Fix: sessiond: metadata not created on app unregistration during start
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
<
CommitLineData
91d76f53 1/*
ab5be9fa
MJ
2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
91d76f53 4 *
ab5be9fa 5 * SPDX-License-Identifier: GPL-2.0-only
91d76f53 6 *
91d76f53
DG
7 */
8
6c1c0768 9#define _LGPL_SOURCE
7972aab2 10#include <inttypes.h>
91d76f53
DG
11#include <pthread.h>
12#include <stdio.h>
13#include <stdlib.h>
099e26bd 14#include <string.h>
aba8e916
DG
15#include <sys/stat.h>
16#include <sys/types.h>
099e26bd 17#include <unistd.h>
0df502fd 18#include <urcu/compiler.h>
331744e3 19#include <signal.h>
bec39940 20
edf4b93e 21#include <common/compat/errno.h>
990570ed 22#include <common/common.h>
86acf0da 23#include <common/sessiond-comm/sessiond-comm.h>
1e307fab 24
7972aab2 25#include "buffer-registry.h"
86acf0da 26#include "fd-limit.h"
8782cc74 27#include "health-sessiond.h"
56fff090 28#include "ust-app.h"
48842b30 29#include "ust-consumer.h"
75018ab6
JG
30#include "lttng-ust-ctl.h"
31#include "lttng-ust-error.h"
0b2dc8df 32#include "utils.h"
fb83fe64 33#include "session.h"
e9404c27
JG
34#include "lttng-sessiond.h"
35#include "notification-thread-commands.h"
5c408ad8 36#include "rotate.h"
d80a6244 37
44cdb3a2
MJ
38struct lttng_ht *ust_app_ht;
39struct lttng_ht *ust_app_ht_by_sock;
40struct lttng_ht *ust_app_ht_by_notify_sock;
41
c4b88406
MD
42static
43int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
44
d9bf3ca4
MD
45/* Next available channel key. Access under next_channel_key_lock. */
46static uint64_t _next_channel_key;
47static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
48
49/* Next available session ID. Access under next_session_id_lock. */
50static uint64_t _next_session_id;
51static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
ffe60014
DG
52
53/*
d9bf3ca4 54 * Return the incremented value of next_channel_key.
ffe60014 55 */
d9bf3ca4 56static uint64_t get_next_channel_key(void)
ffe60014 57{
d9bf3ca4
MD
58 uint64_t ret;
59
60 pthread_mutex_lock(&next_channel_key_lock);
61 ret = ++_next_channel_key;
62 pthread_mutex_unlock(&next_channel_key_lock);
63 return ret;
ffe60014
DG
64}
65
66/*
7972aab2 67 * Return the atomically incremented value of next_session_id.
ffe60014 68 */
d9bf3ca4 69static uint64_t get_next_session_id(void)
ffe60014 70{
d9bf3ca4
MD
71 uint64_t ret;
72
73 pthread_mutex_lock(&next_session_id_lock);
74 ret = ++_next_session_id;
75 pthread_mutex_unlock(&next_session_id_lock);
76 return ret;
ffe60014
DG
77}
78
d65d2de8
DG
79static void copy_channel_attr_to_ustctl(
80 struct ustctl_consumer_channel_attr *attr,
81 struct lttng_ust_channel_attr *uattr)
82{
83 /* Copy event attributes since the layout is different. */
84 attr->subbuf_size = uattr->subbuf_size;
85 attr->num_subbuf = uattr->num_subbuf;
86 attr->overwrite = uattr->overwrite;
87 attr->switch_timer_interval = uattr->switch_timer_interval;
88 attr->read_timer_interval = uattr->read_timer_interval;
89 attr->output = uattr->output;
491d1539 90 attr->blocking_timeout = uattr->u.s.blocking_timeout;
d65d2de8
DG
91}
92
025faf73
DG
93/*
94 * Match function for the hash table lookup.
95 *
96 * It matches an ust app event based on three attributes which are the event
97 * name, the filter bytecode and the loglevel.
98 */
18eace3b
DG
99static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
100{
101 struct ust_app_event *event;
102 const struct ust_app_ht_key *key;
2106efa0 103 int ev_loglevel_value;
18eace3b
DG
104
105 assert(node);
106 assert(_key);
107
108 event = caa_container_of(node, struct ust_app_event, node.node);
109 key = _key;
2106efa0 110 ev_loglevel_value = event->attr.loglevel;
18eace3b 111
1af53eb5 112 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
18eace3b
DG
113
114 /* Event name */
115 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
116 goto no_match;
117 }
118
119 /* Event loglevel. */
2106efa0 120 if (ev_loglevel_value != key->loglevel_type) {
025faf73 121 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
2106efa0
PP
122 && key->loglevel_type == 0 &&
123 ev_loglevel_value == -1) {
025faf73
DG
124 /*
125 * Match is accepted. This is because on event creation, the
126 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
127 * -1 are accepted for this loglevel type since 0 is the one set by
128 * the API when receiving an enable event.
129 */
130 } else {
131 goto no_match;
132 }
18eace3b
DG
133 }
134
135 /* One of the filters is NULL, fail. */
136 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
137 goto no_match;
138 }
139
025faf73
DG
140 if (key->filter && event->filter) {
141 /* Both filters exists, check length followed by the bytecode. */
142 if (event->filter->len != key->filter->len ||
143 memcmp(event->filter->data, key->filter->data,
144 event->filter->len) != 0) {
145 goto no_match;
146 }
18eace3b
DG
147 }
148
1af53eb5
JI
149 /* One of the exclusions is NULL, fail. */
150 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
151 goto no_match;
152 }
153
154 if (key->exclusion && event->exclusion) {
155 /* Both exclusions exists, check count followed by the names. */
156 if (event->exclusion->count != key->exclusion->count ||
157 memcmp(event->exclusion->names, key->exclusion->names,
158 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
159 goto no_match;
160 }
161 }
162
163
025faf73 164 /* Match. */
18eace3b
DG
165 return 1;
166
167no_match:
168 return 0;
18eace3b
DG
169}
170
025faf73
DG
171/*
172 * Unique add of an ust app event in the given ht. This uses the custom
173 * ht_match_ust_app_event match function and the event name as hash.
174 */
d0b96690 175static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
18eace3b
DG
176 struct ust_app_event *event)
177{
178 struct cds_lfht_node *node_ptr;
179 struct ust_app_ht_key key;
d0b96690 180 struct lttng_ht *ht;
18eace3b 181
d0b96690
DG
182 assert(ua_chan);
183 assert(ua_chan->events);
18eace3b
DG
184 assert(event);
185
d0b96690 186 ht = ua_chan->events;
18eace3b
DG
187 key.name = event->attr.name;
188 key.filter = event->filter;
2106efa0 189 key.loglevel_type = event->attr.loglevel;
91c89f23 190 key.exclusion = event->exclusion;
18eace3b
DG
191
192 node_ptr = cds_lfht_add_unique(ht->ht,
193 ht->hash_fct(event->node.key, lttng_ht_seed),
194 ht_match_ust_app_event, &key, &event->node.node);
195 assert(node_ptr == &event->node.node);
196}
197
d88aee68
DG
198/*
199 * Close the notify socket from the given RCU head object. This MUST be called
200 * through a call_rcu().
201 */
202static void close_notify_sock_rcu(struct rcu_head *head)
203{
204 int ret;
205 struct ust_app_notify_sock_obj *obj =
206 caa_container_of(head, struct ust_app_notify_sock_obj, head);
207
208 /* Must have a valid fd here. */
209 assert(obj->fd >= 0);
210
211 ret = close(obj->fd);
212 if (ret) {
213 ERR("close notify sock %d RCU", obj->fd);
214 }
215 lttng_fd_put(LTTNG_FD_APPS, 1);
216
217 free(obj);
218}
219
7972aab2
DG
220/*
221 * Return the session registry according to the buffer type of the given
222 * session.
223 *
224 * A registry per UID object MUST exists before calling this function or else
225 * it assert() if not found. RCU read side lock must be acquired.
226 */
227static struct ust_registry_session *get_session_registry(
228 struct ust_app_session *ua_sess)
229{
230 struct ust_registry_session *registry = NULL;
231
232 assert(ua_sess);
233
234 switch (ua_sess->buffer_type) {
235 case LTTNG_BUFFER_PER_PID:
236 {
237 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
238 if (!reg_pid) {
239 goto error;
240 }
241 registry = reg_pid->registry->reg.ust;
242 break;
243 }
244 case LTTNG_BUFFER_PER_UID:
245 {
246 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
470cc211 247 ua_sess->tracing_id, ua_sess->bits_per_long,
ff588497 248 lttng_credentials_get_uid(&ua_sess->real_credentials));
7972aab2
DG
249 if (!reg_uid) {
250 goto error;
251 }
252 registry = reg_uid->registry->reg.ust;
253 break;
254 }
255 default:
256 assert(0);
257 };
258
259error:
260 return registry;
261}
262
55cc08a6
DG
263/*
264 * Delete ust context safely. RCU read lock must be held before calling
265 * this function.
266 */
267static
fb45065e
MD
268void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
269 struct ust_app *app)
55cc08a6 270{
ffe60014
DG
271 int ret;
272
273 assert(ua_ctx);
274
55cc08a6 275 if (ua_ctx->obj) {
fb45065e 276 pthread_mutex_lock(&app->sock_lock);
ffe60014 277 ret = ustctl_release_object(sock, ua_ctx->obj);
fb45065e 278 pthread_mutex_unlock(&app->sock_lock);
d0b96690
DG
279 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
280 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
281 sock, ua_ctx->obj->handle, ret);
ffe60014 282 }
55cc08a6
DG
283 free(ua_ctx->obj);
284 }
285 free(ua_ctx);
286}
287
d80a6244
DG
288/*
289 * Delete ust app event safely. RCU read lock must be held before calling
290 * this function.
291 */
8b366481 292static
fb45065e
MD
293void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
294 struct ust_app *app)
d80a6244 295{
ffe60014
DG
296 int ret;
297
298 assert(ua_event);
299
53a80697 300 free(ua_event->filter);
951f0b71
JI
301 if (ua_event->exclusion != NULL)
302 free(ua_event->exclusion);
edb67388 303 if (ua_event->obj != NULL) {
fb45065e 304 pthread_mutex_lock(&app->sock_lock);
ffe60014 305 ret = ustctl_release_object(sock, ua_event->obj);
fb45065e 306 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
307 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
308 ERR("UST app sock %d release event obj failed with ret %d",
309 sock, ret);
310 }
edb67388
DG
311 free(ua_event->obj);
312 }
d80a6244
DG
313 free(ua_event);
314}
315
316/*
7972aab2
DG
317 * Release ust data object of the given stream.
318 *
319 * Return 0 on success or else a negative value.
d80a6244 320 */
fb45065e
MD
321static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
322 struct ust_app *app)
d80a6244 323{
7972aab2 324 int ret = 0;
ffe60014
DG
325
326 assert(stream);
327
8b366481 328 if (stream->obj) {
fb45065e 329 pthread_mutex_lock(&app->sock_lock);
ffe60014 330 ret = ustctl_release_object(sock, stream->obj);
fb45065e 331 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
332 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
333 ERR("UST app sock %d release stream obj failed with ret %d",
334 sock, ret);
335 }
4063050c 336 lttng_fd_put(LTTNG_FD_APPS, 2);
8b366481
DG
337 free(stream->obj);
338 }
7972aab2
DG
339
340 return ret;
341}
342
343/*
344 * Delete ust app stream safely. RCU read lock must be held before calling
345 * this function.
346 */
347static
fb45065e
MD
348void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
349 struct ust_app *app)
7972aab2
DG
350{
351 assert(stream);
352
fb45065e 353 (void) release_ust_app_stream(sock, stream, app);
84cd17c6 354 free(stream);
d80a6244
DG
355}
356
36b588ed
MD
357/*
358 * We need to execute ht_destroy outside of RCU read-side critical
0b2dc8df
MD
359 * section and outside of call_rcu thread, so we postpone its execution
360 * using ht_cleanup_push. It is simpler than to change the semantic of
361 * the many callers of delete_ust_app_session().
36b588ed
MD
362 */
363static
364void delete_ust_app_channel_rcu(struct rcu_head *head)
365{
366 struct ust_app_channel *ua_chan =
367 caa_container_of(head, struct ust_app_channel, rcu_head);
368
0b2dc8df
MD
369 ht_cleanup_push(ua_chan->ctx);
370 ht_cleanup_push(ua_chan->events);
36b588ed
MD
371 free(ua_chan);
372}
373
fb83fe64
JD
374/*
375 * Extract the lost packet or discarded events counter when the channel is
376 * being deleted and store the value in the parent channel so we can
377 * access it from lttng list and at stop/destroy.
82cac6d2
JG
378 *
379 * The session list lock must be held by the caller.
fb83fe64
JD
380 */
381static
382void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
383{
384 uint64_t discarded = 0, lost = 0;
385 struct ltt_session *session;
386 struct ltt_ust_channel *uchan;
387
388 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
389 return;
390 }
391
392 rcu_read_lock();
393 session = session_find_by_id(ua_chan->session->tracing_id);
d68ec974
JG
394 if (!session || !session->ust_session) {
395 /*
396 * Not finding the session is not an error because there are
397 * multiple ways the channels can be torn down.
398 *
399 * 1) The session daemon can initiate the destruction of the
400 * ust app session after receiving a destroy command or
401 * during its shutdown/teardown.
402 * 2) The application, since we are in per-pid tracing, is
403 * unregistering and tearing down its ust app session.
404 *
405 * Both paths are protected by the session list lock which
406 * ensures that the accounting of lost packets and discarded
407 * events is done exactly once. The session is then unpublished
408 * from the session list, resulting in this condition.
