62971067ce00f9d1b000580b4a7a10b45121d7ac
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <lttng/ust-error.h>
31 #include <signal.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35
36 #include "buffer-registry.h"
37 #include "fd-limit.h"
38 #include "health-sessiond.h"
39 #include "ust-app.h"
40 #include "ust-consumer.h"
41 #include "ust-ctl.h"
42 #include "utils.h"
43 #include "session.h"
44 #include "lttng-sessiond.h"
45 #include "notification-thread-commands.h"
46 #include "rotate.h"
47
48 static
49 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51 /* Next available channel key. Access under next_channel_key_lock. */
52 static uint64_t _next_channel_key;
53 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55 /* Next available session ID. Access under next_session_id_lock. */
56 static uint64_t _next_session_id;
57 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59 /*
60 * Return the incremented value of next_channel_key.
61 */
62 static uint64_t get_next_channel_key(void)
63 {
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70 }
71
72 /*
73 * Return the atomically incremented value of next_session_id.
74 */
75 static uint64_t get_next_session_id(void)
76 {
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83 }
84
85 static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88 {
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97 }
98
99 /*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106 {
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173 no_match:
174 return 0;
175 }
176
177 /*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183 {
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202 }
203
204 /*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208 static void close_notify_sock_rcu(struct rcu_head *head)
209 {
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224 }
225
226 /*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233 static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235 {
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
254 if (!reg_uid) {
255 goto error;
256 }
257 registry = reg_uid->registry->reg.ust;
258 break;
259 }
260 default:
261 assert(0);
262 };
263
264 error:
265 return registry;
266 }
267
268 /*
269 * Delete ust context safely. RCU read lock must be held before calling
270 * this function.
271 */
272 static
273 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
274 struct ust_app *app)
275 {
276 int ret;
277
278 assert(ua_ctx);
279
280 if (ua_ctx->obj) {
281 pthread_mutex_lock(&app->sock_lock);
282 ret = ustctl_release_object(sock, ua_ctx->obj);
283 pthread_mutex_unlock(&app->sock_lock);
284 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
285 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
286 sock, ua_ctx->obj->handle, ret);
287 }
288 free(ua_ctx->obj);
289 }
290 free(ua_ctx);
291 }
292
293 /*
294 * Delete ust app event safely. RCU read lock must be held before calling
295 * this function.
296 */
297 static
298 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
299 struct ust_app *app)
300 {
301 int ret;
302
303 assert(ua_event);
304
305 free(ua_event->filter);
306 if (ua_event->exclusion != NULL)
307 free(ua_event->exclusion);
308 if (ua_event->obj != NULL) {
309 pthread_mutex_lock(&app->sock_lock);
310 ret = ustctl_release_object(sock, ua_event->obj);
311 pthread_mutex_unlock(&app->sock_lock);
312 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
313 ERR("UST app sock %d release event obj failed with ret %d",
314 sock, ret);
315 }
316 free(ua_event->obj);
317 }
318 free(ua_event);
319 }
320
321 /*
322 * Release ust data object of the given stream.
323 *
324 * Return 0 on success or else a negative value.
325 */
326 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
327 struct ust_app *app)
328 {
329 int ret = 0;
330
331 assert(stream);
332
333 if (stream->obj) {
334 pthread_mutex_lock(&app->sock_lock);
335 ret = ustctl_release_object(sock, stream->obj);
336 pthread_mutex_unlock(&app->sock_lock);
337 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
338 ERR("UST app sock %d release stream obj failed with ret %d",
339 sock, ret);
340 }
341 lttng_fd_put(LTTNG_FD_APPS, 2);
342 free(stream->obj);
343 }
344
345 return ret;
346 }
347
348 /*
349 * Delete ust app stream safely. RCU read lock must be held before calling
350 * this function.
351 */
352 static
353 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
354 struct ust_app *app)
355 {
356 assert(stream);
357
358 (void) release_ust_app_stream(sock, stream, app);
359 free(stream);
360 }
361
362 /*
363 * We need to execute ht_destroy outside of RCU read-side critical
364 * section and outside of call_rcu thread, so we postpone its execution
365 * using ht_cleanup_push. It is simpler than to change the semantic of
366 * the many callers of delete_ust_app_session().
367 */
368 static
369 void delete_ust_app_channel_rcu(struct rcu_head *head)
370 {
371 struct ust_app_channel *ua_chan =
372 caa_container_of(head, struct ust_app_channel, rcu_head);
373
374 ht_cleanup_push(ua_chan->ctx);
375 ht_cleanup_push(ua_chan->events);
376 free(ua_chan);
377 }
378
379 /*
380 * Extract the lost packet or discarded events counter when the channel is
381 * being deleted and store the value in the parent channel so we can
382 * access it from lttng list and at stop/destroy.
383 *
384 * The session list lock must be held by the caller.
385 */
386 static
387 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
388 {
389 uint64_t discarded = 0, lost = 0;
390 struct ltt_session *session;
391 struct ltt_ust_channel *uchan;
392
393 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
394 return;
395 }
396
397 rcu_read_lock();
398 session = session_find_by_id(ua_chan->session->tracing_id);
399 if (!session || !session->ust_session) {
400 /*
401 * Not finding the session is not an error because there are
402 * multiple ways the channels can be torn down.
403 *
404 * 1) The session daemon can initiate the destruction of the
405 * ust app session after receiving a destroy command or
406 * during its shutdown/teardown.
407 * 2) The application, since we are in per-pid tracing, is
408 * unregistering and tearing down its ust app session.
409 *
410 * Both paths are protected by the session list lock which
411 * ensures that the accounting of lost packets and discarded
412 * events is done exactly once. The session is then unpublished
413 * from the session list, resulting in this condition.
414 */
415 goto end;
416 }
417
418 if (ua_chan->attr.overwrite) {
419 consumer_get_lost_packets(ua_chan->session->tracing_id,
420 ua_chan->key, session->ust_session->consumer,
421 &lost);
422 } else {
423 consumer_get_discarded_events(ua_chan->session->tracing_id,
424 ua_chan->key, session->ust_session->consumer,
425 &discarded);
426 }
427 uchan = trace_ust_find_channel_by_name(
428 session->ust_session->domain_global.channels,
429 ua_chan->name);
430 if (!uchan) {
431 ERR("Missing UST channel to store discarded counters");
432 goto end;
433 }
434
435 uchan->per_pid_closed_app_discarded += discarded;
436 uchan->per_pid_closed_app_lost += lost;
437
438 end:
439 rcu_read_unlock();
440 }
441
442 /*
443 * Delete ust app channel safely. RCU read lock must be held before calling
444 * this function.
445 *
446 * The session list lock must be held by the caller.
447 */
448 static
449 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
450 struct ust_app *app)
451 {
452 int ret;
453 struct lttng_ht_iter iter;
454 struct ust_app_event *ua_event;
455 struct ust_app_ctx *ua_ctx;
456 struct ust_app_stream *stream, *stmp;
457 struct ust_registry_session *registry;
458
459 assert(ua_chan);
460
461 DBG3("UST app deleting channel %s", ua_chan->name);
462
463 /* Wipe stream */
464 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
465 cds_list_del(&stream->list);
466 delete_ust_app_stream(sock, stream, app);
467 }
468
469 /* Wipe context */
470 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
471 cds_list_del(&ua_ctx->list);
472 ret = lttng_ht_del(ua_chan->ctx, &iter);
473 assert(!ret);
474 delete_ust_app_ctx(sock, ua_ctx, app);
475 }
476
477 /* Wipe events */
478 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
479 node.node) {
480 ret = lttng_ht_del(ua_chan->events, &iter);
481 assert(!ret);
482 delete_ust_app_event(sock, ua_event, app);
483 }
484
485 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
486 /* Wipe and free registry from session registry. */
487 registry = get_session_registry(ua_chan->session);
488 if (registry) {
489 ust_registry_channel_del_free(registry, ua_chan->key,
490 true);
491 }
492 save_per_pid_lost_discarded_counters(ua_chan);
493 }
494
495 if (ua_chan->obj != NULL) {
496 /* Remove channel from application UST object descriptor. */
497 iter.iter.node = &ua_chan->ust_objd_node.node;
498 ret = lttng_ht_del(app->ust_objd, &iter);
499 assert(!ret);
500 pthread_mutex_lock(&app->sock_lock);
501 ret = ustctl_release_object(sock, ua_chan->obj);
502 pthread_mutex_unlock(&app->sock_lock);
503 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
504 ERR("UST app sock %d release channel obj failed with ret %d",
505 sock, ret);
506 }
507 lttng_fd_put(LTTNG_FD_APPS, 1);
508 free(ua_chan->obj);
509 }
510 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
511 }
512
513 int ust_app_register_done(struct ust_app *app)
514 {
515 int ret;
516
517 pthread_mutex_lock(&app->sock_lock);
518 ret = ustctl_register_done(app->sock);
519 pthread_mutex_unlock(&app->sock_lock);
520 return ret;
521 }
522
523 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
524 {
525 int ret, sock;
526
527 if (app) {
528 pthread_mutex_lock(&app->sock_lock);
529 sock = app->sock;
530 } else {
531 sock = -1;
532 }
533 ret = ustctl_release_object(sock, data);
534 if (app) {
535 pthread_mutex_unlock(&app->sock_lock);
536 }
537 return ret;
538 }
539
540 /*
541 * Push metadata to consumer socket.
542 *
543 * RCU read-side lock must be held to guarantee existance of socket.
544 * Must be called with the ust app session lock held.
545 * Must be called with the registry lock held.
546 *
547 * On success, return the len of metadata pushed or else a negative value.
548 * Returning a -EPIPE return value means we could not send the metadata,
549 * but it can be caused by recoverable errors (e.g. the application has
550 * terminated concurrently).
551 */
552 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
553 struct consumer_socket *socket, int send_zero_data)
554 {
555 int ret;
556 char *metadata_str = NULL;
557 size_t len, offset, new_metadata_len_sent;
558 ssize_t ret_val;
559 uint64_t metadata_key, metadata_version;
560
561 assert(registry);
562 assert(socket);
563
564 metadata_key = registry->metadata_key;
565
566 /*
567 * Means that no metadata was assigned to the session. This can
568 * happens if no start has been done previously.
569 */
570 if (!metadata_key) {
571 return 0;
572 }
573
574 offset = registry->metadata_len_sent;
575 len = registry->metadata_len - registry->metadata_len_sent;
576 new_metadata_len_sent = registry->metadata_len;
577 metadata_version = registry->metadata_version;
578 if (len == 0) {
579 DBG3("No metadata to push for metadata key %" PRIu64,
580 registry->metadata_key);
581 ret_val = len;
582 if (send_zero_data) {
583 DBG("No metadata to push");
584 goto push_data;
585 }
586 goto end;
587 }
588
589 /* Allocate only what we have to send. */
590 metadata_str = zmalloc(len);
591 if (!metadata_str) {
592 PERROR("zmalloc ust app metadata string");
593 ret_val = -ENOMEM;
594 goto error;
595 }
596 /* Copy what we haven't sent out. */
597 memcpy(metadata_str, registry->metadata + offset, len);
598
599 push_data:
600 pthread_mutex_unlock(&registry->lock);
601 /*
602 * We need to unlock the registry while we push metadata to
603 * break a circular dependency between the consumerd metadata
604 * lock and the sessiond registry lock. Indeed, pushing metadata
605 * to the consumerd awaits that it gets pushed all the way to
606 * relayd, but doing so requires grabbing the metadata lock. If
607 * a concurrent metadata request is being performed by
608 * consumerd, this can try to grab the registry lock on the
609 * sessiond while holding the metadata lock on the consumer
610 * daemon. Those push and pull schemes are performed on two
611 * different bidirectionnal communication sockets.
612 */
613 ret = consumer_push_metadata(socket, metadata_key,
614 metadata_str, len, offset, metadata_version);
615 pthread_mutex_lock(&registry->lock);
616 if (ret < 0) {
617 /*
618 * There is an acceptable race here between the registry
619 * metadata key assignment and the creation on the
620 * consumer. The session daemon can concurrently push
621 * metadata for this registry while being created on the
622 * consumer since the metadata key of the registry is
623 * assigned *before* it is setup to avoid the consumer
624 * to ask for metadata that could possibly be not found
625 * in the session daemon.
626 *
627 * The metadata will get pushed either by the session
628 * being stopped or the consumer requesting metadata if
629 * that race is triggered.
630 */
631 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
632 ret = 0;
633 } else {
634 ERR("Error pushing metadata to consumer");
635 }
636 ret_val = ret;
637 goto error_push;
638 } else {
639 /*
640 * Metadata may have been concurrently pushed, since
641 * we're not holding the registry lock while pushing to
642 * consumer. This is handled by the fact that we send
643 * the metadata content, size, and the offset at which
644 * that metadata belongs. This may arrive out of order
645 * on the consumer side, and the consumer is able to
646 * deal with overlapping fragments. The consumer
647 * supports overlapping fragments, which must be
648 * contiguous starting from offset 0. We keep the
649 * largest metadata_len_sent value of the concurrent
650 * send.
651 */
652 registry->metadata_len_sent =
653 max_t(size_t, registry->metadata_len_sent,
654 new_metadata_len_sent);
655 }
656 free(metadata_str);
657 return len;
658
659 end:
660 error:
661 if (ret_val) {
662 /*
663 * On error, flag the registry that the metadata is
664 * closed. We were unable to push anything and this
665 * means that either the consumer is not responding or
666 * the metadata cache has been destroyed on the
667 * consumer.
668 */
669 registry->metadata_closed = 1;
670 }
671 error_push:
672 free(metadata_str);
673 return ret_val;
674 }
675
676 /*
677 * For a given application and session, push metadata to consumer.
678 * Either sock or consumer is required : if sock is NULL, the default
679 * socket to send the metadata is retrieved from consumer, if sock
680 * is not NULL we use it to send the metadata.
681 * RCU read-side lock must be held while calling this function,
682 * therefore ensuring existance of registry. It also ensures existance
683 * of socket throughout this function.
684 *
685 * Return 0 on success else a negative error.
686 * Returning a -EPIPE return value means we could not send the metadata,
687 * but it can be caused by recoverable errors (e.g. the application has
688 * terminated concurrently).
689 */
690 static int push_metadata(struct ust_registry_session *registry,
691 struct consumer_output *consumer)
692 {
693 int ret_val;
694 ssize_t ret;
695 struct consumer_socket *socket;
696
697 assert(registry);
698 assert(consumer);
699
700 pthread_mutex_lock(&registry->lock);
701 if (registry->metadata_closed) {
702 ret_val = -EPIPE;
703 goto error;
704 }
705
706 /* Get consumer socket to use to push the metadata.*/
707 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
708 consumer);
709 if (!socket) {
710 ret_val = -1;
711 goto error;
712 }
713
714 ret = ust_app_push_metadata(registry, socket, 0);
715 if (ret < 0) {
716 ret_val = ret;
717 goto error;
718 }
719 pthread_mutex_unlock(&registry->lock);
720 return 0;
721
722 error:
723 pthread_mutex_unlock(&registry->lock);
724 return ret_val;
725 }
726
727 /*
728 * Send to the consumer a close metadata command for the given session. Once
729 * done, the metadata channel is deleted and the session metadata pointer is
730 * nullified. The session lock MUST be held unless the application is
731 * in the destroy path.
732 *
733 * Return 0 on success else a negative value.
734 */
735 static int close_metadata(struct ust_registry_session *registry,
736 struct consumer_output *consumer)
737 {
738 int ret;
739 struct consumer_socket *socket;
740
741 assert(registry);
742 assert(consumer);
743
744 rcu_read_lock();
745
746 pthread_mutex_lock(&registry->lock);
747
748 if (!registry->metadata_key || registry->metadata_closed) {
749 ret = 0;
750 goto end;
751 }
752
753 /* Get consumer socket to use to push the metadata.*/
754 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
755 consumer);
756 if (!socket) {
757 ret = -1;
758 goto error;
759 }
760
761 ret = consumer_close_metadata(socket, registry->metadata_key);
762 if (ret < 0) {
763 goto error;
764 }
765
766 error:
767 /*
768 * Metadata closed. Even on error this means that the consumer is not
769 * responding or not found so either way a second close should NOT be emit
770 * for this registry.
771 */
772 registry->metadata_closed = 1;
773 end:
774 pthread_mutex_unlock(&registry->lock);
775 rcu_read_unlock();
776 return ret;
777 }
778
779 /*
780 * We need to execute ht_destroy outside of RCU read-side critical
781 * section and outside of call_rcu thread, so we postpone its execution
782 * using ht_cleanup_push. It is simpler than to change the semantic of
783 * the many callers of delete_ust_app_session().
784 */
785 static
786 void delete_ust_app_session_rcu(struct rcu_head *head)
787 {
788 struct ust_app_session *ua_sess =
789 caa_container_of(head, struct ust_app_session, rcu_head);
790
791 ht_cleanup_push(ua_sess->channels);
792 free(ua_sess);
793 }
794
795 /*
796 * Delete ust app session safely. RCU read lock must be held before calling
797 * this function.
798 *
799 * The session list lock must be held by the caller.
800 */
801 static
802 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
803 struct ust_app *app)
804 {
805 int ret;
806 struct lttng_ht_iter iter;
807 struct ust_app_channel *ua_chan;
808 struct ust_registry_session *registry;
809
810 assert(ua_sess);
811
812 pthread_mutex_lock(&ua_sess->lock);
813
814 assert(!ua_sess->deleted);
815 ua_sess->deleted = true;
816
817 registry = get_session_registry(ua_sess);
818 /* Registry can be null on error path during initialization. */
819 if (registry) {
820 /* Push metadata for application before freeing the application. */
821 (void) push_metadata(registry, ua_sess->consumer);
822
823 /*
824 * Don't ask to close metadata for global per UID buffers. Close
825 * metadata only on destroy trace session in this case. Also, the
826 * previous push metadata could have flag the metadata registry to
827 * close so don't send a close command if closed.
828 */
829 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
830 /* And ask to close it for this session registry. */
831 (void) close_metadata(registry, ua_sess->consumer);
832 }
833 }
834
835 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
836 node.node) {
837 ret = lttng_ht_del(ua_sess->channels, &iter);
838 assert(!ret);
839 delete_ust_app_channel(sock, ua_chan, app);
840 }
841
842 /* In case of per PID, the registry is kept in the session. */
843 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
844 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
845 if (reg_pid) {
846 /*
847 * Registry can be null on error path during
848 * initialization.
849 */
850 buffer_reg_pid_remove(reg_pid);
851 buffer_reg_pid_destroy(reg_pid);
852 }
853 }
854
855 if (ua_sess->handle != -1) {
856 pthread_mutex_lock(&app->sock_lock);
857 ret = ustctl_release_handle(sock, ua_sess->handle);
858 pthread_mutex_unlock(&app->sock_lock);
859 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
860 ERR("UST app sock %d release session handle failed with ret %d",
861 sock, ret);
862 }
863 /* Remove session from application UST object descriptor. */
864 iter.iter.node = &ua_sess->ust_objd_node.node;
865 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
866 assert(!ret);
867 }
868
869 pthread_mutex_unlock(&ua_sess->lock);
870
871 consumer_output_put(ua_sess->consumer);
872
873 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
874 }
875
876 /*
877 * Delete a traceable application structure from the global list. Never call
878 * this function outside of a call_rcu call.
879 *
880 * RCU read side lock should _NOT_ be held when calling this function.
881 */
882 static
883 void delete_ust_app(struct ust_app *app)
884 {
885 int ret, sock;
886 struct ust_app_session *ua_sess, *tmp_ua_sess;
887
888 /*
889 * The session list lock must be held during this function to guarantee
890 * the existence of ua_sess.
891 */
892 session_lock_list();
893 /* Delete ust app sessions info */
894 sock = app->sock;
895 app->sock = -1;
896
897 /* Wipe sessions */
898 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
899 teardown_node) {
900 /* Free every object in the session and the session. */
901 rcu_read_lock();
902 delete_ust_app_session(sock, ua_sess, app);
903 rcu_read_unlock();
904 }
905
906 ht_cleanup_push(app->sessions);
907 ht_cleanup_push(app->ust_sessions_objd);
908 ht_cleanup_push(app->ust_objd);
909
910 /*
911 * Wait until we have deleted the application from the sock hash table
912 * before closing this socket, otherwise an application could re-use the
913 * socket ID and race with the teardown, using the same hash table entry.
914 *
915 * It's OK to leave the close in call_rcu. We want it to stay unique for
916 * all RCU readers that could run concurrently with unregister app,
917 * therefore we _need_ to only close that socket after a grace period. So
918 * it should stay in this RCU callback.
919 *
920 * This close() is a very important step of the synchronization model so
921 * every modification to this function must be carefully reviewed.
922 */
923 ret = close(sock);
924 if (ret) {
925 PERROR("close");
926 }
927 lttng_fd_put(LTTNG_FD_APPS, 1);
928
929 DBG2("UST app pid %d deleted", app->pid);
930 free(app);
931 session_unlock_list();
932 }
933
934 /*
935 * URCU intermediate call to delete an UST app.
936 */
937 static
938 void delete_ust_app_rcu(struct rcu_head *head)
939 {
940 struct lttng_ht_node_ulong *node =
941 caa_container_of(head, struct lttng_ht_node_ulong, head);
942 struct ust_app *app =
943 caa_container_of(node, struct ust_app, pid_n);
944
945 DBG3("Call RCU deleting app PID %d", app->pid);
946 delete_ust_app(app);
947 }
948
949 /*
950 * Delete the session from the application ht and delete the data structure by
951 * freeing every object inside and releasing them.
952 *
953 * The session list lock must be held by the caller.
954 */
955 static void destroy_app_session(struct ust_app *app,
956 struct ust_app_session *ua_sess)
957 {
958 int ret;
959 struct lttng_ht_iter iter;
960
961 assert(app);
962 assert(ua_sess);
963
964 iter.iter.node = &ua_sess->node.node;
965 ret = lttng_ht_del(app->sessions, &iter);
966 if (ret) {
967 /* Already scheduled for teardown. */
968 goto end;
969 }
970
971 /* Once deleted, free the data structure. */
972 delete_ust_app_session(app->sock, ua_sess, app);
973
974 end:
975 return;
976 }
977
978 /*
979 * Alloc new UST app session.
