2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <sys/types.h>
28 #include <urcu/compiler.h>
29 #include <lttng/ust-error.h>
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
35 #include "buffer-registry.h"
39 #include "ust-consumer.h"
42 /* Next available channel key. */
43 static unsigned long next_channel_key
;
44 static unsigned long next_session_id
;
47 * Return the atomically incremented value of next_channel_key.
49 static inline unsigned long get_next_channel_key(void)
51 return uatomic_add_return(&next_channel_key
, 1);
55 * Return the atomically incremented value of next_session_id.
57 static inline unsigned long get_next_session_id(void)
59 return uatomic_add_return(&next_session_id
, 1);
62 static void copy_channel_attr_to_ustctl(
63 struct ustctl_consumer_channel_attr
*attr
,
64 struct lttng_ust_channel_attr
*uattr
)
66 /* Copy event attributes since the layout is different. */
67 attr
->subbuf_size
= uattr
->subbuf_size
;
68 attr
->num_subbuf
= uattr
->num_subbuf
;
69 attr
->overwrite
= uattr
->overwrite
;
70 attr
->switch_timer_interval
= uattr
->switch_timer_interval
;
71 attr
->read_timer_interval
= uattr
->read_timer_interval
;
72 attr
->output
= uattr
->output
;
76 * Match function for the hash table lookup.
78 * It matches an ust app event based on three attributes which are the event
79 * name, the filter bytecode and the loglevel.
81 static int ht_match_ust_app_event(struct cds_lfht_node
*node
, const void *_key
)
83 struct ust_app_event
*event
;
84 const struct ust_app_ht_key
*key
;
89 event
= caa_container_of(node
, struct ust_app_event
, node
.node
);
92 /* Match the 3 elements of the key: name, filter and loglevel. */
95 if (strncmp(event
->attr
.name
, key
->name
, sizeof(event
->attr
.name
)) != 0) {
100 if (event
->attr
.loglevel
!= key
->loglevel
) {
101 if (event
->attr
.loglevel_type
== LTTNG_UST_LOGLEVEL_ALL
102 && key
->loglevel
== 0 && event
->attr
.loglevel
== -1) {
104 * Match is accepted. This is because on event creation, the
105 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
106 * -1 are accepted for this loglevel type since 0 is the one set by
107 * the API when receiving an enable event.
114 /* One of the filters is NULL, fail. */
115 if ((key
->filter
&& !event
->filter
) || (!key
->filter
&& event
->filter
)) {
119 if (key
->filter
&& event
->filter
) {
120 /* Both filters exists, check length followed by the bytecode. */
121 if (event
->filter
->len
!= key
->filter
->len
||
122 memcmp(event
->filter
->data
, key
->filter
->data
,
123 event
->filter
->len
) != 0) {
136 * Unique add of an ust app event in the given ht. This uses the custom
137 * ht_match_ust_app_event match function and the event name as hash.
139 static void add_unique_ust_app_event(struct ust_app_channel
*ua_chan
,
140 struct ust_app_event
*event
)
142 struct cds_lfht_node
*node_ptr
;
143 struct ust_app_ht_key key
;
147 assert(ua_chan
->events
);
150 ht
= ua_chan
->events
;
151 key
.name
= event
->attr
.name
;
152 key
.filter
= event
->filter
;
153 key
.loglevel
= event
->attr
.loglevel
;
155 node_ptr
= cds_lfht_add_unique(ht
->ht
,
156 ht
->hash_fct(event
->node
.key
, lttng_ht_seed
),
157 ht_match_ust_app_event
, &key
, &event
->node
.node
);
158 assert(node_ptr
== &event
->node
.node
);
162 * Close the notify socket from the given RCU head object. This MUST be called
163 * through a call_rcu().
165 static void close_notify_sock_rcu(struct rcu_head
*head
)
168 struct ust_app_notify_sock_obj
*obj
=
169 caa_container_of(head
, struct ust_app_notify_sock_obj
, head
);
171 /* Must have a valid fd here. */
172 assert(obj
->fd
>= 0);
174 ret
= close(obj
->fd
);
176 ERR("close notify sock %d RCU", obj
->fd
);
178 lttng_fd_put(LTTNG_FD_APPS
, 1);
184 * Return the session registry according to the buffer type of the given
187 * A registry per UID object MUST exists before calling this function or else
188 * it assert() if not found. RCU read side lock must be acquired.
190 static struct ust_registry_session
*get_session_registry(
191 struct ust_app_session
*ua_sess
)
193 struct ust_registry_session
*registry
= NULL
;
197 switch (ua_sess
->buffer_type
) {
198 case LTTNG_BUFFER_PER_PID
:
200 struct buffer_reg_pid
*reg_pid
= buffer_reg_pid_find(ua_sess
->id
);
204 registry
= reg_pid
->registry
->reg
.ust
;
207 case LTTNG_BUFFER_PER_UID
:
209 struct buffer_reg_uid
*reg_uid
= buffer_reg_uid_find(
210 ua_sess
->tracing_id
, ua_sess
->bits_per_long
, ua_sess
->uid
);
214 registry
= reg_uid
->registry
->reg
.ust
;
226 * Delete ust context safely. RCU read lock must be held before calling
230 void delete_ust_app_ctx(int sock
, struct ust_app_ctx
*ua_ctx
)
237 ret
= ustctl_release_object(sock
, ua_ctx
->obj
);
238 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
239 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
240 sock
, ua_ctx
->obj
->handle
, ret
);
248 * Delete ust app event safely. RCU read lock must be held before calling
252 void delete_ust_app_event(int sock
, struct ust_app_event
*ua_event
)
258 free(ua_event
->filter
);
260 if (ua_event
->obj
!= NULL
) {
261 ret
= ustctl_release_object(sock
, ua_event
->obj
);
262 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
263 ERR("UST app sock %d release event obj failed with ret %d",
272 * Release ust data object of the given stream.
274 * Return 0 on success or else a negative value.
276 static int release_ust_app_stream(int sock
, struct ust_app_stream
*stream
)
283 ret
= ustctl_release_object(sock
, stream
->obj
);
284 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
285 ERR("UST app sock %d release stream obj failed with ret %d",
288 lttng_fd_put(LTTNG_FD_APPS
, 2);
296 * Delete ust app stream safely. RCU read lock must be held before calling
300 void delete_ust_app_stream(int sock
, struct ust_app_stream
*stream
)
304 (void) release_ust_app_stream(sock
, stream
);
309 * Delete ust app channel safely. RCU read lock must be held before calling
313 void delete_ust_app_channel(int sock
, struct ust_app_channel
*ua_chan
,
317 struct lttng_ht_iter iter
;
318 struct ust_app_event
*ua_event
;
319 struct ust_app_ctx
*ua_ctx
;
320 struct ust_app_stream
*stream
, *stmp
;
321 struct ust_registry_session
*registry
;
325 DBG3("UST app deleting channel %s", ua_chan
->name
);
328 cds_list_for_each_entry_safe(stream
, stmp
, &ua_chan
->streams
.head
, list
) {
329 cds_list_del(&stream
->list
);
330 delete_ust_app_stream(sock
, stream
);
334 cds_lfht_for_each_entry(ua_chan
->ctx
->ht
, &iter
.iter
, ua_ctx
, node
.node
) {
335 ret
= lttng_ht_del(ua_chan
->ctx
, &iter
);
337 delete_ust_app_ctx(sock
, ua_ctx
);
339 lttng_ht_destroy(ua_chan
->ctx
);
342 cds_lfht_for_each_entry(ua_chan
->events
->ht
, &iter
.iter
, ua_event
,
344 ret
= lttng_ht_del(ua_chan
->events
, &iter
);
346 delete_ust_app_event(sock
, ua_event
);
348 lttng_ht_destroy(ua_chan
->events
);
350 /* Wipe and free registry from session registry. */
351 registry
= get_session_registry(ua_chan
->session
);
353 ust_registry_channel_del_free(registry
, ua_chan
->key
);
356 if (ua_chan
->obj
!= NULL
) {
357 /* Remove channel from application UST object descriptor. */
358 iter
.iter
.node
= &ua_chan
->ust_objd_node
.node
;
359 lttng_ht_del(app
->ust_objd
, &iter
);
360 ret
= ustctl_release_object(sock
, ua_chan
->obj
);
361 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
362 ERR("UST app sock %d release channel obj failed with ret %d",
365 lttng_fd_put(LTTNG_FD_APPS
, 1);
372 * Push metadata to consumer socket. The socket lock MUST be acquired.
374 * On success, return the len of metadata pushed or else a negative value.
376 ssize_t
ust_app_push_metadata(struct ust_registry_session
*registry
,
377 struct consumer_socket
*socket
, int send_zero_data
)
380 char *metadata_str
= NULL
;
386 /* Should never be 0 which is the initial state. */
387 assert(registry
->metadata_key
);
389 pthread_mutex_lock(®istry
->lock
);
391 offset
= registry
->metadata_len_sent
;
392 len
= registry
->metadata_len
- registry
->metadata_len_sent
;
394 DBG3("No metadata to push for metadata key %" PRIu64
,
395 registry
->metadata_key
);
397 if (send_zero_data
) {
398 DBG("No metadata to push");
404 /* Allocate only what we have to send. */
405 metadata_str
= zmalloc(len
);
407 PERROR("zmalloc ust app metadata string");
411 /* Copy what we haven't send out. */
412 memcpy(metadata_str
, registry
->metadata
+ offset
, len
);
413 registry
->metadata_len_sent
+= len
;
416 pthread_mutex_unlock(®istry
->lock
);
417 ret
= consumer_push_metadata(socket
, registry
->metadata_key
,
418 metadata_str
, len
, offset
);
429 pthread_mutex_unlock(®istry
->lock
);
436 * For a given application and session, push metadata to consumer. The session
437 * lock MUST be acquired here before calling this.
438 * Either sock or consumer is required : if sock is NULL, the default
439 * socket to send the metadata is retrieved from consumer, if sock
440 * is not NULL we use it to send the metadata.
442 * Return 0 on success else a negative error.
444 static int push_metadata(struct ust_registry_session
*registry
,
445 struct consumer_output
*consumer
)
449 struct consumer_socket
*socket
;
457 * Means that no metadata was assigned to the session. This can happens if
458 * no start has been done previously.
460 if (!registry
->metadata_key
) {
462 goto error_rcu_unlock
;
465 /* Get consumer socket to use to push the metadata.*/
466 socket
= consumer_find_socket_by_bitness(registry
->bits_per_long
,
470 goto error_rcu_unlock
;
474 * TODO: Currently, we hold the socket lock around sampling of the next
475 * metadata segment to ensure we send metadata over the consumer socket in
476 * the correct order. This makes the registry lock nest inside the socket
479 * Please note that this is a temporary measure: we should move this lock
480 * back into ust_consumer_push_metadata() when the consumer gets the
481 * ability to reorder the metadata it receives.
483 pthread_mutex_lock(socket
->lock
);
484 ret
= ust_app_push_metadata(registry
, socket
, 0);
485 pthread_mutex_unlock(socket
->lock
);
488 goto error_rcu_unlock
;
500 * Send to the consumer a close metadata command for the given session. Once
501 * done, the metadata channel is deleted and the session metadata pointer is
502 * nullified. The session lock MUST be acquired here unless the application is
503 * in the destroy path.
505 * Return 0 on success else a negative value.
507 static int close_metadata(struct ust_registry_session
*registry
,
508 struct consumer_output
*consumer
)
511 struct consumer_socket
*socket
;
518 if (!registry
->metadata_key
|| registry
->metadata_closed
) {
523 /* Get consumer socket to use to push the metadata.*/
524 socket
= consumer_find_socket_by_bitness(registry
->bits_per_long
,
531 ret
= consumer_close_metadata(socket
, registry
->metadata_key
);
536 /* Metadata successfully closed. Flag the registry. */
537 registry
->metadata_closed
= 1;
545 * Delete ust app session safely. RCU read lock must be held before calling
549 void delete_ust_app_session(int sock
, struct ust_app_session
*ua_sess
,
553 struct lttng_ht_iter iter
;
554 struct ust_app_channel
*ua_chan
;
555 struct ust_registry_session
*registry
;
559 registry
= get_session_registry(ua_sess
);
561 /* Push metadata for application before freeing the application. */
562 (void) push_metadata(registry
, ua_sess
->consumer
);
565 * Don't ask to close metadata for global per UID buffers. Close
566 * metadata only on destroy trace session in this case.
568 if (ua_sess
->buffer_type
!= LTTNG_BUFFER_PER_UID
) {
569 /* And ask to close it for this session registry. */
570 (void) close_metadata(registry
, ua_sess
->consumer
);
574 cds_lfht_for_each_entry(ua_sess
->channels
->ht
, &iter
.iter
, ua_chan
,
576 ret
= lttng_ht_del(ua_sess
->channels
, &iter
);
578 delete_ust_app_channel(sock
, ua_chan
, app
);
580 lttng_ht_destroy(ua_sess
->channels
);
582 /* In case of per PID, the registry is kept in the session. */
583 if (ua_sess
->buffer_type
== LTTNG_BUFFER_PER_PID
) {
584 struct buffer_reg_pid
*reg_pid
= buffer_reg_pid_find(ua_sess
->id
);
586 buffer_reg_pid_remove(reg_pid
);
587 buffer_reg_pid_destroy(reg_pid
);
591 if (ua_sess
->handle
!= -1) {
592 ret
= ustctl_release_handle(sock
, ua_sess
->handle
);
593 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
594 ERR("UST app sock %d release session handle failed with ret %d",
602 * Delete a traceable application structure from the global list. Never call
603 * this function outside of a call_rcu call.
