9a766e4ab68e628cbdec4d9f0432ec0b83dea547
[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
45 static
46 int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
47
48 /* Next available channel key. Access under next_channel_key_lock. */
49 static uint64_t _next_channel_key;
50 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
51
52 /* Next available session ID. Access under next_session_id_lock. */
53 static uint64_t _next_session_id;
54 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
55
56 /*
57 * Return the incremented value of next_channel_key.
58 */
59 static uint64_t get_next_channel_key(void)
60 {
61 uint64_t ret;
62
63 pthread_mutex_lock(&next_channel_key_lock);
64 ret = ++_next_channel_key;
65 pthread_mutex_unlock(&next_channel_key_lock);
66 return ret;
67 }
68
69 /*
70 * Return the atomically incremented value of next_session_id.
71 */
72 static uint64_t get_next_session_id(void)
73 {
74 uint64_t ret;
75
76 pthread_mutex_lock(&next_session_id_lock);
77 ret = ++_next_session_id;
78 pthread_mutex_unlock(&next_session_id_lock);
79 return ret;
80 }
81
82 static void copy_channel_attr_to_ustctl(
83 struct ustctl_consumer_channel_attr *attr,
84 struct lttng_ust_channel_attr *uattr)
85 {
86 /* Copy event attributes since the layout is different. */
87 attr->subbuf_size = uattr->subbuf_size;
88 attr->num_subbuf = uattr->num_subbuf;
89 attr->overwrite = uattr->overwrite;
90 attr->switch_timer_interval = uattr->switch_timer_interval;
91 attr->read_timer_interval = uattr->read_timer_interval;
92 attr->output = uattr->output;
93 }
94
95 /*
96 * Match function for the hash table lookup.
97 *
98 * It matches an ust app event based on three attributes which are the event
99 * name, the filter bytecode and the loglevel.
100 */
101 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
102 {
103 struct ust_app_event *event;
104 const struct ust_app_ht_key *key;
105 int ev_loglevel_value;
106
107 assert(node);
108 assert(_key);
109
110 event = caa_container_of(node, struct ust_app_event, node.node);
111 key = _key;
112 ev_loglevel_value = event->attr.loglevel;
113
114 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
115
116 /* Event name */
117 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
118 goto no_match;
119 }
120
121 /* Event loglevel. */
122 if (ev_loglevel_value != key->loglevel_type) {
123 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
124 && key->loglevel_type == 0 &&
125 ev_loglevel_value == -1) {
126 /*
127 * Match is accepted. This is because on event creation, the
128 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
129 * -1 are accepted for this loglevel type since 0 is the one set by
130 * the API when receiving an enable event.
131 */
132 } else {
133 goto no_match;
134 }
135 }
136
137 /* One of the filters is NULL, fail. */
138 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
139 goto no_match;
140 }
141
142 if (key->filter && event->filter) {
143 /* Both filters exists, check length followed by the bytecode. */
144 if (event->filter->len != key->filter->len ||
145 memcmp(event->filter->data, key->filter->data,
146 event->filter->len) != 0) {
147 goto no_match;
148 }
149 }
150
151 /* One of the exclusions is NULL, fail. */
152 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
153 goto no_match;
154 }
155
156 if (key->exclusion && event->exclusion) {
157 /* Both exclusions exists, check count followed by the names. */
158 if (event->exclusion->count != key->exclusion->count ||
159 memcmp(event->exclusion->names, key->exclusion->names,
160 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
161 goto no_match;
162 }
163 }
164
165
166 /* Match. */
167 return 1;
168
169 no_match:
170 return 0;
171 }
172
173 /*
174 * Unique add of an ust app event in the given ht. This uses the custom
175 * ht_match_ust_app_event match function and the event name as hash.
176 */
177 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
178 struct ust_app_event *event)
179 {
180 struct cds_lfht_node *node_ptr;
181 struct ust_app_ht_key key;
182 struct lttng_ht *ht;
183
184 assert(ua_chan);
185 assert(ua_chan->events);
186 assert(event);
187
188 ht = ua_chan->events;
189 key.name = event->attr.name;
190 key.filter = event->filter;
191 key.loglevel_type = event->attr.loglevel;
192 key.exclusion = event->exclusion;
193
194 node_ptr = cds_lfht_add_unique(ht->ht,
195 ht->hash_fct(event->node.key, lttng_ht_seed),
196 ht_match_ust_app_event, &key, &event->node.node);
197 assert(node_ptr == &event->node.node);
198 }
199
200 /*
201 * Close the notify socket from the given RCU head object. This MUST be called
202 * through a call_rcu().
203 */
204 static void close_notify_sock_rcu(struct rcu_head *head)
205 {
206 int ret;
207 struct ust_app_notify_sock_obj *obj =
208 caa_container_of(head, struct ust_app_notify_sock_obj, head);
209
210 /* Must have a valid fd here. */
211 assert(obj->fd >= 0);
212
213 ret = close(obj->fd);
214 if (ret) {
215 ERR("close notify sock %d RCU", obj->fd);
216 }
217 lttng_fd_put(LTTNG_FD_APPS, 1);
218
219 free(obj);
220 }
221
222 /*
223 * Return the session registry according to the buffer type of the given
224 * session.
225 *
226 * A registry per UID object MUST exists before calling this function or else
227 * it assert() if not found. RCU read side lock must be acquired.
228 */
229 static struct ust_registry_session *get_session_registry(
230 struct ust_app_session *ua_sess)
231 {
232 struct ust_registry_session *registry = NULL;
233
234 assert(ua_sess);
235
236 switch (ua_sess->buffer_type) {
237 case LTTNG_BUFFER_PER_PID:
238 {
239 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
240 if (!reg_pid) {
241 goto error;
242 }
243 registry = reg_pid->registry->reg.ust;
244 break;
245 }
246 case LTTNG_BUFFER_PER_UID:
247 {
248 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
249 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
250 if (!reg_uid) {
251 goto error;
252 }
253 registry = reg_uid->registry->reg.ust;
254 break;
255 }
256 default:
257 assert(0);
258 };
259
260 error:
261 return registry;
262 }
263
264 /*
265 * Delete ust context safely. RCU read lock must be held before calling
266 * this function.
267 */
268 static
269 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
270 struct ust_app *app)
271 {
272 int ret;
273
274 assert(ua_ctx);
275
276 if (ua_ctx->obj) {
277 pthread_mutex_lock(&app->sock_lock);
278 ret = ustctl_release_object(sock, ua_ctx->obj);
279 pthread_mutex_unlock(&app->sock_lock);
280 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
281 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
282 sock, ua_ctx->obj->handle, ret);
283 }
284 free(ua_ctx->obj);
285 }
286 free(ua_ctx);
287 }
288
289 /*
290 * Delete ust app event safely. RCU read lock must be held before calling
291 * this function.
292 */
293 static
294 void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
295 struct ust_app *app)
296 {
297 int ret;
298
299 assert(ua_event);
300
301 free(ua_event->filter);
302 if (ua_event->exclusion != NULL)
303 free(ua_event->exclusion);
304 if (ua_event->obj != NULL) {
305 pthread_mutex_lock(&app->sock_lock);
306 ret = ustctl_release_object(sock, ua_event->obj);
307 pthread_mutex_unlock(&app->sock_lock);
308 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
309 ERR("UST app sock %d release event obj failed with ret %d",
310 sock, ret);
311 }
312 free(ua_event->obj);
313 }
314 free(ua_event);
315 }
316
317 /*
318 * Release ust data object of the given stream.
319 *
320 * Return 0 on success or else a negative value.
321 */
322 static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
323 struct ust_app *app)
324 {
325 int ret = 0;
326
327 assert(stream);
328
329 if (stream->obj) {
330 pthread_mutex_lock(&app->sock_lock);
331 ret = ustctl_release_object(sock, stream->obj);
332 pthread_mutex_unlock(&app->sock_lock);
333 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
334 ERR("UST app sock %d release stream obj failed with ret %d",
335 sock, ret);
336 }
337 lttng_fd_put(LTTNG_FD_APPS, 2);
338 free(stream->obj);
339 }
340
341 return ret;
342 }
343
344 /*
345 * Delete ust app stream safely. RCU read lock must be held before calling
346 * this function.
347 */
348 static
349 void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
350 struct ust_app *app)
351 {
352 assert(stream);
353
354 (void) release_ust_app_stream(sock, stream, app);
355 free(stream);
356 }
357
358 /*
359 * We need to execute ht_destroy outside of RCU read-side critical
360 * section and outside of call_rcu thread, so we postpone its execution
361 * using ht_cleanup_push. It is simpler than to change the semantic of
362 * the many callers of delete_ust_app_session().
363 */
364 static
365 void delete_ust_app_channel_rcu(struct rcu_head *head)
366 {
367 struct ust_app_channel *ua_chan =
368 caa_container_of(head, struct ust_app_channel, rcu_head);
369
370 ht_cleanup_push(ua_chan->ctx);
371 ht_cleanup_push(ua_chan->events);
372 free(ua_chan);
373 }
374
375 /*
376 * Extract the lost packet or discarded events counter when the channel is
377 * being deleted and store the value in the parent channel so we can
378 * access it from lttng list and at stop/destroy.
379 *
380 * The session list lock must be held by the caller.
381 */
382 static
383 void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
384 {
385 uint64_t discarded = 0, lost = 0;
386 struct ltt_session *session;
387 struct ltt_ust_channel *uchan;
388
389 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
390 return;
391 }
392
393 rcu_read_lock();
394 session = session_find_by_id(ua_chan->session->tracing_id);
395 if (!session || !session->ust_session) {
396 /*
397 * Not finding the session is not an error because there are
398 * multiple ways the channels can be torn down.
399 *
400 * 1) The session daemon can initiate the destruction of the
401 * ust app session after receiving a destroy command or
402 * during its shutdown/teardown.
403 * 2) The application, since we are in per-pid tracing, is
404 * unregistering and tearing down its ust app session.
405 *
406 * Both paths are protected by the session list lock which
407 * ensures that the accounting of lost packets and discarded
408 * events is done exactly once. The session is then unpublished
409 * from the session list, resulting in this condition.
410 */
411 goto end;
412 }
413
414 if (ua_chan->attr.overwrite) {
415 consumer_get_lost_packets(ua_chan->session->tracing_id,
416 ua_chan->key, session->ust_session->consumer,
417 &lost);
418 } else {
419 consumer_get_discarded_events(ua_chan->session->tracing_id,
420 ua_chan->key, session->ust_session->consumer,
421 &discarded);
422 }
423 uchan = trace_ust_find_channel_by_name(
424 session->ust_session->domain_global.channels,
425 ua_chan->name);
426 if (!uchan) {
427 ERR("Missing UST channel to store discarded counters");
428 goto end;
429 }
430
431 uchan->per_pid_closed_app_discarded += discarded;
432 uchan->per_pid_closed_app_lost += lost;
433
434 end:
435 rcu_read_unlock();
436 }
437
438 /*
439 * Delete ust app channel safely. RCU read lock must be held before calling
440 * this function.
441 *
442 * The session list lock must be held by the caller.
443 */
444 static
445 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
446 struct ust_app *app)
447 {
448 int ret;
449 struct lttng_ht_iter iter;
450 struct ust_app_event *ua_event;
451 struct ust_app_ctx *ua_ctx;
452 struct ust_app_stream *stream, *stmp;
453 struct ust_registry_session *registry;
454
455 assert(ua_chan);
456
457 DBG3("UST app deleting channel %s", ua_chan->name);
458
459 /* Wipe stream */
460 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
461 cds_list_del(&stream->list);
462 delete_ust_app_stream(sock, stream, app);
463 }
464
465 /* Wipe context */
466 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
467 cds_list_del(&ua_ctx->list);
468 ret = lttng_ht_del(ua_chan->ctx, &iter);
469 assert(!ret);
470 delete_ust_app_ctx(sock, ua_ctx, app);
471 }
472
473 /* Wipe events */
474 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
475 node.node) {
476 ret = lttng_ht_del(ua_chan->events, &iter);
477 assert(!ret);
478 delete_ust_app_event(sock, ua_event, app);
479 }
480
481 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
482 /* Wipe and free registry from session registry. */
483 registry = get_session_registry(ua_chan->session);
484 if (registry) {
485 ust_registry_channel_del_free(registry, ua_chan->key);
486 }
487 save_per_pid_lost_discarded_counters(ua_chan);
488 }
489
490 if (ua_chan->obj != NULL) {
491 /* Remove channel from application UST object descriptor. */
492 iter.iter.node = &ua_chan->ust_objd_node.node;
493 ret = lttng_ht_del(app->ust_objd, &iter);
494 assert(!ret);
495 pthread_mutex_lock(&app->sock_lock);
496 ret = ustctl_release_object(sock, ua_chan->obj);
497 pthread_mutex_unlock(&app->sock_lock);
498 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
499 ERR("UST app sock %d release channel obj failed with ret %d",
500 sock, ret);
501 }
502 lttng_fd_put(LTTNG_FD_APPS, 1);
503 free(ua_chan->obj);
504 }
505 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
506 }
507
508 int ust_app_register_done(struct ust_app *app)
509 {
510 int ret;
511
512 pthread_mutex_lock(&app->sock_lock);
513 ret = ustctl_register_done(app->sock);
514 pthread_mutex_unlock(&app->sock_lock);
515 return ret;
516 }
517
518 int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
519 {
520 int ret, sock;
521
522 if (app) {
523 pthread_mutex_lock(&app->sock_lock);
524 sock = app->sock;
525 } else {
526 sock = -1;
527 }
528 ret = ustctl_release_object(sock, data);
529 if (app) {
530 pthread_mutex_unlock(&app->sock_lock);
531 }
532 return ret;
533 }
534
535 /*
536 * Push metadata to consumer socket.