980 */
981 static
982 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
983 {
984 struct ust_app_session *ua_sess;
985
986 /* Init most of the default value by allocating and zeroing */
987 ua_sess = zmalloc(sizeof(struct ust_app_session));
988 if (ua_sess == NULL) {
989 PERROR("malloc");
990 goto error_free;
991 }
992
993 ua_sess->handle = -1;
994 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
995 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
996 pthread_mutex_init(&ua_sess->lock, NULL);
997
998 return ua_sess;
999
1000 error_free:
1001 return NULL;
1002 }
1003
1004 /*
1005 * Alloc new UST app channel.
1006 */
1007 static
1008 struct ust_app_channel *alloc_ust_app_channel(char *name,
1009 struct ust_app_session *ua_sess,
1010 struct lttng_ust_channel_attr *attr)
1011 {
1012 struct ust_app_channel *ua_chan;
1013
1014 /* Init most of the default value by allocating and zeroing */
1015 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1016 if (ua_chan == NULL) {
1017 PERROR("malloc");
1018 goto error;
1019 }
1020
1021 /* Setup channel name */
1022 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1023 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1024
1025 ua_chan->enabled = 1;
1026 ua_chan->handle = -1;
1027 ua_chan->session = ua_sess;
1028 ua_chan->key = get_next_channel_key();
1029 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1030 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1031 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1032
1033 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1034 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1035
1036 /* Copy attributes */
1037 if (attr) {
1038 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1039 ua_chan->attr.subbuf_size = attr->subbuf_size;
1040 ua_chan->attr.num_subbuf = attr->num_subbuf;
1041 ua_chan->attr.overwrite = attr->overwrite;
1042 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1043 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1044 ua_chan->attr.output = attr->output;
1045 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1046 }
1047 /* By default, the channel is a per cpu channel. */
1048 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1049
1050 DBG3("UST app channel %s allocated", ua_chan->name);
1051
1052 return ua_chan;
1053
1054 error:
1055 return NULL;
1056 }
1057
1058 /*
1059 * Allocate and initialize a UST app stream.
1060 *
1061 * Return newly allocated stream pointer or NULL on error.
1062 */
1063 struct ust_app_stream *ust_app_alloc_stream(void)
1064 {
1065 struct ust_app_stream *stream = NULL;
1066
1067 stream = zmalloc(sizeof(*stream));
1068 if (stream == NULL) {
1069 PERROR("zmalloc ust app stream");
1070 goto error;
1071 }
1072
1073 /* Zero could be a valid value for a handle so flag it to -1. */
1074 stream->handle = -1;
1075
1076 error:
1077 return stream;
1078 }
1079
1080 /*
1081 * Alloc new UST app event.
1082 */
1083 static
1084 struct ust_app_event *alloc_ust_app_event(char *name,
1085 struct lttng_ust_event *attr)
1086 {
1087 struct ust_app_event *ua_event;
1088
1089 /* Init most of the default value by allocating and zeroing */
1090 ua_event = zmalloc(sizeof(struct ust_app_event));
1091 if (ua_event == NULL) {
1092 PERROR("malloc");
1093 goto error;
1094 }
1095
1096 ua_event->enabled = 1;
1097 strncpy(ua_event->name, name, sizeof(ua_event->name));
1098 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1099 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1100
1101 /* Copy attributes */
1102 if (attr) {
1103 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1104 }
1105
1106 DBG3("UST app event %s allocated", ua_event->name);
1107
1108 return ua_event;
1109
1110 error:
1111 return NULL;
1112 }
1113
1114 /*
1115 * Alloc new UST app context.
1116 */
1117 static
1118 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1119 {
1120 struct ust_app_ctx *ua_ctx;
1121
1122 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1123 if (ua_ctx == NULL) {
1124 goto error;
1125 }
1126
1127 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1128
1129 if (uctx) {
1130 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1131 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1132 char *provider_name = NULL, *ctx_name = NULL;
1133
1134 provider_name = strdup(uctx->u.app_ctx.provider_name);
1135 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1136 if (!provider_name || !ctx_name) {
1137 free(provider_name);
1138 free(ctx_name);
1139 goto error;
1140 }
1141
1142 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1143 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1144 }
1145 }
1146
1147 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1148 return ua_ctx;
1149 error:
1150 free(ua_ctx);
1151 return NULL;
1152 }
1153
1154 /*
1155 * Allocate a filter and copy the given original filter.
1156 *
1157 * Return allocated filter or NULL on error.
1158 */
1159 static struct lttng_filter_bytecode *copy_filter_bytecode(
1160 struct lttng_filter_bytecode *orig_f)
1161 {
1162 struct lttng_filter_bytecode *filter = NULL;
1163
1164 /* Copy filter bytecode */
1165 filter = zmalloc(sizeof(*filter) + orig_f->len);
1166 if (!filter) {
1167 PERROR("zmalloc alloc filter bytecode");
1168 goto error;
1169 }
1170
1171 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1172
1173 error:
1174 return filter;
1175 }
1176
1177 /*
1178 * Create a liblttng-ust filter bytecode from given bytecode.
1179 *
1180 * Return allocated filter or NULL on error.
1181 */
1182 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1183 struct lttng_filter_bytecode *orig_f)
1184 {
1185 struct lttng_ust_filter_bytecode *filter = NULL;
1186
1187 /* Copy filter bytecode */
1188 filter = zmalloc(sizeof(*filter) + orig_f->len);
1189 if (!filter) {
1190 PERROR("zmalloc alloc ust filter bytecode");
1191 goto error;
1192 }
1193
1194 assert(sizeof(struct lttng_filter_bytecode) ==
1195 sizeof(struct lttng_ust_filter_bytecode));
1196 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1197 error:
1198 return filter;
1199 }
1200
1201 /*
1202 * Find an ust_app using the sock and return it. RCU read side lock must be
1203 * held before calling this helper function.
1204 */
1205 struct ust_app *ust_app_find_by_sock(int sock)
1206 {
1207 struct lttng_ht_node_ulong *node;
1208 struct lttng_ht_iter iter;
1209
1210 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1211 node = lttng_ht_iter_get_node_ulong(&iter);
1212 if (node == NULL) {
1213 DBG2("UST app find by sock %d not found", sock);
1214 goto error;
1215 }
1216
1217 return caa_container_of(node, struct ust_app, sock_n);
1218
1219 error:
1220 return NULL;
1221 }
1222
1223 /*
1224 * Find an ust_app using the notify sock and return it. RCU read side lock must
1225 * be held before calling this helper function.
1226 */
1227 static struct ust_app *find_app_by_notify_sock(int sock)
1228 {
1229 struct lttng_ht_node_ulong *node;
1230 struct lttng_ht_iter iter;
1231
1232 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1233 &iter);
1234 node = lttng_ht_iter_get_node_ulong(&iter);
1235 if (node == NULL) {
1236 DBG2("UST app find by notify sock %d not found", sock);
1237 goto error;
1238 }
1239
1240 return caa_container_of(node, struct ust_app, notify_sock_n);
1241
1242 error:
1243 return NULL;
1244 }
1245
1246 /*
1247 * Lookup for an ust app event based on event name, filter bytecode and the
1248 * event loglevel.
1249 *
1250 * Return an ust_app_event object or NULL on error.
1251 */
1252 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1253 char *name, struct lttng_filter_bytecode *filter,
1254 int loglevel_value,
1255 const struct lttng_event_exclusion *exclusion)
1256 {
1257 struct lttng_ht_iter iter;
1258 struct lttng_ht_node_str *node;
1259 struct ust_app_event *event = NULL;
1260 struct ust_app_ht_key key;
1261
1262 assert(name);
1263 assert(ht);
1264
1265 /* Setup key for event lookup. */
1266 key.name = name;
1267 key.filter = filter;
1268 key.loglevel_type = loglevel_value;
1269 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1270 key.exclusion = exclusion;
1271
1272 /* Lookup using the event name as hash and a custom match fct. */
1273 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1274 ht_match_ust_app_event, &key, &iter.iter);
1275 node = lttng_ht_iter_get_node_str(&iter);
1276 if (node == NULL) {
1277 goto end;
1278 }
1279
1280 event = caa_container_of(node, struct ust_app_event, node);
1281
1282 end:
1283 return event;
1284 }
1285
1286 /*
1287 * Create the channel context on the tracer.
1288 *
1289 * Called with UST app session lock held.
1290 */
1291 static
1292 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1293 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1294 {
1295 int ret;
1296
1297 health_code_update();
1298
1299 pthread_mutex_lock(&app->sock_lock);
1300 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1301 ua_chan->obj, &ua_ctx->obj);
1302 pthread_mutex_unlock(&app->sock_lock);
1303 if (ret < 0) {
1304 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1305 ERR("UST app create channel context failed for app (pid: %d) "
1306 "with ret %d", app->pid, ret);
1307 } else {
1308 /*
1309 * This is normal behavior, an application can die during the
1310 * creation process. Don't report an error so the execution can
1311 * continue normally.
1312 */
1313 ret = 0;
1314 DBG3("UST app disable event failed. Application is dead.");
1315 }
1316 goto error;
1317 }
1318
1319 ua_ctx->handle = ua_ctx->obj->handle;
1320
1321 DBG2("UST app context handle %d created successfully for channel %s",
1322 ua_ctx->handle, ua_chan->name);
1323
1324 error:
1325 health_code_update();
1326 return ret;
1327 }
1328
1329 /*
1330 * Set the filter on the tracer.
1331 */
1332 static
1333 int set_ust_event_filter(struct ust_app_event *ua_event,
1334 struct ust_app *app)
1335 {
1336 int ret;
1337 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1338
1339 health_code_update();
1340
1341 if (!ua_event->filter) {
1342 ret = 0;
1343 goto error;
1344 }
1345
1346 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1347 if (!ust_bytecode) {
1348 ret = -LTTNG_ERR_NOMEM;
1349 goto error;
1350 }
1351 pthread_mutex_lock(&app->sock_lock);
1352 ret = ustctl_set_filter(app->sock, ust_bytecode,
1353 ua_event->obj);
1354 pthread_mutex_unlock(&app->sock_lock);
1355 if (ret < 0) {
1356 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1357 ERR("UST app event %s filter failed for app (pid: %d) "
1358 "with ret %d", ua_event->attr.name, app->pid, ret);
1359 } else {
1360 /*
1361 * This is normal behavior, an application can die during the
1362 * creation process. Don't report an error so the execution can
1363 * continue normally.
1364 */
1365 ret = 0;
1366 DBG3("UST app filter event failed. Application is dead.");
1367 }
1368 goto error;
1369 }
1370
1371 DBG2("UST filter set successfully for event %s", ua_event->name);
1372
1373 error:
1374 health_code_update();
1375 free(ust_bytecode);
1376 return ret;
1377 }
1378
1379 static
1380 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1381 struct lttng_event_exclusion *exclusion)
1382 {
1383 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1384 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1385 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1386
1387 ust_exclusion = zmalloc(exclusion_alloc_size);
1388 if (!ust_exclusion) {
1389 PERROR("malloc");
1390 goto end;
1391 }
1392
1393 assert(sizeof(struct lttng_event_exclusion) ==
1394 sizeof(struct lttng_ust_event_exclusion));
1395 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1396 end:
1397 return ust_exclusion;
1398 }
1399
1400 /*
1401 * Set event exclusions on the tracer.
1402 */
1403 static
1404 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1405 struct ust_app *app)
1406 {
1407 int ret;
1408 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1409
1410 health_code_update();
1411
1412 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1413 ret = 0;
1414 goto error;
1415 }
1416
1417 ust_exclusion = create_ust_exclusion_from_exclusion(
1418 ua_event->exclusion);
1419 if (!ust_exclusion) {
1420 ret = -LTTNG_ERR_NOMEM;
1421 goto error;
1422 }
1423 pthread_mutex_lock(&app->sock_lock);
1424 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1425 pthread_mutex_unlock(&app->sock_lock);
1426 if (ret < 0) {
1427 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1428 ERR("UST app event %s exclusions failed for app (pid: %d) "
1429 "with ret %d", ua_event->attr.name, app->pid, ret);
1430 } else {
1431 /*
1432 * This is normal behavior, an application can die during the
1433 * creation process. Don't report an error so the execution can
1434 * continue normally.
1435 */
1436 ret = 0;
1437 DBG3("UST app event exclusion failed. Application is dead.");
1438 }
1439 goto error;
1440 }
1441
1442 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1443
1444 error:
1445 health_code_update();
1446 free(ust_exclusion);
1447 return ret;
1448 }
1449
1450 /*
1451 * Disable the specified event on to UST tracer for the UST session.
1452 */
1453 static int disable_ust_event(struct ust_app *app,
1454 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1455 {
1456 int ret;
1457
1458 health_code_update();
1459
1460 pthread_mutex_lock(&app->sock_lock);
1461 ret = ustctl_disable(app->sock, ua_event->obj);
1462 pthread_mutex_unlock(&app->sock_lock);
1463 if (ret < 0) {
1464 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1465 ERR("UST app event %s disable failed for app (pid: %d) "
1466 "and session handle %d with ret %d",
1467 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1468 } else {
1469 /*
1470 * This is normal behavior, an application can die during the
1471 * creation process. Don't report an error so the execution can
1472 * continue normally.
1473 */
1474 ret = 0;
1475 DBG3("UST app disable event failed. Application is dead.");
1476 }
1477 goto error;
1478 }
1479
1480 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1481 ua_event->attr.name, app->pid);
1482
1483 error:
1484 health_code_update();
1485 return ret;
1486 }
1487
1488 /*
1489 * Disable the specified channel on to UST tracer for the UST session.
1490 */
1491 static int disable_ust_channel(struct ust_app *app,
1492 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1493 {
1494 int ret;
1495
1496 health_code_update();
1497
1498 pthread_mutex_lock(&app->sock_lock);
1499 ret = ustctl_disable(app->sock, ua_chan->obj);
1500 pthread_mutex_unlock(&app->sock_lock);
1501 if (ret < 0) {
1502 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1503 ERR("UST app channel %s disable failed for app (pid: %d) "
1504 "and session handle %d with ret %d",
1505 ua_chan->name, app->pid, ua_sess->handle, ret);
1506 } else {
1507 /*
1508 * This is normal behavior, an application can die during the
1509 * creation process. Don't report an error so the execution can
1510 * continue normally.
1511 */
1512 ret = 0;
1513 DBG3("UST app disable channel failed. Application is dead.");
1514 }
1515 goto error;
1516 }
1517
1518 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1519 ua_chan->name, app->pid);
1520
1521 error:
1522 health_code_update();
1523 return ret;
1524 }
1525
1526 /*
1527 * Enable the specified channel on to UST tracer for the UST session.
1528 */
1529 static int enable_ust_channel(struct ust_app *app,
1530 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1531 {
1532 int ret;
1533
1534 health_code_update();
1535
1536 pthread_mutex_lock(&app->sock_lock);
1537 ret = ustctl_enable(app->sock, ua_chan->obj);
1538 pthread_mutex_unlock(&app->sock_lock);
1539 if (ret < 0) {
1540 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1541 ERR("UST app channel %s enable failed for app (pid: %d) "
1542 "and session handle %d with ret %d",
1543 ua_chan->name, app->pid, ua_sess->handle, ret);
1544 } else {
1545 /*
1546 * This is normal behavior, an application can die during the
1547 * creation process. Don't report an error so the execution can
1548 * continue normally.
1549 */
1550 ret = 0;
1551 DBG3("UST app enable channel failed. Application is dead.");
1552 }
1553 goto error;
1554 }
1555
1556 ua_chan->enabled = 1;
1557
1558 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1559 ua_chan->name, app->pid);
1560
1561 error:
1562 health_code_update();
1563 return ret;
1564 }
1565
1566 /*
1567 * Enable the specified event on to UST tracer for the UST session.
1568 */
1569 static int enable_ust_event(struct ust_app *app,
1570 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1571 {
1572 int ret;
1573
1574 health_code_update();
1575
1576 pthread_mutex_lock(&app->sock_lock);
1577 ret = ustctl_enable(app->sock, ua_event->obj);
1578 pthread_mutex_unlock(&app->sock_lock);
1579 if (ret < 0) {
1580 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1581 ERR("UST app event %s enable failed for app (pid: %d) "
1582 "and session handle %d with ret %d",
1583 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1584 } else {
1585 /*
1586 * This is normal behavior, an application can die during the
1587 * creation process. Don't report an error so the execution can
1588 * continue normally.
1589 */
1590 ret = 0;
1591 DBG3("UST app enable event failed. Application is dead.");
1592 }
1593 goto error;
1594 }
1595
1596 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1597 ua_event->attr.name, app->pid);
1598
1599 error:
1600 health_code_update();
1601 return ret;
1602 }
1603
1604 /*
1605 * Send channel and stream buffer to application.
1606 *
1607 * Return 0 on success. On error, a negative value is returned.
1608 */
1609 static int send_channel_pid_to_ust(struct ust_app *app,
1610 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1611 {
1612 int ret;
1613 struct ust_app_stream *stream, *stmp;
1614
1615 assert(app);
1616 assert(ua_sess);
1617 assert(ua_chan);
1618
1619 health_code_update();
1620
1621 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1622 app->sock);
1623
1624 /* Send channel to the application. */
1625 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1626 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1627 ret = -ENOTCONN; /* Caused by app exiting. */
1628 goto error;
1629 } else if (ret < 0) {
1630 goto error;
1631 }
1632
1633 health_code_update();
1634
1635 /* Send all streams to application. */
1636 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1637 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1638 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1639 ret = -ENOTCONN; /* Caused by app exiting. */
1640 goto error;
1641 } else if (ret < 0) {
1642 goto error;
1643 }
1644 /* We don't need the stream anymore once sent to the tracer. */
1645 cds_list_del(&stream->list);
1646 delete_ust_app_stream(-1, stream, app);
1647 }
1648 /* Flag the channel that it is sent to the application. */
1649 ua_chan->is_sent = 1;
1650
1651 error:
1652 health_code_update();
1653 return ret;
1654 }
1655
1656 /*
1657 * Create the specified event onto the UST tracer for a UST session.
1658 *
1659 * Should be called with session mutex held.
1660 */
1661 static
1662 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1663 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1664 {
1665 int ret = 0;
1666
1667 health_code_update();
1668
1669 /* Create UST event on tracer */
1670 pthread_mutex_lock(&app->sock_lock);
1671 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1672 &ua_event->obj);
1673 pthread_mutex_unlock(&app->sock_lock);
1674 if (ret < 0) {
1675 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1676 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1677 ua_event->attr.name, app->pid, ret);
1678 } else {
1679 /*
1680 * This is normal behavior, an application can die during the
1681 * creation process. Don't report an error so the execution can
1682 * continue normally.
1683 */
1684 ret = 0;
1685 DBG3("UST app create event failed. Application is dead.");
1686 }
1687 goto error;
1688 }
1689
1690 ua_event->handle = ua_event->obj->handle;
1691
1692 DBG2("UST app event %s created successfully for pid:%d",
1693 ua_event->attr.name, app->pid);
1694
1695 health_code_update();
1696
1697 /* Set filter if one is present. */
1698 if (ua_event->filter) {
1699 ret = set_ust_event_filter(ua_event, app);
1700 if (ret < 0) {
1701 goto error;
1702 }
1703 }
1704
1705 /* Set exclusions for the event */
1706 if (ua_event->exclusion) {
1707 ret = set_ust_event_exclusion(ua_event, app);
1708 if (ret < 0) {
1709 goto error;
1710 }
1711 }
1712
1713 /* If event not enabled, disable it on the tracer */
1714 if (ua_event->enabled) {
1715 /*
1716 * We now need to explicitly enable the event, since it
1717 * is now disabled at creation.
1718 */
1719 ret = enable_ust_event(app, ua_sess, ua_event);
1720 if (ret < 0) {
1721 /*
1722 * If we hit an EPERM, something is wrong with our enable call. If
1723 * we get an EEXIST, there is a problem on the tracer side since we
1724 * just created it.
1725 */
1726 switch (ret) {
1727 case -LTTNG_UST_ERR_PERM:
1728 /* Code flow problem */
1729 assert(0);
1730 case -LTTNG_UST_ERR_EXIST:
1731 /* It's OK for our use case. */
1732 ret = 0;
1733 break;
1734 default:
1735 break;
1736 }
1737 goto error;
1738 }
1739 }
1740
1741 error:
1742 health_code_update();
1743 return ret;
1744 }
1745
1746 /*
1747 * Copy data between an UST app event and a LTT event.
1748 */
1749 static void shadow_copy_event(struct ust_app_event *ua_event,
1750 struct ltt_ust_event *uevent)
1751 {
1752 size_t exclusion_alloc_size;
1753
1754 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1755 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1756
1757 ua_event->enabled = uevent->enabled;
1758
1759 /* Copy event attributes */
1760 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1761
1762 /* Copy filter bytecode */
1763 if (uevent->filter) {
1764 ua_event->filter = copy_filter_bytecode(uevent->filter);
1765 /* Filter might be NULL here in case of ENONEM. */
1766 }
1767
1768 /* Copy exclusion data */
1769 if (uevent->exclusion) {
1770 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1771 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1772 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1773 if (ua_event->exclusion == NULL) {
1774 PERROR("malloc");
1775 } else {
1776 memcpy(ua_event->exclusion, uevent->exclusion,
1777 exclusion_alloc_size);
1778 }
1779 }
1780 }
1781
1782 /*
1783 * Copy data between an UST app channel and a LTT channel.
1784 */
1785 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1786 struct ltt_ust_channel *uchan)
1787 {
1788 struct lttng_ht_iter iter;
1789 struct ltt_ust_event *uevent;
1790 struct ltt_ust_context *uctx;
1791 struct ust_app_event *ua_event;
1792
1793 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1794
1795 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1796 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1797
1798 ua_chan->tracefile_size = uchan->tracefile_size;
1799 ua_chan->tracefile_count = uchan->tracefile_count;
1800
1801 /* Copy event attributes since the layout is different. */
1802 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1803 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1804 ua_chan->attr.overwrite = uchan->attr.overwrite;
1805 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1806 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1807 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1808 ua_chan->attr.output = uchan->attr.output;
1809 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1810
1811 /*
1812 * Note that the attribute channel type is not set since the channel on the
1813 * tracing registry side does not have this information.