606 void delete_ust_app(struct ust_app
*app
)
609 struct ust_app_session
*ua_sess
, *tmp_ua_sess
;
613 /* Delete ust app sessions info */
617 lttng_ht_destroy(app
->sessions
);
620 cds_list_for_each_entry_safe(ua_sess
, tmp_ua_sess
, &app
->teardown_head
,
622 /* Free every object in the session and the session. */
623 delete_ust_app_session(sock
, ua_sess
, app
);
625 lttng_ht_destroy(app
->ust_objd
);
628 * Wait until we have deleted the application from the sock hash table
629 * before closing this socket, otherwise an application could re-use the
630 * socket ID and race with the teardown, using the same hash table entry.
632 * It's OK to leave the close in call_rcu. We want it to stay unique for
633 * all RCU readers that could run concurrently with unregister app,
634 * therefore we _need_ to only close that socket after a grace period. So
635 * it should stay in this RCU callback.
637 * This close() is a very important step of the synchronization model so
638 * every modification to this function must be carefully reviewed.
644 lttng_fd_put(LTTNG_FD_APPS
, 1);
646 DBG2("UST app pid %d deleted", app
->pid
);
653 * URCU intermediate call to delete an UST app.
656 void delete_ust_app_rcu(struct rcu_head
*head
)
658 struct lttng_ht_node_ulong
*node
=
659 caa_container_of(head
, struct lttng_ht_node_ulong
, head
);
660 struct ust_app
*app
=
661 caa_container_of(node
, struct ust_app
, pid_n
);
663 DBG3("Call RCU deleting app PID %d", app
->pid
);
668 * Delete the session from the application ht and delete the data structure by
669 * freeing every object inside and releasing them.
671 static void destroy_app_session(struct ust_app
*app
,
672 struct ust_app_session
*ua_sess
)
675 struct lttng_ht_iter iter
;
680 iter
.iter
.node
= &ua_sess
->node
.node
;
681 ret
= lttng_ht_del(app
->sessions
, &iter
);
683 /* Already scheduled for teardown. */
687 /* Once deleted, free the data structure. */
688 delete_ust_app_session(app
->sock
, ua_sess
, app
);
695 * Alloc new UST app session.
698 struct ust_app_session
*alloc_ust_app_session(struct ust_app
*app
)
700 struct ust_app_session
*ua_sess
;
702 /* Init most of the default value by allocating and zeroing */
703 ua_sess
= zmalloc(sizeof(struct ust_app_session
));
704 if (ua_sess
== NULL
) {
709 ua_sess
->handle
= -1;
710 ua_sess
->channels
= lttng_ht_new(0, LTTNG_HT_TYPE_STRING
);
711 pthread_mutex_init(&ua_sess
->lock
, NULL
);
720 * Alloc new UST app channel.
723 struct ust_app_channel
*alloc_ust_app_channel(char *name
,
724 struct ust_app_session
*ua_sess
,
725 struct lttng_ust_channel_attr
*attr
)
727 struct ust_app_channel
*ua_chan
;
729 /* Init most of the default value by allocating and zeroing */
730 ua_chan
= zmalloc(sizeof(struct ust_app_channel
));
731 if (ua_chan
== NULL
) {
736 /* Setup channel name */
737 strncpy(ua_chan
->name
, name
, sizeof(ua_chan
->name
));
738 ua_chan
->name
[sizeof(ua_chan
->name
) - 1] = '\0';
740 ua_chan
->enabled
= 1;
741 ua_chan
->handle
= -1;
742 ua_chan
->session
= ua_sess
;
743 ua_chan
->key
= get_next_channel_key();
744 ua_chan
->ctx
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
745 ua_chan
->events
= lttng_ht_new(0, LTTNG_HT_TYPE_STRING
);
746 lttng_ht_node_init_str(&ua_chan
->node
, ua_chan
->name
);
748 CDS_INIT_LIST_HEAD(&ua_chan
->streams
.head
);
750 /* Copy attributes */
752 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
753 ua_chan
->attr
.subbuf_size
= attr
->subbuf_size
;
754 ua_chan
->attr
.num_subbuf
= attr
->num_subbuf
;
755 ua_chan
->attr
.overwrite
= attr
->overwrite
;
756 ua_chan
->attr
.switch_timer_interval
= attr
->switch_timer_interval
;
757 ua_chan
->attr
.read_timer_interval
= attr
->read_timer_interval
;
758 ua_chan
->attr
.output
= attr
->output
;
760 /* By default, the channel is a per cpu channel. */
761 ua_chan
->attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
763 DBG3("UST app channel %s allocated", ua_chan
->name
);
772 * Allocate and initialize a UST app stream.
774 * Return newly allocated stream pointer or NULL on error.
776 struct ust_app_stream
*ust_app_alloc_stream(void)
778 struct ust_app_stream
*stream
= NULL
;
780 stream
= zmalloc(sizeof(*stream
));
781 if (stream
== NULL
) {
782 PERROR("zmalloc ust app stream");
786 /* Zero could be a valid value for a handle so flag it to -1. */
794 * Alloc new UST app event.
797 struct ust_app_event
*alloc_ust_app_event(char *name
,
798 struct lttng_ust_event
*attr
)
800 struct ust_app_event
*ua_event
;
802 /* Init most of the default value by allocating and zeroing */
803 ua_event
= zmalloc(sizeof(struct ust_app_event
));
804 if (ua_event
== NULL
) {
809 ua_event
->enabled
= 1;
810 strncpy(ua_event
->name
, name
, sizeof(ua_event
->name
));
811 ua_event
->name
[sizeof(ua_event
->name
) - 1] = '\0';
812 lttng_ht_node_init_str(&ua_event
->node
, ua_event
->name
);
814 /* Copy attributes */
816 memcpy(&ua_event
->attr
, attr
, sizeof(ua_event
->attr
));
819 DBG3("UST app event %s allocated", ua_event
->name
);
828 * Alloc new UST app context.
831 struct ust_app_ctx
*alloc_ust_app_ctx(struct lttng_ust_context
*uctx
)
833 struct ust_app_ctx
*ua_ctx
;
835 ua_ctx
= zmalloc(sizeof(struct ust_app_ctx
));
836 if (ua_ctx
== NULL
) {
841 memcpy(&ua_ctx
->ctx
, uctx
, sizeof(ua_ctx
->ctx
));
844 DBG3("UST app context %d allocated", ua_ctx
->ctx
.ctx
);
851 * Allocate a filter and copy the given original filter.
853 * Return allocated filter or NULL on error.
855 static struct lttng_ust_filter_bytecode
*alloc_copy_ust_app_filter(
856 struct lttng_ust_filter_bytecode
*orig_f
)
858 struct lttng_ust_filter_bytecode
*filter
= NULL
;
860 /* Copy filter bytecode */
861 filter
= zmalloc(sizeof(*filter
) + orig_f
->len
);
863 PERROR("zmalloc alloc ust app filter");
867 memcpy(filter
, orig_f
, sizeof(*filter
) + orig_f
->len
);
874 * Find an ust_app using the sock and return it. RCU read side lock must be
875 * held before calling this helper function.
878 struct ust_app
*find_app_by_sock(int sock
)
880 struct lttng_ht_node_ulong
*node
;
881 struct lttng_ht_iter iter
;
883 lttng_ht_lookup(ust_app_ht_by_sock
, (void *)((unsigned long) sock
), &iter
);
884 node
= lttng_ht_iter_get_node_ulong(&iter
);
886 DBG2("UST app find by sock %d not found", sock
);
890 return caa_container_of(node
, struct ust_app
, sock_n
);
897 * Find an ust_app using the notify sock and return it. RCU read side lock must
898 * be held before calling this helper function.
900 static struct ust_app
*find_app_by_notify_sock(int sock
)
902 struct lttng_ht_node_ulong
*node
;
903 struct lttng_ht_iter iter
;
905 lttng_ht_lookup(ust_app_ht_by_notify_sock
, (void *)((unsigned long) sock
),
907 node
= lttng_ht_iter_get_node_ulong(&iter
);
909 DBG2("UST app find by notify sock %d not found", sock
);
913 return caa_container_of(node
, struct ust_app
, notify_sock_n
);
920 * Lookup for an ust app event based on event name, filter bytecode and the
923 * Return an ust_app_event object or NULL on error.
925 static struct ust_app_event
*find_ust_app_event(struct lttng_ht
*ht
,
926 char *name
, struct lttng_ust_filter_bytecode
*filter
, int loglevel
)
928 struct lttng_ht_iter iter
;
929 struct lttng_ht_node_str
*node
;
930 struct ust_app_event
*event
= NULL
;
931 struct ust_app_ht_key key
;
936 /* Setup key for event lookup. */
939 key
.loglevel
= loglevel
;
941 /* Lookup using the event name as hash and a custom match fct. */
942 cds_lfht_lookup(ht
->ht
, ht
->hash_fct((void *) name
, lttng_ht_seed
),
943 ht_match_ust_app_event
, &key
, &iter
.iter
);
944 node
= lttng_ht_iter_get_node_str(&iter
);
949 event
= caa_container_of(node
, struct ust_app_event
, node
);
956 * Create the channel context on the tracer.
958 * Called with UST app session lock held.
961 int create_ust_channel_context(struct ust_app_channel
*ua_chan
,
962 struct ust_app_ctx
*ua_ctx
, struct ust_app
*app
)
966 health_code_update();
968 ret
= ustctl_add_context(app
->sock
, &ua_ctx
->ctx
,
969 ua_chan
->obj
, &ua_ctx
->obj
);
971 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
972 ERR("UST app create channel context failed for app (pid: %d) "
973 "with ret %d", app
->pid
, ret
);
975 DBG3("UST app disable event failed. Application is dead.");
980 ua_ctx
->handle
= ua_ctx
->obj
->handle
;
982 DBG2("UST app context handle %d created successfully for channel %s",
983 ua_ctx
->handle
, ua_chan
->name
);
986 health_code_update();
991 * Set the filter on the tracer.
994 int set_ust_event_filter(struct ust_app_event
*ua_event
,
999 health_code_update();
1001 if (!ua_event
->filter
) {
1006 ret
= ustctl_set_filter(app
->sock
, ua_event
->filter
,
1009 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1010 ERR("UST app event %s filter failed for app (pid: %d) "
1011 "with ret %d", ua_event
->attr
.name
, app
->pid
, ret
);
1013 DBG3("UST app filter event failed. Application is dead.");
1018 DBG2("UST filter set successfully for event %s", ua_event
->name
);
1021 health_code_update();
1026 * Disable the specified event on to UST tracer for the UST session.
1028 static int disable_ust_event(struct ust_app
*app
,
1029 struct ust_app_session
*ua_sess
, struct ust_app_event
*ua_event
)
1033 health_code_update();
1035 ret
= ustctl_disable(app
->sock
, ua_event
->obj
);
1037 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1038 ERR("UST app event %s disable failed for app (pid: %d) "
1039 "and session handle %d with ret %d",
1040 ua_event
->attr
.name
, app
->pid
, ua_sess
->handle
, ret
);
1042 DBG3("UST app disable event failed. Application is dead.");
1047 DBG2("UST app event %s disabled successfully for app (pid: %d)",
1048 ua_event
->attr
.name
, app
->pid
);
1051 health_code_update();
1056 * Disable the specified channel on to UST tracer for the UST session.
1058 static int disable_ust_channel(struct ust_app
*app
,
1059 struct ust_app_session
*ua_sess
, struct ust_app_channel
*ua_chan
)
1063 health_code_update();
1065 ret
= ustctl_disable(app
->sock
, ua_chan
->obj
);
1067 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1068 ERR("UST app channel %s disable failed for app (pid: %d) "
1069 "and session handle %d with ret %d",
1070 ua_chan
->name
, app
->pid
, ua_sess
->handle
, ret
);
1072 DBG3("UST app disable channel failed. Application is dead.");
1077 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
1078 ua_chan
->name
, app
->pid
);
1081 health_code_update();
1086 * Enable the specified channel on to UST tracer for the UST session.
1088 static int enable_ust_channel(struct ust_app
*app
,
1089 struct ust_app_session
*ua_sess
, struct ust_app_channel
*ua_chan
)
1093 health_code_update();
1095 ret
= ustctl_enable(app
->sock
, ua_chan
->obj
);
1097 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1098 ERR("UST app channel %s enable failed for app (pid: %d) "
1099 "and session handle %d with ret %d",
1100 ua_chan
->name
, app
->pid
, ua_sess
->handle
, ret
);
1102 DBG3("UST app enable channel failed. Application is dead.");
1107 ua_chan
->enabled
= 1;
1109 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
1110 ua_chan
->name
, app
->pid
);
1113 health_code_update();
1118 * Enable the specified event on to UST tracer for the UST session.
1120 static int enable_ust_event(struct ust_app
*app
,
1121 struct ust_app_session
*ua_sess
, struct ust_app_event
*ua_event
)
1125 health_code_update();
1127 ret
= ustctl_enable(app
->sock
, ua_event
->obj
);
1129 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1130 ERR("UST app event %s enable failed for app (pid: %d) "
1131 "and session handle %d with ret %d",
1132 ua_event
->attr
.name
, app
->pid
, ua_sess
->handle
, ret
);
1134 DBG3("UST app enable event failed. Application is dead.");
1139 DBG2("UST app event %s enabled successfully for app (pid: %d)",
1140 ua_event
->attr
.name
, app
->pid
);
1143 health_code_update();
1148 * Send channel and stream buffer to application.
