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[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
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1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19#define _LGPL_SOURCE
20#include <errno.h>
21#include <inttypes.h>
22#include <pthread.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26#include <sys/stat.h>
27#include <sys/types.h>
28#include <unistd.h>
29#include <urcu/compiler.h>
30#include <lttng/ust-error.h>
31#include <signal.h>
32
33#include <common/common.h>
34#include <common/sessiond-comm/sessiond-comm.h>
35
36#include "buffer-registry.h"
37#include "fd-limit.h"
38#include "health-sessiond.h"
39#include "ust-app.h"
40#include "ust-consumer.h"
41#include "ust-ctl.h"
42#include "utils.h"
43#include "session.h"
44#include "lttng-sessiond.h"
45#include "notification-thread-commands.h"
46#include "rotate.h"
47
48static
49int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
50
51/* Next available channel key. Access under next_channel_key_lock. */
52static uint64_t _next_channel_key;
53static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
54
55/* Next available session ID. Access under next_session_id_lock. */
56static uint64_t _next_session_id;
57static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
58
59/*
60 * Return the incremented value of next_channel_key.
61 */
62static uint64_t get_next_channel_key(void)
63{
64 uint64_t ret;
65
66 pthread_mutex_lock(&next_channel_key_lock);
67 ret = ++_next_channel_key;
68 pthread_mutex_unlock(&next_channel_key_lock);
69 return ret;
70}
71
72/*
73 * Return the atomically incremented value of next_session_id.
74 */
75static uint64_t get_next_session_id(void)
76{
77 uint64_t ret;
78
79 pthread_mutex_lock(&next_session_id_lock);
80 ret = ++_next_session_id;
81 pthread_mutex_unlock(&next_session_id_lock);
82 return ret;
83}
84
85static void copy_channel_attr_to_ustctl(
86 struct ustctl_consumer_channel_attr *attr,
87 struct lttng_ust_channel_attr *uattr)
88{
89 /* Copy event attributes since the layout is different. */
90 attr->subbuf_size = uattr->subbuf_size;
91 attr->num_subbuf = uattr->num_subbuf;
92 attr->overwrite = uattr->overwrite;
93 attr->switch_timer_interval = uattr->switch_timer_interval;
94 attr->read_timer_interval = uattr->read_timer_interval;
95 attr->output = uattr->output;
96 attr->blocking_timeout = uattr->u.s.blocking_timeout;
97}
98
99/*
100 * Match function for the hash table lookup.
101 *
102 * It matches an ust app event based on three attributes which are the event
103 * name, the filter bytecode and the loglevel.
104 */
105static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
106{
107 struct ust_app_event *event;
108 const struct ust_app_ht_key *key;
109 int ev_loglevel_value;
110
111 assert(node);
112 assert(_key);
113
114 event = caa_container_of(node, struct ust_app_event, node.node);
115 key = _key;
116 ev_loglevel_value = event->attr.loglevel;
117
118 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
119
120 /* Event name */
121 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
122 goto no_match;
123 }
124
125 /* Event loglevel. */
126 if (ev_loglevel_value != key->loglevel_type) {
127 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
128 && key->loglevel_type == 0 &&
129 ev_loglevel_value == -1) {
130 /*
131 * Match is accepted. This is because on event creation, the
132 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
133 * -1 are accepted for this loglevel type since 0 is the one set by
134 * the API when receiving an enable event.
135 */
136 } else {
137 goto no_match;
138 }
139 }
140
141 /* One of the filters is NULL, fail. */
142 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
143 goto no_match;
144 }
145
146 if (key->filter && event->filter) {
147 /* Both filters exists, check length followed by the bytecode. */
148 if (event->filter->len != key->filter->len ||
149 memcmp(event->filter->data, key->filter->data,
150 event->filter->len) != 0) {
151 goto no_match;
152 }
153 }
154
155 /* One of the exclusions is NULL, fail. */
156 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
157 goto no_match;
158 }
159
160 if (key->exclusion && event->exclusion) {
161 /* Both exclusions exists, check count followed by the names. */
162 if (event->exclusion->count != key->exclusion->count ||
163 memcmp(event->exclusion->names, key->exclusion->names,
164 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
165 goto no_match;
166 }
167 }
168
169
170 /* Match. */
171 return 1;
172
173no_match:
174 return 0;
175}
176
177/*
178 * Unique add of an ust app event in the given ht. This uses the custom
179 * ht_match_ust_app_event match function and the event name as hash.
180 */
181static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
182 struct ust_app_event *event)
183{
184 struct cds_lfht_node *node_ptr;
185 struct ust_app_ht_key key;
186 struct lttng_ht *ht;
187
188 assert(ua_chan);
189 assert(ua_chan->events);
190 assert(event);
191
192 ht = ua_chan->events;
193 key.name = event->attr.name;
194 key.filter = event->filter;
195 key.loglevel_type = event->attr.loglevel;
196 key.exclusion = event->exclusion;
197
198 node_ptr = cds_lfht_add_unique(ht->ht,
199 ht->hash_fct(event->node.key, lttng_ht_seed),
200 ht_match_ust_app_event, &key, &event->node.node);
201 assert(node_ptr == &event->node.node);
202}
203
204/*
205 * Close the notify socket from the given RCU head object. This MUST be called
206 * through a call_rcu().
207 */
208static void close_notify_sock_rcu(struct rcu_head *head)
209{
210 int ret;
211 struct ust_app_notify_sock_obj *obj =
212 caa_container_of(head, struct ust_app_notify_sock_obj, head);
213
214 /* Must have a valid fd here. */
215 assert(obj->fd >= 0);
216
217 ret = close(obj->fd);
218 if (ret) {
219 ERR("close notify sock %d RCU", obj->fd);
220 }
221 lttng_fd_put(LTTNG_FD_APPS, 1);
222
223 free(obj);
224}
225
226/*
227 * Return the session registry according to the buffer type of the given
228 * session.
229 *
230 * A registry per UID object MUST exists before calling this function or else
231 * it assert() if not found. RCU read side lock must be acquired.
232 */
233static struct ust_registry_session *get_session_registry(
234 struct ust_app_session *ua_sess)
235{
236 struct ust_registry_session *registry = NULL;
237
238 assert(ua_sess);
239
240 switch (ua_sess->buffer_type) {
241 case LTTNG_BUFFER_PER_PID:
242 {
243 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
244 if (!reg_pid) {
245 goto error;
246 }
247 registry = reg_pid->registry->reg.ust;
248 break;
249 }
250 case LTTNG_BUFFER_PER_UID:
251 {
252 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
253 ua_sess->tracing_id, ua_sess->bits_per_long,
254 ua_sess->real_credentials.uid);
255 if (!reg_uid) {
256 goto error;
257 }
258 registry = reg_uid->registry->reg.ust;
259 break;
260 }
261 default:
262 assert(0);
263 };
264
265error:
266 return registry;
267}
268
269/*
270 * Delete ust context safely. RCU read lock must be held before calling
271 * this function.
272 */
273static
274void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
275 struct ust_app *app)
276{
277 int ret;
278
279 assert(ua_ctx);
280
281 if (ua_ctx->obj) {
282 pthread_mutex_lock(&app->sock_lock);
283 ret = ustctl_release_object(sock, ua_ctx->obj);
284 pthread_mutex_unlock(&app->sock_lock);
285 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
286 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
287 sock, ua_ctx->obj->handle, ret);
288 }
289 free(ua_ctx->obj);
290 }
291 free(ua_ctx);
292}
293
294/*
295 * Delete ust app event safely. RCU read lock must be held before calling
296 * this function.
297 */
298static
299void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
300 struct ust_app *app)
301{
302 int ret;
303
304 assert(ua_event);
305
306 free(ua_event->filter);
307 if (ua_event->exclusion != NULL)
308 free(ua_event->exclusion);
309 if (ua_event->obj != NULL) {
310 pthread_mutex_lock(&app->sock_lock);
311 ret = ustctl_release_object(sock, ua_event->obj);
312 pthread_mutex_unlock(&app->sock_lock);
313 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
314 ERR("UST app sock %d release event obj failed with ret %d",
315 sock, ret);
316 }
317 free(ua_event->obj);
318 }
319 free(ua_event);
320}
321
322/*
323 * Release ust data object of the given stream.
324 *
325 * Return 0 on success or else a negative value.
326 */
327static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
328 struct ust_app *app)
329{
330 int ret = 0;
331
332 assert(stream);
333
334 if (stream->obj) {
335 pthread_mutex_lock(&app->sock_lock);
336 ret = ustctl_release_object(sock, stream->obj);
337 pthread_mutex_unlock(&app->sock_lock);
338 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
339 ERR("UST app sock %d release stream obj failed with ret %d",
340 sock, ret);
341 }
342 lttng_fd_put(LTTNG_FD_APPS, 2);
343 free(stream->obj);
344 }
345
346 return ret;
347}
348
349/*
350 * Delete ust app stream safely. RCU read lock must be held before calling
351 * this function.
352 */
353static
354void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
355 struct ust_app *app)
356{
357 assert(stream);
358
359 (void) release_ust_app_stream(sock, stream, app);
360 free(stream);
361}
362
363/*
364 * We need to execute ht_destroy outside of RCU read-side critical
365 * section and outside of call_rcu thread, so we postpone its execution
366 * using ht_cleanup_push. It is simpler than to change the semantic of
367 * the many callers of delete_ust_app_session().
368 */
369static
370void delete_ust_app_channel_rcu(struct rcu_head *head)
371{
372 struct ust_app_channel *ua_chan =
373 caa_container_of(head, struct ust_app_channel, rcu_head);
374
375 ht_cleanup_push(ua_chan->ctx);
376 ht_cleanup_push(ua_chan->events);
377 free(ua_chan);
378}
379
380/*
381 * Extract the lost packet or discarded events counter when the channel is
382 * being deleted and store the value in the parent channel so we can
383 * access it from lttng list and at stop/destroy.
384 *
385 * The session list lock must be held by the caller.
386 */
387static
388void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
389{
390 uint64_t discarded = 0, lost = 0;
391 struct ltt_session *session;
392 struct ltt_ust_channel *uchan;
393
394 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
395 return;
396 }
397
398 rcu_read_lock();
399 session = session_find_by_id(ua_chan->session->tracing_id);
400 if (!session || !session->ust_session) {
401 /*
402 * Not finding the session is not an error because there are
403 * multiple ways the channels can be torn down.
404 *
405 * 1) The session daemon can initiate the destruction of the
406 * ust app session after receiving a destroy command or
407 * during its shutdown/teardown.
408 * 2) The application, since we are in per-pid tracing, is
409 * unregistering and tearing down its ust app session.
410 *
411 * Both paths are protected by the session list lock which
412 * ensures that the accounting of lost packets and discarded
413 * events is done exactly once. The session is then unpublished
414 * from the session list, resulting in this condition.
415 */
416 goto end;
417 }
418
419 if (ua_chan->attr.overwrite) {
420 consumer_get_lost_packets(ua_chan->session->tracing_id,
421 ua_chan->key, session->ust_session->consumer,
422 &lost);
423 } else {
424 consumer_get_discarded_events(ua_chan->session->tracing_id,
425 ua_chan->key, session->ust_session->consumer,
426 &discarded);
427 }
428 uchan = trace_ust_find_channel_by_name(
429 session->ust_session->domain_global.channels,
430 ua_chan->name);
431 if (!uchan) {
432 ERR("Missing UST channel to store discarded counters");
433 goto end;
434 }
435
436 uchan->per_pid_closed_app_discarded += discarded;
437 uchan->per_pid_closed_app_lost += lost;
438
439end:
440 rcu_read_unlock();
441 if (session) {
442 session_put(session);
443 }
444}
445
446/*
447 * Delete ust app channel safely. RCU read lock must be held before calling
448 * this function.
449 *
450 * The session list lock must be held by the caller.
451 */
452static
453void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
454 struct ust_app *app)
455{
456 int ret;
457 struct lttng_ht_iter iter;
458 struct ust_app_event *ua_event;
459 struct ust_app_ctx *ua_ctx;
460 struct ust_app_stream *stream, *stmp;
461 struct ust_registry_session *registry;
462
463 assert(ua_chan);
464
465 DBG3("UST app deleting channel %s", ua_chan->name);
466
467 /* Wipe stream */
468 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
469 cds_list_del(&stream->list);
470 delete_ust_app_stream(sock, stream, app);
471 }
472
473 /* Wipe context */
474 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
475 cds_list_del(&ua_ctx->list);
476 ret = lttng_ht_del(ua_chan->ctx, &iter);
477 assert(!ret);
478 delete_ust_app_ctx(sock, ua_ctx, app);
479 }
480
481 /* Wipe events */
482 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
483 node.node) {
484 ret = lttng_ht_del(ua_chan->events, &iter);
485 assert(!ret);
486 delete_ust_app_event(sock, ua_event, app);
487 }
488
489 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
490 /* Wipe and free registry from session registry. */
491 registry = get_session_registry(ua_chan->session);
492 if (registry) {
493 ust_registry_channel_del_free(registry, ua_chan->key,
494 sock >= 0);
495 }
496 /*
497 * A negative socket can be used by the caller when
498 * cleaning-up a ua_chan in an error path. Skip the
499 * accounting in this case.
500 */
501 if (sock >= 0) {
502 save_per_pid_lost_discarded_counters(ua_chan);
503 }
504 }
505
506 if (ua_chan->obj != NULL) {
507 /* Remove channel from application UST object descriptor. */
508 iter.iter.node = &ua_chan->ust_objd_node.node;
509 ret = lttng_ht_del(app->ust_objd, &iter);
510 assert(!ret);
511 pthread_mutex_lock(&app->sock_lock);
512 ret = ustctl_release_object(sock, ua_chan->obj);
513 pthread_mutex_unlock(&app->sock_lock);
514 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
515 ERR("UST app sock %d release channel obj failed with ret %d",
516 sock, ret);
517 }
518 lttng_fd_put(LTTNG_FD_APPS, 1);
519 free(ua_chan->obj);
520 }
521 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
522}
523
524int ust_app_register_done(struct ust_app *app)
525{
526 int ret;
527
528 pthread_mutex_lock(&app->sock_lock);
529 ret = ustctl_register_done(app->sock);
530 pthread_mutex_unlock(&app->sock_lock);
531 return ret;
532}
533
534int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
535{
536 int ret, sock;
537
538 if (app) {
539 pthread_mutex_lock(&app->sock_lock);
540 sock = app->sock;
541 } else {
542 sock = -1;
543 }
544 ret = ustctl_release_object(sock, data);
545 if (app) {
546 pthread_mutex_unlock(&app->sock_lock);
547 }
548 return ret;
549}
550
551/*
552 * Push metadata to consumer socket.
553 *
554 * RCU read-side lock must be held to guarantee existance of socket.
555 * Must be called with the ust app session lock held.
556 * Must be called with the registry lock held.
557 *
558 * On success, return the len of metadata pushed or else a negative value.
559 * Returning a -EPIPE return value means we could not send the metadata,
560 * but it can be caused by recoverable errors (e.g. the application has
561 * terminated concurrently).
562 */
563ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
564 struct consumer_socket *socket, int send_zero_data)
565{
566 int ret;
567 char *metadata_str = NULL;
568 size_t len, offset, new_metadata_len_sent;
569 ssize_t ret_val;
570 uint64_t metadata_key, metadata_version;
571
572 assert(registry);
573 assert(socket);
574
575 metadata_key = registry->metadata_key;
576
577 /*
578 * Means that no metadata was assigned to the session. This can
579 * happens if no start has been done previously.
580 */
581 if (!metadata_key) {
582 return 0;
583 }
584
585 offset = registry->metadata_len_sent;
586 len = registry->metadata_len - registry->metadata_len_sent;
587 new_metadata_len_sent = registry->metadata_len;
588 metadata_version = registry->metadata_version;
589 if (len == 0) {
590 DBG3("No metadata to push for metadata key %" PRIu64,
591 registry->metadata_key);
592 ret_val = len;
593 if (send_zero_data) {
594 DBG("No metadata to push");
595 goto push_data;
596 }
597 goto end;
598 }
599
600 /* Allocate only what we have to send. */
601 metadata_str = zmalloc(len);
602 if (!metadata_str) {
603 PERROR("zmalloc ust app metadata string");
604 ret_val = -ENOMEM;
605 goto error;
606 }
607 /* Copy what we haven't sent out. */
608 memcpy(metadata_str, registry->metadata + offset, len);
609
610push_data:
611 pthread_mutex_unlock(&registry->lock);
612 /*
613 * We need to unlock the registry while we push metadata to
614 * break a circular dependency between the consumerd metadata
615 * lock and the sessiond registry lock. Indeed, pushing metadata
616 * to the consumerd awaits that it gets pushed all the way to
617 * relayd, but doing so requires grabbing the metadata lock. If
618 * a concurrent metadata request is being performed by
619 * consumerd, this can try to grab the registry lock on the
620 * sessiond while holding the metadata lock on the consumer
621 * daemon. Those push and pull schemes are performed on two
622 * different bidirectionnal communication sockets.
623 */
624 ret = consumer_push_metadata(socket, metadata_key,
625 metadata_str, len, offset, metadata_version);
626 pthread_mutex_lock(&registry->lock);
627 if (ret < 0) {
628 /*
629 * There is an acceptable race here between the registry
630 * metadata key assignment and the creation on the
631 * consumer. The session daemon can concurrently push
632 * metadata for this registry while being created on the
633 * consumer since the metadata key of the registry is
634 * assigned *before* it is setup to avoid the consumer
635 * to ask for metadata that could possibly be not found
636 * in the session daemon.
637 *
638 * The metadata will get pushed either by the session
639 * being stopped or the consumer requesting metadata if
640 * that race is triggered.
641 */
642 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
643 ret = 0;
644 } else {
645 ERR("Error pushing metadata to consumer");
646 }
647 ret_val = ret;
648 goto error_push;
649 } else {
650 /*
651 * Metadata may have been concurrently pushed, since
652 * we're not holding the registry lock while pushing to
653 * consumer. This is handled by the fact that we send
654 * the metadata content, size, and the offset at which
655 * that metadata belongs. This may arrive out of order
656 * on the consumer side, and the consumer is able to
657 * deal with overlapping fragments. The consumer
658 * supports overlapping fragments, which must be
659 * contiguous starting from offset 0. We keep the
660 * largest metadata_len_sent value of the concurrent
661 * send.
662 */
663 registry->metadata_len_sent =
664 max_t(size_t, registry->metadata_len_sent,
665 new_metadata_len_sent);
666 }
667 free(metadata_str);
668 return len;
669
670end:
671error:
672 if (ret_val) {
673 /*
674 * On error, flag the registry that the metadata is
675 * closed. We were unable to push anything and this
676 * means that either the consumer is not responding or
677 * the metadata cache has been destroyed on the
678 * consumer.
679 */
680 registry->metadata_closed = 1;
681 }
682error_push:
683 free(metadata_str);
684 return ret_val;
685}
686
687/*
688 * For a given application and session, push metadata to consumer.
689 * Either sock or consumer is required : if sock is NULL, the default
690 * socket to send the metadata is retrieved from consumer, if sock
691 * is not NULL we use it to send the metadata.
692 * RCU read-side lock must be held while calling this function,
693 * therefore ensuring existance of registry. It also ensures existance
694 * of socket throughout this function.
695 *
696 * Return 0 on success else a negative error.
697 * Returning a -EPIPE return value means we could not send the metadata,
698 * but it can be caused by recoverable errors (e.g. the application has
699 * terminated concurrently).
700 */
701static int push_metadata(struct ust_registry_session *registry,
702 struct consumer_output *consumer)
703{
704 int ret_val;
705 ssize_t ret;
706 struct consumer_socket *socket;
707
708 assert(registry);
709 assert(consumer);
710
711 pthread_mutex_lock(&registry->lock);
712 if (registry->metadata_closed) {
713 ret_val = -EPIPE;
714 goto error;
715 }
716
717 /* Get consumer socket to use to push the metadata.*/
718 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
719 consumer);
720 if (!socket) {
721 ret_val = -1;
722 goto error;
723 }
724
725 ret = ust_app_push_metadata(registry, socket, 0);
726 if (ret < 0) {
727 ret_val = ret;
728 goto error;
729 }
730 pthread_mutex_unlock(&registry->lock);
731 return 0;
732
733error:
734 pthread_mutex_unlock(&registry->lock);
735 return ret_val;
736}
737
738/*
739 * Send to the consumer a close metadata command for the given session. Once
740 * done, the metadata channel is deleted and the session metadata pointer is
741 * nullified. The session lock MUST be held unless the application is
742 * in the destroy path.
743 *
744 * Return 0 on success else a negative value.
745 */
746static int close_metadata(struct ust_registry_session *registry,
747 struct consumer_output *consumer)
748{
749 int ret;
750 struct consumer_socket *socket;
751
752 assert(registry);
753 assert(consumer);
754
755 rcu_read_lock();
756
757 pthread_mutex_lock(&registry->lock);
758
759 if (!registry->metadata_key || registry->metadata_closed) {
760 ret = 0;
761 goto end;
762 }
763
764 /* Get consumer socket to use to push the metadata.*/
765 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
766 consumer);
767 if (!socket) {
768 ret = -1;
769 goto error;
770 }
771
772 ret = consumer_close_metadata(socket, registry->metadata_key);
773 if (ret < 0) {
774 goto error;
775 }
776
777error:
778 /*
779 * Metadata closed. Even on error this means that the consumer is not
780 * responding or not found so either way a second close should NOT be emit
781 * for this registry.
782 */
783 registry->metadata_closed = 1;
784end:
785 pthread_mutex_unlock(&registry->lock);
786 rcu_read_unlock();
787 return ret;
788}
789
790/*
791 * We need to execute ht_destroy outside of RCU read-side critical
792 * section and outside of call_rcu thread, so we postpone its execution
793 * using ht_cleanup_push. It is simpler than to change the semantic of
794 * the many callers of delete_ust_app_session().
795 */
796static
797void delete_ust_app_session_rcu(struct rcu_head *head)
798{
799 struct ust_app_session *ua_sess =
800 caa_container_of(head, struct ust_app_session, rcu_head);
801
802 ht_cleanup_push(ua_sess->channels);
803 free(ua_sess);
804}
805
806/*
807 * Delete ust app session safely. RCU read lock must be held before calling
808 * this function.
809 *
810 * The session list lock must be held by the caller.
811 */
812static
813void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
814 struct ust_app *app)
815{
816 int ret;
817 struct lttng_ht_iter iter;
818 struct ust_app_channel *ua_chan;
819 struct ust_registry_session *registry;
820
821 assert(ua_sess);
822
823 pthread_mutex_lock(&ua_sess->lock);
824
825 assert(!ua_sess->deleted);
826 ua_sess->deleted = true;
827
828 registry = get_session_registry(ua_sess);
829 /* Registry can be null on error path during initialization. */
830 if (registry) {
831 /* Push metadata for application before freeing the application. */
832 (void) push_metadata(registry, ua_sess->consumer);
833
834 /*
835 * Don't ask to close metadata for global per UID buffers. Close
836 * metadata only on destroy trace session in this case. Also, the
837 * previous push metadata could have flag the metadata registry to
838 * close so don't send a close command if closed.
839 */
840 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
841 /* And ask to close it for this session registry. */
842 (void) close_metadata(registry, ua_sess->consumer);
843 }
844 }
845
846 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
847 node.node) {
848 ret = lttng_ht_del(ua_sess->channels, &iter);
849 assert(!ret);
850 delete_ust_app_channel(sock, ua_chan, app);
851 }
852
853 /* In case of per PID, the registry is kept in the session. */
854 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
855 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
856 if (reg_pid) {
857 /*
858 * Registry can be null on error path during
859 * initialization.
