Missing error handling: ust_app_ht_alloc should return error status
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <inttypes.h>
22 #include <pthread.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <urcu/compiler.h>
30 #include <lttng/ust-error.h>
31 #include <signal.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35
36 #include "buffer-registry.h"
37 #include "fd-limit.h"
38 #include "health-sessiond.h"
39 #include "ust-app.h"
40 #include "ust-consumer.h"
41 #include "ust-ctl.h"
42 #include "utils.h"
43
44 /* Next available channel key. Access under next_channel_key_lock. */
45 static uint64_t _next_channel_key;
46 static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
47
48 /* Next available session ID. Access under next_session_id_lock. */
49 static uint64_t _next_session_id;
50 static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
51
52 /*
53 * Return the incremented value of next_channel_key.
54 */
55 static uint64_t get_next_channel_key(void)
56 {
57 uint64_t ret;
58
59 pthread_mutex_lock(&next_channel_key_lock);
60 ret = ++_next_channel_key;
61 pthread_mutex_unlock(&next_channel_key_lock);
62 return ret;
63 }
64
65 /*
66 * Return the atomically incremented value of next_session_id.
67 */
68 static uint64_t get_next_session_id(void)
69 {
70 uint64_t ret;
71
72 pthread_mutex_lock(&next_session_id_lock);
73 ret = ++_next_session_id;
74 pthread_mutex_unlock(&next_session_id_lock);
75 return ret;
76 }
77
78 static void copy_channel_attr_to_ustctl(
79 struct ustctl_consumer_channel_attr *attr,
80 struct lttng_ust_channel_attr *uattr)
81 {
82 /* Copy event attributes since the layout is different. */
83 attr->subbuf_size = uattr->subbuf_size;
84 attr->num_subbuf = uattr->num_subbuf;
85 attr->overwrite = uattr->overwrite;
86 attr->switch_timer_interval = uattr->switch_timer_interval;
87 attr->read_timer_interval = uattr->read_timer_interval;
88 attr->output = uattr->output;
89 }
90
91 /*
92 * Match function for the hash table lookup.
93 *
94 * It matches an ust app event based on three attributes which are the event
95 * name, the filter bytecode and the loglevel.
96 */
97 static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
98 {
99 struct ust_app_event *event;
100 const struct ust_app_ht_key *key;
101
102 assert(node);
103 assert(_key);
104
105 event = caa_container_of(node, struct ust_app_event, node.node);
106 key = _key;
107
108 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
109
110 /* Event name */
111 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
112 goto no_match;
113 }
114
115 /* Event loglevel. */
116 if (event->attr.loglevel != key->loglevel) {
117 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
118 && key->loglevel == 0 && event->attr.loglevel == -1) {
119 /*
120 * Match is accepted. This is because on event creation, the
121 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
122 * -1 are accepted for this loglevel type since 0 is the one set by
123 * the API when receiving an enable event.
124 */
125 } else {
126 goto no_match;
127 }
128 }
129
130 /* One of the filters is NULL, fail. */
131 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
132 goto no_match;
133 }
134
135 if (key->filter && event->filter) {
136 /* Both filters exists, check length followed by the bytecode. */
137 if (event->filter->len != key->filter->len ||
138 memcmp(event->filter->data, key->filter->data,
139 event->filter->len) != 0) {
140 goto no_match;
141 }
142 }
143
144 /* One of the exclusions is NULL, fail. */
145 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
146 goto no_match;
147 }
148
149 if (key->exclusion && event->exclusion) {
150 /* Both exclusions exists, check count followed by the names. */
151 if (event->exclusion->count != key->exclusion->count ||
152 memcmp(event->exclusion->names, key->exclusion->names,
153 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
154 goto no_match;
155 }
156 }
157
158
159 /* Match. */
160 return 1;
161
162 no_match:
163 return 0;
164 }
165
166 /*
167 * Unique add of an ust app event in the given ht. This uses the custom
168 * ht_match_ust_app_event match function and the event name as hash.
169 */
170 static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
171 struct ust_app_event *event)
172 {
173 struct cds_lfht_node *node_ptr;
174 struct ust_app_ht_key key;
175 struct lttng_ht *ht;
176
177 assert(ua_chan);
178 assert(ua_chan->events);
179 assert(event);
180
181 ht = ua_chan->events;
182 key.name = event->attr.name;
183 key.filter = event->filter;
184 key.loglevel = event->attr.loglevel;
185 key.exclusion = event->exclusion;
186
187 node_ptr = cds_lfht_add_unique(ht->ht,
188 ht->hash_fct(event->node.key, lttng_ht_seed),
189 ht_match_ust_app_event, &key, &event->node.node);
190 assert(node_ptr == &event->node.node);
191 }
192
193 /*
194 * Close the notify socket from the given RCU head object. This MUST be called
195 * through a call_rcu().
196 */
197 static void close_notify_sock_rcu(struct rcu_head *head)
198 {
199 int ret;
200 struct ust_app_notify_sock_obj *obj =
201 caa_container_of(head, struct ust_app_notify_sock_obj, head);
202
203 /* Must have a valid fd here. */
204 assert(obj->fd >= 0);
205
206 ret = close(obj->fd);
207 if (ret) {
208 ERR("close notify sock %d RCU", obj->fd);
209 }
210 lttng_fd_put(LTTNG_FD_APPS, 1);
211
212 free(obj);
213 }
214
215 /*
216 * Return the session registry according to the buffer type of the given
217 * session.
218 *
219 * A registry per UID object MUST exists before calling this function or else
220 * it assert() if not found. RCU read side lock must be acquired.
221 */
222 static struct ust_registry_session *get_session_registry(
223 struct ust_app_session *ua_sess)
224 {
225 struct ust_registry_session *registry = NULL;
226
227 assert(ua_sess);
228
229 switch (ua_sess->buffer_type) {
230 case LTTNG_BUFFER_PER_PID:
231 {
232 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
233 if (!reg_pid) {
234 goto error;
235 }
236 registry = reg_pid->registry->reg.ust;
237 break;
238 }
239 case LTTNG_BUFFER_PER_UID:
240 {
241 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
242 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
243 if (!reg_uid) {
244 goto error;
245 }
246 registry = reg_uid->registry->reg.ust;
247 break;
248 }
249 default:
250 assert(0);
251 };
252
253 error:
254 return registry;
255 }
256
257 /*
258 * Delete ust context safely. RCU read lock must be held before calling
259 * this function.
260 */
261 static
262 void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
263 {
264 int ret;
265
266 assert(ua_ctx);
267
268 if (ua_ctx->obj) {
269 ret = ustctl_release_object(sock, ua_ctx->obj);
270 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
271 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
272 sock, ua_ctx->obj->handle, ret);
273 }
274 free(ua_ctx->obj);
275 }
276 free(ua_ctx);
277 }
278
279 /*
280 * Delete ust app event safely. RCU read lock must be held before calling
281 * this function.
282 */
283 static
284 void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
285 {
286 int ret;
287
288 assert(ua_event);
289
290 free(ua_event->filter);
291 if (ua_event->exclusion != NULL)
292 free(ua_event->exclusion);
293 if (ua_event->obj != NULL) {
294 ret = ustctl_release_object(sock, ua_event->obj);
295 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
296 ERR("UST app sock %d release event obj failed with ret %d",
297 sock, ret);
298 }
299 free(ua_event->obj);
300 }
301 free(ua_event);
302 }
303
304 /*
305 * Release ust data object of the given stream.
306 *
307 * Return 0 on success or else a negative value.
308 */
309 static int release_ust_app_stream(int sock, struct ust_app_stream *stream)
310 {
311 int ret = 0;
312
313 assert(stream);
314
315 if (stream->obj) {
316 ret = ustctl_release_object(sock, stream->obj);
317 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
318 ERR("UST app sock %d release stream obj failed with ret %d",
319 sock, ret);
320 }
321 lttng_fd_put(LTTNG_FD_APPS, 2);
322 free(stream->obj);
323 }
324
325 return ret;
326 }
327
328 /*
329 * Delete ust app stream safely. RCU read lock must be held before calling
330 * this function.
331 */
332 static
333 void delete_ust_app_stream(int sock, struct ust_app_stream *stream)
334 {
335 assert(stream);
336
337 (void) release_ust_app_stream(sock, stream);
338 free(stream);
339 }
340
341 /*
342 * We need to execute ht_destroy outside of RCU read-side critical
343 * section and outside of call_rcu thread, so we postpone its execution
344 * using ht_cleanup_push. It is simpler than to change the semantic of
345 * the many callers of delete_ust_app_session().
346 */
347 static
348 void delete_ust_app_channel_rcu(struct rcu_head *head)
349 {
350 struct ust_app_channel *ua_chan =
351 caa_container_of(head, struct ust_app_channel, rcu_head);
352
353 ht_cleanup_push(ua_chan->ctx);
354 ht_cleanup_push(ua_chan->events);
355 free(ua_chan);
356 }
357
358 /*
359 * Delete ust app channel safely. RCU read lock must be held before calling
360 * this function.
361 */
362 static
363 void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
364 struct ust_app *app)
365 {
366 int ret;
367 struct lttng_ht_iter iter;
368 struct ust_app_event *ua_event;
369 struct ust_app_ctx *ua_ctx;
370 struct ust_app_stream *stream, *stmp;
371 struct ust_registry_session *registry;
372
373 assert(ua_chan);
374
375 DBG3("UST app deleting channel %s", ua_chan->name);
376
377 /* Wipe stream */
378 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
379 cds_list_del(&stream->list);
380 delete_ust_app_stream(sock, stream);
381 }
382
383 /* Wipe context */
384 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
385 cds_list_del(&ua_ctx->list);
386 ret = lttng_ht_del(ua_chan->ctx, &iter);
387 assert(!ret);
388 delete_ust_app_ctx(sock, ua_ctx);
389 }
390
391 /* Wipe events */
392 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
393 node.node) {
394 ret = lttng_ht_del(ua_chan->events, &iter);
395 assert(!ret);
396 delete_ust_app_event(sock, ua_event);
397 }
398
399 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
400 /* Wipe and free registry from session registry. */
401 registry = get_session_registry(ua_chan->session);
402 if (registry) {
403 ust_registry_channel_del_free(registry, ua_chan->key);
404 }
405 }
406
407 if (ua_chan->obj != NULL) {
408 /* Remove channel from application UST object descriptor. */
409 iter.iter.node = &ua_chan->ust_objd_node.node;
410 ret = lttng_ht_del(app->ust_objd, &iter);
411 assert(!ret);
412 ret = ustctl_release_object(sock, ua_chan->obj);
413 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
414 ERR("UST app sock %d release channel obj failed with ret %d",
415 sock, ret);
416 }
417 lttng_fd_put(LTTNG_FD_APPS, 1);
418 free(ua_chan->obj);
419 }
420 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
421 }
422
423 /*
424 * Push metadata to consumer socket.
425 *
426 * The socket lock MUST be acquired.
427 * The ust app session lock MUST be acquired.
428 *
429 * On success, return the len of metadata pushed or else a negative value.