1150 * Return 0 on success. On error, a negative value is returned.
1152 static int send_channel_pid_to_ust(struct ust_app
*app
,
1153 struct ust_app_session
*ua_sess
, struct ust_app_channel
*ua_chan
)
1156 struct ust_app_stream
*stream
, *stmp
;
1162 health_code_update();
1164 DBG("UST app sending channel %s to UST app sock %d", ua_chan
->name
,
1167 /* Send channel to the application. */
1168 ret
= ust_consumer_send_channel_to_ust(app
, ua_sess
, ua_chan
);
1173 health_code_update();
1175 /* Send all streams to application. */
1176 cds_list_for_each_entry_safe(stream
, stmp
, &ua_chan
->streams
.head
, list
) {
1177 ret
= ust_consumer_send_stream_to_ust(app
, ua_chan
, stream
);
1181 /* We don't need the stream anymore once sent to the tracer. */
1182 cds_list_del(&stream
->list
);
1183 delete_ust_app_stream(-1, stream
);
1185 /* Flag the channel that it is sent to the application. */
1186 ua_chan
->is_sent
= 1;
1189 health_code_update();
1194 * Create the specified event onto the UST tracer for a UST session.
1196 * Should be called with session mutex held.
1199 int create_ust_event(struct ust_app
*app
, struct ust_app_session
*ua_sess
,
1200 struct ust_app_channel
*ua_chan
, struct ust_app_event
*ua_event
)
1204 health_code_update();
1206 /* Create UST event on tracer */
1207 ret
= ustctl_create_event(app
->sock
, &ua_event
->attr
, ua_chan
->obj
,
1210 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1211 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1212 ua_event
->attr
.name
, app
->pid
, ret
);
1214 DBG3("UST app create event failed. Application is dead.");
1219 ua_event
->handle
= ua_event
->obj
->handle
;
1221 DBG2("UST app event %s created successfully for pid:%d",
1222 ua_event
->attr
.name
, app
->pid
);
1224 health_code_update();
1226 /* Set filter if one is present. */
1227 if (ua_event
->filter
) {
1228 ret
= set_ust_event_filter(ua_event
, app
);
1234 /* If event not enabled, disable it on the tracer */
1235 if (ua_event
->enabled
== 0) {
1236 ret
= disable_ust_event(app
, ua_sess
, ua_event
);
1239 * If we hit an EPERM, something is wrong with our disable call. If
1240 * we get an EEXIST, there is a problem on the tracer side since we
1244 case -LTTNG_UST_ERR_PERM
:
1245 /* Code flow problem */
1247 case -LTTNG_UST_ERR_EXIST
:
1248 /* It's OK for our use case. */
1259 health_code_update();
1264 * Copy data between an UST app event and a LTT event.
1266 static void shadow_copy_event(struct ust_app_event
*ua_event
,
1267 struct ltt_ust_event
*uevent
)
1269 strncpy(ua_event
->name
, uevent
->attr
.name
, sizeof(ua_event
->name
));
1270 ua_event
->name
[sizeof(ua_event
->name
) - 1] = '\0';
1272 ua_event
->enabled
= uevent
->enabled
;
1274 /* Copy event attributes */
1275 memcpy(&ua_event
->attr
, &uevent
->attr
, sizeof(ua_event
->attr
));
1277 /* Copy filter bytecode */
1278 if (uevent
->filter
) {
1279 ua_event
->filter
= alloc_copy_ust_app_filter(uevent
->filter
);
1280 /* Filter might be NULL here in case of ENONEM. */
1285 * Copy data between an UST app channel and a LTT channel.
1287 static void shadow_copy_channel(struct ust_app_channel
*ua_chan
,
1288 struct ltt_ust_channel
*uchan
)
1290 struct lttng_ht_iter iter
;
1291 struct ltt_ust_event
*uevent
;
1292 struct ltt_ust_context
*uctx
;
1293 struct ust_app_event
*ua_event
;
1294 struct ust_app_ctx
*ua_ctx
;
1296 DBG2("UST app shadow copy of channel %s started", ua_chan
->name
);
1298 strncpy(ua_chan
->name
, uchan
->name
, sizeof(ua_chan
->name
));
1299 ua_chan
->name
[sizeof(ua_chan
->name
) - 1] = '\0';
1301 ua_chan
->tracefile_size
= uchan
->tracefile_size
;
1302 ua_chan
->tracefile_count
= uchan
->tracefile_count
;
1304 /* Copy event attributes since the layout is different. */
1305 ua_chan
->attr
.subbuf_size
= uchan
->attr
.subbuf_size
;
1306 ua_chan
->attr
.num_subbuf
= uchan
->attr
.num_subbuf
;
1307 ua_chan
->attr
.overwrite
= uchan
->attr
.overwrite
;
1308 ua_chan
->attr
.switch_timer_interval
= uchan
->attr
.switch_timer_interval
;
1309 ua_chan
->attr
.read_timer_interval
= uchan
->attr
.read_timer_interval
;
1310 ua_chan
->attr
.output
= uchan
->attr
.output
;
1312 * Note that the attribute channel type is not set since the channel on the
1313 * tracing registry side does not have this information.
1316 ua_chan
->enabled
= uchan
->enabled
;
1317 ua_chan
->tracing_channel_id
= uchan
->id
;
1319 cds_lfht_for_each_entry(uchan
->ctx
->ht
, &iter
.iter
, uctx
, node
.node
) {
1320 ua_ctx
= alloc_ust_app_ctx(&uctx
->ctx
);
1321 if (ua_ctx
== NULL
) {
1324 lttng_ht_node_init_ulong(&ua_ctx
->node
,
1325 (unsigned long) ua_ctx
->ctx
.ctx
);
1326 lttng_ht_add_unique_ulong(ua_chan
->ctx
, &ua_ctx
->node
);
1329 /* Copy all events from ltt ust channel to ust app channel */
1330 cds_lfht_for_each_entry(uchan
->events
->ht
, &iter
.iter
, uevent
, node
.node
) {
1331 ua_event
= find_ust_app_event(ua_chan
->events
, uevent
->attr
.name
,
1332 uevent
->filter
, uevent
->attr
.loglevel
);
1333 if (ua_event
== NULL
) {
1334 DBG2("UST event %s not found on shadow copy channel",
1336 ua_event
= alloc_ust_app_event(uevent
->attr
.name
, &uevent
->attr
);
1337 if (ua_event
== NULL
) {
1340 shadow_copy_event(ua_event
, uevent
);
1341 add_unique_ust_app_event(ua_chan
, ua_event
);
1345 DBG3("UST app shadow copy of channel %s done", ua_chan
->name
);
1349 * Copy data between a UST app session and a regular LTT session.
1351 static void shadow_copy_session(struct ust_app_session
*ua_sess
,
1352 struct ltt_ust_session
*usess
, struct ust_app
*app
)
1354 struct lttng_ht_node_str
*ua_chan_node
;
1355 struct lttng_ht_iter iter
;
1356 struct ltt_ust_channel
*uchan
;
1357 struct ust_app_channel
*ua_chan
;
1359 struct tm
*timeinfo
;
1363 /* Get date and time for unique app path */
1365 timeinfo
= localtime(&rawtime
);
1366 strftime(datetime
, sizeof(datetime
), "%Y%m%d-%H%M%S", timeinfo
);
1368 DBG2("Shadow copy of session handle %d", ua_sess
->handle
);
1370 ua_sess
->tracing_id
= usess
->id
;
1371 ua_sess
->id
= get_next_session_id();
1372 ua_sess
->uid
= app
->uid
;
1373 ua_sess
->gid
= app
->gid
;
1374 ua_sess
->euid
= usess
->uid
;
1375 ua_sess
->egid
= usess
->gid
;
1376 ua_sess
->buffer_type
= usess
->buffer_type
;
1377 ua_sess
->bits_per_long
= app
->bits_per_long
;
1378 /* There is only one consumer object per session possible. */
1379 ua_sess
->consumer
= usess
->consumer
;
1381 switch (ua_sess
->buffer_type
) {
1382 case LTTNG_BUFFER_PER_PID
:
1383 ret
= snprintf(ua_sess
->path
, sizeof(ua_sess
->path
),
1384 DEFAULT_UST_TRACE_PID_PATH
"/%s-%d-%s/", app
->name
, app
->pid
,
1387 case LTTNG_BUFFER_PER_UID
:
1388 ret
= snprintf(ua_sess
->path
, sizeof(ua_sess
->path
),
1389 DEFAULT_UST_TRACE_UID_PATH
, ua_sess
->uid
, app
->bits_per_long
);
1396 PERROR("asprintf UST shadow copy session");
1401 /* Iterate over all channels in global domain. */
1402 cds_lfht_for_each_entry(usess
->domain_global
.channels
->ht
, &iter
.iter
,
1404 struct lttng_ht_iter uiter
;
1406 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
1407 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
1408 if (ua_chan_node
!= NULL
) {
1409 /* Session exist. Contiuing. */
1413 DBG2("Channel %s not found on shadow session copy, creating it",
1415 ua_chan
= alloc_ust_app_channel(uchan
->name
, ua_sess
, &uchan
->attr
);
1416 if (ua_chan
== NULL
) {
1417 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
1420 shadow_copy_channel(ua_chan
, uchan
);
1422 * The concept of metadata channel does not exist on the tracing
1423 * registry side of the session daemon so this can only be a per CPU
1424 * channel and not metadata.
1426 ua_chan
->attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
1428 lttng_ht_add_unique_str(ua_sess
->channels
, &ua_chan
->node
);
1436 * Lookup sesison wrapper.
1439 void __lookup_session_by_app(struct ltt_ust_session
*usess
,
1440 struct ust_app
*app
, struct lttng_ht_iter
*iter
)
1442 /* Get right UST app session from app */
1443 lttng_ht_lookup(app
->sessions
, (void *)((unsigned long) usess
->id
), iter
);
1447 * Return ust app session from the app session hashtable using the UST session
1450 static struct ust_app_session
*lookup_session_by_app(
1451 struct ltt_ust_session
*usess
, struct ust_app
*app
)
1453 struct lttng_ht_iter iter
;
1454 struct lttng_ht_node_ulong
*node
;
1456 __lookup_session_by_app(usess
, app
, &iter
);
1457 node
= lttng_ht_iter_get_node_ulong(&iter
);
1462 return caa_container_of(node
, struct ust_app_session
, node
);
1469 * Setup buffer registry per PID for the given session and application. If none
1470 * is found, a new one is created, added to the global registry and
1471 * initialized. If regp is valid, it's set with the newly created object.
1473 * Return 0 on success or else a negative value.
1475 static int setup_buffer_reg_pid(struct ust_app_session
*ua_sess
,
1476 struct ust_app
*app
, struct buffer_reg_pid
**regp
)
1479 struct buffer_reg_pid
*reg_pid
;
1486 reg_pid
= buffer_reg_pid_find(ua_sess
->id
);
1489 * This is the create channel path meaning that if there is NO
1490 * registry available, we have to create one for this session.
1492 ret
= buffer_reg_pid_create(ua_sess
->id
, ®_pid
);
1496 buffer_reg_pid_add(reg_pid
);
1501 /* Initialize registry. */
1502 ret
= ust_registry_session_init(®_pid
->registry
->reg
.ust
, app
,
1503 app
->bits_per_long
, app
->uint8_t_alignment
,
1504 app
->uint16_t_alignment
, app
->uint32_t_alignment
,
1505 app
->uint64_t_alignment
, app
->long_alignment
, app
->byte_order
);
1510 DBG3("UST app buffer registry per PID created successfully");
1522 * Setup buffer registry per UID for the given session and application. If none
1523 * is found, a new one is created, added to the global registry and
1524 * initialized. If regp is valid, it's set with the newly created object.
1526 * Return 0 on success or else a negative value.
1528 static int setup_buffer_reg_uid(struct ltt_ust_session
*usess
,
1529 struct ust_app
*app
, struct buffer_reg_uid
**regp
)
1532 struct buffer_reg_uid
*reg_uid
;
1539 reg_uid
= buffer_reg_uid_find(usess
->id
, app
->bits_per_long
, app
->uid
);
1542 * This is the create channel path meaning that if there is NO
1543 * registry available, we have to create one for this session.
1545 ret
= buffer_reg_uid_create(usess
->id
, app
->bits_per_long
, app
->uid
,
1546 LTTNG_DOMAIN_UST
, ®_uid
);
1550 buffer_reg_uid_add(reg_uid
);
1555 /* Initialize registry. */
1556 ret
= ust_registry_session_init(®_uid
->registry
->reg
.ust
, app
,
1557 app
->bits_per_long
, app
->uint8_t_alignment
,
1558 app
->uint16_t_alignment
, app
->uint32_t_alignment
,
1559 app
->uint64_t_alignment
, app
->long_alignment
, app
->byte_order
);
1563 /* Add node to teardown list of the session. */
1564 cds_list_add(®_uid
->lnode
, &usess
->buffer_reg_uid_list
);
1566 DBG3("UST app buffer registry per UID created successfully");
1578 * Create a session on the tracer side for the given app.