1814 */
1815
1816 ua_chan->enabled = uchan->enabled;
1817 ua_chan->tracing_channel_id = uchan->id;
1818
1819 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1820 struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1821
1822 if (ua_ctx == NULL) {
1823 continue;
1824 }
1825 lttng_ht_node_init_ulong(&ua_ctx->node,
1826 (unsigned long) ua_ctx->ctx.ctx);
1827 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1828 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1829 }
1830
1831 /* Copy all events from ltt ust channel to ust app channel */
1832 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1833 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1834 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1835 if (ua_event == NULL) {
1836 DBG2("UST event %s not found on shadow copy channel",
1837 uevent->attr.name);
1838 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1839 if (ua_event == NULL) {
1840 continue;
1841 }
1842 shadow_copy_event(ua_event, uevent);
1843 add_unique_ust_app_event(ua_chan, ua_event);
1844 }
1845 }
1846
1847 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1848 }
1849
1850 /*
1851 * Copy data between a UST app session and a regular LTT session.
1852 */
1853 static void shadow_copy_session(struct ust_app_session *ua_sess,
1854 struct ltt_ust_session *usess, struct ust_app *app)
1855 {
1856 struct lttng_ht_node_str *ua_chan_node;
1857 struct lttng_ht_iter iter;
1858 struct ltt_ust_channel *uchan;
1859 struct ust_app_channel *ua_chan;
1860 time_t rawtime;
1861 struct tm *timeinfo;
1862 char datetime[16];
1863 int ret;
1864 char tmp_shm_path[PATH_MAX];
1865
1866 /* Get date and time for unique app path */
1867 time(&rawtime);
1868 timeinfo = localtime(&rawtime);
1869 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1870
1871 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1872
1873 ua_sess->tracing_id = usess->id;
1874 ua_sess->id = get_next_session_id();
1875 ua_sess->uid = app->uid;
1876 ua_sess->gid = app->gid;
1877 ua_sess->euid = usess->uid;
1878 ua_sess->egid = usess->gid;
1879 ua_sess->buffer_type = usess->buffer_type;
1880 ua_sess->bits_per_long = app->bits_per_long;
1881
1882 /* There is only one consumer object per session possible. */
1883 consumer_output_get(usess->consumer);
1884 ua_sess->consumer = usess->consumer;
1885
1886 ua_sess->output_traces = usess->output_traces;
1887 ua_sess->live_timer_interval = usess->live_timer_interval;
1888 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1889 &usess->metadata_attr);
1890
1891 switch (ua_sess->buffer_type) {
1892 case LTTNG_BUFFER_PER_PID:
1893 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1894 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1895 datetime);
1896 break;
1897 case LTTNG_BUFFER_PER_UID:
1898 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1899 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1900 break;
1901 default:
1902 assert(0);
1903 goto error;
1904 }
1905 if (ret < 0) {
1906 PERROR("asprintf UST shadow copy session");
1907 assert(0);
1908 goto error;
1909 }
1910
1911 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1912 sizeof(ua_sess->root_shm_path));
1913 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1914 strncpy(ua_sess->shm_path, usess->shm_path,
1915 sizeof(ua_sess->shm_path));
1916 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1917 if (ua_sess->shm_path[0]) {
1918 switch (ua_sess->buffer_type) {
1919 case LTTNG_BUFFER_PER_PID:
1920 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1921 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1922 app->name, app->pid, datetime);
1923 break;
1924 case LTTNG_BUFFER_PER_UID:
1925 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1926 DEFAULT_UST_TRACE_UID_PATH,
1927 app->uid, app->bits_per_long);
1928 break;
1929 default:
1930 assert(0);
1931 goto error;
1932 }
1933 if (ret < 0) {
1934 PERROR("sprintf UST shadow copy session");
1935 assert(0);
1936 goto error;
1937 }
1938 strncat(ua_sess->shm_path, tmp_shm_path,
1939 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1940 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1941 }
1942
1943 /* Iterate over all channels in global domain. */
1944 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1945 uchan, node.node) {
1946 struct lttng_ht_iter uiter;
1947
1948 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1949 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1950 if (ua_chan_node != NULL) {
1951 /* Session exist. Contiuing. */
1952 continue;
1953 }
1954
1955 DBG2("Channel %s not found on shadow session copy, creating it",
1956 uchan->name);
1957 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess,
1958 &uchan->attr);
1959 if (ua_chan == NULL) {
1960 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1961 continue;
1962 }
1963 shadow_copy_channel(ua_chan, uchan);
1964 /*
1965 * The concept of metadata channel does not exist on the tracing
1966 * registry side of the session daemon so this can only be a per CPU
1967 * channel and not metadata.
1968 */
1969 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1970
1971 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1972 }
1973 return;
1974
1975 error:
1976 consumer_output_put(ua_sess->consumer);
1977 }
1978
1979 /*
1980 * Lookup sesison wrapper.
1981 */
1982 static
1983 void __lookup_session_by_app(struct ltt_ust_session *usess,
1984 struct ust_app *app, struct lttng_ht_iter *iter)
1985 {
1986 /* Get right UST app session from app */
1987 lttng_ht_lookup(app->sessions, &usess->id, iter);
1988 }
1989
1990 /*
1991 * Return ust app session from the app session hashtable using the UST session
1992 * id.
1993 */
1994 static struct ust_app_session *lookup_session_by_app(
1995 struct ltt_ust_session *usess, struct ust_app *app)
1996 {
1997 struct lttng_ht_iter iter;
1998 struct lttng_ht_node_u64 *node;
1999
2000 __lookup_session_by_app(usess, app, &iter);
2001 node = lttng_ht_iter_get_node_u64(&iter);
2002 if (node == NULL) {
2003 goto error;
2004 }
2005
2006 return caa_container_of(node, struct ust_app_session, node);
2007
2008 error:
2009 return NULL;
2010 }
2011
2012 /*
2013 * Setup buffer registry per PID for the given session and application. If none
2014 * is found, a new one is created, added to the global registry and
2015 * initialized. If regp is valid, it's set with the newly created object.
2016 *
2017 * Return 0 on success or else a negative value.
2018 */
2019 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
2020 struct ust_app *app, struct buffer_reg_pid **regp)
2021 {
2022 int ret = 0;
2023 struct buffer_reg_pid *reg_pid;
2024
2025 assert(ua_sess);
2026 assert(app);
2027
2028 rcu_read_lock();
2029
2030 reg_pid = buffer_reg_pid_find(ua_sess->id);
2031 if (!reg_pid) {
2032 /*
2033 * This is the create channel path meaning that if there is NO
2034 * registry available, we have to create one for this session.
2035 */
2036 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
2037 ua_sess->root_shm_path, ua_sess->shm_path);
2038 if (ret < 0) {
2039 goto error;
2040 }
2041 } else {
2042 goto end;
2043 }
2044
2045 /* Initialize registry. */
2046 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
2047 app->bits_per_long, app->uint8_t_alignment,
2048 app->uint16_t_alignment, app->uint32_t_alignment,
2049 app->uint64_t_alignment, app->long_alignment,
2050 app->byte_order, app->version.major,
2051 app->version.minor, reg_pid->root_shm_path,
2052 reg_pid->shm_path,
2053 ua_sess->euid, ua_sess->egid);
2054 if (ret < 0) {
2055 /*
2056 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2057 * destroy the buffer registry, because it is always expected
2058 * that if the buffer registry can be found, its ust registry is
2059 * non-NULL.
2060 */
2061 buffer_reg_pid_destroy(reg_pid);
2062 goto error;
2063 }
2064
2065 buffer_reg_pid_add(reg_pid);
2066
2067 DBG3("UST app buffer registry per PID created successfully");
2068
2069 end:
2070 if (regp) {
2071 *regp = reg_pid;
2072 }
2073 error:
2074 rcu_read_unlock();
2075 return ret;
2076 }
2077
2078 /*
2079 * Setup buffer registry per UID for the given session and application. If none
2080 * is found, a new one is created, added to the global registry and
2081 * initialized. If regp is valid, it's set with the newly created object.
2082 *
2083 * Return 0 on success or else a negative value.
2084 */
2085 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2086 struct ust_app_session *ua_sess,
2087 struct ust_app *app, struct buffer_reg_uid **regp)
2088 {
2089 int ret = 0;
2090 struct buffer_reg_uid *reg_uid;
2091
2092 assert(usess);
2093 assert(app);
2094
2095 rcu_read_lock();
2096
2097 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2098 if (!reg_uid) {
2099 /*
2100 * This is the create channel path meaning that if there is NO
2101 * registry available, we have to create one for this session.
2102 */
2103 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2104 LTTNG_DOMAIN_UST, &reg_uid,
2105 ua_sess->root_shm_path, ua_sess->shm_path);
2106 if (ret < 0) {
2107 goto error;
2108 }
2109 } else {
2110 goto end;
2111 }
2112
2113 /* Initialize registry. */
2114 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2115 app->bits_per_long, app->uint8_t_alignment,
2116 app->uint16_t_alignment, app->uint32_t_alignment,
2117 app->uint64_t_alignment, app->long_alignment,
2118 app->byte_order, app->version.major,
2119 app->version.minor, reg_uid->root_shm_path,
2120 reg_uid->shm_path, usess->uid, usess->gid);
2121 if (ret < 0) {
2122 /*
2123 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2124 * destroy the buffer registry, because it is always expected
2125 * that if the buffer registry can be found, its ust registry is
2126 * non-NULL.
2127 */
2128 buffer_reg_uid_destroy(reg_uid, NULL);
2129 goto error;
2130 }
2131 /* Add node to teardown list of the session. */
2132 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2133
2134 buffer_reg_uid_add(reg_uid);
2135
2136 DBG3("UST app buffer registry per UID created successfully");
2137 end:
2138 if (regp) {
2139 *regp = reg_uid;
2140 }
2141 error:
2142 rcu_read_unlock();
2143 return ret;
2144 }
2145
2146 /*
2147 * Create a session on the tracer side for the given app.
2148 *
2149 * On success, ua_sess_ptr is populated with the session pointer or else left
2150 * untouched. If the session was created, is_created is set to 1. On error,
2151 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2152 * be NULL.
2153 *
2154 * Returns 0 on success or else a negative code which is either -ENOMEM or
2155 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2156 */
2157 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2158 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2159 int *is_created)
2160 {
2161 int ret, created = 0;
2162 struct ust_app_session *ua_sess;
2163
2164 assert(usess);
2165 assert(app);
2166 assert(ua_sess_ptr);
2167
2168 health_code_update();
2169
2170 ua_sess = lookup_session_by_app(usess, app);
2171 if (ua_sess == NULL) {
2172 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2173 app->pid, usess->id);
2174 ua_sess = alloc_ust_app_session(app);
2175 if (ua_sess == NULL) {
2176 /* Only malloc can failed so something is really wrong */
2177 ret = -ENOMEM;
2178 goto error;
2179 }
2180 shadow_copy_session(ua_sess, usess, app);
2181 created = 1;
2182 }
2183
2184 switch (usess->buffer_type) {
2185 case LTTNG_BUFFER_PER_PID:
2186 /* Init local registry. */
2187 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2188 if (ret < 0) {
2189 delete_ust_app_session(-1, ua_sess, app);
2190 goto error;
2191 }
2192 break;
2193 case LTTNG_BUFFER_PER_UID:
2194 /* Look for a global registry. If none exists, create one. */
2195 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2196 if (ret < 0) {
2197 delete_ust_app_session(-1, ua_sess, app);
2198 goto error;
2199 }
2200 break;
2201 default:
2202 assert(0);
2203 ret = -EINVAL;
2204 goto error;
2205 }
2206
2207 health_code_update();
2208
2209 if (ua_sess->handle == -1) {
2210 pthread_mutex_lock(&app->sock_lock);
2211 ret = ustctl_create_session(app->sock);
2212 pthread_mutex_unlock(&app->sock_lock);
2213 if (ret < 0) {
2214 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2215 ERR("Creating session for app pid %d with ret %d",
2216 app->pid, ret);
2217 } else {
2218 DBG("UST app creating session failed. Application is dead");
2219 /*
2220 * This is normal behavior, an application can die during the
2221 * creation process. Don't report an error so the execution can
2222 * continue normally. This will get flagged ENOTCONN and the
2223 * caller will handle it.
2224 */
2225 ret = 0;
2226 }
2227 delete_ust_app_session(-1, ua_sess, app);
2228 if (ret != -ENOMEM) {
2229 /*
2230 * Tracer is probably gone or got an internal error so let's
2231 * behave like it will soon unregister or not usable.
2232 */
2233 ret = -ENOTCONN;
2234 }
2235 goto error;
2236 }
2237
2238 ua_sess->handle = ret;
2239
2240 /* Add ust app session to app's HT */
2241 lttng_ht_node_init_u64(&ua_sess->node,
2242 ua_sess->tracing_id);
2243 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2244 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2245 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2246 &ua_sess->ust_objd_node);
2247
2248 DBG2("UST app session created successfully with handle %d", ret);
2249 }
2250
2251 *ua_sess_ptr = ua_sess;
2252 if (is_created) {
2253 *is_created = created;
2254 }
2255
2256 /* Everything went well. */
2257 ret = 0;
2258
2259 error:
2260 health_code_update();
2261 return ret;
2262 }
2263
2264 /*
2265 * Match function for a hash table lookup of ust_app_ctx.
2266 *
2267 * It matches an ust app context based on the context type and, in the case
2268 * of perf counters, their name.
2269 */
2270 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2271 {
2272 struct ust_app_ctx *ctx;
2273 const struct lttng_ust_context_attr *key;
2274
2275 assert(node);
2276 assert(_key);
2277
2278 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2279 key = _key;
2280
2281 /* Context type */
2282 if (ctx->ctx.ctx != key->ctx) {
2283 goto no_match;
2284 }
2285
2286 switch(key->ctx) {
2287 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2288 if (strncmp(key->u.perf_counter.name,
2289 ctx->ctx.u.perf_counter.name,
2290 sizeof(key->u.perf_counter.name))) {
2291 goto no_match;
2292 }
2293 break;
2294 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2295 if (strcmp(key->u.app_ctx.provider_name,
2296 ctx->ctx.u.app_ctx.provider_name) ||
2297 strcmp(key->u.app_ctx.ctx_name,
2298 ctx->ctx.u.app_ctx.ctx_name)) {
2299 goto no_match;
2300 }
2301 break;
2302 default:
2303 break;
2304 }
2305
2306 /* Match. */
2307 return 1;
2308
2309 no_match:
2310 return 0;
2311 }
2312
2313 /*
2314 * Lookup for an ust app context from an lttng_ust_context.
2315 *
2316 * Must be called while holding RCU read side lock.
2317 * Return an ust_app_ctx object or NULL on error.
2318 */
2319 static
2320 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2321 struct lttng_ust_context_attr *uctx)
2322 {
2323 struct lttng_ht_iter iter;
2324 struct lttng_ht_node_ulong *node;
2325 struct ust_app_ctx *app_ctx = NULL;
2326
2327 assert(uctx);
2328 assert(ht);
2329
2330 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2331 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2332 ht_match_ust_app_ctx, uctx, &iter.iter);
2333 node = lttng_ht_iter_get_node_ulong(&iter);
2334 if (!node) {
2335 goto end;
2336 }
2337
2338 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2339
2340 end:
2341 return app_ctx;
2342 }
2343
2344 /*
2345 * Create a context for the channel on the tracer.
2346 *
2347 * Called with UST app session lock held and a RCU read side lock.
2348 */
2349 static
2350 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
2351 struct ust_app_channel *ua_chan,
2352 struct lttng_ust_context_attr *uctx,
2353 struct ust_app *app)
2354 {
2355 int ret = 0;
2356 struct ust_app_ctx *ua_ctx;
2357
2358 DBG2("UST app adding context to channel %s", ua_chan->name);
2359
2360 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2361 if (ua_ctx) {
2362 ret = -EEXIST;
2363 goto error;
2364 }
2365
2366 ua_ctx = alloc_ust_app_ctx(uctx);
2367 if (ua_ctx == NULL) {
2368 /* malloc failed */
2369 ret = -ENOMEM;
2370 goto error;
2371 }
2372
2373 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2374 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2375 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2376
2377 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2378 if (ret < 0) {
2379 goto error;
2380 }
2381
2382 error:
2383 return ret;
2384 }
2385
2386 /*
2387 * Enable on the tracer side a ust app event for the session and channel.
2388 *
2389 * Called with UST app session lock held.
2390 */
2391 static
2392 int enable_ust_app_event(struct ust_app_session *ua_sess,
2393 struct ust_app_event *ua_event, struct ust_app *app)
2394 {
2395 int ret;
2396
2397 ret = enable_ust_event(app, ua_sess, ua_event);
2398 if (ret < 0) {
2399 goto error;
2400 }
2401
2402 ua_event->enabled = 1;
2403
2404 error:
2405 return ret;
2406 }
2407
2408 /*
2409 * Disable on the tracer side a ust app event for the session and channel.
2410 */
2411 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2412 struct ust_app_event *ua_event, struct ust_app *app)
2413 {
2414 int ret;
2415
2416 ret = disable_ust_event(app, ua_sess, ua_event);
2417 if (ret < 0) {
2418 goto error;
2419 }
2420
2421 ua_event->enabled = 0;
2422
2423 error:
2424 return ret;
2425 }
2426
2427 /*
2428 * Lookup ust app channel for session and disable it on the tracer side.
2429 */
2430 static
2431 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2432 struct ust_app_channel *ua_chan, struct ust_app *app)
2433 {
2434 int ret;
2435
2436 ret = disable_ust_channel(app, ua_sess, ua_chan);
2437 if (ret < 0) {
2438 goto error;
2439 }
2440
2441 ua_chan->enabled = 0;
2442
2443 error:
2444 return ret;
2445 }
2446
2447 /*
2448 * Lookup ust app channel for session and enable it on the tracer side. This
2449 * MUST be called with a RCU read side lock acquired.
2450 */
2451 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2452 struct ltt_ust_channel *uchan, struct ust_app *app)
2453 {
2454 int ret = 0;
2455 struct lttng_ht_iter iter;
2456 struct lttng_ht_node_str *ua_chan_node;
2457 struct ust_app_channel *ua_chan;
2458
2459 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2460 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2461 if (ua_chan_node == NULL) {
2462 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2463 uchan->name, ua_sess->tracing_id);
2464 goto error;
2465 }
2466
2467 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2468
2469 ret = enable_ust_channel(app, ua_sess, ua_chan);
2470 if (ret < 0) {
2471 goto error;
2472 }
2473
2474 error:
2475 return ret;
2476 }
2477
2478 /*
2479 * Ask the consumer to create a channel and get it if successful.
2480 *
2481 * Called with UST app session lock held.
2482 *
2483 * Return 0 on success or else a negative value.
2484 */
2485 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2486 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2487 int bitness, struct ust_registry_session *registry)
2488 {
2489 int ret;
2490 unsigned int nb_fd = 0;
2491 struct consumer_socket *socket;
2492
2493 assert(usess);
2494 assert(ua_sess);
2495 assert(ua_chan);
2496 assert(registry);
2497
2498 rcu_read_lock();
2499 health_code_update();
2500
2501 /* Get the right consumer socket for the application. */
2502 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2503 if (!socket) {
2504 ret = -EINVAL;
2505 goto error;
2506 }
2507
2508 health_code_update();
2509
2510 /* Need one fd for the channel. */
2511 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2512 if (ret < 0) {
2513 ERR("Exhausted number of available FD upon create channel");
2514 goto error;
2515 }
2516
2517 /*
2518 * Ask consumer to create channel. The consumer will return the number of
2519 * stream we have to expect.
2520 */
2521 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2522 registry);
2523 if (ret < 0) {
2524 goto error_ask;
2525 }
2526
2527 /*
2528 * Compute the number of fd needed before receiving them. It must be 2 per
2529 * stream (2 being the default value here).
2530 */
2531 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2532
2533 /* Reserve the amount of file descriptor we need. */
2534 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2535 if (ret < 0) {
2536 ERR("Exhausted number of available FD upon create channel");
2537 goto error_fd_get_stream;
2538 }
2539
2540 health_code_update();
2541
2542 /*
2543 * Now get the channel from the consumer. This call wil populate the stream
2544 * list of that channel and set the ust objects.
2545 */
2546 if (usess->consumer->enabled) {
2547 ret = ust_consumer_get_channel(socket, ua_chan);
2548 if (ret < 0) {
2549 goto error_destroy;
2550 }
2551 }
2552
2553 rcu_read_unlock();
2554 return 0;
2555
2556 error_destroy:
2557 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2558 error_fd_get_stream:
2559 /*
2560 * Initiate a destroy channel on the consumer since we had an error
2561 * handling it on our side. The return value is of no importance since we
2562 * already have a ret value set by the previous error that we need to
2563 * return.
2564 */
2565 (void) ust_consumer_destroy_channel(socket, ua_chan);
2566 error_ask:
2567 lttng_fd_put(LTTNG_FD_APPS, 1);
2568 error:
2569 health_code_update();
2570 rcu_read_unlock();
2571 return ret;
2572 }
2573
2574 /*
2575 * Duplicate the ust data object of the ust app stream and save it in the
2576 * buffer registry stream.
2577 *
2578 * Return 0 on success or else a negative value.
2579 */
2580 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2581 struct ust_app_stream *stream)
2582 {
2583 int ret;
2584
2585 assert(reg_stream);
2586 assert(stream);
2587
2588 /* Reserve the amount of file descriptor we need. */
2589 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2590 if (ret < 0) {
2591 ERR("Exhausted number of available FD upon duplicate stream");
2592 goto error;
2593 }
2594
2595 /* Duplicate object for stream once the original is in the registry. */
2596 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2597 reg_stream->obj.ust);
2598 if (ret < 0) {
2599 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2600 reg_stream->obj.ust, stream->obj, ret);
2601 lttng_fd_put(LTTNG_FD_APPS, 2);
2602 goto error;
2603 }
2604 stream->handle = stream->obj->handle;
2605
2606 error:
2607 return ret;
2608 }
2609
2610 /*
2611 * Duplicate the ust data object of the ust app. channel and save it in the
2612 * buffer registry channel.
2613 *
2614 * Return 0 on success or else a negative value.