430 */
431 ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
432 struct consumer_socket *socket, int send_zero_data)
433 {
434 int ret;
435 char *metadata_str = NULL;
436 size_t len, offset;
437 ssize_t ret_val;
438
439 assert(registry);
440 assert(socket);
441
442 /*
443 * On a push metadata error either the consumer is dead or the metadata
444 * channel has been destroyed because its endpoint might have died (e.g:
445 * relayd). If so, the metadata closed flag is set to 1 so we deny pushing
446 * metadata again which is not valid anymore on the consumer side.
447 *
448 * The ust app session mutex locked allows us to make this check without
449 * the registry lock.
450 */
451 if (registry->metadata_closed) {
452 return -EPIPE;
453 }
454
455 pthread_mutex_lock(&registry->lock);
456
457 offset = registry->metadata_len_sent;
458 len = registry->metadata_len - registry->metadata_len_sent;
459 if (len == 0) {
460 DBG3("No metadata to push for metadata key %" PRIu64,
461 registry->metadata_key);
462 ret_val = len;
463 if (send_zero_data) {
464 DBG("No metadata to push");
465 goto push_data;
466 }
467 goto end;
468 }
469
470 /* Allocate only what we have to send. */
471 metadata_str = zmalloc(len);
472 if (!metadata_str) {
473 PERROR("zmalloc ust app metadata string");
474 ret_val = -ENOMEM;
475 goto error;
476 }
477 /* Copy what we haven't send out. */
478 memcpy(metadata_str, registry->metadata + offset, len);
479 registry->metadata_len_sent += len;
480
481 push_data:
482 pthread_mutex_unlock(&registry->lock);
483 ret = consumer_push_metadata(socket, registry->metadata_key,
484 metadata_str, len, offset);
485 if (ret < 0) {
486 /*
487 * There is an acceptable race here between the registry metadata key
488 * assignment and the creation on the consumer. The session daemon can
489 * concurrently push metadata for this registry while being created on
490 * the consumer since the metadata key of the registry is assigned
491 * *before* it is setup to avoid the consumer to ask for metadata that
492 * could possibly be not found in the session daemon.
493 *
494 * The metadata will get pushed either by the session being stopped or
495 * the consumer requesting metadata if that race is triggered.
496 */
497 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
498 ret = 0;
499 }
500
501 /* Update back the actual metadata len sent since it failed here. */
502 pthread_mutex_lock(&registry->lock);
503 registry->metadata_len_sent -= len;
504 pthread_mutex_unlock(&registry->lock);
505 ret_val = ret;
506 goto error_push;
507 }
508
509 free(metadata_str);
510 return len;
511
512 end:
513 error:
514 pthread_mutex_unlock(&registry->lock);
515 error_push:
516 free(metadata_str);
517 return ret_val;
518 }
519
520 /*
521 * For a given application and session, push metadata to consumer. The session
522 * lock MUST be acquired here before calling this.
523 * Either sock or consumer is required : if sock is NULL, the default
524 * socket to send the metadata is retrieved from consumer, if sock
525 * is not NULL we use it to send the metadata.
526 *
527 * Return 0 on success else a negative error.
528 */
529 static int push_metadata(struct ust_registry_session *registry,
530 struct consumer_output *consumer)
531 {
532 int ret_val;
533 ssize_t ret;
534 struct consumer_socket *socket;
535
536 assert(registry);
537 assert(consumer);
538
539 rcu_read_lock();
540
541 /*
542 * Means that no metadata was assigned to the session. This can happens if
543 * no start has been done previously.
544 */
545 if (!registry->metadata_key) {
546 ret_val = 0;
547 goto end_rcu_unlock;
548 }
549
550 /* Get consumer socket to use to push the metadata.*/
551 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
552 consumer);
553 if (!socket) {
554 ret_val = -1;
555 goto error_rcu_unlock;
556 }
557
558 /*
559 * TODO: Currently, we hold the socket lock around sampling of the next
560 * metadata segment to ensure we send metadata over the consumer socket in
561 * the correct order. This makes the registry lock nest inside the socket
562 * lock.
563 *
564 * Please note that this is a temporary measure: we should move this lock
565 * back into ust_consumer_push_metadata() when the consumer gets the
566 * ability to reorder the metadata it receives.
567 */
568 pthread_mutex_lock(socket->lock);
569 ret = ust_app_push_metadata(registry, socket, 0);
570 pthread_mutex_unlock(socket->lock);
571 if (ret < 0) {
572 ret_val = ret;
573 goto error_rcu_unlock;
574 }
575
576 rcu_read_unlock();
577 return 0;
578
579 error_rcu_unlock:
580 /*
581 * On error, flag the registry that the metadata is closed. We were unable
582 * to push anything and this means that either the consumer is not
583 * responding or the metadata cache has been destroyed on the consumer.
584 */
585 registry->metadata_closed = 1;
586 end_rcu_unlock:
587 rcu_read_unlock();
588 return ret_val;
589 }
590
591 /*
592 * Send to the consumer a close metadata command for the given session. Once
593 * done, the metadata channel is deleted and the session metadata pointer is
594 * nullified. The session lock MUST be acquired here unless the application is
595 * in the destroy path.
596 *
597 * Return 0 on success else a negative value.
598 */
599 static int close_metadata(struct ust_registry_session *registry,
600 struct consumer_output *consumer)
601 {
602 int ret;
603 struct consumer_socket *socket;
604
605 assert(registry);
606 assert(consumer);
607
608 rcu_read_lock();
609
610 if (!registry->metadata_key || registry->metadata_closed) {
611 ret = 0;
612 goto end;
613 }
614
615 /* Get consumer socket to use to push the metadata.*/
616 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
617 consumer);
618 if (!socket) {
619 ret = -1;
620 goto error;
621 }
622
623 ret = consumer_close_metadata(socket, registry->metadata_key);
624 if (ret < 0) {
625 goto error;
626 }
627
628 error:
629 /*
630 * Metadata closed. Even on error this means that the consumer is not
631 * responding or not found so either way a second close should NOT be emit
632 * for this registry.
633 */
634 registry->metadata_closed = 1;
635 end:
636 rcu_read_unlock();
637 return ret;
638 }
639
640 /*
641 * We need to execute ht_destroy outside of RCU read-side critical
642 * section and outside of call_rcu thread, so we postpone its execution
643 * using ht_cleanup_push. It is simpler than to change the semantic of
644 * the many callers of delete_ust_app_session().
645 */
646 static
647 void delete_ust_app_session_rcu(struct rcu_head *head)
648 {
649 struct ust_app_session *ua_sess =
650 caa_container_of(head, struct ust_app_session, rcu_head);
651
652 ht_cleanup_push(ua_sess->channels);
653 free(ua_sess);
654 }
655
656 /*
657 * Delete ust app session safely. RCU read lock must be held before calling
658 * this function.
659 */
660 static
661 void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
662 struct ust_app *app)
663 {
664 int ret;
665 struct lttng_ht_iter iter;
666 struct ust_app_channel *ua_chan;
667 struct ust_registry_session *registry;
668
669 assert(ua_sess);
670
671 pthread_mutex_lock(&ua_sess->lock);
672
673 registry = get_session_registry(ua_sess);
674 if (registry && !registry->metadata_closed) {
675 /* Push metadata for application before freeing the application. */
676 (void) push_metadata(registry, ua_sess->consumer);
677
678 /*
679 * Don't ask to close metadata for global per UID buffers. Close
680 * metadata only on destroy trace session in this case. Also, the
681 * previous push metadata could have flag the metadata registry to
682 * close so don't send a close command if closed.
683 */
684 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
685 !registry->metadata_closed) {
686 /* And ask to close it for this session registry. */
687 (void) close_metadata(registry, ua_sess->consumer);
688 }
689 }
690
691 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
692 node.node) {
693 ret = lttng_ht_del(ua_sess->channels, &iter);
694 assert(!ret);
695 delete_ust_app_channel(sock, ua_chan, app);
696 }
697
698 /* In case of per PID, the registry is kept in the session. */
699 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
700 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
701 if (reg_pid) {
702 buffer_reg_pid_remove(reg_pid);
703 buffer_reg_pid_destroy(reg_pid);
704 }
705 }
706
707 if (ua_sess->handle != -1) {
708 ret = ustctl_release_handle(sock, ua_sess->handle);
709 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
710 ERR("UST app sock %d release session handle failed with ret %d",
711 sock, ret);
712 }
713 }
714 pthread_mutex_unlock(&ua_sess->lock);
715
716 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
717 }
718
719 /*
720 * Delete a traceable application structure from the global list. Never call
721 * this function outside of a call_rcu call.
722 *
723 * RCU read side lock should _NOT_ be held when calling this function.
724 */
725 static
726 void delete_ust_app(struct ust_app *app)
727 {
728 int ret, sock;
729 struct ust_app_session *ua_sess, *tmp_ua_sess;
730
731 /* Delete ust app sessions info */
732 sock = app->sock;
733 app->sock = -1;
734
735 /* Wipe sessions */
736 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
737 teardown_node) {
738 /* Free every object in the session and the session. */
739 rcu_read_lock();
740 delete_ust_app_session(sock, ua_sess, app);
741 rcu_read_unlock();
742 }
743
744 ht_cleanup_push(app->sessions);
745 ht_cleanup_push(app->ust_objd);
746
747 /*
748 * Wait until we have deleted the application from the sock hash table
749 * before closing this socket, otherwise an application could re-use the
750 * socket ID and race with the teardown, using the same hash table entry.
751 *
752 * It's OK to leave the close in call_rcu. We want it to stay unique for
753 * all RCU readers that could run concurrently with unregister app,
754 * therefore we _need_ to only close that socket after a grace period. So
755 * it should stay in this RCU callback.
756 *
757 * This close() is a very important step of the synchronization model so
758 * every modification to this function must be carefully reviewed.
759 */
760 ret = close(sock);
761 if (ret) {
762 PERROR("close");
763 }
764 lttng_fd_put(LTTNG_FD_APPS, 1);
765
766 DBG2("UST app pid %d deleted", app->pid);
767 free(app);
768 }
769
770 /*
771 * URCU intermediate call to delete an UST app.
772 */
773 static
774 void delete_ust_app_rcu(struct rcu_head *head)
775 {
776 struct lttng_ht_node_ulong *node =
777 caa_container_of(head, struct lttng_ht_node_ulong, head);
778 struct ust_app *app =
779 caa_container_of(node, struct ust_app, pid_n);
780
781 DBG3("Call RCU deleting app PID %d", app->pid);
782 delete_ust_app(app);
783 }
784
785 /*
786 * Delete the session from the application ht and delete the data structure by
787 * freeing every object inside and releasing them.
788 */
789 static void destroy_app_session(struct ust_app *app,
790 struct ust_app_session *ua_sess)
791 {
792 int ret;
793 struct lttng_ht_iter iter;
794
795 assert(app);
796 assert(ua_sess);
797
798 iter.iter.node = &ua_sess->node.node;
799 ret = lttng_ht_del(app->sessions, &iter);
800 if (ret) {
801 /* Already scheduled for teardown. */
802 goto end;
803 }
804
805 /* Once deleted, free the data structure. */
806 delete_ust_app_session(app->sock, ua_sess, app);
807
808 end:
809 return;
810 }
811
812 /*
813 * Alloc new UST app session.
