Fix: relayd: rotation pending off-by-one
[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 if (session) {
441 session_put(session);
442 }
443 }
444
445 /*
446 * Delete ust app channel safely. RCU read lock must be held before calling
447 * this function.
448 *
449 * The session list lock must be held by the caller.
450 */
451 static
452 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
453 struct ust_app *app)
454 {
455 int ret;
456 struct lttng_ht_iter iter;
457 struct ust_app_event *ua_event;
458 struct ust_app_ctx *ua_ctx;
459 struct ust_app_stream *stream, *stmp;
460 struct ust_registry_session *registry;
461
462 assert(ua_chan);
463
464 DBG3("UST app deleting channel %s", ua_chan->name);
465
466 /* Wipe stream */
467 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
468 cds_list_del(&stream->list);
469 delete_ust_app_stream(sock, stream, app);
470 }
471
472 /* Wipe context */
473 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
474 cds_list_del(&ua_ctx->list);
475 ret = lttng_ht_del(ua_chan->ctx, &iter);
476 assert(!ret);
477 delete_ust_app_ctx(sock, ua_ctx, app);
478 }
479
480 /* Wipe events */
481 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
482 node.node) {
483 ret = lttng_ht_del(ua_chan->events, &iter);
484 assert(!ret);
485 delete_ust_app_event(sock, ua_event, app);
486 }
487
488 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
489 /* Wipe and free registry from session registry. */
490 registry = get_session_registry(ua_chan->session);
491 if (registry) {
492 ust_registry_channel_del_free(registry, ua_chan->key,
493 sock >= 0);
494 }
495 /*
496 * A negative socket can be used by the caller when
497 * cleaning-up a ua_chan in an error path. Skip the
498 * accounting in this case.
499 */
500 if (sock >= 0) {
501 save_per_pid_lost_discarded_counters(ua_chan);
502 }
503 }
504
505 if (ua_chan->obj != NULL) {
506 /* Remove channel from application UST object descriptor. */
507 iter.iter.node = &ua_chan->ust_objd_node.node;
508 ret = lttng_ht_del(app->ust_objd, &iter);
509 assert(!ret);
510 pthread_mutex_lock(&app->sock_lock);
511 ret = ustctl_release_object(sock, ua_chan->obj);
512 pthread_mutex_unlock(&app->sock_lock);
513 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
514 ERR("UST app sock %d release channel obj failed with ret %d",
515 sock, ret);
516 }
517 lttng_fd_put(LTTNG_FD_APPS, 1);
518 free(ua_chan->obj);
519 }
520 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
521 }
522
523 int ust_app_register_done(struct ust_app *app)
524 {
525 int ret;
526
527 pthread_mutex_lock(&app->sock_lock);
528 ret = ustctl_register_done(app->sock);
529 pthread_mutex_unlock(&app->sock_lock);
530 return ret;
531 }
532
533 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
534 {
535 int ret, sock;
536
537 if (app) {
538 pthread_mutex_lock(&app->sock_lock);
539 sock = app->sock;
540 } else {
541 sock = -1;
542 }
543 ret = ustctl_release_object(sock, data);
544 if (app) {
545 pthread_mutex_unlock(&app->sock_lock);
546 }
547 return ret;
548 }
549
550 /*
551 * Push metadata to consumer socket.
552 *
553 * RCU read-side lock must be held to guarantee existance of socket.
554 * Must be called with the ust app session lock held.
555 * Must be called with the registry lock held.
556 *
557 * On success, return the len of metadata pushed or else a negative value.
558 * Returning a -EPIPE return value means we could not send the metadata,
559 * but it can be caused by recoverable errors (e.g. the application has
560 * terminated concurrently).
561 */
562 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
563 struct consumer_socket *socket, int send_zero_data)
564 {
565 int ret;
566 char *metadata_str = NULL;
567 size_t len, offset, new_metadata_len_sent;
568 ssize_t ret_val;
569 uint64_t metadata_key, metadata_version;
570
571 assert(registry);
572 assert(socket);
573
574 metadata_key = registry->metadata_key;
575
576 /*
577 * Means that no metadata was assigned to the session. This can
578 * happens if no start has been done previously.
579 */
580 if (!metadata_key) {
581 return 0;
582 }
583
584 offset = registry->metadata_len_sent;
585 len = registry->metadata_len - registry->metadata_len_sent;
586 new_metadata_len_sent = registry->metadata_len;
587 metadata_version = registry->metadata_version;
588 if (len == 0) {
589 DBG3("No metadata to push for metadata key %" PRIu64,
590 registry->metadata_key);
591 ret_val = len;
592 if (send_zero_data) {
593 DBG("No metadata to push");
594 goto push_data;
595 }
596 goto end;
597 }
598
599 /* Allocate only what we have to send. */
600 metadata_str = zmalloc(len);
601 if (!metadata_str) {
602 PERROR("zmalloc ust app metadata string");
603 ret_val = -ENOMEM;
604 goto error;
605 }
606 /* Copy what we haven't sent out. */
607 memcpy(metadata_str, registry->metadata + offset, len);
608
609 push_data:
610 pthread_mutex_unlock(&registry->lock);
611 /*
612 * We need to unlock the registry while we push metadata to
613 * break a circular dependency between the consumerd metadata
614 * lock and the sessiond registry lock. Indeed, pushing metadata
615 * to the consumerd awaits that it gets pushed all the way to
616 * relayd, but doing so requires grabbing the metadata lock. If
617 * a concurrent metadata request is being performed by
618 * consumerd, this can try to grab the registry lock on the
619 * sessiond while holding the metadata lock on the consumer
620 * daemon. Those push and pull schemes are performed on two
621 * different bidirectionnal communication sockets.
622 */
623 ret = consumer_push_metadata(socket, metadata_key,
624 metadata_str, len, offset, metadata_version);
625 pthread_mutex_lock(&registry->lock);
626 if (ret < 0) {
627 /*
628 * There is an acceptable race here between the registry
629 * metadata key assignment and the creation on the
630 * consumer. The session daemon can concurrently push
631 * metadata for this registry while being created on the
632 * consumer since the metadata key of the registry is
633 * assigned *before* it is setup to avoid the consumer
634 * to ask for metadata that could possibly be not found
635 * in the session daemon.
636 *
637 * The metadata will get pushed either by the session
638 * being stopped or the consumer requesting metadata if
639 * that race is triggered.
640 */
641 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
642 ret = 0;
643 } else {
644 ERR("Error pushing metadata to consumer");
645 }
646 ret_val = ret;
647 goto error_push;
648 } else {
649 /*
650 * Metadata may have been concurrently pushed, since
651 * we're not holding the registry lock while pushing to
652 * consumer. This is handled by the fact that we send
653 * the metadata content, size, and the offset at which
654 * that metadata belongs. This may arrive out of order
655 * on the consumer side, and the consumer is able to
656 * deal with overlapping fragments. The consumer
657 * supports overlapping fragments, which must be
658 * contiguous starting from offset 0. We keep the
659 * largest metadata_len_sent value of the concurrent
660 * send.
661 */
662 registry->metadata_len_sent =
663 max_t(size_t, registry->metadata_len_sent,
664 new_metadata_len_sent);
665 }
666 free(metadata_str);
667 return len;
668
669 end:
670 error:
671 if (ret_val) {
672 /*
673 * On error, flag the registry that the metadata is
674 * closed. We were unable to push anything and this
675 * means that either the consumer is not responding or
676 * the metadata cache has been destroyed on the
677 * consumer.
678 */
679 registry->metadata_closed = 1;
680 }
681 error_push:
682 free(metadata_str);
683 return ret_val;
684 }
685
686 /*
687 * For a given application and session, push metadata to consumer.
688 * Either sock or consumer is required : if sock is NULL, the default
689 * socket to send the metadata is retrieved from consumer, if sock
690 * is not NULL we use it to send the metadata.
691 * RCU read-side lock must be held while calling this function,
692 * therefore ensuring existance of registry. It also ensures existance
693 * of socket throughout this function.
694 *
695 * Return 0 on success else a negative error.
696 * Returning a -EPIPE return value means we could not send the metadata,
697 * but it can be caused by recoverable errors (e.g. the application has
698 * terminated concurrently).
699 */
700 static int push_metadata(struct ust_registry_session *registry,
701 struct consumer_output *consumer)
702 {
703 int ret_val;
704 ssize_t ret;
705 struct consumer_socket *socket;
706
707 assert(registry);
708 assert(consumer);
709
710 pthread_mutex_lock(&registry->lock);
711 if (registry->metadata_closed) {
712 ret_val = -EPIPE;
713 goto error;
714 }
715
716 /* Get consumer socket to use to push the metadata.*/
717 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
718 consumer);
719 if (!socket) {
720 ret_val = -1;
721 goto error;
722 }
723
724 ret = ust_app_push_metadata(registry, socket, 0);
725 if (ret < 0) {
726 ret_val = ret;
727 goto error;
728 }
729 pthread_mutex_unlock(&registry->lock);
730 return 0;
731
732 error:
733 pthread_mutex_unlock(&registry->lock);
734 return ret_val;
735 }
736
737 /*
738 * Send to the consumer a close metadata command for the given session. Once
739 * done, the metadata channel is deleted and the session metadata pointer is
740 * nullified. The session lock MUST be held unless the application is
741 * in the destroy path.
742 *
743 * Return 0 on success else a negative value.
744 */
745 static int close_metadata(struct ust_registry_session *registry,
746 struct consumer_output *consumer)
747 {
748 int ret;
749 struct consumer_socket *socket;
750
751 assert(registry);
752 assert(consumer);
753
754 rcu_read_lock();
755
756 pthread_mutex_lock(&registry->lock);
757
758 if (!registry->metadata_key || registry->metadata_closed) {
759 ret = 0;
760 goto end;
761 }
762
763 /* Get consumer socket to use to push the metadata.*/
764 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
765 consumer);
766 if (!socket) {
767 ret = -1;
768 goto error;
769 }
770
771 ret = consumer_close_metadata(socket, registry->metadata_key);
772 if (ret < 0) {
773 goto error;
774 }
775
776 error:
777 /*
778 * Metadata closed. Even on error this means that the consumer is not
779 * responding or not found so either way a second close should NOT be emit
780 * for this registry.
781 */
782 registry->metadata_closed = 1;
783 end:
784 pthread_mutex_unlock(&registry->lock);
785 rcu_read_unlock();
786 return ret;
787 }
788
789 /*
790 * We need to execute ht_destroy outside of RCU read-side critical
791 * section and outside of call_rcu thread, so we postpone its execution
792 * using ht_cleanup_push. It is simpler than to change the semantic of
793 * the many callers of delete_ust_app_session().
794 */
795 static
796 void delete_ust_app_session_rcu(struct rcu_head *head)
797 {
798 struct ust_app_session *ua_sess =
799 caa_container_of(head, struct ust_app_session, rcu_head);
800
801 ht_cleanup_push(ua_sess->channels);
802 free(ua_sess);
803 }
804
805 /*
806 * Delete ust app session safely. RCU read lock must be held before calling
807 * this function.
808 *
809 * The session list lock must be held by the caller.
810 */
811 static
812 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
813 struct ust_app *app)
814 {
815 int ret;
816 struct lttng_ht_iter iter;
817 struct ust_app_channel *ua_chan;
818 struct ust_registry_session *registry;
819
820 assert(ua_sess);
821
822 pthread_mutex_lock(&ua_sess->lock);
823
824 assert(!ua_sess->deleted);
825 ua_sess->deleted = true;
826
827 registry = get_session_registry(ua_sess);
828 /* Registry can be null on error path during initialization. */
829 if (registry) {
830 /* Push metadata for application before freeing the application. */
831 (void) push_metadata(registry, ua_sess->consumer);
832
833 /*
834 * Don't ask to close metadata for global per UID buffers. Close
835 * metadata only on destroy trace session in this case. Also, the
836 * previous push metadata could have flag the metadata registry to
837 * close so don't send a close command if closed.
838 */
839 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
840 /* And ask to close it for this session registry. */
841 (void) close_metadata(registry, ua_sess->consumer);
842 }
843 }
844
845 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
846 node.node) {
847 ret = lttng_ht_del(ua_sess->channels, &iter);
848 assert(!ret);
849 delete_ust_app_channel(sock, ua_chan, app);
850 }
851
852 /* In case of per PID, the registry is kept in the session. */
853 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
854 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
855 if (reg_pid) {
856 /*
857 * Registry can be null on error path during
858 * initialization.
859 */
860 buffer_reg_pid_remove(reg_pid);
861 buffer_reg_pid_destroy(reg_pid);
862 }
863 }
864
865 if (ua_sess->handle != -1) {
866 pthread_mutex_lock(&app->sock_lock);
867 ret = ustctl_release_handle(sock, ua_sess->handle);
868 pthread_mutex_unlock(&app->sock_lock);
869 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
870 ERR("UST app sock %d release session handle failed with ret %d",
871 sock, ret);
872 }
873 /* Remove session from application UST object descriptor. */
874 iter.iter.node = &ua_sess->ust_objd_node.node;
875 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
876 assert(!ret);
877 }
878
879 pthread_mutex_unlock(&ua_sess->lock);
880
881 consumer_output_put(ua_sess->consumer);
882
883 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
884 }
885
886 /*
887 * Delete a traceable application structure from the global list. Never call
888 * this function outside of a call_rcu call.
889 *
890 * RCU read side lock should _NOT_ be held when calling this function.
891 */
892 static
893 void delete_ust_app(struct ust_app *app)
894 {
895 int ret, sock;
896 struct ust_app_session *ua_sess, *tmp_ua_sess;
897
898 /*
899 * The session list lock must be held during this function to guarantee
900 * the existence of ua_sess.
901 */
902 session_lock_list();
903 /* Delete ust app sessions info */
904 sock = app->sock;
905 app->sock = -1;
906
907 /* Wipe sessions */
908 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
909 teardown_node) {
910 /* Free every object in the session and the session. */
911 rcu_read_lock();
912 delete_ust_app_session(sock, ua_sess, app);
913 rcu_read_unlock();
914 }
915
916 ht_cleanup_push(app->sessions);
917 ht_cleanup_push(app->ust_sessions_objd);
918 ht_cleanup_push(app->ust_objd);
919
920 /*
921 * Wait until we have deleted the application from the sock hash table
922 * before closing this socket, otherwise an application could re-use the
923 * socket ID and race with the teardown, using the same hash table entry.
924 *
925 * It's OK to leave the close in call_rcu. We want it to stay unique for
926 * all RCU readers that could run concurrently with unregister app,
927 * therefore we _need_ to only close that socket after a grace period. So
928 * it should stay in this RCU callback.
929 *
930 * This close() is a very important step of the synchronization model so
931 * every modification to this function must be carefully reviewed.
932 */
933 ret = close(sock);
934 if (ret) {
935 PERROR("close");
936 }
937 lttng_fd_put(LTTNG_FD_APPS, 1);
938
939 DBG2("UST app pid %d deleted", app->pid);
940 free(app);
941 session_unlock_list();
942 }
943
944 /*
945 * URCU intermediate call to delete an UST app.
946 */
947 static
948 void delete_ust_app_rcu(struct rcu_head *head)
949 {
950 struct lttng_ht_node_ulong *node =
951 caa_container_of(head, struct lttng_ht_node_ulong, head);
952 struct ust_app *app =
953 caa_container_of(node, struct ust_app, pid_n);
954
955 DBG3("Call RCU deleting app PID %d", app->pid);
956 delete_ust_app(app);
957 }
958
959 /*
960 * Delete the session from the application ht and delete the data structure by
961 * freeing every object inside and releasing them.
962 *
963 * The session list lock must be held by the caller.
964 */
965 static void destroy_app_session(struct ust_app *app,
966 struct ust_app_session *ua_sess)
967 {
968 int ret;
969 struct lttng_ht_iter iter;
970
971 assert(app);
972 assert(ua_sess);
973
974 iter.iter.node = &ua_sess->node.node;
975 ret = lttng_ht_del(app->sessions, &iter);
976 if (ret) {
977 /* Already scheduled for teardown. */
978 goto end;
979 }
980
981 /* Once deleted, free the data structure. */
982 delete_ust_app_session(app->sock, ua_sess, app);
983
984 end:
985 return;
986 }
987
988 /*
989 * Alloc new UST app session.
990 */
991 static
992 struct ust_app_session *alloc_ust_app_session(void)
993 {
994 struct ust_app_session *ua_sess;
995
996 /* Init most of the default value by allocating and zeroing */
997 ua_sess = zmalloc(sizeof(struct ust_app_session));
998 if (ua_sess == NULL) {
999 PERROR("malloc");
1000 goto error_free;
1001 }
1002
1003 ua_sess->handle = -1;
1004 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1005 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1006 pthread_mutex_init(&ua_sess->lock, NULL);
1007
1008 return ua_sess;
1009
1010 error_free:
1011 return NULL;
1012 }
1013
1014 /*
1015 * Alloc new UST app channel.
1016 */
1017 static
1018 struct ust_app_channel *alloc_ust_app_channel(char *name,
1019 struct ust_app_session *ua_sess,
1020 struct lttng_ust_channel_attr *attr)
1021 {
1022 struct ust_app_channel *ua_chan;
1023
1024 /* Init most of the default value by allocating and zeroing */
1025 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1026 if (ua_chan == NULL) {
1027 PERROR("malloc");
1028 goto error;
1029 }
1030
1031 /* Setup channel name */
1032 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1033 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1034
1035 ua_chan->enabled = 1;
1036 ua_chan->handle = -1;
1037 ua_chan->session = ua_sess;
1038 ua_chan->key = get_next_channel_key();
1039 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1040 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1041 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1042
1043 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1044 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1045
1046 /* Copy attributes */
1047 if (attr) {
1048 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1049 ua_chan->attr.subbuf_size = attr->subbuf_size;
1050 ua_chan->attr.num_subbuf = attr->num_subbuf;
1051 ua_chan->attr.overwrite = attr->overwrite;
1052 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1053 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1054 ua_chan->attr.output = attr->output;
1055 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1056 }
1057 /* By default, the channel is a per cpu channel. */
1058 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1059
1060 DBG3("UST app channel %s allocated", ua_chan->name);
1061
1062 return ua_chan;
1063
1064 error:
1065 return NULL;
1066 }
1067
1068 /*
1069 * Allocate and initialize a UST app stream.
1070 *
1071 * Return newly allocated stream pointer or NULL on error.
1072 */
1073 struct ust_app_stream *ust_app_alloc_stream(void)
1074 {
1075 struct ust_app_stream *stream = NULL;
1076
1077 stream = zmalloc(sizeof(*stream));
1078 if (stream == NULL) {
1079 PERROR("zmalloc ust app stream");
1080 goto error;
1081 }
1082
1083 /* Zero could be a valid value for a handle so flag it to -1. */
1084 stream->handle = -1;
1085
1086 error:
1087 return stream;
1088 }
1089
1090 /*
1091 * Alloc new UST app event.
1092 */
1093 static
1094 struct ust_app_event *alloc_ust_app_event(char *name,
1095 struct lttng_ust_event *attr)
1096 {
1097 struct ust_app_event *ua_event;
1098
1099 /* Init most of the default value by allocating and zeroing */
1100 ua_event = zmalloc(sizeof(struct ust_app_event));
1101 if (ua_event == NULL) {
1102 PERROR("malloc");
1103 goto error;
1104 }
1105
1106 ua_event->enabled = 1;
1107 strncpy(ua_event->name, name, sizeof(ua_event->name));
1108 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1109 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1110
1111 /* Copy attributes */
1112 if (attr) {
1113 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1114 }
1115
1116 DBG3("UST app event %s allocated", ua_event->name);
1117
1118 return ua_event;
1119
1120 error:
1121 return NULL;
1122 }
1123
1124 /*
1125 * Alloc new UST app context.
1126 */
1127 static
1128 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1129 {
1130 struct ust_app_ctx *ua_ctx;
1131
1132 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1133 if (ua_ctx == NULL) {
1134 goto error;
1135 }
1136
1137 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1138
1139 if (uctx) {
1140 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1141 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1142 char *provider_name = NULL, *ctx_name = NULL;
1143
1144 provider_name = strdup(uctx->u.app_ctx.provider_name);
1145 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1146 if (!provider_name || !ctx_name) {
1147 free(provider_name);
1148 free(ctx_name);
1149 goto error;
1150 }
1151
1152 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1153 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1154 }
1155 }
1156
1157 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1158 return ua_ctx;
1159 error:
1160 free(ua_ctx);
1161 return NULL;
1162 }
1163
1164 /*
1165 * Allocate a filter and copy the given original filter.
1166 *
1167 * Return allocated filter or NULL on error.
1168 */
1169 static struct lttng_filter_bytecode *copy_filter_bytecode(
1170 struct lttng_filter_bytecode *orig_f)
1171 {
1172 struct lttng_filter_bytecode *filter = NULL;
1173
1174 /* Copy filter bytecode */
1175 filter = zmalloc(sizeof(*filter) + orig_f->len);
1176 if (!filter) {
1177 PERROR("zmalloc alloc filter bytecode");
1178 goto error;
1179 }
1180
1181 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1182
1183 error:
1184 return filter;
1185 }
1186
1187 /*
1188 * Create a liblttng-ust filter bytecode from given bytecode.
1189 *
1190 * Return allocated filter or NULL on error.