2615 */
2616 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2617 struct ust_app_channel *ua_chan)
2618 {
2619 int ret;
2620
2621 assert(reg_chan);
2622 assert(ua_chan);
2623
2624 /* Need two fds for the channel. */
2625 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2626 if (ret < 0) {
2627 ERR("Exhausted number of available FD upon duplicate channel");
2628 goto error_fd_get;
2629 }
2630
2631 /* Duplicate object for stream once the original is in the registry. */
2632 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2633 if (ret < 0) {
2634 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2635 reg_chan->obj.ust, ua_chan->obj, ret);
2636 goto error;
2637 }
2638 ua_chan->handle = ua_chan->obj->handle;
2639
2640 return 0;
2641
2642 error:
2643 lttng_fd_put(LTTNG_FD_APPS, 1);
2644 error_fd_get:
2645 return ret;
2646 }
2647
2648 /*
2649 * For a given channel buffer registry, setup all streams of the given ust
2650 * application channel.
2651 *
2652 * Return 0 on success or else a negative value.
2653 */
2654 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2655 struct ust_app_channel *ua_chan,
2656 struct ust_app *app)
2657 {
2658 int ret = 0;
2659 struct ust_app_stream *stream, *stmp;
2660
2661 assert(reg_chan);
2662 assert(ua_chan);
2663
2664 DBG2("UST app setup buffer registry stream");
2665
2666 /* Send all streams to application. */
2667 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2668 struct buffer_reg_stream *reg_stream;
2669
2670 ret = buffer_reg_stream_create(&reg_stream);
2671 if (ret < 0) {
2672 goto error;
2673 }
2674
2675 /*
2676 * Keep original pointer and nullify it in the stream so the delete
2677 * stream call does not release the object.
2678 */
2679 reg_stream->obj.ust = stream->obj;
2680 stream->obj = NULL;
2681 buffer_reg_stream_add(reg_stream, reg_chan);
2682
2683 /* We don't need the streams anymore. */
2684 cds_list_del(&stream->list);
2685 delete_ust_app_stream(-1, stream, app);
2686 }
2687
2688 error:
2689 return ret;
2690 }
2691
2692 /*
2693 * Create a buffer registry channel for the given session registry and
2694 * application channel object. If regp pointer is valid, it's set with the
2695 * created object. Important, the created object is NOT added to the session
2696 * registry hash table.
2697 *
2698 * Return 0 on success else a negative value.
2699 */
2700 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2701 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2702 {
2703 int ret;
2704 struct buffer_reg_channel *reg_chan = NULL;
2705
2706 assert(reg_sess);
2707 assert(ua_chan);
2708
2709 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2710
2711 /* Create buffer registry channel. */
2712 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2713 if (ret < 0) {
2714 goto error_create;
2715 }
2716 assert(reg_chan);
2717 reg_chan->consumer_key = ua_chan->key;
2718 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2719 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2720
2721 /* Create and add a channel registry to session. */
2722 ret = ust_registry_channel_add(reg_sess->reg.ust,
2723 ua_chan->tracing_channel_id);
2724 if (ret < 0) {
2725 goto error;
2726 }
2727 buffer_reg_channel_add(reg_sess, reg_chan);
2728
2729 if (regp) {
2730 *regp = reg_chan;
2731 }
2732
2733 return 0;
2734
2735 error:
2736 /* Safe because the registry channel object was not added to any HT. */
2737 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2738 error_create:
2739 return ret;
2740 }
2741
2742 /*
2743 * Setup buffer registry channel for the given session registry and application
2744 * channel object. If regp pointer is valid, it's set with the created object.
2745 *
2746 * Return 0 on success else a negative value.
2747 */
2748 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2749 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2750 struct ust_app *app)
2751 {
2752 int ret;
2753
2754 assert(reg_sess);
2755 assert(reg_chan);
2756 assert(ua_chan);
2757 assert(ua_chan->obj);
2758
2759 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2760
2761 /* Setup all streams for the registry. */
2762 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2763 if (ret < 0) {
2764 goto error;
2765 }
2766
2767 reg_chan->obj.ust = ua_chan->obj;
2768 ua_chan->obj = NULL;
2769
2770 return 0;
2771
2772 error:
2773 buffer_reg_channel_remove(reg_sess, reg_chan);
2774 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2775 return ret;
2776 }
2777
2778 /*
2779 * Send buffer registry channel to the application.
2780 *
2781 * Return 0 on success else a negative value.
2782 */
2783 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2784 struct ust_app *app, struct ust_app_session *ua_sess,
2785 struct ust_app_channel *ua_chan)
2786 {
2787 int ret;
2788 struct buffer_reg_stream *reg_stream;
2789
2790 assert(reg_chan);
2791 assert(app);
2792 assert(ua_sess);
2793 assert(ua_chan);
2794
2795 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2796
2797 ret = duplicate_channel_object(reg_chan, ua_chan);
2798 if (ret < 0) {
2799 goto error;
2800 }
2801
2802 /* Send channel to the application. */
2803 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2804 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2805 ret = -ENOTCONN; /* Caused by app exiting. */
2806 goto error;
2807 } else if (ret < 0) {
2808 goto error;
2809 }
2810
2811 health_code_update();
2812
2813 /* Send all streams to application. */
2814 pthread_mutex_lock(&reg_chan->stream_list_lock);
2815 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2816 struct ust_app_stream stream;
2817
2818 ret = duplicate_stream_object(reg_stream, &stream);
2819 if (ret < 0) {
2820 goto error_stream_unlock;
2821 }
2822
2823 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2824 if (ret < 0) {
2825 (void) release_ust_app_stream(-1, &stream, app);
2826 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2827 ret = -ENOTCONN; /* Caused by app exiting. */
2828 }
2829 goto error_stream_unlock;
2830 }
2831
2832 /*
2833 * The return value is not important here. This function will output an
2834 * error if needed.
2835 */
2836 (void) release_ust_app_stream(-1, &stream, app);
2837 }
2838 ua_chan->is_sent = 1;
2839
2840 error_stream_unlock:
2841 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2842 error:
2843 return ret;
2844 }
2845
2846 /*
2847 * Create and send to the application the created buffers with per UID buffers.
2848 *
2849 * This MUST be called with a RCU read side lock acquired.
2850 * The session list lock and the session's lock must be acquired.
2851 *
2852 * Return 0 on success else a negative value.
2853 */
2854 static int create_channel_per_uid(struct ust_app *app,
2855 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2856 struct ust_app_channel *ua_chan)
2857 {
2858 int ret;
2859 struct buffer_reg_uid *reg_uid;
2860 struct buffer_reg_channel *reg_chan;
2861 bool created = false;
2862
2863 assert(app);
2864 assert(usess);
2865 assert(ua_sess);
2866 assert(ua_chan);
2867
2868 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2869
2870 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2871 /*
2872 * The session creation handles the creation of this global registry
2873 * object. If none can be find, there is a code flow problem or a
2874 * teardown race.
2875 */
2876 assert(reg_uid);
2877
2878 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2879 reg_uid);
2880 if (!reg_chan) {
2881 /* Create the buffer registry channel object. */
2882 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2883 if (ret < 0) {
2884 ERR("Error creating the UST channel \"%s\" registry instance",
2885 ua_chan->name);
2886 goto error;
2887 }
2888 assert(reg_chan);
2889
2890 /*
2891 * Create the buffers on the consumer side. This call populates the
2892 * ust app channel object with all streams and data object.
2893 */
2894 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2895 app->bits_per_long, reg_uid->registry->reg.ust);
2896 if (ret < 0) {
2897 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2898 ua_chan->name);
2899
2900 /*
2901 * Let's remove the previously created buffer registry channel so
2902 * it's not visible anymore in the session registry.
2903 */
2904 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2905 ua_chan->tracing_channel_id, false);
2906 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2907 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2908 goto error;
2909 }
2910
2911 /*
2912 * Setup the streams and add it to the session registry.
2913 */
2914 ret = setup_buffer_reg_channel(reg_uid->registry,
2915 ua_chan, reg_chan, app);
2916 if (ret < 0) {
2917 ERR("Error setting up UST channel \"%s\"",
2918 ua_chan->name);
2919 goto error;
2920 }
2921 created = true;
2922 }
2923
2924 if (created) {
2925 enum lttng_error_code cmd_ret;
2926 struct ltt_session *session;
2927 uint64_t chan_reg_key;
2928 struct ust_registry_channel *chan_reg;
2929
2930 chan_reg_key = ua_chan->tracing_channel_id;
2931
2932 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2933 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2934 chan_reg_key);
2935 assert(chan_reg);
2936 chan_reg->consumer_key = ua_chan->key;
2937 chan_reg = NULL;
2938 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2939
2940 session = session_find_by_id(ua_sess->tracing_id);
2941 assert(session);
2942
2943 assert(pthread_mutex_trylock(&session->lock));
2944 assert(session_trylock_list());
2945 cmd_ret = notification_thread_command_add_channel(
2946 notification_thread_handle, session->name,
2947 ua_sess->euid, ua_sess->egid,
2948 ua_chan->name,
2949 ua_chan->key,
2950 LTTNG_DOMAIN_UST,
2951 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2952 if (cmd_ret != LTTNG_OK) {
2953 ret = - (int) cmd_ret;
2954 ERR("Failed to add channel to notification thread");
2955 goto error;
2956 }
2957 }
2958
2959 /* Send buffers to the application. */
2960 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2961 if (ret < 0) {
2962 if (ret != -ENOTCONN) {
2963 ERR("Error sending channel to application");
2964 }
2965 goto error;
2966 }
2967
2968 error:
2969 return ret;
2970 }
2971
2972 /*
2973 * Create and send to the application the created buffers with per PID buffers.
2974 *
2975 * Called with UST app session lock held.
2976 * The session list lock and the session's lock must be acquired.
2977 *
2978 * Return 0 on success else a negative value.
2979 */
2980 static int create_channel_per_pid(struct ust_app *app,
2981 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2982 struct ust_app_channel *ua_chan)
2983 {
2984 int ret;
2985 struct ust_registry_session *registry;
2986 enum lttng_error_code cmd_ret;
2987 struct ltt_session *session;
2988 uint64_t chan_reg_key;
2989 struct ust_registry_channel *chan_reg;
2990
2991 assert(app);
2992 assert(usess);
2993 assert(ua_sess);
2994 assert(ua_chan);
2995
2996 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2997
2998 rcu_read_lock();
2999
3000 registry = get_session_registry(ua_sess);
3001 /* The UST app session lock is held, registry shall not be null. */
3002 assert(registry);
3003
3004 /* Create and add a new channel registry to session. */
3005 ret = ust_registry_channel_add(registry, ua_chan->key);
3006 if (ret < 0) {
3007 ERR("Error creating the UST channel \"%s\" registry instance",
3008 ua_chan->name);
3009 goto error;
3010 }
3011
3012 /* Create and get channel on the consumer side. */
3013 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
3014 app->bits_per_long, registry);
3015 if (ret < 0) {
3016 ERR("Error creating UST channel \"%s\" on the consumer daemon",
3017 ua_chan->name);
3018 goto error;
3019 }
3020
3021 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
3022 if (ret < 0) {
3023 if (ret != -ENOTCONN) {
3024 ERR("Error sending channel to application");
3025 }
3026 goto error;
3027 }
3028
3029 session = session_find_by_id(ua_sess->tracing_id);
3030 assert(session);
3031
3032 chan_reg_key = ua_chan->key;
3033 pthread_mutex_lock(&registry->lock);
3034 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
3035 assert(chan_reg);
3036 chan_reg->consumer_key = ua_chan->key;
3037 pthread_mutex_unlock(&registry->lock);
3038
3039 assert(pthread_mutex_trylock(&session->lock));
3040 assert(session_trylock_list());
3041
3042 cmd_ret = notification_thread_command_add_channel(
3043 notification_thread_handle, session->name,
3044 ua_sess->euid, ua_sess->egid,
3045 ua_chan->name,
3046 ua_chan->key,
3047 LTTNG_DOMAIN_UST,
3048 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
3049 if (cmd_ret != LTTNG_OK) {
3050 ret = - (int) cmd_ret;
3051 ERR("Failed to add channel to notification thread");
3052 goto error;
3053 }
3054
3055 error:
3056 rcu_read_unlock();
3057 return ret;
3058 }
3059
3060 /*
3061 * From an already allocated ust app channel, create the channel buffers if
3062 * need and send it to the application. This MUST be called with a RCU read
3063 * side lock acquired.
3064 *
3065 * Called with UST app session lock held.
3066 *
3067 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3068 * the application exited concurrently.
3069 */
3070 static int do_create_channel(struct ust_app *app,
3071 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3072 struct ust_app_channel *ua_chan)
3073 {
3074 int ret;
3075
3076 assert(app);
3077 assert(usess);
3078 assert(ua_sess);
3079 assert(ua_chan);
3080
3081 /* Handle buffer type before sending the channel to the application. */
3082 switch (usess->buffer_type) {
3083 case LTTNG_BUFFER_PER_UID:
3084 {
3085 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3086 if (ret < 0) {
3087 goto error;
3088 }
3089 break;
3090 }
3091 case LTTNG_BUFFER_PER_PID:
3092 {
3093 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3094 if (ret < 0) {
3095 goto error;
3096 }
3097 break;
3098 }
3099 default:
3100 assert(0);
3101 ret = -EINVAL;
3102 goto error;
3103 }
3104
3105 /* Initialize ust objd object using the received handle and add it. */
3106 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3107 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3108
3109 /* If channel is not enabled, disable it on the tracer */
3110 if (!ua_chan->enabled) {
3111 ret = disable_ust_channel(app, ua_sess, ua_chan);
3112 if (ret < 0) {
3113 goto error;
3114 }
3115 }
3116
3117 error:
3118 return ret;
3119 }
3120
3121 /*
3122 * Create UST app channel and create it on the tracer. Set ua_chanp of the
3123 * newly created channel if not NULL.
3124 *
3125 * Called with UST app session lock and RCU read-side lock held.
3126 *
3127 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3128 * the application exited concurrently.
3129 */
3130 static int create_ust_app_channel(struct ust_app_session *ua_sess,
3131 struct ltt_ust_channel *uchan, struct ust_app *app,
3132 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3133 struct ust_app_channel **ua_chanp)
3134 {
3135 int ret = 0;
3136 struct lttng_ht_iter iter;
3137 struct lttng_ht_node_str *ua_chan_node;
3138 struct ust_app_channel *ua_chan;
3139
3140 /* Lookup channel in the ust app session */
3141 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3142 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3143 if (ua_chan_node != NULL) {
3144 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3145 goto end;
3146 }
3147
3148 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3149 if (ua_chan == NULL) {
3150 /* Only malloc can fail here */
3151 ret = -ENOMEM;
3152 goto error_alloc;
3153 }
3154 shadow_copy_channel(ua_chan, uchan);
3155
3156 /* Set channel type. */
3157 ua_chan->attr.type = type;
3158
3159 ret = do_create_channel(app, usess, ua_sess, ua_chan);
3160 if (ret < 0) {
3161 goto error;
3162 }
3163
3164 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
3165 app->pid);
3166
3167 /* Only add the channel if successful on the tracer side. */
3168 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3169 end:
3170 if (ua_chanp) {
3171 *ua_chanp = ua_chan;
3172 }
3173
3174 /* Everything went well. */
3175 return 0;
3176
3177 error:
3178 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
3179 error_alloc:
3180 return ret;
3181 }
3182
3183 /*
3184 * Create UST app event and create it on the tracer side.
3185 *
3186 * Called with ust app session mutex held.
3187 */
3188 static
3189 int create_ust_app_event(struct ust_app_session *ua_sess,
3190 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3191 struct ust_app *app)
3192 {
3193 int ret = 0;
3194 struct ust_app_event *ua_event;
3195
3196 /* Get event node */
3197 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3198 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3199 if (ua_event != NULL) {
3200 ret = -EEXIST;
3201 goto end;
3202 }
3203
3204 /* Does not exist so create one */
3205 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3206 if (ua_event == NULL) {
3207 /* Only malloc can failed so something is really wrong */
3208 ret = -ENOMEM;
3209 goto end;
3210 }
3211 shadow_copy_event(ua_event, uevent);
3212
3213 /* Create it on the tracer side */
3214 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3215 if (ret < 0) {
3216 /* Not found previously means that it does not exist on the tracer */
3217 assert(ret != -LTTNG_UST_ERR_EXIST);
3218 goto error;
3219 }
3220
3221 add_unique_ust_app_event(ua_chan, ua_event);
3222
3223 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3224 app->pid);
3225
3226 end:
3227 return ret;
3228
3229 error:
3230 /* Valid. Calling here is already in a read side lock */
3231 delete_ust_app_event(-1, ua_event, app);
3232 return ret;
3233 }
3234
3235 /*
3236 * Create UST metadata and open it on the tracer side.
3237 *
3238 * Called with UST app session lock held and RCU read side lock.
3239 */
3240 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3241 struct ust_app *app, struct consumer_output *consumer)
3242 {
3243 int ret = 0;
3244 struct ust_app_channel *metadata;
3245 struct consumer_socket *socket;
3246 struct ust_registry_session *registry;
3247
3248 assert(ua_sess);
3249 assert(app);
3250 assert(consumer);
3251
3252 registry = get_session_registry(ua_sess);
3253 /* The UST app session is held registry shall not be null. */
3254 assert(registry);
3255
3256 pthread_mutex_lock(&registry->lock);
3257
3258 /* Metadata already exists for this registry or it was closed previously */
3259 if (registry->metadata_key || registry->metadata_closed) {
3260 ret = 0;
3261 goto error;
3262 }
3263
3264 /* Allocate UST metadata */
3265 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3266 if (!metadata) {
3267 /* malloc() failed */
3268 ret = -ENOMEM;
3269 goto error;
3270 }
3271
3272 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3273
3274 /* Need one fd for the channel. */
3275 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3276 if (ret < 0) {
3277 ERR("Exhausted number of available FD upon create metadata");
3278 goto error;
3279 }
3280
3281 /* Get the right consumer socket for the application. */
3282 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3283 if (!socket) {
3284 ret = -EINVAL;
3285 goto error_consumer;
3286 }
3287
3288 /*
3289 * Keep metadata key so we can identify it on the consumer side. Assign it
3290 * to the registry *before* we ask the consumer so we avoid the race of the
3291 * consumer requesting the metadata and the ask_channel call on our side
3292 * did not returned yet.
3293 */
3294 registry->metadata_key = metadata->key;
3295
3296 /*
3297 * Ask the metadata channel creation to the consumer. The metadata object
3298 * will be created by the consumer and kept their. However, the stream is
3299 * never added or monitored until we do a first push metadata to the
3300 * consumer.
3301 */
3302 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3303 registry);
3304 if (ret < 0) {
3305 /* Nullify the metadata key so we don't try to close it later on. */
3306 registry->metadata_key = 0;
3307 goto error_consumer;
3308 }
3309
3310 /*
3311 * The setup command will make the metadata stream be sent to the relayd,
3312 * if applicable, and the thread managing the metadatas. This is important
3313 * because after this point, if an error occurs, the only way the stream
3314 * can be deleted is to be monitored in the consumer.
3315 */
3316 ret = consumer_setup_metadata(socket, metadata->key);
3317 if (ret < 0) {
3318 /* Nullify the metadata key so we don't try to close it later on. */
3319 registry->metadata_key = 0;
3320 goto error_consumer;
3321 }
3322
3323 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3324 metadata->key, app->pid);
3325
3326 error_consumer:
3327 lttng_fd_put(LTTNG_FD_APPS, 1);
3328 delete_ust_app_channel(-1, metadata, app);
3329 error:
3330 pthread_mutex_unlock(&registry->lock);
3331 return ret;
3332 }
3333
3334 /*
3335 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3336 * acquired before calling this function.
3337 */
3338 struct ust_app *ust_app_find_by_pid(pid_t pid)
3339 {
3340 struct ust_app *app = NULL;
3341 struct lttng_ht_node_ulong *node;
3342 struct lttng_ht_iter iter;
3343
3344 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3345 node = lttng_ht_iter_get_node_ulong(&iter);
3346 if (node == NULL) {
3347 DBG2("UST app no found with pid %d", pid);
3348 goto error;
3349 }
3350
3351 DBG2("Found UST app by pid %d", pid);
3352
3353 app = caa_container_of(node, struct ust_app, pid_n);
3354
3355 error:
3356 return app;
3357 }
3358
3359 /*
3360 * Allocate and init an UST app object using the registration information and
3361 * the command socket. This is called when the command socket connects to the
3362 * session daemon.
3363 *
3364 * The object is returned on success or else NULL.
3365 */
3366 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3367 {
3368 struct ust_app *lta = NULL;
3369
3370 assert(msg);
3371 assert(sock >= 0);
3372
3373 DBG3("UST app creating application for socket %d", sock);
3374
3375 if ((msg->bits_per_long == 64 &&
3376 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3377 || (msg->bits_per_long == 32 &&
3378 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3379 ERR("Registration failed: application \"%s\" (pid: %d) has "
3380 "%d-bit long, but no consumerd for this size is available.\n",
3381 msg->name, msg->pid, msg->bits_per_long);
3382 goto error;
3383 }
3384
3385 lta = zmalloc(sizeof(struct ust_app));
3386 if (lta == NULL) {
3387 PERROR("malloc");
3388 goto error;
3389 }
3390
3391 lta->ppid = msg->ppid;
3392 lta->uid = msg->uid;
3393 lta->gid = msg->gid;
3394
3395 lta->bits_per_long = msg->bits_per_long;
3396 lta->uint8_t_alignment = msg->uint8_t_alignment;
3397 lta->uint16_t_alignment = msg->uint16_t_alignment;
3398 lta->uint32_t_alignment = msg->uint32_t_alignment;
3399 lta->uint64_t_alignment = msg->uint64_t_alignment;
3400 lta->long_alignment = msg->long_alignment;
3401 lta->byte_order = msg->byte_order;
3402
3403 lta->v_major = msg->major;
3404 lta->v_minor = msg->minor;
3405 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3406 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3407 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3408 lta->notify_sock = -1;
3409
3410 /* Copy name and make sure it's NULL terminated. */
3411 strncpy(lta->name, msg->name, sizeof(lta->name));
3412 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3413
3414 /*
3415 * Before this can be called, when receiving the registration information,
3416 * the application compatibility is checked. So, at this point, the
3417 * application can work with this session daemon.
3418 */
3419 lta->compatible = 1;
3420
3421 lta->pid = msg->pid;
3422 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3423 lta->sock = sock;
3424 pthread_mutex_init(&lta->sock_lock, NULL);
3425 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3426
3427 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3428 error:
3429 return lta;
3430 }
3431
3432 /*
3433 * For a given application object, add it to every hash table.
