f3e0209014974f54cf547a91162dcb1c40a246e6
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <signal.h>
31
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34
35 #include "buffer-registry.h"
36 #include "fd-limit.h"
37 #include "health-sessiond.h"
38 #include "ust-app.h"
39 #include "ust-consumer.h"
40 #include "lttng-ust-ctl.h"
41 #include "lttng-ust-error.h"
42 #include "utils.h"
43 #include "session.h"
44 #include "lttng-sessiond.h"
45 #include "notification-thread-commands.h"
46 #include "rotate.h"
47
48 static
49 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51 /* Next available channel key. Access under next_channel_key_lock. */
52 static uint64_t _next_channel_key;
53 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55 /* Next available session ID. Access under next_session_id_lock. */
56 static uint64_t _next_session_id;
57 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59 /*
60 * Return the incremented value of next_channel_key.
61 */
62 static uint64_t get_next_channel_key(void)
63 {
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70 }
71
72 /*
73 * Return the atomically incremented value of next_session_id.
74 */
75 static uint64_t get_next_session_id(void)
76 {
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83 }
84
85 static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88 {
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97 }
98
99 /*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106 {
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173 no_match:
174 return 0;
175 }
176
177 /*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183 {
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202 }
203
204 /*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208 static void close_notify_sock_rcu(struct rcu_head *head)
209 {
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224 }
225
226 /*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233 static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235 {
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long,
254 ua_sess->real_credentials.uid);
255 if (!reg_uid) {
256 goto error;
257 }
258 registry = reg_uid->registry->reg.ust;
259 break;
260 }
261 default:
262 assert(0);
263 };
264
265 error:
266 return registry;
267 }
268
269 /*
270 * Delete ust context safely. RCU read lock must be held before calling
271 * this function.
272 */
273 static
274 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
275 struct ust_app *app)
276 {
277 int ret;
278
279 assert(ua_ctx);
280
281 if (ua_ctx->obj) {
282 pthread_mutex_lock(&app->sock_lock);
283 ret = ustctl_release_object(sock, ua_ctx->obj);
284 pthread_mutex_unlock(&app->sock_lock);
285 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
286 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
287 sock, ua_ctx->obj->handle, ret);
288 }
289 free(ua_ctx->obj);
290 }
291 free(ua_ctx);
292 }
293
294 /*
295 * Delete ust app event safely. RCU read lock must be held before calling
296 * this function.
297 */
298 static
299 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
300 struct ust_app *app)
301 {
302 int ret;
303
304 assert(ua_event);
305
306 free(ua_event->filter);
307 if (ua_event->exclusion != NULL)
308 free(ua_event->exclusion);
309 if (ua_event->obj != NULL) {
310 pthread_mutex_lock(&app->sock_lock);
311 ret = ustctl_release_object(sock, ua_event->obj);
312 pthread_mutex_unlock(&app->sock_lock);
313 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
314 ERR("UST app sock %d release event obj failed with ret %d",
315 sock, ret);
316 }
317 free(ua_event->obj);
318 }
319 free(ua_event);
320 }
321
322 /*
323 * Release ust data object of the given stream.
324 *
325 * Return 0 on success or else a negative value.
326 */
327 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
328 struct ust_app *app)
329 {
330 int ret = 0;
331
332 assert(stream);
333
334 if (stream->obj) {
335 pthread_mutex_lock(&app->sock_lock);
336 ret = ustctl_release_object(sock, stream->obj);
337 pthread_mutex_unlock(&app->sock_lock);
338 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
339 ERR("UST app sock %d release stream obj failed with ret %d",
340 sock, ret);
341 }
342 lttng_fd_put(LTTNG_FD_APPS, 2);
343 free(stream->obj);
344 }
345
346 return ret;
347 }
348
349 /*
350 * Delete ust app stream safely. RCU read lock must be held before calling
351 * this function.
352 */
353 static
354 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
355 struct ust_app *app)
356 {
357 assert(stream);
358
359 (void) release_ust_app_stream(sock, stream, app);
360 free(stream);
361 }
362
363 /*
364 * We need to execute ht_destroy outside of RCU read-side critical
365 * section and outside of call_rcu thread, so we postpone its execution
366 * using ht_cleanup_push. It is simpler than to change the semantic of
367 * the many callers of delete_ust_app_session().
368 */
369 static
370 void delete_ust_app_channel_rcu(struct rcu_head *head)
371 {
372 struct ust_app_channel *ua_chan =
373 caa_container_of(head, struct ust_app_channel, rcu_head);
374
375 ht_cleanup_push(ua_chan->ctx);
376 ht_cleanup_push(ua_chan->events);
377 free(ua_chan);
378 }
379
380 /*
381 * Extract the lost packet or discarded events counter when the channel is
382 * being deleted and store the value in the parent channel so we can
383 * access it from lttng list and at stop/destroy.
384 *
385 * The session list lock must be held by the caller.
386 */
387 static
388 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
389 {
390 uint64_t discarded = 0, lost = 0;
391 struct ltt_session *session;
392 struct ltt_ust_channel *uchan;
393
394 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
395 return;
396 }
397
398 rcu_read_lock();
399 session = session_find_by_id(ua_chan->session->tracing_id);
400 if (!session || !session->ust_session) {
401 /*
402 * Not finding the session is not an error because there are
403 * multiple ways the channels can be torn down.
404 *
405 * 1) The session daemon can initiate the destruction of the
406 * ust app session after receiving a destroy command or
407 * during its shutdown/teardown.
408 * 2) The application, since we are in per-pid tracing, is
409 * unregistering and tearing down its ust app session.
410 *
411 * Both paths are protected by the session list lock which
412 * ensures that the accounting of lost packets and discarded
413 * events is done exactly once. The session is then unpublished
414 * from the session list, resulting in this condition.
415 */
416 goto end;
417 }
418
419 if (ua_chan->attr.overwrite) {
420 consumer_get_lost_packets(ua_chan->session->tracing_id,
421 ua_chan->key, session->ust_session->consumer,
422 &lost);
423 } else {
424 consumer_get_discarded_events(ua_chan->session->tracing_id,
425 ua_chan->key, session->ust_session->consumer,
426 &discarded);
427 }
428 uchan = trace_ust_find_channel_by_name(
429 session->ust_session->domain_global.channels,
430 ua_chan->name);
431 if (!uchan) {
432 ERR("Missing UST channel to store discarded counters");
433 goto end;
434 }
435
436 uchan->per_pid_closed_app_discarded += discarded;
437 uchan->per_pid_closed_app_lost += lost;
438
439 end:
440 rcu_read_unlock();
441 if (session) {
442 session_put(session);
443 }
444 }
445
446 /*
447 * Delete ust app channel safely. RCU read lock must be held before calling
448 * this function.
449 *
450 * The session list lock must be held by the caller.
451 */
452 static
453 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
454 struct ust_app *app)
455 {
456 int ret;
457 struct lttng_ht_iter iter;
458 struct ust_app_event *ua_event;
459 struct ust_app_ctx *ua_ctx;
460 struct ust_app_stream *stream, *stmp;
461 struct ust_registry_session *registry;
462
463 assert(ua_chan);
464
465 DBG3("UST app deleting channel %s", ua_chan->name);
466
467 /* Wipe stream */
468 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
469 cds_list_del(&stream->list);
470 delete_ust_app_stream(sock, stream, app);
471 }
472
473 /* Wipe context */
474 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
475 cds_list_del(&ua_ctx->list);
476 ret = lttng_ht_del(ua_chan->ctx, &iter);
477 assert(!ret);
478 delete_ust_app_ctx(sock, ua_ctx, app);
479 }
480
481 /* Wipe events */
482 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
483 node.node) {
484 ret = lttng_ht_del(ua_chan->events, &iter);
485 assert(!ret);
486 delete_ust_app_event(sock, ua_event, app);
487 }
488
489 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
490 /* Wipe and free registry from session registry. */
491 registry = get_session_registry(ua_chan->session);
492 if (registry) {
493 ust_registry_channel_del_free(registry, ua_chan->key,
494 sock >= 0);
495 }
496 /*
497 * A negative socket can be used by the caller when
498 * cleaning-up a ua_chan in an error path. Skip the
499 * accounting in this case.
500 */
501 if (sock >= 0) {
502 save_per_pid_lost_discarded_counters(ua_chan);
503 }
504 }
505
506 if (ua_chan->obj != NULL) {
507 /* Remove channel from application UST object descriptor. */
508 iter.iter.node = &ua_chan->ust_objd_node.node;
509 ret = lttng_ht_del(app->ust_objd, &iter);
510 assert(!ret);
511 pthread_mutex_lock(&app->sock_lock);
512 ret = ustctl_release_object(sock, ua_chan->obj);
513 pthread_mutex_unlock(&app->sock_lock);
514 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
515 ERR("UST app sock %d release channel obj failed with ret %d",
516 sock, ret);
517 }
518 lttng_fd_put(LTTNG_FD_APPS, 1);
519 free(ua_chan->obj);
520 }
521 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
522 }
523
524 int ust_app_register_done(struct ust_app *app)
525 {
526 int ret;
527
528 pthread_mutex_lock(&app->sock_lock);
529 ret = ustctl_register_done(app->sock);
530 pthread_mutex_unlock(&app->sock_lock);
531 return ret;
532 }
533
534 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
535 {
536 int ret, sock;
537
538 if (app) {
539 pthread_mutex_lock(&app->sock_lock);
540 sock = app->sock;
541 } else {
542 sock = -1;
543 }
544 ret = ustctl_release_object(sock, data);
545 if (app) {
546 pthread_mutex_unlock(&app->sock_lock);
547 }
548 return ret;
549 }
550
551 /*
552 * Push metadata to consumer socket.
553 *
554 * RCU read-side lock must be held to guarantee existance of socket.
555 * Must be called with the ust app session lock held.
556 * Must be called with the registry lock held.
557 *
558 * On success, return the len of metadata pushed or else a negative value.
559 * Returning a -EPIPE return value means we could not send the metadata,
560 * but it can be caused by recoverable errors (e.g. the application has
561 * terminated concurrently).
562 */
563 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
564 struct consumer_socket *socket, int send_zero_data)
565 {
566 int ret;
567 char *metadata_str = NULL;
568 size_t len, offset, new_metadata_len_sent;
569 ssize_t ret_val;
570 uint64_t metadata_key, metadata_version;
571
572 assert(registry);
573 assert(socket);
574
575 metadata_key = registry->metadata_key;
576
577 /*
578 * Means that no metadata was assigned to the session. This can
579 * happens if no start has been done previously.
580 */
581 if (!metadata_key) {
582 return 0;
583 }
584
585 offset = registry->metadata_len_sent;
586 len = registry->metadata_len - registry->metadata_len_sent;
587 new_metadata_len_sent = registry->metadata_len;
588 metadata_version = registry->metadata_version;
589 if (len == 0) {
590 DBG3("No metadata to push for metadata key %" PRIu64,
591 registry->metadata_key);
592 ret_val = len;
593 if (send_zero_data) {
594 DBG("No metadata to push");
595 goto push_data;
596 }
597 goto end;
598 }
599
600 /* Allocate only what we have to send. */
601 metadata_str = zmalloc(len);
602 if (!metadata_str) {
603 PERROR("zmalloc ust app metadata string");
604 ret_val = -ENOMEM;
605 goto error;
606 }
607 /* Copy what we haven't sent out. */
608 memcpy(metadata_str, registry->metadata + offset, len);
609
610 push_data:
611 pthread_mutex_unlock(&registry->lock);
612 /*
613 * We need to unlock the registry while we push metadata to
614 * break a circular dependency between the consumerd metadata
615 * lock and the sessiond registry lock. Indeed, pushing metadata
616 * to the consumerd awaits that it gets pushed all the way to
617 * relayd, but doing so requires grabbing the metadata lock. If
618 * a concurrent metadata request is being performed by
619 * consumerd, this can try to grab the registry lock on the
620 * sessiond while holding the metadata lock on the consumer
621 * daemon. Those push and pull schemes are performed on two
622 * different bidirectionnal communication sockets.
623 */
624 ret = consumer_push_metadata(socket, metadata_key,
625 metadata_str, len, offset, metadata_version);
626 pthread_mutex_lock(&registry->lock);
627 if (ret < 0) {
628 /*
629 * There is an acceptable race here between the registry
630 * metadata key assignment and the creation on the
631 * consumer. The session daemon can concurrently push
632 * metadata for this registry while being created on the
633 * consumer since the metadata key of the registry is
634 * assigned *before* it is setup to avoid the consumer
635 * to ask for metadata that could possibly be not found
636 * in the session daemon.
