Cleanup __lttng_print macro indentation
[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 _LGPL_SOURCE
19 #include <errno.h>
20 #include <inttypes.h>
21 #include <pthread.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 #include <urcu/compiler.h>
29 #include <lttng/ust-error.h>
30 #include <signal.h>
31
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34
35 #include "buffer-registry.h"
36 #include "fd-limit.h"
37 #include "health-sessiond.h"
38 #include "ust-app.h"
39 #include "ust-consumer.h"
40 #include "ust-ctl.h"
41 #include "utils.h"
42
43 static
44 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
45
46 /* Next available channel key. Access under next_channel_key_lock. */
47 static uint64_t _next_channel_key;
48 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
49
50 /* Next available session ID. Access under next_session_id_lock. */
51 static uint64_t _next_session_id;
52 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
53
54 /*
55 * Return the incremented value of next_channel_key.
56 */
57 static uint64_t get_next_channel_key(void)
58 {
59 uint64_t ret;
60
61 pthread_mutex_lock(&next_channel_key_lock);
62 ret = ++_next_channel_key;
63 pthread_mutex_unlock(&next_channel_key_lock);
64 return ret;
65 }
66
67 /*
68 * Return the atomically incremented value of next_session_id.
69 */
70 static uint64_t get_next_session_id(void)
71 {
72 uint64_t ret;
73
74 pthread_mutex_lock(&next_session_id_lock);
75 ret = ++_next_session_id;
76 pthread_mutex_unlock(&next_session_id_lock);
77 return ret;
78 }
79
80 static void copy_channel_attr_to_ustctl(
81 struct ustctl_consumer_channel_attr *attr,
82 struct lttng_ust_channel_attr *uattr)
83 {
84 /* Copy event attributes since the layout is different. */
85 attr->subbuf_size = uattr->subbuf_size;
86 attr->num_subbuf = uattr->num_subbuf;
87 attr->overwrite = uattr->overwrite;
88 attr->switch_timer_interval = uattr->switch_timer_interval;
89 attr->read_timer_interval = uattr->read_timer_interval;
90 attr->output = uattr->output;
91 }
92
93 /*
94 * Match function for the hash table lookup.
95 *
96 * It matches an ust app event based on three attributes which are the event
97 * name, the filter bytecode and the loglevel.
98 */
99 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
100 {
101 struct ust_app_event *event;
102 const struct ust_app_ht_key *key;
103 int ev_loglevel_value;
104
105 assert(node);
106 assert(_key);
107
108 event = caa_container_of(node, struct ust_app_event, node.node);
109 key = _key;
110 ev_loglevel_value = event->attr.loglevel;
111
112 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
113
114 /* Event name */
115 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
116 goto no_match;
117 }
118
119 /* Event loglevel. */
120 if (ev_loglevel_value != key->loglevel_type) {
121 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
122 && key->loglevel_type == 0 &&
123 ev_loglevel_value == -1) {
124 /*
125 * Match is accepted. This is because on event creation, the
126 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
127 * -1 are accepted for this loglevel type since 0 is the one set by
128 * the API when receiving an enable event.
129 */
130 } else {
131 goto no_match;
132 }
133 }
134
135 /* One of the filters is NULL, fail. */
136 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
137 goto no_match;
138 }
139
140 if (key->filter && event->filter) {
141 /* Both filters exists, check length followed by the bytecode. */
142 if (event->filter->len != key->filter->len ||
143 memcmp(event->filter->data, key->filter->data,
144 event->filter->len) != 0) {
145 goto no_match;
146 }
147 }
148
149 /* One of the exclusions is NULL, fail. */
150 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
151 goto no_match;
152 }
153
154 if (key->exclusion && event->exclusion) {
155 /* Both exclusions exists, check count followed by the names. */
156 if (event->exclusion->count != key->exclusion->count ||
157 memcmp(event->exclusion->names, key->exclusion->names,
158 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
159 goto no_match;
160 }
161 }
162
163
164 /* Match. */
165 return 1;
166
167 no_match:
168 return 0;
169 }
170
171 /*
172 * Unique add of an ust app event in the given ht. This uses the custom
173 * ht_match_ust_app_event match function and the event name as hash.
174 */
175 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
176 struct ust_app_event *event)
177 {
178 struct cds_lfht_node *node_ptr;
179 struct ust_app_ht_key key;
180 struct lttng_ht *ht;
181
182 assert(ua_chan);
183 assert(ua_chan->events);
184 assert(event);
185
186 ht = ua_chan->events;
187 key.name = event->attr.name;
188 key.filter = event->filter;
189 key.loglevel_type = event->attr.loglevel;
190 key.exclusion = event->exclusion;
191
192 node_ptr = cds_lfht_add_unique(ht->ht,
193 ht->hash_fct(event->node.key, lttng_ht_seed),
194 ht_match_ust_app_event, &key, &event->node.node);
195 assert(node_ptr == &event->node.node);
196 }
197
198 /*
199 * Close the notify socket from the given RCU head object. This MUST be called
200 * through a call_rcu().
201 */
202 static void close_notify_sock_rcu(struct rcu_head *head)
203 {
204 int ret;
205 struct ust_app_notify_sock_obj *obj =
206 caa_container_of(head, struct ust_app_notify_sock_obj, head);
207
208 /* Must have a valid fd here. */
209 assert(obj->fd >= 0);
210
211 ret = close(obj->fd);
212 if (ret) {
213 ERR("close notify sock %d RCU", obj->fd);
214 }
215 lttng_fd_put(LTTNG_FD_APPS, 1);
216
217 free(obj);
218 }
219
220 /*
221 * Return the session registry according to the buffer type of the given
222 * session.
223 *
224 * A registry per UID object MUST exists before calling this function or else
225 * it assert() if not found. RCU read side lock must be acquired.
226 */
227 static struct ust_registry_session *get_session_registry(
228 struct ust_app_session *ua_sess)
229 {
230 struct ust_registry_session *registry = NULL;
231
232 assert(ua_sess);
233
234 switch (ua_sess->buffer_type) {
235 case LTTNG_BUFFER_PER_PID:
236 {
237 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
238 if (!reg_pid) {
239 goto error;
240 }
241 registry = reg_pid->registry->reg.ust;
242 break;
243 }
244 case LTTNG_BUFFER_PER_UID:
245 {
246 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
247 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
248 if (!reg_uid) {
249 goto error;
250 }
251 registry = reg_uid->registry->reg.ust;
252 break;
253 }
254 default:
255 assert(0);
256 };
257
258 error:
259 return registry;
260 }
261
262 /*
263 * Delete ust context safely. RCU read lock must be held before calling
264 * this function.
265 */
266 static
267 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
268 struct ust_app *app)
269 {
270 int ret;
271
272 assert(ua_ctx);
273
274 if (ua_ctx->obj) {
275 pthread_mutex_lock(&app->sock_lock);
276 ret = ustctl_release_object(sock, ua_ctx->obj);
277 pthread_mutex_unlock(&app->sock_lock);
278 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
279 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
280 sock, ua_ctx->obj->handle, ret);
281 }
282 free(ua_ctx->obj);
283 }
284 free(ua_ctx);
285 }
286
287 /*
288 * Delete ust app event safely. RCU read lock must be held before calling
289 * this function.
290 */
291 static
292 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
293 struct ust_app *app)
294 {
295 int ret;
296
297 assert(ua_event);
298
299 free(ua_event->filter);
300 if (ua_event->exclusion != NULL)
301 free(ua_event->exclusion);
302 if (ua_event->obj != NULL) {
303 pthread_mutex_lock(&app->sock_lock);
304 ret = ustctl_release_object(sock, ua_event->obj);
305 pthread_mutex_unlock(&app->sock_lock);
306 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
307 ERR("UST app sock %d release event obj failed with ret %d",
308 sock, ret);
309 }
310 free(ua_event->obj);
311 }
312 free(ua_event);
313 }
314
315 /*
316 * Release ust data object of the given stream.
317 *
318 * Return 0 on success or else a negative value.
319 */
320 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
321 struct ust_app *app)
322 {
323 int ret = 0;
324
325 assert(stream);
326
327 if (stream->obj) {
328 pthread_mutex_lock(&app->sock_lock);
329 ret = ustctl_release_object(sock, stream->obj);
330 pthread_mutex_unlock(&app->sock_lock);
331 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
332 ERR("UST app sock %d release stream obj failed with ret %d",
333 sock, ret);
334 }
335 lttng_fd_put(LTTNG_FD_APPS, 2);
336 free(stream->obj);
337 }
338
339 return ret;
340 }
341
342 /*
343 * Delete ust app stream safely. RCU read lock must be held before calling
344 * this function.
345 */
346 static
347 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
348 struct ust_app *app)
349 {
350 assert(stream);
351
352 (void) release_ust_app_stream(sock, stream, app);
353 free(stream);
354 }
355
356 /*
357 * We need to execute ht_destroy outside of RCU read-side critical
358 * section and outside of call_rcu thread, so we postpone its execution
359 * using ht_cleanup_push. It is simpler than to change the semantic of
360 * the many callers of delete_ust_app_session().
361 */
362 static
363 void delete_ust_app_channel_rcu(struct rcu_head *head)
364 {
365 struct ust_app_channel *ua_chan =
366 caa_container_of(head, struct ust_app_channel, rcu_head);
367
368 ht_cleanup_push(ua_chan->ctx);
369 ht_cleanup_push(ua_chan->events);
370 free(ua_chan);
371 }
372
373 /*
374 * Delete ust app channel safely. RCU read lock must be held before calling
375 * this function.
376 */
377 static
378 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
379 struct ust_app *app)
380 {
381 int ret;
382 struct lttng_ht_iter iter;
383 struct ust_app_event *ua_event;
384 struct ust_app_ctx *ua_ctx;
385 struct ust_app_stream *stream, *stmp;
386 struct ust_registry_session *registry;
387
388 assert(ua_chan);
389
390 DBG3("UST app deleting channel %s", ua_chan->name);
391
392 /* Wipe stream */
393 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
394 cds_list_del(&stream->list);
395 delete_ust_app_stream(sock, stream, app);
396 }
397
398 /* Wipe context */
399 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
400 cds_list_del(&ua_ctx->list);
401 ret = lttng_ht_del(ua_chan->ctx, &iter);
402 assert(!ret);
403 delete_ust_app_ctx(sock, ua_ctx, app);
404 }
405
406 /* Wipe events */
407 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
408 node.node) {
409 ret = lttng_ht_del(ua_chan->events, &iter);
410 assert(!ret);
411 delete_ust_app_event(sock, ua_event, app);
412 }
413
414 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
415 /* Wipe and free registry from session registry. */
416 registry = get_session_registry(ua_chan->session);
417 if (registry) {
418 ust_registry_channel_del_free(registry, ua_chan->key);
419 }
420 }
421
422 if (ua_chan->obj != NULL) {
423 /* Remove channel from application UST object descriptor. */
424 iter.iter.node = &ua_chan->ust_objd_node.node;
425 ret = lttng_ht_del(app->ust_objd, &iter);
426 assert(!ret);
427 pthread_mutex_lock(&app->sock_lock);
428 ret = ustctl_release_object(sock, ua_chan->obj);
429 pthread_mutex_unlock(&app->sock_lock);
430 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
431 ERR("UST app sock %d release channel obj failed with ret %d",
432 sock, ret);
433 }
434 lttng_fd_put(LTTNG_FD_APPS, 1);
435 free(ua_chan->obj);
436 }
437 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
438 }
439
440 int ust_app_register_done(struct ust_app *app)
441 {
442 int ret;
443
444 pthread_mutex_lock(&app->sock_lock);
445 ret = ustctl_register_done(app->sock);
446 pthread_mutex_unlock(&app->sock_lock);
447 return ret;
448 }
449
450 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
451 {
452 int ret, sock;
453
454 if (app) {
455 pthread_mutex_lock(&app->sock_lock);
456 sock = app->sock;
457 } else {
458 sock = -1;
459 }
460 ret = ustctl_release_object(sock, data);
461 if (app) {
462 pthread_mutex_unlock(&app->sock_lock);
463 }
464 return ret;
465 }
466
467 /*
468 * Push metadata to consumer socket.
469 *
470 * RCU read-side lock must be held to guarantee existance of socket.
471 * Must be called with the ust app session lock held.
472 * Must be called with the registry lock held.
473 *
474 * On success, return the len of metadata pushed or else a negative value.
475 * Returning a -EPIPE return value means we could not send the metadata,
476 * but it can be caused by recoverable errors (e.g. the application has
477 * terminated concurrently).
478 */
479 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
480 struct consumer_socket *socket, int send_zero_data)
481 {
482 int ret;
483 char *metadata_str = NULL;
484 size_t len, offset, new_metadata_len_sent;
485 ssize_t ret_val;
486 uint64_t metadata_key;
487
488 assert(registry);
489 assert(socket);
490
491 metadata_key = registry->metadata_key;
492
493 /*
494 * Means that no metadata was assigned to the session. This can
495 * happens if no start has been done previously.
496 */
497 if (!metadata_key) {
498 return 0;
499 }
500
501 /*
502 * On a push metadata error either the consumer is dead or the
503 * metadata channel has been destroyed because its endpoint
504 * might have died (e.g: relayd), or because the application has
505 * exited. If so, the metadata closed flag is set to 1 so we
506 * deny pushing metadata again which is not valid anymore on the
507 * consumer side.
508 */
509 if (registry->metadata_closed) {
510 return -EPIPE;
511 }
512
513 offset = registry->metadata_len_sent;
514 len = registry->metadata_len - registry->metadata_len_sent;
515 new_metadata_len_sent = registry->metadata_len;
516 if (len == 0) {
517 DBG3("No metadata to push for metadata key %" PRIu64,
518 registry->metadata_key);
519 ret_val = len;
520 if (send_zero_data) {
521 DBG("No metadata to push");
522 goto push_data;
523 }
524 goto end;
525 }
526
527 /* Allocate only what we have to send. */
528 metadata_str = zmalloc(len);
529 if (!metadata_str) {
530 PERROR("zmalloc ust app metadata string");
531 ret_val = -ENOMEM;
532 goto error;
533 }
534 /* Copy what we haven't sent out. */
535 memcpy(metadata_str, registry->metadata + offset, len);
536
537 push_data:
538 pthread_mutex_unlock(&registry->lock);
539 /*
540 * We need to unlock the registry while we push metadata to
541 * break a circular dependency between the consumerd metadata
542 * lock and the sessiond registry lock. Indeed, pushing metadata
543 * to the consumerd awaits that it gets pushed all the way to
544 * relayd, but doing so requires grabbing the metadata lock. If
545 * a concurrent metadata request is being performed by
546 * consumerd, this can try to grab the registry lock on the
547 * sessiond while holding the metadata lock on the consumer
548 * daemon. Those push and pull schemes are performed on two
549 * different bidirectionnal communication sockets.
550 */
551 ret = consumer_push_metadata(socket, metadata_key,
552 metadata_str, len, offset);
553 pthread_mutex_lock(&registry->lock);
554 if (ret < 0) {
555 /*
556 * There is an acceptable race here between the registry
557 * metadata key assignment and the creation on the
558 * consumer. The session daemon can concurrently push
559 * metadata for this registry while being created on the
560 * consumer since the metadata key of the registry is
561 * assigned *before* it is setup to avoid the consumer
562 * to ask for metadata that could possibly be not found
563 * in the session daemon.
564 *
565 * The metadata will get pushed either by the session
566 * being stopped or the consumer requesting metadata if
567 * that race is triggered.
568 */
569 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
570 ret = 0;
571 } else {
572 ERR("Error pushing metadata to consumer");
573 }
574 ret_val = ret;
575 goto error_push;
576 } else {
577 /*
578 * Metadata may have been concurrently pushed, since
579 * we're not holding the registry lock while pushing to
580 * consumer. This is handled by the fact that we send
581 * the metadata content, size, and the offset at which
582 * that metadata belongs. This may arrive out of order
583 * on the consumer side, and the consumer is able to
584 * deal with overlapping fragments. The consumer
585 * supports overlapping fragments, which must be
586 * contiguous starting from offset 0. We keep the
587 * largest metadata_len_sent value of the concurrent
588 * send.
589 */
590 registry->metadata_len_sent =
591 max_t(size_t, registry->metadata_len_sent,
592 new_metadata_len_sent);
593 }
594 free(metadata_str);
595 return len;
596
597 end:
598 error:
599 if (ret_val) {
600 /*
601 * On error, flag the registry that the metadata is
602 * closed. We were unable to push anything and this
603 * means that either the consumer is not responding or
604 * the metadata cache has been destroyed on the
605 * consumer.
606 */
607 registry->metadata_closed = 1;
608 }
609 error_push:
610 free(metadata_str);
611 return ret_val;
612 }
613
614 /*
615 * For a given application and session, push metadata to consumer.
616 * Either sock or consumer is required : if sock is NULL, the default
617 * socket to send the metadata is retrieved from consumer, if sock
618 * is not NULL we use it to send the metadata.
619 * RCU read-side lock must be held while calling this function,
620 * therefore ensuring existance of registry. It also ensures existance
621 * of socket throughout this function.
622 *
623 * Return 0 on success else a negative error.
624 * Returning a -EPIPE return value means we could not send the metadata,
625 * but it can be caused by recoverable errors (e.g. the application has
626 * terminated concurrently).
627 */
628 static int push_metadata(struct ust_registry_session *registry,
629 struct consumer_output *consumer)
630 {
631 int ret_val;
632 ssize_t ret;
633 struct consumer_socket *socket;
634
635 assert(registry);
636 assert(consumer);
637
638 pthread_mutex_lock(&registry->lock);
639 if (registry->metadata_closed) {
640 ret_val = -EPIPE;
641 goto error;
642 }
643
644 /* Get consumer socket to use to push the metadata.*/
645 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
646 consumer);
647 if (!socket) {
648 ret_val = -1;
649 goto error;
650 }
651
652 ret = ust_app_push_metadata(registry, socket, 0);
653 if (ret < 0) {
654 ret_val = ret;
655 goto error;
656 }
657 pthread_mutex_unlock(&registry->lock);
658 return 0;
659
660 error:
661 pthread_mutex_unlock(&registry->lock);
662 return ret_val;
663 }
664
665 /*
666 * Send to the consumer a close metadata command for the given session. Once
667 * done, the metadata channel is deleted and the session metadata pointer is
668 * nullified. The session lock MUST be held unless the application is
669 * in the destroy path.
670 *
671 * Return 0 on success else a negative value.
672 */
673 static int close_metadata(struct ust_registry_session *registry,
674 struct consumer_output *consumer)
675 {
676 int ret;
677 struct consumer_socket *socket;
678
679 assert(registry);
680 assert(consumer);
681
682 rcu_read_lock();
683
684 pthread_mutex_lock(&registry->lock);
685
686 if (!registry->metadata_key || registry->metadata_closed) {
687 ret = 0;
688 goto end;
689 }
690
691 /* Get consumer socket to use to push the metadata.*/
692 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
693 consumer);
694 if (!socket) {
695 ret = -1;
696 goto error;
697 }
698
699 ret = consumer_close_metadata(socket, registry->metadata_key);
700 if (ret < 0) {
701 goto error;
702 }
703
704 error:
705 /*
706 * Metadata closed. Even on error this means that the consumer is not
707 * responding or not found so either way a second close should NOT be emit
708 * for this registry.
709 */
710 registry->metadata_closed = 1;
711 end:
712 pthread_mutex_unlock(&registry->lock);
713 rcu_read_unlock();
714 return ret;
715 }
716
717 /*
718 * We need to execute ht_destroy outside of RCU read-side critical
719 * section and outside of call_rcu thread, so we postpone its execution
720 * using ht_cleanup_push. It is simpler than to change the semantic of
721 * the many callers of delete_ust_app_session().