860 */
861 buffer_reg_pid_remove(reg_pid);
862 buffer_reg_pid_destroy(reg_pid);
863 }
864 }
865
866 if (ua_sess->handle != -1) {
867 pthread_mutex_lock(&app->sock_lock);
868 ret = ustctl_release_handle(sock, ua_sess->handle);
869 pthread_mutex_unlock(&app->sock_lock);
870 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
871 ERR("UST app sock %d release session handle failed with ret %d",
872 sock, ret);
873 }
874 /* Remove session from application UST object descriptor. */
875 iter.iter.node = &ua_sess->ust_objd_node.node;
876 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
877 assert(!ret);
878 }
879
880 pthread_mutex_unlock(&ua_sess->lock);
881
882 consumer_output_put(ua_sess->consumer);
883
884 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
885}
886
887/*
888 * Delete a traceable application structure from the global list. Never call
889 * this function outside of a call_rcu call.
890 *
891 * RCU read side lock should _NOT_ be held when calling this function.
892 */
893static
894void delete_ust_app(struct ust_app *app)
895{
896 int ret, sock;
897 struct ust_app_session *ua_sess, *tmp_ua_sess;
898
899 /*
900 * The session list lock must be held during this function to guarantee
901 * the existence of ua_sess.
902 */
903 session_lock_list();
904 /* Delete ust app sessions info */
905 sock = app->sock;
906 app->sock = -1;
907
908 /* Wipe sessions */
909 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
910 teardown_node) {
911 /* Free every object in the session and the session. */
912 rcu_read_lock();
913 delete_ust_app_session(sock, ua_sess, app);
914 rcu_read_unlock();
915 }
916
917 ht_cleanup_push(app->sessions);
918 ht_cleanup_push(app->ust_sessions_objd);
919 ht_cleanup_push(app->ust_objd);
920
921 /*
922 * Wait until we have deleted the application from the sock hash table
923 * before closing this socket, otherwise an application could re-use the
924 * socket ID and race with the teardown, using the same hash table entry.
925 *
926 * It's OK to leave the close in call_rcu. We want it to stay unique for
927 * all RCU readers that could run concurrently with unregister app,
928 * therefore we _need_ to only close that socket after a grace period. So
929 * it should stay in this RCU callback.
930 *
931 * This close() is a very important step of the synchronization model so
932 * every modification to this function must be carefully reviewed.
933 */
934 ret = close(sock);
935 if (ret) {
936 PERROR("close");
937 }
938 lttng_fd_put(LTTNG_FD_APPS, 1);
939
940 DBG2("UST app pid %d deleted", app->pid);
941 free(app);
942 session_unlock_list();
943}
944
945/*
946 * URCU intermediate call to delete an UST app.
947 */
948static
949void delete_ust_app_rcu(struct rcu_head *head)
950{
951 struct lttng_ht_node_ulong *node =
952 caa_container_of(head, struct lttng_ht_node_ulong, head);
953 struct ust_app *app =
954 caa_container_of(node, struct ust_app, pid_n);
955
956 DBG3("Call RCU deleting app PID %d", app->pid);
957 delete_ust_app(app);
958}
959
960/*
961 * Delete the session from the application ht and delete the data structure by
962 * freeing every object inside and releasing them.
963 *
964 * The session list lock must be held by the caller.
965 */
966static void destroy_app_session(struct ust_app *app,
967 struct ust_app_session *ua_sess)
968{
969 int ret;
970 struct lttng_ht_iter iter;
971
972 assert(app);
973 assert(ua_sess);
974
975 iter.iter.node = &ua_sess->node.node;
976 ret = lttng_ht_del(app->sessions, &iter);
977 if (ret) {
978 /* Already scheduled for teardown. */
979 goto end;
980 }
981
982 /* Once deleted, free the data structure. */
983 delete_ust_app_session(app->sock, ua_sess, app);
984
985end:
986 return;
987}
988
989/*
990 * Alloc new UST app session.
991 */
992static
993struct ust_app_session *alloc_ust_app_session(void)
994{
995 struct ust_app_session *ua_sess;
996
997 /* Init most of the default value by allocating and zeroing */
998 ua_sess = zmalloc(sizeof(struct ust_app_session));
999 if (ua_sess == NULL) {
1000 PERROR("malloc");
1001 goto error_free;
1002 }
1003
1004 ua_sess->handle = -1;
1005 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1006 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
1007 pthread_mutex_init(&ua_sess->lock, NULL);
1008
1009 return ua_sess;
1010
1011error_free:
1012 return NULL;
1013}
1014
1015/*
1016 * Alloc new UST app channel.
1017 */
1018static
1019struct ust_app_channel *alloc_ust_app_channel(char *name,
1020 struct ust_app_session *ua_sess,
1021 struct lttng_ust_channel_attr *attr)
1022{
1023 struct ust_app_channel *ua_chan;
1024
1025 /* Init most of the default value by allocating and zeroing */
1026 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1027 if (ua_chan == NULL) {
1028 PERROR("malloc");
1029 goto error;
1030 }
1031
1032 /* Setup channel name */
1033 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1034 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1035
1036 ua_chan->enabled = 1;
1037 ua_chan->handle = -1;
1038 ua_chan->session = ua_sess;
1039 ua_chan->key = get_next_channel_key();
1040 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1041 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1042 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
1043
1044 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
1045 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
1046
1047 /* Copy attributes */
1048 if (attr) {
1049 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
1050 ua_chan->attr.subbuf_size = attr->subbuf_size;
1051 ua_chan->attr.num_subbuf = attr->num_subbuf;
1052 ua_chan->attr.overwrite = attr->overwrite;
1053 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1054 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1055 ua_chan->attr.output = attr->output;
1056 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
1057 }
1058 /* By default, the channel is a per cpu channel. */
1059 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1060
1061 DBG3("UST app channel %s allocated", ua_chan->name);
1062
1063 return ua_chan;
1064
1065error:
1066 return NULL;
1067}
1068
1069/*
1070 * Allocate and initialize a UST app stream.
1071 *
1072 * Return newly allocated stream pointer or NULL on error.
1073 */
1074struct ust_app_stream *ust_app_alloc_stream(void)
1075{
1076 struct ust_app_stream *stream = NULL;
1077
1078 stream = zmalloc(sizeof(*stream));
1079 if (stream == NULL) {
1080 PERROR("zmalloc ust app stream");
1081 goto error;
1082 }
1083
1084 /* Zero could be a valid value for a handle so flag it to -1. */
1085 stream->handle = -1;
1086
1087error:
1088 return stream;
1089}
1090
1091/*
1092 * Alloc new UST app event.
1093 */
1094static
1095struct ust_app_event *alloc_ust_app_event(char *name,
1096 struct lttng_ust_event *attr)
1097{
1098 struct ust_app_event *ua_event;
1099
1100 /* Init most of the default value by allocating and zeroing */
1101 ua_event = zmalloc(sizeof(struct ust_app_event));
1102 if (ua_event == NULL) {
1103 PERROR("Failed to allocate ust_app_event structure");
1104 goto error;
1105 }
1106
1107 ua_event->enabled = 1;
1108 strncpy(ua_event->name, name, sizeof(ua_event->name));
1109 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1110 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
1111
1112 /* Copy attributes */
1113 if (attr) {
1114 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1115 }
1116
1117 DBG3("UST app event %s allocated", ua_event->name);
1118
1119 return ua_event;
1120
1121error:
1122 return NULL;
1123}
1124
1125/*
1126 * Alloc new UST app context.
1127 */
1128static
1129struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
1130{
1131 struct ust_app_ctx *ua_ctx;
1132
1133 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1134 if (ua_ctx == NULL) {
1135 goto error;
1136 }
1137
1138 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1139
1140 if (uctx) {
1141 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
1142 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1143 char *provider_name = NULL, *ctx_name = NULL;
1144
1145 provider_name = strdup(uctx->u.app_ctx.provider_name);
1146 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1147 if (!provider_name || !ctx_name) {
1148 free(provider_name);
1149 free(ctx_name);
1150 goto error;
1151 }
1152
1153 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1154 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1155 }
1156 }
1157
1158 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
1159 return ua_ctx;
1160error:
1161 free(ua_ctx);
1162 return NULL;
1163}
1164
1165/*
1166 * Allocate a filter and copy the given original filter.
1167 *
1168 * Return allocated filter or NULL on error.
1169 */
1170static struct lttng_filter_bytecode *copy_filter_bytecode(
1171 struct lttng_filter_bytecode *orig_f)
1172{
1173 struct lttng_filter_bytecode *filter = NULL;
1174
1175 /* Copy filter bytecode */
1176 filter = zmalloc(sizeof(*filter) + orig_f->len);
1177 if (!filter) {
1178 PERROR("zmalloc alloc filter bytecode");
1179 goto error;
1180 }
1181
1182 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1183
1184error:
1185 return filter;
1186}
1187
1188/*
1189 * Create a liblttng-ust filter bytecode from given bytecode.
1190 *
1191 * Return allocated filter or NULL on error.
1192 */
1193static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1194 struct lttng_filter_bytecode *orig_f)
1195{
1196 struct lttng_ust_filter_bytecode *filter = NULL;
1197
1198 /* Copy filter bytecode */
1199 filter = zmalloc(sizeof(*filter) + orig_f->len);
1200 if (!filter) {
1201 PERROR("zmalloc alloc ust filter bytecode");
1202 goto error;
1203 }
1204
1205 assert(sizeof(struct lttng_filter_bytecode) ==
1206 sizeof(struct lttng_ust_filter_bytecode));
1207 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1208error:
1209 return filter;
1210}
1211
1212/*
1213 * Find an ust_app using the sock and return it. RCU read side lock must be
1214 * held before calling this helper function.
1215 */
1216struct ust_app *ust_app_find_by_sock(int sock)
1217{
1218 struct lttng_ht_node_ulong *node;
1219 struct lttng_ht_iter iter;
1220
1221 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
1222 node = lttng_ht_iter_get_node_ulong(&iter);
1223 if (node == NULL) {
1224 DBG2("UST app find by sock %d not found", sock);
1225 goto error;
1226 }
1227
1228 return caa_container_of(node, struct ust_app, sock_n);
1229
1230error:
1231 return NULL;
1232}
1233
1234/*
1235 * Find an ust_app using the notify sock and return it. RCU read side lock must
1236 * be held before calling this helper function.
1237 */
1238static struct ust_app *find_app_by_notify_sock(int sock)
1239{
1240 struct lttng_ht_node_ulong *node;
1241 struct lttng_ht_iter iter;
1242
1243 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1244 &iter);
1245 node = lttng_ht_iter_get_node_ulong(&iter);
1246 if (node == NULL) {
1247 DBG2("UST app find by notify sock %d not found", sock);
1248 goto error;
1249 }
1250
1251 return caa_container_of(node, struct ust_app, notify_sock_n);
1252
1253error:
1254 return NULL;
1255}
1256
1257/*
1258 * Lookup for an ust app event based on event name, filter bytecode and the
1259 * event loglevel.
1260 *
1261 * Return an ust_app_event object or NULL on error.
1262 */
1263static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
1264 const char *name, const struct lttng_filter_bytecode *filter,
1265 int loglevel_value,
1266 const struct lttng_event_exclusion *exclusion)
1267{
1268 struct lttng_ht_iter iter;
1269 struct lttng_ht_node_str *node;
1270 struct ust_app_event *event = NULL;
1271 struct ust_app_ht_key key;
1272
1273 assert(name);
1274 assert(ht);
1275
1276 /* Setup key for event lookup. */
1277 key.name = name;
1278 key.filter = filter;
1279 key.loglevel_type = loglevel_value;
1280 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
1281 key.exclusion = exclusion;
1282
1283 /* Lookup using the event name as hash and a custom match fct. */
1284 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1285 ht_match_ust_app_event, &key, &iter.iter);
1286 node = lttng_ht_iter_get_node_str(&iter);
1287 if (node == NULL) {
1288 goto end;
1289 }
1290
1291 event = caa_container_of(node, struct ust_app_event, node);
1292
1293end:
1294 return event;
1295}
1296
1297/*
1298 * Create the channel context on the tracer.
1299 *
1300 * Called with UST app session lock held.
1301 */
1302static
1303int create_ust_channel_context(struct ust_app_channel *ua_chan,
1304 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1305{
1306 int ret;
1307
1308 health_code_update();
1309
1310 pthread_mutex_lock(&app->sock_lock);
1311 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
1312 ua_chan->obj, &ua_ctx->obj);
1313 pthread_mutex_unlock(&app->sock_lock);
1314 if (ret < 0) {
1315 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1316 ERR("UST app create channel context failed for app (pid: %d) "
1317 "with ret %d", app->pid, ret);
1318 } else {
1319 /*
1320 * This is normal behavior, an application can die during the
1321 * creation process. Don't report an error so the execution can
1322 * continue normally.
1323 */
1324 ret = 0;
1325 DBG3("UST app add context failed. Application is dead.");
1326 }
1327 goto error;
1328 }
1329
1330 ua_ctx->handle = ua_ctx->obj->handle;
1331
1332 DBG2("UST app context handle %d created successfully for channel %s",
1333 ua_ctx->handle, ua_chan->name);
1334
1335error:
1336 health_code_update();
1337 return ret;
1338}
1339
1340/*
1341 * Set the filter on the tracer.
1342 */
1343static
1344int set_ust_event_filter(struct ust_app_event *ua_event,
1345 struct ust_app *app)
1346{
1347 int ret;
1348 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
1349
1350 health_code_update();
1351
1352 if (!ua_event->filter) {
1353 ret = 0;
1354 goto error;
1355 }
1356
1357 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1358 if (!ust_bytecode) {
1359 ret = -LTTNG_ERR_NOMEM;
1360 goto error;
1361 }
1362 pthread_mutex_lock(&app->sock_lock);
1363 ret = ustctl_set_filter(app->sock, ust_bytecode,
1364 ua_event->obj);
1365 pthread_mutex_unlock(&app->sock_lock);
1366 if (ret < 0) {
1367 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1368 ERR("UST app event %s filter failed for app (pid: %d) "
1369 "with ret %d", ua_event->attr.name, app->pid, ret);
1370 } else {
1371 /*
1372 * This is normal behavior, an application can die during the
1373 * creation process. Don't report an error so the execution can
1374 * continue normally.
1375 */
1376 ret = 0;
1377 DBG3("UST app filter event failed. Application is dead.");
1378 }
1379 goto error;
1380 }
1381
1382 DBG2("UST filter set successfully for event %s", ua_event->name);
1383
1384error:
1385 health_code_update();
1386 free(ust_bytecode);
1387 return ret;
1388}
1389
1390static
1391struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1392 struct lttng_event_exclusion *exclusion)
1393{
1394 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1395 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1396 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1397
1398 ust_exclusion = zmalloc(exclusion_alloc_size);
1399 if (!ust_exclusion) {
1400 PERROR("malloc");
1401 goto end;
1402 }
1403
1404 assert(sizeof(struct lttng_event_exclusion) ==
1405 sizeof(struct lttng_ust_event_exclusion));
1406 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1407end:
1408 return ust_exclusion;
1409}
1410
1411/*
1412 * Set event exclusions on the tracer.
1413 */
1414static
1415int set_ust_event_exclusion(struct ust_app_event *ua_event,
1416 struct ust_app *app)
1417{
1418 int ret;
1419 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1420
1421 health_code_update();
1422
1423 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1424 ret = 0;
1425 goto error;
1426 }
1427
1428 ust_exclusion = create_ust_exclusion_from_exclusion(
1429 ua_event->exclusion);
1430 if (!ust_exclusion) {
1431 ret = -LTTNG_ERR_NOMEM;
1432 goto error;
1433 }
1434 pthread_mutex_lock(&app->sock_lock);
1435 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
1436 pthread_mutex_unlock(&app->sock_lock);
1437 if (ret < 0) {
1438 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1439 ERR("UST app event %s exclusions failed for app (pid: %d) "
1440 "with ret %d", ua_event->attr.name, app->pid, ret);
1441 } else {
1442 /*
1443 * This is normal behavior, an application can die during the
1444 * creation process. Don't report an error so the execution can
1445 * continue normally.
1446 */
1447 ret = 0;
1448 DBG3("UST app event exclusion failed. Application is dead.");
1449 }
1450 goto error;
1451 }
1452
1453 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1454
1455error:
1456 health_code_update();
1457 free(ust_exclusion);
1458 return ret;
1459}
1460
1461/*
1462 * Disable the specified event on to UST tracer for the UST session.
1463 */
1464static int disable_ust_event(struct ust_app *app,
1465 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1466{
1467 int ret;
1468
1469 health_code_update();
1470
1471 pthread_mutex_lock(&app->sock_lock);
1472 ret = ustctl_disable(app->sock, ua_event->obj);
1473 pthread_mutex_unlock(&app->sock_lock);
1474 if (ret < 0) {
1475 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1476 ERR("UST app event %s disable failed for app (pid: %d) "
1477 "and session handle %d with ret %d",
1478 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1479 } else {
1480 /*
1481 * This is normal behavior, an application can die during the
1482 * creation process. Don't report an error so the execution can
1483 * continue normally.
1484 */
1485 ret = 0;
1486 DBG3("UST app disable event failed. Application is dead.");
1487 }
1488 goto error;
1489 }
1490
1491 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1492 ua_event->attr.name, app->pid);
1493
1494error:
1495 health_code_update();
1496 return ret;
1497}
1498
1499/*
1500 * Disable the specified channel on to UST tracer for the UST session.
1501 */
1502static int disable_ust_channel(struct ust_app *app,
1503 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1504{
1505 int ret;
1506
1507 health_code_update();
1508
1509 pthread_mutex_lock(&app->sock_lock);
1510 ret = ustctl_disable(app->sock, ua_chan->obj);
1511 pthread_mutex_unlock(&app->sock_lock);
1512 if (ret < 0) {
1513 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1514 ERR("UST app channel %s disable failed for app (pid: %d) "
1515 "and session handle %d with ret %d",
1516 ua_chan->name, app->pid, ua_sess->handle, ret);
1517 } else {
1518 /*
1519 * This is normal behavior, an application can die during the
1520 * creation process. Don't report an error so the execution can
1521 * continue normally.
1522 */
1523 ret = 0;
1524 DBG3("UST app disable channel failed. Application is dead.");
1525 }
1526 goto error;
1527 }
1528
1529 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1530 ua_chan->name, app->pid);
1531
1532error:
1533 health_code_update();
1534 return ret;
1535}
1536
1537/*
1538 * Enable the specified channel on to UST tracer for the UST session.
1539 */
1540static int enable_ust_channel(struct ust_app *app,
1541 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1542{
1543 int ret;
1544
1545 health_code_update();
1546
1547 pthread_mutex_lock(&app->sock_lock);
1548 ret = ustctl_enable(app->sock, ua_chan->obj);
1549 pthread_mutex_unlock(&app->sock_lock);
1550 if (ret < 0) {
1551 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1552 ERR("UST app channel %s enable failed for app (pid: %d) "
1553 "and session handle %d with ret %d",
1554 ua_chan->name, app->pid, ua_sess->handle, ret);
1555 } else {
1556 /*
1557 * This is normal behavior, an application can die during the
1558 * creation process. Don't report an error so the execution can
1559 * continue normally.
1560 */
1561 ret = 0;
1562 DBG3("UST app enable channel failed. Application is dead.");
1563 }
1564 goto error;
1565 }
1566
1567 ua_chan->enabled = 1;
1568
1569 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1570 ua_chan->name, app->pid);
1571
1572error:
1573 health_code_update();
1574 return ret;
1575}
1576
1577/*
1578 * Enable the specified event on to UST tracer for the UST session.
1579 */
1580static int enable_ust_event(struct ust_app *app,
1581 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1582{
1583 int ret;
1584
1585 health_code_update();
1586
1587 pthread_mutex_lock(&app->sock_lock);
1588 ret = ustctl_enable(app->sock, ua_event->obj);
1589 pthread_mutex_unlock(&app->sock_lock);
1590 if (ret < 0) {
1591 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1592 ERR("UST app event %s enable failed for app (pid: %d) "
1593 "and session handle %d with ret %d",
1594 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1595 } else {
1596 /*
1597 * This is normal behavior, an application can die during the
1598 * creation process. Don't report an error so the execution can
1599 * continue normally.
1600 */
1601 ret = 0;
1602 DBG3("UST app enable event failed. Application is dead.");
1603 }
1604 goto error;
1605 }
1606
1607 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1608 ua_event->attr.name, app->pid);
1609
1610error:
1611 health_code_update();
1612 return ret;
1613}
1614
1615/*
1616 * Send channel and stream buffer to application.
1617 *
1618 * Return 0 on success. On error, a negative value is returned.
1619 */
1620static int send_channel_pid_to_ust(struct ust_app *app,
1621 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1622{
1623 int ret;
1624 struct ust_app_stream *stream, *stmp;
1625
1626 assert(app);
1627 assert(ua_sess);
1628 assert(ua_chan);
1629
1630 health_code_update();
1631
1632 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1633 app->sock);
1634
1635 /* Send channel to the application. */
1636 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
1637 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1638 ret = -ENOTCONN; /* Caused by app exiting. */
1639 goto error;
1640 } else if (ret < 0) {
1641 goto error;
1642 }
1643
1644 health_code_update();
1645
1646 /* Send all streams to application. */
1647 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1648 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
1649 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1650 ret = -ENOTCONN; /* Caused by app exiting. */
1651 goto error;
1652 } else if (ret < 0) {
1653 goto error;
1654 }
1655 /* We don't need the stream anymore once sent to the tracer. */
1656 cds_list_del(&stream->list);
1657 delete_ust_app_stream(-1, stream, app);
1658 }
1659 /* Flag the channel that it is sent to the application. */
1660 ua_chan->is_sent = 1;
1661
1662error:
1663 health_code_update();
1664 return ret;
1665}
1666
1667/*
1668 * Create the specified event onto the UST tracer for a UST session.
1669 *
1670 * Should be called with session mutex held.
1671 */
1672static
1673int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1674 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
1675{
1676 int ret = 0;
1677
1678 health_code_update();
1679
1680 /* Create UST event on tracer */
1681 pthread_mutex_lock(&app->sock_lock);
1682 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
1683 &ua_event->obj);
1684 pthread_mutex_unlock(&app->sock_lock);
1685 if (ret < 0) {
1686 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1687 abort();
1688 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1689 ua_event->attr.name, app->pid, ret);
1690 } else {
1691 /*
1692 * This is normal behavior, an application can die during the
1693 * creation process. Don't report an error so the execution can
1694 * continue normally.
1695 */
1696 ret = 0;
1697 DBG3("UST app create event failed. Application is dead.");
1698 }
1699 goto error;
1700 }
1701
1702 ua_event->handle = ua_event->obj->handle;
1703
1704 DBG2("UST app event %s created successfully for pid:%d",
1705 ua_event->attr.name, app->pid);
1706
1707 health_code_update();
1708
1709 /* Set filter if one is present. */
1710 if (ua_event->filter) {
1711 ret = set_ust_event_filter(ua_event, app);
1712 if (ret < 0) {
1713 goto error;
1714 }
1715 }
1716
1717 /* Set exclusions for the event */
1718 if (ua_event->exclusion) {
1719 ret = set_ust_event_exclusion(ua_event, app);
1720 if (ret < 0) {
1721 goto error;
1722 }
1723 }
1724
1725 /* If event not enabled, disable it on the tracer */
1726 if (ua_event->enabled) {
1727 /*
1728 * We now need to explicitly enable the event, since it
1729 * is now disabled at creation.
