = ust_registry_channel_add(reg_sess->reg.ust,
2669 ua_chan->tracing_channel_id);
2670 if (ret < 0) {
2671 goto error;
2672 }
2673 buffer_reg_channel_add(reg_sess, reg_chan);
2674
2675 if (regp) {
2676 *regp = reg_chan;
2677 }
2678
2679 return 0;
2680
2681 error:
2682 /* Safe because the registry channel object was not added to any HT. */
2683 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2684 error_create:
2685 return ret;
2686 }
2687
2688 /*
2689 * Setup buffer registry channel for the given session registry and application
2690 * channel object. If regp pointer is valid, it's set with the created object.
2691 *
2692 * Return 0 on success else a negative value.
2693 */
2694 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2695 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2696 struct ust_app *app)
2697 {
2698 int ret;
2699
2700 assert(reg_sess);
2701 assert(reg_chan);
2702 assert(ua_chan);
2703 assert(ua_chan->obj);
2704
2705 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2706
2707 /* Setup all streams for the registry. */
2708 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2709 if (ret < 0) {
2710 goto error;
2711 }
2712
2713 reg_chan->obj.ust = ua_chan->obj;
2714 ua_chan->obj = NULL;
2715
2716 return 0;
2717
2718 error:
2719 buffer_reg_channel_remove(reg_sess, reg_chan);
2720 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2721 return ret;
2722 }
2723
2724 /*
2725 * Send buffer registry channel to the application.
2726 *
2727 * Return 0 on success else a negative value.
2728 */
2729 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2730 struct ust_app *app, struct ust_app_session *ua_sess,
2731 struct ust_app_channel *ua_chan)
2732 {
2733 int ret;
2734 struct buffer_reg_stream *reg_stream;
2735
2736 assert(reg_chan);
2737 assert(app);
2738 assert(ua_sess);
2739 assert(ua_chan);
2740
2741 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2742
2743 ret = duplicate_channel_object(reg_chan, ua_chan);
2744 if (ret < 0) {
2745 goto error;
2746 }
2747
2748 /* Send channel to the application. */
2749 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2750 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2751 ret = -ENOTCONN; /* Caused by app exiting. */
2752 goto error;
2753 } else if (ret < 0) {
2754 goto error;
2755 }
2756
2757 health_code_update();
2758
2759 /* Send all streams to application. */
2760 pthread_mutex_lock(&reg_chan->stream_list_lock);
2761 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2762 struct ust_app_stream stream;
2763
2764 ret = duplicate_stream_object(reg_stream, &stream);
2765 if (ret < 0) {
2766 goto error_stream_unlock;
2767 }
2768
2769 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2770 if (ret < 0) {
2771 (void) release_ust_app_stream(-1, &stream, app);
2772 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2773 ret = -ENOTCONN; /* Caused by app exiting. */
2774 }
2775 goto error_stream_unlock;
2776 }
2777
2778 /*
2779 * The return value is not important here. This function will output an
2780 * error if needed.
2781 */
2782 (void) release_ust_app_stream(-1, &stream, app);
2783 }
2784 ua_chan->is_sent = 1;
2785
2786 error_stream_unlock:
2787 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2788 error:
2789 return ret;
2790 }
2791
2792 /*
2793 * Create and send to the application the created buffers with per UID buffers.
2794 *
2795 * This MUST be called with a RCU read side lock acquired.
2796 * The session list lock and the session's lock must be acquired.
2797 *
2798 * Return 0 on success else a negative value.
2799 */
2800 static int create_channel_per_uid(struct ust_app *app,
2801 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2802 struct ust_app_channel *ua_chan)
2803 {
2804 int ret;
2805 struct buffer_reg_uid *reg_uid;
2806 struct buffer_reg_channel *reg_chan;
2807 struct ltt_session *session = NULL;
2808 enum lttng_error_code notification_ret;
2809 struct ust_registry_channel *chan_reg;
2810
2811 assert(app);
2812 assert(usess);
2813 assert(ua_sess);
2814 assert(ua_chan);
2815
2816 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2817
2818 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2819 /*
2820 * The session creation handles the creation of this global registry
2821 * object. If none can be find, there is a code flow problem or a
2822 * teardown race.