1580 * On success, ua_sess_ptr is populated with the session pointer or else left
1581 * untouched. If the session was created, is_created is set to 1. On error,
1582 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
1585 * Returns 0 on success or else a negative code which is either -ENOMEM or
1586 * -ENOTCONN which is the default code if the ustctl_create_session fails.
1588 static int create_ust_app_session(struct ltt_ust_session
*usess
,
1589 struct ust_app
*app
, struct ust_app_session
**ua_sess_ptr
,
1592 int ret
, created
= 0;
1593 struct ust_app_session
*ua_sess
;
1597 assert(ua_sess_ptr
);
1599 health_code_update();
1601 ua_sess
= lookup_session_by_app(usess
, app
);
1602 if (ua_sess
== NULL
) {
1603 DBG2("UST app pid: %d session id %d not found, creating it",
1604 app
->pid
, usess
->id
);
1605 ua_sess
= alloc_ust_app_session(app
);
1606 if (ua_sess
== NULL
) {
1607 /* Only malloc can failed so something is really wrong */
1611 shadow_copy_session(ua_sess
, usess
, app
);
1615 switch (usess
->buffer_type
) {
1616 case LTTNG_BUFFER_PER_PID
:
1617 /* Init local registry. */
1618 ret
= setup_buffer_reg_pid(ua_sess
, app
, NULL
);
1623 case LTTNG_BUFFER_PER_UID
:
1624 /* Look for a global registry. If none exists, create one. */
1625 ret
= setup_buffer_reg_uid(usess
, app
, NULL
);
1636 health_code_update();
1638 if (ua_sess
->handle
== -1) {
1639 ret
= ustctl_create_session(app
->sock
);
1641 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
1642 ERR("Creating session for app pid %d with ret %d",
1645 DBG("UST app creating session failed. Application is dead");
1647 delete_ust_app_session(-1, ua_sess
, app
);
1648 if (ret
!= -ENOMEM
) {
1650 * Tracer is probably gone or got an internal error so let's
1651 * behave like it will soon unregister or not usable.
1658 ua_sess
->handle
= ret
;
1660 /* Add ust app session to app's HT */
1661 lttng_ht_node_init_ulong(&ua_sess
->node
,
1662 (unsigned long) ua_sess
->tracing_id
);
1663 lttng_ht_add_unique_ulong(app
->sessions
, &ua_sess
->node
);
1665 DBG2("UST app session created successfully with handle %d", ret
);
1668 *ua_sess_ptr
= ua_sess
;
1670 *is_created
= created
;
1673 /* Everything went well. */
1677 health_code_update();
1682 * Create a context for the channel on the tracer.
1684 * Called with UST app session lock held and a RCU read side lock.
1687 int create_ust_app_channel_context(struct ust_app_session
*ua_sess
,
1688 struct ust_app_channel
*ua_chan
, struct lttng_ust_context
*uctx
,
1689 struct ust_app
*app
)
1692 struct lttng_ht_iter iter
;
1693 struct lttng_ht_node_ulong
*node
;
1694 struct ust_app_ctx
*ua_ctx
;
1696 DBG2("UST app adding context to channel %s", ua_chan
->name
);
1698 lttng_ht_lookup(ua_chan
->ctx
, (void *)((unsigned long)uctx
->ctx
), &iter
);
1699 node
= lttng_ht_iter_get_node_ulong(&iter
);
1705 ua_ctx
= alloc_ust_app_ctx(uctx
);
1706 if (ua_ctx
== NULL
) {
1712 lttng_ht_node_init_ulong(&ua_ctx
->node
, (unsigned long) ua_ctx
->ctx
.ctx
);
1713 lttng_ht_add_unique_ulong(ua_chan
->ctx
, &ua_ctx
->node
);
1715 ret
= create_ust_channel_context(ua_chan
, ua_ctx
, app
);
1725 * Enable on the tracer side a ust app event for the session and channel.
1727 * Called with UST app session lock held.
1730 int enable_ust_app_event(struct ust_app_session
*ua_sess
,
1731 struct ust_app_event
*ua_event
, struct ust_app
*app
)
1735 ret
= enable_ust_event(app
, ua_sess
, ua_event
);
1740 ua_event
->enabled
= 1;
1747 * Disable on the tracer side a ust app event for the session and channel.
1749 static int disable_ust_app_event(struct ust_app_session
*ua_sess
,
1750 struct ust_app_event
*ua_event
, struct ust_app
*app
)
1754 ret
= disable_ust_event(app
, ua_sess
, ua_event
);
1759 ua_event
->enabled
= 0;
1766 * Lookup ust app channel for session and disable it on the tracer side.
1769 int disable_ust_app_channel(struct ust_app_session
*ua_sess
,
1770 struct ust_app_channel
*ua_chan
, struct ust_app
*app
)
1774 ret
= disable_ust_channel(app
, ua_sess
, ua_chan
);
1779 ua_chan
->enabled
= 0;
1786 * Lookup ust app channel for session and enable it on the tracer side. This
1787 * MUST be called with a RCU read side lock acquired.
1789 static int enable_ust_app_channel(struct ust_app_session
*ua_sess
,
1790 struct ltt_ust_channel
*uchan
, struct ust_app
*app
)
1793 struct lttng_ht_iter iter
;
1794 struct lttng_ht_node_str
*ua_chan_node
;
1795 struct ust_app_channel
*ua_chan
;
1797 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &iter
);
1798 ua_chan_node
= lttng_ht_iter_get_node_str(&iter
);
1799 if (ua_chan_node
== NULL
) {
1800 DBG2("Unable to find channel %s in ust session id %u",
1801 uchan
->name
, ua_sess
->tracing_id
);
1805 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
1807 ret
= enable_ust_channel(app
, ua_sess
, ua_chan
);
1817 * Ask the consumer to create a channel and get it if successful.
1819 * Return 0 on success or else a negative value.
1821 static int do_consumer_create_channel(struct ltt_ust_session
*usess
,
1822 struct ust_app_session
*ua_sess
, struct ust_app_channel
*ua_chan
,
1823 int bitness
, struct ust_registry_session
*registry
)
1826 unsigned int nb_fd
= 0;
1827 struct consumer_socket
*socket
;
1835 health_code_update();
1837 /* Get the right consumer socket for the application. */
1838 socket
= consumer_find_socket_by_bitness(bitness
, usess
->consumer
);
1844 health_code_update();
1846 /* Need one fd for the channel. */
1847 ret
= lttng_fd_get(LTTNG_FD_APPS
, 1);
1849 ERR("Exhausted number of available FD upon create channel");
1854 * Ask consumer to create channel. The consumer will return the number of
1855 * stream we have to expect.
1857 ret
= ust_consumer_ask_channel(ua_sess
, ua_chan
, usess
->consumer
, socket
,
1864 * Compute the number of fd needed before receiving them. It must be 2 per
1865 * stream (2 being the default value here).
1867 nb_fd
= DEFAULT_UST_STREAM_FD_NUM
* ua_chan
->expected_stream_count
;
1869 /* Reserve the amount of file descriptor we need. */
1870 ret
= lttng_fd_get(LTTNG_FD_APPS
, nb_fd
);
1872 ERR("Exhausted number of available FD upon create channel");
1873 goto error_fd_get_stream
;
1876 health_code_update();
1879 * Now get the channel from the consumer. This call wil populate the stream
1880 * list of that channel and set the ust objects.
1882 ret
= ust_consumer_get_channel(socket
, ua_chan
);
1891 lttng_fd_put(LTTNG_FD_APPS
, nb_fd
);
1892 error_fd_get_stream
:
1894 * Initiate a destroy channel on the consumer since we had an error
1895 * handling it on our side. The return value is of no importance since we
1896 * already have a ret value set by the previous error that we need to
1899 (void) ust_consumer_destroy_channel(socket
, ua_chan
);
1901 lttng_fd_put(LTTNG_FD_APPS
, 1);
1903 health_code_update();
1909 * Duplicate the ust data object of the ust app stream and save it in the
1910 * buffer registry stream.
1912 * Return 0 on success or else a negative value.
1914 static int duplicate_stream_object(struct buffer_reg_stream
*reg_stream
,
1915 struct ust_app_stream
*stream
)
1922 /* Reserve the amount of file descriptor we need. */
1923 ret
= lttng_fd_get(LTTNG_FD_APPS
, 2);
1925 ERR("Exhausted number of available FD upon duplicate stream");
1929 /* Duplicate object for stream once the original is in the registry. */
1930 ret
= ustctl_duplicate_ust_object_data(&stream
->obj
,
1931 reg_stream
->obj
.ust
);
1933 ERR("Duplicate stream obj from %p to %p failed with ret %d",
1934 reg_stream
->obj
.ust
, stream
->obj
, ret
);
1935 lttng_fd_put(LTTNG_FD_APPS
, 2);
1938 stream
->handle
= stream
->obj
->handle
;
1945 * Duplicate the ust data object of the ust app. channel and save it in the
1946 * buffer registry channel.
1948 * Return 0 on success or else a negative value.
1950 static int duplicate_channel_object(struct buffer_reg_channel
*reg_chan
,
1951 struct ust_app_channel
*ua_chan
)
1958 /* Need two fds for the channel. */
1959 ret
= lttng_fd_get(LTTNG_FD_APPS
, 1);
1961 ERR("Exhausted number of available FD upon duplicate channel");
1965 /* Duplicate object for stream once the original is in the registry. */
1966 ret
= ustctl_duplicate_ust_object_data(&ua_chan
->obj
, reg_chan
->obj
.ust
);
1968 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
1969 reg_chan
->obj
.ust
, ua_chan
->obj
, ret
);
1972 ua_chan
->handle
= ua_chan
->obj
->handle
;
1977 lttng_fd_put(LTTNG_FD_APPS
, 1);
1983 * For a given channel buffer registry, setup all streams of the given ust
1984 * application channel.
1986 * Return 0 on success or else a negative value.
1988 static int setup_buffer_reg_streams(struct buffer_reg_channel
*reg_chan
,
1989 struct ust_app_channel
*ua_chan
)
1992 struct ust_app_stream
*stream
, *stmp
;
1997 DBG2("UST app setup buffer registry stream");
1999 /* Send all streams to application. */
2000 cds_list_for_each_entry_safe(stream
, stmp
, &ua_chan
->streams
.head
, list
) {
2001 struct buffer_reg_stream
*reg_stream
;
2003 ret
= buffer_reg_stream_create(®_stream
);
2009 * Keep original pointer and nullify it in the stream so the delete
2010 * stream call does not release the object.
2012 reg_stream
->obj
.ust
= stream
->obj
;
2014 buffer_reg_stream_add(reg_stream
, reg_chan
);
2016 /* We don't need the streams anymore. */
2017 cds_list_del(&stream
->list
);
2018 delete_ust_app_stream(-1, stream
);
2026 * Create a buffer registry channel for the given session registry and
2027 * application channel object. If regp pointer is valid, it's set with the
2028 * created object. Important, the created object is NOT added to the session
2029 * registry hash table.
2031 * Return 0 on success else a negative value.
2033 static int create_buffer_reg_channel(struct buffer_reg_session
*reg_sess
,
2034 struct ust_app_channel
*ua_chan
, struct buffer_reg_channel
**regp
)
2037 struct buffer_reg_channel
*reg_chan
= NULL
;
2042 DBG2("UST app creating buffer registry channel for %s", ua_chan
->name
);
2044 /* Create buffer registry channel. */
2045 ret
= buffer_reg_channel_create(ua_chan
->tracing_channel_id
, ®_chan
);
2050 reg_chan
->consumer_key
= ua_chan
->key
;
2052 /* Create and add a channel registry to session. */
2053 ret
= ust_registry_channel_add(reg_sess
->reg
.ust
,
2054 ua_chan
->tracing_channel_id
);
2058 buffer_reg_channel_add(reg_sess
, reg_chan
);
2067 /* Safe because the registry channel object was not added to any HT. */
2068 buffer_reg_channel_destroy(reg_chan
, LTTNG_DOMAIN_UST
);
2074 * Setup buffer registry channel for the given session registry and application
2075 * channel object. If regp pointer is valid, it's set with the created object.
2077 * Return 0 on success else a negative value.
2079 static int setup_buffer_reg_channel(struct buffer_reg_session
*reg_sess
,
2080 struct ust_app_channel
*ua_chan
, struct buffer_reg_channel
*reg_chan
)
2087 assert(ua_chan
->obj
);
2089 DBG2("UST app setup buffer registry channel for %s", ua_chan
->name
);
2091 /* Setup all streams for the registry. */
2092 ret
= setup_buffer_reg_streams(reg_chan
, ua_chan
);
2097 reg_chan
->obj
.ust
= ua_chan
->obj
;
2098 ua_chan
->obj
= NULL
;
2103 buffer_reg_channel_remove(reg_sess
, reg_chan
);
2104 buffer_reg_channel_destroy(reg_chan
, LTTNG_DOMAIN_UST
);
2109 * Send buffer registry channel to the application.
2111 * Return 0 on success else a negative value.