1191 */
1192 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1193 struct lttng_filter_bytecode *orig_f)
1194 {
1195 struct lttng_ust_filter_bytecode *filter = NULL;
1196
1197 /* Copy filter bytecode */
1198 filter = zmalloc(sizeof(*filter) + orig_f->len);
1199 if (!filter) {
1200 PERROR("zmalloc alloc ust filter bytecode");
1201 goto error;
1202 }
1203
1204 assert(sizeof(struct lttng_filter_bytecode) ==
1205 sizeof(struct lttng_ust_filter_bytecode));
1206 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1207 error:
1208 return filter;
1209 }
1210
1211 /*
1212 * Find an ust_app using the sock and return it. RCU read side lock must be
1213 * held before calling this helper function.
1214 */
1215 struct ust_app *ust_app_find_by_sock(int sock)
1216 {
1217 struct lttng_ht_node_ulong *node;
1218 struct lttng_ht_iter iter;
1219
1220 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1221 node = lttng_ht_iter_get_node_ulong(&iter);
1222 if (node == NULL) {
1223 DBG2("UST app find by sock %d not found", sock);
1224 goto error;
1225 }
1226
1227 return caa_container_of(node, struct ust_app, sock_n);
1228
1229 error:
1230 return NULL;
1231 }
1232
1233 /*
1234 * Find an ust_app using the notify sock and return it. RCU read side lock must
1235 * be held before calling this helper function.
1236 */
1237 static struct ust_app *find_app_by_notify_sock(int sock)
1238 {
1239 struct lttng_ht_node_ulong *node;
1240 struct lttng_ht_iter iter;
1241
1242 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1243 &iter);
1244 node = lttng_ht_iter_get_node_ulong(&iter);
1245 if (node == NULL) {
1246 DBG2("UST app find by notify sock %d not found", sock);
1247 goto error;
1248 }
1249
1250 return caa_container_of(node, struct ust_app, notify_sock_n);
1251
1252 error:
1253 return NULL;
1254 }
1255
1256 /*
1257 * Lookup for an ust app event based on event name, filter bytecode and the
1258 * event loglevel.
1259 *
1260 * Return an ust_app_event object or NULL on error.
1261 */
1262 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1263 char *name, struct lttng_filter_bytecode *filter,
1264 int loglevel_value,
1265 const struct lttng_event_exclusion *exclusion)
1266 {
1267 struct lttng_ht_iter iter;
1268 struct lttng_ht_node_str *node;
1269 struct ust_app_event *event = NULL;
1270 struct ust_app_ht_key key;
1271
1272 assert(name);
1273 assert(ht);
1274
1275 /* Setup key for event lookup. */
1276 key.name = name;
1277 key.filter = filter;
1278 key.loglevel_type = loglevel_value;
1279 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1280 key.exclusion = exclusion;
1281
1282 /* Lookup using the event name as hash and a custom match fct. */
1283 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1284 ht_match_ust_app_event, &key, &iter.iter);
1285 node = lttng_ht_iter_get_node_str(&iter);
1286 if (node == NULL) {
1287 goto end;
1288 }
1289
1290 event = caa_container_of(node, struct ust_app_event, node);
1291
1292 end:
1293 return event;
1294 }
1295
1296 /*
1297 * Create the channel context on the tracer.
1298 *
1299 * Called with UST app session lock held.
1300 */
1301 static
1302 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1303 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1304 {
1305 int ret;
1306
1307 health_code_update();
1308
1309 pthread_mutex_lock(&app->sock_lock);
1310 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1311 ua_chan->obj, &ua_ctx->obj);
1312 pthread_mutex_unlock(&app->sock_lock);
1313 if (ret < 0) {
1314 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1315 ERR("UST app create channel context failed for app (pid: %d) "
1316 "with ret %d", app->pid, ret);
1317 } else {
1318 /*
1319 * This is normal behavior, an application can die during the
1320 * creation process. Don't report an error so the execution can
1321 * continue normally.
1322 */
1323 ret = 0;
1324 DBG3("UST app disable event failed. Application is dead.");
1325 }
1326 goto error;
1327 }
1328
1329 ua_ctx->handle = ua_ctx->obj->handle;
1330
1331 DBG2("UST app context handle %d created successfully for channel %s",
1332 ua_ctx->handle, ua_chan->name);
1333
1334 error:
1335 health_code_update();
1336 return ret;
1337 }
1338
1339 /*
1340 * Set the filter on the tracer.
1341 */
1342 static
1343 int set_ust_event_filter(struct ust_app_event *ua_event,
1344 struct ust_app *app)
1345 {
1346 int ret;
1347 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1348
1349 health_code_update();
1350
1351 if (!ua_event->filter) {
1352 ret = 0;
1353 goto error;
1354 }
1355
1356 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1357 if (!ust_bytecode) {
1358 ret = -LTTNG_ERR_NOMEM;
1359 goto error;
1360 }
1361 pthread_mutex_lock(&app->sock_lock);
1362 ret = ustctl_set_filter(app->sock, ust_bytecode,
1363 ua_event->obj);
1364 pthread_mutex_unlock(&app->sock_lock);
1365 if (ret < 0) {
1366 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1367 ERR("UST app event %s filter failed for app (pid: %d) "
1368 "with ret %d", ua_event->attr.name, app->pid, ret);
1369 } else {
1370 /*
1371 * This is normal behavior, an application can die during the
1372 * creation process. Don't report an error so the execution can
1373 * continue normally.
1374 */
1375 ret = 0;
1376 DBG3("UST app filter event failed. Application is dead.");
1377 }
1378 goto error;
1379 }
1380
1381 DBG2("UST filter set successfully for event %s", ua_event->name);
1382
1383 error:
1384 health_code_update();
1385 free(ust_bytecode);
1386 return ret;
1387 }
1388
1389 static
1390 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1391 struct lttng_event_exclusion *exclusion)
1392 {
1393 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1394 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1395 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1396
1397 ust_exclusion = zmalloc(exclusion_alloc_size);
1398 if (!ust_exclusion) {
1399 PERROR("malloc");
1400 goto end;
1401 }
1402
1403 assert(sizeof(struct lttng_event_exclusion) ==
1404 sizeof(struct lttng_ust_event_exclusion));
1405 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1406 end:
1407 return ust_exclusion;
1408 }
1409
1410 /*
1411 * Set event exclusions on the tracer.
1412 */
1413 static
1414 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1415 struct ust_app *app)
1416 {
1417 int ret;
1418 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1419
1420 health_code_update();
1421
1422 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1423 ret = 0;
1424 goto error;
1425 }
1426
1427 ust_exclusion = create_ust_exclusion_from_exclusion(
1428 ua_event->exclusion);
1429 if (!ust_exclusion) {
1430 ret = -LTTNG_ERR_NOMEM;
1431 goto error;
1432 }
1433 pthread_mutex_lock(&app->sock_lock);
1434 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1435 pthread_mutex_unlock(&app->sock_lock);
1436 if (ret < 0) {
1437 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1438 ERR("UST app event %s exclusions failed for app (pid: %d) "
1439 "with ret %d", ua_event->attr.name, app->pid, ret);
1440 } else {
1441 /*
1442 * This is normal behavior, an application can die during the
1443 * creation process. Don't report an error so the execution can
1444 * continue normally.
1445 */
1446 ret = 0;
1447 DBG3("UST app event exclusion failed. Application is dead.");
1448 }
1449 goto error;
1450 }
1451
1452 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1453
1454 error:
1455 health_code_update();
1456 free(ust_exclusion);
1457 return ret;
1458 }
1459
1460 /*
1461 * Disable the specified event on to UST tracer for the UST session.
1462 */
1463 static int disable_ust_event(struct ust_app *app,
1464 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1465 {
1466 int ret;
1467
1468 health_code_update();
1469
1470 pthread_mutex_lock(&app->sock_lock);
1471 ret = ustctl_disable(app->sock, ua_event->obj);
1472 pthread_mutex_unlock(&app->sock_lock);
1473 if (ret < 0) {
1474 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1475 ERR("UST app event %s disable failed for app (pid: %d) "
1476 "and session handle %d with ret %d",
1477 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1478 } else {
1479 /*
1480 * This is normal behavior, an application can die during the
1481 * creation process. Don't report an error so the execution can
1482 * continue normally.
1483 */
1484 ret = 0;
1485 DBG3("UST app disable event failed. Application is dead.");
1486 }
1487 goto error;
1488 }
1489
1490 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1491 ua_event->attr.name, app->pid);
1492
1493 error:
1494 health_code_update();
1495 return ret;
1496 }
1497
1498 /*
1499 * Disable the specified channel on to UST tracer for the UST session.
1500 */
1501 static int disable_ust_channel(struct ust_app *app,
1502 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1503 {
1504 int ret;
1505
1506 health_code_update();
1507
1508 pthread_mutex_lock(&app->sock_lock);
1509 ret = ustctl_disable(app->sock, ua_chan->obj);
1510 pthread_mutex_unlock(&app->sock_lock);
1511 if (ret < 0) {
1512 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1513 ERR("UST app channel %s disable failed for app (pid: %d) "
1514 "and session handle %d with ret %d",
1515 ua_chan->name, app->pid, ua_sess->handle, ret);
1516 } else {
1517 /*
1518 * This is normal behavior, an application can die during the
1519 * creation process. Don't report an error so the execution can
1520 * continue normally.
1521 */
1522 ret = 0;
1523 DBG3("UST app disable channel failed. Application is dead.");
1524 }
1525 goto error;
1526 }
1527
1528 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1529 ua_chan->name, app->pid);
1530
1531 error:
1532 health_code_update();
1533 return ret;
1534 }
1535
1536 /*
1537 * Enable the specified channel on to UST tracer for the UST session.
1538 */
1539 static int enable_ust_channel(struct ust_app *app,
1540 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1541 {
1542 int ret;
1543
1544 health_code_update();
1545
1546 pthread_mutex_lock(&app->sock_lock);
1547 ret = ustctl_enable(app->sock, ua_chan->obj);
1548 pthread_mutex_unlock(&app->sock_lock);
1549 if (ret < 0) {
1550 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1551 ERR("UST app channel %s enable failed for app (pid: %d) "
1552 "and session handle %d with ret %d",
1553 ua_chan->name, app->pid, ua_sess->handle, ret);
1554 } else {
1555 /*
1556 * This is normal behavior, an application can die during the
1557 * creation process. Don't report an error so the execution can
1558 * continue normally.
1559 */
1560 ret = 0;
1561 DBG3("UST app enable channel failed. Application is dead.");
1562 }
1563 goto error;
1564 }
1565
1566 ua_chan->enabled = 1;
1567
1568 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1569 ua_chan->name, app->pid);
1570
1571 error:
1572 health_code_update();
1573 return ret;
1574 }
1575
1576 /*
1577 * Enable the specified event on to UST tracer for the UST session.
1578 */
1579 static int enable_ust_event(struct ust_app *app,
1580 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1581 {
1582 int ret;
1583
1584 health_code_update();
1585
1586 pthread_mutex_lock(&app->sock_lock);
1587 ret = ustctl_enable(app->sock, ua_event->obj);
1588 pthread_mutex_unlock(&app->sock_lock);
1589 if (ret < 0) {
1590 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1591 ERR("UST app event %s enable failed for app (pid: %d) "
1592 "and session handle %d with ret %d",
1593 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1594 } else {
1595 /*
1596 * This is normal behavior, an application can die during the
1597 * creation process. Don't report an error so the execution can
1598 * continue normally.
1599 */
1600 ret = 0;
1601 DBG3("UST app enable event failed. Application is dead.");
1602 }
1603 goto error;
1604 }
1605
1606 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1607 ua_event->attr.name, app->pid);
1608
1609 error:
1610 health_code_update();
1611 return ret;
1612 }
1613
1614 /*
1615 * Send channel and stream buffer to application.
1616 *
1617 * Return 0 on success. On error, a negative value is returned.
1618 */
1619 static int send_channel_pid_to_ust(struct ust_app *app,
1620 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1621 {
1622 int ret;
1623 struct ust_app_stream *stream, *stmp;
1624
1625 assert(app);
1626 assert(ua_sess);
1627 assert(ua_chan);
1628
1629 health_code_update();
1630
1631 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1632 app->sock);
1633
1634 /* Send channel to the application. */
1635 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1636 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1637 ret = -ENOTCONN; /* Caused by app exiting. */
1638 goto error;
1639 } else if (ret < 0) {
1640 goto error;
1641 }
1642
1643 health_code_update();
1644
1645 /* Send all streams to application. */
1646 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1647 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1648 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1649 ret = -ENOTCONN; /* Caused by app exiting. */
1650 goto error;
1651 } else if (ret < 0) {
1652 goto error;
1653 }
1654 /* We don't need the stream anymore once sent to the tracer. */
1655 cds_list_del(&stream->list);
1656 delete_ust_app_stream(-1, stream, app);
1657 }
1658 /* Flag the channel that it is sent to the application. */
1659 ua_chan->is_sent = 1;
1660
1661 error:
1662 health_code_update();
1663 return ret;
1664 }
1665
1666 /*
1667 * Create the specified event onto the UST tracer for a UST session.
1668 *
1669 * Should be called with session mutex held.
1670 */
1671 static
1672 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1673 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1674 {
1675 int ret = 0;
1676
1677 health_code_update();
1678
1679 /* Create UST event on tracer */
1680 pthread_mutex_lock(&app->sock_lock);
1681 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1682 &ua_event->obj);
1683 pthread_mutex_unlock(&app->sock_lock);
1684 if (ret < 0) {
1685 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1686 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1687 ua_event->attr.name, app->pid, ret);
1688 } else {
1689 /*
1690 * This is normal behavior, an application can die during the
1691 * creation process. Don't report an error so the execution can
1692 * continue normally.
1693 */
1694 ret = 0;
1695 DBG3("UST app create event failed. Application is dead.");
1696 }
1697 goto error;
1698 }
1699
1700 ua_event->handle = ua_event->obj->handle;
1701
1702 DBG2("UST app event %s created successfully for pid:%d",
1703 ua_event->attr.name, app->pid);
1704
1705 health_code_update();
1706
1707 /* Set filter if one is present. */
1708 if (ua_event->filter) {
1709 ret = set_ust_event_filter(ua_event, app);
1710 if (ret < 0) {
1711 goto error;
1712 }
1713 }
1714
1715 /* Set exclusions for the event */
1716 if (ua_event->exclusion) {
1717 ret = set_ust_event_exclusion(ua_event, app);
1718 if (ret < 0) {
1719 goto error;
1720 }
1721 }
1722
1723 /* If event not enabled, disable it on the tracer */
1724 if (ua_event->enabled) {
1725 /*
1726 * We now need to explicitly enable the event, since it
1727 * is now disabled at creation.
1728 */
1729 ret = enable_ust_event(app, ua_sess, ua_event);
1730 if (ret < 0) {
1731 /*
1732 * If we hit an EPERM, something is wrong with our enable call. If
1733 * we get an EEXIST, there is a problem on the tracer side since we
1734 * just created it.
1735 */
1736 switch (ret) {
1737 case -LTTNG_UST_ERR_PERM:
1738 /* Code flow problem */
1739 assert(0);
1740 case -LTTNG_UST_ERR_EXIST:
1741 /* It's OK for our use case. */
1742 ret = 0;
1743 break;
1744 default:
1745 break;
1746 }
1747 goto error;
1748 }
1749 }
1750
1751 error:
1752 health_code_update();
1753 return ret;
1754 }
1755
1756 /*
1757 * Copy data between an UST app event and a LTT event.
1758 */
1759 static void shadow_copy_event(struct ust_app_event *ua_event,
1760 struct ltt_ust_event *uevent)
1761 {
1762 size_t exclusion_alloc_size;
1763
1764 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1765 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1766
1767 ua_event->enabled = uevent->enabled;
1768
1769 /* Copy event attributes */
1770 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1771
1772 /* Copy filter bytecode */
1773 if (uevent->filter) {
1774 ua_event->filter = copy_filter_bytecode(uevent->filter);
1775 /* Filter might be NULL here in case of ENONEM. */
1776 }
1777
1778 /* Copy exclusion data */
1779 if (uevent->exclusion) {
1780 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1781 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1782 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1783 if (ua_event->exclusion == NULL) {
1784 PERROR("malloc");
1785 } else {
1786 memcpy(ua_event->exclusion, uevent->exclusion,
1787 exclusion_alloc_size);
1788 }
1789 }
1790 }
1791
1792 /*
1793 * Copy data between an UST app channel and a LTT channel.
1794 */
1795 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1796 struct ltt_ust_channel *uchan)
1797 {
1798 struct lttng_ht_iter iter;
1799 struct ltt_ust_event *uevent;
1800 struct ltt_ust_context *uctx;
1801 struct ust_app_event *ua_event;
1802
1803 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1804
1805 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1806 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1807
1808 ua_chan->tracefile_size = uchan->tracefile_size;
1809 ua_chan->tracefile_count = uchan->tracefile_count;
1810
1811 /* Copy event attributes since the layout is different. */
1812 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1813 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1814 ua_chan->attr.overwrite = uchan->attr.overwrite;
1815 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1816 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1817 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1818 ua_chan->attr.output = uchan->attr.output;
1819 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1820
1821 /*
1822 * Note that the attribute channel type is not set since the channel on the
1823 * tracing registry side does not have this information.
1824 */
1825
1826 ua_chan->enabled = uchan->enabled;
1827 ua_chan->tracing_channel_id = uchan->id;
1828
1829 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1830 struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1831
1832 if (ua_ctx == NULL) {
1833 continue;
1834 }
1835 lttng_ht_node_init_ulong(&ua_ctx->node,
1836 (unsigned long) ua_ctx->ctx.ctx);
1837 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1838 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1839 }
1840
1841 /* Copy all events from ltt ust channel to ust app channel */
1842 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1843 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1844 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1845 if (ua_event == NULL) {
1846 DBG2("UST event %s not found on shadow copy channel",
1847 uevent->attr.name);
1848 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1849 if (ua_event == NULL) {
1850 continue;
1851 }
1852 shadow_copy_event(ua_event, uevent);
1853 add_unique_ust_app_event(ua_chan, ua_event);
1854 }
1855 }
1856
1857 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1858 }
1859
1860 /*
1861 * Copy data between a UST app session and a regular LTT session.
1862 */
1863 static void shadow_copy_session(struct ust_app_session *ua_sess,
1864 struct ltt_ust_session *usess, struct ust_app *app)
1865 {
1866 struct lttng_ht_node_str *ua_chan_node;
1867 struct lttng_ht_iter iter;
1868 struct ltt_ust_channel *uchan;
1869 struct ust_app_channel *ua_chan;
1870 time_t rawtime;
1871 struct tm *timeinfo;
1872 char datetime[16];
1873 int ret;
1874 char tmp_shm_path[PATH_MAX];
1875
1876 /* Get date and time for unique app path */
1877 time(&rawtime);
1878 timeinfo = localtime(&rawtime);
1879 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1880
1881 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1882
1883 ua_sess->tracing_id = usess->id;
1884 ua_sess->id = get_next_session_id();
1885 ua_sess->uid = app->uid;
1886 ua_sess->gid = app->gid;
1887 ua_sess->euid = usess->uid;
1888 ua_sess->egid = usess->gid;
1889 ua_sess->buffer_type = usess->buffer_type;
1890 ua_sess->bits_per_long = app->bits_per_long;
1891
1892 /* There is only one consumer object per session possible. */
1893 consumer_output_get(usess->consumer);
1894 ua_sess->consumer = usess->consumer;
1895
1896 ua_sess->output_traces = usess->output_traces;
1897 ua_sess->live_timer_interval = usess->live_timer_interval;
1898 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1899 &usess->metadata_attr);
1900
1901 switch (ua_sess->buffer_type) {
1902 case LTTNG_BUFFER_PER_PID:
1903 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1904 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1905 datetime);
1906 break;
1907 case LTTNG_BUFFER_PER_UID:
1908 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1909 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1910 break;
1911 default:
1912 assert(0);
1913 goto error;
1914 }
1915 if (ret < 0) {
1916 PERROR("asprintf UST shadow copy session");
1917 assert(0);
1918 goto error;
1919 }
1920
1921 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1922 sizeof(ua_sess->root_shm_path));
1923 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1924 strncpy(ua_sess->shm_path, usess->shm_path,
1925 sizeof(ua_sess->shm_path));
1926 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1927 if (ua_sess->shm_path[0]) {
1928 switch (ua_sess->buffer_type) {
1929 case LTTNG_BUFFER_PER_PID:
1930 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1931 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1932 app->name, app->pid, datetime);
1933 break;
1934 case LTTNG_BUFFER_PER_UID:
1935 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1936 DEFAULT_UST_TRACE_UID_PATH,
1937 app->uid, app->bits_per_long);
1938 break;
1939 default:
1940 assert(0);
1941 goto error;
1942 }
1943 if (ret < 0) {
1944 PERROR("sprintf UST shadow copy session");
1945 assert(0);
1946 goto error;
1947 }
1948 strncat(ua_sess->shm_path, tmp_shm_path,
1949 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1950 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1951 }
1952
1953 /* Iterate over all channels in global domain. */
1954 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1955 uchan, node.node) {
1956 struct lttng_ht_iter uiter;
1957
1958 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1959 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1960 if (ua_chan_node != NULL) {
1961 /* Session exist. Contiuing. */
1962 continue;
1963 }
1964
1965 DBG2("Channel %s not found on shadow session copy, creating it",
1966 uchan->name);
1967 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess,
1968 &uchan->attr);
1969 if (ua_chan == NULL) {
1970 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1971 continue;
1972 }
1973 shadow_copy_channel(ua_chan, uchan);
1974 /*
1975 * The concept of metadata channel does not exist on the tracing
1976 * registry side of the session daemon so this can only be a per CPU
1977 * channel and not metadata.
1978 */
1979 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1980
1981 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1982 }
1983 return;
1984
1985 error:
1986 consumer_output_put(ua_sess->consumer);
1987 }
1988
1989 /*
1990 * Lookup sesison wrapper.