722 */
723 static
724 void delete_ust_app_session_rcu(struct rcu_head *head)
725 {
726 struct ust_app_session *ua_sess =
727 caa_container_of(head, struct ust_app_session, rcu_head);
728
729 ht_cleanup_push(ua_sess->channels);
730 free(ua_sess);
731 }
732
733 /*
734 * Delete ust app session safely. RCU read lock must be held before calling
735 * this function.
736 */
737 static
738 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
739 struct ust_app *app)
740 {
741 int ret;
742 struct lttng_ht_iter iter;
743 struct ust_app_channel *ua_chan;
744 struct ust_registry_session *registry;
745
746 assert(ua_sess);
747
748 pthread_mutex_lock(&ua_sess->lock);
749
750 assert(!ua_sess->deleted);
751 ua_sess->deleted = true;
752
753 registry = get_session_registry(ua_sess);
754 if (registry) {
755 /* Push metadata for application before freeing the application. */
756 (void) push_metadata(registry, ua_sess->consumer);
757
758 /*
759 * Don't ask to close metadata for global per UID buffers. Close
760 * metadata only on destroy trace session in this case. Also, the
761 * previous push metadata could have flag the metadata registry to
762 * close so don't send a close command if closed.
763 */
764 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
765 /* And ask to close it for this session registry. */
766 (void) close_metadata(registry, ua_sess->consumer);
767 }
768 }
769
770 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
771 node.node) {
772 ret = lttng_ht_del(ua_sess->channels, &iter);
773 assert(!ret);
774 delete_ust_app_channel(sock, ua_chan, app);
775 }
776
777 /* In case of per PID, the registry is kept in the session. */
778 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
779 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
780 if (reg_pid) {
781 buffer_reg_pid_remove(reg_pid);
782 buffer_reg_pid_destroy(reg_pid);
783 }
784 }
785
786 if (ua_sess->handle != -1) {
787 pthread_mutex_lock(&app->sock_lock);
788 ret = ustctl_release_handle(sock, ua_sess->handle);
789 pthread_mutex_unlock(&app->sock_lock);
790 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
791 ERR("UST app sock %d release session handle failed with ret %d",
792 sock, ret);
793 }
794 }
795 pthread_mutex_unlock(&ua_sess->lock);
796
797 consumer_output_put(ua_sess->consumer);
798
799 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
800 }
801
802 /*
803 * Delete a traceable application structure from the global list. Never call
804 * this function outside of a call_rcu call.
805 *
806 * RCU read side lock should _NOT_ be held when calling this function.
807 */
808 static
809 void delete_ust_app(struct ust_app *app)
810 {
811 int ret, sock;
812 struct ust_app_session *ua_sess, *tmp_ua_sess;
813
814 /* Delete ust app sessions info */
815 sock = app->sock;
816 app->sock = -1;
817
818 /* Wipe sessions */
819 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
820 teardown_node) {
821 /* Free every object in the session and the session. */
822 rcu_read_lock();
823 delete_ust_app_session(sock, ua_sess, app);
824 rcu_read_unlock();
825 }
826
827 ht_cleanup_push(app->sessions);
828 ht_cleanup_push(app->ust_objd);
829
830 /*
831 * Wait until we have deleted the application from the sock hash table
832 * before closing this socket, otherwise an application could re-use the
833 * socket ID and race with the teardown, using the same hash table entry.
834 *
835 * It's OK to leave the close in call_rcu. We want it to stay unique for
836 * all RCU readers that could run concurrently with unregister app,
837 * therefore we _need_ to only close that socket after a grace period. So
838 * it should stay in this RCU callback.
839 *
840 * This close() is a very important step of the synchronization model so
841 * every modification to this function must be carefully reviewed.
842 */
843 ret = close(sock);
844 if (ret) {
845 PERROR("close");
846 }
847 lttng_fd_put(LTTNG_FD_APPS, 1);
848
849 DBG2("UST app pid %d deleted", app->pid);
850 free(app);
851 }
852
853 /*
854 * URCU intermediate call to delete an UST app.
855 */
856 static
857 void delete_ust_app_rcu(struct rcu_head *head)
858 {
859 struct lttng_ht_node_ulong *node =
860 caa_container_of(head, struct lttng_ht_node_ulong, head);
861 struct ust_app *app =
862 caa_container_of(node, struct ust_app, pid_n);
863
864 DBG3("Call RCU deleting app PID %d", app->pid);
865 delete_ust_app(app);
866 }
867
868 /*
869 * Delete the session from the application ht and delete the data structure by
870 * freeing every object inside and releasing them.
871 */
872 static void destroy_app_session(struct ust_app *app,
873 struct ust_app_session *ua_sess)
874 {
875 int ret;
876 struct lttng_ht_iter iter;
877
878 assert(app);
879 assert(ua_sess);
880
881 iter.iter.node = &ua_sess->node.node;
882 ret = lttng_ht_del(app->sessions, &iter);
883 if (ret) {
884 /* Already scheduled for teardown. */
885 goto end;
886 }
887
888 /* Once deleted, free the data structure. */
889 delete_ust_app_session(app->sock, ua_sess, app);
890
891 end:
892 return;
893 }
894
895 /*
896 * Alloc new UST app session.
897 */
898 static
899 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
900 {
901 struct ust_app_session *ua_sess;
902
903 /* Init most of the default value by allocating and zeroing */
904 ua_sess = zmalloc(sizeof(struct ust_app_session));
905 if (ua_sess == NULL) {
906 PERROR("malloc");
907 goto error_free;
908 }
909
910 ua_sess->handle = -1;
911 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
912 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
913 pthread_mutex_init(&ua_sess->lock, NULL);
914
915 return ua_sess;
916
917 error_free:
918 return NULL;
919 }
920
921 /*
922 * Alloc new UST app channel.
923 */
924 static
925 struct ust_app_channel *alloc_ust_app_channel(char *name,
926 struct ust_app_session *ua_sess,
927 struct lttng_ust_channel_attr *attr)
928 {
929 struct ust_app_channel *ua_chan;
930
931 /* Init most of the default value by allocating and zeroing */
932 ua_chan = zmalloc(sizeof(struct ust_app_channel));
933 if (ua_chan == NULL) {
934 PERROR("malloc");
935 goto error;
936 }
937
938 /* Setup channel name */
939 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
940 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
941
942 ua_chan->enabled = 1;
943 ua_chan->handle = -1;
944 ua_chan->session = ua_sess;
945 ua_chan->key = get_next_channel_key();
946 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
947 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
948 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
949
950 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
951 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
952
953 /* Copy attributes */
954 if (attr) {
955 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
956 ua_chan->attr.subbuf_size = attr->subbuf_size;
957 ua_chan->attr.num_subbuf = attr->num_subbuf;
958 ua_chan->attr.overwrite = attr->overwrite;
959 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
960 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
961 ua_chan->attr.output = attr->output;
962 }
963 /* By default, the channel is a per cpu channel. */
964 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
965
966 DBG3("UST app channel %s allocated", ua_chan->name);
967
968 return ua_chan;
969
970 error:
971 return NULL;
972 }
973
974 /*
975 * Allocate and initialize a UST app stream.
976 *
977 * Return newly allocated stream pointer or NULL on error.
978 */
979 struct ust_app_stream *ust_app_alloc_stream(void)
980 {
981 struct ust_app_stream *stream = NULL;
982
983 stream = zmalloc(sizeof(*stream));
984 if (stream == NULL) {
985 PERROR("zmalloc ust app stream");
986 goto error;
987 }
988
989 /* Zero could be a valid value for a handle so flag it to -1. */
990 stream->handle = -1;
991
992 error:
993 return stream;
994 }
995
996 /*
997 * Alloc new UST app event.
998 */
999 static
1000 struct ust_app_event *alloc_ust_app_event(char *name,
1001 struct lttng_ust_event *attr)
1002 {
1003 struct ust_app_event *ua_event;
1004
1005 /* Init most of the default value by allocating and zeroing */
1006 ua_event = zmalloc(sizeof(struct ust_app_event));
1007 if (ua_event == NULL) {
1008 PERROR("malloc");
1009 goto error;
1010 }
1011
1012 ua_event->enabled = 1;
1013 strncpy(ua_event->name, name, sizeof(ua_event->name));
1014 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1015 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1016
1017 /* Copy attributes */
1018 if (attr) {
1019 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1020 }
1021
1022 DBG3("UST app event %s allocated", ua_event->name);
1023
1024 return ua_event;
1025
1026 error:
1027 return NULL;
1028 }
1029
1030 /*
1031 * Alloc new UST app context.
1032 */
1033 static
1034 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
1035 {
1036 struct ust_app_ctx *ua_ctx;
1037
1038 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1039 if (ua_ctx == NULL) {
1040 goto error;
1041 }
1042
1043 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1044
1045 if (uctx) {
1046 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1047 }
1048
1049 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1050
1051 error:
1052 return ua_ctx;
1053 }
1054
1055 /*
1056 * Allocate a filter and copy the given original filter.
1057 *
1058 * Return allocated filter or NULL on error.
1059 */
1060 static struct lttng_filter_bytecode *copy_filter_bytecode(
1061 struct lttng_filter_bytecode *orig_f)
1062 {
1063 struct lttng_filter_bytecode *filter = NULL;
1064
1065 /* Copy filter bytecode */
1066 filter = zmalloc(sizeof(*filter) + orig_f->len);
1067 if (!filter) {
1068 PERROR("zmalloc alloc filter bytecode");
1069 goto error;
1070 }
1071
1072 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1073
1074 error:
1075 return filter;
1076 }
1077
1078 /*
1079 * Create a liblttng-ust filter bytecode from given bytecode.
1080 *
1081 * Return allocated filter or NULL on error.
1082 */
1083 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1084 struct lttng_filter_bytecode *orig_f)
1085 {
1086 struct lttng_ust_filter_bytecode *filter = NULL;
1087
1088 /* Copy filter bytecode */
1089 filter = zmalloc(sizeof(*filter) + orig_f->len);
1090 if (!filter) {
1091 PERROR("zmalloc alloc ust filter bytecode");
1092 goto error;
1093 }
1094
1095 assert(sizeof(struct lttng_filter_bytecode) ==
1096 sizeof(struct lttng_ust_filter_bytecode));
1097 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1098 error:
1099 return filter;
1100 }
1101
1102 /*
1103 * Find an ust_app using the sock and return it. RCU read side lock must be
1104 * held before calling this helper function.
1105 */
1106 struct ust_app *ust_app_find_by_sock(int sock)
1107 {
1108 struct lttng_ht_node_ulong *node;
1109 struct lttng_ht_iter iter;
1110
1111 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1112 node = lttng_ht_iter_get_node_ulong(&iter);
1113 if (node == NULL) {
1114 DBG2("UST app find by sock %d not found", sock);
1115 goto error;
1116 }
1117
1118 return caa_container_of(node, struct ust_app, sock_n);
1119
1120 error:
1121 return NULL;
1122 }
1123
1124 /*
1125 * Find an ust_app using the notify sock and return it. RCU read side lock must
1126 * be held before calling this helper function.
1127 */
1128 static struct ust_app *find_app_by_notify_sock(int sock)
1129 {
1130 struct lttng_ht_node_ulong *node;
1131 struct lttng_ht_iter iter;
1132
1133 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1134 &iter);
1135 node = lttng_ht_iter_get_node_ulong(&iter);
1136 if (node == NULL) {
1137 DBG2("UST app find by notify sock %d not found", sock);
1138 goto error;
1139 }
1140
1141 return caa_container_of(node, struct ust_app, notify_sock_n);
1142
1143 error:
1144 return NULL;
1145 }
1146
1147 /*
1148 * Lookup for an ust app event based on event name, filter bytecode and the
1149 * event loglevel.
1150 *
1151 * Return an ust_app_event object or NULL on error.
1152 */
1153 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1154 char *name, struct lttng_filter_bytecode *filter,
1155 int loglevel_value,
1156 const struct lttng_event_exclusion *exclusion)
1157 {
1158 struct lttng_ht_iter iter;
1159 struct lttng_ht_node_str *node;
1160 struct ust_app_event *event = NULL;
1161 struct ust_app_ht_key key;
1162
1163 assert(name);
1164 assert(ht);
1165
1166 /* Setup key for event lookup. */
1167 key.name = name;
1168 key.filter = filter;
1169 key.loglevel_type = loglevel_value;
1170 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1171 key.exclusion = exclusion;
1172
1173 /* Lookup using the event name as hash and a custom match fct. */
1174 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1175 ht_match_ust_app_event, &key, &iter.iter);
1176 node = lttng_ht_iter_get_node_str(&iter);
1177 if (node == NULL) {
1178 goto end;
1179 }
1180
1181 event = caa_container_of(node, struct ust_app_event, node);
1182
1183 end:
1184 return event;
1185 }
1186
1187 /*
1188 * Create the channel context on the tracer.
1189 *
1190 * Called with UST app session lock held.
1191 */
1192 static
1193 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1194 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1195 {
1196 int ret;
1197
1198 health_code_update();
1199
1200 pthread_mutex_lock(&app->sock_lock);
1201 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1202 ua_chan->obj, &ua_ctx->obj);
1203 pthread_mutex_unlock(&app->sock_lock);
1204 if (ret < 0) {
1205 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1206 ERR("UST app create channel context failed for app (pid: %d) "
1207 "with ret %d", app->pid, ret);
1208 } else {
1209 /*
1210 * This is normal behavior, an application can die during the
1211 * creation process. Don't report an error so the execution can
1212 * continue normally.
1213 */
1214 ret = 0;
1215 DBG3("UST app disable event failed. Application is dead.");
1216 }
1217 goto error;
1218 }
1219
1220 ua_ctx->handle = ua_ctx->obj->handle;
1221
1222 DBG2("UST app context handle %d created successfully for channel %s",
1223 ua_ctx->handle, ua_chan->name);
1224
1225 error:
1226 health_code_update();
1227 return ret;
1228 }
1229
1230 /*
1231 * Set the filter on the tracer.
1232 */
1233 static
1234 int set_ust_event_filter(struct ust_app_event *ua_event,
1235 struct ust_app *app)
1236 {
1237 int ret;
1238 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1239
1240 health_code_update();
1241
1242 if (!ua_event->filter) {
1243 ret = 0;
1244 goto error;
1245 }
1246
1247 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1248 if (!ust_bytecode) {
1249 ret = -LTTNG_ERR_NOMEM;
1250 goto error;
1251 }
1252 pthread_mutex_lock(&app->sock_lock);
1253 ret = ustctl_set_filter(app->sock, ust_bytecode,
1254 ua_event->obj);
1255 pthread_mutex_unlock(&app->sock_lock);
1256 if (ret < 0) {
1257 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1258 ERR("UST app event %s filter failed for app (pid: %d) "
1259 "with ret %d", ua_event->attr.name, app->pid, ret);
1260 } else {
1261 /*
1262 * This is normal behavior, an application can die during the
1263 * creation process. Don't report an error so the execution can
1264 * continue normally.
1265 */
1266 ret = 0;
1267 DBG3("UST app filter event failed. Application is dead.");
1268 }
1269 goto error;
1270 }
1271
1272 DBG2("UST filter set successfully for event %s", ua_event->name);
1273
1274 error:
1275 health_code_update();
1276 free(ust_bytecode);
1277 return ret;
1278 }
1279
1280 static
1281 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1282 struct lttng_event_exclusion *exclusion)
1283 {
1284 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1285 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1286 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1287
1288 ust_exclusion = zmalloc(exclusion_alloc_size);
1289 if (!ust_exclusion) {
1290 PERROR("malloc");
1291 goto end;
1292 }
1293
1294 assert(sizeof(struct lttng_event_exclusion) ==
1295 sizeof(struct lttng_ust_event_exclusion));
1296 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1297 end:
1298 return ust_exclusion;
1299 }
1300
1301 /*
1302 * Set event exclusions on the tracer.
1303 */
1304 static
1305 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1306 struct ust_app *app)
1307 {
1308 int ret;
1309 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1310
1311 health_code_update();
1312
1313 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1314 ret = 0;
1315 goto error;
1316 }
1317
1318 ust_exclusion = create_ust_exclusion_from_exclusion(
1319 ua_event->exclusion);
1320 if (!ust_exclusion) {
1321 ret = -LTTNG_ERR_NOMEM;
1322 goto error;
1323 }
1324 pthread_mutex_lock(&app->sock_lock);
1325 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1326 pthread_mutex_unlock(&app->sock_lock);
1327 if (ret < 0) {
1328 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1329 ERR("UST app event %s exclusions failed for app (pid: %d) "
1330 "with ret %d", ua_event->attr.name, app->pid, ret);
1331 } else {
1332 /*
1333 * This is normal behavior, an application can die during the
1334 * creation process. Don't report an error so the execution can
1335 * continue normally.
1336 */
1337 ret = 0;
1338 DBG3("UST app event exclusion failed. Application is dead.");
1339 }
1340 goto error;
1341 }
1342
1343 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1344
1345 error:
1346 health_code_update();
1347 free(ust_exclusion);
1348 return ret;
1349 }
1350
1351 /*
1352 * Disable the specified event on to UST tracer for the UST session.
1353 */
1354 static int disable_ust_event(struct ust_app *app,
1355 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1356 {
1357 int ret;
1358
1359 health_code_update();
1360
1361 pthread_mutex_lock(&app->sock_lock);
1362 ret = ustctl_disable(app->sock, ua_event->obj);
1363 pthread_mutex_unlock(&app->sock_lock);
1364 if (ret < 0) {
1365 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1366 ERR("UST app event %s disable failed for app (pid: %d) "
1367 "and session handle %d with ret %d",
1368 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1369 } else {
1370 /*
1371 * This is normal behavior, an application can die during the
1372 * creation process. Don't report an error so the execution can
1373 * continue normally.
1374 */
1375 ret = 0;
1376 DBG3("UST app disable event failed. Application is dead.");
1377 }
1378 goto error;
1379 }
1380
1381 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1382 ua_event->attr.name, app->pid);
1383
1384 error:
1385 health_code_update();
1386 return ret;
1387 }
1388
1389 /*
1390 * Disable the specified channel on to UST tracer for the UST session.
1391 */
1392 static int disable_ust_channel(struct ust_app *app,
1393 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1394 {
1395 int ret;
1396
1397 health_code_update();
1398
1399 pthread_mutex_lock(&app->sock_lock);
1400 ret = ustctl_disable(app->sock, ua_chan->obj);
1401 pthread_mutex_unlock(&app->sock_lock);
1402 if (ret < 0) {
1403 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1404 ERR("UST app channel %s disable failed for app (pid: %d) "
1405 "and session handle %d with ret %d",
1406 ua_chan->name, app->pid, ua_sess->handle, ret);
1407 } else {
1408 /*
1409 * This is normal behavior, an application can die during the
1410 * creation process. Don't report an error so the execution can
1411 * continue normally.
1412 */
1413 ret = 0;
1414 DBG3("UST app disable channel failed. Application is dead.");
1415 }
1416 goto error;
1417 }
1418
1419 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1420 ua_chan->name, app->pid);
1421
1422 error:
1423 health_code_update();
1424 return ret;
1425 }
1426
1427 /*
1428 * Enable the specified channel on to UST tracer for the UST session.
