Perform the clean-up of application notify sockets in main thread
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <lttng/ust-error.h>
31 #include <signal.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35
36 #include "buffer-registry.h"
37 #include "fd-limit.h"
38 #include "health-sessiond.h"
39 #include "ust-app.h"
40 #include "ust-consumer.h"
41 #include "ust-ctl.h"
42 #include "utils.h"
43 #include "session.h"
44 #include "lttng-sessiond.h"
45 #include "notification-thread-commands.h"
46 #include "rotate.h"
47
48 static
49 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51 /* Next available channel key. Access under next_channel_key_lock. */
52 static uint64_t _next_channel_key;
53 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55 /* Next available session ID. Access under next_session_id_lock. */
56 static uint64_t _next_session_id;
57 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59 /*
60 * Return the incremented value of next_channel_key.
61 */
62 static uint64_t get_next_channel_key(void)
63 {
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70 }
71
72 /*
73 * Return the atomically incremented value of next_session_id.
74 */
75 static uint64_t get_next_session_id(void)
76 {
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83 }
84
85 static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88 {
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97 }
98
99 /*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106 {
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173 no_match:
174 return 0;
175 }
176
177 /*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183 {
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202 }
203
204 /*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208 static void close_notify_sock_rcu(struct rcu_head *head)
209 {
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224 }
225
226 /*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233 static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235 {
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
254 if (!reg_uid) {
255 goto error;
256 }
257 registry = reg_uid->registry->reg.ust;
258 break;
259 }
260 default:
261 assert(0);
262 };
263
264 error:
265 return registry;
266 }
267
268 /*
269 * Delete ust context safely. RCU read lock must be held before calling
270 * this function.
271 */
272 static
273 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
274 struct ust_app *app)
275 {
276 int ret;
277
278 assert(ua_ctx);
279
280 if (ua_ctx->obj) {
281 pthread_mutex_lock(&app->sock_lock);
282 ret = ustctl_release_object(sock, ua_ctx->obj);
283 pthread_mutex_unlock(&app->sock_lock);
284 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
285 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
286 sock, ua_ctx->obj->handle, ret);
287 }
288 free(ua_ctx->obj);
289 }
290 free(ua_ctx);
291 }
292
293 /*
294 * Delete ust app event safely. RCU read lock must be held before calling
295 * this function.
296 */
297 static
298 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
299 struct ust_app *app)
300 {
301 int ret;
302
303 assert(ua_event);
304
305 free(ua_event->filter);
306 if (ua_event->exclusion != NULL)
307 free(ua_event->exclusion);
308 if (ua_event->obj != NULL) {
309 pthread_mutex_lock(&app->sock_lock);
310 ret = ustctl_release_object(sock, ua_event->obj);
311 pthread_mutex_unlock(&app->sock_lock);
312 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
313 ERR("UST app sock %d release event obj failed with ret %d",
314 sock, ret);
315 }
316 free(ua_event->obj);
317 }
318 free(ua_event);
319 }
320
321 /*
322 * Release ust data object of the given stream.
323 *
324 * Return 0 on success or else a negative value.
325 */
326 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
327 struct ust_app *app)
328 {
329 int ret = 0;
330
331 assert(stream);
332
333 if (stream->obj) {
334 pthread_mutex_lock(&app->sock_lock);
335 ret = ustctl_release_object(sock, stream->obj);
336 pthread_mutex_unlock(&app->sock_lock);
337 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
338 ERR("UST app sock %d release stream obj failed with ret %d",
339 sock, ret);
340 }
341 lttng_fd_put(LTTNG_FD_APPS, 2);
342 free(stream->obj);
343 }
344
345 return ret;
346 }
347
348 /*
349 * Delete ust app stream safely. RCU read lock must be held before calling
350 * this function.
351 */
352 static
353 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
354 struct ust_app *app)
355 {
356 assert(stream);
357
358 (void) release_ust_app_stream(sock, stream, app);
359 free(stream);
360 }
361
362 /*
363 * We need to execute ht_destroy outside of RCU read-side critical
364 * section and outside of call_rcu thread, so we postpone its execution
365 * using ht_cleanup_push. It is simpler than to change the semantic of
366 * the many callers of delete_ust_app_session().
367 */
368 static
369 void delete_ust_app_channel_rcu(struct rcu_head *head)
370 {
371 struct ust_app_channel *ua_chan =
372 caa_container_of(head, struct ust_app_channel, rcu_head);
373
374 ht_cleanup_push(ua_chan->ctx);
375 ht_cleanup_push(ua_chan->events);
376 free(ua_chan);
377 }
378
379 /*
380 * Extract the lost packet or discarded events counter when the channel is
381 * being deleted and store the value in the parent channel so we can
382 * access it from lttng list and at stop/destroy.
383 *
384 * The session list lock must be held by the caller.
385 */
386 static
387 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
388 {
389 uint64_t discarded = 0, lost = 0;
390 struct ltt_session *session;
391 struct ltt_ust_channel *uchan;
392
393 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
394 return;
395 }
396
397 rcu_read_lock();
398 session = session_find_by_id(ua_chan->session->tracing_id);
399 if (!session || !session->ust_session) {
400 /*
401 * Not finding the session is not an error because there are
402 * multiple ways the channels can be torn down.
403 *
404 * 1) The session daemon can initiate the destruction of the
405 * ust app session after receiving a destroy command or
406 * during its shutdown/teardown.
407 * 2) The application, since we are in per-pid tracing, is
408 * unregistering and tearing down its ust app session.
409 *
410 * Both paths are protected by the session list lock which
411 * ensures that the accounting of lost packets and discarded
412 * events is done exactly once. The session is then unpublished
413 * from the session list, resulting in this condition.
414 */
415 goto end;
416 }
417
418 if (ua_chan->attr.overwrite) {
419 consumer_get_lost_packets(ua_chan->session->tracing_id,
420 ua_chan->key, session->ust_session->consumer,
421 &lost);
422 } else {
423 consumer_get_discarded_events(ua_chan->session->tracing_id,
424 ua_chan->key, session->ust_session->consumer,
425 &discarded);
426 }
427 uchan = trace_ust_find_channel_by_name(
428 session->ust_session->domain_global.channels,
429 ua_chan->name);
430 if (!uchan) {
431 ERR("Missing UST channel to store discarded counters");
432 goto end;
433 }
434
435 uchan->per_pid_closed_app_discarded += discarded;
436 uchan->per_pid_closed_app_lost += lost;
437
438 end:
439 rcu_read_unlock();
440 if (session) {
441 session_put(session);
442 }
443 }
444
445 /*
446 * Delete ust app channel safely. RCU read lock must be held before calling
447 * this function.
448 *
449 * The session list lock must be held by the caller.
450 */
451 static
452 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
453 struct ust_app *app)
454 {
455 int ret;
456 struct lttng_ht_iter iter;
457 struct ust_app_event *ua_event;
458 struct ust_app_ctx *ua_ctx;
459 struct ust_app_stream *stream, *stmp;
460 struct ust_registry_session *registry;
461
462 assert(ua_chan);
463
464 DBG3("UST app deleting channel %s", ua_chan->name);
465
466 /* Wipe stream */
467 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
468 cds_list_del(&stream->list);
469 delete_ust_app_stream(sock, stream, app);
470 }
471
472 /* Wipe context */
473 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
474 cds_list_del(&ua_ctx->list);
475 ret = lttng_ht_del(ua_chan->ctx, &iter);
476 assert(!ret);
477 delete_ust_app_ctx(sock, ua_ctx, app);
478 }
479
480 /* Wipe events */
481 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
482 node.node) {
483 ret = lttng_ht_del(ua_chan->events, &iter);
484 assert(!ret);
485 delete_ust_app_event(sock, ua_event, app);
486 }
487
488 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
489 /* Wipe and free registry from session registry. */
490 registry = get_session_registry(ua_chan->session);
491 if (registry) {
492 ust_registry_channel_del_free(registry, ua_chan->key,
493 sock >= 0);
494 }
495 /*
496 * A negative socket can be used by the caller when
497 * cleaning-up a ua_chan in an error path. Skip the
498 * accounting in this case.
499 */
500 if (sock >= 0) {
501 save_per_pid_lost_discarded_counters(ua_chan);
502 }
503 }
504
505 if (ua_chan->obj != NULL) {
506 /* Remove channel from application UST object descriptor. */
507 iter.iter.node = &ua_chan->ust_objd_node.node;
508 ret = lttng_ht_del(app->ust_objd, &iter);
509 assert(!ret);
510 pthread_mutex_lock(&app->sock_lock);
511 ret = ustctl_release_object(sock, ua_chan->obj);
512 pthread_mutex_unlock(&app->sock_lock);
513 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
514 ERR("UST app sock %d release channel obj failed with ret %d",
515 sock, ret);
516 }
517 lttng_fd_put(LTTNG_FD_APPS, 1);
518 free(ua_chan->obj);
519 }
520 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
521 }
522
523 int ust_app_register_done(struct ust_app *app)
524 {
525 int ret;
526
527 pthread_mutex_lock(&app->sock_lock);
528 ret = ustctl_register_done(app->sock);
529 pthread_mutex_unlock(&app->sock_lock);
530 return ret;
531 }
532
533 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
534 {
535 int ret, sock;
536
537 if (app) {
538 pthread_mutex_lock(&app->sock_lock);
539 sock = app->sock;
540 } else {
541 sock = -1;
542 }
543 ret = ustctl_release_object(sock, data);
544 if (app) {
545 pthread_mutex_unlock(&app->sock_lock);
546 }
547 return ret;
548 }
549
550 /*
551 * Push metadata to consumer socket.
552 *
553 * RCU read-side lock must be held to guarantee existance of socket.
554 * Must be called with the ust app session lock held.
555 * Must be called with the registry lock held.
556 *
557 * On success, return the len of metadata pushed or else a negative value.
558 * Returning a -EPIPE return value means we could not send the metadata,
559 * but it can be caused by recoverable errors (e.g. the application has
560 * terminated concurrently).
561 */
562 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
563 struct consumer_socket *socket, int send_zero_data)
564 {
565 int ret;
566 char *metadata_str = NULL;
567 size_t len, offset, new_metadata_len_sent;
568 ssize_t ret_val;
569 uint64_t metadata_key, metadata_version;
570
571 assert(registry);
572 assert(socket);
573
574 metadata_key = registry->metadata_key;
575
576 /*
577 * Means that no metadata was assigned to the session. This can
578 * happens if no start has been done previously.