1991 */
1992 static
1993 void __lookup_session_by_app(struct ltt_ust_session *usess,
1994 struct ust_app *app, struct lttng_ht_iter *iter)
1995 {
1996 /* Get right UST app session from app */
1997 lttng_ht_lookup(app->sessions, &usess->id, iter);
1998 }
1999
2000 /*
2001 * Return ust app session from the app session hashtable using the UST session
2002 * id.
2003 */
2004 static struct ust_app_session *lookup_session_by_app(
2005 struct ltt_ust_session *usess, struct ust_app *app)
2006 {
2007 struct lttng_ht_iter iter;
2008 struct lttng_ht_node_u64 *node;
2009
2010 __lookup_session_by_app(usess, app, &iter);
2011 node = lttng_ht_iter_get_node_u64(&iter);
2012 if (node == NULL) {
2013 goto error;
2014 }
2015
2016 return caa_container_of(node, struct ust_app_session, node);
2017
2018 error:
2019 return NULL;
2020 }
2021
2022 /*
2023 * Setup buffer registry per PID for the given session and application. If none
2024 * is found, a new one is created, added to the global registry and
2025 * initialized. If regp is valid, it's set with the newly created object.
2026 *
2027 * Return 0 on success or else a negative value.
2028 */
2029 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
2030 struct ust_app *app, struct buffer_reg_pid **regp)
2031 {
2032 int ret = 0;
2033 struct buffer_reg_pid *reg_pid;
2034
2035 assert(ua_sess);
2036 assert(app);
2037
2038 rcu_read_lock();
2039
2040 reg_pid = buffer_reg_pid_find(ua_sess->id);
2041 if (!reg_pid) {
2042 /*
2043 * This is the create channel path meaning that if there is NO
2044 * registry available, we have to create one for this session.
2045 */
2046 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
2047 ua_sess->root_shm_path, ua_sess->shm_path);
2048 if (ret < 0) {
2049 goto error;
2050 }
2051 } else {
2052 goto end;
2053 }
2054
2055 /* Initialize registry. */
2056 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
2057 app->bits_per_long, app->uint8_t_alignment,
2058 app->uint16_t_alignment, app->uint32_t_alignment,
2059 app->uint64_t_alignment, app->long_alignment,
2060 app->byte_order, app->version.major,
2061 app->version.minor, reg_pid->root_shm_path,
2062 reg_pid->shm_path,
2063 ua_sess->euid, ua_sess->egid);
2064 if (ret < 0) {
2065 /*
2066 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2067 * destroy the buffer registry, because it is always expected
2068 * that if the buffer registry can be found, its ust registry is
2069 * non-NULL.
2070 */
2071 buffer_reg_pid_destroy(reg_pid);
2072 goto error;
2073 }
2074
2075 buffer_reg_pid_add(reg_pid);
2076
2077 DBG3("UST app buffer registry per PID created successfully");
2078
2079 end:
2080 if (regp) {
2081 *regp = reg_pid;
2082 }
2083 error:
2084 rcu_read_unlock();
2085 return ret;
2086 }
2087
2088 /*
2089 * Setup buffer registry per UID for the given session and application. If none
2090 * is found, a new one is created, added to the global registry and
2091 * initialized. If regp is valid, it's set with the newly created object.
2092 *
2093 * Return 0 on success or else a negative value.
2094 */
2095 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2096 struct ust_app_session *ua_sess,
2097 struct ust_app *app, struct buffer_reg_uid **regp)
2098 {
2099 int ret = 0;
2100 struct buffer_reg_uid *reg_uid;
2101
2102 assert(usess);
2103 assert(app);
2104
2105 rcu_read_lock();
2106
2107 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2108 if (!reg_uid) {
2109 /*
2110 * This is the create channel path meaning that if there is NO
2111 * registry available, we have to create one for this session.
2112 */
2113 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2114 LTTNG_DOMAIN_UST, &reg_uid,
2115 ua_sess->root_shm_path, ua_sess->shm_path);
2116 if (ret < 0) {
2117 goto error;
2118 }
2119 } else {
2120 goto end;
2121 }
2122
2123 /* Initialize registry. */
2124 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2125 app->bits_per_long, app->uint8_t_alignment,
2126 app->uint16_t_alignment, app->uint32_t_alignment,
2127 app->uint64_t_alignment, app->long_alignment,
2128 app->byte_order, app->version.major,
2129 app->version.minor, reg_uid->root_shm_path,
2130 reg_uid->shm_path, usess->uid, usess->gid);
2131 if (ret < 0) {
2132 /*
2133 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2134 * destroy the buffer registry, because it is always expected
2135 * that if the buffer registry can be found, its ust registry is
2136 * non-NULL.
2137 */
2138 buffer_reg_uid_destroy(reg_uid, NULL);
2139 goto error;
2140 }
2141 /* Add node to teardown list of the session. */
2142 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2143
2144 buffer_reg_uid_add(reg_uid);
2145
2146 DBG3("UST app buffer registry per UID created successfully");
2147 end:
2148 if (regp) {
2149 *regp = reg_uid;
2150 }
2151 error:
2152 rcu_read_unlock();
2153 return ret;
2154 }
2155
2156 /*
2157 * Create a session on the tracer side for the given app.
2158 *
2159 * On success, ua_sess_ptr is populated with the session pointer or else left
2160 * untouched. If the session was created, is_created is set to 1. On error,
2161 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2162 * be NULL.
2163 *
2164 * Returns 0 on success or else a negative code which is either -ENOMEM or
2165 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2166 */
2167 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2168 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2169 int *is_created)
2170 {
2171 int ret, created = 0;
2172 struct ust_app_session *ua_sess;
2173
2174 assert(usess);
2175 assert(app);
2176 assert(ua_sess_ptr);
2177
2178 health_code_update();
2179
2180 ua_sess = lookup_session_by_app(usess, app);
2181 if (ua_sess == NULL) {
2182 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2183 app->pid, usess->id);
2184 ua_sess = alloc_ust_app_session();
2185 if (ua_sess == NULL) {
2186 /* Only malloc can failed so something is really wrong */
2187 ret = -ENOMEM;
2188 goto error;
2189 }
2190 shadow_copy_session(ua_sess, usess, app);
2191 created = 1;
2192 }
2193
2194 switch (usess->buffer_type) {
2195 case LTTNG_BUFFER_PER_PID:
2196 /* Init local registry. */
2197 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2198 if (ret < 0) {
2199 delete_ust_app_session(-1, ua_sess, app);
2200 goto error;
2201 }
2202 break;
2203 case LTTNG_BUFFER_PER_UID:
2204 /* Look for a global registry. If none exists, create one. */
2205 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2206 if (ret < 0) {
2207 delete_ust_app_session(-1, ua_sess, app);
2208 goto error;
2209 }
2210 break;
2211 default:
2212 assert(0);
2213 ret = -EINVAL;
2214 goto error;
2215 }
2216
2217 health_code_update();
2218
2219 if (ua_sess->handle == -1) {
2220 pthread_mutex_lock(&app->sock_lock);
2221 ret = ustctl_create_session(app->sock);
2222 pthread_mutex_unlock(&app->sock_lock);
2223 if (ret < 0) {
2224 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2225 ERR("Creating session for app pid %d with ret %d",
2226 app->pid, ret);
2227 } else {
2228 DBG("UST app creating session failed. Application is dead");
2229 /*
2230 * This is normal behavior, an application can die during the
2231 * creation process. Don't report an error so the execution can
2232 * continue normally. This will get flagged ENOTCONN and the
2233 * caller will handle it.
2234 */
2235 ret = 0;
2236 }
2237 delete_ust_app_session(-1, ua_sess, app);
2238 if (ret != -ENOMEM) {
2239 /*
2240 * Tracer is probably gone or got an internal error so let's
2241 * behave like it will soon unregister or not usable.
2242 */
2243 ret = -ENOTCONN;
2244 }
2245 goto error;
2246 }
2247
2248 ua_sess->handle = ret;
2249
2250 /* Add ust app session to app's HT */
2251 lttng_ht_node_init_u64(&ua_sess->node,
2252 ua_sess->tracing_id);
2253 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2254 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2255 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2256 &ua_sess->ust_objd_node);
2257
2258 DBG2("UST app session created successfully with handle %d", ret);
2259 }
2260
2261 *ua_sess_ptr = ua_sess;
2262 if (is_created) {
2263 *is_created = created;
2264 }
2265
2266 /* Everything went well. */
2267 ret = 0;
2268
2269 error:
2270 health_code_update();
2271 return ret;
2272 }
2273
2274 /*
2275 * Match function for a hash table lookup of ust_app_ctx.
2276 *
2277 * It matches an ust app context based on the context type and, in the case
2278 * of perf counters, their name.
2279 */
2280 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2281 {
2282 struct ust_app_ctx *ctx;
2283 const struct lttng_ust_context_attr *key;
2284
2285 assert(node);
2286 assert(_key);
2287
2288 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2289 key = _key;
2290
2291 /* Context type */
2292 if (ctx->ctx.ctx != key->ctx) {
2293 goto no_match;
2294 }
2295
2296 switch(key->ctx) {
2297 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2298 if (strncmp(key->u.perf_counter.name,
2299 ctx->ctx.u.perf_counter.name,
2300 sizeof(key->u.perf_counter.name))) {
2301 goto no_match;
2302 }
2303 break;
2304 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2305 if (strcmp(key->u.app_ctx.provider_name,
2306 ctx->ctx.u.app_ctx.provider_name) ||
2307 strcmp(key->u.app_ctx.ctx_name,
2308 ctx->ctx.u.app_ctx.ctx_name)) {
2309 goto no_match;
2310 }
2311 break;
2312 default:
2313 break;
2314 }
2315
2316 /* Match. */
2317 return 1;
2318
2319 no_match:
2320 return 0;
2321 }
2322
2323 /*
2324 * Lookup for an ust app context from an lttng_ust_context.
2325 *
2326 * Must be called while holding RCU read side lock.
2327 * Return an ust_app_ctx object or NULL on error.
2328 */
2329 static
2330 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2331 struct lttng_ust_context_attr *uctx)
2332 {
2333 struct lttng_ht_iter iter;
2334 struct lttng_ht_node_ulong *node;
2335 struct ust_app_ctx *app_ctx = NULL;
2336
2337 assert(uctx);
2338 assert(ht);
2339
2340 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2341 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2342 ht_match_ust_app_ctx, uctx, &iter.iter);
2343 node = lttng_ht_iter_get_node_ulong(&iter);
2344 if (!node) {
2345 goto end;
2346 }
2347
2348 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2349
2350 end:
2351 return app_ctx;
2352 }
2353
2354 /*
2355 * Create a context for the channel on the tracer.
2356 *
2357 * Called with UST app session lock held and a RCU read side lock.
2358 */
2359 static
2360 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2361 struct lttng_ust_context_attr *uctx,
2362 struct ust_app *app)
2363 {
2364 int ret = 0;
2365 struct ust_app_ctx *ua_ctx;
2366
2367 DBG2("UST app adding context to channel %s", ua_chan->name);
2368
2369 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2370 if (ua_ctx) {
2371 ret = -EEXIST;
2372 goto error;
2373 }
2374
2375 ua_ctx = alloc_ust_app_ctx(uctx);
2376 if (ua_ctx == NULL) {
2377 /* malloc failed */
2378 ret = -ENOMEM;
2379 goto error;
2380 }
2381
2382 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2383 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2384 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2385
2386 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2387 if (ret < 0) {
2388 goto error;
2389 }
2390
2391 error:
2392 return ret;
2393 }
2394
2395 /*
2396 * Enable on the tracer side a ust app event for the session and channel.
2397 *
2398 * Called with UST app session lock held.
2399 */
2400 static
2401 int enable_ust_app_event(struct ust_app_session *ua_sess,
2402 struct ust_app_event *ua_event, struct ust_app *app)
2403 {
2404 int ret;
2405
2406 ret = enable_ust_event(app, ua_sess, ua_event);
2407 if (ret < 0) {
2408 goto error;
2409 }
2410
2411 ua_event->enabled = 1;
2412
2413 error:
2414 return ret;
2415 }
2416
2417 /*
2418 * Disable on the tracer side a ust app event for the session and channel.
2419 */
2420 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2421 struct ust_app_event *ua_event, struct ust_app *app)
2422 {
2423 int ret;
2424
2425 ret = disable_ust_event(app, ua_sess, ua_event);
2426 if (ret < 0) {
2427 goto error;
2428 }
2429
2430 ua_event->enabled = 0;
2431
2432 error:
2433 return ret;
2434 }
2435
2436 /*
2437 * Lookup ust app channel for session and disable it on the tracer side.
2438 */
2439 static
2440 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2441 struct ust_app_channel *ua_chan, struct ust_app *app)
2442 {
2443 int ret;
2444
2445 ret = disable_ust_channel(app, ua_sess, ua_chan);
2446 if (ret < 0) {
2447 goto error;
2448 }
2449
2450 ua_chan->enabled = 0;
2451
2452 error:
2453 return ret;
2454 }
2455
2456 /*
2457 * Lookup ust app channel for session and enable it on the tracer side. This
2458 * MUST be called with a RCU read side lock acquired.
2459 */
2460 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2461 struct ltt_ust_channel *uchan, struct ust_app *app)
2462 {
2463 int ret = 0;
2464 struct lttng_ht_iter iter;
2465 struct lttng_ht_node_str *ua_chan_node;
2466 struct ust_app_channel *ua_chan;
2467
2468 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2469 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2470 if (ua_chan_node == NULL) {
2471 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2472 uchan->name, ua_sess->tracing_id);
2473 goto error;
2474 }
2475
2476 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2477
2478 ret = enable_ust_channel(app, ua_sess, ua_chan);
2479 if (ret < 0) {
2480 goto error;
2481 }
2482
2483 error:
2484 return ret;
2485 }
2486
2487 /*
2488 * Ask the consumer to create a channel and get it if successful.
2489 *
2490 * Called with UST app session lock held.
2491 *
2492 * Return 0 on success or else a negative value.
2493 */
2494 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2495 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2496 int bitness, struct ust_registry_session *registry,
2497 uint64_t trace_archive_id)
2498 {
2499 int ret;
2500 unsigned int nb_fd = 0;
2501 struct consumer_socket *socket;
2502
2503 assert(usess);
2504 assert(ua_sess);
2505 assert(ua_chan);
2506 assert(registry);
2507
2508 rcu_read_lock();
2509 health_code_update();
2510
2511 /* Get the right consumer socket for the application. */
2512 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2513 if (!socket) {
2514 ret = -EINVAL;
2515 goto error;
2516 }
2517
2518 health_code_update();
2519
2520 /* Need one fd for the channel. */
2521 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2522 if (ret < 0) {
2523 ERR("Exhausted number of available FD upon create channel");
2524 goto error;
2525 }
2526
2527 /*
2528 * Ask consumer to create channel. The consumer will return the number of
2529 * stream we have to expect.
2530 */
2531 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2532 registry, trace_archive_id);
2533 if (ret < 0) {
2534 goto error_ask;
2535 }
2536
2537 /*
2538 * Compute the number of fd needed before receiving them. It must be 2 per
2539 * stream (2 being the default value here).
2540 */
2541 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2542
2543 /* Reserve the amount of file descriptor we need. */
2544 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2545 if (ret < 0) {
2546 ERR("Exhausted number of available FD upon create channel");
2547 goto error_fd_get_stream;
2548 }
2549
2550 health_code_update();
2551
2552 /*
2553 * Now get the channel from the consumer. This call wil populate the stream
2554 * list of that channel and set the ust objects.
2555 */
2556 if (usess->consumer->enabled) {
2557 ret = ust_consumer_get_channel(socket, ua_chan);
2558 if (ret < 0) {
2559 goto error_destroy;
2560 }
2561 }
2562
2563 rcu_read_unlock();
2564 return 0;
2565
2566 error_destroy:
2567 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2568 error_fd_get_stream:
2569 /*
2570 * Initiate a destroy channel on the consumer since we had an error
2571 * handling it on our side. The return value is of no importance since we
2572 * already have a ret value set by the previous error that we need to
2573 * return.
2574 */
2575 (void) ust_consumer_destroy_channel(socket, ua_chan);
2576 error_ask:
2577 lttng_fd_put(LTTNG_FD_APPS, 1);
2578 error:
2579 health_code_update();
2580 rcu_read_unlock();
2581 return ret;
2582 }
2583
2584 /*
2585 * Duplicate the ust data object of the ust app stream and save it in the
2586 * buffer registry stream.
2587 *
2588 * Return 0 on success or else a negative value.
2589 */
2590 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2591 struct ust_app_stream *stream)
2592 {
2593 int ret;
2594
2595 assert(reg_stream);
2596 assert(stream);
2597
2598 /* Reserve the amount of file descriptor we need. */
2599 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2600 if (ret < 0) {
2601 ERR("Exhausted number of available FD upon duplicate stream");
2602 goto error;
2603 }
2604
2605 /* Duplicate object for stream once the original is in the registry. */
2606 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2607 reg_stream->obj.ust);
2608 if (ret < 0) {
2609 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2610 reg_stream->obj.ust, stream->obj, ret);
2611 lttng_fd_put(LTTNG_FD_APPS, 2);
2612 goto error;
2613 }
2614 stream->handle = stream->obj->handle;
2615
2616 error:
2617 return ret;
2618 }
2619
2620 /*
2621 * Duplicate the ust data object of the ust app. channel and save it in the
2622 * buffer registry channel.
2623 *
2624 * Return 0 on success or else a negative value.
2625 */
2626 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2627 struct ust_app_channel *ua_chan)
2628 {
2629 int ret;
2630
2631 assert(reg_chan);
2632 assert(ua_chan);
2633
2634 /* Need two fds for the channel. */
2635 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2636 if (ret < 0) {
2637 ERR("Exhausted number of available FD upon duplicate channel");
2638 goto error_fd_get;
2639 }
2640
2641 /* Duplicate object for stream once the original is in the registry. */
2642 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2643 if (ret < 0) {
2644 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2645 reg_chan->obj.ust, ua_chan->obj, ret);
2646 goto error;
2647 }
2648 ua_chan->handle = ua_chan->obj->handle;
2649
2650 return 0;
2651
2652 error:
2653 lttng_fd_put(LTTNG_FD_APPS, 1);
2654 error_fd_get:
2655 return ret;
2656 }
2657
2658 /*
2659 * For a given channel buffer registry, setup all streams of the given ust
2660 * application channel.
2661 *
2662 * Return 0 on success or else a negative value.
2663 */
2664 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2665 struct ust_app_channel *ua_chan,
2666 struct ust_app *app)
2667 {
2668 int ret = 0;
2669 struct ust_app_stream *stream, *stmp;
2670
2671 assert(reg_chan);
2672 assert(ua_chan);
2673
2674 DBG2("UST app setup buffer registry stream");
2675
2676 /* Send all streams to application. */
2677 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2678 struct buffer_reg_stream *reg_stream;
2679
2680 ret = buffer_reg_stream_create(&reg_stream);
2681 if (ret < 0) {
2682 goto error;
2683 }
2684
2685 /*
2686 * Keep original pointer and nullify it in the stream so the delete
2687 * stream call does not release the object.
2688 */
2689 reg_stream->obj.ust = stream->obj;
2690 stream->obj = NULL;
2691 buffer_reg_stream_add(reg_stream, reg_chan);
2692
2693 /* We don't need the streams anymore. */
2694 cds_list_del(&stream->list);
2695 delete_ust_app_stream(-1, stream, app);
2696 }
2697
2698 error:
2699 return ret;
2700 }
2701
2702 /*
2703 * Create a buffer registry channel for the given session registry and
2704 * application channel object. If regp pointer is valid, it's set with the
2705 * created object. Important, the created object is NOT added to the session
2706 * registry hash table.
2707 *
2708 * Return 0 on success else a negative value.
2709 */
2710 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2711 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2712 {
2713 int ret;
2714 struct buffer_reg_channel *reg_chan = NULL;
2715
2716 assert(reg_sess);
2717 assert(ua_chan);
2718
2719 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2720
2721 /* Create buffer registry channel. */
2722 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2723 if (ret < 0) {
2724 goto error_create;
2725 }
2726 assert(reg_chan);
2727 reg_chan->consumer_key = ua_chan->key;
2728 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2729 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2730
2731 /* Create and add a channel registry to session. */
2732 ret = ust_registry_channel_add(reg_sess->reg.ust,
2733 ua_chan->tracing_channel_id);
2734 if (ret < 0) {
2735 goto error;
2736 }
2737 buffer_reg_channel_add(reg_sess, reg_chan);
2738
2739 if (regp) {
2740 *regp = reg_chan;
2741 }
2742
2743 return 0;
2744
2745 error:
2746 /* Safe because the registry channel object was not added to any HT. */
2747 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2748 error_create:
2749 return ret;
2750 }
2751
2752 /*
2753 * Setup buffer registry channel for the given session registry and application
2754 * channel object. If regp pointer is valid, it's set with the created object.
2755 *
2756 * Return 0 on success else a negative value.
2757 */
2758 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2759 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2760 struct ust_app *app)
2761 {
2762 int ret;
2763
2764 assert(reg_sess);
2765 assert(reg_chan);
2766 assert(ua_chan);
2767 assert(ua_chan->obj);
2768
2769 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2770
2771 /* Setup all streams for the registry. */
2772 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2773 if (ret < 0) {
2774 goto error;
2775 }
2776
2777 reg_chan->obj.ust = ua_chan->obj;
2778 ua_chan->obj = NULL;
2779
2780 return 0;
2781
2782 error:
2783 buffer_reg_channel_remove(reg_sess, reg_chan);
2784 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2785 return ret;
2786 }
2787
2788 /*
2789 * Send buffer registry channel to the application.