2113 static int send_channel_uid_to_ust(struct buffer_reg_channel
*reg_chan
,
2114 struct ust_app
*app
, struct ust_app_session
*ua_sess
,
2115 struct ust_app_channel
*ua_chan
)
2118 struct buffer_reg_stream
*reg_stream
;
2125 DBG("UST app sending buffer registry channel to ust sock %d", app
->sock
);
2127 ret
= duplicate_channel_object(reg_chan
, ua_chan
);
2132 /* Send channel to the application. */
2133 ret
= ust_consumer_send_channel_to_ust(app
, ua_sess
, ua_chan
);
2138 health_code_update();
2140 /* Send all streams to application. */
2141 pthread_mutex_lock(®_chan
->stream_list_lock
);
2142 cds_list_for_each_entry(reg_stream
, ®_chan
->streams
, lnode
) {
2143 struct ust_app_stream stream
;
2145 ret
= duplicate_stream_object(reg_stream
, &stream
);
2147 goto error_stream_unlock
;
2150 ret
= ust_consumer_send_stream_to_ust(app
, ua_chan
, &stream
);
2152 goto error_stream_unlock
;
2156 * The return value is not important here. This function will output an
2159 (void) release_ust_app_stream(-1, &stream
);
2161 ua_chan
->is_sent
= 1;
2163 error_stream_unlock
:
2164 pthread_mutex_unlock(®_chan
->stream_list_lock
);
2170 * Create and send to the application the created buffers with per UID buffers.
2172 * Return 0 on success else a negative value.
2174 static int create_channel_per_uid(struct ust_app
*app
,
2175 struct ltt_ust_session
*usess
, struct ust_app_session
*ua_sess
,
2176 struct ust_app_channel
*ua_chan
)
2179 struct buffer_reg_uid
*reg_uid
;
2180 struct buffer_reg_channel
*reg_chan
;
2187 DBG("UST app creating channel %s with per UID buffers", ua_chan
->name
);
2189 reg_uid
= buffer_reg_uid_find(usess
->id
, app
->bits_per_long
, app
->uid
);
2191 * The session creation handles the creation of this global registry
2192 * object. If none can be find, there is a code flow problem or a
2197 reg_chan
= buffer_reg_channel_find(ua_chan
->tracing_channel_id
,
2200 /* Create the buffer registry channel object. */
2201 ret
= create_buffer_reg_channel(reg_uid
->registry
, ua_chan
, ®_chan
);
2208 * Create the buffers on the consumer side. This call populates the
2209 * ust app channel object with all streams and data object.
2211 ret
= do_consumer_create_channel(usess
, ua_sess
, ua_chan
,
2212 app
->bits_per_long
, reg_uid
->registry
->reg
.ust
);
2218 * Setup the streams and add it to the session registry.
2220 ret
= setup_buffer_reg_channel(reg_uid
->registry
, ua_chan
, reg_chan
);
2227 /* Send buffers to the application. */
2228 ret
= send_channel_uid_to_ust(reg_chan
, app
, ua_sess
, ua_chan
);
2238 * Create and send to the application the created buffers with per PID buffers.
2240 * Return 0 on success else a negative value.
2242 static int create_channel_per_pid(struct ust_app
*app
,
2243 struct ltt_ust_session
*usess
, struct ust_app_session
*ua_sess
,
2244 struct ust_app_channel
*ua_chan
)
2247 struct ust_registry_session
*registry
;
2254 DBG("UST app creating channel %s with per PID buffers", ua_chan
->name
);
2258 registry
= get_session_registry(ua_sess
);
2261 /* Create and add a new channel registry to session. */
2262 ret
= ust_registry_channel_add(registry
, ua_chan
->key
);
2267 /* Create and get channel on the consumer side. */
2268 ret
= do_consumer_create_channel(usess
, ua_sess
, ua_chan
,
2269 app
->bits_per_long
, registry
);
2274 ret
= send_channel_pid_to_ust(app
, ua_sess
, ua_chan
);
2285 * From an already allocated ust app channel, create the channel buffers if
2286 * need and send it to the application. This MUST be called with a RCU read
2287 * side lock acquired.
2289 * Return 0 on success or else a negative value.
2291 static int do_create_channel(struct ust_app
*app
,
2292 struct ltt_ust_session
*usess
, struct ust_app_session
*ua_sess
,
2293 struct ust_app_channel
*ua_chan
)
2302 /* Handle buffer type before sending the channel to the application. */
2303 switch (usess
->buffer_type
) {
2304 case LTTNG_BUFFER_PER_UID
:
2306 ret
= create_channel_per_uid(app
, usess
, ua_sess
, ua_chan
);
2312 case LTTNG_BUFFER_PER_PID
:
2314 ret
= create_channel_per_pid(app
, usess
, ua_sess
, ua_chan
);
2326 /* Initialize ust objd object using the received handle and add it. */
2327 lttng_ht_node_init_ulong(&ua_chan
->ust_objd_node
, ua_chan
->handle
);
2328 lttng_ht_add_unique_ulong(app
->ust_objd
, &ua_chan
->ust_objd_node
);
2330 /* If channel is not enabled, disable it on the tracer */
2331 if (!ua_chan
->enabled
) {
2332 ret
= disable_ust_channel(app
, ua_sess
, ua_chan
);
2343 * Create UST app channel and create it on the tracer. Set ua_chanp of the
2344 * newly created channel if not NULL.
2346 * Called with UST app session lock held.
2348 * Return 0 on success or else a negative value.
2350 static int create_ust_app_channel(struct ust_app_session
*ua_sess
,
2351 struct ltt_ust_channel
*uchan
, struct ust_app
*app
,
2352 enum lttng_ust_chan_type type
, struct ltt_ust_session
*usess
,
2353 struct ust_app_channel
**ua_chanp
)
2356 struct lttng_ht_iter iter
;
2357 struct lttng_ht_node_str
*ua_chan_node
;
2358 struct ust_app_channel
*ua_chan
;
2360 /* Lookup channel in the ust app session */
2361 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &iter
);
2362 ua_chan_node
= lttng_ht_iter_get_node_str(&iter
);
2363 if (ua_chan_node
!= NULL
) {
2364 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
2368 ua_chan
= alloc_ust_app_channel(uchan
->name
, ua_sess
, &uchan
->attr
);
2369 if (ua_chan
== NULL
) {
2370 /* Only malloc can fail here */
2374 shadow_copy_channel(ua_chan
, uchan
);
2376 /* Set channel type. */
2377 ua_chan
->attr
.type
= type
;
2379 ret
= do_create_channel(app
, usess
, ua_sess
, ua_chan
);
2384 DBG2("UST app create channel %s for PID %d completed", ua_chan
->name
,
2387 /* Only add the channel if successful on the tracer side. */
2388 lttng_ht_add_unique_str(ua_sess
->channels
, &ua_chan
->node
);
2392 *ua_chanp
= ua_chan
;
2395 /* Everything went well. */
2399 delete_ust_app_channel(ua_chan
->is_sent
? app
->sock
: -1, ua_chan
, app
);
2404 * Create UST app event and create it on the tracer side.
2406 * Called with ust app session mutex held.
2409 int create_ust_app_event(struct ust_app_session
*ua_sess
,
2410 struct ust_app_channel
*ua_chan
, struct ltt_ust_event
*uevent
,
2411 struct ust_app
*app
)
2414 struct ust_app_event
*ua_event
;
2416 /* Get event node */
2417 ua_event
= find_ust_app_event(ua_chan
->events
, uevent
->attr
.name
,
2418 uevent
->filter
, uevent
->attr
.loglevel
);
2419 if (ua_event
!= NULL
) {
2424 /* Does not exist so create one */
2425 ua_event
= alloc_ust_app_event(uevent
->attr
.name
, &uevent
->attr
);
2426 if (ua_event
== NULL
) {
2427 /* Only malloc can failed so something is really wrong */
2431 shadow_copy_event(ua_event
, uevent
);
2433 /* Create it on the tracer side */
2434 ret
= create_ust_event(app
, ua_sess
, ua_chan
, ua_event
);
2436 /* Not found previously means that it does not exist on the tracer */
2437 assert(ret
!= -LTTNG_UST_ERR_EXIST
);
2441 add_unique_ust_app_event(ua_chan
, ua_event
);
2443 DBG2("UST app create event %s for PID %d completed", ua_event
->name
,
2450 /* Valid. Calling here is already in a read side lock */
2451 delete_ust_app_event(-1, ua_event
);
2456 * Create UST metadata and open it on the tracer side.
2458 * Called with UST app session lock held and RCU read side lock.
2460 static int create_ust_app_metadata(struct ust_app_session
*ua_sess
,
2461 struct ust_app
*app
, struct consumer_output
*consumer
,
2462 struct ustctl_consumer_channel_attr
*attr
)
2465 struct ust_app_channel
*metadata
;
2466 struct consumer_socket
*socket
;
2467 struct ust_registry_session
*registry
;
2473 registry
= get_session_registry(ua_sess
);
2476 /* Metadata already exists for this registry. */
2477 if (registry
->metadata_key
) {
2482 /* Allocate UST metadata */
2483 metadata
= alloc_ust_app_channel(DEFAULT_METADATA_NAME
, ua_sess
, NULL
);
2485 /* malloc() failed */
2491 /* Set default attributes for metadata. */
2492 metadata
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
2493 metadata
->attr
.subbuf_size
= default_get_metadata_subbuf_size();
2494 metadata
->attr
.num_subbuf
= DEFAULT_METADATA_SUBBUF_NUM
;
2495 metadata
->attr
.switch_timer_interval
= DEFAULT_UST_CHANNEL_SWITCH_TIMER
;
2496 metadata
->attr
.read_timer_interval
= DEFAULT_UST_CHANNEL_READ_TIMER
;
2497 metadata
->attr
.output
= LTTNG_UST_MMAP
;
2498 metadata
->attr
.type
= LTTNG_UST_CHAN_METADATA
;
2500 memcpy(&metadata
->attr
, attr
, sizeof(metadata
->attr
));
2501 metadata
->attr
.output
= LTTNG_UST_MMAP
;
2502 metadata
->attr
.type
= LTTNG_UST_CHAN_METADATA
;
2505 /* Get the right consumer socket for the application. */
2506 socket
= consumer_find_socket_by_bitness(app
->bits_per_long
, consumer
);
2509 goto error_consumer
;
2512 /* Need one fd for the channel. */
2513 ret
= lttng_fd_get(LTTNG_FD_APPS
, 1);
2515 ERR("Exhausted number of available FD upon create metadata");
2520 * Keep metadata key so we can identify it on the consumer side. Assign it
2521 * to the registry *before* we ask the consumer so we avoid the race of the
2522 * consumer requesting the metadata and the ask_channel call on our side
2523 * did not returned yet.
2525 registry
->metadata_key
= metadata
->key
;
2528 * Ask the metadata channel creation to the consumer. The metadata object
2529 * will be created by the consumer and kept their. However, the stream is
2530 * never added or monitored until we do a first push metadata to the
2533 ret
= ust_consumer_ask_channel(ua_sess
, metadata
, consumer
, socket
,
2537 * Safe because the metadata obj pointer is not set so the delete below
2538 * will not put a FD back again.
2540 lttng_fd_put(LTTNG_FD_APPS
, 1);
2541 goto error_consumer
;
2545 * The setup command will make the metadata stream be sent to the relayd,
2546 * if applicable, and the thread managing the metadatas. This is important
2547 * because after this point, if an error occurs, the only way the stream
2548 * can be deleted is to be monitored in the consumer.
2550 ret
= consumer_setup_metadata(socket
, metadata
->key
);
2553 * Safe because the metadata obj pointer is not set so the delete below
2554 * will not put a FD back again.
2556 lttng_fd_put(LTTNG_FD_APPS
, 1);
2557 goto error_consumer
;
2560 DBG2("UST metadata with key %" PRIu64
" created for app pid %d",
2561 metadata
->key
, app
->pid
);
2564 delete_ust_app_channel(-1, metadata
, app
);
2570 * Return pointer to traceable apps list.
2572 struct lttng_ht
*ust_app_get_ht(void)
2578 * Return ust app pointer or NULL if not found. RCU read side lock MUST be
2579 * acquired before calling this function.
2581 struct ust_app
*ust_app_find_by_pid(pid_t pid
)
2583 struct ust_app
*app
= NULL
;
2584 struct lttng_ht_node_ulong
*node
;
2585 struct lttng_ht_iter iter
;
2587 lttng_ht_lookup(ust_app_ht
, (void *)((unsigned long) pid
), &iter
);
2588 node
= lttng_ht_iter_get_node_ulong(&iter
);
2590 DBG2("UST app no found with pid %d", pid
);
2594 DBG2("Found UST app by pid %d", pid
);
2596 app
= caa_container_of(node
, struct ust_app
, pid_n
);
2603 * Allocate and init an UST app object using the registration information and
2604 * the command socket. This is called when the command socket connects to the
2607 * The object is returned on success or else NULL.