409 */
fb83fe64
JD
410 goto end;
411 }
412
413 if (ua_chan->attr.overwrite) {
414 consumer_get_lost_packets(ua_chan->session->tracing_id,
415 ua_chan->key, session->ust_session->consumer,
416 &lost);
417 } else {
418 consumer_get_discarded_events(ua_chan->session->tracing_id,
419 ua_chan->key, session->ust_session->consumer,
420 &discarded);
421 }
422 uchan = trace_ust_find_channel_by_name(
423 session->ust_session->domain_global.channels,
424 ua_chan->name);
425 if (!uchan) {
426 ERR("Missing UST channel to store discarded counters");
427 goto end;
428 }
429
430 uchan->per_pid_closed_app_discarded += discarded;
431 uchan->per_pid_closed_app_lost += lost;
432
433end:
434 rcu_read_unlock();
e32d7f27
JG
435 if (session) {
436 session_put(session);
437 }
fb83fe64
JD
438}
439
d80a6244
DG
440/*
441 * Delete ust app channel safely. RCU read lock must be held before calling
442 * this function.
82cac6d2
JG
443 *
444 * The session list lock must be held by the caller.
d80a6244 445 */
8b366481 446static
d0b96690
DG
447void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
448 struct ust_app *app)
d80a6244
DG
449{
450 int ret;
bec39940 451 struct lttng_ht_iter iter;
d80a6244 452 struct ust_app_event *ua_event;
55cc08a6 453 struct ust_app_ctx *ua_ctx;
030a66fa 454 struct ust_app_stream *stream, *stmp;
7972aab2 455 struct ust_registry_session *registry;
d80a6244 456
ffe60014
DG
457 assert(ua_chan);
458
459 DBG3("UST app deleting channel %s", ua_chan->name);
460
55cc08a6 461 /* Wipe stream */
d80a6244 462 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
84cd17c6 463 cds_list_del(&stream->list);
fb45065e 464 delete_ust_app_stream(sock, stream, app);
d80a6244
DG
465 }
466
55cc08a6 467 /* Wipe context */
bec39940 468 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
31746f93 469 cds_list_del(&ua_ctx->list);
bec39940 470 ret = lttng_ht_del(ua_chan->ctx, &iter);
55cc08a6 471 assert(!ret);
fb45065e 472 delete_ust_app_ctx(sock, ua_ctx, app);
55cc08a6 473 }
d80a6244 474
55cc08a6 475 /* Wipe events */
bec39940
DG
476 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
477 node.node) {
478 ret = lttng_ht_del(ua_chan->events, &iter);
525b0740 479 assert(!ret);
fb45065e 480 delete_ust_app_event(sock, ua_event, app);
d80a6244 481 }
edb67388 482
c8335706
MD
483 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
484 /* Wipe and free registry from session registry. */
485 registry = get_session_registry(ua_chan->session);
486 if (registry) {
e9404c27 487 ust_registry_channel_del_free(registry, ua_chan->key,
e38d96f9
MD
488 sock >= 0);
489 }
45798a31
JG
490 /*
491 * A negative socket can be used by the caller when
492 * cleaning-up a ua_chan in an error path. Skip the
493 * accounting in this case.
494 */
e38d96f9
MD
495 if (sock >= 0) {
496 save_per_pid_lost_discarded_counters(ua_chan);
c8335706 497 }
7972aab2 498 }
d0b96690 499
edb67388 500 if (ua_chan->obj != NULL) {
d0b96690
DG
501 /* Remove channel from application UST object descriptor. */
502 iter.iter.node = &ua_chan->ust_objd_node.node;
c6e62271
DG
503 ret = lttng_ht_del(app->ust_objd, &iter);
504 assert(!ret);
fb45065e 505 pthread_mutex_lock(&app->sock_lock);
ffe60014 506 ret = ustctl_release_object(sock, ua_chan->obj);
fb45065e 507 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
508 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
509 ERR("UST app sock %d release channel obj failed with ret %d",
510 sock, ret);
511 }
7972aab2 512 lttng_fd_put(LTTNG_FD_APPS, 1);
edb67388
DG
513 free(ua_chan->obj);
514 }
36b588ed 515 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
d80a6244
DG
516}
517
fb45065e
MD
518int ust_app_register_done(struct ust_app *app)
519{
520 int ret;
521
522 pthread_mutex_lock(&app->sock_lock);
523 ret = ustctl_register_done(app->sock);
524 pthread_mutex_unlock(&app->sock_lock);
525 return ret;
526}
527
528int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
529{
530 int ret, sock;
531
532 if (app) {
533 pthread_mutex_lock(&app->sock_lock);
534 sock = app->sock;
535 } else {
536 sock = -1;
537 }
538 ret = ustctl_release_object(sock, data);
539 if (app) {
540 pthread_mutex_unlock(&app->sock_lock);
541 }
542 return ret;
543}
544
331744e3 545/*
1b532a60
DG
546 * Push metadata to consumer socket.
547 *
dc2bbdae
MD
548 * RCU read-side lock must be held to guarantee existance of socket.
549 * Must be called with the ust app session lock held.
550 * Must be called with the registry lock held.
331744e3
JD
551 *
552 * On success, return the len of metadata pushed or else a negative value.
2c57e06d
MD
553 * Returning a -EPIPE return value means we could not send the metadata,
554 * but it can be caused by recoverable errors (e.g. the application has
555 * terminated concurrently).
331744e3
JD
556 */
557ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
558 struct consumer_socket *socket, int send_zero_data)
559{
560 int ret;
561 char *metadata_str = NULL;
c585821b 562 size_t len, offset, new_metadata_len_sent;
331744e3 563 ssize_t ret_val;
93ec662e 564 uint64_t metadata_key, metadata_version;
331744e3
JD
565
566 assert(registry);
567 assert(socket);
1b532a60 568
c585821b
MD
569 metadata_key = registry->metadata_key;
570
ce34fcd0 571 /*
dc2bbdae
MD
572 * Means that no metadata was assigned to the session. This can
573 * happens if no start has been done previously.
ce34fcd0 574 */
c585821b 575 if (!metadata_key) {
ce34fcd0
MD
576 return 0;
577 }
578
331744e3
JD
579 offset = registry->metadata_len_sent;
580 len = registry->metadata_len - registry->metadata_len_sent;
c585821b 581 new_metadata_len_sent = registry->metadata_len;
93ec662e 582 metadata_version = registry->metadata_version;
331744e3
JD
583 if (len == 0) {
584 DBG3("No metadata to push for metadata key %" PRIu64,
585 registry->metadata_key);
586 ret_val = len;
587 if (send_zero_data) {
588 DBG("No metadata to push");
589 goto push_data;
590 }
591 goto end;
592 }
593
594 /* Allocate only what we have to send. */
595 metadata_str = zmalloc(len);
596 if (!metadata_str) {
597 PERROR("zmalloc ust app metadata string");
598 ret_val = -ENOMEM;
599 goto error;
600 }
c585821b 601 /* Copy what we haven't sent out. */
331744e3 602 memcpy(metadata_str, registry->metadata + offset, len);
331744e3
JD
603
604push_data:
c585821b
MD
605 pthread_mutex_unlock(&registry->lock);
606 /*
607 * We need to unlock the registry while we push metadata to
608 * break a circular dependency between the consumerd metadata
609 * lock and the sessiond registry lock. Indeed, pushing metadata
610 * to the consumerd awaits that it gets pushed all the way to
611 * relayd, but doing so requires grabbing the metadata lock. If
612 * a concurrent metadata request is being performed by
613 * consumerd, this can try to grab the registry lock on the
614 * sessiond while holding the metadata lock on the consumer
615 * daemon. Those push and pull schemes are performed on two
616 * different bidirectionnal communication sockets.
617 */
618 ret = consumer_push_metadata(socket, metadata_key,
93ec662e 619 metadata_str, len, offset, metadata_version);
c585821b 620 pthread_mutex_lock(&registry->lock);
331744e3 621 if (ret < 0) {
000baf6a 622 /*
dc2bbdae
MD
623 * There is an acceptable race here between the registry
624 * metadata key assignment and the creation on the
625 * consumer. The session daemon can concurrently push
626 * metadata for this registry while being created on the
627 * consumer since the metadata key of the registry is
628 * assigned *before* it is setup to avoid the consumer
629 * to ask for metadata that could possibly be not found
630 * in the session daemon.
000baf6a 631 *
dc2bbdae
MD
632 * The metadata will get pushed either by the session
633 * being stopped or the consumer requesting metadata if
634 * that race is triggered.
000baf6a
DG
635 */
636 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
637 ret = 0;
c585821b
MD
638 } else {
639 ERR("Error pushing metadata to consumer");
000baf6a 640 }
331744e3
JD
641 ret_val = ret;
642 goto error_push;
c585821b
MD
643 } else {
644 /*
645 * Metadata may have been concurrently pushed, since
646 * we're not holding the registry lock while pushing to
647 * consumer. This is handled by the fact that we send
648 * the metadata content, size, and the offset at which
649 * that metadata belongs. This may arrive out of order
650 * on the consumer side, and the consumer is able to
651 * deal with overlapping fragments. The consumer
652 * supports overlapping fragments, which must be
653 * contiguous starting from offset 0. We keep the
654 * largest metadata_len_sent value of the concurrent
655 * send.
656 */
657 registry->metadata_len_sent =
658 max_t(size_t, registry->metadata_len_sent,
659 new_metadata_len_sent);
331744e3 660 }
331744e3
JD
661 free(metadata_str);
662 return len;
663
664end:
665error:
ce34fcd0
MD
666 if (ret_val) {
667 /*
dc2bbdae
MD
668 * On error, flag the registry that the metadata is
669 * closed. We were unable to push anything and this
670 * means that either the consumer is not responding or
671 * the metadata cache has been destroyed on the
672 * consumer.
ce34fcd0
MD
673 */
674 registry->metadata_closed = 1;
675 }
331744e3
JD
676error_push:
677 free(metadata_str);
678 return ret_val;
679}
680
d88aee68 681/*
ce34fcd0 682 * For a given application and session, push metadata to consumer.
331744e3
JD
683 * Either sock or consumer is required : if sock is NULL, the default
684 * socket to send the metadata is retrieved from consumer, if sock
685 * is not NULL we use it to send the metadata.
ce34fcd0 686 * RCU read-side lock must be held while calling this function,
dc2bbdae
MD
687 * therefore ensuring existance of registry. It also ensures existance
688 * of socket throughout this function.
d88aee68
DG
689 *
690 * Return 0 on success else a negative error.
2c57e06d
MD
691 * Returning a -EPIPE return value means we could not send the metadata,
692 * but it can be caused by recoverable errors (e.g. the application has
693 * terminated concurrently).
d88aee68 694 */
7972aab2
DG
695static int push_metadata(struct ust_registry_session *registry,
696 struct consumer_output *consumer)
d88aee68 697{
331744e3
JD
698 int ret_val;
699 ssize_t ret;
d88aee68
DG
700 struct consumer_socket *socket;
701
7972aab2
DG
702 assert(registry);
703 assert(consumer);
704
ce34fcd0 705 pthread_mutex_lock(&registry->lock);
ce34fcd0 706 if (registry->metadata_closed) {
dc2bbdae
MD
707 ret_val = -EPIPE;
708 goto error;
d88aee68
DG
709 }
710
d88aee68 711 /* Get consumer socket to use to push the metadata.*/
7972aab2
DG
712 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
713 consumer);
d88aee68 714 if (!socket) {
331744e3 715 ret_val = -1;
ce34fcd0 716 goto error;
d88aee68
DG
717 }
718
331744e3 719 ret = ust_app_push_metadata(registry, socket, 0);
d88aee68 720 if (ret < 0) {
331744e3 721 ret_val = ret;
ce34fcd0 722 goto error;
d88aee68 723 }
dc2bbdae 724 pthread_mutex_unlock(&registry->lock);
d88aee68
DG
725 return 0;
726
ce34fcd0 727error:
dc2bbdae 728 pthread_mutex_unlock(&registry->lock);
331744e3 729 return ret_val;
d88aee68
DG
730}
731
732/*
733 * Send to the consumer a close metadata command for the given session. Once
734 * done, the metadata channel is deleted and the session metadata pointer is
dc2bbdae 735 * nullified. The session lock MUST be held unless the application is
d88aee68
DG
736 * in the destroy path.
737 *
a70ac2f4
MD
738 * Do not hold the registry lock while communicating with the consumerd, because
739 * doing so causes inter-process deadlocks between consumerd and sessiond with
740 * the metadata request notification.
741 *
d88aee68
DG
742 * Return 0 on success else a negative value.
743 */
7972aab2
DG
744static int close_metadata(struct ust_registry_session *registry,
745 struct consumer_output *consumer)
d88aee68
DG
746{
747 int ret;
748 struct consumer_socket *socket;
a70ac2f4
MD
749 uint64_t metadata_key;
750 bool registry_was_already_closed;
d88aee68 751
7972aab2
DG
752 assert(registry);
753 assert(consumer);
d88aee68 754
7972aab2
DG
755 rcu_read_lock();
756
ce34fcd0 757 pthread_mutex_lock(&registry->lock);
a70ac2f4
MD
758 metadata_key = registry->metadata_key;
759 registry_was_already_closed = registry->metadata_closed;
760 if (metadata_key != 0) {
761 /*
762 * Metadata closed. Even on error this means that the consumer
763 * is not responding or not found so either way a second close
764 * should NOT be emit for this registry.
765 */
766 registry->metadata_closed = 1;
767 }
768 pthread_mutex_unlock(&registry->lock);
ce34fcd0 769
a70ac2f4 770 if (metadata_key == 0 || registry_was_already_closed) {
d88aee68 771 ret = 0;
1b532a60 772 goto end;
d88aee68
DG
773 }
774
d88aee68 775 /* Get consumer socket to use to push the metadata.*/
7972aab2
DG
776 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
777 consumer);
d88aee68
DG
778 if (!socket) {
779 ret = -1;
a70ac2f4 780 goto end;
d88aee68
DG
781 }
782
a70ac2f4 783 ret = consumer_close_metadata(socket, metadata_key);
d88aee68 784 if (ret < 0) {
a70ac2f4 785 goto end;
d88aee68
DG
786 }
787
1b532a60 788end:
7972aab2 789 rcu_read_unlock();
d88aee68
DG
790 return ret;
791}
792
36b588ed
MD
793/*
794 * We need to execute ht_destroy outside of RCU read-side critical
0b2dc8df
MD
795 * section and outside of call_rcu thread, so we postpone its execution
796 * using ht_cleanup_push. It is simpler than to change the semantic of
797 * the many callers of delete_ust_app_session().