579 */
580 if (!metadata_key) {
581 return 0;
582 }
583
584 offset = registry->metadata_len_sent;
585 len = registry->metadata_len - registry->metadata_len_sent;
586 new_metadata_len_sent = registry->metadata_len;
587 metadata_version = registry->metadata_version;
588 if (len == 0) {
589 DBG3("No metadata to push for metadata key %" PRIu64,
590 registry->metadata_key);
591 ret_val = len;
592 if (send_zero_data) {
593 DBG("No metadata to push");
594 goto push_data;
595 }
596 goto end;
597 }
598
599 /* Allocate only what we have to send. */
600 metadata_str = zmalloc(len);
601 if (!metadata_str) {
602 PERROR("zmalloc ust app metadata string");
603 ret_val = -ENOMEM;
604 goto error;
605 }
606 /* Copy what we haven't sent out. */
607 memcpy(metadata_str, registry->metadata + offset, len);
608
609 push_data:
610 pthread_mutex_unlock(&registry->lock);
611 /*
612 * We need to unlock the registry while we push metadata to
613 * break a circular dependency between the consumerd metadata
614 * lock and the sessiond registry lock. Indeed, pushing metadata
615 * to the consumerd awaits that it gets pushed all the way to
616 * relayd, but doing so requires grabbing the metadata lock. If
617 * a concurrent metadata request is being performed by
618 * consumerd, this can try to grab the registry lock on the
619 * sessiond while holding the metadata lock on the consumer
620 * daemon. Those push and pull schemes are performed on two
621 * different bidirectionnal communication sockets.
622 */
623 ret = consumer_push_metadata(socket, metadata_key,
624 metadata_str, len, offset, metadata_version);
625 pthread_mutex_lock(&registry->lock);
626 if (ret < 0) {
627 /*
628 * There is an acceptable race here between the registry
629 * metadata key assignment and the creation on the
630 * consumer. The session daemon can concurrently push
631 * metadata for this registry while being created on the
632 * consumer since the metadata key of the registry is
633 * assigned *before* it is setup to avoid the consumer
634 * to ask for metadata that could possibly be not found
635 * in the session daemon.
636 *
637 * The metadata will get pushed either by the session
638 * being stopped or the consumer requesting metadata if
639 * that race is triggered.
640 */
641 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
642 ret = 0;
643 } else {
644 ERR("Error pushing metadata to consumer");
645 }
646 ret_val = ret;
647 goto error_push;
648 } else {
649 /*
650 * Metadata may have been concurrently pushed, since
651 * we're not holding the registry lock while pushing to
652 * consumer. This is handled by the fact that we send
653 * the metadata content, size, and the offset at which
654 * that metadata belongs. This may arrive out of order
655 * on the consumer side, and the consumer is able to
656 * deal with overlapping fragments. The consumer
657 * supports overlapping fragments, which must be
658 * contiguous starting from offset 0. We keep the
659 * largest metadata_len_sent value of the concurrent
660 * send.
661 */
662 registry->metadata_len_sent =
663 max_t(size_t, registry->metadata_len_sent,
664 new_metadata_len_sent);
665 }
666 free(metadata_str);
667 return len;
668
669 end:
670 error:
671 if (ret_val) {
672 /*
673 * On error, flag the registry that the metadata is
674 * closed. We were unable to push anything and this
675 * means that either the consumer is not responding or
676 * the metadata cache has been destroyed on the
677 * consumer.
678 */
679 registry->metadata_closed = 1;
680 }
681 error_push:
682 free(metadata_str);
683 return ret_val;
684 }
685
686 /*
687 * For a given application and session, push metadata to consumer.
688 * Either sock or consumer is required : if sock is NULL, the default
689 * socket to send the metadata is retrieved from consumer, if sock
690 * is not NULL we use it to send the metadata.
691 * RCU read-side lock must be held while calling this function,
692 * therefore ensuring existance of registry. It also ensures existance
693 * of socket throughout this function.
694 *
695 * Return 0 on success else a negative error.
696 * Returning a -EPIPE return value means we could not send the metadata,
697 * but it can be caused by recoverable errors (e.g. the application has
698 * terminated concurrently).
699 */
700 static int push_metadata(struct ust_registry_session *registry,
701 struct consumer_output *consumer)
702 {
703 int ret_val;
704 ssize_t ret;
705 struct consumer_socket *socket;
706
707 assert(registry);
708 assert(consumer);
709
710 pthread_mutex_lock(&registry->lock);
711 if (registry->metadata_closed) {
712 ret_val = -EPIPE;
713 goto error;
714 }
715
716 /* Get consumer socket to use to push the metadata.*/
717 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
718 consumer);
719 if (!socket) {
720 ret_val = -1;
721 goto error;
722 }
723
724 ret = ust_app_push_metadata(registry, socket, 0);
725 if (ret < 0) {
726 ret_val = ret;
727 goto error;
728 }
729 pthread_mutex_unlock(&registry->lock);
730 return 0;
731
732 error:
733 pthread_mutex_unlock(&registry->lock);
734 return ret_val;
735 }
736
737 /*
738 * Send to the consumer a close metadata command for the given session. Once
739 * done, the metadata channel is deleted and the session metadata pointer is
740 * nullified. The session lock MUST be held unless the application is
741 * in the destroy path.
742 *
743 * Return 0 on success else a negative value.
744 */
745 static int close_metadata(struct ust_registry_session *registry,
746 struct consumer_output *consumer)
747 {
748 int ret;
749 struct consumer_socket *socket;
750
751 assert(registry);
752 assert(consumer);
753
754 rcu_read_lock();
755
756 pthread_mutex_lock(&registry->lock);
757
758 if (!registry->metadata_key || registry->metadata_closed) {
759 ret = 0;
760 goto end;
761 }
762
763 /* Get consumer socket to use to push the metadata.*/
764 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
765 consumer);
766 if (!socket) {
767 ret = -1;
768 goto error;
769 }
770
771 ret = consumer_close_metadata(socket, registry->metadata_key);
772 if (ret < 0) {
773 goto error;
774 }
775
776 error:
777 /*
778 * Metadata closed. Even on error this means that the consumer is not
779 * responding or not found so either way a second close should NOT be emit
780 * for this registry.
781 */
782 registry->metadata_closed = 1;
783 end:
784 pthread_mutex_unlock(&registry->lock);
785 rcu_read_unlock();
786 return ret;
787 }
788
789 /*
790 * We need to execute ht_destroy outside of RCU read-side critical
791 * section and outside of call_rcu thread, so we postpone its execution
792 * using ht_cleanup_push. It is simpler than to change the semantic of
793 * the many callers of delete_ust_app_session().
794 */
795 static
796 void delete_ust_app_session_rcu(struct rcu_head *head)
797 {
798 struct ust_app_session *ua_sess =
799 caa_container_of(head, struct ust_app_session, rcu_head);
800
801 ht_cleanup_push(ua_sess->channels);
802 free(ua_sess);
803 }
804
805 /*
806 * Delete ust app session safely. RCU read lock must be held before calling
807 * this function.
808 *
809 * The session list lock must be held by the caller.
810 */
811 static
812 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
813 struct ust_app *app)
814 {
815 int ret;
816 struct lttng_ht_iter iter;
817 struct ust_app_channel *ua_chan;
818 struct ust_registry_session *registry;
819
820 assert(ua_sess);
821
822 pthread_mutex_lock(&ua_sess->lock);
823
824 assert(!ua_sess->deleted);
825 ua_sess->deleted = true;
826
827 registry = get_session_registry(ua_sess);
828 /* Registry can be null on error path during initialization. */
829 if (registry) {
830 /* Push metadata for application before freeing the application. */
831 (void) push_metadata(registry, ua_sess->consumer);
832
833 /*
834 * Don't ask to close metadata for global per UID buffers. Close
835 * metadata only on destroy trace session in this case. Also, the
836 * previous push metadata could have flag the metadata registry to
837 * close so don't send a close command if closed.
838 */
839 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
840 /* And ask to close it for this session registry. */
841 (void) close_metadata(registry, ua_sess->consumer);
842 }
843 }
844
845 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
846 node.node) {
847 ret = lttng_ht_del(ua_sess->channels, &iter);
848 assert(!ret);
849 delete_ust_app_channel(sock, ua_chan, app);
850 }
851
852 /* In case of per PID, the registry is kept in the session. */
853 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
854 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
855 if (reg_pid) {
856 /*
857 * Registry can be null on error path during
858 * initialization.
859 */
860 buffer_reg_pid_remove(reg_pid);
861 buffer_reg_pid_destroy(reg_pid);
862 }
863 }
864
865 if (ua_sess->handle != -1) {
866 pthread_mutex_lock(&app->sock_lock);
867 ret = ustctl_release_handle(sock, ua_sess->handle);
868 pthread_mutex_unlock(&app->sock_lock);
869 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
870 ERR("UST app sock %d release session handle failed with ret %d",
871 sock, ret);
872 }
873 /* Remove session from application UST object descriptor. */
874 iter.iter.node = &ua_sess->ust_objd_node.node;
875 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
876 assert(!ret);
877 }
878
879 pthread_mutex_unlock(&ua_sess->lock);
880
881 consumer_output_put(ua_sess->consumer);
882
883 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
884 }
885
886 /*
887 * Delete a traceable application structure from the global list. Never call
888 * this function outside of a call_rcu call.
889 *
890 * RCU read side lock should _NOT_ be held when calling this function.
891 */
892 static
893 void delete_ust_app(struct ust_app *app)
894 {
895 int ret, sock;
896 struct ust_app_session *ua_sess, *tmp_ua_sess;
897
898 /*
899 * The session list lock must be held during this function to guarantee
900 * the existence of ua_sess.
901 */
902 session_lock_list();
903 /* Delete ust app sessions info */
904 sock = app->sock;
905 app->sock = -1;
906
907 /* Wipe sessions */
908 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
909 teardown_node) {
910 /* Free every object in the session and the session. */
911 rcu_read_lock();
912 delete_ust_app_session(sock, ua_sess, app);
913 rcu_read_unlock();
914 }
915
916 ht_cleanup_push(app->sessions);
917 ht_cleanup_push(app->ust_sessions_objd);
918 ht_cleanup_push(app->ust_objd);
919
920 /*
921 * Wait until we have deleted the application from the sock hash table
922 * before closing this socket, otherwise an application could re-use the
923 * socket ID and race with the teardown, using the same hash table entry.
924 *
925 * It's OK to leave the close in call_rcu. We want it to stay unique for
926 * all RCU readers that could run concurrently with unregister app,
927 * therefore we _need_ to only close that socket after a grace period. So
928 * it should stay in this RCU callback.