537 *
538 * RCU read-side lock must be held to guarantee existance of socket.
539 * Must be called with the ust app session lock held.
540 * Must be called with the registry lock held.
541 *
542 * On success, return the len of metadata pushed or else a negative value.
543 * Returning a -EPIPE return value means we could not send the metadata,
544 * but it can be caused by recoverable errors (e.g. the application has
545 * terminated concurrently).
546 */
547 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
548 struct consumer_socket *socket, int send_zero_data)
549 {
550 int ret;
551 char *metadata_str = NULL;
552 size_t len, offset, new_metadata_len_sent;
553 ssize_t ret_val;
554 uint64_t metadata_key, metadata_version;
555
556 assert(registry);
557 assert(socket);
558
559 metadata_key = registry->metadata_key;
560
561 /*
562 * Means that no metadata was assigned to the session. This can
563 * happens if no start has been done previously.
564 */
565 if (!metadata_key) {
566 return 0;
567 }
568
569 /*
570 * On a push metadata error either the consumer is dead or the
571 * metadata channel has been destroyed because its endpoint
572 * might have died (e.g: relayd), or because the application has
573 * exited. If so, the metadata closed flag is set to 1 so we
574 * deny pushing metadata again which is not valid anymore on the
575 * consumer side.
576 */
577 if (registry->metadata_closed) {
578 return -EPIPE;
579 }
580
581 offset = registry->metadata_len_sent;
582 len = registry->metadata_len - registry->metadata_len_sent;
583 new_metadata_len_sent = registry->metadata_len;
584 metadata_version = registry->metadata_version;
585 if (len == 0) {
586 DBG3("No metadata to push for metadata key %" PRIu64,
587 registry->metadata_key);
588 ret_val = len;
589 if (send_zero_data) {
590 DBG("No metadata to push");
591 goto push_data;
592 }
593 goto end;
594 }
595
596 /* Allocate only what we have to send. */
597 metadata_str = zmalloc(len);
598 if (!metadata_str) {
599 PERROR("zmalloc ust app metadata string");
600 ret_val = -ENOMEM;
601 goto error;
602 }
603 /* Copy what we haven't sent out. */
604 memcpy(metadata_str, registry->metadata + offset, len);
605
606 push_data:
607 pthread_mutex_unlock(&registry->lock);
608 /*
609 * We need to unlock the registry while we push metadata to
610 * break a circular dependency between the consumerd metadata
611 * lock and the sessiond registry lock. Indeed, pushing metadata
612 * to the consumerd awaits that it gets pushed all the way to
613 * relayd, but doing so requires grabbing the metadata lock. If
614 * a concurrent metadata request is being performed by
615 * consumerd, this can try to grab the registry lock on the
616 * sessiond while holding the metadata lock on the consumer
617 * daemon. Those push and pull schemes are performed on two
618 * different bidirectionnal communication sockets.
619 */
620 ret = consumer_push_metadata(socket, metadata_key,
621 metadata_str, len, offset, metadata_version);
622 pthread_mutex_lock(&registry->lock);
623 if (ret < 0) {
624 /*
625 * There is an acceptable race here between the registry
626 * metadata key assignment and the creation on the
627 * consumer. The session daemon can concurrently push
628 * metadata for this registry while being created on the
629 * consumer since the metadata key of the registry is
630 * assigned *before* it is setup to avoid the consumer
631 * to ask for metadata that could possibly be not found
632 * in the session daemon.
633 *
634 * The metadata will get pushed either by the session
635 * being stopped or the consumer requesting metadata if
636 * that race is triggered.
637 */
638 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
639 ret = 0;
640 } else {
641 ERR("Error pushing metadata to consumer");
642 }
643 ret_val = ret;
644 goto error_push;
645 } else {
646 /*
647 * Metadata may have been concurrently pushed, since
648 * we're not holding the registry lock while pushing to
649 * consumer. This is handled by the fact that we send
650 * the metadata content, size, and the offset at which
651 * that metadata belongs. This may arrive out of order
652 * on the consumer side, and the consumer is able to
653 * deal with overlapping fragments. The consumer
654 * supports overlapping fragments, which must be
655 * contiguous starting from offset 0. We keep the
656 * largest metadata_len_sent value of the concurrent
657 * send.
658 */
659 registry->metadata_len_sent =
660 max_t(size_t, registry->metadata_len_sent,
661 new_metadata_len_sent);
662 }
663 free(metadata_str);
664 return len;
665
666 end:
667 error:
668 if (ret_val) {
669 /*
670 * On error, flag the registry that the metadata is
671 * closed. We were unable to push anything and this
672 * means that either the consumer is not responding or
673 * the metadata cache has been destroyed on the
674 * consumer.
675 */
676 registry->metadata_closed = 1;
677 }
678 error_push:
679 free(metadata_str);
680 return ret_val;
681 }
682
683 /*
684 * For a given application and session, push metadata to consumer.
685 * Either sock or consumer is required : if sock is NULL, the default
686 * socket to send the metadata is retrieved from consumer, if sock
687 * is not NULL we use it to send the metadata.
688 * RCU read-side lock must be held while calling this function,
689 * therefore ensuring existance of registry. It also ensures existance
690 * of socket throughout this function.
691 *
692 * Return 0 on success else a negative error.
693 * Returning a -EPIPE return value means we could not send the metadata,
694 * but it can be caused by recoverable errors (e.g. the application has
695 * terminated concurrently).
696 */
697 static int push_metadata(struct ust_registry_session *registry,
698 struct consumer_output *consumer)
699 {
700 int ret_val;
701 ssize_t ret;
702 struct consumer_socket *socket;
703
704 assert(registry);
705 assert(consumer);
706
707 pthread_mutex_lock(&registry->lock);
708 if (registry->metadata_closed) {
709 ret_val = -EPIPE;
710 goto error;
711 }
712
713 /* Get consumer socket to use to push the metadata.*/
714 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
715 consumer);
716 if (!socket) {
717 ret_val = -1;
718 goto error;
719 }
720
721 ret = ust_app_push_metadata(registry, socket, 0);
722 if (ret < 0) {
723 ret_val = ret;
724 goto error;
725 }
726 pthread_mutex_unlock(&registry->lock);
727 return 0;
728
729 error:
730 pthread_mutex_unlock(&registry->lock);
731 return ret_val;
732 }
733
734 /*
735 * Send to the consumer a close metadata command for the given session. Once
736 * done, the metadata channel is deleted and the session metadata pointer is
737 * nullified. The session lock MUST be held unless the application is
738 * in the destroy path.
739 *
740 * Return 0 on success else a negative value.
741 */
742 static int close_metadata(struct ust_registry_session *registry,
743 struct consumer_output *consumer)
744 {
745 int ret;
746 struct consumer_socket *socket;
747
748 assert(registry);
749 assert(consumer);
750
751 rcu_read_lock();
752
753 pthread_mutex_lock(&registry->lock);
754
755 if (!registry->metadata_key || registry->metadata_closed) {
756 ret = 0;
757 goto end;
758 }
759
760 /* Get consumer socket to use to push the metadata.*/
761 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
762 consumer);
763 if (!socket) {
764 ret = -1;
765 goto error;
766 }
767
768 ret = consumer_close_metadata(socket, registry->metadata_key);
769 if (ret < 0) {
770 goto error;
771 }
772
773 error:
774 /*
775 * Metadata closed. Even on error this means that the consumer is not
776 * responding or not found so either way a second close should NOT be emit
777 * for this registry.
778 */
779 registry->metadata_closed = 1;
780 end:
781 pthread_mutex_unlock(&registry->lock);
782 rcu_read_unlock();
783 return ret;
784 }
785
786 /*
787 * We need to execute ht_destroy outside of RCU read-side critical
788 * section and outside of call_rcu thread, so we postpone its execution
789 * using ht_cleanup_push. It is simpler than to change the semantic of
790 * the many callers of delete_ust_app_session().
791 */
792 static
793 void delete_ust_app_session_rcu(struct rcu_head *head)
794 {
795 struct ust_app_session *ua_sess =
796 caa_container_of(head, struct ust_app_session, rcu_head);
797
798 ht_cleanup_push(ua_sess->channels);
799 free(ua_sess);
800 }
801
802 /*
803 * Delete ust app session safely. RCU read lock must be held before calling
804 * this function.
805 *
806 * The session list lock must be held by the caller.
807 */
808 static
809 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
810 struct ust_app *app)
811 {
812 int ret;
813 struct lttng_ht_iter iter;
814 struct ust_app_channel *ua_chan;
815 struct ust_registry_session *registry;
816
817 assert(ua_sess);
818
819 pthread_mutex_lock(&ua_sess->lock);
820
821 assert(!ua_sess->deleted);
822 ua_sess->deleted = true;
823
824 registry = get_session_registry(ua_sess);
825 if (registry) {
826 /* Push metadata for application before freeing the application. */
827 (void) push_metadata(registry, ua_sess->consumer);
828
829 /*
830 * Don't ask to close metadata for global per UID buffers. Close
831 * metadata only on destroy trace session in this case. Also, the
832 * previous push metadata could have flag the metadata registry to
833 * close so don't send a close command if closed.
834 */
835 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
836 /* And ask to close it for this session registry. */
837 (void) close_metadata(registry, ua_sess->consumer);
838 }
839 }
840
841 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
842 node.node) {
843 ret = lttng_ht_del(ua_sess->channels, &iter);
844 assert(!ret);
845 delete_ust_app_channel(sock, ua_chan, app);
846 }
847
848 /* In case of per PID, the registry is kept in the session. */
849 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
850 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
851 if (reg_pid) {
852 buffer_reg_pid_remove(reg_pid);
853 buffer_reg_pid_destroy(reg_pid);
854 }
855 }
856
857 if (ua_sess->handle != -1) {
858 pthread_mutex_lock(&app->sock_lock);
859 ret = ustctl_release_handle(sock, ua_sess->handle);
860 pthread_mutex_unlock(&app->sock_lock);
861 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
862 ERR("UST app sock %d release session handle failed with ret %d",
863 sock, ret);
864 }
865 /* Remove session from application UST object descriptor. */
866 iter.iter.node = &ua_sess->ust_objd_node.node;
867 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
868 assert(!ret);
869 }
870
871 pthread_mutex_unlock(&ua_sess->lock);
872
873 consumer_output_put(ua_sess->consumer);
874
875 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
876 }
877
878 /*
879 * Delete a traceable application structure from the global list. Never call
880 * this function outside of a call_rcu call.
881 *
882 * RCU read side lock should _NOT_ be held when calling this function.
883 */
884 static
885 void delete_ust_app(struct ust_app *app)
886 {
887 int ret, sock;
888 struct ust_app_session *ua_sess, *tmp_ua_sess;
889
890 /*
891 * The session list lock must be held during this function to guarantee
892 * the existence of ua_sess.
893 */
894 session_lock_list();
895 /* Delete ust app sessions info */
896 sock = app->sock;
897 app->sock = -1;
898
899 /* Wipe sessions */
900 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
901 teardown_node) {
902 /* Free every object in the session and the session. */
903 rcu_read_lock();
904 delete_ust_app_session(sock, ua_sess, app);
905 rcu_read_unlock();
906 }
907
908 ht_cleanup_push(app->sessions);
909 ht_cleanup_push(app->ust_sessions_objd);
910 ht_cleanup_push(app->ust_objd);
911
912 /*
913 * Wait until we have deleted the application from the sock hash table
914 * before closing this socket, otherwise an application could re-use the
915 * socket ID and race with the teardown, using the same hash table entry.
916 *
917 * It's OK to leave the close in call_rcu. We want it to stay unique for
918 * all RCU readers that could run concurrently with unregister app,
919 * therefore we _need_ to only close that socket after a grace period. So
920 * it should stay in this RCU callback.
921 *
922 * This close() is a very important step of the synchronization model so
923 * every modification to this function must be carefully reviewed.