637 *
638 * The metadata will get pushed either by the session
639 * being stopped or the consumer requesting metadata if
640 * that race is triggered.
641 */
642 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
643 ret = 0;
644 } else {
645 ERR("Error pushing metadata to consumer");
646 }
647 ret_val = ret;
648 goto error_push;
649 } else {
650 /*
651 * Metadata may have been concurrently pushed, since
652 * we're not holding the registry lock while pushing to
653 * consumer. This is handled by the fact that we send
654 * the metadata content, size, and the offset at which
655 * that metadata belongs. This may arrive out of order
656 * on the consumer side, and the consumer is able to
657 * deal with overlapping fragments. The consumer
658 * supports overlapping fragments, which must be
659 * contiguous starting from offset 0. We keep the
660 * largest metadata_len_sent value of the concurrent
661 * send.
662 */
663 registry->metadata_len_sent =
664 max_t(size_t, registry->metadata_len_sent,
665 new_metadata_len_sent);
666 }
667 free(metadata_str);
668 return len;
669
670 end:
671 error:
672 if (ret_val) {
673 /*
674 * On error, flag the registry that the metadata is
675 * closed. We were unable to push anything and this
676 * means that either the consumer is not responding or
677 * the metadata cache has been destroyed on the
678 * consumer.
679 */
680 registry->metadata_closed = 1;
681 }
682 error_push:
683 free(metadata_str);
684 return ret_val;
685 }
686
687 /*
688 * For a given application and session, push metadata to consumer.
689 * Either sock or consumer is required : if sock is NULL, the default
690 * socket to send the metadata is retrieved from consumer, if sock
691 * is not NULL we use it to send the metadata.
692 * RCU read-side lock must be held while calling this function,
693 * therefore ensuring existance of registry. It also ensures existance
694 * of socket throughout this function.
695 *
696 * Return 0 on success else a negative error.
697 * Returning a -EPIPE return value means we could not send the metadata,
698 * but it can be caused by recoverable errors (e.g. the application has
699 * terminated concurrently).
700 */
701 static int push_metadata(struct ust_registry_session *registry,
702 struct consumer_output *consumer)
703 {
704 int ret_val;
705 ssize_t ret;
706 struct consumer_socket *socket;
707
708 assert(registry);
709 assert(consumer);
710
711 pthread_mutex_lock(&registry->lock);
712 if (registry->metadata_closed) {
713 ret_val = -EPIPE;
714 goto error;
715 }
716
717 /* Get consumer socket to use to push the metadata.*/
718 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
719 consumer);
720 if (!socket) {
721 ret_val = -1;
722 goto error;
723 }
724
725 ret = ust_app_push_metadata(registry, socket, 0);
726 if (ret < 0) {
727 ret_val = ret;
728 goto error;
729 }
730 pthread_mutex_unlock(&registry->lock);
731 return 0;
732
733 error:
734 pthread_mutex_unlock(&registry->lock);
735 return ret_val;
736 }
737
738 /*
739 * Send to the consumer a close metadata command for the given session. Once
740 * done, the metadata channel is deleted and the session metadata pointer is
741 * nullified. The session lock MUST be held unless the application is
742 * in the destroy path.
743 *
744 * Do not hold the registry lock while communicating with the consumerd, because
745 * doing so causes inter-process deadlocks between consumerd and sessiond with
746 * the metadata request notification.
747 *
748 * Return 0 on success else a negative value.
749 */
750 static int close_metadata(struct ust_registry_session *registry,
751 struct consumer_output *consumer)
752 {
753 int ret;
754 struct consumer_socket *socket;
755 uint64_t metadata_key;
756 bool registry_was_already_closed;
757
758 assert(registry);
759 assert(consumer);
760
761 rcu_read_lock();
762
763 pthread_mutex_lock(&registry->lock);
764 metadata_key = registry->metadata_key;
765 registry_was_already_closed = registry->metadata_closed;
766 if (metadata_key != 0) {
767 /*
768 * Metadata closed. Even on error this means that the consumer
769 * is not responding or not found so either way a second close
770 * should NOT be emit for this registry.
771 */
772 registry->metadata_closed = 1;
773 }
774 pthread_mutex_unlock(&registry->lock);
775
776 if (metadata_key == 0 || registry_was_already_closed) {
777 ret = 0;
778 goto end;
779 }
780
781 /* Get consumer socket to use to push the metadata.*/
782 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
783 consumer);
784 if (!socket) {
785 ret = -1;
786 goto end;
787 }
788
789 ret = consumer_close_metadata(socket, metadata_key);
790 if (ret < 0) {
791 goto end;
792 }
793
794 end:
795 rcu_read_unlock();
796 return ret;
797 }
798
799 /*
800 * We need to execute ht_destroy outside of RCU read-side critical
801 * section and outside of call_rcu thread, so we postpone its execution
802 * using ht_cleanup_push. It is simpler than to change the semantic of
803 * the many callers of delete_ust_app_session().
804 */
805 static
806 void delete_ust_app_session_rcu(struct rcu_head *head)
807 {
808 struct ust_app_session *ua_sess =
809 caa_container_of(head, struct ust_app_session, rcu_head);
810
811 ht_cleanup_push(ua_sess->channels);
812 free(ua_sess);
813 }
814
815 /*
816 * Delete ust app session safely. RCU read lock must be held before calling
817 * this function.
818 *
819 * The session list lock must be held by the caller.
820 */
821 static
822 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
823 struct ust_app *app)
824 {
825 int ret;
826 struct lttng_ht_iter iter;
827 struct ust_app_channel *ua_chan;
828 struct ust_registry_session *registry;
829
830 assert(ua_sess);
831
832 pthread_mutex_lock(&ua_sess->lock);
833
834 assert(!ua_sess->deleted);
835 ua_sess->deleted = true;
836
837 registry = get_session_registry(ua_sess);
838 /* Registry can be null on error path during initialization. */
839 if (registry) {
840 /* Push metadata for application before freeing the application. */
841 (void) push_metadata(registry, ua_sess->consumer);
842
843 /*
844 * Don't ask to close metadata for global per UID buffers. Close
845 * metadata only on destroy trace session in this case. Also, the
846 * previous push metadata could have flag the metadata registry to
847 * close so don't send a close command if closed.
848 */
849 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
850 /* And ask to close it for this session registry. */
851 (void) close_metadata(registry, ua_sess->consumer);
852 }
853 }
854
855 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
856 node.node) {
857 ret = lttng_ht_del(ua_sess->channels, &iter);
858 assert(!ret);
859 delete_ust_app_channel(sock, ua_chan, app);
860 }
861
862 /* In case of per PID, the registry is kept in the session. */
863 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
864 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
865 if (reg_pid) {
866 /*
867 * Registry can be null on error path during
868 * initialization.
869 */
870 buffer_reg_pid_remove(reg_pid);
871 buffer_reg_pid_destroy(reg_pid);
872 }
873 }
874
875 if (ua_sess->handle != -1) {
876 pthread_mutex_lock(&app->sock_lock);
877 ret = ustctl_release_handle(sock, ua_sess->handle);
878 pthread_mutex_unlock(&app->sock_lock);
879 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
880 ERR("UST app sock %d release session handle failed with ret %d",
881 sock, ret);
882 }
883 /* Remove session from application UST object descriptor. */
884 iter.iter.node = &ua_sess->ust_objd_node.node;
885 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
886 assert(!ret);
887 }
888
889 pthread_mutex_unlock(&ua_sess->lock);
890
891 consumer_output_put(ua_sess->consumer);
892
893 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
894 }
895
896 /*
897 * Delete a traceable application structure from the global list. Never call
898 * this function outside of a call_rcu call.
899 *
900 * RCU read side lock should _NOT_ be held when calling this function.
901 */
902 static
903 void delete_ust_app(struct ust_app *app)
904 {
905 int ret, sock;
906 struct ust_app_session *ua_sess, *tmp_ua_sess;
907
908 /*
909 * The session list lock must be held during this function to guarantee
910 * the existence of ua_sess.
911 */
912 session_lock_list();
913 /* Delete ust app sessions info */
914 sock = app->sock;
915 app->sock = -1;
916
917 /* Wipe sessions */
918 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
919 teardown_node) {
920 /* Free every object in the session and the session. */
921 rcu_read_lock();
922 delete_ust_app_session(sock, ua_sess, app);
923 rcu_read_unlock();
924 }
925
926 ht_cleanup_push(app->sessions);
927 ht_cleanup_push(app->ust_sessions_objd);
928 ht_cleanup_push(app->ust_objd);
929
930 /*
931 * Wait until we have deleted the application from the sock hash table
932 * before closing this socket, otherwise an application could re-use the
933 * socket ID and race with the teardown, using the same hash table entry.
934 *
935 * It's OK to leave the close in call_rcu. We want it to stay unique for
936 * all RCU readers that could run concurrently with unregister app,
937 * therefore we _need_ to only close that socket after a grace period. So
938 * it should stay in this RCU callback.
939 *
940 * This close() is a very important step of the synchronization model so
941 * every modification to this function must be carefully reviewed.
942 */
943 ret = close(sock);
944 if (ret) {
945 PERROR("close");
946 }
947 lttng_fd_put(LTTNG_FD_APPS, 1);
948
949 DBG2("UST app pid %d deleted", app->pid);
950 free(app);
951 session_unlock_list();
952 }
953
954 /*
955 * URCU intermediate call to delete an UST app.
956 */
957 static
958 void delete_ust_app_rcu(struct rcu_head *head)
959 {
960 struct lttng_ht_node_ulong *node =
961 caa_container_of(head, struct lttng_ht_node_ulong, head);
962 struct ust_app *app =
963 caa_container_of(node, struct ust_app, pid_n);
964
965 DBG3("Call RCU deleting app PID %d", app->pid);
966 delete_ust_app(app);
967 }
968
969 /*
970 * Delete the session from the application ht and delete the data structure by
971 * freeing every object inside and releasing them.
972 *
973 * The session list lock must be held by the caller.
974 */
975 static void destroy_app_session(struct ust_app *app,
976 struct ust_app_session *ua_sess)
977 {
978 int ret;
979 struct lttng_ht_iter iter;
980
981 assert(app);
982 assert(ua_sess);
983
984 iter.iter.node = &ua_sess->node.node;
985 ret = lttng_ht_del(app->sessions, &iter);
986 if (ret) {
987 /* Already scheduled for teardown. */
988 goto end;
989 }
990
991 /* Once deleted, free the data structure. */
992 delete_ust_app_session(app->sock, ua_sess, app);
993
994 end:
995 return;
996 }
997
998 /*
999 * Alloc new UST app session.
1000 */
1001 static
1002 struct ust_app_session *alloc_ust_app_session(void)
1003 {
1004 struct ust_app_session *ua_sess;
1005
1006 /* Init most of the default value by allocating and zeroing */
1007 ua_sess = zmalloc(sizeof(struct ust_app_session));
1008 if (ua_sess == NULL) {
1009 PERROR("malloc");
1010 goto error_free;
1011 }
1012
1013 ua_sess->handle = -1;
1014 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1015 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1016 pthread_mutex_init(&ua_sess->lock, NULL);
1017
1018 return ua_sess;
1019
1020 error_free:
1021 return NULL;
1022 }
1023
1024 /*
1025 * Alloc new UST app channel.
1026 */
1027 static
1028 struct ust_app_channel *alloc_ust_app_channel(char *name,
1029 struct ust_app_session *ua_sess,
1030 struct lttng_ust_channel_attr *attr)
1031 {
1032 struct ust_app_channel *ua_chan;
1033
1034 /* Init most of the default value by allocating and zeroing */
1035 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1036 if (ua_chan == NULL) {
1037 PERROR("malloc");
1038 goto error;
1039 }
1040
1041 /* Setup channel name */
1042 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1043 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1044
1045 ua_chan->enabled = 1;
1046 ua_chan->handle = -1;
1047 ua_chan->session = ua_sess;
1048 ua_chan->key = get_next_channel_key();
1049 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1050 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1051 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1052
1053 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1054 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1055
1056 /* Copy attributes */
1057 if (attr) {
1058 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1059 ua_chan->attr.subbuf_size = attr->subbuf_size;
1060 ua_chan->attr.num_subbuf = attr->num_subbuf;
1061 ua_chan->attr.overwrite = attr->overwrite;
1062 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1063 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1064 ua_chan->attr.output = attr->output;
1065 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1066 }
1067 /* By default, the channel is a per cpu channel. */
1068 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1069
1070 DBG3("UST app channel %s allocated", ua_chan->name);
1071
1072 return ua_chan;
1073
1074 error:
1075 return NULL;
1076 }
1077
1078 /*
1079 * Allocate and initialize a UST app stream.