929 *
930 * This close() is a very important step of the synchronization model so
931 * every modification to this function must be carefully reviewed.
932 */
933 ret = close(sock);
934 if (ret) {
935 PERROR("close");
936 }
937 lttng_fd_put(LTTNG_FD_APPS, 1);
938
939 DBG2("UST app pid %d deleted", app->pid);
940 free(app);
941 session_unlock_list();
942 }
943
944 /*
945 * URCU intermediate call to delete an UST app.
946 */
947 static
948 void delete_ust_app_rcu(struct rcu_head *head)
949 {
950 struct lttng_ht_node_ulong *node =
951 caa_container_of(head, struct lttng_ht_node_ulong, head);
952 struct ust_app *app =
953 caa_container_of(node, struct ust_app, pid_n);
954
955 DBG3("Call RCU deleting app PID %d", app->pid);
956 delete_ust_app(app);
957 }
958
959 /*
960 * Delete the session from the application ht and delete the data structure by
961 * freeing every object inside and releasing them.
962 *
963 * The session list lock must be held by the caller.
964 */
965 static void destroy_app_session(struct ust_app *app,
966 struct ust_app_session *ua_sess)
967 {
968 int ret;
969 struct lttng_ht_iter iter;
970
971 assert(app);
972 assert(ua_sess);
973
974 iter.iter.node = &ua_sess->node.node;
975 ret = lttng_ht_del(app->sessions, &iter);
976 if (ret) {
977 /* Already scheduled for teardown. */
978 goto end;
979 }
980
981 /* Once deleted, free the data structure. */
982 delete_ust_app_session(app->sock, ua_sess, app);
983
984 end:
985 return;
986 }
987
988 /*
989 * Alloc new UST app session.
990 */
991 static
992 struct ust_app_session *alloc_ust_app_session(void)
993 {
994 struct ust_app_session *ua_sess;
995
996 /* Init most of the default value by allocating and zeroing */
997 ua_sess = zmalloc(sizeof(struct ust_app_session));
998 if (ua_sess == NULL) {
999 PERROR("malloc");
1000 goto error_free;
1001 }
1002
1003 ua_sess->handle = -1;
1004 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1005 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1006 pthread_mutex_init(&ua_sess->lock, NULL);
1007
1008 return ua_sess;
1009
1010 error_free:
1011 return NULL;
1012 }
1013
1014 /*
1015 * Alloc new UST app channel.
1016 */
1017 static
1018 struct ust_app_channel *alloc_ust_app_channel(char *name,
1019 struct ust_app_session *ua_sess,
1020 struct lttng_ust_channel_attr *attr)
1021 {
1022 struct ust_app_channel *ua_chan;
1023
1024 /* Init most of the default value by allocating and zeroing */
1025 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1026 if (ua_chan == NULL) {
1027 PERROR("malloc");
1028 goto error;
1029 }
1030
1031 /* Setup channel name */
1032 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1033 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1034
1035 ua_chan->enabled = 1;
1036 ua_chan->handle = -1;
1037 ua_chan->session = ua_sess;
1038 ua_chan->key = get_next_channel_key();
1039 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1040 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1041 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1042
1043 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1044 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1045
1046 /* Copy attributes */
1047 if (attr) {
1048 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1049 ua_chan->attr.subbuf_size = attr->subbuf_size;
1050 ua_chan->attr.num_subbuf = attr->num_subbuf;
1051 ua_chan->attr.overwrite = attr->overwrite;
1052 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1053 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1054 ua_chan->attr.output = attr->output;
1055 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1056 }
1057 /* By default, the channel is a per cpu channel. */
1058 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1059
1060 DBG3("UST app channel %s allocated", ua_chan->name);
1061
1062 return ua_chan;
1063
1064 error:
1065 return NULL;
1066 }
1067
1068 /*
1069 * Allocate and initialize a UST app stream.
1070 *
1071 * Return newly allocated stream pointer or NULL on error.
1072 */
1073 struct ust_app_stream *ust_app_alloc_stream(void)
1074 {
1075 struct ust_app_stream *stream = NULL;
1076
1077 stream = zmalloc(sizeof(*stream));
1078 if (stream == NULL) {
1079 PERROR("zmalloc ust app stream");
1080 goto error;
1081 }
1082
1083 /* Zero could be a valid value for a handle so flag it to -1. */
1084 stream->handle = -1;
1085
1086 error:
1087 return stream;
1088 }
1089
1090 /*
1091 * Alloc new UST app event.
1092 */
1093 static
1094 struct ust_app_event *alloc_ust_app_event(char *name,
1095 struct lttng_ust_event *attr)
1096 {
1097 struct ust_app_event *ua_event;
1098
1099 /* Init most of the default value by allocating and zeroing */
1100 ua_event = zmalloc(sizeof(struct ust_app_event));
1101 if (ua_event == NULL) {
1102 PERROR("malloc");
1103 goto error;
1104 }
1105
1106 ua_event->enabled = 1;
1107 strncpy(ua_event->name, name, sizeof(ua_event->name));
1108 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1109 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1110
1111 /* Copy attributes */
1112 if (attr) {
1113 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1114 }
1115
1116 DBG3("UST app event %s allocated", ua_event->name);
1117
1118 return ua_event;
1119
1120 error:
1121 return NULL;
1122 }
1123
1124 /*
1125 * Alloc new UST app context.
1126 */
1127 static
1128 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1129 {
1130 struct ust_app_ctx *ua_ctx;
1131
1132 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1133 if (ua_ctx == NULL) {
1134 goto error;
1135 }
1136
1137 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1138
1139 if (uctx) {
1140 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1141 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1142 char *provider_name = NULL, *ctx_name = NULL;
1143
1144 provider_name = strdup(uctx->u.app_ctx.provider_name);
1145 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1146 if (!provider_name || !ctx_name) {
1147 free(provider_name);
1148 free(ctx_name);
1149 goto error;
1150 }
1151
1152 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1153 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1154 }
1155 }
1156
1157 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1158 return ua_ctx;
1159 error:
1160 free(ua_ctx);
1161 return NULL;
1162 }
1163
1164 /*
1165 * Allocate a filter and copy the given original filter.
1166 *
1167 * Return allocated filter or NULL on error.
1168 */
1169 static struct lttng_filter_bytecode *copy_filter_bytecode(
1170 struct lttng_filter_bytecode *orig_f)
1171 {
1172 struct lttng_filter_bytecode *filter = NULL;
1173
1174 /* Copy filter bytecode */
1175 filter = zmalloc(sizeof(*filter) + orig_f->len);
1176 if (!filter) {
1177 PERROR("zmalloc alloc filter bytecode");
1178 goto error;
1179 }
1180
1181 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1182
1183 error:
1184 return filter;
1185 }
1186
1187 /*
1188 * Create a liblttng-ust filter bytecode from given bytecode.
1189 *
1190 * Return allocated filter or NULL on error.
1191 */
1192 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1193 struct lttng_filter_bytecode *orig_f)
1194 {
1195 struct lttng_ust_filter_bytecode *filter = NULL;
1196
1197 /* Copy filter bytecode */
1198 filter = zmalloc(sizeof(*filter) + orig_f->len);
1199 if (!filter) {
1200 PERROR("zmalloc alloc ust filter bytecode");
1201 goto error;
1202 }
1203
1204 assert(sizeof(struct lttng_filter_bytecode) ==
1205 sizeof(struct lttng_ust_filter_bytecode));
1206 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1207 error:
1208 return filter;
1209 }
1210
1211 /*
1212 * Find an ust_app using the sock and return it. RCU read side lock must be
1213 * held before calling this helper function.
1214 */
1215 struct ust_app *ust_app_find_by_sock(int sock)
1216 {
1217 struct lttng_ht_node_ulong *node;
1218 struct lttng_ht_iter iter;
1219
1220 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1221 node = lttng_ht_iter_get_node_ulong(&iter);
1222 if (node == NULL) {
1223 DBG2("UST app find by sock %d not found", sock);
1224 goto error;
1225 }
1226
1227 return caa_container_of(node, struct ust_app, sock_n);
1228
1229 error:
1230 return NULL;
1231 }
1232
1233 /*
1234 * Find an ust_app using the notify sock and return it. RCU read side lock must
1235 * be held before calling this helper function.
1236 */
1237 static struct ust_app *find_app_by_notify_sock(int sock)
1238 {
1239 struct lttng_ht_node_ulong *node;
1240 struct lttng_ht_iter iter;
1241
1242 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1243 &iter);
1244 node = lttng_ht_iter_get_node_ulong(&iter);
1245 if (node == NULL) {
1246 DBG2("UST app find by notify sock %d not found", sock);
1247 goto error;
1248 }
1249
1250 return caa_container_of(node, struct ust_app, notify_sock_n);
1251
1252 error:
1253 return NULL;
1254 }
1255
1256 /*
1257 * Lookup for an ust app event based on event name, filter bytecode and the
1258 * event loglevel.
1259 *
1260 * Return an ust_app_event object or NULL on error.
1261 */
1262 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1263 char *name, struct lttng_filter_bytecode *filter,
1264 int loglevel_value,
1265 const struct lttng_event_exclusion *exclusion)
1266 {
1267 struct lttng_ht_iter iter;
1268 struct lttng_ht_node_str *node;
1269 struct ust_app_event *event = NULL;
1270 struct ust_app_ht_key key;
1271
1272 assert(name);
1273 assert(ht);
1274
1275 /* Setup key for event lookup. */
1276 key.name = name;
1277 key.filter = filter;
1278 key.loglevel_type = loglevel_value;
1279 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1280 key.exclusion = exclusion;
1281
1282 /* Lookup using the event name as hash and a custom match fct. */
1283 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1284 ht_match_ust_app_event, &key, &iter.iter);
1285 node = lttng_ht_iter_get_node_str(&iter);
1286 if (node == NULL) {
1287 goto end;
1288 }
1289
1290 event = caa_container_of(node, struct ust_app_event, node);
1291
1292 end:
1293 return event;
1294 }
1295
1296 /*
1297 * Create the channel context on the tracer.
1298 *
1299 * Called with UST app session lock held.
1300 */
1301 static
1302 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1303 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1304 {
1305 int ret;
1306
1307 health_code_update();
1308
1309 pthread_mutex_lock(&app->sock_lock);
1310 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1311 ua_chan->obj, &ua_ctx->obj);
1312 pthread_mutex_unlock(&app->sock_lock);
1313 if (ret < 0) {
1314 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1315 ERR("UST app create channel context failed for app (pid: %d) "
1316 "with ret %d", app->pid, ret);
1317 } else {
1318 /*
1319 * This is normal behavior, an application can die during the
1320 * creation process. Don't report an error so the execution can
1321 * continue normally.