36b588ed
MD
798 */
799static
800void delete_ust_app_session_rcu(struct rcu_head *head)
801{
802 struct ust_app_session *ua_sess =
803 caa_container_of(head, struct ust_app_session, rcu_head);
804
0b2dc8df 805 ht_cleanup_push(ua_sess->channels);
36b588ed
MD
806 free(ua_sess);
807}
808
d80a6244
DG
809/*
810 * Delete ust app session safely. RCU read lock must be held before calling
811 * this function.
82cac6d2
JG
812 *
813 * The session list lock must be held by the caller.
d80a6244 814 */
8b366481 815static
d0b96690
DG
816void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
817 struct ust_app *app)
d80a6244
DG
818{
819 int ret;
bec39940 820 struct lttng_ht_iter iter;
d80a6244 821 struct ust_app_channel *ua_chan;
7972aab2 822 struct ust_registry_session *registry;
d80a6244 823
d88aee68
DG
824 assert(ua_sess);
825
1b532a60
DG
826 pthread_mutex_lock(&ua_sess->lock);
827
b161602a
MD
828 assert(!ua_sess->deleted);
829 ua_sess->deleted = true;
830
7972aab2 831 registry = get_session_registry(ua_sess);
fad1ed2f 832 /* Registry can be null on error path during initialization. */
ce34fcd0 833 if (registry) {
d88aee68 834 /* Push metadata for application before freeing the application. */
7972aab2 835 (void) push_metadata(registry, ua_sess->consumer);
d88aee68 836
7972aab2
DG
837 /*
838 * Don't ask to close metadata for global per UID buffers. Close
1b532a60
DG
839 * metadata only on destroy trace session in this case. Also, the
840 * previous push metadata could have flag the metadata registry to
841 * close so don't send a close command if closed.
7972aab2 842 */
ce34fcd0 843 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
7972aab2
DG
844 /* And ask to close it for this session registry. */
845 (void) close_metadata(registry, ua_sess->consumer);
846 }
d80a6244
DG
847 }
848
bec39940
DG
849 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
850 node.node) {
851 ret = lttng_ht_del(ua_sess->channels, &iter);
525b0740 852 assert(!ret);
d0b96690 853 delete_ust_app_channel(sock, ua_chan, app);
d80a6244 854 }
d80a6244 855
7972aab2
DG
856 /* In case of per PID, the registry is kept in the session. */
857 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
858 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
859 if (reg_pid) {
fad1ed2f
JR
860 /*
861 * Registry can be null on error path during
862 * initialization.
863 */
7972aab2
DG
864 buffer_reg_pid_remove(reg_pid);
865 buffer_reg_pid_destroy(reg_pid);
866 }
867 }
d0b96690 868
aee6bafd 869 if (ua_sess->handle != -1) {
fb45065e 870 pthread_mutex_lock(&app->sock_lock);
ffe60014 871 ret = ustctl_release_handle(sock, ua_sess->handle);
fb45065e 872 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
873 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
874 ERR("UST app sock %d release session handle failed with ret %d",
875 sock, ret);
876 }
10b56aef
MD
877 /* Remove session from application UST object descriptor. */
878 iter.iter.node = &ua_sess->ust_objd_node.node;
879 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
880 assert(!ret);
aee6bafd 881 }
10b56aef 882
1b532a60
DG
883 pthread_mutex_unlock(&ua_sess->lock);
884
6addfa37
MD
885 consumer_output_put(ua_sess->consumer);
886
36b588ed 887 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
d80a6244 888}
91d76f53
DG
889
890/*
284d8f55
DG
891 * Delete a traceable application structure from the global list. Never call
892 * this function outside of a call_rcu call.
36b588ed
MD
893 *
894 * RCU read side lock should _NOT_ be held when calling this function.
91d76f53 895 */
8b366481
DG
896static
897void delete_ust_app(struct ust_app *app)
91d76f53 898{
8b366481 899 int ret, sock;
d42f20df 900 struct ust_app_session *ua_sess, *tmp_ua_sess;
44d3bd01 901
82cac6d2
JG
902 /*
903 * The session list lock must be held during this function to guarantee
904 * the existence of ua_sess.
905 */
906 session_lock_list();
d80a6244 907 /* Delete ust app sessions info */
852d0037
DG
908 sock = app->sock;
909 app->sock = -1;
d80a6244 910
8b366481 911 /* Wipe sessions */
d42f20df
DG
912 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
913 teardown_node) {
914 /* Free every object in the session and the session. */
36b588ed 915 rcu_read_lock();
d0b96690 916 delete_ust_app_session(sock, ua_sess, app);
36b588ed 917 rcu_read_unlock();
d80a6244 918 }
36b588ed 919
0b2dc8df 920 ht_cleanup_push(app->sessions);
10b56aef 921 ht_cleanup_push(app->ust_sessions_objd);
0b2dc8df 922 ht_cleanup_push(app->ust_objd);
d80a6244 923
6414a713 924 /*
852d0037
DG
925 * Wait until we have deleted the application from the sock hash table
926 * before closing this socket, otherwise an application could re-use the
927 * socket ID and race with the teardown, using the same hash table entry.
928 *
929 * It's OK to leave the close in call_rcu. We want it to stay unique for
930 * all RCU readers that could run concurrently with unregister app,
931 * therefore we _need_ to only close that socket after a grace period. So
932 * it should stay in this RCU callback.
933 *
934 * This close() is a very important step of the synchronization model so
935 * every modification to this function must be carefully reviewed.
6414a713 936 */
799e2c4f
MD
937 ret = close(sock);
938 if (ret) {
939 PERROR("close");
940 }
4063050c 941 lttng_fd_put(LTTNG_FD_APPS, 1);
d80a6244 942
852d0037 943 DBG2("UST app pid %d deleted", app->pid);
284d8f55 944 free(app);
82cac6d2 945 session_unlock_list();
099e26bd
DG
946}
947
948/*
f6a9efaa 949 * URCU intermediate call to delete an UST app.
099e26bd 950 */
8b366481
DG
951static
952void delete_ust_app_rcu(struct rcu_head *head)
099e26bd 953{
bec39940
DG
954 struct lttng_ht_node_ulong *node =
955 caa_container_of(head, struct lttng_ht_node_ulong, head);
f6a9efaa 956 struct ust_app *app =
852d0037 957 caa_container_of(node, struct ust_app, pid_n);
f6a9efaa 958
852d0037 959 DBG3("Call RCU deleting app PID %d", app->pid);
f6a9efaa 960 delete_ust_app(app);
099e26bd
DG
961}
962
ffe60014
DG
963/*
964 * Delete the session from the application ht and delete the data structure by
965 * freeing every object inside and releasing them.
82cac6d2
JG
966 *
967 * The session list lock must be held by the caller.
ffe60014 968 */
d0b96690 969static void destroy_app_session(struct ust_app *app,
ffe60014
DG
970 struct ust_app_session *ua_sess)
971{
972 int ret;
973 struct lttng_ht_iter iter;
974
975 assert(app);
976 assert(ua_sess);
977
978 iter.iter.node = &ua_sess->node.node;
979 ret = lttng_ht_del(app->sessions, &iter);
980 if (ret) {
981 /* Already scheduled for teardown. */
982 goto end;
983 }
984
985 /* Once deleted, free the data structure. */
d0b96690 986 delete_ust_app_session(app->sock, ua_sess, app);
ffe60014
DG
987
988end:
989 return;
990}
991
8b366481
DG
992/*
993 * Alloc new UST app session.
994 */
995static
40bbd087 996struct ust_app_session *alloc_ust_app_session(void)
8b366481
DG
997{
998 struct ust_app_session *ua_sess;
999
1000 /* Init most of the default value by allocating and zeroing */
1001 ua_sess = zmalloc(sizeof(struct ust_app_session));
1002 if (ua_sess == NULL) {
1003 PERROR("malloc");
ffe60014 1004 goto error_free;
8b366481
DG
1005 }
1006
1007 ua_sess->handle = -1;
bec39940 1008 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
ad7a9107 1009 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
84ad93e8 1010 pthread_mutex_init(&ua_sess->lock, NULL);
ad7a9107 1011
8b366481
DG
1012 return ua_sess;
1013
ffe60014 1014error_free:
8b366481
DG
1015 return NULL;
1016}
1017
1018/*
1019 * Alloc new UST app channel.
1020 */
1021static
b53d4e59 1022struct ust_app_channel *alloc_ust_app_channel(const char *name,
d0b96690 1023 struct ust_app_session *ua_sess,
ffe60014 1024 struct lttng_ust_channel_attr *attr)
8b366481
DG
1025{
1026 struct ust_app_channel *ua_chan;
1027
1028 /* Init most of the default value by allocating and zeroing */
1029 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1030 if (ua_chan == NULL) {
1031 PERROR("malloc");
1032 goto error;
1033 }
1034
1035 /* Setup channel name */
1036 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1037 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1038
1039 ua_chan->enabled = 1;
1040 ua_chan->handle = -1;
45893984 1041 ua_chan->session = ua_sess;
ffe60014 1042 ua_chan->key = get_next_channel_key();
bec39940
DG
1043 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1044 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1045 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
8b366481
DG
1046
1047 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
31746f93 1048 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
8b366481
DG
1049
1050 /* Copy attributes */
1051 if (attr) {
ffe60014 1052 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
2fe6e7f5
DG
1053 ua_chan->attr.subbuf_size = attr->subbuf_size;
1054 ua_chan->attr.num_subbuf = attr->num_subbuf;
1055 ua_chan->attr.overwrite = attr->overwrite;
1056 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1057 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1058 ua_chan->attr.output = attr->output;
491d1539 1059 ua_chan->attr.blocking_timeout = attr->u.s.blocking_timeout;
8b366481 1060 }
ffe60014
DG
1061 /* By default, the channel is a per cpu channel. */
1062 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
8b366481
DG
1063
1064 DBG3("UST app channel %s allocated", ua_chan->name);
1065
1066 return ua_chan;
1067
1068error:
1069 return NULL;
1070}
1071
37f1c236
DG
1072/*
1073 * Allocate and initialize a UST app stream.
1074 *
1075 * Return newly allocated stream pointer or NULL on error.
1076 */
ffe60014 1077struct ust_app_stream *ust_app_alloc_stream(void)
37f1c236
DG
1078{
1079 struct ust_app_stream *stream = NULL;
1080
1081 stream = zmalloc(sizeof(*stream));
1082 if (stream == NULL) {
1083 PERROR("zmalloc ust app stream");
1084 goto error;
1085 }
1086
1087 /* Zero could be a valid value for a handle so flag it to -1. */
1088 stream->handle = -1;
1089
1090error:
1091 return stream;
1092}
1093
8b366481
DG
1094/*
1095 * Alloc new UST app event.
1096 */
1097static
1098struct ust_app_event *alloc_ust_app_event(char *name,
1099 struct lttng_ust_event *attr)
1100{
1101 struct ust_app_event *ua_event;
1102
1103 /* Init most of the default value by allocating and zeroing */
1104 ua_event = zmalloc(sizeof(struct ust_app_event));
1105 if (ua_event == NULL) {
20533947 1106 PERROR("Failed to allocate ust_app_event structure");
8b366481
DG
1107 goto error;
1108 }
1109
1110 ua_event->enabled = 1;
1111 strncpy(ua_event->name, name, sizeof(ua_event->name));
1112 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
bec39940 1113 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
8b366481
DG
1114
1115 /* Copy attributes */
1116 if (attr) {
1117 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1118 }
1119
1120 DBG3("UST app event %s allocated", ua_event->name);
1121
1122 return ua_event;
1123
1124error:
1125 return NULL;
1126}
1127
1128/*
1129 * Alloc new UST app context.
1130 */
1131static
bdf64013 1132struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
8b366481
DG
1133{
1134 struct ust_app_ctx *ua_ctx;
1135
1136 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1137 if (ua_ctx == NULL) {
1138 goto error;
1139 }
1140
31746f93
DG
1141 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1142
8b366481
DG
1143 if (uctx) {
1144 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
bdf64013 1145 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
f3db82be 1146 char *provider_name = NULL, *ctx_name = NULL;
bdf64013
JG
1147
1148 provider_name = strdup(uctx->u.app_ctx.provider_name);
1149 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1150 if (!provider_name || !ctx_name) {
1151 free(provider_name);
1152 free(ctx_name);
1153 goto error;
1154 }
1155
1156 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1157 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1158 }
8b366481
DG
1159 }
1160
1161 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
8b366481 1162 return ua_ctx;
bdf64013
JG
1163error:
1164 free(ua_ctx);
1165 return NULL;
8b366481
DG
1166}
1167
025faf73
DG
1168/*
1169 * Allocate a filter and copy the given original filter.
1170 *
1171 * Return allocated filter or NULL on error.
1172 */
51755dc8
JG
1173static struct lttng_filter_bytecode *copy_filter_bytecode(
1174 struct lttng_filter_bytecode *orig_f)
025faf73 1175{
51755dc8 1176 struct lttng_filter_bytecode *filter = NULL;
025faf73
DG
1177
1178 /* Copy filter bytecode */
1179 filter = zmalloc(sizeof(*filter) + orig_f->len);
1180 if (!filter) {
51755dc8 1181 PERROR("zmalloc alloc filter bytecode");
025faf73
DG
1182 goto error;
1183 }
1184
1185 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1186
1187error:
1188 return filter;
1189}
1190
51755dc8
JG
1191/*
1192 * Create a liblttng-ust filter bytecode from given bytecode.
1193 *
1194 * Return allocated filter or NULL on error.