1080 *
1081 * Return newly allocated stream pointer or NULL on error.
1082 */
1083 struct ust_app_stream *ust_app_alloc_stream(void)
1084 {
1085 struct ust_app_stream *stream = NULL;
1086
1087 stream = zmalloc(sizeof(*stream));
1088 if (stream == NULL) {
1089 PERROR("zmalloc ust app stream");
1090 goto error;
1091 }
1092
1093 /* Zero could be a valid value for a handle so flag it to -1. */
1094 stream->handle = -1;
1095
1096 error:
1097 return stream;
1098 }
1099
1100 /*
1101 * Alloc new UST app event.
1102 */
1103 static
1104 struct ust_app_event *alloc_ust_app_event(char *name,
1105 struct lttng_ust_event *attr)
1106 {
1107 struct ust_app_event *ua_event;
1108
1109 /* Init most of the default value by allocating and zeroing */
1110 ua_event = zmalloc(sizeof(struct ust_app_event));
1111 if (ua_event == NULL) {
1112 PERROR("Failed to allocate ust_app_event structure");
1113 goto error;
1114 }
1115
1116 ua_event->enabled = 1;
1117 strncpy(ua_event->name, name, sizeof(ua_event->name));
1118 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1119 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1120
1121 /* Copy attributes */
1122 if (attr) {
1123 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1124 }
1125
1126 DBG3("UST app event %s allocated", ua_event->name);
1127
1128 return ua_event;
1129
1130 error:
1131 return NULL;
1132 }
1133
1134 /*
1135 * Alloc new UST app context.
1136 */
1137 static
1138 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1139 {
1140 struct ust_app_ctx *ua_ctx;
1141
1142 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1143 if (ua_ctx == NULL) {
1144 goto error;
1145 }
1146
1147 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1148
1149 if (uctx) {
1150 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1151 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1152 char *provider_name = NULL, *ctx_name = NULL;
1153
1154 provider_name = strdup(uctx->u.app_ctx.provider_name);
1155 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1156 if (!provider_name || !ctx_name) {
1157 free(provider_name);
1158 free(ctx_name);
1159 goto error;
1160 }
1161
1162 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1163 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1164 }
1165 }
1166
1167 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1168 return ua_ctx;
1169 error:
1170 free(ua_ctx);
1171 return NULL;
1172 }
1173
1174 /*
1175 * Allocate a filter and copy the given original filter.
1176 *
1177 * Return allocated filter or NULL on error.
1178 */
1179 static struct lttng_filter_bytecode *copy_filter_bytecode(
1180 struct lttng_filter_bytecode *orig_f)
1181 {
1182 struct lttng_filter_bytecode *filter = NULL;
1183
1184 /* Copy filter bytecode */
1185 filter = zmalloc(sizeof(*filter) + orig_f->len);
1186 if (!filter) {
1187 PERROR("zmalloc alloc filter bytecode");
1188 goto error;
1189 }
1190
1191 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1192
1193 error:
1194 return filter;
1195 }
1196
1197 /*
1198 * Create a liblttng-ust filter bytecode from given bytecode.
1199 *
1200 * Return allocated filter or NULL on error.
1201 */
1202 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1203 struct lttng_filter_bytecode *orig_f)
1204 {
1205 struct lttng_ust_filter_bytecode *filter = NULL;
1206
1207 /* Copy filter bytecode */
1208 filter = zmalloc(sizeof(*filter) + orig_f->len);
1209 if (!filter) {
1210 PERROR("zmalloc alloc ust filter bytecode");
1211 goto error;
1212 }
1213
1214 assert(sizeof(struct lttng_filter_bytecode) ==
1215 sizeof(struct lttng_ust_filter_bytecode));
1216 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1217 error:
1218 return filter;
1219 }
1220
1221 /*
1222 * Find an ust_app using the sock and return it. RCU read side lock must be
1223 * held before calling this helper function.
1224 */
1225 struct ust_app *ust_app_find_by_sock(int sock)
1226 {
1227 struct lttng_ht_node_ulong *node;
1228 struct lttng_ht_iter iter;
1229
1230 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1231 node = lttng_ht_iter_get_node_ulong(&iter);
1232 if (node == NULL) {
1233 DBG2("UST app find by sock %d not found", sock);
1234 goto error;
1235 }
1236
1237 return caa_container_of(node, struct ust_app, sock_n);
1238
1239 error:
1240 return NULL;
1241 }
1242
1243 /*
1244 * Find an ust_app using the notify sock and return it. RCU read side lock must
1245 * be held before calling this helper function.
1246 */
1247 static struct ust_app *find_app_by_notify_sock(int sock)
1248 {
1249 struct lttng_ht_node_ulong *node;
1250 struct lttng_ht_iter iter;
1251
1252 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1253 &iter);
1254 node = lttng_ht_iter_get_node_ulong(&iter);
1255 if (node == NULL) {
1256 DBG2("UST app find by notify sock %d not found", sock);
1257 goto error;
1258 }
1259
1260 return caa_container_of(node, struct ust_app, notify_sock_n);
1261
1262 error:
1263 return NULL;
1264 }
1265
1266 /*
1267 * Lookup for an ust app event based on event name, filter bytecode and the
1268 * event loglevel.
1269 *
1270 * Return an ust_app_event object or NULL on error.
1271 */
1272 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1273 const char *name, const struct lttng_filter_bytecode *filter,
1274 int loglevel_value,
1275 const struct lttng_event_exclusion *exclusion)
1276 {
1277 struct lttng_ht_iter iter;
1278 struct lttng_ht_node_str *node;
1279 struct ust_app_event *event = NULL;
1280 struct ust_app_ht_key key;
1281
1282 assert(name);
1283 assert(ht);
1284
1285 /* Setup key for event lookup. */
1286 key.name = name;
1287 key.filter = filter;
1288 key.loglevel_type = loglevel_value;
1289 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1290 key.exclusion = exclusion;
1291
1292 /* Lookup using the event name as hash and a custom match fct. */
1293 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1294 ht_match_ust_app_event, &key, &iter.iter);
1295 node = lttng_ht_iter_get_node_str(&iter);
1296 if (node == NULL) {
1297 goto end;
1298 }
1299
1300 event = caa_container_of(node, struct ust_app_event, node);
1301
1302 end:
1303 return event;
1304 }
1305
1306 /*
1307 * Create the channel context on the tracer.
1308 *
1309 * Called with UST app session lock held.
1310 */
1311 static
1312 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1313 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1314 {
1315 int ret;
1316
1317 health_code_update();
1318
1319 pthread_mutex_lock(&app->sock_lock);
1320 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1321 ua_chan->obj, &ua_ctx->obj);
1322 pthread_mutex_unlock(&app->sock_lock);
1323 if (ret < 0) {
1324 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1325 ERR("UST app create channel context failed for app (pid: %d) "
1326 "with ret %d", app->pid, ret);
1327 } else {
1328 /*
1329 * This is normal behavior, an application can die during the
1330 * creation process. Don't report an error so the execution can
1331 * continue normally.
1332 */
1333 ret = 0;
1334 DBG3("UST app add context failed. Application is dead.");
1335 }
1336 goto error;
1337 }
1338
1339 ua_ctx->handle = ua_ctx->obj->handle;
1340
1341 DBG2("UST app context handle %d created successfully for channel %s",
1342 ua_ctx->handle, ua_chan->name);
1343
1344 error:
1345 health_code_update();
1346 return ret;
1347 }
1348
1349 /*
1350 * Set the filter on the tracer.
1351 */
1352 static
1353 int set_ust_event_filter(struct ust_app_event *ua_event,
1354 struct ust_app *app)
1355 {
1356 int ret;
1357 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1358
1359 health_code_update();
1360
1361 if (!ua_event->filter) {
1362 ret = 0;
1363 goto error;
1364 }
1365
1366 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1367 if (!ust_bytecode) {
1368 ret = -LTTNG_ERR_NOMEM;
1369 goto error;
1370 }
1371 pthread_mutex_lock(&app->sock_lock);
1372 ret = ustctl_set_filter(app->sock, ust_bytecode,
1373 ua_event->obj);
1374 pthread_mutex_unlock(&app->sock_lock);
1375 if (ret < 0) {
1376 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1377 ERR("UST app event %s filter failed for app (pid: %d) "
1378 "with ret %d", ua_event->attr.name, app->pid, ret);
1379 } else {
1380 /*
1381 * This is normal behavior, an application can die during the
1382 * creation process. Don't report an error so the execution can
1383 * continue normally.
1384 */
1385 ret = 0;
1386 DBG3("UST app filter event failed. Application is dead.");
1387 }
1388 goto error;
1389 }
1390
1391 DBG2("UST filter set successfully for event %s", ua_event->name);
1392
1393 error:
1394 health_code_update();
1395 free(ust_bytecode);
1396 return ret;
1397 }
1398
1399 static
1400 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1401 struct lttng_event_exclusion *exclusion)
1402 {
1403 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1404 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1405 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1406
1407 ust_exclusion = zmalloc(exclusion_alloc_size);
1408 if (!ust_exclusion) {
1409 PERROR("malloc");
1410 goto end;
1411 }
1412
1413 assert(sizeof(struct lttng_event_exclusion) ==
1414 sizeof(struct lttng_ust_event_exclusion));
1415 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1416 end:
1417 return ust_exclusion;
1418 }
1419
1420 /*
1421 * Set event exclusions on the tracer.
1422 */
1423 static
1424 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1425 struct ust_app *app)
1426 {
1427 int ret;
1428 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1429
1430 health_code_update();
1431
1432 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1433 ret = 0;
1434 goto error;
1435 }
1436
1437 ust_exclusion = create_ust_exclusion_from_exclusion(
1438 ua_event->exclusion);
1439 if (!ust_exclusion) {
1440 ret = -LTTNG_ERR_NOMEM;
1441 goto error;
1442 }
1443 pthread_mutex_lock(&app->sock_lock);
1444 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1445 pthread_mutex_unlock(&app->sock_lock);
1446 if (ret < 0) {
1447 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1448 ERR("UST app event %s exclusions failed for app (pid: %d) "
1449 "with ret %d", ua_event->attr.name, app->pid, ret);
1450 } else {
1451 /*
1452 * This is normal behavior, an application can die during the
1453 * creation process. Don't report an error so the execution can
1454 * continue normally.
1455 */
1456 ret = 0;
1457 DBG3("UST app event exclusion failed. Application is dead.");
1458 }
1459 goto error;
1460 }
1461
1462 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1463
1464 error:
1465 health_code_update();
1466 free(ust_exclusion);
1467 return ret;
1468 }
1469
1470 /*
1471 * Disable the specified event on to UST tracer for the UST session.
1472 */
1473 static int disable_ust_event(struct ust_app *app,
1474 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1475 {
1476 int ret;
1477
1478 health_code_update();
1479
1480 pthread_mutex_lock(&app->sock_lock);
1481 ret = ustctl_disable(app->sock, ua_event->obj);
1482 pthread_mutex_unlock(&app->sock_lock);
1483 if (ret < 0) {
1484 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1485 ERR("UST app event %s disable failed for app (pid: %d) "
1486 "and session handle %d with ret %d",
1487 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1488 } else {
1489 /*
1490 * This is normal behavior, an application can die during the
1491 * creation process. Don't report an error so the execution can
1492 * continue normally.
1493 */
1494 ret = 0;
1495 DBG3("UST app disable event failed. Application is dead.");
1496 }
1497 goto error;
1498 }
1499
1500 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1501 ua_event->attr.name, app->pid);
1502
1503 error:
1504 health_code_update();
1505 return ret;
1506 }
1507
1508 /*
1509 * Disable the specified channel on to UST tracer for the UST session.
1510 */
1511 static int disable_ust_channel(struct ust_app *app,
1512 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1513 {
1514 int ret;
1515
1516 health_code_update();
1517
1518 pthread_mutex_lock(&app->sock_lock);
1519 ret = ustctl_disable(app->sock, ua_chan->obj);
1520 pthread_mutex_unlock(&app->sock_lock);
1521 if (ret < 0) {
1522 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1523 ERR("UST app channel %s disable failed for app (pid: %d) "
1524 "and session handle %d with ret %d",
1525 ua_chan->name, app->pid, ua_sess->handle, ret);
1526 } else {
1527 /*
1528 * This is normal behavior, an application can die during the
1529 * creation process. Don't report an error so the execution can
1530 * continue normally.
