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