Test: Add the new log4j agent
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <errno.h>
20 #include <inttypes.h>
21 #include <pthread.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 #include <urcu/compiler.h>
29 #include <lttng/ust-error.h>
30 #include <signal.h>
31
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34
35 #include "buffer-registry.h"
36 #include "fd-limit.h"
37 #include "health-sessiond.h"
38 #include "ust-app.h"
39 #include "ust-consumer.h"
40 #include "ust-ctl.h"
41 #include "utils.h"
42
43 /* Next available channel key. Access under next_channel_key_lock. */
44 static uint64_t _next_channel_key;
45 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
46
47 /* Next available session ID. Access under next_session_id_lock. */
48 static uint64_t _next_session_id;
49 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
50
51 /*
52 * Return the incremented value of next_channel_key.
53 */
54 static uint64_t get_next_channel_key(void)
55 {
56 uint64_t ret;
57
58 pthread_mutex_lock(&next_channel_key_lock);
59 ret = ++_next_channel_key;
60 pthread_mutex_unlock(&next_channel_key_lock);
61 return ret;
62 }
63
64 /*
65 * Return the atomically incremented value of next_session_id.
66 */
67 static uint64_t get_next_session_id(void)
68 {
69 uint64_t ret;
70
71 pthread_mutex_lock(&next_session_id_lock);
72 ret = ++_next_session_id;
73 pthread_mutex_unlock(&next_session_id_lock);
74 return ret;
75 }
76
77 static void copy_channel_attr_to_ustctl(
78 struct ustctl_consumer_channel_attr *attr,
79 struct lttng_ust_channel_attr *uattr)
80 {
81 /* Copy event attributes since the layout is different. */
82 attr->subbuf_size = uattr->subbuf_size;
83 attr->num_subbuf = uattr->num_subbuf;
84 attr->overwrite = uattr->overwrite;
85 attr->switch_timer_interval = uattr->switch_timer_interval;
86 attr->read_timer_interval = uattr->read_timer_interval;
87 attr->output = uattr->output;
88 }
89
90 /*
91 * Match function for the hash table lookup.
92 *
93 * It matches an ust app event based on three attributes which are the event
94 * name, the filter bytecode and the loglevel.
95 */
96 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
97 {
98 struct ust_app_event *event;
99 const struct ust_app_ht_key *key;
100
101 assert(node);
102 assert(_key);
103
104 event = caa_container_of(node, struct ust_app_event, node.node);
105 key = _key;
106
107 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
108
109 /* Event name */
110 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
111 goto no_match;
112 }
113
114 /* Event loglevel. */
115 if (event->attr.loglevel != key->loglevel) {
116 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
117 && key->loglevel == 0 && event->attr.loglevel == -1) {
118 /*
119 * Match is accepted. This is because on event creation, the
120 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
121 * -1 are accepted for this loglevel type since 0 is the one set by
122 * the API when receiving an enable event.
123 */
124 } else {
125 goto no_match;
126 }
127 }
128
129 /* One of the filters is NULL, fail. */
130 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
131 goto no_match;
132 }
133
134 if (key->filter && event->filter) {
135 /* Both filters exists, check length followed by the bytecode. */
136 if (event->filter->len != key->filter->len ||
137 memcmp(event->filter->data, key->filter->data,
138 event->filter->len) != 0) {
139 goto no_match;
140 }
141 }
142
143 /* One of the exclusions is NULL, fail. */
144 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
145 goto no_match;
146 }
147
148 if (key->exclusion && event->exclusion) {
149 /* Both exclusions exists, check count followed by the names. */
150 if (event->exclusion->count != key->exclusion->count ||
151 memcmp(event->exclusion->names, key->exclusion->names,
152 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
153 goto no_match;
154 }
155 }
156
157
158 /* Match. */
159 return 1;
160
161 no_match:
162 return 0;
163 }
164
165 /*
166 * Unique add of an ust app event in the given ht. This uses the custom
167 * ht_match_ust_app_event match function and the event name as hash.
168 */
169 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
170 struct ust_app_event *event)
171 {
172 struct cds_lfht_node *node_ptr;
173 struct ust_app_ht_key key;
174 struct lttng_ht *ht;
175
176 assert(ua_chan);
177 assert(ua_chan->events);
178 assert(event);
179
180 ht = ua_chan->events;
181 key.name = event->attr.name;
182 key.filter = event->filter;
183 key.loglevel = event->attr.loglevel;
184 key.exclusion = event->exclusion;
185
186 node_ptr = cds_lfht_add_unique(ht->ht,
187 ht->hash_fct(event->node.key, lttng_ht_seed),
188 ht_match_ust_app_event, &key, &event->node.node);
189 assert(node_ptr == &event->node.node);
190 }
191
192 /*
193 * Close the notify socket from the given RCU head object. This MUST be called
194 * through a call_rcu().
195 */
196 static void close_notify_sock_rcu(struct rcu_head *head)
197 {
198 int ret;
199 struct ust_app_notify_sock_obj *obj =
200 caa_container_of(head, struct ust_app_notify_sock_obj, head);
201
202 /* Must have a valid fd here. */
203 assert(obj->fd >= 0);
204
205 ret = close(obj->fd);
206 if (ret) {
207 ERR("close notify sock %d RCU", obj->fd);
208 }
209 lttng_fd_put(LTTNG_FD_APPS, 1);
210
211 free(obj);
212 }
213
214 /*
215 * Return the session registry according to the buffer type of the given
216 * session.
217 *
218 * A registry per UID object MUST exists before calling this function or else
219 * it assert() if not found. RCU read side lock must be acquired.
220 */
221 static struct ust_registry_session *get_session_registry(
222 struct ust_app_session *ua_sess)
223 {
224 struct ust_registry_session *registry = NULL;
225
226 assert(ua_sess);
227
228 switch (ua_sess->buffer_type) {
229 case LTTNG_BUFFER_PER_PID:
230 {
231 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
232 if (!reg_pid) {
233 goto error;
234 }
235 registry = reg_pid->registry->reg.ust;
236 break;
237 }
238 case LTTNG_BUFFER_PER_UID:
239 {
240 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
241 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
242 if (!reg_uid) {
243 goto error;
244 }
245 registry = reg_uid->registry->reg.ust;
246 break;
247 }
248 default:
249 assert(0);
250 };
251
252 error:
253 return registry;
254 }
255
256 /*
257 * Delete ust context safely. RCU read lock must be held before calling
258 * this function.
259 */
260 static
261 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
262 {
263 int ret;
264
265 assert(ua_ctx);
266
267 if (ua_ctx->obj) {
268 ret = ustctl_release_object(sock, ua_ctx->obj);
269 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
270 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
271 sock, ua_ctx->obj->handle, ret);
272 }
273 free(ua_ctx->obj);
274 }
275 free(ua_ctx);
276 }
277
278 /*
279 * Delete ust app event safely. RCU read lock must be held before calling
280 * this function.
281 */
282 static
283 void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
284 {
285 int ret;
286
287 assert(ua_event);
288
289 free(ua_event->filter);
290 if (ua_event->exclusion != NULL)
291 free(ua_event->exclusion);
292 if (ua_event->obj != NULL) {
293 ret = ustctl_release_object(sock, ua_event->obj);
294 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
295 ERR("UST app sock %d release event obj failed with ret %d",
296 sock, ret);
297 }
298 free(ua_event->obj);
299 }
300 free(ua_event);
301 }
302
303 /*
304 * Release ust data object of the given stream.
305 *
306 * Return 0 on success or else a negative value.
307 */
308 static int release_ust_app_stream(int sock, struct ust_app_stream *stream)
309 {
310 int ret = 0;
311
312 assert(stream);
313
314 if (stream->obj) {
315 ret = ustctl_release_object(sock, stream->obj);
316 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
317 ERR("UST app sock %d release stream obj failed with ret %d",
318 sock, ret);
319 }
320 lttng_fd_put(LTTNG_FD_APPS, 2);
321 free(stream->obj);
322 }
323
324 return ret;
325 }
326
327 /*
328 * Delete ust app stream safely. RCU read lock must be held before calling
329 * this function.
330 */
331 static
332 void delete_ust_app_stream(int sock, struct ust_app_stream *stream)
333 {
334 assert(stream);
335
336 (void) release_ust_app_stream(sock, stream);
337 free(stream);
338 }
339
340 /*
341 * We need to execute ht_destroy outside of RCU read-side critical
342 * section and outside of call_rcu thread, so we postpone its execution
343 * using ht_cleanup_push. It is simpler than to change the semantic of
344 * the many callers of delete_ust_app_session().
345 */
346 static
347 void delete_ust_app_channel_rcu(struct rcu_head *head)
348 {
349 struct ust_app_channel *ua_chan =
350 caa_container_of(head, struct ust_app_channel, rcu_head);
351
352 ht_cleanup_push(ua_chan->ctx);
353 ht_cleanup_push(ua_chan->events);
354 free(ua_chan);
355 }
356
357 /*
358 * Delete ust app channel safely. RCU read lock must be held before calling
359 * this function.
360 */
361 static
362 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
363 struct ust_app *app)
364 {
365 int ret;
366 struct lttng_ht_iter iter;
367 struct ust_app_event *ua_event;
368 struct ust_app_ctx *ua_ctx;
369 struct ust_app_stream *stream, *stmp;
370 struct ust_registry_session *registry;
371
372 assert(ua_chan);
373
374 DBG3("UST app deleting channel %s", ua_chan->name);
375
376 /* Wipe stream */
377 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
378 cds_list_del(&stream->list);
379 delete_ust_app_stream(sock, stream);
380 }
381
382 /* Wipe context */
383 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
384 cds_list_del(&ua_ctx->list);
385 ret = lttng_ht_del(ua_chan->ctx, &iter);
386 assert(!ret);
387 delete_ust_app_ctx(sock, ua_ctx);
388 }
389
390 /* Wipe events */
391 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
392 node.node) {
393 ret = lttng_ht_del(ua_chan->events, &iter);
394 assert(!ret);
395 delete_ust_app_event(sock, ua_event);
396 }
397
398 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
399 /* Wipe and free registry from session registry. */
400 registry = get_session_registry(ua_chan->session);
401 if (registry) {
402 ust_registry_channel_del_free(registry, ua_chan->key);
403 }
404 }
405
406 if (ua_chan->obj != NULL) {
407 /* Remove channel from application UST object descriptor. */
408 iter.iter.node = &ua_chan->ust_objd_node.node;
409 ret = lttng_ht_del(app->ust_objd, &iter);
410 assert(!ret);
411 ret = ustctl_release_object(sock, ua_chan->obj);
412 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
413 ERR("UST app sock %d release channel obj failed with ret %d",
414 sock, ret);
415 }
416 lttng_fd_put(LTTNG_FD_APPS, 1);
417 free(ua_chan->obj);
418 }
419 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
420 }
421
422 /*
423 * Push metadata to consumer socket.
424 *
425 * The socket lock MUST be acquired.
426 * The ust app session lock MUST be acquired.
427 *
428 * On success, return the len of metadata pushed or else a negative value.
429 */
430 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
431 struct consumer_socket *socket, int send_zero_data)
432 {
433 int ret;
434 char *metadata_str = NULL;
435 size_t len, offset;
436 ssize_t ret_val;
437
438 assert(registry);
439 assert(socket);
440
441 /*
442 * On a push metadata error either the consumer is dead or the metadata
443 * channel has been destroyed because its endpoint might have died (e.g:
444 * relayd). If so, the metadata closed flag is set to 1 so we deny pushing
445 * metadata again which is not valid anymore on the consumer side.
446 *
447 * The ust app session mutex locked allows us to make this check without
448 * the registry lock.
449 */
450 if (registry->metadata_closed) {
451 return -EPIPE;
452 }
453
454 pthread_mutex_lock(&registry->lock);
455
456 offset = registry->metadata_len_sent;
457 len = registry->metadata_len - registry->metadata_len_sent;
458 if (len == 0) {
459 DBG3("No metadata to push for metadata key %" PRIu64,
460 registry->metadata_key);
461 ret_val = len;
462 if (send_zero_data) {
463 DBG("No metadata to push");
464 goto push_data;
465 }
466 goto end;
467 }
468
469 /* Allocate only what we have to send. */
470 metadata_str = zmalloc(len);
471 if (!metadata_str) {
472 PERROR("zmalloc ust app metadata string");
473 ret_val = -ENOMEM;
474 goto error;
475 }
476 /* Copy what we haven't send out. */
477 memcpy(metadata_str, registry->metadata + offset, len);
478 registry->metadata_len_sent += len;
479
480 push_data:
481 pthread_mutex_unlock(&registry->lock);
482 ret = consumer_push_metadata(socket, registry->metadata_key,
483 metadata_str, len, offset);
484 if (ret < 0) {
485 /*
486 * There is an acceptable race here between the registry metadata key
487 * assignment and the creation on the consumer. The session daemon can
488 * concurrently push metadata for this registry while being created on
489 * the consumer since the metadata key of the registry is assigned
490 * *before* it is setup to avoid the consumer to ask for metadata that
491 * could possibly be not found in the session daemon.
492 *
493 * The metadata will get pushed either by the session being stopped or
494 * the consumer requesting metadata if that race is triggered.
495 */
496 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
497 ret = 0;
498 }
499
500 /* Update back the actual metadata len sent since it failed here. */
501 pthread_mutex_lock(&registry->lock);
502 registry->metadata_len_sent -= len;
503 pthread_mutex_unlock(&registry->lock);
504 ret_val = ret;
505 goto error_push;
506 }
507
508 free(metadata_str);
509 return len;
510
511 end:
512 error:
513 pthread_mutex_unlock(&registry->lock);
514 error_push:
515 free(metadata_str);
516 return ret_val;
517 }
518
519 /*
520 * For a given application and session, push metadata to consumer. The session
521 * lock MUST be acquired here before calling this.
522 * Either sock or consumer is required : if sock is NULL, the default
523 * socket to send the metadata is retrieved from consumer, if sock
524 * is not NULL we use it to send the metadata.
525 *
526 * Return 0 on success else a negative error.
527 */
528 static int push_metadata(struct ust_registry_session *registry,
529 struct consumer_output *consumer)
530 {
531 int ret_val;
532 ssize_t ret;
533 struct consumer_socket *socket;
534
535 assert(registry);
536 assert(consumer);
537
538 rcu_read_lock();
539
540 /*
541 * Means that no metadata was assigned to the session. This can happens if
542 * no start has been done previously.
543 */
544 if (!registry->metadata_key) {
545 ret_val = 0;
546 goto end_rcu_unlock;
547 }
548
549 /* Get consumer socket to use to push the metadata.*/
550 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
551 consumer);
552 if (!socket) {
553 ret_val = -1;
554 goto error_rcu_unlock;
555 }
556
557 /*
558 * TODO: Currently, we hold the socket lock around sampling of the next
559 * metadata segment to ensure we send metadata over the consumer socket in
560 * the correct order. This makes the registry lock nest inside the socket
561 * lock.
562 *
563 * Please note that this is a temporary measure: we should move this lock
564 * back into ust_consumer_push_metadata() when the consumer gets the
565 * ability to reorder the metadata it receives.
566 */
567 pthread_mutex_lock(socket->lock);
568 ret = ust_app_push_metadata(registry, socket, 0);
569 pthread_mutex_unlock(socket->lock);
570 if (ret < 0) {
571 ret_val = ret;
572 goto error_rcu_unlock;
573 }
574
575 rcu_read_unlock();
576 return 0;
577
578 error_rcu_unlock:
579 /*
580 * On error, flag the registry that the metadata is closed. We were unable
581 * to push anything and this means that either the consumer is not
582 * responding or the metadata cache has been destroyed on the consumer.
583 */
584 registry->metadata_closed = 1;
585 end_rcu_unlock:
586 rcu_read_unlock();
587 return ret_val;
588 }
589
590 /*
591 * Send to the consumer a close metadata command for the given session. Once
592 * done, the metadata channel is deleted and the session metadata pointer is
593 * nullified. The session lock MUST be acquired here unless the application is
594 * in the destroy path.
595 *
596 * Return 0 on success else a negative value.
597 */
598 static int close_metadata(struct ust_registry_session *registry,
599 struct consumer_output *consumer)
600 {
601 int ret;
602 struct consumer_socket *socket;
603
604 assert(registry);
605 assert(consumer);
606
607 rcu_read_lock();
608
609 if (!registry->metadata_key || registry->metadata_closed) {
610 ret = 0;
611 goto end;
612 }
613
614 /* Get consumer socket to use to push the metadata.*/
615 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
616 consumer);
617 if (!socket) {
618 ret = -1;
619 goto error;
620 }
621
622 ret = consumer_close_metadata(socket, registry->metadata_key);
623 if (ret < 0) {
624 goto error;
625 }
626
627 error:
628 /*
629 * Metadata closed. Even on error this means that the consumer is not
630 * responding or not found so either way a second close should NOT be emit
631 * for this registry.
632 */
633 registry->metadata_closed = 1;
634 end:
635 rcu_read_unlock();
636 return ret;
637 }
638
639 /*
640 * We need to execute ht_destroy outside of RCU read-side critical
641 * section and outside of call_rcu thread, so we postpone its execution
642 * using ht_cleanup_push. It is simpler than to change the semantic of
643 * the many callers of delete_ust_app_session().
644 */
645 static
646 void delete_ust_app_session_rcu(struct rcu_head *head)
647 {
648 struct ust_app_session *ua_sess =
649 caa_container_of(head, struct ust_app_session, rcu_head);
650
651 ht_cleanup_push(ua_sess->channels);
652 free(ua_sess);
653 }
654
655 /*
656 * Delete ust app session safely. RCU read lock must be held before calling
657 * this function.