1531 */
1532 ret = 0;
1533 DBG3("UST app disable channel failed. Application is dead.");
1534 }
1535 goto error;
1536 }
1537
1538 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1539 ua_chan->name, app->pid);
1540
1541 error:
1542 health_code_update();
1543 return ret;
1544 }
1545
1546 /*
1547 * Enable the specified channel on to UST tracer for the UST session.
1548 */
1549 static int enable_ust_channel(struct ust_app *app,
1550 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1551 {
1552 int ret;
1553
1554 health_code_update();
1555
1556 pthread_mutex_lock(&app->sock_lock);
1557 ret = ustctl_enable(app->sock, ua_chan->obj);
1558 pthread_mutex_unlock(&app->sock_lock);
1559 if (ret < 0) {
1560 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1561 ERR("UST app channel %s enable failed for app (pid: %d) "
1562 "and session handle %d with ret %d",
1563 ua_chan->name, app->pid, ua_sess->handle, ret);
1564 } else {
1565 /*
1566 * This is normal behavior, an application can die during the
1567 * creation process. Don't report an error so the execution can
1568 * continue normally.
1569 */
1570 ret = 0;
1571 DBG3("UST app enable channel failed. Application is dead.");
1572 }
1573 goto error;
1574 }
1575
1576 ua_chan->enabled = 1;
1577
1578 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1579 ua_chan->name, app->pid);
1580
1581 error:
1582 health_code_update();
1583 return ret;
1584 }
1585
1586 /*
1587 * Enable the specified event on to UST tracer for the UST session.
1588 */
1589 static int enable_ust_event(struct ust_app *app,
1590 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1591 {
1592 int ret;
1593
1594 health_code_update();
1595
1596 pthread_mutex_lock(&app->sock_lock);
1597 ret = ustctl_enable(app->sock, ua_event->obj);
1598 pthread_mutex_unlock(&app->sock_lock);
1599 if (ret < 0) {
1600 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1601 ERR("UST app event %s enable failed for app (pid: %d) "
1602 "and session handle %d with ret %d",
1603 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1604 } else {
1605 /*
1606 * This is normal behavior, an application can die during the
1607 * creation process. Don't report an error so the execution can
1608 * continue normally.
1609 */
1610 ret = 0;
1611 DBG3("UST app enable event failed. Application is dead.");
1612 }
1613 goto error;
1614 }
1615
1616 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1617 ua_event->attr.name, app->pid);
1618
1619 error:
1620 health_code_update();
1621 return ret;
1622 }
1623
1624 /*
1625 * Send channel and stream buffer to application.
1626 *
1627 * Return 0 on success. On error, a negative value is returned.
1628 */
1629 static int send_channel_pid_to_ust(struct ust_app *app,
1630 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1631 {
1632 int ret;
1633 struct ust_app_stream *stream, *stmp;
1634
1635 assert(app);
1636 assert(ua_sess);
1637 assert(ua_chan);
1638
1639 health_code_update();
1640
1641 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1642 app->sock);
1643
1644 /* Send channel to the application. */
1645 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1646 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1647 ret = -ENOTCONN; /* Caused by app exiting. */
1648 goto error;
1649 } else if (ret < 0) {
1650 goto error;
1651 }
1652
1653 health_code_update();
1654
1655 /* Send all streams to application. */
1656 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1657 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1658 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1659 ret = -ENOTCONN; /* Caused by app exiting. */
1660 goto error;
1661 } else if (ret < 0) {
1662 goto error;
1663 }
1664 /* We don't need the stream anymore once sent to the tracer. */
1665 cds_list_del(&stream->list);
1666 delete_ust_app_stream(-1, stream, app);
1667 }
1668 /* Flag the channel that it is sent to the application. */
1669 ua_chan->is_sent = 1;
1670
1671 error:
1672 health_code_update();
1673 return ret;
1674 }
1675
1676 /*
1677 * Create the specified event onto the UST tracer for a UST session.
1678 *
1679 * Should be called with session mutex held.
1680 */
1681 static
1682 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1683 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1684 {
1685 int ret = 0;
1686
1687 health_code_update();
1688
1689 /* Create UST event on tracer */
1690 pthread_mutex_lock(&app->sock_lock);
1691 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1692 &ua_event->obj);
1693 pthread_mutex_unlock(&app->sock_lock);
1694 if (ret < 0) {
1695 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1696 abort();
1697 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1698 ua_event->attr.name, app->pid, ret);
1699 } else {
1700 /*
1701 * This is normal behavior, an application can die during the
1702 * creation process. Don't report an error so the execution can
1703 * continue normally.
1704 */
1705 ret = 0;
1706 DBG3("UST app create event failed. Application is dead.");
1707 }
1708 goto error;
1709 }
1710
1711 ua_event->handle = ua_event->obj->handle;
1712
1713 DBG2("UST app event %s created successfully for pid:%d",
1714 ua_event->attr.name, app->pid);
1715
1716 health_code_update();
1717
1718 /* Set filter if one is present. */
1719 if (ua_event->filter) {
1720 ret = set_ust_event_filter(ua_event, app);
1721 if (ret < 0) {
1722 goto error;
1723 }
1724 }
1725
1726 /* Set exclusions for the event */
1727 if (ua_event->exclusion) {
1728 ret = set_ust_event_exclusion(ua_event, app);
1729 if (ret < 0) {
1730 goto error;
1731 }
1732 }
1733
1734 /* If event not enabled, disable it on the tracer */
1735 if (ua_event->enabled) {
1736 /*
1737 * We now need to explicitly enable the event, since it
1738 * is now disabled at creation.
1739 */
1740 ret = enable_ust_event(app, ua_sess, ua_event);
1741 if (ret < 0) {
1742 /*
1743 * If we hit an EPERM, something is wrong with our enable call. If
1744 * we get an EEXIST, there is a problem on the tracer side since we
1745 * just created it.
1746 */
1747 switch (ret) {
1748 case -LTTNG_UST_ERR_PERM:
1749 /* Code flow problem */
1750 assert(0);
1751 case -LTTNG_UST_ERR_EXIST:
1752 /* It's OK for our use case. */
1753 ret = 0;
1754 break;
1755 default:
1756 break;
1757 }
1758 goto error;
1759 }
1760 }
1761
1762 error:
1763 health_code_update();
1764 return ret;
1765 }
1766
1767 /*
1768 * Copy data between an UST app event and a LTT event.
1769 */
1770 static void shadow_copy_event(struct ust_app_event *ua_event,
1771 struct ltt_ust_event *uevent)
1772 {
1773 size_t exclusion_alloc_size;
1774
1775 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1776 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1777
1778 ua_event->enabled = uevent->enabled;
1779
1780 /* Copy event attributes */
1781 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1782
1783 /* Copy filter bytecode */
1784 if (uevent->filter) {
1785 ua_event->filter = copy_filter_bytecode(uevent->filter);
1786 /* Filter might be NULL here in case of ENONEM. */
1787 }
1788
1789 /* Copy exclusion data */
1790 if (uevent->exclusion) {
1791 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1792 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1793 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1794 if (ua_event->exclusion == NULL) {
1795 PERROR("malloc");
1796 } else {
1797 memcpy(ua_event->exclusion, uevent->exclusion,
1798 exclusion_alloc_size);
1799 }
1800 }
1801 }
1802
1803 /*
1804 * Copy data between an UST app channel and a LTT channel.
1805 */
1806 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1807 struct ltt_ust_channel *uchan)
1808 {
1809 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1810
1811 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1812 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1813
1814 ua_chan->tracefile_size = uchan->tracefile_size;
1815 ua_chan->tracefile_count = uchan->tracefile_count;
1816
1817 /* Copy event attributes since the layout is different. */
1818 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1819 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1820 ua_chan->attr.overwrite = uchan->attr.overwrite;
1821 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1822 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1823 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1824 ua_chan->attr.output = uchan->attr.output;
1825 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1826
1827 /*
1828 * Note that the attribute channel type is not set since the channel on the
1829 * tracing registry side does not have this information.
1830 */
1831
1832 ua_chan->enabled = uchan->enabled;
1833 ua_chan->tracing_channel_id = uchan->id;
1834
1835 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1836 }
1837
1838 /*
1839 * Copy data between a UST app session and a regular LTT session.
1840 */
1841 static void shadow_copy_session(struct ust_app_session *ua_sess,
1842 struct ltt_ust_session *usess, struct ust_app *app)
1843 {
1844 struct tm *timeinfo;
1845 char datetime[16];
1846 int ret;
1847 char tmp_shm_path[PATH_MAX];
1848
1849 timeinfo = localtime(&app->registration_time);
1850 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1851
1852 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1853
1854 ua_sess->tracing_id = usess->id;
1855 ua_sess->id = get_next_session_id();
1856 ua_sess->real_credentials.uid = app->uid;
1857 ua_sess->real_credentials.gid = app->gid;
1858 ua_sess->effective_credentials.uid = usess->uid;
1859 ua_sess->effective_credentials.gid = usess->gid;
1860 ua_sess->buffer_type = usess->buffer_type;
1861 ua_sess->bits_per_long = app->bits_per_long;
1862
1863 /* There is only one consumer object per session possible. */
1864 consumer_output_get(usess->consumer);
1865 ua_sess->consumer = usess->consumer;
1866
1867 ua_sess->output_traces = usess->output_traces;
1868 ua_sess->live_timer_interval = usess->live_timer_interval;
1869 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1870 &usess->metadata_attr);
1871
1872 switch (ua_sess->buffer_type) {
1873 case LTTNG_BUFFER_PER_PID:
1874 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1875 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1876 datetime);
1877 break;
1878 case LTTNG_BUFFER_PER_UID:
1879 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1880 DEFAULT_UST_TRACE_UID_PATH,
1881 ua_sess->real_credentials.uid,
1882 app->bits_per_long);
1883 break;
1884 default:
1885 assert(0);
1886 goto error;
1887 }
1888 if (ret < 0) {
1889 PERROR("asprintf UST shadow copy session");
1890 assert(0);
1891 goto error;
1892 }
1893
1894 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1895 sizeof(ua_sess->root_shm_path));
1896 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1897 strncpy(ua_sess->shm_path, usess->shm_path,
1898 sizeof(ua_sess->shm_path));
1899 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1900 if (ua_sess->shm_path[0]) {
1901 switch (ua_sess->buffer_type) {
1902 case LTTNG_BUFFER_PER_PID:
1903 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1904 "/" DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1905 app->name, app->pid, datetime);
1906 break;
1907 case LTTNG_BUFFER_PER_UID:
1908 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1909 "/" DEFAULT_UST_TRACE_UID_PATH,
1910 app->uid, app->bits_per_long);
1911 break;
1912 default:
1913 assert(0);
1914 goto error;
1915 }
1916 if (ret < 0) {
1917 PERROR("sprintf UST shadow copy session");
1918 assert(0);
1919 goto error;
1920 }
1921 strncat(ua_sess->shm_path, tmp_shm_path,
1922 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1923 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1924 }
1925 return;
1926
1927 error:
1928 consumer_output_put(ua_sess->consumer);
1929 }
1930
1931 /*
1932 * Lookup sesison wrapper.
1933 */
1934 static
1935 void __lookup_session_by_app(const struct ltt_ust_session *usess,
1936 struct ust_app *app, struct lttng_ht_iter *iter)
1937 {
1938 /* Get right UST app session from app */
1939 lttng_ht_lookup(app->sessions, &usess->id, iter);
1940 }
1941
1942 /*
1943 * Return ust app session from the app session hashtable using the UST session
1944 * id.
1945 */
1946 static struct ust_app_session *lookup_session_by_app(
1947 const struct ltt_ust_session *usess, struct ust_app *app)
1948 {
1949 struct lttng_ht_iter iter;
1950 struct lttng_ht_node_u64 *node;
1951
1952 __lookup_session_by_app(usess, app, &iter);
1953 node = lttng_ht_iter_get_node_u64(&iter);
1954 if (node == NULL) {
1955 goto error;
1956 }
1957
1958 return caa_container_of(node, struct ust_app_session, node);
1959
1960 error:
1961 return NULL;
1962 }
1963
1964 /*
1965 * Setup buffer registry per PID for the given session and application. If none
1966 * is found, a new one is created, added to the global registry and
1967 * initialized. If regp is valid, it's set with the newly created object.