1195 */
1196static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1197 struct lttng_filter_bytecode *orig_f)
1198{
1199 struct lttng_ust_filter_bytecode *filter = NULL;
1200
1201 /* Copy filter bytecode */
1202 filter = zmalloc(sizeof(*filter) + orig_f->len);
1203 if (!filter) {
1204 PERROR("zmalloc alloc ust filter bytecode");
1205 goto error;
1206 }
1207
1208 assert(sizeof(struct lttng_filter_bytecode) ==
1209 sizeof(struct lttng_ust_filter_bytecode));
1210 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1211error:
1212 return filter;
1213}
1214
099e26bd 1215/*
421cb601
DG
1216 * Find an ust_app using the sock and return it. RCU read side lock must be
1217 * held before calling this helper function.
099e26bd 1218 */
f20baf8e 1219struct ust_app *ust_app_find_by_sock(int sock)
099e26bd 1220{
bec39940 1221 struct lttng_ht_node_ulong *node;
bec39940 1222 struct lttng_ht_iter iter;
f6a9efaa 1223
852d0037 1224 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
bec39940 1225 node = lttng_ht_iter_get_node_ulong(&iter);
f6a9efaa
DG
1226 if (node == NULL) {
1227 DBG2("UST app find by sock %d not found", sock);
f6a9efaa
DG
1228 goto error;
1229 }
852d0037
DG
1230
1231 return caa_container_of(node, struct ust_app, sock_n);
f6a9efaa
DG
1232
1233error:
1234 return NULL;
099e26bd
DG
1235}
1236
d0b96690
DG
1237/*
1238 * Find an ust_app using the notify sock and return it. RCU read side lock must
1239 * be held before calling this helper function.
1240 */
1241static struct ust_app *find_app_by_notify_sock(int sock)
1242{
1243 struct lttng_ht_node_ulong *node;
1244 struct lttng_ht_iter iter;
1245
1246 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1247 &iter);
1248 node = lttng_ht_iter_get_node_ulong(&iter);
1249 if (node == NULL) {
1250 DBG2("UST app find by notify sock %d not found", sock);
1251 goto error;
1252 }
1253
1254 return caa_container_of(node, struct ust_app, notify_sock_n);
1255
1256error:
1257 return NULL;
1258}
1259
025faf73
DG
1260/*
1261 * Lookup for an ust app event based on event name, filter bytecode and the
1262 * event loglevel.
1263 *
1264 * Return an ust_app_event object or NULL on error.
1265 */
18eace3b 1266static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
88e3c2f5 1267 const char *name, const struct lttng_filter_bytecode *filter,
2106efa0 1268 int loglevel_value,
39c5a3a7 1269 const struct lttng_event_exclusion *exclusion)
18eace3b
DG
1270{
1271 struct lttng_ht_iter iter;
1272 struct lttng_ht_node_str *node;
1273 struct ust_app_event *event = NULL;
1274 struct ust_app_ht_key key;
18eace3b
DG
1275
1276 assert(name);
1277 assert(ht);
1278
1279 /* Setup key for event lookup. */
1280 key.name = name;
1281 key.filter = filter;
2106efa0 1282 key.loglevel_type = loglevel_value;
39c5a3a7 1283 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
51755dc8 1284 key.exclusion = exclusion;
18eace3b 1285
025faf73
DG
1286 /* Lookup using the event name as hash and a custom match fct. */
1287 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1288 ht_match_ust_app_event, &key, &iter.iter);
18eace3b
DG
1289 node = lttng_ht_iter_get_node_str(&iter);
1290 if (node == NULL) {
1291 goto end;
1292 }
1293
1294 event = caa_container_of(node, struct ust_app_event, node);
1295
1296end:
18eace3b
DG
1297 return event;
1298}
1299
55cc08a6
DG
1300/*
1301 * Create the channel context on the tracer.
d0b96690
DG
1302 *
1303 * Called with UST app session lock held.
55cc08a6
DG
1304 */
1305static
1306int create_ust_channel_context(struct ust_app_channel *ua_chan,
1307 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1308{
1309 int ret;
1310
840cb59c 1311 health_code_update();
86acf0da 1312
fb45065e 1313 pthread_mutex_lock(&app->sock_lock);
852d0037 1314 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
55cc08a6 1315 ua_chan->obj, &ua_ctx->obj);
fb45065e 1316 pthread_mutex_unlock(&app->sock_lock);
55cc08a6 1317 if (ret < 0) {
ffe60014
DG
1318 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1319 ERR("UST app create channel context failed for app (pid: %d) "
1320 "with ret %d", app->pid, ret);
1321 } else {
3757b385
DG
1322 /*
1323 * This is normal behavior, an application can die during the
1324 * creation process. Don't report an error so the execution can
1325 * continue normally.
1326 */
1327 ret = 0;
88e3c2f5 1328 DBG3("UST app add context failed. Application is dead.");
ffe60014 1329 }
55cc08a6
DG
1330 goto error;
1331 }
1332
1333 ua_ctx->handle = ua_ctx->obj->handle;
1334
d0b96690
DG
1335 DBG2("UST app context handle %d created successfully for channel %s",
1336 ua_ctx->handle, ua_chan->name);
55cc08a6
DG
1337
1338error:
840cb59c 1339 health_code_update();
55cc08a6
DG
1340 return ret;
1341}
1342
53a80697
MD
1343/*
1344 * Set the filter on the tracer.
1345 */
1346static
1347int set_ust_event_filter(struct ust_app_event *ua_event,
1348 struct ust_app *app)
1349{
1350 int ret;
51755dc8 1351 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
53a80697 1352
840cb59c 1353 health_code_update();
86acf0da 1354
53a80697 1355 if (!ua_event->filter) {
86acf0da
DG
1356 ret = 0;
1357 goto error;
53a80697
MD
1358 }
1359
51755dc8
JG
1360 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1361 if (!ust_bytecode) {
1362 ret = -LTTNG_ERR_NOMEM;
1363 goto error;
1364 }
fb45065e 1365 pthread_mutex_lock(&app->sock_lock);
51755dc8 1366 ret = ustctl_set_filter(app->sock, ust_bytecode,
53a80697 1367 ua_event->obj);
fb45065e 1368 pthread_mutex_unlock(&app->sock_lock);
53a80697 1369 if (ret < 0) {
ffe60014
DG
1370 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1371 ERR("UST app event %s filter failed for app (pid: %d) "
1372 "with ret %d", ua_event->attr.name, app->pid, ret);
1373 } else {
3757b385
DG
1374 /*
1375 * This is normal behavior, an application can die during the
1376 * creation process. Don't report an error so the execution can
1377 * continue normally.
1378 */
1379 ret = 0;
ffe60014
DG
1380 DBG3("UST app filter event failed. Application is dead.");
1381 }
53a80697
MD
1382 goto error;
1383 }
1384
1385 DBG2("UST filter set successfully for event %s", ua_event->name);
1386
1387error:
840cb59c 1388 health_code_update();
51755dc8 1389 free(ust_bytecode);
53a80697
MD
1390 return ret;
1391}
1392
51755dc8
JG
1393static
1394struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1395 struct lttng_event_exclusion *exclusion)
1396{
1397 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1398 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1399 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1400
1401 ust_exclusion = zmalloc(exclusion_alloc_size);
1402 if (!ust_exclusion) {
1403 PERROR("malloc");
1404 goto end;
1405 }
1406
1407 assert(sizeof(struct lttng_event_exclusion) ==
1408 sizeof(struct lttng_ust_event_exclusion));
1409 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1410end:
1411 return ust_exclusion;
1412}
1413
7cc9a73c
JI
1414/*
1415 * Set event exclusions on the tracer.
1416 */
1417static
1418int set_ust_event_exclusion(struct ust_app_event *ua_event,
1419 struct ust_app *app)
1420{
1421 int ret;
51755dc8 1422 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
7cc9a73c
JI
1423
1424 health_code_update();
1425
1426 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1427 ret = 0;
1428 goto error;
1429 }
1430
51755dc8
JG
1431 ust_exclusion = create_ust_exclusion_from_exclusion(
1432 ua_event->exclusion);
1433 if (!ust_exclusion) {
1434 ret = -LTTNG_ERR_NOMEM;
1435 goto error;
1436 }
fb45065e 1437 pthread_mutex_lock(&app->sock_lock);
51755dc8 1438 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
fb45065e 1439 pthread_mutex_unlock(&app->sock_lock);
7cc9a73c
JI
1440 if (ret < 0) {
1441 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1442 ERR("UST app event %s exclusions failed for app (pid: %d) "
1443 "with ret %d", ua_event->attr.name, app->pid, ret);
1444 } else {
1445 /*
1446 * This is normal behavior, an application can die during the
1447 * creation process. Don't report an error so the execution can
1448 * continue normally.
1449 */
1450 ret = 0;
1451 DBG3("UST app event exclusion failed. Application is dead.");
1452 }
1453 goto error;
1454 }
1455
1456 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1457
1458error:
1459 health_code_update();
51755dc8 1460 free(ust_exclusion);
7cc9a73c
JI
1461 return ret;
1462}
1463
9730260e
DG
1464/*
1465 * Disable the specified event on to UST tracer for the UST session.
1466 */
1467static int disable_ust_event(struct ust_app *app,
1468 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1469{
1470 int ret;
1471
840cb59c 1472 health_code_update();
86acf0da 1473
fb45065e 1474 pthread_mutex_lock(&app->sock_lock);
852d0037 1475 ret = ustctl_disable(app->sock, ua_event->obj);
fb45065e 1476 pthread_mutex_unlock(&app->sock_lock);
9730260e 1477 if (ret < 0) {
ffe60014
DG
1478 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1479 ERR("UST app event %s disable failed for app (pid: %d) "
1480 "and session handle %d with ret %d",
1481 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1482 } else {
3757b385
DG
1483 /*
1484 * This is normal behavior, an application can die during the
1485 * creation process. Don't report an error so the execution can
1486 * continue normally.
1487 */
1488 ret = 0;
ffe60014
DG
1489 DBG3("UST app disable event failed. Application is dead.");
1490 }
9730260e
DG
1491 goto error;
1492 }
1493
1494 DBG2("UST app event %s disabled successfully for app (pid: %d)",
852d0037 1495 ua_event->attr.name, app->pid);
9730260e
DG
1496
1497error:
840cb59c 1498 health_code_update();
9730260e
DG
1499 return ret;
1500}
1501
78f0bacd
DG
1502/*
1503 * Disable the specified channel on to UST tracer for the UST session.
1504 */
1505static int disable_ust_channel(struct ust_app *app,
1506 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1507{
1508 int ret;
1509
840cb59c 1510 health_code_update();
86acf0da 1511
fb45065e 1512 pthread_mutex_lock(&app->sock_lock);
852d0037 1513 ret = ustctl_disable(app->sock, ua_chan->obj);
fb45065e 1514 pthread_mutex_unlock(&app->sock_lock);
78f0bacd 1515 if (ret < 0) {
ffe60014
DG
1516 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1517 ERR("UST app channel %s disable failed for app (pid: %d) "
1518 "and session handle %d with ret %d",
1519 ua_chan->name, app->pid, ua_sess->handle, ret);
1520 } else {
3757b385
DG
1521 /*
1522 * This is normal behavior, an application can die during the
1523 * creation process. Don't report an error so the execution can
1524 * continue normally.
1525 */
1526 ret = 0;
ffe60014
DG
1527 DBG3("UST app disable channel failed. Application is dead.");
1528 }
78f0bacd
DG
1529 goto error;
1530 }
1531
78f0bacd 1532 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
852d0037 1533 ua_chan->name, app->pid);
78f0bacd
DG
1534
1535error:
840cb59c 1536 health_code_update();
78f0bacd
DG
1537 return ret;
1538}
1539
1540/*
1541 * Enable the specified channel on to UST tracer for the UST session.
1542 */
1543static int enable_ust_channel(struct ust_app *app,
1544 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1545{
1546 int ret;
1547
840cb59c 1548 health_code_update();
86acf0da 1549
fb45065e 1550 pthread_mutex_lock(&app->sock_lock);
852d0037 1551 ret = ustctl_enable(app->sock, ua_chan->obj);
fb45065e 1552 pthread_mutex_unlock(&app->sock_lock);
78f0bacd 1553 if (ret < 0) {
ffe60014
DG
1554 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1555 ERR("UST app channel %s enable failed for app (pid: %d) "
1556 "and session handle %d with ret %d",
1557 ua_chan->name, app->pid, ua_sess->handle, ret);
1558 } else {
3757b385
DG
1559 /*
1560 * This is normal behavior, an application can die during the
1561 * creation process. Don't report an error so the execution can
1562 * continue normally.
1563 */
1564 ret = 0;
ffe60014
DG
1565 DBG3("UST app enable channel failed. Application is dead.");
1566 }
78f0bacd
DG
1567 goto error;
1568 }
1569
1570 ua_chan->enabled = 1;
1571
1572 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
852d0037 1573 ua_chan->name, app->pid);
78f0bacd
DG
1574
1575error:
840cb59c 1576 health_code_update();
78f0bacd
DG
1577 return ret;
1578}
1579
edb67388
DG
1580/*
1581 * Enable the specified event on to UST tracer for the UST session.
1582 */
1583static int enable_ust_event(struct ust_app *app,
1584 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1585{
1586 int ret;
1587
840cb59c 1588 health_code_update();
86acf0da 1589
fb45065e 1590 pthread_mutex_lock(&app->sock_lock);
852d0037 1591 ret = ustctl_enable(app->sock, ua_event->obj);
fb45065e 1592 pthread_mutex_unlock(&app->sock_lock);
edb67388 1593 if (ret < 0) {
ffe60014
DG
1594 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1595 ERR("UST app event %s enable failed for app (pid: %d) "
1596 "and session handle %d with ret %d",
1597 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1598 } else {
3757b385
DG
1599 /*
1600 * This is normal behavior, an application can die during the
1601 * creation process. Don't report an error so the execution can
1602 * continue normally.
1603 */
1604 ret = 0;
ffe60014
DG
1605 DBG3("UST app enable event failed. Application is dead.");
1606 }
edb67388
DG
1607 goto error;
1608 }
1609
1610 DBG2("UST app event %s enabled successfully for app (pid: %d)",
852d0037 1611 ua_event->attr.name, app->pid);
edb67388
DG
1612
1613error:
840cb59c 1614 health_code_update();
edb67388
DG
1615 return ret;
1616}
1617
099e26bd 1618/*
7972aab2 1619 * Send channel and stream buffer to application.