924 */
925 ret = close(sock);
926 if (ret) {
927 PERROR("close");
928 }
929 lttng_fd_put(LTTNG_FD_APPS, 1);
930
931 DBG2("UST app pid %d deleted", app->pid);
932 free(app);
933 session_unlock_list();
934 }
935
936 /*
937 * URCU intermediate call to delete an UST app.
938 */
939 static
940 void delete_ust_app_rcu(struct rcu_head *head)
941 {
942 struct lttng_ht_node_ulong *node =
943 caa_container_of(head, struct lttng_ht_node_ulong, head);
944 struct ust_app *app =
945 caa_container_of(node, struct ust_app, pid_n);
946
947 DBG3("Call RCU deleting app PID %d", app->pid);
948 delete_ust_app(app);
949 }
950
951 /*
952 * Delete the session from the application ht and delete the data structure by
953 * freeing every object inside and releasing them.
954 *
955 * The session list lock must be held by the caller.
956 */
957 static void destroy_app_session(struct ust_app *app,
958 struct ust_app_session *ua_sess)
959 {
960 int ret;
961 struct lttng_ht_iter iter;
962
963 assert(app);
964 assert(ua_sess);
965
966 iter.iter.node = &ua_sess->node.node;
967 ret = lttng_ht_del(app->sessions, &iter);
968 if (ret) {
969 /* Already scheduled for teardown. */
970 goto end;
971 }
972
973 /* Once deleted, free the data structure. */
974 delete_ust_app_session(app->sock, ua_sess, app);
975
976 end:
977 return;
978 }
979
980 /*
981 * Alloc new UST app session.
982 */
983 static
984 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
985 {
986 struct ust_app_session *ua_sess;
987
988 /* Init most of the default value by allocating and zeroing */
989 ua_sess = zmalloc(sizeof(struct ust_app_session));
990 if (ua_sess == NULL) {
991 PERROR("malloc");
992 goto error_free;
993 }
994
995 ua_sess->handle = -1;
996 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
997 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
998 pthread_mutex_init(&ua_sess->lock, NULL);
999
1000 return ua_sess;
1001
1002 error_free:
1003 return NULL;
1004 }
1005
1006 /*
1007 * Alloc new UST app channel.
1008 */
1009 static
1010 struct ust_app_channel *alloc_ust_app_channel(char *name,
1011 struct ust_app_session *ua_sess,
1012 struct lttng_ust_channel_attr *attr)
1013 {
1014 struct ust_app_channel *ua_chan;
1015
1016 /* Init most of the default value by allocating and zeroing */
1017 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1018 if (ua_chan == NULL) {
1019 PERROR("malloc");
1020 goto error;
1021 }
1022
1023 /* Setup channel name */
1024 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1025 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1026
1027 ua_chan->enabled = 1;
1028 ua_chan->handle = -1;
1029 ua_chan->session = ua_sess;
1030 ua_chan->key = get_next_channel_key();
1031 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1032 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1033 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1034
1035 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1036 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1037
1038 /* Copy attributes */
1039 if (attr) {
1040 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1041 ua_chan->attr.subbuf_size = attr->subbuf_size;
1042 ua_chan->attr.num_subbuf = attr->num_subbuf;
1043 ua_chan->attr.overwrite = attr->overwrite;
1044 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1045 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1046 ua_chan->attr.output = attr->output;
1047 }
1048 /* By default, the channel is a per cpu channel. */
1049 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1050
1051 DBG3("UST app channel %s allocated", ua_chan->name);
1052
1053 return ua_chan;
1054
1055 error:
1056 return NULL;
1057 }
1058
1059 /*
1060 * Allocate and initialize a UST app stream.
1061 *
1062 * Return newly allocated stream pointer or NULL on error.
1063 */
1064 struct ust_app_stream *ust_app_alloc_stream(void)
1065 {
1066 struct ust_app_stream *stream = NULL;
1067
1068 stream = zmalloc(sizeof(*stream));
1069 if (stream == NULL) {
1070 PERROR("zmalloc ust app stream");
1071 goto error;
1072 }
1073
1074 /* Zero could be a valid value for a handle so flag it to -1. */
1075 stream->handle = -1;
1076
1077 error:
1078 return stream;
1079 }
1080
1081 /*
1082 * Alloc new UST app event.
1083 */
1084 static
1085 struct ust_app_event *alloc_ust_app_event(char *name,
1086 struct lttng_ust_event *attr)
1087 {
1088 struct ust_app_event *ua_event;
1089
1090 /* Init most of the default value by allocating and zeroing */
1091 ua_event = zmalloc(sizeof(struct ust_app_event));
1092 if (ua_event == NULL) {
1093 PERROR("malloc");
1094 goto error;
1095 }
1096
1097 ua_event->enabled = 1;
1098 strncpy(ua_event->name, name, sizeof(ua_event->name));
1099 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1100 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1101
1102 /* Copy attributes */
1103 if (attr) {
1104 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1105 }
1106
1107 DBG3("UST app event %s allocated", ua_event->name);
1108
1109 return ua_event;
1110
1111 error:
1112 return NULL;
1113 }
1114
1115 /*
1116 * Alloc new UST app context.
1117 */
1118 static
1119 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1120 {
1121 struct ust_app_ctx *ua_ctx;
1122
1123 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1124 if (ua_ctx == NULL) {
1125 goto error;
1126 }
1127
1128 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1129
1130 if (uctx) {
1131 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1132 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1133 char *provider_name = NULL, *ctx_name = NULL;
1134
1135 provider_name = strdup(uctx->u.app_ctx.provider_name);
1136 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1137 if (!provider_name || !ctx_name) {
1138 free(provider_name);
1139 free(ctx_name);
1140 goto error;
1141 }
1142
1143 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1144 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1145 }
1146 }
1147
1148 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1149 return ua_ctx;
1150 error:
1151 free(ua_ctx);
1152 return NULL;
1153 }
1154
1155 /*
1156 * Allocate a filter and copy the given original filter.
1157 *
1158 * Return allocated filter or NULL on error.
1159 */
1160 static struct lttng_filter_bytecode *copy_filter_bytecode(
1161 struct lttng_filter_bytecode *orig_f)
1162 {
1163 struct lttng_filter_bytecode *filter = NULL;
1164
1165 /* Copy filter bytecode */
1166 filter = zmalloc(sizeof(*filter) + orig_f->len);
1167 if (!filter) {
1168 PERROR("zmalloc alloc filter bytecode");
1169 goto error;
1170 }
1171
1172 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1173
1174 error:
1175 return filter;
1176 }
1177
1178 /*
1179 * Create a liblttng-ust filter bytecode from given bytecode.
1180 *
1181 * Return allocated filter or NULL on error.
1182 */
1183 static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1184 struct lttng_filter_bytecode *orig_f)
1185 {
1186 struct lttng_ust_filter_bytecode *filter = NULL;
1187
1188 /* Copy filter bytecode */
1189 filter = zmalloc(sizeof(*filter) + orig_f->len);
1190 if (!filter) {
1191 PERROR("zmalloc alloc ust filter bytecode");
1192 goto error;
1193 }
1194
1195 assert(sizeof(struct lttng_filter_bytecode) ==
1196 sizeof(struct lttng_ust_filter_bytecode));
1197 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1198 error:
1199 return filter;
1200 }
1201
1202 /*
1203 * Find an ust_app using the sock and return it. RCU read side lock must be
1204 * held before calling this helper function.
1205 */
1206 struct ust_app *ust_app_find_by_sock(int sock)
1207 {
1208 struct lttng_ht_node_ulong *node;
1209 struct lttng_ht_iter iter;
1210
1211 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1212 node = lttng_ht_iter_get_node_ulong(&iter);
1213 if (node == NULL) {
1214 DBG2("UST app find by sock %d not found", sock);
1215 goto error;
1216 }
1217
1218 return caa_container_of(node, struct ust_app, sock_n);
1219
1220 error:
1221 return NULL;
1222 }
1223
1224 /*
1225 * Find an ust_app using the notify sock and return it. RCU read side lock must
1226 * be held before calling this helper function.
1227 */
1228 static struct ust_app *find_app_by_notify_sock(int sock)
1229 {
1230 struct lttng_ht_node_ulong *node;
1231 struct lttng_ht_iter iter;
1232
1233 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1234 &iter);
1235 node = lttng_ht_iter_get_node_ulong(&iter);
1236 if (node == NULL) {
1237 DBG2("UST app find by notify sock %d not found", sock);
1238 goto error;
1239 }
1240
1241 return caa_container_of(node, struct ust_app, notify_sock_n);
1242
1243 error:
1244 return NULL;
1245 }
1246
1247 /*
1248 * Lookup for an ust app event based on event name, filter bytecode and the
1249 * event loglevel.
1250 *
1251 * Return an ust_app_event object or NULL on error.
1252 */
1253 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1254 char *name, struct lttng_filter_bytecode *filter,
1255 int loglevel_value,
1256 const struct lttng_event_exclusion *exclusion)
1257 {
1258 struct lttng_ht_iter iter;
1259 struct lttng_ht_node_str *node;
1260 struct ust_app_event *event = NULL;
1261 struct ust_app_ht_key key;
1262
1263 assert(name);
1264 assert(ht);
1265
1266 /* Setup key for event lookup. */
1267 key.name = name;
1268 key.filter = filter;
1269 key.loglevel_type = loglevel_value;
1270 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1271 key.exclusion = exclusion;
1272
1273 /* Lookup using the event name as hash and a custom match fct. */
1274 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1275 ht_match_ust_app_event, &key, &iter.iter);
1276 node = lttng_ht_iter_get_node_str(&iter);
1277 if (node == NULL) {
1278 goto end;
1279 }
1280
1281 event = caa_container_of(node, struct ust_app_event, node);
1282
1283 end:
1284 return event;
1285 }
1286
1287 /*
1288 * Create the channel context on the tracer.
1289 *
1290 * Called with UST app session lock held.
1291 */
1292 static
1293 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1294 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1295 {
1296 int ret;
1297
1298 health_code_update();
1299
1300 pthread_mutex_lock(&app->sock_lock);
1301 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1302 ua_chan->obj, &ua_ctx->obj);
1303 pthread_mutex_unlock(&app->sock_lock);
1304 if (ret < 0) {
1305 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1306 ERR("UST app create channel context failed for app (pid: %d) "
1307 "with ret %d", app->pid, ret);
1308 } else {
1309 /*
1310 * This is normal behavior, an application can die during the
1311 * creation process. Don't report an error so the execution can
1312 * continue normally.
1313 */
1314 ret = 0;
1315 DBG3("UST app disable event failed. Application is dead.");
1316 }
1317 goto error;
1318 }
1319
1320 ua_ctx->handle = ua_ctx->obj->handle;
1321
1322 DBG2("UST app context handle %d created successfully for channel %s",
1323 ua_ctx->handle, ua_chan->name);
1324
1325 error:
1326 health_code_update();
1327 return ret;
1328 }
1329
1330 /*
1331 * Set the filter on the tracer.
1332 */
1333 static
1334 int set_ust_event_filter(struct ust_app_event *ua_event,
1335 struct ust_app *app)
1336 {
1337 int ret;
1338 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1339
1340 health_code_update();
1341
1342 if (!ua_event->filter) {
1343 ret = 0;
1344 goto error;
1345 }
1346
1347 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1348 if (!ust_bytecode) {
1349 ret = -LTTNG_ERR_NOMEM;
1350 goto error;
1351 }
1352 pthread_mutex_lock(&app->sock_lock);
1353 ret = ustctl_set_filter(app->sock, ust_bytecode,
1354 ua_event->obj);
1355 pthread_mutex_unlock(&app->sock_lock);
1356 if (ret < 0) {
1357 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1358 ERR("UST app event %s filter failed for app (pid: %d) "
1359 "with ret %d", ua_event->attr.name, app->pid, ret);
1360 } else {
1361 /*
1362 * This is normal behavior, an application can die during the
1363 * creation process. Don't report an error so the execution can
1364 * continue normally.
1365 */
1366 ret = 0;
1367 DBG3("UST app filter event failed. Application is dead.");
1368 }
1369 goto error;
1370 }
1371
1372 DBG2("UST filter set successfully for event %s", ua_event->name);
1373
1374 error:
1375 health_code_update();
1376 free(ust_bytecode);
1377 return ret;
1378 }
1379
1380 static
1381 struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1382 struct lttng_event_exclusion *exclusion)
1383 {
1384 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1385 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1386 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1387
1388 ust_exclusion = zmalloc(exclusion_alloc_size);
1389 if (!ust_exclusion) {
1390 PERROR("malloc");
1391 goto end;
1392 }
1393
1394 assert(sizeof(struct lttng_event_exclusion) ==
1395 sizeof(struct lttng_ust_event_exclusion));
1396 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1397 end:
1398 return ust_exclusion;
1399 }
1400
1401 /*
1402 * Set event exclusions on the tracer.