1968 *
1969 * Return 0 on success or else a negative value.
1970 */
1971 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1972 struct ust_app *app, struct buffer_reg_pid **regp)
1973 {
1974 int ret = 0;
1975 struct buffer_reg_pid *reg_pid;
1976
1977 assert(ua_sess);
1978 assert(app);
1979
1980 rcu_read_lock();
1981
1982 reg_pid = buffer_reg_pid_find(ua_sess->id);
1983 if (!reg_pid) {
1984 /*
1985 * This is the create channel path meaning that if there is NO
1986 * registry available, we have to create one for this session.
1987 */
1988 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1989 ua_sess->root_shm_path, ua_sess->shm_path);
1990 if (ret < 0) {
1991 goto error;
1992 }
1993 } else {
1994 goto end;
1995 }
1996
1997 /* Initialize registry. */
1998 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1999 app->bits_per_long, app->uint8_t_alignment,
2000 app->uint16_t_alignment, app->uint32_t_alignment,
2001 app->uint64_t_alignment, app->long_alignment,
2002 app->byte_order, app->version.major, app->version.minor,
2003 reg_pid->root_shm_path, reg_pid->shm_path,
2004 ua_sess->effective_credentials.uid,
2005 ua_sess->effective_credentials.gid, ua_sess->tracing_id,
2006 app->uid);
2007 if (ret < 0) {
2008 /*
2009 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2010 * destroy the buffer registry, because it is always expected
2011 * that if the buffer registry can be found, its ust registry is
2012 * non-NULL.
2013 */
2014 buffer_reg_pid_destroy(reg_pid);
2015 goto error;
2016 }
2017
2018 buffer_reg_pid_add(reg_pid);
2019
2020 DBG3("UST app buffer registry per PID created successfully");
2021
2022 end:
2023 if (regp) {
2024 *regp = reg_pid;
2025 }
2026 error:
2027 rcu_read_unlock();
2028 return ret;
2029 }
2030
2031 /*
2032 * Setup buffer registry per UID for the given session and application. If none
2033 * is found, a new one is created, added to the global registry and
2034 * initialized. If regp is valid, it's set with the newly created object.
2035 *
2036 * Return 0 on success or else a negative value.
2037 */
2038 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2039 struct ust_app_session *ua_sess,
2040 struct ust_app *app, struct buffer_reg_uid **regp)
2041 {
2042 int ret = 0;
2043 struct buffer_reg_uid *reg_uid;
2044
2045 assert(usess);
2046 assert(app);
2047
2048 rcu_read_lock();
2049
2050 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2051 if (!reg_uid) {
2052 /*
2053 * This is the create channel path meaning that if there is NO
2054 * registry available, we have to create one for this session.
2055 */
2056 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2057 LTTNG_DOMAIN_UST, &reg_uid,
2058 ua_sess->root_shm_path, ua_sess->shm_path);
2059 if (ret < 0) {
2060 goto error;
2061 }
2062 } else {
2063 goto end;
2064 }
2065
2066 /* Initialize registry. */
2067 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2068 app->bits_per_long, app->uint8_t_alignment,
2069 app->uint16_t_alignment, app->uint32_t_alignment,
2070 app->uint64_t_alignment, app->long_alignment,
2071 app->byte_order, app->version.major,
2072 app->version.minor, reg_uid->root_shm_path,
2073 reg_uid->shm_path, usess->uid, usess->gid,
2074 ua_sess->tracing_id, app->uid);
2075 if (ret < 0) {
2076 /*
2077 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2078 * destroy the buffer registry, because it is always expected
2079 * that if the buffer registry can be found, its ust registry is
2080 * non-NULL.
2081 */
2082 buffer_reg_uid_destroy(reg_uid, NULL);
2083 goto error;
2084 }
2085 /* Add node to teardown list of the session. */
2086 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2087
2088 buffer_reg_uid_add(reg_uid);
2089
2090 DBG3("UST app buffer registry per UID created successfully");
2091 end:
2092 if (regp) {
2093 *regp = reg_uid;
2094 }
2095 error:
2096 rcu_read_unlock();
2097 return ret;
2098 }
2099
2100 /*
2101 * Create a session on the tracer side for the given app.
2102 *
2103 * On success, ua_sess_ptr is populated with the session pointer or else left
2104 * untouched. If the session was created, is_created is set to 1. On error,
2105 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2106 * be NULL.
2107 *
2108 * Returns 0 on success or else a negative code which is either -ENOMEM or
2109 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2110 */
2111 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2112 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2113 int *is_created)
2114 {
2115 int ret, created = 0;
2116 struct ust_app_session *ua_sess;
2117
2118 assert(usess);
2119 assert(app);
2120 assert(ua_sess_ptr);
2121
2122 health_code_update();
2123
2124 ua_sess = lookup_session_by_app(usess, app);
2125 if (ua_sess == NULL) {
2126 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2127 app->pid, usess->id);
2128 ua_sess = alloc_ust_app_session();
2129 if (ua_sess == NULL) {
2130 /* Only malloc can failed so something is really wrong */
2131 ret = -ENOMEM;
2132 goto error;
2133 }
2134 shadow_copy_session(ua_sess, usess, app);
2135 created = 1;
2136 }
2137
2138 switch (usess->buffer_type) {
2139 case LTTNG_BUFFER_PER_PID:
2140 /* Init local registry. */
2141 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2142 if (ret < 0) {
2143 delete_ust_app_session(-1, ua_sess, app);
2144 goto error;
2145 }
2146 break;
2147 case LTTNG_BUFFER_PER_UID:
2148 /* Look for a global registry. If none exists, create one. */
2149 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2150 if (ret < 0) {
2151 delete_ust_app_session(-1, ua_sess, app);
2152 goto error;
2153 }
2154 break;
2155 default:
2156 assert(0);
2157 ret = -EINVAL;
2158 goto error;
2159 }
2160
2161 health_code_update();
2162
2163 if (ua_sess->handle == -1) {
2164 pthread_mutex_lock(&app->sock_lock);
2165 ret = ustctl_create_session(app->sock);
2166 pthread_mutex_unlock(&app->sock_lock);
2167 if (ret < 0) {
2168 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2169 ERR("Creating session for app pid %d with ret %d",
2170 app->pid, ret);
2171 } else {
2172 DBG("UST app creating session failed. Application is dead");
2173 /*
2174 * This is normal behavior, an application can die during the
2175 * creation process. Don't report an error so the execution can
2176 * continue normally. This will get flagged ENOTCONN and the
2177 * caller will handle it.
2178 */
2179 ret = 0;
2180 }
2181 delete_ust_app_session(-1, ua_sess, app);
2182 if (ret != -ENOMEM) {
2183 /*
2184 * Tracer is probably gone or got an internal error so let's
2185 * behave like it will soon unregister or not usable.
2186 */
2187 ret = -ENOTCONN;
2188 }
2189 goto error;
2190 }
2191
2192 ua_sess->handle = ret;
2193
2194 /* Add ust app session to app's HT */
2195 lttng_ht_node_init_u64(&ua_sess->node,
2196 ua_sess->tracing_id);
2197 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2198 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2199 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2200 &ua_sess->ust_objd_node);
2201
2202 DBG2("UST app session created successfully with handle %d", ret);
2203 }
2204
2205 *ua_sess_ptr = ua_sess;
2206 if (is_created) {
2207 *is_created = created;
2208 }
2209
2210 /* Everything went well. */
2211 ret = 0;
2212
2213 error:
2214 health_code_update();
2215 return ret;
2216 }
2217
2218 /*
2219 * Match function for a hash table lookup of ust_app_ctx.
2220 *
2221 * It matches an ust app context based on the context type and, in the case
2222 * of perf counters, their name.
2223 */
2224 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2225 {
2226 struct ust_app_ctx *ctx;
2227 const struct lttng_ust_context_attr *key;
2228
2229 assert(node);
2230 assert(_key);
2231
2232 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2233 key = _key;
2234
2235 /* Context type */
2236 if (ctx->ctx.ctx != key->ctx) {
2237 goto no_match;
2238 }
2239
2240 switch(key->ctx) {
2241 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2242 if (strncmp(key->u.perf_counter.name,
2243 ctx->ctx.u.perf_counter.name,
2244 sizeof(key->u.perf_counter.name))) {
2245 goto no_match;
2246 }
2247 break;
2248 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2249 if (strcmp(key->u.app_ctx.provider_name,
2250 ctx->ctx.u.app_ctx.provider_name) ||
2251 strcmp(key->u.app_ctx.ctx_name,
2252 ctx->ctx.u.app_ctx.ctx_name)) {
2253 goto no_match;
2254 }
2255 break;
2256 default:
2257 break;
2258 }
2259
2260 /* Match. */
2261 return 1;
2262
2263 no_match:
2264 return 0;
2265 }
2266
2267 /*
2268 * Lookup for an ust app context from an lttng_ust_context.
2269 *
2270 * Must be called while holding RCU read side lock.
2271 * Return an ust_app_ctx object or NULL on error.
2272 */
2273 static
2274 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2275 struct lttng_ust_context_attr *uctx)
2276 {
2277 struct lttng_ht_iter iter;
2278 struct lttng_ht_node_ulong *node;
2279 struct ust_app_ctx *app_ctx = NULL;
2280
2281 assert(uctx);
2282 assert(ht);
2283
2284 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2285 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2286 ht_match_ust_app_ctx, uctx, &iter.iter);
2287 node = lttng_ht_iter_get_node_ulong(&iter);
2288 if (!node) {
2289 goto end;
2290 }
2291
2292 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2293
2294 end:
2295 return app_ctx;
2296 }
2297
2298 /*
2299 * Create a context for the channel on the tracer.
2300 *
2301 * Called with UST app session lock held and a RCU read side lock.
2302 */
2303 static
2304 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2305 struct lttng_ust_context_attr *uctx,
2306 struct ust_app *app)
2307 {
2308 int ret = 0;
2309 struct ust_app_ctx *ua_ctx;
2310
2311 DBG2("UST app adding context to channel %s", ua_chan->name);
2312
2313 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2314 if (ua_ctx) {
2315 ret = -EEXIST;
2316 goto error;
2317 }
2318
2319 ua_ctx = alloc_ust_app_ctx(uctx);
2320 if (ua_ctx == NULL) {
2321 /* malloc failed */
2322 ret = -ENOMEM;
2323 goto error;
2324 }
2325
2326 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2327 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2328 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2329
2330 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2331 if (ret < 0) {
2332 goto error;
2333 }
2334
2335 error:
2336 return ret;
2337 }
2338
2339 /*
2340 * Enable on the tracer side a ust app event for the session and channel.
2341 *
2342 * Called with UST app session lock held.
2343 */
2344 static
2345 int enable_ust_app_event(struct ust_app_session *ua_sess,
2346 struct ust_app_event *ua_event, struct ust_app *app)
2347 {
2348 int ret;
2349
2350 ret = enable_ust_event(app, ua_sess, ua_event);
2351 if (ret < 0) {
2352 goto error;
2353 }
2354
2355 ua_event->enabled = 1;
2356
2357 error:
2358 return ret;
2359 }
2360
2361 /*
2362 * Disable on the tracer side a ust app event for the session and channel.
2363 */
2364 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2365 struct ust_app_event *ua_event, struct ust_app *app)
2366 {
2367 int ret;
2368
2369 ret = disable_ust_event(app, ua_sess, ua_event);
2370 if (ret < 0) {
2371 goto error;
2372 }
2373
2374 ua_event->enabled = 0;
2375
2376 error:
2377 return ret;
2378 }
2379
2380 /*
2381 * Lookup ust app channel for session and disable it on the tracer side.
2382 */
2383 static
2384 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2385 struct ust_app_channel *ua_chan, struct ust_app *app)
2386 {
2387 int ret;
2388
2389 ret = disable_ust_channel(app, ua_sess, ua_chan);
2390 if (ret < 0) {
2391 goto error;
2392 }
2393
2394 ua_chan->enabled = 0;
2395
2396 error:
2397 return ret;
2398 }
2399
2400 /*
2401 * Lookup ust app channel for session and enable it on the tracer side. This
2402 * MUST be called with a RCU read side lock acquired.