4f3ab6ee 1620 *
ffe60014 1621 * Return 0 on success. On error, a negative value is returned.
4f3ab6ee 1622 */
7972aab2
DG
1623static int send_channel_pid_to_ust(struct ust_app *app,
1624 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
4f3ab6ee
DG
1625{
1626 int ret;
ffe60014 1627 struct ust_app_stream *stream, *stmp;
4f3ab6ee
DG
1628
1629 assert(app);
ffe60014 1630 assert(ua_sess);
4f3ab6ee 1631 assert(ua_chan);
4f3ab6ee 1632
840cb59c 1633 health_code_update();
4f3ab6ee 1634
7972aab2
DG
1635 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1636 app->sock);
86acf0da 1637
ffe60014
DG
1638 /* Send channel to the application. */
1639 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
a7169585
MD
1640 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1641 ret = -ENOTCONN; /* Caused by app exiting. */
1642 goto error;
1643 } else if (ret < 0) {
b551a063
DG
1644 goto error;
1645 }
1646
d88aee68
DG
1647 health_code_update();
1648
ffe60014
DG
1649 /* Send all streams to application. */
1650 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1651 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
a7169585
MD
1652 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1653 ret = -ENOTCONN; /* Caused by app exiting. */
1654 goto error;
1655 } else if (ret < 0) {
ffe60014
DG
1656 goto error;
1657 }
1658 /* We don't need the stream anymore once sent to the tracer. */
1659 cds_list_del(&stream->list);
fb45065e 1660 delete_ust_app_stream(-1, stream, app);
ffe60014 1661 }
ffe60014
DG
1662 /* Flag the channel that it is sent to the application. */
1663 ua_chan->is_sent = 1;
ffe60014 1664
b551a063 1665error:
840cb59c 1666 health_code_update();
b551a063
DG
1667 return ret;
1668}
1669
91d76f53 1670/*
5b4a0ec0 1671 * Create the specified event onto the UST tracer for a UST session.
d0b96690
DG
1672 *
1673 * Should be called with session mutex held.
91d76f53 1674 */
edb67388
DG
1675static
1676int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1677 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
91d76f53 1678{
5b4a0ec0 1679 int ret = 0;
284d8f55 1680
840cb59c 1681 health_code_update();
86acf0da 1682
5b4a0ec0 1683 /* Create UST event on tracer */
fb45065e 1684 pthread_mutex_lock(&app->sock_lock);
852d0037 1685 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
5b4a0ec0 1686 &ua_event->obj);
fb45065e 1687 pthread_mutex_unlock(&app->sock_lock);
5b4a0ec0 1688 if (ret < 0) {
ffe60014 1689 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
88e3c2f5 1690 abort();
ffe60014
DG
1691 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1692 ua_event->attr.name, app->pid, ret);
1693 } else {
3757b385
DG
1694 /*
1695 * This is normal behavior, an application can die during the
1696 * creation process. Don't report an error so the execution can
1697 * continue normally.
1698 */
1699 ret = 0;
ffe60014
DG
1700 DBG3("UST app create event failed. Application is dead.");
1701 }
5b4a0ec0 1702 goto error;
91d76f53 1703 }
f6a9efaa 1704
5b4a0ec0 1705 ua_event->handle = ua_event->obj->handle;
284d8f55 1706
5b4a0ec0 1707 DBG2("UST app event %s created successfully for pid:%d",
852d0037 1708 ua_event->attr.name, app->pid);
f6a9efaa 1709
840cb59c 1710 health_code_update();
86acf0da 1711
025faf73
DG
1712 /* Set filter if one is present. */
1713 if (ua_event->filter) {
1714 ret = set_ust_event_filter(ua_event, app);
1715 if (ret < 0) {
1716 goto error;
1717 }
1718 }
1719
7cc9a73c
JI
1720 /* Set exclusions for the event */
1721 if (ua_event->exclusion) {
1722 ret = set_ust_event_exclusion(ua_event, app);
1723 if (ret < 0) {
1724 goto error;
1725 }
1726 }
1727
8535a6d9 1728 /* If event not enabled, disable it on the tracer */
40113787
MD
1729 if (ua_event->enabled) {
1730 /*
1731 * We now need to explicitly enable the event, since it
1732 * is now disabled at creation.
1733 */
1734 ret = enable_ust_event(app, ua_sess, ua_event);
1735 if (ret < 0) {
1736 /*
1737 * If we hit an EPERM, something is wrong with our enable call. If
1738 * we get an EEXIST, there is a problem on the tracer side since we
1739 * just created it.
1740 */
1741 switch (ret) {
1742 case -LTTNG_UST_ERR_PERM:
1743 /* Code flow problem */
1744 assert(0);
1745 case -LTTNG_UST_ERR_EXIST:
1746 /* It's OK for our use case. */
1747 ret = 0;
1748 break;
1749 default:
1750 break;
1751 }
1752 goto error;
1753 }
8535a6d9
DG
1754 }
1755
5b4a0ec0 1756error:
840cb59c 1757 health_code_update();
5b4a0ec0 1758 return ret;
91d76f53 1759}
48842b30 1760
5b4a0ec0
DG
1761/*
1762 * Copy data between an UST app event and a LTT event.
1763 */
421cb601 1764static void shadow_copy_event(struct ust_app_event *ua_event,
48842b30
DG
1765 struct ltt_ust_event *uevent)
1766{
b4ffad32
JI
1767 size_t exclusion_alloc_size;
1768
48842b30
DG
1769 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1770 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1771
fc34caaa
DG
1772 ua_event->enabled = uevent->enabled;
1773
5b4a0ec0
DG
1774 /* Copy event attributes */
1775 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1776
53a80697
MD
1777 /* Copy filter bytecode */
1778 if (uevent->filter) {
51755dc8 1779 ua_event->filter = copy_filter_bytecode(uevent->filter);
025faf73 1780 /* Filter might be NULL here in case of ENONEM. */
53a80697 1781 }
b4ffad32
JI
1782
1783 /* Copy exclusion data */
1784 if (uevent->exclusion) {
51755dc8 1785 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
b4ffad32
JI
1786 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1787 ua_event->exclusion = zmalloc(exclusion_alloc_size);
5f8df26c
JI
1788 if (ua_event->exclusion == NULL) {
1789 PERROR("malloc");
1790 } else {
1791 memcpy(ua_event->exclusion, uevent->exclusion,
1792 exclusion_alloc_size);
b4ffad32
JI
1793 }
1794 }
48842b30
DG
1795}
1796
5b4a0ec0
DG
1797/*
1798 * Copy data between an UST app channel and a LTT channel.
1799 */
421cb601 1800static void shadow_copy_channel(struct ust_app_channel *ua_chan,
48842b30
DG
1801 struct ltt_ust_channel *uchan)
1802{
fc34caaa 1803 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
48842b30
DG
1804
1805 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1806 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
ffe60014 1807
1624d5b7
JD
1808 ua_chan->tracefile_size = uchan->tracefile_size;
1809 ua_chan->tracefile_count = uchan->tracefile_count;
1810
ffe60014
DG
1811 /* Copy event attributes since the layout is different. */
1812 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1813 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1814 ua_chan->attr.overwrite = uchan->attr.overwrite;
1815 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1816 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
e9404c27 1817 ua_chan->monitor_timer_interval = uchan->monitor_timer_interval;
ffe60014 1818 ua_chan->attr.output = uchan->attr.output;
491d1539
MD
1819 ua_chan->attr.blocking_timeout = uchan->attr.u.s.blocking_timeout;
1820
ffe60014
DG
1821 /*
1822 * Note that the attribute channel type is not set since the channel on the
1823 * tracing registry side does not have this information.
1824 */
48842b30 1825
fc34caaa 1826 ua_chan->enabled = uchan->enabled;
7972aab2 1827 ua_chan->tracing_channel_id = uchan->id;
fc34caaa 1828
fc34caaa 1829 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
48842b30
DG
1830}
1831
5b4a0ec0
DG
1832/*
1833 * Copy data between a UST app session and a regular LTT session.
1834 */
421cb601 1835static void shadow_copy_session(struct ust_app_session *ua_sess,
bec39940 1836 struct ltt_ust_session *usess, struct ust_app *app)
48842b30 1837{
477d7741
MD
1838 struct tm *timeinfo;
1839 char datetime[16];
1840 int ret;
d7ba1388 1841 char tmp_shm_path[PATH_MAX];
477d7741 1842
940c4592 1843 timeinfo = localtime(&app->registration_time);
477d7741 1844 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
48842b30 1845
421cb601 1846 DBG2("Shadow copy of session handle %d", ua_sess->handle);
48842b30 1847
7972aab2
DG
1848 ua_sess->tracing_id = usess->id;
1849 ua_sess->id = get_next_session_id();
ff588497
JR
1850 LTTNG_OPTIONAL_SET(&ua_sess->real_credentials.uid, app->uid);
1851 LTTNG_OPTIONAL_SET(&ua_sess->real_credentials.gid, app->gid);
1852 LTTNG_OPTIONAL_SET(&ua_sess->effective_credentials.uid, usess->uid);
1853 LTTNG_OPTIONAL_SET(&ua_sess->effective_credentials.gid, usess->gid);
7972aab2
DG
1854 ua_sess->buffer_type = usess->buffer_type;
1855 ua_sess->bits_per_long = app->bits_per_long;
6addfa37 1856
7972aab2 1857 /* There is only one consumer object per session possible. */
6addfa37 1858 consumer_output_get(usess->consumer);
7972aab2 1859 ua_sess->consumer = usess->consumer;
6addfa37 1860
2bba9e53 1861 ua_sess->output_traces = usess->output_traces;
ecc48a90 1862 ua_sess->live_timer_interval = usess->live_timer_interval;
84ad93e8
DG
1863 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1864 &usess->metadata_attr);
7972aab2
DG
1865
1866 switch (ua_sess->buffer_type) {
1867 case LTTNG_BUFFER_PER_PID:
1868 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
dec56f6c 1869 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
7972aab2
DG
1870 datetime);
1871 break;
1872 case LTTNG_BUFFER_PER_UID:
1873 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
470cc211 1874 DEFAULT_UST_TRACE_UID_PATH,
ff588497 1875 lttng_credentials_get_uid(&ua_sess->real_credentials),
470cc211 1876 app->bits_per_long);
7972aab2
DG
1877 break;
1878 default:
1879 assert(0);
1880 goto error;
1881 }
477d7741
MD
1882 if (ret < 0) {
1883 PERROR("asprintf UST shadow copy session");
477d7741 1884 assert(0);
7972aab2 1885 goto error;
477d7741
MD
1886 }
1887
3d071855
MD
1888 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1889 sizeof(ua_sess->root_shm_path));
1890 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
d7ba1388
MD
1891 strncpy(ua_sess->shm_path, usess->shm_path,
1892 sizeof(ua_sess->shm_path));
1893 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1894 if (ua_sess->shm_path[0]) {
1895 switch (ua_sess->buffer_type) {
1896 case LTTNG_BUFFER_PER_PID:
1897 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
5da88b0f 1898 "/" DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
d7ba1388
MD
1899 app->name, app->pid, datetime);
1900 break;
1901 case LTTNG_BUFFER_PER_UID:
1902 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
5da88b0f 1903 "/" DEFAULT_UST_TRACE_UID_PATH,
d7ba1388
MD
1904 app->uid, app->bits_per_long);
1905 break;
1906 default:
1907 assert(0);
1908 goto error;
1909 }
1910 if (ret < 0) {
1911 PERROR("sprintf UST shadow copy session");
1912 assert(0);
1913 goto error;
1914 }
1915 strncat(ua_sess->shm_path, tmp_shm_path,
1916 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1917 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1918 }
6addfa37 1919 return;
7972aab2
DG
1920
1921error:
6addfa37 1922 consumer_output_put(ua_sess->consumer);
48842b30
DG
1923}
1924
78f0bacd
DG
1925/*
1926 * Lookup sesison wrapper.
1927 */
84cd17c6 1928static
fb9a95c4 1929void __lookup_session_by_app(const struct ltt_ust_session *usess,
bec39940 1930 struct ust_app *app, struct lttng_ht_iter *iter)
84cd17c6
MD
1931{
1932 /* Get right UST app session from app */
d9bf3ca4 1933 lttng_ht_lookup(app->sessions, &usess->id, iter);
84cd17c6
MD
1934}
1935
421cb601
DG
1936/*
1937 * Return ust app session from the app session hashtable using the UST session
a991f516 1938 * id.
421cb601 1939 */
48842b30 1940static struct ust_app_session *lookup_session_by_app(
fb9a95c4 1941 const struct ltt_ust_session *usess, struct ust_app *app)
48842b30 1942{
bec39940 1943 struct lttng_ht_iter iter;
d9bf3ca4 1944 struct lttng_ht_node_u64 *node;
48842b30 1945
84cd17c6 1946 __lookup_session_by_app(usess, app, &iter);
d9bf3ca4 1947 node = lttng_ht_iter_get_node_u64(&iter);
48842b30
DG
1948 if (node == NULL) {
1949 goto error;
1950 }
1951
1952 return caa_container_of(node, struct ust_app_session, node);
1953
1954error:
1955 return NULL;
1956}
1957
7972aab2
DG
1958/*
1959 * Setup buffer registry per PID for the given session and application. If none
1960 * is found, a new one is created, added to the global registry and
1961 * initialized. If regp is valid, it's set with the newly created object.
1962 *
1963 * Return 0 on success or else a negative value.
1964 */
1965static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
1966 struct ust_app *app, struct buffer_reg_pid **regp)
1967{
1968 int ret = 0;
1969 struct buffer_reg_pid *reg_pid;
1970
1971 assert(ua_sess);
1972 assert(app);
1973
1974 rcu_read_lock();
1975
1976 reg_pid = buffer_reg_pid_find(ua_sess->id);
1977 if (!reg_pid) {
1978 /*
1979 * This is the create channel path meaning that if there is NO
1980 * registry available, we have to create one for this session.