1429 */
1430 static int enable_ust_channel(struct ust_app *app,
1431 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1432 {
1433 int ret;
1434
1435 health_code_update();
1436
1437 pthread_mutex_lock(&app->sock_lock);
1438 ret = ustctl_enable(app->sock, ua_chan->obj);
1439 pthread_mutex_unlock(&app->sock_lock);
1440 if (ret < 0) {
1441 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1442 ERR("UST app channel %s enable failed for app (pid: %d) "
1443 "and session handle %d with ret %d",
1444 ua_chan->name, app->pid, ua_sess->handle, ret);
1445 } else {
1446 /*
1447 * This is normal behavior, an application can die during the
1448 * creation process. Don't report an error so the execution can
1449 * continue normally.
1450 */
1451 ret = 0;
1452 DBG3("UST app enable channel failed. Application is dead.");
1453 }
1454 goto error;
1455 }
1456
1457 ua_chan->enabled = 1;
1458
1459 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1460 ua_chan->name, app->pid);
1461
1462 error:
1463 health_code_update();
1464 return ret;
1465 }
1466
1467 /*
1468 * Enable the specified event on to UST tracer for the UST session.
1469 */
1470 static int enable_ust_event(struct ust_app *app,
1471 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1472 {
1473 int ret;
1474
1475 health_code_update();
1476
1477 pthread_mutex_lock(&app->sock_lock);
1478 ret = ustctl_enable(app->sock, ua_event->obj);
1479 pthread_mutex_unlock(&app->sock_lock);
1480 if (ret < 0) {
1481 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1482 ERR("UST app event %s enable failed for app (pid: %d) "
1483 "and session handle %d with ret %d",
1484 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1485 } else {
1486 /*
1487 * This is normal behavior, an application can die during the
1488 * creation process. Don't report an error so the execution can
1489 * continue normally.
1490 */
1491 ret = 0;
1492 DBG3("UST app enable event failed. Application is dead.");
1493 }
1494 goto error;
1495 }
1496
1497 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1498 ua_event->attr.name, app->pid);
1499
1500 error:
1501 health_code_update();
1502 return ret;
1503 }
1504
1505 /*
1506 * Send channel and stream buffer to application.
1507 *
1508 * Return 0 on success. On error, a negative value is returned.
1509 */
1510 static int send_channel_pid_to_ust(struct ust_app *app,
1511 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1512 {
1513 int ret;
1514 struct ust_app_stream *stream, *stmp;
1515
1516 assert(app);
1517 assert(ua_sess);
1518 assert(ua_chan);
1519
1520 health_code_update();
1521
1522 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1523 app->sock);
1524
1525 /* Send channel to the application. */
1526 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1527 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1528 ret = -ENOTCONN; /* Caused by app exiting. */
1529 goto error;
1530 } else if (ret < 0) {
1531 goto error;
1532 }
1533
1534 health_code_update();
1535
1536 /* Send all streams to application. */
1537 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1538 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1539 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1540 ret = -ENOTCONN; /* Caused by app exiting. */
1541 goto error;
1542 } else if (ret < 0) {
1543 goto error;
1544 }
1545 /* We don't need the stream anymore once sent to the tracer. */
1546 cds_list_del(&stream->list);
1547 delete_ust_app_stream(-1, stream, app);
1548 }
1549 /* Flag the channel that it is sent to the application. */
1550 ua_chan->is_sent = 1;
1551
1552 error:
1553 health_code_update();
1554 return ret;
1555 }
1556
1557 /*
1558 * Create the specified event onto the UST tracer for a UST session.
1559 *
1560 * Should be called with session mutex held.
1561 */
1562 static
1563 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1564 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1565 {
1566 int ret = 0;
1567
1568 health_code_update();
1569
1570 /* Create UST event on tracer */
1571 pthread_mutex_lock(&app->sock_lock);
1572 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1573 &ua_event->obj);
1574 pthread_mutex_unlock(&app->sock_lock);
1575 if (ret < 0) {
1576 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1577 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1578 ua_event->attr.name, app->pid, ret);
1579 } else {
1580 /*
1581 * This is normal behavior, an application can die during the
1582 * creation process. Don't report an error so the execution can
1583 * continue normally.
1584 */
1585 ret = 0;
1586 DBG3("UST app create event failed. Application is dead.");
1587 }
1588 goto error;
1589 }
1590
1591 ua_event->handle = ua_event->obj->handle;
1592
1593 DBG2("UST app event %s created successfully for pid:%d",
1594 ua_event->attr.name, app->pid);
1595
1596 health_code_update();
1597
1598 /* Set filter if one is present. */
1599 if (ua_event->filter) {
1600 ret = set_ust_event_filter(ua_event, app);
1601 if (ret < 0) {
1602 goto error;
1603 }
1604 }
1605
1606 /* Set exclusions for the event */
1607 if (ua_event->exclusion) {
1608 ret = set_ust_event_exclusion(ua_event, app);
1609 if (ret < 0) {
1610 goto error;
1611 }
1612 }
1613
1614 /* If event not enabled, disable it on the tracer */
1615 if (ua_event->enabled) {
1616 /*
1617 * We now need to explicitly enable the event, since it
1618 * is now disabled at creation.
1619 */
1620 ret = enable_ust_event(app, ua_sess, ua_event);
1621 if (ret < 0) {
1622 /*
1623 * If we hit an EPERM, something is wrong with our enable call. If
1624 * we get an EEXIST, there is a problem on the tracer side since we
1625 * just created it.
1626 */
1627 switch (ret) {
1628 case -LTTNG_UST_ERR_PERM:
1629 /* Code flow problem */
1630 assert(0);
1631 case -LTTNG_UST_ERR_EXIST:
1632 /* It's OK for our use case. */
1633 ret = 0;
1634 break;
1635 default:
1636 break;
1637 }
1638 goto error;
1639 }
1640 }
1641
1642 error:
1643 health_code_update();
1644 return ret;
1645 }
1646
1647 /*
1648 * Copy data between an UST app event and a LTT event.
1649 */
1650 static void shadow_copy_event(struct ust_app_event *ua_event,
1651 struct ltt_ust_event *uevent)
1652 {
1653 size_t exclusion_alloc_size;
1654
1655 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1656 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1657
1658 ua_event->enabled = uevent->enabled;
1659
1660 /* Copy event attributes */
1661 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1662
1663 /* Copy filter bytecode */
1664 if (uevent->filter) {
1665 ua_event->filter = copy_filter_bytecode(uevent->filter);
1666 /* Filter might be NULL here in case of ENONEM. */
1667 }
1668
1669 /* Copy exclusion data */
1670 if (uevent->exclusion) {
1671 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1672 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1673 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1674 if (ua_event->exclusion == NULL) {
1675 PERROR("malloc");
1676 } else {
1677 memcpy(ua_event->exclusion, uevent->exclusion,
1678 exclusion_alloc_size);
1679 }
1680 }
1681 }
1682
1683 /*
1684 * Copy data between an UST app channel and a LTT channel.
1685 */
1686 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1687 struct ltt_ust_channel *uchan)
1688 {
1689 struct lttng_ht_iter iter;
1690 struct ltt_ust_event *uevent;
1691 struct ltt_ust_context *uctx;
1692 struct ust_app_event *ua_event;
1693 struct ust_app_ctx *ua_ctx;
1694
1695 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1696
1697 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1698 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1699
1700 ua_chan->tracefile_size = uchan->tracefile_size;
1701 ua_chan->tracefile_count = uchan->tracefile_count;
1702
1703 /* Copy event attributes since the layout is different. */
1704 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1705 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1706 ua_chan->attr.overwrite = uchan->attr.overwrite;
1707 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1708 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1709 ua_chan->attr.output = uchan->attr.output;
1710 /*
1711 * Note that the attribute channel type is not set since the channel on the
1712 * tracing registry side does not have this information.
1713 */
1714
1715 ua_chan->enabled = uchan->enabled;
1716 ua_chan->tracing_channel_id = uchan->id;
1717
1718 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1719 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1720 if (ua_ctx == NULL) {
1721 continue;
1722 }
1723 lttng_ht_node_init_ulong(&ua_ctx->node,
1724 (unsigned long) ua_ctx->ctx.ctx);
1725 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1726 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1727 }
1728
1729 /* Copy all events from ltt ust channel to ust app channel */
1730 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1731 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1732 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1733 if (ua_event == NULL) {
1734 DBG2("UST event %s not found on shadow copy channel",
1735 uevent->attr.name);
1736 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1737 if (ua_event == NULL) {
1738 continue;
1739 }
1740 shadow_copy_event(ua_event, uevent);
1741 add_unique_ust_app_event(ua_chan, ua_event);
1742 }
1743 }
1744
1745 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1746 }
1747
1748 /*
1749 * Copy data between a UST app session and a regular LTT session.
1750 */
1751 static void shadow_copy_session(struct ust_app_session *ua_sess,
1752 struct ltt_ust_session *usess, struct ust_app *app)
1753 {
1754 struct lttng_ht_node_str *ua_chan_node;
1755 struct lttng_ht_iter iter;
1756 struct ltt_ust_channel *uchan;
1757 struct ust_app_channel *ua_chan;
1758 time_t rawtime;
1759 struct tm *timeinfo;
1760 char datetime[16];
1761 int ret;
1762 char tmp_shm_path[PATH_MAX];
1763
1764 /* Get date and time for unique app path */
1765 time(&rawtime);
1766 timeinfo = localtime(&rawtime);
1767 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1768
1769 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1770
1771 ua_sess->tracing_id = usess->id;
1772 ua_sess->id = get_next_session_id();
1773 ua_sess->uid = app->uid;
1774 ua_sess->gid = app->gid;
1775 ua_sess->euid = usess->uid;
1776 ua_sess->egid = usess->gid;
1777 ua_sess->buffer_type = usess->buffer_type;
1778 ua_sess->bits_per_long = app->bits_per_long;
1779
1780 /* There is only one consumer object per session possible. */
1781 consumer_output_get(usess->consumer);
1782 ua_sess->consumer = usess->consumer;
1783
1784 ua_sess->output_traces = usess->output_traces;
1785 ua_sess->live_timer_interval = usess->live_timer_interval;
1786 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1787 &usess->metadata_attr);
1788
1789 switch (ua_sess->buffer_type) {
1790 case LTTNG_BUFFER_PER_PID:
1791 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1792 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1793 datetime);
1794 break;
1795 case LTTNG_BUFFER_PER_UID:
1796 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1797 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1798 break;
1799 default:
1800 assert(0);
1801 goto error;
1802 }
1803 if (ret < 0) {
1804 PERROR("asprintf UST shadow copy session");
1805 assert(0);
1806 goto error;
1807 }
1808
1809 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1810 sizeof(ua_sess->root_shm_path));
1811 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1812 strncpy(ua_sess->shm_path, usess->shm_path,
1813 sizeof(ua_sess->shm_path));
1814 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1815 if (ua_sess->shm_path[0]) {
1816 switch (ua_sess->buffer_type) {
1817 case LTTNG_BUFFER_PER_PID:
1818 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1819 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1820 app->name, app->pid, datetime);
1821 break;
1822 case LTTNG_BUFFER_PER_UID:
1823 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1824 DEFAULT_UST_TRACE_UID_PATH,
1825 app->uid, app->bits_per_long);
1826 break;
1827 default:
1828 assert(0);
1829 goto error;
1830 }
1831 if (ret < 0) {
1832 PERROR("sprintf UST shadow copy session");
1833 assert(0);
1834 goto error;
1835 }
1836 strncat(ua_sess->shm_path, tmp_shm_path,
1837 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1838 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1839 }
1840
1841 /* Iterate over all channels in global domain. */
1842 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1843 uchan, node.node) {
1844 struct lttng_ht_iter uiter;
1845
1846 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1847 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1848 if (ua_chan_node != NULL) {
1849 /* Session exist. Contiuing. */
1850 continue;
1851 }
1852
1853 DBG2("Channel %s not found on shadow session copy, creating it",
1854 uchan->name);
1855 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1856 if (ua_chan == NULL) {
1857 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1858 continue;
1859 }
1860 shadow_copy_channel(ua_chan, uchan);
1861 /*
1862 * The concept of metadata channel does not exist on the tracing
1863 * registry side of the session daemon so this can only be a per CPU
1864 * channel and not metadata.
1865 */
1866 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1867
1868 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1869 }
1870 return;
1871
1872 error:
1873 consumer_output_put(ua_sess->consumer);
1874 }
1875
1876 /*
1877 * Lookup sesison wrapper.
1878 */
1879 static
1880 void __lookup_session_by_app(struct ltt_ust_session *usess,
1881 struct ust_app *app, struct lttng_ht_iter *iter)
1882 {
1883 /* Get right UST app session from app */
1884 lttng_ht_lookup(app->sessions, &usess->id, iter);
1885 }
1886
1887 /*
1888 * Return ust app session from the app session hashtable using the UST session
1889 * id.
1890 */
1891 static struct ust_app_session *lookup_session_by_app(
1892 struct ltt_ust_session *usess, struct ust_app *app)
1893 {
1894 struct lttng_ht_iter iter;
1895 struct lttng_ht_node_u64 *node;
1896
1897 __lookup_session_by_app(usess, app, &iter);
1898 node = lttng_ht_iter_get_node_u64(&iter);
1899 if (node == NULL) {
1900 goto error;
1901 }
1902
1903 return caa_container_of(node, struct ust_app_session, node);
1904
1905 error:
1906 return NULL;
1907 }
1908
1909 /*
1910 * Setup buffer registry per PID for the given session and application. If none
1911 * is found, a new one is created, added to the global registry and
1912 * initialized. If regp is valid, it's set with the newly created object.
1913 *
1914 * Return 0 on success or else a negative value.
1915 */
1916 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1917 struct ust_app *app, struct buffer_reg_pid **regp)
1918 {
1919 int ret = 0;
1920 struct buffer_reg_pid *reg_pid;
1921
1922 assert(ua_sess);
1923 assert(app);
1924
1925 rcu_read_lock();
1926
1927 reg_pid = buffer_reg_pid_find(ua_sess->id);
1928 if (!reg_pid) {
1929 /*
1930 * This is the create channel path meaning that if there is NO
1931 * registry available, we have to create one for this session.
1932 */
1933 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1934 ua_sess->root_shm_path, ua_sess->shm_path);
1935 if (ret < 0) {
1936 goto error;
1937 }
1938 } else {
1939 goto end;
1940 }
1941
1942 /* Initialize registry. */
1943 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1944 app->bits_per_long, app->uint8_t_alignment,
1945 app->uint16_t_alignment, app->uint32_t_alignment,
1946 app->uint64_t_alignment, app->long_alignment,
1947 app->byte_order, app->version.major,
1948 app->version.minor, reg_pid->root_shm_path,
1949 reg_pid->shm_path,
1950 ua_sess->euid, ua_sess->egid);
1951 if (ret < 0) {
1952 /*
1953 * reg_pid->registry->reg.ust is NULL upon error, so we need to
1954 * destroy the buffer registry, because it is always expected
1955 * that if the buffer registry can be found, its ust registry is
1956 * non-NULL.
1957 */
1958 buffer_reg_pid_destroy(reg_pid);
1959 goto error;
1960 }
1961
1962 buffer_reg_pid_add(reg_pid);
1963
1964 DBG3("UST app buffer registry per PID created successfully");
1965
1966 end:
1967 if (regp) {
1968 *regp = reg_pid;
1969 }
1970 error:
1971 rcu_read_unlock();
1972 return ret;
1973 }
1974
1975 /*
1976 * Setup buffer registry per UID for the given session and application. If none
1977 * is found, a new one is created, added to the global registry and
1978 * initialized. If regp is valid, it's set with the newly created object.
1979 *
1980 * Return 0 on success or else a negative value.
1981 */
1982 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1983 struct ust_app_session *ua_sess,
1984 struct ust_app *app, struct buffer_reg_uid **regp)
1985 {
1986 int ret = 0;
1987 struct buffer_reg_uid *reg_uid;
1988
1989 assert(usess);
1990 assert(app);
1991
1992 rcu_read_lock();
1993
1994 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1995 if (!reg_uid) {
1996 /*
1997 * This is the create channel path meaning that if there is NO
1998 * registry available, we have to create one for this session.
1999 */
2000 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2001 LTTNG_DOMAIN_UST, &reg_uid,
2002 ua_sess->root_shm_path, ua_sess->shm_path);
2003 if (ret < 0) {
2004 goto error;
2005 }
2006 } else {
2007 goto end;
2008 }
2009
2010 /* Initialize registry. */
2011 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2012 app->bits_per_long, app->uint8_t_alignment,
2013 app->uint16_t_alignment, app->uint32_t_alignment,
2014 app->uint64_t_alignment, app->long_alignment,
2015 app->byte_order, app->version.major,
2016 app->version.minor, reg_uid->root_shm_path,
2017 reg_uid->shm_path, usess->uid, usess->gid);
2018 if (ret < 0) {
2019 /*
2020 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2021 * destroy the buffer registry, because it is always expected
2022 * that if the buffer registry can be found, its ust registry is
2023 * non-NULL.
2024 */
2025 buffer_reg_uid_destroy(reg_uid, NULL);
2026 goto error;
2027 }
2028 /* Add node to teardown list of the session. */
2029 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2030
2031 buffer_reg_uid_add(reg_uid);
2032
2033 DBG3("UST app buffer registry per UID created successfully");
2034 end:
2035 if (regp) {
2036 *regp = reg_uid;
2037 }
2038 error:
2039 rcu_read_unlock();
2040 return ret;
2041 }
2042
2043 /*
2044 * Create a session on the tracer side for the given app.
2045 *
2046 * On success, ua_sess_ptr is populated with the session pointer or else left
2047 * untouched. If the session was created, is_created is set to 1. On error,
2048 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2049 * be NULL.
2050 *
2051 * Returns 0 on success or else a negative code which is either -ENOMEM or
2052 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2053 */
2054 static int create_ust_app_session(struct ltt_ust_session *usess,
2055 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2056 int *is_created)
2057 {
2058 int ret, created = 0;
2059 struct ust_app_session *ua_sess;
2060
2061 assert(usess);
2062 assert(app);
2063 assert(ua_sess_ptr);
2064
2065 health_code_update();
2066
2067 ua_sess = lookup_session_by_app(usess, app);
2068 if (ua_sess == NULL) {
2069 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2070 app->pid, usess->id);
2071 ua_sess = alloc_ust_app_session(app);
2072 if (ua_sess == NULL) {
2073 /* Only malloc can failed so something is really wrong */
2074 ret = -ENOMEM;
2075 goto error;
2076 }
2077 shadow_copy_session(ua_sess, usess, app);
2078 created = 1;
2079 }
2080
2081 switch (usess->buffer_type) {
2082 case LTTNG_BUFFER_PER_PID:
2083 /* Init local registry. */
2084 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2085 if (ret < 0) {
2086 delete_ust_app_session(-1, ua_sess, app);
2087 goto error;
2088 }
2089 break;
2090 case LTTNG_BUFFER_PER_UID:
2091 /* Look for a global registry. If none exists, create one. */
2092 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2093 if (ret < 0) {
2094 delete_ust_app_session(-1, ua_sess, app);
2095 goto error;
2096 }
2097 break;
2098 default:
2099 assert(0);
2100 ret = -EINVAL;
2101 goto error;
2102 }
2103
2104 health_code_update();
2105
2106 if (ua_sess->handle == -1) {
2107 pthread_mutex_lock(&app->sock_lock);
2108 ret = ustctl_create_session(app->sock);
2109 pthread_mutex_unlock(&app->sock_lock);
2110 if (ret < 0) {
2111 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2112 ERR("Creating session for app pid %d with ret %d",
2113 app->pid, ret);
2114 } else {
2115 DBG("UST app creating session failed. Application is dead");
2116 /*
2117 * This is normal behavior, an application can die during the
2118 * creation process. Don't report an error so the execution can
2119 * continue normally. This will get flagged ENOTCONN and the
2120 * caller will handle it.