1322 */
1323 ret = 0;
1324 DBG3("UST app disable event failed. Application is dead.");
1325 }
1326 goto error;
1327 }
1328
1329 ua_ctx->handle = ua_ctx->obj->handle;
1330
1331 DBG2("UST app context handle %d created successfully for channel %s",
1332 ua_ctx->handle, ua_chan->name);
1333
1334 error:
1335 health_code_update();
1336 return ret;
1337 }
1338
1339 /*
1340 * Set the filter on the tracer.
1341 */
1342 static
1343 int set_ust_event_filter(struct ust_app_event *ua_event,
1344 struct ust_app *app)
1345 {
1346 int ret;
1347 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1348
1349 health_code_update();
1350
1351 if (!ua_event->filter) {
1352 ret = 0;
1353 goto error;
1354 }
1355
1356 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1357 if (!ust_bytecode) {
1358 ret = -LTTNG_ERR_NOMEM;
1359 goto error;
1360 }
1361 pthread_mutex_lock(&app->sock_lock);
1362 ret = ustctl_set_filter(app->sock, ust_bytecode,
1363 ua_event->obj);
1364 pthread_mutex_unlock(&app->sock_lock);
1365 if (ret < 0) {
1366 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1367 ERR("UST app event %s filter failed for app (pid: %d) "
1368 "with ret %d", ua_event->attr.name, app->pid, ret);
1369 } else {
1370 /*
1371 * This is normal behavior, an application can die during the
1372 * creation process. Don't report an error so the execution can
1373 * continue normally.
1374 */
1375 ret = 0;
1376 DBG3("UST app filter event failed. Application is dead.");
1377 }
1378 goto error;
1379 }
1380
1381 DBG2("UST filter set successfully for event %s", ua_event->name);
1382
1383 error:
1384 health_code_update();
1385 free(ust_bytecode);
1386 return ret;
1387 }
1388
1389 static
1390 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1391 struct lttng_event_exclusion *exclusion)
1392 {
1393 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1394 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1395 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1396
1397 ust_exclusion = zmalloc(exclusion_alloc_size);
1398 if (!ust_exclusion) {
1399 PERROR("malloc");
1400 goto end;
1401 }
1402
1403 assert(sizeof(struct lttng_event_exclusion) ==
1404 sizeof(struct lttng_ust_event_exclusion));
1405 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1406 end:
1407 return ust_exclusion;
1408 }
1409
1410 /*
1411 * Set event exclusions on the tracer.
1412 */
1413 static
1414 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1415 struct ust_app *app)
1416 {
1417 int ret;
1418 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1419
1420 health_code_update();
1421
1422 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1423 ret = 0;
1424 goto error;
1425 }
1426
1427 ust_exclusion = create_ust_exclusion_from_exclusion(
1428 ua_event->exclusion);
1429 if (!ust_exclusion) {
1430 ret = -LTTNG_ERR_NOMEM;
1431 goto error;
1432 }
1433 pthread_mutex_lock(&app->sock_lock);
1434 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1435 pthread_mutex_unlock(&app->sock_lock);
1436 if (ret < 0) {
1437 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1438 ERR("UST app event %s exclusions failed for app (pid: %d) "
1439 "with ret %d", ua_event->attr.name, app->pid, ret);
1440 } else {
1441 /*
1442 * This is normal behavior, an application can die during the
1443 * creation process. Don't report an error so the execution can
1444 * continue normally.
1445 */
1446 ret = 0;
1447 DBG3("UST app event exclusion failed. Application is dead.");
1448 }
1449 goto error;
1450 }
1451
1452 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1453
1454 error:
1455 health_code_update();
1456 free(ust_exclusion);
1457 return ret;
1458 }
1459
1460 /*
1461 * Disable the specified event on to UST tracer for the UST session.
1462 */
1463 static int disable_ust_event(struct ust_app *app,
1464 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1465 {
1466 int ret;
1467
1468 health_code_update();
1469
1470 pthread_mutex_lock(&app->sock_lock);
1471 ret = ustctl_disable(app->sock, ua_event->obj);
1472 pthread_mutex_unlock(&app->sock_lock);
1473 if (ret < 0) {
1474 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1475 ERR("UST app event %s disable failed for app (pid: %d) "
1476 "and session handle %d with ret %d",
1477 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1478 } else {
1479 /*
1480 * This is normal behavior, an application can die during the
1481 * creation process. Don't report an error so the execution can
1482 * continue normally.
1483 */
1484 ret = 0;
1485 DBG3("UST app disable event failed. Application is dead.");
1486 }
1487 goto error;
1488 }
1489
1490 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1491 ua_event->attr.name, app->pid);
1492
1493 error:
1494 health_code_update();
1495 return ret;
1496 }
1497
1498 /*
1499 * Disable the specified channel on to UST tracer for the UST session.
1500 */
1501 static int disable_ust_channel(struct ust_app *app,
1502 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1503 {
1504 int ret;
1505
1506 health_code_update();
1507
1508 pthread_mutex_lock(&app->sock_lock);
1509 ret = ustctl_disable(app->sock, ua_chan->obj);
1510 pthread_mutex_unlock(&app->sock_lock);
1511 if (ret < 0) {
1512 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1513 ERR("UST app channel %s disable failed for app (pid: %d) "
1514 "and session handle %d with ret %d",
1515 ua_chan->name, app->pid, ua_sess->handle, ret);
1516 } else {
1517 /*
1518 * This is normal behavior, an application can die during the
1519 * creation process. Don't report an error so the execution can
1520 * continue normally.
1521 */
1522 ret = 0;
1523 DBG3("UST app disable channel failed. Application is dead.");
1524 }
1525 goto error;
1526 }
1527
1528 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1529 ua_chan->name, app->pid);
1530
1531 error:
1532 health_code_update();
1533 return ret;
1534 }
1535
1536 /*
1537 * Enable the specified channel on to UST tracer for the UST session.
1538 */
1539 static int enable_ust_channel(struct ust_app *app,
1540 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1541 {
1542 int ret;
1543
1544 health_code_update();
1545
1546 pthread_mutex_lock(&app->sock_lock);
1547 ret = ustctl_enable(app->sock, ua_chan->obj);
1548 pthread_mutex_unlock(&app->sock_lock);
1549 if (ret < 0) {
1550 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1551 ERR("UST app channel %s enable failed for app (pid: %d) "
1552 "and session handle %d with ret %d",
1553 ua_chan->name, app->pid, ua_sess->handle, ret);
1554 } else {
1555 /*
1556 * This is normal behavior, an application can die during the
1557 * creation process. Don't report an error so the execution can
1558 * continue normally.
1559 */
1560 ret = 0;
1561 DBG3("UST app enable channel failed. Application is dead.");
1562 }
1563 goto error;
1564 }
1565
1566 ua_chan->enabled = 1;
1567
1568 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1569 ua_chan->name, app->pid);
1570
1571 error:
1572 health_code_update();
1573 return ret;
1574 }
1575
1576 /*
1577 * Enable the specified event on to UST tracer for the UST session.
1578 */
1579 static int enable_ust_event(struct ust_app *app,
1580 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1581 {
1582 int ret;
1583
1584 health_code_update();
1585
1586 pthread_mutex_lock(&app->sock_lock);
1587 ret = ustctl_enable(app->sock, ua_event->obj);
1588 pthread_mutex_unlock(&app->sock_lock);
1589 if (ret < 0) {
1590 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1591 ERR("UST app event %s enable failed for app (pid: %d) "
1592 "and session handle %d with ret %d",
1593 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1594 } else {
1595 /*
1596 * This is normal behavior, an application can die during the
1597 * creation process. Don't report an error so the execution can
1598 * continue normally.
1599 */
1600 ret = 0;
1601 DBG3("UST app enable event failed. Application is dead.");
1602 }
1603 goto error;
1604 }
1605
1606 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1607 ua_event->attr.name, app->pid);
1608
1609 error:
1610 health_code_update();
1611 return ret;
1612 }
1613
1614 /*
1615 * Send channel and stream buffer to application.
1616 *
1617 * Return 0 on success. On error, a negative value is returned.
1618 */
1619 static int send_channel_pid_to_ust(struct ust_app *app,
1620 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1621 {
1622 int ret;
1623 struct ust_app_stream *stream, *stmp;
1624
1625 assert(app);
1626 assert(ua_sess);
1627 assert(ua_chan);
1628
1629 health_code_update();
1630
1631 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1632 app->sock);
1633
1634 /* Send channel to the application. */
1635 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1636 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1637 ret = -ENOTCONN; /* Caused by app exiting. */
1638 goto error;
1639 } else if (ret < 0) {
1640 goto error;
1641 }
1642
1643 health_code_update();
1644
1645 /* Send all streams to application. */
1646 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1647 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1648 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1649 ret = -ENOTCONN; /* Caused by app exiting. */
1650 goto error;
1651 } else if (ret < 0) {
1652 goto error;
1653 }
1654 /* We don't need the stream anymore once sent to the tracer. */
1655 cds_list_del(&stream->list);
1656 delete_ust_app_stream(-1, stream, app);
1657 }
1658 /* Flag the channel that it is sent to the application. */
1659 ua_chan->is_sent = 1;
1660
1661 error:
1662 health_code_update();
1663 return ret;
1664 }
1665
1666 /*
1667 * Create the specified event onto the UST tracer for a UST session.
1668 *
1669 * Should be called with session mutex held.
1670 */
1671 static
1672 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1673 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1674 {
1675 int ret = 0;
1676
1677 health_code_update();
1678
1679 /* Create UST event on tracer */
1680 pthread_mutex_lock(&app->sock_lock);
1681 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1682 &ua_event->obj);
1683 pthread_mutex_unlock(&app->sock_lock);
1684 if (ret < 0) {
1685 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1686 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1687 ua_event->attr.name, app->pid, ret);
1688 } else {
1689 /*
1690 * This is normal behavior, an application can die during the
1691 * creation process. Don't report an error so the execution can
1692 * continue normally.