1981 */
d7ba1388 1982 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
3d071855 1983 ua_sess->root_shm_path, ua_sess->shm_path);
7972aab2
DG
1984 if (ret < 0) {
1985 goto error;
1986 }
7972aab2
DG
1987 } else {
1988 goto end;
1989 }
1990
1991 /* Initialize registry. */
1992 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
1993 app->bits_per_long, app->uint8_t_alignment,
1994 app->uint16_t_alignment, app->uint32_t_alignment,
af6142cf 1995 app->uint64_t_alignment, app->long_alignment,
470cc211
JG
1996 app->byte_order, app->version.major, app->version.minor,
1997 reg_pid->root_shm_path, reg_pid->shm_path,
ff588497
JR
1998 lttng_credentials_get_uid(&ua_sess->effective_credentials),
1999 lttng_credentials_get_gid(&ua_sess->effective_credentials),
2000 ua_sess->tracing_id,
8de88061 2001 app->uid);
7972aab2 2002 if (ret < 0) {
286c991a
MD
2003 /*
2004 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2005 * destroy the buffer registry, because it is always expected
2006 * that if the buffer registry can be found, its ust registry is
2007 * non-NULL.
2008 */
2009 buffer_reg_pid_destroy(reg_pid);
7972aab2
DG
2010 goto error;
2011 }
2012
286c991a
MD
2013 buffer_reg_pid_add(reg_pid);
2014
7972aab2
DG
2015 DBG3("UST app buffer registry per PID created successfully");
2016
2017end:
2018 if (regp) {
2019 *regp = reg_pid;
2020 }
2021error:
2022 rcu_read_unlock();
2023 return ret;
2024}
2025
2026/*
2027 * Setup buffer registry per UID for the given session and application. If none
2028 * is found, a new one is created, added to the global registry and
2029 * initialized. If regp is valid, it's set with the newly created object.
2030 *
2031 * Return 0 on success or else a negative value.
2032 */
2033static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
d7ba1388 2034 struct ust_app_session *ua_sess,
7972aab2
DG
2035 struct ust_app *app, struct buffer_reg_uid **regp)
2036{
2037 int ret = 0;
2038 struct buffer_reg_uid *reg_uid;
2039
2040 assert(usess);
2041 assert(app);
2042
2043 rcu_read_lock();
2044
2045 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2046 if (!reg_uid) {
2047 /*
2048 * This is the create channel path meaning that if there is NO
2049 * registry available, we have to create one for this session.
2050 */
2051 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
3d071855
MD
2052 LTTNG_DOMAIN_UST, &reg_uid,
2053 ua_sess->root_shm_path, ua_sess->shm_path);
7972aab2
DG
2054 if (ret < 0) {
2055 goto error;
2056 }
7972aab2
DG
2057 } else {
2058 goto end;
2059 }
2060
2061 /* Initialize registry. */
af6142cf 2062 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
7972aab2
DG
2063 app->bits_per_long, app->uint8_t_alignment,
2064 app->uint16_t_alignment, app->uint32_t_alignment,
af6142cf
MD
2065 app->uint64_t_alignment, app->long_alignment,
2066 app->byte_order, app->version.major,
3d071855 2067 app->version.minor, reg_uid->root_shm_path,
8de88061
JR
2068 reg_uid->shm_path, usess->uid, usess->gid,
2069 ua_sess->tracing_id, app->uid);
7972aab2 2070 if (ret < 0) {
286c991a
MD
2071 /*
2072 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2073 * destroy the buffer registry, because it is always expected
2074 * that if the buffer registry can be found, its ust registry is
2075 * non-NULL.
2076 */
2077 buffer_reg_uid_destroy(reg_uid, NULL);
7972aab2
DG
2078 goto error;
2079 }
2080 /* Add node to teardown list of the session. */
2081 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2082
286c991a 2083 buffer_reg_uid_add(reg_uid);
7972aab2 2084
286c991a 2085 DBG3("UST app buffer registry per UID created successfully");
7972aab2
DG
2086end:
2087 if (regp) {
2088 *regp = reg_uid;
2089 }
2090error:
2091 rcu_read_unlock();
2092 return ret;
2093}
2094
421cb601 2095/*
3d8ca23b 2096 * Create a session on the tracer side for the given app.
421cb601 2097 *
3d8ca23b
DG
2098 * On success, ua_sess_ptr is populated with the session pointer or else left
2099 * untouched. If the session was created, is_created is set to 1. On error,
2100 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2101 * be NULL.
2102 *
2103 * Returns 0 on success or else a negative code which is either -ENOMEM or
2104 * -ENOTCONN which is the default code if the ustctl_create_session fails.
421cb601 2105 */
03f91eaa 2106static int find_or_create_ust_app_session(struct ltt_ust_session *usess,
3d8ca23b
DG
2107 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2108 int *is_created)
421cb601 2109{
3d8ca23b 2110 int ret, created = 0;
421cb601
DG
2111 struct ust_app_session *ua_sess;
2112
3d8ca23b
DG
2113 assert(usess);
2114 assert(app);
2115 assert(ua_sess_ptr);
2116
840cb59c 2117 health_code_update();
86acf0da 2118
421cb601
DG
2119 ua_sess = lookup_session_by_app(usess, app);
2120 if (ua_sess == NULL) {
d9bf3ca4 2121 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
852d0037 2122 app->pid, usess->id);
40bbd087 2123 ua_sess = alloc_ust_app_session();
421cb601
DG
2124 if (ua_sess == NULL) {
2125 /* Only malloc can failed so something is really wrong */
3d8ca23b
DG
2126 ret = -ENOMEM;
2127 goto error;
421cb601 2128 }
477d7741 2129 shadow_copy_session(ua_sess, usess, app);
3d8ca23b 2130 created = 1;
421cb601
DG
2131 }
2132
7972aab2
DG
2133 switch (usess->buffer_type) {
2134 case LTTNG_BUFFER_PER_PID:
2135 /* Init local registry. */
2136 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
421cb601 2137 if (ret < 0) {
e64207cf 2138 delete_ust_app_session(-1, ua_sess, app);
7972aab2
DG
2139 goto error;
2140 }
2141 break;
2142 case LTTNG_BUFFER_PER_UID:
2143 /* Look for a global registry. If none exists, create one. */
d7ba1388 2144 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
7972aab2 2145 if (ret < 0) {
e64207cf 2146 delete_ust_app_session(-1, ua_sess, app);
7972aab2
DG
2147 goto error;
2148 }
2149 break;
2150 default:
2151 assert(0);
2152 ret = -EINVAL;
2153 goto error;
2154 }
2155
2156 health_code_update();
2157
2158 if (ua_sess->handle == -1) {
fb45065e 2159 pthread_mutex_lock(&app->sock_lock);
7972aab2 2160 ret = ustctl_create_session(app->sock);
fb45065e 2161 pthread_mutex_unlock(&app->sock_lock);
7972aab2
DG
2162 if (ret < 0) {
2163 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2164 ERR("Creating session for app pid %d with ret %d",
ffe60014
DG
2165 app->pid, ret);
2166 } else {
2167 DBG("UST app creating session failed. Application is dead");
3757b385
DG
2168 /*
2169 * This is normal behavior, an application can die during the
2170 * creation process. Don't report an error so the execution can
2171 * continue normally. This will get flagged ENOTCONN and the
2172 * caller will handle it.
2173 */
2174 ret = 0;
ffe60014 2175 }
d0b96690 2176 delete_ust_app_session(-1, ua_sess, app);
3d8ca23b
DG
2177 if (ret != -ENOMEM) {
2178 /*
2179 * Tracer is probably gone or got an internal error so let's
2180 * behave like it will soon unregister or not usable.
2181 */
2182 ret = -ENOTCONN;
2183 }
2184 goto error;
421cb601
DG
2185 }
2186
7972aab2
DG
2187 ua_sess->handle = ret;
2188
2189 /* Add ust app session to app's HT */
d9bf3ca4
MD
2190 lttng_ht_node_init_u64(&ua_sess->node,
2191 ua_sess->tracing_id);
2192 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
10b56aef
MD
2193 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2194 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2195 &ua_sess->ust_objd_node);
7972aab2
DG
2196
2197 DBG2("UST app session created successfully with handle %d", ret);
2198 }
2199
2200 *ua_sess_ptr = ua_sess;
2201 if (is_created) {
2202 *is_created = created;
2203 }
2204
2205 /* Everything went well. */
2206 ret = 0;
2207
2208error:
2209 health_code_update();
2210 return ret;
2211}
2212
6a6b2068
JG
2213/*
2214 * Match function for a hash table lookup of ust_app_ctx.
2215 *
2216 * It matches an ust app context based on the context type and, in the case
2217 * of perf counters, their name.
2218 */
2219static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2220{
2221 struct ust_app_ctx *ctx;
bdf64013 2222 const struct lttng_ust_context_attr *key;
6a6b2068
JG
2223
2224 assert(node);
2225 assert(_key);
2226
2227 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2228 key = _key;
2229
2230 /* Context type */
2231 if (ctx->ctx.ctx != key->ctx) {
2232 goto no_match;
2233 }
2234
bdf64013
JG
2235 switch(key->ctx) {
2236 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
6a6b2068 2237 if (strncmp(key->u.perf_counter.name,
bdf64013
JG
2238 ctx->ctx.u.perf_counter.name,
2239 sizeof(key->u.perf_counter.name))) {
2240 goto no_match;
2241 }
2242 break;
2243 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2244 if (strcmp(key->u.app_ctx.provider_name,
2245 ctx->ctx.u.app_ctx.provider_name) ||
2246 strcmp(key->u.app_ctx.ctx_name,
2247 ctx->ctx.u.app_ctx.ctx_name)) {
6a6b2068
JG
2248 goto no_match;
2249 }
bdf64013
JG
2250 break;
2251 default:
2252 break;
6a6b2068
JG
2253 }
2254
2255 /* Match. */
2256 return 1;
2257
2258no_match:
2259 return 0;
2260}
2261
2262/*
2263 * Lookup for an ust app context from an lttng_ust_context.
2264 *
be184a0f 2265 * Must be called while holding RCU read side lock.
6a6b2068
JG
2266 * Return an ust_app_ctx object or NULL on error.
2267 */
2268static
2269struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
bdf64013 2270 struct lttng_ust_context_attr *uctx)
6a6b2068
JG
2271{
2272 struct lttng_ht_iter iter;
2273 struct lttng_ht_node_ulong *node;
2274 struct ust_app_ctx *app_ctx = NULL;
2275
2276 assert(uctx);
2277 assert(ht);
2278
2279 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2280 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2281 ht_match_ust_app_ctx, uctx, &iter.iter);
2282 node = lttng_ht_iter_get_node_ulong(&iter);
2283 if (!node) {
2284 goto end;
2285 }
2286
2287 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2288
2289end:
2290 return app_ctx;
2291}
2292
7972aab2
DG
2293/*
2294 * Create a context for the channel on the tracer.
2295 *
2296 * Called with UST app session lock held and a RCU read side lock.
2297 */
2298static
c9edf082 2299int create_ust_app_channel_context(struct ust_app_channel *ua_chan,
f3db82be 2300 struct lttng_ust_context_attr *uctx,
7972aab2
DG
2301 struct ust_app *app)
2302{
2303 int ret = 0;
7972aab2
DG
2304 struct ust_app_ctx *ua_ctx;
2305
2306 DBG2("UST app adding context to channel %s", ua_chan->name);
2307
6a6b2068
JG
2308 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2309 if (ua_ctx) {
7972aab2
DG
2310 ret = -EEXIST;
2311 goto error;
2312 }
2313
2314 ua_ctx = alloc_ust_app_ctx(uctx);
2315 if (ua_ctx == NULL) {
2316 /* malloc failed */
7682f304 2317 ret = -ENOMEM;
7972aab2
DG
2318 goto error;
2319 }
2320
2321 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
aa3514e9 2322 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
31746f93 2323 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
7972aab2
DG
2324
2325 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2326 if (ret < 0) {
2327 goto error;
2328 }
2329
2330error:
2331 return ret;
2332}
2333
2334/*
2335 * Enable on the tracer side a ust app event for the session and channel.
2336 *
2337 * Called with UST app session lock held.
2338 */
2339static
2340int enable_ust_app_event(struct ust_app_session *ua_sess,
2341 struct ust_app_event *ua_event, struct ust_app *app)
2342{
2343 int ret;
2344
2345 ret = enable_ust_event(app, ua_sess, ua_event);
2346 if (ret < 0) {
2347 goto error;
2348 }
2349
2350 ua_event->enabled = 1;
2351
2352error:
2353 return ret;
2354}
2355
2356/*
2357 * Disable on the tracer side a ust app event for the session and channel.
2358 */
2359static int disable_ust_app_event(struct ust_app_session *ua_sess,
2360 struct ust_app_event *ua_event, struct ust_app *app)
2361{
2362 int ret;
2363
2364 ret = disable_ust_event(app, ua_sess, ua_event);
2365 if (ret < 0) {
2366 goto error;
2367 }
2368
2369 ua_event->enabled = 0;
2370
2371error:
2372 return ret;
2373}
2374
2375/*
2376 * Lookup ust app channel for session and disable it on the tracer side.
2377 */
2378static
2379int disable_ust_app_channel(struct ust_app_session *ua_sess,
2380 struct ust_app_channel *ua_chan, struct ust_app *app)
2381{
2382 int ret;
2383
2384 ret = disable_ust_channel(app, ua_sess, ua_chan);
2385 if (ret < 0) {
2386 goto error;
2387 }
2388
2389 ua_chan->enabled = 0;
2390
2391error:
2392 return ret;
2393}
2394
2395/*
2396 * Lookup ust app channel for session and enable it on the tracer side. This
2397 * MUST be called with a RCU read side lock acquired.