3434 */
3435 void ust_app_add(struct ust_app *app)
3436 {
3437 assert(app);
3438 assert(app->notify_sock >= 0);
3439
3440 rcu_read_lock();
3441
3442 /*
3443 * On a re-registration, we want to kick out the previous registration of
3444 * that pid
3445 */
3446 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3447
3448 /*
3449 * The socket _should_ be unique until _we_ call close. So, a add_unique
3450 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3451 * already in the table.
3452 */
3453 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3454
3455 /* Add application to the notify socket hash table. */
3456 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3457 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3458
3459 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3460 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3461 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3462 app->v_minor);
3463
3464 rcu_read_unlock();
3465 }
3466
3467 /*
3468 * Set the application version into the object.
3469 *
3470 * Return 0 on success else a negative value either an errno code or a
3471 * LTTng-UST error code.
3472 */
3473 int ust_app_version(struct ust_app *app)
3474 {
3475 int ret;
3476
3477 assert(app);
3478
3479 pthread_mutex_lock(&app->sock_lock);
3480 ret = ustctl_tracer_version(app->sock, &app->version);
3481 pthread_mutex_unlock(&app->sock_lock);
3482 if (ret < 0) {
3483 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3484 ERR("UST app %d version failed with ret %d", app->sock, ret);
3485 } else {
3486 DBG3("UST app %d version failed. Application is dead", app->sock);
3487 }
3488 }
3489
3490 return ret;
3491 }
3492
3493 /*
3494 * Unregister app by removing it from the global traceable app list and freeing
3495 * the data struct.
3496 *
3497 * The socket is already closed at this point so no close to sock.
3498 */
3499 void ust_app_unregister(int sock)
3500 {
3501 struct ust_app *lta;
3502 struct lttng_ht_node_ulong *node;
3503 struct lttng_ht_iter ust_app_sock_iter;
3504 struct lttng_ht_iter iter;
3505 struct ust_app_session *ua_sess;
3506 int ret;
3507
3508 rcu_read_lock();
3509
3510 /* Get the node reference for a call_rcu */
3511 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3512 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3513 assert(node);
3514
3515 lta = caa_container_of(node, struct ust_app, sock_n);
3516 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3517
3518 /*
3519 * For per-PID buffers, perform "push metadata" and flush all
3520 * application streams before removing app from hash tables,
3521 * ensuring proper behavior of data_pending check.
3522 * Remove sessions so they are not visible during deletion.
3523 */
3524 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3525 node.node) {
3526 struct ust_registry_session *registry;
3527
3528 ret = lttng_ht_del(lta->sessions, &iter);
3529 if (ret) {
3530 /* The session was already removed so scheduled for teardown. */
3531 continue;
3532 }
3533
3534 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3535 (void) ust_app_flush_app_session(lta, ua_sess);
3536 }
3537
3538 /*
3539 * Add session to list for teardown. This is safe since at this point we
3540 * are the only one using this list.
3541 */
3542 pthread_mutex_lock(&ua_sess->lock);
3543
3544 if (ua_sess->deleted) {
3545 pthread_mutex_unlock(&ua_sess->lock);
3546 continue;
3547 }
3548
3549 /*
3550 * Normally, this is done in the delete session process which is
3551 * executed in the call rcu below. However, upon registration we can't
3552 * afford to wait for the grace period before pushing data or else the
3553 * data pending feature can race between the unregistration and stop
3554 * command where the data pending command is sent *before* the grace
3555 * period ended.
3556 *
3557 * The close metadata below nullifies the metadata pointer in the
3558 * session so the delete session will NOT push/close a second time.
3559 */
3560 registry = get_session_registry(ua_sess);
3561 if (registry) {
3562 /* Push metadata for application before freeing the application. */
3563 (void) push_metadata(registry, ua_sess->consumer);
3564
3565 /*
3566 * Don't ask to close metadata for global per UID buffers. Close
3567 * metadata only on destroy trace session in this case. Also, the
3568 * previous push metadata could have flag the metadata registry to
3569 * close so don't send a close command if closed.
3570 */
3571 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3572 /* And ask to close it for this session registry. */
3573 (void) close_metadata(registry, ua_sess->consumer);
3574 }
3575 }
3576 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3577
3578 pthread_mutex_unlock(&ua_sess->lock);
3579 }
3580
3581 /* Remove application from PID hash table */
3582 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3583 assert(!ret);
3584
3585 /*
3586 * Remove application from notify hash table. The thread handling the
3587 * notify socket could have deleted the node so ignore on error because
3588 * either way it's valid. The close of that socket is handled by the
3589 * apps_notify_thread.
3590 */
3591 iter.iter.node = &lta->notify_sock_n.node;
3592 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3593
3594 /*
3595 * Ignore return value since the node might have been removed before by an
3596 * add replace during app registration because the PID can be reassigned by
3597 * the OS.
3598 */
3599 iter.iter.node = &lta->pid_n.node;
3600 ret = lttng_ht_del(ust_app_ht, &iter);
3601 if (ret) {
3602 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3603 lta->pid);
3604 }
3605
3606 /* Free memory */
3607 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3608
3609 rcu_read_unlock();
3610 return;
3611 }
3612
3613 /*
3614 * Fill events array with all events name of all registered apps.
3615 */
3616 int ust_app_list_events(struct lttng_event **events)
3617 {
3618 int ret, handle;
3619 size_t nbmem, count = 0;
3620 struct lttng_ht_iter iter;
3621 struct ust_app *app;
3622 struct lttng_event *tmp_event;
3623
3624 nbmem = UST_APP_EVENT_LIST_SIZE;
3625 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3626 if (tmp_event == NULL) {
3627 PERROR("zmalloc ust app events");
3628 ret = -ENOMEM;
3629 goto error;
3630 }
3631
3632 rcu_read_lock();
3633
3634 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3635 struct lttng_ust_tracepoint_iter uiter;
3636
3637 health_code_update();
3638
3639 if (!app->compatible) {
3640 /*
3641 * TODO: In time, we should notice the caller of this error by
3642 * telling him that this is a version error.
3643 */
3644 continue;
3645 }
3646 pthread_mutex_lock(&app->sock_lock);
3647 handle = ustctl_tracepoint_list(app->sock);
3648 if (handle < 0) {
3649 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3650 ERR("UST app list events getting handle failed for app pid %d",
3651 app->pid);
3652 }
3653 pthread_mutex_unlock(&app->sock_lock);
3654 continue;
3655 }
3656
3657 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3658 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3659 /* Handle ustctl error. */
3660 if (ret < 0) {
3661 int release_ret;
3662
3663 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3664 ERR("UST app tp list get failed for app %d with ret %d",
3665 app->sock, ret);
3666 } else {
3667 DBG3("UST app tp list get failed. Application is dead");
3668 /*
3669 * This is normal behavior, an application can die during the
3670 * creation process. Don't report an error so the execution can
3671 * continue normally. Continue normal execution.
3672 */
3673 break;
3674 }
3675 free(tmp_event);
3676 release_ret = ustctl_release_handle(app->sock, handle);
3677 if (release_ret < 0 &&
3678 release_ret != -LTTNG_UST_ERR_EXITING &&
3679 release_ret != -EPIPE) {
3680 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3681 }
3682 pthread_mutex_unlock(&app->sock_lock);
3683 goto rcu_error;
3684 }
3685
3686 health_code_update();
3687 if (count >= nbmem) {
3688 /* In case the realloc fails, we free the memory */
3689 struct lttng_event *new_tmp_event;
3690 size_t new_nbmem;
3691
3692 new_nbmem = nbmem << 1;
3693 DBG2("Reallocating event list from %zu to %zu entries",
3694 nbmem, new_nbmem);
3695 new_tmp_event = realloc(tmp_event,
3696 new_nbmem * sizeof(struct lttng_event));
3697 if (new_tmp_event == NULL) {
3698 int release_ret;
3699
3700 PERROR("realloc ust app events");
3701 free(tmp_event);
3702 ret = -ENOMEM;
3703 release_ret = ustctl_release_handle(app->sock, handle);
3704 if (release_ret < 0 &&
3705 release_ret != -LTTNG_UST_ERR_EXITING &&
3706 release_ret != -EPIPE) {
3707 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3708 }
3709 pthread_mutex_unlock(&app->sock_lock);
3710 goto rcu_error;
3711 }
3712 /* Zero the new memory */
3713 memset(new_tmp_event + nbmem, 0,
3714 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3715 nbmem = new_nbmem;
3716 tmp_event = new_tmp_event;
3717 }
3718 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3719 tmp_event[count].loglevel = uiter.loglevel;
3720 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3721 tmp_event[count].pid = app->pid;
3722 tmp_event[count].enabled = -1;
3723 count++;
3724 }
3725 ret = ustctl_release_handle(app->sock, handle);
3726 pthread_mutex_unlock(&app->sock_lock);
3727 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3728 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3729 }
3730 }
3731
3732 ret = count;
3733 *events = tmp_event;
3734
3735 DBG2("UST app list events done (%zu events)", count);
3736
3737 rcu_error:
3738 rcu_read_unlock();
3739 error:
3740 health_code_update();
3741 return ret;
3742 }
3743
3744 /*
3745 * Fill events array with all events name of all registered apps.
3746 */
3747 int ust_app_list_event_fields(struct lttng_event_field **fields)
3748 {
3749 int ret, handle;
3750 size_t nbmem, count = 0;
3751 struct lttng_ht_iter iter;
3752 struct ust_app *app;
3753 struct lttng_event_field *tmp_event;
3754
3755 nbmem = UST_APP_EVENT_LIST_SIZE;
3756 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3757 if (tmp_event == NULL) {
3758 PERROR("zmalloc ust app event fields");
3759 ret = -ENOMEM;
3760 goto error;
3761 }
3762
3763 rcu_read_lock();
3764
3765 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3766 struct lttng_ust_field_iter uiter;
3767
3768 health_code_update();
3769
3770 if (!app->compatible) {
3771 /*
3772 * TODO: In time, we should notice the caller of this error by
3773 * telling him that this is a version error.
3774 */
3775 continue;
3776 }
3777 pthread_mutex_lock(&app->sock_lock);
3778 handle = ustctl_tracepoint_field_list(app->sock);
3779 if (handle < 0) {
3780 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3781 ERR("UST app list field getting handle failed for app pid %d",
3782 app->pid);
3783 }
3784 pthread_mutex_unlock(&app->sock_lock);
3785 continue;
3786 }
3787
3788 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3789 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3790 /* Handle ustctl error. */
3791 if (ret < 0) {
3792 int release_ret;
3793
3794 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3795 ERR("UST app tp list field failed for app %d with ret %d",
3796 app->sock, ret);
3797 } else {
3798 DBG3("UST app tp list field failed. Application is dead");
3799 /*
3800 * This is normal behavior, an application can die during the
3801 * creation process. Don't report an error so the execution can
3802 * continue normally. Reset list and count for next app.
3803 */
3804 break;
3805 }
3806 free(tmp_event);
3807 release_ret = ustctl_release_handle(app->sock, handle);
3808 pthread_mutex_unlock(&app->sock_lock);
3809 if (release_ret < 0 &&
3810 release_ret != -LTTNG_UST_ERR_EXITING &&
3811 release_ret != -EPIPE) {
3812 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3813 }
3814 goto rcu_error;
3815 }
3816
3817 health_code_update();
3818 if (count >= nbmem) {
3819 /* In case the realloc fails, we free the memory */
3820 struct lttng_event_field *new_tmp_event;
3821 size_t new_nbmem;
3822
3823 new_nbmem = nbmem << 1;
3824 DBG2("Reallocating event field list from %zu to %zu entries",
3825 nbmem, new_nbmem);
3826 new_tmp_event = realloc(tmp_event,
3827 new_nbmem * sizeof(struct lttng_event_field));
3828 if (new_tmp_event == NULL) {
3829 int release_ret;
3830
3831 PERROR("realloc ust app event fields");
3832 free(tmp_event);
3833 ret = -ENOMEM;
3834 release_ret = ustctl_release_handle(app->sock, handle);
3835 pthread_mutex_unlock(&app->sock_lock);
3836 if (release_ret &&
3837 release_ret != -LTTNG_UST_ERR_EXITING &&
3838 release_ret != -EPIPE) {
3839 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3840 }
3841 goto rcu_error;
3842 }
3843 /* Zero the new memory */
3844 memset(new_tmp_event + nbmem, 0,
3845 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3846 nbmem = new_nbmem;
3847 tmp_event = new_tmp_event;
3848 }
3849
3850 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3851 /* Mapping between these enums matches 1 to 1. */
3852 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3853 tmp_event[count].nowrite = uiter.nowrite;
3854
3855 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3856 tmp_event[count].event.loglevel = uiter.loglevel;
3857 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3858 tmp_event[count].event.pid = app->pid;
3859 tmp_event[count].event.enabled = -1;
3860 count++;
3861 }
3862 ret = ustctl_release_handle(app->sock, handle);
3863 pthread_mutex_unlock(&app->sock_lock);
3864 if (ret < 0 &&
3865 ret != -LTTNG_UST_ERR_EXITING &&
3866 ret != -EPIPE) {
3867 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3868 }
3869 }
3870
3871 ret = count;
3872 *fields = tmp_event;
3873
3874 DBG2("UST app list event fields done (%zu events)", count);
3875
3876 rcu_error:
3877 rcu_read_unlock();
3878 error:
3879 health_code_update();
3880 return ret;
3881 }
3882
3883 /*
3884 * Free and clean all traceable apps of the global list.
3885 *
3886 * Should _NOT_ be called with RCU read-side lock held.
3887 */
3888 void ust_app_clean_list(void)
3889 {
3890 int ret;
3891 struct ust_app *app;
3892 struct lttng_ht_iter iter;
3893
3894 DBG2("UST app cleaning registered apps hash table");
3895
3896 rcu_read_lock();
3897
3898 if (ust_app_ht) {
3899 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3900 ret = lttng_ht_del(ust_app_ht, &iter);
3901 assert(!ret);
3902 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3903 }
3904 }
3905
3906 /* Cleanup socket hash table */
3907 if (ust_app_ht_by_sock) {
3908 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3909 sock_n.node) {
3910 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3911 assert(!ret);
3912 }
3913 }
3914
3915 /* Cleanup notify socket hash table */
3916 if (ust_app_ht_by_notify_sock) {
3917 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3918 notify_sock_n.node) {
3919 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3920 assert(!ret);
3921 }
3922 }
3923 rcu_read_unlock();
3924
3925 /* Destroy is done only when the ht is empty */
3926 if (ust_app_ht) {
3927 ht_cleanup_push(ust_app_ht);
3928 }
3929 if (ust_app_ht_by_sock) {
3930 ht_cleanup_push(ust_app_ht_by_sock);
3931 }
3932 if (ust_app_ht_by_notify_sock) {
3933 ht_cleanup_push(ust_app_ht_by_notify_sock);
3934 }
3935 }
3936
3937 /*
3938 * Init UST app hash table.
3939 */
3940 int ust_app_ht_alloc(void)
3941 {
3942 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3943 if (!ust_app_ht) {
3944 return -1;
3945 }
3946 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3947 if (!ust_app_ht_by_sock) {
3948 return -1;
3949 }
3950 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3951 if (!ust_app_ht_by_notify_sock) {
3952 return -1;
3953 }
3954 return 0;
3955 }
3956
3957 /*
3958 * For a specific UST session, disable the channel for all registered apps.
3959 */
3960 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3961 struct ltt_ust_channel *uchan)
3962 {
3963 int ret = 0;
3964 struct lttng_ht_iter iter;
3965 struct lttng_ht_node_str *ua_chan_node;
3966 struct ust_app *app;
3967 struct ust_app_session *ua_sess;
3968 struct ust_app_channel *ua_chan;
3969
3970 if (usess == NULL || uchan == NULL) {
3971 ERR("Disabling UST global channel with NULL values");
3972 ret = -1;
3973 goto error;
3974 }
3975
3976 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3977 uchan->name, usess->id);
3978
3979 rcu_read_lock();
3980
3981 /* For every registered applications */
3982 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3983 struct lttng_ht_iter uiter;
3984 if (!app->compatible) {
3985 /*
3986 * TODO: In time, we should notice the caller of this error by
3987 * telling him that this is a version error.
3988 */
3989 continue;
3990 }
3991 ua_sess = lookup_session_by_app(usess, app);
3992 if (ua_sess == NULL) {
3993 continue;
3994 }
3995
3996 /* Get channel */
3997 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3998 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3999 /* If the session if found for the app, the channel must be there */
4000 assert(ua_chan_node);
4001
4002 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4003 /* The channel must not be already disabled */
4004 assert(ua_chan->enabled == 1);
4005
4006 /* Disable channel onto application */
4007 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
4008 if (ret < 0) {
4009 /* XXX: We might want to report this error at some point... */
4010 continue;
4011 }
4012 }
4013
4014 rcu_read_unlock();
4015
4016 error:
4017 return ret;
4018 }
4019
4020 /*
4021 * For a specific UST session, enable the channel for all registered apps.
4022 */
4023 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
4024 struct ltt_ust_channel *uchan)
4025 {
4026 int ret = 0;
4027 struct lttng_ht_iter iter;
4028 struct ust_app *app;
4029 struct ust_app_session *ua_sess;
4030
4031 if (usess == NULL || uchan == NULL) {
4032 ERR("Adding UST global channel to NULL values");
4033 ret = -1;
4034 goto error;
4035 }
4036
4037 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
4038 uchan->name, usess->id);
4039
4040 rcu_read_lock();
4041
4042 /* For every registered applications */
4043 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4044 if (!app->compatible) {
4045 /*
4046 * TODO: In time, we should notice the caller of this error by
4047 * telling him that this is a version error.
4048 */
4049 continue;
4050 }
4051 ua_sess = lookup_session_by_app(usess, app);
4052 if (ua_sess == NULL) {
4053 continue;
4054 }
4055
4056 /* Enable channel onto application */
4057 ret = enable_ust_app_channel(ua_sess, uchan, app);
4058 if (ret < 0) {
4059 /* XXX: We might want to report this error at some point... */
4060 continue;
4061 }
4062 }
4063
4064 rcu_read_unlock();
4065
4066 error:
4067 return ret;
4068 }
4069
4070 /*
4071 * Disable an event in a channel and for a specific session.
4072 */
4073 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
4074 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4075 {
4076 int ret = 0;
4077 struct lttng_ht_iter iter, uiter;
4078 struct lttng_ht_node_str *ua_chan_node;
4079 struct ust_app *app;
4080 struct ust_app_session *ua_sess;
4081 struct ust_app_channel *ua_chan;
4082 struct ust_app_event *ua_event;
4083
4084 DBG("UST app disabling event %s for all apps in channel "
4085 "%s for session id %" PRIu64,
4086 uevent->attr.name, uchan->name, usess->id);
4087
4088 rcu_read_lock();
4089
4090 /* For all registered applications */
4091 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4092 if (!app->compatible) {
4093 /*
4094 * TODO: In time, we should notice the caller of this error by
4095 * telling him that this is a version error.
4096 */
4097 continue;
4098 }
4099 ua_sess = lookup_session_by_app(usess, app);
4100 if (ua_sess == NULL) {
4101 /* Next app */
4102 continue;
4103 }
4104
4105 /* Lookup channel in the ust app session */
4106 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4107 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4108 if (ua_chan_node == NULL) {
4109 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
4110 "Skipping", uchan->name, usess->id, app->pid);
4111 continue;
4112 }
4113 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4114
4115 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4116 uevent->filter, uevent->attr.loglevel,
4117 uevent->exclusion);
4118 if (ua_event == NULL) {
4119 DBG2("Event %s not found in channel %s for app pid %d."
4120 "Skipping", uevent->attr.name, uchan->name, app->pid);
4121 continue;
4122 }
4123
4124 ret = disable_ust_app_event(ua_sess, ua_event, app);
4125 if (ret < 0) {
4126 /* XXX: Report error someday... */
4127 continue;
4128 }
4129 }
4130
4131 rcu_read_unlock();
4132
4133 return ret;
4134 }
4135
4136 /*
4137 * For a specific UST session, create the channel for all registered apps.
4138 */
4139 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
4140 struct ltt_ust_channel *uchan)
4141 {
4142 int ret = 0, created;
4143 struct lttng_ht_iter iter;
4144 struct ust_app *app;
4145 struct ust_app_session *ua_sess = NULL;
4146
4147 /* Very wrong code flow */
4148 assert(usess);
4149 assert(uchan);
4150
4151 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
4152 uchan->name, usess->id);
4153
4154 rcu_read_lock();
4155
4156 /* For every registered applications */
4157 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4158 if (!app->compatible) {
4159 /*
4160 * TODO: In time, we should notice the caller of this error by
4161 * telling him that this is a version error.
4162 */
4163 continue;
4164 }
4165 if (!trace_ust_pid_tracker_lookup(usess, app->pid)) {
4166 /* Skip. */
4167 continue;
4168 }
4169
4170 /*
4171 * Create session on the tracer side and add it to app session HT. Note
4172 * that if session exist, it will simply return a pointer to the ust
4173 * app session.
4174 */
4175 ret = find_or_create_ust_app_session(usess, app, &ua_sess, &created);
4176 if (ret < 0) {
4177 switch (ret) {
4178 case -ENOTCONN:
4179 /*
4180 * The application's socket is not valid. Either a bad socket
4181 * or a timeout on it. We can't inform the caller that for a
4182 * specific app, the session failed so lets continue here.
4183 */
4184 ret = 0; /* Not an error. */
4185 continue;
4186 case -ENOMEM:
4187 default:
4188 goto error_rcu_unlock;
4189 }
4190 }
4191 assert(ua_sess);
4192
4193 pthread_mutex_lock(&ua_sess->lock);
4194
4195 if (ua_sess->deleted) {
4196 pthread_mutex_unlock(&ua_sess->lock);
4197 continue;
4198 }
4199
4200 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
4201 sizeof(uchan->name))) {
4202 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
4203 ret = 0;
4204 } else {
4205 /* Create channel onto application. We don't need the chan ref. */
4206 ret = create_ust_app_channel(ua_sess, uchan, app,
4207 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
4208 }
4209 pthread_mutex_unlock(&ua_sess->lock);
4210 if (ret < 0) {
4211 /* Cleanup the created session if it's the case. */
4212 if (created) {
4213 destroy_app_session(app, ua_sess);
4214 }
4215 switch (ret) {
4216 case -ENOTCONN:
4217 /*
4218 * The application's socket is not valid. Either a bad socket
4219 * or a timeout on it. We can't inform the caller that for a
4220 * specific app, the session failed so lets continue here.