1693 */
1694 ret = 0;
1695 DBG3("UST app create event failed. Application is dead.");
1696 }
1697 goto error;
1698 }
1699
1700 ua_event->handle = ua_event->obj->handle;
1701
1702 DBG2("UST app event %s created successfully for pid:%d",
1703 ua_event->attr.name, app->pid);
1704
1705 health_code_update();
1706
1707 /* Set filter if one is present. */
1708 if (ua_event->filter) {
1709 ret = set_ust_event_filter(ua_event, app);
1710 if (ret < 0) {
1711 goto error;
1712 }
1713 }
1714
1715 /* Set exclusions for the event */
1716 if (ua_event->exclusion) {
1717 ret = set_ust_event_exclusion(ua_event, app);
1718 if (ret < 0) {
1719 goto error;
1720 }
1721 }
1722
1723 /* If event not enabled, disable it on the tracer */
1724 if (ua_event->enabled) {
1725 /*
1726 * We now need to explicitly enable the event, since it
1727 * is now disabled at creation.
1728 */
1729 ret = enable_ust_event(app, ua_sess, ua_event);
1730 if (ret < 0) {
1731 /*
1732 * If we hit an EPERM, something is wrong with our enable call. If
1733 * we get an EEXIST, there is a problem on the tracer side since we
1734 * just created it.
1735 */
1736 switch (ret) {
1737 case -LTTNG_UST_ERR_PERM:
1738 /* Code flow problem */
1739 assert(0);
1740 case -LTTNG_UST_ERR_EXIST:
1741 /* It's OK for our use case. */
1742 ret = 0;
1743 break;
1744 default:
1745 break;
1746 }
1747 goto error;
1748 }
1749 }
1750
1751 error:
1752 health_code_update();
1753 return ret;
1754 }
1755
1756 /*
1757 * Copy data between an UST app event and a LTT event.
1758 */
1759 static void shadow_copy_event(struct ust_app_event *ua_event,
1760 struct ltt_ust_event *uevent)
1761 {
1762 size_t exclusion_alloc_size;
1763
1764 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1765 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1766
1767 ua_event->enabled = uevent->enabled;
1768
1769 /* Copy event attributes */
1770 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1771
1772 /* Copy filter bytecode */
1773 if (uevent->filter) {
1774 ua_event->filter = copy_filter_bytecode(uevent->filter);
1775 /* Filter might be NULL here in case of ENONEM. */
1776 }
1777
1778 /* Copy exclusion data */
1779 if (uevent->exclusion) {
1780 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1781 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1782 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1783 if (ua_event->exclusion == NULL) {
1784 PERROR("malloc");
1785 } else {
1786 memcpy(ua_event->exclusion, uevent->exclusion,
1787 exclusion_alloc_size);
1788 }
1789 }
1790 }
1791
1792 /*
1793 * Copy data between an UST app channel and a LTT channel.
1794 */
1795 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1796 struct ltt_ust_channel *uchan)
1797 {
1798 struct lttng_ht_iter iter;
1799 struct ltt_ust_event *uevent;
1800 struct ltt_ust_context *uctx;
1801 struct ust_app_event *ua_event;
1802
1803 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1804
1805 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1806 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1807
1808 ua_chan->tracefile_size = uchan->tracefile_size;
1809 ua_chan->tracefile_count = uchan->tracefile_count;
1810
1811 /* Copy event attributes since the layout is different. */
1812 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1813 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1814 ua_chan->attr.overwrite = uchan->attr.overwrite;
1815 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1816 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1817 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1818 ua_chan->attr.output = uchan->attr.output;
1819 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1820
1821 /*
1822 * Note that the attribute channel type is not set since the channel on the
1823 * tracing registry side does not have this information.
1824 */
1825
1826 ua_chan->enabled = uchan->enabled;
1827 ua_chan->tracing_channel_id = uchan->id;
1828
1829 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1830 struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1831
1832 if (ua_ctx == NULL) {
1833 continue;
1834 }
1835 lttng_ht_node_init_ulong(&ua_ctx->node,
1836 (unsigned long) ua_ctx->ctx.ctx);
1837 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1838 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1839 }
1840
1841 /* Copy all events from ltt ust channel to ust app channel */
1842 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1843 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1844 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1845 if (ua_event == NULL) {
1846 DBG2("UST event %s not found on shadow copy channel",
1847 uevent->attr.name);
1848 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1849 if (ua_event == NULL) {
1850 continue;
1851 }
1852 shadow_copy_event(ua_event, uevent);
1853 add_unique_ust_app_event(ua_chan, ua_event);
1854 }
1855 }
1856
1857 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1858 }
1859
1860 /*
1861 * Copy data between a UST app session and a regular LTT session.
1862 */
1863 static void shadow_copy_session(struct ust_app_session *ua_sess,
1864 struct ltt_ust_session *usess, struct ust_app *app)
1865 {
1866 struct lttng_ht_node_str *ua_chan_node;
1867 struct lttng_ht_iter iter;
1868 struct ltt_ust_channel *uchan;
1869 struct ust_app_channel *ua_chan;
1870 time_t rawtime;
1871 struct tm *timeinfo;
1872 char datetime[16];
1873 int ret;
1874 char tmp_shm_path[PATH_MAX];
1875
1876 /* Get date and time for unique app path */
1877 time(&rawtime);
1878 timeinfo = localtime(&rawtime);
1879 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1880
1881 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1882
1883 ua_sess->tracing_id = usess->id;
1884 ua_sess->id = get_next_session_id();
1885 ua_sess->uid = app->uid;
1886 ua_sess->gid = app->gid;
1887 ua_sess->euid = usess->uid;
1888 ua_sess->egid = usess->gid;
1889 ua_sess->buffer_type = usess->buffer_type;
1890 ua_sess->bits_per_long = app->bits_per_long;
1891
1892 /* There is only one consumer object per session possible. */
1893 consumer_output_get(usess->consumer);
1894 ua_sess->consumer = usess->consumer;
1895
1896 ua_sess->output_traces = usess->output_traces;
1897 ua_sess->live_timer_interval = usess->live_timer_interval;
1898 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1899 &usess->metadata_attr);
1900
1901 switch (ua_sess->buffer_type) {
1902 case LTTNG_BUFFER_PER_PID:
1903 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1904 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1905 datetime);
1906 break;
1907 case LTTNG_BUFFER_PER_UID:
1908 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1909 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1910 break;
1911 default:
1912 assert(0);
1913 goto error;
1914 }
1915 if (ret < 0) {
1916 PERROR("asprintf UST shadow copy session");
1917 assert(0);
1918 goto error;
1919 }
1920
1921 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1922 sizeof(ua_sess->root_shm_path));
1923 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1924 strncpy(ua_sess->shm_path, usess->shm_path,
1925 sizeof(ua_sess->shm_path));
1926 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1927 if (ua_sess->shm_path[0]) {
1928 switch (ua_sess->buffer_type) {
1929 case LTTNG_BUFFER_PER_PID:
1930 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1931 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1932 app->name, app->pid, datetime);
1933 break;
1934 case LTTNG_BUFFER_PER_UID:
1935 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1936 DEFAULT_UST_TRACE_UID_PATH,
1937 app->uid, app->bits_per_long);
1938 break;
1939 default:
1940 assert(0);
1941 goto error;
1942 }
1943 if (ret < 0) {
1944 PERROR("sprintf UST shadow copy session");
1945 assert(0);
1946 goto error;
1947 }
1948 strncat(ua_sess->shm_path, tmp_shm_path,
1949 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1950 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1951 }
1952
1953 /* Iterate over all channels in global domain. */
1954 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1955 uchan, node.node) {
1956 struct lttng_ht_iter uiter;
1957
1958 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1959 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1960 if (ua_chan_node != NULL) {
1961 /* Session exist. Contiuing. */
1962 continue;
1963 }
1964
1965 DBG2("Channel %s not found on shadow session copy, creating it",
1966 uchan->name);
1967 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess,
1968 &uchan->attr);
1969 if (ua_chan == NULL) {
1970 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1971 continue;
1972 }
1973 shadow_copy_channel(ua_chan, uchan);
1974 /*
1975 * The concept of metadata channel does not exist on the tracing
1976 * registry side of the session daemon so this can only be a per CPU
1977 * channel and not metadata.
1978 */
1979 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1980
1981 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1982 }
1983 return;
1984
1985 error:
1986 consumer_output_put(ua_sess->consumer);
1987 }
1988
1989 /*
1990 * Lookup sesison wrapper.
1991 */
1992 static
1993 void __lookup_session_by_app(struct ltt_ust_session *usess,
1994 struct ust_app *app, struct lttng_ht_iter *iter)
1995 {
1996 /* Get right UST app session from app */
1997 lttng_ht_lookup(app->sessions, &usess->id, iter);
1998 }
1999
2000 /*
2001 * Return ust app session from the app session hashtable using the UST session
2002 * id.
2003 */
2004 static struct ust_app_session *lookup_session_by_app(
2005 struct ltt_ust_session *usess, struct ust_app *app)
2006 {
2007 struct lttng_ht_iter iter;
2008 struct lttng_ht_node_u64 *node;
2009
2010 __lookup_session_by_app(usess, app, &iter);
2011 node = lttng_ht_iter_get_node_u64(&iter);
2012 if (node == NULL) {
2013 goto error;
2014 }
2015
2016 return caa_container_of(node, struct ust_app_session, node);
2017
2018 error:
2019 return NULL;
2020 }
2021
2022 /*
2023 * Setup buffer registry per PID for the given session and application. If none
2024 * is found, a new one is created, added to the global registry and
2025 * initialized. If regp is valid, it's set with the newly created object.
2026 *
2027 * Return 0 on success or else a negative value.
2028 */
2029 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
2030 struct ust_app *app, struct buffer_reg_pid **regp)
2031 {
2032 int ret = 0;
2033 struct buffer_reg_pid *reg_pid;
2034
2035 assert(ua_sess);
2036 assert(app);
2037
2038 rcu_read_lock();
2039
2040 reg_pid = buffer_reg_pid_find(ua_sess->id);
2041 if (!reg_pid) {
2042 /*
2043 * This is the create channel path meaning that if there is NO
2044 * registry available, we have to create one for this session.
2045 */
2046 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
2047 ua_sess->root_shm_path, ua_sess->shm_path);
2048 if (ret < 0) {
2049 goto error;
2050 }
2051 } else {
2052 goto end;
2053 }
2054
2055 /* Initialize registry. */
2056 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
2057 app->bits_per_long, app->uint8_t_alignment,
2058 app->uint16_t_alignment, app->uint32_t_alignment,
2059 app->uint64_t_alignment, app->long_alignment,
2060 app->byte_order, app->version.major,
2061 app->version.minor, reg_pid->root_shm_path,
2062 reg_pid->shm_path,
2063 ua_sess->euid, ua_sess->egid);
2064 if (ret < 0) {
2065 /*
2066 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2067 * destroy the buffer registry, because it is always expected
2068 * that if the buffer registry can be found, its ust registry is
2069 * non-NULL.