2403 */
2404 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2405 struct ltt_ust_channel *uchan, struct ust_app *app)
2406 {
2407 int ret = 0;
2408 struct lttng_ht_iter iter;
2409 struct lttng_ht_node_str *ua_chan_node;
2410 struct ust_app_channel *ua_chan;
2411
2412 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2413 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2414 if (ua_chan_node == NULL) {
2415 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2416 uchan->name, ua_sess->tracing_id);
2417 goto error;
2418 }
2419
2420 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2421
2422 ret = enable_ust_channel(app, ua_sess, ua_chan);
2423 if (ret < 0) {
2424 goto error;
2425 }
2426
2427 error:
2428 return ret;
2429 }
2430
2431 /*
2432 * Ask the consumer to create a channel and get it if successful.
2433 *
2434 * Called with UST app session lock held.
2435 *
2436 * Return 0 on success or else a negative value.
2437 */
2438 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2439 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2440 int bitness, struct ust_registry_session *registry,
2441 uint64_t trace_archive_id)
2442 {
2443 int ret;
2444 unsigned int nb_fd = 0;
2445 struct consumer_socket *socket;
2446
2447 assert(usess);
2448 assert(ua_sess);
2449 assert(ua_chan);
2450 assert(registry);
2451
2452 rcu_read_lock();
2453 health_code_update();
2454
2455 /* Get the right consumer socket for the application. */
2456 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2457 if (!socket) {
2458 ret = -EINVAL;
2459 goto error;
2460 }
2461
2462 health_code_update();
2463
2464 /* Need one fd for the channel. */
2465 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2466 if (ret < 0) {
2467 ERR("Exhausted number of available FD upon create channel");
2468 goto error;
2469 }
2470
2471 /*
2472 * Ask consumer to create channel. The consumer will return the number of
2473 * stream we have to expect.
2474 */
2475 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2476 registry, usess->current_trace_chunk);
2477 if (ret < 0) {
2478 goto error_ask;
2479 }
2480
2481 /*
2482 * Compute the number of fd needed before receiving them. It must be 2 per
2483 * stream (2 being the default value here).
2484 */
2485 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2486
2487 /* Reserve the amount of file descriptor we need. */
2488 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2489 if (ret < 0) {
2490 ERR("Exhausted number of available FD upon create channel");
2491 goto error_fd_get_stream;
2492 }
2493
2494 health_code_update();
2495
2496 /*
2497 * Now get the channel from the consumer. This call wil populate the stream
2498 * list of that channel and set the ust objects.
2499 */
2500 if (usess->consumer->enabled) {
2501 ret = ust_consumer_get_channel(socket, ua_chan);
2502 if (ret < 0) {
2503 goto error_destroy;
2504 }
2505 }
2506
2507 rcu_read_unlock();
2508 return 0;
2509
2510 error_destroy:
2511 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2512 error_fd_get_stream:
2513 /*
2514 * Initiate a destroy channel on the consumer since we had an error
2515 * handling it on our side. The return value is of no importance since we
2516 * already have a ret value set by the previous error that we need to
2517 * return.
2518 */
2519 (void) ust_consumer_destroy_channel(socket, ua_chan);
2520 error_ask:
2521 lttng_fd_put(LTTNG_FD_APPS, 1);
2522 error:
2523 health_code_update();
2524 rcu_read_unlock();
2525 return ret;
2526 }
2527
2528 /*
2529 * Duplicate the ust data object of the ust app stream and save it in the
2530 * buffer registry stream.
2531 *
2532 * Return 0 on success or else a negative value.
2533 */
2534 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2535 struct ust_app_stream *stream)
2536 {
2537 int ret;
2538
2539 assert(reg_stream);
2540 assert(stream);
2541
2542 /* Reserve the amount of file descriptor we need. */
2543 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2544 if (ret < 0) {
2545 ERR("Exhausted number of available FD upon duplicate stream");
2546 goto error;
2547 }
2548
2549 /* Duplicate object for stream once the original is in the registry. */
2550 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2551 reg_stream->obj.ust);
2552 if (ret < 0) {
2553 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2554 reg_stream->obj.ust, stream->obj, ret);
2555 lttng_fd_put(LTTNG_FD_APPS, 2);
2556 goto error;
2557 }
2558 stream->handle = stream->obj->handle;
2559
2560 error:
2561 return ret;
2562 }
2563
2564 /*
2565 * Duplicate the ust data object of the ust app. channel and save it in the
2566 * buffer registry channel.
2567 *
2568 * Return 0 on success or else a negative value.
2569 */
2570 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2571 struct ust_app_channel *ua_chan)
2572 {
2573 int ret;
2574
2575 assert(reg_chan);
2576 assert(ua_chan);
2577
2578 /* Need two fds for the channel. */
2579 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2580 if (ret < 0) {
2581 ERR("Exhausted number of available FD upon duplicate channel");
2582 goto error_fd_get;
2583 }
2584
2585 /* Duplicate object for stream once the original is in the registry. */
2586 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2587 if (ret < 0) {
2588 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2589 reg_chan->obj.ust, ua_chan->obj, ret);
2590 goto error;
2591 }
2592 ua_chan->handle = ua_chan->obj->handle;
2593
2594 return 0;
2595
2596 error:
2597 lttng_fd_put(LTTNG_FD_APPS, 1);
2598 error_fd_get:
2599 return ret;
2600 }
2601
2602 /*
2603 * For a given channel buffer registry, setup all streams of the given ust
2604 * application channel.
2605 *
2606 * Return 0 on success or else a negative value.
2607 */
2608 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2609 struct ust_app_channel *ua_chan,
2610 struct ust_app *app)
2611 {
2612 int ret = 0;
2613 struct ust_app_stream *stream, *stmp;
2614
2615 assert(reg_chan);
2616 assert(ua_chan);
2617
2618 DBG2("UST app setup buffer registry stream");
2619
2620 /* Send all streams to application. */
2621 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2622 struct buffer_reg_stream *reg_stream;
2623
2624 ret = buffer_reg_stream_create(&reg_stream);
2625 if (ret < 0) {
2626 goto error;
2627 }
2628
2629 /*
2630 * Keep original pointer and nullify it in the stream so the delete
2631 * stream call does not release the object.
2632 */
2633 reg_stream->obj.ust = stream->obj;
2634 stream->obj = NULL;
2635 buffer_reg_stream_add(reg_stream, reg_chan);
2636
2637 /* We don't need the streams anymore. */
2638 cds_list_del(&stream->list);
2639 delete_ust_app_stream(-1, stream, app);
2640 }
2641
2642 error:
2643 return ret;
2644 }
2645
2646 /*
2647 * Create a buffer registry channel for the given session registry and
2648 * application channel object. If regp pointer is valid, it's set with the
2649 * created object. Important, the created object is NOT added to the session
2650 * registry hash table.
2651 *
2652 * Return 0 on success else a negative value.
2653 */
2654 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2655 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2656 {
2657 int ret;
2658 struct buffer_reg_channel *reg_chan = NULL;
2659
2660 assert(reg_sess);
2661 assert(ua_chan);
2662
2663 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2664
2665 /* Create buffer registry channel. */
2666 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2667 if (ret < 0) {
2668 goto error_create;
2669 }
2670 assert(reg_chan);
2671 reg_chan->consumer_key = ua_chan->key;
2672 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2673 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2674
2675 /* Create and add a channel registry to session. */
2676 ret = ust_registry_channel_add(reg_sess->reg.ust,
2677 ua_chan->tracing_channel_id);
2678 if (ret < 0) {
2679 goto error;
2680 }
2681 buffer_reg_channel_add(reg_sess, reg_chan);
2682
2683 if (regp) {
2684 *regp = reg_chan;
2685 }
2686
2687 return 0;
2688
2689 error:
2690 /* Safe because the registry channel object was not added to any HT. */
2691 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2692 error_create:
2693 return ret;
2694 }
2695
2696 /*
2697 * Setup buffer registry channel for the given session registry and application
2698 * channel object. If regp pointer is valid, it's set with the created object.
2699 *
2700 * Return 0 on success else a negative value.
2701 */
2702 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2703 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2704 struct ust_app *app)
2705 {
2706 int ret;
2707
2708 assert(reg_sess);
2709 assert(reg_chan);
2710 assert(ua_chan);
2711 assert(ua_chan->obj);
2712
2713 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2714
2715 /* Setup all streams for the registry. */
2716 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2717 if (ret < 0) {
2718 goto error;
2719 }
2720
2721 reg_chan->obj.ust = ua_chan->obj;
2722 ua_chan->obj = NULL;
2723
2724 return 0;
2725
2726 error:
2727 buffer_reg_channel_remove(reg_sess, reg_chan);
2728 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2729 return ret;
2730 }
2731
2732 /*
2733 * Send buffer registry channel to the application.
2734 *
2735 * Return 0 on success else a negative value.
2736 */
2737 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2738 struct ust_app *app, struct ust_app_session *ua_sess,
2739 struct ust_app_channel *ua_chan)
2740 {
2741 int ret;
2742 struct buffer_reg_stream *reg_stream;
2743
2744 assert(reg_chan);
2745 assert(app);
2746 assert(ua_sess);
2747 assert(ua_chan);
2748
2749 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2750
2751 ret = duplicate_channel_object(reg_chan, ua_chan);
2752 if (ret < 0) {
2753 goto error;
2754 }
2755
2756 /* Send channel to the application. */
2757 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2758 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2759 ret = -ENOTCONN; /* Caused by app exiting. */
2760 goto error;
2761 } else if (ret < 0) {
2762 goto error;
2763 }
2764
2765 health_code_update();
2766
2767 /* Send all streams to application. */
2768 pthread_mutex_lock(&reg_chan->stream_list_lock);
2769 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2770 struct ust_app_stream stream;
2771
2772 ret = duplicate_stream_object(reg_stream, &stream);
2773 if (ret < 0) {
2774 goto error_stream_unlock;
2775 }
2776
2777 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2778 if (ret < 0) {
2779 (void) release_ust_app_stream(-1, &stream, app);
2780 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2781 ret = -ENOTCONN; /* Caused by app exiting. */
2782 }
2783 goto error_stream_unlock;
2784 }
2785
2786 /*
2787 * The return value is not important here. This function will output an
2788 * error if needed.
2789 */
2790 (void) release_ust_app_stream(-1, &stream, app);
2791 }
2792 ua_chan->is_sent = 1;
2793
2794 error_stream_unlock:
2795 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2796 error:
2797 return ret;
2798 }
2799
2800 /*
2801 * Create and send to the application the created buffers with per UID buffers.
2802 *
2803 * This MUST be called with a RCU read side lock acquired.
2804 * The session list lock and the session's lock must be acquired.
2805 *
2806 * Return 0 on success else a negative value.
2807 */
2808 static int create_channel_per_uid(struct ust_app *app,
2809 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2810 struct ust_app_channel *ua_chan)
2811 {
2812 int ret;
2813 struct buffer_reg_uid *reg_uid;
2814 struct buffer_reg_channel *reg_chan;
2815 struct ltt_session *session = NULL;
2816 enum lttng_error_code notification_ret;
2817 struct ust_registry_channel *chan_reg;
2818
2819 assert(app);
2820 assert(usess);
2821 assert(ua_sess);
2822 assert(ua_chan);
2823
2824 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2825
2826 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2827 /*
2828 * The session creation handles the creation of this global registry
2829 * object. If none can be find, there is a code flow problem or a
2830 * teardown race.
2831 */
2832 assert(reg_uid);
2833
2834 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2835 reg_uid);
2836 if (reg_chan) {
2837 goto send_channel;
2838 }
2839
2840 /* Create the buffer registry channel object. */
2841 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2842 if (ret < 0) {
2843 ERR("Error creating the UST channel \"%s\" registry instance",
2844 ua_chan->name);
2845 goto error;
2846 }
2847
2848 session = session_find_by_id(ua_sess->tracing_id);
2849 assert(session);
2850 assert(pthread_mutex_trylock(&session->lock));
2851 assert(session_trylock_list());
2852
2853 /*
2854 * Create the buffers on the consumer side. This call populates the
2855 * ust app channel object with all streams and data object.
2856 */
2857 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2858 app->bits_per_long, reg_uid->registry->reg.ust,
2859 session->most_recent_chunk_id.value);
2860 if (ret < 0) {
2861 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2862 ua_chan->name);
2863
2864 /*
2865 * Let's remove the previously created buffer registry channel so
2866 * it's not visible anymore in the session registry.
2867 */
2868 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2869 ua_chan->tracing_channel_id, false);
2870 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2871 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2872 goto error;
2873 }
2874
2875 /*
2876 * Setup the streams and add it to the session registry.