2823 */
2824 assert(reg_uid);
2825
2826 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2827 reg_uid);
2828 if (reg_chan) {
2829 goto send_channel;
2830 }
2831
2832 /* Create the buffer registry channel object. */
2833 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2834 if (ret < 0) {
2835 ERR("Error creating the UST channel \"%s\" registry instance",
2836 ua_chan->name);
2837 goto error;
2838 }
2839
2840 session = session_find_by_id(ua_sess->tracing_id);
2841 assert(session);
2842 assert(pthread_mutex_trylock(&session->lock));
2843 assert(session_trylock_list());
2844
2845 /*
2846 * Create the buffers on the consumer side. This call populates the
2847 * ust app channel object with all streams and data object.
2848 */
2849 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2850 app->bits_per_long, reg_uid->registry->reg.ust,
2851 session->most_recent_chunk_id.value);
2852 if (ret < 0) {
2853 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2854 ua_chan->name);
2855
2856 /*
2857 * Let's remove the previously created buffer registry channel so
2858 * it's not visible anymore in the session registry.
2859 */
2860 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2861 ua_chan->tracing_channel_id, false);
2862 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2863 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2864 goto error;
2865 }
2866
2867 /*
2868 * Setup the streams and add it to the session registry.
2869 */
2870 ret = setup_buffer_reg_channel(reg_uid->registry,
2871 ua_chan, reg_chan, app);
2872 if (ret < 0) {
2873 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2874 goto error;
2875 }
2876
2877 /* Notify the notification subsystem of the channel's creation. */
2878 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2879 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2880 ua_chan->tracing_channel_id);
2881 assert(chan_reg);
2882 chan_reg->consumer_key = ua_chan->key;
2883 chan_reg = NULL;
2884 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2885
2886 notification_ret = notification_thread_command_add_channel(
2887 notification_thread_handle, session->name,
2888 ua_sess->effective_credentials.uid,
2889 ua_sess->effective_credentials.gid, ua_chan->name,
2890 ua_chan->key, LTTNG_DOMAIN_UST,
2891 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2892 if (notification_ret != LTTNG_OK) {
2893 ret = - (int) notification_ret;
2894 ERR("Failed to add channel to notification thread");
2895 goto error;
2896 }
2897
2898 send_channel:
2899 /* Send buffers to the application. */
2900 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2901 if (ret < 0) {
2902 if (ret != -ENOTCONN) {
2903 ERR("Error sending channel to application");
2904 }
2905 goto error;
2906 }
2907
2908 error:
2909 if (session) {
2910 session_put(session);
2911 }
2912 return ret;
2913 }
2914
2915 /*
2916 * Create and send to the application the created buffers with per PID buffers.
2917 *
2918 * Called with UST app session lock held.
2919 * The session list lock and the session's lock must be acquired.
2920 *
2921 * Return 0 on success else a negative value.