2121 */
2122 ret = 0;
2123 }
2124 delete_ust_app_session(-1, ua_sess, app);
2125 if (ret != -ENOMEM) {
2126 /*
2127 * Tracer is probably gone or got an internal error so let's
2128 * behave like it will soon unregister or not usable.
2129 */
2130 ret = -ENOTCONN;
2131 }
2132 goto error;
2133 }
2134
2135 ua_sess->handle = ret;
2136
2137 /* Add ust app session to app's HT */
2138 lttng_ht_node_init_u64(&ua_sess->node,
2139 ua_sess->tracing_id);
2140 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2141
2142 DBG2("UST app session created successfully with handle %d", ret);
2143 }
2144
2145 *ua_sess_ptr = ua_sess;
2146 if (is_created) {
2147 *is_created = created;
2148 }
2149
2150 /* Everything went well. */
2151 ret = 0;
2152
2153 error:
2154 health_code_update();
2155 return ret;
2156 }
2157
2158 /*
2159 * Match function for a hash table lookup of ust_app_ctx.
2160 *
2161 * It matches an ust app context based on the context type and, in the case
2162 * of perf counters, their name.
2163 */
2164 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2165 {
2166 struct ust_app_ctx *ctx;
2167 const struct lttng_ust_context *key;
2168
2169 assert(node);
2170 assert(_key);
2171
2172 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2173 key = _key;
2174
2175 /* Context type */
2176 if (ctx->ctx.ctx != key->ctx) {
2177 goto no_match;
2178 }
2179
2180 /* Check the name in the case of perf thread counters. */
2181 if (key->ctx == LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER) {
2182 if (strncmp(key->u.perf_counter.name,
2183 ctx->ctx.u.perf_counter.name,
2184 sizeof(key->u.perf_counter.name))) {
2185 goto no_match;
2186 }
2187 }
2188
2189 /* Match. */
2190 return 1;
2191
2192 no_match:
2193 return 0;
2194 }
2195
2196 /*
2197 * Lookup for an ust app context from an lttng_ust_context.
2198 *
2199 * Must be called while holding RCU read side lock.
2200 * Return an ust_app_ctx object or NULL on error.
2201 */
2202 static
2203 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2204 struct lttng_ust_context *uctx)
2205 {
2206 struct lttng_ht_iter iter;
2207 struct lttng_ht_node_ulong *node;
2208 struct ust_app_ctx *app_ctx = NULL;
2209
2210 assert(uctx);
2211 assert(ht);
2212
2213 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2214 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2215 ht_match_ust_app_ctx, uctx, &iter.iter);
2216 node = lttng_ht_iter_get_node_ulong(&iter);
2217 if (!node) {
2218 goto end;
2219 }
2220
2221 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2222
2223 end:
2224 return app_ctx;
2225 }
2226
2227 /*
2228 * Create a context for the channel on the tracer.
2229 *
2230 * Called with UST app session lock held and a RCU read side lock.
2231 */
2232 static
2233 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
2234 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
2235 struct ust_app *app)
2236 {
2237 int ret = 0;
2238 struct ust_app_ctx *ua_ctx;
2239
2240 DBG2("UST app adding context to channel %s", ua_chan->name);
2241
2242 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2243 if (ua_ctx) {
2244 ret = -EEXIST;
2245 goto error;
2246 }
2247
2248 ua_ctx = alloc_ust_app_ctx(uctx);
2249 if (ua_ctx == NULL) {
2250 /* malloc failed */
2251 ret = -1;
2252 goto error;
2253 }
2254
2255 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2256 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2257 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2258
2259 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2260 if (ret < 0) {
2261 goto error;
2262 }
2263
2264 error:
2265 return ret;
2266 }
2267
2268 /*
2269 * Enable on the tracer side a ust app event for the session and channel.
2270 *
2271 * Called with UST app session lock held.
2272 */
2273 static
2274 int enable_ust_app_event(struct ust_app_session *ua_sess,
2275 struct ust_app_event *ua_event, struct ust_app *app)
2276 {
2277 int ret;
2278
2279 ret = enable_ust_event(app, ua_sess, ua_event);
2280 if (ret < 0) {
2281 goto error;
2282 }
2283
2284 ua_event->enabled = 1;
2285
2286 error:
2287 return ret;
2288 }
2289
2290 /*
2291 * Disable on the tracer side a ust app event for the session and channel.
2292 */
2293 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2294 struct ust_app_event *ua_event, struct ust_app *app)
2295 {
2296 int ret;
2297
2298 ret = disable_ust_event(app, ua_sess, ua_event);
2299 if (ret < 0) {
2300 goto error;
2301 }
2302
2303 ua_event->enabled = 0;
2304
2305 error:
2306 return ret;
2307 }
2308
2309 /*
2310 * Lookup ust app channel for session and disable it on the tracer side.
2311 */
2312 static
2313 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2314 struct ust_app_channel *ua_chan, struct ust_app *app)
2315 {
2316 int ret;
2317
2318 ret = disable_ust_channel(app, ua_sess, ua_chan);
2319 if (ret < 0) {
2320 goto error;
2321 }
2322
2323 ua_chan->enabled = 0;
2324
2325 error:
2326 return ret;
2327 }
2328
2329 /*
2330 * Lookup ust app channel for session and enable it on the tracer side. This
2331 * MUST be called with a RCU read side lock acquired.
2332 */
2333 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2334 struct ltt_ust_channel *uchan, struct ust_app *app)
2335 {
2336 int ret = 0;
2337 struct lttng_ht_iter iter;
2338 struct lttng_ht_node_str *ua_chan_node;
2339 struct ust_app_channel *ua_chan;
2340
2341 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2342 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2343 if (ua_chan_node == NULL) {
2344 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2345 uchan->name, ua_sess->tracing_id);
2346 goto error;
2347 }
2348
2349 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2350
2351 ret = enable_ust_channel(app, ua_sess, ua_chan);
2352 if (ret < 0) {
2353 goto error;
2354 }
2355
2356 error:
2357 return ret;
2358 }
2359
2360 /*
2361 * Ask the consumer to create a channel and get it if successful.
2362 *
2363 * Return 0 on success or else a negative value.
2364 */
2365 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2366 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2367 int bitness, struct ust_registry_session *registry)
2368 {
2369 int ret;
2370 unsigned int nb_fd = 0;
2371 struct consumer_socket *socket;
2372
2373 assert(usess);
2374 assert(ua_sess);
2375 assert(ua_chan);
2376 assert(registry);
2377
2378 rcu_read_lock();
2379 health_code_update();
2380
2381 /* Get the right consumer socket for the application. */
2382 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2383 if (!socket) {
2384 ret = -EINVAL;
2385 goto error;
2386 }
2387
2388 health_code_update();
2389
2390 /* Need one fd for the channel. */
2391 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2392 if (ret < 0) {
2393 ERR("Exhausted number of available FD upon create channel");
2394 goto error;
2395 }
2396
2397 /*
2398 * Ask consumer to create channel. The consumer will return the number of
2399 * stream we have to expect.
2400 */
2401 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2402 registry);
2403 if (ret < 0) {
2404 goto error_ask;
2405 }
2406
2407 /*
2408 * Compute the number of fd needed before receiving them. It must be 2 per
2409 * stream (2 being the default value here).
2410 */
2411 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2412
2413 /* Reserve the amount of file descriptor we need. */
2414 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2415 if (ret < 0) {
2416 ERR("Exhausted number of available FD upon create channel");
2417 goto error_fd_get_stream;
2418 }
2419
2420 health_code_update();
2421
2422 /*
2423 * Now get the channel from the consumer. This call wil populate the stream
2424 * list of that channel and set the ust objects.
2425 */
2426 if (usess->consumer->enabled) {
2427 ret = ust_consumer_get_channel(socket, ua_chan);
2428 if (ret < 0) {
2429 goto error_destroy;
2430 }
2431 }
2432
2433 rcu_read_unlock();
2434 return 0;
2435
2436 error_destroy:
2437 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2438 error_fd_get_stream:
2439 /*
2440 * Initiate a destroy channel on the consumer since we had an error
2441 * handling it on our side. The return value is of no importance since we
2442 * already have a ret value set by the previous error that we need to
2443 * return.
2444 */
2445 (void) ust_consumer_destroy_channel(socket, ua_chan);
2446 error_ask:
2447 lttng_fd_put(LTTNG_FD_APPS, 1);
2448 error:
2449 health_code_update();
2450 rcu_read_unlock();
2451 return ret;
2452 }
2453
2454 /*
2455 * Duplicate the ust data object of the ust app stream and save it in the
2456 * buffer registry stream.
2457 *
2458 * Return 0 on success or else a negative value.
2459 */
2460 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2461 struct ust_app_stream *stream)
2462 {
2463 int ret;
2464
2465 assert(reg_stream);
2466 assert(stream);
2467
2468 /* Reserve the amount of file descriptor we need. */
2469 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2470 if (ret < 0) {
2471 ERR("Exhausted number of available FD upon duplicate stream");
2472 goto error;
2473 }
2474
2475 /* Duplicate object for stream once the original is in the registry. */
2476 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2477 reg_stream->obj.ust);
2478 if (ret < 0) {
2479 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2480 reg_stream->obj.ust, stream->obj, ret);
2481 lttng_fd_put(LTTNG_FD_APPS, 2);
2482 goto error;
2483 }
2484 stream->handle = stream->obj->handle;
2485
2486 error:
2487 return ret;
2488 }
2489
2490 /*
2491 * Duplicate the ust data object of the ust app. channel and save it in the
2492 * buffer registry channel.
2493 *
2494 * Return 0 on success or else a negative value.
2495 */
2496 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2497 struct ust_app_channel *ua_chan)
2498 {
2499 int ret;
2500
2501 assert(reg_chan);
2502 assert(ua_chan);
2503
2504 /* Need two fds for the channel. */
2505 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2506 if (ret < 0) {
2507 ERR("Exhausted number of available FD upon duplicate channel");
2508 goto error_fd_get;
2509 }
2510
2511 /* Duplicate object for stream once the original is in the registry. */
2512 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2513 if (ret < 0) {
2514 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2515 reg_chan->obj.ust, ua_chan->obj, ret);
2516 goto error;
2517 }
2518 ua_chan->handle = ua_chan->obj->handle;
2519
2520 return 0;
2521
2522 error:
2523 lttng_fd_put(LTTNG_FD_APPS, 1);
2524 error_fd_get:
2525 return ret;
2526 }
2527
2528 /*
2529 * For a given channel buffer registry, setup all streams of the given ust
2530 * application channel.
2531 *
2532 * Return 0 on success or else a negative value.
2533 */
2534 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2535 struct ust_app_channel *ua_chan,
2536 struct ust_app *app)
2537 {
2538 int ret = 0;
2539 struct ust_app_stream *stream, *stmp;
2540
2541 assert(reg_chan);
2542 assert(ua_chan);
2543
2544 DBG2("UST app setup buffer registry stream");
2545
2546 /* Send all streams to application. */
2547 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2548 struct buffer_reg_stream *reg_stream;
2549
2550 ret = buffer_reg_stream_create(&reg_stream);
2551 if (ret < 0) {
2552 goto error;
2553 }
2554
2555 /*
2556 * Keep original pointer and nullify it in the stream so the delete
2557 * stream call does not release the object.
2558 */
2559 reg_stream->obj.ust = stream->obj;
2560 stream->obj = NULL;
2561 buffer_reg_stream_add(reg_stream, reg_chan);
2562
2563 /* We don't need the streams anymore. */
2564 cds_list_del(&stream->list);
2565 delete_ust_app_stream(-1, stream, app);
2566 }
2567
2568 error:
2569 return ret;
2570 }
2571
2572 /*
2573 * Create a buffer registry channel for the given session registry and
2574 * application channel object. If regp pointer is valid, it's set with the
2575 * created object. Important, the created object is NOT added to the session
2576 * registry hash table.
2577 *
2578 * Return 0 on success else a negative value.
2579 */
2580 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2581 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2582 {
2583 int ret;
2584 struct buffer_reg_channel *reg_chan = NULL;
2585
2586 assert(reg_sess);
2587 assert(ua_chan);
2588
2589 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2590
2591 /* Create buffer registry channel. */
2592 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2593 if (ret < 0) {
2594 goto error_create;
2595 }
2596 assert(reg_chan);
2597 reg_chan->consumer_key = ua_chan->key;
2598 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2599 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2600
2601 /* Create and add a channel registry to session. */
2602 ret = ust_registry_channel_add(reg_sess->reg.ust,
2603 ua_chan->tracing_channel_id);
2604 if (ret < 0) {
2605 goto error;
2606 }
2607 buffer_reg_channel_add(reg_sess, reg_chan);
2608
2609 if (regp) {
2610 *regp = reg_chan;
2611 }
2612
2613 return 0;
2614
2615 error:
2616 /* Safe because the registry channel object was not added to any HT. */
2617 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2618 error_create:
2619 return ret;
2620 }
2621
2622 /*
2623 * Setup buffer registry channel for the given session registry and application
2624 * channel object. If regp pointer is valid, it's set with the created object.
2625 *
2626 * Return 0 on success else a negative value.
2627 */
2628 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2629 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2630 struct ust_app *app)
2631 {
2632 int ret;
2633
2634 assert(reg_sess);
2635 assert(reg_chan);
2636 assert(ua_chan);
2637 assert(ua_chan->obj);
2638
2639 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2640
2641 /* Setup all streams for the registry. */
2642 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2643 if (ret < 0) {
2644 goto error;
2645 }
2646
2647 reg_chan->obj.ust = ua_chan->obj;
2648 ua_chan->obj = NULL;
2649
2650 return 0;
2651
2652 error:
2653 buffer_reg_channel_remove(reg_sess, reg_chan);
2654 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2655 return ret;
2656 }
2657
2658 /*
2659 * Send buffer registry channel to the application.
2660 *
2661 * Return 0 on success else a negative value.
2662 */
2663 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2664 struct ust_app *app, struct ust_app_session *ua_sess,
2665 struct ust_app_channel *ua_chan)
2666 {
2667 int ret;
2668 struct buffer_reg_stream *reg_stream;
2669
2670 assert(reg_chan);
2671 assert(app);
2672 assert(ua_sess);
2673 assert(ua_chan);
2674
2675 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2676
2677 ret = duplicate_channel_object(reg_chan, ua_chan);
2678 if (ret < 0) {
2679 goto error;
2680 }
2681
2682 /* Send channel to the application. */
2683 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2684 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2685 ret = -ENOTCONN; /* Caused by app exiting. */
2686 goto error;
2687 } else if (ret < 0) {
2688 goto error;
2689 }
2690
2691 health_code_update();
2692
2693 /* Send all streams to application. */
2694 pthread_mutex_lock(&reg_chan->stream_list_lock);
2695 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2696 struct ust_app_stream stream;
2697
2698 ret = duplicate_stream_object(reg_stream, &stream);
2699 if (ret < 0) {
2700 goto error_stream_unlock;
2701 }
2702
2703 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2704 if (ret < 0) {
2705 (void) release_ust_app_stream(-1, &stream, app);
2706 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2707 ret = -ENOTCONN; /* Caused by app exiting. */
2708 goto error_stream_unlock;
2709 } else if (ret < 0) {
2710 goto error_stream_unlock;
2711 }
2712 goto error_stream_unlock;
2713 }
2714
2715 /*
2716 * The return value is not important here. This function will output an
2717 * error if needed.
2718 */
2719 (void) release_ust_app_stream(-1, &stream, app);
2720 }
2721 ua_chan->is_sent = 1;
2722
2723 error_stream_unlock:
2724 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2725 error:
2726 return ret;
2727 }
2728
2729 /*
2730 * Create and send to the application the created buffers with per UID buffers.
2731 *
2732 * Return 0 on success else a negative value.
2733 */
2734 static int create_channel_per_uid(struct ust_app *app,
2735 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2736 struct ust_app_channel *ua_chan)
2737 {
2738 int ret;
2739 struct buffer_reg_uid *reg_uid;
2740 struct buffer_reg_channel *reg_chan;
2741
2742 assert(app);
2743 assert(usess);
2744 assert(ua_sess);
2745 assert(ua_chan);
2746
2747 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2748
2749 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2750 /*
2751 * The session creation handles the creation of this global registry
2752 * object. If none can be find, there is a code flow problem or a
2753 * teardown race.
2754 */
2755 assert(reg_uid);
2756
2757 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2758 reg_uid);
2759 if (!reg_chan) {
2760 /* Create the buffer registry channel object. */
2761 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2762 if (ret < 0) {
2763 ERR("Error creating the UST channel \"%s\" registry instance",
2764 ua_chan->name);
2765 goto error;
2766 }
2767 assert(reg_chan);
2768
2769 /*
2770 * Create the buffers on the consumer side. This call populates the
2771 * ust app channel object with all streams and data object.
2772 */
2773 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2774 app->bits_per_long, reg_uid->registry->reg.ust);
2775 if (ret < 0) {
2776 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2777 ua_chan->name);
2778
2779 /*
2780 * Let's remove the previously created buffer registry channel so
2781 * it's not visible anymore in the session registry.
2782 */
2783 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2784 ua_chan->tracing_channel_id);
2785 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2786 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2787 goto error;
2788 }
2789
2790 /*
2791 * Setup the streams and add it to the session registry.
2792 */
2793 ret = setup_buffer_reg_channel(reg_uid->registry,
2794 ua_chan, reg_chan, app);
2795 if (ret < 0) {
2796 ERR("Error setting up UST channel \"%s\"",
2797 ua_chan->name);
2798 goto error;
2799 }
2800
2801 }
2802
2803 /* Send buffers to the application. */
2804 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2805 if (ret < 0) {
2806 if (ret != -ENOTCONN) {
2807 ERR("Error sending channel to application");
2808 }
2809 goto error;
2810 }
2811
2812 error:
2813 return ret;
2814 }
2815
2816 /*
2817 * Create and send to the application the created buffers with per PID buffers.
2818 *
2819 * Return 0 on success else a negative value.
2820 */
2821 static int create_channel_per_pid(struct ust_app *app,
2822 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2823 struct ust_app_channel *ua_chan)
2824 {
2825 int ret;
2826 struct ust_registry_session *registry;
2827
2828 assert(app);
2829 assert(usess);
2830 assert(ua_sess);
2831 assert(ua_chan);
2832
2833 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2834
2835 rcu_read_lock();
2836
2837 registry = get_session_registry(ua_sess);
2838 assert(registry);
2839
2840 /* Create and add a new channel registry to session. */
2841 ret = ust_registry_channel_add(registry, ua_chan->key);
2842 if (ret < 0) {
2843 ERR("Error creating the UST channel \"%s\" registry instance",
2844 ua_chan->name);
2845 goto error;
2846 }
2847
2848 /* Create and get channel on the consumer side. */
2849 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2850 app->bits_per_long, registry);
2851 if (ret < 0) {
2852 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2853 ua_chan->name);
2854 goto error;
2855 }
2856
2857 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2858 if (ret < 0) {
2859 if (ret != -ENOTCONN) {
2860 ERR("Error sending channel to application");
2861 }
2862 goto error;
2863 }
2864
2865 error:
2866 rcu_read_unlock();
2867 return ret;
2868 }
2869
2870 /*
2871 * From an already allocated ust app channel, create the channel buffers if
2872 * need and send it to the application. This MUST be called with a RCU read
2873 * side lock acquired.
2874 *
2875 * Return 0 on success or else a negative value. Returns -ENOTCONN if
2876 * the application exited concurrently.