2790 *
2791 * Return 0 on success else a negative value.
2792 */
2793 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2794 struct ust_app *app, struct ust_app_session *ua_sess,
2795 struct ust_app_channel *ua_chan)
2796 {
2797 int ret;
2798 struct buffer_reg_stream *reg_stream;
2799
2800 assert(reg_chan);
2801 assert(app);
2802 assert(ua_sess);
2803 assert(ua_chan);
2804
2805 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2806
2807 ret = duplicate_channel_object(reg_chan, ua_chan);
2808 if (ret < 0) {
2809 goto error;
2810 }
2811
2812 /* Send channel to the application. */
2813 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2814 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2815 ret = -ENOTCONN; /* Caused by app exiting. */
2816 goto error;
2817 } else if (ret < 0) {
2818 goto error;
2819 }
2820
2821 health_code_update();
2822
2823 /* Send all streams to application. */
2824 pthread_mutex_lock(&reg_chan->stream_list_lock);
2825 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2826 struct ust_app_stream stream;
2827
2828 ret = duplicate_stream_object(reg_stream, &stream);
2829 if (ret < 0) {
2830 goto error_stream_unlock;
2831 }
2832
2833 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2834 if (ret < 0) {
2835 (void) release_ust_app_stream(-1, &stream, app);
2836 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2837 ret = -ENOTCONN; /* Caused by app exiting. */
2838 }
2839 goto error_stream_unlock;
2840 }
2841
2842 /*
2843 * The return value is not important here. This function will output an
2844 * error if needed.
2845 */
2846 (void) release_ust_app_stream(-1, &stream, app);
2847 }
2848 ua_chan->is_sent = 1;
2849
2850 error_stream_unlock:
2851 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2852 error:
2853 return ret;
2854 }
2855
2856 /*
2857 * Create and send to the application the created buffers with per UID buffers.
2858 *
2859 * This MUST be called with a RCU read side lock acquired.
2860 * The session list lock and the session's lock must be acquired.
2861 *
2862 * Return 0 on success else a negative value.
2863 */
2864 static int create_channel_per_uid(struct ust_app *app,
2865 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2866 struct ust_app_channel *ua_chan)
2867 {
2868 int ret;
2869 struct buffer_reg_uid *reg_uid;
2870 struct buffer_reg_channel *reg_chan;
2871 struct ltt_session *session = NULL;
2872 enum lttng_error_code notification_ret;
2873 struct ust_registry_channel *chan_reg;
2874
2875 assert(app);
2876 assert(usess);
2877 assert(ua_sess);
2878 assert(ua_chan);
2879
2880 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2881
2882 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2883 /*
2884 * The session creation handles the creation of this global registry
2885 * object. If none can be find, there is a code flow problem or a
2886 * teardown race.
2887 */
2888 assert(reg_uid);
2889
2890 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2891 reg_uid);
2892 if (reg_chan) {
2893 goto send_channel;
2894 }
2895
2896 /* Create the buffer registry channel object. */
2897 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2898 if (ret < 0) {
2899 ERR("Error creating the UST channel \"%s\" registry instance",
2900 ua_chan->name);
2901 goto error;
2902 }
2903
2904 session = session_find_by_id(ua_sess->tracing_id);
2905 assert(session);
2906 assert(pthread_mutex_trylock(&session->lock));
2907 assert(session_trylock_list());
2908
2909 /*
2910 * Create the buffers on the consumer side. This call populates the
2911 * ust app channel object with all streams and data object.
2912 */
2913 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2914 app->bits_per_long, reg_uid->registry->reg.ust,
2915 session->current_archive_id);
2916 if (ret < 0) {
2917 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2918 ua_chan->name);
2919
2920 /*
2921 * Let's remove the previously created buffer registry channel so
2922 * it's not visible anymore in the session registry.
2923 */
2924 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2925 ua_chan->tracing_channel_id, false);
2926 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2927 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2928 goto error;
2929 }
2930
2931 /*
2932 * Setup the streams and add it to the session registry.
2933 */
2934 ret = setup_buffer_reg_channel(reg_uid->registry,
2935 ua_chan, reg_chan, app);
2936 if (ret < 0) {
2937 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2938 goto error;
2939 }
2940
2941 /* Notify the notification subsystem of the channel's creation. */
2942 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2943 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2944 ua_chan->tracing_channel_id);
2945 assert(chan_reg);
2946 chan_reg->consumer_key = ua_chan->key;
2947 chan_reg = NULL;
2948 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2949
2950 notification_ret = notification_thread_command_add_channel(
2951 notification_thread_handle, session->name,
2952 ua_sess->euid, ua_sess->egid,
2953 ua_chan->name,
2954 ua_chan->key,
2955 LTTNG_DOMAIN_UST,
2956 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2957 if (notification_ret != LTTNG_OK) {
2958 ret = - (int) notification_ret;
2959 ERR("Failed to add channel to notification thread");
2960 goto error;
2961 }
2962
2963 send_channel:
2964 /* Send buffers to the application. */
2965 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2966 if (ret < 0) {
2967 if (ret != -ENOTCONN) {
2968 ERR("Error sending channel to application");
2969 }
2970 goto error;
2971 }
2972
2973 error:
2974 if (session) {
2975 session_put(session);
2976 }
2977 return ret;
2978 }
2979
2980 /*
2981 * Create and send to the application the created buffers with per PID buffers.
2982 *
2983 * Called with UST app session lock held.
2984 * The session list lock and the session's lock must be acquired.
2985 *
2986 * Return 0 on success else a negative value.
2987 */
2988 static int create_channel_per_pid(struct ust_app *app,
2989 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2990 struct ust_app_channel *ua_chan)
2991 {
2992 int ret;
2993 struct ust_registry_session *registry;
2994 enum lttng_error_code cmd_ret;
2995 struct ltt_session *session = NULL;
2996 uint64_t chan_reg_key;
2997 struct ust_registry_channel *chan_reg;
2998
2999 assert(app);
3000 assert(usess);
3001 assert(ua_sess);
3002 assert(ua_chan);
3003
3004 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
3005
3006 rcu_read_lock();
3007
3008 registry = get_session_registry(ua_sess);
3009 /* The UST app session lock is held, registry shall not be null. */
3010 assert(registry);
3011
3012 /* Create and add a new channel registry to session. */
3013 ret = ust_registry_channel_add(registry, ua_chan->key);
3014 if (ret < 0) {
3015 ERR("Error creating the UST channel \"%s\" registry instance",
3016 ua_chan->name);
3017 goto error;
3018 }
3019
3020 session = session_find_by_id(ua_sess->tracing_id);
3021 assert(session);
3022
3023 assert(pthread_mutex_trylock(&session->lock));
3024 assert(session_trylock_list());
3025
3026 /* Create and get channel on the consumer side. */
3027 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
3028 app->bits_per_long, registry,
3029 session->current_archive_id);
3030 if (ret < 0) {
3031 ERR("Error creating UST channel \"%s\" on the consumer daemon",
3032 ua_chan->name);
3033 goto error_remove_from_registry;
3034 }
3035
3036 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
3037 if (ret < 0) {
3038 if (ret != -ENOTCONN) {
3039 ERR("Error sending channel to application");
3040 }
3041 goto error_remove_from_registry;
3042 }
3043
3044 chan_reg_key = ua_chan->key;
3045 pthread_mutex_lock(&registry->lock);
3046 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
3047 assert(chan_reg);
3048 chan_reg->consumer_key = ua_chan->key;
3049 pthread_mutex_unlock(&registry->lock);
3050
3051 cmd_ret = notification_thread_command_add_channel(
3052 notification_thread_handle, session->name,
3053 ua_sess->euid, ua_sess->egid,
3054 ua_chan->name,
3055 ua_chan->key,
3056 LTTNG_DOMAIN_UST,
3057 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
3058 if (cmd_ret != LTTNG_OK) {
3059 ret = - (int) cmd_ret;
3060 ERR("Failed to add channel to notification thread");
3061 goto error_remove_from_registry;
3062 }
3063
3064 error_remove_from_registry:
3065 if (ret) {
3066 ust_registry_channel_del_free(registry, ua_chan->key, false);
3067 }
3068 error:
3069 rcu_read_unlock();
3070 if (session) {
3071 session_put(session);
3072 }
3073 return ret;
3074 }
3075
3076 /*
3077 * From an already allocated ust app channel, create the channel buffers if
3078 * need and send it to the application. This MUST be called with a RCU read
3079 * side lock acquired.
3080 *
3081 * Called with UST app session lock held.
3082 *
3083 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3084 * the application exited concurrently.
3085 */
3086 static int do_create_channel(struct ust_app *app,
3087 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3088 struct ust_app_channel *ua_chan)
3089 {
3090 int ret;
3091
3092 assert(app);
3093 assert(usess);
3094 assert(ua_sess);
3095 assert(ua_chan);
3096
3097 /* Handle buffer type before sending the channel to the application. */
3098 switch (usess->buffer_type) {
3099 case LTTNG_BUFFER_PER_UID:
3100 {
3101 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3102 if (ret < 0) {
3103 goto error;
3104 }
3105 break;
3106 }
3107 case LTTNG_BUFFER_PER_PID:
3108 {
3109 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3110 if (ret < 0) {
3111 goto error;
3112 }
3113 break;
3114 }
3115 default:
3116 assert(0);
3117 ret = -EINVAL;
3118 goto error;
3119 }
3120
3121 /* Initialize ust objd object using the received handle and add it. */
3122 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3123 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3124
3125 /* If channel is not enabled, disable it on the tracer */
3126 if (!ua_chan->enabled) {
3127 ret = disable_ust_channel(app, ua_sess, ua_chan);
3128 if (ret < 0) {
3129 goto error;
3130 }
3131 }
3132
3133 error:
3134 return ret;
3135 }
3136
3137 /*
3138 * Create UST app channel and create it on the tracer. Set ua_chanp of the
3139 * newly created channel if not NULL.
3140 *
3141 * Called with UST app session lock and RCU read-side lock held.
3142 *
3143 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3144 * the application exited concurrently.
3145 */
3146 static int create_ust_app_channel(struct ust_app_session *ua_sess,
3147 struct ltt_ust_channel *uchan, struct ust_app *app,
3148 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3149 struct ust_app_channel **ua_chanp)
3150 {
3151 int ret = 0;
3152 struct lttng_ht_iter iter;
3153 struct lttng_ht_node_str *ua_chan_node;
3154 struct ust_app_channel *ua_chan;
3155
3156 /* Lookup channel in the ust app session */
3157 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3158 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3159 if (ua_chan_node != NULL) {
3160 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3161 goto end;
3162 }
3163
3164 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3165 if (ua_chan == NULL) {
3166 /* Only malloc can fail here */
3167 ret = -ENOMEM;
3168 goto error_alloc;
3169 }
3170 shadow_copy_channel(ua_chan, uchan);
3171
3172 /* Set channel type. */
3173 ua_chan->attr.type = type;
3174
3175 ret = do_create_channel(app, usess, ua_sess, ua_chan);
3176 if (ret < 0) {
3177 goto error;
3178 }
3179
3180 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
3181 app->pid);
3182
3183 /* Only add the channel if successful on the tracer side. */
3184 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3185 end:
3186 if (ua_chanp) {
3187 *ua_chanp = ua_chan;
3188 }
3189
3190 /* Everything went well. */
3191 return 0;
3192
3193 error:
3194 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
3195 error_alloc:
3196 return ret;
3197 }
3198
3199 /*
3200 * Create UST app event and create it on the tracer side.
3201 *
3202 * Called with ust app session mutex held.
3203 */
3204 static
3205 int create_ust_app_event(struct ust_app_session *ua_sess,
3206 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3207 struct ust_app *app)
3208 {
3209 int ret = 0;
3210 struct ust_app_event *ua_event;
3211
3212 /* Get event node */
3213 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3214 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3215 if (ua_event != NULL) {
3216 ret = -EEXIST;
3217 goto end;
3218 }
3219
3220 /* Does not exist so create one */
3221 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3222 if (ua_event == NULL) {
3223 /* Only malloc can failed so something is really wrong */
3224 ret = -ENOMEM;
3225 goto end;
3226 }
3227 shadow_copy_event(ua_event, uevent);
3228
3229 /* Create it on the tracer side */
3230 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3231 if (ret < 0) {
3232 /* Not found previously means that it does not exist on the tracer */
3233 assert(ret != -LTTNG_UST_ERR_EXIST);
3234 goto error;
3235 }
3236
3237 add_unique_ust_app_event(ua_chan, ua_event);
3238
3239 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3240 app->pid);
3241
3242 end:
3243 return ret;
3244
3245 error:
3246 /* Valid. Calling here is already in a read side lock */
3247 delete_ust_app_event(-1, ua_event, app);
3248 return ret;
3249 }
3250
3251 /*
3252 * Create UST metadata and open it on the tracer side.
3253 *
3254 * Called with UST app session lock held and RCU read side lock.
3255 */
3256 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3257 struct ust_app *app, struct consumer_output *consumer)
3258 {
3259 int ret = 0;
3260 struct ust_app_channel *metadata;
3261 struct consumer_socket *socket;
3262 struct ust_registry_session *registry;
3263 struct ltt_session *session = NULL;
3264
3265 assert(ua_sess);
3266 assert(app);
3267 assert(consumer);
3268
3269 registry = get_session_registry(ua_sess);
3270 /* The UST app session is held registry shall not be null. */
3271 assert(registry);
3272
3273 pthread_mutex_lock(&registry->lock);
3274
3275 /* Metadata already exists for this registry or it was closed previously */
3276 if (registry->metadata_key || registry->metadata_closed) {
3277 ret = 0;
3278 goto error;
3279 }
3280
3281 /* Allocate UST metadata */
3282 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3283 if (!metadata) {
3284 /* malloc() failed */
3285 ret = -ENOMEM;
3286 goto error;
3287 }
3288
3289 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3290
3291 /* Need one fd for the channel. */
3292 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3293 if (ret < 0) {
3294 ERR("Exhausted number of available FD upon create metadata");
3295 goto error;
3296 }
3297
3298 /* Get the right consumer socket for the application. */
3299 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3300 if (!socket) {
3301 ret = -EINVAL;
3302 goto error_consumer;
3303 }
3304
3305 /*
3306 * Keep metadata key so we can identify it on the consumer side. Assign it
3307 * to the registry *before* we ask the consumer so we avoid the race of the
3308 * consumer requesting the metadata and the ask_channel call on our side
3309 * did not returned yet.
3310 */
3311 registry->metadata_key = metadata->key;
3312
3313 session = session_find_by_id(ua_sess->tracing_id);
3314 assert(session);
3315
3316 assert(pthread_mutex_trylock(&session->lock));
3317 assert(session_trylock_list());
3318
3319 /*
3320 * Ask the metadata channel creation to the consumer. The metadata object
3321 * will be created by the consumer and kept their. However, the stream is
3322 * never added or monitored until we do a first push metadata to the
3323 * consumer.
3324 */
3325 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3326 registry, session->current_archive_id);
3327 if (ret < 0) {
3328 /* Nullify the metadata key so we don't try to close it later on. */
3329 registry->metadata_key = 0;
3330 goto error_consumer;
3331 }
3332
3333 /*
3334 * The setup command will make the metadata stream be sent to the relayd,
3335 * if applicable, and the thread managing the metadatas. This is important
3336 * because after this point, if an error occurs, the only way the stream
3337 * can be deleted is to be monitored in the consumer.
3338 */
3339 ret = consumer_setup_metadata(socket, metadata->key);
3340 if (ret < 0) {
3341 /* Nullify the metadata key so we don't try to close it later on. */
3342 registry->metadata_key = 0;
3343 goto error_consumer;
3344 }
3345
3346 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3347 metadata->key, app->pid);
3348
3349 error_consumer:
3350 lttng_fd_put(LTTNG_FD_APPS, 1);
3351 delete_ust_app_channel(-1, metadata, app);
3352 error:
3353 pthread_mutex_unlock(&registry->lock);
3354 if (session) {
3355 session_put(session);
3356 }
3357 return ret;
3358 }
3359
3360 /*
3361 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3362 * acquired before calling this function.
3363 */
3364 struct ust_app *ust_app_find_by_pid(pid_t pid)
3365 {
3366 struct ust_app *app = NULL;
3367 struct lttng_ht_node_ulong *node;
3368 struct lttng_ht_iter iter;
3369
3370 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3371 node = lttng_ht_iter_get_node_ulong(&iter);
3372 if (node == NULL) {
3373 DBG2("UST app no found with pid %d", pid);
3374 goto error;
3375 }
3376
3377 DBG2("Found UST app by pid %d", pid);
3378
3379 app = caa_container_of(node, struct ust_app, pid_n);
3380
3381 error:
3382 return app;
3383 }
3384
3385 /*
3386 * Allocate and init an UST app object using the registration information and
3387 * the command socket. This is called when the command socket connects to the
3388 * session daemon.
3389 *
3390 * The object is returned on success or else NULL.
3391 */
3392 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3393 {
3394 struct ust_app *lta = NULL;
3395
3396 assert(msg);
3397 assert(sock >= 0);
3398
3399 DBG3("UST app creating application for socket %d", sock);
3400
3401 if ((msg->bits_per_long == 64 &&
3402 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3403 || (msg->bits_per_long == 32 &&
3404 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3405 ERR("Registration failed: application \"%s\" (pid: %d) has "
3406 "%d-bit long, but no consumerd for this size is available.\n",
3407 msg->name, msg->pid, msg->bits_per_long);
3408 goto error;
3409 }
3410
3411 lta = zmalloc(sizeof(struct ust_app));
3412 if (lta == NULL) {
3413 PERROR("malloc");
3414 goto error;
3415 }
3416
3417 lta->ppid = msg->ppid;
3418 lta->uid = msg->uid;
3419 lta->gid = msg->gid;
3420
3421 lta->bits_per_long = msg->bits_per_long;
3422 lta->uint8_t_alignment = msg->uint8_t_alignment;
3423 lta->uint16_t_alignment = msg->uint16_t_alignment;
3424 lta->uint32_t_alignment = msg->uint32_t_alignment;
3425 lta->uint64_t_alignment = msg->uint64_t_alignment;
3426 lta->long_alignment = msg->long_alignment;
3427 lta->byte_order = msg->byte_order;
3428
3429 lta->v_major = msg->major;
3430 lta->v_minor = msg->minor;
3431 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3432 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3433 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3434 lta->notify_sock = -1;
3435
3436 /* Copy name and make sure it's NULL terminated. */
3437 strncpy(lta->name, msg->name, sizeof(lta->name));
3438 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3439
3440 /*
3441 * Before this can be called, when receiving the registration information,
3442 * the application compatibility is checked. So, at this point, the
3443 * application can work with this session daemon.
3444 */
3445 lta->compatible = 1;
3446
3447 lta->pid = msg->pid;
3448 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3449 lta->sock = sock;
3450 pthread_mutex_init(&lta->sock_lock, NULL);
3451 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3452
3453 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3454 error:
3455 return lta;
3456 }
3457
3458 /*
3459 * For a given application object, add it to every hash table.
3460 */
3461 void ust_app_add(struct ust_app *app)
3462 {
3463 assert(app);
3464 assert(app->notify_sock >= 0);
3465
3466 rcu_read_lock();
3467
3468 /*
3469 * On a re-registration, we want to kick out the previous registration of
3470 * that pid
3471 */
3472 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3473
3474 /*
3475 * The socket _should_ be unique until _we_ call close. So, a add_unique
3476 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3477 * already in the table.
3478 */
3479 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3480
3481 /* Add application to the notify socket hash table. */
3482 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3483 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3484
3485 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3486 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3487 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3488 app->v_minor);
3489
3490 rcu_read_unlock();
3491 }
3492
3493 /*
3494 * Set the application version into the object.
3495 *
3496 * Return 0 on success else a negative value either an errno code or a
3497 * LTTng-UST error code.
3498 */
3499 int ust_app_version(struct ust_app *app)
3500 {
3501 int ret;
3502
3503 assert(app);
3504
3505 pthread_mutex_lock(&app->sock_lock);
3506 ret = ustctl_tracer_version(app->sock, &app->version);
3507 pthread_mutex_unlock(&app->sock_lock);
3508 if (ret < 0) {
3509 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3510 ERR("UST app %d version failed with ret %d", app->sock, ret);
3511 } else {
3512 DBG3("UST app %d version failed. Application is dead", app->sock);
3513 }
3514 }
3515
3516 return ret;
3517 }
3518
3519 /*
3520 * Unregister app by removing it from the global traceable app list and freeing
3521 * the data struct.
3522 *
3523 * The socket is already closed at this point so no close to sock.
3524 */
3525 void ust_app_unregister(int sock)
3526 {
3527 struct ust_app *lta;
3528 struct lttng_ht_node_ulong *node;
3529 struct lttng_ht_iter ust_app_sock_iter;
3530 struct lttng_ht_iter iter;
3531 struct ust_app_session *ua_sess;
3532 int ret;
3533
3534 rcu_read_lock();
3535
3536 /* Get the node reference for a call_rcu */
3537 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3538 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3539 assert(node);
3540
3541 lta = caa_container_of(node, struct ust_app, sock_n);
3542 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3543
3544 /*
3545 * For per-PID buffers, perform "push metadata" and flush all
3546 * application streams before removing app from hash tables,
3547 * ensuring proper behavior of data_pending check.
3548 * Remove sessions so they are not visible during deletion.