1730 */
1731 ret = enable_ust_event(app, ua_sess, ua_event);
1732 if (ret < 0) {
1733 /*
1734 * If we hit an EPERM, something is wrong with our enable call. If
1735 * we get an EEXIST, there is a problem on the tracer side since we
1736 * just created it.
1737 */
1738 switch (ret) {
1739 case -LTTNG_UST_ERR_PERM:
1740 /* Code flow problem */
1741 assert(0);
1742 case -LTTNG_UST_ERR_EXIST:
1743 /* It's OK for our use case. */
1744 ret = 0;
1745 break;
1746 default:
1747 break;
1748 }
1749 goto error;
1750 }
1751 }
1752
1753error:
1754 health_code_update();
1755 return ret;
1756}
1757
1758/*
1759 * Copy data between an UST app event and a LTT event.
1760 */
1761static void shadow_copy_event(struct ust_app_event *ua_event,
1762 struct ltt_ust_event *uevent)
1763{
1764 size_t exclusion_alloc_size;
1765
1766 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1767 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1768
1769 ua_event->enabled = uevent->enabled;
1770
1771 /* Copy event attributes */
1772 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1773
1774 /* Copy filter bytecode */
1775 if (uevent->filter) {
1776 ua_event->filter = copy_filter_bytecode(uevent->filter);
1777 /* Filter might be NULL here in case of ENONEM. */
1778 }
1779
1780 /* Copy exclusion data */
1781 if (uevent->exclusion) {
1782 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
1783 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1784 ua_event->exclusion = zmalloc(exclusion_alloc_size);
1785 if (ua_event->exclusion == NULL) {
1786 PERROR("malloc");
1787 } else {
1788 memcpy(ua_event->exclusion, uevent->exclusion,
1789 exclusion_alloc_size);
1790 }
1791 }
1792}
1793
1794/*
1795 * Copy data between an UST app channel and a LTT channel.
1796 */
1797static void shadow_copy_channel(struct ust_app_channel *ua_chan,
1798 struct ltt_ust_channel *uchan)
1799{
1800 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
1801
1802 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1803 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1804
1805 ua_chan->tracefile_size = uchan->tracefile_size;
1806 ua_chan->tracefile_count = uchan->tracefile_count;
1807
1808 /* Copy event attributes since the layout is different. */
1809 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1810 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1811 ua_chan->attr.overwrite = uchan->attr.overwrite;
1812 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1813 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1814 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
1815 ua_chan->attr.output = uchan->attr.output;
1816 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1817
1818 /*
1819 * Note that the attribute channel type is not set since the channel on the
1820 * tracing registry side does not have this information.
1821 */
1822
1823 ua_chan->enabled = uchan->enabled;
1824 ua_chan->tracing_channel_id = uchan->id;
1825
1826 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
1827}
1828
1829/*
1830 * Copy data between a UST app session and a regular LTT session.
1831 */
1832static void shadow_copy_session(struct ust_app_session *ua_sess,
1833 struct ltt_ust_session *usess, struct ust_app *app)
1834{
1835 struct tm *timeinfo;
1836 char datetime[16];
1837 int ret;
1838 char tmp_shm_path[PATH_MAX];
1839
1840 timeinfo = localtime(&app->registration_time);
1841 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1842
1843 DBG2("Shadow copy of session handle %d", ua_sess->handle);
1844
1845 ua_sess->tracing_id = usess->id;
1846 ua_sess->id = get_next_session_id();
1847 ua_sess->real_credentials.uid = app->uid;
1848 ua_sess->real_credentials.gid = app->gid;
1849 ua_sess->effective_credentials.uid = usess->uid;
1850 ua_sess->effective_credentials.gid = usess->gid;
1851 ua_sess->buffer_type = usess->buffer_type;
1852 ua_sess->bits_per_long = app->bits_per_long;
1853
1854 /* There is only one consumer object per session possible. */
1855 consumer_output_get(usess->consumer);
1856 ua_sess->consumer = usess->consumer;
1857
1858 ua_sess->output_traces = usess->output_traces;
1859 ua_sess->live_timer_interval = usess->live_timer_interval;
1860 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1861 &usess->metadata_attr);
1862
1863 switch (ua_sess->buffer_type) {
1864 case LTTNG_BUFFER_PER_PID:
1865 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1866 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
1867 datetime);
1868 break;
1869 case LTTNG_BUFFER_PER_UID:
1870 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1871 DEFAULT_UST_TRACE_UID_PATH,
1872 ua_sess->real_credentials.uid,
1873 app->bits_per_long);
1874 break;
1875 default:
1876 assert(0);
1877 goto error;
1878 }
1879 if (ret < 0) {
1880 PERROR("asprintf UST shadow copy session");
1881 assert(0);
1882 goto error;
1883 }
1884
1885 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1886 sizeof(ua_sess->root_shm_path));
1887 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
1888 strncpy(ua_sess->shm_path, usess->shm_path,
1889 sizeof(ua_sess->shm_path));
1890 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1891 if (ua_sess->shm_path[0]) {
1892 switch (ua_sess->buffer_type) {
1893 case LTTNG_BUFFER_PER_PID:
1894 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1895 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1896 app->name, app->pid, datetime);
1897 break;
1898 case LTTNG_BUFFER_PER_UID:
1899 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1900 DEFAULT_UST_TRACE_UID_PATH,
1901 app->uid, app->bits_per_long);
1902 break;
1903 default:
1904 assert(0);
1905 goto error;
1906 }
1907 if (ret < 0) {
1908 PERROR("sprintf UST shadow copy session");
1909 assert(0);
1910 goto error;
1911 }
1912 strncat(ua_sess->shm_path, tmp_shm_path,
1913 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1914 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1915 }
1916 return;
1917
1918error:
1919 consumer_output_put(ua_sess->consumer);
1920}
1921
1922/*
1923 * Lookup sesison wrapper.
1924 */
1925static
1926void __lookup_session_by_app(const struct ltt_ust_session *usess,
1927 struct ust_app *app, struct lttng_ht_iter *iter)
1928{
1929 /* Get right UST app session from app */
1930 lttng_ht_lookup(app->sessions, &usess->id, iter);
1931}
1932
1933/*
1934 * Return ust app session from the app session hashtable using the UST session
1935 * id.
1936 */
1937static struct ust_app_session *lookup_session_by_app(
1938 const struct ltt_ust_session *usess, struct ust_app *app)
1939{
1940 struct lttng_ht_iter iter;
1941 struct lttng_ht_node_u64 *node;
1942
1943 __lookup_session_by_app(usess, app, &iter);
1944 node = lttng_ht_iter_get_node_u64(&iter);
1945 if (node == NULL) {
1946 goto error;
1947 }
1948
1949 return caa_container_of(node, struct ust_app_session, node);
1950
1951error:
1952 return NULL;
1953}
1954
1955/*
1956 * Setup buffer registry per PID for the given session and application. If none
1957 * is found, a new one is created, added to the global registry and
1958 * initialized. If regp is valid, it's set with the newly created object.
1959 *
1960 * Return 0 on success or else a negative value.
1961 */
1962static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1963 struct ust_app *app, struct buffer_reg_pid **regp)
1964{
1965 int ret = 0;
1966 struct buffer_reg_pid *reg_pid;
1967
1968 assert(ua_sess);
1969 assert(app);
1970
1971 rcu_read_lock();
1972
1973 reg_pid = buffer_reg_pid_find(ua_sess->id);
1974 if (!reg_pid) {
1975 /*
1976 * This is the create channel path meaning that if there is NO
1977 * registry available, we have to create one for this session.
1978 */
1979 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
1980 ua_sess->root_shm_path, ua_sess->shm_path);
1981 if (ret < 0) {
1982 goto error;
1983 }
1984 } else {
1985 goto end;
1986 }
1987
1988 /* Initialize registry. */
1989 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1990 app->bits_per_long, app->uint8_t_alignment,
1991 app->uint16_t_alignment, app->uint32_t_alignment,
1992 app->uint64_t_alignment, app->long_alignment,
1993 app->byte_order, app->version.major, app->version.minor,
1994 reg_pid->root_shm_path, reg_pid->shm_path,
1995 ua_sess->effective_credentials.uid,
1996 ua_sess->effective_credentials.gid, ua_sess->tracing_id,
1997 app->uid);
1998 if (ret < 0) {
1999 /*
2000 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2001 * destroy the buffer registry, because it is always expected
2002 * that if the buffer registry can be found, its ust registry is
2003 * non-NULL.
2004 */
2005 buffer_reg_pid_destroy(reg_pid);
2006 goto error;
2007 }
2008
2009 buffer_reg_pid_add(reg_pid);
2010
2011 DBG3("UST app buffer registry per PID created successfully");
2012
2013end:
2014 if (regp) {
2015 *regp = reg_pid;
2016 }
2017error:
2018 rcu_read_unlock();
2019 return ret;
2020}
2021
2022/*
2023 * Setup buffer registry per UID for the given session and application. If none
2024 * is found, a new one is created, added to the global registry and
2025 * initialized. If regp is valid, it's set with the newly created object.
2026 *
2027 * Return 0 on success or else a negative value.
2028 */
2029static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
2030 struct ust_app_session *ua_sess,
2031 struct ust_app *app, struct buffer_reg_uid **regp)
2032{
2033 int ret = 0;
2034 struct buffer_reg_uid *reg_uid;
2035
2036 assert(usess);
2037 assert(app);
2038
2039 rcu_read_lock();
2040
2041 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2042 if (!reg_uid) {
2043 /*
2044 * This is the create channel path meaning that if there is NO
2045 * registry available, we have to create one for this session.
2046 */
2047 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
2048 LTTNG_DOMAIN_UST, &reg_uid,
2049 ua_sess->root_shm_path, ua_sess->shm_path);
2050 if (ret < 0) {
2051 goto error;
2052 }
2053 } else {
2054 goto end;
2055 }
2056
2057 /* Initialize registry. */
2058 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
2059 app->bits_per_long, app->uint8_t_alignment,
2060 app->uint16_t_alignment, app->uint32_t_alignment,
2061 app->uint64_t_alignment, app->long_alignment,
2062 app->byte_order, app->version.major,
2063 app->version.minor, reg_uid->root_shm_path,
2064 reg_uid->shm_path, usess->uid, usess->gid,
2065 ua_sess->tracing_id, app->uid);
2066 if (ret < 0) {
2067 /*
2068 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2069 * destroy the buffer registry, because it is always expected
2070 * that if the buffer registry can be found, its ust registry is
2071 * non-NULL.
2072 */
2073 buffer_reg_uid_destroy(reg_uid, NULL);
2074 goto error;
2075 }
2076 /* Add node to teardown list of the session. */
2077 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2078
2079 buffer_reg_uid_add(reg_uid);
2080
2081 DBG3("UST app buffer registry per UID created successfully");
2082end:
2083 if (regp) {
2084 *regp = reg_uid;
2085 }
2086error:
2087 rcu_read_unlock();
2088 return ret;
2089}
2090
2091/*
2092 * Create a session on the tracer side for the given app.
2093 *
2094 * On success, ua_sess_ptr is populated with the session pointer or else left
2095 * untouched. If the session was created, is_created is set to 1. On error,
2096 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2097 * be NULL.
2098 *
2099 * Returns 0 on success or else a negative code which is either -ENOMEM or
2100 * -ENOTCONN which is the default code if the ustctl_create_session fails.
2101 */
2102static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
2103 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2104 int *is_created)
2105{
2106 int ret, created = 0;
2107 struct ust_app_session *ua_sess;
2108
2109 assert(usess);
2110 assert(app);
2111 assert(ua_sess_ptr);
2112
2113 health_code_update();
2114
2115 ua_sess = lookup_session_by_app(usess, app);
2116 if (ua_sess == NULL) {
2117 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
2118 app->pid, usess->id);
2119 ua_sess = alloc_ust_app_session();
2120 if (ua_sess == NULL) {
2121 /* Only malloc can failed so something is really wrong */
2122 ret = -ENOMEM;
2123 goto error;
2124 }
2125 shadow_copy_session(ua_sess, usess, app);
2126 created = 1;
2127 }
2128
2129 switch (usess->buffer_type) {
2130 case LTTNG_BUFFER_PER_PID:
2131 /* Init local registry. */
2132 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
2133 if (ret < 0) {
2134 delete_ust_app_session(-1, ua_sess, app);
2135 goto error;
2136 }
2137 break;
2138 case LTTNG_BUFFER_PER_UID:
2139 /* Look for a global registry. If none exists, create one. */
2140 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
2141 if (ret < 0) {
2142 delete_ust_app_session(-1, ua_sess, app);
2143 goto error;
2144 }
2145 break;
2146 default:
2147 assert(0);
2148 ret = -EINVAL;
2149 goto error;
2150 }
2151
2152 health_code_update();
2153
2154 if (ua_sess->handle == -1) {
2155 pthread_mutex_lock(&app->sock_lock);
2156 ret = ustctl_create_session(app->sock);
2157 pthread_mutex_unlock(&app->sock_lock);
2158 if (ret < 0) {
2159 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2160 ERR("Creating session for app pid %d with ret %d",
2161 app->pid, ret);
2162 } else {
2163 DBG("UST app creating session failed. Application is dead");
2164 /*
2165 * This is normal behavior, an application can die during the
2166 * creation process. Don't report an error so the execution can
2167 * continue normally. This will get flagged ENOTCONN and the
2168 * caller will handle it.
2169 */
2170 ret = 0;
2171 }
2172 delete_ust_app_session(-1, ua_sess, app);
2173 if (ret != -ENOMEM) {
2174 /*
2175 * Tracer is probably gone or got an internal error so let's
2176 * behave like it will soon unregister or not usable.
2177 */
2178 ret = -ENOTCONN;
2179 }
2180 goto error;
2181 }
2182
2183 ua_sess->handle = ret;
2184
2185 /* Add ust app session to app's HT */
2186 lttng_ht_node_init_u64(&ua_sess->node,
2187 ua_sess->tracing_id);
2188 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
2189 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2190 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2191 &ua_sess->ust_objd_node);
2192
2193 DBG2("UST app session created successfully with handle %d", ret);
2194 }
2195
2196 *ua_sess_ptr = ua_sess;
2197 if (is_created) {
2198 *is_created = created;
2199 }
2200
2201 /* Everything went well. */
2202 ret = 0;
2203
2204error:
2205 health_code_update();
2206 return ret;
2207}
2208
2209/*
2210 * Match function for a hash table lookup of ust_app_ctx.
2211 *
2212 * It matches an ust app context based on the context type and, in the case
2213 * of perf counters, their name.
2214 */
2215static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2216{
2217 struct ust_app_ctx *ctx;
2218 const struct lttng_ust_context_attr *key;
2219
2220 assert(node);
2221 assert(_key);
2222
2223 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2224 key = _key;
2225
2226 /* Context type */
2227 if (ctx->ctx.ctx != key->ctx) {
2228 goto no_match;
2229 }
2230
2231 switch(key->ctx) {
2232 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
2233 if (strncmp(key->u.perf_counter.name,
2234 ctx->ctx.u.perf_counter.name,
2235 sizeof(key->u.perf_counter.name))) {
2236 goto no_match;
2237 }
2238 break;
2239 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2240 if (strcmp(key->u.app_ctx.provider_name,
2241 ctx->ctx.u.app_ctx.provider_name) ||
2242 strcmp(key->u.app_ctx.ctx_name,
2243 ctx->ctx.u.app_ctx.ctx_name)) {
2244 goto no_match;
2245 }
2246 break;
2247 default:
2248 break;
2249 }
2250
2251 /* Match. */
2252 return 1;
2253
2254no_match:
2255 return 0;
2256}
2257
2258/*
2259 * Lookup for an ust app context from an lttng_ust_context.
2260 *
2261 * Must be called while holding RCU read side lock.
2262 * Return an ust_app_ctx object or NULL on error.
2263 */
2264static
2265struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
2266 struct lttng_ust_context_attr *uctx)
2267{
2268 struct lttng_ht_iter iter;
2269 struct lttng_ht_node_ulong *node;
2270 struct ust_app_ctx *app_ctx = NULL;
2271
2272 assert(uctx);
2273 assert(ht);
2274
2275 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2276 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2277 ht_match_ust_app_ctx, uctx, &iter.iter);
2278 node = lttng_ht_iter_get_node_ulong(&iter);
2279 if (!node) {
2280 goto end;
2281 }
2282
2283 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2284
2285end:
2286 return app_ctx;
2287}
2288
2289/*
2290 * Create a context for the channel on the tracer.
2291 *
2292 * Called with UST app session lock held and a RCU read side lock.
2293 */
2294static
2295int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
2296 struct lttng_ust_context_attr *uctx,
2297 struct ust_app *app)
2298{
2299 int ret = 0;
2300 struct ust_app_ctx *ua_ctx;
2301
2302 DBG2("UST app adding context to channel %s", ua_chan->name);
2303
2304 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2305 if (ua_ctx) {
2306 ret = -EEXIST;
2307 goto error;
2308 }
2309
2310 ua_ctx = alloc_ust_app_ctx(uctx);
2311 if (ua_ctx == NULL) {
2312 /* malloc failed */
2313 ret = -ENOMEM;
2314 goto error;
2315 }
2316
2317 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
2318 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
2319 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
2320
2321 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2322 if (ret < 0) {
2323 goto error;
2324 }
2325
2326error:
2327 return ret;
2328}
2329
2330/*
2331 * Enable on the tracer side a ust app event for the session and channel.
2332 *
2333 * Called with UST app session lock held.
2334 */
2335static
2336int enable_ust_app_event(struct ust_app_session *ua_sess,
2337 struct ust_app_event *ua_event, struct ust_app *app)
2338{
2339 int ret;
2340
2341 ret = enable_ust_event(app, ua_sess, ua_event);
2342 if (ret < 0) {
2343 goto error;
2344 }
2345
2346 ua_event->enabled = 1;
2347
2348error:
2349 return ret;
2350}
2351
2352/*
2353 * Disable on the tracer side a ust app event for the session and channel.
2354 */
2355static int disable_ust_app_event(struct ust_app_session *ua_sess,
2356 struct ust_app_event *ua_event, struct ust_app *app)
2357{
2358 int ret;
2359
2360 ret = disable_ust_event(app, ua_sess, ua_event);
2361 if (ret < 0) {
2362 goto error;
2363 }
2364
2365 ua_event->enabled = 0;
2366
2367error:
2368 return ret;
2369}
2370
2371/*
2372 * Lookup ust app channel for session and disable it on the tracer side.
2373 */
2374static
2375int disable_ust_app_channel(struct ust_app_session *ua_sess,
2376 struct ust_app_channel *ua_chan, struct ust_app *app)
2377{
2378 int ret;
2379
2380 ret = disable_ust_channel(app, ua_sess, ua_chan);
2381 if (ret < 0) {
2382 goto error;
2383 }
2384
2385 ua_chan->enabled = 0;
2386
2387error:
2388 return ret;
2389}
2390
2391/*
2392 * Lookup ust app channel for session and enable it on the tracer side. This
2393 * MUST be called with a RCU read side lock acquired.
2394 */
2395static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2396 struct ltt_ust_channel *uchan, struct ust_app *app)
2397{
2398 int ret = 0;
2399 struct lttng_ht_iter iter;
2400 struct lttng_ht_node_str *ua_chan_node;
2401 struct ust_app_channel *ua_chan;
2402
2403 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2404 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2405 if (ua_chan_node == NULL) {
2406 DBG2("Unable to find channel %s in ust session id %" PRIu64,
2407 uchan->name, ua_sess->tracing_id);
2408 goto error;
2409 }
2410
2411 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2412
2413 ret = enable_ust_channel(app, ua_sess, ua_chan);
2414 if (ret < 0) {
2415 goto error;
2416 }
2417
2418error:
2419 return ret;
2420}
2421
2422/*
2423 * Ask the consumer to create a channel and get it if successful.
2424 *
2425 * Called with UST app session lock held.
2426 *
2427 * Return 0 on success or else a negative value.
2428 */
2429static int do_consumer_create_channel(struct ltt_ust_session *usess,
2430 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2431 int bitness, struct ust_registry_session *registry,
2432 uint64_t trace_archive_id)
2433{
2434 int ret;
2435 unsigned int nb_fd = 0;
2436 struct consumer_socket *socket;
2437
2438 assert(usess);
2439 assert(ua_sess);
2440 assert(ua_chan);
2441 assert(registry);
2442
2443 rcu_read_lock();
2444 health_code_update();
2445
2446 /* Get the right consumer socket for the application. */
2447 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2448 if (!socket) {
2449 ret = -EINVAL;
2450 goto error;
2451 }
2452
2453 health_code_update();
2454
2455 /* Need one fd for the channel. */
2456 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2457 if (ret < 0) {
2458 ERR("Exhausted number of available FD upon create channel");
2459 goto error;
2460 }
2461
2462 /*
2463 * Ask consumer to create channel. The consumer will return the number of
2464 * stream we have to expect.
2465 */
2466 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2467 registry, usess->current_trace_chunk);
2468 if (ret < 0) {
2469 goto error_ask;
2470 }
2471
2472 /*
2473 * Compute the number of fd needed before receiving them. It must be 2 per
2474 * stream (2 being the default value here).
2475 */
2476 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2477
2478 /* Reserve the amount of file descriptor we need. */
2479 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2480 if (ret < 0) {
2481 ERR("Exhausted number of available FD upon create channel");
2482 goto error_fd_get_stream;
2483 }
2484
2485 health_code_update();
2486
2487 /*
2488 * Now get the channel from the consumer. This call wil populate the stream
2489 * list of that channel and set the ust objects.
2490 */
2491 if (usess->consumer->enabled) {
2492 ret = ust_consumer_get_channel(socket, ua_chan);
2493 if (ret < 0) {
2494 goto error_destroy;
2495 }
2496 }
2497
2498 rcu_read_unlock();
2499 return 0;
2500
2501error_destroy:
2502 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2503error_fd_get_stream:
2504 /*
2505 * Initiate a destroy channel on the consumer since we had an error
2506 * handling it on our side. The return value is of no importance since we
2507 * already have a ret value set by the previous error that we need to
2508 * return.
2509 */
2510 (void) ust_consumer_destroy_channel(socket, ua_chan);
2511error_ask:
2512 lttng_fd_put(LTTNG_FD_APPS, 1);
2513error:
2514 health_code_update();
2515 rcu_read_unlock();
2516 return ret;
2517}
2518
2519/*
2520 * Duplicate the ust data object of the ust app stream and save it in the
2521 * buffer registry stream.
2522 *
2523 * Return 0 on success or else a negative value.
2524 */
2525static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2526 struct ust_app_stream *stream)
2527{
2528 int ret;
2529
2530 assert(reg_stream);
2531 assert(stream);
2532
2533 /* Reserve the amount of file descriptor we need. */
2534 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2535 if (ret < 0) {
2536 ERR("Exhausted number of available FD upon duplicate stream");
2537 goto error;
2538 }
2539
2540 /* Duplicate object for stream once the original is in the registry. */
2541 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2542 reg_stream->obj.ust);
2543 if (ret < 0) {
2544 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2545 reg_stream->obj.ust, stream->obj, ret);
2546 lttng_fd_put(LTTNG_FD_APPS, 2);
2547 goto error;
2548 }
2549 stream->handle = stream->obj->handle;
2550
2551error:
2552 return ret;
2553}
2554
2555/*
2556 * Duplicate the ust data object of the ust app. channel and save it in the
2557 * buffer registry channel.