2922 */
2923 static int create_channel_per_pid(struct ust_app *app,
2924 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2925 struct ust_app_channel *ua_chan)
2926 {
2927 int ret;
2928 struct ust_registry_session *registry;
2929 enum lttng_error_code cmd_ret;
2930 struct ltt_session *session = NULL;
2931 uint64_t chan_reg_key;
2932 struct ust_registry_channel *chan_reg;
2933
2934 assert(app);
2935 assert(usess);
2936 assert(ua_sess);
2937 assert(ua_chan);
2938
2939 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2940
2941 rcu_read_lock();
2942
2943 registry = get_session_registry(ua_sess);
2944 /* The UST app session lock is held, registry shall not be null. */
2945 assert(registry);
2946
2947 /* Create and add a new channel registry to session. */
2948 ret = ust_registry_channel_add(registry, ua_chan->key);
2949 if (ret < 0) {
2950 ERR("Error creating the UST channel \"%s\" registry instance",
2951 ua_chan->name);
2952 goto error;
2953 }
2954
2955 session = session_find_by_id(ua_sess->tracing_id);
2956 assert(session);
2957
2958 assert(pthread_mutex_trylock(&session->lock));
2959 assert(session_trylock_list());
2960
2961 /* Create and get channel on the consumer side. */
2962 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2963 app->bits_per_long, registry,
2964 session->most_recent_chunk_id.value);
2965 if (ret < 0) {
2966 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2967 ua_chan->name);
2968 goto error_remove_from_registry;
2969 }
2970
2971 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2972 if (ret < 0) {
2973 if (ret != -ENOTCONN) {
2974 ERR("Error sending channel to application");
2975 }
2976 goto error_remove_from_registry;
2977 }
2978
2979 chan_reg_key = ua_chan->key;
2980 pthread_mutex_lock(&registry->lock);
2981 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2982 assert(chan_reg);
2983 chan_reg->consumer_key = ua_chan->key;
2984 pthread_mutex_unlock(&registry->lock);
2985
2986 cmd_ret = notification_thread_command_add_channel(
2987 notification_thread_handle, session->name,
2988 ua_sess->effective_credentials.uid,
2989 ua_sess->effective_credentials.gid, ua_chan->name,
2990 ua_chan->key, LTTNG_DOMAIN_UST,
2991 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2992 if (cmd_ret != LTTNG_OK) {
2993 ret = - (int) cmd_ret;
2994 ERR("Failed to add channel to notification thread");
2995 goto error_remove_from_registry;
2996 }
2997
2998 error_remove_from_registry:
2999 if (ret) {
3000 ust_registry_channel_del_free(registry, ua_chan->key, false);
3001 }
3002 error:
3003 rcu_read_unlock();
3004 if (session) {
3005 session_put(session);
3006 }
3007 return ret;
3008 }
3009
3010 /*
3011 * From an already allocated ust app channel, create the channel buffers if
3012 * needed and send them to the application. This MUST be called with a RCU read
3013 * side lock acquired.
3014 *
3015 * Called with UST app session lock held.
3016 *
3017 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3018 * the application exited concurrently.
3019 */
3020 static int ust_app_channel_send(struct ust_app *app,
3021 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3022 struct ust_app_channel *ua_chan)
3023 {
3024 int ret;
3025
3026 assert(app);
3027 assert(usess);
3028 assert(usess->active);
3029 assert(ua_sess);
3030 assert(ua_chan);
3031
3032 /* Handle buffer type before sending the channel to the application. */
3033 switch (usess->buffer_type) {
3034 case LTTNG_BUFFER_PER_UID:
3035 {
3036 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3037 if (ret < 0) {
3038 goto error;
3039 }
3040 break;
3041 }
3042 case LTTNG_BUFFER_PER_PID:
3043 {
3044 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3045 if (ret < 0) {
3046 goto error;
3047 }
3048 break;
3049 }
3050 default:
3051 assert(0);
3052 ret = -EINVAL;
3053 goto error;
3054 }
3055
3056 /* Initialize ust objd object using the received handle and add it. */
3057 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3058 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3059
3060 /* If channel is not enabled, disable it on the tracer */
3061 if (!ua_chan->enabled) {
3062 ret = disable_ust_channel(app, ua_sess, ua_chan);
3063 if (ret < 0) {
3064 goto error;
3065 }
3066 }
3067
3068 error:
3069 return ret;
3070 }
3071
3072 /*
3073 * Create UST app channel and return it through ua_chanp if not NULL.
3074 *
3075 * Called with UST app session lock and RCU read-side lock held.
3076 *
3077 * Return 0 on success or else a negative value.
