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