2877 */
2878 static int do_create_channel(struct ust_app *app,
2879 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2880 struct ust_app_channel *ua_chan)
2881 {
2882 int ret;
2883
2884 assert(app);
2885 assert(usess);
2886 assert(ua_sess);
2887 assert(ua_chan);
2888
2889 /* Handle buffer type before sending the channel to the application. */
2890 switch (usess->buffer_type) {
2891 case LTTNG_BUFFER_PER_UID:
2892 {
2893 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2894 if (ret < 0) {
2895 goto error;
2896 }
2897 break;
2898 }
2899 case LTTNG_BUFFER_PER_PID:
2900 {
2901 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2902 if (ret < 0) {
2903 goto error;
2904 }
2905 break;
2906 }
2907 default:
2908 assert(0);
2909 ret = -EINVAL;
2910 goto error;
2911 }
2912
2913 /* Initialize ust objd object using the received handle and add it. */
2914 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2915 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2916
2917 /* If channel is not enabled, disable it on the tracer */
2918 if (!ua_chan->enabled) {
2919 ret = disable_ust_channel(app, ua_sess, ua_chan);
2920 if (ret < 0) {
2921 goto error;
2922 }
2923 }
2924
2925 error:
2926 return ret;
2927 }
2928
2929 /*
2930 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2931 * newly created channel if not NULL.
2932 *
2933 * Called with UST app session lock and RCU read-side lock held.
2934 *
2935 * Return 0 on success or else a negative value. Returns -ENOTCONN if
2936 * the application exited concurrently.
2937 */
2938 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2939 struct ltt_ust_channel *uchan, struct ust_app *app,
2940 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2941 struct ust_app_channel **ua_chanp)
2942 {
2943 int ret = 0;
2944 struct lttng_ht_iter iter;
2945 struct lttng_ht_node_str *ua_chan_node;
2946 struct ust_app_channel *ua_chan;
2947
2948 /* Lookup channel in the ust app session */
2949 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2950 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2951 if (ua_chan_node != NULL) {
2952 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2953 goto end;
2954 }
2955
2956 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2957 if (ua_chan == NULL) {
2958 /* Only malloc can fail here */
2959 ret = -ENOMEM;
2960 goto error_alloc;
2961 }
2962 shadow_copy_channel(ua_chan, uchan);
2963
2964 /* Set channel type. */
2965 ua_chan->attr.type = type;
2966
2967 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2968 if (ret < 0) {
2969 goto error;
2970 }
2971
2972 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2973 app->pid);
2974
2975 /* Only add the channel if successful on the tracer side. */
2976 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2977
2978 end:
2979 if (ua_chanp) {
2980 *ua_chanp = ua_chan;
2981 }
2982
2983 /* Everything went well. */
2984 return 0;
2985
2986 error:
2987 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2988 error_alloc:
2989 return ret;
2990 }
2991
2992 /*
2993 * Create UST app event and create it on the tracer side.
2994 *
2995 * Called with ust app session mutex held.
2996 */
2997 static
2998 int create_ust_app_event(struct ust_app_session *ua_sess,
2999 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3000 struct ust_app *app)
3001 {
3002 int ret = 0;
3003 struct ust_app_event *ua_event;
3004
3005 /* Get event node */
3006 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3007 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3008 if (ua_event != NULL) {
3009 ret = -EEXIST;
3010 goto end;
3011 }
3012
3013 /* Does not exist so create one */
3014 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3015 if (ua_event == NULL) {
3016 /* Only malloc can failed so something is really wrong */
3017 ret = -ENOMEM;
3018 goto end;
3019 }
3020 shadow_copy_event(ua_event, uevent);
3021
3022 /* Create it on the tracer side */
3023 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3024 if (ret < 0) {
3025 /* Not found previously means that it does not exist on the tracer */
3026 assert(ret != -LTTNG_UST_ERR_EXIST);
3027 goto error;
3028 }
3029
3030 add_unique_ust_app_event(ua_chan, ua_event);
3031
3032 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3033 app->pid);
3034
3035 end:
3036 return ret;
3037
3038 error:
3039 /* Valid. Calling here is already in a read side lock */
3040 delete_ust_app_event(-1, ua_event, app);
3041 return ret;
3042 }
3043
3044 /*
3045 * Create UST metadata and open it on the tracer side.
3046 *
3047 * Called with UST app session lock held and RCU read side lock.
3048 */
3049 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3050 struct ust_app *app, struct consumer_output *consumer)
3051 {
3052 int ret = 0;
3053 struct ust_app_channel *metadata;
3054 struct consumer_socket *socket;
3055 struct ust_registry_session *registry;
3056
3057 assert(ua_sess);
3058 assert(app);
3059 assert(consumer);
3060
3061 registry = get_session_registry(ua_sess);
3062 assert(registry);
3063
3064 pthread_mutex_lock(&registry->lock);
3065
3066 /* Metadata already exists for this registry or it was closed previously */
3067 if (registry->metadata_key || registry->metadata_closed) {
3068 ret = 0;
3069 goto error;
3070 }
3071
3072 /* Allocate UST metadata */
3073 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3074 if (!metadata) {
3075 /* malloc() failed */
3076 ret = -ENOMEM;
3077 goto error;
3078 }
3079
3080 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3081
3082 /* Need one fd for the channel. */
3083 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3084 if (ret < 0) {
3085 ERR("Exhausted number of available FD upon create metadata");
3086 goto error;
3087 }
3088
3089 /* Get the right consumer socket for the application. */
3090 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3091 if (!socket) {
3092 ret = -EINVAL;
3093 goto error_consumer;
3094 }
3095
3096 /*
3097 * Keep metadata key so we can identify it on the consumer side. Assign it
3098 * to the registry *before* we ask the consumer so we avoid the race of the
3099 * consumer requesting the metadata and the ask_channel call on our side
3100 * did not returned yet.
3101 */
3102 registry->metadata_key = metadata->key;
3103
3104 /*
3105 * Ask the metadata channel creation to the consumer. The metadata object
3106 * will be created by the consumer and kept their. However, the stream is
3107 * never added or monitored until we do a first push metadata to the
3108 * consumer.
3109 */
3110 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3111 registry);
3112 if (ret < 0) {
3113 /* Nullify the metadata key so we don't try to close it later on. */
3114 registry->metadata_key = 0;
3115 goto error_consumer;
3116 }
3117
3118 /*
3119 * The setup command will make the metadata stream be sent to the relayd,
3120 * if applicable, and the thread managing the metadatas. This is important
3121 * because after this point, if an error occurs, the only way the stream
3122 * can be deleted is to be monitored in the consumer.
3123 */
3124 ret = consumer_setup_metadata(socket, metadata->key);
3125 if (ret < 0) {
3126 /* Nullify the metadata key so we don't try to close it later on. */
3127 registry->metadata_key = 0;
3128 goto error_consumer;
3129 }
3130
3131 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3132 metadata->key, app->pid);
3133
3134 error_consumer:
3135 lttng_fd_put(LTTNG_FD_APPS, 1);
3136 delete_ust_app_channel(-1, metadata, app);
3137 error:
3138 pthread_mutex_unlock(&registry->lock);
3139 return ret;
3140 }
3141
3142 /*
3143 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3144 * acquired before calling this function.
3145 */
3146 struct ust_app *ust_app_find_by_pid(pid_t pid)
3147 {
3148 struct ust_app *app = NULL;
3149 struct lttng_ht_node_ulong *node;
3150 struct lttng_ht_iter iter;
3151
3152 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3153 node = lttng_ht_iter_get_node_ulong(&iter);
3154 if (node == NULL) {
3155 DBG2("UST app no found with pid %d", pid);
3156 goto error;
3157 }
3158
3159 DBG2("Found UST app by pid %d", pid);
3160
3161 app = caa_container_of(node, struct ust_app, pid_n);
3162
3163 error:
3164 return app;
3165 }
3166
3167 /*
3168 * Allocate and init an UST app object using the registration information and
3169 * the command socket. This is called when the command socket connects to the
3170 * session daemon.
3171 *
3172 * The object is returned on success or else NULL.
3173 */
3174 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3175 {
3176 struct ust_app *lta = NULL;
3177
3178 assert(msg);
3179 assert(sock >= 0);
3180
3181 DBG3("UST app creating application for socket %d", sock);
3182
3183 if ((msg->bits_per_long == 64 &&
3184 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3185 || (msg->bits_per_long == 32 &&
3186 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3187 ERR("Registration failed: application \"%s\" (pid: %d) has "
3188 "%d-bit long, but no consumerd for this size is available.\n",
3189 msg->name, msg->pid, msg->bits_per_long);
3190 goto error;
3191 }
3192
3193 lta = zmalloc(sizeof(struct ust_app));
3194 if (lta == NULL) {
3195 PERROR("malloc");
3196 goto error;
3197 }
3198
3199 lta->ppid = msg->ppid;
3200 lta->uid = msg->uid;
3201 lta->gid = msg->gid;
3202
3203 lta->bits_per_long = msg->bits_per_long;
3204 lta->uint8_t_alignment = msg->uint8_t_alignment;
3205 lta->uint16_t_alignment = msg->uint16_t_alignment;
3206 lta->uint32_t_alignment = msg->uint32_t_alignment;
3207 lta->uint64_t_alignment = msg->uint64_t_alignment;
3208 lta->long_alignment = msg->long_alignment;
3209 lta->byte_order = msg->byte_order;
3210
3211 lta->v_major = msg->major;
3212 lta->v_minor = msg->minor;
3213 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3214 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3215 lta->notify_sock = -1;
3216
3217 /* Copy name and make sure it's NULL terminated. */
3218 strncpy(lta->name, msg->name, sizeof(lta->name));
3219 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3220
3221 /*
3222 * Before this can be called, when receiving the registration information,
3223 * the application compatibility is checked. So, at this point, the
3224 * application can work with this session daemon.
3225 */
3226 lta->compatible = 1;
3227
3228 lta->pid = msg->pid;
3229 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3230 lta->sock = sock;
3231 pthread_mutex_init(&lta->sock_lock, NULL);
3232 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3233
3234 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3235 error:
3236 return lta;
3237 }
3238
3239 /*
3240 * For a given application object, add it to every hash table.
3241 */
3242 void ust_app_add(struct ust_app *app)
3243 {
3244 assert(app);
3245 assert(app->notify_sock >= 0);
3246
3247 rcu_read_lock();
3248
3249 /*
3250 * On a re-registration, we want to kick out the previous registration of
3251 * that pid
3252 */
3253 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3254
3255 /*
3256 * The socket _should_ be unique until _we_ call close. So, a add_unique
3257 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3258 * already in the table.
3259 */
3260 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3261
3262 /* Add application to the notify socket hash table. */
3263 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3264 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3265
3266 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3267 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3268 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3269 app->v_minor);
3270
3271 rcu_read_unlock();
3272 }
3273
3274 /*
3275 * Set the application version into the object.
3276 *
3277 * Return 0 on success else a negative value either an errno code or a
3278 * LTTng-UST error code.
3279 */
3280 int ust_app_version(struct ust_app *app)
3281 {
3282 int ret;
3283
3284 assert(app);
3285
3286 pthread_mutex_lock(&app->sock_lock);
3287 ret = ustctl_tracer_version(app->sock, &app->version);
3288 pthread_mutex_unlock(&app->sock_lock);
3289 if (ret < 0) {
3290 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3291 ERR("UST app %d version failed with ret %d", app->sock, ret);
3292 } else {
3293 DBG3("UST app %d version failed. Application is dead", app->sock);
3294 }
3295 }
3296
3297 return ret;
3298 }
3299
3300 /*
3301 * Unregister app by removing it from the global traceable app list and freeing
3302 * the data struct.
3303 *
3304 * The socket is already closed at this point so no close to sock.
3305 */
3306 void ust_app_unregister(int sock)
3307 {
3308 struct ust_app *lta;
3309 struct lttng_ht_node_ulong *node;
3310 struct lttng_ht_iter ust_app_sock_iter;
3311 struct lttng_ht_iter iter;
3312 struct ust_app_session *ua_sess;
3313 int ret;
3314
3315 rcu_read_lock();
3316
3317 /* Get the node reference for a call_rcu */
3318 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3319 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3320 assert(node);
3321
3322 lta = caa_container_of(node, struct ust_app, sock_n);
3323 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3324
3325 /*
3326 * For per-PID buffers, perform "push metadata" and flush all
3327 * application streams before removing app from hash tables,
3328 * ensuring proper behavior of data_pending check.
3329 * Remove sessions so they are not visible during deletion.
3330 */
3331 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3332 node.node) {
3333 struct ust_registry_session *registry;
3334
3335 ret = lttng_ht_del(lta->sessions, &iter);
3336 if (ret) {
3337 /* The session was already removed so scheduled for teardown. */
3338 continue;
3339 }
3340
3341 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3342 (void) ust_app_flush_app_session(lta, ua_sess);
3343 }
3344
3345 /*
3346 * Add session to list for teardown. This is safe since at this point we
3347 * are the only one using this list.
3348 */
3349 pthread_mutex_lock(&ua_sess->lock);
3350
3351 if (ua_sess->deleted) {
3352 pthread_mutex_unlock(&ua_sess->lock);
3353 continue;
3354 }
3355
3356 /*
3357 * Normally, this is done in the delete session process which is
3358 * executed in the call rcu below. However, upon registration we can't
3359 * afford to wait for the grace period before pushing data or else the
3360 * data pending feature can race between the unregistration and stop
3361 * command where the data pending command is sent *before* the grace
3362 * period ended.
3363 *
3364 * The close metadata below nullifies the metadata pointer in the
3365 * session so the delete session will NOT push/close a second time.
3366 */
3367 registry = get_session_registry(ua_sess);
3368 if (registry) {
3369 /* Push metadata for application before freeing the application. */
3370 (void) push_metadata(registry, ua_sess->consumer);
3371
3372 /*
3373 * Don't ask to close metadata for global per UID buffers. Close
3374 * metadata only on destroy trace session in this case. Also, the
3375 * previous push metadata could have flag the metadata registry to
3376 * close so don't send a close command if closed.
3377 */
3378 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3379 /* And ask to close it for this session registry. */
3380 (void) close_metadata(registry, ua_sess->consumer);
3381 }
3382 }
3383 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3384
3385 pthread_mutex_unlock(&ua_sess->lock);
3386 }
3387
3388 /* Remove application from PID hash table */
3389 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3390 assert(!ret);
3391
3392 /*
3393 * Remove application from notify hash table. The thread handling the
3394 * notify socket could have deleted the node so ignore on error because
3395 * either way it's valid. The close of that socket is handled by the other
3396 * thread.
3397 */
3398 iter.iter.node = &lta->notify_sock_n.node;
3399 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3400
3401 /*
3402 * Ignore return value since the node might have been removed before by an
3403 * add replace during app registration because the PID can be reassigned by
3404 * the OS.
3405 */
3406 iter.iter.node = &lta->pid_n.node;
3407 ret = lttng_ht_del(ust_app_ht, &iter);
3408 if (ret) {
3409 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3410 lta->pid);
3411 }
3412
3413 /* Free memory */
3414 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3415
3416 rcu_read_unlock();
3417 return;
3418 }
3419
3420 /*
3421 * Fill events array with all events name of all registered apps.
3422 */
3423 int ust_app_list_events(struct lttng_event **events)
3424 {
3425 int ret, handle;
3426 size_t nbmem, count = 0;
3427 struct lttng_ht_iter iter;
3428 struct ust_app *app;
3429 struct lttng_event *tmp_event;
3430
3431 nbmem = UST_APP_EVENT_LIST_SIZE;
3432 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3433 if (tmp_event == NULL) {
3434 PERROR("zmalloc ust app events");
3435 ret = -ENOMEM;
3436 goto error;
3437 }
3438
3439 rcu_read_lock();
3440
3441 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3442 struct lttng_ust_tracepoint_iter uiter;
3443
3444 health_code_update();
3445
3446 if (!app->compatible) {
3447 /*
3448 * TODO: In time, we should notice the caller of this error by
3449 * telling him that this is a version error.
3450 */
3451 continue;
3452 }
3453 pthread_mutex_lock(&app->sock_lock);
3454 handle = ustctl_tracepoint_list(app->sock);
3455 if (handle < 0) {
3456 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3457 ERR("UST app list events getting handle failed for app pid %d",
3458 app->pid);
3459 }
3460 pthread_mutex_unlock(&app->sock_lock);
3461 continue;
3462 }
3463
3464 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3465 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3466 /* Handle ustctl error. */
3467 if (ret < 0) {
3468 int release_ret;
3469
3470 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3471 ERR("UST app tp list get failed for app %d with ret %d",
3472 app->sock, ret);
3473 } else {
3474 DBG3("UST app tp list get failed. Application is dead");
3475 /*
3476 * This is normal behavior, an application can die during the
3477 * creation process. Don't report an error so the execution can
3478 * continue normally. Continue normal execution.
3479 */
3480 break;
3481 }
3482 free(tmp_event);
3483 release_ret = ustctl_release_handle(app->sock, handle);
3484 if (release_ret < 0 &&
3485 release_ret != -LTTNG_UST_ERR_EXITING &&
3486 release_ret != -EPIPE) {
3487 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3488 }
3489 pthread_mutex_unlock(&app->sock_lock);
3490 goto rcu_error;
3491 }
3492
3493 health_code_update();
3494 if (count >= nbmem) {
3495 /* In case the realloc fails, we free the memory */
3496 struct lttng_event *new_tmp_event;
3497 size_t new_nbmem;
3498
3499 new_nbmem = nbmem << 1;
3500 DBG2("Reallocating event list from %zu to %zu entries",
3501 nbmem, new_nbmem);
3502 new_tmp_event = realloc(tmp_event,
3503 new_nbmem * sizeof(struct lttng_event));
3504 if (new_tmp_event == NULL) {
3505 int release_ret;
3506
3507 PERROR("realloc ust app events");
3508 free(tmp_event);
3509 ret = -ENOMEM;
3510 release_ret = ustctl_release_handle(app->sock, handle);
3511 if (release_ret < 0 &&
3512 release_ret != -LTTNG_UST_ERR_EXITING &&
3513 release_ret != -EPIPE) {
3514 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3515 }
3516 pthread_mutex_unlock(&app->sock_lock);
3517 goto rcu_error;
3518 }
3519 /* Zero the new memory */
3520 memset(new_tmp_event + nbmem, 0,
3521 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3522 nbmem = new_nbmem;
3523 tmp_event = new_tmp_event;
3524 }
3525 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3526 tmp_event[count].loglevel = uiter.loglevel;
3527 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3528 tmp_event[count].pid = app->pid;
3529 tmp_event[count].enabled = -1;
3530 count++;
3531 }
3532 ret = ustctl_release_handle(app->sock, handle);
3533 pthread_mutex_unlock(&app->sock_lock);
3534 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3535 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3536 }
3537 }
3538
3539 ret = count;
3540 *events = tmp_event;
3541
3542 DBG2("UST app list events done (%zu events)", count);
3543
3544 rcu_error:
3545 rcu_read_unlock();
3546 error:
3547 health_code_update();
3548 return ret;
3549 }
3550
3551 /*
3552 * Fill events array with all events name of all registered apps.
3553 */
3554 int ust_app_list_event_fields(struct lttng_event_field **fields)
3555 {
3556 int ret, handle;
3557 size_t nbmem, count = 0;
3558 struct lttng_ht_iter iter;
3559 struct ust_app *app;
3560 struct lttng_event_field *tmp_event;
3561
3562 nbmem = UST_APP_EVENT_LIST_SIZE;
3563 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3564 if (tmp_event == NULL) {
3565 PERROR("zmalloc ust app event fields");
3566 ret = -ENOMEM;
3567 goto error;
3568 }
3569
3570 rcu_read_lock();
3571
3572 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3573 struct lttng_ust_field_iter uiter;
3574
3575 health_code_update();
3576
3577 if (!app->compatible) {
3578 /*
3579 * TODO: In time, we should notice the caller of this error by
3580 * telling him that this is a version error.