3078 */
3079 static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3080 struct ltt_ust_channel *uchan,
3081 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3082 struct ust_app_channel **ua_chanp)
3083 {
3084 int ret = 0;
3085 struct lttng_ht_iter iter;
3086 struct lttng_ht_node_str *ua_chan_node;
3087 struct ust_app_channel *ua_chan;
3088
3089 /* Lookup channel in the ust app session */
3090 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3091 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3092 if (ua_chan_node != NULL) {
3093 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3094 goto end;
3095 }
3096
3097 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3098 if (ua_chan == NULL) {
3099 /* Only malloc can fail here */
3100 ret = -ENOMEM;
3101 goto error;
3102 }
3103 shadow_copy_channel(ua_chan, uchan);
3104
3105 /* Set channel type. */
3106 ua_chan->attr.type = type;
3107
3108 /* Only add the channel if successful on the tracer side. */
3109 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3110 end:
3111 if (ua_chanp) {
3112 *ua_chanp = ua_chan;
3113 }
3114
3115 /* Everything went well. */
3116 return 0;
3117
3118 error:
3119 return ret;
3120 }
3121
3122 /*
3123 * Create UST app event and create it on the tracer side.
3124 *
3125 * Called with ust app session mutex held.
3126 */
3127 static
3128 int create_ust_app_event(struct ust_app_session *ua_sess,
3129 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3130 struct ust_app *app)
3131 {
3132 int ret = 0;
3133 struct ust_app_event *ua_event;
3134
3135 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3136 if (ua_event == NULL) {
3137 /* Only malloc can failed so something is really wrong */
3138 ret = -ENOMEM;
3139 goto end;
3140 }
3141 shadow_copy_event(ua_event, uevent);
3142
3143 /* Create it on the tracer side */
3144 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3145 if (ret < 0) {
3146 /* Not found previously means that it does not exist on the tracer */
3147 assert(ret != -LTTNG_UST_ERR_EXIST);
3148 goto error;
3149 }
3150
3151 add_unique_ust_app_event(ua_chan, ua_event);
3152
3153 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3154 app->pid);
3155
3156 end:
3157 return ret;
3158
3159 error:
3160 /* Valid. Calling here is already in a read side lock */
3161 delete_ust_app_event(-1, ua_event, app);
3162 return ret;
3163 }
3164
3165 /*
3166 * Create UST metadata and open it on the tracer side.
3167 *
3168 * Called with UST app session lock held and RCU read side lock.
3169 */
3170 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3171 struct ust_app *app, struct consumer_output *consumer)
3172 {
3173 int ret = 0;
3174 struct ust_app_channel *metadata;
3175 struct consumer_socket *socket;
3176 struct ust_registry_session *registry;
3177 struct ltt_session *session = NULL;
3178
3179 assert(ua_sess);
3180 assert(app);
3181 assert(consumer);
3182
3183 registry = get_session_registry(ua_sess);
3184 /* The UST app session is held registry shall not be null. */
3185 assert(registry);
3186
3187 pthread_mutex_lock(&registry->lock);
3188
3189 /* Metadata already exists for this registry or it was closed previously */
3190 if (registry->metadata_key || registry->metadata_closed) {
3191 ret = 0;
3192 goto error;
3193 }
3194
3195 /* Allocate UST metadata */
3196 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3197 if (!metadata) {
3198 /* malloc() failed */
3199 ret = -ENOMEM;
3200 goto error;
3201 }
3202
3203 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3204
3205 /* Need one fd for the channel. */
3206 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3207 if (ret < 0) {
3208 ERR("Exhausted number of available FD upon create metadata");
3209 goto error;
3210 }
3211
3212 /* Get the right consumer socket for the application. */
3213 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3214 if (!socket) {
3215 ret = -EINVAL;
3216 goto error_consumer;
3217 }
3218
3219 /*
3220 * Keep metadata key so we can identify it on the consumer side. Assign it
3221 * to the registry *before* we ask the consumer so we avoid the race of the
3222 * consumer requesting the metadata and the ask_channel call on our side
3223 * did not returned yet.