658 */
659 static
660 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
661 struct ust_app *app)
662 {
663 int ret;
664 struct lttng_ht_iter iter;
665 struct ust_app_channel *ua_chan;
666 struct ust_registry_session *registry;
667
668 assert(ua_sess);
669
670 pthread_mutex_lock(&ua_sess->lock);
671
672 registry = get_session_registry(ua_sess);
673 if (registry && !registry->metadata_closed) {
674 /* Push metadata for application before freeing the application. */
675 (void) push_metadata(registry, ua_sess->consumer);
676
677 /*
678 * Don't ask to close metadata for global per UID buffers. Close
679 * metadata only on destroy trace session in this case. Also, the
680 * previous push metadata could have flag the metadata registry to
681 * close so don't send a close command if closed.
682 */
683 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
684 !registry->metadata_closed) {
685 /* And ask to close it for this session registry. */
686 (void) close_metadata(registry, ua_sess->consumer);
687 }
688 }
689
690 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
691 node.node) {
692 ret = lttng_ht_del(ua_sess->channels, &iter);
693 assert(!ret);
694 delete_ust_app_channel(sock, ua_chan, app);
695 }
696
697 /* In case of per PID, the registry is kept in the session. */
698 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
699 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
700 if (reg_pid) {
701 buffer_reg_pid_remove(reg_pid);
702 buffer_reg_pid_destroy(reg_pid);
703 }
704 }
705
706 if (ua_sess->handle != -1) {
707 ret = ustctl_release_handle(sock, ua_sess->handle);
708 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
709 ERR("UST app sock %d release session handle failed with ret %d",
710 sock, ret);
711 }
712 }
713 pthread_mutex_unlock(&ua_sess->lock);
714
715 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
716 }
717
718 /*
719 * Delete a traceable application structure from the global list. Never call
720 * this function outside of a call_rcu call.
721 *
722 * RCU read side lock should _NOT_ be held when calling this function.
723 */
724 static
725 void delete_ust_app(struct ust_app *app)
726 {
727 int ret, sock;
728 struct ust_app_session *ua_sess, *tmp_ua_sess;
729
730 /* Delete ust app sessions info */
731 sock = app->sock;
732 app->sock = -1;
733
734 /* Wipe sessions */
735 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
736 teardown_node) {
737 /* Free every object in the session and the session. */
738 rcu_read_lock();
739 delete_ust_app_session(sock, ua_sess, app);
740 rcu_read_unlock();
741 }
742
743 ht_cleanup_push(app->sessions);
744 ht_cleanup_push(app->ust_objd);
745
746 /*
747 * Wait until we have deleted the application from the sock hash table
748 * before closing this socket, otherwise an application could re-use the
749 * socket ID and race with the teardown, using the same hash table entry.
750 *
751 * It's OK to leave the close in call_rcu. We want it to stay unique for
752 * all RCU readers that could run concurrently with unregister app,
753 * therefore we _need_ to only close that socket after a grace period. So
754 * it should stay in this RCU callback.
755 *
756 * This close() is a very important step of the synchronization model so
757 * every modification to this function must be carefully reviewed.
758 */
759 ret = close(sock);
760 if (ret) {
761 PERROR("close");
762 }
763 lttng_fd_put(LTTNG_FD_APPS, 1);
764
765 DBG2("UST app pid %d deleted", app->pid);
766 free(app);
767 }
768
769 /*
770 * URCU intermediate call to delete an UST app.
771 */
772 static
773 void delete_ust_app_rcu(struct rcu_head *head)
774 {
775 struct lttng_ht_node_ulong *node =
776 caa_container_of(head, struct lttng_ht_node_ulong, head);
777 struct ust_app *app =
778 caa_container_of(node, struct ust_app, pid_n);
779
780 DBG3("Call RCU deleting app PID %d", app->pid);
781 delete_ust_app(app);
782 }
783
784 /*
785 * Delete the session from the application ht and delete the data structure by
786 * freeing every object inside and releasing them.
787 */
788 static void destroy_app_session(struct ust_app *app,
789 struct ust_app_session *ua_sess)
790 {
791 int ret;
792 struct lttng_ht_iter iter;
793
794 assert(app);
795 assert(ua_sess);
796
797 iter.iter.node = &ua_sess->node.node;
798 ret = lttng_ht_del(app->sessions, &iter);
799 if (ret) {
800 /* Already scheduled for teardown. */
801 goto end;
802 }
803
804 /* Once deleted, free the data structure. */
805 delete_ust_app_session(app->sock, ua_sess, app);
806
807 end:
808 return;
809 }
810
811 /*
812 * Alloc new UST app session.
813 */
814 static
815 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
816 {
817 struct ust_app_session *ua_sess;
818
819 /* Init most of the default value by allocating and zeroing */
820 ua_sess = zmalloc(sizeof(struct ust_app_session));
821 if (ua_sess == NULL) {
822 PERROR("malloc");
823 goto error_free;
824 }
825
826 ua_sess->handle = -1;
827 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
828 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
829 pthread_mutex_init(&ua_sess->lock, NULL);
830
831 return ua_sess;
832
833 error_free:
834 return NULL;
835 }
836
837 /*
838 * Alloc new UST app channel.
839 */
840 static
841 struct ust_app_channel *alloc_ust_app_channel(char *name,
842 struct ust_app_session *ua_sess,
843 struct lttng_ust_channel_attr *attr)
844 {
845 struct ust_app_channel *ua_chan;
846
847 /* Init most of the default value by allocating and zeroing */
848 ua_chan = zmalloc(sizeof(struct ust_app_channel));
849 if (ua_chan == NULL) {
850 PERROR("malloc");
851 goto error;
852 }
853
854 /* Setup channel name */
855 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
856 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
857
858 ua_chan->enabled = 1;
859 ua_chan->handle = -1;
860 ua_chan->session = ua_sess;
861 ua_chan->key = get_next_channel_key();
862 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
863 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
864 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
865
866 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
867 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
868
869 /* Copy attributes */
870 if (attr) {
871 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
872 ua_chan->attr.subbuf_size = attr->subbuf_size;
873 ua_chan->attr.num_subbuf = attr->num_subbuf;
874 ua_chan->attr.overwrite = attr->overwrite;
875 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
876 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
877 ua_chan->attr.output = attr->output;
878 }
879 /* By default, the channel is a per cpu channel. */
880 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
881
882 DBG3("UST app channel %s allocated", ua_chan->name);
883
884 return ua_chan;
885
886 error:
887 return NULL;
888 }
889
890 /*
891 * Allocate and initialize a UST app stream.
892 *
893 * Return newly allocated stream pointer or NULL on error.
894 */
895 struct ust_app_stream *ust_app_alloc_stream(void)
896 {
897 struct ust_app_stream *stream = NULL;
898
899 stream = zmalloc(sizeof(*stream));
900 if (stream == NULL) {
901 PERROR("zmalloc ust app stream");
902 goto error;
903 }
904
905 /* Zero could be a valid value for a handle so flag it to -1. */
906 stream->handle = -1;
907
908 error:
909 return stream;
910 }
911
912 /*
913 * Alloc new UST app event.
914 */
915 static
916 struct ust_app_event *alloc_ust_app_event(char *name,
917 struct lttng_ust_event *attr)
918 {
919 struct ust_app_event *ua_event;
920
921 /* Init most of the default value by allocating and zeroing */
922 ua_event = zmalloc(sizeof(struct ust_app_event));
923 if (ua_event == NULL) {
924 PERROR("malloc");
925 goto error;
926 }
927
928 ua_event->enabled = 1;
929 strncpy(ua_event->name, name, sizeof(ua_event->name));
930 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
931 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
932
933 /* Copy attributes */
934 if (attr) {
935 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
936 }
937
938 DBG3("UST app event %s allocated", ua_event->name);
939
940 return ua_event;
941
942 error:
943 return NULL;
944 }
945
946 /*
947 * Alloc new UST app context.
948 */
949 static
950 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
951 {
952 struct ust_app_ctx *ua_ctx;
953
954 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
955 if (ua_ctx == NULL) {
956 goto error;
957 }
958
959 CDS_INIT_LIST_HEAD(&ua_ctx->list);
960
961 if (uctx) {
962 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
963 }
964
965 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
966
967 error:
968 return ua_ctx;
969 }
970
971 /*
972 * Allocate a filter and copy the given original filter.
973 *
974 * Return allocated filter or NULL on error.
975 */
976 static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
977 struct lttng_ust_filter_bytecode *orig_f)
978 {
979 struct lttng_ust_filter_bytecode *filter = NULL;
980
981 /* Copy filter bytecode */
982 filter = zmalloc(sizeof(*filter) + orig_f->len);
983 if (!filter) {
984 PERROR("zmalloc alloc ust app filter");
985 goto error;
986 }
987
988 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
989
990 error:
991 return filter;
992 }
993
994 /*
995 * Find an ust_app using the sock and return it. RCU read side lock must be
996 * held before calling this helper function.
997 */
998 struct ust_app *ust_app_find_by_sock(int sock)
999 {
1000 struct lttng_ht_node_ulong *node;
1001 struct lttng_ht_iter iter;
1002
1003 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1004 node = lttng_ht_iter_get_node_ulong(&iter);
1005 if (node == NULL) {
1006 DBG2("UST app find by sock %d not found", sock);
1007 goto error;
1008 }
1009
1010 return caa_container_of(node, struct ust_app, sock_n);
1011
1012 error:
1013 return NULL;
1014 }
1015
1016 /*
1017 * Find an ust_app using the notify sock and return it. RCU read side lock must
1018 * be held before calling this helper function.
1019 */
1020 static struct ust_app *find_app_by_notify_sock(int sock)
1021 {
1022 struct lttng_ht_node_ulong *node;
1023 struct lttng_ht_iter iter;
1024
1025 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1026 &iter);
1027 node = lttng_ht_iter_get_node_ulong(&iter);
1028 if (node == NULL) {
1029 DBG2("UST app find by notify sock %d not found", sock);
1030 goto error;
1031 }
1032
1033 return caa_container_of(node, struct ust_app, notify_sock_n);
1034
1035 error:
1036 return NULL;
1037 }
1038
1039 /*
1040 * Lookup for an ust app event based on event name, filter bytecode and the
1041 * event loglevel.
1042 *
1043 * Return an ust_app_event object or NULL on error.
1044 */
1045 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1046 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel,
1047 const struct lttng_event_exclusion *exclusion)
1048 {
1049 struct lttng_ht_iter iter;
1050 struct lttng_ht_node_str *node;
1051 struct ust_app_event *event = NULL;
1052 struct ust_app_ht_key key;
1053
1054 assert(name);
1055 assert(ht);
1056
1057 /* Setup key for event lookup. */
1058 key.name = name;
1059 key.filter = filter;
1060 key.loglevel = loglevel;
1061 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1062 key.exclusion = (struct lttng_ust_event_exclusion *)exclusion;
1063
1064 /* Lookup using the event name as hash and a custom match fct. */
1065 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1066 ht_match_ust_app_event, &key, &iter.iter);
1067 node = lttng_ht_iter_get_node_str(&iter);
1068 if (node == NULL) {
1069 goto end;
1070 }
1071
1072 event = caa_container_of(node, struct ust_app_event, node);
1073
1074 end:
1075 return event;
1076 }
1077
1078 /*
1079 * Create the channel context on the tracer.
1080 *
1081 * Called with UST app session lock held.
1082 */
1083 static
1084 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1085 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1086 {
1087 int ret;
1088
1089 health_code_update();
1090
1091 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1092 ua_chan->obj, &ua_ctx->obj);
1093 if (ret < 0) {
1094 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1095 ERR("UST app create channel context failed for app (pid: %d) "
1096 "with ret %d", app->pid, ret);
1097 } else {
1098 /*
1099 * This is normal behavior, an application can die during the
1100 * creation process. Don't report an error so the execution can
1101 * continue normally.
1102 */
1103 ret = 0;
1104 DBG3("UST app disable event failed. Application is dead.");
1105 }
1106 goto error;
1107 }
1108
1109 ua_ctx->handle = ua_ctx->obj->handle;
1110
1111 DBG2("UST app context handle %d created successfully for channel %s",
1112 ua_ctx->handle, ua_chan->name);
1113
1114 error:
1115 health_code_update();
1116 return ret;
1117 }
1118
1119 /*
1120 * Set the filter on the tracer.
1121 */
1122 static
1123 int set_ust_event_filter(struct ust_app_event *ua_event,
1124 struct ust_app *app)
1125 {
1126 int ret;
1127
1128 health_code_update();
1129
1130 if (!ua_event->filter) {
1131 ret = 0;
1132 goto error;
1133 }
1134
1135 ret = ustctl_set_filter(app->sock, ua_event->filter,
1136 ua_event->obj);
1137 if (ret < 0) {
1138 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1139 ERR("UST app event %s filter failed for app (pid: %d) "
1140 "with ret %d", ua_event->attr.name, app->pid, ret);
1141 } else {
1142 /*
1143 * This is normal behavior, an application can die during the
1144 * creation process. Don't report an error so the execution can
1145 * continue normally.
1146 */
1147 ret = 0;
1148 DBG3("UST app filter event failed. Application is dead.");
1149 }
1150 goto error;
1151 }
1152
1153 DBG2("UST filter set successfully for event %s", ua_event->name);
1154
1155 error:
1156 health_code_update();
1157 return ret;
1158 }
1159
1160 /*
1161 * Set event exclusions on the tracer.
1162 */
1163 static
1164 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1165 struct ust_app *app)
1166 {
1167 int ret;
1168
1169 health_code_update();
1170
1171 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1172 ret = 0;
1173 goto error;
1174 }
1175
1176 ret = ustctl_set_exclusion(app->sock, ua_event->exclusion,
1177 ua_event->obj);
1178 if (ret < 0) {
1179 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1180 ERR("UST app event %s exclusions failed for app (pid: %d) "
1181 "with ret %d", ua_event->attr.name, app->pid, ret);
1182 } else {
1183 /*
1184 * This is normal behavior, an application can die during the
1185 * creation process. Don't report an error so the execution can
1186 * continue normally.
1187 */
1188 ret = 0;
1189 DBG3("UST app event exclusion failed. Application is dead.");
1190 }
1191 goto error;
1192 }
1193
1194 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1195
1196 error:
1197 health_code_update();
1198 return ret;
1199 }
1200
1201 /*
1202 * Disable the specified event on to UST tracer for the UST session.
1203 */
1204 static int disable_ust_event(struct ust_app *app,
1205 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1206 {
1207 int ret;
1208
1209 health_code_update();
1210
1211 ret = ustctl_disable(app->sock, ua_event->obj);
1212 if (ret < 0) {
1213 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1214 ERR("UST app event %s disable failed for app (pid: %d) "
1215 "and session handle %d with ret %d",
1216 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1217 } else {
1218 /*
1219 * This is normal behavior, an application can die during the
1220 * creation process. Don't report an error so the execution can
1221 * continue normally.
1222 */
1223 ret = 0;
1224 DBG3("UST app disable event failed. Application is dead.");
1225 }
1226 goto error;
1227 }
1228
1229 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1230 ua_event->attr.name, app->pid);
1231
1232 error:
1233 health_code_update();
1234 return ret;
1235 }
1236
1237 /*
1238 * Disable the specified channel on to UST tracer for the UST session.
1239 */
1240 static int disable_ust_channel(struct ust_app *app,
1241 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1242 {
1243 int ret;
1244
1245 health_code_update();
1246
1247 ret = ustctl_disable(app->sock, ua_chan->obj);
1248 if (ret < 0) {
1249 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1250 ERR("UST app channel %s disable failed for app (pid: %d) "
1251 "and session handle %d with ret %d",
1252 ua_chan->name, app->pid, ua_sess->handle, ret);
1253 } else {
1254 /*
1255 * This is normal behavior, an application can die during the
1256 * creation process. Don't report an error so the execution can
1257 * continue normally.
1258 */
1259 ret = 0;
1260 DBG3("UST app disable channel failed. Application is dead.");
1261 }
1262 goto error;
1263 }
1264
1265 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1266 ua_chan->name, app->pid);
1267
1268 error:
1269 health_code_update();
1270 return ret;
1271 }
1272
1273 /*
1274 * Enable the specified channel on to UST tracer for the UST session.
1275 */
1276 static int enable_ust_channel(struct ust_app *app,
1277 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1278 {
1279 int ret;
1280
1281 health_code_update();
1282
1283 ret = ustctl_enable(app->sock, ua_chan->obj);
1284 if (ret < 0) {
1285 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1286 ERR("UST app channel %s enable failed for app (pid: %d) "
1287 "and session handle %d with ret %d",
1288 ua_chan->name, app->pid, ua_sess->handle, ret);
1289 } else {
1290 /*
1291 * This is normal behavior, an application can die during the
1292 * creation process. Don't report an error so the execution can
1293 * continue normally.
1294 */
1295 ret = 0;
1296 DBG3("UST app enable channel failed. Application is dead.");
1297 }
1298 goto error;
1299 }
1300
1301 ua_chan->enabled = 1;
1302
1303 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1304 ua_chan->name, app->pid);
1305
1306 error:
1307 health_code_update();
1308 return ret;
1309 }
1310
1311 /*
1312 * Enable the specified event on to UST tracer for the UST session.