814 */
815 static
816 struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
817 {
818 struct ust_app_session *ua_sess;
819
820 /* Init most of the default value by allocating and zeroing */
821 ua_sess = zmalloc(sizeof(struct ust_app_session));
822 if (ua_sess == NULL) {
823 PERROR("malloc");
824 goto error_free;
825 }
826
827 ua_sess->handle = -1;
828 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
829 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
830 pthread_mutex_init(&ua_sess->lock, NULL);
831
832 return ua_sess;
833
834 error_free:
835 return NULL;
836 }
837
838 /*
839 * Alloc new UST app channel.
840 */
841 static
842 struct ust_app_channel *alloc_ust_app_channel(char *name,
843 struct ust_app_session *ua_sess,
844 struct lttng_ust_channel_attr *attr)
845 {
846 struct ust_app_channel *ua_chan;
847
848 /* Init most of the default value by allocating and zeroing */
849 ua_chan = zmalloc(sizeof(struct ust_app_channel));
850 if (ua_chan == NULL) {
851 PERROR("malloc");
852 goto error;
853 }
854
855 /* Setup channel name */
856 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
857 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
858
859 ua_chan->enabled = 1;
860 ua_chan->handle = -1;
861 ua_chan->session = ua_sess;
862 ua_chan->key = get_next_channel_key();
863 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
864 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
865 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
866
867 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
868 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
869
870 /* Copy attributes */
871 if (attr) {
872 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
873 ua_chan->attr.subbuf_size = attr->subbuf_size;
874 ua_chan->attr.num_subbuf = attr->num_subbuf;
875 ua_chan->attr.overwrite = attr->overwrite;
876 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
877 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
878 ua_chan->attr.output = attr->output;
879 }
880 /* By default, the channel is a per cpu channel. */
881 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
882
883 DBG3("UST app channel %s allocated", ua_chan->name);
884
885 return ua_chan;
886
887 error:
888 return NULL;
889 }
890
891 /*
892 * Allocate and initialize a UST app stream.
893 *
894 * Return newly allocated stream pointer or NULL on error.
895 */
896 struct ust_app_stream *ust_app_alloc_stream(void)
897 {
898 struct ust_app_stream *stream = NULL;
899
900 stream = zmalloc(sizeof(*stream));
901 if (stream == NULL) {
902 PERROR("zmalloc ust app stream");
903 goto error;
904 }
905
906 /* Zero could be a valid value for a handle so flag it to -1. */
907 stream->handle = -1;
908
909 error:
910 return stream;
911 }
912
913 /*
914 * Alloc new UST app event.
915 */
916 static
917 struct ust_app_event *alloc_ust_app_event(char *name,
918 struct lttng_ust_event *attr)
919 {
920 struct ust_app_event *ua_event;
921
922 /* Init most of the default value by allocating and zeroing */
923 ua_event = zmalloc(sizeof(struct ust_app_event));
924 if (ua_event == NULL) {
925 PERROR("malloc");
926 goto error;
927 }
928
929 ua_event->enabled = 1;
930 strncpy(ua_event->name, name, sizeof(ua_event->name));
931 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
932 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
933
934 /* Copy attributes */
935 if (attr) {
936 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
937 }
938
939 DBG3("UST app event %s allocated", ua_event->name);
940
941 return ua_event;
942
943 error:
944 return NULL;
945 }
946
947 /*
948 * Alloc new UST app context.
949 */
950 static
951 struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context *uctx)
952 {
953 struct ust_app_ctx *ua_ctx;
954
955 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
956 if (ua_ctx == NULL) {
957 goto error;
958 }
959
960 CDS_INIT_LIST_HEAD(&ua_ctx->list);
961
962 if (uctx) {
963 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
964 }
965
966 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
967
968 error:
969 return ua_ctx;
970 }
971
972 /*
973 * Allocate a filter and copy the given original filter.
974 *
975 * Return allocated filter or NULL on error.
976 */
977 static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
978 struct lttng_ust_filter_bytecode *orig_f)
979 {
980 struct lttng_ust_filter_bytecode *filter = NULL;
981
982 /* Copy filter bytecode */
983 filter = zmalloc(sizeof(*filter) + orig_f->len);
984 if (!filter) {
985 PERROR("zmalloc alloc ust app filter");
986 goto error;
987 }
988
989 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
990
991 error:
992 return filter;
993 }
994
995 /*
996 * Find an ust_app using the sock and return it. RCU read side lock must be
997 * held before calling this helper function.
998 */
999 struct ust_app *ust_app_find_by_sock(int sock)
1000 {
1001 struct lttng_ht_node_ulong *node;
1002 struct lttng_ht_iter iter;
1003
1004 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1005 node = lttng_ht_iter_get_node_ulong(&iter);
1006 if (node == NULL) {
1007 DBG2("UST app find by sock %d not found", sock);
1008 goto error;
1009 }
1010
1011 return caa_container_of(node, struct ust_app, sock_n);
1012
1013 error:
1014 return NULL;
1015 }
1016
1017 /*
1018 * Find an ust_app using the notify sock and return it. RCU read side lock must
1019 * be held before calling this helper function.
1020 */
1021 static struct ust_app *find_app_by_notify_sock(int sock)
1022 {
1023 struct lttng_ht_node_ulong *node;
1024 struct lttng_ht_iter iter;
1025
1026 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1027 &iter);
1028 node = lttng_ht_iter_get_node_ulong(&iter);
1029 if (node == NULL) {
1030 DBG2("UST app find by notify sock %d not found", sock);
1031 goto error;
1032 }
1033
1034 return caa_container_of(node, struct ust_app, notify_sock_n);
1035
1036 error:
1037 return NULL;
1038 }
1039
1040 /*
1041 * Lookup for an ust app event based on event name, filter bytecode and the
1042 * event loglevel.
1043 *
1044 * Return an ust_app_event object or NULL on error.
1045 */
1046 static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1047 char *name, struct lttng_ust_filter_bytecode *filter, int loglevel,
1048 const struct lttng_event_exclusion *exclusion)
1049 {
1050 struct lttng_ht_iter iter;
1051 struct lttng_ht_node_str *node;
1052 struct ust_app_event *event = NULL;
1053 struct ust_app_ht_key key;
1054
1055 assert(name);
1056 assert(ht);
1057
1058 /* Setup key for event lookup. */
1059 key.name = name;
1060 key.filter = filter;
1061 key.loglevel = loglevel;
1062 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1063 key.exclusion = (struct lttng_ust_event_exclusion *)exclusion;
1064
1065 /* Lookup using the event name as hash and a custom match fct. */
1066 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1067 ht_match_ust_app_event, &key, &iter.iter);
1068 node = lttng_ht_iter_get_node_str(&iter);
1069 if (node == NULL) {
1070 goto end;
1071 }
1072
1073 event = caa_container_of(node, struct ust_app_event, node);
1074
1075 end:
1076 return event;
1077 }
1078
1079 /*
1080 * Create the channel context on the tracer.
1081 *
1082 * Called with UST app session lock held.
1083 */
1084 static
1085 int create_ust_channel_context(struct ust_app_channel *ua_chan,
1086 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1087 {
1088 int ret;
1089
1090 health_code_update();
1091
1092 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1093 ua_chan->obj, &ua_ctx->obj);
1094 if (ret < 0) {
1095 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1096 ERR("UST app create channel context failed for app (pid: %d) "
1097 "with ret %d", app->pid, ret);
1098 } else {
1099 /*
1100 * This is normal behavior, an application can die during the
1101 * creation process. Don't report an error so the execution can
1102 * continue normally.
1103 */
1104 ret = 0;
1105 DBG3("UST app disable event failed. Application is dead.");
1106 }
1107 goto error;
1108 }
1109
1110 ua_ctx->handle = ua_ctx->obj->handle;
1111
1112 DBG2("UST app context handle %d created successfully for channel %s",
1113 ua_ctx->handle, ua_chan->name);
1114
1115 error:
1116 health_code_update();
1117 return ret;
1118 }
1119
1120 /*
1121 * Set the filter on the tracer.
1122 */
1123 static
1124 int set_ust_event_filter(struct ust_app_event *ua_event,
1125 struct ust_app *app)
1126 {
1127 int ret;
1128
1129 health_code_update();
1130
1131 if (!ua_event->filter) {
1132 ret = 0;
1133 goto error;
1134 }
1135
1136 ret = ustctl_set_filter(app->sock, ua_event->filter,
1137 ua_event->obj);
1138 if (ret < 0) {
1139 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1140 ERR("UST app event %s filter failed for app (pid: %d) "
1141 "with ret %d", ua_event->attr.name, app->pid, ret);
1142 } else {
1143 /*
1144 * This is normal behavior, an application can die during the
1145 * creation process. Don't report an error so the execution can
1146 * continue normally.
1147 */
1148 ret = 0;
1149 DBG3("UST app filter event failed. Application is dead.");
1150 }
1151 goto error;
1152 }
1153
1154 DBG2("UST filter set successfully for event %s", ua_event->name);
1155
1156 error:
1157 health_code_update();
1158 return ret;
1159 }
1160
1161 /*
1162 * Set event exclusions on the tracer.
1163 */
1164 static
1165 int set_ust_event_exclusion(struct ust_app_event *ua_event,
1166 struct ust_app *app)
1167 {
1168 int ret;
1169
1170 health_code_update();
1171
1172 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1173 ret = 0;
1174 goto error;
1175 }
1176
1177 ret = ustctl_set_exclusion(app->sock, ua_event->exclusion,
1178 ua_event->obj);
1179 if (ret < 0) {
1180 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1181 ERR("UST app event %s exclusions failed for app (pid: %d) "
1182 "with ret %d", ua_event->attr.name, app->pid, ret);
1183 } else {
1184 /*
1185 * This is normal behavior, an application can die during the
1186 * creation process. Don't report an error so the execution can
1187 * continue normally.
1188 */
1189 ret = 0;
1190 DBG3("UST app event exclusion failed. Application is dead.");
1191 }
1192 goto error;
1193 }
1194
1195 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1196
1197 error:
1198 health_code_update();
1199 return ret;
1200 }
1201
1202 /*
1203 * Disable the specified event on to UST tracer for the UST session.
1204 */
1205 static int disable_ust_event(struct ust_app *app,
1206 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1207 {
1208 int ret;
1209
1210 health_code_update();
1211
1212 ret = ustctl_disable(app->sock, ua_event->obj);
1213 if (ret < 0) {
1214 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1215 ERR("UST app event %s disable failed for app (pid: %d) "
1216 "and session handle %d with ret %d",
1217 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1218 } else {
1219 /*
1220 * This is normal behavior, an application can die during the
1221 * creation process. Don't report an error so the execution can
1222 * continue normally.
1223 */
1224 ret = 0;
1225 DBG3("UST app disable event failed. Application is dead.");
1226 }
1227 goto error;
1228 }
1229
1230 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1231 ua_event->attr.name, app->pid);
1232
1233 error:
1234 health_code_update();
1235 return ret;
1236 }
1237
1238 /*
1239 * Disable the specified channel on to UST tracer for the UST session.