3224 */
3225 registry->metadata_key = metadata->key;
3226
3227 session = session_find_by_id(ua_sess->tracing_id);
3228 assert(session);
3229
3230 assert(pthread_mutex_trylock(&session->lock));
3231 assert(session_trylock_list());
3232
3233 /*
3234 * Ask the metadata channel creation to the consumer. The metadata object
3235 * will be created by the consumer and kept their. However, the stream is
3236 * never added or monitored until we do a first push metadata to the
3237 * consumer.
3238 */
3239 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3240 registry, session->current_trace_chunk);
3241 if (ret < 0) {
3242 /* Nullify the metadata key so we don't try to close it later on. */
3243 registry->metadata_key = 0;
3244 goto error_consumer;
3245 }
3246
3247 /*
3248 * The setup command will make the metadata stream be sent to the relayd,
3249 * if applicable, and the thread managing the metadatas. This is important
3250 * because after this point, if an error occurs, the only way the stream
3251 * can be deleted is to be monitored in the consumer.
3252 */
3253 ret = consumer_setup_metadata(socket, metadata->key);
3254 if (ret < 0) {
3255 /* Nullify the metadata key so we don't try to close it later on. */
3256 registry->metadata_key = 0;
3257 goto error_consumer;
3258 }
3259
3260 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3261 metadata->key, app->pid);
3262
3263 error_consumer:
3264 lttng_fd_put(LTTNG_FD_APPS, 1);
3265 delete_ust_app_channel(-1, metadata, app);
3266 error:
3267 pthread_mutex_unlock(&registry->lock);
3268 if (session) {
3269 session_put(session);
3270 }
3271 return ret;
3272 }
3273
3274 /*
3275 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3276 * acquired before calling this function.
3277 */
3278 struct ust_app *ust_app_find_by_pid(pid_t pid)
3279 {
3280 struct ust_app *app = NULL;
3281 struct lttng_ht_node_ulong *node;
3282 struct lttng_ht_iter iter;
3283
3284 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3285 node = lttng_ht_iter_get_node_ulong(&iter);
3286 if (node == NULL) {
3287 DBG2("UST app no found with pid %d", pid);
3288 goto error;
3289 }
3290
3291 DBG2("Found UST app by pid %d", pid);
3292
3293 app = caa_container_of(node, struct ust_app, pid_n);
3294
3295 error:
3296 return app;
3297 }
3298
3299 /*
3300 * Allocate and init an UST app object using the registration information and
3301 * the command socket. This is called when the command socket connects to the
3302 * session daemon.
3303 *
3304 * The object is returned on success or else NULL.
3305 */
3306 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3307 {
3308 struct ust_app *lta = NULL;
3309
3310 assert(msg);
3311 assert(sock >= 0);
3312
3313 DBG3("UST app creating application for socket %d", sock);
3314
3315 if ((msg->bits_per_long == 64 &&
3316 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3317 || (msg->bits_per_long == 32 &&
3318 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3319 ERR("Registration failed: application \"%s\" (pid: %d) has "
3320 "%d-bit long, but no consumerd for this size is available.\n",
3321 msg->name, msg->pid, msg->bits_per_long);
3322 goto error;
3323 }
3324
3325 lta = zmalloc(sizeof(struct ust_app));
3326 if (lta == NULL) {
3327 PERROR("malloc");
3328 goto error;
3329 }
3330
3331 lta->ppid = msg->ppid;
3332 lta->uid = msg->uid;
3333 lta->gid = msg->gid;
3334
3335 lta->bits_per_long = msg->bits_per_long;
3336 lta->uint8_t_alignment = msg->uint8_t_alignment;
3337 lta->uint16_t_alignment = msg->uint16_t_alignment;
3338 lta->uint32_t_alignment = msg->uint32_t_alignment;
3339 lta->uint64_t_alignment = msg->uint64_t_alignment;
3340 lta->long_alignment = msg->long_alignment;
3341 lta->byte_order = msg->byte_order;
3342
3343 lta->v_major = msg->major;
3344 lta->v_minor = msg->minor;
3345 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3346 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3347 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3348 lta->notify_sock = -1;
3349
3350 /* Copy name and make sure it's NULL terminated. */
3351 strncpy(lta->name, msg->name, sizeof(lta->name));
3352 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3353
3354 /*
3355 * Before this can be called, when receiving the registration information,
3356 * the application compatibility is checked. So, at this point, the
3357 * application can work with this session daemon.