2877 */
2878 ret = setup_buffer_reg_channel(reg_uid->registry,
2879 ua_chan, reg_chan, app);
2880 if (ret < 0) {
2881 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2882 goto error;
2883 }
2884
2885 /* Notify the notification subsystem of the channel's creation. */
2886 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2887 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2888 ua_chan->tracing_channel_id);
2889 assert(chan_reg);
2890 chan_reg->consumer_key = ua_chan->key;
2891 chan_reg = NULL;
2892 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2893
2894 notification_ret = notification_thread_command_add_channel(
2895 notification_thread_handle, session->name,
2896 ua_sess->effective_credentials.uid,
2897 ua_sess->effective_credentials.gid, ua_chan->name,
2898 ua_chan->key, LTTNG_DOMAIN_UST,
2899 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2900 if (notification_ret != LTTNG_OK) {
2901 ret = - (int) notification_ret;
2902 ERR("Failed to add channel to notification thread");
2903 goto error;
2904 }
2905
2906 send_channel:
2907 /* Send buffers to the application. */
2908 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2909 if (ret < 0) {
2910 if (ret != -ENOTCONN) {
2911 ERR("Error sending channel to application");
2912 }
2913 goto error;
2914 }
2915
2916 error:
2917 if (session) {
2918 session_put(session);
2919 }
2920 return ret;
2921 }
2922
2923 /*
2924 * Create and send to the application the created buffers with per PID buffers.
2925 *
2926 * Called with UST app session lock held.
2927 * The session list lock and the session's lock must be acquired.
2928 *
2929 * Return 0 on success else a negative value.
2930 */
2931 static int create_channel_per_pid(struct ust_app *app,
2932 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2933 struct ust_app_channel *ua_chan)
2934 {
2935 int ret;
2936 struct ust_registry_session *registry;
2937 enum lttng_error_code cmd_ret;
2938 struct ltt_session *session = NULL;
2939 uint64_t chan_reg_key;
2940 struct ust_registry_channel *chan_reg;
2941
2942 assert(app);
2943 assert(usess);
2944 assert(ua_sess);
2945 assert(ua_chan);
2946
2947 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2948
2949 rcu_read_lock();
2950
2951 registry = get_session_registry(ua_sess);
2952 /* The UST app session lock is held, registry shall not be null. */
2953 assert(registry);
2954
2955 /* Create and add a new channel registry to session. */
2956 ret = ust_registry_channel_add(registry, ua_chan->key);
2957 if (ret < 0) {
2958 ERR("Error creating the UST channel \"%s\" registry instance",
2959 ua_chan->name);
2960 goto error;
2961 }
2962
2963 session = session_find_by_id(ua_sess->tracing_id);
2964 assert(session);
2965
2966 assert(pthread_mutex_trylock(&session->lock));
2967 assert(session_trylock_list());
2968
2969 /* Create and get channel on the consumer side. */
2970 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2971 app->bits_per_long, registry,
2972 session->most_recent_chunk_id.value);
2973 if (ret < 0) {
2974 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2975 ua_chan->name);
2976 goto error_remove_from_registry;
2977 }
2978
2979 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2980 if (ret < 0) {
2981 if (ret != -ENOTCONN) {
2982 ERR("Error sending channel to application");
2983 }
2984 goto error_remove_from_registry;
2985 }
2986
2987 chan_reg_key = ua_chan->key;
2988 pthread_mutex_lock(&registry->lock);
2989 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2990 assert(chan_reg);
2991 chan_reg->consumer_key = ua_chan->key;
2992 pthread_mutex_unlock(&registry->lock);
2993
2994 cmd_ret = notification_thread_command_add_channel(
2995 notification_thread_handle, session->name,
2996 ua_sess->effective_credentials.uid,
2997 ua_sess->effective_credentials.gid, ua_chan->name,
2998 ua_chan->key, LTTNG_DOMAIN_UST,
2999 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
3000 if (cmd_ret != LTTNG_OK) {
3001 ret = - (int) cmd_ret;
3002 ERR("Failed to add channel to notification thread");
3003 goto error_remove_from_registry;
3004 }
3005
3006 error_remove_from_registry:
3007 if (ret) {
3008 ust_registry_channel_del_free(registry, ua_chan->key, false);
3009 }
3010 error:
3011 rcu_read_unlock();
3012 if (session) {
3013 session_put(session);
3014 }
3015 return ret;
3016 }
3017
3018 /*
3019 * From an already allocated ust app channel, create the channel buffers if
3020 * needed and send them to the application. This MUST be called with a RCU read
3021 * side lock acquired.
3022 *
3023 * Called with UST app session lock held.
3024 *
3025 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3026 * the application exited concurrently.
3027 */
3028 static int ust_app_channel_send(struct ust_app *app,
3029 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3030 struct ust_app_channel *ua_chan)
3031 {
3032 int ret;
3033
3034 assert(app);
3035 assert(usess);
3036 assert(usess->active);
3037 assert(ua_sess);
3038 assert(ua_chan);
3039
3040 /* Handle buffer type before sending the channel to the application. */
3041 switch (usess->buffer_type) {
3042 case LTTNG_BUFFER_PER_UID:
3043 {
3044 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3045 if (ret < 0) {
3046 goto error;
3047 }
3048 break;
3049 }
3050 case LTTNG_BUFFER_PER_PID:
3051 {
3052 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3053 if (ret < 0) {
3054 goto error;
3055 }
3056 break;
3057 }
3058 default:
3059 assert(0);
3060 ret = -EINVAL;
3061 goto error;
3062 }
3063
3064 /* Initialize ust objd object using the received handle and add it. */
3065 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3066 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3067
3068 /* If channel is not enabled, disable it on the tracer */
3069 if (!ua_chan->enabled) {
3070 ret = disable_ust_channel(app, ua_sess, ua_chan);
3071 if (ret < 0) {
3072 goto error;
3073 }
3074 }
3075
3076 error:
3077 return ret;
3078 }
3079
3080 /*
3081 * Create UST app channel and return it through ua_chanp if not NULL.
3082 *
3083 * Called with UST app session lock and RCU read-side lock held.
3084 *
3085 * Return 0 on success or else a negative value.
3086 */
3087 static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3088 struct ltt_ust_channel *uchan,
3089 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3090 struct ust_app_channel **ua_chanp)
3091 {
3092 int ret = 0;
3093 struct lttng_ht_iter iter;
3094 struct lttng_ht_node_str *ua_chan_node;
3095 struct ust_app_channel *ua_chan;
3096
3097 /* Lookup channel in the ust app session */
3098 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3099 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3100 if (ua_chan_node != NULL) {
3101 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3102 goto end;
3103 }
3104
3105 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3106 if (ua_chan == NULL) {
3107 /* Only malloc can fail here */
3108 ret = -ENOMEM;
3109 goto error;
3110 }
3111 shadow_copy_channel(ua_chan, uchan);
3112
3113 /* Set channel type. */
3114 ua_chan->attr.type = type;
3115
3116 /* Only add the channel if successful on the tracer side. */
3117 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3118 end:
3119 if (ua_chanp) {
3120 *ua_chanp = ua_chan;
3121 }
3122
3123 /* Everything went well. */
3124 return 0;
3125
3126 error:
3127 return ret;
3128 }
3129
3130 /*
3131 * Create UST app event and create it on the tracer side.
3132 *
3133 * Called with ust app session mutex held.
3134 */
3135 static
3136 int create_ust_app_event(struct ust_app_session *ua_sess,
3137 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3138 struct ust_app *app)
3139 {
3140 int ret = 0;
3141 struct ust_app_event *ua_event;
3142
3143 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3144 if (ua_event == NULL) {
3145 /* Only failure mode of alloc_ust_app_event(). */
3146 ret = -ENOMEM;
3147 goto end;
3148 }
3149 shadow_copy_event(ua_event, uevent);
3150
3151 /* Create it on the tracer side */
3152 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3153 if (ret < 0) {
3154 /*
3155 * Not found previously means that it does not exist on the
3156 * tracer. If the application reports that the event existed,
3157 * it means there is a bug in the sessiond or lttng-ust
3158 * (or corruption, etc.)
3159 */
3160 if (ret == -LTTNG_UST_ERR_EXIST) {
3161 ERR("Tracer for application reported that an event being created already existed: "
3162 "event_name = \"%s\", pid = %d, ppid = %d, uid = %d, gid = %d",
3163 uevent->attr.name,
3164 app->pid, app->ppid, app->uid,
3165 app->gid);
3166 }
3167 goto error;
3168 }
3169
3170 add_unique_ust_app_event(ua_chan, ua_event);
3171
3172 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3173 app->pid);
3174
3175 end:
3176 return ret;
3177
3178 error:
3179 /* Valid. Calling here is already in a read side lock */
3180 delete_ust_app_event(-1, ua_event, app);
3181 return ret;
3182 }
3183
3184 /*
3185 * Create UST metadata and open it on the tracer side.
3186 *
3187 * Called with UST app session lock held and RCU read side lock.
3188 */
3189 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3190 struct ust_app *app, struct consumer_output *consumer)
3191 {
3192 int ret = 0;
3193 struct ust_app_channel *metadata;
3194 struct consumer_socket *socket;
3195 struct ust_registry_session *registry;
3196 struct ltt_session *session = NULL;
3197
3198 assert(ua_sess);
3199 assert(app);
3200 assert(consumer);
3201
3202 registry = get_session_registry(ua_sess);
3203 /* The UST app session is held registry shall not be null. */
3204 assert(registry);
3205
3206 pthread_mutex_lock(&registry->lock);
3207
3208 /* Metadata already exists for this registry or it was closed previously */
3209 if (registry->metadata_key || registry->metadata_closed) {
3210 ret = 0;
3211 goto error;
3212 }
3213
3214 /* Allocate UST metadata */
3215 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3216 if (!metadata) {
3217 /* malloc() failed */
3218 ret = -ENOMEM;
3219 goto error;
3220 }
3221
3222 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3223
3224 /* Need one fd for the channel. */
3225 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3226 if (ret < 0) {
3227 ERR("Exhausted number of available FD upon create metadata");
3228 goto error;
3229 }
3230
3231 /* Get the right consumer socket for the application. */
3232 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3233 if (!socket) {
3234 ret = -EINVAL;
3235 goto error_consumer;
3236 }
3237
3238 /*
3239 * Keep metadata key so we can identify it on the consumer side. Assign it
3240 * to the registry *before* we ask the consumer so we avoid the race of the
3241 * consumer requesting the metadata and the ask_channel call on our side
3242 * did not returned yet.
3243 */
3244 registry->metadata_key = metadata->key;
3245
3246 session = session_find_by_id(ua_sess->tracing_id);
3247 assert(session);
3248
3249 assert(pthread_mutex_trylock(&session->lock));
3250 assert(session_trylock_list());
3251
3252 /*
3253 * Ask the metadata channel creation to the consumer. The metadata object
3254 * will be created by the consumer and kept their. However, the stream is
3255 * never added or monitored until we do a first push metadata to the
3256 * consumer.
3257 */
3258 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3259 registry, session->current_trace_chunk);
3260 if (ret < 0) {
3261 /* Nullify the metadata key so we don't try to close it later on. */
3262 registry->metadata_key = 0;
3263 goto error_consumer;
3264 }
3265
3266 /*
3267 * The setup command will make the metadata stream be sent to the relayd,
3268 * if applicable, and the thread managing the metadatas. This is important
3269 * because after this point, if an error occurs, the only way the stream
3270 * can be deleted is to be monitored in the consumer.
3271 */
3272 ret = consumer_setup_metadata(socket, metadata->key);
3273 if (ret < 0) {
3274 /* Nullify the metadata key so we don't try to close it later on. */
3275 registry->metadata_key = 0;
3276 goto error_consumer;
3277 }
3278
3279 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3280 metadata->key, app->pid);
3281
3282 error_consumer:
3283 lttng_fd_put(LTTNG_FD_APPS, 1);
3284 delete_ust_app_channel(-1, metadata, app);
3285 error:
3286 pthread_mutex_unlock(&registry->lock);
3287 if (session) {
3288 session_put(session);
3289 }
3290 return ret;
3291 }
3292
3293 /*
3294 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3295 * acquired before calling this function.