2398 */
2399static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2400 struct ltt_ust_channel *uchan, struct ust_app *app)
2401{
2402 int ret = 0;
2403 struct lttng_ht_iter iter;
2404 struct lttng_ht_node_str *ua_chan_node;
2405 struct ust_app_channel *ua_chan;
2406
2407 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2408 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2409 if (ua_chan_node == NULL) {
d9bf3ca4 2410 DBG2("Unable to find channel %s in ust session id %" PRIu64,
7972aab2
DG
2411 uchan->name, ua_sess->tracing_id);
2412 goto error;
2413 }
2414
2415 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2416
2417 ret = enable_ust_channel(app, ua_sess, ua_chan);
2418 if (ret < 0) {
2419 goto error;
2420 }
2421
2422error:
2423 return ret;
2424}
2425
2426/*
2427 * Ask the consumer to create a channel and get it if successful.
2428 *
fad1ed2f
JR
2429 * Called with UST app session lock held.
2430 *
7972aab2
DG
2431 * Return 0 on success or else a negative value.
2432 */
2433static int do_consumer_create_channel(struct ltt_ust_session *usess,
2434 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
e098433c
JG
2435 int bitness, struct ust_registry_session *registry,
2436 uint64_t trace_archive_id)
7972aab2
DG
2437{
2438 int ret;
2439 unsigned int nb_fd = 0;
2440 struct consumer_socket *socket;
2441
2442 assert(usess);
2443 assert(ua_sess);
2444 assert(ua_chan);
2445 assert(registry);
2446
2447 rcu_read_lock();
2448 health_code_update();
2449
2450 /* Get the right consumer socket for the application. */
2451 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2452 if (!socket) {
2453 ret = -EINVAL;
2454 goto error;
2455 }
2456
2457 health_code_update();
2458
2459 /* Need one fd for the channel. */
2460 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2461 if (ret < 0) {
2462 ERR("Exhausted number of available FD upon create channel");
2463 goto error;
2464 }
2465
2466 /*
2467 * Ask consumer to create channel. The consumer will return the number of
2468 * stream we have to expect.
2469 */
2470 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
d2956687 2471 registry, usess->current_trace_chunk);
7972aab2
DG
2472 if (ret < 0) {
2473 goto error_ask;
2474 }
2475
2476 /*
2477 * Compute the number of fd needed before receiving them. It must be 2 per
2478 * stream (2 being the default value here).
2479 */
2480 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2481
2482 /* Reserve the amount of file descriptor we need. */
2483 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2484 if (ret < 0) {
2485 ERR("Exhausted number of available FD upon create channel");
2486 goto error_fd_get_stream;
2487 }
2488
2489 health_code_update();
2490
2491 /*
2492 * Now get the channel from the consumer. This call wil populate the stream
2493 * list of that channel and set the ust objects.
2494 */
d9078d0c
DG
2495 if (usess->consumer->enabled) {
2496 ret = ust_consumer_get_channel(socket, ua_chan);
2497 if (ret < 0) {
2498 goto error_destroy;
2499 }
7972aab2
DG
2500 }
2501
2502 rcu_read_unlock();
2503 return 0;
2504
2505error_destroy:
2506 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2507error_fd_get_stream:
2508 /*
2509 * Initiate a destroy channel on the consumer since we had an error
2510 * handling it on our side. The return value is of no importance since we
2511 * already have a ret value set by the previous error that we need to
2512 * return.
2513 */
2514 (void) ust_consumer_destroy_channel(socket, ua_chan);
2515error_ask:
2516 lttng_fd_put(LTTNG_FD_APPS, 1);
2517error:
2518 health_code_update();
2519 rcu_read_unlock();
2520 return ret;
2521}
2522
2523/*
2524 * Duplicate the ust data object of the ust app stream and save it in the
2525 * buffer registry stream.
2526 *
2527 * Return 0 on success or else a negative value.
2528 */
2529static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2530 struct ust_app_stream *stream)
2531{
2532 int ret;
2533
2534 assert(reg_stream);
2535 assert(stream);
2536
2537 /* Reserve the amount of file descriptor we need. */
2538 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2539 if (ret < 0) {
2540 ERR("Exhausted number of available FD upon duplicate stream");
2541 goto error;
2542 }
2543
2544 /* Duplicate object for stream once the original is in the registry. */
2545 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2546 reg_stream->obj.ust);
2547 if (ret < 0) {
2548 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2549 reg_stream->obj.ust, stream->obj, ret);
2550 lttng_fd_put(LTTNG_FD_APPS, 2);
2551 goto error;
2552 }
2553 stream->handle = stream->obj->handle;
2554
2555error:
2556 return ret;
2557}
2558
2559/*
2560 * Duplicate the ust data object of the ust app. channel and save it in the
2561 * buffer registry channel.
2562 *
2563 * Return 0 on success or else a negative value.
2564 */
2565static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2566 struct ust_app_channel *ua_chan)
2567{
2568 int ret;
2569
2570 assert(reg_chan);
2571 assert(ua_chan);
2572
2573 /* Need two fds for the channel. */
2574 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2575 if (ret < 0) {
2576 ERR("Exhausted number of available FD upon duplicate channel");
2577 goto error_fd_get;
2578 }
2579
2580 /* Duplicate object for stream once the original is in the registry. */
2581 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2582 if (ret < 0) {
2583 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2584 reg_chan->obj.ust, ua_chan->obj, ret);
2585 goto error;
2586 }
2587 ua_chan->handle = ua_chan->obj->handle;
2588
2589 return 0;
2590
2591error:
2592 lttng_fd_put(LTTNG_FD_APPS, 1);
2593error_fd_get:
2594 return ret;
2595}
2596
2597/*
2598 * For a given channel buffer registry, setup all streams of the given ust
2599 * application channel.
2600 *
2601 * Return 0 on success or else a negative value.
2602 */
2603static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
fb45065e
MD
2604 struct ust_app_channel *ua_chan,
2605 struct ust_app *app)
7972aab2
DG
2606{
2607 int ret = 0;
2608 struct ust_app_stream *stream, *stmp;
2609
2610 assert(reg_chan);
2611 assert(ua_chan);
2612
2613 DBG2("UST app setup buffer registry stream");
2614
2615 /* Send all streams to application. */
2616 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2617 struct buffer_reg_stream *reg_stream;
2618
2619 ret = buffer_reg_stream_create(&reg_stream);
2620 if (ret < 0) {
2621 goto error;
2622 }
2623
2624 /*
2625 * Keep original pointer and nullify it in the stream so the delete
2626 * stream call does not release the object.
2627 */
2628 reg_stream->obj.ust = stream->obj;
2629 stream->obj = NULL;
2630 buffer_reg_stream_add(reg_stream, reg_chan);
421cb601 2631
7972aab2
DG
2632 /* We don't need the streams anymore. */
2633 cds_list_del(&stream->list);
fb45065e 2634 delete_ust_app_stream(-1, stream, app);
7972aab2 2635 }
421cb601 2636
7972aab2
DG
2637error:
2638 return ret;
2639}
2640
2641/*
2642 * Create a buffer registry channel for the given session registry and
2643 * application channel object. If regp pointer is valid, it's set with the
2644 * created object. Important, the created object is NOT added to the session
2645 * registry hash table.
2646 *
2647 * Return 0 on success else a negative value.
2648 */
2649static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2650 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2651{
2652 int ret;
2653 struct buffer_reg_channel *reg_chan = NULL;
2654
2655 assert(reg_sess);
2656 assert(ua_chan);
2657
2658 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2659
2660 /* Create buffer registry channel. */
2661 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2662 if (ret < 0) {
2663 goto error_create;
421cb601 2664 }
7972aab2
DG
2665 assert(reg_chan);
2666 reg_chan->consumer_key = ua_chan->key;
8c924c7b 2667 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
d07ceecd 2668 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
421cb601 2669
7972aab2
DG
2670 /* Create and add a channel registry to session. */
2671 ret = ust_registry_channel_add(reg_sess->reg.ust,
2672 ua_chan->tracing_channel_id);
2673 if (ret < 0) {
2674 goto error;
d88aee68 2675 }
7972aab2 2676 buffer_reg_channel_add(reg_sess, reg_chan);
d88aee68 2677
7972aab2
DG
2678 if (regp) {
2679 *regp = reg_chan;
3d8ca23b 2680 }
d88aee68 2681
7972aab2 2682 return 0;
3d8ca23b
DG
2683
2684error:
7972aab2
DG
2685 /* Safe because the registry channel object was not added to any HT. */
2686 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2687error_create:
3d8ca23b 2688 return ret;
421cb601
DG
2689}
2690
55cc08a6 2691/*
7972aab2
DG
2692 * Setup buffer registry channel for the given session registry and application
2693 * channel object. If regp pointer is valid, it's set with the created object.
d0b96690 2694 *
7972aab2 2695 * Return 0 on success else a negative value.
55cc08a6 2696 */
7972aab2 2697static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
fb45065e
MD
2698 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2699 struct ust_app *app)
55cc08a6 2700{
7972aab2 2701 int ret;
55cc08a6 2702
7972aab2
DG
2703 assert(reg_sess);
2704 assert(reg_chan);
2705 assert(ua_chan);
2706 assert(ua_chan->obj);
55cc08a6 2707
7972aab2 2708 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
55cc08a6 2709
7972aab2 2710 /* Setup all streams for the registry. */
fb45065e 2711 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
7972aab2 2712 if (ret < 0) {
55cc08a6
DG
2713 goto error;
2714 }
2715
7972aab2
DG
2716 reg_chan->obj.ust = ua_chan->obj;
2717 ua_chan->obj = NULL;
55cc08a6 2718
7972aab2 2719 return 0;
55cc08a6
DG
2720
2721error:
7972aab2
DG
2722 buffer_reg_channel_remove(reg_sess, reg_chan);
2723 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
55cc08a6
DG
2724 return ret;
2725}
2726
edb67388 2727/*
7972aab2 2728 * Send buffer registry channel to the application.
d0b96690 2729 *
7972aab2 2730 * Return 0 on success else a negative value.
edb67388 2731 */
7972aab2
DG
2732static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2733 struct ust_app *app, struct ust_app_session *ua_sess,
2734 struct ust_app_channel *ua_chan)
edb67388
DG
2735{
2736 int ret;
7972aab2 2737 struct buffer_reg_stream *reg_stream;
edb67388 2738
7972aab2
DG
2739 assert(reg_chan);
2740 assert(app);
2741 assert(ua_sess);
2742 assert(ua_chan);
2743
2744 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2745
2746 ret = duplicate_channel_object(reg_chan, ua_chan);
edb67388
DG
2747 if (ret < 0) {
2748 goto error;
2749 }
2750
7972aab2
DG
2751 /* Send channel to the application. */
2752 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
a7169585
MD
2753 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2754 ret = -ENOTCONN; /* Caused by app exiting. */
2755 goto error;
2756 } else if (ret < 0) {
7972aab2
DG
2757 goto error;
2758 }
2759
2760 health_code_update();
2761
2762 /* Send all streams to application. */
2763 pthread_mutex_lock(&reg_chan->stream_list_lock);
2764 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2765 struct ust_app_stream stream;
2766
2767 ret = duplicate_stream_object(reg_stream, &stream);
2768 if (ret < 0) {
2769 goto error_stream_unlock;
2770 }
2771
2772 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2773 if (ret < 0) {
fb45065e 2774 (void) release_ust_app_stream(-1, &stream, app);
a7169585
MD
2775 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2776 ret = -ENOTCONN; /* Caused by app exiting. */
a7169585 2777 }
7972aab2
DG
2778 goto error_stream_unlock;
2779 }
edb67388 2780
7972aab2
DG
2781 /*
2782 * The return value is not important here. This function will output an
2783 * error if needed.
2784 */
fb45065e 2785 (void) release_ust_app_stream(-1, &stream, app);
7972aab2
DG
2786 }
2787 ua_chan->is_sent = 1;
2788
2789error_stream_unlock:
2790 pthread_mutex_unlock(&reg_chan->stream_list_lock);
edb67388
DG
2791error:
2792 return ret;
2793}
2794
9730260e 2795/*
7972aab2
DG
2796 * Create and send to the application the created buffers with per UID buffers.
2797 *
9acdc1d6 2798 * This MUST be called with a RCU read side lock acquired.
71e0a100 2799 * The session list lock and the session's lock must be acquired.
9acdc1d6 2800 *
7972aab2 2801 * Return 0 on success else a negative value.
9730260e 2802 */
7972aab2
DG
2803static int create_channel_per_uid(struct ust_app *app,
2804 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2805 struct ust_app_channel *ua_chan)
9730260e
DG
2806{
2807 int ret;
7972aab2
DG
2808 struct buffer_reg_uid *reg_uid;
2809 struct buffer_reg_channel *reg_chan;
e32d7f27 2810 struct ltt_session *session = NULL;
e098433c
JG
2811 enum lttng_error_code notification_ret;
2812 struct ust_registry_channel *chan_reg;
9730260e 2813
7972aab2
DG
2814 assert(app);
2815 assert(usess);
2816 assert(ua_sess);
2817 assert(ua_chan);
2818
2819 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2820
2821 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2822 /*
2823 * The session creation handles the creation of this global registry
2824 * object. If none can be find, there is a code flow problem or a
2825 * teardown race.
2826 */
2827 assert(reg_uid);
2828
2829 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2830 reg_uid);
2721f7ea
JG
2831 if (reg_chan) {
2832 goto send_channel;
2833 }
7972aab2 2834
2721f7ea
JG
2835 /* Create the buffer registry channel object. */
2836 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2837 if (ret < 0) {
2838 ERR("Error creating the UST channel \"%s\" registry instance",
f14256d6 2839 ua_chan->name);
2721f7ea
JG
2840 goto error;
2841 }
f14256d6 2842
e098433c
JG
2843 session = session_find_by_id(ua_sess->tracing_id);
2844 assert(session);
2845 assert(pthread_mutex_trylock(&session->lock));
2846 assert(session_trylock_list());
2847
2721f7ea
JG
2848 /*
2849 * Create the buffers on the consumer side. This call populates the
2850 * ust app channel object with all streams and data object.