1313 */
1314 static int enable_ust_event(struct ust_app *app,
1315 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1316 {
1317 int ret;
1318
1319 health_code_update();
1320
1321 ret = ustctl_enable(app->sock, ua_event->obj);
1322 if (ret < 0) {
1323 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1324 ERR("UST app event %s enable failed for app (pid: %d) "
1325 "and session handle %d with ret %d",
1326 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1327 } else {
1328 /*
1329 * This is normal behavior, an application can die during the
1330 * creation process. Don't report an error so the execution can
1331 * continue normally.
1332 */
1333 ret = 0;
1334 DBG3("UST app enable event failed. Application is dead.");
1335 }
1336 goto error;
1337 }
1338
1339 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1340 ua_event->attr.name, app->pid);
1341
1342 error:
1343 health_code_update();
1344 return ret;
1345 }
1346
1347 /*
1348 * Send channel and stream buffer to application.
1349 *
1350 * Return 0 on success. On error, a negative value is returned.
1351 */
1352 static int send_channel_pid_to_ust(struct ust_app *app,
1353 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1354 {
1355 int ret;
1356 struct ust_app_stream *stream, *stmp;
1357
1358 assert(app);
1359 assert(ua_sess);
1360 assert(ua_chan);
1361
1362 health_code_update();
1363
1364 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1365 app->sock);
1366
1367 /* Send channel to the application. */
1368 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1369 if (ret < 0) {
1370 goto error;
1371 }
1372
1373 health_code_update();
1374
1375 /* Send all streams to application. */
1376 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1377 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1378 if (ret < 0) {
1379 goto error;
1380 }
1381 /* We don't need the stream anymore once sent to the tracer. */
1382 cds_list_del(&stream->list);
1383 delete_ust_app_stream(-1, stream);
1384 }
1385 /* Flag the channel that it is sent to the application. */
1386 ua_chan->is_sent = 1;
1387
1388 error:
1389 health_code_update();
1390 return ret;
1391 }
1392
1393 /*
1394 * Create the specified event onto the UST tracer for a UST session.
1395 *
1396 * Should be called with session mutex held.
1397 */
1398 static
1399 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1400 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1401 {
1402 int ret = 0;
1403
1404 health_code_update();
1405
1406 /* Create UST event on tracer */
1407 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1408 &ua_event->obj);
1409 if (ret < 0) {
1410 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1411 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1412 ua_event->attr.name, app->pid, ret);
1413 } else {
1414 /*
1415 * This is normal behavior, an application can die during the
1416 * creation process. Don't report an error so the execution can
1417 * continue normally.
1418 */
1419 ret = 0;
1420 DBG3("UST app create event failed. Application is dead.");
1421 }
1422 goto error;
1423 }
1424
1425 ua_event->handle = ua_event->obj->handle;
1426
1427 DBG2("UST app event %s created successfully for pid:%d",
1428 ua_event->attr.name, app->pid);
1429
1430 health_code_update();
1431
1432 /* Set filter if one is present. */
1433 if (ua_event->filter) {
1434 ret = set_ust_event_filter(ua_event, app);
1435 if (ret < 0) {
1436 goto error;
1437 }
1438 }
1439
1440 /* Set exclusions for the event */
1441 if (ua_event->exclusion) {
1442 ret = set_ust_event_exclusion(ua_event, app);
1443 if (ret < 0) {
1444 goto error;
1445 }
1446 }
1447
1448 /* If event not enabled, disable it on the tracer */
1449 if (ua_event->enabled == 0) {
1450 ret = disable_ust_event(app, ua_sess, ua_event);
1451 if (ret < 0) {
1452 /*
1453 * If we hit an EPERM, something is wrong with our disable call. If
1454 * we get an EEXIST, there is a problem on the tracer side since we
1455 * just created it.
1456 */
1457 switch (ret) {
1458 case -LTTNG_UST_ERR_PERM:
1459 /* Code flow problem */
1460 assert(0);
1461 case -LTTNG_UST_ERR_EXIST:
1462 /* It's OK for our use case. */
1463 ret = 0;
1464 break;
1465 default:
1466 break;
1467 }
1468 goto error;
1469 }
1470 }
1471
1472 error:
1473 health_code_update();
1474 return ret;
1475 }
1476
1477 /*
1478 * Copy data between an UST app event and a LTT event.
1479 */
1480 static void shadow_copy_event(struct ust_app_event *ua_event,
1481 struct ltt_ust_event *uevent)
1482 {
1483 size_t exclusion_alloc_size;
1484
1485 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1486 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1487
1488 ua_event->enabled = uevent->enabled;
1489
1490 /* Copy event attributes */
1491 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1492
1493 /* Copy filter bytecode */
1494 if (uevent->filter) {
1495 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1496 /* Filter might be NULL here in case of ENONEM. */
1497 }
1498
1499 /* Copy exclusion data */
1500 if (uevent->exclusion) {
1501 exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1502 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1503 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1504 if (ua_event->exclusion == NULL) {
1505 PERROR("malloc");
1506 } else {
1507 memcpy(ua_event->exclusion, uevent->exclusion,
1508 exclusion_alloc_size);
1509 }
1510 }
1511 }
1512
1513 /*
1514 * Copy data between an UST app channel and a LTT channel.
1515 */
1516 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1517 struct ltt_ust_channel *uchan)
1518 {
1519 struct lttng_ht_iter iter;
1520 struct ltt_ust_event *uevent;
1521 struct ltt_ust_context *uctx;
1522 struct ust_app_event *ua_event;
1523 struct ust_app_ctx *ua_ctx;
1524
1525 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1526
1527 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1528 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1529
1530 ua_chan->tracefile_size = uchan->tracefile_size;
1531 ua_chan->tracefile_count = uchan->tracefile_count;
1532
1533 /* Copy event attributes since the layout is different. */
1534 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1535 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1536 ua_chan->attr.overwrite = uchan->attr.overwrite;
1537 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1538 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1539 ua_chan->attr.output = uchan->attr.output;
1540 /*
1541 * Note that the attribute channel type is not set since the channel on the
1542 * tracing registry side does not have this information.
1543 */
1544
1545 ua_chan->enabled = uchan->enabled;
1546 ua_chan->tracing_channel_id = uchan->id;
1547
1548 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1549 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1550 if (ua_ctx == NULL) {
1551 continue;
1552 }
1553 lttng_ht_node_init_ulong(&ua_ctx->node,
1554 (unsigned long) ua_ctx->ctx.ctx);
1555 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1556 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1557 }
1558
1559 /* Copy all events from ltt ust channel to ust app channel */
1560 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1561 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1562 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1563 if (ua_event == NULL) {
1564 DBG2("UST event %s not found on shadow copy channel",
1565 uevent->attr.name);
1566 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1567 if (ua_event == NULL) {
1568 continue;
1569 }
1570 shadow_copy_event(ua_event, uevent);
1571 add_unique_ust_app_event(ua_chan, ua_event);
1572 }
1573 }
1574
1575 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1576 }
1577
1578 /*
1579 * Copy data between a UST app session and a regular LTT session.
1580 */
1581 static void shadow_copy_session(struct ust_app_session *ua_sess,
1582 struct ltt_ust_session *usess, struct ust_app *app)
1583 {
1584 struct lttng_ht_node_str *ua_chan_node;
1585 struct lttng_ht_iter iter;
1586 struct ltt_ust_channel *uchan;
1587 struct ust_app_channel *ua_chan;
1588 time_t rawtime;
1589 struct tm *timeinfo;
1590 char datetime[16];
1591 int ret;
1592
1593 /* Get date and time for unique app path */
1594 time(&rawtime);
1595 timeinfo = localtime(&rawtime);
1596 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1597
1598 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1599
1600 ua_sess->tracing_id = usess->id;
1601 ua_sess->id = get_next_session_id();
1602 ua_sess->uid = app->uid;
1603 ua_sess->gid = app->gid;
1604 ua_sess->euid = usess->uid;
1605 ua_sess->egid = usess->gid;
1606 ua_sess->buffer_type = usess->buffer_type;
1607 ua_sess->bits_per_long = app->bits_per_long;
1608 /* There is only one consumer object per session possible. */
1609 ua_sess->consumer = usess->consumer;
1610 ua_sess->output_traces = usess->output_traces;
1611 ua_sess->live_timer_interval = usess->live_timer_interval;
1612 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1613 &usess->metadata_attr);
1614
1615 switch (ua_sess->buffer_type) {
1616 case LTTNG_BUFFER_PER_PID:
1617 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1618 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1619 datetime);
1620 break;
1621 case LTTNG_BUFFER_PER_UID:
1622 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1623 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1624 break;
1625 default:
1626 assert(0);
1627 goto error;
1628 }
1629 if (ret < 0) {
1630 PERROR("asprintf UST shadow copy session");
1631 assert(0);
1632 goto error;
1633 }
1634
1635 /* Iterate over all channels in global domain. */
1636 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1637 uchan, node.node) {
1638 struct lttng_ht_iter uiter;
1639
1640 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1641 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1642 if (ua_chan_node != NULL) {
1643 /* Session exist. Contiuing. */
1644 continue;
1645 }
1646
1647 DBG2("Channel %s not found on shadow session copy, creating it",
1648 uchan->name);
1649 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1650 if (ua_chan == NULL) {
1651 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1652 continue;
1653 }
1654 shadow_copy_channel(ua_chan, uchan);
1655 /*
1656 * The concept of metadata channel does not exist on the tracing
1657 * registry side of the session daemon so this can only be a per CPU
1658 * channel and not metadata.
1659 */
1660 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1661
1662 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1663 }
1664
1665 error:
1666 return;
1667 }
1668
1669 /*
1670 * Lookup sesison wrapper.
1671 */
1672 static
1673 void __lookup_session_by_app(struct ltt_ust_session *usess,
1674 struct ust_app *app, struct lttng_ht_iter *iter)
1675 {
1676 /* Get right UST app session from app */
1677 lttng_ht_lookup(app->sessions, &usess->id, iter);
1678 }
1679
1680 /*
1681 * Return ust app session from the app session hashtable using the UST session
1682 * id.
1683 */
1684 static struct ust_app_session *lookup_session_by_app(
1685 struct ltt_ust_session *usess, struct ust_app *app)
1686 {
1687 struct lttng_ht_iter iter;
1688 struct lttng_ht_node_u64 *node;
1689
1690 __lookup_session_by_app(usess, app, &iter);
1691 node = lttng_ht_iter_get_node_u64(&iter);
1692 if (node == NULL) {
1693 goto error;
1694 }
1695
1696 return caa_container_of(node, struct ust_app_session, node);
1697
1698 error:
1699 return NULL;
1700 }
1701
1702 /*
1703 * Setup buffer registry per PID for the given session and application. If none
1704 * is found, a new one is created, added to the global registry and
1705 * initialized. If regp is valid, it's set with the newly created object.
1706 *
1707 * Return 0 on success or else a negative value.
1708 */
1709 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1710 struct ust_app *app, struct buffer_reg_pid **regp)
1711 {
1712 int ret = 0;
1713 struct buffer_reg_pid *reg_pid;
1714
1715 assert(ua_sess);
1716 assert(app);
1717
1718 rcu_read_lock();
1719
1720 reg_pid = buffer_reg_pid_find(ua_sess->id);
1721 if (!reg_pid) {
1722 /*
1723 * This is the create channel path meaning that if there is NO
1724 * registry available, we have to create one for this session.
1725 */
1726 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1727 if (ret < 0) {
1728 goto error;
1729 }
1730 buffer_reg_pid_add(reg_pid);
1731 } else {
1732 goto end;
1733 }
1734
1735 /* Initialize registry. */
1736 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1737 app->bits_per_long, app->uint8_t_alignment,
1738 app->uint16_t_alignment, app->uint32_t_alignment,
1739 app->uint64_t_alignment, app->long_alignment,
1740 app->byte_order, app->version.major,
1741 app->version.minor);
1742 if (ret < 0) {
1743 goto error;
1744 }
1745
1746 DBG3("UST app buffer registry per PID created successfully");
1747
1748 end:
1749 if (regp) {
1750 *regp = reg_pid;
1751 }
1752 error:
1753 rcu_read_unlock();
1754 return ret;
1755 }
1756
1757 /*
1758 * Setup buffer registry per UID for the given session and application. If none
1759 * is found, a new one is created, added to the global registry and
1760 * initialized. If regp is valid, it's set with the newly created object.
1761 *
1762 * Return 0 on success or else a negative value.
1763 */
1764 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1765 struct ust_app *app, struct buffer_reg_uid **regp)
1766 {
1767 int ret = 0;
1768 struct buffer_reg_uid *reg_uid;
1769
1770 assert(usess);
1771 assert(app);
1772
1773 rcu_read_lock();
1774
1775 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1776 if (!reg_uid) {
1777 /*
1778 * This is the create channel path meaning that if there is NO
1779 * registry available, we have to create one for this session.
1780 */
1781 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1782 LTTNG_DOMAIN_UST, &reg_uid);
1783 if (ret < 0) {
1784 goto error;
1785 }
1786 buffer_reg_uid_add(reg_uid);
1787 } else {
1788 goto end;
1789 }
1790
1791 /* Initialize registry. */
1792 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1793 app->bits_per_long, app->uint8_t_alignment,
1794 app->uint16_t_alignment, app->uint32_t_alignment,
1795 app->uint64_t_alignment, app->long_alignment,
1796 app->byte_order, app->version.major,
1797 app->version.minor);
1798 if (ret < 0) {
1799 goto error;
1800 }
1801 /* Add node to teardown list of the session. */
1802 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1803
1804 DBG3("UST app buffer registry per UID created successfully");
1805
1806 end:
1807 if (regp) {
1808 *regp = reg_uid;
1809 }
1810 error:
1811 rcu_read_unlock();
1812 return ret;
1813 }
1814
1815 /*
1816 * Create a session on the tracer side for the given app.
1817 *
1818 * On success, ua_sess_ptr is populated with the session pointer or else left
1819 * untouched. If the session was created, is_created is set to 1. On error,
1820 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1821 * be NULL.
1822 *
1823 * Returns 0 on success or else a negative code which is either -ENOMEM or
1824 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1825 */
1826 static int create_ust_app_session(struct ltt_ust_session *usess,
1827 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1828 int *is_created)
1829 {
1830 int ret, created = 0;
1831 struct ust_app_session *ua_sess;
1832
1833 assert(usess);
1834 assert(app);
1835 assert(ua_sess_ptr);
1836
1837 health_code_update();
1838
1839 ua_sess = lookup_session_by_app(usess, app);
1840 if (ua_sess == NULL) {
1841 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1842 app->pid, usess->id);
1843 ua_sess = alloc_ust_app_session(app);
1844 if (ua_sess == NULL) {
1845 /* Only malloc can failed so something is really wrong */
1846 ret = -ENOMEM;
1847 goto error;
1848 }
1849 shadow_copy_session(ua_sess, usess, app);
1850 created = 1;
1851 }
1852
1853 switch (usess->buffer_type) {
1854 case LTTNG_BUFFER_PER_PID:
1855 /* Init local registry. */
1856 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1857 if (ret < 0) {
1858 goto error;
1859 }
1860 break;
1861 case LTTNG_BUFFER_PER_UID:
1862 /* Look for a global registry. If none exists, create one. */
1863 ret = setup_buffer_reg_uid(usess, app, NULL);
1864 if (ret < 0) {
1865 goto error;
1866 }
1867 break;
1868 default:
1869 assert(0);
1870 ret = -EINVAL;
1871 goto error;
1872 }
1873
1874 health_code_update();
1875
1876 if (ua_sess->handle == -1) {
1877 ret = ustctl_create_session(app->sock);
1878 if (ret < 0) {
1879 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1880 ERR("Creating session for app pid %d with ret %d",
1881 app->pid, ret);
1882 } else {
1883 DBG("UST app creating session failed. Application is dead");
1884 /*
1885 * This is normal behavior, an application can die during the
1886 * creation process. Don't report an error so the execution can
1887 * continue normally. This will get flagged ENOTCONN and the
1888 * caller will handle it.
1889 */
1890 ret = 0;
1891 }
1892 delete_ust_app_session(-1, ua_sess, app);
1893 if (ret != -ENOMEM) {
1894 /*
1895 * Tracer is probably gone or got an internal error so let's
1896 * behave like it will soon unregister or not usable.
1897 */
1898 ret = -ENOTCONN;
1899 }
1900 goto error;
1901 }
1902
1903 ua_sess->handle = ret;
1904
1905 /* Add ust app session to app's HT */
1906 lttng_ht_node_init_u64(&ua_sess->node,
1907 ua_sess->tracing_id);
1908 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1909
1910 DBG2("UST app session created successfully with handle %d", ret);
1911 }
1912
1913 *ua_sess_ptr = ua_sess;
1914 if (is_created) {
1915 *is_created = created;
1916 }
1917
1918 /* Everything went well. */
1919 ret = 0;
1920
1921 error:
1922 health_code_update();
1923 return ret;
1924 }
1925
1926 /*
1927 * Create a context for the channel on the tracer.
1928 *
1929 * Called with UST app session lock held and a RCU read side lock.