3358 */
3359 lta->compatible = 1;
3360
3361 lta->pid = msg->pid;
3362 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3363 lta->sock = sock;
3364 pthread_mutex_init(&lta->sock_lock, NULL);
3365 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3366
3367 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3368 error:
3369 return lta;
3370 }
3371
3372 /*
3373 * For a given application object, add it to every hash table.
3374 */
3375 void ust_app_add(struct ust_app *app)
3376 {
3377 assert(app);
3378 assert(app->notify_sock >= 0);
3379
3380 rcu_read_lock();
3381
3382 /*
3383 * On a re-registration, we want to kick out the previous registration of
3384 * that pid
3385 */
3386 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3387
3388 /*
3389 * The socket _should_ be unique until _we_ call close. So, a add_unique
3390 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3391 * already in the table.
3392 */
3393 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3394
3395 /* Add application to the notify socket hash table. */
3396 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3397 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3398
3399 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3400 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3401 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3402 app->v_minor);
3403
3404 rcu_read_unlock();
3405 }
3406
3407 /*
3408 * Set the application version into the object.
3409 *
3410 * Return 0 on success else a negative value either an errno code or a
3411 * LTTng-UST error code.
3412 */
3413 int ust_app_version(struct ust_app *app)
3414 {
3415 int ret;
3416
3417 assert(app);
3418
3419 pthread_mutex_lock(&app->sock_lock);
3420 ret = ustctl_tracer_version(app->sock, &app->version);
3421 pthread_mutex_unlock(&app->sock_lock);
3422 if (ret < 0) {
3423 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3424 ERR("UST app %d version failed with ret %d", app->sock, ret);
3425 } else {
3426 DBG3("UST app %d version failed. Application is dead", app->sock);
3427 }
3428 }
3429
3430 return ret;
3431 }
3432
3433 /*
3434 * Unregister app by removing it from the global traceable app list and freeing
3435 * the data struct.
3436 *
3437 * The socket is already closed at this point so no close to sock.
3438 */
3439 void ust_app_unregister(int sock)
3440 {
3441 struct ust_app *lta;
3442 struct lttng_ht_node_ulong *node;
3443 struct lttng_ht_iter ust_app_sock_iter;
3444 struct lttng_ht_iter iter;
3445 struct ust_app_session *ua_sess;
3446 int ret;
3447
3448 rcu_read_lock();
3449
3450 /* Get the node reference for a call_rcu */
3451 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3452 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3453 assert(node);
3454
3455 lta = caa_container_of(node, struct ust_app, sock_n);
3456 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3457
3458 /*
3459 * For per-PID buffers, perform "push metadata" and flush all
3460 * application streams before removing app from hash tables,
3461 * ensuring proper behavior of data_pending check.
3462 * Remove sessions so they are not visible during deletion.
3463 */
3464 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3465 node.node) {
3466 struct ust_registry_session *registry;
3467
3468 ret = lttng_ht_del(lta->sessions, &iter);
3469 if (ret) {
3470 /* The session was already removed so scheduled for teardown. */
3471 continue;
3472 }
3473
3474 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3475 (void) ust_app_flush_app_session(lta, ua_sess);
3476 }
3477
3478 /*
3479 * Add session to list for teardown. This is safe since at this point we
3480 * are the only one using this list.