1403 */
1404 static
1405 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1406 struct ust_app *app)
1407 {
1408 int ret;
1409 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1410
1411 health_code_update();
1412
1413 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1414 ret = 0;
1415 goto error;
1416 }
1417
1418 ust_exclusion = create_ust_exclusion_from_exclusion(
1419 ua_event->exclusion);
1420 if (!ust_exclusion) {
1421 ret = -LTTNG_ERR_NOMEM;
1422 goto error;
1423 }
1424 pthread_mutex_lock(&app->sock_lock);
1425 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1426 pthread_mutex_unlock(&app->sock_lock);
1427 if (ret < 0) {
1428 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1429 ERR("UST app event %s exclusions failed for app (pid: %d) "
1430 "with ret %d", ua_event->attr.name, app->pid, ret);
1431 } else {
1432 /*
1433 * This is normal behavior, an application can die during the
1434 * creation process. Don't report an error so the execution can
1435 * continue normally.
1436 */
1437 ret = 0;
1438 DBG3("UST app event exclusion failed. Application is dead.");
1439 }
1440 goto error;
1441 }
1442
1443 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1444
1445 error:
1446 health_code_update();
1447 free(ust_exclusion);
1448 return ret;
1449 }
1450
1451 /*
1452 * Disable the specified event on to UST tracer for the UST session.
1453 */
1454 static int disable_ust_event(struct ust_app *app,
1455 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1456 {
1457 int ret;
1458
1459 health_code_update();
1460
1461 pthread_mutex_lock(&app->sock_lock);
1462 ret = ustctl_disable(app->sock, ua_event->obj);
1463 pthread_mutex_unlock(&app->sock_lock);
1464 if (ret < 0) {
1465 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1466 ERR("UST app event %s disable failed for app (pid: %d) "
1467 "and session handle %d with ret %d",
1468 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1469 } else {
1470 /*
1471 * This is normal behavior, an application can die during the
1472 * creation process. Don't report an error so the execution can
1473 * continue normally.
1474 */
1475 ret = 0;
1476 DBG3("UST app disable event failed. Application is dead.");
1477 }
1478 goto error;
1479 }
1480
1481 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1482 ua_event->attr.name, app->pid);
1483
1484 error:
1485 health_code_update();
1486 return ret;
1487 }
1488
1489 /*
1490 * Disable the specified channel on to UST tracer for the UST session.
1491 */
1492 static int disable_ust_channel(struct ust_app *app,
1493 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1494 {
1495 int ret;
1496
1497 health_code_update();
1498
1499 pthread_mutex_lock(&app->sock_lock);
1500 ret = ustctl_disable(app->sock, ua_chan->obj);
1501 pthread_mutex_unlock(&app->sock_lock);
1502 if (ret < 0) {
1503 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1504 ERR("UST app channel %s disable failed for app (pid: %d) "
1505 "and session handle %d with ret %d",
1506 ua_chan->name, app->pid, ua_sess->handle, ret);
1507 } else {
1508 /*
1509 * This is normal behavior, an application can die during the
1510 * creation process. Don't report an error so the execution can
1511 * continue normally.
1512 */
1513 ret = 0;
1514 DBG3("UST app disable channel failed. Application is dead.");
1515 }
1516 goto error;
1517 }
1518
1519 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1520 ua_chan->name, app->pid);
1521
1522 error:
1523 health_code_update();
1524 return ret;
1525 }
1526
1527 /*
1528 * Enable the specified channel on to UST tracer for the UST session.
1529 */
1530 static int enable_ust_channel(struct ust_app *app,
1531 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1532 {
1533 int ret;
1534
1535 health_code_update();
1536
1537 pthread_mutex_lock(&app->sock_lock);
1538 ret = ustctl_enable(app->sock, ua_chan->obj);
1539 pthread_mutex_unlock(&app->sock_lock);
1540 if (ret < 0) {
1541 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1542 ERR("UST app channel %s enable failed for app (pid: %d) "
1543 "and session handle %d with ret %d",
1544 ua_chan->name, app->pid, ua_sess->handle, ret);
1545 } else {
1546 /*
1547 * This is normal behavior, an application can die during the
1548 * creation process. Don't report an error so the execution can
1549 * continue normally.
1550 */
1551 ret = 0;
1552 DBG3("UST app enable channel failed. Application is dead.");
1553 }
1554 goto error;
1555 }
1556
1557 ua_chan->enabled = 1;
1558
1559 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1560 ua_chan->name, app->pid);
1561
1562 error:
1563 health_code_update();
1564 return ret;
1565 }
1566
1567 /*
1568 * Enable the specified event on to UST tracer for the UST session.
1569 */
1570 static int enable_ust_event(struct ust_app *app,
1571 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1572 {
1573 int ret;
1574
1575 health_code_update();
1576
1577 pthread_mutex_lock(&app->sock_lock);
1578 ret = ustctl_enable(app->sock, ua_event->obj);
1579 pthread_mutex_unlock(&app->sock_lock);
1580 if (ret < 0) {
1581 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1582 ERR("UST app event %s enable failed for app (pid: %d) "
1583 "and session handle %d with ret %d",
1584 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1585 } else {
1586 /*
1587 * This is normal behavior, an application can die during the
1588 * creation process. Don't report an error so the execution can
1589 * continue normally.
1590 */
1591 ret = 0;
1592 DBG3("UST app enable event failed. Application is dead.");
1593 }
1594 goto error;
1595 }
1596
1597 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1598 ua_event->attr.name, app->pid);
1599
1600 error:
1601 health_code_update();
1602 return ret;
1603 }
1604
1605 /*
1606 * Send channel and stream buffer to application.
1607 *
1608 * Return 0 on success. On error, a negative value is returned.
1609 */
1610 static int send_channel_pid_to_ust(struct ust_app *app,
1611 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1612 {
1613 int ret;
1614 struct ust_app_stream *stream, *stmp;
1615
1616 assert(app);
1617 assert(ua_sess);
1618 assert(ua_chan);
1619
1620 health_code_update();
1621
1622 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1623 app->sock);
1624
1625 /* Send channel to the application. */
1626 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1627 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1628 ret = -ENOTCONN; /* Caused by app exiting. */
1629 goto error;
1630 } else if (ret < 0) {
1631 goto error;
1632 }
1633
1634 health_code_update();
1635
1636 /* Send all streams to application. */
1637 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1638 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1639 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1640 ret = -ENOTCONN; /* Caused by app exiting. */
1641 goto error;
1642 } else if (ret < 0) {
1643 goto error;
1644 }
1645 /* We don't need the stream anymore once sent to the tracer. */
1646 cds_list_del(&stream->list);
1647 delete_ust_app_stream(-1, stream, app);
1648 }
1649 /* Flag the channel that it is sent to the application. */
1650 ua_chan->is_sent = 1;
1651
1652 error:
1653 health_code_update();
1654 return ret;
1655 }
1656
1657 /*
1658 * Create the specified event onto the UST tracer for a UST session.
1659 *
1660 * Should be called with session mutex held.
1661 */
1662 static
1663 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1664 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1665 {
1666 int ret = 0;
1667
1668 health_code_update();
1669
1670 /* Create UST event on tracer */
1671 pthread_mutex_lock(&app->sock_lock);
1672 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1673 &ua_event->obj);
1674 pthread_mutex_unlock(&app->sock_lock);
1675 if (ret < 0) {
1676 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1677 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1678 ua_event->attr.name, app->pid, ret);
1679 } else {
1680 /*
1681 * This is normal behavior, an application can die during the
1682 * creation process. Don't report an error so the execution can
1683 * continue normally.
1684 */
1685 ret = 0;
1686 DBG3("UST app create event failed. Application is dead.");
1687 }
1688 goto error;
1689 }
1690
1691 ua_event->handle = ua_event->obj->handle;
1692
1693 DBG2("UST app event %s created successfully for pid:%d",
1694 ua_event->attr.name, app->pid);
1695
1696 health_code_update();
1697
1698 /* Set filter if one is present. */
1699 if (ua_event->filter) {
1700 ret = set_ust_event_filter(ua_event, app);
1701 if (ret < 0) {
1702 goto error;
1703 }
1704 }
1705
1706 /* Set exclusions for the event */
1707 if (ua_event->exclusion) {
1708 ret = set_ust_event_exclusion(ua_event, app);
1709 if (ret < 0) {
1710 goto error;
1711 }
1712 }
1713
1714 /* If event not enabled, disable it on the tracer */
1715 if (ua_event->enabled) {
1716 /*
1717 * We now need to explicitly enable the event, since it
1718 * is now disabled at creation.
1719 */
1720 ret = enable_ust_event(app, ua_sess, ua_event);
1721 if (ret < 0) {
1722 /*
1723 * If we hit an EPERM, something is wrong with our enable call. If
1724 * we get an EEXIST, there is a problem on the tracer side since we
1725 * just created it.
1726 */
1727 switch (ret) {
1728 case -LTTNG_UST_ERR_PERM:
1729 /* Code flow problem */
1730 assert(0);
1731 case -LTTNG_UST_ERR_EXIST:
1732 /* It's OK for our use case. */
1733 ret = 0;
1734 break;
1735 default:
1736 break;
1737 }
1738 goto error;
1739 }
1740 }
1741
1742 error:
1743 health_code_update();
1744 return ret;
1745 }
1746
1747 /*
1748 * Copy data between an UST app event and a LTT event.
1749 */
1750 static void shadow_copy_event(struct ust_app_event *ua_event,
1751 struct ltt_ust_event *uevent)
1752 {
1753 size_t exclusion_alloc_size;
1754
1755 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1756 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1757
1758 ua_event->enabled = uevent->enabled;
1759
1760 /* Copy event attributes */
1761 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1762
1763 /* Copy filter bytecode */
1764 if (uevent->filter) {
1765 ua_event->filter = copy_filter_bytecode(uevent->filter);
1766 /* Filter might be NULL here in case of ENONEM. */
1767 }
1768
1769 /* Copy exclusion data */
1770 if (uevent->exclusion) {
1771 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1772 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1773 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1774 if (ua_event->exclusion == NULL) {
1775 PERROR("malloc");
1776 } else {
1777 memcpy(ua_event->exclusion, uevent->exclusion,
1778 exclusion_alloc_size);
1779 }
1780 }
1781 }
1782
1783 /*
1784 * Copy data between an UST app channel and a LTT channel.
1785 */
1786 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1787 struct ltt_ust_channel *uchan)
1788 {
1789 struct lttng_ht_iter iter;
1790 struct ltt_ust_event *uevent;
1791 struct ltt_ust_context *uctx;
1792 struct ust_app_event *ua_event;
1793
1794 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1795
1796 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1797 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1798
1799 ua_chan->tracefile_size = uchan->tracefile_size;
1800 ua_chan->tracefile_count = uchan->tracefile_count;
1801
1802 /* Copy event attributes since the layout is different. */
1803 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1804 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1805 ua_chan->attr.overwrite = uchan->attr.overwrite;
1806 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1807 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1808 ua_chan->attr.output = uchan->attr.output;
1809 /*
1810 * Note that the attribute channel type is not set since the channel on the
1811 * tracing registry side does not have this information.
1812 */
1813
1814 ua_chan->enabled = uchan->enabled;
1815 ua_chan->tracing_channel_id = uchan->id;
1816
1817 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1818 struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1819
1820 if (ua_ctx == NULL) {
1821 continue;
1822 }
1823 lttng_ht_node_init_ulong(&ua_ctx->node,
1824 (unsigned long) ua_ctx->ctx.ctx);
1825 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1826 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1827 }
1828
1829 /* Copy all events from ltt ust channel to ust app channel */
1830 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1831 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1832 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1833 if (ua_event == NULL) {
1834 DBG2("UST event %s not found on shadow copy channel",
1835 uevent->attr.name);
1836 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1837 if (ua_event == NULL) {
1838 continue;
1839 }
1840 shadow_copy_event(ua_event, uevent);
1841 add_unique_ust_app_event(ua_chan, ua_event);
1842 }
1843 }
1844
1845 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1846 }
1847
1848 /*
1849 * Copy data between a UST app session and a regular LTT session.