1930 */
1931 static
1932 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
1933 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
1934 struct ust_app *app)
1935 {
1936 int ret = 0;
1937 struct lttng_ht_iter iter;
1938 struct lttng_ht_node_ulong *node;
1939 struct ust_app_ctx *ua_ctx;
1940
1941 DBG2("UST app adding context to channel %s", ua_chan->name);
1942
1943 lttng_ht_lookup(ua_chan->ctx, (void *)((unsigned long)uctx->ctx), &iter);
1944 node = lttng_ht_iter_get_node_ulong(&iter);
1945 if (node != NULL) {
1946 ret = -EEXIST;
1947 goto error;
1948 }
1949
1950 ua_ctx = alloc_ust_app_ctx(uctx);
1951 if (ua_ctx == NULL) {
1952 /* malloc failed */
1953 ret = -1;
1954 goto error;
1955 }
1956
1957 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
1958 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1959 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1960
1961 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
1962 if (ret < 0) {
1963 goto error;
1964 }
1965
1966 error:
1967 return ret;
1968 }
1969
1970 /*
1971 * Enable on the tracer side a ust app event for the session and channel.
1972 *
1973 * Called with UST app session lock held.
1974 */
1975 static
1976 int enable_ust_app_event(struct ust_app_session *ua_sess,
1977 struct ust_app_event *ua_event, struct ust_app *app)
1978 {
1979 int ret;
1980
1981 ret = enable_ust_event(app, ua_sess, ua_event);
1982 if (ret < 0) {
1983 goto error;
1984 }
1985
1986 ua_event->enabled = 1;
1987
1988 error:
1989 return ret;
1990 }
1991
1992 /*
1993 * Disable on the tracer side a ust app event for the session and channel.
1994 */
1995 static int disable_ust_app_event(struct ust_app_session *ua_sess,
1996 struct ust_app_event *ua_event, struct ust_app *app)
1997 {
1998 int ret;
1999
2000 ret = disable_ust_event(app, ua_sess, ua_event);
2001 if (ret < 0) {
2002 goto error;
2003 }
2004
2005 ua_event->enabled = 0;
2006
2007 error:
2008 return ret;
2009 }
2010
2011 /*
2012 * Lookup ust app channel for session and disable it on the tracer side.
2013 */
2014 static
2015 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2016 struct ust_app_channel *ua_chan, struct ust_app *app)
2017 {
2018 int ret;
2019
2020 ret = disable_ust_channel(app, ua_sess, ua_chan);
2021 if (ret < 0) {
2022 goto error;
2023 }
2024
2025 ua_chan->enabled = 0;
2026
2027 error:
2028 return ret;
2029 }
2030
2031 /*
2032 * Lookup ust app channel for session and enable it on the tracer side. This
2033 * MUST be called with a RCU read side lock acquired.
2034 */
2035 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2036 struct ltt_ust_channel *uchan, struct ust_app *app)
2037 {
2038 int ret = 0;
2039 struct lttng_ht_iter iter;
2040 struct lttng_ht_node_str *ua_chan_node;
2041 struct ust_app_channel *ua_chan;
2042
2043 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2044 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2045 if (ua_chan_node == NULL) {
2046 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2047 uchan->name, ua_sess->tracing_id);
2048 goto error;
2049 }
2050
2051 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2052
2053 ret = enable_ust_channel(app, ua_sess, ua_chan);
2054 if (ret < 0) {
2055 goto error;
2056 }
2057
2058 error:
2059 return ret;
2060 }
2061
2062 /*
2063 * Ask the consumer to create a channel and get it if successful.
2064 *
2065 * Return 0 on success or else a negative value.
2066 */
2067 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2068 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2069 int bitness, struct ust_registry_session *registry)
2070 {
2071 int ret;
2072 unsigned int nb_fd = 0;
2073 struct consumer_socket *socket;
2074
2075 assert(usess);
2076 assert(ua_sess);
2077 assert(ua_chan);
2078 assert(registry);
2079
2080 rcu_read_lock();
2081 health_code_update();
2082
2083 /* Get the right consumer socket for the application. */
2084 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2085 if (!socket) {
2086 ret = -EINVAL;
2087 goto error;
2088 }
2089
2090 health_code_update();
2091
2092 /* Need one fd for the channel. */
2093 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2094 if (ret < 0) {
2095 ERR("Exhausted number of available FD upon create channel");
2096 goto error;
2097 }
2098
2099 /*
2100 * Ask consumer to create channel. The consumer will return the number of
2101 * stream we have to expect.
2102 */
2103 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2104 registry);
2105 if (ret < 0) {
2106 goto error_ask;
2107 }
2108
2109 /*
2110 * Compute the number of fd needed before receiving them. It must be 2 per
2111 * stream (2 being the default value here).
2112 */
2113 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2114
2115 /* Reserve the amount of file descriptor we need. */
2116 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2117 if (ret < 0) {
2118 ERR("Exhausted number of available FD upon create channel");
2119 goto error_fd_get_stream;
2120 }
2121
2122 health_code_update();
2123
2124 /*
2125 * Now get the channel from the consumer. This call wil populate the stream
2126 * list of that channel and set the ust objects.
2127 */
2128 if (usess->consumer->enabled) {
2129 ret = ust_consumer_get_channel(socket, ua_chan);
2130 if (ret < 0) {
2131 goto error_destroy;
2132 }
2133 }
2134
2135 rcu_read_unlock();
2136 return 0;
2137
2138 error_destroy:
2139 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2140 error_fd_get_stream:
2141 /*
2142 * Initiate a destroy channel on the consumer since we had an error
2143 * handling it on our side. The return value is of no importance since we
2144 * already have a ret value set by the previous error that we need to
2145 * return.
2146 */
2147 (void) ust_consumer_destroy_channel(socket, ua_chan);
2148 error_ask:
2149 lttng_fd_put(LTTNG_FD_APPS, 1);
2150 error:
2151 health_code_update();
2152 rcu_read_unlock();
2153 return ret;
2154 }
2155
2156 /*
2157 * Duplicate the ust data object of the ust app stream and save it in the
2158 * buffer registry stream.
2159 *
2160 * Return 0 on success or else a negative value.
2161 */
2162 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2163 struct ust_app_stream *stream)
2164 {
2165 int ret;
2166
2167 assert(reg_stream);
2168 assert(stream);
2169
2170 /* Reserve the amount of file descriptor we need. */
2171 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2172 if (ret < 0) {
2173 ERR("Exhausted number of available FD upon duplicate stream");
2174 goto error;
2175 }
2176
2177 /* Duplicate object for stream once the original is in the registry. */
2178 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2179 reg_stream->obj.ust);
2180 if (ret < 0) {
2181 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2182 reg_stream->obj.ust, stream->obj, ret);
2183 lttng_fd_put(LTTNG_FD_APPS, 2);
2184 goto error;
2185 }
2186 stream->handle = stream->obj->handle;
2187
2188 error:
2189 return ret;
2190 }
2191
2192 /*
2193 * Duplicate the ust data object of the ust app. channel and save it in the
2194 * buffer registry channel.
2195 *
2196 * Return 0 on success or else a negative value.
2197 */
2198 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2199 struct ust_app_channel *ua_chan)
2200 {
2201 int ret;
2202
2203 assert(reg_chan);
2204 assert(ua_chan);
2205
2206 /* Need two fds for the channel. */
2207 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2208 if (ret < 0) {
2209 ERR("Exhausted number of available FD upon duplicate channel");
2210 goto error_fd_get;
2211 }
2212
2213 /* Duplicate object for stream once the original is in the registry. */
2214 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2215 if (ret < 0) {
2216 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2217 reg_chan->obj.ust, ua_chan->obj, ret);
2218 goto error;
2219 }
2220 ua_chan->handle = ua_chan->obj->handle;
2221
2222 return 0;
2223
2224 error:
2225 lttng_fd_put(LTTNG_FD_APPS, 1);
2226 error_fd_get:
2227 return ret;
2228 }
2229
2230 /*
2231 * For a given channel buffer registry, setup all streams of the given ust
2232 * application channel.
2233 *
2234 * Return 0 on success or else a negative value.
2235 */
2236 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2237 struct ust_app_channel *ua_chan)
2238 {
2239 int ret = 0;
2240 struct ust_app_stream *stream, *stmp;
2241
2242 assert(reg_chan);
2243 assert(ua_chan);
2244
2245 DBG2("UST app setup buffer registry stream");
2246
2247 /* Send all streams to application. */
2248 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2249 struct buffer_reg_stream *reg_stream;
2250
2251 ret = buffer_reg_stream_create(&reg_stream);
2252 if (ret < 0) {
2253 goto error;
2254 }
2255
2256 /*
2257 * Keep original pointer and nullify it in the stream so the delete
2258 * stream call does not release the object.
2259 */
2260 reg_stream->obj.ust = stream->obj;
2261 stream->obj = NULL;
2262 buffer_reg_stream_add(reg_stream, reg_chan);
2263
2264 /* We don't need the streams anymore. */
2265 cds_list_del(&stream->list);
2266 delete_ust_app_stream(-1, stream);
2267 }
2268
2269 error:
2270 return ret;
2271 }
2272
2273 /*
2274 * Create a buffer registry channel for the given session registry and
2275 * application channel object. If regp pointer is valid, it's set with the
2276 * created object. Important, the created object is NOT added to the session
2277 * registry hash table.
2278 *
2279 * Return 0 on success else a negative value.
2280 */
2281 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2282 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2283 {
2284 int ret;
2285 struct buffer_reg_channel *reg_chan = NULL;
2286
2287 assert(reg_sess);
2288 assert(ua_chan);
2289
2290 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2291
2292 /* Create buffer registry channel. */
2293 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2294 if (ret < 0) {
2295 goto error_create;
2296 }
2297 assert(reg_chan);
2298 reg_chan->consumer_key = ua_chan->key;
2299 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2300
2301 /* Create and add a channel registry to session. */
2302 ret = ust_registry_channel_add(reg_sess->reg.ust,
2303 ua_chan->tracing_channel_id);
2304 if (ret < 0) {
2305 goto error;
2306 }
2307 buffer_reg_channel_add(reg_sess, reg_chan);
2308
2309 if (regp) {
2310 *regp = reg_chan;
2311 }
2312
2313 return 0;
2314
2315 error:
2316 /* Safe because the registry channel object was not added to any HT. */
2317 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2318 error_create:
2319 return ret;
2320 }
2321
2322 /*
2323 * Setup buffer registry channel for the given session registry and application
2324 * channel object. If regp pointer is valid, it's set with the created object.
2325 *
2326 * Return 0 on success else a negative value.
2327 */
2328 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2329 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2330 {
2331 int ret;
2332
2333 assert(reg_sess);
2334 assert(reg_chan);
2335 assert(ua_chan);
2336 assert(ua_chan->obj);
2337
2338 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2339
2340 /* Setup all streams for the registry. */
2341 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2342 if (ret < 0) {
2343 goto error;
2344 }
2345
2346 reg_chan->obj.ust = ua_chan->obj;
2347 ua_chan->obj = NULL;
2348
2349 return 0;
2350
2351 error:
2352 buffer_reg_channel_remove(reg_sess, reg_chan);
2353 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2354 return ret;
2355 }
2356
2357 /*
2358 * Send buffer registry channel to the application.
2359 *
2360 * Return 0 on success else a negative value.
2361 */
2362 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2363 struct ust_app *app, struct ust_app_session *ua_sess,
2364 struct ust_app_channel *ua_chan)
2365 {
2366 int ret;
2367 struct buffer_reg_stream *reg_stream;
2368
2369 assert(reg_chan);
2370 assert(app);
2371 assert(ua_sess);
2372 assert(ua_chan);
2373
2374 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2375
2376 ret = duplicate_channel_object(reg_chan, ua_chan);
2377 if (ret < 0) {
2378 goto error;
2379 }
2380
2381 /* Send channel to the application. */
2382 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2383 if (ret < 0) {
2384 goto error;
2385 }
2386
2387 health_code_update();
2388
2389 /* Send all streams to application. */
2390 pthread_mutex_lock(&reg_chan->stream_list_lock);
2391 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2392 struct ust_app_stream stream;
2393
2394 ret = duplicate_stream_object(reg_stream, &stream);
2395 if (ret < 0) {
2396 goto error_stream_unlock;
2397 }
2398
2399 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2400 if (ret < 0) {
2401 (void) release_ust_app_stream(-1, &stream);
2402 goto error_stream_unlock;
2403 }
2404
2405 /*
2406 * The return value is not important here. This function will output an
2407 * error if needed.
2408 */
2409 (void) release_ust_app_stream(-1, &stream);
2410 }
2411 ua_chan->is_sent = 1;
2412
2413 error_stream_unlock:
2414 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2415 error:
2416 return ret;
2417 }
2418
2419 /*
2420 * Create and send to the application the created buffers with per UID buffers.
2421 *
2422 * Return 0 on success else a negative value.
2423 */
2424 static int create_channel_per_uid(struct ust_app *app,
2425 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2426 struct ust_app_channel *ua_chan)
2427 {
2428 int ret;
2429 struct buffer_reg_uid *reg_uid;
2430 struct buffer_reg_channel *reg_chan;
2431
2432 assert(app);
2433 assert(usess);
2434 assert(ua_sess);
2435 assert(ua_chan);
2436
2437 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2438
2439 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2440 /*
2441 * The session creation handles the creation of this global registry
2442 * object. If none can be find, there is a code flow problem or a
2443 * teardown race.
2444 */
2445 assert(reg_uid);
2446
2447 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2448 reg_uid);
2449 if (!reg_chan) {
2450 /* Create the buffer registry channel object. */
2451 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2452 if (ret < 0) {
2453 goto error;
2454 }
2455 assert(reg_chan);
2456
2457 /*
2458 * Create the buffers on the consumer side. This call populates the
2459 * ust app channel object with all streams and data object.
2460 */
2461 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2462 app->bits_per_long, reg_uid->registry->reg.ust);
2463 if (ret < 0) {
2464 /*
2465 * Let's remove the previously created buffer registry channel so
2466 * it's not visible anymore in the session registry.
2467 */
2468 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2469 ua_chan->tracing_channel_id);
2470 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2471 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2472 goto error;
2473 }
2474
2475 /*
2476 * Setup the streams and add it to the session registry.
2477 */
2478 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2479 if (ret < 0) {
2480 goto error;
2481 }
2482
2483 }
2484
2485 /* Send buffers to the application. */
2486 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2487 if (ret < 0) {
2488 goto error;
2489 }
2490
2491 error:
2492 return ret;
2493 }
2494
2495 /*
2496 * Create and send to the application the created buffers with per PID buffers.
2497 *
2498 * Return 0 on success else a negative value.
2499 */
2500 static int create_channel_per_pid(struct ust_app *app,
2501 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2502 struct ust_app_channel *ua_chan)
2503 {
2504 int ret;
2505 struct ust_registry_session *registry;
2506
2507 assert(app);
2508 assert(usess);
2509 assert(ua_sess);
2510 assert(ua_chan);
2511
2512 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2513
2514 rcu_read_lock();
2515
2516 registry = get_session_registry(ua_sess);
2517 assert(registry);
2518
2519 /* Create and add a new channel registry to session. */
2520 ret = ust_registry_channel_add(registry, ua_chan->key);
2521 if (ret < 0) {
2522 goto error;
2523 }
2524
2525 /* Create and get channel on the consumer side. */
2526 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2527 app->bits_per_long, registry);
2528 if (ret < 0) {
2529 goto error;
2530 }
2531
2532 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2533 if (ret < 0) {
2534 goto error;
2535 }
2536
2537 error:
2538 rcu_read_unlock();
2539 return ret;
2540 }
2541
2542 /*
2543 * From an already allocated ust app channel, create the channel buffers if
2544 * need and send it to the application. This MUST be called with a RCU read
2545 * side lock acquired.
2546 *
2547 * Return 0 on success or else a negative value.
2548 */
2549 static int do_create_channel(struct ust_app *app,
2550 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2551 struct ust_app_channel *ua_chan)
2552 {
2553 int ret;
2554
2555 assert(app);
2556 assert(usess);
2557 assert(ua_sess);
2558 assert(ua_chan);
2559
2560 /* Handle buffer type before sending the channel to the application. */
2561 switch (usess->buffer_type) {
2562 case LTTNG_BUFFER_PER_UID:
2563 {
2564 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2565 if (ret < 0) {
2566 goto error;
2567 }
2568 break;
2569 }
2570 case LTTNG_BUFFER_PER_PID:
2571 {
2572 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2573 if (ret < 0) {
2574 goto error;
2575 }
2576 break;
2577 }
2578 default:
2579 assert(0);
2580 ret = -EINVAL;
2581 goto error;
2582 }
2583
2584 /* Initialize ust objd object using the received handle and add it. */
2585 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2586 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2587
2588 /* If channel is not enabled, disable it on the tracer */
2589 if (!ua_chan->enabled) {
2590 ret = disable_ust_channel(app, ua_sess, ua_chan);
2591 if (ret < 0) {
2592 goto error;
2593 }
2594 }
2595
2596 error:
2597 return ret;
2598 }
2599
2600 /*
2601 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2602 * newly created channel if not NULL.
2603 *
2604 * Called with UST app session lock and RCU read-side lock held.
2605 *
2606 * Return 0 on success or else a negative value.
2607 */
2608 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2609 struct ltt_ust_channel *uchan, struct ust_app *app,
2610 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2611 struct ust_app_channel **ua_chanp)
2612 {
2613 int ret = 0;
2614 struct lttng_ht_iter iter;
2615 struct lttng_ht_node_str *ua_chan_node;
2616 struct ust_app_channel *ua_chan;
2617
2618 /* Lookup channel in the ust app session */
2619 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2620 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2621 if (ua_chan_node != NULL) {
2622 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2623 goto end;
2624 }
2625
2626 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2627 if (ua_chan == NULL) {
2628 /* Only malloc can fail here */
2629 ret = -ENOMEM;
2630 goto error_alloc;
2631 }
2632 shadow_copy_channel(ua_chan, uchan);
2633
2634 /* Set channel type. */
2635 ua_chan->attr.type = type;
2636
2637 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2638 if (ret < 0) {
2639 goto error;
2640 }
2641
2642 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2643 app->pid);
2644
2645 /* Only add the channel if successful on the tracer side. */
2646 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2647
2648 end:
2649 if (ua_chanp) {
2650 *ua_chanp = ua_chan;
2651 }
2652
2653 /* Everything went well. */
2654 return 0;
2655
2656 error:
2657 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2658 error_alloc:
2659 return ret;
2660 }
2661
2662 /*
2663 * Create UST app event and create it on the tracer side.