1240 */
1241 static int disable_ust_channel(struct ust_app *app,
1242 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1243 {
1244 int ret;
1245
1246 health_code_update();
1247
1248 ret = ustctl_disable(app->sock, ua_chan->obj);
1249 if (ret < 0) {
1250 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1251 ERR("UST app channel %s disable failed for app (pid: %d) "
1252 "and session handle %d with ret %d",
1253 ua_chan->name, app->pid, ua_sess->handle, ret);
1254 } else {
1255 /*
1256 * This is normal behavior, an application can die during the
1257 * creation process. Don't report an error so the execution can
1258 * continue normally.
1259 */
1260 ret = 0;
1261 DBG3("UST app disable channel failed. Application is dead.");
1262 }
1263 goto error;
1264 }
1265
1266 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1267 ua_chan->name, app->pid);
1268
1269 error:
1270 health_code_update();
1271 return ret;
1272 }
1273
1274 /*
1275 * Enable the specified channel on to UST tracer for the UST session.
1276 */
1277 static int enable_ust_channel(struct ust_app *app,
1278 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1279 {
1280 int ret;
1281
1282 health_code_update();
1283
1284 ret = ustctl_enable(app->sock, ua_chan->obj);
1285 if (ret < 0) {
1286 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1287 ERR("UST app channel %s enable failed for app (pid: %d) "
1288 "and session handle %d with ret %d",
1289 ua_chan->name, app->pid, ua_sess->handle, ret);
1290 } else {
1291 /*
1292 * This is normal behavior, an application can die during the
1293 * creation process. Don't report an error so the execution can
1294 * continue normally.
1295 */
1296 ret = 0;
1297 DBG3("UST app enable channel failed. Application is dead.");
1298 }
1299 goto error;
1300 }
1301
1302 ua_chan->enabled = 1;
1303
1304 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1305 ua_chan->name, app->pid);
1306
1307 error:
1308 health_code_update();
1309 return ret;
1310 }
1311
1312 /*
1313 * Enable the specified event on to UST tracer for the UST session.
1314 */
1315 static int enable_ust_event(struct ust_app *app,
1316 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1317 {
1318 int ret;
1319
1320 health_code_update();
1321
1322 ret = ustctl_enable(app->sock, ua_event->obj);
1323 if (ret < 0) {
1324 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1325 ERR("UST app event %s enable failed for app (pid: %d) "
1326 "and session handle %d with ret %d",
1327 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1328 } else {
1329 /*
1330 * This is normal behavior, an application can die during the
1331 * creation process. Don't report an error so the execution can
1332 * continue normally.
1333 */
1334 ret = 0;
1335 DBG3("UST app enable event failed. Application is dead.");
1336 }
1337 goto error;
1338 }
1339
1340 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1341 ua_event->attr.name, app->pid);
1342
1343 error:
1344 health_code_update();
1345 return ret;
1346 }
1347
1348 /*
1349 * Send channel and stream buffer to application.
1350 *
1351 * Return 0 on success. On error, a negative value is returned.
1352 */
1353 static int send_channel_pid_to_ust(struct ust_app *app,
1354 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1355 {
1356 int ret;
1357 struct ust_app_stream *stream, *stmp;
1358
1359 assert(app);
1360 assert(ua_sess);
1361 assert(ua_chan);
1362
1363 health_code_update();
1364
1365 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1366 app->sock);
1367
1368 /* Send channel to the application. */
1369 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1370 if (ret < 0) {
1371 goto error;
1372 }
1373
1374 health_code_update();
1375
1376 /* Send all streams to application. */
1377 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1378 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1379 if (ret < 0) {
1380 goto error;
1381 }
1382 /* We don't need the stream anymore once sent to the tracer. */
1383 cds_list_del(&stream->list);
1384 delete_ust_app_stream(-1, stream);
1385 }
1386 /* Flag the channel that it is sent to the application. */
1387 ua_chan->is_sent = 1;
1388
1389 error:
1390 health_code_update();
1391 return ret;
1392 }
1393
1394 /*
1395 * Create the specified event onto the UST tracer for a UST session.
1396 *
1397 * Should be called with session mutex held.
1398 */
1399 static
1400 int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1401 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1402 {
1403 int ret = 0;
1404
1405 health_code_update();
1406
1407 /* Create UST event on tracer */
1408 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1409 &ua_event->obj);
1410 if (ret < 0) {
1411 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1412 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1413 ua_event->attr.name, app->pid, ret);
1414 } else {
1415 /*
1416 * This is normal behavior, an application can die during the
1417 * creation process. Don't report an error so the execution can
1418 * continue normally.
1419 */
1420 ret = 0;
1421 DBG3("UST app create event failed. Application is dead.");
1422 }
1423 goto error;
1424 }
1425
1426 ua_event->handle = ua_event->obj->handle;
1427
1428 DBG2("UST app event %s created successfully for pid:%d",
1429 ua_event->attr.name, app->pid);
1430
1431 health_code_update();
1432
1433 /* Set filter if one is present. */
1434 if (ua_event->filter) {
1435 ret = set_ust_event_filter(ua_event, app);
1436 if (ret < 0) {
1437 goto error;
1438 }
1439 }
1440
1441 /* Set exclusions for the event */
1442 if (ua_event->exclusion) {
1443 ret = set_ust_event_exclusion(ua_event, app);
1444 if (ret < 0) {
1445 goto error;
1446 }
1447 }
1448
1449 /* If event not enabled, disable it on the tracer */
1450 if (ua_event->enabled) {
1451 /*
1452 * We now need to explicitly enable the event, since it
1453 * is now disabled at creation.
1454 */
1455 ret = enable_ust_event(app, ua_sess, ua_event);
1456 if (ret < 0) {
1457 /*
1458 * If we hit an EPERM, something is wrong with our enable call. If
1459 * we get an EEXIST, there is a problem on the tracer side since we
1460 * just created it.
1461 */
1462 switch (ret) {
1463 case -LTTNG_UST_ERR_PERM:
1464 /* Code flow problem */
1465 assert(0);
1466 case -LTTNG_UST_ERR_EXIST:
1467 /* It's OK for our use case. */
1468 ret = 0;
1469 break;
1470 default:
1471 break;
1472 }
1473 goto error;
1474 }
1475 }
1476
1477 error:
1478 health_code_update();
1479 return ret;
1480 }
1481
1482 /*
1483 * Copy data between an UST app event and a LTT event.
1484 */
1485 static void shadow_copy_event(struct ust_app_event *ua_event,
1486 struct ltt_ust_event *uevent)
1487 {
1488 size_t exclusion_alloc_size;
1489
1490 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1491 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1492
1493 ua_event->enabled = uevent->enabled;
1494
1495 /* Copy event attributes */
1496 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1497
1498 /* Copy filter bytecode */
1499 if (uevent->filter) {
1500 ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
1501 /* Filter might be NULL here in case of ENONEM. */
1502 }
1503
1504 /* Copy exclusion data */
1505 if (uevent->exclusion) {
1506 exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1507 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1508 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1509 if (ua_event->exclusion == NULL) {
1510 PERROR("malloc");
1511 } else {
1512 memcpy(ua_event->exclusion, uevent->exclusion,
1513 exclusion_alloc_size);
1514 }
1515 }
1516 }
1517
1518 /*
1519 * Copy data between an UST app channel and a LTT channel.
1520 */
1521 static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1522 struct ltt_ust_channel *uchan)
1523 {
1524 struct lttng_ht_iter iter;
1525 struct ltt_ust_event *uevent;
1526 struct ltt_ust_context *uctx;
1527 struct ust_app_event *ua_event;
1528 struct ust_app_ctx *ua_ctx;
1529
1530 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1531
1532 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1533 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1534
1535 ua_chan->tracefile_size = uchan->tracefile_size;
1536 ua_chan->tracefile_count = uchan->tracefile_count;
1537
1538 /* Copy event attributes since the layout is different. */
1539 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1540 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1541 ua_chan->attr.overwrite = uchan->attr.overwrite;
1542 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1543 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1544 ua_chan->attr.output = uchan->attr.output;
1545 /*
1546 * Note that the attribute channel type is not set since the channel on the
1547 * tracing registry side does not have this information.
1548 */
1549
1550 ua_chan->enabled = uchan->enabled;
1551 ua_chan->tracing_channel_id = uchan->id;
1552
1553 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
1554 ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1555 if (ua_ctx == NULL) {
1556 continue;
1557 }
1558 lttng_ht_node_init_ulong(&ua_ctx->node,
1559 (unsigned long) ua_ctx->ctx.ctx);
1560 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
1561 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
1562 }
1563
1564 /* Copy all events from ltt ust channel to ust app channel */
1565 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
1566 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
1567 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
1568 if (ua_event == NULL) {
1569 DBG2("UST event %s not found on shadow copy channel",
1570 uevent->attr.name);
1571 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
1572 if (ua_event == NULL) {
1573 continue;
1574 }
1575 shadow_copy_event(ua_event, uevent);
1576 add_unique_ust_app_event(ua_chan, ua_event);
1577 }
1578 }
1579
1580 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1581 }
1582
1583 /*
1584 * Copy data between a UST app session and a regular LTT session.
1585 */
1586 static void shadow_copy_session(struct ust_app_session *ua_sess,
1587 struct ltt_ust_session *usess, struct ust_app *app)
1588 {
1589 struct lttng_ht_node_str *ua_chan_node;
1590 struct lttng_ht_iter iter;
1591 struct ltt_ust_channel *uchan;
1592 struct ust_app_channel *ua_chan;
1593 time_t rawtime;
1594 struct tm *timeinfo;
1595 char datetime[16];
1596 int ret;
1597
1598 /* Get date and time for unique app path */
1599 time(&rawtime);
1600 timeinfo = localtime(&rawtime);
1601 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1602
1603 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1604
1605 ua_sess->tracing_id = usess->id;
1606 ua_sess->id = get_next_session_id();
1607 ua_sess->uid = app->uid;
1608 ua_sess->gid = app->gid;
1609 ua_sess->euid = usess->uid;
1610 ua_sess->egid = usess->gid;
1611 ua_sess->buffer_type = usess->buffer_type;
1612 ua_sess->bits_per_long = app->bits_per_long;
1613 /* There is only one consumer object per session possible. */
1614 ua_sess->consumer = usess->consumer;
1615 ua_sess->output_traces = usess->output_traces;
1616 ua_sess->live_timer_interval = usess->live_timer_interval;
1617 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1618 &usess->metadata_attr);
1619
1620 switch (ua_sess->buffer_type) {
1621 case LTTNG_BUFFER_PER_PID:
1622 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1623 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1624 datetime);
1625 break;
1626 case LTTNG_BUFFER_PER_UID:
1627 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1628 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1629 break;
1630 default:
1631 assert(0);
1632 goto error;
1633 }
1634 if (ret < 0) {
1635 PERROR("asprintf UST shadow copy session");
1636 assert(0);
1637 goto error;
1638 }
1639
1640 /* Iterate over all channels in global domain. */
1641 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1642 uchan, node.node) {
1643 struct lttng_ht_iter uiter;
1644
1645 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1646 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
1647 if (ua_chan_node != NULL) {
1648 /* Session exist. Contiuing. */
1649 continue;
1650 }
1651
1652 DBG2("Channel %s not found on shadow session copy, creating it",
1653 uchan->name);
1654 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
1655 if (ua_chan == NULL) {
1656 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1657 continue;
1658 }
1659 shadow_copy_channel(ua_chan, uchan);
1660 /*
1661 * The concept of metadata channel does not exist on the tracing
1662 * registry side of the session daemon so this can only be a per CPU
1663 * channel and not metadata.