2558 *
2559 * Return 0 on success or else a negative value.
2560 */
2561static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2562 struct ust_app_channel *ua_chan)
2563{
2564 int ret;
2565
2566 assert(reg_chan);
2567 assert(ua_chan);
2568
2569 /* Need two fds for the channel. */
2570 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2571 if (ret < 0) {
2572 ERR("Exhausted number of available FD upon duplicate channel");
2573 goto error_fd_get;
2574 }
2575
2576 /* Duplicate object for stream once the original is in the registry. */
2577 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2578 if (ret < 0) {
2579 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2580 reg_chan->obj.ust, ua_chan->obj, ret);
2581 goto error;
2582 }
2583 ua_chan->handle = ua_chan->obj->handle;
2584
2585 return 0;
2586
2587error:
2588 lttng_fd_put(LTTNG_FD_APPS, 1);
2589error_fd_get:
2590 return ret;
2591}
2592
2593/*
2594 * For a given channel buffer registry, setup all streams of the given ust
2595 * application channel.
2596 *
2597 * Return 0 on success or else a negative value.
2598 */
2599static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
2600 struct ust_app_channel *ua_chan,
2601 struct ust_app *app)
2602{
2603 int ret = 0;
2604 struct ust_app_stream *stream, *stmp;
2605
2606 assert(reg_chan);
2607 assert(ua_chan);
2608
2609 DBG2("UST app setup buffer registry stream");
2610
2611 /* Send all streams to application. */
2612 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2613 struct buffer_reg_stream *reg_stream;
2614
2615 ret = buffer_reg_stream_create(&reg_stream);
2616 if (ret < 0) {
2617 goto error;
2618 }
2619
2620 /*
2621 * Keep original pointer and nullify it in the stream so the delete
2622 * stream call does not release the object.
2623 */
2624 reg_stream->obj.ust = stream->obj;
2625 stream->obj = NULL;
2626 buffer_reg_stream_add(reg_stream, reg_chan);
2627
2628 /* We don't need the streams anymore. */
2629 cds_list_del(&stream->list);
2630 delete_ust_app_stream(-1, stream, app);
2631 }
2632
2633error:
2634 return ret;
2635}
2636
2637/*
2638 * Create a buffer registry channel for the given session registry and
2639 * application channel object. If regp pointer is valid, it's set with the
2640 * created object. Important, the created object is NOT added to the session
2641 * registry hash table.
2642 *
2643 * Return 0 on success else a negative value.
2644 */
2645static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2646 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2647{
2648 int ret;
2649 struct buffer_reg_channel *reg_chan = NULL;
2650
2651 assert(reg_sess);
2652 assert(ua_chan);
2653
2654 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2655
2656 /* Create buffer registry channel. */
2657 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2658 if (ret < 0) {
2659 goto error_create;
2660 }
2661 assert(reg_chan);
2662 reg_chan->consumer_key = ua_chan->key;
2663 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
2664 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
2665
2666 /* Create and add a channel registry to session. */
2667 ret = ust_registry_channel_add(reg_sess->reg.ust,
2668 ua_chan->tracing_channel_id);
2669 if (ret < 0) {
2670 goto error;
2671 }
2672 buffer_reg_channel_add(reg_sess, reg_chan);
2673
2674 if (regp) {
2675 *regp = reg_chan;
2676 }
2677
2678 return 0;
2679
2680error:
2681 /* Safe because the registry channel object was not added to any HT. */
2682 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2683error_create:
2684 return ret;
2685}
2686
2687/*
2688 * Setup buffer registry channel for the given session registry and application
2689 * channel object. If regp pointer is valid, it's set with the created object.
2690 *
2691 * Return 0 on success else a negative value.
2692 */
2693static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2694 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2695 struct ust_app *app)
2696{
2697 int ret;
2698
2699 assert(reg_sess);
2700 assert(reg_chan);
2701 assert(ua_chan);
2702 assert(ua_chan->obj);
2703
2704 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
2705
2706 /* Setup all streams for the registry. */
2707 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
2708 if (ret < 0) {
2709 goto error;
2710 }
2711
2712 reg_chan->obj.ust = ua_chan->obj;
2713 ua_chan->obj = NULL;
2714
2715 return 0;
2716
2717error:
2718 buffer_reg_channel_remove(reg_sess, reg_chan);
2719 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2720 return ret;
2721}
2722
2723/*
2724 * Send buffer registry channel to the application.
2725 *
2726 * Return 0 on success else a negative value.
2727 */
2728static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2729 struct ust_app *app, struct ust_app_session *ua_sess,
2730 struct ust_app_channel *ua_chan)
2731{
2732 int ret;
2733 struct buffer_reg_stream *reg_stream;
2734
2735 assert(reg_chan);
2736 assert(app);
2737 assert(ua_sess);
2738 assert(ua_chan);
2739
2740 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2741
2742 ret = duplicate_channel_object(reg_chan, ua_chan);
2743 if (ret < 0) {
2744 goto error;
2745 }
2746
2747 /* Send channel to the application. */
2748 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
2749 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2750 ret = -ENOTCONN; /* Caused by app exiting. */
2751 goto error;
2752 } else if (ret < 0) {
2753 goto error;
2754 }
2755
2756 health_code_update();
2757
2758 /* Send all streams to application. */
2759 pthread_mutex_lock(&reg_chan->stream_list_lock);
2760 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2761 struct ust_app_stream stream;
2762
2763 ret = duplicate_stream_object(reg_stream, &stream);
2764 if (ret < 0) {
2765 goto error_stream_unlock;
2766 }
2767
2768 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2769 if (ret < 0) {
2770 (void) release_ust_app_stream(-1, &stream, app);
2771 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2772 ret = -ENOTCONN; /* Caused by app exiting. */
2773 }
2774 goto error_stream_unlock;
2775 }
2776
2777 /*
2778 * The return value is not important here. This function will output an
2779 * error if needed.
2780 */
2781 (void) release_ust_app_stream(-1, &stream, app);
2782 }
2783 ua_chan->is_sent = 1;
2784
2785error_stream_unlock:
2786 pthread_mutex_unlock(&reg_chan->stream_list_lock);
2787error:
2788 return ret;
2789}
2790
2791/*
2792 * Create and send to the application the created buffers with per UID buffers.
2793 *
2794 * This MUST be called with a RCU read side lock acquired.
2795 * The session list lock and the session's lock must be acquired.
2796 *
2797 * Return 0 on success else a negative value.
2798 */
2799static int create_channel_per_uid(struct ust_app *app,
2800 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2801 struct ust_app_channel *ua_chan)
2802{
2803 int ret;
2804 struct buffer_reg_uid *reg_uid;
2805 struct buffer_reg_channel *reg_chan;
2806 struct ltt_session *session = NULL;
2807 enum lttng_error_code notification_ret;
2808 struct ust_registry_channel *chan_reg;
2809
2810 assert(app);
2811 assert(usess);
2812 assert(ua_sess);
2813 assert(ua_chan);
2814
2815 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2816
2817 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2818 /*
2819 * The session creation handles the creation of this global registry
2820 * object. If none can be find, there is a code flow problem or a
2821 * teardown race.
2822 */
2823 assert(reg_uid);
2824
2825 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2826 reg_uid);
2827 if (reg_chan) {
2828 goto send_channel;
2829 }
2830
2831 /* Create the buffer registry channel object. */
2832 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2833 if (ret < 0) {
2834 ERR("Error creating the UST channel \"%s\" registry instance",
2835 ua_chan->name);
2836 goto error;
2837 }
2838
2839 session = session_find_by_id(ua_sess->tracing_id);
2840 assert(session);
2841 assert(pthread_mutex_trylock(&session->lock));
2842 assert(session_trylock_list());
2843
2844 /*
2845 * Create the buffers on the consumer side. This call populates the
2846 * ust app channel object with all streams and data object.
2847 */
2848 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2849 app->bits_per_long, reg_uid->registry->reg.ust,
2850 session->most_recent_chunk_id.value);
2851 if (ret < 0) {
2852 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2853 ua_chan->name);
2854
2855 /*
2856 * Let's remove the previously created buffer registry channel so
2857 * it's not visible anymore in the session registry.
2858 */
2859 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2860 ua_chan->tracing_channel_id, false);
2861 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2862 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2863 goto error;
2864 }
2865
2866 /*
2867 * Setup the streams and add it to the session registry.
2868 */
2869 ret = setup_buffer_reg_channel(reg_uid->registry,
2870 ua_chan, reg_chan, app);
2871 if (ret < 0) {
2872 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2873 goto error;
2874 }
2875
2876 /* Notify the notification subsystem of the channel's creation. */
2877 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2878 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2879 ua_chan->tracing_channel_id);
2880 assert(chan_reg);
2881 chan_reg->consumer_key = ua_chan->key;
2882 chan_reg = NULL;
2883 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
2884
2885 notification_ret = notification_thread_command_add_channel(
2886 notification_thread_handle, session->name,
2887 ua_sess->effective_credentials.uid,
2888 ua_sess->effective_credentials.gid, ua_chan->name,
2889 ua_chan->key, LTTNG_DOMAIN_UST,
2890 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2891 if (notification_ret != LTTNG_OK) {
2892 ret = - (int) notification_ret;
2893 ERR("Failed to add channel to notification thread");
2894 goto error;
2895 }
2896
2897send_channel:
2898 /* Send buffers to the application. */
2899 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2900 if (ret < 0) {
2901 if (ret != -ENOTCONN) {
2902 ERR("Error sending channel to application");
2903 }
2904 goto error;
2905 }
2906
2907error:
2908 if (session) {
2909 session_put(session);
2910 }
2911 return ret;
2912}
2913
2914/*
2915 * Create and send to the application the created buffers with per PID buffers.
2916 *
2917 * Called with UST app session lock held.
2918 * The session list lock and the session's lock must be acquired.
2919 *
2920 * Return 0 on success else a negative value.
2921 */
2922static int create_channel_per_pid(struct ust_app *app,
2923 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2924 struct ust_app_channel *ua_chan)
2925{
2926 int ret;
2927 struct ust_registry_session *registry;
2928 enum lttng_error_code cmd_ret;
2929 struct ltt_session *session = NULL;
2930 uint64_t chan_reg_key;
2931 struct ust_registry_channel *chan_reg;
2932
2933 assert(app);
2934 assert(usess);
2935 assert(ua_sess);
2936 assert(ua_chan);
2937
2938 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2939
2940 rcu_read_lock();
2941
2942 registry = get_session_registry(ua_sess);
2943 /* The UST app session lock is held, registry shall not be null. */
2944 assert(registry);
2945
2946 /* Create and add a new channel registry to session. */
2947 ret = ust_registry_channel_add(registry, ua_chan->key);
2948 if (ret < 0) {
2949 ERR("Error creating the UST channel \"%s\" registry instance",
2950 ua_chan->name);
2951 goto error;
2952 }
2953
2954 session = session_find_by_id(ua_sess->tracing_id);
2955 assert(session);
2956
2957 assert(pthread_mutex_trylock(&session->lock));
2958 assert(session_trylock_list());
2959
2960 /* Create and get channel on the consumer side. */
2961 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2962 app->bits_per_long, registry,
2963 session->most_recent_chunk_id.value);
2964 if (ret < 0) {
2965 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2966 ua_chan->name);
2967 goto error_remove_from_registry;
2968 }
2969
2970 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2971 if (ret < 0) {
2972 if (ret != -ENOTCONN) {
2973 ERR("Error sending channel to application");
2974 }
2975 goto error_remove_from_registry;
2976 }
2977
2978 chan_reg_key = ua_chan->key;
2979 pthread_mutex_lock(&registry->lock);
2980 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2981 assert(chan_reg);
2982 chan_reg->consumer_key = ua_chan->key;
2983 pthread_mutex_unlock(&registry->lock);
2984
2985 cmd_ret = notification_thread_command_add_channel(
2986 notification_thread_handle, session->name,
2987 ua_sess->effective_credentials.uid,
2988 ua_sess->effective_credentials.gid, ua_chan->name,
2989 ua_chan->key, LTTNG_DOMAIN_UST,
2990 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2991 if (cmd_ret != LTTNG_OK) {
2992 ret = - (int) cmd_ret;
2993 ERR("Failed to add channel to notification thread");
2994 goto error_remove_from_registry;
2995 }
2996
2997error_remove_from_registry:
2998 if (ret) {
2999 ust_registry_channel_del_free(registry, ua_chan->key, false);
3000 }
3001error:
3002 rcu_read_unlock();
3003 if (session) {
3004 session_put(session);
3005 }
3006 return ret;
3007}
3008
3009/*
3010 * From an already allocated ust app channel, create the channel buffers if
3011 * needed and send them to the application. This MUST be called with a RCU read
3012 * side lock acquired.
3013 *
3014 * Called with UST app session lock held.
3015 *
3016 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3017 * the application exited concurrently.
3018 */
3019static int ust_app_channel_send(struct ust_app *app,
3020 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3021 struct ust_app_channel *ua_chan)
3022{
3023 int ret;
3024
3025 assert(app);
3026 assert(usess);
3027 assert(usess->active);
3028 assert(ua_sess);
3029 assert(ua_chan);
3030
3031 /* Handle buffer type before sending the channel to the application. */
3032 switch (usess->buffer_type) {
3033 case LTTNG_BUFFER_PER_UID:
3034 {
3035 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3036 if (ret < 0) {
3037 goto error;
3038 }
3039 break;
3040 }
3041 case LTTNG_BUFFER_PER_PID:
3042 {
3043 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3044 if (ret < 0) {
3045 goto error;
3046 }
3047 break;
3048 }
3049 default:
3050 assert(0);
3051 ret = -EINVAL;
3052 goto error;
3053 }
3054
3055 /* Initialize ust objd object using the received handle and add it. */
3056 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3057 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
3058
3059 /* If channel is not enabled, disable it on the tracer */
3060 if (!ua_chan->enabled) {
3061 ret = disable_ust_channel(app, ua_sess, ua_chan);
3062 if (ret < 0) {
3063 goto error;
3064 }
3065 }
3066
3067error:
3068 return ret;
3069}
3070
3071/*
3072 * Create UST app channel and return it through ua_chanp if not NULL.
3073 *
3074 * Called with UST app session lock and RCU read-side lock held.
3075 *
3076 * Return 0 on success or else a negative value.
3077 */
3078static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3079 struct ltt_ust_channel *uchan,
3080 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
3081 struct ust_app_channel **ua_chanp)
3082{
3083 int ret = 0;
3084 struct lttng_ht_iter iter;
3085 struct lttng_ht_node_str *ua_chan_node;
3086 struct ust_app_channel *ua_chan;
3087
3088 /* Lookup channel in the ust app session */
3089 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3090 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
3091 if (ua_chan_node != NULL) {
3092 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3093 goto end;
3094 }
3095
3096 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
3097 if (ua_chan == NULL) {
3098 /* Only malloc can fail here */
3099 ret = -ENOMEM;
3100 goto error;
3101 }
3102 shadow_copy_channel(ua_chan, uchan);
3103
3104 /* Set channel type. */
3105 ua_chan->attr.type = type;
3106
3107 /* Only add the channel if successful on the tracer side. */
3108 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3109end:
3110 if (ua_chanp) {
3111 *ua_chanp = ua_chan;
3112 }
3113
3114 /* Everything went well. */
3115 return 0;
3116
3117error:
3118 return ret;
3119}
3120
3121/*
3122 * Create UST app event and create it on the tracer side.
3123 *
3124 * Called with ust app session mutex held.
3125 */
3126static
3127int create_ust_app_event(struct ust_app_session *ua_sess,
3128 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3129 struct ust_app *app)
3130{
3131 int ret = 0;
3132 struct ust_app_event *ua_event;
3133
3134 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3135 if (ua_event == NULL) {
3136 /* Only failure mode of alloc_ust_app_event(). */
3137 ret = -ENOMEM;
3138 goto end;
3139 }
3140 shadow_copy_event(ua_event, uevent);
3141
3142 /* Create it on the tracer side */
3143 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
3144 if (ret < 0) {
3145 /*
3146 * Not found previously means that it does not exist on the
3147 * tracer. If the application reports that the event existed,
3148 * it means there is a bug in the sessiond or lttng-ust
3149 * (or corruption, etc.)
3150 */
3151 if (ret == -LTTNG_UST_ERR_EXIST) {
3152 ERR("Tracer for application reported that an event being created already existed: "
3153 "event_name = \"%s\", pid = %d, ppid = %d, uid = %d, gid = %d",
3154 uevent->attr.name,
3155 app->pid, app->ppid, app->uid,
3156 app->gid);
3157 }
3158 goto error;
3159 }
3160
3161 add_unique_ust_app_event(ua_chan, ua_event);
3162
3163 DBG2("UST app create event %s for PID %d completed", ua_event->name,
3164 app->pid);
3165
3166end:
3167 return ret;
3168
3169error:
3170 /* Valid. Calling here is already in a read side lock */
3171 delete_ust_app_event(-1, ua_event, app);
3172 return ret;
3173}
3174
3175/*
3176 * Create UST metadata and open it on the tracer side.
3177 *
3178 * Called with UST app session lock held and RCU read side lock.
3179 */
3180static int create_ust_app_metadata(struct ust_app_session *ua_sess,
3181 struct ust_app *app, struct consumer_output *consumer)
3182{
3183 int ret = 0;
3184 struct ust_app_channel *metadata;
3185 struct consumer_socket *socket;
3186 struct ust_registry_session *registry;
3187 struct ltt_session *session = NULL;
3188
3189 assert(ua_sess);
3190 assert(app);
3191 assert(consumer);
3192
3193 registry = get_session_registry(ua_sess);
3194 /* The UST app session is held registry shall not be null. */
3195 assert(registry);
3196
3197 pthread_mutex_lock(&registry->lock);
3198
3199 /* Metadata already exists for this registry or it was closed previously */
3200 if (registry->metadata_key || registry->metadata_closed) {
3201 ret = 0;
3202 goto error;
3203 }
3204
3205 /* Allocate UST metadata */
3206 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
3207 if (!metadata) {
3208 /* malloc() failed */
3209 ret = -ENOMEM;
3210 goto error;
3211 }
3212
3213 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
3214
3215 /* Need one fd for the channel. */
3216 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3217 if (ret < 0) {
3218 ERR("Exhausted number of available FD upon create metadata");
3219 goto error;
3220 }
3221
3222 /* Get the right consumer socket for the application. */
3223 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3224 if (!socket) {
3225 ret = -EINVAL;
3226 goto error_consumer;
3227 }
3228
3229 /*
3230 * Keep metadata key so we can identify it on the consumer side. Assign it
3231 * to the registry *before* we ask the consumer so we avoid the race of the
3232 * consumer requesting the metadata and the ask_channel call on our side
3233 * did not returned yet.
3234 */
3235 registry->metadata_key = metadata->key;
3236
3237 session = session_find_by_id(ua_sess->tracing_id);
3238 assert(session);
3239
3240 assert(pthread_mutex_trylock(&session->lock));
3241 assert(session_trylock_list());
3242
3243 /*
3244 * Ask the metadata channel creation to the consumer. The metadata object
3245 * will be created by the consumer and kept their. However, the stream is
3246 * never added or monitored until we do a first push metadata to the
3247 * consumer.
3248 */
3249 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3250 registry, session->current_trace_chunk);
3251 if (ret < 0) {
3252 /* Nullify the metadata key so we don't try to close it later on. */
3253 registry->metadata_key = 0;
3254 goto error_consumer;
3255 }
3256
3257 /*
3258 * The setup command will make the metadata stream be sent to the relayd,
3259 * if applicable, and the thread managing the metadatas. This is important
3260 * because after this point, if an error occurs, the only way the stream
3261 * can be deleted is to be monitored in the consumer.
3262 */
3263 ret = consumer_setup_metadata(socket, metadata->key);
3264 if (ret < 0) {
3265 /* Nullify the metadata key so we don't try to close it later on. */
3266 registry->metadata_key = 0;
3267 goto error_consumer;
3268 }
3269
3270 DBG2("UST metadata with key %" PRIu64 " created for app pid %d",
3271 metadata->key, app->pid);
3272
3273error_consumer:
3274 lttng_fd_put(LTTNG_FD_APPS, 1);
3275 delete_ust_app_channel(-1, metadata, app);
3276error:
3277 pthread_mutex_unlock(&registry->lock);
3278 if (session) {
3279 session_put(session);
3280 }
3281 return ret;
3282}
3283
3284/*
3285 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
3286 * acquired before calling this function.
3287 */
3288struct ust_app *ust_app_find_by_pid(pid_t pid)
3289{
3290 struct ust_app *app = NULL;
3291 struct lttng_ht_node_ulong *node;
3292 struct lttng_ht_iter iter;
3293
3294 lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) pid), &iter);
3295 node = lttng_ht_iter_get_node_ulong(&iter);
3296 if (node == NULL) {
3297 DBG2("UST app no found with pid %d", pid);
3298 goto error;
3299 }
3300
3301 DBG2("Found UST app by pid %d", pid);
3302
3303 app = caa_container_of(node, struct ust_app, pid_n);
3304
3305error:
3306 return app;
3307}
3308
3309/*
3310 * Allocate and init an UST app object using the registration information and
3311 * the command socket. This is called when the command socket connects to the
3312 * session daemon.
3313 *
3314 * The object is returned on success or else NULL.
3315 */
3316struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
3317{
3318 struct ust_app *lta = NULL;
3319
3320 assert(msg);
3321 assert(sock >= 0);
3322
3323 DBG3("UST app creating application for socket %d", sock);
3324
3325 if ((msg->bits_per_long == 64 &&
3326 (uatomic_read(&ust_consumerd64_fd) == -EINVAL))
3327 || (msg->bits_per_long == 32 &&
3328 (uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
3329 ERR("Registration failed: application \"%s\" (pid: %d) has "
3330 "%d-bit long, but no consumerd for this size is available.\n",
3331 msg->name, msg->pid, msg->bits_per_long);
3332 goto error;
3333 }
3334
3335 lta = zmalloc(sizeof(struct ust_app));
3336 if (lta == NULL) {
3337 PERROR("malloc");
3338 goto error;
3339 }
3340
3341 lta->ppid = msg->ppid;
3342 lta->uid = msg->uid;
3343 lta->gid = msg->gid;
3344
3345 lta->bits_per_long = msg->bits_per_long;
3346 lta->uint8_t_alignment = msg->uint8_t_alignment;
3347 lta->uint16_t_alignment = msg->uint16_t_alignment;
3348 lta->uint32_t_alignment = msg->uint32_t_alignment;
3349 lta->uint64_t_alignment = msg->uint64_t_alignment;
3350 lta->long_alignment = msg->long_alignment;
3351 lta->byte_order = msg->byte_order;
3352
3353 lta->v_major = msg->major;
3354 lta->v_minor = msg->minor;
3355 lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3356 lta->ust_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3357 lta->ust_sessions_objd = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3358 lta->notify_sock = -1;
3359
3360 /* Copy name and make sure it's NULL terminated. */
3361 strncpy(lta->name, msg->name, sizeof(lta->name));
3362 lta->name[UST_APP_PROCNAME_LEN] = '\0';
3363
3364 /*
3365 * Before this can be called, when receiving the registration information,
3366 * the application compatibility is checked. So, at this point, the
3367 * application can work with this session daemon.