2664 *
2665 * Called with ust app session mutex held.
2666 */
2667 static
2668 int create_ust_app_event(struct ust_app_session *ua_sess,
2669 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2670 struct ust_app *app)
2671 {
2672 int ret = 0;
2673 struct ust_app_event *ua_event;
2674
2675 /* Get event node */
2676 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2677 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
2678 if (ua_event != NULL) {
2679 ret = -EEXIST;
2680 goto end;
2681 }
2682
2683 /* Does not exist so create one */
2684 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2685 if (ua_event == NULL) {
2686 /* Only malloc can failed so something is really wrong */
2687 ret = -ENOMEM;
2688 goto end;
2689 }
2690 shadow_copy_event(ua_event, uevent);
2691
2692 /* Create it on the tracer side */
2693 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2694 if (ret < 0) {
2695 /* Not found previously means that it does not exist on the tracer */
2696 assert(ret != -LTTNG_UST_ERR_EXIST);
2697 goto error;
2698 }
2699
2700 add_unique_ust_app_event(ua_chan, ua_event);
2701
2702 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2703 app->pid);
2704
2705 end:
2706 return ret;
2707
2708 error:
2709 /* Valid. Calling here is already in a read side lock */
2710 delete_ust_app_event(-1, ua_event);
2711 return ret;
2712 }
2713
2714 /*
2715 * Create UST metadata and open it on the tracer side.
2716 *
2717 * Called with UST app session lock held and RCU read side lock.
2718 */
2719 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2720 struct ust_app *app, struct consumer_output *consumer)
2721 {
2722 int ret = 0;
2723 struct ust_app_channel *metadata;
2724 struct consumer_socket *socket;
2725 struct ust_registry_session *registry;
2726
2727 assert(ua_sess);
2728 assert(app);
2729 assert(consumer);
2730
2731 registry = get_session_registry(ua_sess);
2732 assert(registry);
2733
2734 /* Metadata already exists for this registry or it was closed previously */
2735 if (registry->metadata_key || registry->metadata_closed) {
2736 ret = 0;
2737 goto error;
2738 }
2739
2740 /* Allocate UST metadata */
2741 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2742 if (!metadata) {
2743 /* malloc() failed */
2744 ret = -ENOMEM;
2745 goto error;
2746 }
2747
2748 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
2749
2750 /* Need one fd for the channel. */
2751 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2752 if (ret < 0) {
2753 ERR("Exhausted number of available FD upon create metadata");
2754 goto error;
2755 }
2756
2757 /* Get the right consumer socket for the application. */
2758 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2759 if (!socket) {
2760 ret = -EINVAL;
2761 goto error_consumer;
2762 }
2763
2764 /*
2765 * Keep metadata key so we can identify it on the consumer side. Assign it
2766 * to the registry *before* we ask the consumer so we avoid the race of the
2767 * consumer requesting the metadata and the ask_channel call on our side
2768 * did not returned yet.
2769 */
2770 registry->metadata_key = metadata->key;
2771
2772 /*
2773 * Ask the metadata channel creation to the consumer. The metadata object
2774 * will be created by the consumer and kept their. However, the stream is
2775 * never added or monitored until we do a first push metadata to the
2776 * consumer.
2777 */
2778 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2779 registry);
2780 if (ret < 0) {
2781 /* Nullify the metadata key so we don't try to close it later on. */
2782 registry->metadata_key = 0;
2783 goto error_consumer;
2784 }
2785
2786 /*
2787 * The setup command will make the metadata stream be sent to the relayd,
2788 * if applicable, and the thread managing the metadatas. This is important
2789 * because after this point, if an error occurs, the only way the stream
2790 * can be deleted is to be monitored in the consumer.
2791 */
2792 ret = consumer_setup_metadata(socket, metadata->key);
2793 if (ret < 0) {
2794 /* Nullify the metadata key so we don't try to close it later on. */
2795 registry->metadata_key = 0;
2796 goto error_consumer;
2797 }
2798
2799 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2800 metadata->key, app->pid);
2801
2802 error_consumer:
2803 lttng_fd_put(LTTNG_FD_APPS, 1);
2804 delete_ust_app_channel(-1, metadata, app);
2805 error:
2806 return ret;
2807 }
2808
2809 /*
2810 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2811 * acquired before calling this function.
2812 */
2813 struct ust_app *ust_app_find_by_pid(pid_t pid)
2814 {
2815 struct ust_app *app = NULL;
2816 struct lttng_ht_node_ulong *node;
2817 struct lttng_ht_iter iter;
2818
2819 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2820 node = lttng_ht_iter_get_node_ulong(&iter);
2821 if (node == NULL) {
2822 DBG2("UST app no found with pid %d", pid);
2823 goto error;
2824 }
2825
2826 DBG2("Found UST app by pid %d", pid);
2827
2828 app = caa_container_of(node, struct ust_app, pid_n);
2829
2830 error:
2831 return app;
2832 }
2833
2834 /*
2835 * Allocate and init an UST app object using the registration information and
2836 * the command socket. This is called when the command socket connects to the
2837 * session daemon.
2838 *
2839 * The object is returned on success or else NULL.
2840 */
2841 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2842 {
2843 struct ust_app *lta = NULL;
2844
2845 assert(msg);
2846 assert(sock >= 0);
2847
2848 DBG3("UST app creating application for socket %d", sock);
2849
2850 if ((msg->bits_per_long == 64 &&
2851 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2852 || (msg->bits_per_long == 32 &&
2853 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2854 ERR("Registration failed: application \"%s\" (pid: %d) has "
2855 "%d-bit long, but no consumerd for this size is available.\n",
2856 msg->name, msg->pid, msg->bits_per_long);
2857 goto error;
2858 }
2859
2860 lta = zmalloc(sizeof(struct ust_app));
2861 if (lta == NULL) {
2862 PERROR("malloc");
2863 goto error;
2864 }
2865
2866 lta->ppid = msg->ppid;
2867 lta->uid = msg->uid;
2868 lta->gid = msg->gid;
2869
2870 lta->bits_per_long = msg->bits_per_long;
2871 lta->uint8_t_alignment = msg->uint8_t_alignment;
2872 lta->uint16_t_alignment = msg->uint16_t_alignment;
2873 lta->uint32_t_alignment = msg->uint32_t_alignment;
2874 lta->uint64_t_alignment = msg->uint64_t_alignment;
2875 lta->long_alignment = msg->long_alignment;
2876 lta->byte_order = msg->byte_order;
2877
2878 lta->v_major = msg->major;
2879 lta->v_minor = msg->minor;
2880 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2881 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2882 lta->notify_sock = -1;
2883
2884 /* Copy name and make sure it's NULL terminated. */
2885 strncpy(lta->name, msg->name, sizeof(lta->name));
2886 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2887
2888 /*
2889 * Before this can be called, when receiving the registration information,
2890 * the application compatibility is checked. So, at this point, the
2891 * application can work with this session daemon.
2892 */
2893 lta->compatible = 1;
2894
2895 lta->pid = msg->pid;
2896 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
2897 lta->sock = sock;
2898 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
2899
2900 CDS_INIT_LIST_HEAD(&lta->teardown_head);
2901
2902 error:
2903 return lta;
2904 }
2905
2906 /*
2907 * For a given application object, add it to every hash table.
2908 */
2909 void ust_app_add(struct ust_app *app)
2910 {
2911 assert(app);
2912 assert(app->notify_sock >= 0);
2913
2914 rcu_read_lock();
2915
2916 /*
2917 * On a re-registration, we want to kick out the previous registration of
2918 * that pid
2919 */
2920 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
2921
2922 /*
2923 * The socket _should_ be unique until _we_ call close. So, a add_unique
2924 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
2925 * already in the table.
2926 */
2927 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
2928
2929 /* Add application to the notify socket hash table. */
2930 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
2931 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
2932
2933 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
2934 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
2935 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
2936 app->v_minor);
2937
2938 rcu_read_unlock();
2939 }
2940
2941 /*
2942 * Set the application version into the object.
2943 *
2944 * Return 0 on success else a negative value either an errno code or a
2945 * LTTng-UST error code.
2946 */
2947 int ust_app_version(struct ust_app *app)
2948 {
2949 int ret;
2950
2951 assert(app);
2952
2953 ret = ustctl_tracer_version(app->sock, &app->version);
2954 if (ret < 0) {
2955 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
2956 ERR("UST app %d version failed with ret %d", app->sock, ret);
2957 } else {
2958 DBG3("UST app %d version failed. Application is dead", app->sock);
2959 }
2960 }
2961
2962 return ret;
2963 }
2964
2965 /*
2966 * Unregister app by removing it from the global traceable app list and freeing
2967 * the data struct.
2968 *
2969 * The socket is already closed at this point so no close to sock.
2970 */
2971 void ust_app_unregister(int sock)
2972 {
2973 struct ust_app *lta;
2974 struct lttng_ht_node_ulong *node;
2975 struct lttng_ht_iter iter;
2976 struct ust_app_session *ua_sess;
2977 int ret;
2978
2979 rcu_read_lock();
2980
2981 /* Get the node reference for a call_rcu */
2982 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
2983 node = lttng_ht_iter_get_node_ulong(&iter);
2984 assert(node);
2985
2986 lta = caa_container_of(node, struct ust_app, sock_n);
2987 DBG("PID %d unregistering with sock %d", lta->pid, sock);
2988
2989 /* Remove application from PID hash table */
2990 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
2991 assert(!ret);
2992
2993 /*
2994 * Remove application from notify hash table. The thread handling the
2995 * notify socket could have deleted the node so ignore on error because
2996 * either way it's valid. The close of that socket is handled by the other
2997 * thread.
2998 */
2999 iter.iter.node = &lta->notify_sock_n.node;
3000 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3001
3002 /*
3003 * Ignore return value since the node might have been removed before by an
3004 * add replace during app registration because the PID can be reassigned by
3005 * the OS.
3006 */
3007 iter.iter.node = &lta->pid_n.node;
3008 ret = lttng_ht_del(ust_app_ht, &iter);
3009 if (ret) {
3010 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3011 lta->pid);
3012 }
3013
3014 /* Remove sessions so they are not visible during deletion.*/
3015 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3016 node.node) {
3017 struct ust_registry_session *registry;
3018
3019 ret = lttng_ht_del(lta->sessions, &iter);
3020 if (ret) {
3021 /* The session was already removed so scheduled for teardown. */
3022 continue;
3023 }
3024
3025 /*
3026 * Add session to list for teardown. This is safe since at this point we
3027 * are the only one using this list.
3028 */
3029 pthread_mutex_lock(&ua_sess->lock);
3030
3031 /*
3032 * Normally, this is done in the delete session process which is
3033 * executed in the call rcu below. However, upon registration we can't
3034 * afford to wait for the grace period before pushing data or else the
3035 * data pending feature can race between the unregistration and stop
3036 * command where the data pending command is sent *before* the grace
3037 * period ended.
3038 *
3039 * The close metadata below nullifies the metadata pointer in the
3040 * session so the delete session will NOT push/close a second time.
3041 */
3042 registry = get_session_registry(ua_sess);
3043 if (registry && !registry->metadata_closed) {
3044 /* Push metadata for application before freeing the application. */
3045 (void) push_metadata(registry, ua_sess->consumer);
3046
3047 /*
3048 * Don't ask to close metadata for global per UID buffers. Close
3049 * metadata only on destroy trace session in this case. Also, the
3050 * previous push metadata could have flag the metadata registry to
3051 * close so don't send a close command if closed.
3052 */
3053 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
3054 !registry->metadata_closed) {
3055 /* And ask to close it for this session registry. */
3056 (void) close_metadata(registry, ua_sess->consumer);
3057 }
3058 }
3059
3060 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3061 pthread_mutex_unlock(&ua_sess->lock);
3062 }
3063
3064 /* Free memory */
3065 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3066
3067 rcu_read_unlock();
3068 return;
3069 }
3070
3071 /*
3072 * Fill events array with all events name of all registered apps.
3073 */
3074 int ust_app_list_events(struct lttng_event **events)
3075 {
3076 int ret, handle;
3077 size_t nbmem, count = 0;
3078 struct lttng_ht_iter iter;
3079 struct ust_app *app;
3080 struct lttng_event *tmp_event;
3081
3082 nbmem = UST_APP_EVENT_LIST_SIZE;
3083 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3084 if (tmp_event == NULL) {
3085 PERROR("zmalloc ust app events");
3086 ret = -ENOMEM;
3087 goto error;
3088 }
3089
3090 rcu_read_lock();
3091
3092 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3093 struct lttng_ust_tracepoint_iter uiter;
3094
3095 health_code_update();
3096
3097 if (!app->compatible) {
3098 /*
3099 * TODO: In time, we should notice the caller of this error by
3100 * telling him that this is a version error.
3101 */
3102 continue;
3103 }
3104 handle = ustctl_tracepoint_list(app->sock);
3105 if (handle < 0) {
3106 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3107 ERR("UST app list events getting handle failed for app pid %d",
3108 app->pid);
3109 }
3110 continue;
3111 }
3112
3113 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3114 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3115 /* Handle ustctl error. */
3116 if (ret < 0) {
3117 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3118 ERR("UST app tp list get failed for app %d with ret %d",
3119 app->sock, ret);
3120 } else {
3121 DBG3("UST app tp list get failed. Application is dead");
3122 /*
3123 * This is normal behavior, an application can die during the
3124 * creation process. Don't report an error so the execution can
3125 * continue normally. Continue normal execution.
3126 */
3127 break;
3128 }
3129 free(tmp_event);
3130 goto rcu_error;
3131 }
3132
3133 health_code_update();
3134 if (count >= nbmem) {
3135 /* In case the realloc fails, we free the memory */
3136 struct lttng_event *new_tmp_event;
3137 size_t new_nbmem;
3138
3139 new_nbmem = nbmem << 1;
3140 DBG2("Reallocating event list from %zu to %zu entries",
3141 nbmem, new_nbmem);
3142 new_tmp_event = realloc(tmp_event,
3143 new_nbmem * sizeof(struct lttng_event));
3144 if (new_tmp_event == NULL) {
3145 PERROR("realloc ust app events");
3146 free(tmp_event);
3147 ret = -ENOMEM;
3148 goto rcu_error;
3149 }
3150 /* Zero the new memory */
3151 memset(new_tmp_event + nbmem, 0,
3152 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3153 nbmem = new_nbmem;
3154 tmp_event = new_tmp_event;
3155 }
3156 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3157 tmp_event[count].loglevel = uiter.loglevel;
3158 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3159 tmp_event[count].pid = app->pid;
3160 tmp_event[count].enabled = -1;
3161 count++;
3162 }
3163 }
3164
3165 ret = count;
3166 *events = tmp_event;
3167
3168 DBG2("UST app list events done (%zu events)", count);
3169
3170 rcu_error:
3171 rcu_read_unlock();
3172 error:
3173 health_code_update();
3174 return ret;
3175 }
3176
3177 /*
3178 * Fill events array with all events name of all registered apps.
3179 */
3180 int ust_app_list_event_fields(struct lttng_event_field **fields)
3181 {
3182 int ret, handle;
3183 size_t nbmem, count = 0;
3184 struct lttng_ht_iter iter;
3185 struct ust_app *app;
3186 struct lttng_event_field *tmp_event;
3187
3188 nbmem = UST_APP_EVENT_LIST_SIZE;
3189 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3190 if (tmp_event == NULL) {
3191 PERROR("zmalloc ust app event fields");
3192 ret = -ENOMEM;
3193 goto error;
3194 }
3195
3196 rcu_read_lock();
3197
3198 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3199 struct lttng_ust_field_iter uiter;
3200
3201 health_code_update();
3202
3203 if (!app->compatible) {
3204 /*
3205 * TODO: In time, we should notice the caller of this error by
3206 * telling him that this is a version error.
3207 */
3208 continue;
3209 }
3210 handle = ustctl_tracepoint_field_list(app->sock);
3211 if (handle < 0) {
3212 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3213 ERR("UST app list field getting handle failed for app pid %d",
3214 app->pid);
3215 }
3216 continue;
3217 }
3218
3219 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3220 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3221 /* Handle ustctl error. */
3222 if (ret < 0) {
3223 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3224 ERR("UST app tp list field failed for app %d with ret %d",
3225 app->sock, ret);
3226 } else {
3227 DBG3("UST app tp list field failed. Application is dead");
3228 /*
3229 * This is normal behavior, an application can die during the
3230 * creation process. Don't report an error so the execution can
3231 * continue normally. Reset list and count for next app.