1850 */
1851 static void shadow_copy_session(struct ust_app_session *ua_sess,
1852 struct ltt_ust_session *usess, struct ust_app *app)
1853 {
1854 struct lttng_ht_node_str *ua_chan_node;
1855 struct lttng_ht_iter iter;
1856 struct ltt_ust_channel *uchan;
1857 struct ust_app_channel *ua_chan;
1858 time_t rawtime;
1859 struct tm *timeinfo;
1860 char datetime[16];
1861 int ret;
1862 char tmp_shm_path[PATH_MAX];
1863
1864 /* Get date and time for unique app path */
1865 time(&rawtime);
1866 timeinfo = localtime(&rawtime);
1867 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1868
1869 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1870
1871 ua_sess->tracing_id = usess->id;
1872 ua_sess->id = get_next_session_id();
1873 ua_sess->uid = app->uid;
1874 ua_sess->gid = app->gid;
1875 ua_sess->euid = usess->uid;
1876 ua_sess->egid = usess->gid;
1877 ua_sess->buffer_type = usess->buffer_type;
1878 ua_sess->bits_per_long = app->bits_per_long;
1879
1880 /* There is only one consumer object per session possible. */
1881 consumer_output_get(usess->consumer);
1882 ua_sess->consumer = usess->consumer;
1883
1884 ua_sess->output_traces = usess->output_traces;
1885 ua_sess->live_timer_interval = usess->live_timer_interval;
1886 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1887 &usess->metadata_attr);
1888
1889 switch (ua_sess->buffer_type) {
1890 case LTTNG_BUFFER_PER_PID:
1891 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1892 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1893 datetime);
1894 break;
1895 case LTTNG_BUFFER_PER_UID:
1896 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1897 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1898 break;
1899 default:
1900 assert(0);
1901 goto error;
1902 }
1903 if (ret < 0) {
1904 PERROR("asprintf UST shadow copy session");
1905 assert(0);
1906 goto error;
1907 }
1908
1909 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1910 sizeof(ua_sess->root_shm_path));
1911 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1912 strncpy(ua_sess->shm_path, usess->shm_path,
1913 sizeof(ua_sess->shm_path));
1914 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1915 if (ua_sess->shm_path[0]) {
1916 switch (ua_sess->buffer_type) {
1917 case LTTNG_BUFFER_PER_PID:
1918 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1919 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1920 app->name, app->pid, datetime);
1921 break;
1922 case LTTNG_BUFFER_PER_UID:
1923 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1924 DEFAULT_UST_TRACE_UID_PATH,
1925 app->uid, app->bits_per_long);
1926 break;
1927 default:
1928 assert(0);
1929 goto error;
1930 }
1931 if (ret < 0) {
1932 PERROR("sprintf UST shadow copy session");
1933 assert(0);
1934 goto error;
1935 }
1936 strncat(ua_sess->shm_path, tmp_shm_path,
1937 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1938 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1939 }
1940
1941 /* Iterate over all channels in global domain. */
1942 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1943 uchan, node.node) {
1944 struct lttng_ht_iter uiter;
1945
1946 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1947 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1948 if (ua_chan_node != NULL) {
1949 /* Session exist. Contiuing. */
1950 continue;
1951 }
1952
1953 DBG2("Channel %s not found on shadow session copy, creating it",
1954 uchan->name);
1955 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess,
1956 &uchan->attr);
1957 if (ua_chan == NULL) {
1958 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1959 continue;
1960 }
1961 shadow_copy_channel(ua_chan, uchan);
1962 /*
1963 * The concept of metadata channel does not exist on the tracing
1964 * registry side of the session daemon so this can only be a per CPU
1965 * channel and not metadata.
1966 */
1967 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1968
1969 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1970 }
1971 return;
1972
1973 error:
1974 consumer_output_put(ua_sess->consumer);
1975 }
1976
1977 /*
1978 * Lookup sesison wrapper.
1979 */
1980 static
1981 void __lookup_session_by_app(struct ltt_ust_session *usess,
1982 struct ust_app *app, struct lttng_ht_iter *iter)
1983 {
1984 /* Get right UST app session from app */
1985 lttng_ht_lookup(app->sessions, &usess->id, iter);
1986 }
1987
1988 /*
1989 * Return ust app session from the app session hashtable using the UST session
1990 * id.
1991 */
1992 static struct ust_app_session *lookup_session_by_app(
1993 struct ltt_ust_session *usess, struct ust_app *app)
1994 {
1995 struct lttng_ht_iter iter;
1996 struct lttng_ht_node_u64 *node;
1997
1998 __lookup_session_by_app(usess, app, &iter);
1999 node = lttng_ht_iter_get_node_u64(&iter);
2000 if (node == NULL) {
2001 goto error;
2002 }
2003
2004 return caa_container_of(node, struct ust_app_session, node);
2005
2006 error:
2007 return NULL;
2008 }
2009
2010 /*
2011 * Setup buffer registry per PID for the given session and application. If none
2012 * is found, a new one is created, added to the global registry and
2013 * initialized. If regp is valid, it's set with the newly created object.
2014 *
2015 * Return 0 on success or else a negative value.
2016 */
2017 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
2018 struct ust_app *app, struct buffer_reg_pid **regp)
2019 {
2020 int ret = 0;
2021 struct buffer_reg_pid *reg_pid;
2022
2023 assert(ua_sess);
2024 assert(app);
2025
2026 rcu_read_lock();
2027
2028 reg_pid = buffer_reg_pid_find(ua_sess->id);
2029 if (!reg_pid) {
2030 /*
2031 * This is the create channel path meaning that if there is NO
2032 * registry available, we have to create one for this session.
2033 */
2034 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
2035 ua_sess->root_shm_path, ua_sess->shm_path);
2036 if (ret < 0) {
2037 goto error;
2038 }
2039 } else {
2040 goto end;
2041 }
2042
2043 /* Initialize registry. */
2044 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
2045 app->bits_per_long, app->uint8_t_alignment,
2046 app->uint16_t_alignment, app->uint32_t_alignment,
2047 app->uint64_t_alignment, app->long_alignment,
2048 app->byte_order, app->version.major,
2049 app->version.minor, reg_pid->root_shm_path,
2050 reg_pid->shm_path,
2051 ua_sess->euid, ua_sess->egid);
2052 if (ret < 0) {
2053 /*
2054 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2055 * destroy the buffer registry, because it is always expected
2056 * that if the buffer registry can be found, its ust registry is
2057 * non-NULL.
2058 */
2059 buffer_reg_pid_destroy(reg_pid);
2060 goto error;
2061 }
2062
2063 buffer_reg_pid_add(reg_pid);
2064
2065 DBG3("UST app buffer registry per PID created successfully");
2066
2067 end:
2068 if (regp) {
2069 *regp = reg_pid;
2070 }
2071 error:
2072 rcu_read_unlock();
2073 return ret;
2074 }
2075
2076 /*
2077 * Setup buffer registry per UID for the given session and application. If none
2078 * is found, a new one is created, added to the global registry and
2079 * initialized. If regp is valid, it's set with the newly created object.
2080 *
2081 * Return 0 on success or else a negative value.
2082 */
2083 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2084 struct ust_app_session *ua_sess,
2085 struct ust_app *app, struct buffer_reg_uid **regp)
2086 {
2087 int ret = 0;
2088 struct buffer_reg_uid *reg_uid;
2089
2090 assert(usess);
2091 assert(app);
2092
2093 rcu_read_lock();
2094
2095 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2096 if (!reg_uid) {
2097 /*
2098 * This is the create channel path meaning that if there is NO
2099 * registry available, we have to create one for this session.
2100 */
2101 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2102 LTTNG_DOMAIN_UST, &reg_uid,
2103 ua_sess->root_shm_path, ua_sess->shm_path);
2104 if (ret < 0) {
2105 goto error;
2106 }
2107 } else {
2108 goto end;
2109 }
2110
2111 /* Initialize registry. */
2112 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2113 app->bits_per_long, app->uint8_t_alignment,
2114 app->uint16_t_alignment, app->uint32_t_alignment,
2115 app->uint64_t_alignment, app->long_alignment,
2116 app->byte_order, app->version.major,
2117 app->version.minor, reg_uid->root_shm_path,
2118 reg_uid->shm_path, usess->uid, usess->gid);
2119 if (ret < 0) {
2120 /*
2121 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2122 * destroy the buffer registry, because it is always expected
2123 * that if the buffer registry can be found, its ust registry is
2124 * non-NULL.
2125 */
2126 buffer_reg_uid_destroy(reg_uid, NULL);
2127 goto error;
2128 }
2129 /* Add node to teardown list of the session. */
2130 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2131
2132 buffer_reg_uid_add(reg_uid);
2133
2134 DBG3("UST app buffer registry per UID created successfully");
2135 end:
2136 if (regp) {
2137 *regp = reg_uid;
2138 }
2139 error:
2140 rcu_read_unlock();
2141 return ret;
2142 }
2143
2144 /*
2145 * Create a session on the tracer side for the given app.
2146 *
2147 * On success, ua_sess_ptr is populated with the session pointer or else left
2148 * untouched. If the session was created, is_created is set to 1. On error,
2149 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2150 * be NULL.
2151 *
2152 * Returns 0 on success or else a negative code which is either -ENOMEM or
2153 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2154 */
2155 static int create_ust_app_session(struct ltt_ust_session *usess,
2156 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2157 int *is_created)
2158 {
2159 int ret, created = 0;
2160 struct ust_app_session *ua_sess;
2161
2162 assert(usess);
2163 assert(app);
2164 assert(ua_sess_ptr);
2165
2166 health_code_update();
2167
2168 ua_sess = lookup_session_by_app(usess, app);
2169 if (ua_sess == NULL) {
2170 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2171 app->pid, usess->id);
2172 ua_sess = alloc_ust_app_session(app);
2173 if (ua_sess == NULL) {
2174 /* Only malloc can failed so something is really wrong */
2175 ret = -ENOMEM;
2176 goto error;
2177 }
2178 shadow_copy_session(ua_sess, usess, app);
2179 created = 1;
2180 }
2181
2182 switch (usess->buffer_type) {
2183 case LTTNG_BUFFER_PER_PID:
2184 /* Init local registry. */
2185 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2186 if (ret < 0) {
2187 delete_ust_app_session(-1, ua_sess, app);
2188 goto error;
2189 }
2190 break;
2191 case LTTNG_BUFFER_PER_UID:
2192 /* Look for a global registry. If none exists, create one. */
2193 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2194 if (ret < 0) {
2195 delete_ust_app_session(-1, ua_sess, app);
2196 goto error;
2197 }
2198 break;
2199 default:
2200 assert(0);
2201 ret = -EINVAL;
2202 goto error;
2203 }
2204
2205 health_code_update();
2206
2207 if (ua_sess->handle == -1) {
2208 pthread_mutex_lock(&app->sock_lock);
2209 ret = ustctl_create_session(app->sock);
2210 pthread_mutex_unlock(&app->sock_lock);
2211 if (ret < 0) {
2212 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2213 ERR("Creating session for app pid %d with ret %d",
2214 app->pid, ret);
2215 } else {
2216 DBG("UST app creating session failed. Application is dead");
2217 /*
2218 * This is normal behavior, an application can die during the
2219 * creation process. Don't report an error so the execution can
2220 * continue normally. This will get flagged ENOTCONN and the
2221 * caller will handle it.
2222 */
2223 ret = 0;
2224 }
2225 delete_ust_app_session(-1, ua_sess, app);
2226 if (ret != -ENOMEM) {
2227 /*
2228 * Tracer is probably gone or got an internal error so let's
2229 * behave like it will soon unregister or not usable.
2230 */
2231 ret = -ENOTCONN;
2232 }
2233 goto error;
2234 }
2235
2236 ua_sess->handle = ret;
2237
2238 /* Add ust app session to app's HT */
2239 lttng_ht_node_init_u64(&ua_sess->node,
2240 ua_sess->tracing_id);
2241 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2242 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2243 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2244 &ua_sess->ust_objd_node);
2245
2246 DBG2("UST app session created successfully with handle %d", ret);
2247 }
2248
2249 *ua_sess_ptr = ua_sess;
2250 if (is_created) {
2251 *is_created = created;
2252 }
2253
2254 /* Everything went well. */
2255 ret = 0;
2256
2257 error:
2258 health_code_update();
2259 return ret;
2260 }
2261
2262 /*
2263 * Match function for a hash table lookup of ust_app_ctx.
2264 *
2265 * It matches an ust app context based on the context type and, in the case
2266 * of perf counters, their name.
2267 */
2268 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2269 {
2270 struct ust_app_ctx *ctx;
2271 const struct lttng_ust_context_attr *key;
2272
2273 assert(node);
2274 assert(_key);
2275
2276 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2277 key = _key;
2278
2279 /* Context type */
2280 if (ctx->ctx.ctx != key->ctx) {
2281 goto no_match;
2282 }
2283
2284 switch(key->ctx) {
2285 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2286 if (strncmp(key->u.perf_counter.name,
2287 ctx->ctx.u.perf_counter.name,
2288 sizeof(key->u.perf_counter.name))) {
2289 goto no_match;
2290 }
2291 break;
2292 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2293 if (strcmp(key->u.app_ctx.provider_name,
2294 ctx->ctx.u.app_ctx.provider_name) ||
2295 strcmp(key->u.app_ctx.ctx_name,
2296 ctx->ctx.u.app_ctx.ctx_name)) {
2297 goto no_match;
2298 }
2299 break;
2300 default:
2301 break;
2302 }
2303
2304 /* Match. */
2305 return 1;
2306
2307 no_match:
2308 return 0;
2309 }
2310
2311 /*
2312 * Lookup for an ust app context from an lttng_ust_context.
2313 *
2314 * Must be called while holding RCU read side lock.
2315 * Return an ust_app_ctx object or NULL on error.