3368 */
3369 lta->compatible = 1;
3370
3371 lta->pid = msg->pid;
3372 lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long) lta->pid);
3373 lta->sock = sock;
3374 pthread_mutex_init(&lta->sock_lock, NULL);
3375 lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
3376
3377 CDS_INIT_LIST_HEAD(&lta->teardown_head);
3378error:
3379 return lta;
3380}
3381
3382/*
3383 * For a given application object, add it to every hash table.
3384 */
3385void ust_app_add(struct ust_app *app)
3386{
3387 assert(app);
3388 assert(app->notify_sock >= 0);
3389
3390 app->registration_time = time(NULL);
3391
3392 rcu_read_lock();
3393
3394 /*
3395 * On a re-registration, we want to kick out the previous registration of
3396 * that pid
3397 */
3398 lttng_ht_add_replace_ulong(ust_app_ht, &app->pid_n);
3399
3400 /*
3401 * The socket _should_ be unique until _we_ call close. So, a add_unique
3402 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
3403 * already in the table.
3404 */
3405 lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &app->sock_n);
3406
3407 /* Add application to the notify socket hash table. */
3408 lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock);
3409 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n);
3410
3411 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
3412 "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid,
3413 app->gid, app->sock, app->name, app->notify_sock, app->v_major,
3414 app->v_minor);
3415
3416 rcu_read_unlock();
3417}
3418
3419/*
3420 * Set the application version into the object.
3421 *
3422 * Return 0 on success else a negative value either an errno code or a
3423 * LTTng-UST error code.
3424 */
3425int ust_app_version(struct ust_app *app)
3426{
3427 int ret;
3428
3429 assert(app);
3430
3431 pthread_mutex_lock(&app->sock_lock);
3432 ret = ustctl_tracer_version(app->sock, &app->version);
3433 pthread_mutex_unlock(&app->sock_lock);
3434 if (ret < 0) {
3435 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3436 ERR("UST app %d version failed with ret %d", app->sock, ret);
3437 } else {
3438 DBG3("UST app %d version failed. Application is dead", app->sock);
3439 }
3440 }
3441
3442 return ret;
3443}
3444
3445/*
3446 * Unregister app by removing it from the global traceable app list and freeing
3447 * the data struct.
3448 *
3449 * The socket is already closed at this point so no close to sock.
3450 */
3451void ust_app_unregister(int sock)
3452{
3453 struct ust_app *lta;
3454 struct lttng_ht_node_ulong *node;
3455 struct lttng_ht_iter ust_app_sock_iter;
3456 struct lttng_ht_iter iter;
3457 struct ust_app_session *ua_sess;
3458 int ret;
3459
3460 rcu_read_lock();
3461
3462 /* Get the node reference for a call_rcu */
3463 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &ust_app_sock_iter);
3464 node = lttng_ht_iter_get_node_ulong(&ust_app_sock_iter);
3465 assert(node);
3466
3467 lta = caa_container_of(node, struct ust_app, sock_n);
3468 DBG("PID %d unregistering with sock %d", lta->pid, sock);
3469
3470 /*
3471 * For per-PID buffers, perform "push metadata" and flush all
3472 * application streams before removing app from hash tables,
3473 * ensuring proper behavior of data_pending check.
3474 * Remove sessions so they are not visible during deletion.
3475 */
3476 cds_lfht_for_each_entry(lta->sessions->ht, &iter.iter, ua_sess,
3477 node.node) {
3478 struct ust_registry_session *registry;
3479
3480 ret = lttng_ht_del(lta->sessions, &iter);
3481 if (ret) {
3482 /* The session was already removed so scheduled for teardown. */
3483 continue;
3484 }
3485
3486 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
3487 (void) ust_app_flush_app_session(lta, ua_sess);
3488 }
3489
3490 /*
3491 * Add session to list for teardown. This is safe since at this point we
3492 * are the only one using this list.
3493 */
3494 pthread_mutex_lock(&ua_sess->lock);
3495
3496 if (ua_sess->deleted) {
3497 pthread_mutex_unlock(&ua_sess->lock);
3498 continue;
3499 }
3500
3501 /*
3502 * Normally, this is done in the delete session process which is
3503 * executed in the call rcu below. However, upon registration we can't
3504 * afford to wait for the grace period before pushing data or else the
3505 * data pending feature can race between the unregistration and stop
3506 * command where the data pending command is sent *before* the grace
3507 * period ended.
3508 *
3509 * The close metadata below nullifies the metadata pointer in the
3510 * session so the delete session will NOT push/close a second time.
3511 */
3512 registry = get_session_registry(ua_sess);
3513 if (registry) {
3514 /* Push metadata for application before freeing the application. */
3515 (void) push_metadata(registry, ua_sess->consumer);
3516
3517 /*
3518 * Don't ask to close metadata for global per UID buffers. Close
3519 * metadata only on destroy trace session in this case. Also, the
3520 * previous push metadata could have flag the metadata registry to
3521 * close so don't send a close command if closed.
3522 */
3523 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
3524 /* And ask to close it for this session registry. */
3525 (void) close_metadata(registry, ua_sess->consumer);
3526 }
3527 }
3528 cds_list_add(&ua_sess->teardown_node, &lta->teardown_head);
3529
3530 pthread_mutex_unlock(&ua_sess->lock);
3531 }
3532
3533 /* Remove application from PID hash table */
3534 ret = lttng_ht_del(ust_app_ht_by_sock, &ust_app_sock_iter);
3535 assert(!ret);
3536
3537 /*
3538 * Remove application from notify hash table. The thread handling the
3539 * notify socket could have deleted the node so ignore on error because
3540 * either way it's valid. The close of that socket is handled by the
3541 * apps_notify_thread.
3542 */
3543 iter.iter.node = &lta->notify_sock_n.node;
3544 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
3545
3546 /*
3547 * Ignore return value since the node might have been removed before by an
3548 * add replace during app registration because the PID can be reassigned by
3549 * the OS.
3550 */
3551 iter.iter.node = &lta->pid_n.node;
3552 ret = lttng_ht_del(ust_app_ht, &iter);
3553 if (ret) {
3554 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
3555 lta->pid);
3556 }
3557
3558 /* Free memory */
3559 call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
3560
3561 rcu_read_unlock();
3562 return;
3563}
3564
3565/*
3566 * Fill events array with all events name of all registered apps.
3567 */
3568int ust_app_list_events(struct lttng_event **events)
3569{
3570 int ret, handle;
3571 size_t nbmem, count = 0;
3572 struct lttng_ht_iter iter;
3573 struct ust_app *app;
3574 struct lttng_event *tmp_event;
3575
3576 nbmem = UST_APP_EVENT_LIST_SIZE;
3577 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
3578 if (tmp_event == NULL) {
3579 PERROR("zmalloc ust app events");
3580 ret = -ENOMEM;
3581 goto error;
3582 }
3583
3584 rcu_read_lock();
3585
3586 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3587 struct lttng_ust_tracepoint_iter uiter;
3588
3589 health_code_update();
3590
3591 if (!app->compatible) {
3592 /*
3593 * TODO: In time, we should notice the caller of this error by
3594 * telling him that this is a version error.
3595 */
3596 continue;
3597 }
3598 pthread_mutex_lock(&app->sock_lock);
3599 handle = ustctl_tracepoint_list(app->sock);
3600 if (handle < 0) {
3601 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3602 ERR("UST app list events getting handle failed for app pid %d",
3603 app->pid);
3604 }
3605 pthread_mutex_unlock(&app->sock_lock);
3606 continue;
3607 }
3608
3609 while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
3610 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3611 /* Handle ustctl error. */
3612 if (ret < 0) {
3613 int release_ret;
3614
3615 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3616 ERR("UST app tp list get failed for app %d with ret %d",
3617 app->sock, ret);
3618 } else {
3619 DBG3("UST app tp list get failed. Application is dead");
3620 /*
3621 * This is normal behavior, an application can die during the
3622 * creation process. Don't report an error so the execution can
3623 * continue normally. Continue normal execution.
3624 */
3625 break;
3626 }
3627 free(tmp_event);
3628 release_ret = ustctl_release_handle(app->sock, handle);
3629 if (release_ret < 0 &&
3630 release_ret != -LTTNG_UST_ERR_EXITING &&
3631 release_ret != -EPIPE) {
3632 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3633 }
3634 pthread_mutex_unlock(&app->sock_lock);
3635 goto rcu_error;
3636 }
3637
3638 health_code_update();
3639 if (count >= nbmem) {
3640 /* In case the realloc fails, we free the memory */
3641 struct lttng_event *new_tmp_event;
3642 size_t new_nbmem;
3643
3644 new_nbmem = nbmem << 1;
3645 DBG2("Reallocating event list from %zu to %zu entries",
3646 nbmem, new_nbmem);
3647 new_tmp_event = realloc(tmp_event,
3648 new_nbmem * sizeof(struct lttng_event));
3649 if (new_tmp_event == NULL) {
3650 int release_ret;
3651
3652 PERROR("realloc ust app events");
3653 free(tmp_event);
3654 ret = -ENOMEM;
3655 release_ret = ustctl_release_handle(app->sock, handle);
3656 if (release_ret < 0 &&
3657 release_ret != -LTTNG_UST_ERR_EXITING &&
3658 release_ret != -EPIPE) {
3659 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3660 }
3661 pthread_mutex_unlock(&app->sock_lock);
3662 goto rcu_error;
3663 }
3664 /* Zero the new memory */
3665 memset(new_tmp_event + nbmem, 0,
3666 (new_nbmem - nbmem) * sizeof(struct lttng_event));
3667 nbmem = new_nbmem;
3668 tmp_event = new_tmp_event;
3669 }
3670 memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
3671 tmp_event[count].loglevel = uiter.loglevel;
3672 tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
3673 tmp_event[count].pid = app->pid;
3674 tmp_event[count].enabled = -1;
3675 count++;
3676 }
3677 ret = ustctl_release_handle(app->sock, handle);
3678 pthread_mutex_unlock(&app->sock_lock);
3679 if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3680 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3681 }
3682 }
3683
3684 ret = count;
3685 *events = tmp_event;
3686
3687 DBG2("UST app list events done (%zu events)", count);
3688
3689rcu_error:
3690 rcu_read_unlock();
3691error:
3692 health_code_update();
3693 return ret;
3694}
3695
3696/*
3697 * Fill events array with all events name of all registered apps.
3698 */
3699int ust_app_list_event_fields(struct lttng_event_field **fields)
3700{
3701 int ret, handle;
3702 size_t nbmem, count = 0;
3703 struct lttng_ht_iter iter;
3704 struct ust_app *app;
3705 struct lttng_event_field *tmp_event;
3706
3707 nbmem = UST_APP_EVENT_LIST_SIZE;
3708 tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
3709 if (tmp_event == NULL) {
3710 PERROR("zmalloc ust app event fields");
3711 ret = -ENOMEM;
3712 goto error;
3713 }
3714
3715 rcu_read_lock();
3716
3717 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3718 struct lttng_ust_field_iter uiter;
3719
3720 health_code_update();
3721
3722 if (!app->compatible) {
3723 /*
3724 * TODO: In time, we should notice the caller of this error by
3725 * telling him that this is a version error.
3726 */
3727 continue;
3728 }
3729 pthread_mutex_lock(&app->sock_lock);
3730 handle = ustctl_tracepoint_field_list(app->sock);
3731 if (handle < 0) {
3732 if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
3733 ERR("UST app list field getting handle failed for app pid %d",
3734 app->pid);
3735 }
3736 pthread_mutex_unlock(&app->sock_lock);
3737 continue;
3738 }
3739
3740 while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
3741 &uiter)) != -LTTNG_UST_ERR_NOENT) {
3742 /* Handle ustctl error. */
3743 if (ret < 0) {
3744 int release_ret;
3745
3746 if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
3747 ERR("UST app tp list field failed for app %d with ret %d",
3748 app->sock, ret);
3749 } else {
3750 DBG3("UST app tp list field failed. Application is dead");
3751 /*
3752 * This is normal behavior, an application can die during the
3753 * creation process. Don't report an error so the execution can
3754 * continue normally. Reset list and count for next app.
3755 */
3756 break;
3757 }
3758 free(tmp_event);
3759 release_ret = ustctl_release_handle(app->sock, handle);
3760 pthread_mutex_unlock(&app->sock_lock);
3761 if (release_ret < 0 &&
3762 release_ret != -LTTNG_UST_ERR_EXITING &&
3763 release_ret != -EPIPE) {
3764 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3765 }
3766 goto rcu_error;
3767 }
3768
3769 health_code_update();
3770 if (count >= nbmem) {
3771 /* In case the realloc fails, we free the memory */
3772 struct lttng_event_field *new_tmp_event;
3773 size_t new_nbmem;
3774
3775 new_nbmem = nbmem << 1;
3776 DBG2("Reallocating event field list from %zu to %zu entries",
3777 nbmem, new_nbmem);
3778 new_tmp_event = realloc(tmp_event,
3779 new_nbmem * sizeof(struct lttng_event_field));
3780 if (new_tmp_event == NULL) {
3781 int release_ret;
3782
3783 PERROR("realloc ust app event fields");
3784 free(tmp_event);
3785 ret = -ENOMEM;
3786 release_ret = ustctl_release_handle(app->sock, handle);
3787 pthread_mutex_unlock(&app->sock_lock);
3788 if (release_ret &&
3789 release_ret != -LTTNG_UST_ERR_EXITING &&
3790 release_ret != -EPIPE) {
3791 ERR("Error releasing app handle for app %d with ret %d", app->sock, release_ret);
3792 }
3793 goto rcu_error;
3794 }
3795 /* Zero the new memory */
3796 memset(new_tmp_event + nbmem, 0,
3797 (new_nbmem - nbmem) * sizeof(struct lttng_event_field));
3798 nbmem = new_nbmem;
3799 tmp_event = new_tmp_event;
3800 }
3801
3802 memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
3803 /* Mapping between these enums matches 1 to 1. */
3804 tmp_event[count].type = (enum lttng_event_field_type) uiter.type;
3805 tmp_event[count].nowrite = uiter.nowrite;
3806
3807 memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
3808 tmp_event[count].event.loglevel = uiter.loglevel;
3809 tmp_event[count].event.type = LTTNG_EVENT_TRACEPOINT;
3810 tmp_event[count].event.pid = app->pid;
3811 tmp_event[count].event.enabled = -1;
3812 count++;
3813 }
3814 ret = ustctl_release_handle(app->sock, handle);
3815 pthread_mutex_unlock(&app->sock_lock);
3816 if (ret < 0 &&
3817 ret != -LTTNG_UST_ERR_EXITING &&
3818 ret != -EPIPE) {
3819 ERR("Error releasing app handle for app %d with ret %d", app->sock, ret);
3820 }
3821 }
3822
3823 ret = count;
3824 *fields = tmp_event;
3825
3826 DBG2("UST app list event fields done (%zu events)", count);
3827
3828rcu_error:
3829 rcu_read_unlock();
3830error:
3831 health_code_update();
3832 return ret;
3833}
3834
3835/*
3836 * Free and clean all traceable apps of the global list.
3837 *
3838 * Should _NOT_ be called with RCU read-side lock held.
3839 */
3840void ust_app_clean_list(void)
3841{
3842 int ret;
3843 struct ust_app *app;
3844 struct lttng_ht_iter iter;
3845
3846 DBG2("UST app cleaning registered apps hash table");
3847
3848 rcu_read_lock();
3849
3850 /* Cleanup notify socket hash table */
3851 if (ust_app_ht_by_notify_sock) {
3852 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
3853 notify_sock_n.node) {
3854 struct cds_lfht_node *node;
3855 struct ust_app *app;
3856
3857 node = cds_lfht_iter_get_node(&iter.iter);
3858 if (!node) {
3859 continue;
3860 }
3861
3862 app = container_of(node, struct ust_app,
3863 notify_sock_n.node);
3864 ust_app_notify_sock_unregister(app->notify_sock);
3865 }
3866 }
3867
3868 if (ust_app_ht) {
3869 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3870 ret = lttng_ht_del(ust_app_ht, &iter);
3871 assert(!ret);
3872 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
3873 }
3874 }
3875
3876 /* Cleanup socket hash table */
3877 if (ust_app_ht_by_sock) {
3878 cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
3879 sock_n.node) {
3880 ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
3881 assert(!ret);
3882 }
3883 }
3884
3885 rcu_read_unlock();
3886
3887 /* Destroy is done only when the ht is empty */
3888 if (ust_app_ht) {
3889 ht_cleanup_push(ust_app_ht);
3890 }
3891 if (ust_app_ht_by_sock) {
3892 ht_cleanup_push(ust_app_ht_by_sock);
3893 }
3894 if (ust_app_ht_by_notify_sock) {
3895 ht_cleanup_push(ust_app_ht_by_notify_sock);
3896 }
3897}
3898
3899/*
3900 * Init UST app hash table.
3901 */
3902int ust_app_ht_alloc(void)
3903{
3904 ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3905 if (!ust_app_ht) {
3906 return -1;
3907 }
3908 ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3909 if (!ust_app_ht_by_sock) {
3910 return -1;
3911 }
3912 ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3913 if (!ust_app_ht_by_notify_sock) {
3914 return -1;
3915 }
3916 return 0;
3917}
3918
3919/*
3920 * For a specific UST session, disable the channel for all registered apps.
3921 */
3922int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
3923 struct ltt_ust_channel *uchan)
3924{
3925 int ret = 0;
3926 struct lttng_ht_iter iter;
3927 struct lttng_ht_node_str *ua_chan_node;
3928 struct ust_app *app;
3929 struct ust_app_session *ua_sess;
3930 struct ust_app_channel *ua_chan;
3931
3932 assert(usess->active);
3933 DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
3934 uchan->name, usess->id);
3935
3936 rcu_read_lock();
3937
3938 /* For every registered applications */
3939 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3940 struct lttng_ht_iter uiter;
3941 if (!app->compatible) {
3942 /*
3943 * TODO: In time, we should notice the caller of this error by
3944 * telling him that this is a version error.
3945 */
3946 continue;
3947 }
3948 ua_sess = lookup_session_by_app(usess, app);
3949 if (ua_sess == NULL) {
3950 continue;
3951 }
3952
3953 /* Get channel */
3954 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
3955 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
3956 /* If the session if found for the app, the channel must be there */
3957 assert(ua_chan_node);
3958
3959 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
3960 /* The channel must not be already disabled */
3961 assert(ua_chan->enabled == 1);
3962
3963 /* Disable channel onto application */
3964 ret = disable_ust_app_channel(ua_sess, ua_chan, app);
3965 if (ret < 0) {
3966 /* XXX: We might want to report this error at some point... */
3967 continue;
3968 }
3969 }
3970
3971 rcu_read_unlock();
3972 return ret;
3973}
3974
3975/*
3976 * For a specific UST session, enable the channel for all registered apps.
3977 */
3978int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
3979 struct ltt_ust_channel *uchan)
3980{
3981 int ret = 0;
3982 struct lttng_ht_iter iter;
3983 struct ust_app *app;
3984 struct ust_app_session *ua_sess;
3985
3986 assert(usess->active);
3987 DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
3988 uchan->name, usess->id);
3989
3990 rcu_read_lock();
3991
3992 /* For every registered applications */
3993 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
3994 if (!app->compatible) {
3995 /*
3996 * TODO: In time, we should notice the caller of this error by
3997 * telling him that this is a version error.
3998 */
3999 continue;
4000 }
4001 ua_sess = lookup_session_by_app(usess, app);
4002 if (ua_sess == NULL) {
4003 continue;
4004 }
4005
4006 /* Enable channel onto application */
4007 ret = enable_ust_app_channel(ua_sess, uchan, app);
4008 if (ret < 0) {
4009 /* XXX: We might want to report this error at some point... */
4010 continue;
4011 }
4012 }
4013
4014 rcu_read_unlock();
4015 return ret;
4016}
4017
4018/*
4019 * Disable an event in a channel and for a specific session.
4020 */
4021int ust_app_disable_event_glb(struct ltt_ust_session *usess,
4022 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4023{
4024 int ret = 0;
4025 struct lttng_ht_iter iter, uiter;
4026 struct lttng_ht_node_str *ua_chan_node;
4027 struct ust_app *app;
4028 struct ust_app_session *ua_sess;
4029 struct ust_app_channel *ua_chan;
4030 struct ust_app_event *ua_event;
4031
4032 assert(usess->active);
4033 DBG("UST app disabling event %s for all apps in channel "
4034 "%s for session id %" PRIu64,
4035 uevent->attr.name, uchan->name, usess->id);
4036
4037 rcu_read_lock();
4038
4039 /* For all registered applications */
4040 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4041 if (!app->compatible) {
4042 /*
4043 * TODO: In time, we should notice the caller of this error by
4044 * telling him that this is a version error.
4045 */
4046 continue;
4047 }
4048 ua_sess = lookup_session_by_app(usess, app);
4049 if (ua_sess == NULL) {
4050 /* Next app */
4051 continue;
4052 }
4053
4054 /* Lookup channel in the ust app session */
4055 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4056 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4057 if (ua_chan_node == NULL) {
4058 DBG2("Channel %s not found in session id %" PRIu64 " for app pid %d."
4059 "Skipping", uchan->name, usess->id, app->pid);
4060 continue;
4061 }
4062 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4063
4064 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4065 uevent->filter, uevent->attr.loglevel,
4066 uevent->exclusion);
4067 if (ua_event == NULL) {
4068 DBG2("Event %s not found in channel %s for app pid %d."
4069 "Skipping", uevent->attr.name, uchan->name, app->pid);
4070 continue;
4071 }
4072
4073 ret = disable_ust_app_event(ua_sess, ua_event, app);
4074 if (ret < 0) {
4075 /* XXX: Report error someday... */
4076 continue;
4077 }
4078 }
4079
4080 rcu_read_unlock();
4081 return ret;
4082}
4083
4084/* The ua_sess lock must be held by the caller. */
4085static
4086int ust_app_channel_create(struct ltt_ust_session *usess,
4087 struct ust_app_session *ua_sess,
4088 struct ltt_ust_channel *uchan, struct ust_app *app,
4089 struct ust_app_channel **_ua_chan)
4090{
4091 int ret = 0;
4092 struct ust_app_channel *ua_chan = NULL;
4093
4094 assert(ua_sess);
4095 ASSERT_LOCKED(ua_sess->lock);
4096
4097 if (!strncmp(uchan->name, DEFAULT_METADATA_NAME,
4098 sizeof(uchan->name))) {
4099 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
4100 &uchan->attr);
4101 ret = 0;
4102 } else {
4103 struct ltt_ust_context *uctx = NULL;
4104
4105 /*
4106 * Create channel onto application and synchronize its
4107 * configuration.
4108 */
4109 ret = ust_app_channel_allocate(ua_sess, uchan,
4110 LTTNG_UST_CHAN_PER_CPU, usess,
4111 &ua_chan);
4112 if (ret == 0) {
4113 ret = ust_app_channel_send(app, usess,
4114 ua_sess, ua_chan);
4115 } else {
4116 goto end;
4117 }
4118
4119 /* Add contexts. */
4120 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
4121 ret = create_ust_app_channel_context(ua_chan,
4122 &uctx->ctx, app);
4123 if (ret) {
4124 goto end;
4125 }
4126 }
4127 }
4128 if (ret < 0) {
4129 switch (ret) {
4130 case -ENOTCONN:
4131 /*
4132 * The application's socket is not valid. Either a bad socket
4133 * or a timeout on it. We can't inform the caller that for a
4134 * specific app, the session failed so lets continue here.
4135 */
4136 ret = 0; /* Not an error. */
4137 break;
4138 case -ENOMEM:
4139 default:
4140 break;
4141 }
4142 }
4143end:
4144 if (ret == 0 && _ua_chan) {
4145 /*
4146 * Only return the application's channel on success. Note
4147 * that the channel can still be part of the application's
4148 * channel hashtable on error.