2851 */
2852 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
e098433c 2853 app->bits_per_long, reg_uid->registry->reg.ust,
d2956687 2854 session->most_recent_chunk_id.value);
2721f7ea
JG
2855 if (ret < 0) {
2856 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2857 ua_chan->name);
7972aab2
DG
2858
2859 /*
2721f7ea
JG
2860 * Let's remove the previously created buffer registry channel so
2861 * it's not visible anymore in the session registry.
7972aab2 2862 */
2721f7ea
JG
2863 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2864 ua_chan->tracing_channel_id, false);
2865 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2866 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2867 goto error;
7972aab2
DG
2868 }
2869
2721f7ea
JG
2870 /*
2871 * Setup the streams and add it to the session registry.
2872 */
2873 ret = setup_buffer_reg_channel(reg_uid->registry,
2874 ua_chan, reg_chan, app);
2875 if (ret < 0) {
2876 ERR("Error setting up UST channel \"%s\"", ua_chan->name);
2877 goto error;
2878 }
2879
e098433c
JG
2880 /* Notify the notification subsystem of the channel's creation. */
2881 pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
2882 chan_reg = ust_registry_channel_find(reg_uid->registry->reg.ust,
2883 ua_chan->tracing_channel_id);
2884 assert(chan_reg);
2885 chan_reg->consumer_key = ua_chan->key;
2886 chan_reg = NULL;
2887 pthread_mutex_unlock(&reg_uid->registry->reg.ust->lock);
e9404c27 2888
e098433c
JG
2889 notification_ret = notification_thread_command_add_channel(
2890 notification_thread_handle, session->name,
ff588497
JR
2891 lttng_credentials_get_uid(&ua_sess->effective_credentials),
2892 lttng_credentials_get_gid(&ua_sess->effective_credentials),
2893 ua_chan->name,
470cc211 2894 ua_chan->key, LTTNG_DOMAIN_UST,
e098433c
JG
2895 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2896 if (notification_ret != LTTNG_OK) {
2897 ret = - (int) notification_ret;
2898 ERR("Failed to add channel to notification thread");
2899 goto error;
e9404c27
JG
2900 }
2901
2721f7ea 2902send_channel:
66ff8e3f
JG
2903 /* Send buffers to the application. */
2904 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
2905 if (ret < 0) {
2906 if (ret != -ENOTCONN) {
2907 ERR("Error sending channel to application");
2908 }
2909 goto error;
2910 }
2911
9730260e 2912error:
e32d7f27
JG
2913 if (session) {
2914 session_put(session);
2915 }
9730260e
DG
2916 return ret;
2917}
2918
78f0bacd 2919/*
7972aab2
DG
2920 * Create and send to the application the created buffers with per PID buffers.
2921 *
fad1ed2f 2922 * Called with UST app session lock held.
71e0a100 2923 * The session list lock and the session's lock must be acquired.
fad1ed2f 2924 *
7972aab2 2925 * Return 0 on success else a negative value.
78f0bacd 2926 */
7972aab2
DG
2927static int create_channel_per_pid(struct ust_app *app,
2928 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2929 struct ust_app_channel *ua_chan)
78f0bacd 2930{
8535a6d9 2931 int ret;
7972aab2 2932 struct ust_registry_session *registry;
e9404c27 2933 enum lttng_error_code cmd_ret;
e32d7f27 2934 struct ltt_session *session = NULL;
e9404c27
JG
2935 uint64_t chan_reg_key;
2936 struct ust_registry_channel *chan_reg;
78f0bacd 2937
7972aab2
DG
2938 assert(app);
2939 assert(usess);
2940 assert(ua_sess);
2941 assert(ua_chan);
2942
2943 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2944
2945 rcu_read_lock();
2946
2947 registry = get_session_registry(ua_sess);
fad1ed2f 2948 /* The UST app session lock is held, registry shall not be null. */
7972aab2
DG
2949 assert(registry);
2950
2951 /* Create and add a new channel registry to session. */
2952 ret = ust_registry_channel_add(registry, ua_chan->key);
78f0bacd 2953 if (ret < 0) {
f14256d6
MD
2954 ERR("Error creating the UST channel \"%s\" registry instance",
2955 ua_chan->name);
78f0bacd
DG
2956 goto error;
2957 }
2958
e098433c
JG
2959 session = session_find_by_id(ua_sess->tracing_id);
2960 assert(session);
2961
2962 assert(pthread_mutex_trylock(&session->lock));
2963 assert(session_trylock_list());
2964
7972aab2
DG
2965 /* Create and get channel on the consumer side. */
2966 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
e098433c 2967 app->bits_per_long, registry,
d2956687 2968 session->most_recent_chunk_id.value);
7972aab2 2969 if (ret < 0) {
f14256d6
MD
2970 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2971 ua_chan->name);
5b951542 2972 goto error_remove_from_registry;
7972aab2
DG
2973 }
2974
2975 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2976 if (ret < 0) {
a7169585
MD
2977 if (ret != -ENOTCONN) {
2978 ERR("Error sending channel to application");
2979 }
5b951542 2980 goto error_remove_from_registry;
7972aab2 2981 }
8535a6d9 2982
e9404c27
JG
2983 chan_reg_key = ua_chan->key;
2984 pthread_mutex_lock(&registry->lock);
2985 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
2986 assert(chan_reg);
2987 chan_reg->consumer_key = ua_chan->key;
2988 pthread_mutex_unlock(&registry->lock);
2989
2990 cmd_ret = notification_thread_command_add_channel(
2991 notification_thread_handle, session->name,
ff588497
JR
2992 lttng_credentials_get_uid(&ua_sess->effective_credentials),
2993 lttng_credentials_get_gid(&ua_sess->effective_credentials),
2994 ua_chan->name,
470cc211 2995 ua_chan->key, LTTNG_DOMAIN_UST,
e9404c27
JG
2996 ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
2997 if (cmd_ret != LTTNG_OK) {
2998 ret = - (int) cmd_ret;
2999 ERR("Failed to add channel to notification thread");
5b951542 3000 goto error_remove_from_registry;
e9404c27
JG
3001 }
3002
5b951542
MD
3003error_remove_from_registry:
3004 if (ret) {
3005 ust_registry_channel_del_free(registry, ua_chan->key, false);
3006 }
78f0bacd 3007error:
7972aab2 3008 rcu_read_unlock();
e32d7f27
JG
3009 if (session) {
3010 session_put(session);
3011 }
78f0bacd
DG
3012 return ret;
3013}
3014
3015/*
7972aab2 3016 * From an already allocated ust app channel, create the channel buffers if
88e3c2f5 3017 * needed and send them to the application. This MUST be called with a RCU read
7972aab2
DG
3018 * side lock acquired.
3019 *
fad1ed2f
JR
3020 * Called with UST app session lock held.
3021 *
a7169585
MD
3022 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3023 * the application exited concurrently.
78f0bacd 3024 */
88e3c2f5 3025static int ust_app_channel_send(struct ust_app *app,
7972aab2
DG
3026 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
3027 struct ust_app_channel *ua_chan)
78f0bacd 3028{
7972aab2 3029 int ret;
78f0bacd 3030
7972aab2
DG
3031 assert(app);
3032 assert(usess);
88e3c2f5 3033 assert(usess->active);
7972aab2
DG
3034 assert(ua_sess);
3035 assert(ua_chan);
3036
3037 /* Handle buffer type before sending the channel to the application. */
3038 switch (usess->buffer_type) {
3039 case LTTNG_BUFFER_PER_UID:
3040 {
3041 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3042 if (ret < 0) {
3043 goto error;
3044 }
3045 break;
3046 }
3047 case LTTNG_BUFFER_PER_PID:
3048 {
3049 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3050 if (ret < 0) {
3051 goto error;
3052 }
3053 break;
3054 }
3055 default:
3056 assert(0);
3057 ret = -EINVAL;
78f0bacd
DG
3058 goto error;
3059 }
3060
7972aab2
DG
3061 /* Initialize ust objd object using the received handle and add it. */
3062 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3063 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
78f0bacd 3064
7972aab2
DG
3065 /* If channel is not enabled, disable it on the tracer */
3066 if (!ua_chan->enabled) {
3067 ret = disable_ust_channel(app, ua_sess, ua_chan);
3068 if (ret < 0) {
3069 goto error;
3070 }
78f0bacd
DG
3071 }
3072
3073error:
3074 return ret;
3075}
3076
284d8f55 3077/*
88e3c2f5 3078 * Create UST app channel and return it through ua_chanp if not NULL.
d0b96690 3079 *
36b588ed 3080 * Called with UST app session lock and RCU read-side lock held.
7972aab2 3081 *
88e3c2f5 3082 * Return 0 on success or else a negative value.
284d8f55 3083 */
88e3c2f5
JG
3084static int ust_app_channel_allocate(struct ust_app_session *ua_sess,
3085 struct ltt_ust_channel *uchan,
7972aab2 3086 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
4d710ac2 3087 struct ust_app_channel **ua_chanp)
5b4a0ec0
DG
3088{
3089 int ret = 0;
bec39940
DG
3090 struct lttng_ht_iter iter;
3091 struct lttng_ht_node_str *ua_chan_node;
5b4a0ec0
DG
3092 struct ust_app_channel *ua_chan;
3093
3094 /* Lookup channel in the ust app session */
bec39940
DG
3095 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3096 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
fc34caaa 3097 if (ua_chan_node != NULL) {
5b4a0ec0 3098 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
fc34caaa 3099 goto end;
5b4a0ec0
DG
3100 }
3101
d0b96690 3102 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
fc34caaa
DG
3103 if (ua_chan == NULL) {
3104 /* Only malloc can fail here */
4d710ac2 3105 ret = -ENOMEM;
88e3c2f5 3106 goto error;
fc34caaa
DG
3107 }
3108 shadow_copy_channel(ua_chan, uchan);
3109
ffe60014
DG
3110 /* Set channel type. */
3111 ua_chan->attr.type = type;
3112
d0b96690
DG
3113 /* Only add the channel if successful on the tracer side. */
3114 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
fc34caaa 3115end:
4d710ac2
DG
3116 if (ua_chanp) {
3117 *ua_chanp = ua_chan;
3118 }
3119
3120 /* Everything went well. */
3121 return 0;
5b4a0ec0
DG
3122
3123error:
4d710ac2 3124 return ret;
5b4a0ec0
DG
3125}
3126
3127/*
3128 * Create UST app event and create it on the tracer side.
d0b96690
DG
3129 *
3130 * Called with ust app session mutex held.
5b4a0ec0 3131 */
edb67388
DG
3132static
3133int create_ust_app_event(struct ust_app_session *ua_sess,
3134 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3135 struct ust_app *app)
284d8f55 3136{
edb67388 3137 int ret = 0;
5b4a0ec0 3138 struct ust_app_event *ua_event;
284d8f55 3139
edb67388
DG
3140 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3141 if (ua_event == NULL) {
20533947 3142 /* Only failure mode of alloc_ust_app_event(). */
edb67388 3143 ret = -ENOMEM;
fc34caaa 3144 goto end;
5b4a0ec0 3145 }
edb67388 3146 shadow_copy_event(ua_event, uevent);
5b4a0ec0 3147
edb67388 3148 /* Create it on the tracer side */
5b4a0ec0 3149 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
284d8f55 3150 if (ret < 0) {
e9f11505
JG
3151 /*
3152 * Not found previously means that it does not exist on the
3153 * tracer. If the application reports that the event existed,
3154 * it means there is a bug in the sessiond or lttng-ust
3155 * (or corruption, etc.)
3156 */
3157 if (ret == -LTTNG_UST_ERR_EXIST) {
3158 ERR("Tracer for application reported that an event being created already existed: "
3159 "event_name = \"%s\", pid = %d, ppid = %d, uid = %d, gid = %d",
3160 uevent->attr.name,
3161 app->pid, app->ppid, app->uid,
3162 app->gid);
3163 }
284d8f55
DG
3164 goto error;
3165 }
3166
d0b96690 3167 add_unique_ust_app_event(ua_chan, ua_event);
284d8f55 3168
fc34caaa 3169 DBG2("UST app create event %s for PID %d completed", ua_event->name,
852d0037 3170 app->pid);
7f79d3a1 3171
edb67388 3172end:
fc34caaa
DG
3173 return ret;
3174
5b4a0ec0 3175error:
fc34caaa 3176 /* Valid. Calling here is already in a read side lock */
fb45065e 3177 delete_ust_app_event(-1, ua_event, app);
edb67388 3178 return ret;
5b4a0ec0
DG
3179}
3180
3181/*
3182 * Create UST metadata and open it on the tracer side.
d0b96690 3183 *
7972aab2 3184 * Called with UST app session lock held and RCU read side lock.
5b4a0ec0
DG
3185 */
3186static int create_ust_app_metadata(struct ust_app_session *ua_sess,
ad7a9107 3187 struct ust_app *app, struct consumer_output *consumer)
5b4a0ec0
DG
3188{
3189 int ret = 0;
ffe60014 3190 struct ust_app_channel *metadata;
d88aee68 3191 struct consumer_socket *socket;
7972aab2 3192 struct ust_registry_session *registry;
e32d7f27 3193 struct ltt_session *session = NULL;
5b4a0ec0 3194
ffe60014
DG
3195 assert(ua_sess);
3196 assert(app);
d88aee68 3197 assert(consumer);
5b4a0ec0 3198
7972aab2 3199 registry = get_session_registry(ua_sess);
fad1ed2f 3200 /* The UST app session is held registry shall not be null. */
7972aab2
DG
3201 assert(registry);
3202
ce34fcd0
MD
3203 pthread_mutex_lock(&registry->lock);
3204
1b532a60
DG
3205 /* Metadata already exists for this registry or it was closed previously */
3206 if (registry->metadata_key || registry->metadata_closed) {
7972aab2
DG
3207 ret = 0;
3208 goto error;
5b4a0ec0
DG
3209 }
3210
ffe60014 3211 /* Allocate UST metadata */
d0b96690 3212 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
ffe60014
DG
3213 if (!metadata) {
3214 /* malloc() failed */