3481 */
3482 pthread_mutex_lock(&ua_sess->lock);
3483
3484 if (ua_sess->deleted) {
3485 pthread_mutex_unlock(&ua_sess->lock);
3486 continue;
3487 }
3488
3489 /*
3490 * Normally, this is done in the delete session process which is
3491 * executed in the call rcu below. However, upon registration we can't
3492 * afford to wait for the grace period before pushing data or else the
3493 * data pending feature can race between the unregistration and stop
3494 * command where the data pending command is sent *before* the grace
3495 * period ended.
3496 *
3497 * The close metadata below nullifies the metadata pointer in the
3498 * session so the delete session will NOT push/close a second time.
3499 */
3500 registry = get_session_registry(ua_sess);
3501 if (registry) {
3502 /* Push metadata for application before freeing the application. */
3503 (void) push_metadata(registry, ua_sess->consumer);
3504
3505 /*
3506 * Don't ask to close metadata for global per UID buffers. Close
3507 * metadata only on destroy trace session in this case. Also, the
3508 * previous push metadata could have flag the metadata registry to
3509 * close so don't send a close command if closed.
3510 */
3511 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3512 /* And ask to close it for this session registry. */
3513 (void) close_metadata(registry, ua_sess->consumer);
3514 }
3515 }
3516 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3517
3518 pthread_mutex_unlock(&ua_sess->lock);
3519 }
3520
3521 /* Remove application from PID hash table */
3522 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3523 assert(!ret);
3524
3525 /*
3526 * Remove application from notify hash table. The thread handling the
3527 * notify socket could have deleted the node so ignore on error because
3528 * either way it's valid. The close of that socket is handled by the
3529 * apps_notify_thread.
3530 */
3531 iter.iter.node = &lta->notify_sock_n.node;
3532 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3533
3534 /*
3535 * Ignore return value since the node might have been removed before by an
3536 * add replace during app registration because the PID can be reassigned by
3537 * the OS.
3538 */
3539 iter.iter.node = &lta->pid_n.node;
3540 ret = lttng_ht_del(ust_app_ht, &iter);
3541 if (ret) {
3542 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3543 lta->pid);
3544 }
3545
3546 /* Free memory */
3547 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3548
3549 rcu_read_unlock();
3550 return;
3551 }
3552
3553 /*
3554 * Fill events array with all events name of all registered apps.
3555 */
3556 int ust_app_list_events(struct lttng_event **events)
3557 {
3558 int ret, handle;
3559 size_t nbmem, count = 0;
3560 struct lttng_ht_iter iter;
3561 struct ust_app *app;
3562 struct lttng_event *tmp_event;
3563
3564 nbmem = UST_APP_EVENT_LIST_SIZE;
3565 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3566 if (tmp_event == NULL) {
3567 PERROR("zmalloc ust app events");
3568 ret = -ENOMEM;
3569 goto error;
3570 }
3571
3572 rcu_read_lock();
3573
3574 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3575 struct lttng_ust_tracepoint_iter uiter;
3576
3577 health_code_update();
3578
3579 if (!app->compatible) {
3580 /*
3581 * TODO: In time, we should notice the caller of this error by
3582 * telling him that this is a version error.
3583 */
3584 continue;
3585 }
3586 pthread_mutex_lock(&app->sock_lock);
3587 handle = ustctl_tracepoint_list(app->sock);
3588 if (handle < 0) {
3589 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3590 ERR("UST app list events getting handle failed for app pid %d",
3591 app->pid);
3592 }
3593 pthread_mutex_unlock(&app->sock_lock);
3594 continue;
3595 }
3596
3597 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3598 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3599 /* Handle ustctl error. */
3600 if (ret < 0) {
3601 int release_ret;
3602
3603 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3604 ERR("UST app tp list get failed for app %d with ret %d",
3605 app->sock, ret);
3606 } else {
3607 DBG3("UST app tp list get failed. Application is dead");
3608 /*
3609 * This is normal behavior, an application can die during the
3610 * creation process. Don't report an error so the execution can
3611 * continue normally. Continue normal execution.