4149 */
4150 *_ua_chan = ua_chan;
4151 }
4152 return ret;
4153}
4154
4155/*
4156 * For a specific UST session, create the channel for all registered apps.
4157 */
4158int ust_app_create_channel_glb(struct ltt_ust_session *usess,
4159 struct ltt_ust_channel *uchan)
4160{
4161 int ret = 0;
4162 struct cds_lfht_iter iter;
4163 struct ust_app *app;
4164
4165 assert(usess);
4166 assert(usess->active);
4167 assert(uchan);
4168
4169 DBG2("UST app adding channel %s to UST domain for session id %" PRIu64,
4170 uchan->name, usess->id);
4171
4172 rcu_read_lock();
4173 /* For every registered applications */
4174 cds_lfht_for_each_entry(ust_app_ht->ht, &iter, app, pid_n.node) {
4175 struct ust_app_session *ua_sess;
4176 int session_was_created = 0;
4177
4178 if (!app->compatible ||
4179 !trace_ust_pid_tracker_lookup(usess, app->pid)) {
4180 goto error_rcu_unlock;
4181 }
4182
4183 /*
4184 * Create session on the tracer side and add it to app session HT. Note
4185 * that if session exist, it will simply return a pointer to the ust
4186 * app session.
4187 */
4188 ret = find_or_create_ust_app_session(usess, app, &ua_sess,
4189 &session_was_created);
4190 if (ret < 0) {
4191 switch (ret) {
4192 case -ENOTCONN:
4193 /*
4194 * The application's socket is not valid. Either a bad
4195 * socket or a timeout on it. We can't inform the caller
4196 * that for a specific app, the session failed so lets
4197 * continue here; it is not an error.
4198 */
4199 ret = 0;
4200 goto error_rcu_unlock;
4201 case -ENOMEM:
4202 default:
4203 goto error_rcu_unlock;
4204 }
4205 }
4206
4207 if (ua_sess->deleted) {
4208 continue;
4209 }
4210 ret = ust_app_channel_create(usess, ua_sess, uchan, app, NULL);
4211 if (ret) {
4212 if (session_was_created) {
4213 destroy_app_session(app, ua_sess);
4214 }
4215 /* Continue to the next application. */
4216 }
4217 }
4218
4219error_rcu_unlock:
4220 rcu_read_unlock();
4221 return ret;
4222}
4223
4224/*
4225 * Enable event for a specific session and channel on the tracer.
4226 */
4227int ust_app_enable_event_glb(struct ltt_ust_session *usess,
4228 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4229{
4230 int ret = 0;
4231 struct lttng_ht_iter iter, uiter;
4232 struct lttng_ht_node_str *ua_chan_node;
4233 struct ust_app *app;
4234 struct ust_app_session *ua_sess;
4235 struct ust_app_channel *ua_chan;
4236 struct ust_app_event *ua_event;
4237
4238 assert(usess->active);
4239 DBG("UST app enabling event %s for all apps for session id %" PRIu64,
4240 uevent->attr.name, usess->id);
4241
4242 /*
4243 * NOTE: At this point, this function is called only if the session and
4244 * channel passed are already created for all apps. and enabled on the
4245 * tracer also.
4246 */
4247
4248 rcu_read_lock();
4249
4250 /* For all registered applications */
4251 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4252 if (!app->compatible) {
4253 /*
4254 * TODO: In time, we should notice the caller of this error by
4255 * telling him that this is a version error.
4256 */
4257 continue;
4258 }
4259 ua_sess = lookup_session_by_app(usess, app);
4260 if (!ua_sess) {
4261 /* The application has problem or is probably dead. */
4262 continue;
4263 }
4264
4265 pthread_mutex_lock(&ua_sess->lock);
4266
4267 if (ua_sess->deleted) {
4268 pthread_mutex_unlock(&ua_sess->lock);
4269 continue;
4270 }
4271
4272 /* Lookup channel in the ust app session */
4273 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4274 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4275 /*
4276 * It is possible that the channel cannot be found is
4277 * the channel/event creation occurs concurrently with
4278 * an application exit.
4279 */
4280 if (!ua_chan_node) {
4281 pthread_mutex_unlock(&ua_sess->lock);
4282 continue;
4283 }
4284
4285 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4286
4287 /* Get event node */
4288 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
4289 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
4290 if (ua_event == NULL) {
4291 DBG3("UST app enable event %s not found for app PID %d."
4292 "Skipping app", uevent->attr.name, app->pid);
4293 goto next_app;
4294 }
4295
4296 ret = enable_ust_app_event(ua_sess, ua_event, app);
4297 if (ret < 0) {
4298 pthread_mutex_unlock(&ua_sess->lock);
4299 goto error;
4300 }
4301 next_app:
4302 pthread_mutex_unlock(&ua_sess->lock);
4303 }
4304
4305error:
4306 rcu_read_unlock();
4307 return ret;
4308}
4309
4310/*
4311 * For a specific existing UST session and UST channel, creates the event for
4312 * all registered apps.
4313 */
4314int ust_app_create_event_glb(struct ltt_ust_session *usess,
4315 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent)
4316{
4317 int ret = 0;
4318 struct lttng_ht_iter iter, uiter;
4319 struct lttng_ht_node_str *ua_chan_node;
4320 struct ust_app *app;
4321 struct ust_app_session *ua_sess;
4322 struct ust_app_channel *ua_chan;
4323
4324 assert(usess->active);
4325 DBG("UST app creating event %s for all apps for session id %" PRIu64,
4326 uevent->attr.name, usess->id);
4327
4328 rcu_read_lock();
4329
4330 /* For all registered applications */
4331 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4332 if (!app->compatible) {
4333 /*
4334 * TODO: In time, we should notice the caller of this error by
4335 * telling him that this is a version error.
4336 */
4337 continue;
4338 }
4339 ua_sess = lookup_session_by_app(usess, app);
4340 if (!ua_sess) {
4341 /* The application has problem or is probably dead. */
4342 continue;
4343 }
4344
4345 pthread_mutex_lock(&ua_sess->lock);
4346
4347 if (ua_sess->deleted) {
4348 pthread_mutex_unlock(&ua_sess->lock);
4349 continue;
4350 }
4351
4352 /* Lookup channel in the ust app session */
4353 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
4354 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
4355 /* If the channel is not found, there is a code flow error */
4356 assert(ua_chan_node);
4357
4358 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
4359
4360 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
4361 pthread_mutex_unlock(&ua_sess->lock);
4362 if (ret < 0) {
4363 if (ret != -LTTNG_UST_ERR_EXIST) {
4364 /* Possible value at this point: -ENOMEM. If so, we stop! */
4365 break;
4366 }
4367 DBG2("UST app event %s already exist on app PID %d",
4368 uevent->attr.name, app->pid);
4369 continue;
4370 }
4371 }
4372
4373 rcu_read_unlock();
4374 return ret;
4375}
4376
4377/*
4378 * Start tracing for a specific UST session and app.
4379 *
4380 * Called with UST app session lock held.
4381 *
4382 */
4383static
4384int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
4385{
4386 int ret = 0;
4387 struct ust_app_session *ua_sess;
4388
4389 DBG("Starting tracing for ust app pid %d", app->pid);
4390
4391 rcu_read_lock();
4392
4393 if (!app->compatible) {
4394 goto end;
4395 }
4396
4397 ua_sess = lookup_session_by_app(usess, app);
4398 if (ua_sess == NULL) {
4399 /* The session is in teardown process. Ignore and continue. */
4400 goto end;
4401 }
4402
4403 pthread_mutex_lock(&ua_sess->lock);
4404
4405 if (ua_sess->deleted) {
4406 pthread_mutex_unlock(&ua_sess->lock);
4407 goto end;
4408 }
4409
4410 /* Upon restart, we skip the setup, already done */
4411 if (ua_sess->started) {
4412 goto skip_setup;
4413 }
4414
4415 /*
4416 * Create the metadata for the application. This returns gracefully if a
4417 * metadata was already set for the session.
4418 */
4419 ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
4420 if (ret < 0) {
4421 goto error_unlock;
4422 }
4423
4424 health_code_update();
4425
4426skip_setup:
4427 /* This starts the UST tracing */
4428 pthread_mutex_lock(&app->sock_lock);
4429 ret = ustctl_start_session(app->sock, ua_sess->handle);
4430 pthread_mutex_unlock(&app->sock_lock);
4431 if (ret < 0) {
4432 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4433 ERR("Error starting tracing for app pid: %d (ret: %d)",
4434 app->pid, ret);
4435 } else {
4436 DBG("UST app start session failed. Application is dead.");
4437 /*
4438 * This is normal behavior, an application can die during the
4439 * creation process. Don't report an error so the execution can
4440 * continue normally.
4441 */
4442 pthread_mutex_unlock(&ua_sess->lock);
4443 goto end;
4444 }
4445 goto error_unlock;
4446 }
4447
4448 /* Indicate that the session has been started once */
4449 ua_sess->started = 1;
4450
4451 pthread_mutex_unlock(&ua_sess->lock);
4452
4453 health_code_update();
4454
4455 /* Quiescent wait after starting trace */
4456 pthread_mutex_lock(&app->sock_lock);
4457 ret = ustctl_wait_quiescent(app->sock);
4458 pthread_mutex_unlock(&app->sock_lock);
4459 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4460 ERR("UST app wait quiescent failed for app pid %d ret %d",
4461 app->pid, ret);
4462 }
4463
4464end:
4465 rcu_read_unlock();
4466 health_code_update();
4467 return 0;
4468
4469error_unlock:
4470 pthread_mutex_unlock(&ua_sess->lock);
4471 rcu_read_unlock();
4472 health_code_update();
4473 return -1;
4474}
4475
4476/*
4477 * Stop tracing for a specific UST session and app.
4478 */
4479static
4480int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
4481{
4482 int ret = 0;
4483 struct ust_app_session *ua_sess;
4484 struct ust_registry_session *registry;
4485
4486 DBG("Stopping tracing for ust app pid %d", app->pid);
4487
4488 rcu_read_lock();
4489
4490 if (!app->compatible) {
4491 goto end_no_session;
4492 }
4493
4494 ua_sess = lookup_session_by_app(usess, app);
4495 if (ua_sess == NULL) {
4496 goto end_no_session;
4497 }
4498
4499 pthread_mutex_lock(&ua_sess->lock);
4500
4501 if (ua_sess->deleted) {
4502 pthread_mutex_unlock(&ua_sess->lock);
4503 goto end_no_session;
4504 }
4505
4506 /*
4507 * If started = 0, it means that stop trace has been called for a session
4508 * that was never started. It's possible since we can have a fail start
4509 * from either the application manager thread or the command thread. Simply
4510 * indicate that this is a stop error.
4511 */
4512 if (!ua_sess->started) {
4513 goto error_rcu_unlock;
4514 }
4515
4516 health_code_update();
4517
4518 /* This inhibits UST tracing */
4519 pthread_mutex_lock(&app->sock_lock);
4520 ret = ustctl_stop_session(app->sock, ua_sess->handle);
4521 pthread_mutex_unlock(&app->sock_lock);
4522 if (ret < 0) {
4523 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4524 ERR("Error stopping tracing for app pid: %d (ret: %d)",
4525 app->pid, ret);
4526 } else {
4527 DBG("UST app stop session failed. Application is dead.");
4528 /*
4529 * This is normal behavior, an application can die during the
4530 * creation process. Don't report an error so the execution can
4531 * continue normally.
4532 */
4533 goto end_unlock;
4534 }
4535 goto error_rcu_unlock;
4536 }
4537
4538 health_code_update();
4539
4540 /* Quiescent wait after stopping trace */
4541 pthread_mutex_lock(&app->sock_lock);
4542 ret = ustctl_wait_quiescent(app->sock);
4543 pthread_mutex_unlock(&app->sock_lock);
4544 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4545 ERR("UST app wait quiescent failed for app pid %d ret %d",
4546 app->pid, ret);
4547 }
4548
4549 health_code_update();
4550
4551 registry = get_session_registry(ua_sess);
4552
4553 /* The UST app session is held registry shall not be null. */
4554 assert(registry);
4555
4556 /* Push metadata for application before freeing the application. */
4557 (void) push_metadata(registry, ua_sess->consumer);
4558
4559end_unlock:
4560 pthread_mutex_unlock(&ua_sess->lock);
4561end_no_session:
4562 rcu_read_unlock();
4563 health_code_update();
4564 return 0;
4565
4566error_rcu_unlock:
4567 pthread_mutex_unlock(&ua_sess->lock);
4568 rcu_read_unlock();
4569 health_code_update();
4570 return -1;
4571}
4572
4573static
4574int ust_app_flush_app_session(struct ust_app *app,
4575 struct ust_app_session *ua_sess)
4576{
4577 int ret, retval = 0;
4578 struct lttng_ht_iter iter;
4579 struct ust_app_channel *ua_chan;
4580 struct consumer_socket *socket;
4581
4582 DBG("Flushing app session buffers for ust app pid %d", app->pid);
4583
4584 rcu_read_lock();
4585
4586 if (!app->compatible) {
4587 goto end_not_compatible;
4588 }
4589
4590 pthread_mutex_lock(&ua_sess->lock);
4591
4592 if (ua_sess->deleted) {
4593 goto end_deleted;
4594 }
4595
4596 health_code_update();
4597
4598 /* Flushing buffers */
4599 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4600 ua_sess->consumer);
4601
4602 /* Flush buffers and push metadata. */
4603 switch (ua_sess->buffer_type) {
4604 case LTTNG_BUFFER_PER_PID:
4605 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
4606 node.node) {
4607 health_code_update();
4608 ret = consumer_flush_channel(socket, ua_chan->key);
4609 if (ret) {
4610 ERR("Error flushing consumer channel");
4611 retval = -1;
4612 continue;
4613 }
4614 }
4615 break;
4616 case LTTNG_BUFFER_PER_UID:
4617 default:
4618 assert(0);
4619 break;
4620 }
4621
4622 health_code_update();
4623
4624end_deleted:
4625 pthread_mutex_unlock(&ua_sess->lock);
4626
4627end_not_compatible:
4628 rcu_read_unlock();
4629 health_code_update();
4630 return retval;
4631}
4632
4633/*
4634 * Flush buffers for all applications for a specific UST session.
4635 * Called with UST session lock held.
4636 */
4637static
4638int ust_app_flush_session(struct ltt_ust_session *usess)
4639
4640{
4641 int ret = 0;
4642
4643 DBG("Flushing session buffers for all ust apps");
4644
4645 rcu_read_lock();
4646
4647 /* Flush buffers and push metadata. */
4648 switch (usess->buffer_type) {
4649 case LTTNG_BUFFER_PER_UID:
4650 {
4651 struct buffer_reg_uid *reg;
4652 struct lttng_ht_iter iter;
4653
4654 /* Flush all per UID buffers associated to that session. */
4655 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4656 struct ust_registry_session *ust_session_reg;
4657 struct buffer_reg_channel *reg_chan;
4658 struct consumer_socket *socket;
4659
4660 /* Get consumer socket to use to push the metadata.*/
4661 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
4662 usess->consumer);
4663 if (!socket) {
4664 /* Ignore request if no consumer is found for the session. */
4665 continue;
4666 }
4667
4668 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
4669 reg_chan, node.node) {
4670 /*
4671 * The following call will print error values so the return
4672 * code is of little importance because whatever happens, we
4673 * have to try them all.
4674 */
4675 (void) consumer_flush_channel(socket, reg_chan->consumer_key);
4676 }
4677
4678 ust_session_reg = reg->registry->reg.ust;
4679 /* Push metadata. */
4680 (void) push_metadata(ust_session_reg, usess->consumer);
4681 }
4682 break;
4683 }
4684 case LTTNG_BUFFER_PER_PID:
4685 {
4686 struct ust_app_session *ua_sess;
4687 struct lttng_ht_iter iter;
4688 struct ust_app *app;
4689
4690 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4691 ua_sess = lookup_session_by_app(usess, app);
4692 if (ua_sess == NULL) {
4693 continue;
4694 }
4695 (void) ust_app_flush_app_session(app, ua_sess);
4696 }
4697 break;
4698 }
4699 default:
4700 ret = -1;
4701 assert(0);
4702 break;
4703 }
4704
4705 rcu_read_unlock();
4706 health_code_update();
4707 return ret;
4708}
4709
4710static
4711int ust_app_clear_quiescent_app_session(struct ust_app *app,
4712 struct ust_app_session *ua_sess)
4713{
4714 int ret = 0;
4715 struct lttng_ht_iter iter;
4716 struct ust_app_channel *ua_chan;
4717 struct consumer_socket *socket;
4718
4719 DBG("Clearing stream quiescent state for ust app pid %d", app->pid);
4720
4721 rcu_read_lock();
4722
4723 if (!app->compatible) {
4724 goto end_not_compatible;
4725 }
4726
4727 pthread_mutex_lock(&ua_sess->lock);
4728
4729 if (ua_sess->deleted) {
4730 goto end_unlock;
4731 }
4732
4733 health_code_update();
4734
4735 socket = consumer_find_socket_by_bitness(app->bits_per_long,
4736 ua_sess->consumer);
4737 if (!socket) {
4738 ERR("Failed to find consumer (%" PRIu32 ") socket",
4739 app->bits_per_long);
4740 ret = -1;
4741 goto end_unlock;
4742 }
4743
4744 /* Clear quiescent state. */
4745 switch (ua_sess->buffer_type) {
4746 case LTTNG_BUFFER_PER_PID:
4747 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter,
4748 ua_chan, node.node) {
4749 health_code_update();
4750 ret = consumer_clear_quiescent_channel(socket,
4751 ua_chan->key);
4752 if (ret) {
4753 ERR("Error clearing quiescent state for consumer channel");
4754 ret = -1;
4755 continue;
4756 }
4757 }
4758 break;
4759 case LTTNG_BUFFER_PER_UID:
4760 default:
4761 assert(0);
4762 ret = -1;
4763 break;
4764 }
4765
4766 health_code_update();
4767
4768end_unlock:
4769 pthread_mutex_unlock(&ua_sess->lock);
4770
4771end_not_compatible:
4772 rcu_read_unlock();
4773 health_code_update();
4774 return ret;
4775}
4776
4777/*
4778 * Clear quiescent state in each stream for all applications for a
4779 * specific UST session.
4780 * Called with UST session lock held.
4781 */
4782static
4783int ust_app_clear_quiescent_session(struct ltt_ust_session *usess)
4784
4785{
4786 int ret = 0;
4787
4788 DBG("Clearing stream quiescent state for all ust apps");
4789
4790 rcu_read_lock();
4791
4792 switch (usess->buffer_type) {
4793 case LTTNG_BUFFER_PER_UID:
4794 {
4795 struct lttng_ht_iter iter;
4796 struct buffer_reg_uid *reg;
4797
4798 /*
4799 * Clear quiescent for all per UID buffers associated to
4800 * that session.
4801 */
4802 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
4803 struct consumer_socket *socket;
4804 struct buffer_reg_channel *reg_chan;
4805
4806 /* Get associated consumer socket.*/
4807 socket = consumer_find_socket_by_bitness(
4808 reg->bits_per_long, usess->consumer);
4809 if (!socket) {
4810 /*
4811 * Ignore request if no consumer is found for
4812 * the session.
4813 */
4814 continue;
4815 }
4816
4817 cds_lfht_for_each_entry(reg->registry->channels->ht,
4818 &iter.iter, reg_chan, node.node) {
4819 /*
4820 * The following call will print error values so
4821 * the return code is of little importance
4822 * because whatever happens, we have to try them
4823 * all.
4824 */
4825 (void) consumer_clear_quiescent_channel(socket,
4826 reg_chan->consumer_key);
4827 }
4828 }
4829 break;
4830 }
4831 case LTTNG_BUFFER_PER_PID:
4832 {
4833 struct ust_app_session *ua_sess;
4834 struct lttng_ht_iter iter;
4835 struct ust_app *app;
4836
4837 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
4838 pid_n.node) {
4839 ua_sess = lookup_session_by_app(usess, app);
4840 if (ua_sess == NULL) {
4841 continue;
4842 }
4843 (void) ust_app_clear_quiescent_app_session(app,
4844 ua_sess);
4845 }
4846 break;
4847 }
4848 default:
4849 ret = -1;
4850 assert(0);
4851 break;
4852 }
4853
4854 rcu_read_unlock();
4855 health_code_update();
4856 return ret;
4857}
4858
4859/*
4860 * Destroy a specific UST session in apps.
4861 */
4862static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
4863{
4864 int ret;
4865 struct ust_app_session *ua_sess;
4866 struct lttng_ht_iter iter;
4867 struct lttng_ht_node_u64 *node;
4868
4869 DBG("Destroy tracing for ust app pid %d", app->pid);
4870
4871 rcu_read_lock();
4872
4873 if (!app->compatible) {
4874 goto end;
4875 }
4876
4877 __lookup_session_by_app(usess, app, &iter);
4878 node = lttng_ht_iter_get_node_u64(&iter);
4879 if (node == NULL) {
4880 /* Session is being or is deleted. */
4881 goto end;
4882 }
4883 ua_sess = caa_container_of(node, struct ust_app_session, node);
4884
4885 health_code_update();
4886 destroy_app_session(app, ua_sess);
4887
4888 health_code_update();
4889
4890 /* Quiescent wait after stopping trace */
4891 pthread_mutex_lock(&app->sock_lock);
4892 ret = ustctl_wait_quiescent(app->sock);
4893 pthread_mutex_unlock(&app->sock_lock);
4894 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
4895 ERR("UST app wait quiescent failed for app pid %d ret %d",
4896 app->pid, ret);
4897 }
4898end:
4899 rcu_read_unlock();
4900 health_code_update();
4901 return 0;
4902}
4903
4904/*
4905 * Start tracing for the UST session.
4906 */
4907int ust_app_start_trace_all(struct ltt_ust_session *usess)
4908{
4909 struct lttng_ht_iter iter;
4910 struct ust_app *app;
4911
4912 DBG("Starting all UST traces");
4913
4914 /*
4915 * Even though the start trace might fail, flag this session active so
4916 * other application coming in are started by default.
4917 */
4918 usess->active = 1;
4919
4920 rcu_read_lock();
4921
4922 /*
4923 * In a start-stop-start use-case, we need to clear the quiescent state
4924 * of each channel set by the prior stop command, thus ensuring that a
4925 * following stop or destroy is sure to grab a timestamp_end near those
4926 * operations, even if the packet is empty.
4927 */
4928 (void) ust_app_clear_quiescent_session(usess);
4929
4930 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4931 ust_app_global_update(usess, app);
4932 }
4933
4934 rcu_read_unlock();
4935
4936 return 0;
4937}
4938
4939/*
4940 * Start tracing for the UST session.
4941 * Called with UST session lock held.
4942 */
4943int ust_app_stop_trace_all(struct ltt_ust_session *usess)
4944{
4945 int ret = 0;
4946 struct lttng_ht_iter iter;
4947 struct ust_app *app;
4948
4949 DBG("Stopping all UST traces");
4950
4951 /*
4952 * Even though the stop trace might fail, flag this session inactive so
4953 * other application coming in are not started by default.
4954 */
4955 usess->active = 0;
4956
4957 rcu_read_lock();
4958
4959 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4960 ret = ust_app_stop_trace(usess, app);
4961 if (ret < 0) {
4962 /* Continue to next apps even on error */
4963 continue;
4964 }
4965 }
4966
4967 (void) ust_app_flush_session(usess);
4968
4969 rcu_read_unlock();
4970
4971 return 0;
4972}
4973
4974/*
4975 * Destroy app UST session.