2070 */
2071 buffer_reg_pid_destroy(reg_pid);
2072 goto error;
2073 }
2074
2075 buffer_reg_pid_add(reg_pid);
2076
2077 DBG3("UST app buffer registry per PID created successfully");
2078
2079 end:
2080 if (regp) {
2081 *regp = reg_pid;
2082 }
2083 error:
2084 rcu_read_unlock();
2085 return ret;
2086 }
2087
2088 /*
2089 * Setup buffer registry per UID for the given session and application. If none
2090 * is found, a new one is created, added to the global registry and
2091 * initialized. If regp is valid, it's set with the newly created object.
2092 *
2093 * Return 0 on success or else a negative value.
2094 */
2095 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2096 struct ust_app_session *ua_sess,
2097 struct ust_app *app, struct buffer_reg_uid **regp)
2098 {
2099 int ret = 0;
2100 struct buffer_reg_uid *reg_uid;
2101
2102 assert(usess);
2103 assert(app);
2104
2105 rcu_read_lock();
2106
2107 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2108 if (!reg_uid) {
2109 /*
2110 * This is the create channel path meaning that if there is NO
2111 * registry available, we have to create one for this session.
2112 */
2113 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2114 LTTNG_DOMAIN_UST, &reg_uid,
2115 ua_sess->root_shm_path, ua_sess->shm_path);
2116 if (ret < 0) {
2117 goto error;
2118 }
2119 } else {
2120 goto end;
2121 }
2122
2123 /* Initialize registry. */
2124 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2125 app->bits_per_long, app->uint8_t_alignment,
2126 app->uint16_t_alignment, app->uint32_t_alignment,
2127 app->uint64_t_alignment, app->long_alignment,
2128 app->byte_order, app->version.major,
2129 app->version.minor, reg_uid->root_shm_path,
2130 reg_uid->shm_path, usess->uid, usess->gid);
2131 if (ret < 0) {
2132 /*
2133 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2134 * destroy the buffer registry, because it is always expected
2135 * that if the buffer registry can be found, its ust registry is
2136 * non-NULL.
2137 */
2138 buffer_reg_uid_destroy(reg_uid, NULL);
2139 goto error;
2140 }
2141 /* Add node to teardown list of the session. */
2142 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2143
2144 buffer_reg_uid_add(reg_uid);
2145
2146 DBG3("UST app buffer registry per UID created successfully");
2147 end:
2148 if (regp) {
2149 *regp = reg_uid;
2150 }
2151 error:
2152 rcu_read_unlock();
2153 return ret;
2154 }
2155
2156 /*
2157 * Create a session on the tracer side for the given app.
2158 *
2159 * On success, ua_sess_ptr is populated with the session pointer or else left
2160 * untouched. If the session was created, is_created is set to 1. On error,
2161 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2162 * be NULL.
2163 *
2164 * Returns 0 on success or else a negative code which is either -ENOMEM or
2165 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2166 */
2167 static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2168 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2169 int *is_created)
2170 {
2171 int ret, created = 0;
2172 struct ust_app_session *ua_sess;
2173
2174 assert(usess);
2175 assert(app);
2176 assert(ua_sess_ptr);
2177
2178 health_code_update();
2179
2180 ua_sess = lookup_session_by_app(usess, app);
2181 if (ua_sess == NULL) {
2182 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2183 app->pid, usess->id);
2184 ua_sess = alloc_ust_app_session();
2185 if (ua_sess == NULL) {
2186 /* Only malloc can failed so something is really wrong */
2187 ret = -ENOMEM;
2188 goto error;
2189 }
2190 shadow_copy_session(ua_sess, usess, app);
2191 created = 1;
2192 }
2193
2194 switch (usess->buffer_type) {
2195 case LTTNG_BUFFER_PER_PID:
2196 /* Init local registry. */
2197 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2198 if (ret < 0) {
2199 delete_ust_app_session(-1, ua_sess, app);
2200 goto error;
2201 }
2202 break;
2203 case LTTNG_BUFFER_PER_UID:
2204 /* Look for a global registry. If none exists, create one. */
2205 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2206 if (ret < 0) {
2207 delete_ust_app_session(-1, ua_sess, app);
2208 goto error;
2209 }
2210 break;
2211 default:
2212 assert(0);
2213 ret = -EINVAL;
2214 goto error;
2215 }
2216
2217 health_code_update();
2218
2219 if (ua_sess->handle == -1) {
2220 pthread_mutex_lock(&app->sock_lock);
2221 ret = ustctl_create_session(app->sock);
2222 pthread_mutex_unlock(&app->sock_lock);
2223 if (ret < 0) {
2224 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2225 ERR("Creating session for app pid %d with ret %d",
2226 app->pid, ret);
2227 } else {
2228 DBG("UST app creating session failed. Application is dead");
2229 /*
2230 * This is normal behavior, an application can die during the
2231 * creation process. Don't report an error so the execution can
2232 * continue normally. This will get flagged ENOTCONN and the
2233 * caller will handle it.
2234 */
2235 ret = 0;
2236 }
2237 delete_ust_app_session(-1, ua_sess, app);
2238 if (ret != -ENOMEM) {
2239 /*
2240 * Tracer is probably gone or got an internal error so let's
2241 * behave like it will soon unregister or not usable.
2242 */
2243 ret = -ENOTCONN;
2244 }
2245 goto error;
2246 }
2247
2248 ua_sess->handle = ret;
2249
2250 /* Add ust app session to app's HT */
2251 lttng_ht_node_init_u64(&ua_sess->node,
2252 ua_sess->tracing_id);
2253 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2254 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2255 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2256 &ua_sess->ust_objd_node);
2257
2258 DBG2("UST app session created successfully with handle %d", ret);
2259 }
2260
2261 *ua_sess_ptr = ua_sess;
2262 if (is_created) {
2263 *is_created = created;
2264 }
2265
2266 /* Everything went well. */
2267 ret = 0;
2268
2269 error:
2270 health_code_update();
2271 return ret;
2272 }
2273
2274 /*
2275 * Match function for a hash table lookup of ust_app_ctx.
2276 *
2277 * It matches an ust app context based on the context type and, in the case
2278 * of perf counters, their name.
2279 */
2280 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2281 {
2282 struct ust_app_ctx *ctx;
2283 const struct lttng_ust_context_attr *key;
2284
2285 assert(node);
2286 assert(_key);
2287
2288 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2289 key = _key;
2290
2291 /* Context type */
2292 if (ctx->ctx.ctx != key->ctx) {
2293 goto no_match;
2294 }
2295
2296 switch(key->ctx) {
2297 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2298 if (strncmp(key->u.perf_counter.name,
2299 ctx->ctx.u.perf_counter.name,
2300 sizeof(key->u.perf_counter.name))) {
2301 goto no_match;
2302 }
2303 break;
2304 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2305 if (strcmp(key->u.app_ctx.provider_name,
2306 ctx->ctx.u.app_ctx.provider_name) ||
2307 strcmp(key->u.app_ctx.ctx_name,
2308 ctx->ctx.u.app_ctx.ctx_name)) {
2309 goto no_match;
2310 }
2311 break;
2312 default:
2313 break;
2314 }
2315
2316 /* Match. */
2317 return 1;
2318
2319 no_match:
2320 return 0;
2321 }
2322
2323 /*
2324 * Lookup for an ust app context from an lttng_ust_context.
2325 *
2326 * Must be called while holding RCU read side lock.
2327 * Return an ust_app_ctx object or NULL on error.
2328 */
2329 static
2330 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2331 struct lttng_ust_context_attr *uctx)
2332 {
2333 struct lttng_ht_iter iter;
2334 struct lttng_ht_node_ulong *node;
2335 struct ust_app_ctx *app_ctx = NULL;
2336
2337 assert(uctx);
2338 assert(ht);
2339
2340 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2341 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2342 ht_match_ust_app_ctx, uctx, &iter.iter);
2343 node = lttng_ht_iter_get_node_ulong(&iter);
2344 if (!node) {
2345 goto end;
2346 }
2347
2348 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2349
2350 end:
2351 return app_ctx;
2352 }
2353
2354 /*
2355 * Create a context for the channel on the tracer.
2356 *
2357 * Called with UST app session lock held and a RCU read side lock.
2358 */
2359 static
2360 int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2361 struct lttng_ust_context_attr *uctx,
2362 struct ust_app *app)
2363 {
2364 int ret = 0;
2365 struct ust_app_ctx *ua_ctx;
2366
2367 DBG2("UST app adding context to channel %s", ua_chan->name);
2368
2369 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2370 if (ua_ctx) {
2371 ret = -EEXIST;
2372 goto error;
2373 }
2374
2375 ua_ctx = alloc_ust_app_ctx(uctx);
2376 if (ua_ctx == NULL) {
2377 /* malloc failed */
2378 ret = -ENOMEM;
2379 goto error;
2380 }
2381
2382 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2383 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2384 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2385
2386 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2387 if (ret < 0) {
2388 goto error;
2389 }
2390
2391 error:
2392 return ret;
2393 }
2394
2395 /*
2396 * Enable on the tracer side a ust app event for the session and channel.
2397 *
2398 * Called with UST app session lock held.
2399 */
2400 static
2401 int enable_ust_app_event(struct ust_app_session *ua_sess,
2402 struct ust_app_event *ua_event, struct ust_app *app)
2403 {
2404 int ret;
2405
2406 ret = enable_ust_event(app, ua_sess, ua_event);
2407 if (ret < 0) {
2408 goto error;
2409 }
2410
2411 ua_event->enabled = 1;
2412
2413 error:
2414 return ret;
2415 }
2416
2417 /*
2418 * Disable on the tracer side a ust app event for the session and channel.
2419 */
2420 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2421 struct ust_app_event *ua_event, struct ust_app *app)
2422 {
2423 int ret;
2424
2425 ret = disable_ust_event(app, ua_sess, ua_event);
2426 if (ret < 0) {
2427 goto error;
2428 }
2429
2430 ua_event->enabled = 0;
2431
2432 error:
2433 return ret;
2434 }
2435
2436 /*
2437 * Lookup ust app channel for session and disable it on the tracer side.
2438 */
2439 static
2440 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2441 struct ust_app_channel *ua_chan, struct ust_app *app)
2442 {
2443 int ret;
2444
2445 ret = disable_ust_channel(app, ua_sess, ua_chan);
2446 if (ret < 0) {
2447 goto error;
2448 }
2449
2450 ua_chan->enabled = 0;
2451
2452 error:
2453 return ret;
2454 }
2455
2456 /*
2457 * Lookup ust app channel for session and enable it on the tracer side. This
2458 * MUST be called with a RCU read side lock acquired.