1664 */
1665 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1666
1667 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
1668 }
1669
1670 error:
1671 return;
1672 }
1673
1674 /*
1675 * Lookup sesison wrapper.
1676 */
1677 static
1678 void __lookup_session_by_app(struct ltt_ust_session *usess,
1679 struct ust_app *app, struct lttng_ht_iter *iter)
1680 {
1681 /* Get right UST app session from app */
1682 lttng_ht_lookup(app->sessions, &usess->id, iter);
1683 }
1684
1685 /*
1686 * Return ust app session from the app session hashtable using the UST session
1687 * id.
1688 */
1689 static struct ust_app_session *lookup_session_by_app(
1690 struct ltt_ust_session *usess, struct ust_app *app)
1691 {
1692 struct lttng_ht_iter iter;
1693 struct lttng_ht_node_u64 *node;
1694
1695 __lookup_session_by_app(usess, app, &iter);
1696 node = lttng_ht_iter_get_node_u64(&iter);
1697 if (node == NULL) {
1698 goto error;
1699 }
1700
1701 return caa_container_of(node, struct ust_app_session, node);
1702
1703 error:
1704 return NULL;
1705 }
1706
1707 /*
1708 * Setup buffer registry per PID for the given session and application. If none
1709 * is found, a new one is created, added to the global registry and
1710 * initialized. If regp is valid, it's set with the newly created object.
1711 *
1712 * Return 0 on success or else a negative value.
1713 */
1714 static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1715 struct ust_app *app, struct buffer_reg_pid **regp)
1716 {
1717 int ret = 0;
1718 struct buffer_reg_pid *reg_pid;
1719
1720 assert(ua_sess);
1721 assert(app);
1722
1723 rcu_read_lock();
1724
1725 reg_pid = buffer_reg_pid_find(ua_sess->id);
1726 if (!reg_pid) {
1727 /*
1728 * This is the create channel path meaning that if there is NO
1729 * registry available, we have to create one for this session.
1730 */
1731 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid);
1732 if (ret < 0) {
1733 goto error;
1734 }
1735 } else {
1736 goto end;
1737 }
1738
1739 /* Initialize registry. */
1740 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1741 app->bits_per_long, app->uint8_t_alignment,
1742 app->uint16_t_alignment, app->uint32_t_alignment,
1743 app->uint64_t_alignment, app->long_alignment,
1744 app->byte_order, app->version.major,
1745 app->version.minor);
1746 if (ret < 0) {
1747 /*
1748 * reg_pid->registry->reg.ust is NULL upon error, so we need to
1749 * destroy the buffer registry, because it is always expected
1750 * that if the buffer registry can be found, its ust registry is
1751 * non-NULL.
1752 */
1753 buffer_reg_pid_destroy(reg_pid);
1754 goto error;
1755 }
1756
1757 buffer_reg_pid_add(reg_pid);
1758
1759 DBG3("UST app buffer registry per PID created successfully");
1760
1761 end:
1762 if (regp) {
1763 *regp = reg_pid;
1764 }
1765 error:
1766 rcu_read_unlock();
1767 return ret;
1768 }
1769
1770 /*
1771 * Setup buffer registry per UID for the given session and application. If none
1772 * is found, a new one is created, added to the global registry and
1773 * initialized. If regp is valid, it's set with the newly created object.
1774 *
1775 * Return 0 on success or else a negative value.
1776 */
1777 static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
1778 struct ust_app *app, struct buffer_reg_uid **regp)
1779 {
1780 int ret = 0;
1781 struct buffer_reg_uid *reg_uid;
1782
1783 assert(usess);
1784 assert(app);
1785
1786 rcu_read_lock();
1787
1788 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
1789 if (!reg_uid) {
1790 /*
1791 * This is the create channel path meaning that if there is NO
1792 * registry available, we have to create one for this session.
1793 */
1794 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
1795 LTTNG_DOMAIN_UST, &reg_uid);
1796 if (ret < 0) {
1797 goto error;
1798 }
1799 } else {
1800 goto end;
1801 }
1802
1803 /* Initialize registry. */
1804 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
1805 app->bits_per_long, app->uint8_t_alignment,
1806 app->uint16_t_alignment, app->uint32_t_alignment,
1807 app->uint64_t_alignment, app->long_alignment,
1808 app->byte_order, app->version.major,
1809 app->version.minor);
1810 if (ret < 0) {
1811 /*
1812 * reg_uid->registry->reg.ust is NULL upon error, so we need to
1813 * destroy the buffer registry, because it is always expected
1814 * that if the buffer registry can be found, its ust registry is
1815 * non-NULL.
1816 */
1817 buffer_reg_uid_destroy(reg_uid, NULL);
1818 goto error;
1819 }
1820 /* Add node to teardown list of the session. */
1821 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
1822
1823 buffer_reg_uid_add(reg_uid);
1824
1825 DBG3("UST app buffer registry per UID created successfully");
1826 end:
1827 if (regp) {
1828 *regp = reg_uid;
1829 }
1830 error:
1831 rcu_read_unlock();
1832 return ret;
1833 }
1834
1835 /*
1836 * Create a session on the tracer side for the given app.
1837 *
1838 * On success, ua_sess_ptr is populated with the session pointer or else left
1839 * untouched. If the session was created, is_created is set to 1. On error,
1840 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1841 * be NULL.
1842 *
1843 * Returns 0 on success or else a negative code which is either -ENOMEM or
1844 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1845 */
1846 static int create_ust_app_session(struct ltt_ust_session *usess,
1847 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
1848 int *is_created)
1849 {
1850 int ret, created = 0;
1851 struct ust_app_session *ua_sess;
1852
1853 assert(usess);
1854 assert(app);
1855 assert(ua_sess_ptr);
1856
1857 health_code_update();
1858
1859 ua_sess = lookup_session_by_app(usess, app);
1860 if (ua_sess == NULL) {
1861 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
1862 app->pid, usess->id);
1863 ua_sess = alloc_ust_app_session(app);
1864 if (ua_sess == NULL) {
1865 /* Only malloc can failed so something is really wrong */
1866 ret = -ENOMEM;
1867 goto error;
1868 }
1869 shadow_copy_session(ua_sess, usess, app);
1870 created = 1;
1871 }
1872
1873 switch (usess->buffer_type) {
1874 case LTTNG_BUFFER_PER_PID:
1875 /* Init local registry. */
1876 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
1877 if (ret < 0) {
1878 delete_ust_app_session(-1, ua_sess, app);
1879 goto error;
1880 }
1881 break;
1882 case LTTNG_BUFFER_PER_UID:
1883 /* Look for a global registry. If none exists, create one. */
1884 ret = setup_buffer_reg_uid(usess, app, NULL);
1885 if (ret < 0) {
1886 delete_ust_app_session(-1, ua_sess, app);
1887 goto error;
1888 }
1889 break;
1890 default:
1891 assert(0);
1892 ret = -EINVAL;
1893 goto error;
1894 }
1895
1896 health_code_update();
1897
1898 if (ua_sess->handle == -1) {
1899 ret = ustctl_create_session(app->sock);
1900 if (ret < 0) {
1901 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1902 ERR("Creating session for app pid %d with ret %d",
1903 app->pid, ret);
1904 } else {
1905 DBG("UST app creating session failed. Application is dead");
1906 /*
1907 * This is normal behavior, an application can die during the
1908 * creation process. Don't report an error so the execution can
1909 * continue normally. This will get flagged ENOTCONN and the
1910 * caller will handle it.
1911 */
1912 ret = 0;
1913 }
1914 delete_ust_app_session(-1, ua_sess, app);
1915 if (ret != -ENOMEM) {
1916 /*
1917 * Tracer is probably gone or got an internal error so let's
1918 * behave like it will soon unregister or not usable.
1919 */
1920 ret = -ENOTCONN;
1921 }
1922 goto error;
1923 }
1924
1925 ua_sess->handle = ret;
1926
1927 /* Add ust app session to app's HT */
1928 lttng_ht_node_init_u64(&ua_sess->node,
1929 ua_sess->tracing_id);
1930 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
1931
1932 DBG2("UST app session created successfully with handle %d", ret);
1933 }
1934
1935 *ua_sess_ptr = ua_sess;
1936 if (is_created) {
1937 *is_created = created;
1938 }
1939
1940 /* Everything went well. */
1941 ret = 0;
1942
1943 error:
1944 health_code_update();
1945 return ret;
1946 }
1947
1948 /*
1949 * Match function for a hash table lookup of ust_app_ctx.
1950 *
1951 * It matches an ust app context based on the context type and, in the case
1952 * of perf counters, their name.
1953 */
1954 static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
1955 {
1956 struct ust_app_ctx *ctx;
1957 const struct lttng_ust_context *key;
1958
1959 assert(node);
1960 assert(_key);
1961
1962 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
1963 key = _key;
1964
1965 /* Context type */
1966 if (ctx->ctx.ctx != key->ctx) {
1967 goto no_match;
1968 }
1969
1970 /* Check the name in the case of perf thread counters. */
1971 if (key->ctx == LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER) {
1972 if (strncmp(key->u.perf_counter.name,
1973 ctx->ctx.u.perf_counter.name,
1974 sizeof(key->u.perf_counter.name))) {
1975 goto no_match;
1976 }
1977 }
1978
1979 /* Match. */
1980 return 1;
1981
1982 no_match:
1983 return 0;
1984 }
1985
1986 /*
1987 * Lookup for an ust app context from an lttng_ust_context.
1988 *
1989 * Must be called while holding RCU read side lock.
1990 * Return an ust_app_ctx object or NULL on error.
1991 */
1992 static
1993 struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
1994 struct lttng_ust_context *uctx)
1995 {
1996 struct lttng_ht_iter iter;
1997 struct lttng_ht_node_ulong *node;
1998 struct ust_app_ctx *app_ctx = NULL;
1999
2000 assert(uctx);
2001 assert(ht);
2002
2003 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2004 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2005 ht_match_ust_app_ctx, uctx, &iter.iter);
2006 node = lttng_ht_iter_get_node_ulong(&iter);
2007 if (!node) {
2008 goto end;
2009 }
2010
2011 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2012
2013 end:
2014 return app_ctx;
2015 }
2016
2017 /*
2018 * Create a context for the channel on the tracer.
2019 *
2020 * Called with UST app session lock held and a RCU read side lock.