3232 */
3233 break;
3234 }
3235 free(tmp_event);
3236 goto rcu_error;
3237 }
3238
3239 health_code_update();
3240 if (count >= nbmem) {
3241 /* In case the realloc fails, we free the memory */
3242 struct lttng_event_field *new_tmp_event;
3243 size_t new_nbmem;
3244
3245 new_nbmem = nbmem << 1;
3246 DBG2("Reallocating event field list from %zu to %zu entries",
3247 nbmem, new_nbmem);
3248 new_tmp_event = realloc(tmp_event,
3249 new_nbmem * sizeof(struct lttng_event_field));
3250 if (new_tmp_event == NULL) {
3251 PERROR("realloc ust app event fields");
3252 free(tmp_event);
3253 ret = -ENOMEM;
3254 goto rcu_error;
3255 }
3256 /* Zero the new memory */
3257 memset(new_tmp_event + nbmem, 0,
3258 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3259 nbmem = new_nbmem;
3260 tmp_event = new_tmp_event;
3261 }
3262
3263 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3264 /* Mapping between these enums matches 1 to 1. */
3265 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3266 tmp_event[count].nowrite = uiter.nowrite;
3267
3268 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3269 tmp_event[count].event.loglevel = uiter.loglevel;
3270 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3271 tmp_event[count].event.pid = app->pid;
3272 tmp_event[count].event.enabled = -1;
3273 count++;
3274 }
3275 }
3276
3277 ret = count;
3278 *fields = tmp_event;
3279
3280 DBG2("UST app list event fields done (%zu events)", count);
3281
3282 rcu_error:
3283 rcu_read_unlock();
3284 error:
3285 health_code_update();
3286 return ret;
3287 }
3288
3289 /*
3290 * Free and clean all traceable apps of the global list.
3291 *
3292 * Should _NOT_ be called with RCU read-side lock held.
3293 */
3294 void ust_app_clean_list(void)
3295 {
3296 int ret;
3297 struct ust_app *app;
3298 struct lttng_ht_iter iter;
3299
3300 DBG2("UST app cleaning registered apps hash table");
3301
3302 rcu_read_lock();
3303
3304 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3305 ret = lttng_ht_del(ust_app_ht, &iter);
3306 assert(!ret);
3307 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3308 }
3309
3310 /* Cleanup socket hash table */
3311 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3312 sock_n.node) {
3313 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3314 assert(!ret);
3315 }
3316
3317 /* Cleanup notify socket hash table */
3318 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3319 notify_sock_n.node) {
3320 ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3321 assert(!ret);
3322 }
3323 rcu_read_unlock();
3324
3325 /* Destroy is done only when the ht is empty */
3326 ht_cleanup_push(ust_app_ht);
3327 ht_cleanup_push(ust_app_ht_by_sock);
3328 ht_cleanup_push(ust_app_ht_by_notify_sock);
3329 }
3330
3331 /*
3332 * Init UST app hash table.
3333 */
3334 void ust_app_ht_alloc(void)
3335 {
3336 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3337 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3338 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3339 }
3340
3341 /*
3342 * For a specific UST session, disable the channel for all registered apps.
3343 */
3344 int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3345 struct ltt_ust_channel *uchan)
3346 {
3347 int ret = 0;
3348 struct lttng_ht_iter iter;
3349 struct lttng_ht_node_str *ua_chan_node;
3350 struct ust_app *app;
3351 struct ust_app_session *ua_sess;
3352 struct ust_app_channel *ua_chan;
3353
3354 if (usess == NULL || uchan == NULL) {
3355 ERR("Disabling UST global channel with NULL values");
3356 ret = -1;
3357 goto error;
3358 }
3359
3360 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3361 uchan->name, usess->id);
3362
3363 rcu_read_lock();
3364
3365 /* For every registered applications */
3366 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3367 struct lttng_ht_iter uiter;
3368 if (!app->compatible) {
3369 /*
3370 * TODO: In time, we should notice the caller of this error by
3371 * telling him that this is a version error.
3372 */
3373 continue;
3374 }
3375 ua_sess = lookup_session_by_app(usess, app);
3376 if (ua_sess == NULL) {
3377 continue;
3378 }
3379
3380 /* Get channel */
3381 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3382 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3383 /* If the session if found for the app, the channel must be there */
3384 assert(ua_chan_node);
3385
3386 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3387 /* The channel must not be already disabled */
3388 assert(ua_chan->enabled == 1);
3389
3390 /* Disable channel onto application */
3391 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3392 if (ret < 0) {
3393 /* XXX: We might want to report this error at some point... */
3394 continue;
3395 }
3396 }
3397
3398 rcu_read_unlock();
3399
3400 error:
3401 return ret;
3402 }
3403
3404 /*
3405 * For a specific UST session, enable the channel for all registered apps.
3406 */
3407 int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3408 struct ltt_ust_channel *uchan)
3409 {
3410 int ret = 0;
3411 struct lttng_ht_iter iter;
3412 struct ust_app *app;
3413 struct ust_app_session *ua_sess;
3414
3415 if (usess == NULL || uchan == NULL) {
3416 ERR("Adding UST global channel to NULL values");
3417 ret = -1;
3418 goto error;
3419 }
3420
3421 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3422 uchan->name, usess->id);
3423
3424 rcu_read_lock();
3425
3426 /* For every registered applications */
3427 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3428 if (!app->compatible) {
3429 /*
3430 * TODO: In time, we should notice the caller of this error by
3431 * telling him that this is a version error.
3432 */
3433 continue;
3434 }
3435 ua_sess = lookup_session_by_app(usess, app);
3436 if (ua_sess == NULL) {
3437 continue;
3438 }
3439
3440 /* Enable channel onto application */
3441 ret = enable_ust_app_channel(ua_sess, uchan, app);
3442 if (ret < 0) {
3443 /* XXX: We might want to report this error at some point... */
3444 continue;
3445 }
3446 }
3447
3448 rcu_read_unlock();
3449
3450 error:
3451 return ret;
3452 }
3453
3454 /*
3455 * Disable an event in a channel and for a specific session.
3456 */
3457 int ust_app_disable_event_glb(struct ltt_ust_session *usess,
3458 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3459 {
3460 int ret = 0;
3461 struct lttng_ht_iter iter, uiter;
3462 struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
3463 struct ust_app *app;
3464 struct ust_app_session *ua_sess;
3465 struct ust_app_channel *ua_chan;
3466 struct ust_app_event *ua_event;
3467
3468 DBG("UST app disabling event %s for all apps in channel "
3469 "%s for session id %" PRIu64,
3470 uevent->attr.name, uchan->name, usess->id);
3471
3472 rcu_read_lock();
3473
3474 /* For all registered applications */
3475 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3476 if (!app->compatible) {
3477 /*
3478 * TODO: In time, we should notice the caller of this error by
3479 * telling him that this is a version error.
3480 */
3481 continue;
3482 }
3483 ua_sess = lookup_session_by_app(usess, app);
3484 if (ua_sess == NULL) {
3485 /* Next app */
3486 continue;
3487 }
3488
3489 /* Lookup channel in the ust app session */
3490 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3491 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3492 if (ua_chan_node == NULL) {
3493 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
3494 "Skipping", uchan->name, usess->id, app->pid);
3495 continue;
3496 }
3497 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3498
3499 lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
3500 ua_event_node = lttng_ht_iter_get_node_str(&uiter);
3501 if (ua_event_node == NULL) {
3502 DBG2("Event %s not found in channel %s for app pid %d."
3503 "Skipping", uevent->attr.name, uchan->name, app->pid);
3504 continue;
3505 }
3506 ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
3507
3508 ret = disable_ust_app_event(ua_sess, ua_event, app);
3509 if (ret < 0) {
3510 /* XXX: Report error someday... */
3511 continue;
3512 }
3513 }
3514
3515 rcu_read_unlock();
3516
3517 return ret;
3518 }
3519
3520 /*
3521 * For a specific UST session, create the channel for all registered apps.
3522 */
3523 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
3524 struct ltt_ust_channel *uchan)
3525 {
3526 int ret = 0, created;
3527 struct lttng_ht_iter iter;
3528 struct ust_app *app;
3529 struct ust_app_session *ua_sess = NULL;
3530
3531 /* Very wrong code flow */
3532 assert(usess);
3533 assert(uchan);
3534
3535 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
3536 uchan->name, usess->id);
3537
3538 rcu_read_lock();
3539
3540 /* For every registered applications */
3541 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3542 if (!app->compatible) {
3543 /*
3544 * TODO: In time, we should notice the caller of this error by
3545 * telling him that this is a version error.
3546 */
3547 continue;
3548 }
3549 /*
3550 * Create session on the tracer side and add it to app session HT. Note
3551 * that if session exist, it will simply return a pointer to the ust
3552 * app session.
3553 */
3554 ret = create_ust_app_session(usess, app, &ua_sess, &created);
3555 if (ret < 0) {
3556 switch (ret) {
3557 case -ENOTCONN:
3558 /*
3559 * The application's socket is not valid. Either a bad socket
3560 * or a timeout on it. We can't inform the caller that for a
3561 * specific app, the session failed so lets continue here.
3562 */
3563 continue;
3564 case -ENOMEM:
3565 default:
3566 goto error_rcu_unlock;
3567 }
3568 }
3569 assert(ua_sess);
3570
3571 pthread_mutex_lock(&ua_sess->lock);
3572 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
3573 sizeof(uchan->name))) {
3574 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr);
3575 ret = 0;
3576 } else {
3577 /* Create channel onto application. We don't need the chan ref. */
3578 ret = create_ust_app_channel(ua_sess, uchan, app,
3579 LTTNG_UST_CHAN_PER_CPU, usess, NULL);
3580 }
3581 pthread_mutex_unlock(&ua_sess->lock);
3582 if (ret < 0) {
3583 if (ret == -ENOMEM) {
3584 /* No more memory is a fatal error. Stop right now. */
3585 goto error_rcu_unlock;
3586 }
3587 /* Cleanup the created session if it's the case. */
3588 if (created) {
3589 destroy_app_session(app, ua_sess);
3590 }
3591 }
3592 }
3593
3594 error_rcu_unlock:
3595 rcu_read_unlock();
3596 return ret;
3597 }
3598
3599 /*
3600 * Enable event for a specific session and channel on the tracer.
3601 */
3602 int ust_app_enable_event_glb(struct ltt_ust_session *usess,
3603 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3604 {
3605 int ret = 0;
3606 struct lttng_ht_iter iter, uiter;
3607 struct lttng_ht_node_str *ua_chan_node;
3608 struct ust_app *app;
3609 struct ust_app_session *ua_sess;
3610 struct ust_app_channel *ua_chan;
3611 struct ust_app_event *ua_event;
3612
3613 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
3614 uevent->attr.name, usess->id);
3615
3616 /*
3617 * NOTE: At this point, this function is called only if the session and
3618 * channel passed are already created for all apps. and enabled on the
3619 * tracer also.
3620 */
3621
3622 rcu_read_lock();
3623
3624 /* For all registered applications */
3625 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3626 if (!app->compatible) {
3627 /*
3628 * TODO: In time, we should notice the caller of this error by
3629 * telling him that this is a version error.
3630 */
3631 continue;
3632 }
3633 ua_sess = lookup_session_by_app(usess, app);
3634 if (!ua_sess) {
3635 /* The application has problem or is probably dead. */
3636 continue;
3637 }
3638
3639 pthread_mutex_lock(&ua_sess->lock);
3640
3641 /* Lookup channel in the ust app session */
3642 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3643 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3644 /* If the channel is not found, there is a code flow error */
3645 assert(ua_chan_node);
3646
3647 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3648
3649 /* Get event node */
3650 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
3651 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
3652 if (ua_event == NULL) {
3653 DBG3("UST app enable event %s not found for app PID %d."
3654 "Skipping app", uevent->attr.name, app->pid);
3655 goto next_app;
3656 }
3657
3658 ret = enable_ust_app_event(ua_sess, ua_event, app);
3659 if (ret < 0) {
3660 pthread_mutex_unlock(&ua_sess->lock);
3661 goto error;
3662 }
3663 next_app:
3664 pthread_mutex_unlock(&ua_sess->lock);
3665 }
3666
3667 error:
3668 rcu_read_unlock();
3669 return ret;
3670 }
3671
3672 /*
3673 * For a specific existing UST session and UST channel, creates the event for
3674 * all registered apps.
3675 */
3676 int ust_app_create_event_glb(struct ltt_ust_session *usess,
3677 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
3678 {
3679 int ret = 0;
3680 struct lttng_ht_iter iter, uiter;
3681 struct lttng_ht_node_str *ua_chan_node;
3682 struct ust_app *app;
3683 struct ust_app_session *ua_sess;
3684 struct ust_app_channel *ua_chan;
3685
3686 DBG("UST app creating event %s for all apps for session id %" PRIu64,
3687 uevent->attr.name, usess->id);
3688
3689 rcu_read_lock();
3690
3691 /* For all registered applications */
3692 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3693 if (!app->compatible) {
3694 /*
3695 * TODO: In time, we should notice the caller of this error by
3696 * telling him that this is a version error.
3697 */
3698 continue;
3699 }
3700 ua_sess = lookup_session_by_app(usess, app);
3701 if (!ua_sess) {
3702 /* The application has problem or is probably dead. */
3703 continue;
3704 }
3705
3706 pthread_mutex_lock(&ua_sess->lock);
3707 /* Lookup channel in the ust app session */
3708 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3709 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3710 /* If the channel is not found, there is a code flow error */
3711 assert(ua_chan_node);
3712
3713 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3714
3715 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
3716 pthread_mutex_unlock(&ua_sess->lock);
3717 if (ret < 0) {
3718 if (ret != -LTTNG_UST_ERR_EXIST) {
3719 /* Possible value at this point: -ENOMEM. If so, we stop! */
3720 break;
3721 }
3722 DBG2("UST app event %s already exist on app PID %d",
3723 uevent->attr.name, app->pid);
3724 continue;
3725 }
3726 }
3727
3728 rcu_read_unlock();
3729
3730 return ret;
3731 }
3732
3733 /*
3734 * Start tracing for a specific UST session and app.
3735 */
3736 static
3737 int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
3738 {
3739 int ret = 0;
3740 struct ust_app_session *ua_sess;
3741
3742 DBG("Starting tracing for ust app pid %d", app->pid);
3743
3744 rcu_read_lock();
3745
3746 if (!app->compatible) {
3747 goto end;
3748 }
3749
3750 ua_sess = lookup_session_by_app(usess, app);
3751 if (ua_sess == NULL) {
3752 /* The session is in teardown process. Ignore and continue. */
3753 goto end;
3754 }
3755
3756 pthread_mutex_lock(&ua_sess->lock);
3757
3758 /* Upon restart, we skip the setup, already done */
3759 if (ua_sess->started) {
3760 goto skip_setup;
3761 }
3762
3763 /* Create directories if consumer is LOCAL and has a path defined. */
3764 if (usess->consumer->type == CONSUMER_DST_LOCAL &&
3765 strlen(usess->consumer->dst.trace_path) > 0) {
3766 ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
3767 S_IRWXU | S_IRWXG, ua_sess->euid, ua_sess->egid);
3768 if (ret < 0) {
3769 if (ret != -EEXIST) {
3770 ERR("Trace directory creation error");
3771 goto error_unlock;
3772 }
3773 }
3774 }
3775
3776 /*
3777 * Create the metadata for the application. This returns gracefully if a
3778 * metadata was already set for the session.
3779 */
3780 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
3781 if (ret < 0) {
3782 goto error_unlock;
3783 }
3784
3785 health_code_update();
3786
3787 skip_setup:
3788 /* This start the UST tracing */
3789 ret = ustctl_start_session(app->sock, ua_sess->handle);
3790 if (ret < 0) {
3791 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3792 ERR("Error starting tracing for app pid: %d (ret: %d)",
3793 app->pid, ret);
3794 } else {
3795 DBG("UST app start session failed. Application is dead.");
3796 /*
3797 * This is normal behavior, an application can die during the
3798 * creation process. Don't report an error so the execution can
3799 * continue normally.
3800 */
3801 pthread_mutex_unlock(&ua_sess->lock);
3802 goto end;
3803 }
3804 goto error_unlock;
3805 }
3806
3807 /* Indicate that the session has been started once */
3808 ua_sess->started = 1;
3809
3810 pthread_mutex_unlock(&ua_sess->lock);
3811
3812 health_code_update();
3813
3814 /* Quiescent wait after starting trace */
3815 ret = ustctl_wait_quiescent(app->sock);
3816 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3817 ERR("UST app wait quiescent failed for app pid %d ret %d",
3818 app->pid, ret);
3819 }
3820
3821 end:
3822 rcu_read_unlock();
3823 health_code_update();
3824 return 0;
3825
3826 error_unlock:
3827 pthread_mutex_unlock(&ua_sess->lock);
3828 rcu_read_unlock();
3829 health_code_update();
3830 return -1;
3831 }
3832
3833 /*
3834 * Stop tracing for a specific UST session and app.
3835 */
3836 static
3837 int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
3838 {
3839 int ret = 0;
3840 struct ust_app_session *ua_sess;
3841 struct ust_registry_session *registry;
3842
3843 DBG("Stopping tracing for ust app pid %d", app->pid);
3844
3845 rcu_read_lock();
3846
3847 if (!app->compatible) {
3848 goto end_no_session;
3849 }
3850
3851 ua_sess = lookup_session_by_app(usess, app);
3852 if (ua_sess == NULL) {
3853 goto end_no_session;
3854 }
3855
3856 pthread_mutex_lock(&ua_sess->lock);
3857
3858 /*
3859 * If started = 0, it means that stop trace has been called for a session
3860 * that was never started. It's possible since we can have a fail start
3861 * from either the application manager thread or the command thread. Simply
3862 * indicate that this is a stop error.