3612 */
3613 break;
3614 }
3615 free(tmp_event);
3616 release_ret = ustctl_release_handle(app->sock, handle);
3617 if (release_ret < 0 &&
3618 release_ret != -LTTNG_UST_ERR_EXITING &&
3619 release_ret != -EPIPE) {
3620 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3621 }
3622 pthread_mutex_unlock(&app->sock_lock);
3623 goto rcu_error;
3624 }
3625
3626 health_code_update();
3627 if (count >= nbmem) {
3628 /* In case the realloc fails, we free the memory */
3629 struct lttng_event *new_tmp_event;
3630 size_t new_nbmem;
3631
3632 new_nbmem = nbmem << 1;
3633 DBG2("Reallocating event list from %zu to %zu entries",
3634 nbmem, new_nbmem);
3635 new_tmp_event = realloc(tmp_event,
3636 new_nbmem * sizeof(struct lttng_event));
3637 if (new_tmp_event == NULL) {
3638 int release_ret;
3639
3640 PERROR("realloc ust app events");
3641 free(tmp_event);
3642 ret = -ENOMEM;
3643 release_ret = ustctl_release_handle(app->sock, handle);
3644 if (release_ret < 0 &&
3645 release_ret != -LTTNG_UST_ERR_EXITING &&
3646 release_ret != -EPIPE) {
3647 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3648 }
3649 pthread_mutex_unlock(&app->sock_lock);
3650 goto rcu_error;
3651 }
3652 /* Zero the new memory */
3653 memset(new_tmp_event + nbmem, 0,
3654 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3655 nbmem = new_nbmem;
3656 tmp_event = new_tmp_event;
3657 }
3658 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3659 tmp_event[count].loglevel = uiter.loglevel;
3660 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3661 tmp_event[count].pid = app->pid;
3662 tmp_event[count].enabled = -1;
3663 count++;
3664 }
3665 ret = ustctl_release_handle(app->sock, handle);
3666 pthread_mutex_unlock(&app->sock_lock);
3667 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3668 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3669 }
3670 }
3671
3672 ret = count;
3673 *events = tmp_event;
3674
3675 DBG2("UST app list events done (%zu events)", count);
3676
3677 rcu_error:
3678 rcu_read_unlock();
3679 error:
3680 health_code_update();
3681 return ret;
3682 }
3683
3684 /*
3685 * Fill events array with all events name of all registered apps.
3686 */
3687 int ust_app_list_event_fields(struct lttng_event_field **fields)
3688 {
3689 int ret, handle;
3690 size_t nbmem, count = 0;
3691 struct lttng_ht_iter iter;
3692 struct ust_app *app;
3693 struct lttng_event_field *tmp_event;
3694
3695 nbmem = UST_APP_EVENT_LIST_SIZE;
3696 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3697 if (tmp_event == NULL) {
3698 PERROR("zmalloc ust app event fields");
3699 ret = -ENOMEM;
3700 goto error;
3701 }
3702
3703 rcu_read_lock();
3704
3705 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3706 struct lttng_ust_field_iter uiter;
3707
3708 health_code_update();
3709
3710 if (!app->compatible) {
3711 /*
3712 * TODO: In time, we should notice the caller of this error by
3713 * telling him that this is a version error.
3714 */
3715 continue;
3716 }
3717 pthread_mutex_lock(&app->sock_lock);
3718 handle = ustctl_tracepoint_field_list(app->sock);
3719 if (handle < 0) {
3720 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3721 ERR("UST app list field getting handle failed for app pid %d",
3722 app->pid);
3723 }
3724 pthread_mutex_unlock(&app->sock_lock);
3725 continue;
3726 }
3727