2021 */
2022 static
2023 int create_ust_app_channel_context(struct ust_app_session *ua_sess,
2024 struct ust_app_channel *ua_chan, struct lttng_ust_context *uctx,
2025 struct ust_app *app)
2026 {
2027 int ret = 0;
2028 struct ust_app_ctx *ua_ctx;
2029
2030 DBG2("UST app adding context to channel %s", ua_chan->name);
2031
2032 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2033 if (ua_ctx) {
2034 ret = -EEXIST;
2035 goto error;
2036 }
2037
2038 ua_ctx = alloc_ust_app_ctx(uctx);
2039 if (ua_ctx == NULL) {
2040 /* malloc failed */
2041 ret = -1;
2042 goto error;
2043 }
2044
2045 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2046 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2047 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2048
2049 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2050 if (ret < 0) {
2051 goto error;
2052 }
2053
2054 error:
2055 return ret;
2056 }
2057
2058 /*
2059 * Enable on the tracer side a ust app event for the session and channel.
2060 *
2061 * Called with UST app session lock held.
2062 */
2063 static
2064 int enable_ust_app_event(struct ust_app_session *ua_sess,
2065 struct ust_app_event *ua_event, struct ust_app *app)
2066 {
2067 int ret;
2068
2069 ret = enable_ust_event(app, ua_sess, ua_event);
2070 if (ret < 0) {
2071 goto error;
2072 }
2073
2074 ua_event->enabled = 1;
2075
2076 error:
2077 return ret;
2078 }
2079
2080 /*
2081 * Disable on the tracer side a ust app event for the session and channel.
2082 */
2083 static int disable_ust_app_event(struct ust_app_session *ua_sess,
2084 struct ust_app_event *ua_event, struct ust_app *app)
2085 {
2086 int ret;
2087
2088 ret = disable_ust_event(app, ua_sess, ua_event);
2089 if (ret < 0) {
2090 goto error;
2091 }
2092
2093 ua_event->enabled = 0;
2094
2095 error:
2096 return ret;
2097 }
2098
2099 /*
2100 * Lookup ust app channel for session and disable it on the tracer side.
2101 */
2102 static
2103 int disable_ust_app_channel(struct ust_app_session *ua_sess,
2104 struct ust_app_channel *ua_chan, struct ust_app *app)
2105 {
2106 int ret;
2107
2108 ret = disable_ust_channel(app, ua_sess, ua_chan);
2109 if (ret < 0) {
2110 goto error;
2111 }
2112
2113 ua_chan->enabled = 0;
2114
2115 error:
2116 return ret;
2117 }
2118
2119 /*
2120 * Lookup ust app channel for session and enable it on the tracer side. This
2121 * MUST be called with a RCU read side lock acquired.
2122 */
2123 static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2124 struct ltt_ust_channel *uchan, struct ust_app *app)
2125 {
2126 int ret = 0;
2127 struct lttng_ht_iter iter;
2128 struct lttng_ht_node_str *ua_chan_node;
2129 struct ust_app_channel *ua_chan;
2130
2131 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2132 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2133 if (ua_chan_node == NULL) {
2134 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2135 uchan->name, ua_sess->tracing_id);
2136 goto error;
2137 }
2138
2139 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2140
2141 ret = enable_ust_channel(app, ua_sess, ua_chan);
2142 if (ret < 0) {
2143 goto error;
2144 }
2145
2146 error:
2147 return ret;
2148 }
2149
2150 /*
2151 * Ask the consumer to create a channel and get it if successful.
2152 *
2153 * Return 0 on success or else a negative value.
2154 */
2155 static int do_consumer_create_channel(struct ltt_ust_session *usess,
2156 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2157 int bitness, struct ust_registry_session *registry)
2158 {
2159 int ret;
2160 unsigned int nb_fd = 0;
2161 struct consumer_socket *socket;
2162
2163 assert(usess);
2164 assert(ua_sess);
2165 assert(ua_chan);
2166 assert(registry);
2167
2168 rcu_read_lock();
2169 health_code_update();
2170
2171 /* Get the right consumer socket for the application. */
2172 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2173 if (!socket) {
2174 ret = -EINVAL;
2175 goto error;
2176 }
2177
2178 health_code_update();
2179
2180 /* Need one fd for the channel. */
2181 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2182 if (ret < 0) {
2183 ERR("Exhausted number of available FD upon create channel");
2184 goto error;
2185 }
2186
2187 /*
2188 * Ask consumer to create channel. The consumer will return the number of
2189 * stream we have to expect.
2190 */
2191 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2192 registry);
2193 if (ret < 0) {
2194 goto error_ask;
2195 }
2196
2197 /*
2198 * Compute the number of fd needed before receiving them. It must be 2 per
2199 * stream (2 being the default value here).
2200 */
2201 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2202
2203 /* Reserve the amount of file descriptor we need. */
2204 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2205 if (ret < 0) {
2206 ERR("Exhausted number of available FD upon create channel");
2207 goto error_fd_get_stream;
2208 }
2209
2210 health_code_update();
2211
2212 /*
2213 * Now get the channel from the consumer. This call wil populate the stream
2214 * list of that channel and set the ust objects.
2215 */
2216 if (usess->consumer->enabled) {
2217 ret = ust_consumer_get_channel(socket, ua_chan);
2218 if (ret < 0) {
2219 goto error_destroy;
2220 }
2221 }
2222
2223 rcu_read_unlock();
2224 return 0;
2225
2226 error_destroy:
2227 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2228 error_fd_get_stream:
2229 /*
2230 * Initiate a destroy channel on the consumer since we had an error
2231 * handling it on our side. The return value is of no importance since we
2232 * already have a ret value set by the previous error that we need to
2233 * return.
2234 */
2235 (void) ust_consumer_destroy_channel(socket, ua_chan);
2236 error_ask:
2237 lttng_fd_put(LTTNG_FD_APPS, 1);
2238 error:
2239 health_code_update();
2240 rcu_read_unlock();
2241 return ret;
2242 }
2243
2244 /*
2245 * Duplicate the ust data object of the ust app stream and save it in the
2246 * buffer registry stream.
2247 *
2248 * Return 0 on success or else a negative value.
2249 */
2250 static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2251 struct ust_app_stream *stream)
2252 {
2253 int ret;
2254
2255 assert(reg_stream);
2256 assert(stream);
2257
2258 /* Reserve the amount of file descriptor we need. */
2259 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2260 if (ret < 0) {
2261 ERR("Exhausted number of available FD upon duplicate stream");
2262 goto error;
2263 }
2264
2265 /* Duplicate object for stream once the original is in the registry. */
2266 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2267 reg_stream->obj.ust);
2268 if (ret < 0) {
2269 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2270 reg_stream->obj.ust, stream->obj, ret);
2271 lttng_fd_put(LTTNG_FD_APPS, 2);
2272 goto error;
2273 }
2274 stream->handle = stream->obj->handle;
2275
2276 error:
2277 return ret;
2278 }
2279
2280 /*
2281 * Duplicate the ust data object of the ust app. channel and save it in the
2282 * buffer registry channel.
2283 *
2284 * Return 0 on success or else a negative value.
2285 */
2286 static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2287 struct ust_app_channel *ua_chan)
2288 {
2289 int ret;
2290
2291 assert(reg_chan);
2292 assert(ua_chan);
2293
2294 /* Need two fds for the channel. */
2295 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2296 if (ret < 0) {
2297 ERR("Exhausted number of available FD upon duplicate channel");
2298 goto error_fd_get;
2299 }
2300
2301 /* Duplicate object for stream once the original is in the registry. */
2302 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2303 if (ret < 0) {
2304 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2305 reg_chan->obj.ust, ua_chan->obj, ret);
2306 goto error;
2307 }
2308 ua_chan->handle = ua_chan->obj->handle;
2309
2310 return 0;
2311
2312 error:
2313 lttng_fd_put(LTTNG_FD_APPS, 1);
2314 error_fd_get:
2315 return ret;
2316 }
2317
2318 /*
2319 * For a given channel buffer registry, setup all streams of the given ust
2320 * application channel.
2321 *
2322 * Return 0 on success or else a negative value.
2323 */
2324 static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2325 struct ust_app_channel *ua_chan)
2326 {
2327 int ret = 0;
2328 struct ust_app_stream *stream, *stmp;
2329
2330 assert(reg_chan);
2331 assert(ua_chan);
2332
2333 DBG2("UST app setup buffer registry stream");
2334
2335 /* Send all streams to application. */
2336 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2337 struct buffer_reg_stream *reg_stream;
2338
2339 ret = buffer_reg_stream_create(&reg_stream);
2340 if (ret < 0) {
2341 goto error;
2342 }
2343
2344 /*
2345 * Keep original pointer and nullify it in the stream so the delete
2346 * stream call does not release the object.
2347 */
2348 reg_stream->obj.ust = stream->obj;
2349 stream->obj = NULL;
2350 buffer_reg_stream_add(reg_stream, reg_chan);
2351
2352 /* We don't need the streams anymore. */
2353 cds_list_del(&stream->list);
2354 delete_ust_app_stream(-1, stream);
2355 }
2356
2357 error:
2358 return ret;
2359 }
2360
2361 /*
2362 * Create a buffer registry channel for the given session registry and
2363 * application channel object. If regp pointer is valid, it's set with the
2364 * created object. Important, the created object is NOT added to the session
2365 * registry hash table.
2366 *
2367 * Return 0 on success else a negative value.
2368 */
2369 static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2370 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2371 {
2372 int ret;
2373 struct buffer_reg_channel *reg_chan = NULL;
2374
2375 assert(reg_sess);
2376 assert(ua_chan);
2377
2378 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2379
2380 /* Create buffer registry channel. */
2381 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2382 if (ret < 0) {
2383 goto error_create;
2384 }
2385 assert(reg_chan);
2386 reg_chan->consumer_key = ua_chan->key;
2387 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2388
2389 /* Create and add a channel registry to session. */
2390 ret = ust_registry_channel_add(reg_sess->reg.ust,
2391 ua_chan->tracing_channel_id);
2392 if (ret < 0) {
2393 goto error;
2394 }
2395 buffer_reg_channel_add(reg_sess, reg_chan);
2396
2397 if (regp) {
2398 *regp = reg_chan;
2399 }
2400
2401 return 0;
2402
2403 error:
2404 /* Safe because the registry channel object was not added to any HT. */
2405 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2406 error_create:
2407 return ret;
2408 }
2409
2410 /*
2411 * Setup buffer registry channel for the given session registry and application
2412 * channel object. If regp pointer is valid, it's set with the created object.
2413 *
2414 * Return 0 on success else a negative value.
2415 */
2416 static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2417 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan)
2418 {
2419 int ret;
2420
2421 assert(reg_sess);
2422 assert(reg_chan);
2423 assert(ua_chan);
2424 assert(ua_chan->obj);
2425
2426 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2427
2428 /* Setup all streams for the registry. */
2429 ret = setup_buffer_reg_streams(reg_chan, ua_chan);
2430 if (ret < 0) {
2431 goto error;
2432 }
2433
2434 reg_chan->obj.ust = ua_chan->obj;
2435 ua_chan->obj = NULL;
2436
2437 return 0;
2438
2439 error:
2440 buffer_reg_channel_remove(reg_sess, reg_chan);
2441 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2442 return ret;
2443 }
2444
2445 /*
2446 * Send buffer registry channel to the application.
2447 *
2448 * Return 0 on success else a negative value.