2316 */
2317 static
2318 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2319 struct lttng_ust_context_attr *uctx)
2320 {
2321 struct lttng_ht_iter iter;
2322 struct lttng_ht_node_ulong *node;
2323 struct ust_app_ctx *app_ctx = NULL;
2324
2325 assert(uctx);
2326 assert(ht);
2327
2328 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2329 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2330 ht_match_ust_app_ctx, uctx, &iter.iter);
2331 node = lttng_ht_iter_get_node_ulong(&iter);
2332 if (!node) {
2333 goto end;
2334 }
2335
2336 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2337
2338 end:
2339 return app_ctx;
2340 }
2341
2342 /*
2343 * Create a context for the channel on the tracer.
2344 *
2345 * Called with UST app session lock held and a RCU read side lock.
2346 */
2347 static
2348 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
2349 struct ust_app_channel *ua_chan,
2350 struct lttng_ust_context_attr *uctx,
2351 struct ust_app *app)
2352 {
2353 int ret = 0;
2354 struct ust_app_ctx *ua_ctx;
2355
2356 DBG2("UST app adding context to channel %s", ua_chan->name);
2357
2358 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2359 if (ua_ctx) {
2360 ret = -EEXIST;
2361 goto error;
2362 }
2363
2364 ua_ctx = alloc_ust_app_ctx(uctx);
2365 if (ua_ctx == NULL) {
2366 /* malloc failed */
2367 ret = -1;
2368 goto error;
2369 }
2370
2371 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2372 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2373 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2374
2375 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2376 if (ret < 0) {
2377 goto error;
2378 }
2379
2380 error:
2381 return ret;
2382 }
2383
2384 /*
2385 * Enable on the tracer side a ust app event for the session and channel.
2386 *
2387 * Called with UST app session lock held.
2388 */
2389 static
2390 int enable_ust_app_event(struct ust_app_session *ua_sess,
2391 struct ust_app_event *ua_event, struct ust_app *app)
2392 {
2393 int ret;
2394
2395 ret = enable_ust_event(app, ua_sess, ua_event);
2396 if (ret < 0) {
2397 goto error;
2398 }
2399
2400 ua_event->enabled = 1;
2401
2402 error:
2403 return ret;
2404 }
2405
2406 /*
2407 * Disable on the tracer side a ust app event for the session and channel.
2408 */
2409 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2410 struct ust_app_event *ua_event, struct ust_app *app)
2411 {
2412 int ret;
2413
2414 ret = disable_ust_event(app, ua_sess, ua_event);
2415 if (ret < 0) {
2416 goto error;
2417 }
2418
2419 ua_event->enabled = 0;
2420
2421 error:
2422 return ret;
2423 }
2424
2425 /*
2426 * Lookup ust app channel for session and disable it on the tracer side.
2427 */
2428 static
2429 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2430 struct ust_app_channel *ua_chan, struct ust_app *app)
2431 {
2432 int ret;
2433
2434 ret = disable_ust_channel(app, ua_sess, ua_chan);
2435 if (ret < 0) {
2436 goto error;
2437 }
2438
2439 ua_chan->enabled = 0;
2440
2441 error:
2442 return ret;
2443 }
2444
2445 /*
2446 * Lookup ust app channel for session and enable it on the tracer side. This
2447 * MUST be called with a RCU read side lock acquired.
2448 */
2449 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2450 struct ltt_ust_channel *uchan, struct ust_app *app)
2451 {
2452 int ret = 0;
2453 struct lttng_ht_iter iter;
2454 struct lttng_ht_node_str *ua_chan_node;
2455 struct ust_app_channel *ua_chan;
2456
2457 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2458 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2459 if (ua_chan_node == NULL) {
2460 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2461 uchan->name, ua_sess->tracing_id);
2462 goto error;
2463 }
2464
2465 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2466
2467 ret = enable_ust_channel(app, ua_sess, ua_chan);
2468 if (ret < 0) {
2469 goto error;
2470 }
2471
2472 error:
2473 return ret;
2474 }
2475
2476 /*
2477 * Ask the consumer to create a channel and get it if successful.
2478 *
2479 * Return 0 on success or else a negative value.
2480 */
2481 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2482 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2483 int bitness, struct ust_registry_session *registry)
2484 {
2485 int ret;
2486 unsigned int nb_fd = 0;
2487 struct consumer_socket *socket;
2488
2489 assert(usess);
2490 assert(ua_sess);
2491 assert(ua_chan);
2492 assert(registry);
2493
2494 rcu_read_lock();
2495 health_code_update();
2496
2497 /* Get the right consumer socket for the application. */
2498 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2499 if (!socket) {
2500 ret = -EINVAL;
2501 goto error;
2502 }
2503
2504 health_code_update();
2505
2506 /* Need one fd for the channel. */
2507 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2508 if (ret < 0) {
2509 ERR("Exhausted number of available FD upon create channel");
2510 goto error;
2511 }
2512
2513 /*
2514 * Ask consumer to create channel. The consumer will return the number of
2515 * stream we have to expect.
2516 */
2517 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2518 registry);
2519 if (ret < 0) {
2520 goto error_ask;
2521 }
2522
2523 /*
2524 * Compute the number of fd needed before receiving them. It must be 2 per
2525 * stream (2 being the default value here).
2526 */
2527 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2528
2529 /* Reserve the amount of file descriptor we need. */
2530 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2531 if (ret < 0) {
2532 ERR("Exhausted number of available FD upon create channel");
2533 goto error_fd_get_stream;
2534 }
2535
2536 health_code_update();
2537
2538 /*
2539 * Now get the channel from the consumer. This call wil populate the stream
2540 * list of that channel and set the ust objects.
2541 */
2542 if (usess->consumer->enabled) {
2543 ret = ust_consumer_get_channel(socket, ua_chan);
2544 if (ret < 0) {
2545 goto error_destroy;
2546 }
2547 }
2548
2549 rcu_read_unlock();
2550 return 0;
2551
2552 error_destroy:
2553 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2554 error_fd_get_stream:
2555 /*
2556 * Initiate a destroy channel on the consumer since we had an error
2557 * handling it on our side. The return value is of no importance since we
2558 * already have a ret value set by the previous error that we need to
2559 * return.
2560 */
2561 (void) ust_consumer_destroy_channel(socket, ua_chan);
2562 error_ask:
2563 lttng_fd_put(LTTNG_FD_APPS, 1);
2564 error:
2565 health_code_update();
2566 rcu_read_unlock();
2567 return ret;
2568 }
2569
2570 /*
2571 * Duplicate the ust data object of the ust app stream and save it in the
2572 * buffer registry stream.
2573 *
2574 * Return 0 on success or else a negative value.
2575 */
2576 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2577 struct ust_app_stream *stream)
2578 {
2579 int ret;
2580
2581 assert(reg_stream);
2582 assert(stream);
2583
2584 /* Reserve the amount of file descriptor we need. */
2585 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2586 if (ret < 0) {
2587 ERR("Exhausted number of available FD upon duplicate stream");
2588 goto error;
2589 }
2590
2591 /* Duplicate object for stream once the original is in the registry. */
2592 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2593 reg_stream->obj.ust);
2594 if (ret < 0) {
2595 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2596 reg_stream->obj.ust, stream->obj, ret);
2597 lttng_fd_put(LTTNG_FD_APPS, 2);
2598 goto error;
2599 }
2600 stream->handle = stream->obj->handle;
2601
2602 error:
2603 return ret;
2604 }
2605
2606 /*
2607 * Duplicate the ust data object of the ust app. channel and save it in the
2608 * buffer registry channel.
2609 *
2610 * Return 0 on success or else a negative value.
2611 */
2612 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2613 struct ust_app_channel *ua_chan)
2614 {
2615 int ret;
2616
2617 assert(reg_chan);
2618 assert(ua_chan);
2619
2620 /* Need two fds for the channel. */
2621 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2622 if (ret < 0) {
2623 ERR("Exhausted number of available FD upon duplicate channel");
2624 goto error_fd_get;
2625 }
2626
2627 /* Duplicate object for stream once the original is in the registry. */
2628 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2629 if (ret < 0) {
2630 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2631 reg_chan->obj.ust, ua_chan->obj, ret);
2632 goto error;
2633 }
2634 ua_chan->handle = ua_chan->obj->handle;
2635
2636 return 0;
2637
2638 error:
2639 lttng_fd_put(LTTNG_FD_APPS, 1);
2640 error_fd_get:
2641 return ret;
2642 }
2643
2644 /*
2645 * For a given channel buffer registry, setup all streams of the given ust
2646 * application channel.
2647 *
2648 * Return 0 on success or else a negative value.
2649 */
2650 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2651 struct ust_app_channel *ua_chan,
2652 struct ust_app *app)
2653 {
2654 int ret = 0;
2655 struct ust_app_stream *stream, *stmp;
2656
2657 assert(reg_chan);
2658 assert(ua_chan);
2659
2660 DBG2("UST app setup buffer registry stream");
2661
2662 /* Send all streams to application. */
2663 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2664 struct buffer_reg_stream *reg_stream;
2665
2666 ret = buffer_reg_stream_create(&reg_stream);
2667 if (ret < 0) {
2668 goto error;
2669 }
2670
2671 /*
2672 * Keep original pointer and nullify it in the stream so the delete
2673 * stream call does not release the object.
2674 */
2675 reg_stream->obj.ust = stream->obj;
2676 stream->obj = NULL;
2677 buffer_reg_stream_add(reg_stream, reg_chan);
2678
2679 /* We don't need the streams anymore. */
2680 cds_list_del(&stream->list);
2681 delete_ust_app_stream(-1, stream, app);
2682 }
2683
2684 error:
2685 return ret;
2686 }
2687
2688 /*
2689 * Create a buffer registry channel for the given session registry and
2690 * application channel object. If regp pointer is valid, it's set with the
2691 * created object. Important, the created object is NOT added to the session
2692 * registry hash table.
2693 *
2694 * Return 0 on success else a negative value.
2695 */
2696 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2697 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2698 {
2699 int ret;
2700 struct buffer_reg_channel *reg_chan = NULL;
2701
2702 assert(reg_sess);
2703 assert(ua_chan);
2704
2705 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2706
2707 /* Create buffer registry channel. */
2708 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2709 if (ret < 0) {
2710 goto error_create;
2711 }
2712 assert(reg_chan);
2713 reg_chan->consumer_key = ua_chan->key;
2714 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2715 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2716
2717 /* Create and add a channel registry to session. */
2718 ret = ust_registry_channel_add(reg_sess->reg.ust,
2719 ua_chan->tracing_channel_id);
2720 if (ret < 0) {
2721 goto error;
2722 }
2723 buffer_reg_channel_add(reg_sess, reg_chan);
2724
2725 if (regp) {
2726 *regp = reg_chan;
2727 }
2728
2729 return 0;
2730
2731 error:
2732 /* Safe because the registry channel object was not added to any HT. */
2733 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2734 error_create:
2735 return ret;
2736 }
2737
2738 /*
2739 * Setup buffer registry channel for the given session registry and application
2740 * channel object. If regp pointer is valid, it's set with the created object.
2741 *
2742 * Return 0 on success else a negative value.
2743 */
2744 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2745 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2746 struct ust_app *app)
2747 {
2748 int ret;
2749
2750 assert(reg_sess);
2751 assert(reg_chan);
2752 assert(ua_chan);
2753 assert(ua_chan->obj);
2754
2755 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2756
2757 /* Setup all streams for the registry. */
2758 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2759 if (ret < 0) {
2760 goto error;
2761 }
2762
2763 reg_chan->obj.ust = ua_chan->obj;
2764 ua_chan->obj = NULL;
2765
2766 return 0;
2767
2768 error:
2769 buffer_reg_channel_remove(reg_sess, reg_chan);
2770 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2771 return ret;
2772 }
2773
2774 /*
2775 * Send buffer registry channel to the application.
2776 *
2777 * Return 0 on success else a negative value.
2778 */
2779 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2780 struct ust_app *app, struct ust_app_session *ua_sess,
2781 struct ust_app_channel *ua_chan)
2782 {
2783 int ret;
2784 struct buffer_reg_stream *reg_stream;
2785
2786 assert(reg_chan);
2787 assert(app);
2788 assert(ua_sess);
2789 assert(ua_chan);
2790
2791 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2792
2793 ret = duplicate_channel_object(reg_chan, ua_chan);
2794 if (ret < 0) {
2795 goto error;
2796 }
2797
2798 /* Send channel to the application. */
2799 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2800 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2801 ret = -ENOTCONN; /* Caused by app exiting. */
2802 goto error;
2803 } else if (ret < 0) {
2804 goto error;
2805 }
2806
2807 health_code_update();
2808
2809 /* Send all streams to application. */
2810 pthread_mutex_lock(&reg_chan->stream_list_lock);
2811 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2812 struct ust_app_stream stream;
2813
2814 ret = duplicate_stream_object(reg_stream, &stream);
2815 if (ret < 0) {
2816 goto error_stream_unlock;
2817 }
2818
2819 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2820 if (ret < 0) {
2821 (void) release_ust_app_stream(-1, &stream, app);
2822 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2823 ret = -ENOTCONN; /* Caused by app exiting. */
2824 goto error_stream_unlock;
2825 } else if (ret < 0) {
2826 goto error_stream_unlock;
2827 }
2828 goto error_stream_unlock;
2829 }
2830
2831 /*
2832 * The return value is not important here. This function will output an
2833 * error if needed.
