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