3581 */
3582 continue;
3583 }
3584 pthread_mutex_lock(&app->sock_lock);
3585 handle = ustctl_tracepoint_field_list(app->sock);
3586 if (handle < 0) {
3587 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3588 ERR("UST app list field getting handle failed for app pid %d",
3589 app->pid);
3590 }
3591 pthread_mutex_unlock(&app->sock_lock);
3592 continue;
3593 }
3594
3595 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3596 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3597 /* Handle ustctl error. */
3598 if (ret < 0) {
3599 int release_ret;
3600
3601 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3602 ERR("UST app tp list field failed for app %d with ret %d",
3603 app->sock, ret);
3604 } else {
3605 DBG3("UST app tp list field failed. Application is dead");
3606 /*
3607 * This is normal behavior, an application can die during the
3608 * creation process. Don't report an error so the execution can
3609 * continue normally. Reset list and count for next app.
3610 */
3611 break;
3612 }
3613 free(tmp_event);
3614 release_ret = ustctl_release_handle(app->sock, handle);
3615 pthread_mutex_unlock(&app->sock_lock);
3616 if (release_ret < 0 &&
3617 release_ret != -LTTNG_UST_ERR_EXITING &&
3618 release_ret != -EPIPE) {
3619 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3620 }
3621 goto rcu_error;
3622 }
3623
3624 health_code_update();
3625 if (count >= nbmem) {
3626 /* In case the realloc fails, we free the memory */
3627 struct lttng_event_field *new_tmp_event;
3628 size_t new_nbmem;
3629
3630 new_nbmem = nbmem << 1;
3631 DBG2("Reallocating event field list from %zu to %zu entries",
3632 nbmem, new_nbmem);
3633 new_tmp_event = realloc(tmp_event,
3634 new_nbmem * sizeof(struct lttng_event_field));
3635 if (new_tmp_event == NULL) {
3636 int release_ret;
3637
3638 PERROR("realloc ust app event fields");
3639 free(tmp_event);
3640 ret = -ENOMEM;
3641 release_ret = ustctl_release_handle(app->sock, handle);
3642 pthread_mutex_unlock(&app->sock_lock);
3643 if (release_ret &&
3644 release_ret != -LTTNG_UST_ERR_EXITING &&
3645 release_ret != -EPIPE) {
3646 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3647 }
3648 goto rcu_error;
3649 }
3650 /* Zero the new memory */
3651 memset(new_tmp_event + nbmem, 0,
3652 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3653 nbmem = new_nbmem;
3654 tmp_event = new_tmp_event;
3655 }
3656
3657 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3658 /* Mapping between these enums matches 1 to 1. */
3659 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3660 tmp_event[count].nowrite = uiter.nowrite;
3661
3662 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3663 tmp_event[count].event.loglevel = uiter.loglevel;
3664 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3665 tmp_event[count].event.pid = app->pid;
3666 tmp_event[count].event.enabled = -1;
3667 count++;
3668 }
3669 ret = ustctl_release_handle(app->sock, handle);
3670 pthread_mutex_unlock(&app->sock_lock);
3671 if (ret < 0 &&
3672 ret != -LTTNG_UST_ERR_EXITING &&
3673 ret != -EPIPE) {
3674 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3675 }
3676 }
3677
3678 ret = count;
3679 *fields = tmp_event;
3680
3681 DBG2("UST app list event fields done (%zu events)", count);
3682
3683 rcu_error:
3684 rcu_read_unlock();
3685 error:
3686 health_code_update();
3687 return ret;
3688 }
3689
3690 /*
3691 * Free and clean all traceable apps of the global list.
3692 *
3693 * Should _NOT_ be called with RCU read-side lock held.
3694 */
3695 void ust_app_clean_list(void)
3696 {
3697 int ret;
3698 struct ust_app *app;
3699 struct lttng_ht_iter iter;
3700
3701 DBG2("UST app cleaning registered apps hash table");
3702
3703 rcu_read_lock();
3704
3705 if (ust_app_ht) {
3706 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3707 ret = lttng_ht_del(ust_app_ht, &iter);
3708 assert(!ret);
3709 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3710 }
3711 }
3712
3713 /* Cleanup socket hash table */
3714 if (ust_app_ht_by_sock) {
3715 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3716 sock_n.node) {
3717 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3718 assert(!ret);
3719 }
3720 }
3721
3722 /* Cleanup notify socket hash table */
3723 if (ust_app_ht_by_notify_sock) {
3724 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3725 notify_sock_n.node) {
3726 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3727 assert(!ret);
3728 }
3729 }
3730 rcu_read_unlock();
3731
3732 /* Destroy is done only when the ht is empty */
3733 if (ust_app_ht) {
3734 ht_cleanup_push(ust_app_ht);
3735 }
3736 if (ust_app_ht_by_sock) {
3737 ht_cleanup_push(ust_app_ht_by_sock);
3738 }
3739 if (ust_app_ht_by_notify_sock) {
3740 ht_cleanup_push(ust_app_ht_by_notify_sock);
3741 }
3742 }
3743
3744 /*
3745 * Init UST app hash table.
3746 */
3747 int ust_app_ht_alloc(void)
3748 {
3749 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3750 if (!ust_app_ht) {
3751 return -1;
3752 }
3753 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3754 if (!ust_app_ht_by_sock) {
3755 return -1;
3756 }
3757 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3758 if (!ust_app_ht_by_notify_sock) {
3759 return -1;
3760 }
3761 return 0;
3762 }
3763
3764 /*
3765 * For a specific UST session, disable the channel for all registered apps.
3766 */
3767 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3768 struct ltt_ust_channel *uchan)
3769 {
3770 int ret = 0;
3771 struct lttng_ht_iter iter;
3772 struct lttng_ht_node_str *ua_chan_node;
3773 struct ust_app *app;
3774 struct ust_app_session *ua_sess;
3775 struct ust_app_channel *ua_chan;
3776
3777 if (usess == NULL || uchan == NULL) {
3778 ERR("Disabling UST global channel with NULL values");
3779 ret = -1;
3780 goto error;
3781 }
3782
3783 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3784 uchan->name, usess->id);
3785
3786 rcu_read_lock();
3787
3788 /* For every registered applications */
3789 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3790 struct lttng_ht_iter uiter;
3791 if (!app->compatible) {
3792 /*
3793 * TODO: In time, we should notice the caller of this error by
3794 * telling him that this is a version error.
3795 */
3796 continue;
3797 }
3798 ua_sess = lookup_session_by_app(usess, app);
3799 if (ua_sess == NULL) {
3800 continue;
3801 }
3802
3803 /* Get channel */
3804 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3805 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3806 /* If the session if found for the app, the channel must be there */
3807 assert(ua_chan_node);
3808
3809 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3810 /* The channel must not be already disabled */
3811 assert(ua_chan->enabled == 1);
3812
3813 /* Disable channel onto application */
3814 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3815 if (ret < 0) {
3816 /* XXX: We might want to report this error at some point... */
3817 continue;
3818 }
3819 }
3820
3821 rcu_read_unlock();
3822
3823 error:
3824 return ret;
3825 }
3826
3827 /*
3828 * For a specific UST session, enable the channel for all registered apps.
3829 */
3830 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3831 struct ltt_ust_channel *uchan)
3832 {
3833 int ret = 0;
3834 struct lttng_ht_iter iter;
3835 struct ust_app *app;
3836 struct ust_app_session *ua_sess;
3837
3838 if (usess == NULL || uchan == NULL) {
3839 ERR("Adding UST global channel to NULL values");
3840 ret = -1;
3841 goto error;
3842 }
3843
3844 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3845 uchan->name, usess->id);
3846
3847 rcu_read_lock();
3848
3849 /* For every registered applications */
3850 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3851 if (!app->compatible) {
3852 /*
3853 * TODO: In time, we should notice the caller of this error by
3854 * telling him that this is a version error.
3855 */
3856 continue;
3857 }
3858 ua_sess = lookup_session_by_app(usess, app);
3859 if (ua_sess == NULL) {
3860 continue;
3861 }
3862
3863 /* Enable channel onto application */
3864 ret = enable_ust_app_channel(ua_sess, uchan, app);
3865 if (ret < 0) {
3866 /* XXX: We might want to report this error at some point... */
3867 continue;
3868 }
3869 }
3870
3871 rcu_read_unlock();
3872
3873 error:
3874 return ret;
3875 }
3876
3877 /*
3878 * Disable an event in a channel and for a specific session.
3879 */
3880 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3881 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3882 {
3883 int ret = 0;
3884 struct lttng_ht_iter iter, uiter;
3885 struct lttng_ht_node_str *ua_chan_node;
3886 struct ust_app *app;
3887 struct ust_app_session *ua_sess;
3888 struct ust_app_channel *ua_chan;
3889 struct ust_app_event *ua_event;
3890
3891 DBG("UST app disabling event %s for all apps in channel "
3892 "%s for session id %" PRIu64,
3893 uevent->attr.name, uchan->name, usess->id);
3894
3895 rcu_read_lock();
3896
3897 /* For all registered applications */
3898 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3899 if (!app->compatible) {
3900 /*
3901 * TODO: In time, we should notice the caller of this error by
3902 * telling him that this is a version error.
3903 */
3904 continue;
3905 }
3906 ua_sess = lookup_session_by_app(usess, app);
3907 if (ua_sess == NULL) {
3908 /* Next app */
3909 continue;
3910 }
3911
3912 /* Lookup channel in the ust app session */
3913 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3914 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3915 if (ua_chan_node == NULL) {
3916 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3917 "Skipping", uchan->name, usess->id, app->pid);
3918 continue;
3919 }
3920 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3921
3922 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3923 uevent->filter, uevent->attr.loglevel,
3924 uevent->exclusion);
3925 if (ua_event == NULL) {
3926 DBG2("Event %s not found in channel %s for app pid %d."
3927 "Skipping", uevent->attr.name, uchan->name, app->pid);
3928 continue;
3929 }
3930
3931 ret = disable_ust_app_event(ua_sess, ua_event, app);
3932 if (ret < 0) {
3933 /* XXX: Report error someday... */
3934 continue;
3935 }
3936 }
3937
3938 rcu_read_unlock();
3939
3940 return ret;
3941 }
3942
3943 /*
3944 * For a specific UST session, create the channel for all registered apps.
3945 */
3946 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3947 struct ltt_ust_channel *uchan)
3948 {
3949 int ret = 0, created;
3950 struct lttng_ht_iter iter;
3951 struct ust_app *app;
3952 struct ust_app_session *ua_sess = NULL;
3953
3954 /* Very wrong code flow */
3955 assert(usess);
3956 assert(uchan);
3957
3958 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3959 uchan->name, usess->id);
3960
3961 rcu_read_lock();
3962
3963 /* For every registered applications */
3964 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3965 if (!app->compatible) {
3966 /*
3967 * TODO: In time, we should notice the caller of this error by
3968 * telling him that this is a version error.
3969 */
3970 continue;
3971 }
3972 if (!trace_ust_pid_tracker_lookup(usess, app->pid)) {
3973 /* Skip. */
3974 continue;
3975 }
3976
3977 /*
3978 * Create session on the tracer side and add it to app session HT. Note
3979 * that if session exist, it will simply return a pointer to the ust
3980 * app session.
3981 */
3982 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3983 if (ret < 0) {
3984 switch (ret) {
3985 case -ENOTCONN:
3986 /*
3987 * The application's socket is not valid. Either a bad socket
3988 * or a timeout on it. We can't inform the caller that for a
3989 * specific app, the session failed so lets continue here.
3990 */
3991 ret = 0; /* Not an error. */
3992 continue;
3993 case -ENOMEM:
3994 default:
3995 goto error_rcu_unlock;
3996 }
3997 }
3998 assert(ua_sess);
3999
4000 pthread_mutex_lock(&ua_sess->lock);
4001
4002 if (ua_sess->deleted) {
4003 pthread_mutex_unlock(&ua_sess->lock);
4004 continue;
4005 }
4006
4007 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
4008 sizeof(uchan->name))) {
4009 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
4010 ret = 0;
4011 } else {
4012 /* Create channel onto application. We don't need the chan ref. */
4013 ret = create_ust_app_channel(ua_sess, uchan, app,
4014 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
4015 }
4016 pthread_mutex_unlock(&ua_sess->lock);
4017 if (ret < 0) {
4018 /* Cleanup the created session if it's the case. */
4019 if (created) {
4020 destroy_app_session(app, ua_sess);
4021 }
4022 switch (ret) {
4023 case -ENOTCONN:
4024 /*
4025 * The application's socket is not valid. Either a bad socket
4026 * or a timeout on it. We can't inform the caller that for a
4027 * specific app, the session failed so lets continue here.
4028 */
4029 ret = 0; /* Not an error. */
4030 continue;
4031 case -ENOMEM:
4032 default:
4033 goto error_rcu_unlock;
4034 }
4035 }
4036 }
4037
4038 error_rcu_unlock:
4039 rcu_read_unlock();
4040 return ret;
4041 }
4042
4043 /*
4044 * Enable event for a specific session and channel on the tracer.
4045 */
4046 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
4047 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4048 {
4049 int ret = 0;
4050 struct lttng_ht_iter iter, uiter;
4051 struct lttng_ht_node_str *ua_chan_node;
4052 struct ust_app *app;
4053 struct ust_app_session *ua_sess;
4054 struct ust_app_channel *ua_chan;
4055 struct ust_app_event *ua_event;
4056
4057 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
4058 uevent->attr.name, usess->id);
4059
4060 /*
4061 * NOTE: At this point, this function is called only if the session and
4062 * channel passed are already created for all apps. and enabled on the
4063 * tracer also.
4064 */
4065
4066 rcu_read_lock();
4067
4068 /* For all registered applications */
4069 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4070 if (!app->compatible) {
4071 /*
4072 * TODO: In time, we should notice the caller of this error by
4073 * telling him that this is a version error.
4074 */
4075 continue;
4076 }
4077 ua_sess = lookup_session_by_app(usess, app);
4078 if (!ua_sess) {
4079 /* The application has problem or is probably dead. */
4080 continue;
4081 }
4082
4083 pthread_mutex_lock(&ua_sess->lock);
4084
4085 if (ua_sess->deleted) {
4086 pthread_mutex_unlock(&ua_sess->lock);
4087 continue;
4088 }
4089
4090 /* Lookup channel in the ust app session */
4091 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4092 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4093 /*
4094 * It is possible that the channel cannot be found is
4095 * the channel/event creation occurs concurrently with
4096 * an application exit.
4097 */
4098 if (!ua_chan_node) {
4099 pthread_mutex_unlock(&ua_sess->lock);
4100 continue;
4101 }
4102
4103 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4104
4105 /* Get event node */
4106 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4107 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4108 if (ua_event == NULL) {
4109 DBG3("UST app enable event %s not found for app PID %d."
4110 "Skipping app", uevent->attr.name, app->pid);
4111 goto next_app;
4112 }
4113
4114 ret = enable_ust_app_event(ua_sess, ua_event, app);
4115 if (ret < 0) {
4116 pthread_mutex_unlock(&ua_sess->lock);
4117 goto error;
4118 }
4119 next_app:
4120 pthread_mutex_unlock(&ua_sess->lock);
4121 }
4122
4123 error:
4124 rcu_read_unlock();
4125 return ret;
4126 }
4127
4128 /*
4129 * For a specific existing UST session and UST channel, creates the event for
4130 * all registered apps.
4131 */
4132 int ust_app_create_event_glb(struct ltt_ust_session *usess,
4133 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4134 {
4135 int ret = 0;
4136 struct lttng_ht_iter iter, uiter;
4137 struct lttng_ht_node_str *ua_chan_node;
4138 struct ust_app *app;
4139 struct ust_app_session *ua_sess;
4140 struct ust_app_channel *ua_chan;
4141
4142 DBG("UST app creating event %s for all apps for session id %" PRIu64,
4143 uevent->attr.name, usess->id);
4144
4145 rcu_read_lock();
4146
4147 /* For all registered applications */
4148 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4149 if (!app->compatible) {
4150 /*
4151 * TODO: In time, we should notice the caller of this error by
4152 * telling him that this is a version error.
4153 */
4154 continue;
4155 }
4156 ua_sess = lookup_session_by_app(usess, app);
4157 if (!ua_sess) {
4158 /* The application has problem or is probably dead. */
4159 continue;
4160 }
4161
4162 pthread_mutex_lock(&ua_sess->lock);
4163
4164 if (ua_sess->deleted) {
4165 pthread_mutex_unlock(&ua_sess->lock);
4166 continue;
4167 }
4168
4169 /* Lookup channel in the ust app session */
4170 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4171 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4172 /* If the channel is not found, there is a code flow error */
4173 assert(ua_chan_node);
4174
4175 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4176
4177 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4178 pthread_mutex_unlock(&ua_sess->lock);
4179 if (ret < 0) {
4180 if (ret != -LTTNG_UST_ERR_EXIST) {
4181 /* Possible value at this point: -ENOMEM. If so, we stop! */
4182 break;
4183 }
4184 DBG2("UST app event %s already exist on app PID %d",
4185 uevent->attr.name, app->pid);
4186 continue;
4187 }
4188 }
4189
4190 rcu_read_unlock();
4191
4192 return ret;
4193 }
4194
4195 /*
4196 * Start tracing for a specific UST session and app.
4197 */
4198 static
4199 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
4200 {
4201 int ret = 0;
4202 struct ust_app_session *ua_sess;
4203
4204 DBG("Starting tracing for ust app pid %d", app->pid);
4205
4206 rcu_read_lock();
4207
4208 if (!app->compatible) {
4209 goto end;
4210 }
4211
4212 ua_sess = lookup_session_by_app(usess, app);
4213 if (ua_sess == NULL) {
4214 /* The session is in teardown process. Ignore and continue. */
4215 goto end;
4216 }
4217
4218 pthread_mutex_lock(&ua_sess->lock);
4219
4220 if (ua_sess->deleted) {
4221 pthread_mutex_unlock(&ua_sess->lock);
4222 goto end;
4223 }
4224
4225 /* Upon restart, we skip the setup, already done */
4226 if (ua_sess->started) {
4227 goto skip_setup;
4228 }
4229
4230 /* Create directories if consumer is LOCAL and has a path defined. */
4231 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
4232 strlen(usess->consumer->dst.trace_path) > 0) {
4233 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
4234 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
4235 if (ret < 0) {
4236 if (errno != EEXIST) {
4237 ERR("Trace directory creation error");
4238 goto error_unlock;
4239 }
4240 }
4241 }
4242
4243 /*
4244 * Create the metadata for the application. This returns gracefully if a
4245 * metadata was already set for the session.
4246 */
4247 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
4248 if (ret < 0) {
4249 goto error_unlock;
4250 }
4251
4252 health_code_update();
4253
4254 skip_setup:
4255 /* This start the UST tracing */
4256 pthread_mutex_lock(&app->sock_lock);
4257 ret = ustctl_start_session(app->sock, ua_sess->handle);
4258 pthread_mutex_unlock(&app->sock_lock);
4259 if (ret < 0) {
4260 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4261 ERR("Error starting tracing for app pid: %d (ret: %d)",
4262 app->pid, ret);
4263 } else {
4264 DBG("UST app start session failed. Application is dead.");
4265 /*
4266 * This is normal behavior, an application can die during the
4267 * creation process. Don't report an error so the execution can
4268 * continue normally.