2609 struct ust_app
*ust_app_create(struct ust_register_msg
*msg
, int sock
)
2611 struct ust_app
*lta
= NULL
;
2616 DBG3("UST app creating application for socket %d", sock
);
2618 if ((msg
->bits_per_long
== 64 &&
2619 (uatomic_read(&ust_consumerd64_fd
) == -EINVAL
))
2620 || (msg
->bits_per_long
== 32 &&
2621 (uatomic_read(&ust_consumerd32_fd
) == -EINVAL
))) {
2622 ERR("Registration failed: application \"%s\" (pid: %d) has "
2623 "%d-bit long, but no consumerd for this size is available.\n",
2624 msg
->name
, msg
->pid
, msg
->bits_per_long
);
2628 lta
= zmalloc(sizeof(struct ust_app
));
2634 lta
->ppid
= msg
->ppid
;
2635 lta
->uid
= msg
->uid
;
2636 lta
->gid
= msg
->gid
;
2638 lta
->bits_per_long
= msg
->bits_per_long
;
2639 lta
->uint8_t_alignment
= msg
->uint8_t_alignment
;
2640 lta
->uint16_t_alignment
= msg
->uint16_t_alignment
;
2641 lta
->uint32_t_alignment
= msg
->uint32_t_alignment
;
2642 lta
->uint64_t_alignment
= msg
->uint64_t_alignment
;
2643 lta
->long_alignment
= msg
->long_alignment
;
2644 lta
->byte_order
= msg
->byte_order
;
2646 lta
->v_major
= msg
->major
;
2647 lta
->v_minor
= msg
->minor
;
2648 lta
->sessions
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
2649 lta
->ust_objd
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
2650 lta
->notify_sock
= -1;
2652 /* Copy name and make sure it's NULL terminated. */
2653 strncpy(lta
->name
, msg
->name
, sizeof(lta
->name
));
2654 lta
->name
[UST_APP_PROCNAME_LEN
] = '\0';
2657 * Before this can be called, when receiving the registration information,
2658 * the application compatibility is checked. So, at this point, the
2659 * application can work with this session daemon.
2661 lta
->compatible
= 1;
2663 lta
->pid
= msg
->pid
;
2664 lttng_ht_node_init_ulong(<a
->pid_n
, (unsigned long) lta
->pid
);
2666 lttng_ht_node_init_ulong(<a
->sock_n
, (unsigned long) lta
->sock
);
2668 CDS_INIT_LIST_HEAD(<a
->teardown_head
);
2675 * For a given application object, add it to every hash table.
2677 void ust_app_add(struct ust_app
*app
)
2680 assert(app
->notify_sock
>= 0);
2685 * On a re-registration, we want to kick out the previous registration of
2688 lttng_ht_add_replace_ulong(ust_app_ht
, &app
->pid_n
);
2691 * The socket _should_ be unique until _we_ call close. So, a add_unique
2692 * for the ust_app_ht_by_sock is used which asserts fail if the entry was
2693 * already in the table.
2695 lttng_ht_add_unique_ulong(ust_app_ht_by_sock
, &app
->sock_n
);
2697 /* Add application to the notify socket hash table. */
2698 lttng_ht_node_init_ulong(&app
->notify_sock_n
, app
->notify_sock
);
2699 lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock
, &app
->notify_sock_n
);
2701 DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s "
2702 "notify_sock:%d (version %d.%d)", app
->pid
, app
->ppid
, app
->uid
,
2703 app
->gid
, app
->sock
, app
->name
, app
->notify_sock
, app
->v_major
,
2710 * Set the application version into the object.
2712 * Return 0 on success else a negative value either an errno code or a
2713 * LTTng-UST error code.
2715 int ust_app_version(struct ust_app
*app
)
2721 ret
= ustctl_tracer_version(app
->sock
, &app
->version
);
2723 if (ret
!= -LTTNG_UST_ERR_EXITING
&& ret
!= -EPIPE
) {
2724 ERR("UST app %d verson failed with ret %d", app
->sock
, ret
);
2726 DBG3("UST app %d verion failed. Application is dead", app
->sock
);
2734 * Unregister app by removing it from the global traceable app list and freeing
2737 * The socket is already closed at this point so no close to sock.
2739 void ust_app_unregister(int sock
)
2741 struct ust_app
*lta
;
2742 struct lttng_ht_node_ulong
*node
;
2743 struct lttng_ht_iter iter
;
2744 struct ust_app_session
*ua_sess
;
2749 /* Get the node reference for a call_rcu */
2750 lttng_ht_lookup(ust_app_ht_by_sock
, (void *)((unsigned long) sock
), &iter
);
2751 node
= lttng_ht_iter_get_node_ulong(&iter
);
2754 lta
= caa_container_of(node
, struct ust_app
, sock_n
);
2755 DBG("PID %d unregistering with sock %d", lta
->pid
, sock
);
2757 /* Remove application from PID hash table */
2758 ret
= lttng_ht_del(ust_app_ht_by_sock
, &iter
);
2762 * Remove application from notify hash table. The thread handling the
2763 * notify socket could have deleted the node so ignore on error because
2764 * either way it's valid. The close of that socket is handled by the other
2767 iter
.iter
.node
= <a
->notify_sock_n
.node
;
2768 (void) lttng_ht_del(ust_app_ht_by_notify_sock
, &iter
);
2771 * Ignore return value since the node might have been removed before by an
2772 * add replace during app registration because the PID can be reassigned by
2775 iter
.iter
.node
= <a
->pid_n
.node
;
2776 ret
= lttng_ht_del(ust_app_ht
, &iter
);
2778 DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
2782 /* Remove sessions so they are not visible during deletion.*/
2783 cds_lfht_for_each_entry(lta
->sessions
->ht
, &iter
.iter
, ua_sess
,
2785 struct ust_registry_session
*registry
;
2787 ret
= lttng_ht_del(lta
->sessions
, &iter
);
2789 /* The session was already removed so scheduled for teardown. */
2794 * Add session to list for teardown. This is safe since at this point we
2795 * are the only one using this list.
2797 pthread_mutex_lock(&ua_sess
->lock
);
2800 * Normally, this is done in the delete session process which is
2801 * executed in the call rcu below. However, upon registration we can't
2802 * afford to wait for the grace period before pushing data or else the
2803 * data pending feature can race between the unregistration and stop
2804 * command where the data pending command is sent *before* the grace
2807 * The close metadata below nullifies the metadata pointer in the
2808 * session so the delete session will NOT push/close a second time.
2810 registry
= get_session_registry(ua_sess
);
2812 /* Push metadata for application before freeing the application. */
2813 (void) push_metadata(registry
, ua_sess
->consumer
);
2816 * Don't ask to close metadata for global per UID buffers. Close
2817 * metadata only on destroy trace session in this case.
2819 if (ua_sess
->buffer_type
!= LTTNG_BUFFER_PER_UID
) {
2820 /* And ask to close it for this session registry. */
2821 (void) close_metadata(registry
, ua_sess
->consumer
);
2825 cds_list_add(&ua_sess
->teardown_node
, <a
->teardown_head
);
2826 pthread_mutex_unlock(&ua_sess
->lock
);
2830 call_rcu(<a
->pid_n
.head
, delete_ust_app_rcu
);
2837 * Return traceable_app_count
2839 unsigned long ust_app_list_count(void)
2841 unsigned long count
;
2844 count
= lttng_ht_get_count(ust_app_ht
);
2851 * Fill events array with all events name of all registered apps.
2853 int ust_app_list_events(struct lttng_event
**events
)
2856 size_t nbmem
, count
= 0;
2857 struct lttng_ht_iter iter
;
2858 struct ust_app
*app
;
2859 struct lttng_event
*tmp_event
;
2861 nbmem
= UST_APP_EVENT_LIST_SIZE
;
2862 tmp_event
= zmalloc(nbmem
* sizeof(struct lttng_event
));
2863 if (tmp_event
== NULL
) {
2864 PERROR("zmalloc ust app events");
2871 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
2872 struct lttng_ust_tracepoint_iter uiter
;
2874 health_code_update();
2876 if (!app
->compatible
) {
2878 * TODO: In time, we should notice the caller of this error by
2879 * telling him that this is a version error.
2883 handle
= ustctl_tracepoint_list(app
->sock
);
2885 if (handle
!= -EPIPE
&& handle
!= -LTTNG_UST_ERR_EXITING
) {
2886 ERR("UST app list events getting handle failed for app pid %d",
2892 while ((ret
= ustctl_tracepoint_list_get(app
->sock
, handle
,
2893 &uiter
)) != -LTTNG_UST_ERR_NOENT
) {
2894 /* Handle ustctl error. */
2897 if (ret
!= -LTTNG_UST_ERR_EXITING
|| ret
!= -EPIPE
) {
2898 ERR("UST app tp list get failed for app %d with ret %d",
2901 DBG3("UST app tp list get failed. Application is dead");
2906 health_code_update();
2907 if (count
>= nbmem
) {
2908 /* In case the realloc fails, we free the memory */
2911 DBG2("Reallocating event list from %zu to %zu entries", nbmem
,
2914 ptr
= realloc(tmp_event
, nbmem
* sizeof(struct lttng_event
));
2916 PERROR("realloc ust app events");
2923 memcpy(tmp_event
[count
].name
, uiter
.name
, LTTNG_UST_SYM_NAME_LEN
);
2924 tmp_event
[count
].loglevel
= uiter
.loglevel
;
2925 tmp_event
[count
].type
= (enum lttng_event_type
) LTTNG_UST_TRACEPOINT
;
2926 tmp_event
[count
].pid
= app
->pid
;
2927 tmp_event
[count
].enabled
= -1;
2933 *events
= tmp_event
;
2935 DBG2("UST app list events done (%zu events)", count
);
2940 health_code_update();
2945 * Fill events array with all events name of all registered apps.
2947 int ust_app_list_event_fields(struct lttng_event_field
**fields
)
2950 size_t nbmem
, count
= 0;
2951 struct lttng_ht_iter iter
;
2952 struct ust_app
*app
;
2953 struct lttng_event_field
*tmp_event
;
2955 nbmem
= UST_APP_EVENT_LIST_SIZE
;
2956 tmp_event
= zmalloc(nbmem
* sizeof(struct lttng_event_field
));
2957 if (tmp_event
== NULL
) {
2958 PERROR("zmalloc ust app event fields");
2965 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
2966 struct lttng_ust_field_iter uiter
;
2968 health_code_update();
2970 if (!app
->compatible
) {
2972 * TODO: In time, we should notice the caller of this error by
2973 * telling him that this is a version error.
2977 handle
= ustctl_tracepoint_field_list(app
->sock
);
2979 if (handle
!= -EPIPE
&& handle
!= -LTTNG_UST_ERR_EXITING
) {
2980 ERR("UST app list field getting handle failed for app pid %d",
2986 while ((ret
= ustctl_tracepoint_field_list_get(app
->sock
, handle
,
2987 &uiter
)) != -LTTNG_UST_ERR_NOENT
) {
2988 /* Handle ustctl error. */
2991 if (ret
!= -LTTNG_UST_ERR_EXITING
|| ret
!= -EPIPE
) {
2992 ERR("UST app tp list field failed for app %d with ret %d",
2995 DBG3("UST app tp list field failed. Application is dead");
3000 health_code_update();
3001 if (count
>= nbmem
) {
3002 /* In case the realloc fails, we free the memory */
3005 DBG2("Reallocating event field list from %zu to %zu entries", nbmem
,
3008 ptr
= realloc(tmp_event
, nbmem
* sizeof(struct lttng_event_field
));
3010 PERROR("realloc ust app event fields");
3018 memcpy(tmp_event
[count
].field_name
, uiter
.field_name
, LTTNG_UST_SYM_NAME_LEN
);
3019 tmp_event
[count
].type
= uiter
.type
;
3020 tmp_event
[count
].nowrite
= uiter
.nowrite
;
3022 memcpy(tmp_event
[count
].event
.name
, uiter
.event_name
, LTTNG_UST_SYM_NAME_LEN
);
3023 tmp_event
[count
].event
.loglevel
= uiter
.loglevel
;
3024 tmp_event
[count
].event
.type
= LTTNG_UST_TRACEPOINT
;
3025 tmp_event
[count
].event
.pid
= app
->pid
;
3026 tmp_event
[count
].event
.enabled
= -1;
3032 *fields
= tmp_event
;
3034 DBG2("UST app list event fields done (%zu events)", count
);
3039 health_code_update();
3044 * Free and clean all traceable apps of the global list.
3046 void ust_app_clean_list(void)
3049 struct ust_app
*app
;
3050 struct lttng_ht_iter iter
;
3052 DBG2("UST app cleaning registered apps hash table");
3056 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3057 ret
= lttng_ht_del(ust_app_ht
, &iter
);
3059 call_rcu(&app
->pid_n
.head
, delete_ust_app_rcu
);
3062 /* Cleanup socket hash table */
3063 cds_lfht_for_each_entry(ust_app_ht_by_sock
->ht
, &iter
.iter
, app
,
3065 ret
= lttng_ht_del(ust_app_ht_by_sock
, &iter
);
3069 /* Cleanup notify socket hash table */
3070 cds_lfht_for_each_entry(ust_app_ht_by_notify_sock
->ht
, &iter
.iter
, app
,
3071 notify_sock_n
.node
) {
3072 ret
= lttng_ht_del(ust_app_ht_by_notify_sock
, &iter
);
3076 /* Destroy is done only when the ht is empty */
3077 lttng_ht_destroy(ust_app_ht
);
3078 lttng_ht_destroy(ust_app_ht_by_sock
);
3079 lttng_ht_destroy(ust_app_ht_by_notify_sock
);
3085 * Init UST app hash table.
3087 void ust_app_ht_alloc(void)
3089 ust_app_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
3090 ust_app_ht_by_sock
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
3091 ust_app_ht_by_notify_sock
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
3095 * For a specific UST session, disable the channel for all registered apps.