4221 */
4222 ret = 0; /* Not an error. */
4223 continue;
4224 case -ENOMEM:
4225 default:
4226 goto error_rcu_unlock;
4227 }
4228 }
4229 }
4230
4231 error_rcu_unlock:
4232 rcu_read_unlock();
4233 return ret;
4234 }
4235
4236 /*
4237 * Enable event for a specific session and channel on the tracer.
4238 */
4239 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
4240 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4241 {
4242 int ret = 0;
4243 struct lttng_ht_iter iter, uiter;
4244 struct lttng_ht_node_str *ua_chan_node;
4245 struct ust_app *app;
4246 struct ust_app_session *ua_sess;
4247 struct ust_app_channel *ua_chan;
4248 struct ust_app_event *ua_event;
4249
4250 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
4251 uevent->attr.name, usess->id);
4252
4253 /*
4254 * NOTE: At this point, this function is called only if the session and
4255 * channel passed are already created for all apps. and enabled on the
4256 * tracer also.
4257 */
4258
4259 rcu_read_lock();
4260
4261 /* For all registered applications */
4262 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4263 if (!app->compatible) {
4264 /*
4265 * TODO: In time, we should notice the caller of this error by
4266 * telling him that this is a version error.
4267 */
4268 continue;
4269 }
4270 ua_sess = lookup_session_by_app(usess, app);
4271 if (!ua_sess) {
4272 /* The application has problem or is probably dead. */
4273 continue;
4274 }
4275
4276 pthread_mutex_lock(&ua_sess->lock);
4277
4278 if (ua_sess->deleted) {
4279 pthread_mutex_unlock(&ua_sess->lock);
4280 continue;
4281 }
4282
4283 /* Lookup channel in the ust app session */
4284 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4285 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4286 /*
4287 * It is possible that the channel cannot be found is
4288 * the channel/event creation occurs concurrently with
4289 * an application exit.
4290 */
4291 if (!ua_chan_node) {
4292 pthread_mutex_unlock(&ua_sess->lock);
4293 continue;
4294 }
4295
4296 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4297
4298 /* Get event node */
4299 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4300 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4301 if (ua_event == NULL) {
4302 DBG3("UST app enable event %s not found for app PID %d."
4303 "Skipping app", uevent->attr.name, app->pid);
4304 goto next_app;
4305 }
4306
4307 ret = enable_ust_app_event(ua_sess, ua_event, app);
4308 if (ret < 0) {
4309 pthread_mutex_unlock(&ua_sess->lock);
4310 goto error;
4311 }
4312 next_app:
4313 pthread_mutex_unlock(&ua_sess->lock);
4314 }
4315
4316 error:
4317 rcu_read_unlock();
4318 return ret;
4319 }
4320
4321 /*
4322 * For a specific existing UST session and UST channel, creates the event for
4323 * all registered apps.
4324 */
4325 int ust_app_create_event_glb(struct ltt_ust_session *usess,
4326 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4327 {
4328 int ret = 0;
4329 struct lttng_ht_iter iter, uiter;
4330 struct lttng_ht_node_str *ua_chan_node;
4331 struct ust_app *app;
4332 struct ust_app_session *ua_sess;
4333 struct ust_app_channel *ua_chan;
4334
4335 DBG("UST app creating event %s for all apps for session id %" PRIu64,
4336 uevent->attr.name, usess->id);
4337
4338 rcu_read_lock();
4339
4340 /* For all registered applications */
4341 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4342 if (!app->compatible) {
4343 /*
4344 * TODO: In time, we should notice the caller of this error by
4345 * telling him that this is a version error.
4346 */
4347 continue;
4348 }
4349 ua_sess = lookup_session_by_app(usess, app);
4350 if (!ua_sess) {
4351 /* The application has problem or is probably dead. */
4352 continue;
4353 }
4354
4355 pthread_mutex_lock(&ua_sess->lock);
4356
4357 if (ua_sess->deleted) {
4358 pthread_mutex_unlock(&ua_sess->lock);
4359 continue;
4360 }
4361
4362 /* Lookup channel in the ust app session */
4363 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4364 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4365 /* If the channel is not found, there is a code flow error */
4366 assert(ua_chan_node);
4367
4368 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4369
4370 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4371 pthread_mutex_unlock(&ua_sess->lock);
4372 if (ret < 0) {
4373 if (ret != -LTTNG_UST_ERR_EXIST) {
4374 /* Possible value at this point: -ENOMEM. If so, we stop! */
4375 break;
4376 }
4377 DBG2("UST app event %s already exist on app PID %d",
4378 uevent->attr.name, app->pid);
4379 continue;
4380 }
4381 }
4382
4383 rcu_read_unlock();
4384
4385 return ret;
4386 }
4387
4388 /*
4389 * Start tracing for a specific UST session and app.
4390 *
4391 * Called with UST app session lock held.
4392 *
4393 */
4394 static
4395 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
4396 {
4397 int ret = 0;
4398 struct ust_app_session *ua_sess;
4399
4400 DBG("Starting tracing for ust app pid %d", app->pid);
4401
4402 rcu_read_lock();
4403
4404 if (!app->compatible) {
4405 goto end;
4406 }
4407
4408 ua_sess = lookup_session_by_app(usess, app);
4409 if (ua_sess == NULL) {
4410 /* The session is in teardown process. Ignore and continue. */
4411 goto end;
4412 }
4413
4414 pthread_mutex_lock(&ua_sess->lock);
4415
4416 if (ua_sess->deleted) {
4417 pthread_mutex_unlock(&ua_sess->lock);
4418 goto end;
4419 }
4420
4421 /* Upon restart, we skip the setup, already done */
4422 if (ua_sess->started) {
4423 goto skip_setup;
4424 }
4425
4426 /* Create directories if consumer is LOCAL and has a path defined. */
4427 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
4428 usess->consumer->dst.session_root_path[0] != '\0') {
4429 char *tmp_path;
4430
4431 tmp_path = zmalloc(LTTNG_PATH_MAX);
4432 if (!tmp_path) {
4433 ERR("Alloc tmp_path");
4434 goto error_unlock;
4435 }
4436 ret = snprintf(tmp_path, LTTNG_PATH_MAX, "%s%s%s",
4437 usess->consumer->dst.session_root_path,
4438 usess->consumer->chunk_path,
4439 usess->consumer->subdir);
4440 if (ret >= LTTNG_PATH_MAX) {
4441 ERR("Local destination path exceeds the maximal allowed length of %i bytes (needs %i bytes) with path = \"%s%s%s\"",
4442 LTTNG_PATH_MAX, ret,
4443 usess->consumer->dst.session_root_path,
4444 usess->consumer->chunk_path,
4445 usess->consumer->subdir);
4446 goto error_unlock;
4447 }
4448
4449 DBG("Creating directory path for local tracing: \"%s\"",
4450 tmp_path);
4451 ret = run_as_mkdir_recursive(tmp_path, S_IRWXU | S_IRWXG,
4452 ua_sess->euid, ua_sess->egid);
4453 free(tmp_path);
4454 if (ret < 0) {
4455 if (errno != EEXIST) {
4456 ERR("Trace directory creation error");
4457 goto error_unlock;
4458 }
4459 }
4460 }
4461
4462 /*
4463 * Create the metadata for the application. This returns gracefully if a
4464 * metadata was already set for the session.
4465 */
4466 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
4467 if (ret < 0) {
4468 goto error_unlock;
4469 }
4470
4471 health_code_update();
4472
4473 skip_setup:
4474 /* This start the UST tracing */
4475 pthread_mutex_lock(&app->sock_lock);
4476 ret = ustctl_start_session(app->sock, ua_sess->handle);
4477 pthread_mutex_unlock(&app->sock_lock);
4478 if (ret < 0) {
4479 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4480 ERR("Error starting tracing for app pid: %d (ret: %d)",
4481 app->pid, ret);
4482 } else {
4483 DBG("UST app start session failed. Application is dead.");
4484 /*
4485 * This is normal behavior, an application can die during the
4486 * creation process. Don't report an error so the execution can
4487 * continue normally.
4488 */
4489 pthread_mutex_unlock(&ua_sess->lock);
4490 goto end;
4491 }
4492 goto error_unlock;
4493 }
4494
4495 /* Indicate that the session has been started once */
4496 ua_sess->started = 1;
4497
4498 pthread_mutex_unlock(&ua_sess->lock);
4499
4500 health_code_update();
4501
4502 /* Quiescent wait after starting trace */
4503 pthread_mutex_lock(&app->sock_lock);
4504 ret = ustctl_wait_quiescent(app->sock);
4505 pthread_mutex_unlock(&app->sock_lock);
4506 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4507 ERR("UST app wait quiescent failed for app pid %d ret %d",
4508 app->pid, ret);
4509 }
4510
4511 end:
4512 rcu_read_unlock();
4513 health_code_update();
4514 return 0;
4515
4516 error_unlock:
4517 pthread_mutex_unlock(&ua_sess->lock);
4518 rcu_read_unlock();
4519 health_code_update();
4520 return -1;
4521 }
4522
4523 /*
4524 * Stop tracing for a specific UST session and app.
4525 */
4526 static
4527 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
4528 {
4529 int ret = 0;
4530 struct ust_app_session *ua_sess;
4531 struct ust_registry_session *registry;
4532
4533 DBG("Stopping tracing for ust app pid %d", app->pid);
4534
4535 rcu_read_lock();
4536
4537 if (!app->compatible) {
4538 goto end_no_session;
4539 }
4540
4541 ua_sess = lookup_session_by_app(usess, app);
4542 if (ua_sess == NULL) {
4543 goto end_no_session;
4544 }
4545
4546 pthread_mutex_lock(&ua_sess->lock);
4547
4548 if (ua_sess->deleted) {
4549 pthread_mutex_unlock(&ua_sess->lock);
4550 goto end_no_session;
4551 }
4552
4553 /*
4554 * If started = 0, it means that stop trace has been called for a session
4555 * that was never started. It's possible since we can have a fail start
4556 * from either the application manager thread or the command thread. Simply
4557 * indicate that this is a stop error.
4558 */
4559 if (!ua_sess->started) {
4560 goto error_rcu_unlock;
4561 }
4562
4563 health_code_update();
4564
4565 /* This inhibits UST tracing */
4566 pthread_mutex_lock(&app->sock_lock);
4567 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4568 pthread_mutex_unlock(&app->sock_lock);
4569 if (ret < 0) {
4570 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4571 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4572 app->pid, ret);
4573 } else {
4574 DBG("UST app stop session failed. Application is dead.");
4575 /*
4576 * This is normal behavior, an application can die during the
4577 * creation process. Don't report an error so the execution can
4578 * continue normally.
4579 */
4580 goto end_unlock;
4581 }
4582 goto error_rcu_unlock;
4583 }
4584
4585 health_code_update();
4586
4587 /* Quiescent wait after stopping trace */
4588 pthread_mutex_lock(&app->sock_lock);
4589 ret = ustctl_wait_quiescent(app->sock);
4590 pthread_mutex_unlock(&app->sock_lock);
4591 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4592 ERR("UST app wait quiescent failed for app pid %d ret %d",
4593 app->pid, ret);
4594 }
4595
4596 health_code_update();
4597
4598 registry = get_session_registry(ua_sess);
4599
4600 /* The UST app session is held registry shall not be null. */
4601 assert(registry);
4602
4603 /* Push metadata for application before freeing the application. */
4604 (void) push_metadata(registry, ua_sess->consumer);
4605
4606 end_unlock:
4607 pthread_mutex_unlock(&ua_sess->lock);
4608 end_no_session:
4609 rcu_read_unlock();
4610 health_code_update();
4611 return 0;
4612
4613 error_rcu_unlock:
4614 pthread_mutex_unlock(&ua_sess->lock);
4615 rcu_read_unlock();
4616 health_code_update();
4617 return -1;
4618 }
4619
4620 static
4621 int ust_app_flush_app_session(struct ust_app *app,
4622 struct ust_app_session *ua_sess)
4623 {
4624 int ret, retval = 0;
4625 struct lttng_ht_iter iter;
4626 struct ust_app_channel *ua_chan;
4627 struct consumer_socket *socket;
4628
4629 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4630
4631 rcu_read_lock();
4632
4633 if (!app->compatible) {
4634 goto end_not_compatible;
4635 }
4636
4637 pthread_mutex_lock(&ua_sess->lock);
4638
4639 if (ua_sess->deleted) {
4640 goto end_deleted;
4641 }
4642
4643 health_code_update();
4644
4645 /* Flushing buffers */
4646 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4647 ua_sess->consumer);
4648
4649 /* Flush buffers and push metadata. */
4650 switch (ua_sess->buffer_type) {
4651 case LTTNG_BUFFER_PER_PID:
4652 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4653 node.node) {
4654 health_code_update();
4655 ret = consumer_flush_channel(socket, ua_chan->key);
4656 if (ret) {
4657 ERR("Error flushing consumer channel");
4658 retval = -1;
4659 continue;
4660 }
4661 }
4662 break;
4663 case LTTNG_BUFFER_PER_UID:
4664 default:
4665 assert(0);
4666 break;
4667 }
4668
4669 health_code_update();
4670
4671 end_deleted:
4672 pthread_mutex_unlock(&ua_sess->lock);
4673
4674 end_not_compatible:
4675 rcu_read_unlock();
4676 health_code_update();
4677 return retval;
4678 }
4679
4680 /*
4681 * Flush buffers for all applications for a specific UST session.
4682 * Called with UST session lock held.
4683 */
4684 static
4685 int ust_app_flush_session(struct ltt_ust_session *usess)
4686
4687 {
4688 int ret = 0;
4689
4690 DBG("Flushing session buffers for all ust apps");
4691
4692 rcu_read_lock();
4693
4694 /* Flush buffers and push metadata. */
4695 switch (usess->buffer_type) {
4696 case LTTNG_BUFFER_PER_UID:
4697 {
4698 struct buffer_reg_uid *reg;
4699 struct lttng_ht_iter iter;
4700
4701 /* Flush all per UID buffers associated to that session. */
4702 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4703 struct ust_registry_session *ust_session_reg;
4704 struct buffer_reg_channel *reg_chan;
4705 struct consumer_socket *socket;
4706
4707 /* Get consumer socket to use to push the metadata.*/
4708 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4709 usess->consumer);
4710 if (!socket) {
4711 /* Ignore request if no consumer is found for the session. */
4712 continue;
4713 }
4714
4715 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4716 reg_chan, node.node) {
4717 /*
4718 * The following call will print error values so the return
4719 * code is of little importance because whatever happens, we
4720 * have to try them all.
4721 */
4722 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4723 }
4724
4725 ust_session_reg = reg->registry->reg.ust;
4726 /* Push metadata. */
4727 (void) push_metadata(ust_session_reg, usess->consumer);
4728 }
4729 break;
4730 }
4731 case LTTNG_BUFFER_PER_PID:
4732 {
4733 struct ust_app_session *ua_sess;
4734 struct lttng_ht_iter iter;
4735 struct ust_app *app;
4736
4737 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4738 ua_sess = lookup_session_by_app(usess, app);
4739 if (ua_sess == NULL) {
4740 continue;
4741 }
4742 (void) ust_app_flush_app_session(app, ua_sess);
4743 }
4744 break;
4745 }
4746 default:
4747 ret = -1;
4748 assert(0);
4749 break;
4750 }
4751
4752 rcu_read_unlock();
4753 health_code_update();
4754 return ret;
4755 }
4756
4757 static
4758 int ust_app_clear_quiescent_app_session(struct ust_app *app,
4759 struct ust_app_session *ua_sess)
4760 {
4761 int ret = 0;
4762 struct lttng_ht_iter iter;
4763 struct ust_app_channel *ua_chan;
4764 struct consumer_socket *socket;
4765
4766 DBG("Clearing stream quiescent state for ust app pid %d", app->pid);
4767
4768 rcu_read_lock();
4769
4770 if (!app->compatible) {
4771 goto end_not_compatible;
4772 }
4773
4774 pthread_mutex_lock(&ua_sess->lock);
4775
4776 if (ua_sess->deleted) {
4777 goto end_unlock;
4778 }
4779
4780 health_code_update();
4781
4782 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4783 ua_sess->consumer);
4784 if (!socket) {
4785 ERR("Failed to find consumer (%" PRIu32 ") socket",
4786 app->bits_per_long);
4787 ret = -1;
4788 goto end_unlock;
4789 }
4790
4791 /* Clear quiescent state. */
4792 switch (ua_sess->buffer_type) {
4793 case LTTNG_BUFFER_PER_PID:
4794 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter,
4795 ua_chan, node.node) {
4796 health_code_update();
4797 ret = consumer_clear_quiescent_channel(socket,
4798 ua_chan->key);
4799 if (ret) {
4800 ERR("Error clearing quiescent state for consumer channel");
4801 ret = -1;
4802 continue;
4803 }
4804 }
4805 break;
4806 case LTTNG_BUFFER_PER_UID:
4807 default:
4808 assert(0);
4809 ret = -1;
4810 break;
4811 }
4812
4813 health_code_update();
4814
4815 end_unlock:
4816 pthread_mutex_unlock(&ua_sess->lock);
4817
4818 end_not_compatible:
4819 rcu_read_unlock();
4820 health_code_update();
4821 return ret;
4822 }
4823
4824 /*
4825 * Clear quiescent state in each stream for all applications for a
4826 * specific UST session.
4827 * Called with UST session lock held.
4828 */
4829 static
4830 int ust_app_clear_quiescent_session(struct ltt_ust_session *usess)
4831
4832 {
4833 int ret = 0;
4834
4835 DBG("Clearing stream quiescent state for all ust apps");
4836
4837 rcu_read_lock();
4838
4839 switch (usess->buffer_type) {
4840 case LTTNG_BUFFER_PER_UID:
4841 {
4842 struct lttng_ht_iter iter;
4843 struct buffer_reg_uid *reg;
4844
4845 /*
4846 * Clear quiescent for all per UID buffers associated to
4847 * that session.
4848 */
4849 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4850 struct consumer_socket *socket;
4851 struct buffer_reg_channel *reg_chan;
4852
4853 /* Get associated consumer socket.*/
4854 socket = consumer_find_socket_by_bitness(
4855 reg->bits_per_long, usess->consumer);
4856 if (!socket) {
4857 /*
4858 * Ignore request if no consumer is found for
4859 * the session.
4860 */
4861 continue;
4862 }
4863
4864 cds_lfht_for_each_entry(reg->registry->channels->ht,
4865 &iter.iter, reg_chan, node.node) {
4866 /*
4867 * The following call will print error values so
4868 * the return code is of little importance
4869 * because whatever happens, we have to try them
4870 * all.
4871 */
4872 (void) consumer_clear_quiescent_channel(socket,
4873 reg_chan->consumer_key);
4874 }
4875 }
4876 break;
4877 }
4878 case LTTNG_BUFFER_PER_PID:
4879 {
4880 struct ust_app_session *ua_sess;
4881 struct lttng_ht_iter iter;
4882 struct ust_app *app;
4883
4884 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
4885 pid_n.node) {
4886 ua_sess = lookup_session_by_app(usess, app);
4887 if (ua_sess == NULL) {
4888 continue;
4889 }
4890 (void) ust_app_clear_quiescent_app_session(app,
4891 ua_sess);
4892 }
4893 break;
4894 }
4895 default:
4896 ret = -1;
4897 assert(0);
4898 break;
4899 }
4900
4901 rcu_read_unlock();
4902 health_code_update();
4903 return ret;
4904 }
4905
4906 /*
4907 * Destroy a specific UST session in apps.
4908 */
4909 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4910 {
4911 int ret;
4912 struct ust_app_session *ua_sess;
4913 struct lttng_ht_iter iter;
4914 struct lttng_ht_node_u64 *node;
4915
4916 DBG("Destroy tracing for ust app pid %d", app->pid);
4917
4918 rcu_read_lock();
4919
4920 if (!app->compatible) {
4921 goto end;
4922 }
4923
4924 __lookup_session_by_app(usess, app, &iter);
4925 node = lttng_ht_iter_get_node_u64(&iter);
4926 if (node == NULL) {
4927 /* Session is being or is deleted. */
4928 goto end;
4929 }
4930 ua_sess = caa_container_of(node, struct ust_app_session, node);
4931
4932 health_code_update();
4933 destroy_app_session(app, ua_sess);
4934
4935 health_code_update();
4936
4937 /* Quiescent wait after stopping trace */
4938 pthread_mutex_lock(&app->sock_lock);
4939 ret = ustctl_wait_quiescent(app->sock);
4940 pthread_mutex_unlock(&app->sock_lock);
4941 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4942 ERR("UST app wait quiescent failed for app pid %d ret %d",
4943 app->pid, ret);
4944 }
4945 end:
4946 rcu_read_unlock();
4947 health_code_update();
4948 return 0;
4949 }
4950
4951 /*
4952 * Start tracing for the UST session.
4953 */
4954 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4955 {
4956 int ret = 0;
4957 struct lttng_ht_iter iter;
4958 struct ust_app *app;
4959
4960 DBG("Starting all UST traces");
4961
4962 rcu_read_lock();
4963
4964 /*
4965 * In a start-stop-start use-case, we need to clear the quiescent state
4966 * of each channel set by the prior stop command, thus ensuring that a
4967 * following stop or destroy is sure to grab a timestamp_end near those
4968 * operations, even if the packet is empty.
4969 */
4970 (void) ust_app_clear_quiescent_session(usess);
4971
4972 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4973 ret = ust_app_start_trace(usess, app);
4974 if (ret < 0) {
4975 /* Continue to next apps even on error */
4976 continue;
4977 }
4978 }
4979
4980 rcu_read_unlock();
4981
4982 return 0;
4983 }
4984
4985 /*
4986 * Start tracing for the UST session.
4987 * Called with UST session lock held.