2834 */
2835 (void) release_ust_app_stream(-1, &stream, app);
2836 }
2837 ua_chan->is_sent = 1;
2838
2839 error_stream_unlock:
2840 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2841 error:
2842 return ret;
2843 }
2844
2845 /*
2846 * Create and send to the application the created buffers with per UID buffers.
2847 *
2848 * Return 0 on success else a negative value.
2849 */
2850 static int create_channel_per_uid(struct ust_app *app,
2851 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2852 struct ust_app_channel *ua_chan)
2853 {
2854 int ret;
2855 struct buffer_reg_uid *reg_uid;
2856 struct buffer_reg_channel *reg_chan;
2857
2858 assert(app);
2859 assert(usess);
2860 assert(ua_sess);
2861 assert(ua_chan);
2862
2863 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2864
2865 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2866 /*
2867 * The session creation handles the creation of this global registry
2868 * object. If none can be find, there is a code flow problem or a
2869 * teardown race.
2870 */
2871 assert(reg_uid);
2872
2873 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2874 reg_uid);
2875 if (!reg_chan) {
2876 /* Create the buffer registry channel object. */
2877 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2878 if (ret < 0) {
2879 ERR("Error creating the UST channel \"%s\" registry instance",
2880 ua_chan->name);
2881 goto error;
2882 }
2883 assert(reg_chan);
2884
2885 /*
2886 * Create the buffers on the consumer side. This call populates the
2887 * ust app channel object with all streams and data object.
2888 */
2889 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2890 app->bits_per_long, reg_uid->registry->reg.ust);
2891 if (ret < 0) {
2892 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2893 ua_chan->name);
2894
2895 /*
2896 * Let's remove the previously created buffer registry channel so
2897 * it's not visible anymore in the session registry.
2898 */
2899 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2900 ua_chan->tracing_channel_id);
2901 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2902 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2903 goto error;
2904 }
2905
2906 /*
2907 * Setup the streams and add it to the session registry.
2908 */
2909 ret = setup_buffer_reg_channel(reg_uid->registry,
2910 ua_chan, reg_chan, app);
2911 if (ret < 0) {
2912 ERR("Error setting up UST channel \"%s\"",
2913 ua_chan->name);
2914 goto error;
2915 }
2916
2917 }
2918
2919 /* Send buffers to the application. */
2920 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2921 if (ret < 0) {
2922 if (ret != -ENOTCONN) {
2923 ERR("Error sending channel to application");
2924 }
2925 goto error;
2926 }
2927
2928 error:
2929 return ret;
2930 }
2931
2932 /*
2933 * Create and send to the application the created buffers with per PID buffers.
2934 *
2935 * Return 0 on success else a negative value.
2936 */
2937 static int create_channel_per_pid(struct ust_app *app,
2938 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2939 struct ust_app_channel *ua_chan)
2940 {
2941 int ret;
2942 struct ust_registry_session *registry;
2943
2944 assert(app);
2945 assert(usess);
2946 assert(ua_sess);
2947 assert(ua_chan);
2948
2949 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2950
2951 rcu_read_lock();
2952
2953 registry = get_session_registry(ua_sess);
2954 assert(registry);
2955
2956 /* Create and add a new channel registry to session. */
2957 ret = ust_registry_channel_add(registry, ua_chan->key);
2958 if (ret < 0) {
2959 ERR("Error creating the UST channel \"%s\" registry instance",
2960 ua_chan->name);
2961 goto error;
2962 }
2963
2964 /* Create and get channel on the consumer side. */
2965 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2966 app->bits_per_long, registry);
2967 if (ret < 0) {
2968 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2969 ua_chan->name);
2970 goto error;
2971 }
2972
2973 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2974 if (ret < 0) {
2975 if (ret != -ENOTCONN) {
2976 ERR("Error sending channel to application");
2977 }
2978 goto error;
2979 }
2980
2981 error:
2982 rcu_read_unlock();
2983 return ret;
2984 }
2985
2986 /*
2987 * From an already allocated ust app channel, create the channel buffers if
2988 * need and send it to the application. This MUST be called with a RCU read
2989 * side lock acquired.
2990 *
2991 * Return 0 on success or else a negative value. Returns -ENOTCONN if
2992 * the application exited concurrently.
2993 */
2994 static int do_create_channel(struct ust_app *app,
2995 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2996 struct ust_app_channel *ua_chan)
2997 {
2998 int ret;
2999
3000 assert(app);
3001 assert(usess);
3002 assert(ua_sess);
3003 assert(ua_chan);
3004
3005 /* Handle buffer type before sending the channel to the application. */
3006 switch (usess->buffer_type) {
3007 case LTTNG_BUFFER_PER_UID:
3008 {
3009 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3010 if (ret < 0) {
3011 goto error;
3012 }
3013 break;
3014 }
3015 case LTTNG_BUFFER_PER_PID:
3016 {
3017 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3018 if (ret < 0) {
3019 goto error;
3020 }
3021 break;
3022 }
3023 default:
3024 assert(0);
3025 ret = -EINVAL;
3026 goto error;
3027 }
3028
3029 /* Initialize ust objd object using the received handle and add it. */
3030 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3031 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3032
3033 /* If channel is not enabled, disable it on the tracer */
3034 if (!ua_chan->enabled) {
3035 ret = disable_ust_channel(app, ua_sess, ua_chan);
3036 if (ret < 0) {
3037 goto error;
3038 }
3039 }
3040
3041 error:
3042 return ret;
3043 }
3044
3045 /*
3046 * Create UST app channel and create it on the tracer. Set ua_chanp of the
3047 * newly created channel if not NULL.
3048 *
3049 * Called with UST app session lock and RCU read-side lock held.
3050 *
3051 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3052 * the application exited concurrently.
3053 */
3054 static int create_ust_app_channel(struct ust_app_session *ua_sess,
3055 struct ltt_ust_channel *uchan, struct ust_app *app,
3056 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3057 struct ust_app_channel **ua_chanp)
3058 {
3059 int ret = 0;
3060 struct lttng_ht_iter iter;
3061 struct lttng_ht_node_str *ua_chan_node;
3062 struct ust_app_channel *ua_chan;
3063
3064 /* Lookup channel in the ust app session */
3065 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3066 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3067 if (ua_chan_node != NULL) {
3068 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3069 goto end;
3070 }
3071
3072 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3073 if (ua_chan == NULL) {
3074 /* Only malloc can fail here */
3075 ret = -ENOMEM;
3076 goto error_alloc;
3077 }
3078 shadow_copy_channel(ua_chan, uchan);
3079
3080 /* Set channel type. */
3081 ua_chan->attr.type = type;
3082
3083 ret = do_create_channel(app, usess, ua_sess, ua_chan);
3084 if (ret < 0) {
3085 goto error;
3086 }
3087
3088 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
3089 app->pid);
3090
3091 /* Only add the channel if successful on the tracer side. */
3092 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3093
3094 end:
3095 if (ua_chanp) {
3096 *ua_chanp = ua_chan;
3097 }
3098
3099 /* Everything went well. */
3100 return 0;
3101
3102 error:
3103 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
3104 error_alloc:
3105 return ret;
3106 }
3107
3108 /*
3109 * Create UST app event and create it on the tracer side.
3110 *
3111 * Called with ust app session mutex held.
3112 */
3113 static
3114 int create_ust_app_event(struct ust_app_session *ua_sess,
3115 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3116 struct ust_app *app)
3117 {
3118 int ret = 0;
3119 struct ust_app_event *ua_event;
3120
3121 /* Get event node */
3122 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3123 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3124 if (ua_event != NULL) {
3125 ret = -EEXIST;
3126 goto end;
3127 }
3128
3129 /* Does not exist so create one */
3130 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3131 if (ua_event == NULL) {
3132 /* Only malloc can failed so something is really wrong */
3133 ret = -ENOMEM;
3134 goto end;
3135 }
3136 shadow_copy_event(ua_event, uevent);
3137
3138 /* Create it on the tracer side */
3139 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3140 if (ret < 0) {
3141 /* Not found previously means that it does not exist on the tracer */
3142 assert(ret != -LTTNG_UST_ERR_EXIST);
3143 goto error;
3144 }
3145
3146 add_unique_ust_app_event(ua_chan, ua_event);
3147
3148 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3149 app->pid);
3150
3151 end:
3152 return ret;
3153
3154 error:
3155 /* Valid. Calling here is already in a read side lock */
3156 delete_ust_app_event(-1, ua_event, app);
3157 return ret;
3158 }
3159
3160 /*
3161 * Create UST metadata and open it on the tracer side.
3162 *
3163 * Called with UST app session lock held and RCU read side lock.
3164 */
3165 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3166 struct ust_app *app, struct consumer_output *consumer)
3167 {
3168 int ret = 0;
3169 struct ust_app_channel *metadata;
3170 struct consumer_socket *socket;
3171 struct ust_registry_session *registry;
3172
3173 assert(ua_sess);
3174 assert(app);
3175 assert(consumer);
3176
3177 registry = get_session_registry(ua_sess);
3178 assert(registry);
3179
3180 pthread_mutex_lock(&registry->lock);
3181
3182 /* Metadata already exists for this registry or it was closed previously */
3183 if (registry->metadata_key || registry->metadata_closed) {
3184 ret = 0;
3185 goto error;
3186 }
3187
3188 /* Allocate UST metadata */
3189 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3190 if (!metadata) {
3191 /* malloc() failed */
3192 ret = -ENOMEM;
3193 goto error;
3194 }
3195
3196 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3197
3198 /* Need one fd for the channel. */
3199 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3200 if (ret < 0) {
3201 ERR("Exhausted number of available FD upon create metadata");
3202 goto error;
3203 }
3204
3205 /* Get the right consumer socket for the application. */
3206 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3207 if (!socket) {
3208 ret = -EINVAL;
3209 goto error_consumer;
3210 }
3211
3212 /*
3213 * Keep metadata key so we can identify it on the consumer side. Assign it
3214 * to the registry *before* we ask the consumer so we avoid the race of the
3215 * consumer requesting the metadata and the ask_channel call on our side
3216 * did not returned yet.
3217 */
3218 registry->metadata_key = metadata->key;
3219
3220 /*
3221 * Ask the metadata channel creation to the consumer. The metadata object
3222 * will be created by the consumer and kept their. However, the stream is
3223 * never added or monitored until we do a first push metadata to the
3224 * consumer.
3225 */
3226 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3227 registry);
3228 if (ret < 0) {
3229 /* Nullify the metadata key so we don't try to close it later on. */
3230 registry->metadata_key = 0;
3231 goto error_consumer;
3232 }
3233
3234 /*
3235 * The setup command will make the metadata stream be sent to the relayd,
3236 * if applicable, and the thread managing the metadatas. This is important
3237 * because after this point, if an error occurs, the only way the stream
3238 * can be deleted is to be monitored in the consumer.
3239 */
3240 ret = consumer_setup_metadata(socket, metadata->key);
3241 if (ret < 0) {
3242 /* Nullify the metadata key so we don't try to close it later on. */
3243 registry->metadata_key = 0;
3244 goto error_consumer;
3245 }
3246
3247 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3248 metadata->key, app->pid);
3249
3250 error_consumer:
3251 lttng_fd_put(LTTNG_FD_APPS, 1);
3252 delete_ust_app_channel(-1, metadata, app);
3253 error:
3254 pthread_mutex_unlock(&registry->lock);
3255 return ret;
3256 }
3257
3258 /*
3259 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3260 * acquired before calling this function.
3261 */
3262 struct ust_app *ust_app_find_by_pid(pid_t pid)
3263 {
3264 struct ust_app *app = NULL;
3265 struct lttng_ht_node_ulong *node;
3266 struct lttng_ht_iter iter;
3267
3268 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3269 node = lttng_ht_iter_get_node_ulong(&iter);
3270 if (node == NULL) {
3271 DBG2("UST app no found with pid %d", pid);
3272 goto error;
3273 }
3274
3275 DBG2("Found UST app by pid %d", pid);
3276
3277 app = caa_container_of(node, struct ust_app, pid_n);
3278
3279 error:
3280 return app;
3281 }
3282
3283 /*
3284 * Allocate and init an UST app object using the registration information and
3285 * the command socket. This is called when the command socket connects to the
3286 * session daemon.
3287 *
3288 * The object is returned on success or else NULL.