4976 */
4977int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
4978{
4979 int ret = 0;
4980 struct lttng_ht_iter iter;
4981 struct ust_app *app;
4982
4983 DBG("Destroy all UST traces");
4984
4985 rcu_read_lock();
4986
4987 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
4988 ret = destroy_trace(usess, app);
4989 if (ret < 0) {
4990 /* Continue to next apps even on error */
4991 continue;
4992 }
4993 }
4994
4995 rcu_read_unlock();
4996
4997 return 0;
4998}
4999
5000/* The ua_sess lock must be held by the caller. */
5001static
5002int find_or_create_ust_app_channel(
5003 struct ltt_ust_session *usess,
5004 struct ust_app_session *ua_sess,
5005 struct ust_app *app,
5006 struct ltt_ust_channel *uchan,
5007 struct ust_app_channel **ua_chan)
5008{
5009 int ret = 0;
5010 struct lttng_ht_iter iter;
5011 struct lttng_ht_node_str *ua_chan_node;
5012
5013 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &iter);
5014 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
5015 if (ua_chan_node) {
5016 *ua_chan = caa_container_of(ua_chan_node,
5017 struct ust_app_channel, node);
5018 goto end;
5019 }
5020
5021 ret = ust_app_channel_create(usess, ua_sess, uchan, app, ua_chan);
5022 if (ret) {
5023 goto end;
5024 }
5025end:
5026 return ret;
5027}
5028
5029static
5030int ust_app_channel_synchronize_event(struct ust_app_channel *ua_chan,
5031 struct ltt_ust_event *uevent, struct ust_app_session *ua_sess,
5032 struct ust_app *app)
5033{
5034 int ret = 0;
5035 struct ust_app_event *ua_event = NULL;
5036
5037 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
5038 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
5039 if (!ua_event) {
5040 ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
5041 if (ret < 0) {
5042 goto end;
5043 }
5044 } else {
5045 if (ua_event->enabled != uevent->enabled) {
5046 ret = uevent->enabled ?
5047 enable_ust_app_event(ua_sess, ua_event, app) :
5048 disable_ust_app_event(ua_sess, ua_event, app);
5049 }
5050 }
5051
5052end:
5053 return ret;
5054}
5055
5056/*
5057 * The caller must ensure that the application is compatible and is tracked
5058 * by the PID tracker.
5059 */
5060static
5061void ust_app_synchronize(struct ltt_ust_session *usess,
5062 struct ust_app *app)
5063{
5064 int ret = 0;
5065 struct cds_lfht_iter uchan_iter;
5066 struct ltt_ust_channel *uchan;
5067 struct ust_app_session *ua_sess = NULL;
5068
5069 /*
5070 * The application's configuration should only be synchronized for
5071 * active sessions.
5072 */
5073 assert(usess->active);
5074
5075 ret = find_or_create_ust_app_session(usess, app, &ua_sess, NULL);
5076 if (ret < 0) {
5077 /* Tracer is probably gone or ENOMEM. */
5078 goto error;
5079 }
5080 assert(ua_sess);
5081
5082 pthread_mutex_lock(&ua_sess->lock);
5083 if (ua_sess->deleted) {
5084 pthread_mutex_unlock(&ua_sess->lock);
5085 goto end;
5086 }
5087
5088 rcu_read_lock();
5089 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &uchan_iter,
5090 uchan, node.node) {
5091 struct ust_app_channel *ua_chan;
5092 struct cds_lfht_iter uevent_iter;
5093 struct ltt_ust_event *uevent;
5094
5095 /*
5096 * Search for a matching ust_app_channel. If none is found,
5097 * create it. Creating the channel will cause the ua_chan
5098 * structure to be allocated, the channel buffers to be
5099 * allocated (if necessary) and sent to the application, and
5100 * all enabled contexts will be added to the channel.
5101 */
5102 ret = find_or_create_ust_app_channel(usess, ua_sess,
5103 app, uchan, &ua_chan);
5104 if (ret) {
5105 /* Tracer is probably gone or ENOMEM. */
5106 goto error_unlock;
5107 }
5108
5109 if (!ua_chan) {
5110 /* ua_chan will be NULL for the metadata channel */
5111 continue;
5112 }
5113
5114 cds_lfht_for_each_entry(uchan->events->ht, &uevent_iter, uevent,
5115 node.node) {
5116 ret = ust_app_channel_synchronize_event(ua_chan,
5117 uevent, ua_sess, app);
5118 if (ret) {
5119 goto error_unlock;
5120 }
5121 }
5122
5123 if (ua_chan->enabled != uchan->enabled) {
5124 ret = uchan->enabled ?
5125 enable_ust_app_channel(ua_sess, uchan, app) :
5126 disable_ust_app_channel(ua_sess, ua_chan, app);
5127 if (ret) {
5128 goto error_unlock;
5129 }
5130 }
5131 }
5132 rcu_read_unlock();
5133
5134end:
5135 pthread_mutex_unlock(&ua_sess->lock);
5136 /* Everything went well at this point. */
5137 return;
5138
5139error_unlock:
5140 rcu_read_unlock();
5141 pthread_mutex_unlock(&ua_sess->lock);
5142error:
5143 if (ua_sess) {
5144 destroy_app_session(app, ua_sess);
5145 }
5146 return;
5147}
5148
5149static
5150void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
5151{
5152 struct ust_app_session *ua_sess;
5153
5154 ua_sess = lookup_session_by_app(usess, app);
5155 if (ua_sess == NULL) {
5156 return;
5157 }
5158 destroy_app_session(app, ua_sess);
5159}
5160
5161/*
5162 * Add channels/events from UST global domain to registered apps at sock.
5163 *
5164 * Called with session lock held.
5165 * Called with RCU read-side lock held.
5166 */
5167void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
5168{
5169 assert(usess);
5170 assert(usess->active);
5171
5172 DBG2("UST app global update for app sock %d for session id %" PRIu64,
5173 app->sock, usess->id);
5174
5175 if (!app->compatible) {
5176 return;
5177 }
5178 if (trace_ust_pid_tracker_lookup(usess, app->pid)) {
5179 /*
5180 * Synchronize the application's internal tracing configuration
5181 * and start tracing.
5182 */
5183 ust_app_synchronize(usess, app);
5184 ust_app_start_trace(usess, app);
5185 } else {
5186 ust_app_global_destroy(usess, app);
5187 }
5188}
5189
5190/*
5191 * Called with session lock held.
5192 */
5193void ust_app_global_update_all(struct ltt_ust_session *usess)
5194{
5195 struct lttng_ht_iter iter;
5196 struct ust_app *app;
5197
5198 rcu_read_lock();
5199 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5200 ust_app_global_update(usess, app);
5201 }
5202 rcu_read_unlock();
5203}
5204
5205/*
5206 * Add context to a specific channel for global UST domain.
5207 */
5208int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
5209 struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
5210{
5211 int ret = 0;
5212 struct lttng_ht_node_str *ua_chan_node;
5213 struct lttng_ht_iter iter, uiter;
5214 struct ust_app_channel *ua_chan = NULL;
5215 struct ust_app_session *ua_sess;
5216 struct ust_app *app;
5217
5218 assert(usess->active);
5219
5220 rcu_read_lock();
5221 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5222 if (!app->compatible) {
5223 /*
5224 * TODO: In time, we should notice the caller of this error by
5225 * telling him that this is a version error.
5226 */
5227 continue;
5228 }
5229 ua_sess = lookup_session_by_app(usess, app);
5230 if (ua_sess == NULL) {
5231 continue;
5232 }
5233
5234 pthread_mutex_lock(&ua_sess->lock);
5235
5236 if (ua_sess->deleted) {
5237 pthread_mutex_unlock(&ua_sess->lock);
5238 continue;
5239 }
5240
5241 /* Lookup channel in the ust app session */
5242 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
5243 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
5244 if (ua_chan_node == NULL) {
5245 goto next_app;
5246 }
5247 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
5248 node);
5249 ret = create_ust_app_channel_context(ua_chan, &uctx->ctx, app);
5250 if (ret < 0) {
5251 goto next_app;
5252 }
5253 next_app:
5254 pthread_mutex_unlock(&ua_sess->lock);
5255 }
5256
5257 rcu_read_unlock();
5258 return ret;
5259}
5260
5261/*
5262 * Receive registration and populate the given msg structure.
5263 *
5264 * On success return 0 else a negative value returned by the ustctl call.
5265 */
5266int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
5267{
5268 int ret;
5269 uint32_t pid, ppid, uid, gid;
5270
5271 assert(msg);
5272
5273 ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
5274 &pid, &ppid, &uid, &gid,
5275 &msg->bits_per_long,
5276 &msg->uint8_t_alignment,
5277 &msg->uint16_t_alignment,
5278 &msg->uint32_t_alignment,
5279 &msg->uint64_t_alignment,
5280 &msg->long_alignment,
5281 &msg->byte_order,
5282 msg->name);
5283 if (ret < 0) {
5284 switch (-ret) {
5285 case EPIPE:
5286 case ECONNRESET:
5287 case LTTNG_UST_ERR_EXITING:
5288 DBG3("UST app recv reg message failed. Application died");
5289 break;
5290 case LTTNG_UST_ERR_UNSUP_MAJOR:
5291 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
5292 msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
5293 LTTNG_UST_ABI_MINOR_VERSION);
5294 break;
5295 default:
5296 ERR("UST app recv reg message failed with ret %d", ret);
5297 break;
5298 }
5299 goto error;
5300 }
5301 msg->pid = (pid_t) pid;
5302 msg->ppid = (pid_t) ppid;
5303 msg->uid = (uid_t) uid;
5304 msg->gid = (gid_t) gid;
5305
5306error:
5307 return ret;
5308}
5309
5310/*
5311 * Return a ust app session object using the application object and the
5312 * session object descriptor has a key. If not found, NULL is returned.
5313 * A RCU read side lock MUST be acquired when calling this function.
5314*/
5315static struct ust_app_session *find_session_by_objd(struct ust_app *app,
5316 int objd)
5317{
5318 struct lttng_ht_node_ulong *node;
5319 struct lttng_ht_iter iter;
5320 struct ust_app_session *ua_sess = NULL;
5321
5322 assert(app);
5323
5324 lttng_ht_lookup(app->ust_sessions_objd, (void *)((unsigned long) objd), &iter);
5325 node = lttng_ht_iter_get_node_ulong(&iter);
5326 if (node == NULL) {
5327 DBG2("UST app session find by objd %d not found", objd);
5328 goto error;
5329 }
5330
5331 ua_sess = caa_container_of(node, struct ust_app_session, ust_objd_node);
5332
5333error:
5334 return ua_sess;
5335}
5336
5337/*
5338 * Return a ust app channel object using the application object and the channel
5339 * object descriptor has a key. If not found, NULL is returned. A RCU read side
5340 * lock MUST be acquired before calling this function.
5341 */
5342static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
5343 int objd)
5344{
5345 struct lttng_ht_node_ulong *node;
5346 struct lttng_ht_iter iter;
5347 struct ust_app_channel *ua_chan = NULL;
5348
5349 assert(app);
5350
5351 lttng_ht_lookup(app->ust_objd, (void *)((unsigned long) objd), &iter);
5352 node = lttng_ht_iter_get_node_ulong(&iter);
5353 if (node == NULL) {
5354 DBG2("UST app channel find by objd %d not found", objd);
5355 goto error;
5356 }
5357
5358 ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
5359
5360error:
5361 return ua_chan;
5362}
5363
5364/*
5365 * Reply to a register channel notification from an application on the notify
5366 * socket. The channel metadata is also created.
5367 *
5368 * The session UST registry lock is acquired in this function.
5369 *
5370 * On success 0 is returned else a negative value.
5371 */
5372static int reply_ust_register_channel(int sock, int cobjd,
5373 size_t nr_fields, struct ustctl_field *fields)
5374{
5375 int ret, ret_code = 0;
5376 uint32_t chan_id;
5377 uint64_t chan_reg_key;
5378 enum ustctl_channel_header type;
5379 struct ust_app *app;
5380 struct ust_app_channel *ua_chan;
5381 struct ust_app_session *ua_sess;
5382 struct ust_registry_session *registry;
5383 struct ust_registry_channel *chan_reg;
5384
5385 rcu_read_lock();
5386
5387 /* Lookup application. If not found, there is a code flow error. */
5388 app = find_app_by_notify_sock(sock);
5389 if (!app) {
5390 DBG("Application socket %d is being torn down. Abort event notify",
5391 sock);
5392 ret = 0;
5393 goto error_rcu_unlock;
5394 }
5395
5396 /* Lookup channel by UST object descriptor. */
5397 ua_chan = find_channel_by_objd(app, cobjd);
5398 if (!ua_chan) {
5399 DBG("Application channel is being torn down. Abort event notify");
5400 ret = 0;
5401 goto error_rcu_unlock;
5402 }
5403
5404 assert(ua_chan->session);
5405 ua_sess = ua_chan->session;
5406
5407 /* Get right session registry depending on the session buffer type. */
5408 registry = get_session_registry(ua_sess);
5409 if (!registry) {
5410 DBG("Application session is being torn down. Abort event notify");
5411 ret = 0;
5412 goto error_rcu_unlock;
5413 };
5414
5415 /* Depending on the buffer type, a different channel key is used. */
5416 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5417 chan_reg_key = ua_chan->tracing_channel_id;
5418 } else {
5419 chan_reg_key = ua_chan->key;
5420 }
5421
5422 pthread_mutex_lock(&registry->lock);
5423
5424 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
5425 assert(chan_reg);
5426
5427 if (!chan_reg->register_done) {
5428 /*
5429 * TODO: eventually use the registry event count for
5430 * this channel to better guess header type for per-pid
5431 * buffers.
5432 */
5433 type = USTCTL_CHANNEL_HEADER_LARGE;
5434 chan_reg->nr_ctx_fields = nr_fields;
5435 chan_reg->ctx_fields = fields;
5436 fields = NULL;
5437 chan_reg->header_type = type;
5438 } else {
5439 /* Get current already assigned values. */
5440 type = chan_reg->header_type;
5441 }
5442 /* Channel id is set during the object creation. */
5443 chan_id = chan_reg->chan_id;
5444
5445 /* Append to metadata */
5446 if (!chan_reg->metadata_dumped) {
5447 ret_code = ust_metadata_channel_statedump(registry, chan_reg);
5448 if (ret_code) {
5449 ERR("Error appending channel metadata (errno = %d)", ret_code);
5450 goto reply;
5451 }
5452 }
5453
5454reply:
5455 DBG3("UST app replying to register channel key %" PRIu64
5456 " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
5457 ret_code);
5458
5459 ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
5460 if (ret < 0) {
5461 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5462 ERR("UST app reply channel failed with ret %d", ret);
5463 } else {
5464 DBG3("UST app reply channel failed. Application died");
5465 }
5466 goto error;
5467 }
5468
5469 /* This channel registry registration is completed. */
5470 chan_reg->register_done = 1;
5471
5472error:
5473 pthread_mutex_unlock(&registry->lock);
5474error_rcu_unlock:
5475 rcu_read_unlock();
5476 free(fields);
5477 return ret;
5478}
5479
5480/*
5481 * Add event to the UST channel registry. When the event is added to the
5482 * registry, the metadata is also created. Once done, this replies to the
5483 * application with the appropriate error code.
5484 *
5485 * The session UST registry lock is acquired in the function.
5486 *
5487 * On success 0 is returned else a negative value.
5488 */
5489static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
5490 char *sig, size_t nr_fields, struct ustctl_field *fields,
5491 int loglevel_value, char *model_emf_uri)
5492{
5493 int ret, ret_code;
5494 uint32_t event_id = 0;
5495 uint64_t chan_reg_key;
5496 struct ust_app *app;
5497 struct ust_app_channel *ua_chan;
5498 struct ust_app_session *ua_sess;
5499 struct ust_registry_session *registry;
5500
5501 rcu_read_lock();
5502
5503 /* Lookup application. If not found, there is a code flow error. */
5504 app = find_app_by_notify_sock(sock);
5505 if (!app) {
5506 DBG("Application socket %d is being torn down. Abort event notify",
5507 sock);
5508 ret = 0;
5509 goto error_rcu_unlock;
5510 }
5511
5512 /* Lookup channel by UST object descriptor. */
5513 ua_chan = find_channel_by_objd(app, cobjd);
5514 if (!ua_chan) {
5515 DBG("Application channel is being torn down. Abort event notify");
5516 ret = 0;
5517 goto error_rcu_unlock;
5518 }
5519
5520 assert(ua_chan->session);
5521 ua_sess = ua_chan->session;
5522
5523 registry = get_session_registry(ua_sess);
5524 if (!registry) {
5525 DBG("Application session is being torn down. Abort event notify");
5526 ret = 0;
5527 goto error_rcu_unlock;
5528 }
5529
5530 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
5531 chan_reg_key = ua_chan->tracing_channel_id;
5532 } else {
5533 chan_reg_key = ua_chan->key;
5534 }
5535
5536 pthread_mutex_lock(&registry->lock);
5537
5538 /*
5539 * From this point on, this call acquires the ownership of the sig, fields
5540 * and model_emf_uri meaning any free are done inside it if needed. These
5541 * three variables MUST NOT be read/write after this.
5542 */
5543 ret_code = ust_registry_create_event(registry, chan_reg_key,
5544 sobjd, cobjd, name, sig, nr_fields, fields,
5545 loglevel_value, model_emf_uri, ua_sess->buffer_type,
5546 &event_id, app);
5547 sig = NULL;
5548 fields = NULL;
5549 model_emf_uri = NULL;
5550
5551 /*
5552 * The return value is returned to ustctl so in case of an error, the
5553 * application can be notified. In case of an error, it's important not to
5554 * return a negative error or else the application will get closed.
5555 */
5556 ret = ustctl_reply_register_event(sock, event_id, ret_code);
5557 if (ret < 0) {
5558 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5559 ERR("UST app reply event failed with ret %d", ret);
5560 } else {
5561 DBG3("UST app reply event failed. Application died");
5562 }
5563 /*
5564 * No need to wipe the create event since the application socket will
5565 * get close on error hence cleaning up everything by itself.
5566 */
5567 goto error;
5568 }
5569
5570 DBG3("UST registry event %s with id %" PRId32 " added successfully",
5571 name, event_id);
5572
5573error:
5574 pthread_mutex_unlock(&registry->lock);
5575error_rcu_unlock:
5576 rcu_read_unlock();
5577 free(sig);
5578 free(fields);
5579 free(model_emf_uri);
5580 return ret;
5581}
5582
5583/*
5584 * Add enum to the UST session registry. Once done, this replies to the
5585 * application with the appropriate error code.
5586 *
5587 * The session UST registry lock is acquired within this function.
5588 *
5589 * On success 0 is returned else a negative value.
5590 */
5591static int add_enum_ust_registry(int sock, int sobjd, char *name,
5592 struct ustctl_enum_entry *entries, size_t nr_entries)
5593{
5594 int ret = 0, ret_code;
5595 struct ust_app *app;
5596 struct ust_app_session *ua_sess;
5597 struct ust_registry_session *registry;
5598 uint64_t enum_id = -1ULL;
5599
5600 rcu_read_lock();
5601
5602 /* Lookup application. If not found, there is a code flow error. */
5603 app = find_app_by_notify_sock(sock);
5604 if (!app) {
5605 /* Return an error since this is not an error */
5606 DBG("Application socket %d is being torn down. Aborting enum registration",
5607 sock);
5608 free(entries);
5609 goto error_rcu_unlock;
5610 }
5611
5612 /* Lookup session by UST object descriptor. */
5613 ua_sess = find_session_by_objd(app, sobjd);
5614 if (!ua_sess) {
5615 /* Return an error since this is not an error */
5616 DBG("Application session is being torn down (session not found). Aborting enum registration.");
5617 free(entries);
5618 goto error_rcu_unlock;
5619 }
5620
5621 registry = get_session_registry(ua_sess);
5622 if (!registry) {
5623 DBG("Application session is being torn down (registry not found). Aborting enum registration.");
5624 free(entries);
5625 goto error_rcu_unlock;
5626 }
5627
5628 pthread_mutex_lock(&registry->lock);
5629
5630 /*
5631 * From this point on, the callee acquires the ownership of
5632 * entries. The variable entries MUST NOT be read/written after
5633 * call.
5634 */
5635 ret_code = ust_registry_create_or_find_enum(registry, sobjd, name,
5636 entries, nr_entries, &enum_id);
5637 entries = NULL;
5638
5639 /*
5640 * The return value is returned to ustctl so in case of an error, the
5641 * application can be notified. In case of an error, it's important not to
5642 * return a negative error or else the application will get closed.
5643 */
5644 ret = ustctl_reply_register_enum(sock, enum_id, ret_code);
5645 if (ret < 0) {
5646 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5647 ERR("UST app reply enum failed with ret %d", ret);
5648 } else {
5649 DBG3("UST app reply enum failed. Application died");
5650 }
5651 /*
5652 * No need to wipe the create enum since the application socket will
5653 * get close on error hence cleaning up everything by itself.
5654 */
5655 goto error;
5656 }
5657
5658 DBG3("UST registry enum %s added successfully or already found", name);
5659
5660error:
5661 pthread_mutex_unlock(&registry->lock);
5662error_rcu_unlock:
5663 rcu_read_unlock();
5664 return ret;
5665}
5666
5667/*
5668 * Handle application notification through the given notify socket.
5669 *
5670 * Return 0 on success or else a negative value.
5671 */
5672int ust_app_recv_notify(int sock)
5673{
5674 int ret;
5675 enum ustctl_notify_cmd cmd;
5676
5677 DBG3("UST app receiving notify from sock %d", sock);
5678
5679 ret = ustctl_recv_notify(sock, &cmd);
5680 if (ret < 0) {
5681 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5682 ERR("UST app recv notify failed with ret %d", ret);
5683 } else {
5684 DBG3("UST app recv notify failed. Application died");
5685 }
5686 goto error;
5687 }
5688
5689 switch (cmd) {
5690 case USTCTL_NOTIFY_CMD_EVENT:
5691 {
5692 int sobjd, cobjd, loglevel_value;
5693 char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
5694 size_t nr_fields;
5695 struct ustctl_field *fields;
5696
5697 DBG2("UST app ustctl register event received");
5698
5699 ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
5700 &loglevel_value, &sig, &nr_fields, &fields,
5701 &model_emf_uri);
5702 if (ret < 0) {
5703 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5704 ERR("UST app recv event failed with ret %d", ret);
5705 } else {
5706 DBG3("UST app recv event failed. Application died");
5707 }
5708 goto error;
5709 }
5710
5711 /*
5712 * Add event to the UST registry coming from the notify socket. This
5713 * call will free if needed the sig, fields and model_emf_uri. This
5714 * code path loses the ownsership of these variables and transfer them
5715 * to the this function.
5716 */
5717 ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
5718 fields, loglevel_value, model_emf_uri);
5719 if (ret < 0) {
5720 goto error;
5721 }
5722
5723 break;
5724 }
5725 case USTCTL_NOTIFY_CMD_CHANNEL:
5726 {
5727 int sobjd, cobjd;
5728 size_t nr_fields;
5729 struct ustctl_field *fields;
5730
5731 DBG2("UST app ustctl register channel received");
5732
5733 ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
5734 &fields);
5735 if (ret < 0) {
5736 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5737 ERR("UST app recv channel failed with ret %d", ret);
5738 } else {
5739 DBG3("UST app recv channel failed. Application died");
5740 }
5741 goto error;
5742 }
5743
5744 /*
5745 * The fields ownership are transfered to this function call meaning
5746 * that if needed it will be freed. After this, it's invalid to access
5747 * fields or clean it up.