4269 */
4270 pthread_mutex_unlock(&ua_sess->lock);
4271 goto end;
4272 }
4273 goto error_unlock;
4274 }
4275
4276 /* Indicate that the session has been started once */
4277 ua_sess->started = 1;
4278
4279 pthread_mutex_unlock(&ua_sess->lock);
4280
4281 health_code_update();
4282
4283 /* Quiescent wait after starting trace */
4284 pthread_mutex_lock(&app->sock_lock);
4285 ret = ustctl_wait_quiescent(app->sock);
4286 pthread_mutex_unlock(&app->sock_lock);
4287 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4288 ERR("UST app wait quiescent failed for app pid %d ret %d",
4289 app->pid, ret);
4290 }
4291
4292 end:
4293 rcu_read_unlock();
4294 health_code_update();
4295 return 0;
4296
4297 error_unlock:
4298 pthread_mutex_unlock(&ua_sess->lock);
4299 rcu_read_unlock();
4300 health_code_update();
4301 return -1;
4302 }
4303
4304 /*
4305 * Stop tracing for a specific UST session and app.
4306 */
4307 static
4308 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
4309 {
4310 int ret = 0;
4311 struct ust_app_session *ua_sess;
4312 struct ust_registry_session *registry;
4313
4314 DBG("Stopping tracing for ust app pid %d", app->pid);
4315
4316 rcu_read_lock();
4317
4318 if (!app->compatible) {
4319 goto end_no_session;
4320 }
4321
4322 ua_sess = lookup_session_by_app(usess, app);
4323 if (ua_sess == NULL) {
4324 goto end_no_session;
4325 }
4326
4327 pthread_mutex_lock(&ua_sess->lock);
4328
4329 if (ua_sess->deleted) {
4330 pthread_mutex_unlock(&ua_sess->lock);
4331 goto end_no_session;
4332 }
4333
4334 /*
4335 * If started = 0, it means that stop trace has been called for a session
4336 * that was never started. It's possible since we can have a fail start
4337 * from either the application manager thread or the command thread. Simply
4338 * indicate that this is a stop error.
4339 */
4340 if (!ua_sess->started) {
4341 goto error_rcu_unlock;
4342 }
4343
4344 health_code_update();
4345
4346 /* This inhibits UST tracing */
4347 pthread_mutex_lock(&app->sock_lock);
4348 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4349 pthread_mutex_unlock(&app->sock_lock);
4350 if (ret < 0) {
4351 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4352 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4353 app->pid, ret);
4354 } else {
4355 DBG("UST app stop session failed. Application is dead.");
4356 /*
4357 * This is normal behavior, an application can die during the
4358 * creation process. Don't report an error so the execution can
4359 * continue normally.
4360 */
4361 goto end_unlock;
4362 }
4363 goto error_rcu_unlock;
4364 }
4365
4366 health_code_update();
4367
4368 /* Quiescent wait after stopping trace */
4369 pthread_mutex_lock(&app->sock_lock);
4370 ret = ustctl_wait_quiescent(app->sock);
4371 pthread_mutex_unlock(&app->sock_lock);
4372 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4373 ERR("UST app wait quiescent failed for app pid %d ret %d",
4374 app->pid, ret);
4375 }
4376
4377 health_code_update();
4378
4379 registry = get_session_registry(ua_sess);
4380 assert(registry);
4381
4382 /* Push metadata for application before freeing the application. */
4383 (void) push_metadata(registry, ua_sess->consumer);
4384
4385 end_unlock:
4386 pthread_mutex_unlock(&ua_sess->lock);
4387 end_no_session:
4388 rcu_read_unlock();
4389 health_code_update();
4390 return 0;
4391
4392 error_rcu_unlock:
4393 pthread_mutex_unlock(&ua_sess->lock);
4394 rcu_read_unlock();
4395 health_code_update();
4396 return -1;
4397 }
4398
4399 static
4400 int ust_app_flush_app_session(struct ust_app *app,
4401 struct ust_app_session *ua_sess)
4402 {
4403 int ret, retval = 0;
4404 struct lttng_ht_iter iter;
4405 struct ust_app_channel *ua_chan;
4406 struct consumer_socket *socket;
4407
4408 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4409
4410 rcu_read_lock();
4411
4412 if (!app->compatible) {
4413 goto end_not_compatible;
4414 }
4415
4416 pthread_mutex_lock(&ua_sess->lock);
4417
4418 if (ua_sess->deleted) {
4419 goto end_deleted;
4420 }
4421
4422 health_code_update();
4423
4424 /* Flushing buffers */
4425 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4426 ua_sess->consumer);
4427
4428 /* Flush buffers and push metadata. */
4429 switch (ua_sess->buffer_type) {
4430 case LTTNG_BUFFER_PER_PID:
4431 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4432 node.node) {
4433 health_code_update();
4434 assert(ua_chan->is_sent);
4435 ret = consumer_flush_channel(socket, ua_chan->key);
4436 if (ret) {
4437 ERR("Error flushing consumer channel");
4438 retval = -1;
4439 continue;
4440 }
4441 }
4442 break;
4443 case LTTNG_BUFFER_PER_UID:
4444 default:
4445 assert(0);
4446 break;
4447 }
4448
4449 health_code_update();
4450
4451 end_deleted:
4452 pthread_mutex_unlock(&ua_sess->lock);
4453
4454 end_not_compatible:
4455 rcu_read_unlock();
4456 health_code_update();
4457 return retval;
4458 }
4459
4460 /*
4461 * Flush buffers for all applications for a specific UST session.
4462 * Called with UST session lock held.
4463 */
4464 static
4465 int ust_app_flush_session(struct ltt_ust_session *usess)
4466
4467 {
4468 int ret = 0;
4469
4470 DBG("Flushing session buffers for all ust apps");
4471
4472 rcu_read_lock();
4473
4474 /* Flush buffers and push metadata. */
4475 switch (usess->buffer_type) {
4476 case LTTNG_BUFFER_PER_UID:
4477 {
4478 struct buffer_reg_uid *reg;
4479 struct lttng_ht_iter iter;
4480
4481 /* Flush all per UID buffers associated to that session. */
4482 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4483 struct ust_registry_session *ust_session_reg;
4484 struct buffer_reg_channel *reg_chan;
4485 struct consumer_socket *socket;
4486
4487 /* Get consumer socket to use to push the metadata.*/
4488 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4489 usess->consumer);
4490 if (!socket) {
4491 /* Ignore request if no consumer is found for the session. */
4492 continue;
4493 }
4494
4495 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4496 reg_chan, node.node) {
4497 /*
4498 * The following call will print error values so the return
4499 * code is of little importance because whatever happens, we
4500 * have to try them all.
4501 */
4502 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4503 }
4504
4505 ust_session_reg = reg->registry->reg.ust;
4506 /* Push metadata. */
4507 (void) push_metadata(ust_session_reg, usess->consumer);
4508 }
4509 break;
4510 }
4511 case LTTNG_BUFFER_PER_PID:
4512 {
4513 struct ust_app_session *ua_sess;
4514 struct lttng_ht_iter iter;
4515 struct ust_app *app;
4516
4517 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4518 ua_sess = lookup_session_by_app(usess, app);
4519 if (ua_sess == NULL) {
4520 continue;
4521 }
4522 (void) ust_app_flush_app_session(app, ua_sess);
4523 }
4524 break;
4525 }
4526 default:
4527 ret = -1;
4528 assert(0);
4529 break;
4530 }
4531
4532 rcu_read_unlock();
4533 health_code_update();
4534 return ret;
4535 }
4536
4537 /*
4538 * Destroy a specific UST session in apps.
4539 */
4540 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4541 {
4542 int ret;
4543 struct ust_app_session *ua_sess;
4544 struct lttng_ht_iter iter;
4545 struct lttng_ht_node_u64 *node;
4546
4547 DBG("Destroy tracing for ust app pid %d", app->pid);
4548
4549 rcu_read_lock();
4550
4551 if (!app->compatible) {
4552 goto end;
4553 }
4554
4555 __lookup_session_by_app(usess, app, &iter);
4556 node = lttng_ht_iter_get_node_u64(&iter);
4557 if (node == NULL) {
4558 /* Session is being or is deleted. */
4559 goto end;
4560 }
4561 ua_sess = caa_container_of(node, struct ust_app_session, node);
4562
4563 health_code_update();
4564 destroy_app_session(app, ua_sess);
4565
4566 health_code_update();
4567
4568 /* Quiescent wait after stopping trace */
4569 pthread_mutex_lock(&app->sock_lock);
4570 ret = ustctl_wait_quiescent(app->sock);
4571 pthread_mutex_unlock(&app->sock_lock);
4572 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4573 ERR("UST app wait quiescent failed for app pid %d ret %d",
4574 app->pid, ret);
4575 }
4576 end:
4577 rcu_read_unlock();
4578 health_code_update();
4579 return 0;
4580 }
4581
4582 /*
4583 * Start tracing for the UST session.
4584 */
4585 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4586 {
4587 int ret = 0;
4588 struct lttng_ht_iter iter;
4589 struct ust_app *app;
4590
4591 DBG("Starting all UST traces");
4592
4593 rcu_read_lock();
4594
4595 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4596 ret = ust_app_start_trace(usess, app);
4597 if (ret < 0) {
4598 /* Continue to next apps even on error */
4599 continue;
4600 }
4601 }
4602
4603 rcu_read_unlock();
4604
4605 return 0;
4606 }
4607
4608 /*
4609 * Start tracing for the UST session.
4610 * Called with UST session lock held.
4611 */
4612 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4613 {
4614 int ret = 0;
4615 struct lttng_ht_iter iter;
4616 struct ust_app *app;
4617
4618 DBG("Stopping all UST traces");
4619
4620 rcu_read_lock();
4621
4622 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4623 ret = ust_app_stop_trace(usess, app);
4624 if (ret < 0) {
4625 /* Continue to next apps even on error */
4626 continue;
4627 }
4628 }
4629
4630 (void) ust_app_flush_session(usess);
4631
4632 rcu_read_unlock();
4633
4634 return 0;
4635 }
4636
4637 /*
4638 * Destroy app UST session.
4639 */
4640 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4641 {
4642 int ret = 0;
4643 struct lttng_ht_iter iter;
4644 struct ust_app *app;
4645
4646 DBG("Destroy all UST traces");
4647
4648 rcu_read_lock();
4649
4650 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4651 ret = destroy_trace(usess, app);
4652 if (ret < 0) {
4653 /* Continue to next apps even on error */
4654 continue;
4655 }
4656 }
4657
4658 rcu_read_unlock();
4659
4660 return 0;
4661 }
4662
4663 static
4664 void ust_app_global_create(struct ltt_ust_session *usess, struct ust_app *app)
4665 {
4666 int ret = 0;
4667 struct lttng_ht_iter iter, uiter;
4668 struct ust_app_session *ua_sess = NULL;
4669 struct ust_app_channel *ua_chan;
4670 struct ust_app_event *ua_event;
4671 struct ust_app_ctx *ua_ctx;
4672 int is_created = 0;
4673
4674 ret = create_ust_app_session(usess, app, &ua_sess, &is_created);
4675 if (ret < 0) {
4676 /* Tracer is probably gone or ENOMEM. */
4677 goto error;
4678 }
4679 if (!is_created) {
4680 /* App session already created. */
4681 goto end;
4682 }
4683 assert(ua_sess);
4684
4685 pthread_mutex_lock(&ua_sess->lock);
4686
4687 if (ua_sess->deleted) {
4688 pthread_mutex_unlock(&ua_sess->lock);
4689 goto end;
4690 }
4691
4692 /*
4693 * We can iterate safely here over all UST app session since the create ust
4694 * app session above made a shadow copy of the UST global domain from the
4695 * ltt ust session.
4696 */
4697 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4698 node.node) {
4699 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4700 if (ret < 0 && ret != -ENOTCONN) {
4701 /*
4702 * Stop everything. On error, the application
4703 * failed, no more file descriptor are available
4704 * or ENOMEM so stopping here is the only thing
4705 * we can do for now. The only exception is
4706 * -ENOTCONN, which indicates that the application
4707 * has exit.
4708 */
4709 goto error_unlock;
4710 }
4711
4712 /*
4713 * Add context using the list so they are enabled in the same order the
4714 * user added them.
4715 */
4716 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4717 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4718 if (ret < 0) {
4719 goto error_unlock;
4720 }
4721 }
4722
4723
4724 /* For each events */
4725 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4726 node.node) {
4727 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4728 if (ret < 0) {
4729 goto error_unlock;
4730 }
4731 }
4732 }
4733
4734 pthread_mutex_unlock(&ua_sess->lock);
4735
4736 if (usess->active) {
4737 ret = ust_app_start_trace(usess, app);
4738 if (ret < 0) {
4739 goto error;
4740 }
4741
4742 DBG2("UST trace started for app pid %d", app->pid);
4743 }
4744 end:
4745 /* Everything went well at this point. */
4746 return;
4747
4748 error_unlock:
4749 pthread_mutex_unlock(&ua_sess->lock);
4750 error:
4751 if (ua_sess) {
4752 destroy_app_session(app, ua_sess);
4753 }
4754 return;
4755 }
4756
4757 static
4758 void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
4759 {
4760 struct ust_app_session *ua_sess;
4761
4762 ua_sess = lookup_session_by_app(usess, app);
4763 if (ua_sess == NULL) {
4764 return;
4765 }
4766 destroy_app_session(app, ua_sess);
4767 }
4768
4769 /*
4770 * Add channels/events from UST global domain to registered apps at sock.
4771 *
4772 * Called with session lock held.
4773 * Called with RCU read-side lock held.
4774 */
4775 void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
4776 {
4777 assert(usess);
4778
4779 DBG2("UST app global update for app sock %d for session id %" PRIu64,
4780 app->sock, usess->id);
4781
4782 if (!app->compatible) {
4783 return;
4784 }
4785
4786 if (trace_ust_pid_tracker_lookup(usess, app->pid)) {
4787 ust_app_global_create(usess, app);
4788 } else {
4789 ust_app_global_destroy(usess, app);
4790 }
4791 }
4792
4793 /*
4794 * Called with session lock held.
4795 */
4796 void ust_app_global_update_all(struct ltt_ust_session *usess)
4797 {
4798 struct lttng_ht_iter iter;
4799 struct ust_app *app;
4800
4801 rcu_read_lock();
4802 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4803 ust_app_global_update(usess, app);
4804 }
4805 rcu_read_unlock();
4806 }
4807
4808 /*
4809 * Add context to a specific channel for global UST domain.
4810 */
4811 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4812 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4813 {
4814 int ret = 0;
4815 struct lttng_ht_node_str *ua_chan_node;
4816 struct lttng_ht_iter iter, uiter;
4817 struct ust_app_channel *ua_chan = NULL;
4818 struct ust_app_session *ua_sess;
4819 struct ust_app *app;
4820
4821 rcu_read_lock();
4822
4823 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4824 if (!app->compatible) {
4825 /*
4826 * TODO: In time, we should notice the caller of this error by
4827 * telling him that this is a version error.
4828 */
4829 continue;
4830 }
4831 ua_sess = lookup_session_by_app(usess, app);
4832 if (ua_sess == NULL) {
4833 continue;
4834 }
4835
4836 pthread_mutex_lock(&ua_sess->lock);
4837
4838 if (ua_sess->deleted) {
4839 pthread_mutex_unlock(&ua_sess->lock);
4840 continue;
4841 }
4842
4843 /* Lookup channel in the ust app session */
4844 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4845 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4846 if (ua_chan_node == NULL) {
4847 goto next_app;
4848 }
4849 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4850 node);
4851 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4852 if (ret < 0) {
4853 goto next_app;
4854 }
4855 next_app:
4856 pthread_mutex_unlock(&ua_sess->lock);
4857 }
4858
4859 rcu_read_unlock();
4860 return ret;
4861 }
4862
4863 /*
4864 * Enable event for a channel from a UST session for a specific PID.
4865 */
4866 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4867 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4868 {
4869 int ret = 0;
4870 struct lttng_ht_iter iter;
4871 struct lttng_ht_node_str *ua_chan_node;
4872 struct ust_app *app;
4873 struct ust_app_session *ua_sess;
4874 struct ust_app_channel *ua_chan;
4875 struct ust_app_event *ua_event;
4876
4877 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4878
4879 rcu_read_lock();
4880
4881 app = ust_app_find_by_pid(pid);
4882 if (app == NULL) {
4883 ERR("UST app enable event per PID %d not found", pid);
4884 ret = -1;
4885 goto end;
4886 }
4887
4888 if (!app->compatible) {
4889 ret = 0;
4890 goto end;
4891 }
4892
4893 ua_sess = lookup_session_by_app(usess, app);
4894 if (!ua_sess) {
4895 /* The application has problem or is probably dead. */
4896 ret = 0;
4897 goto end;
4898 }
4899
4900 pthread_mutex_lock(&ua_sess->lock);
4901
4902 if (ua_sess->deleted) {
4903 ret = 0;
4904 goto end_unlock;
4905 }
4906
4907 /* Lookup channel in the ust app session */
4908 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4909 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4910 /* If the channel is not found, there is a code flow error */
4911 assert(ua_chan_node);
4912
4913 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4914
4915 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4916 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4917 if (ua_event == NULL) {
4918 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4919 if (ret < 0) {
4920 goto end_unlock;
4921 }
4922 } else {
4923 ret = enable_ust_app_event(ua_sess, ua_event, app);
4924 if (ret < 0) {
4925 goto end_unlock;
4926 }
4927 }
4928
4929 end_unlock:
4930 pthread_mutex_unlock(&ua_sess->lock);
4931 end:
4932 rcu_read_unlock();
4933 return ret;
4934 }
4935
4936 /*
4937 * Calibrate registered applications.
4938 */
4939 int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4940 {
4941 int ret = 0;
4942 struct lttng_ht_iter iter;
4943 struct ust_app *app;
4944
4945 rcu_read_lock();
4946
4947 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4948 if (!app->compatible) {
4949 /*
4950 * TODO: In time, we should notice the caller of this error by
4951 * telling him that this is a version error.
4952 */
4953 continue;
4954 }
4955
4956 health_code_update();
4957
4958 pthread_mutex_lock(&app->sock_lock);
4959 ret = ustctl_calibrate(app->sock, calibrate);
4960 pthread_mutex_unlock(&app->sock_lock);
4961 if (ret < 0) {
4962 switch (ret) {
4963 case -ENOSYS:
4964 /* Means that it's not implemented on the tracer side. */
4965 ret = 0;
4966 break;
4967 default:
4968 DBG2("Calibrate app PID %d returned with error %d",
4969 app->pid, ret);
4970 break;
4971 }
4972 }
4973 }
4974
4975 DBG("UST app global domain calibration finished");
4976
4977 rcu_read_unlock();
4978
4979 health_code_update();
4980
4981 return ret;
4982 }
4983
4984 /*
4985 * Receive registration and populate the given msg structure.
4986 *
4987 * On success return 0 else a negative value returned by the ustctl call.
4988 */
4989 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4990 {
4991 int ret;
4992 uint32_t pid, ppid, uid, gid;
4993
4994 assert(msg);
4995
4996 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4997 &pid, &ppid, &uid, &gid,
4998 &msg->bits_per_long,
4999 &msg->uint8_t_alignment,
5000 &msg->uint16_t_alignment,
5001 &msg->uint32_t_alignment,
5002 &msg->uint64_t_alignment,
5003 &msg->long_alignment,
5004 &msg->byte_order,
5005 msg->name);
5006 if (ret < 0) {
5007 switch (-ret) {
5008 case EPIPE:
5009 case ECONNRESET:
5010 case LTTNG_UST_ERR_EXITING:
5011 DBG3("UST app recv reg message failed. Application died");
5012 break;
5013 case LTTNG_UST_ERR_UNSUP_MAJOR:
5014 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
5015 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
5016 LTTNG_UST_ABI_MINOR_VERSION);
5017 break;
5018 default:
5019 ERR("UST app recv reg message failed with ret %d", ret);
5020 break;
5021 }
5022 goto error;
5023 }
5024 msg->pid = (pid_t) pid;
5025 msg->ppid = (pid_t) ppid;
5026 msg->uid = (uid_t) uid;
5027 msg->gid = (gid_t) gid;
5028
5029 error:
5030 return ret;
5031 }
5032
5033 /*
5034 * Return a ust app channel object using the application object and the channel
5035 * object descriptor has a key. If not found, NULL is returned. A RCU read side
5036 * lock MUST be acquired before calling this function.