3549 */
3550 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3551 node.node) {
3552 struct ust_registry_session *registry;
3553
3554 ret = lttng_ht_del(lta->sessions, &iter);
3555 if (ret) {
3556 /* The session was already removed so scheduled for teardown. */
3557 continue;
3558 }
3559
3560 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3561 (void) ust_app_flush_app_session(lta, ua_sess);
3562 }
3563
3564 /*
3565 * Add session to list for teardown. This is safe since at this point we
3566 * are the only one using this list.
3567 */
3568 pthread_mutex_lock(&ua_sess->lock);
3569
3570 if (ua_sess->deleted) {
3571 pthread_mutex_unlock(&ua_sess->lock);
3572 continue;
3573 }
3574
3575 /*
3576 * Normally, this is done in the delete session process which is
3577 * executed in the call rcu below. However, upon registration we can't
3578 * afford to wait for the grace period before pushing data or else the
3579 * data pending feature can race between the unregistration and stop
3580 * command where the data pending command is sent *before* the grace
3581 * period ended.
3582 *
3583 * The close metadata below nullifies the metadata pointer in the
3584 * session so the delete session will NOT push/close a second time.
3585 */
3586 registry = get_session_registry(ua_sess);
3587 if (registry) {
3588 /* Push metadata for application before freeing the application. */
3589 (void) push_metadata(registry, ua_sess->consumer);
3590
3591 /*
3592 * Don't ask to close metadata for global per UID buffers. Close
3593 * metadata only on destroy trace session in this case. Also, the
3594 * previous push metadata could have flag the metadata registry to
3595 * close so don't send a close command if closed.
3596 */
3597 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3598 /* And ask to close it for this session registry. */
3599 (void) close_metadata(registry, ua_sess->consumer);
3600 }
3601 }
3602 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3603
3604 pthread_mutex_unlock(&ua_sess->lock);
3605 }
3606
3607 /* Remove application from PID hash table */
3608 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3609 assert(!ret);
3610
3611 /*
3612 * Remove application from notify hash table. The thread handling the
3613 * notify socket could have deleted the node so ignore on error because
3614 * either way it's valid. The close of that socket is handled by the
3615 * apps_notify_thread.
3616 */
3617 iter.iter.node = &lta->notify_sock_n.node;
3618 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3619
3620 /*
3621 * Ignore return value since the node might have been removed before by an
3622 * add replace during app registration because the PID can be reassigned by
3623 * the OS.
3624 */
3625 iter.iter.node = &lta->pid_n.node;
3626 ret = lttng_ht_del(ust_app_ht, &iter);
3627 if (ret) {
3628 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3629 lta->pid);
3630 }
3631
3632 /* Free memory */
3633 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3634
3635 rcu_read_unlock();
3636 return;
3637 }
3638
3639 /*
3640 * Fill events array with all events name of all registered apps.
3641 */
3642 int ust_app_list_events(struct lttng_event **events)
3643 {
3644 int ret, handle;
3645 size_t nbmem, count = 0;
3646 struct lttng_ht_iter iter;
3647 struct ust_app *app;
3648 struct lttng_event *tmp_event;
3649
3650 nbmem = UST_APP_EVENT_LIST_SIZE;
3651 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3652 if (tmp_event == NULL) {
3653 PERROR("zmalloc ust app events");
3654 ret = -ENOMEM;
3655 goto error;
3656 }
3657
3658 rcu_read_lock();
3659
3660 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3661 struct lttng_ust_tracepoint_iter uiter;
3662
3663 health_code_update();
3664
3665 if (!app->compatible) {
3666 /*
3667 * TODO: In time, we should notice the caller of this error by
3668 * telling him that this is a version error.
3669 */
3670 continue;
3671 }
3672 pthread_mutex_lock(&app->sock_lock);
3673 handle = ustctl_tracepoint_list(app->sock);
3674 if (handle < 0) {
3675 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3676 ERR("UST app list events getting handle failed for app pid %d",
3677 app->pid);
3678 }
3679 pthread_mutex_unlock(&app->sock_lock);
3680 continue;
3681 }
3682
3683 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3684 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3685 /* Handle ustctl error. */
3686 if (ret < 0) {
3687 int release_ret;
3688
3689 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3690 ERR("UST app tp list get failed for app %d with ret %d",
3691 app->sock, ret);
3692 } else {
3693 DBG3("UST app tp list get failed. Application is dead");
3694 /*
3695 * This is normal behavior, an application can die during the
3696 * creation process. Don't report an error so the execution can
3697 * continue normally. Continue normal execution.
3698 */
3699 break;
3700 }
3701 free(tmp_event);
3702 release_ret = ustctl_release_handle(app->sock, handle);
3703 if (release_ret < 0 &&
3704 release_ret != -LTTNG_UST_ERR_EXITING &&
3705 release_ret != -EPIPE) {
3706 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3707 }
3708 pthread_mutex_unlock(&app->sock_lock);
3709 goto rcu_error;
3710 }
3711
3712 health_code_update();
3713 if (count >= nbmem) {
3714 /* In case the realloc fails, we free the memory */
3715 struct lttng_event *new_tmp_event;
3716 size_t new_nbmem;
3717
3718 new_nbmem = nbmem << 1;
3719 DBG2("Reallocating event list from %zu to %zu entries",
3720 nbmem, new_nbmem);
3721 new_tmp_event = realloc(tmp_event,
3722 new_nbmem * sizeof(struct lttng_event));
3723 if (new_tmp_event == NULL) {
3724 int release_ret;
3725
3726 PERROR("realloc ust app events");
3727 free(tmp_event);
3728 ret = -ENOMEM;
3729 release_ret = ustctl_release_handle(app->sock, handle);
3730 if (release_ret < 0 &&
3731 release_ret != -LTTNG_UST_ERR_EXITING &&
3732 release_ret != -EPIPE) {
3733 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3734 }
3735 pthread_mutex_unlock(&app->sock_lock);
3736 goto rcu_error;
3737 }
3738 /* Zero the new memory */
3739 memset(new_tmp_event + nbmem, 0,
3740 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3741 nbmem = new_nbmem;
3742 tmp_event = new_tmp_event;
3743 }
3744 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3745 tmp_event[count].loglevel = uiter.loglevel;
3746 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3747 tmp_event[count].pid = app->pid;
3748 tmp_event[count].enabled = -1;
3749 count++;
3750 }
3751 ret = ustctl_release_handle(app->sock, handle);
3752 pthread_mutex_unlock(&app->sock_lock);
3753 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3754 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3755 }
3756 }
3757
3758 ret = count;
3759 *events = tmp_event;
3760
3761 DBG2("UST app list events done (%zu events)", count);
3762
3763 rcu_error:
3764 rcu_read_unlock();
3765 error:
3766 health_code_update();
3767 return ret;
3768 }
3769
3770 /*
3771 * Fill events array with all events name of all registered apps.
3772 */
3773 int ust_app_list_event_fields(struct lttng_event_field **fields)
3774 {
3775 int ret, handle;
3776 size_t nbmem, count = 0;
3777 struct lttng_ht_iter iter;
3778 struct ust_app *app;
3779 struct lttng_event_field *tmp_event;
3780
3781 nbmem = UST_APP_EVENT_LIST_SIZE;
3782 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3783 if (tmp_event == NULL) {
3784 PERROR("zmalloc ust app event fields");
3785 ret = -ENOMEM;
3786 goto error;
3787 }
3788
3789 rcu_read_lock();
3790
3791 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3792 struct lttng_ust_field_iter uiter;
3793
3794 health_code_update();
3795
3796 if (!app->compatible) {
3797 /*
3798 * TODO: In time, we should notice the caller of this error by
3799 * telling him that this is a version error.
3800 */
3801 continue;
3802 }
3803 pthread_mutex_lock(&app->sock_lock);
3804 handle = ustctl_tracepoint_field_list(app->sock);
3805 if (handle < 0) {
3806 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3807 ERR("UST app list field getting handle failed for app pid %d",
3808 app->pid);
3809 }
3810 pthread_mutex_unlock(&app->sock_lock);
3811 continue;
3812 }
3813
3814 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3815 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3816 /* Handle ustctl error. */
3817 if (ret < 0) {
3818 int release_ret;
3819
3820 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3821 ERR("UST app tp list field failed for app %d with ret %d",
3822 app->sock, ret);
3823 } else {
3824 DBG3("UST app tp list field failed. Application is dead");
3825 /*
3826 * This is normal behavior, an application can die during the
3827 * creation process. Don't report an error so the execution can
3828 * continue normally. Reset list and count for next app.
3829 */
3830 break;
3831 }
3832 free(tmp_event);
3833 release_ret = ustctl_release_handle(app->sock, handle);
3834 pthread_mutex_unlock(&app->sock_lock);
3835 if (release_ret < 0 &&
3836 release_ret != -LTTNG_UST_ERR_EXITING &&
3837 release_ret != -EPIPE) {
3838 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3839 }
3840 goto rcu_error;
3841 }
3842
3843 health_code_update();
3844 if (count >= nbmem) {
3845 /* In case the realloc fails, we free the memory */
3846 struct lttng_event_field *new_tmp_event;
3847 size_t new_nbmem;
3848
3849 new_nbmem = nbmem << 1;
3850 DBG2("Reallocating event field list from %zu to %zu entries",
3851 nbmem, new_nbmem);
3852 new_tmp_event = realloc(tmp_event,
3853 new_nbmem * sizeof(struct lttng_event_field));
3854 if (new_tmp_event == NULL) {
3855 int release_ret;
3856
3857 PERROR("realloc ust app event fields");
3858 free(tmp_event);
3859 ret = -ENOMEM;
3860 release_ret = ustctl_release_handle(app->sock, handle);
3861 pthread_mutex_unlock(&app->sock_lock);
3862 if (release_ret &&
3863 release_ret != -LTTNG_UST_ERR_EXITING &&
3864 release_ret != -EPIPE) {
3865 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3866 }
3867 goto rcu_error;
3868 }
3869 /* Zero the new memory */
3870 memset(new_tmp_event + nbmem, 0,
3871 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3872 nbmem = new_nbmem;
3873 tmp_event = new_tmp_event;
3874 }
3875
3876 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3877 /* Mapping between these enums matches 1 to 1. */
3878 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3879 tmp_event[count].nowrite = uiter.nowrite;
3880
3881 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3882 tmp_event[count].event.loglevel = uiter.loglevel;
3883 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3884 tmp_event[count].event.pid = app->pid;
3885 tmp_event[count].event.enabled = -1;
3886 count++;
3887 }
3888 ret = ustctl_release_handle(app->sock, handle);
3889 pthread_mutex_unlock(&app->sock_lock);
3890 if (ret < 0 &&
3891 ret != -LTTNG_UST_ERR_EXITING &&
3892 ret != -EPIPE) {
3893 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3894 }
3895 }
3896
3897 ret = count;
3898 *fields = tmp_event;
3899
3900 DBG2("UST app list event fields done (%zu events)", count);
3901
3902 rcu_error:
3903 rcu_read_unlock();
3904 error:
3905 health_code_update();
3906 return ret;
3907 }
3908
3909 /*
3910 * Free and clean all traceable apps of the global list.
3911 *
3912 * Should _NOT_ be called with RCU read-side lock held.
3913 */
3914 void ust_app_clean_list(void)
3915 {
3916 int ret;
3917 struct ust_app *app;
3918 struct lttng_ht_iter iter;
3919
3920 DBG2("UST app cleaning registered apps hash table");
3921
3922 rcu_read_lock();
3923
3924 /* Cleanup notify socket hash table */
3925 if (ust_app_ht_by_notify_sock) {
3926 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3927 notify_sock_n.node) {
3928 struct cds_lfht_node *node;
3929 struct ust_app *app;
3930
3931 node = cds_lfht_iter_get_node(&iter.iter);
3932 if (!node) {
3933 continue;
3934 }
3935
3936 app = container_of(node, struct ust_app,
3937 notify_sock_n.node);
3938 ust_app_notify_sock_unregister(app->notify_sock);
3939 }
3940 }
3941
3942 if (ust_app_ht) {
3943 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3944 ret = lttng_ht_del(ust_app_ht, &iter);
3945 assert(!ret);
3946 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3947 }
3948 }
3949
3950 /* Cleanup socket hash table */
3951 if (ust_app_ht_by_sock) {
3952 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3953 sock_n.node) {
3954 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3955 assert(!ret);
3956 }
3957 }
3958
3959 rcu_read_unlock();
3960
3961 /* Destroy is done only when the ht is empty */
3962 if (ust_app_ht) {
3963 ht_cleanup_push(ust_app_ht);
3964 }
3965 if (ust_app_ht_by_sock) {
3966 ht_cleanup_push(ust_app_ht_by_sock);
3967 }
3968 if (ust_app_ht_by_notify_sock) {
3969 ht_cleanup_push(ust_app_ht_by_notify_sock);
3970 }
3971 }
3972
3973 /*
3974 * Init UST app hash table.
3975 */
3976 int ust_app_ht_alloc(void)
3977 {
3978 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3979 if (!ust_app_ht) {
3980 return -1;
3981 }
3982 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3983 if (!ust_app_ht_by_sock) {
3984 return -1;
3985 }
3986 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3987 if (!ust_app_ht_by_notify_sock) {
3988 return -1;
3989 }
3990 return 0;
3991 }
3992
3993 /*
3994 * For a specific UST session, disable the channel for all registered apps.
3995 */
3996 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3997 struct ltt_ust_channel *uchan)
3998 {
3999 int ret = 0;
4000 struct lttng_ht_iter iter;
4001 struct lttng_ht_node_str *ua_chan_node;
4002 struct ust_app *app;
4003 struct ust_app_session *ua_sess;
4004 struct ust_app_channel *ua_chan;
4005
4006 if (usess == NULL || uchan == NULL) {
4007 ERR("Disabling UST global channel with NULL values");
4008 ret = -1;
4009 goto error;
4010 }
4011
4012 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
4013 uchan->name, usess->id);
4014
4015 rcu_read_lock();
4016
4017 /* For every registered applications */
4018 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4019 struct lttng_ht_iter uiter;
4020 if (!app->compatible) {
4021 /*
4022 * TODO: In time, we should notice the caller of this error by
4023 * telling him that this is a version error.
4024 */
4025 continue;
4026 }
4027 ua_sess = lookup_session_by_app(usess, app);
4028 if (ua_sess == NULL) {
4029 continue;
4030 }
4031
4032 /* Get channel */
4033 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4034 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4035 /* If the session if found for the app, the channel must be there */
4036 assert(ua_chan_node);
4037
4038 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4039 /* The channel must not be already disabled */
4040 assert(ua_chan->enabled == 1);
4041
4042 /* Disable channel onto application */
4043 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
4044 if (ret < 0) {
4045 /* XXX: We might want to report this error at some point... */
4046 continue;
4047 }
4048 }
4049
4050 rcu_read_unlock();
4051
4052 error:
4053 return ret;
4054 }
4055
4056 /*
4057 * For a specific UST session, enable the channel for all registered apps.
4058 */
4059 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
4060 struct ltt_ust_channel *uchan)
4061 {
4062 int ret = 0;
4063 struct lttng_ht_iter iter;
4064 struct ust_app *app;
4065 struct ust_app_session *ua_sess;
4066
4067 if (usess == NULL || uchan == NULL) {
4068 ERR("Adding UST global channel to NULL values");
4069 ret = -1;
4070 goto error;
4071 }
4072
4073 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
4074 uchan->name, usess->id);
4075
4076 rcu_read_lock();
4077
4078 /* For every registered applications */
4079 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4080 if (!app->compatible) {
4081 /*
4082 * TODO: In time, we should notice the caller of this error by
4083 * telling him that this is a version error.
4084 */
4085 continue;
4086 }
4087 ua_sess = lookup_session_by_app(usess, app);
4088 if (ua_sess == NULL) {
4089 continue;
4090 }
4091
4092 /* Enable channel onto application */
4093 ret = enable_ust_app_channel(ua_sess, uchan, app);
4094 if (ret < 0) {
4095 /* XXX: We might want to report this error at some point... */
4096 continue;
4097 }
4098 }
4099
4100 rcu_read_unlock();
4101
4102 error:
4103 return ret;
4104 }
4105
4106 /*
4107 * Disable an event in a channel and for a specific session.
4108 */
4109 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
4110 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4111 {
4112 int ret = 0;
4113 struct lttng_ht_iter iter, uiter;
4114 struct lttng_ht_node_str *ua_chan_node;
4115 struct ust_app *app;
4116 struct ust_app_session *ua_sess;
4117 struct ust_app_channel *ua_chan;
4118 struct ust_app_event *ua_event;
4119
4120 DBG("UST app disabling event %s for all apps in channel "
4121 "%s for session id %" PRIu64,
4122 uevent->attr.name, uchan->name, usess->id);
4123
4124 rcu_read_lock();
4125
4126 /* For all registered applications */
4127 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4128 if (!app->compatible) {
4129 /*
4130 * TODO: In time, we should notice the caller of this error by
4131 * telling him that this is a version error.
4132 */
4133 continue;
4134 }
4135 ua_sess = lookup_session_by_app(usess, app);
4136 if (ua_sess == NULL) {
4137 /* Next app */
4138 continue;
4139 }
4140
4141 /* Lookup channel in the ust app session */
4142 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4143 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4144 if (ua_chan_node == NULL) {
4145 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
4146 "Skipping", uchan->name, usess->id, app->pid);
4147 continue;
4148 }
4149 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4150
4151 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4152 uevent->filter, uevent->attr.loglevel,
4153 uevent->exclusion);
4154 if (ua_event == NULL) {
4155 DBG2("Event %s not found in channel %s for app pid %d."
4156 "Skipping", uevent->attr.name, uchan->name, app->pid);
4157 continue;
4158 }
4159
4160 ret = disable_ust_app_event(ua_sess, ua_event, app);
4161 if (ret < 0) {
4162 /* XXX: Report error someday... */
4163 continue;
4164 }
4165 }
4166
4167 rcu_read_unlock();
4168
4169 return ret;
4170 }
4171
4172 /*
4173 * For a specific UST session, create the channel for all registered apps.
4174 */
4175 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
4176 struct ltt_ust_channel *uchan)
4177 {
4178 int ret = 0, created;
4179 struct lttng_ht_iter iter;
4180 struct ust_app *app;
4181 struct ust_app_session *ua_sess = NULL;
4182
4183 /* Very wrong code flow */
4184 assert(usess);
4185 assert(uchan);
4186
4187 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
4188 uchan->name, usess->id);
4189
4190 rcu_read_lock();
4191
4192 /* For every registered applications */
4193 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4194 if (!app->compatible) {
4195 /*
4196 * TODO: In time, we should notice the caller of this error by
4197 * telling him that this is a version error.
4198 */
4199 continue;
4200 }
4201 if (!trace_ust_pid_tracker_lookup(usess, app->pid)) {
4202 /* Skip. */
4203 continue;
4204 }
4205
4206 /*
4207 * Create session on the tracer side and add it to app session HT. Note
4208 * that if session exist, it will simply return a pointer to the ust
4209 * app session.
4210 */
4211 ret = find_or_create_ust_app_session(usess, app, &ua_sess, &created);
4212 if (ret < 0) {
4213 switch (ret) {
4214 case -ENOTCONN:
4215 /*
4216 * The application's socket is not valid. Either a bad socket
4217 * or a timeout on it. We can't inform the caller that for a
4218 * specific app, the session failed so lets continue here.
4219 */
4220 ret = 0; /* Not an error. */
4221 continue;
4222 case -ENOMEM:
4223 default:
4224 goto error_rcu_unlock;
4225 }
4226 }
4227 assert(ua_sess);
4228
4229 pthread_mutex_lock(&ua_sess->lock);
4230
4231 if (ua_sess->deleted) {
4232 pthread_mutex_unlock(&ua_sess->lock);
4233 continue;
4234 }
4235
4236 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
4237 sizeof(uchan->name))) {
4238 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
4239 ret = 0;
4240 } else {
4241 /* Create channel onto application. We don't need the chan ref. */
4242 ret = create_ust_app_channel(ua_sess, uchan, app,
4243 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
4244 }
4245 pthread_mutex_unlock(&ua_sess->lock);
4246 if (ret < 0) {
4247 /* Cleanup the created session if it's the case. */
4248 if (created) {
4249 destroy_app_session(app, ua_sess);
4250 }
4251 switch (ret) {
4252 case -ENOTCONN:
4253 /*
4254 * The application's socket is not valid. Either a bad socket
4255 * or a timeout on it. We can't inform the caller that for a
4256 * specific app, the session failed so lets continue here.
4257 */
4258 ret = 0; /* Not an error. */
4259 continue;
4260 case -ENOMEM:
4261 default:
4262 goto error_rcu_unlock;
4263 }
4264 }
4265 }
4266
4267 error_rcu_unlock:
4268 rcu_read_unlock();
4269 return ret;
4270 }
4271
4272 /*
4273 * Enable event for a specific session and channel on the tracer.
4274 */
4275 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
4276 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4277 {
4278 int ret = 0;
4279 struct lttng_ht_iter iter, uiter;
4280 struct lttng_ht_node_str *ua_chan_node;
4281 struct ust_app *app;
4282 struct ust_app_session *ua_sess;
4283 struct ust_app_channel *ua_chan;
4284 struct ust_app_event *ua_event;
4285
4286 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
4287 uevent->attr.name, usess->id);
4288
4289 /*
4290 * NOTE: At this point, this function is called only if the session and
4291 * channel passed are already created for all apps. and enabled on the
4292 * tracer also.
4293 */
4294
4295 rcu_read_lock();
4296
4297 /* For all registered applications */
4298 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4299 if (!app->compatible) {
4300 /*
4301 * TODO: In time, we should notice the caller of this error by
4302 * telling him that this is a version error.