2449 */
2450 static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2451 struct ust_app *app, struct ust_app_session *ua_sess,
2452 struct ust_app_channel *ua_chan)
2453 {
2454 int ret;
2455 struct buffer_reg_stream *reg_stream;
2456
2457 assert(reg_chan);
2458 assert(app);
2459 assert(ua_sess);
2460 assert(ua_chan);
2461
2462 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2463
2464 ret = duplicate_channel_object(reg_chan, ua_chan);
2465 if (ret < 0) {
2466 goto error;
2467 }
2468
2469 /* Send channel to the application. */
2470 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2471 if (ret < 0) {
2472 goto error;
2473 }
2474
2475 health_code_update();
2476
2477 /* Send all streams to application. */
2478 pthread_mutex_lock(&reg_chan->stream_list_lock);
2479 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2480 struct ust_app_stream stream;
2481
2482 ret = duplicate_stream_object(reg_stream, &stream);
2483 if (ret < 0) {
2484 goto error_stream_unlock;
2485 }
2486
2487 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2488 if (ret < 0) {
2489 (void) release_ust_app_stream(-1, &stream);
2490 goto error_stream_unlock;
2491 }
2492
2493 /*
2494 * The return value is not important here. This function will output an
2495 * error if needed.
2496 */
2497 (void) release_ust_app_stream(-1, &stream);
2498 }
2499 ua_chan->is_sent = 1;
2500
2501 error_stream_unlock:
2502 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2503 error:
2504 return ret;
2505 }
2506
2507 /*
2508 * Create and send to the application the created buffers with per UID buffers.
2509 *
2510 * Return 0 on success else a negative value.
2511 */
2512 static int create_channel_per_uid(struct ust_app *app,
2513 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2514 struct ust_app_channel *ua_chan)
2515 {
2516 int ret;
2517 struct buffer_reg_uid *reg_uid;
2518 struct buffer_reg_channel *reg_chan;
2519
2520 assert(app);
2521 assert(usess);
2522 assert(ua_sess);
2523 assert(ua_chan);
2524
2525 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2526
2527 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2528 /*
2529 * The session creation handles the creation of this global registry
2530 * object. If none can be find, there is a code flow problem or a
2531 * teardown race.
2532 */
2533 assert(reg_uid);
2534
2535 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2536 reg_uid);
2537 if (!reg_chan) {
2538 /* Create the buffer registry channel object. */
2539 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2540 if (ret < 0) {
2541 ERR("Error creating the UST channel \"%s\" registry instance",
2542 ua_chan->name);
2543 goto error;
2544 }
2545 assert(reg_chan);
2546
2547 /*
2548 * Create the buffers on the consumer side. This call populates the
2549 * ust app channel object with all streams and data object.
2550 */
2551 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2552 app->bits_per_long, reg_uid->registry->reg.ust);
2553 if (ret < 0) {
2554 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2555 ua_chan->name);
2556
2557 /*
2558 * Let's remove the previously created buffer registry channel so
2559 * it's not visible anymore in the session registry.
2560 */
2561 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2562 ua_chan->tracing_channel_id);
2563 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2564 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2565 goto error;
2566 }
2567
2568 /*
2569 * Setup the streams and add it to the session registry.
2570 */
2571 ret = setup_buffer_reg_channel(reg_uid->registry, ua_chan, reg_chan);
2572 if (ret < 0) {
2573 ERR("Error setting up UST channel \"%s\"",
2574 ua_chan->name);
2575 goto error;
2576 }
2577
2578 }
2579
2580 /* Send buffers to the application. */
2581 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2582 if (ret < 0) {
2583 /*
2584 * Don't report error to the console, since it may be
2585 * caused by application concurrently exiting.
2586 */
2587 goto error;
2588 }
2589
2590 error:
2591 return ret;
2592 }
2593
2594 /*
2595 * Create and send to the application the created buffers with per PID buffers.
2596 *
2597 * Return 0 on success else a negative value.
2598 */
2599 static int create_channel_per_pid(struct ust_app *app,
2600 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2601 struct ust_app_channel *ua_chan)
2602 {
2603 int ret;
2604 struct ust_registry_session *registry;
2605
2606 assert(app);
2607 assert(usess);
2608 assert(ua_sess);
2609 assert(ua_chan);
2610
2611 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2612
2613 rcu_read_lock();
2614
2615 registry = get_session_registry(ua_sess);
2616 assert(registry);
2617
2618 /* Create and add a new channel registry to session. */
2619 ret = ust_registry_channel_add(registry, ua_chan->key);
2620 if (ret < 0) {
2621 ERR("Error creating the UST channel \"%s\" registry instance",
2622 ua_chan->name);
2623 goto error;
2624 }
2625
2626 /* Create and get channel on the consumer side. */
2627 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2628 app->bits_per_long, registry);
2629 if (ret < 0) {
2630 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2631 ua_chan->name);
2632 goto error;
2633 }
2634
2635 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2636 if (ret < 0) {
2637 /*
2638 * Don't report error to the console, since it may be
2639 * caused by application concurrently exiting.
2640 */
2641 goto error;
2642 }
2643
2644 error:
2645 rcu_read_unlock();
2646 return ret;
2647 }
2648
2649 /*
2650 * From an already allocated ust app channel, create the channel buffers if
2651 * need and send it to the application. This MUST be called with a RCU read
2652 * side lock acquired.
2653 *
2654 * Return 0 on success or else a negative value.
2655 */
2656 static int do_create_channel(struct ust_app *app,
2657 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2658 struct ust_app_channel *ua_chan)
2659 {
2660 int ret;
2661
2662 assert(app);
2663 assert(usess);
2664 assert(ua_sess);
2665 assert(ua_chan);
2666
2667 /* Handle buffer type before sending the channel to the application. */
2668 switch (usess->buffer_type) {
2669 case LTTNG_BUFFER_PER_UID:
2670 {
2671 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
2672 if (ret < 0) {
2673 goto error;
2674 }
2675 break;
2676 }
2677 case LTTNG_BUFFER_PER_PID:
2678 {
2679 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
2680 if (ret < 0) {
2681 goto error;
2682 }
2683 break;
2684 }
2685 default:
2686 assert(0);
2687 ret = -EINVAL;
2688 goto error;
2689 }
2690
2691 /* Initialize ust objd object using the received handle and add it. */
2692 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
2693 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
2694
2695 /* If channel is not enabled, disable it on the tracer */
2696 if (!ua_chan->enabled) {
2697 ret = disable_ust_channel(app, ua_sess, ua_chan);
2698 if (ret < 0) {
2699 goto error;
2700 }
2701 }
2702
2703 error:
2704 return ret;
2705 }
2706
2707 /*
2708 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2709 * newly created channel if not NULL.
2710 *
2711 * Called with UST app session lock and RCU read-side lock held.
2712 *
2713 * Return 0 on success or else a negative value.
2714 */
2715 static int create_ust_app_channel(struct ust_app_session *ua_sess,
2716 struct ltt_ust_channel *uchan, struct ust_app *app,
2717 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
2718 struct ust_app_channel **ua_chanp)
2719 {
2720 int ret = 0;
2721 struct lttng_ht_iter iter;
2722 struct lttng_ht_node_str *ua_chan_node;
2723 struct ust_app_channel *ua_chan;
2724
2725 /* Lookup channel in the ust app session */
2726 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2727 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2728 if (ua_chan_node != NULL) {
2729 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2730 goto end;
2731 }
2732
2733 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
2734 if (ua_chan == NULL) {
2735 /* Only malloc can fail here */
2736 ret = -ENOMEM;
2737 goto error_alloc;
2738 }
2739 shadow_copy_channel(ua_chan, uchan);
2740
2741 /* Set channel type. */
2742 ua_chan->attr.type = type;
2743
2744 ret = do_create_channel(app, usess, ua_sess, ua_chan);
2745 if (ret < 0) {
2746 goto error;
2747 }
2748
2749 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
2750 app->pid);
2751
2752 /* Only add the channel if successful on the tracer side. */
2753 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
2754
2755 end:
2756 if (ua_chanp) {
2757 *ua_chanp = ua_chan;
2758 }
2759
2760 /* Everything went well. */
2761 return 0;
2762
2763 error:
2764 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
2765 error_alloc:
2766 return ret;
2767 }
2768
2769 /*
2770 * Create UST app event and create it on the tracer side.
2771 *
2772 * Called with ust app session mutex held.
2773 */
2774 static
2775 int create_ust_app_event(struct ust_app_session *ua_sess,
2776 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
2777 struct ust_app *app)
2778 {
2779 int ret = 0;
2780 struct ust_app_event *ua_event;
2781
2782 /* Get event node */
2783 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
2784 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
2785 if (ua_event != NULL) {
2786 ret = -EEXIST;
2787 goto end;
2788 }
2789
2790 /* Does not exist so create one */
2791 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
2792 if (ua_event == NULL) {
2793 /* Only malloc can failed so something is really wrong */
2794 ret = -ENOMEM;
2795 goto end;
2796 }
2797 shadow_copy_event(ua_event, uevent);
2798
2799 /* Create it on the tracer side */
2800 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
2801 if (ret < 0) {
2802 /* Not found previously means that it does not exist on the tracer */
2803 assert(ret != -LTTNG_UST_ERR_EXIST);
2804 goto error;
2805 }
2806
2807 add_unique_ust_app_event(ua_chan, ua_event);
2808
2809 DBG2("UST app create event %s for PID %d completed", ua_event->name,
2810 app->pid);
2811
2812 end:
2813 return ret;
2814
2815 error:
2816 /* Valid. Calling here is already in a read side lock */
2817 delete_ust_app_event(-1, ua_event);
2818 return ret;
2819 }
2820
2821 /*
2822 * Create UST metadata and open it on the tracer side.
2823 *
2824 * Called with UST app session lock held and RCU read side lock.
2825 */
2826 static int create_ust_app_metadata(struct ust_app_session *ua_sess,
2827 struct ust_app *app, struct consumer_output *consumer)
2828 {
2829 int ret = 0;
2830 struct ust_app_channel *metadata;
2831 struct consumer_socket *socket;
2832 struct ust_registry_session *registry;
2833
2834 assert(ua_sess);
2835 assert(app);
2836 assert(consumer);
2837
2838 registry = get_session_registry(ua_sess);
2839 assert(registry);
2840
2841 /* Metadata already exists for this registry or it was closed previously */
2842 if (registry->metadata_key || registry->metadata_closed) {
2843 ret = 0;
2844 goto error;
2845 }
2846
2847 /* Allocate UST metadata */
2848 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
2849 if (!metadata) {
2850 /* malloc() failed */
2851 ret = -ENOMEM;
2852 goto error;
2853 }
2854
2855 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
2856
2857 /* Need one fd for the channel. */
2858 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2859 if (ret < 0) {
2860 ERR("Exhausted number of available FD upon create metadata");
2861 goto error;
2862 }
2863
2864 /* Get the right consumer socket for the application. */
2865 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
2866 if (!socket) {
2867 ret = -EINVAL;
2868 goto error_consumer;
2869 }
2870
2871 /*
2872 * Keep metadata key so we can identify it on the consumer side. Assign it
2873 * to the registry *before* we ask the consumer so we avoid the race of the
2874 * consumer requesting the metadata and the ask_channel call on our side
2875 * did not returned yet.