3289 */
3290 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3291 {
3292 struct ust_app *lta = NULL;
3293
3294 assert(msg);
3295 assert(sock >= 0);
3296
3297 DBG3("UST app creating application for socket %d", sock);
3298
3299 if ((msg->bits_per_long == 64 &&
3300 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3301 || (msg->bits_per_long == 32 &&
3302 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3303 ERR("Registration failed: application \"%s\" (pid: %d) has "
3304 "%d-bit long, but no consumerd for this size is available.\n",
3305 msg->name, msg->pid, msg->bits_per_long);
3306 goto error;
3307 }
3308
3309 lta = zmalloc(sizeof(struct ust_app));
3310 if (lta == NULL) {
3311 PERROR("malloc");
3312 goto error;
3313 }
3314
3315 lta->ppid = msg->ppid;
3316 lta->uid = msg->uid;
3317 lta->gid = msg->gid;
3318
3319 lta->bits_per_long = msg->bits_per_long;
3320 lta->uint8_t_alignment = msg->uint8_t_alignment;
3321 lta->uint16_t_alignment = msg->uint16_t_alignment;
3322 lta->uint32_t_alignment = msg->uint32_t_alignment;
3323 lta->uint64_t_alignment = msg->uint64_t_alignment;
3324 lta->long_alignment = msg->long_alignment;
3325 lta->byte_order = msg->byte_order;
3326
3327 lta->v_major = msg->major;
3328 lta->v_minor = msg->minor;
3329 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3330 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3331 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3332 lta->notify_sock = -1;
3333
3334 /* Copy name and make sure it's NULL terminated. */
3335 strncpy(lta->name, msg->name, sizeof(lta->name));
3336 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3337
3338 /*
3339 * Before this can be called, when receiving the registration information,
3340 * the application compatibility is checked. So, at this point, the
3341 * application can work with this session daemon.
3342 */
3343 lta->compatible = 1;
3344
3345 lta->pid = msg->pid;
3346 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3347 lta->sock = sock;
3348 pthread_mutex_init(&lta->sock_lock, NULL);
3349 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3350
3351 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3352 error:
3353 return lta;
3354 }
3355
3356 /*
3357 * For a given application object, add it to every hash table.
3358 */
3359 void ust_app_add(struct ust_app *app)
3360 {
3361 assert(app);
3362 assert(app->notify_sock >= 0);
3363
3364 rcu_read_lock();
3365
3366 /*
3367 * On a re-registration, we want to kick out the previous registration of
3368 * that pid
3369 */
3370 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3371
3372 /*
3373 * The socket _should_ be unique until _we_ call close. So, a add_unique
3374 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3375 * already in the table.
3376 */
3377 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3378
3379 /* Add application to the notify socket hash table. */
3380 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3381 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3382
3383 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3384 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3385 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3386 app->v_minor);
3387
3388 rcu_read_unlock();
3389 }
3390
3391 /*
3392 * Set the application version into the object.
3393 *
3394 * Return 0 on success else a negative value either an errno code or a
3395 * LTTng-UST error code.
3396 */
3397 int ust_app_version(struct ust_app *app)
3398 {
3399 int ret;
3400
3401 assert(app);
3402
3403 pthread_mutex_lock(&app->sock_lock);
3404 ret = ustctl_tracer_version(app->sock, &app->version);
3405 pthread_mutex_unlock(&app->sock_lock);
3406 if (ret < 0) {
3407 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3408 ERR("UST app %d version failed with ret %d", app->sock, ret);
3409 } else {
3410 DBG3("UST app %d version failed. Application is dead", app->sock);
3411 }
3412 }
3413
3414 return ret;
3415 }
3416
3417 /*
3418 * Unregister app by removing it from the global traceable app list and freeing
3419 * the data struct.
3420 *
3421 * The socket is already closed at this point so no close to sock.
3422 */
3423 void ust_app_unregister(int sock)
3424 {
3425 struct ust_app *lta;
3426 struct lttng_ht_node_ulong *node;
3427 struct lttng_ht_iter ust_app_sock_iter;
3428 struct lttng_ht_iter iter;
3429 struct ust_app_session *ua_sess;
3430 int ret;
3431
3432 rcu_read_lock();
3433
3434 /* Get the node reference for a call_rcu */
3435 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3436 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3437 assert(node);
3438
3439 lta = caa_container_of(node, struct ust_app, sock_n);
3440 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3441
3442 /*
3443 * For per-PID buffers, perform "push metadata" and flush all
3444 * application streams before removing app from hash tables,
3445 * ensuring proper behavior of data_pending check.
3446 * Remove sessions so they are not visible during deletion.
3447 */
3448 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3449 node.node) {
3450 struct ust_registry_session *registry;
3451
3452 ret = lttng_ht_del(lta->sessions, &iter);
3453 if (ret) {
3454 /* The session was already removed so scheduled for teardown. */
3455 continue;
3456 }
3457
3458 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3459 (void) ust_app_flush_app_session(lta, ua_sess);
3460 }
3461
3462 /*
3463 * Add session to list for teardown. This is safe since at this point we
3464 * are the only one using this list.
3465 */
3466 pthread_mutex_lock(&ua_sess->lock);
3467
3468 if (ua_sess->deleted) {
3469 pthread_mutex_unlock(&ua_sess->lock);
3470 continue;
3471 }
3472
3473 /*
3474 * Normally, this is done in the delete session process which is
3475 * executed in the call rcu below. However, upon registration we can't
3476 * afford to wait for the grace period before pushing data or else the
3477 * data pending feature can race between the unregistration and stop
3478 * command where the data pending command is sent *before* the grace
3479 * period ended.
3480 *
3481 * The close metadata below nullifies the metadata pointer in the
3482 * session so the delete session will NOT push/close a second time.
3483 */
3484 registry = get_session_registry(ua_sess);
3485 if (registry) {
3486 /* Push metadata for application before freeing the application. */
3487 (void) push_metadata(registry, ua_sess->consumer);
3488
3489 /*
3490 * Don't ask to close metadata for global per UID buffers. Close
3491 * metadata only on destroy trace session in this case. Also, the
3492 * previous push metadata could have flag the metadata registry to
3493 * close so don't send a close command if closed.
3494 */
3495 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3496 /* And ask to close it for this session registry. */
3497 (void) close_metadata(registry, ua_sess->consumer);
3498 }
3499 }
3500 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3501
3502 pthread_mutex_unlock(&ua_sess->lock);
3503 }
3504
3505 /* Remove application from PID hash table */
3506 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3507 assert(!ret);
3508
3509 /*
3510 * Remove application from notify hash table. The thread handling the
3511 * notify socket could have deleted the node so ignore on error because
3512 * either way it's valid. The close of that socket is handled by the other
3513 * thread.
3514 */
3515 iter.iter.node = &lta->notify_sock_n.node;
3516 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3517
3518 /*
3519 * Ignore return value since the node might have been removed before by an
3520 * add replace during app registration because the PID can be reassigned by
3521 * the OS.
3522 */
3523 iter.iter.node = &lta->pid_n.node;
3524 ret = lttng_ht_del(ust_app_ht, &iter);
3525 if (ret) {
3526 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3527 lta->pid);
3528 }
3529
3530 /* Free memory */
3531 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3532
3533 rcu_read_unlock();
3534 return;
3535 }
3536
3537 /*
3538 * Fill events array with all events name of all registered apps.
3539 */
3540 int ust_app_list_events(struct lttng_event **events)
3541 {
3542 int ret, handle;
3543 size_t nbmem, count = 0;
3544 struct lttng_ht_iter iter;
3545 struct ust_app *app;
3546 struct lttng_event *tmp_event;
3547
3548 nbmem = UST_APP_EVENT_LIST_SIZE;
3549 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3550 if (tmp_event == NULL) {
3551 PERROR("zmalloc ust app events");
3552 ret = -ENOMEM;
3553 goto error;
3554 }
3555
3556 rcu_read_lock();
3557
3558 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3559 struct lttng_ust_tracepoint_iter uiter;
3560
3561 health_code_update();
3562
3563 if (!app->compatible) {
3564 /*
3565 * TODO: In time, we should notice the caller of this error by
3566 * telling him that this is a version error.
3567 */
3568 continue;
3569 }
3570 pthread_mutex_lock(&app->sock_lock);
3571 handle = ustctl_tracepoint_list(app->sock);
3572 if (handle < 0) {
3573 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3574 ERR("UST app list events getting handle failed for app pid %d",
3575 app->pid);
3576 }
3577 pthread_mutex_unlock(&app->sock_lock);
3578 continue;
3579 }
3580
3581 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3582 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3583 /* Handle ustctl error. */
3584 if (ret < 0) {
3585 int release_ret;
3586
3587 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3588 ERR("UST app tp list get failed for app %d with ret %d",
3589 app->sock, ret);
3590 } else {
3591 DBG3("UST app tp list get failed. Application is dead");
3592 /*
3593 * This is normal behavior, an application can die during the
3594 * creation process. Don't report an error so the execution can
3595 * continue normally. Continue normal execution.
3596 */
3597 break;
3598 }
3599 free(tmp_event);
3600 release_ret = ustctl_release_handle(app->sock, handle);
3601 if (release_ret < 0 &&
3602 release_ret != -LTTNG_UST_ERR_EXITING &&
3603 release_ret != -EPIPE) {
3604 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3605 }
3606 pthread_mutex_unlock(&app->sock_lock);
3607 goto rcu_error;
3608 }
3609
3610 health_code_update();
3611 if (count >= nbmem) {
3612 /* In case the realloc fails, we free the memory */
3613 struct lttng_event *new_tmp_event;
3614 size_t new_nbmem;
3615
3616 new_nbmem = nbmem << 1;
3617 DBG2("Reallocating event list from %zu to %zu entries",
3618 nbmem, new_nbmem);
3619 new_tmp_event = realloc(tmp_event,
3620 new_nbmem * sizeof(struct lttng_event));
3621 if (new_tmp_event == NULL) {
3622 int release_ret;
3623
3624 PERROR("realloc ust app events");
3625 free(tmp_event);
3626 ret = -ENOMEM;
3627 release_ret = ustctl_release_handle(app->sock, handle);
3628 if (release_ret < 0 &&
3629 release_ret != -LTTNG_UST_ERR_EXITING &&
3630 release_ret != -EPIPE) {
3631 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3632 }
3633 pthread_mutex_unlock(&app->sock_lock);
3634 goto rcu_error;
3635 }
3636 /* Zero the new memory */
3637 memset(new_tmp_event + nbmem, 0,
3638 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3639 nbmem = new_nbmem;
3640 tmp_event = new_tmp_event;
3641 }
3642 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3643 tmp_event[count].loglevel = uiter.loglevel;
3644 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3645 tmp_event[count].pid = app->pid;
3646 tmp_event[count].enabled = -1;
3647 count++;
3648 }
3649 ret = ustctl_release_handle(app->sock, handle);
3650 pthread_mutex_unlock(&app->sock_lock);
3651 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3652 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3653 }
3654 }
3655
3656 ret = count;
3657 *events = tmp_event;
3658
3659 DBG2("UST app list events done (%zu events)", count);
3660
3661 rcu_error:
3662 rcu_read_unlock();
3663 error:
3664 health_code_update();
3665 return ret;
3666 }
3667
3668 /*
3669 * Fill events array with all events name of all registered apps.
3670 */
3671 int ust_app_list_event_fields(struct lttng_event_field **fields)
3672 {
3673 int ret, handle;
3674 size_t nbmem, count = 0;
3675 struct lttng_ht_iter iter;
3676 struct ust_app *app;
3677 struct lttng_event_field *tmp_event;
3678
3679 nbmem = UST_APP_EVENT_LIST_SIZE;
3680 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3681 if (tmp_event == NULL) {
3682 PERROR("zmalloc ust app event fields");
3683 ret = -ENOMEM;
3684 goto error;
3685 }
3686
3687 rcu_read_lock();
3688
3689 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3690 struct lttng_ust_field_iter uiter;
3691
3692 health_code_update();
3693
3694 if (!app->compatible) {
3695 /*
3696 * TODO: In time, we should notice the caller of this error by
3697 * telling him that this is a version error.
3698 */
3699 continue;
3700 }
3701 pthread_mutex_lock(&app->sock_lock);
3702 handle = ustctl_tracepoint_field_list(app->sock);
3703 if (handle < 0) {
3704 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3705 ERR("UST app list field getting handle failed for app pid %d",
3706 app->pid);
3707 }
3708 pthread_mutex_unlock(&app->sock_lock);
3709 continue;
3710 }
3711
3712 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3713 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3714 /* Handle ustctl error. */
3715 if (ret < 0) {
3716 int release_ret;
3717
3718 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3719 ERR("UST app tp list field failed for app %d with ret %d",
3720 app->sock, ret);
3721 } else {
3722 DBG3("UST app tp list field failed. Application is dead");
3723 /*
3724 * This is normal behavior, an application can die during the