3097 int ust_app_disable_channel_glb(struct ltt_ust_session
*usess
,
3098 struct ltt_ust_channel
*uchan
)
3101 struct lttng_ht_iter iter
;
3102 struct lttng_ht_node_str
*ua_chan_node
;
3103 struct ust_app
*app
;
3104 struct ust_app_session
*ua_sess
;
3105 struct ust_app_channel
*ua_chan
;
3107 if (usess
== NULL
|| uchan
== NULL
) {
3108 ERR("Disabling UST global channel with NULL values");
3113 DBG2("UST app disabling channel %s from global domain for session id %d",
3114 uchan
->name
, usess
->id
);
3118 /* For every registered applications */
3119 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3120 struct lttng_ht_iter uiter
;
3121 if (!app
->compatible
) {
3123 * TODO: In time, we should notice the caller of this error by
3124 * telling him that this is a version error.
3128 ua_sess
= lookup_session_by_app(usess
, app
);
3129 if (ua_sess
== NULL
) {
3134 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
3135 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
3136 /* If the session if found for the app, the channel must be there */
3137 assert(ua_chan_node
);
3139 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
3140 /* The channel must not be already disabled */
3141 assert(ua_chan
->enabled
== 1);
3143 /* Disable channel onto application */
3144 ret
= disable_ust_app_channel(ua_sess
, ua_chan
, app
);
3146 /* XXX: We might want to report this error at some point... */
3158 * For a specific UST session, enable the channel for all registered apps.
3160 int ust_app_enable_channel_glb(struct ltt_ust_session
*usess
,
3161 struct ltt_ust_channel
*uchan
)
3164 struct lttng_ht_iter iter
;
3165 struct ust_app
*app
;
3166 struct ust_app_session
*ua_sess
;
3168 if (usess
== NULL
|| uchan
== NULL
) {
3169 ERR("Adding UST global channel to NULL values");
3174 DBG2("UST app enabling channel %s to global domain for session id %d",
3175 uchan
->name
, usess
->id
);
3179 /* For every registered applications */
3180 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3181 if (!app
->compatible
) {
3183 * TODO: In time, we should notice the caller of this error by
3184 * telling him that this is a version error.
3188 ua_sess
= lookup_session_by_app(usess
, app
);
3189 if (ua_sess
== NULL
) {
3193 /* Enable channel onto application */
3194 ret
= enable_ust_app_channel(ua_sess
, uchan
, app
);
3196 /* XXX: We might want to report this error at some point... */
3208 * Disable an event in a channel and for a specific session.
3210 int ust_app_disable_event_glb(struct ltt_ust_session
*usess
,
3211 struct ltt_ust_channel
*uchan
, struct ltt_ust_event
*uevent
)
3214 struct lttng_ht_iter iter
, uiter
;
3215 struct lttng_ht_node_str
*ua_chan_node
, *ua_event_node
;
3216 struct ust_app
*app
;
3217 struct ust_app_session
*ua_sess
;
3218 struct ust_app_channel
*ua_chan
;
3219 struct ust_app_event
*ua_event
;
3221 DBG("UST app disabling event %s for all apps in channel "
3222 "%s for session id %d", uevent
->attr
.name
, uchan
->name
, usess
->id
);
3226 /* For all registered applications */
3227 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3228 if (!app
->compatible
) {
3230 * TODO: In time, we should notice the caller of this error by
3231 * telling him that this is a version error.
3235 ua_sess
= lookup_session_by_app(usess
, app
);
3236 if (ua_sess
== NULL
) {
3241 /* Lookup channel in the ust app session */
3242 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
3243 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
3244 if (ua_chan_node
== NULL
) {
3245 DBG2("Channel %s not found in session id %d for app pid %d."
3246 "Skipping", uchan
->name
, usess
->id
, app
->pid
);
3249 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
3251 lttng_ht_lookup(ua_chan
->events
, (void *)uevent
->attr
.name
, &uiter
);
3252 ua_event_node
= lttng_ht_iter_get_node_str(&uiter
);
3253 if (ua_event_node
== NULL
) {
3254 DBG2("Event %s not found in channel %s for app pid %d."
3255 "Skipping", uevent
->attr
.name
, uchan
->name
, app
->pid
);
3258 ua_event
= caa_container_of(ua_event_node
, struct ust_app_event
, node
);
3260 ret
= disable_ust_app_event(ua_sess
, ua_event
, app
);
3262 /* XXX: Report error someday... */
3273 * For a specific UST session and UST channel, the event for all
3276 int ust_app_disable_all_event_glb(struct ltt_ust_session
*usess
,
3277 struct ltt_ust_channel
*uchan
)
3280 struct lttng_ht_iter iter
, uiter
;
3281 struct lttng_ht_node_str
*ua_chan_node
;
3282 struct ust_app
*app
;
3283 struct ust_app_session
*ua_sess
;
3284 struct ust_app_channel
*ua_chan
;
3285 struct ust_app_event
*ua_event
;
3287 DBG("UST app disabling all event for all apps in channel "
3288 "%s for session id %d", uchan
->name
, usess
->id
);
3292 /* For all registered applications */
3293 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3294 if (!app
->compatible
) {
3296 * TODO: In time, we should notice the caller of this error by
3297 * telling him that this is a version error.
3301 ua_sess
= lookup_session_by_app(usess
, app
);
3303 /* The application has problem or is probably dead. */
3307 /* Lookup channel in the ust app session */
3308 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
3309 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
3310 /* If the channel is not found, there is a code flow error */
3311 assert(ua_chan_node
);
3313 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
3315 /* Disable each events of channel */
3316 cds_lfht_for_each_entry(ua_chan
->events
->ht
, &uiter
.iter
, ua_event
,
3318 ret
= disable_ust_app_event(ua_sess
, ua_event
, app
);
3320 /* XXX: Report error someday... */
3332 * For a specific UST session, create the channel for all registered apps.
3334 int ust_app_create_channel_glb(struct ltt_ust_session
*usess
,
3335 struct ltt_ust_channel
*uchan
)
3337 int ret
= 0, created
;
3338 struct lttng_ht_iter iter
;
3339 struct ust_app
*app
;
3340 struct ust_app_session
*ua_sess
= NULL
;
3342 /* Very wrong code flow */
3346 DBG2("UST app adding channel %s to UST domain for session id %d",
3347 uchan
->name
, usess
->id
);
3351 /* For every registered applications */
3352 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3353 if (!app
->compatible
) {
3355 * TODO: In time, we should notice the caller of this error by
3356 * telling him that this is a version error.
3361 * Create session on the tracer side and add it to app session HT. Note
3362 * that if session exist, it will simply return a pointer to the ust
3365 ret
= create_ust_app_session(usess
, app
, &ua_sess
, &created
);
3370 * The application's socket is not valid. Either a bad socket
3371 * or a timeout on it. We can't inform the caller that for a
3372 * specific app, the session failed so lets continue here.
3377 goto error_rcu_unlock
;
3382 pthread_mutex_lock(&ua_sess
->lock
);
3383 if (!strncmp(uchan
->name
, DEFAULT_METADATA_NAME
,
3384 sizeof(uchan
->name
))) {
3385 struct ustctl_consumer_channel_attr attr
;
3386 copy_channel_attr_to_ustctl(&attr
, &uchan
->attr
);
3387 ret
= create_ust_app_metadata(ua_sess
, app
, usess
->consumer
,
3390 /* Create channel onto application. We don't need the chan ref. */
3391 ret
= create_ust_app_channel(ua_sess
, uchan
, app
,
3392 LTTNG_UST_CHAN_PER_CPU
, usess
, NULL
);
3394 pthread_mutex_unlock(&ua_sess
->lock
);
3396 if (ret
== -ENOMEM
) {
3397 /* No more memory is a fatal error. Stop right now. */
3398 goto error_rcu_unlock
;
3400 /* Cleanup the created session if it's the case. */
3402 destroy_app_session(app
, ua_sess
);
3413 * Enable event for a specific session and channel on the tracer.
3415 int ust_app_enable_event_glb(struct ltt_ust_session
*usess
,
3416 struct ltt_ust_channel
*uchan
, struct ltt_ust_event
*uevent
)
3419 struct lttng_ht_iter iter
, uiter
;
3420 struct lttng_ht_node_str
*ua_chan_node
;
3421 struct ust_app
*app
;
3422 struct ust_app_session
*ua_sess
;
3423 struct ust_app_channel
*ua_chan
;
3424 struct ust_app_event
*ua_event
;
3426 DBG("UST app enabling event %s for all apps for session id %d",
3427 uevent
->attr
.name
, usess
->id
);
3430 * NOTE: At this point, this function is called only if the session and
3431 * channel passed are already created for all apps. and enabled on the
3437 /* For all registered applications */
3438 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3439 if (!app
->compatible
) {
3441 * TODO: In time, we should notice the caller of this error by
3442 * telling him that this is a version error.
3446 ua_sess
= lookup_session_by_app(usess
, app
);
3448 /* The application has problem or is probably dead. */
3452 pthread_mutex_lock(&ua_sess
->lock
);
3454 /* Lookup channel in the ust app session */
3455 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
3456 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
3457 /* If the channel is not found, there is a code flow error */
3458 assert(ua_chan_node
);
3460 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
3462 /* Get event node */
3463 ua_event
= find_ust_app_event(ua_chan
->events
, uevent
->attr
.name
,
3464 uevent
->filter
, uevent
->attr
.loglevel
);
3465 if (ua_event
== NULL
) {
3466 DBG3("UST app enable event %s not found for app PID %d."
3467 "Skipping app", uevent
->attr
.name
, app
->pid
);
3471 ret
= enable_ust_app_event(ua_sess
, ua_event
, app
);
3473 pthread_mutex_unlock(&ua_sess
->lock
);
3477 pthread_mutex_unlock(&ua_sess
->lock
);
3486 * For a specific existing UST session and UST channel, creates the event for
3487 * all registered apps.
3489 int ust_app_create_event_glb(struct ltt_ust_session
*usess
,
3490 struct ltt_ust_channel
*uchan
, struct ltt_ust_event
*uevent
)
3493 struct lttng_ht_iter iter
, uiter
;
3494 struct lttng_ht_node_str
*ua_chan_node
;
3495 struct ust_app
*app
;
3496 struct ust_app_session
*ua_sess
;
3497 struct ust_app_channel
*ua_chan
;
3499 DBG("UST app creating event %s for all apps for session id %d",
3500 uevent
->attr
.name
, usess
->id
);
3504 /* For all registered applications */
3505 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3506 if (!app
->compatible
) {
3508 * TODO: In time, we should notice the caller of this error by
3509 * telling him that this is a version error.
3513 ua_sess
= lookup_session_by_app(usess
, app
);
3515 /* The application has problem or is probably dead. */
3519 pthread_mutex_lock(&ua_sess
->lock
);
3520 /* Lookup channel in the ust app session */
3521 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
3522 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
3523 /* If the channel is not found, there is a code flow error */
3524 assert(ua_chan_node
);
3526 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
3528 ret
= create_ust_app_event(ua_sess
, ua_chan
, uevent
, app
);
3529 pthread_mutex_unlock(&ua_sess
->lock
);
3531 if (ret
!= -LTTNG_UST_ERR_EXIST
) {
3532 /* Possible value at this point: -ENOMEM. If so, we stop! */
3535 DBG2("UST app event %s already exist on app PID %d",
3536 uevent
->attr
.name
, app
->pid
);
3547 * Start tracing for a specific UST session and app.
3549 int ust_app_start_trace(struct ltt_ust_session
*usess
, struct ust_app
*app
)
3552 struct ust_app_session
*ua_sess
;
3554 DBG("Starting tracing for ust app pid %d", app
->pid
);
3558 if (!app
->compatible
) {
3562 ua_sess
= lookup_session_by_app(usess
, app
);
3563 if (ua_sess
== NULL
) {
3564 /* The session is in teardown process. Ignore and continue. */
3568 pthread_mutex_lock(&ua_sess
->lock
);
3570 /* Upon restart, we skip the setup, already done */
3571 if (ua_sess
->started
) {
3575 /* Create directories if consumer is LOCAL and has a path defined. */
3576 if (usess
->consumer
->type
== CONSUMER_DST_LOCAL
&&
3577 strlen(usess
->consumer
->dst
.trace_path
) > 0) {
3578 ret
= run_as_mkdir_recursive(usess
->consumer
->dst
.trace_path
,
3579 S_IRWXU
| S_IRWXG
, ua_sess
->euid
, ua_sess
->egid
);
3581 if (ret
!= -EEXIST
) {
3582 ERR("Trace directory creation error");
3589 * Create the metadata for the application. This returns gracefully if a
3590 * metadata was already set for the session.
3592 ret
= create_ust_app_metadata(ua_sess
, app
, usess
->consumer
, NULL
);
3597 health_code_update();
3600 /* This start the UST tracing */
3601 ret
= ustctl_start_session(app
->sock
, ua_sess
->handle
);
3603 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
3604 ERR("Error starting tracing for app pid: %d (ret: %d)",
3607 DBG("UST app start session failed. Application is dead.");
3612 /* Indicate that the session has been started once */
3613 ua_sess
->started
= 1;
3615 pthread_mutex_unlock(&ua_sess
->lock
);
3617 health_code_update();
3619 /* Quiescent wait after starting trace */
3620 ret
= ustctl_wait_quiescent(app
->sock
);
3621 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
3622 ERR("UST app wait quiescent failed for app pid %d ret %d",
3628 health_code_update();
3632 pthread_mutex_unlock(&ua_sess
->lock
);
3634 health_code_update();
3639 * Stop tracing for a specific UST session and app.