4303 */
4304 continue;
4305 }
4306 ua_sess = lookup_session_by_app(usess, app);
4307 if (!ua_sess) {
4308 /* The application has problem or is probably dead. */
4309 continue;
4310 }
4311
4312 pthread_mutex_lock(&ua_sess->lock);
4313
4314 if (ua_sess->deleted) {
4315 pthread_mutex_unlock(&ua_sess->lock);
4316 continue;
4317 }
4318
4319 /* Lookup channel in the ust app session */
4320 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4321 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4322 /*
4323 * It is possible that the channel cannot be found is
4324 * the channel/event creation occurs concurrently with
4325 * an application exit.
4326 */
4327 if (!ua_chan_node) {
4328 pthread_mutex_unlock(&ua_sess->lock);
4329 continue;
4330 }
4331
4332 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4333
4334 /* Get event node */
4335 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4336 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4337 if (ua_event == NULL) {
4338 DBG3("UST app enable event %s not found for app PID %d."
4339 "Skipping app", uevent->attr.name, app->pid);
4340 goto next_app;
4341 }
4342
4343 ret = enable_ust_app_event(ua_sess, ua_event, app);
4344 if (ret < 0) {
4345 pthread_mutex_unlock(&ua_sess->lock);
4346 goto error;
4347 }
4348 next_app:
4349 pthread_mutex_unlock(&ua_sess->lock);
4350 }
4351
4352 error:
4353 rcu_read_unlock();
4354 return ret;
4355 }
4356
4357 /*
4358 * For a specific existing UST session and UST channel, creates the event for
4359 * all registered apps.
4360 */
4361 int ust_app_create_event_glb(struct ltt_ust_session *usess,
4362 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4363 {
4364 int ret = 0;
4365 struct lttng_ht_iter iter, uiter;
4366 struct lttng_ht_node_str *ua_chan_node;
4367 struct ust_app *app;
4368 struct ust_app_session *ua_sess;
4369 struct ust_app_channel *ua_chan;
4370
4371 DBG("UST app creating event %s for all apps for session id %" PRIu64,
4372 uevent->attr.name, usess->id);
4373
4374 rcu_read_lock();
4375
4376 /* For all registered applications */
4377 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4378 if (!app->compatible) {
4379 /*
4380 * TODO: In time, we should notice the caller of this error by
4381 * telling him that this is a version error.
4382 */
4383 continue;
4384 }
4385 ua_sess = lookup_session_by_app(usess, app);
4386 if (!ua_sess) {
4387 /* The application has problem or is probably dead. */
4388 continue;
4389 }
4390
4391 pthread_mutex_lock(&ua_sess->lock);
4392
4393 if (ua_sess->deleted) {
4394 pthread_mutex_unlock(&ua_sess->lock);
4395 continue;
4396 }
4397
4398 /* Lookup channel in the ust app session */
4399 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4400 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4401 /* If the channel is not found, there is a code flow error */
4402 assert(ua_chan_node);
4403
4404 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4405
4406 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4407 pthread_mutex_unlock(&ua_sess->lock);
4408 if (ret < 0) {
4409 if (ret != -LTTNG_UST_ERR_EXIST) {
4410 /* Possible value at this point: -ENOMEM. If so, we stop! */
4411 break;
4412 }
4413 DBG2("UST app event %s already exist on app PID %d",
4414 uevent->attr.name, app->pid);
4415 continue;
4416 }
4417 }
4418
4419 rcu_read_unlock();
4420
4421 return ret;
4422 }
4423
4424 /*
4425 * Start tracing for a specific UST session and app.
4426 *
4427 * Called with UST app session lock held.
4428 *
4429 */
4430 static
4431 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
4432 {
4433 int ret = 0;
4434 struct ust_app_session *ua_sess;
4435
4436 DBG("Starting tracing for ust app pid %d", app->pid);
4437
4438 rcu_read_lock();
4439
4440 if (!app->compatible) {
4441 goto end;
4442 }
4443
4444 ua_sess = lookup_session_by_app(usess, app);
4445 if (ua_sess == NULL) {
4446 /* The session is in teardown process. Ignore and continue. */
4447 goto end;
4448 }
4449
4450 pthread_mutex_lock(&ua_sess->lock);
4451
4452 if (ua_sess->deleted) {
4453 pthread_mutex_unlock(&ua_sess->lock);
4454 goto end;
4455 }
4456
4457 /* Upon restart, we skip the setup, already done */
4458 if (ua_sess->started) {
4459 goto skip_setup;
4460 }
4461
4462 /* Create directories if consumer is LOCAL and has a path defined. */
4463 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
4464 usess->consumer->dst.session_root_path[0] != '\0') {
4465 char *tmp_path;
4466
4467 tmp_path = zmalloc(LTTNG_PATH_MAX);
4468 if (!tmp_path) {
4469 ERR("Alloc tmp_path");
4470 goto error_unlock;
4471 }
4472 ret = snprintf(tmp_path, LTTNG_PATH_MAX, "%s%s%s",
4473 usess->consumer->dst.session_root_path,
4474 usess->consumer->chunk_path,
4475 usess->consumer->subdir);
4476 if (ret >= LTTNG_PATH_MAX) {
4477 ERR("Local destination path exceeds the maximal allowed length of %i bytes (needs %i bytes) with path = \"%s%s%s\"",
4478 LTTNG_PATH_MAX, ret,
4479 usess->consumer->dst.session_root_path,
4480 usess->consumer->chunk_path,
4481 usess->consumer->subdir);
4482 free(tmp_path);
4483 goto error_unlock;
4484 }
4485
4486 DBG("Creating directory path for local tracing: \"%s\"",
4487 tmp_path);
4488 ret = run_as_mkdir_recursive(tmp_path, S_IRWXU | S_IRWXG,
4489 ua_sess->euid, ua_sess->egid);
4490 free(tmp_path);
4491 if (ret < 0) {
4492 if (errno != EEXIST) {
4493 ERR("Trace directory creation error");
4494 goto error_unlock;
4495 }
4496 }
4497 }
4498
4499 /*
4500 * Create the metadata for the application. This returns gracefully if a
4501 * metadata was already set for the session.
4502 */
4503 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
4504 if (ret < 0) {
4505 goto error_unlock;
4506 }
4507
4508 health_code_update();
4509
4510 skip_setup:
4511 /* This start the UST tracing */
4512 pthread_mutex_lock(&app->sock_lock);
4513 ret = ustctl_start_session(app->sock, ua_sess->handle);
4514 pthread_mutex_unlock(&app->sock_lock);
4515 if (ret < 0) {
4516 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4517 ERR("Error starting tracing for app pid: %d (ret: %d)",
4518 app->pid, ret);
4519 } else {
4520 DBG("UST app start session failed. Application is dead.");
4521 /*
4522 * This is normal behavior, an application can die during the
4523 * creation process. Don't report an error so the execution can
4524 * continue normally.
4525 */
4526 pthread_mutex_unlock(&ua_sess->lock);
4527 goto end;
4528 }
4529 goto error_unlock;
4530 }
4531
4532 /* Indicate that the session has been started once */
4533 ua_sess->started = 1;
4534
4535 pthread_mutex_unlock(&ua_sess->lock);
4536
4537 health_code_update();
4538
4539 /* Quiescent wait after starting trace */
4540 pthread_mutex_lock(&app->sock_lock);
4541 ret = ustctl_wait_quiescent(app->sock);
4542 pthread_mutex_unlock(&app->sock_lock);
4543 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4544 ERR("UST app wait quiescent failed for app pid %d ret %d",
4545 app->pid, ret);
4546 }
4547
4548 end:
4549 rcu_read_unlock();
4550 health_code_update();
4551 return 0;
4552
4553 error_unlock:
4554 pthread_mutex_unlock(&ua_sess->lock);
4555 rcu_read_unlock();
4556 health_code_update();
4557 return -1;
4558 }
4559
4560 /*
4561 * Stop tracing for a specific UST session and app.
4562 */
4563 static
4564 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
4565 {
4566 int ret = 0;
4567 struct ust_app_session *ua_sess;
4568 struct ust_registry_session *registry;
4569
4570 DBG("Stopping tracing for ust app pid %d", app->pid);
4571
4572 rcu_read_lock();
4573
4574 if (!app->compatible) {
4575 goto end_no_session;
4576 }
4577
4578 ua_sess = lookup_session_by_app(usess, app);
4579 if (ua_sess == NULL) {
4580 goto end_no_session;
4581 }
4582
4583 pthread_mutex_lock(&ua_sess->lock);
4584
4585 if (ua_sess->deleted) {
4586 pthread_mutex_unlock(&ua_sess->lock);
4587 goto end_no_session;
4588 }
4589
4590 /*
4591 * If started = 0, it means that stop trace has been called for a session
4592 * that was never started. It's possible since we can have a fail start
4593 * from either the application manager thread or the command thread. Simply
4594 * indicate that this is a stop error.
4595 */
4596 if (!ua_sess->started) {
4597 goto error_rcu_unlock;
4598 }
4599
4600 health_code_update();
4601
4602 /* This inhibits UST tracing */
4603 pthread_mutex_lock(&app->sock_lock);
4604 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4605 pthread_mutex_unlock(&app->sock_lock);
4606 if (ret < 0) {
4607 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4608 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4609 app->pid, ret);
4610 } else {
4611 DBG("UST app stop session failed. Application is dead.");
4612 /*
4613 * This is normal behavior, an application can die during the
4614 * creation process. Don't report an error so the execution can
4615 * continue normally.
4616 */
4617 goto end_unlock;
4618 }
4619 goto error_rcu_unlock;
4620 }
4621
4622 health_code_update();
4623
4624 /* Quiescent wait after stopping trace */
4625 pthread_mutex_lock(&app->sock_lock);
4626 ret = ustctl_wait_quiescent(app->sock);
4627 pthread_mutex_unlock(&app->sock_lock);
4628 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4629 ERR("UST app wait quiescent failed for app pid %d ret %d",
4630 app->pid, ret);
4631 }
4632
4633 health_code_update();
4634
4635 registry = get_session_registry(ua_sess);
4636
4637 /* The UST app session is held registry shall not be null. */
4638 assert(registry);
4639
4640 /* Push metadata for application before freeing the application. */
4641 (void) push_metadata(registry, ua_sess->consumer);
4642
4643 end_unlock:
4644 pthread_mutex_unlock(&ua_sess->lock);
4645 end_no_session:
4646 rcu_read_unlock();
4647 health_code_update();
4648 return 0;
4649
4650 error_rcu_unlock:
4651 pthread_mutex_unlock(&ua_sess->lock);
4652 rcu_read_unlock();
4653 health_code_update();
4654 return -1;
4655 }
4656
4657 static
4658 int ust_app_flush_app_session(struct ust_app *app,
4659 struct ust_app_session *ua_sess)
4660 {
4661 int ret, retval = 0;
4662 struct lttng_ht_iter iter;
4663 struct ust_app_channel *ua_chan;
4664 struct consumer_socket *socket;
4665
4666 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4667
4668 rcu_read_lock();
4669
4670 if (!app->compatible) {
4671 goto end_not_compatible;
4672 }
4673
4674 pthread_mutex_lock(&ua_sess->lock);
4675
4676 if (ua_sess->deleted) {
4677 goto end_deleted;
4678 }
4679
4680 health_code_update();
4681
4682 /* Flushing buffers */
4683 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4684 ua_sess->consumer);
4685
4686 /* Flush buffers and push metadata. */
4687 switch (ua_sess->buffer_type) {
4688 case LTTNG_BUFFER_PER_PID:
4689 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4690 node.node) {
4691 health_code_update();
4692 ret = consumer_flush_channel(socket, ua_chan->key);
4693 if (ret) {
4694 ERR("Error flushing consumer channel");
4695 retval = -1;
4696 continue;
4697 }
4698 }
4699 break;
4700 case LTTNG_BUFFER_PER_UID:
4701 default:
4702 assert(0);
4703 break;
4704 }
4705
4706 health_code_update();
4707
4708 end_deleted:
4709 pthread_mutex_unlock(&ua_sess->lock);
4710
4711 end_not_compatible:
4712 rcu_read_unlock();
4713 health_code_update();
4714 return retval;
4715 }
4716
4717 /*
4718 * Flush buffers for all applications for a specific UST session.
4719 * Called with UST session lock held.
4720 */
4721 static
4722 int ust_app_flush_session(struct ltt_ust_session *usess)
4723
4724 {
4725 int ret = 0;
4726
4727 DBG("Flushing session buffers for all ust apps");
4728
4729 rcu_read_lock();
4730
4731 /* Flush buffers and push metadata. */
4732 switch (usess->buffer_type) {
4733 case LTTNG_BUFFER_PER_UID:
4734 {
4735 struct buffer_reg_uid *reg;
4736 struct lttng_ht_iter iter;
4737
4738 /* Flush all per UID buffers associated to that session. */
4739 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4740 struct ust_registry_session *ust_session_reg;
4741 struct buffer_reg_channel *reg_chan;
4742 struct consumer_socket *socket;
4743
4744 /* Get consumer socket to use to push the metadata.*/
4745 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4746 usess->consumer);
4747 if (!socket) {
4748 /* Ignore request if no consumer is found for the session. */
4749 continue;
4750 }
4751
4752 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4753 reg_chan, node.node) {
4754 /*
4755 * The following call will print error values so the return
4756 * code is of little importance because whatever happens, we
4757 * have to try them all.
4758 */
4759 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4760 }
4761
4762 ust_session_reg = reg->registry->reg.ust;
4763 /* Push metadata. */
4764 (void) push_metadata(ust_session_reg, usess->consumer);
4765 }
4766 break;
4767 }
4768 case LTTNG_BUFFER_PER_PID:
4769 {
4770 struct ust_app_session *ua_sess;
4771 struct lttng_ht_iter iter;
4772 struct ust_app *app;
4773
4774 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4775 ua_sess = lookup_session_by_app(usess, app);
4776 if (ua_sess == NULL) {
4777 continue;
4778 }
4779 (void) ust_app_flush_app_session(app, ua_sess);
4780 }
4781 break;
4782 }
4783 default:
4784 ret = -1;
4785 assert(0);
4786 break;
4787 }
4788
4789 rcu_read_unlock();
4790 health_code_update();
4791 return ret;
4792 }
4793
4794 static
4795 int ust_app_clear_quiescent_app_session(struct ust_app *app,
4796 struct ust_app_session *ua_sess)
4797 {
4798 int ret = 0;
4799 struct lttng_ht_iter iter;
4800 struct ust_app_channel *ua_chan;
4801 struct consumer_socket *socket;
4802
4803 DBG("Clearing stream quiescent state for ust app pid %d", app->pid);
4804
4805 rcu_read_lock();
4806
4807 if (!app->compatible) {
4808 goto end_not_compatible;
4809 }
4810
4811 pthread_mutex_lock(&ua_sess->lock);
4812
4813 if (ua_sess->deleted) {
4814 goto end_unlock;
4815 }
4816
4817 health_code_update();
4818
4819 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4820 ua_sess->consumer);
4821 if (!socket) {
4822 ERR("Failed to find consumer (%" PRIu32 ") socket",
4823 app->bits_per_long);
4824 ret = -1;
4825 goto end_unlock;
4826 }
4827
4828 /* Clear quiescent state. */
4829 switch (ua_sess->buffer_type) {
4830 case LTTNG_BUFFER_PER_PID:
4831 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter,
4832 ua_chan, node.node) {
4833 health_code_update();
4834 ret = consumer_clear_quiescent_channel(socket,
4835 ua_chan->key);
4836 if (ret) {
4837 ERR("Error clearing quiescent state for consumer channel");
4838 ret = -1;
4839 continue;
4840 }
4841 }
4842 break;
4843 case LTTNG_BUFFER_PER_UID:
4844 default:
4845 assert(0);
4846 ret = -1;
4847 break;
4848 }
4849
4850 health_code_update();
4851
4852 end_unlock:
4853 pthread_mutex_unlock(&ua_sess->lock);
4854
4855 end_not_compatible:
4856 rcu_read_unlock();
4857 health_code_update();
4858 return ret;
4859 }
4860
4861 /*
4862 * Clear quiescent state in each stream for all applications for a
4863 * specific UST session.
4864 * Called with UST session lock held.
4865 */
4866 static
4867 int ust_app_clear_quiescent_session(struct ltt_ust_session *usess)
4868
4869 {
4870 int ret = 0;
4871
4872 DBG("Clearing stream quiescent state for all ust apps");
4873
4874 rcu_read_lock();
4875
4876 switch (usess->buffer_type) {
4877 case LTTNG_BUFFER_PER_UID:
4878 {
4879 struct lttng_ht_iter iter;
4880 struct buffer_reg_uid *reg;
4881
4882 /*
4883 * Clear quiescent for all per UID buffers associated to
4884 * that session.
4885 */
4886 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4887 struct consumer_socket *socket;
4888 struct buffer_reg_channel *reg_chan;
4889
4890 /* Get associated consumer socket.*/
4891 socket = consumer_find_socket_by_bitness(
4892 reg->bits_per_long, usess->consumer);
4893 if (!socket) {
4894 /*
4895 * Ignore request if no consumer is found for
4896 * the session.
4897 */
4898 continue;
4899 }
4900
4901 cds_lfht_for_each_entry(reg->registry->channels->ht,
4902 &iter.iter, reg_chan, node.node) {
4903 /*
4904 * The following call will print error values so
4905 * the return code is of little importance
4906 * because whatever happens, we have to try them
4907 * all.
4908 */
4909 (void) consumer_clear_quiescent_channel(socket,
4910 reg_chan->consumer_key);
4911 }
4912 }
4913 break;
4914 }
4915 case LTTNG_BUFFER_PER_PID:
4916 {
4917 struct ust_app_session *ua_sess;
4918 struct lttng_ht_iter iter;
4919 struct ust_app *app;
4920
4921 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
4922 pid_n.node) {
4923 ua_sess = lookup_session_by_app(usess, app);
4924 if (ua_sess == NULL) {
4925 continue;
4926 }
4927 (void) ust_app_clear_quiescent_app_session(app,
4928 ua_sess);
4929 }
4930 break;
4931 }
4932 default:
4933 ret = -1;
4934 assert(0);
4935 break;
4936 }
4937
4938 rcu_read_unlock();
4939 health_code_update();
4940 return ret;
4941 }
4942
4943 /*
4944 * Destroy a specific UST session in apps.
4945 */
4946 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4947 {
4948 int ret;
4949 struct ust_app_session *ua_sess;
4950 struct lttng_ht_iter iter;
4951 struct lttng_ht_node_u64 *node;
4952
4953 DBG("Destroy tracing for ust app pid %d", app->pid);
4954
4955 rcu_read_lock();
4956
4957 if (!app->compatible) {
4958 goto end;
4959 }
4960
4961 __lookup_session_by_app(usess, app, &iter);
4962 node = lttng_ht_iter_get_node_u64(&iter);
4963 if (node == NULL) {
4964 /* Session is being or is deleted. */
4965 goto end;
4966 }
4967 ua_sess = caa_container_of(node, struct ust_app_session, node);
4968
4969 health_code_update();
4970 destroy_app_session(app, ua_sess);
4971
4972 health_code_update();
4973
4974 /* Quiescent wait after stopping trace */
4975 pthread_mutex_lock(&app->sock_lock);
4976 ret = ustctl_wait_quiescent(app->sock);
4977 pthread_mutex_unlock(&app->sock_lock);
4978 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4979 ERR("UST app wait quiescent failed for app pid %d ret %d",
4980 app->pid, ret);
4981 }
4982 end:
4983 rcu_read_unlock();
4984 health_code_update();
4985 return 0;
4986 }
4987
4988 /*
4989 * Start tracing for the UST session.
4990 */
4991 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4992 {
4993 int ret = 0;
4994 struct lttng_ht_iter iter;
4995 struct ust_app *app;
4996
4997 DBG("Starting all UST traces");
4998
4999 rcu_read_lock();
5000
5001 /*
5002 * In a start-stop-start use-case, we need to clear the quiescent state
5003 * of each channel set by the prior stop command, thus ensuring that a
5004 * following stop or destroy is sure to grab a timestamp_end near those
5005 * operations, even if the packet is empty.
5006 */
5007 (void) ust_app_clear_quiescent_session(usess);
5008
5009 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5010 ret = ust_app_start_trace(usess, app);
5011 if (ret < 0) {
5012 /* Continue to next apps even on error */
5013 continue;
5014 }
5015 }
5016
5017 rcu_read_unlock();
5018
5019 return 0;
5020 }
5021
5022 /*
5023 * Start tracing for the UST session.
5024 * Called with UST session lock held.
5025 */
5026 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
5027 {
5028 int ret = 0;
5029 struct lttng_ht_iter iter;
5030 struct ust_app *app;
5031
5032 DBG("Stopping all UST traces");
5033
5034 rcu_read_lock();
5035
5036 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5037 ret = ust_app_stop_trace(usess, app);
5038 if (ret < 0) {
5039 /* Continue to next apps even on error */
5040 continue;
5041 }
5042 }
5043
5044 (void) ust_app_flush_session(usess);
5045
5046 rcu_read_unlock();
5047
5048 return 0;
5049 }
5050
5051 /*
5052 * Destroy app UST session.