4988 */
4989 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4990 {
4991 int ret = 0;
4992 struct lttng_ht_iter iter;
4993 struct ust_app *app;
4994
4995 DBG("Stopping all UST traces");
4996
4997 rcu_read_lock();
4998
4999 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5000 ret = ust_app_stop_trace(usess, app);
5001 if (ret < 0) {
5002 /* Continue to next apps even on error */
5003 continue;
5004 }
5005 }
5006
5007 (void) ust_app_flush_session(usess);
5008
5009 rcu_read_unlock();
5010
5011 return 0;
5012 }
5013
5014 /*
5015 * Destroy app UST session.
5016 */
5017 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
5018 {
5019 int ret = 0;
5020 struct lttng_ht_iter iter;
5021 struct ust_app *app;
5022
5023 DBG("Destroy all UST traces");
5024
5025 rcu_read_lock();
5026
5027 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5028 ret = destroy_trace(usess, app);
5029 if (ret < 0) {
5030 /* Continue to next apps even on error */
5031 continue;
5032 }
5033 }
5034
5035 rcu_read_unlock();
5036
5037 return 0;
5038 }
5039
5040 static
5041 void ust_app_global_create(struct ltt_ust_session *usess, struct ust_app *app)
5042 {
5043 int ret = 0;
5044 struct lttng_ht_iter iter, uiter;
5045 struct ust_app_session *ua_sess = NULL;
5046 struct ust_app_channel *ua_chan;
5047 struct ust_app_event *ua_event;
5048 struct ust_app_ctx *ua_ctx;
5049 int is_created = 0;
5050
5051 ret = find_or_create_ust_app_session(usess, app, &ua_sess, &is_created);
5052 if (ret < 0) {
5053 /* Tracer is probably gone or ENOMEM. */
5054 goto error;
5055 }
5056 if (!is_created) {
5057 /* App session already created. */
5058 goto end;
5059 }
5060 assert(ua_sess);
5061
5062 pthread_mutex_lock(&ua_sess->lock);
5063
5064 if (ua_sess->deleted) {
5065 pthread_mutex_unlock(&ua_sess->lock);
5066 goto end;
5067 }
5068
5069 /*
5070 * We can iterate safely here over all UST app session since the create ust
5071 * app session above made a shadow copy of the UST global domain from the
5072 * ltt ust session.
5073 */
5074 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
5075 node.node) {
5076 ret = do_create_channel(app, usess, ua_sess, ua_chan);
5077 if (ret < 0 && ret != -ENOTCONN) {
5078 /*
5079 * Stop everything. On error, the application
5080 * failed, no more file descriptor are available
5081 * or ENOMEM so stopping here is the only thing
5082 * we can do for now. The only exception is
5083 * -ENOTCONN, which indicates that the application
5084 * has exit.
5085 */
5086 goto error_unlock;
5087 }
5088
5089 /*
5090 * Add context using the list so they are enabled in the same order the
5091 * user added them.
5092 */
5093 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
5094 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
5095 if (ret < 0) {
5096 goto error_unlock;
5097 }
5098 }
5099
5100
5101 /* For each events */
5102 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
5103 node.node) {
5104 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
5105 if (ret < 0) {
5106 goto error_unlock;
5107 }
5108 }
5109 }
5110
5111 pthread_mutex_unlock(&ua_sess->lock);
5112
5113 if (usess->active) {
5114 ret = ust_app_start_trace(usess, app);
5115 if (ret < 0) {
5116 goto error;
5117 }
5118
5119 DBG2("UST trace started for app pid %d", app->pid);
5120 }
5121 end:
5122 /* Everything went well at this point. */
5123 return;
5124
5125 error_unlock:
5126 pthread_mutex_unlock(&ua_sess->lock);
5127 error:
5128 if (ua_sess) {
5129 destroy_app_session(app, ua_sess);
5130 }
5131 return;
5132 }
5133
5134 static
5135 void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
5136 {
5137 struct ust_app_session *ua_sess;
5138
5139 ua_sess = lookup_session_by_app(usess, app);
5140 if (ua_sess == NULL) {
5141 return;
5142 }
5143 destroy_app_session(app, ua_sess);
5144 }
5145
5146 /*
5147 * Add channels/events from UST global domain to registered apps at sock.
5148 *
5149 * Called with session lock held.
5150 * Called with RCU read-side lock held.
5151 */
5152 void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
5153 {
5154 assert(usess);
5155
5156 DBG2("UST app global update for app sock %d for session id %" PRIu64,
5157 app->sock, usess->id);
5158
5159 if (!app->compatible) {
5160 return;
5161 }
5162
5163 if (trace_ust_pid_tracker_lookup(usess, app->pid)) {
5164 ust_app_global_create(usess, app);
5165 } else {
5166 ust_app_global_destroy(usess, app);
5167 }
5168 }
5169
5170 /*
5171 * Called with session lock held.
5172 */
5173 void ust_app_global_update_all(struct ltt_ust_session *usess)
5174 {
5175 struct lttng_ht_iter iter;
5176 struct ust_app *app;
5177
5178 rcu_read_lock();
5179 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5180 ust_app_global_update(usess, app);
5181 }
5182 rcu_read_unlock();
5183 }
5184
5185 /*
5186 * Add context to a specific channel for global UST domain.
5187 */
5188 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
5189 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
5190 {
5191 int ret = 0;
5192 struct lttng_ht_node_str *ua_chan_node;
5193 struct lttng_ht_iter iter, uiter;
5194 struct ust_app_channel *ua_chan = NULL;
5195 struct ust_app_session *ua_sess;
5196 struct ust_app *app;
5197
5198 rcu_read_lock();
5199
5200 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5201 if (!app->compatible) {
5202 /*
5203 * TODO: In time, we should notice the caller of this error by
5204 * telling him that this is a version error.
5205 */
5206 continue;
5207 }
5208 ua_sess = lookup_session_by_app(usess, app);
5209 if (ua_sess == NULL) {
5210 continue;
5211 }
5212
5213 pthread_mutex_lock(&ua_sess->lock);
5214
5215 if (ua_sess->deleted) {
5216 pthread_mutex_unlock(&ua_sess->lock);
5217 continue;
5218 }
5219
5220 /* Lookup channel in the ust app session */
5221 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
5222 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
5223 if (ua_chan_node == NULL) {
5224 goto next_app;
5225 }
5226 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
5227 node);
5228 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
5229 if (ret < 0) {
5230 goto next_app;
5231 }
5232 next_app:
5233 pthread_mutex_unlock(&ua_sess->lock);
5234 }
5235
5236 rcu_read_unlock();
5237 return ret;
5238 }
5239
5240 /*
5241 * Enable event for a channel from a UST session for a specific PID.
5242 */
5243 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
5244 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
5245 {
5246 int ret = 0;
5247 struct lttng_ht_iter iter;
5248 struct lttng_ht_node_str *ua_chan_node;
5249 struct ust_app *app;
5250 struct ust_app_session *ua_sess;
5251 struct ust_app_channel *ua_chan;
5252 struct ust_app_event *ua_event;
5253
5254 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
5255
5256 rcu_read_lock();
5257
5258 app = ust_app_find_by_pid(pid);
5259 if (app == NULL) {
5260 ERR("UST app enable event per PID %d not found", pid);
5261 ret = -1;
5262 goto end;
5263 }
5264
5265 if (!app->compatible) {
5266 ret = 0;
5267 goto end;
5268 }
5269
5270 ua_sess = lookup_session_by_app(usess, app);
5271 if (!ua_sess) {
5272 /* The application has problem or is probably dead. */
5273 ret = 0;
5274 goto end;
5275 }
5276
5277 pthread_mutex_lock(&ua_sess->lock);
5278
5279 if (ua_sess->deleted) {
5280 ret = 0;
5281 goto end_unlock;
5282 }
5283
5284 /* Lookup channel in the ust app session */
5285 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
5286 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
5287 /* If the channel is not found, there is a code flow error */
5288 assert(ua_chan_node);
5289
5290 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
5291
5292 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
5293 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
5294 if (ua_event == NULL) {
5295 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
5296 if (ret < 0) {
5297 goto end_unlock;
5298 }
5299 } else {
5300 ret = enable_ust_app_event(ua_sess, ua_event, app);
5301 if (ret < 0) {
5302 goto end_unlock;
5303 }
5304 }
5305
5306 end_unlock:
5307 pthread_mutex_unlock(&ua_sess->lock);
5308 end:
5309 rcu_read_unlock();
5310 return ret;
5311 }
5312
5313 /*
5314 * Receive registration and populate the given msg structure.
5315 *
5316 * On success return 0 else a negative value returned by the ustctl call.
5317 */
5318 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
5319 {
5320 int ret;
5321 uint32_t pid, ppid, uid, gid;
5322
5323 assert(msg);
5324
5325 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
5326 &pid, &ppid, &uid, &gid,
5327 &msg->bits_per_long,
5328 &msg->uint8_t_alignment,
5329 &msg->uint16_t_alignment,
5330 &msg->uint32_t_alignment,
5331 &msg->uint64_t_alignment,
5332 &msg->long_alignment,
5333 &msg->byte_order,
5334 msg->name);
5335 if (ret < 0) {
5336 switch (-ret) {
5337 case EPIPE:
5338 case ECONNRESET:
5339 case LTTNG_UST_ERR_EXITING:
5340 DBG3("UST app recv reg message failed. Application died");
5341 break;
5342 case LTTNG_UST_ERR_UNSUP_MAJOR:
5343 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
5344 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
5345 LTTNG_UST_ABI_MINOR_VERSION);
5346 break;
5347 default:
5348 ERR("UST app recv reg message failed with ret %d", ret);
5349 break;
5350 }
5351 goto error;
5352 }
5353 msg->pid = (pid_t) pid;
5354 msg->ppid = (pid_t) ppid;
5355 msg->uid = (uid_t) uid;
5356 msg->gid = (gid_t) gid;
5357
5358 error:
5359 return ret;
5360 }
5361
5362 /*
5363 * Return a ust app session object using the application object and the
5364 * session object descriptor has a key. If not found, NULL is returned.
5365 * A RCU read side lock MUST be acquired when calling this function.
5366 */
5367 static struct ust_app_session *find_session_by_objd(struct ust_app *app,
5368 int objd)
5369 {
5370 struct lttng_ht_node_ulong *node;
5371 struct lttng_ht_iter iter;
5372 struct ust_app_session *ua_sess = NULL;
5373
5374 assert(app);
5375
5376 lttng_ht_lookup(app->ust_sessions_objd, (void *)((unsigned long) objd), &iter);
5377 node = lttng_ht_iter_get_node_ulong(&iter);
5378 if (node == NULL) {
5379 DBG2("UST app session find by objd %d not found", objd);
5380 goto error;
5381 }
5382
5383 ua_sess = caa_container_of(node, struct ust_app_session, ust_objd_node);
5384
5385 error:
5386 return ua_sess;
5387 }
5388
5389 /*
5390 * Return a ust app channel object using the application object and the channel
5391 * object descriptor has a key. If not found, NULL is returned. A RCU read side
5392 * lock MUST be acquired before calling this function.
5393 */
5394 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
5395 int objd)
5396 {
5397 struct lttng_ht_node_ulong *node;
5398 struct lttng_ht_iter iter;
5399 struct ust_app_channel *ua_chan = NULL;
5400
5401 assert(app);
5402
5403 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
5404 node = lttng_ht_iter_get_node_ulong(&iter);
5405 if (node == NULL) {
5406 DBG2("UST app channel find by objd %d not found", objd);
5407 goto error;
5408 }
5409
5410 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
5411
5412 error:
5413 return ua_chan;
5414 }
5415
5416 /*
5417 * Reply to a register channel notification from an application on the notify
5418 * socket. The channel metadata is also created.
5419 *
5420 * The session UST registry lock is acquired in this function.
5421 *
5422 * On success 0 is returned else a negative value.
5423 */
5424 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
5425 size_t nr_fields, struct ustctl_field *fields)
5426 {
5427 int ret, ret_code = 0;
5428 uint32_t chan_id, reg_count;
5429 uint64_t chan_reg_key;
5430 enum ustctl_channel_header type;
5431 struct ust_app *app;
5432 struct ust_app_channel *ua_chan;
5433 struct ust_app_session *ua_sess;
5434 struct ust_registry_session *registry;
5435 struct ust_registry_channel *chan_reg;
5436
5437 rcu_read_lock();
5438
5439 /* Lookup application. If not found, there is a code flow error. */
5440 app = find_app_by_notify_sock(sock);
5441 if (!app) {
5442 DBG("Application socket %d is being torn down. Abort event notify",
5443 sock);
5444 ret = 0;
5445 goto error_rcu_unlock;
5446 }
5447
5448 /* Lookup channel by UST object descriptor. */
5449 ua_chan = find_channel_by_objd(app, cobjd);
5450 if (!ua_chan) {
5451 DBG("Application channel is being torn down. Abort event notify");
5452 ret = 0;
5453 goto error_rcu_unlock;
5454 }
5455
5456 assert(ua_chan->session);
5457 ua_sess = ua_chan->session;
5458
5459 /* Get right session registry depending on the session buffer type. */
5460 registry = get_session_registry(ua_sess);
5461 if (!registry) {
5462 DBG("Application session is being torn down. Abort event notify");
5463 ret = 0;
5464 goto error_rcu_unlock;
5465 };
5466
5467 /* Depending on the buffer type, a different channel key is used. */
5468 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5469 chan_reg_key = ua_chan->tracing_channel_id;
5470 } else {
5471 chan_reg_key = ua_chan->key;
5472 }
5473
5474 pthread_mutex_lock(&registry->lock);
5475
5476 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
5477 assert(chan_reg);
5478
5479 if (!chan_reg->register_done) {
5480 reg_count = ust_registry_get_event_count(chan_reg);
5481 if (reg_count < 31) {
5482 type = USTCTL_CHANNEL_HEADER_COMPACT;
5483 } else {
5484 type = USTCTL_CHANNEL_HEADER_LARGE;
5485 }
5486
5487 chan_reg->nr_ctx_fields = nr_fields;
5488 chan_reg->ctx_fields = fields;
5489 fields = NULL;
5490 chan_reg->header_type = type;
5491 } else {
5492 /* Get current already assigned values. */
5493 type = chan_reg->header_type;
5494 }
5495 /* Channel id is set during the object creation. */
5496 chan_id = chan_reg->chan_id;
5497
5498 /* Append to metadata */
5499 if (!chan_reg->metadata_dumped) {
5500 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
5501 if (ret_code) {
5502 ERR("Error appending channel metadata (errno = %d)", ret_code);
5503 goto reply;
5504 }
5505 }
5506
5507 reply:
5508 DBG3("UST app replying to register channel key %" PRIu64
5509 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
5510 ret_code);
5511
5512 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
5513 if (ret < 0) {
5514 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5515 ERR("UST app reply channel failed with ret %d", ret);
5516 } else {
5517 DBG3("UST app reply channel failed. Application died");
5518 }
5519 goto error;
5520 }
5521
5522 /* This channel registry registration is completed. */
5523 chan_reg->register_done = 1;
5524
5525 error:
5526 pthread_mutex_unlock(&registry->lock);
5527 error_rcu_unlock:
5528 rcu_read_unlock();
5529 free(fields);
5530 return ret;
5531 }
5532
5533 /*
5534 * Add event to the UST channel registry. When the event is added to the
5535 * registry, the metadata is also created. Once done, this replies to the
5536 * application with the appropriate error code.
5537 *
5538 * The session UST registry lock is acquired in the function.
5539 *
5540 * On success 0 is returned else a negative value.
5541 */
5542 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
5543 char *sig, size_t nr_fields, struct ustctl_field *fields,
5544 int loglevel_value, char *model_emf_uri)
5545 {
5546 int ret, ret_code;
5547 uint32_t event_id = 0;
5548 uint64_t chan_reg_key;
5549 struct ust_app *app;
5550 struct ust_app_channel *ua_chan;
5551 struct ust_app_session *ua_sess;
5552 struct ust_registry_session *registry;
5553
5554 rcu_read_lock();
5555
5556 /* Lookup application. If not found, there is a code flow error. */
5557 app = find_app_by_notify_sock(sock);
5558 if (!app) {
5559 DBG("Application socket %d is being torn down. Abort event notify",
5560 sock);
5561 ret = 0;
5562 goto error_rcu_unlock;
5563 }
5564
5565 /* Lookup channel by UST object descriptor. */
5566 ua_chan = find_channel_by_objd(app, cobjd);
5567 if (!ua_chan) {
5568 DBG("Application channel is being torn down. Abort event notify");
5569 ret = 0;
5570 goto error_rcu_unlock;
5571 }
5572
5573 assert(ua_chan->session);
5574 ua_sess = ua_chan->session;
5575
5576 registry = get_session_registry(ua_sess);
5577 if (!registry) {
5578 DBG("Application session is being torn down. Abort event notify");
5579 ret = 0;
5580 goto error_rcu_unlock;
5581 }
5582
5583 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5584 chan_reg_key = ua_chan->tracing_channel_id;
5585 } else {
5586 chan_reg_key = ua_chan->key;
5587 }
5588
5589 pthread_mutex_lock(&registry->lock);
5590
5591 /*
5592 * From this point on, this call acquires the ownership of the sig, fields
5593 * and model_emf_uri meaning any free are done inside it if needed. These
5594 * three variables MUST NOT be read/write after this.
5595 */
5596 ret_code = ust_registry_create_event(registry, chan_reg_key,
5597 sobjd, cobjd, name, sig, nr_fields, fields,
5598 loglevel_value, model_emf_uri, ua_sess->buffer_type,
5599 &event_id, app);
5600 sig = NULL;
5601 fields = NULL;
5602 model_emf_uri = NULL;
5603
5604 /*
5605 * The return value is returned to ustctl so in case of an error, the
5606 * application can be notified. In case of an error, it's important not to
5607 * return a negative error or else the application will get closed.
5608 */
5609 ret = ustctl_reply_register_event(sock, event_id, ret_code);
5610 if (ret < 0) {
5611 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5612 ERR("UST app reply event failed with ret %d", ret);
5613 } else {
5614 DBG3("UST app reply event failed. Application died");
5615 }
5616 /*
5617 * No need to wipe the create event since the application socket will
5618 * get close on error hence cleaning up everything by itself.
5619 */
5620 goto error;
5621 }
5622
5623 DBG3("UST registry event %s with id %" PRId32 " added successfully",
5624 name, event_id);
5625
5626 error:
5627 pthread_mutex_unlock(&registry->lock);
5628 error_rcu_unlock:
5629 rcu_read_unlock();
5630 free(sig);
5631 free(fields);
5632 free(model_emf_uri);
5633 return ret;
5634 }
5635
5636 /*
5637 * Add enum to the UST session registry. Once done, this replies to the
5638 * application with the appropriate error code.
5639 *
5640 * The session UST registry lock is acquired within this function.
5641 *
5642 * On success 0 is returned else a negative value.
5643 */
5644 static int add_enum_ust_registry(int sock, int sobjd, char *name,
5645 struct ustctl_enum_entry *entries, size_t nr_entries)
5646 {
5647 int ret = 0, ret_code;
5648 struct ust_app *app;
5649 struct ust_app_session *ua_sess;
5650 struct ust_registry_session *registry;
5651 uint64_t enum_id = -1ULL;
5652
5653 rcu_read_lock();
5654
5655 /* Lookup application. If not found, there is a code flow error. */
5656 app = find_app_by_notify_sock(sock);
5657 if (!app) {
5658 /* Return an error since this is not an error */
5659 DBG("Application socket %d is being torn down. Aborting enum registration",
5660 sock);
5661 free(entries);
5662 goto error_rcu_unlock;
5663 }
5664
5665 /* Lookup session by UST object descriptor. */
5666 ua_sess = find_session_by_objd(app, sobjd);
5667 if (!ua_sess) {
5668 /* Return an error since this is not an error */
5669 DBG("Application session is being torn down (session not found). Aborting enum registration.");
5670 free(entries);
5671 goto error_rcu_unlock;
5672 }
5673
5674 registry = get_session_registry(ua_sess);
5675 if (!registry) {
5676 DBG("Application session is being torn down (registry not found). Aborting enum registration.");
5677 free(entries);
5678 goto error_rcu_unlock;
5679 }
5680
5681 pthread_mutex_lock(&registry->lock);
5682
5683 /*
5684 * From this point on, the callee acquires the ownership of
5685 * entries. The variable entries MUST NOT be read/written after
5686 * call.
5687 */
5688 ret_code = ust_registry_create_or_find_enum(registry, sobjd, name,
5689 entries, nr_entries, &enum_id);
5690 entries = NULL;
5691
5692 /*
5693 * The return value is returned to ustctl so in case of an error, the
5694 * application can be notified. In case of an error, it's important not to
5695 * return a negative error or else the application will get closed.
5696 */
5697 ret = ustctl_reply_register_enum(sock, enum_id, ret_code);
5698 if (ret < 0) {
5699 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5700 ERR("UST app reply enum failed with ret %d", ret);
5701 } else {
5702 DBG3("UST app reply enum failed. Application died");
5703 }
5704 /*
5705 * No need to wipe the create enum since the application socket will
5706 * get close on error hence cleaning up everything by itself.
5707 */
5708 goto error;
5709 }
5710
5711 DBG3("UST registry enum %s added successfully or already found", name);
5712
5713 error:
5714 pthread_mutex_unlock(&registry->lock);
5715 error_rcu_unlock:
5716 rcu_read_unlock();
5717 return ret;
5718 }
5719
5720 /*
5721 * Handle application notification through the given notify socket.
5722 *
5723 * Return 0 on success or else a negative value.
5724 */
5725 int ust_app_recv_notify(int sock)
5726 {
5727 int ret;
5728 enum ustctl_notify_cmd cmd;
5729
5730 DBG3("UST app receiving notify from sock %d", sock);
5731
5732 ret = ustctl_recv_notify(sock, &cmd);
5733 if (ret < 0) {
5734 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5735 ERR("UST app recv notify failed with ret %d", ret);
5736 } else {
5737 DBG3("UST app recv notify failed. Application died");
5738 }
5739 goto error;
5740 }
5741
5742 switch (cmd) {
5743 case USTCTL_NOTIFY_CMD_EVENT:
5744 {
5745 int sobjd, cobjd, loglevel_value;
5746 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
5747 size_t nr_fields;
5748 struct ustctl_field *fields;
5749
5750 DBG2("UST app ustctl register event received");
5751
5752 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
5753 &loglevel_value, &sig, &nr_fields, &fields,
5754 &model_emf_uri);
5755 if (ret < 0) {
5756 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5757 ERR("UST app recv event failed with ret %d", ret);
5758 } else {
5759 DBG3("UST app recv event failed. Application died");
5760 }
5761 goto error;
5762 }
5763
5764 /*
5765 * Add event to the UST registry coming from the notify socket. This
5766 * call will free if needed the sig, fields and model_emf_uri. This
5767 * code path loses the ownsership of these variables and transfer them
5768 * to the this function.
