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