5053 */
5054 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
5055 {
5056 int ret = 0;
5057 struct lttng_ht_iter iter;
5058 struct ust_app *app;
5059
5060 DBG("Destroy all UST traces");
5061
5062 rcu_read_lock();
5063
5064 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5065 ret = destroy_trace(usess, app);
5066 if (ret < 0) {
5067 /* Continue to next apps even on error */
5068 continue;
5069 }
5070 }
5071
5072 rcu_read_unlock();
5073
5074 return 0;
5075 }
5076
5077 static
5078 void ust_app_global_create(struct ltt_ust_session *usess, struct ust_app *app)
5079 {
5080 int ret = 0;
5081 struct lttng_ht_iter iter, uiter;
5082 struct ust_app_session *ua_sess = NULL;
5083 struct ust_app_channel *ua_chan;
5084 struct ust_app_event *ua_event;
5085 struct ust_app_ctx *ua_ctx;
5086 int is_created = 0;
5087
5088 ret = find_or_create_ust_app_session(usess, app, &ua_sess, &is_created);
5089 if (ret < 0) {
5090 /* Tracer is probably gone or ENOMEM. */
5091 goto error;
5092 }
5093 if (!is_created) {
5094 /* App session already created. */
5095 goto end;
5096 }
5097 assert(ua_sess);
5098
5099 pthread_mutex_lock(&ua_sess->lock);
5100
5101 if (ua_sess->deleted) {
5102 pthread_mutex_unlock(&ua_sess->lock);
5103 goto end;
5104 }
5105
5106 /*
5107 * We can iterate safely here over all UST app session since the create ust
5108 * app session above made a shadow copy of the UST global domain from the
5109 * ltt ust session.
5110 */
5111 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
5112 node.node) {
5113 ret = do_create_channel(app, usess, ua_sess, ua_chan);
5114 if (ret < 0 && ret != -ENOTCONN) {
5115 /*
5116 * Stop everything. On error, the application
5117 * failed, no more file descriptor are available
5118 * or ENOMEM so stopping here is the only thing
5119 * we can do for now. The only exception is
5120 * -ENOTCONN, which indicates that the application
5121 * has exit.
5122 */
5123 goto error_unlock;
5124 }
5125
5126 /*
5127 * Add context using the list so they are enabled in the same order the
5128 * user added them.
5129 */
5130 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
5131 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
5132 if (ret < 0) {
5133 goto error_unlock;
5134 }
5135 }
5136
5137
5138 /* For each events */
5139 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
5140 node.node) {
5141 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
5142 if (ret < 0) {
5143 goto error_unlock;
5144 }
5145 }
5146 }
5147
5148 pthread_mutex_unlock(&ua_sess->lock);
5149
5150 if (usess->active) {
5151 ret = ust_app_start_trace(usess, app);
5152 if (ret < 0) {
5153 goto error;
5154 }
5155
5156 DBG2("UST trace started for app pid %d", app->pid);
5157 }
5158 end:
5159 /* Everything went well at this point. */
5160 return;
5161
5162 error_unlock:
5163 pthread_mutex_unlock(&ua_sess->lock);
5164 error:
5165 if (ua_sess) {
5166 destroy_app_session(app, ua_sess);
5167 }
5168 return;
5169 }
5170
5171 static
5172 void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
5173 {
5174 struct ust_app_session *ua_sess;
5175
5176 ua_sess = lookup_session_by_app(usess, app);
5177 if (ua_sess == NULL) {
5178 return;
5179 }
5180 destroy_app_session(app, ua_sess);
5181 }
5182
5183 /*
5184 * Add channels/events from UST global domain to registered apps at sock.
5185 *
5186 * Called with session lock held.
5187 * Called with RCU read-side lock held.
5188 */
5189 void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
5190 {
5191 assert(usess);
5192
5193 DBG2("UST app global update for app sock %d for session id %" PRIu64,
5194 app->sock, usess->id);
5195
5196 if (!app->compatible) {
5197 return;
5198 }
5199
5200 if (trace_ust_pid_tracker_lookup(usess, app->pid)) {
5201 ust_app_global_create(usess, app);
5202 } else {
5203 ust_app_global_destroy(usess, app);
5204 }
5205 }
5206
5207 /*
5208 * Called with session lock held.
5209 */
5210 void ust_app_global_update_all(struct ltt_ust_session *usess)
5211 {
5212 struct lttng_ht_iter iter;
5213 struct ust_app *app;
5214
5215 rcu_read_lock();
5216 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5217 ust_app_global_update(usess, app);
5218 }
5219 rcu_read_unlock();
5220 }
5221
5222 /*
5223 * Add context to a specific channel for global UST domain.
5224 */
5225 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
5226 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
5227 {
5228 int ret = 0;
5229 struct lttng_ht_node_str *ua_chan_node;
5230 struct lttng_ht_iter iter, uiter;
5231 struct ust_app_channel *ua_chan = NULL;
5232 struct ust_app_session *ua_sess;
5233 struct ust_app *app;
5234
5235 rcu_read_lock();
5236
5237 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5238 if (!app->compatible) {
5239 /*
5240 * TODO: In time, we should notice the caller of this error by
5241 * telling him that this is a version error.
5242 */
5243 continue;
5244 }
5245 ua_sess = lookup_session_by_app(usess, app);
5246 if (ua_sess == NULL) {
5247 continue;
5248 }
5249
5250 pthread_mutex_lock(&ua_sess->lock);
5251
5252 if (ua_sess->deleted) {
5253 pthread_mutex_unlock(&ua_sess->lock);
5254 continue;
5255 }
5256
5257 /* Lookup channel in the ust app session */
5258 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
5259 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
5260 if (ua_chan_node == NULL) {
5261 goto next_app;
5262 }
5263 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
5264 node);
5265 ret = create_ust_app_channel_context(ua_chan, &uctx->ctx, app);
5266 if (ret < 0) {
5267 goto next_app;
5268 }
5269 next_app:
5270 pthread_mutex_unlock(&ua_sess->lock);
5271 }
5272
5273 rcu_read_unlock();
5274 return ret;
5275 }
5276
5277 /*
5278 * Enable event for a channel from a UST session for a specific PID.
5279 */
5280 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
5281 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
5282 {
5283 int ret = 0;
5284 struct lttng_ht_iter iter;
5285 struct lttng_ht_node_str *ua_chan_node;
5286 struct ust_app *app;
5287 struct ust_app_session *ua_sess;
5288 struct ust_app_channel *ua_chan;
5289 struct ust_app_event *ua_event;
5290
5291 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
5292
5293 rcu_read_lock();
5294
5295 app = ust_app_find_by_pid(pid);
5296 if (app == NULL) {
5297 ERR("UST app enable event per PID %d not found", pid);
5298 ret = -1;
5299 goto end;
5300 }
5301
5302 if (!app->compatible) {
5303 ret = 0;
5304 goto end;
5305 }
5306
5307 ua_sess = lookup_session_by_app(usess, app);
5308 if (!ua_sess) {
5309 /* The application has problem or is probably dead. */
5310 ret = 0;
5311 goto end;
5312 }
5313
5314 pthread_mutex_lock(&ua_sess->lock);
5315
5316 if (ua_sess->deleted) {
5317 ret = 0;
5318 goto end_unlock;
5319 }
5320
5321 /* Lookup channel in the ust app session */
5322 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
5323 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
5324 /* If the channel is not found, there is a code flow error */
5325 assert(ua_chan_node);
5326
5327 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
5328
5329 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
5330 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
5331 if (ua_event == NULL) {
5332 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
5333 if (ret < 0) {
5334 goto end_unlock;
5335 }
5336 } else {
5337 ret = enable_ust_app_event(ua_sess, ua_event, app);
5338 if (ret < 0) {
5339 goto end_unlock;
5340 }
5341 }
5342
5343 end_unlock:
5344 pthread_mutex_unlock(&ua_sess->lock);
5345 end:
5346 rcu_read_unlock();
5347 return ret;
5348 }
5349
5350 /*
5351 * Receive registration and populate the given msg structure.
5352 *
5353 * On success return 0 else a negative value returned by the ustctl call.
5354 */
5355 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
5356 {
5357 int ret;
5358 uint32_t pid, ppid, uid, gid;
5359
5360 assert(msg);
5361
5362 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
5363 &pid, &ppid, &uid, &gid,
5364 &msg->bits_per_long,
5365 &msg->uint8_t_alignment,
5366 &msg->uint16_t_alignment,
5367 &msg->uint32_t_alignment,
5368 &msg->uint64_t_alignment,
5369 &msg->long_alignment,
5370 &msg->byte_order,
5371 msg->name);
5372 if (ret < 0) {
5373 switch (-ret) {
5374 case EPIPE:
5375 case ECONNRESET:
5376 case LTTNG_UST_ERR_EXITING:
5377 DBG3("UST app recv reg message failed. Application died");
5378 break;
5379 case LTTNG_UST_ERR_UNSUP_MAJOR:
5380 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
5381 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
5382 LTTNG_UST_ABI_MINOR_VERSION);
5383 break;
5384 default:
5385 ERR("UST app recv reg message failed with ret %d", ret);
5386 break;
5387 }
5388 goto error;
5389 }
5390 msg->pid = (pid_t) pid;
5391 msg->ppid = (pid_t) ppid;
5392 msg->uid = (uid_t) uid;
5393 msg->gid = (gid_t) gid;
5394
5395 error:
5396 return ret;
5397 }
5398
5399 /*
5400 * Return a ust app session object using the application object and the
5401 * session object descriptor has a key. If not found, NULL is returned.
5402 * A RCU read side lock MUST be acquired when calling this function.
5403 */
5404 static struct ust_app_session *find_session_by_objd(struct ust_app *app,
5405 int objd)
5406 {
5407 struct lttng_ht_node_ulong *node;
5408 struct lttng_ht_iter iter;
5409 struct ust_app_session *ua_sess = NULL;
5410
5411 assert(app);
5412
5413 lttng_ht_lookup(app->ust_sessions_objd, (void *)((unsigned long) objd), &iter);
5414 node = lttng_ht_iter_get_node_ulong(&iter);
5415 if (node == NULL) {
5416 DBG2("UST app session find by objd %d not found", objd);
5417 goto error;
5418 }
5419
5420 ua_sess = caa_container_of(node, struct ust_app_session, ust_objd_node);
5421
5422 error:
5423 return ua_sess;
5424 }
5425
5426 /*
5427 * Return a ust app channel object using the application object and the channel
5428 * object descriptor has a key. If not found, NULL is returned. A RCU read side
5429 * lock MUST be acquired before calling this function.
5430 */
5431 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
5432 int objd)
5433 {
5434 struct lttng_ht_node_ulong *node;
5435 struct lttng_ht_iter iter;
5436 struct ust_app_channel *ua_chan = NULL;
5437
5438 assert(app);
5439
5440 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
5441 node = lttng_ht_iter_get_node_ulong(&iter);
5442 if (node == NULL) {
5443 DBG2("UST app channel find by objd %d not found", objd);
5444 goto error;
5445 }
5446
5447 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
5448
5449 error:
5450 return ua_chan;
5451 }
5452
5453 /*
5454 * Reply to a register channel notification from an application on the notify
5455 * socket. The channel metadata is also created.
5456 *
5457 * The session UST registry lock is acquired in this function.
5458 *
5459 * On success 0 is returned else a negative value.
5460 */
5461 static int reply_ust_register_channel(int sock, int cobjd,
5462 size_t nr_fields, struct ustctl_field *fields)
5463 {
5464 int ret, ret_code = 0;
5465 uint32_t chan_id;
5466 uint64_t chan_reg_key;
5467 enum ustctl_channel_header type;
5468 struct ust_app *app;
5469 struct ust_app_channel *ua_chan;
5470 struct ust_app_session *ua_sess;
5471 struct ust_registry_session *registry;
5472 struct ust_registry_channel *chan_reg;
5473
5474 rcu_read_lock();
5475
5476 /* Lookup application. If not found, there is a code flow error. */
5477 app = find_app_by_notify_sock(sock);
5478 if (!app) {
5479 DBG("Application socket %d is being torn down. Abort event notify",
5480 sock);
5481 ret = 0;
5482 goto error_rcu_unlock;
5483 }
5484
5485 /* Lookup channel by UST object descriptor. */
5486 ua_chan = find_channel_by_objd(app, cobjd);
5487 if (!ua_chan) {
5488 DBG("Application channel is being torn down. Abort event notify");
5489 ret = 0;
5490 goto error_rcu_unlock;
5491 }
5492
5493 assert(ua_chan->session);
5494 ua_sess = ua_chan->session;
5495
5496 /* Get right session registry depending on the session buffer type. */
5497 registry = get_session_registry(ua_sess);
5498 if (!registry) {
5499 DBG("Application session is being torn down. Abort event notify");
5500 ret = 0;
5501 goto error_rcu_unlock;
5502 };
5503
5504 /* Depending on the buffer type, a different channel key is used. */
5505 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5506 chan_reg_key = ua_chan->tracing_channel_id;
5507 } else {
5508 chan_reg_key = ua_chan->key;
5509 }
5510
5511 pthread_mutex_lock(&registry->lock);
5512
5513 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
5514 assert(chan_reg);
5515
5516 if (!chan_reg->register_done) {
5517 /*
5518 * TODO: eventually use the registry event count for
5519 * this channel to better guess header type for per-pid
5520 * buffers.
5521 */
5522 type = USTCTL_CHANNEL_HEADER_LARGE;
5523 chan_reg->nr_ctx_fields = nr_fields;
5524 chan_reg->ctx_fields = fields;
5525 fields = NULL;
5526 chan_reg->header_type = type;
5527 } else {
5528 /* Get current already assigned values. */
5529 type = chan_reg->header_type;
5530 }
5531 /* Channel id is set during the object creation. */
5532 chan_id = chan_reg->chan_id;
5533
5534 /* Append to metadata */
5535 if (!chan_reg->metadata_dumped) {
5536 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
5537 if (ret_code) {
5538 ERR("Error appending channel metadata (errno = %d)", ret_code);
5539 goto reply;
5540 }
5541 }
5542
5543 reply:
5544 DBG3("UST app replying to register channel key %" PRIu64
5545 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
5546 ret_code);
5547
5548 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
5549 if (ret < 0) {
5550 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5551 ERR("UST app reply channel failed with ret %d", ret);
5552 } else {
5553 DBG3("UST app reply channel failed. Application died");
5554 }
5555 goto error;
5556 }
5557
5558 /* This channel registry registration is completed. */
5559 chan_reg->register_done = 1;
5560
5561 error:
5562 pthread_mutex_unlock(&registry->lock);
5563 error_rcu_unlock:
5564 rcu_read_unlock();
5565 free(fields);
5566 return ret;
5567 }
5568
5569 /*
5570 * Add event to the UST channel registry. When the event is added to the
5571 * registry, the metadata is also created. Once done, this replies to the
5572 * application with the appropriate error code.
5573 *
5574 * The session UST registry lock is acquired in the function.
5575 *
5576 * On success 0 is returned else a negative value.
5577 */
5578 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
5579 char *sig, size_t nr_fields, struct ustctl_field *fields,
5580 int loglevel_value, char *model_emf_uri)
5581 {
5582 int ret, ret_code;
5583 uint32_t event_id = 0;
5584 uint64_t chan_reg_key;
5585 struct ust_app *app;
5586 struct ust_app_channel *ua_chan;
5587 struct ust_app_session *ua_sess;
5588 struct ust_registry_session *registry;
5589
5590 rcu_read_lock();
5591
5592 /* Lookup application. If not found, there is a code flow error. */
5593 app = find_app_by_notify_sock(sock);
5594 if (!app) {
5595 DBG("Application socket %d is being torn down. Abort event notify",
5596 sock);
5597 ret = 0;
5598 goto error_rcu_unlock;
5599 }
5600
5601 /* Lookup channel by UST object descriptor. */
5602 ua_chan = find_channel_by_objd(app, cobjd);
5603 if (!ua_chan) {
5604 DBG("Application channel is being torn down. Abort event notify");
5605 ret = 0;
5606 goto error_rcu_unlock;
5607 }
5608
5609 assert(ua_chan->session);
5610 ua_sess = ua_chan->session;
5611
5612 registry = get_session_registry(ua_sess);
5613 if (!registry) {
5614 DBG("Application session is being torn down. Abort event notify");
5615 ret = 0;
5616 goto error_rcu_unlock;
5617 }
5618
5619 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5620 chan_reg_key = ua_chan->tracing_channel_id;
5621 } else {
5622 chan_reg_key = ua_chan->key;
5623 }
5624
5625 pthread_mutex_lock(&registry->lock);
5626
5627 /*
5628 * From this point on, this call acquires the ownership of the sig, fields
5629 * and model_emf_uri meaning any free are done inside it if needed. These
5630 * three variables MUST NOT be read/write after this.
5631 */
5632 ret_code = ust_registry_create_event(registry, chan_reg_key,
5633 sobjd, cobjd, name, sig, nr_fields, fields,
5634 loglevel_value, model_emf_uri, ua_sess->buffer_type,
5635 &event_id, app);
5636 sig = NULL;
5637 fields = NULL;
5638 model_emf_uri = NULL;
5639
5640 /*
5641 * The return value is returned to ustctl so in case of an error, the
5642 * application can be notified. In case of an error, it's important not to
5643 * return a negative error or else the application will get closed.
5644 */
5645 ret = ustctl_reply_register_event(sock, event_id, ret_code);
5646 if (ret < 0) {
5647 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5648 ERR("UST app reply event failed with ret %d", ret);
5649 } else {
5650 DBG3("UST app reply event failed. Application died");
5651 }
5652 /*
5653 * No need to wipe the create event since the application socket will
5654 * get close on error hence cleaning up everything by itself.
5655 */
5656 goto error;
5657 }
5658
5659 DBG3("UST registry event %s with id %" PRId32 " added successfully",
5660 name, event_id);
5661
5662 error:
5663 pthread_mutex_unlock(&registry->lock);
5664 error_rcu_unlock:
5665 rcu_read_unlock();
5666 free(sig);
5667 free(fields);
5668 free(model_emf_uri);
5669 return ret;
5670 }
5671
5672 /*
5673 * Add enum to the UST session registry. Once done, this replies to the
5674 * application with the appropriate error code.
5675 *
5676 * The session UST registry lock is acquired within this function.
5677 *
5678 * On success 0 is returned else a negative value.
5679 */
5680 static int add_enum_ust_registry(int sock, int sobjd, char *name,
5681 struct ustctl_enum_entry *entries, size_t nr_entries)
5682 {
5683 int ret = 0, ret_code;
5684 struct ust_app *app;
5685 struct ust_app_session *ua_sess;
5686 struct ust_registry_session *registry;
5687 uint64_t enum_id = -1ULL;
5688
5689 rcu_read_lock();
5690
5691 /* Lookup application. If not found, there is a code flow error. */
5692 app = find_app_by_notify_sock(sock);
5693 if (!app) {
5694 /* Return an error since this is not an error */
5695 DBG("Application socket %d is being torn down. Aborting enum registration",
5696 sock);
5697 free(entries);
5698 goto error_rcu_unlock;
5699 }
5700
5701 /* Lookup session by UST object descriptor. */
5702 ua_sess = find_session_by_objd(app, sobjd);
5703 if (!ua_sess) {
5704 /* Return an error since this is not an error */
5705 DBG("Application session is being torn down (session not found). Aborting enum registration.");
5706 free(entries);
5707 goto error_rcu_unlock;
5708 }
5709
5710 registry = get_session_registry(ua_sess);
5711 if (!registry) {
5712 DBG("Application session is being torn down (registry not found). Aborting enum registration.");
5713 free(entries);
5714 goto error_rcu_unlock;
5715 }
5716
5717 pthread_mutex_lock(&registry->lock);
5718
5719 /*
5720 * From this point on, the callee acquires the ownership of
5721 * entries. The variable entries MUST NOT be read/written after
5722 * call.
5723 */
5724 ret_code = ust_registry_create_or_find_enum(registry, sobjd, name,
5725 entries, nr_entries, &enum_id);
5726 entries = NULL;
5727
5728 /*
5729 * The return value is returned to ustctl so in case of an error, the
5730 * application can be notified. In case of an error, it's important not to
5731 * return a negative error or else the application will get closed.
5732 */
5733 ret = ustctl_reply_register_enum(sock, enum_id, ret_code);
5734 if (ret < 0) {
5735 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5736 ERR("UST app reply enum failed with ret %d", ret);
5737 } else {
5738 DBG3("UST app reply enum failed. Application died");
5739 }
5740 /*
5741 * No need to wipe the create enum since the application socket will
5742 * get close on error hence cleaning up everything by itself.
5743 */
5744 goto error;
5745 }
5746
5747 DBG3("UST registry enum %s added successfully or already found", name);
5748
5749 error:
5750 pthread_mutex_unlock(&registry->lock);
5751 error_rcu_unlock:
5752 rcu_read_unlock();
5753 return ret;
5754 }
5755
5756 /*
5757 * Handle application notification through the given notify socket.
5758 *
5759 * Return 0 on success or else a negative value.
5760 */
5761 int ust_app_recv_notify(int sock)
5762 {
5763 int ret;
5764 enum ustctl_notify_cmd cmd;
5765
5766 DBG3("UST app receiving notify from sock %d", sock);
5767
5768 ret = ustctl_recv_notify(sock, &cmd);
5769 if (ret < 0) {
5770 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5771 ERR("UST app recv notify failed with ret %d", ret);
5772 } else {
5773 DBG3("UST app recv notify failed. Application died");
5774 }
5775 goto error;
5776 }
5777
5778 switch (cmd) {
5779 case USTCTL_NOTIFY_CMD_EVENT:
5780 {
5781 int sobjd, cobjd, loglevel_value;
5782 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
5783 size_t nr_fields;
5784 struct ustctl_field *fields;
5785
5786 DBG2("UST app ustctl register event received");
5787
5788 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
5789 &loglevel_value, &sig, &nr_fields, &fields,
5790 &model_emf_uri);
5791 if (ret < 0) {
5792 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5793 ERR("UST app recv event failed with ret %d", ret);
5794 } else {
5795 DBG3("UST app recv event failed. Application died");
5796 }
5797 goto error;
5798 }
5799
5800 /*
5801 * Add event to the UST registry coming from the notify socket. This
5802 * call will free if needed the sig, fields and model_emf_uri. This
5803 * code path loses the ownsership of these variables and transfer them
5804 * to the this function.