3863 */
3864 if (!ua_sess->started) {
3865 goto error_rcu_unlock;
3866 }
3867
3868 health_code_update();
3869
3870 /* This inhibits UST tracing */
3871 ret = ustctl_stop_session(app->sock, ua_sess->handle);
3872 if (ret < 0) {
3873 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3874 ERR("Error stopping tracing for app pid: %d (ret: %d)",
3875 app->pid, ret);
3876 } else {
3877 DBG("UST app stop session failed. Application is dead.");
3878 /*
3879 * This is normal behavior, an application can die during the
3880 * creation process. Don't report an error so the execution can
3881 * continue normally.
3882 */
3883 goto end_unlock;
3884 }
3885 goto error_rcu_unlock;
3886 }
3887
3888 health_code_update();
3889
3890 /* Quiescent wait after stopping trace */
3891 ret = ustctl_wait_quiescent(app->sock);
3892 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3893 ERR("UST app wait quiescent failed for app pid %d ret %d",
3894 app->pid, ret);
3895 }
3896
3897 health_code_update();
3898
3899 registry = get_session_registry(ua_sess);
3900 assert(registry);
3901
3902 if (!registry->metadata_closed) {
3903 /* Push metadata for application before freeing the application. */
3904 (void) push_metadata(registry, ua_sess->consumer);
3905 }
3906
3907 end_unlock:
3908 pthread_mutex_unlock(&ua_sess->lock);
3909 end_no_session:
3910 rcu_read_unlock();
3911 health_code_update();
3912 return 0;
3913
3914 error_rcu_unlock:
3915 pthread_mutex_unlock(&ua_sess->lock);
3916 rcu_read_unlock();
3917 health_code_update();
3918 return -1;
3919 }
3920
3921 /*
3922 * Flush buffers for a specific UST session and app.
3923 */
3924 static
3925 int ust_app_flush_trace(struct ltt_ust_session *usess, struct ust_app *app)
3926 {
3927 int ret = 0;
3928 struct lttng_ht_iter iter;
3929 struct ust_app_session *ua_sess;
3930 struct ust_app_channel *ua_chan;
3931
3932 DBG("Flushing buffers for ust app pid %d", app->pid);
3933
3934 rcu_read_lock();
3935
3936 if (!app->compatible) {
3937 goto end_no_session;
3938 }
3939
3940 ua_sess = lookup_session_by_app(usess, app);
3941 if (ua_sess == NULL) {
3942 goto end_no_session;
3943 }
3944
3945 pthread_mutex_lock(&ua_sess->lock);
3946
3947 health_code_update();
3948
3949 /* Flushing buffers */
3950 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
3951 node.node) {
3952 health_code_update();
3953 assert(ua_chan->is_sent);
3954 ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
3955 if (ret < 0) {
3956 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
3957 ERR("UST app PID %d channel %s flush failed with ret %d",
3958 app->pid, ua_chan->name, ret);
3959 } else {
3960 DBG3("UST app failed to flush %s. Application is dead.",
3961 ua_chan->name);
3962 /*
3963 * This is normal behavior, an application can die during the
3964 * creation process. Don't report an error so the execution can
3965 * continue normally.
3966 */
3967 }
3968 /* Continuing flushing all buffers */
3969 continue;
3970 }
3971 }
3972
3973 health_code_update();
3974
3975 pthread_mutex_unlock(&ua_sess->lock);
3976 end_no_session:
3977 rcu_read_unlock();
3978 health_code_update();
3979 return 0;
3980 }
3981
3982 /*
3983 * Destroy a specific UST session in apps.
3984 */
3985 static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
3986 {
3987 int ret;
3988 struct ust_app_session *ua_sess;
3989 struct lttng_ht_iter iter;
3990 struct lttng_ht_node_u64 *node;
3991
3992 DBG("Destroy tracing for ust app pid %d", app->pid);
3993
3994 rcu_read_lock();
3995
3996 if (!app->compatible) {
3997 goto end;
3998 }
3999
4000 __lookup_session_by_app(usess, app, &iter);
4001 node = lttng_ht_iter_get_node_u64(&iter);
4002 if (node == NULL) {
4003 /* Session is being or is deleted. */
4004 goto end;
4005 }
4006 ua_sess = caa_container_of(node, struct ust_app_session, node);
4007
4008 health_code_update();
4009 destroy_app_session(app, ua_sess);
4010
4011 health_code_update();
4012
4013 /* Quiescent wait after stopping trace */
4014 ret = ustctl_wait_quiescent(app->sock);
4015 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4016 ERR("UST app wait quiescent failed for app pid %d ret %d",
4017 app->pid, ret);
4018 }
4019 end:
4020 rcu_read_unlock();
4021 health_code_update();
4022 return 0;
4023 }
4024
4025 /*
4026 * Start tracing for the UST session.
4027 */
4028 int ust_app_start_trace_all(struct ltt_ust_session *usess)
4029 {
4030 int ret = 0;
4031 struct lttng_ht_iter iter;
4032 struct ust_app *app;
4033
4034 DBG("Starting all UST traces");
4035
4036 rcu_read_lock();
4037
4038 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4039 ret = ust_app_start_trace(usess, app);
4040 if (ret < 0) {
4041 /* Continue to next apps even on error */
4042 continue;
4043 }
4044 }
4045
4046 rcu_read_unlock();
4047
4048 return 0;
4049 }
4050
4051 /*
4052 * Start tracing for the UST session.
4053 */
4054 int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4055 {
4056 int ret = 0;
4057 struct lttng_ht_iter iter;
4058 struct ust_app *app;
4059
4060 DBG("Stopping all UST traces");
4061
4062 rcu_read_lock();
4063
4064 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4065 ret = ust_app_stop_trace(usess, app);
4066 if (ret < 0) {
4067 /* Continue to next apps even on error */
4068 continue;
4069 }
4070 }
4071
4072 /* Flush buffers and push metadata (for UID buffers). */
4073 switch (usess->buffer_type) {
4074 case LTTNG_BUFFER_PER_UID:
4075 {
4076 struct buffer_reg_uid *reg;
4077
4078 /* Flush all per UID buffers associated to that session. */
4079 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4080 struct ust_registry_session *ust_session_reg;
4081 struct buffer_reg_channel *reg_chan;
4082 struct consumer_socket *socket;
4083
4084 /* Get consumer socket to use to push the metadata.*/
4085 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4086 usess->consumer);
4087 if (!socket) {
4088 /* Ignore request if no consumer is found for the session. */
4089 continue;
4090 }
4091
4092 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4093 reg_chan, node.node) {
4094 /*
4095 * The following call will print error values so the return
4096 * code is of little importance because whatever happens, we
4097 * have to try them all.
4098 */
4099 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4100 }
4101
4102 ust_session_reg = reg->registry->reg.ust;
4103 if (!ust_session_reg->metadata_closed) {
4104 /* Push metadata. */
4105 (void) push_metadata(ust_session_reg, usess->consumer);
4106 }
4107 }
4108
4109 break;
4110 }
4111 case LTTNG_BUFFER_PER_PID:
4112 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4113 ret = ust_app_flush_trace(usess, app);
4114 if (ret < 0) {
4115 /* Continue to next apps even on error */
4116 continue;
4117 }
4118 }
4119 break;
4120 default:
4121 assert(0);
4122 break;
4123 }
4124
4125 rcu_read_unlock();
4126
4127 return 0;
4128 }
4129
4130 /*
4131 * Destroy app UST session.
4132 */
4133 int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4134 {
4135 int ret = 0;
4136 struct lttng_ht_iter iter;
4137 struct ust_app *app;
4138
4139 DBG("Destroy all UST traces");
4140
4141 rcu_read_lock();
4142
4143 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4144 ret = destroy_trace(usess, app);
4145 if (ret < 0) {
4146 /* Continue to next apps even on error */
4147 continue;
4148 }
4149 }
4150
4151 rcu_read_unlock();
4152
4153 return 0;
4154 }
4155
4156 /*
4157 * Add channels/events from UST global domain to registered apps at sock.
4158 */
4159 void ust_app_global_update(struct ltt_ust_session *usess, int sock)
4160 {
4161 int ret = 0;
4162 struct lttng_ht_iter iter, uiter;
4163 struct ust_app *app;
4164 struct ust_app_session *ua_sess = NULL;
4165 struct ust_app_channel *ua_chan;
4166 struct ust_app_event *ua_event;
4167 struct ust_app_ctx *ua_ctx;
4168
4169 assert(usess);
4170 assert(sock >= 0);
4171
4172 DBG2("UST app global update for app sock %d for session id %" PRIu64, sock,
4173 usess->id);
4174
4175 rcu_read_lock();
4176
4177 app = ust_app_find_by_sock(sock);
4178 if (app == NULL) {
4179 /*
4180 * Application can be unregistered before so this is possible hence
4181 * simply stopping the update.
4182 */
4183 DBG3("UST app update failed to find app sock %d", sock);
4184 goto error;
4185 }
4186
4187 if (!app->compatible) {
4188 goto error;
4189 }
4190
4191 ret = create_ust_app_session(usess, app, &ua_sess, NULL);
4192 if (ret < 0) {
4193 /* Tracer is probably gone or ENOMEM. */
4194 goto error;
4195 }
4196 assert(ua_sess);
4197
4198 pthread_mutex_lock(&ua_sess->lock);
4199
4200 /*
4201 * We can iterate safely here over all UST app session since the create ust
4202 * app session above made a shadow copy of the UST global domain from the
4203 * ltt ust session.
4204 */
4205 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4206 node.node) {
4207 ret = do_create_channel(app, usess, ua_sess, ua_chan);
4208 if (ret < 0) {
4209 /*
4210 * Stop everything. On error, the application failed, no more
4211 * file descriptor are available or ENOMEM so stopping here is
4212 * the only thing we can do for now.
4213 */
4214 goto error_unlock;
4215 }
4216
4217 /*
4218 * Add context using the list so they are enabled in the same order the
4219 * user added them.
4220 */
4221 cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) {
4222 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
4223 if (ret < 0) {
4224 goto error_unlock;
4225 }
4226 }
4227
4228
4229 /* For each events */
4230 cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event,
4231 node.node) {
4232 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
4233 if (ret < 0) {
4234 goto error_unlock;
4235 }
4236 }
4237 }
4238
4239 pthread_mutex_unlock(&ua_sess->lock);
4240
4241 if (usess->active) {
4242 ret = ust_app_start_trace(usess, app);
4243 if (ret < 0) {
4244 goto error;
4245 }
4246
4247 DBG2("UST trace started for app pid %d", app->pid);
4248 }
4249
4250 /* Everything went well at this point. */
4251 rcu_read_unlock();
4252 return;
4253
4254 error_unlock:
4255 pthread_mutex_unlock(&ua_sess->lock);
4256 error:
4257 if (ua_sess) {
4258 destroy_app_session(app, ua_sess);
4259 }
4260 rcu_read_unlock();
4261 return;
4262 }
4263
4264 /*
4265 * Add context to a specific channel for global UST domain.
4266 */
4267 int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
4268 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
4269 {
4270 int ret = 0;
4271 struct lttng_ht_node_str *ua_chan_node;
4272 struct lttng_ht_iter iter, uiter;
4273 struct ust_app_channel *ua_chan = NULL;
4274 struct ust_app_session *ua_sess;
4275 struct ust_app *app;
4276
4277 rcu_read_lock();
4278
4279 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4280 if (!app->compatible) {
4281 /*
4282 * TODO: In time, we should notice the caller of this error by
4283 * telling him that this is a version error.
4284 */
4285 continue;
4286 }
4287 ua_sess = lookup_session_by_app(usess, app);
4288 if (ua_sess == NULL) {
4289 continue;
4290 }
4291
4292 pthread_mutex_lock(&ua_sess->lock);
4293 /* Lookup channel in the ust app session */
4294 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4295 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4296 if (ua_chan_node == NULL) {
4297 goto next_app;
4298 }
4299 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
4300 node);
4301 ret = create_ust_app_channel_context(ua_sess, ua_chan, &uctx->ctx, app);
4302 if (ret < 0) {
4303 goto next_app;
4304 }
4305 next_app:
4306 pthread_mutex_unlock(&ua_sess->lock);
4307 }
4308
4309 rcu_read_unlock();
4310 return ret;
4311 }
4312
4313 /*
4314 * Enable event for a channel from a UST session for a specific PID.
4315 */
4316 int ust_app_enable_event_pid(struct ltt_ust_session *usess,
4317 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid)
4318 {
4319 int ret = 0;
4320 struct lttng_ht_iter iter;
4321 struct lttng_ht_node_str *ua_chan_node;
4322 struct ust_app *app;
4323 struct ust_app_session *ua_sess;
4324 struct ust_app_channel *ua_chan;
4325 struct ust_app_event *ua_event;
4326
4327 DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid);
4328
4329 rcu_read_lock();
4330
4331 app = ust_app_find_by_pid(pid);
4332 if (app == NULL) {
4333 ERR("UST app enable event per PID %d not found", pid);
4334 ret = -1;
4335 goto end;
4336 }
4337
4338 if (!app->compatible) {
4339 ret = 0;
4340 goto end;
4341 }
4342
4343 ua_sess = lookup_session_by_app(usess, app);
4344 if (!ua_sess) {
4345 /* The application has problem or is probably dead. */
4346 ret = 0;
4347 goto end;
4348 }
4349
4350 pthread_mutex_lock(&ua_sess->lock);
4351 /* Lookup channel in the ust app session */
4352 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
4353 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
4354 /* If the channel is not found, there is a code flow error */
4355 assert(ua_chan_node);
4356
4357 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4358
4359 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4360 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4361 if (ua_event == NULL) {
4362 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4363 if (ret < 0) {
4364 goto end_unlock;
4365 }
4366 } else {
4367 ret = enable_ust_app_event(ua_sess, ua_event, app);
4368 if (ret < 0) {
4369 goto end_unlock;
4370 }
4371 }
4372
4373 end_unlock:
4374 pthread_mutex_unlock(&ua_sess->lock);
4375 end:
4376 rcu_read_unlock();
4377 return ret;
4378 }
4379
4380 /*
4381 * Calibrate registered applications.
4382 */
4383 int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
4384 {
4385 int ret = 0;
4386 struct lttng_ht_iter iter;
4387 struct ust_app *app;
4388
4389 rcu_read_lock();
4390
4391 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4392 if (!app->compatible) {
4393 /*
4394 * TODO: In time, we should notice the caller of this error by
4395 * telling him that this is a version error.
4396 */
4397 continue;
4398 }
4399
4400 health_code_update();
4401
4402 ret = ustctl_calibrate(app->sock, calibrate);
4403 if (ret < 0) {
4404 switch (ret) {
4405 case -ENOSYS:
4406 /* Means that it's not implemented on the tracer side. */
4407 ret = 0;
4408 break;
4409 default:
4410 DBG2("Calibrate app PID %d returned with error %d",
4411 app->pid, ret);
4412 break;
4413 }
4414 }
4415 }
4416
4417 DBG("UST app global domain calibration finished");
4418
4419 rcu_read_unlock();
4420
4421 health_code_update();
4422
4423 return ret;
4424 }
4425
4426 /*
4427 * Receive registration and populate the given msg structure.
4428 *
4429 * On success return 0 else a negative value returned by the ustctl call.
4430 */
4431 int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
4432 {
4433 int ret;
4434 uint32_t pid, ppid, uid, gid;
4435
4436 assert(msg);
4437
4438 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
4439 &pid, &ppid, &uid, &gid,
4440 &msg->bits_per_long,
4441 &msg->uint8_t_alignment,
4442 &msg->uint16_t_alignment,
4443 &msg->uint32_t_alignment,
4444 &msg->uint64_t_alignment,
4445 &msg->long_alignment,
4446 &msg->byte_order,
4447 msg->name);
4448 if (ret < 0) {
4449 switch (-ret) {
4450 case EPIPE:
4451 case ECONNRESET:
4452 case LTTNG_UST_ERR_EXITING:
4453 DBG3("UST app recv reg message failed. Application died");
4454 break;
4455 case LTTNG_UST_ERR_UNSUP_MAJOR:
4456 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4457 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
4458 LTTNG_UST_ABI_MINOR_VERSION);
4459 break;
4460 default:
4461 ERR("UST app recv reg message failed with ret %d", ret);
4462 break;
4463 }
4464 goto error;
4465 }
4466 msg->pid = (pid_t) pid;
4467 msg->ppid = (pid_t) ppid;
4468 msg->uid = (uid_t) uid;
4469 msg->gid = (gid_t) gid;
4470
4471 error:
4472 return ret;
4473 }
4474
4475 /*
4476 * Return a ust app channel object using the application object and the channel
4477 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4478 * lock MUST be acquired before calling this function.
4479 */
4480 static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
4481 int objd)
4482 {
4483 struct lttng_ht_node_ulong *node;
4484 struct lttng_ht_iter iter;
4485 struct ust_app_channel *ua_chan = NULL;
4486
4487 assert(app);
4488
4489 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
4490 node = lttng_ht_iter_get_node_ulong(&iter);
4491 if (node == NULL) {
4492 DBG2("UST app channel find by objd %d not found", objd);
4493 goto error;
4494 }
4495
4496 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
4497
4498 error:
4499 return ua_chan;
4500 }
4501
4502 /*
4503 * Reply to a register channel notification from an application on the notify
4504 * socket. The channel metadata is also created.
4505 *
4506 * The session UST registry lock is acquired in this function.
4507 *
4508 * On success 0 is returned else a negative value.