5037 */
5038 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
5039 int objd)
5040 {
5041 struct lttng_ht_node_ulong *node;
5042 struct lttng_ht_iter iter;
5043 struct ust_app_channel *ua_chan = NULL;
5044
5045 assert(app);
5046
5047 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
5048 node = lttng_ht_iter_get_node_ulong(&iter);
5049 if (node == NULL) {
5050 DBG2("UST app channel find by objd %d not found", objd);
5051 goto error;
5052 }
5053
5054 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
5055
5056 error:
5057 return ua_chan;
5058 }
5059
5060 /*
5061 * Reply to a register channel notification from an application on the notify
5062 * socket. The channel metadata is also created.
5063 *
5064 * The session UST registry lock is acquired in this function.
5065 *
5066 * On success 0 is returned else a negative value.
5067 */
5068 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
5069 size_t nr_fields, struct ustctl_field *fields)
5070 {
5071 int ret, ret_code = 0;
5072 uint32_t chan_id, reg_count;
5073 uint64_t chan_reg_key;
5074 enum ustctl_channel_header type;
5075 struct ust_app *app;
5076 struct ust_app_channel *ua_chan;
5077 struct ust_app_session *ua_sess;
5078 struct ust_registry_session *registry;
5079 struct ust_registry_channel *chan_reg;
5080
5081 rcu_read_lock();
5082
5083 /* Lookup application. If not found, there is a code flow error. */
5084 app = find_app_by_notify_sock(sock);
5085 if (!app) {
5086 DBG("Application socket %d is being teardown. Abort event notify",
5087 sock);
5088 ret = 0;
5089 free(fields);
5090 goto error_rcu_unlock;
5091 }
5092
5093 /* Lookup channel by UST object descriptor. */
5094 ua_chan = find_channel_by_objd(app, cobjd);
5095 if (!ua_chan) {
5096 DBG("Application channel is being teardown. Abort event notify");
5097 ret = 0;
5098 free(fields);
5099 goto error_rcu_unlock;
5100 }
5101
5102 assert(ua_chan->session);
5103 ua_sess = ua_chan->session;
5104
5105 /* Get right session registry depending on the session buffer type. */
5106 registry = get_session_registry(ua_sess);
5107 assert(registry);
5108
5109 /* Depending on the buffer type, a different channel key is used. */
5110 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5111 chan_reg_key = ua_chan->tracing_channel_id;
5112 } else {
5113 chan_reg_key = ua_chan->key;
5114 }
5115
5116 pthread_mutex_lock(&registry->lock);
5117
5118 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
5119 assert(chan_reg);
5120
5121 if (!chan_reg->register_done) {
5122 reg_count = ust_registry_get_event_count(chan_reg);
5123 if (reg_count < 31) {
5124 type = USTCTL_CHANNEL_HEADER_COMPACT;
5125 } else {
5126 type = USTCTL_CHANNEL_HEADER_LARGE;
5127 }
5128
5129 chan_reg->nr_ctx_fields = nr_fields;
5130 chan_reg->ctx_fields = fields;
5131 chan_reg->header_type = type;
5132 } else {
5133 /* Get current already assigned values. */
5134 type = chan_reg->header_type;
5135 free(fields);
5136 /* Set to NULL so the error path does not do a double free. */
5137 fields = NULL;
5138 }
5139 /* Channel id is set during the object creation. */
5140 chan_id = chan_reg->chan_id;
5141
5142 /* Append to metadata */
5143 if (!chan_reg->metadata_dumped) {
5144 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
5145 if (ret_code) {
5146 ERR("Error appending channel metadata (errno = %d)", ret_code);
5147 goto reply;
5148 }
5149 }
5150
5151 reply:
5152 DBG3("UST app replying to register channel key %" PRIu64
5153 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
5154 ret_code);
5155
5156 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
5157 if (ret < 0) {
5158 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5159 ERR("UST app reply channel failed with ret %d", ret);
5160 } else {
5161 DBG3("UST app reply channel failed. Application died");
5162 }
5163 goto error;
5164 }
5165
5166 /* This channel registry registration is completed. */
5167 chan_reg->register_done = 1;
5168
5169 error:
5170 pthread_mutex_unlock(&registry->lock);
5171 error_rcu_unlock:
5172 rcu_read_unlock();
5173 if (ret) {
5174 free(fields);
5175 }
5176 return ret;
5177 }
5178
5179 /*
5180 * Add event to the UST channel registry. When the event is added to the
5181 * registry, the metadata is also created. Once done, this replies to the
5182 * application with the appropriate error code.
5183 *
5184 * The session UST registry lock is acquired in the function.
5185 *
5186 * On success 0 is returned else a negative value.
5187 */
5188 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
5189 char *sig, size_t nr_fields, struct ustctl_field *fields,
5190 int loglevel_value, char *model_emf_uri)
5191 {
5192 int ret, ret_code;
5193 uint32_t event_id = 0;
5194 uint64_t chan_reg_key;
5195 struct ust_app *app;
5196 struct ust_app_channel *ua_chan;
5197 struct ust_app_session *ua_sess;
5198 struct ust_registry_session *registry;
5199
5200 rcu_read_lock();
5201
5202 /* Lookup application. If not found, there is a code flow error. */
5203 app = find_app_by_notify_sock(sock);
5204 if (!app) {
5205 DBG("Application socket %d is being teardown. Abort event notify",
5206 sock);
5207 ret = 0;
5208 free(sig);
5209 free(fields);
5210 free(model_emf_uri);
5211 goto error_rcu_unlock;
5212 }
5213
5214 /* Lookup channel by UST object descriptor. */
5215 ua_chan = find_channel_by_objd(app, cobjd);
5216 if (!ua_chan) {
5217 DBG("Application channel is being teardown. Abort event notify");
5218 ret = 0;
5219 free(sig);
5220 free(fields);
5221 free(model_emf_uri);
5222 goto error_rcu_unlock;
5223 }
5224
5225 assert(ua_chan->session);
5226 ua_sess = ua_chan->session;
5227
5228 registry = get_session_registry(ua_sess);
5229 assert(registry);
5230
5231 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5232 chan_reg_key = ua_chan->tracing_channel_id;
5233 } else {
5234 chan_reg_key = ua_chan->key;
5235 }
5236
5237 pthread_mutex_lock(&registry->lock);
5238
5239 /*
5240 * From this point on, this call acquires the ownership of the sig, fields
5241 * and model_emf_uri meaning any free are done inside it if needed. These
5242 * three variables MUST NOT be read/write after this.
5243 */
5244 ret_code = ust_registry_create_event(registry, chan_reg_key,
5245 sobjd, cobjd, name, sig, nr_fields, fields,
5246 loglevel_value, model_emf_uri, ua_sess->buffer_type,
5247 &event_id, app);
5248
5249 /*
5250 * The return value is returned to ustctl so in case of an error, the
5251 * application can be notified. In case of an error, it's important not to
5252 * return a negative error or else the application will get closed.
5253 */
5254 ret = ustctl_reply_register_event(sock, event_id, ret_code);
5255 if (ret < 0) {
5256 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5257 ERR("UST app reply event failed with ret %d", ret);
5258 } else {
5259 DBG3("UST app reply event failed. Application died");
5260 }
5261 /*
5262 * No need to wipe the create event since the application socket will
5263 * get close on error hence cleaning up everything by itself.
5264 */
5265 goto error;
5266 }
5267
5268 DBG3("UST registry event %s with id %" PRId32 " added successfully",
5269 name, event_id);
5270
5271 error:
5272 pthread_mutex_unlock(&registry->lock);
5273 error_rcu_unlock:
5274 rcu_read_unlock();
5275 return ret;
5276 }
5277
5278 /*
5279 * Handle application notification through the given notify socket.
5280 *
5281 * Return 0 on success or else a negative value.
5282 */
5283 int ust_app_recv_notify(int sock)
5284 {
5285 int ret;
5286 enum ustctl_notify_cmd cmd;
5287
5288 DBG3("UST app receiving notify from sock %d", sock);
5289
5290 ret = ustctl_recv_notify(sock, &cmd);
5291 if (ret < 0) {
5292 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5293 ERR("UST app recv notify failed with ret %d", ret);
5294 } else {
5295 DBG3("UST app recv notify failed. Application died");
5296 }
5297 goto error;
5298 }
5299
5300 switch (cmd) {
5301 case USTCTL_NOTIFY_CMD_EVENT:
5302 {
5303 int sobjd, cobjd, loglevel_value;
5304 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
5305 size_t nr_fields;
5306 struct ustctl_field *fields;
5307
5308 DBG2("UST app ustctl register event received");
5309
5310 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
5311 &loglevel_value, &sig, &nr_fields, &fields,
5312 &model_emf_uri);
5313 if (ret < 0) {
5314 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5315 ERR("UST app recv event failed with ret %d", ret);
5316 } else {
5317 DBG3("UST app recv event failed. Application died");
5318 }
5319 goto error;
5320 }
5321
5322 /*
5323 * Add event to the UST registry coming from the notify socket. This
5324 * call will free if needed the sig, fields and model_emf_uri. This
5325 * code path loses the ownsership of these variables and transfer them
5326 * to the this function.
5327 */
5328 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
5329 fields, loglevel_value, model_emf_uri);
5330 if (ret < 0) {
5331 goto error;
5332 }
5333
5334 break;
5335 }
5336 case USTCTL_NOTIFY_CMD_CHANNEL:
5337 {
5338 int sobjd, cobjd;
5339 size_t nr_fields;
5340 struct ustctl_field *fields;
5341
5342 DBG2("UST app ustctl register channel received");
5343
5344 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
5345 &fields);
5346 if (ret < 0) {
5347 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5348 ERR("UST app recv channel failed with ret %d", ret);
5349 } else {
5350 DBG3("UST app recv channel failed. Application died");
5351 }
5352 goto error;
5353 }
5354
5355 /*
5356 * The fields ownership are transfered to this function call meaning
5357 * that if needed it will be freed. After this, it's invalid to access
5358 * fields or clean it up.
5359 */
5360 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
5361 fields);
5362 if (ret < 0) {
5363 goto error;
5364 }
5365
5366 break;
5367 }
5368 default:
5369 /* Should NEVER happen. */
5370 assert(0);
5371 }
5372
5373 error:
5374 return ret;
5375 }
5376
5377 /*
5378 * Once the notify socket hangs up, this is called. First, it tries to find the
5379 * corresponding application. On failure, the call_rcu to close the socket is
5380 * executed. If an application is found, it tries to delete it from the notify
5381 * socket hash table. Whathever the result, it proceeds to the call_rcu.
5382 *
5383 * Note that an object needs to be allocated here so on ENOMEM failure, the
5384 * call RCU is not done but the rest of the cleanup is.
5385 */
5386 void ust_app_notify_sock_unregister(int sock)
5387 {
5388 int err_enomem = 0;
5389 struct lttng_ht_iter iter;
5390 struct ust_app *app;
5391 struct ust_app_notify_sock_obj *obj;
5392
5393 assert(sock >= 0);
5394
5395 rcu_read_lock();
5396
5397 obj = zmalloc(sizeof(*obj));
5398 if (!obj) {
5399 /*
5400 * An ENOMEM is kind of uncool. If this strikes we continue the
5401 * procedure but the call_rcu will not be called. In this case, we
5402 * accept the fd leak rather than possibly creating an unsynchronized
5403 * state between threads.
5404 *
5405 * TODO: The notify object should be created once the notify socket is
5406 * registered and stored independantely from the ust app object. The
5407 * tricky part is to synchronize the teardown of the application and
5408 * this notify object. Let's keep that in mind so we can avoid this
5409 * kind of shenanigans with ENOMEM in the teardown path.
5410 */
5411 err_enomem = 1;
5412 } else {
5413 obj->fd = sock;
5414 }
5415
5416 DBG("UST app notify socket unregister %d", sock);
5417
5418 /*
5419 * Lookup application by notify socket. If this fails, this means that the
5420 * hash table delete has already been done by the application
5421 * unregistration process so we can safely close the notify socket in a
5422 * call RCU.
5423 */
5424 app = find_app_by_notify_sock(sock);
5425 if (!app) {
5426 goto close_socket;
5427 }
5428
5429 iter.iter.node = &app->notify_sock_n.node;
5430
5431 /*
5432 * Whatever happens here either we fail or succeed, in both cases we have
5433 * to close the socket after a grace period to continue to the call RCU
5434 * here. If the deletion is successful, the application is not visible
5435 * anymore by other threads and is it fails it means that it was already
5436 * deleted from the hash table so either way we just have to close the
5437 * socket.
5438 */
5439 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5440
5441 close_socket:
5442 rcu_read_unlock();
5443
5444 /*
5445 * Close socket after a grace period to avoid for the socket to be reused
5446 * before the application object is freed creating potential race between
5447 * threads trying to add unique in the global hash table.
5448 */
5449 if (!err_enomem) {
5450 call_rcu(&obj->head, close_notify_sock_rcu);
5451 }
5452 }
5453
5454 /*
5455 * Destroy a ust app data structure and free its memory.
5456 */
5457 void ust_app_destroy(struct ust_app *app)
5458 {
5459 if (!app) {
5460 return;
5461 }
5462
5463 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5464 }
5465
5466 /*
5467 * Take a snapshot for a given UST session. The snapshot is sent to the given
5468 * output.
5469 *
5470 * Return 0 on success or else a negative value.
5471 */
5472 int ust_app_snapshot_record(struct ltt_ust_session *usess,
5473 struct snapshot_output *output, int wait,
5474 uint64_t nb_packets_per_stream)
5475 {
5476 int ret = 0;
5477 unsigned int snapshot_done = 0;
5478 struct lttng_ht_iter iter;
5479 struct ust_app *app;
5480 char pathname[PATH_MAX];
5481
5482 assert(usess);
5483 assert(output);
5484
5485 rcu_read_lock();
5486
5487 switch (usess->buffer_type) {
5488 case LTTNG_BUFFER_PER_UID:
5489 {
5490 struct buffer_reg_uid *reg;
5491
5492 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5493 struct buffer_reg_channel *reg_chan;
5494 struct consumer_socket *socket;
5495
5496 /* Get consumer socket to use to push the metadata.*/
5497 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5498 usess->consumer);
5499 if (!socket) {
5500 ret = -EINVAL;
5501 goto error;
5502 }
5503
5504 memset(pathname, 0, sizeof(pathname));
5505 ret = snprintf(pathname, sizeof(pathname),
5506 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
5507 reg->uid, reg->bits_per_long);
5508 if (ret < 0) {
5509 PERROR("snprintf snapshot path");
5510 goto error;
5511 }
5512
5513 /* Add the UST default trace dir to path. */
5514 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5515 reg_chan, node.node) {
5516 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key,
5517 output, 0, usess->uid, usess->gid, pathname, wait,
5518 nb_packets_per_stream);
5519 if (ret < 0) {
5520 goto error;
5521 }
5522 }
5523 ret = consumer_snapshot_channel(socket,
5524 reg->registry->reg.ust->metadata_key, output, 1,
5525 usess->uid, usess->gid, pathname, wait, 0);
5526 if (ret < 0) {
5527 goto error;
5528 }
5529 snapshot_done = 1;
5530 }
5531 break;
5532 }
5533 case LTTNG_BUFFER_PER_PID:
5534 {
5535 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5536 struct consumer_socket *socket;
5537 struct lttng_ht_iter chan_iter;
5538 struct ust_app_channel *ua_chan;
5539 struct ust_app_session *ua_sess;
5540 struct ust_registry_session *registry;
5541
5542 ua_sess = lookup_session_by_app(usess, app);
5543 if (!ua_sess) {
5544 /* Session not associated with this app. */
5545 continue;
5546 }
5547
5548 /* Get the right consumer socket for the application. */
5549 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5550 output->consumer);
5551 if (!socket) {
5552 ret = -EINVAL;
5553 goto error;
5554 }
5555
5556 /* Add the UST default trace dir to path. */
5557 memset(pathname, 0, sizeof(pathname));
5558 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
5559 ua_sess->path);
5560 if (ret < 0) {
5561 PERROR("snprintf snapshot path");
5562 goto error;
5563 }
5564
5565 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5566 ua_chan, node.node) {
5567 ret = consumer_snapshot_channel(socket, ua_chan->key, output,
5568 0, ua_sess->euid, ua_sess->egid, pathname, wait,
5569 nb_packets_per_stream);
5570 if (ret < 0) {
5571 goto error;
5572 }
5573 }
5574
5575 registry = get_session_registry(ua_sess);
5576 assert(registry);
5577 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5578 1, ua_sess->euid, ua_sess->egid, pathname, wait, 0);
5579 if (ret < 0) {
5580 goto error;
5581 }
5582 snapshot_done = 1;
5583 }
5584 break;
5585 }
5586 default:
5587 assert(0);
5588 break;
5589 }
5590
5591 if (!snapshot_done) {
5592 /*
5593 * If no snapshot was made and we are not in the error path, this means
5594 * that there are no buffers thus no (prior) application to snapshot
5595 * data from so we have simply NO data.
5596 */
5597 ret = -ENODATA;
5598 }
5599
5600 error:
5601 rcu_read_unlock();
5602 return ret;
5603 }
5604
5605 /*
5606 * Return the size taken by one more packet per stream.
5607 */
5608 uint64_t ust_app_get_size_one_more_packet_per_stream(struct ltt_ust_session *usess,
5609 uint64_t cur_nr_packets)
5610 {
5611 uint64_t tot_size = 0;
5612 struct ust_app *app;
5613 struct lttng_ht_iter iter;
5614
5615 assert(usess);
5616
5617 switch (usess->buffer_type) {
5618 case LTTNG_BUFFER_PER_UID:
5619 {
5620 struct buffer_reg_uid *reg;
5621
5622 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5623 struct buffer_reg_channel *reg_chan;
5624
5625 rcu_read_lock();
5626 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5627 reg_chan, node.node) {
5628 if (cur_nr_packets >= reg_chan->num_subbuf) {
5629 /*
5630 * Don't take channel into account if we
5631 * already grab all its packets.
5632 */
5633 continue;
5634 }
5635 tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
5636 }
5637 rcu_read_unlock();
5638 }
5639 break;
5640 }
5641 case LTTNG_BUFFER_PER_PID:
5642 {
5643 rcu_read_lock();
5644 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5645 struct ust_app_channel *ua_chan;
5646 struct ust_app_session *ua_sess;
5647 struct lttng_ht_iter chan_iter;
5648
5649 ua_sess = lookup_session_by_app(usess, app);
5650 if (!ua_sess) {
5651 /* Session not associated with this app. */
5652 continue;
5653 }
5654
5655 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5656 ua_chan, node.node) {
5657 if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
5658 /*
5659 * Don't take channel into account if we
5660 * already grab all its packets.
5661 */
5662 continue;
5663 }
5664 tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
5665 }
5666 }
5667 rcu_read_unlock();
5668 break;
5669 }
5670 default:
5671 assert(0);
5672 break;
5673 }
5674
5675 return tot_size;
5676 }
This page took 0.150375 seconds and 4 git commands to generate.