5769 */
5770 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
5771 fields, loglevel_value, model_emf_uri);
5772 if (ret < 0) {
5773 goto error;
5774 }
5775
5776 break;
5777 }
5778 case USTCTL_NOTIFY_CMD_CHANNEL:
5779 {
5780 int sobjd, cobjd;
5781 size_t nr_fields;
5782 struct ustctl_field *fields;
5783
5784 DBG2("UST app ustctl register channel received");
5785
5786 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
5787 &fields);
5788 if (ret < 0) {
5789 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5790 ERR("UST app recv channel failed with ret %d", ret);
5791 } else {
5792 DBG3("UST app recv channel failed. Application died");
5793 }
5794 goto error;
5795 }
5796
5797 /*
5798 * The fields ownership are transfered to this function call meaning
5799 * that if needed it will be freed. After this, it's invalid to access
5800 * fields or clean it up.
5801 */
5802 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
5803 fields);
5804 if (ret < 0) {
5805 goto error;
5806 }
5807
5808 break;
5809 }
5810 case USTCTL_NOTIFY_CMD_ENUM:
5811 {
5812 int sobjd;
5813 char name[LTTNG_UST_SYM_NAME_LEN];
5814 size_t nr_entries;
5815 struct ustctl_enum_entry *entries;
5816
5817 DBG2("UST app ustctl register enum received");
5818
5819 ret = ustctl_recv_register_enum(sock, &sobjd, name,
5820 &entries, &nr_entries);
5821 if (ret < 0) {
5822 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5823 ERR("UST app recv enum failed with ret %d", ret);
5824 } else {
5825 DBG3("UST app recv enum failed. Application died");
5826 }
5827 goto error;
5828 }
5829
5830 /* Callee assumes ownership of entries */
5831 ret = add_enum_ust_registry(sock, sobjd, name,
5832 entries, nr_entries);
5833 if (ret < 0) {
5834 goto error;
5835 }
5836
5837 break;
5838 }
5839 default:
5840 /* Should NEVER happen. */
5841 assert(0);
5842 }
5843
5844 error:
5845 return ret;
5846 }
5847
5848 /*
5849 * Once the notify socket hangs up, this is called. First, it tries to find the
5850 * corresponding application. On failure, the call_rcu to close the socket is
5851 * executed. If an application is found, it tries to delete it from the notify
5852 * socket hash table. Whathever the result, it proceeds to the call_rcu.
5853 *
5854 * Note that an object needs to be allocated here so on ENOMEM failure, the
5855 * call RCU is not done but the rest of the cleanup is.
5856 */
5857 void ust_app_notify_sock_unregister(int sock)
5858 {
5859 int err_enomem = 0;
5860 struct lttng_ht_iter iter;
5861 struct ust_app *app;
5862 struct ust_app_notify_sock_obj *obj;
5863
5864 assert(sock >= 0);
5865
5866 rcu_read_lock();
5867
5868 obj = zmalloc(sizeof(*obj));
5869 if (!obj) {
5870 /*
5871 * An ENOMEM is kind of uncool. If this strikes we continue the
5872 * procedure but the call_rcu will not be called. In this case, we
5873 * accept the fd leak rather than possibly creating an unsynchronized
5874 * state between threads.
5875 *
5876 * TODO: The notify object should be created once the notify socket is
5877 * registered and stored independantely from the ust app object. The
5878 * tricky part is to synchronize the teardown of the application and
5879 * this notify object. Let's keep that in mind so we can avoid this
5880 * kind of shenanigans with ENOMEM in the teardown path.
5881 */
5882 err_enomem = 1;
5883 } else {
5884 obj->fd = sock;
5885 }
5886
5887 DBG("UST app notify socket unregister %d", sock);
5888
5889 /*
5890 * Lookup application by notify socket. If this fails, this means that the
5891 * hash table delete has already been done by the application
5892 * unregistration process so we can safely close the notify socket in a
5893 * call RCU.
5894 */
5895 app = find_app_by_notify_sock(sock);
5896 if (!app) {
5897 goto close_socket;
5898 }
5899
5900 iter.iter.node = &app->notify_sock_n.node;
5901
5902 /*
5903 * Whatever happens here either we fail or succeed, in both cases we have
5904 * to close the socket after a grace period to continue to the call RCU
5905 * here. If the deletion is successful, the application is not visible
5906 * anymore by other threads and is it fails it means that it was already
5907 * deleted from the hash table so either way we just have to close the
5908 * socket.
5909 */
5910 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5911
5912 close_socket:
5913 rcu_read_unlock();
5914
5915 /*
5916 * Close socket after a grace period to avoid for the socket to be reused
5917 * before the application object is freed creating potential race between
5918 * threads trying to add unique in the global hash table.
5919 */
5920 if (!err_enomem) {
5921 call_rcu(&obj->head, close_notify_sock_rcu);
5922 }
5923 }
5924
5925 /*
5926 * Destroy a ust app data structure and free its memory.
5927 */
5928 void ust_app_destroy(struct ust_app *app)
5929 {
5930 if (!app) {
5931 return;
5932 }
5933
5934 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5935 }
5936
5937 /*
5938 * Take a snapshot for a given UST session. The snapshot is sent to the given
5939 * output.
5940 *
5941 * Return 0 on success or else a negative value.
5942 */
5943 int ust_app_snapshot_record(struct ltt_ust_session *usess,
5944 struct snapshot_output *output, int wait,
5945 uint64_t nb_packets_per_stream)
5946 {
5947 int ret = 0;
5948 struct lttng_ht_iter iter;
5949 struct ust_app *app;
5950 char pathname[PATH_MAX];
5951
5952 assert(usess);
5953 assert(output);
5954
5955 rcu_read_lock();
5956
5957 switch (usess->buffer_type) {
5958 case LTTNG_BUFFER_PER_UID:
5959 {
5960 struct buffer_reg_uid *reg;
5961
5962 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5963 struct buffer_reg_channel *reg_chan;
5964 struct consumer_socket *socket;
5965
5966 /* Get consumer socket to use to push the metadata.*/
5967 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5968 usess->consumer);
5969 if (!socket) {
5970 ret = -EINVAL;
5971 goto error;
5972 }
5973
5974 memset(pathname, 0, sizeof(pathname));
5975 ret = snprintf(pathname, sizeof(pathname),
5976 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
5977 reg->uid, reg->bits_per_long);
5978 if (ret < 0) {
5979 PERROR("snprintf snapshot path");
5980 goto error;
5981 }
5982
5983 /* Add the UST default trace dir to path. */
5984 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5985 reg_chan, node.node) {
5986 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key,
5987 output, 0, usess->uid, usess->gid, pathname, wait,
5988 nb_packets_per_stream);
5989 if (ret < 0) {
5990 goto error;
5991 }
5992 }
5993 ret = consumer_snapshot_channel(socket,
5994 reg->registry->reg.ust->metadata_key, output, 1,
5995 usess->uid, usess->gid, pathname, wait, 0);
5996 if (ret < 0) {
5997 goto error;
5998 }
5999 }
6000 break;
6001 }
6002 case LTTNG_BUFFER_PER_PID:
6003 {
6004 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6005 struct consumer_socket *socket;
6006 struct lttng_ht_iter chan_iter;
6007 struct ust_app_channel *ua_chan;
6008 struct ust_app_session *ua_sess;
6009 struct ust_registry_session *registry;
6010
6011 ua_sess = lookup_session_by_app(usess, app);
6012 if (!ua_sess) {
6013 /* Session not associated with this app. */
6014 continue;
6015 }
6016
6017 /* Get the right consumer socket for the application. */
6018 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6019 output->consumer);
6020 if (!socket) {
6021 ret = -EINVAL;
6022 goto error;
6023 }
6024
6025 /* Add the UST default trace dir to path. */
6026 memset(pathname, 0, sizeof(pathname));
6027 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
6028 ua_sess->path);
6029 if (ret < 0) {
6030 PERROR("snprintf snapshot path");
6031 goto error;
6032 }
6033
6034 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6035 ua_chan, node.node) {
6036 ret = consumer_snapshot_channel(socket, ua_chan->key, output,
6037 0, ua_sess->euid, ua_sess->egid, pathname, wait,
6038 nb_packets_per_stream);
6039 if (ret < 0) {
6040 goto error;
6041 }
6042 }
6043
6044 registry = get_session_registry(ua_sess);
6045 if (!registry) {
6046 DBG("Application session is being torn down. Abort snapshot record.");
6047 ret = -1;
6048 goto error;
6049 }
6050 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
6051 1, ua_sess->euid, ua_sess->egid, pathname, wait, 0);
6052 if (ret < 0) {
6053 goto error;
6054 }
6055 }
6056 break;
6057 }
6058 default:
6059 assert(0);
6060 break;
6061 }
6062
6063 error:
6064 rcu_read_unlock();
6065 return ret;
6066 }
6067
6068 /*
6069 * Return the size taken by one more packet per stream.
6070 */
6071 uint64_t ust_app_get_size_one_more_packet_per_stream(struct ltt_ust_session *usess,
6072 uint64_t cur_nr_packets)
6073 {
6074 uint64_t tot_size = 0;
6075 struct ust_app *app;
6076 struct lttng_ht_iter iter;
6077
6078 assert(usess);
6079
6080 switch (usess->buffer_type) {
6081 case LTTNG_BUFFER_PER_UID:
6082 {
6083 struct buffer_reg_uid *reg;
6084
6085 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6086 struct buffer_reg_channel *reg_chan;
6087
6088 rcu_read_lock();
6089 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6090 reg_chan, node.node) {
6091 if (cur_nr_packets >= reg_chan->num_subbuf) {
6092 /*
6093 * Don't take channel into account if we
6094 * already grab all its packets.
6095 */
6096 continue;
6097 }
6098 tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
6099 }
6100 rcu_read_unlock();
6101 }
6102 break;
6103 }
6104 case LTTNG_BUFFER_PER_PID:
6105 {
6106 rcu_read_lock();
6107 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6108 struct ust_app_channel *ua_chan;
6109 struct ust_app_session *ua_sess;
6110 struct lttng_ht_iter chan_iter;
6111
6112 ua_sess = lookup_session_by_app(usess, app);
6113 if (!ua_sess) {
6114 /* Session not associated with this app. */
6115 continue;
6116 }
6117
6118 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6119 ua_chan, node.node) {
6120 if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
6121 /*
6122 * Don't take channel into account if we
6123 * already grab all its packets.
6124 */
6125 continue;
6126 }
6127 tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
6128 }
6129 }
6130 rcu_read_unlock();
6131 break;
6132 }
6133 default:
6134 assert(0);
6135 break;
6136 }
6137
6138 return tot_size;
6139 }
6140
6141 int ust_app_uid_get_channel_runtime_stats(uint64_t ust_session_id,
6142 struct cds_list_head *buffer_reg_uid_list,
6143 struct consumer_output *consumer, uint64_t uchan_id,
6144 int overwrite, uint64_t *discarded, uint64_t *lost)
6145 {
6146 int ret;
6147 uint64_t consumer_chan_key;
6148
6149 *discarded = 0;
6150 *lost = 0;
6151
6152 ret = buffer_reg_uid_consumer_channel_key(
6153 buffer_reg_uid_list, ust_session_id,
6154 uchan_id, &consumer_chan_key);
6155 if (ret < 0) {
6156 /* Not found */
6157 ret = 0;
6158 goto end;
6159 }
6160
6161 if (overwrite) {
6162 ret = consumer_get_lost_packets(ust_session_id,
6163 consumer_chan_key, consumer, lost);
6164 } else {
6165 ret = consumer_get_discarded_events(ust_session_id,
6166 consumer_chan_key, consumer, discarded);
6167 }
6168
6169 end:
6170 return ret;
6171 }
6172
6173 int ust_app_pid_get_channel_runtime_stats(struct ltt_ust_session *usess,
6174 struct ltt_ust_channel *uchan,
6175 struct consumer_output *consumer, int overwrite,
6176 uint64_t *discarded, uint64_t *lost)
6177 {
6178 int ret = 0;
6179 struct lttng_ht_iter iter;
6180 struct lttng_ht_node_str *ua_chan_node;
6181 struct ust_app *app;
6182 struct ust_app_session *ua_sess;
6183 struct ust_app_channel *ua_chan;
6184
6185 *discarded = 0;
6186 *lost = 0;
6187
6188 rcu_read_lock();
6189 /*
6190 * Iterate over every registered applications. Sum counters for
6191 * all applications containing requested session and channel.
6192 */
6193 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6194 struct lttng_ht_iter uiter;
6195
6196 ua_sess = lookup_session_by_app(usess, app);
6197 if (ua_sess == NULL) {
6198 continue;
6199 }
6200
6201 /* Get channel */
6202 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &uiter);
6203 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
6204 /* If the session is found for the app, the channel must be there */
6205 assert(ua_chan_node);
6206
6207 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
6208
6209 if (overwrite) {
6210 uint64_t _lost;
6211
6212 ret = consumer_get_lost_packets(usess->id, ua_chan->key,
6213 consumer, &_lost);
6214 if (ret < 0) {
6215 break;
6216 }
6217 (*lost) += _lost;
6218 } else {
6219 uint64_t _discarded;
6220
6221 ret = consumer_get_discarded_events(usess->id,
6222 ua_chan->key, consumer, &_discarded);
6223 if (ret < 0) {
6224 break;
6225 }
6226 (*discarded) += _discarded;
6227 }
6228 }
6229
6230 rcu_read_unlock();
6231 return ret;
6232 }
6233
6234 static
6235 int ust_app_regenerate_statedump(struct ltt_ust_session *usess,
6236 struct ust_app *app)
6237 {
6238 int ret = 0;
6239 struct ust_app_session *ua_sess;
6240
6241 DBG("Regenerating the metadata for ust app pid %d", app->pid);
6242
6243 rcu_read_lock();
6244
6245 ua_sess = lookup_session_by_app(usess, app);
6246 if (ua_sess == NULL) {
6247 /* The session is in teardown process. Ignore and continue. */
6248 goto end;
6249 }
6250
6251 pthread_mutex_lock(&ua_sess->lock);
6252
6253 if (ua_sess->deleted) {
6254 goto end_unlock;
6255 }
6256
6257 pthread_mutex_lock(&app->sock_lock);
6258 ret = ustctl_regenerate_statedump(app->sock, ua_sess->handle);
6259 pthread_mutex_unlock(&app->sock_lock);
6260
6261 end_unlock:
6262 pthread_mutex_unlock(&ua_sess->lock);
6263
6264 end:
6265 rcu_read_unlock();
6266 health_code_update();
6267 return ret;
6268 }
6269
6270 /*
6271 * Regenerate the statedump for each app in the session.
6272 */
6273 int ust_app_regenerate_statedump_all(struct ltt_ust_session *usess)
6274 {
6275 int ret = 0;
6276 struct lttng_ht_iter iter;
6277 struct ust_app *app;
6278
6279 DBG("Regenerating the metadata for all UST apps");
6280
6281 rcu_read_lock();
6282
6283 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6284 if (!app->compatible) {
6285 continue;
6286 }
6287
6288 ret = ust_app_regenerate_statedump(usess, app);
6289 if (ret < 0) {
6290 /* Continue to the next app even on error */
6291 continue;
6292 }
6293 }
6294
6295 rcu_read_unlock();
6296
6297 return 0;
6298 }
6299
6300 /*
6301 * Rotate all the channels of a session.
6302 *
6303 * Return 0 on success or else a negative value.
6304 */
6305 int ust_app_rotate_session(struct ltt_session *session, bool *ust_active)
6306 {
6307 int ret = 0;
6308 struct lttng_ht_iter iter;
6309 struct ust_app *app;
6310 struct ltt_ust_session *usess = session->ust_session;
6311 char pathname[LTTNG_PATH_MAX];
6312
6313 assert(usess);
6314
6315 rcu_read_lock();
6316
6317 switch (usess->buffer_type) {
6318 case LTTNG_BUFFER_PER_UID:
6319 {
6320 struct buffer_reg_uid *reg;
6321
6322 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6323 struct buffer_reg_channel *reg_chan;
6324 struct consumer_socket *socket;
6325
6326 /* Get consumer socket to use to push the metadata.*/
6327 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
6328 usess->consumer);
6329 if (!socket) {
6330 ret = -EINVAL;
6331 goto error;
6332 }
6333
6334 /*
6335 * Account the metadata channel first to make sure the
6336 * number of channels waiting for a rotation cannot
6337 * reach 0 before we complete the iteration over all
6338 * the channels.
6339 */
6340 ret = rotate_add_channel_pending(
6341 reg->registry->reg.ust->metadata_key,
6342 LTTNG_DOMAIN_UST, session);
6343 if (ret < 0) {
6344 ret = reg->bits_per_long == 32 ?
6345 -LTTNG_ERR_UST_CONSUMER32_FAIL :
6346 -LTTNG_ERR_UST_CONSUMER64_FAIL;
6347 goto error;
6348 }
6349
6350 ret = snprintf(pathname, sizeof(pathname),
6351 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
6352 reg->uid, reg->bits_per_long);
6353 if (ret < 0 || ret == sizeof(pathname)) {
6354 PERROR("Failed to format rotation path");
6355 goto error;
6356 }
6357
6358 /* Rotate the data channels. */
6359 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6360 reg_chan, node.node) {
6361 ret = rotate_add_channel_pending(
6362 reg_chan->consumer_key,
6363 LTTNG_DOMAIN_UST, session);
6364 if (ret < 0) {
6365 ret = reg->bits_per_long == 32 ?
6366 -LTTNG_ERR_UST_CONSUMER32_FAIL :
6367 -LTTNG_ERR_UST_CONSUMER64_FAIL;
6368 goto error;
6369 }
6370 ret = consumer_rotate_channel(socket,
6371 reg_chan->consumer_key,
6372 usess->uid, usess->gid,
6373 usess->consumer, pathname,
6374 /* is_metadata_channel */ false,
6375 session->current_archive_id,
6376 &session->rotate_pending_relay);
6377 if (ret < 0) {
6378 goto error;
6379 }
6380 }
6381
6382 (void) push_metadata(reg->registry->reg.ust, usess->consumer);
6383
6384 ret = consumer_rotate_channel(socket,
6385 reg->registry->reg.ust->metadata_key,
6386 usess->uid, usess->gid,
6387 usess->consumer, pathname,
6388 /* is_metadata_channel */ true,
6389 session->current_archive_id,
6390 &session->rotate_pending_relay);
6391 if (ret < 0) {
6392 goto error;
6393 }
6394 *ust_active = true;
6395 }
6396 break;
6397 }
6398 case LTTNG_BUFFER_PER_PID:
6399 {
6400 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6401 struct consumer_socket *socket;
6402 struct lttng_ht_iter chan_iter;
6403 struct ust_app_channel *ua_chan;
6404 struct ust_app_session *ua_sess;
6405 struct ust_registry_session *registry;
6406
6407 ua_sess = lookup_session_by_app(usess, app);
6408 if (!ua_sess) {
6409 /* Session not associated with this app. */
6410 continue;
6411 }
6412 ret = snprintf(pathname, sizeof(pathname),
6413 DEFAULT_UST_TRACE_DIR "/%s",
6414 ua_sess->path);
6415 if (ret < 0 || ret == sizeof(pathname)) {
6416 PERROR("Failed to format rotation path");
6417 goto error;
6418 }
6419
6420 /* Get the right consumer socket for the application. */
6421 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6422 usess->consumer);
6423 if (!socket) {
6424 ret = -EINVAL;
6425 goto error;
6426 }
6427
6428 registry = get_session_registry(ua_sess);
6429 if (!registry) {
6430 DBG("Application session is being torn down. Abort snapshot record.");
6431 ret = -1;
6432 goto error;
6433 }
6434
6435 /*
6436 * Account the metadata channel first to make sure the
6437 * number of channels waiting for a rotation cannot
6438 * reach 0 before we complete the iteration over all
6439 * the channels.
6440 */
6441 ret = rotate_add_channel_pending(registry->metadata_key,
6442 LTTNG_DOMAIN_UST, session);
6443 if (ret < 0) {
6444 ret = app->bits_per_long == 32 ?
6445 -LTTNG_ERR_UST_CONSUMER32_FAIL :
6446 -LTTNG_ERR_UST_CONSUMER64_FAIL;
6447 goto error;
6448 }
6449
6450 /* Rotate the data channels. */
6451 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6452 ua_chan, node.node) {
6453 ret = rotate_add_channel_pending(
6454 ua_chan->key, LTTNG_DOMAIN_UST,
6455 session);
6456 if (ret < 0) {
6457 ret = app->bits_per_long == 32 ?
6458 -LTTNG_ERR_UST_CONSUMER32_FAIL :
6459 -LTTNG_ERR_UST_CONSUMER64_FAIL;
6460 goto error;
6461 }
6462 ret = consumer_rotate_channel(socket, ua_chan->key,
6463 ua_sess->euid, ua_sess->egid,
6464 ua_sess->consumer, pathname,
6465 /* is_metadata_channel */ false,
6466 session->current_archive_id,
6467 &session->rotate_pending_relay);
6468 if (ret < 0) {
6469 goto error;
6470 }
6471 }
6472
6473 /* Rotate the metadata channel. */
6474 (void) push_metadata(registry, usess->consumer);
6475 ret = consumer_rotate_channel(socket, registry->metadata_key,
6476 ua_sess->euid, ua_sess->egid,
6477 ua_sess->consumer, pathname,
6478 /* is_metadata_channel */ true,
6479 session->current_archive_id,
6480 &session->rotate_pending_relay);
6481 if (ret < 0) {
6482 goto error;
6483 }
6484 *ust_active = true;
6485 }
6486 break;
6487 }
6488 default:
6489 assert(0);
6490 break;
6491 }
6492
6493 ret = LTTNG_OK;
6494
6495 error:
6496 rcu_read_unlock();
6497 return ret;
6498 }
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