4509 */
4510 static int reply_ust_register_channel(int sock, int sobjd, int cobjd,
4511 size_t nr_fields, struct ustctl_field *fields)
4512 {
4513 int ret, ret_code = 0;
4514 uint32_t chan_id, reg_count;
4515 uint64_t chan_reg_key;
4516 enum ustctl_channel_header type;
4517 struct ust_app *app;
4518 struct ust_app_channel *ua_chan;
4519 struct ust_app_session *ua_sess;
4520 struct ust_registry_session *registry;
4521 struct ust_registry_channel *chan_reg;
4522
4523 rcu_read_lock();
4524
4525 /* Lookup application. If not found, there is a code flow error. */
4526 app = find_app_by_notify_sock(sock);
4527 if (!app) {
4528 DBG("Application socket %d is being teardown. Abort event notify",
4529 sock);
4530 ret = 0;
4531 free(fields);
4532 goto error_rcu_unlock;
4533 }
4534
4535 /* Lookup channel by UST object descriptor. */
4536 ua_chan = find_channel_by_objd(app, cobjd);
4537 if (!ua_chan) {
4538 DBG("Application channel is being teardown. Abort event notify");
4539 ret = 0;
4540 free(fields);
4541 goto error_rcu_unlock;
4542 }
4543
4544 assert(ua_chan->session);
4545 ua_sess = ua_chan->session;
4546
4547 /* Get right session registry depending on the session buffer type. */
4548 registry = get_session_registry(ua_sess);
4549 assert(registry);
4550
4551 /* Depending on the buffer type, a different channel key is used. */
4552 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4553 chan_reg_key = ua_chan->tracing_channel_id;
4554 } else {
4555 chan_reg_key = ua_chan->key;
4556 }
4557
4558 pthread_mutex_lock(&registry->lock);
4559
4560 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
4561 assert(chan_reg);
4562
4563 if (!chan_reg->register_done) {
4564 reg_count = ust_registry_get_event_count(chan_reg);
4565 if (reg_count < 31) {
4566 type = USTCTL_CHANNEL_HEADER_COMPACT;
4567 } else {
4568 type = USTCTL_CHANNEL_HEADER_LARGE;
4569 }
4570
4571 chan_reg->nr_ctx_fields = nr_fields;
4572 chan_reg->ctx_fields = fields;
4573 chan_reg->header_type = type;
4574 } else {
4575 /* Get current already assigned values. */
4576 type = chan_reg->header_type;
4577 free(fields);
4578 /* Set to NULL so the error path does not do a double free. */
4579 fields = NULL;
4580 }
4581 /* Channel id is set during the object creation. */
4582 chan_id = chan_reg->chan_id;
4583
4584 /* Append to metadata */
4585 if (!chan_reg->metadata_dumped) {
4586 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
4587 if (ret_code) {
4588 ERR("Error appending channel metadata (errno = %d)", ret_code);
4589 goto reply;
4590 }
4591 }
4592
4593 reply:
4594 DBG3("UST app replying to register channel key %" PRIu64
4595 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
4596 ret_code);
4597
4598 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
4599 if (ret < 0) {
4600 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4601 ERR("UST app reply channel failed with ret %d", ret);
4602 } else {
4603 DBG3("UST app reply channel failed. Application died");
4604 }
4605 goto error;
4606 }
4607
4608 /* This channel registry registration is completed. */
4609 chan_reg->register_done = 1;
4610
4611 error:
4612 pthread_mutex_unlock(&registry->lock);
4613 error_rcu_unlock:
4614 rcu_read_unlock();
4615 if (ret) {
4616 free(fields);
4617 }
4618 return ret;
4619 }
4620
4621 /*
4622 * Add event to the UST channel registry. When the event is added to the
4623 * registry, the metadata is also created. Once done, this replies to the
4624 * application with the appropriate error code.
4625 *
4626 * The session UST registry lock is acquired in the function.
4627 *
4628 * On success 0 is returned else a negative value.
4629 */
4630 static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
4631 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
4632 char *model_emf_uri)
4633 {
4634 int ret, ret_code;
4635 uint32_t event_id = 0;
4636 uint64_t chan_reg_key;
4637 struct ust_app *app;
4638 struct ust_app_channel *ua_chan;
4639 struct ust_app_session *ua_sess;
4640 struct ust_registry_session *registry;
4641
4642 rcu_read_lock();
4643
4644 /* Lookup application. If not found, there is a code flow error. */
4645 app = find_app_by_notify_sock(sock);
4646 if (!app) {
4647 DBG("Application socket %d is being teardown. Abort event notify",
4648 sock);
4649 ret = 0;
4650 free(sig);
4651 free(fields);
4652 free(model_emf_uri);
4653 goto error_rcu_unlock;
4654 }
4655
4656 /* Lookup channel by UST object descriptor. */
4657 ua_chan = find_channel_by_objd(app, cobjd);
4658 if (!ua_chan) {
4659 DBG("Application channel is being teardown. Abort event notify");
4660 ret = 0;
4661 free(sig);
4662 free(fields);
4663 free(model_emf_uri);
4664 goto error_rcu_unlock;
4665 }
4666
4667 assert(ua_chan->session);
4668 ua_sess = ua_chan->session;
4669
4670 registry = get_session_registry(ua_sess);
4671 assert(registry);
4672
4673 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
4674 chan_reg_key = ua_chan->tracing_channel_id;
4675 } else {
4676 chan_reg_key = ua_chan->key;
4677 }
4678
4679 pthread_mutex_lock(&registry->lock);
4680
4681 /*
4682 * From this point on, this call acquires the ownership of the sig, fields
4683 * and model_emf_uri meaning any free are done inside it if needed. These
4684 * three variables MUST NOT be read/write after this.
4685 */
4686 ret_code = ust_registry_create_event(registry, chan_reg_key,
4687 sobjd, cobjd, name, sig, nr_fields, fields, loglevel,
4688 model_emf_uri, ua_sess->buffer_type, &event_id,
4689 app);
4690
4691 /*
4692 * The return value is returned to ustctl so in case of an error, the
4693 * application can be notified. In case of an error, it's important not to
4694 * return a negative error or else the application will get closed.
4695 */
4696 ret = ustctl_reply_register_event(sock, event_id, ret_code);
4697 if (ret < 0) {
4698 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4699 ERR("UST app reply event failed with ret %d", ret);
4700 } else {
4701 DBG3("UST app reply event failed. Application died");
4702 }
4703 /*
4704 * No need to wipe the create event since the application socket will
4705 * get close on error hence cleaning up everything by itself.
4706 */
4707 goto error;
4708 }
4709
4710 DBG3("UST registry event %s with id %" PRId32 " added successfully",
4711 name, event_id);
4712
4713 error:
4714 pthread_mutex_unlock(&registry->lock);
4715 error_rcu_unlock:
4716 rcu_read_unlock();
4717 return ret;
4718 }
4719
4720 /*
4721 * Handle application notification through the given notify socket.
4722 *
4723 * Return 0 on success or else a negative value.
4724 */
4725 int ust_app_recv_notify(int sock)
4726 {
4727 int ret;
4728 enum ustctl_notify_cmd cmd;
4729
4730 DBG3("UST app receiving notify from sock %d", sock);
4731
4732 ret = ustctl_recv_notify(sock, &cmd);
4733 if (ret < 0) {
4734 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4735 ERR("UST app recv notify failed with ret %d", ret);
4736 } else {
4737 DBG3("UST app recv notify failed. Application died");
4738 }
4739 goto error;
4740 }
4741
4742 switch (cmd) {
4743 case USTCTL_NOTIFY_CMD_EVENT:
4744 {
4745 int sobjd, cobjd, loglevel;
4746 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
4747 size_t nr_fields;
4748 struct ustctl_field *fields;
4749
4750 DBG2("UST app ustctl register event received");
4751
4752 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name, &loglevel,
4753 &sig, &nr_fields, &fields, &model_emf_uri);
4754 if (ret < 0) {
4755 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4756 ERR("UST app recv event failed with ret %d", ret);
4757 } else {
4758 DBG3("UST app recv event failed. Application died");
4759 }
4760 goto error;
4761 }
4762
4763 /*
4764 * Add event to the UST registry coming from the notify socket. This
4765 * call will free if needed the sig, fields and model_emf_uri. This
4766 * code path loses the ownsership of these variables and transfer them
4767 * to the this function.
4768 */
4769 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
4770 fields, loglevel, model_emf_uri);
4771 if (ret < 0) {
4772 goto error;
4773 }
4774
4775 break;
4776 }
4777 case USTCTL_NOTIFY_CMD_CHANNEL:
4778 {
4779 int sobjd, cobjd;
4780 size_t nr_fields;
4781 struct ustctl_field *fields;
4782
4783 DBG2("UST app ustctl register channel received");
4784
4785 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
4786 &fields);
4787 if (ret < 0) {
4788 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4789 ERR("UST app recv channel failed with ret %d", ret);
4790 } else {
4791 DBG3("UST app recv channel failed. Application died");
4792 }
4793 goto error;
4794 }
4795
4796 /*
4797 * The fields ownership are transfered to this function call meaning
4798 * that if needed it will be freed. After this, it's invalid to access
4799 * fields or clean it up.
4800 */
4801 ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields,
4802 fields);
4803 if (ret < 0) {
4804 goto error;
4805 }
4806
4807 break;
4808 }
4809 default:
4810 /* Should NEVER happen. */
4811 assert(0);
4812 }
4813
4814 error:
4815 return ret;
4816 }
4817
4818 /*
4819 * Once the notify socket hangs up, this is called. First, it tries to find the
4820 * corresponding application. On failure, the call_rcu to close the socket is
4821 * executed. If an application is found, it tries to delete it from the notify
4822 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4823 *
4824 * Note that an object needs to be allocated here so on ENOMEM failure, the
4825 * call RCU is not done but the rest of the cleanup is.
4826 */
4827 void ust_app_notify_sock_unregister(int sock)
4828 {
4829 int err_enomem = 0;
4830 struct lttng_ht_iter iter;
4831 struct ust_app *app;
4832 struct ust_app_notify_sock_obj *obj;
4833
4834 assert(sock >= 0);
4835
4836 rcu_read_lock();
4837
4838 obj = zmalloc(sizeof(*obj));
4839 if (!obj) {
4840 /*
4841 * An ENOMEM is kind of uncool. If this strikes we continue the
4842 * procedure but the call_rcu will not be called. In this case, we
4843 * accept the fd leak rather than possibly creating an unsynchronized
4844 * state between threads.
4845 *
4846 * TODO: The notify object should be created once the notify socket is
4847 * registered and stored independantely from the ust app object. The
4848 * tricky part is to synchronize the teardown of the application and
4849 * this notify object. Let's keep that in mind so we can avoid this
4850 * kind of shenanigans with ENOMEM in the teardown path.
4851 */
4852 err_enomem = 1;
4853 } else {
4854 obj->fd = sock;
4855 }
4856
4857 DBG("UST app notify socket unregister %d", sock);
4858
4859 /*
4860 * Lookup application by notify socket. If this fails, this means that the
4861 * hash table delete has already been done by the application
4862 * unregistration process so we can safely close the notify socket in a
4863 * call RCU.
4864 */
4865 app = find_app_by_notify_sock(sock);
4866 if (!app) {
4867 goto close_socket;
4868 }
4869
4870 iter.iter.node = &app->notify_sock_n.node;
4871
4872 /*
4873 * Whatever happens here either we fail or succeed, in both cases we have
4874 * to close the socket after a grace period to continue to the call RCU
4875 * here. If the deletion is successful, the application is not visible
4876 * anymore by other threads and is it fails it means that it was already
4877 * deleted from the hash table so either way we just have to close the
4878 * socket.
4879 */
4880 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
4881
4882 close_socket:
4883 rcu_read_unlock();
4884
4885 /*
4886 * Close socket after a grace period to avoid for the socket to be reused
4887 * before the application object is freed creating potential race between
4888 * threads trying to add unique in the global hash table.
4889 */
4890 if (!err_enomem) {
4891 call_rcu(&obj->head, close_notify_sock_rcu);
4892 }
4893 }
4894
4895 /*
4896 * Destroy a ust app data structure and free its memory.
4897 */
4898 void ust_app_destroy(struct ust_app *app)
4899 {
4900 if (!app) {
4901 return;
4902 }
4903
4904 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
4905 }
4906
4907 /*
4908 * Take a snapshot for a given UST session. The snapshot is sent to the given
4909 * output.
4910 *
4911 * Return 0 on success or else a negative value.
4912 */
4913 int ust_app_snapshot_record(struct ltt_ust_session *usess,
4914 struct snapshot_output *output, int wait, uint64_t max_stream_size)
4915 {
4916 int ret = 0;
4917 unsigned int snapshot_done = 0;
4918 struct lttng_ht_iter iter;
4919 struct ust_app *app;
4920 char pathname[PATH_MAX];
4921
4922 assert(usess);
4923 assert(output);
4924
4925 rcu_read_lock();
4926
4927 switch (usess->buffer_type) {
4928 case LTTNG_BUFFER_PER_UID:
4929 {
4930 struct buffer_reg_uid *reg;
4931
4932 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4933 struct buffer_reg_channel *reg_chan;
4934 struct consumer_socket *socket;
4935
4936 /* Get consumer socket to use to push the metadata.*/
4937 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4938 usess->consumer);
4939 if (!socket) {
4940 ret = -EINVAL;
4941 goto error;
4942 }
4943
4944 memset(pathname, 0, sizeof(pathname));
4945 ret = snprintf(pathname, sizeof(pathname),
4946 DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
4947 reg->uid, reg->bits_per_long);
4948 if (ret < 0) {
4949 PERROR("snprintf snapshot path");
4950 goto error;
4951 }
4952
4953 /* Add the UST default trace dir to path. */
4954 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4955 reg_chan, node.node) {
4956 ret = consumer_snapshot_channel(socket, reg_chan->consumer_key,
4957 output, 0, usess->uid, usess->gid, pathname, wait,
4958 max_stream_size);
4959 if (ret < 0) {
4960 goto error;
4961 }
4962 }
4963 ret = consumer_snapshot_channel(socket,
4964 reg->registry->reg.ust->metadata_key, output, 1,
4965 usess->uid, usess->gid, pathname, wait, max_stream_size);
4966 if (ret < 0) {
4967 goto error;
4968 }
4969 snapshot_done = 1;
4970 }
4971 break;
4972 }
4973 case LTTNG_BUFFER_PER_PID:
4974 {
4975 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4976 struct consumer_socket *socket;
4977 struct lttng_ht_iter chan_iter;
4978 struct ust_app_channel *ua_chan;
4979 struct ust_app_session *ua_sess;
4980 struct ust_registry_session *registry;
4981
4982 ua_sess = lookup_session_by_app(usess, app);
4983 if (!ua_sess) {
4984 /* Session not associated with this app. */
4985 continue;
4986 }
4987
4988 /* Get the right consumer socket for the application. */
4989 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4990 output->consumer);
4991 if (!socket) {
4992 ret = -EINVAL;
4993 goto error;
4994 }
4995
4996 /* Add the UST default trace dir to path. */
4997 memset(pathname, 0, sizeof(pathname));
4998 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
4999 ua_sess->path);
5000 if (ret < 0) {
5001 PERROR("snprintf snapshot path");
5002 goto error;
5003 }
5004
5005 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5006 ua_chan, node.node) {
5007 ret = consumer_snapshot_channel(socket, ua_chan->key, output,
5008 0, ua_sess->euid, ua_sess->egid, pathname, wait,
5009 max_stream_size);
5010 if (ret < 0) {
5011 goto error;
5012 }
5013 }
5014
5015 registry = get_session_registry(ua_sess);
5016 assert(registry);
5017 ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
5018 1, ua_sess->euid, ua_sess->egid, pathname, wait,
5019 max_stream_size);
5020 if (ret < 0) {
5021 goto error;
5022 }
5023 snapshot_done = 1;
5024 }
5025 break;
5026 }
5027 default:
5028 assert(0);
5029 break;
5030 }
5031
5032 if (!snapshot_done) {
5033 /*
5034 * If no snapshot was made and we are not in the error path, this means
5035 * that there are no buffers thus no (prior) application to snapshot
5036 * data from so we have simply NO data.
5037 */
5038 ret = -ENODATA;
5039 }
5040
5041 error:
5042 rcu_read_unlock();
5043 return ret;
5044 }
5045
5046 /*
5047 * Return the number of streams for a UST session.
5048 */
5049 unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
5050 {
5051 unsigned int ret = 0;
5052 struct ust_app *app;
5053 struct lttng_ht_iter iter;
5054
5055 assert(usess);
5056
5057 switch (usess->buffer_type) {
5058 case LTTNG_BUFFER_PER_UID:
5059 {
5060 struct buffer_reg_uid *reg;
5061
5062 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5063 struct buffer_reg_channel *reg_chan;
5064
5065 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5066 reg_chan, node.node) {
5067 ret += reg_chan->stream_count;
5068 }
5069 }
5070 break;
5071 }
5072 case LTTNG_BUFFER_PER_PID:
5073 {
5074 rcu_read_lock();
5075 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5076 struct ust_app_channel *ua_chan;
5077 struct ust_app_session *ua_sess;
5078 struct lttng_ht_iter chan_iter;
5079
5080 ua_sess = lookup_session_by_app(usess, app);
5081 if (!ua_sess) {
5082 /* Session not associated with this app. */
5083 continue;
5084 }
5085
5086 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
5087 ua_chan, node.node) {
5088 ret += ua_chan->streams.count;
5089 }
5090 }
5091 rcu_read_unlock();
5092 break;
5093 }
5094 default:
5095 assert(0);
5096 break;
5097 }
5098
5099 return ret;
5100 }
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