5748 */
5749 ret = reply_ust_register_channel(sock, cobjd, nr_fields,
5750 fields);
5751 if (ret < 0) {
5752 goto error;
5753 }
5754
5755 break;
5756 }
5757 case USTCTL_NOTIFY_CMD_ENUM:
5758 {
5759 int sobjd;
5760 char name[LTTNG_UST_SYM_NAME_LEN];
5761 size_t nr_entries;
5762 struct ustctl_enum_entry *entries;
5763
5764 DBG2("UST app ustctl register enum received");
5765
5766 ret = ustctl_recv_register_enum(sock, &sobjd, name,
5767 &entries, &nr_entries);
5768 if (ret < 0) {
5769 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
5770 ERR("UST app recv enum failed with ret %d", ret);
5771 } else {
5772 DBG3("UST app recv enum failed. Application died");
5773 }
5774 goto error;
5775 }
5776
5777 /* Callee assumes ownership of entries */
5778 ret = add_enum_ust_registry(sock, sobjd, name,
5779 entries, nr_entries);
5780 if (ret < 0) {
5781 goto error;
5782 }
5783
5784 break;
5785 }
5786 default:
5787 /* Should NEVER happen. */
5788 assert(0);
5789 }
5790
5791error:
5792 return ret;
5793}
5794
5795/*
5796 * Once the notify socket hangs up, this is called. First, it tries to find the
5797 * corresponding application. On failure, the call_rcu to close the socket is
5798 * executed. If an application is found, it tries to delete it from the notify
5799 * socket hash table. Whathever the result, it proceeds to the call_rcu.
5800 *
5801 * Note that an object needs to be allocated here so on ENOMEM failure, the
5802 * call RCU is not done but the rest of the cleanup is.
5803 */
5804void ust_app_notify_sock_unregister(int sock)
5805{
5806 int err_enomem = 0;
5807 struct lttng_ht_iter iter;
5808 struct ust_app *app;
5809 struct ust_app_notify_sock_obj *obj;
5810
5811 assert(sock >= 0);
5812
5813 rcu_read_lock();
5814
5815 obj = zmalloc(sizeof(*obj));
5816 if (!obj) {
5817 /*
5818 * An ENOMEM is kind of uncool. If this strikes we continue the
5819 * procedure but the call_rcu will not be called. In this case, we
5820 * accept the fd leak rather than possibly creating an unsynchronized
5821 * state between threads.
5822 *
5823 * TODO: The notify object should be created once the notify socket is
5824 * registered and stored independantely from the ust app object. The
5825 * tricky part is to synchronize the teardown of the application and
5826 * this notify object. Let's keep that in mind so we can avoid this
5827 * kind of shenanigans with ENOMEM in the teardown path.
5828 */
5829 err_enomem = 1;
5830 } else {
5831 obj->fd = sock;
5832 }
5833
5834 DBG("UST app notify socket unregister %d", sock);
5835
5836 /*
5837 * Lookup application by notify socket. If this fails, this means that the
5838 * hash table delete has already been done by the application
5839 * unregistration process so we can safely close the notify socket in a
5840 * call RCU.
5841 */
5842 app = find_app_by_notify_sock(sock);
5843 if (!app) {
5844 goto close_socket;
5845 }
5846
5847 iter.iter.node = &app->notify_sock_n.node;
5848
5849 /*
5850 * Whatever happens here either we fail or succeed, in both cases we have
5851 * to close the socket after a grace period to continue to the call RCU
5852 * here. If the deletion is successful, the application is not visible
5853 * anymore by other threads and is it fails it means that it was already
5854 * deleted from the hash table so either way we just have to close the
5855 * socket.
5856 */
5857 (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
5858
5859close_socket:
5860 rcu_read_unlock();
5861
5862 /*
5863 * Close socket after a grace period to avoid for the socket to be reused
5864 * before the application object is freed creating potential race between
5865 * threads trying to add unique in the global hash table.
5866 */
5867 if (!err_enomem) {
5868 call_rcu(&obj->head, close_notify_sock_rcu);
5869 }
5870}
5871
5872/*
5873 * Destroy a ust app data structure and free its memory.
5874 */
5875void ust_app_destroy(struct ust_app *app)
5876{
5877 if (!app) {
5878 return;
5879 }
5880
5881 call_rcu(&app->pid_n.head, delete_ust_app_rcu);
5882}
5883
5884/*
5885 * Take a snapshot for a given UST session. The snapshot is sent to the given
5886 * output.
5887 *
5888 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
5889 */
5890enum lttng_error_code ust_app_snapshot_record(
5891 const struct ltt_ust_session *usess,
5892 const struct consumer_output *output, int wait,
5893 uint64_t nb_packets_per_stream)
5894{
5895 int ret = 0;
5896 enum lttng_error_code status = LTTNG_OK;
5897 struct lttng_ht_iter iter;
5898 struct ust_app *app;
5899 char *trace_path = NULL;
5900
5901 assert(usess);
5902 assert(output);
5903
5904 rcu_read_lock();
5905
5906 switch (usess->buffer_type) {
5907 case LTTNG_BUFFER_PER_UID:
5908 {
5909 struct buffer_reg_uid *reg;
5910
5911 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
5912 struct buffer_reg_channel *reg_chan;
5913 struct consumer_socket *socket;
5914 char pathname[PATH_MAX];
5915
5916 if (!reg->registry->reg.ust->metadata_key) {
5917 /* Skip since no metadata is present */
5918 continue;
5919 }
5920
5921 /* Get consumer socket to use to push the metadata.*/
5922 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
5923 usess->consumer);
5924 if (!socket) {
5925 status = LTTNG_ERR_INVALID;
5926 goto error;
5927 }
5928
5929 memset(pathname, 0, sizeof(pathname));
5930 /*
5931 * DEFAULT_UST_TRACE_UID_PATH already contains a path
5932 * separator.
5933 */
5934 ret = snprintf(pathname, sizeof(pathname),
5935 DEFAULT_UST_TRACE_DIR DEFAULT_UST_TRACE_UID_PATH,
5936 reg->uid, reg->bits_per_long);
5937 if (ret < 0) {
5938 PERROR("snprintf snapshot path");
5939 status = LTTNG_ERR_INVALID;
5940 goto error;
5941 }
5942 /* Free path allowed on previous iteration. */
5943 free(trace_path);
5944 trace_path = setup_channel_trace_path(usess->consumer, pathname);
5945 if (!trace_path) {
5946 status = LTTNG_ERR_INVALID;
5947 goto error;
5948 }
5949 /* Add the UST default trace dir to path. */
5950 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
5951 reg_chan, node.node) {
5952 status = consumer_snapshot_channel(socket,
5953 reg_chan->consumer_key,
5954 output, 0, usess->uid,
5955 usess->gid, trace_path, wait,
5956 nb_packets_per_stream);
5957 if (status != LTTNG_OK) {
5958 goto error;
5959 }
5960 }
5961 status = consumer_snapshot_channel(socket,
5962 reg->registry->reg.ust->metadata_key, output, 1,
5963 usess->uid, usess->gid, trace_path, wait, 0);
5964 if (status != LTTNG_OK) {
5965 goto error;
5966 }
5967 }
5968 break;
5969 }
5970 case LTTNG_BUFFER_PER_PID:
5971 {
5972 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
5973 struct consumer_socket *socket;
5974 struct lttng_ht_iter chan_iter;
5975 struct ust_app_channel *ua_chan;
5976 struct ust_app_session *ua_sess;
5977 struct ust_registry_session *registry;
5978 char pathname[PATH_MAX];
5979
5980 ua_sess = lookup_session_by_app(usess, app);
5981 if (!ua_sess) {
5982 /* Session not associated with this app. */
5983 continue;
5984 }
5985
5986 /* Get the right consumer socket for the application. */
5987 socket = consumer_find_socket_by_bitness(app->bits_per_long,
5988 output);
5989 if (!socket) {
5990 status = LTTNG_ERR_INVALID;
5991 goto error;
5992 }
5993
5994 /* Add the UST default trace dir to path. */
5995 memset(pathname, 0, sizeof(pathname));
5996 ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "%s",
5997 ua_sess->path);
5998 if (ret < 0) {
5999 status = LTTNG_ERR_INVALID;
6000 PERROR("snprintf snapshot path");
6001 goto error;
6002 }
6003 /* Free path allowed on previous iteration. */
6004 free(trace_path);
6005 trace_path = setup_channel_trace_path(usess->consumer, pathname);
6006 if (!trace_path) {
6007 status = LTTNG_ERR_INVALID;
6008 goto error;
6009 }
6010 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6011 ua_chan, node.node) {
6012 status = consumer_snapshot_channel(socket,
6013 ua_chan->key, output, 0,
6014 ua_sess->effective_credentials
6015 .uid,
6016 ua_sess->effective_credentials
6017 .gid,
6018 trace_path, wait,
6019 nb_packets_per_stream);
6020 switch (status) {
6021 case LTTNG_OK:
6022 break;
6023 case LTTNG_ERR_CHAN_NOT_FOUND:
6024 continue;
6025 default:
6026 goto error;
6027 }
6028 }
6029
6030 registry = get_session_registry(ua_sess);
6031 if (!registry) {
6032 DBG("Application session is being torn down. Skip application.");
6033 continue;
6034 }
6035 status = consumer_snapshot_channel(socket,
6036 registry->metadata_key, output, 1,
6037 ua_sess->effective_credentials.uid,
6038 ua_sess->effective_credentials.gid,
6039 trace_path, wait, 0);
6040 switch (status) {
6041 case LTTNG_OK:
6042 break;
6043 case LTTNG_ERR_CHAN_NOT_FOUND:
6044 continue;
6045 default:
6046 goto error;
6047 }
6048 }
6049 break;
6050 }
6051 default:
6052 assert(0);
6053 break;
6054 }
6055
6056error:
6057 free(trace_path);
6058 rcu_read_unlock();
6059 return status;
6060}
6061
6062/*
6063 * Return the size taken by one more packet per stream.
6064 */
6065uint64_t ust_app_get_size_one_more_packet_per_stream(
6066 const struct ltt_ust_session *usess, uint64_t cur_nr_packets)
6067{
6068 uint64_t tot_size = 0;
6069 struct ust_app *app;
6070 struct lttng_ht_iter iter;
6071
6072 assert(usess);
6073
6074 switch (usess->buffer_type) {
6075 case LTTNG_BUFFER_PER_UID:
6076 {
6077 struct buffer_reg_uid *reg;
6078
6079 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6080 struct buffer_reg_channel *reg_chan;
6081
6082 rcu_read_lock();
6083 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6084 reg_chan, node.node) {
6085 if (cur_nr_packets >= reg_chan->num_subbuf) {
6086 /*
6087 * Don't take channel into account if we
6088 * already grab all its packets.
6089 */
6090 continue;
6091 }
6092 tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
6093 }
6094 rcu_read_unlock();
6095 }
6096 break;
6097 }
6098 case LTTNG_BUFFER_PER_PID:
6099 {
6100 rcu_read_lock();
6101 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6102 struct ust_app_channel *ua_chan;
6103 struct ust_app_session *ua_sess;
6104 struct lttng_ht_iter chan_iter;
6105
6106 ua_sess = lookup_session_by_app(usess, app);
6107 if (!ua_sess) {
6108 /* Session not associated with this app. */
6109 continue;
6110 }
6111
6112 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6113 ua_chan, node.node) {
6114 if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
6115 /*
6116 * Don't take channel into account if we
6117 * already grab all its packets.
6118 */
6119 continue;
6120 }
6121 tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
6122 }
6123 }
6124 rcu_read_unlock();
6125 break;
6126 }
6127 default:
6128 assert(0);
6129 break;
6130 }
6131
6132 return tot_size;
6133}
6134
6135int ust_app_uid_get_channel_runtime_stats(uint64_t ust_session_id,
6136 struct cds_list_head *buffer_reg_uid_list,
6137 struct consumer_output *consumer, uint64_t uchan_id,
6138 int overwrite, uint64_t *discarded, uint64_t *lost)
6139{
6140 int ret;
6141 uint64_t consumer_chan_key;
6142
6143 *discarded = 0;
6144 *lost = 0;
6145
6146 ret = buffer_reg_uid_consumer_channel_key(
6147 buffer_reg_uid_list, uchan_id, &consumer_chan_key);
6148 if (ret < 0) {
6149 /* Not found */
6150 ret = 0;
6151 goto end;
6152 }
6153
6154 if (overwrite) {
6155 ret = consumer_get_lost_packets(ust_session_id,
6156 consumer_chan_key, consumer, lost);
6157 } else {
6158 ret = consumer_get_discarded_events(ust_session_id,
6159 consumer_chan_key, consumer, discarded);
6160 }
6161
6162end:
6163 return ret;
6164}
6165
6166int ust_app_pid_get_channel_runtime_stats(struct ltt_ust_session *usess,
6167 struct ltt_ust_channel *uchan,
6168 struct consumer_output *consumer, int overwrite,
6169 uint64_t *discarded, uint64_t *lost)
6170{
6171 int ret = 0;
6172 struct lttng_ht_iter iter;
6173 struct lttng_ht_node_str *ua_chan_node;
6174 struct ust_app *app;
6175 struct ust_app_session *ua_sess;
6176 struct ust_app_channel *ua_chan;
6177
6178 *discarded = 0;
6179 *lost = 0;
6180
6181 rcu_read_lock();
6182 /*
6183 * Iterate over every registered applications. Sum counters for
6184 * all applications containing requested session and channel.
6185 */
6186 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6187 struct lttng_ht_iter uiter;
6188
6189 ua_sess = lookup_session_by_app(usess, app);
6190 if (ua_sess == NULL) {
6191 continue;
6192 }
6193
6194 /* Get channel */
6195 lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &uiter);
6196 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
6197 /* If the session is found for the app, the channel must be there */
6198 assert(ua_chan_node);
6199
6200 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
6201
6202 if (overwrite) {
6203 uint64_t _lost;
6204
6205 ret = consumer_get_lost_packets(usess->id, ua_chan->key,
6206 consumer, &_lost);
6207 if (ret < 0) {
6208 break;
6209 }
6210 (*lost) += _lost;
6211 } else {
6212 uint64_t _discarded;
6213
6214 ret = consumer_get_discarded_events(usess->id,
6215 ua_chan->key, consumer, &_discarded);
6216 if (ret < 0) {
6217 break;
6218 }
6219 (*discarded) += _discarded;
6220 }
6221 }
6222
6223 rcu_read_unlock();
6224 return ret;
6225}
6226
6227static
6228int ust_app_regenerate_statedump(struct ltt_ust_session *usess,
6229 struct ust_app *app)
6230{
6231 int ret = 0;
6232 struct ust_app_session *ua_sess;
6233
6234 DBG("Regenerating the metadata for ust app pid %d", app->pid);
6235
6236 rcu_read_lock();
6237
6238 ua_sess = lookup_session_by_app(usess, app);
6239 if (ua_sess == NULL) {
6240 /* The session is in teardown process. Ignore and continue. */
6241 goto end;
6242 }
6243
6244 pthread_mutex_lock(&ua_sess->lock);
6245
6246 if (ua_sess->deleted) {
6247 goto end_unlock;
6248 }
6249
6250 pthread_mutex_lock(&app->sock_lock);
6251 ret = ustctl_regenerate_statedump(app->sock, ua_sess->handle);
6252 pthread_mutex_unlock(&app->sock_lock);
6253
6254end_unlock:
6255 pthread_mutex_unlock(&ua_sess->lock);
6256
6257end:
6258 rcu_read_unlock();
6259 health_code_update();
6260 return ret;
6261}
6262
6263/*
6264 * Regenerate the statedump for each app in the session.
6265 */
6266int ust_app_regenerate_statedump_all(struct ltt_ust_session *usess)
6267{
6268 int ret = 0;
6269 struct lttng_ht_iter iter;
6270 struct ust_app *app;
6271
6272 DBG("Regenerating the metadata for all UST apps");
6273
6274 rcu_read_lock();
6275
6276 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6277 if (!app->compatible) {
6278 continue;
6279 }
6280
6281 ret = ust_app_regenerate_statedump(usess, app);
6282 if (ret < 0) {
6283 /* Continue to the next app even on error */
6284 continue;
6285 }
6286 }
6287
6288 rcu_read_unlock();
6289
6290 return 0;
6291}
6292
6293/*
6294 * Rotate all the channels of a session.
6295 *
6296 * Return LTTNG_OK on success or else an LTTng error code.
6297 */
6298enum lttng_error_code ust_app_rotate_session(struct ltt_session *session)
6299{
6300 int ret;
6301 enum lttng_error_code cmd_ret = LTTNG_OK;
6302 struct lttng_ht_iter iter;
6303 struct ust_app *app;
6304 struct ltt_ust_session *usess = session->ust_session;
6305
6306 assert(usess);
6307
6308 rcu_read_lock();
6309
6310 switch (usess->buffer_type) {
6311 case LTTNG_BUFFER_PER_UID:
6312 {
6313 struct buffer_reg_uid *reg;
6314
6315 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6316 struct buffer_reg_channel *reg_chan;
6317 struct consumer_socket *socket;
6318
6319 /* Get consumer socket to use to push the metadata.*/
6320 socket = consumer_find_socket_by_bitness(reg->bits_per_long,
6321 usess->consumer);
6322 if (!socket) {
6323 cmd_ret = LTTNG_ERR_INVALID;
6324 goto error;
6325 }
6326
6327 /* Rotate the data channels. */
6328 cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
6329 reg_chan, node.node) {
6330 ret = consumer_rotate_channel(socket,
6331 reg_chan->consumer_key,
6332 usess->uid, usess->gid,
6333 usess->consumer,
6334 /* is_metadata_channel */ false);
6335 if (ret < 0) {
6336 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6337 goto error;
6338 }
6339 }
6340
6341 (void) push_metadata(reg->registry->reg.ust, usess->consumer);
6342
6343 ret = consumer_rotate_channel(socket,
6344 reg->registry->reg.ust->metadata_key,
6345 usess->uid, usess->gid,
6346 usess->consumer,
6347 /* is_metadata_channel */ true);
6348 if (ret < 0) {
6349 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6350 goto error;
6351 }
6352 }
6353 break;
6354 }
6355 case LTTNG_BUFFER_PER_PID:
6356 {
6357 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
6358 struct consumer_socket *socket;
6359 struct lttng_ht_iter chan_iter;
6360 struct ust_app_channel *ua_chan;
6361 struct ust_app_session *ua_sess;
6362 struct ust_registry_session *registry;
6363
6364 ua_sess = lookup_session_by_app(usess, app);
6365 if (!ua_sess) {
6366 /* Session not associated with this app. */
6367 continue;
6368 }
6369
6370 /* Get the right consumer socket for the application. */
6371 socket = consumer_find_socket_by_bitness(app->bits_per_long,
6372 usess->consumer);
6373 if (!socket) {
6374 cmd_ret = LTTNG_ERR_INVALID;
6375 goto error;
6376 }
6377
6378 registry = get_session_registry(ua_sess);
6379 if (!registry) {
6380 DBG("Application session is being torn down. Skip application.");
6381 continue;
6382 }
6383
6384 /* Rotate the data channels. */
6385 cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
6386 ua_chan, node.node) {
6387 ret = consumer_rotate_channel(socket,
6388 ua_chan->key,
6389 ua_sess->effective_credentials
6390 .uid,
6391 ua_sess->effective_credentials
6392 .gid,
6393 ua_sess->consumer,
6394 /* is_metadata_channel */ false);
6395 if (ret < 0) {
6396 /* Per-PID buffer and application going away. */
6397 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6398 continue;
6399 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6400 goto error;
6401 }
6402 }
6403
6404 /* Rotate the metadata channel. */
6405 (void) push_metadata(registry, usess->consumer);
6406 ret = consumer_rotate_channel(socket,
6407 registry->metadata_key,
6408 ua_sess->effective_credentials.uid,
6409 ua_sess->effective_credentials.gid,
6410 ua_sess->consumer,
6411 /* is_metadata_channel */ true);
6412 if (ret < 0) {
6413 /* Per-PID buffer and application going away. */
6414 if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
6415 continue;
6416 cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
6417 goto error;
6418 }
6419 }
6420 break;
6421 }
6422 default:
6423 assert(0);
6424 break;
6425 }
6426
6427 cmd_ret = LTTNG_OK;
6428
6429error:
6430 rcu_read_unlock();
6431 return cmd_ret;
6432}
6433
6434enum lttng_error_code ust_app_create_channel_subdirectories(
6435 const struct ltt_ust_session *usess)
6436{
6437 enum lttng_error_code ret = LTTNG_OK;
6438 struct lttng_ht_iter iter;
6439 enum lttng_trace_chunk_status chunk_status;
6440 char *pathname_index;
6441 int fmt_ret;
6442
6443 assert(usess->current_trace_chunk);
6444 rcu_read_lock();
6445
6446 switch (usess->buffer_type) {
6447 case LTTNG_BUFFER_PER_UID:
6448 {
6449 struct buffer_reg_uid *reg;
6450
6451 cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
6452 fmt_ret = asprintf(&pathname_index,
6453 DEFAULT_UST_TRACE_DIR DEFAULT_UST_TRACE_UID_PATH "/" DEFAULT_INDEX_DIR,
6454 reg->uid, reg->bits_per_long);
6455 if (fmt_ret < 0) {
6456 ERR("Failed to format channel index directory");
6457 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6458 goto error;
6459 }
6460
6461 /*
6462 * Create the index subdirectory which will take care
6463 * of implicitly creating the channel's path.
6464 */
6465 chunk_status = lttng_trace_chunk_create_subdirectory(
6466 usess->current_trace_chunk,
6467 pathname_index);
6468 free(pathname_index);
6469 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6470 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6471 goto error;
6472 }
6473 }
6474 break;
6475 }
6476 case LTTNG_BUFFER_PER_PID:
6477 {
6478 struct ust_app *app;
6479
6480 cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
6481 pid_n.node) {
6482 struct ust_app_session *ua_sess;
6483 struct ust_registry_session *registry;
6484
6485 ua_sess = lookup_session_by_app(usess, app);
6486 if (!ua_sess) {
6487 /* Session not associated with this app. */
6488 continue;
6489 }
6490
6491 registry = get_session_registry(ua_sess);
6492 if (!registry) {
6493 DBG("Application session is being torn down. Skip application.");
6494 continue;
6495 }
6496
6497 fmt_ret = asprintf(&pathname_index,
6498 DEFAULT_UST_TRACE_DIR "%s/" DEFAULT_INDEX_DIR,
6499 ua_sess->path);
6500 if (fmt_ret < 0) {
6501 ERR("Failed to format channel index directory");
6502 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6503 goto error;
6504 }
6505 /*
6506 * Create the index subdirectory which will take care
6507 * of implicitly creating the channel's path.
6508 */
6509 chunk_status = lttng_trace_chunk_create_subdirectory(
6510 usess->current_trace_chunk,
6511 pathname_index);
6512 free(pathname_index);
6513 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
6514 ret = LTTNG_ERR_CREATE_DIR_FAIL;
6515 goto error;
6516 }
6517 }
6518 break;
6519 }
6520 default:
6521 abort();
6522 }
6523
6524 ret = LTTNG_OK;
6525error:
6526 rcu_read_unlock();
6527 return ret;
6528}
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