2459 */
2460 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2461 struct ltt_ust_channel *uchan, struct ust_app *app)
2462 {
2463 int ret = 0;
2464 struct lttng_ht_iter iter;
2465 struct lttng_ht_node_str *ua_chan_node;
2466 struct ust_app_channel *ua_chan;
2467
2468 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2469 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2470 if (ua_chan_node == NULL) {
2471 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2472 uchan->name, ua_sess->tracing_id);
2473 goto error;
2474 }
2475
2476 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2477
2478 ret = enable_ust_channel(app, ua_sess, ua_chan);
2479 if (ret < 0) {
2480 goto error;
2481 }
2482
2483 error:
2484 return ret;
2485 }
2486
2487 /*
2488 * Ask the consumer to create a channel and get it if successful.
2489 *
2490 * Called with UST app session lock held.
2491 *
2492 * Return 0 on success or else a negative value.
2493 */
2494 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2495 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2496 int bitness, struct ust_registry_session *registry,
2497 uint64_t trace_archive_id)
2498 {
2499 int ret;
2500 unsigned int nb_fd = 0;
2501 struct consumer_socket *socket;
2502
2503 assert(usess);
2504 assert(ua_sess);
2505 assert(ua_chan);
2506 assert(registry);
2507
2508 rcu_read_lock();
2509 health_code_update();
2510
2511 /* Get the right consumer socket for the application. */
2512 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2513 if (!socket) {
2514 ret = -EINVAL;
2515 goto error;
2516 }
2517
2518 health_code_update();
2519
2520 /* Need one fd for the channel. */
2521 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2522 if (ret < 0) {
2523 ERR("Exhausted number of available FD upon create channel");
2524 goto error;
2525 }
2526
2527 /*
2528 * Ask consumer to create channel. The consumer will return the number of
2529 * stream we have to expect.
2530 */
2531 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2532 registry, trace_archive_id);
2533 if (ret < 0) {
2534 goto error_ask;
2535 }
2536
2537 /*
2538 * Compute the number of fd needed before receiving them. It must be 2 per
2539 * stream (2 being the default value here).
2540 */
2541 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2542
2543 /* Reserve the amount of file descriptor we need. */
2544 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2545 if (ret < 0) {
2546 ERR("Exhausted number of available FD upon create channel");
2547 goto error_fd_get_stream;
2548 }
2549
2550 health_code_update();
2551
2552 /*
2553 * Now get the channel from the consumer. This call wil populate the stream
2554 * list of that channel and set the ust objects.
2555 */
2556 if (usess->consumer->enabled) {
2557 ret = ust_consumer_get_channel(socket, ua_chan);
2558 if (ret < 0) {
2559 goto error_destroy;
2560 }
2561 }
2562
2563 rcu_read_unlock();
2564 return 0;
2565
2566 error_destroy:
2567 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2568 error_fd_get_stream:
2569 /*
2570 * Initiate a destroy channel on the consumer since we had an error
2571 * handling it on our side. The return value is of no importance since we
2572 * already have a ret value set by the previous error that we need to
2573 * return.
2574 */
2575 (void) ust_consumer_destroy_channel(socket, ua_chan);
2576 error_ask:
2577 lttng_fd_put(LTTNG_FD_APPS, 1);
2578 error:
2579 health_code_update();
2580 rcu_read_unlock();
2581 return ret;
2582 }
2583
2584 /*
2585 * Duplicate the ust data object of the ust app stream and save it in the
2586 * buffer registry stream.
2587 *
2588 * Return 0 on success or else a negative value.
2589 */
2590 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2591 struct ust_app_stream *stream)
2592 {
2593 int ret;
2594
2595 assert(reg_stream);
2596 assert(stream);
2597
2598 /* Reserve the amount of file descriptor we need. */
2599 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2600 if (ret < 0) {
2601 ERR("Exhausted number of available FD upon duplicate stream");
2602 goto error;
2603 }
2604
2605 /* Duplicate object for stream once the original is in the registry. */
2606 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2607 reg_stream->obj.ust);
2608 if (ret < 0) {
2609 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2610 reg_stream->obj.ust, stream->obj, ret);
2611 lttng_fd_put(LTTNG_FD_APPS, 2);
2612 goto error;
2613 }
2614 stream->handle = stream->obj->handle;
2615
2616 error:
2617 return ret;
2618 }
2619
2620 /*
2621 * Duplicate the ust data object of the ust app. channel and save it in the
2622 * buffer registry channel.
2623 *
2624 * Return 0 on success or else a negative value.
2625 */
2626 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2627 struct ust_app_channel *ua_chan)
2628 {
2629 int ret;
2630
2631 assert(reg_chan);
2632 assert(ua_chan);
2633
2634 /* Need two fds for the channel. */
2635 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2636 if (ret < 0) {
2637 ERR("Exhausted number of available FD upon duplicate channel");
2638 goto error_fd_get;
2639 }
2640
2641 /* Duplicate object for stream once the original is in the registry. */
2642 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2643 if (ret < 0) {
2644 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2645 reg_chan->obj.ust, ua_chan->obj, ret);
2646 goto error;
2647 }
2648 ua_chan->handle = ua_chan->obj->handle;
2649
2650 return 0;
2651
2652 error:
2653 lttng_fd_put(LTTNG_FD_APPS, 1);
2654 error_fd_get:
2655 return ret;
2656 }
2657
2658 /*
2659 * For a given channel buffer registry, setup all streams of the given ust
2660 * application channel.
2661 *
2662 * Return 0 on success or else a negative value.
2663 */
2664 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2665 struct ust_app_channel *ua_chan,
2666 struct ust_app *app)
2667 {
2668 int ret = 0;
2669 struct ust_app_stream *stream, *stmp;
2670
2671 assert(reg_chan);
2672 assert(ua_chan);
2673
2674 DBG2("UST app setup buffer registry stream");
2675
2676 /* Send all streams to application. */
2677 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2678 struct buffer_reg_stream *reg_stream;
2679
2680 ret = buffer_reg_stream_create(&reg_stream);
2681 if (ret < 0) {
2682 goto error;
2683 }
2684
2685 /*
2686 * Keep original pointer and nullify it in the stream so the delete
2687 * stream call does not release the object.
2688 */
2689 reg_stream->obj.ust = stream->obj;
2690 stream->obj = NULL;
2691 buffer_reg_stream_add(reg_stream, reg_chan);
2692
2693 /* We don't need the streams anymore. */
2694 cds_list_del(&stream->list);
2695 delete_ust_app_stream(-1, stream, app);
2696 }
2697
2698 error:
2699 return ret;
2700 }
2701
2702 /*
2703 * Create a buffer registry channel for the given session registry and
2704 * application channel object. If regp pointer is valid, it's set with the
2705 * created object. Important, the created object is NOT added to the session
2706 * registry hash table.
2707 *
2708 * Return 0 on success else a negative value.
2709 */
2710 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2711 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2712 {
2713 int ret;
2714 struct buffer_reg_channel *reg_chan = NULL;
2715
2716 assert(reg_sess);
2717 assert(ua_chan);
2718
2719 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2720
2721 /* Create buffer registry channel. */
2722 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2723 if (ret < 0) {
2724 goto error_create;
2725 }
2726 assert(reg_chan);
2727 reg_chan->consumer_key = ua_chan->key;
2728 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2729 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2730
2731 /* Create and add a channel registry to session. */
2732 ret = ust_registry_channel_add(reg_sess->reg.ust,
2733 ua_chan->tracing_channel_id);
2734 if (ret < 0) {
2735 goto error;
2736 }
2737 buffer_reg_channel_add(reg_sess, reg_chan);
2738
2739 if (regp) {
2740 *regp = reg_chan;
2741 }
2742
2743 return 0;
2744
2745 error:
2746 /* Safe because the registry channel object was not added to any HT. */
2747 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2748 error_create:
2749 return ret;
2750 }
2751
2752 /*
2753 * Setup buffer registry channel for the given session registry and application
2754 * channel object. If regp pointer is valid, it's set with the created object.
2755 *
2756 * Return 0 on success else a negative value.
2757 */
2758 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2759 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2760 struct ust_app *app)
2761 {
2762 int ret;
2763
2764 assert(reg_sess);
2765 assert(reg_chan);
2766 assert(ua_chan);
2767 assert(ua_chan->obj);
2768
2769 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2770
2771 /* Setup all streams for the registry. */
2772 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2773 if (ret < 0) {
2774 goto error;
2775 }
2776
2777 reg_chan->obj.ust = ua_chan->obj;
2778 ua_chan->obj = NULL;
2779
2780 return 0;
2781
2782 error:
2783 buffer_reg_channel_remove(reg_sess, reg_chan);
2784 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2785 return ret;
2786 }
2787
2788 /*
2789 * Send buffer registry channel to the application.
2790 *
2791 * Return 0 on success else a negative value.
2792 */
2793 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2794 struct ust_app *app, struct ust_app_session *ua_sess,
2795 struct ust_app_channel *ua_chan)
2796 {
2797 int ret;
2798 struct buffer_reg_stream *reg_stream;
2799
2800 assert(reg_chan);
2801 assert(app);
2802 assert(ua_sess);
2803 assert(ua_chan);
2804
2805 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2806
2807 ret = duplicate_channel_object(reg_chan, ua_chan);
2808 if (ret < 0) {
2809 goto error;
2810 }
2811
2812 /* Send channel to the application. */
2813 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2814 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2815 ret = -ENOTCONN; /* Caused by app exiting. */
2816 goto error;
2817 } else if (ret < 0) {
2818 goto error;
2819 }
2820
2821 health_code_update();
2822
2823 /* Send all streams to application. */
2824 pthread_mutex_lock(&reg_chan->stream_list_lock);
2825 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2826 struct ust_app_stream stream;
2827
2828 ret = duplicate_stream_object(reg_stream, &stream);
2829 if (ret < 0) {
2830 goto error_stream_unlock;
2831 }
2832
2833 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2834 if (ret < 0) {
2835 (void) release_ust_app_stream(-1, &stream, app);
2836 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2837 ret = -ENOTCONN; /* Caused by app exiting. */
2838 }
2839 goto error_stream_unlock;
2840 }
2841
2842 /*
2843 * The return value is not important here. This function will output an
2844 * error if needed.