5805 */
5806 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
5807 fields, loglevel_value, model_emf_uri);
5808 if (ret < 0) {
5809 goto error;
5810 }
5811
5812 break;
5813 }
5814 case USTCTL_NOTIFY_CMD_CHANNEL:
5815 {
5816 int sobjd, cobjd;
5817 size_t nr_fields;
5818 struct ustctl_field *fields;
5819
5820 DBG2("UST app ustctl register channel received");
5821
5822 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
5823 &fields);
5824 if (ret < 0) {
5825 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5826 ERR("UST app recv channel failed with ret %d", ret);
5827 } else {
5828 DBG3("UST app recv channel failed. Application died");
5829 }
5830 goto error;
5831 }
5832
5833 /*
5834 * The fields ownership are transfered to this function call meaning
5835 * that if needed it will be freed. After this, it's invalid to access
5836 * fields or clean it up.
5837 */
5838 ret = reply_ust_register_channel(sock, cobjd, nr_fields,
5839 fields);
5840 if (ret < 0) {
5841 goto error;
5842 }
5843
5844 break;
5845 }
5846 case USTCTL_NOTIFY_CMD_ENUM:
5847 {
5848 int sobjd;
5849 char name[LTTNG_UST_SYM_NAME_LEN];
5850 size_t nr_entries;
5851 struct ustctl_enum_entry *entries;
5852
5853 DBG2("UST app ustctl register enum received");
5854
5855 ret = ustctl_recv_register_enum(sock, &sobjd, name,
5856 &entries, &nr_entries);
5857 if (ret < 0) {
5858 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5859 ERR("UST app recv enum failed with ret %d", ret);
5860 } else {
5861 DBG3("UST app recv enum failed. Application died");
5862 }
5863 goto error;
5864 }
5865
5866 /* Callee assumes ownership of entries */
5867 ret = add_enum_ust_registry(sock, sobjd, name,
5868 entries, nr_entries);
5869 if (ret < 0) {
5870 goto error;
5871 }
5872
5873 break;
5874 }
5875 default:
5876 /* Should NEVER happen. */
5877 assert(0);
5878 }
5879
5880 error:
5881 return ret;
5882 }
5883
5884 /*
5885 * Once the notify socket hangs up, this is called. First, it tries to find the
5886 * corresponding application. On failure, the call_rcu to close the socket is
5887 * executed. If an application is found, it tries to delete it from the notify
5888 * socket hash table. Whathever the result, it proceeds to the call_rcu.
5889 *
5890 * Note that an object needs to be allocated here so on ENOMEM failure, the
5891 * call RCU is not done but the rest of the cleanup is.
5892 */
5893 void ust_app_notify_sock_unregister(int sock)
5894 {
5895 int err_enomem = 0;
5896 struct lttng_ht_iter iter;
5897 struct ust_app *app;
5898 struct ust_app_notify_sock_obj *obj;
5899
5900 assert(sock >= 0);
5901
5902 rcu_read_lock();
5903
5904 obj = zmalloc(sizeof(*obj));
5905 if (!obj) {
5906 /*
5907 * An ENOMEM is kind of uncool. If this strikes we continue the
5908 * procedure but the call_rcu will not be called. In this case, we
5909 * accept the fd leak rather than possibly creating an unsynchronized
5910 * state between threads.
5911 *
5912 * TODO: The notify object should be created once the notify socket is
5913 * registered and stored independantely from the ust app object. The
5914 * tricky part is to synchronize the teardown of the application and
5915 * this notify object. Let's keep that in mind so we can avoid this
5916 * kind of shenanigans with ENOMEM in the teardown path.
5917 */
5918 err_enomem = 1;
5919 } else {
5920 obj->fd = sock;
5921 }
5922
5923 DBG("UST app notify socket unregister %d", sock);
5924
5925 /*
5926 * Lookup application by notify socket. If this fails, this means that the
5927 * hash table delete has already been done by the application
5928 * unregistration process so we can safely close the notify socket in a
5929 * call RCU.
5930 */
5931 app = find_app_by_notify_sock(sock);
5932 if (!app) {
5933 goto close_socket;
5934 }
5935
5936 iter.iter.node = &app->notify_sock_n.node;
5937
5938 /*
5939 * Whatever happens here either we fail or succeed, in both cases we have
5940 * to close the socket after a grace period to continue to the call RCU
5941 * here. If the deletion is successful, the application is not visible
5942 * anymore by other threads and is it fails it means that it was already
5943 * deleted from the hash table so either way we just have to close the
5944 * socket.
5945 */
5946 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5947
5948 close_socket:
5949 rcu_read_unlock();
5950
5951 /*
5952 * Close socket after a grace period to avoid for the socket to be reused
5953 * before the application object is freed creating potential race between
5954 * threads trying to add unique in the global hash table.
5955 */
5956 if (!err_enomem) {
5957 call_rcu(&obj->head, close_notify_sock_rcu);
5958 }
5959 }
5960
5961 /*
5962 * Destroy a ust app data structure and free its memory.
5963 */
5964 void ust_app_destroy(struct ust_app *app)
5965 {
5966 if (!app) {
5967 return;
5968 }
5969
5970 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5971 }
5972
5973 /*
5974 * Take a snapshot for a given UST session. The snapshot is sent to the given
5975 * output.
5976 *
5977 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
5978 */
5979 enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess,
5980 struct snapshot_output *output, int wait,
5981 uint64_t nb_packets_per_stream)
5982 {
5983 int ret = 0;
5984 enum lttng_error_code status = LTTNG_OK;
5985 struct lttng_ht_iter iter;
5986 struct ust_app *app;
5987 char pathname[PATH_MAX];
5988 struct ltt_session *session = NULL;
5989 uint64_t trace_archive_id;
5990
5991 assert(usess);
5992 assert(output);
5993
5994 rcu_read_lock();
5995
5996 session = session_find_by_id(usess->id);
5997 assert(session);
5998 assert(pthread_mutex_trylock(&session->lock));
5999 assert(session_trylock_list());
6000 trace_archive_id = session->current_archive_id;
6001
6002 switch (usess->buffer_type) {
6003 case LTTNG_BUFFER_PER_UID:
6004 {
6005 struct buffer_reg_uid *reg;
6006
6007 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6008 struct buffer_reg_channel *reg_chan;
6009 struct consumer_socket *socket;
6010
6011 if (!reg->registry->reg.ust->metadata_key) {
6012 /* Skip since no metadata is present */
6013 continue;
6014 }
6015
6016 /* Get consumer socket to use to push the metadata.*/
6017 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
6018 usess->consumer);
6019 if (!socket) {
6020 status = LTTNG_ERR_INVALID;
6021 goto error;
6022 }
6023
6024 memset(pathname, 0, sizeof(pathname));
6025 ret = snprintf(pathname, sizeof(pathname),
6026 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
6027 reg->uid, reg->bits_per_long);
6028 if (ret < 0) {
6029 PERROR("snprintf snapshot path");
6030 status = LTTNG_ERR_INVALID;
6031 goto error;
6032 }
6033
6034 /* Add the UST default trace dir to path. */
6035 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6036 reg_chan, node.node) {
6037 status = consumer_snapshot_channel(socket,
6038 reg_chan->consumer_key,
6039 output, 0, usess->uid,
6040 usess->gid, pathname, wait,
6041 nb_packets_per_stream,
6042 trace_archive_id);
6043 if (status != LTTNG_OK) {
6044 goto error;
6045 }
6046 }
6047 status = consumer_snapshot_channel(socket,
6048 reg->registry->reg.ust->metadata_key, output, 1,
6049 usess->uid, usess->gid, pathname, wait, 0,
6050 trace_archive_id);
6051 if (status != LTTNG_OK) {
6052 goto error;
6053 }
6054 }
6055 break;
6056 }
6057 case LTTNG_BUFFER_PER_PID:
6058 {
6059 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6060 struct consumer_socket *socket;
6061 struct lttng_ht_iter chan_iter;
6062 struct ust_app_channel *ua_chan;
6063 struct ust_app_session *ua_sess;
6064 struct ust_registry_session *registry;
6065
6066 ua_sess = lookup_session_by_app(usess, app);
6067 if (!ua_sess) {
6068 /* Session not associated with this app. */
6069 continue;
6070 }
6071
6072 /* Get the right consumer socket for the application. */
6073 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6074 output->consumer);
6075 if (!socket) {
6076 status = LTTNG_ERR_INVALID;
6077 goto error;
6078 }
6079
6080 /* Add the UST default trace dir to path. */
6081 memset(pathname, 0, sizeof(pathname));
6082 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
6083 ua_sess->path);
6084 if (ret < 0) {
6085 status = LTTNG_ERR_INVALID;
6086 PERROR("snprintf snapshot path");
6087 goto error;
6088 }
6089
6090 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6091 ua_chan, node.node) {
6092 status = consumer_snapshot_channel(socket,
6093 ua_chan->key, output,
6094 0, ua_sess->euid, ua_sess->egid,
6095 pathname, wait,
6096 nb_packets_per_stream,
6097 trace_archive_id);
6098 switch (status) {
6099 case LTTNG_OK:
6100 break;
6101 case LTTNG_ERR_CHAN_NOT_FOUND:
6102 continue;
6103 default:
6104 goto error;
6105 }
6106 }
6107
6108 registry = get_session_registry(ua_sess);
6109 if (!registry) {
6110 DBG("Application session is being torn down. Skip application.");
6111 continue;
6112 }
6113 status = consumer_snapshot_channel(socket,
6114 registry->metadata_key, output,
6115 1, ua_sess->euid, ua_sess->egid,
6116 pathname, wait, 0,
6117 trace_archive_id);
6118 switch (status) {
6119 case LTTNG_OK:
6120 break;
6121 case LTTNG_ERR_CHAN_NOT_FOUND:
6122 continue;
6123 default:
6124 goto error;
6125 }
6126 }
6127 break;
6128 }
6129 default:
6130 assert(0);
6131 break;
6132 }
6133
6134 error:
6135 rcu_read_unlock();
6136 if (session) {
6137 session_put(session);
6138 }
6139 return status;
6140 }
6141
6142 /*
6143 * Return the size taken by one more packet per stream.
6144 */
6145 uint64_t ust_app_get_size_one_more_packet_per_stream(struct ltt_ust_session *usess,
6146 uint64_t cur_nr_packets)
6147 {
6148 uint64_t tot_size = 0;
6149 struct ust_app *app;
6150 struct lttng_ht_iter iter;
6151
6152 assert(usess);
6153
6154 switch (usess->buffer_type) {
6155 case LTTNG_BUFFER_PER_UID:
6156 {
6157 struct buffer_reg_uid *reg;
6158
6159 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6160 struct buffer_reg_channel *reg_chan;
6161
6162 rcu_read_lock();
6163 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6164 reg_chan, node.node) {
6165 if (cur_nr_packets >= reg_chan->num_subbuf) {
6166 /*
6167 * Don't take channel into account if we
6168 * already grab all its packets.
6169 */
6170 continue;
6171 }
6172 tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
6173 }
6174 rcu_read_unlock();
6175 }
6176 break;
6177 }
6178 case LTTNG_BUFFER_PER_PID:
6179 {
6180 rcu_read_lock();
6181 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6182 struct ust_app_channel *ua_chan;
6183 struct ust_app_session *ua_sess;
6184 struct lttng_ht_iter chan_iter;
6185
6186 ua_sess = lookup_session_by_app(usess, app);
6187 if (!ua_sess) {
6188 /* Session not associated with this app. */
6189 continue;
6190 }
6191
6192 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6193 ua_chan, node.node) {
6194 if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
6195 /*
6196 * Don't take channel into account if we
6197 * already grab all its packets.
6198 */
6199 continue;
6200 }
6201 tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
6202 }
6203 }
6204 rcu_read_unlock();
6205 break;
6206 }
6207 default:
6208 assert(0);
6209 break;
6210 }
6211
6212 return tot_size;
6213 }
6214
6215 int ust_app_uid_get_channel_runtime_stats(uint64_t ust_session_id,
6216 struct cds_list_head *buffer_reg_uid_list,
6217 struct consumer_output *consumer, uint64_t uchan_id,
6218 int overwrite, uint64_t *discarded, uint64_t *lost)
6219 {
6220 int ret;
6221 uint64_t consumer_chan_key;
6222
6223 *discarded = 0;
6224 *lost = 0;
6225
6226 ret = buffer_reg_uid_consumer_channel_key(
6227 buffer_reg_uid_list, uchan_id, &consumer_chan_key);
6228 if (ret < 0) {
6229 /* Not found */
6230 ret = 0;
6231 goto end;
6232 }
6233
6234 if (overwrite) {
6235 ret = consumer_get_lost_packets(ust_session_id,
6236 consumer_chan_key, consumer, lost);
6237 } else {
6238 ret = consumer_get_discarded_events(ust_session_id,
6239 consumer_chan_key, consumer, discarded);
6240 }
6241
6242 end:
6243 return ret;
6244 }
6245
6246 int ust_app_pid_get_channel_runtime_stats(struct ltt_ust_session *usess,
6247 struct ltt_ust_channel *uchan,
6248 struct consumer_output *consumer, int overwrite,
6249 uint64_t *discarded, uint64_t *lost)
6250 {
6251 int ret = 0;
6252 struct lttng_ht_iter iter;
6253 struct lttng_ht_node_str *ua_chan_node;
6254 struct ust_app *app;
6255 struct ust_app_session *ua_sess;
6256 struct ust_app_channel *ua_chan;
6257
6258 *discarded = 0;
6259 *lost = 0;
6260
6261 rcu_read_lock();
6262 /*
6263 * Iterate over every registered applications. Sum counters for
6264 * all applications containing requested session and channel.
6265 */
6266 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6267 struct lttng_ht_iter uiter;
6268
6269 ua_sess = lookup_session_by_app(usess, app);
6270 if (ua_sess == NULL) {
6271 continue;
6272 }
6273
6274 /* Get channel */
6275 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &uiter);
6276 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
6277 /* If the session is found for the app, the channel must be there */
6278 assert(ua_chan_node);
6279
6280 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
6281
6282 if (overwrite) {
6283 uint64_t _lost;
6284
6285 ret = consumer_get_lost_packets(usess->id, ua_chan->key,
6286 consumer, &_lost);
6287 if (ret < 0) {
6288 break;
6289 }
6290 (*lost) += _lost;
6291 } else {
6292 uint64_t _discarded;
6293
6294 ret = consumer_get_discarded_events(usess->id,
6295 ua_chan->key, consumer, &_discarded);
6296 if (ret < 0) {
6297 break;
6298 }
6299 (*discarded) += _discarded;
6300 }
6301 }
6302
6303 rcu_read_unlock();
6304 return ret;
6305 }
6306
6307 static
6308 int ust_app_regenerate_statedump(struct ltt_ust_session *usess,
6309 struct ust_app *app)
6310 {
6311 int ret = 0;
6312 struct ust_app_session *ua_sess;
6313
6314 DBG("Regenerating the metadata for ust app pid %d", app->pid);
6315
6316 rcu_read_lock();
6317
6318 ua_sess = lookup_session_by_app(usess, app);
6319 if (ua_sess == NULL) {
6320 /* The session is in teardown process. Ignore and continue. */
6321 goto end;
6322 }
6323
6324 pthread_mutex_lock(&ua_sess->lock);
6325
6326 if (ua_sess->deleted) {
6327 goto end_unlock;
6328 }
6329
6330 pthread_mutex_lock(&app->sock_lock);
6331 ret = ustctl_regenerate_statedump(app->sock, ua_sess->handle);
6332 pthread_mutex_unlock(&app->sock_lock);
6333
6334 end_unlock:
6335 pthread_mutex_unlock(&ua_sess->lock);
6336
6337 end:
6338 rcu_read_unlock();
6339 health_code_update();
6340 return ret;
6341 }
6342
6343 /*
6344 * Regenerate the statedump for each app in the session.
6345 */
6346 int ust_app_regenerate_statedump_all(struct ltt_ust_session *usess)
6347 {
6348 int ret = 0;
6349 struct lttng_ht_iter iter;
6350 struct ust_app *app;
6351
6352 DBG("Regenerating the metadata for all UST apps");
6353
6354 rcu_read_lock();
6355
6356 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6357 if (!app->compatible) {
6358 continue;
6359 }
6360
6361 ret = ust_app_regenerate_statedump(usess, app);
6362 if (ret < 0) {
6363 /* Continue to the next app even on error */
6364 continue;
6365 }
6366 }
6367
6368 rcu_read_unlock();
6369
6370 return 0;
6371 }
6372
6373 /*
6374 * Rotate all the channels of a session.
6375 *
6376 * Return LTTNG_OK on success or else an LTTng error code.
6377 */
6378 enum lttng_error_code ust_app_rotate_session(struct ltt_session *session)
6379 {
6380 int ret;
6381 enum lttng_error_code cmd_ret = LTTNG_OK;
6382 struct lttng_ht_iter iter;
6383 struct ust_app *app;
6384 struct ltt_ust_session *usess = session->ust_session;
6385 char pathname[LTTNG_PATH_MAX];
6386
6387 assert(usess);
6388
6389 rcu_read_lock();
6390
6391 switch (usess->buffer_type) {
6392 case LTTNG_BUFFER_PER_UID:
6393 {
6394 struct buffer_reg_uid *reg;
6395
6396 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6397 struct buffer_reg_channel *reg_chan;
6398 struct consumer_socket *socket;
6399
6400 /* Get consumer socket to use to push the metadata.*/
6401 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
6402 usess->consumer);
6403 if (!socket) {
6404 cmd_ret = LTTNG_ERR_INVALID;
6405 goto error;
6406 }
6407
6408 ret = snprintf(pathname, sizeof(pathname),
6409 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
6410 reg->uid, reg->bits_per_long);
6411 if (ret < 0 || ret == sizeof(pathname)) {
6412 PERROR("Failed to format rotation path");
6413 cmd_ret = LTTNG_ERR_INVALID;
6414 goto error;
6415 }
6416
6417 /* Rotate the data channels. */
6418 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6419 reg_chan, node.node) {
6420 ret = consumer_rotate_channel(socket,
6421 reg_chan->consumer_key,
6422 usess->uid, usess->gid,
6423 usess->consumer, pathname,
6424 /* is_metadata_channel */ false,
6425 session->current_archive_id);
6426 if (ret < 0) {
6427 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6428 goto error;
6429 }
6430 }
6431
6432 (void) push_metadata(reg->registry->reg.ust, usess->consumer);
6433
6434 ret = consumer_rotate_channel(socket,
6435 reg->registry->reg.ust->metadata_key,
6436 usess->uid, usess->gid,
6437 usess->consumer, pathname,
6438 /* is_metadata_channel */ true,
6439 session->current_archive_id);
6440 if (ret < 0) {
6441 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6442 goto error;
6443 }
6444 }
6445 break;
6446 }
6447 case LTTNG_BUFFER_PER_PID:
6448 {
6449 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6450 struct consumer_socket *socket;
6451 struct lttng_ht_iter chan_iter;
6452 struct ust_app_channel *ua_chan;
6453 struct ust_app_session *ua_sess;
6454 struct ust_registry_session *registry;
6455
6456 ua_sess = lookup_session_by_app(usess, app);
6457 if (!ua_sess) {
6458 /* Session not associated with this app. */
6459 continue;
6460 }
6461 ret = snprintf(pathname, sizeof(pathname),
6462 DEFAULT_UST_TRACE_DIR "/%s",
6463 ua_sess->path);
6464 if (ret < 0 || ret == sizeof(pathname)) {
6465 PERROR("Failed to format rotation path");
6466 cmd_ret = LTTNG_ERR_INVALID;
6467 goto error;
6468 }
6469
6470 /* Get the right consumer socket for the application. */
6471 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6472 usess->consumer);
6473 if (!socket) {
6474 cmd_ret = LTTNG_ERR_INVALID;
6475 goto error;
6476 }
6477
6478 registry = get_session_registry(ua_sess);
6479 if (!registry) {
6480 DBG("Application session is being torn down. Skip application.");
6481 continue;
6482 }
6483
6484
6485 /* Rotate the data channels. */
6486 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6487 ua_chan, node.node) {
6488 ret = consumer_rotate_channel(socket, ua_chan->key,
6489 ua_sess->euid, ua_sess->egid,
6490 ua_sess->consumer, pathname,
6491 /* is_metadata_channel */ false,
6492 session->current_archive_id);
6493 if (ret < 0) {
6494 /* Per-PID buffer and application going away. */
6495 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6496 continue;
6497 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6498 goto error;
6499 }
6500 }
6501
6502 /* Rotate the metadata channel. */
6503 (void) push_metadata(registry, usess->consumer);
6504 ret = consumer_rotate_channel(socket, registry->metadata_key,
6505 ua_sess->euid, ua_sess->egid,
6506 ua_sess->consumer, pathname,
6507 /* is_metadata_channel */ true,
6508 session->current_archive_id);
6509 if (ret < 0) {
6510 /* Per-PID buffer and application going away. */
6511 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6512 continue;
6513 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6514 goto error;
6515 }
6516 }
6517 break;
6518 }
6519 default:
6520 assert(0);
6521 break;
6522 }
6523
6524 cmd_ret = LTTNG_OK;
6525
6526 error:
6527 rcu_read_unlock();
6528 return cmd_ret;
6529 }
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