3296 */
3297 struct ust_app *ust_app_find_by_pid(pid_t pid)
3298 {
3299 struct ust_app *app = NULL;
3300 struct lttng_ht_node_ulong *node;
3301 struct lttng_ht_iter iter;
3302
3303 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3304 node = lttng_ht_iter_get_node_ulong(&iter);
3305 if (node == NULL) {
3306 DBG2("UST app no found with pid %d", pid);
3307 goto error;
3308 }
3309
3310 DBG2("Found UST app by pid %d", pid);
3311
3312 app = caa_container_of(node, struct ust_app, pid_n);
3313
3314 error:
3315 return app;
3316 }
3317
3318 /*
3319 * Allocate and init an UST app object using the registration information and
3320 * the command socket. This is called when the command socket connects to the
3321 * session daemon.
3322 *
3323 * The object is returned on success or else NULL.
3324 */
3325 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3326 {
3327 struct ust_app *lta = NULL;
3328
3329 assert(msg);
3330 assert(sock >= 0);
3331
3332 DBG3("UST app creating application for socket %d", sock);
3333
3334 if ((msg->bits_per_long == 64 &&
3335 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3336 || (msg->bits_per_long == 32 &&
3337 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3338 ERR("Registration failed: application \"%s\" (pid: %d) has "
3339 "%d-bit long, but no consumerd for this size is available.\n",
3340 msg->name, msg->pid, msg->bits_per_long);
3341 goto error;
3342 }
3343
3344 lta = zmalloc(sizeof(struct ust_app));
3345 if (lta == NULL) {
3346 PERROR("malloc");
3347 goto error;
3348 }
3349
3350 lta->ppid = msg->ppid;
3351 lta->uid = msg->uid;
3352 lta->gid = msg->gid;
3353
3354 lta->bits_per_long = msg->bits_per_long;
3355 lta->uint8_t_alignment = msg->uint8_t_alignment;
3356 lta->uint16_t_alignment = msg->uint16_t_alignment;
3357 lta->uint32_t_alignment = msg->uint32_t_alignment;
3358 lta->uint64_t_alignment = msg->uint64_t_alignment;
3359 lta->long_alignment = msg->long_alignment;
3360 lta->byte_order = msg->byte_order;
3361
3362 lta->v_major = msg->major;
3363 lta->v_minor = msg->minor;
3364 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3365 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3366 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3367 lta->notify_sock = -1;
3368
3369 /* Copy name and make sure it's NULL terminated. */
3370 strncpy(lta->name, msg->name, sizeof(lta->name));
3371 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3372
3373 /*
3374 * Before this can be called, when receiving the registration information,
3375 * the application compatibility is checked. So, at this point, the
3376 * application can work with this session daemon.
3377 */
3378 lta->compatible = 1;
3379
3380 lta->pid = msg->pid;
3381 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3382 lta->sock = sock;
3383 pthread_mutex_init(&lta->sock_lock, NULL);
3384 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3385
3386 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3387 error:
3388 return lta;
3389 }
3390
3391 /*
3392 * For a given application object, add it to every hash table.
3393 */
3394 void ust_app_add(struct ust_app *app)
3395 {
3396 assert(app);
3397 assert(app->notify_sock >= 0);
3398
3399 app->registration_time = time(NULL);
3400
3401 rcu_read_lock();
3402
3403 /*
3404 * On a re-registration, we want to kick out the previous registration of
3405 * that pid
3406 */
3407 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3408
3409 /*
3410 * The socket _should_ be unique until _we_ call close. So, a add_unique
3411 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3412 * already in the table.
3413 */
3414 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3415
3416 /* Add application to the notify socket hash table. */
3417 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3418 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3419
3420 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3421 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3422 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3423 app->v_minor);
3424
3425 rcu_read_unlock();
3426 }
3427
3428 /*
3429 * Set the application version into the object.
3430 *
3431 * Return 0 on success else a negative value either an errno code or a
3432 * LTTng-UST error code.
3433 */
3434 int ust_app_version(struct ust_app *app)
3435 {
3436 int ret;
3437
3438 assert(app);
3439
3440 pthread_mutex_lock(&app->sock_lock);
3441 ret = ustctl_tracer_version(app->sock, &app->version);
3442 pthread_mutex_unlock(&app->sock_lock);
3443 if (ret < 0) {
3444 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3445 ERR("UST app %d version failed with ret %d", app->sock, ret);
3446 } else {
3447 DBG3("UST app %d version failed. Application is dead", app->sock);
3448 }
3449 }
3450
3451 return ret;
3452 }
3453
3454 /*
3455 * Unregister app by removing it from the global traceable app list and freeing
3456 * the data struct.
3457 *
3458 * The socket is already closed at this point so no close to sock.
3459 */
3460 void ust_app_unregister(int sock)
3461 {
3462 struct ust_app *lta;
3463 struct lttng_ht_node_ulong *node;
3464 struct lttng_ht_iter ust_app_sock_iter;
3465 struct lttng_ht_iter iter;
3466 struct ust_app_session *ua_sess;
3467 int ret;
3468
3469 rcu_read_lock();
3470
3471 /* Get the node reference for a call_rcu */
3472 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3473 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3474 assert(node);
3475
3476 lta = caa_container_of(node, struct ust_app, sock_n);
3477 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3478
3479 /*
3480 * For per-PID buffers, perform "push metadata" and flush all
3481 * application streams before removing app from hash tables,
3482 * ensuring proper behavior of data_pending check.
3483 * Remove sessions so they are not visible during deletion.
3484 */
3485 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3486 node.node) {
3487 struct ust_registry_session *registry;
3488
3489 ret = lttng_ht_del(lta->sessions, &iter);
3490 if (ret) {
3491 /* The session was already removed so scheduled for teardown. */
3492 continue;
3493 }
3494
3495 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3496 (void) ust_app_flush_app_session(lta, ua_sess);
3497 }
3498
3499 /*
3500 * Add session to list for teardown. This is safe since at this point we
3501 * are the only one using this list.
3502 */
3503 pthread_mutex_lock(&ua_sess->lock);
3504
3505 if (ua_sess->deleted) {
3506 pthread_mutex_unlock(&ua_sess->lock);
3507 continue;
3508 }
3509
3510 /*
3511 * Normally, this is done in the delete session process which is
3512 * executed in the call rcu below. However, upon registration we can't
3513 * afford to wait for the grace period before pushing data or else the
3514 * data pending feature can race between the unregistration and stop
3515 * command where the data pending command is sent *before* the grace
3516 * period ended.
3517 *
3518 * The close metadata below nullifies the metadata pointer in the
3519 * session so the delete session will NOT push/close a second time.
3520 */
3521 registry = get_session_registry(ua_sess);
3522 if (registry) {
3523 /* Push metadata for application before freeing the application. */
3524 (void) push_metadata(registry, ua_sess->consumer);
3525
3526 /*
3527 * Don't ask to close metadata for global per UID buffers. Close
3528 * metadata only on destroy trace session in this case. Also, the
3529 * previous push metadata could have flag the metadata registry to
3530 * close so don't send a close command if closed.
3531 */
3532 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3533 /* And ask to close it for this session registry. */
3534 (void) close_metadata(registry, ua_sess->consumer);
3535 }
3536 }
3537 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3538
3539 pthread_mutex_unlock(&ua_sess->lock);
3540 }
3541
3542 /* Remove application from PID hash table */
3543 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3544 assert(!ret);
3545
3546 /*
3547 * Remove application from notify hash table. The thread handling the
3548 * notify socket could have deleted the node so ignore on error because
3549 * either way it's valid. The close of that socket is handled by the
3550 * apps_notify_thread.
3551 */
3552 iter.iter.node = &lta->notify_sock_n.node;
3553 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3554
3555 /*
3556 * Ignore return value since the node might have been removed before by an
3557 * add replace during app registration because the PID can be reassigned by
3558 * the OS.
3559 */
3560 iter.iter.node = &lta->pid_n.node;
3561 ret = lttng_ht_del(ust_app_ht, &iter);
3562 if (ret) {
3563 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3564 lta->pid);
3565 }
3566
3567 /* Free memory */
3568 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3569
3570 rcu_read_unlock();
3571 return;
3572 }
3573
3574 /*
3575 * Fill events array with all events name of all registered apps.
3576 */
3577 int ust_app_list_events(struct lttng_event **events)
3578 {
3579 int ret, handle;
3580 size_t nbmem, count = 0;
3581 struct lttng_ht_iter iter;
3582 struct ust_app *app;
3583 struct lttng_event *tmp_event;
3584
3585 nbmem = UST_APP_EVENT_LIST_SIZE;
3586 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3587 if (tmp_event == NULL) {
3588 PERROR("zmalloc ust app events");
3589 ret = -ENOMEM;
3590 goto error;
3591 }
3592
3593 rcu_read_lock();
3594
3595 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3596 struct lttng_ust_tracepoint_iter uiter;
3597
3598 health_code_update();
3599
3600 if (!app->compatible) {
3601 /*
3602 * TODO: In time, we should notice the caller of this error by
3603 * telling him that this is a version error.
3604 */
3605 continue;
3606 }
3607 pthread_mutex_lock(&app->sock_lock);
3608 handle = ustctl_tracepoint_list(app->sock);
3609 if (handle < 0) {
3610 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3611 ERR("UST app list events getting handle failed for app pid %d",
3612 app->pid);
3613 }
3614 pthread_mutex_unlock(&app->sock_lock);
3615 continue;
3616 }
3617
3618 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3619 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3620 /* Handle ustctl error. */
3621 if (ret < 0) {
3622 int release_ret;
3623
3624 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3625 ERR("UST app tp list get failed for app %d with ret %d",
3626 app->sock, ret);
3627 } else {
3628 DBG3("UST app tp list get failed. Application is dead");
3629 /*
3630 * This is normal behavior, an application can die during the
3631 * creation process. Don't report an error so the execution can
3632 * continue normally. Continue normal execution.
3633 */
3634 break;
3635 }
3636 free(tmp_event);
3637 release_ret = ustctl_release_handle(app->sock, handle);
3638 if (release_ret < 0 &&
3639 release_ret != -LTTNG_UST_ERR_EXITING &&
3640 release_ret != -EPIPE) {
3641 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3642 }
3643 pthread_mutex_unlock(&app->sock_lock);
3644 goto rcu_error;
3645 }
3646
3647 health_code_update();
3648 if (count >= nbmem) {
3649 /* In case the realloc fails, we free the memory */
3650 struct lttng_event *new_tmp_event;
3651 size_t new_nbmem;
3652
3653 new_nbmem = nbmem << 1;
3654 DBG2("Reallocating event list from %zu to %zu entries",
3655 nbmem, new_nbmem);
3656 new_tmp_event = realloc(tmp_event,
3657 new_nbmem * sizeof(struct lttng_event));
3658 if (new_tmp_event == NULL) {
3659 int release_ret;
3660
3661 PERROR("realloc ust app events");
3662 free(tmp_event);
3663 ret = -ENOMEM;
3664 release_ret = ustctl_release_handle(app->sock, handle);
3665 if (release_ret < 0 &&
3666 release_ret != -LTTNG_UST_ERR_EXITING &&
3667 release_ret != -EPIPE) {
3668 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3669 }
3670 pthread_mutex_unlock(&app->sock_lock);
3671 goto rcu_error;
3672 }
3673 /* Zero the new memory */
3674 memset(new_tmp_event + nbmem, 0,
3675 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3676 nbmem = new_nbmem;
3677 tmp_event = new_tmp_event;
3678 }
3679 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3680 tmp_event[count].loglevel = uiter.loglevel;
3681 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3682 tmp_event[count].pid = app->pid;
3683 tmp_event[count].enabled = -1;
3684 count++;
3685 }
3686 ret = ustctl_release_handle(app->sock, handle);
3687 pthread_mutex_unlock(&app->sock_lock);
3688 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3689 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3690 }
3691 }
3692
3693 ret = count;
3694 *events = tmp_event;
3695
3696 DBG2("UST app list events done (%zu events)", count);
3697
3698 rcu_error:
3699 rcu_read_unlock();
3700 error:
3701 health_code_update();
3702 return ret;
3703 }
3704
3705 /*
3706 * Fill events array with all events name of all registered apps.
3707 */
3708 int ust_app_list_event_fields(struct lttng_event_field **fields)
3709 {
3710 int ret, handle;
3711 size_t nbmem, count = 0;
3712 struct lttng_ht_iter iter;
3713 struct ust_app *app;
3714 struct lttng_event_field *tmp_event;
3715
3716 nbmem = UST_APP_EVENT_LIST_SIZE;
3717 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3718 if (tmp_event == NULL) {
3719 PERROR("zmalloc ust app event fields");
3720 ret = -ENOMEM;
3721 goto error;
3722 }
3723
3724 rcu_read_lock();
3725
3726 cds_lfht_for_each_entry