2845 */
2846 (void) release_ust_app_stream(-1, &stream, app);
2847 }
2848 ua_chan->is_sent = 1;
2849
2850 error_stream_unlock:
2851 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2852 error:
2853 return ret;
2854 }
2855
2856 /*
2857 * Create and send to the application the created buffers with per UID buffers.
2858 *
2859 * This MUST be called with a RCU read side lock acquired.
2860 * The session list lock and the session's lock must be acquired.
2861 *
2862 * Return 0 on success else a negative value.
2863 */
2864 static int create_channel_per_uid(struct ust_app *app,
2865 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2866 struct ust_app_channel *ua_chan)
2867 {
2868 int ret;
2869 struct buffer_reg_uid *reg_uid;
2870 struct buffer_reg_channel *reg_chan;
2871 struct ltt_session *session = NULL;
2872 enum lttng_error_code notification_ret;
2873 struct ust_registry_channel *chan_reg;
2874
2875 assert(app);
2876 assert(usess);
2877 assert(ua_sess);
2878 assert(ua_chan);
2879
2880 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2881
2882 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2883 /*
2884 * The session creation handles the creation of this global registry
2885 * object. If none can be find, there is a code flow problem or a
2886 * teardown race.
2887 */
2888 assert(reg_uid);
2889
2890 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2891 reg_uid);
2892 if (reg_chan) {
2893 goto send_channel;
2894 }
2895
2896 /* Create the buffer registry channel object. */
2897 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2898 if (ret < 0) {
2899 ERR("Error creating the UST channel \"%s\" registry instance",
2900 ua_chan->name);
2901 goto error;
2902 }
2903
2904 session = session_find_by_id(ua_sess->tracing_id);
2905 assert(session);
2906 assert(pthread_mutex_trylock(&session->lock));
2907 assert(session_trylock_list());
2908
2909 /*
2910 * Create the buffers on the consumer side. This call populates the
2911 * ust app channel object with all streams and data object.
2912 */
2913 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2914 app->bits_per_long, reg_uid->registry->reg.ust,
2915 session->current_archive_id);
2916 if (ret < 0) {
2917 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2918 ua_chan->name);
2919
2920 /*
2921 * Let's remove the previously created buffer registry channel so
2922 * it's not visible anymore in the session registry.
2923 */
2924 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2925 ua_chan->tracing_channel_id, false);
2926 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2927 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2928 goto error;
2929 }
2930
2931 /*
2932 * Setup the streams and add it to the session registry.
2933 */
2934 ret = setup_buffer_reg_channel(reg_uid->registry,
2935 ua_chan, reg_chan, app);
2936 if (ret < 0) {
2937 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2938 goto error;
2939 }
2940
2941 /* Notify the notification subsystem of the channel's creation. */
2942 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2943 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2944 ua_chan->tracing_channel_id);
2945 assert(chan_reg);
2946 chan_reg->consumer_key = ua_chan->key;
2947 chan_reg = NULL;
2948 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2949
2950 notification_ret = notification_thread_command_add_channel(
2951 notification_thread_handle, session->name,
2952 ua_sess->euid, ua_sess->egid,
2953 ua_chan->name,
2954 ua_chan->key,
2955 LTTNG_DOMAIN_UST,
2956 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2957 if (notification_ret != LTTNG_OK) {
2958 ret = - (int) notification_ret;
2959 ERR("Failed to add channel to notification thread");
2960 goto error;
2961 }
2962
2963 send_channel:
2964 /* Send buffers to the application. */
2965 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2966 if (ret < 0) {
2967 if (ret != -ENOTCONN) {
2968 ERR("Error sending channel to application");
2969 }
2970 goto error;
2971 }
2972
2973 error:
2974 if (session) {
2975 session_put(session);
2976 }
2977 return ret;
2978 }
2979
2980 /*
2981 * Create and send to the application the created buffers with per PID buffers.
2982 *
2983 * Called with UST app session lock held.
2984 * The session list lock and the session's lock must be acquired.
2985 *
2986 * Return 0 on success else a negative value.
2987 */
2988 static int create_channel_per_pid(struct ust_app *app,
2989 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2990 struct ust_app_channel *ua_chan)
2991 {
2992 int ret;
2993 struct ust_registry_session *registry;
2994 enum lttng_error_code cmd_ret;
2995 struct ltt_session *session = NULL;
2996 uint64_t chan_reg_key;
2997 struct ust_registry_channel *chan_reg;
2998
2999 assert(app);
3000 assert(usess);
3001 assert(ua_sess);
3002 assert(ua_chan);
3003
3004 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
3005
3006 rcu_read_lock();
3007
3008 registry = get_session_registry(ua_sess);
3009 /* The UST app session lock is held, registry shall not be null. */
3010 assert(registry);
3011
3012 /* Create and add a new channel registry to session. */
3013 ret = ust_registry_channel_add(registry, ua_chan->key);
3014 if (ret < 0) {
3015 ERR("Error creating the UST channel \"%s\" registry instance",
3016 ua_chan->name);
3017 goto error;
3018 }
3019
3020 session = session_find_by_id(ua_sess->tracing_id);
3021 assert(session);
3022
3023 assert(pthread_mutex_trylock(&session->lock));
3024 assert(session_trylock_list());
3025
3026 /* Create and get channel on the consumer side. */
3027 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
3028 app->bits_per_long, registry,
3029 session->current_archive_id);
3030 if (ret < 0) {
3031 ERR("Error creating UST channel \"%s\" on the consumer daemon",
3032 ua_chan->name);
3033 goto error_remove_from_registry;
3034 }
3035
3036 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
3037 if (ret < 0) {
3038 if (ret != -ENOTCONN) {
3039 ERR("Error sending channel to application");
3040 }
3041 goto error_remove_from_registry;
3042 }
3043
3044 chan_reg_key = ua_chan->key;
3045 pthread_mutex_lock(&registry->lock);
3046 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
3047 assert(chan_reg);
3048 chan_reg->consumer_key = ua_chan->key;
3049 pthread_mutex_unlock(&registry->lock);
3050
3051 cmd_ret = notification_thread_command_add_channel(
3052 notification_thread_handle, session->name,
3053 ua_sess->euid, ua_sess->egid,
3054 ua_chan->name,
3055 ua_chan->key,
3056 LTTNG_DOMAIN_UST,
3057 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
3058 if (cmd_ret != LTTNG_OK) {
3059 ret = - (int) cmd_ret;
3060 ERR("Failed to add channel to notification thread");
3061 goto error_remove_from_registry;
3062 }
3063
3064 error_remove_from_registry:
3065 if (ret) {
3066 ust_registry_channel_del_free(registry, ua_chan->key, false);
3067 }
3068 error:
3069 rcu_read_unlock();
3070 if (session) {
3071 session_put(session);
3072 }
3073 return ret;
3074 }
3075
3076 /*
3077 * From an already allocated ust app channel, create the channel buffers if
3078 * need and send it to the application. This MUST be called with a RCU read
3079 * side lock acquired.
3080 *
3081 * Called with UST app session lock held.
3082 *
3083 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3084 * the application exited concurrently.
3085 */
3086 static int do_create_channel(struct ust_app *app,
3087 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3088 struct ust_app_channel *ua_chan)
3089 {
3090 int ret;
3091
3092 assert(app);
3093 assert(usess);
3094 assert(ua_sess);
3095 assert(ua_chan);
3096
3097 /* Handle buffer type before sending the channel to the application. */
3098 switch (usess->buffer_type) {
3099 case LTTNG_BUFFER_PER_UID:
3100 {
3101 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3102 if (ret < 0) {
3103 goto error;
3104 }
3105 break;
3106 }
3107 case LTTNG_BUFFER_PER_PID:
3108 {
3109 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3110 if (ret < 0) {
3111 goto error;
3112 }
3113 break;
3114 }
3115 default:
3116 assert(0);
3117 ret = -EINVAL;
3118 goto error;
3119 }
3120
3121 /* Initialize ust objd object using the received handle and add it. */
3122 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3123 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3124
3125 /* If channel is not enabled, disable it on the tracer */
3126 if (!ua_chan->enabled) {
3127 ret = disable_ust_channel(app, ua_sess, ua_chan);
3128 if (ret < 0) {
3129 goto error;
3130 }
3131 }
3132
3133 error:
3134 return ret;
3135 }
3136
3137 /*
3138 * Create UST app channel and create it on the tracer. Set ua_chanp of the
3139 * newly created channel if not NULL.
3140 *
3141 * Called with UST app session lock and RCU read-side lock held.
3142 *
3143 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3144 * the application exited concurrently.
3145 */
3146 static int create_ust_app_channel(struct ust_app_session *ua_sess,
3147 struct ltt_ust_channel *uchan, struct ust_app *app,
3148 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3149 struct ust_app_channel **ua_chanp)
3150 {
3151 int ret = 0;
3152 struct lttng_ht_iter iter;
3153 struct lttng_ht_node_str *ua_chan_node;
3154 struct ust_app_channel *ua_chan;
3155
3156 /* Lookup channel in the ust app session */
3157 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3158 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3159 if (ua_chan_node != NULL) {
3160 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3161 goto end;
3162 }
3163
3164 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3165 if (ua_chan == NULL) {
3166 /* Only malloc can fail here */
3167 ret = -ENOMEM;
3168 goto error_alloc;
3169 }
3170 shadow_copy_channel(ua_chan, uchan);
3171
3172 /* Set channel type. */
3173 ua_chan->attr.type = type;
3174
3175 ret = do_create_channel(app, usess, ua_sess, ua_chan);
3176 if (ret < 0) {
3177 goto error;
3178 }
3179
3180 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
3181 app->pid);
3182
3183 /* Only add the channel if successful on the tracer side. */
3184 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3185 end:
3186 if (ua_chanp) {
3187 *ua_chanp = ua_chan;
3188 }
3189
3190 /* Everything went well. */
3191 return 0;
3192
3193 error:
3194 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
3195 error_alloc:
3196 return ret;
3197 }
3198
3199 /*
3200 * Create UST app event and create it on the tracer side.
3201 *
3202 * Called with ust app session mutex held.
3203 */
3204 static
3205 int create_ust_app_event(struct ust_app_session *ua_sess,
3206 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3207 struct ust_app *app)
3208 {
3209 int ret = 0;
3210 struct ust_app_event *ua_event;
3211
3212 /* Get event node */
3213 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3214 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3215 if (ua_event != NULL) {
3216 ret = -EEXIST;
3217 goto end;
3218 }
3219
3220 /* Does not exist so create one */
3221 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3222 if (ua_event == NULL) {
3223 /* Only malloc can failed so something is really wrong */
3224 ret = -ENOMEM;