2876 */
2877 registry->metadata_key = metadata->key;
2878
2879 /*
2880 * Ask the metadata channel creation to the consumer. The metadata object
2881 * will be created by the consumer and kept their. However, the stream is
2882 * never added or monitored until we do a first push metadata to the
2883 * consumer.
2884 */
2885 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
2886 registry);
2887 if (ret < 0) {
2888 /* Nullify the metadata key so we don't try to close it later on. */
2889 registry->metadata_key = 0;
2890 goto error_consumer;
2891 }
2892
2893 /*
2894 * The setup command will make the metadata stream be sent to the relayd,
2895 * if applicable, and the thread managing the metadatas. This is important
2896 * because after this point, if an error occurs, the only way the stream
2897 * can be deleted is to be monitored in the consumer.
2898 */
2899 ret = consumer_setup_metadata(socket, metadata->key);
2900 if (ret < 0) {
2901 /* Nullify the metadata key so we don't try to close it later on. */
2902 registry->metadata_key = 0;
2903 goto error_consumer;
2904 }
2905
2906 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
2907 metadata->key, app->pid);
2908
2909 error_consumer:
2910 lttng_fd_put(LTTNG_FD_APPS, 1);
2911 delete_ust_app_channel(-1, metadata, app);
2912 error:
2913 return ret;
2914 }
2915
2916 /*
2917 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2918 * acquired before calling this function.
2919 */
2920 struct ust_app *ust_app_find_by_pid(pid_t pid)
2921 {
2922 struct ust_app *app = NULL;
2923 struct lttng_ht_node_ulong *node;
2924 struct lttng_ht_iter iter;
2925
2926 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
2927 node = lttng_ht_iter_get_node_ulong(&iter);
2928 if (node == NULL) {
2929 DBG2("UST app no found with pid %d", pid);
2930 goto error;
2931 }
2932
2933 DBG2("Found UST app by pid %d", pid);
2934
2935 app = caa_container_of(node, struct ust_app, pid_n);
2936
2937 error:
2938 return app;
2939 }
2940
2941 /*
2942 * Allocate and init an UST app object using the registration information and
2943 * the command socket. This is called when the command socket connects to the
2944 * session daemon.
2945 *
2946 * The object is returned on success or else NULL.
2947 */
2948 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
2949 {
2950 struct ust_app *lta = NULL;
2951
2952 assert(msg);
2953 assert(sock >= 0);
2954
2955 DBG3("UST app creating application for socket %d", sock);
2956
2957 if ((msg->bits_per_long == 64 &&
2958 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
2959 || (msg->bits_per_long == 32 &&
2960 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
2961 ERR("Registration failed: application \"%s\" (pid: %d) has "
2962 "%d-bit long, but no consumerd for this size is available.\n",
2963 msg->name, msg->pid, msg->bits_per_long);
2964 goto error;
2965 }
2966
2967 lta = zmalloc(sizeof(struct ust_app));
2968 if (lta == NULL) {
2969 PERROR("malloc");
2970 goto error;
2971 }
2972
2973 lta->ppid = msg->ppid;
2974 lta->uid = msg->uid;
2975 lta->gid = msg->gid;
2976
2977 lta->bits_per_long = msg->bits_per_long;
2978 lta->uint8_t_alignment = msg->uint8_t_alignment;
2979 lta->uint16_t_alignment = msg->uint16_t_alignment;
2980 lta->uint32_t_alignment = msg->uint32_t_alignment;
2981 lta->uint64_t_alignment = msg->uint64_t_alignment;
2982 lta->long_alignment = msg->long_alignment;
2983 lta->byte_order = msg->byte_order;
2984
2985 lta->v_major = msg->major;
2986 lta->v_minor = msg->minor;
2987 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2988 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
2989 lta->notify_sock = -1;
2990
2991 /* Copy name and make sure it's NULL terminated. */
2992 strncpy(lta->name, msg->name, sizeof(lta->name));
2993 lta->name[UST_APP_PROCNAME_LEN] = '\0';
2994
2995 /*
2996 * Before this can be called, when receiving the registration information,
2997 * the application compatibility is checked. So, at this point, the
2998 * application can work with this session daemon.
2999 */
3000 lta->compatible = 1;
3001
3002 lta->pid = msg->pid;
3003 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3004 lta->sock = sock;
3005 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3006
3007 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3008
3009 error:
3010 return lta;
3011 }
3012
3013 /*
3014 * For a given application object, add it to every hash table.
3015 */
3016 void ust_app_add(struct ust_app *app)
3017 {
3018 assert(app);
3019 assert(app->notify_sock >= 0);
3020
3021 rcu_read_lock();
3022
3023 /*
3024 * On a re-registration, we want to kick out the previous registration of
3025 * that pid
3026 */
3027 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3028
3029 /*
3030 * The socket _should_ be unique until _we_ call close. So, a add_unique
3031 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3032 * already in the table.
3033 */
3034 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3035
3036 /* Add application to the notify socket hash table. */
3037 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3038 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3039
3040 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3041 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3042 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3043 app->v_minor);
3044
3045 rcu_read_unlock();
3046 }
3047
3048 /*
3049 * Set the application version into the object.
3050 *
3051 * Return 0 on success else a negative value either an errno code or a
3052 * LTTng-UST error code.
3053 */
3054 int ust_app_version(struct ust_app *app)
3055 {
3056 int ret;
3057
3058 assert(app);
3059
3060 ret = ustctl_tracer_version(app->sock, &app->version);
3061 if (ret < 0) {
3062 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3063 ERR("UST app %d version failed with ret %d", app->sock, ret);
3064 } else {
3065 DBG3("UST app %d version failed. Application is dead", app->sock);
3066 }
3067 }
3068
3069 return ret;
3070 }
3071
3072 /*
3073 * Unregister app by removing it from the global traceable app list and freeing
3074 * the data struct.
3075 *
3076 * The socket is already closed at this point so no close to sock.
3077 */
3078 void ust_app_unregister(int sock)
3079 {
3080 struct ust_app *lta;
3081 struct lttng_ht_node_ulong *node;
3082 struct lttng_ht_iter iter;
3083 struct ust_app_session *ua_sess;
3084 int ret;
3085
3086 rcu_read_lock();
3087
3088 /* Get the node reference for a call_rcu */
3089 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
3090 node = lttng_ht_iter_get_node_ulong(&iter);
3091 assert(node);
3092
3093 lta = caa_container_of(node, struct ust_app, sock_n);
3094 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3095
3096 /* Remove application from PID hash table */
3097 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3098 assert(!ret);
3099
3100 /*
3101 * Remove application from notify hash table. The thread handling the
3102 * notify socket could have deleted the node so ignore on error because
3103 * either way it's valid. The close of that socket is handled by the other
3104 * thread.
3105 */
3106 iter.iter.node = &lta->notify_sock_n.node;
3107 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3108
3109 /*
3110 * Ignore return value since the node might have been removed before by an
3111 * add replace during app registration because the PID can be reassigned by
3112 * the OS.
3113 */
3114 iter.iter.node = &lta->pid_n.node;
3115 ret = lttng_ht_del(ust_app_ht, &iter);
3116 if (ret) {
3117 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3118 lta->pid);
3119 }
3120
3121 /* Remove sessions so they are not visible during deletion.*/
3122 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3123 node.node) {
3124 struct ust_registry_session *registry;
3125
3126 ret = lttng_ht_del(lta->sessions, &iter);
3127 if (ret) {
3128 /* The session was already removed so scheduled for teardown. */
3129 continue;
3130 }
3131
3132 /*
3133 * Add session to list for teardown. This is safe since at this point we
3134 * are the only one using this list.
3135 */
3136 pthread_mutex_lock(&ua_sess->lock);
3137
3138 /*
3139 * Normally, this is done in the delete session process which is
3140 * executed in the call rcu below. However, upon registration we can't
3141 * afford to wait for the grace period before pushing data or else the
3142 * data pending feature can race between the unregistration and stop
3143 * command where the data pending command is sent *before* the grace
3144 * period ended.
3145 *
3146 * The close metadata below nullifies the metadata pointer in the
3147 * session so the delete session will NOT push/close a second time.
3148 */
3149 registry = get_session_registry(ua_sess);
3150 if (registry && !registry->metadata_closed) {
3151 /* Push metadata for application before freeing the application. */
3152 (void) push_metadata(registry, ua_sess->consumer);
3153
3154 /*
3155 * Don't ask to close metadata for global per UID buffers. Close
3156 * metadata only on destroy trace session in this case. Also, the
3157 * previous push metadata could have flag the metadata registry to
3158 * close so don't send a close command if closed.
3159 */
3160 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
3161 !registry->metadata_closed) {
3162 /* And ask to close it for this session registry. */
3163 (void) close_metadata(registry, ua_sess->consumer);
3164 }
3165 }
3166
3167 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3168 pthread_mutex_unlock(&ua_sess->lock);
3169 }
3170
3171 /* Free memory */
3172 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3173
3174 rcu_read_unlock();
3175 return;
3176 }
3177
3178 /*
3179 * Fill events array with all events name of all registered apps.
3180 */
3181 int ust_app_list_events(struct lttng_event **events)
3182 {
3183 int ret, handle;
3184 size_t nbmem, count = 0;
3185 struct lttng_ht_iter iter;
3186 struct ust_app *app;
3187 struct lttng_event *tmp_event;
3188
3189 nbmem = UST_APP_EVENT_LIST_SIZE;
3190 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3191 if (tmp_event == NULL) {
3192 PERROR("zmalloc ust app events");
3193 ret = -ENOMEM;
3194 goto error;
3195 }
3196
3197 rcu_read_lock();
3198
3199 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3200 struct lttng_ust_tracepoint_iter uiter;
3201
3202 health_code_update();
3203
3204 if (!app->compatible) {
3205 /*
3206 * TODO: In time, we should notice the caller of this error by
3207 * telling him that this is a version error.
3208 */
3209 continue;
3210 }
3211 handle = ustctl_tracepoint_list(app->sock);
3212 if (handle < 0) {
3213 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3214 ERR("UST app list events getting handle failed for app pid %d",
3215 app->pid);
3216 }
3217 continue;
3218 }
3219
3220 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3221 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3222 /* Handle ustctl error. */
3223 if (ret < 0) {
3224 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3225 ERR("UST app tp list get failed for app %d with ret %d",
3226 app->sock, ret);
3227 } else {
3228 DBG3("UST app tp list get failed. Application is dead");
3229 /*
3230 * This is normal behavior, an application can die during the
3231 * creation process. Don't report an error so the execution can
3232 * continue normally. Continue normal execution.
3233 */
3234 break;
3235 }
3236 free(tmp_event);
3237 goto rcu_error;
3238 }
3239
3240 health_code_update();
3241 if (count >= nbmem) {
3242 /* In case the realloc fails, we free the memory */
3243 struct lttng_event *new_tmp_event;
3244 size_t new_nbmem;
3245
3246 new_nbmem = nbmem << 1;
3247 DBG2("Reallocating event list from %zu to %zu entries",