3641 int ust_app_stop_trace(struct ltt_ust_session
*usess
, struct ust_app
*app
)
3644 struct lttng_ht_iter iter
;
3645 struct ust_app_session
*ua_sess
;
3646 struct ust_app_channel
*ua_chan
;
3647 struct ust_registry_session
*registry
;
3649 DBG("Stopping tracing for ust app pid %d", app
->pid
);
3653 if (!app
->compatible
) {
3654 goto end_no_session
;
3657 ua_sess
= lookup_session_by_app(usess
, app
);
3658 if (ua_sess
== NULL
) {
3659 goto end_no_session
;
3662 pthread_mutex_lock(&ua_sess
->lock
);
3665 * If started = 0, it means that stop trace has been called for a session
3666 * that was never started. It's possible since we can have a fail start
3667 * from either the application manager thread or the command thread. Simply
3668 * indicate that this is a stop error.
3670 if (!ua_sess
->started
) {
3671 goto error_rcu_unlock
;
3674 health_code_update();
3676 /* This inhibits UST tracing */
3677 ret
= ustctl_stop_session(app
->sock
, ua_sess
->handle
);
3679 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
3680 ERR("Error stopping tracing for app pid: %d (ret: %d)",
3683 DBG("UST app stop session failed. Application is dead.");
3685 goto error_rcu_unlock
;
3688 health_code_update();
3690 /* Quiescent wait after stopping trace */
3691 ret
= ustctl_wait_quiescent(app
->sock
);
3692 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
3693 ERR("UST app wait quiescent failed for app pid %d ret %d",
3697 health_code_update();
3699 /* Flushing buffers */
3700 cds_lfht_for_each_entry(ua_sess
->channels
->ht
, &iter
.iter
, ua_chan
,
3702 health_code_update();
3703 assert(ua_chan
->is_sent
);
3704 ret
= ustctl_sock_flush_buffer(app
->sock
, ua_chan
->obj
);
3706 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
3707 ERR("UST app PID %d channel %s flush failed with ret %d",
3708 app
->pid
, ua_chan
->name
, ret
);
3710 DBG3("UST app failed to flush %s. Application is dead.",
3712 /* No need to continue. */
3715 /* Continuing flushing all buffers */
3720 health_code_update();
3722 registry
= get_session_registry(ua_sess
);
3724 /* Push metadata for application before freeing the application. */
3725 (void) push_metadata(registry
, ua_sess
->consumer
);
3727 pthread_mutex_unlock(&ua_sess
->lock
);
3730 health_code_update();
3734 pthread_mutex_unlock(&ua_sess
->lock
);
3736 health_code_update();
3741 * Destroy a specific UST session in apps.
3743 static int destroy_trace(struct ltt_ust_session
*usess
, struct ust_app
*app
)
3746 struct ust_app_session
*ua_sess
;
3747 struct lttng_ht_iter iter
;
3748 struct lttng_ht_node_ulong
*node
;
3750 DBG("Destroy tracing for ust app pid %d", app
->pid
);
3754 if (!app
->compatible
) {
3758 __lookup_session_by_app(usess
, app
, &iter
);
3759 node
= lttng_ht_iter_get_node_ulong(&iter
);
3761 /* Session is being or is deleted. */
3764 ua_sess
= caa_container_of(node
, struct ust_app_session
, node
);
3766 health_code_update();
3767 destroy_app_session(app
, ua_sess
);
3769 health_code_update();
3771 /* Quiescent wait after stopping trace */
3772 ret
= ustctl_wait_quiescent(app
->sock
);
3773 if (ret
< 0 && ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
3774 ERR("UST app wait quiescent failed for app pid %d ret %d",
3779 health_code_update();
3784 * Start tracing for the UST session.
3786 int ust_app_start_trace_all(struct ltt_ust_session
*usess
)
3789 struct lttng_ht_iter iter
;
3790 struct ust_app
*app
;
3792 DBG("Starting all UST traces");
3796 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3797 ret
= ust_app_start_trace(usess
, app
);
3799 /* Continue to next apps even on error */
3810 * Start tracing for the UST session.
3812 int ust_app_stop_trace_all(struct ltt_ust_session
*usess
)
3815 struct lttng_ht_iter iter
;
3816 struct ust_app
*app
;
3818 DBG("Stopping all UST traces");
3822 /* Flush all per UID buffers associated to that session. */
3823 if (usess
->buffer_type
== LTTNG_BUFFER_PER_UID
) {
3824 struct buffer_reg_uid
*reg
;
3825 cds_list_for_each_entry(reg
, &usess
->buffer_reg_uid_list
, lnode
) {
3826 struct buffer_reg_channel
*reg_chan
;
3827 struct consumer_socket
*socket
;
3829 /* Get consumer socket to use to push the metadata.*/
3830 socket
= consumer_find_socket_by_bitness(reg
->bits_per_long
,
3833 /* Ignore request if no consumer is found for the session. */
3837 cds_lfht_for_each_entry(reg
->registry
->channels
->ht
, &iter
.iter
,
3838 reg_chan
, node
.node
) {
3840 * The following call will print error values so the return
3841 * code is of little importance because whatever happens, we
3842 * have to try them all.
3844 (void) consumer_flush_channel(socket
, reg_chan
->consumer_key
);
3849 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3850 ret
= ust_app_stop_trace(usess
, app
);
3852 /* Continue to next apps even on error */
3863 * Destroy app UST session.
3865 int ust_app_destroy_trace_all(struct ltt_ust_session
*usess
)
3868 struct lttng_ht_iter iter
;
3869 struct ust_app
*app
;
3871 DBG("Destroy all UST traces");
3875 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
3876 ret
= destroy_trace(usess
, app
);
3878 /* Continue to next apps even on error */
3889 * Add channels/events from UST global domain to registered apps at sock.
3891 void ust_app_global_update(struct ltt_ust_session
*usess
, int sock
)
3894 struct lttng_ht_iter iter
, uiter
, iter_ctx
;
3895 struct ust_app
*app
;
3896 struct ust_app_session
*ua_sess
= NULL
;
3897 struct ust_app_channel
*ua_chan
;
3898 struct ust_app_event
*ua_event
;
3899 struct ust_app_ctx
*ua_ctx
;
3904 DBG2("UST app global update for app sock %d for session id %d", sock
,
3909 app
= find_app_by_sock(sock
);
3912 * Application can be unregistered before so this is possible hence
3913 * simply stopping the update.
3915 DBG3("UST app update failed to find app sock %d", sock
);
3919 if (!app
->compatible
) {
3923 ret
= create_ust_app_session(usess
, app
, &ua_sess
, NULL
);
3925 /* Tracer is probably gone or ENOMEM. */
3930 pthread_mutex_lock(&ua_sess
->lock
);
3933 * We can iterate safely here over all UST app session since the create ust
3934 * app session above made a shadow copy of the UST global domain from the
3937 cds_lfht_for_each_entry(ua_sess
->channels
->ht
, &iter
.iter
, ua_chan
,
3940 * For a metadata channel, handle it differently.
3942 if (!strncmp(ua_chan
->name
, DEFAULT_METADATA_NAME
,
3943 sizeof(ua_chan
->name
))) {
3944 ret
= create_ust_app_metadata(ua_sess
, app
, usess
->consumer
,
3949 /* Remove it from the hash table and continue!. */
3950 ret
= lttng_ht_del(ua_sess
->channels
, &iter
);
3952 delete_ust_app_channel(-1, ua_chan
, app
);
3955 ret
= do_create_channel(app
, usess
, ua_sess
, ua_chan
);
3958 * Stop everything. On error, the application failed, no more
3959 * file descriptor are available or ENOMEM so stopping here is
3960 * the only thing we can do for now.
3966 cds_lfht_for_each_entry(ua_chan
->ctx
->ht
, &iter_ctx
.iter
, ua_ctx
,
3968 ret
= create_ust_channel_context(ua_chan
, ua_ctx
, app
);
3975 /* For each events */
3976 cds_lfht_for_each_entry(ua_chan
->events
->ht
, &uiter
.iter
, ua_event
,
3978 ret
= create_ust_event(app
, ua_sess
, ua_chan
, ua_event
);
3985 pthread_mutex_unlock(&ua_sess
->lock
);
3987 if (usess
->start_trace
) {
3988 ret
= ust_app_start_trace(usess
, app
);
3993 DBG2("UST trace started for app pid %d", app
->pid
);
3996 /* Everything went well at this point. */
4001 pthread_mutex_unlock(&ua_sess
->lock
);
4004 destroy_app_session(app
, ua_sess
);
4011 * Add context to a specific channel for global UST domain.
4013 int ust_app_add_ctx_channel_glb(struct ltt_ust_session
*usess
,
4014 struct ltt_ust_channel
*uchan
, struct ltt_ust_context
*uctx
)
4017 struct lttng_ht_node_str
*ua_chan_node
;
4018 struct lttng_ht_iter iter
, uiter
;
4019 struct ust_app_channel
*ua_chan
= NULL
;
4020 struct ust_app_session
*ua_sess
;
4021 struct ust_app
*app
;
4025 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
4026 if (!app
->compatible
) {
4028 * TODO: In time, we should notice the caller of this error by
4029 * telling him that this is a version error.
4033 ua_sess
= lookup_session_by_app(usess
, app
);
4034 if (ua_sess
== NULL
) {
4038 pthread_mutex_lock(&ua_sess
->lock
);
4039 /* Lookup channel in the ust app session */
4040 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &uiter
);
4041 ua_chan_node
= lttng_ht_iter_get_node_str(&uiter
);
4042 if (ua_chan_node
== NULL
) {
4045 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
,
4047 ret
= create_ust_app_channel_context(ua_sess
, ua_chan
, &uctx
->ctx
, app
);
4052 pthread_mutex_unlock(&ua_sess
->lock
);
4060 * Enable event for a channel from a UST session for a specific PID.
4062 int ust_app_enable_event_pid(struct ltt_ust_session
*usess
,
4063 struct ltt_ust_channel
*uchan
, struct ltt_ust_event
*uevent
, pid_t pid
)
4066 struct lttng_ht_iter iter
;
4067 struct lttng_ht_node_str
*ua_chan_node
;
4068 struct ust_app
*app
;
4069 struct ust_app_session
*ua_sess
;
4070 struct ust_app_channel
*ua_chan
;
4071 struct ust_app_event
*ua_event
;
4073 DBG("UST app enabling event %s for PID %d", uevent
->attr
.name
, pid
);
4077 app
= ust_app_find_by_pid(pid
);
4079 ERR("UST app enable event per PID %d not found", pid
);
4084 if (!app
->compatible
) {
4089 ua_sess
= lookup_session_by_app(usess
, app
);
4091 /* The application has problem or is probably dead. */
4096 pthread_mutex_lock(&ua_sess
->lock
);
4097 /* Lookup channel in the ust app session */
4098 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &iter
);
4099 ua_chan_node
= lttng_ht_iter_get_node_str(&iter
);
4100 /* If the channel is not found, there is a code flow error */
4101 assert(ua_chan_node
);
4103 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
4105 ua_event
= find_ust_app_event(ua_chan
->events
, uevent
->attr
.name
,
4106 uevent
->filter
, uevent
->attr
.loglevel
);
4107 if (ua_event
== NULL
) {
4108 ret
= create_ust_app_event(ua_sess
, ua_chan
, uevent
, app
);
4113 ret
= enable_ust_app_event(ua_sess
, ua_event
, app
);
4120 pthread_mutex_unlock(&ua_sess
->lock
);
4127 * Disable event for a channel from a UST session for a specific PID.
4129 int ust_app_disable_event_pid(struct ltt_ust_session
*usess
,
4130 struct ltt_ust_channel
*uchan
, struct ltt_ust_event
*uevent
, pid_t pid
)
4133 struct lttng_ht_iter iter
;
4134 struct lttng_ht_node_str
*ua_chan_node
, *ua_event_node
;
4135 struct ust_app
*app
;
4136 struct ust_app_session
*ua_sess
;
4137 struct ust_app_channel
*ua_chan
;
4138 struct ust_app_event
*ua_event
;
4140 DBG("UST app disabling event %s for PID %d", uevent
->attr
.name
, pid
);
4144 app
= ust_app_find_by_pid(pid
);
4146 ERR("UST app disable event per PID %d not found", pid
);
4151 if (!app
->compatible
) {
4156 ua_sess
= lookup_session_by_app(usess
, app
);
4158 /* The application has problem or is probably dead. */
4162 /* Lookup channel in the ust app session */
4163 lttng_ht_lookup(ua_sess
->channels
, (void *)uchan
->name
, &iter
);
4164 ua_chan_node
= lttng_ht_iter_get_node_str(&iter
);
4165 if (ua_chan_node
== NULL
) {
4166 /* Channel does not exist, skip disabling */
4169 ua_chan
= caa_container_of(ua_chan_node
, struct ust_app_channel
, node
);
4171 lttng_ht_lookup(ua_chan
->events
, (void *)uevent
->attr
.name
, &iter
);
4172 ua_event_node
= lttng_ht_iter_get_node_str(&iter
);
4173 if (ua_event_node
== NULL
) {
4174 /* Event does not exist, skip disabling */
4177 ua_event
= caa_container_of(ua_event_node
, struct ust_app_event
, node
);
4179 ret
= disable_ust_app_event(ua_sess
, ua_event
, app
);
4190 * Calibrate registered applications.
4192 int ust_app_calibrate_glb(struct lttng_ust_calibrate
*calibrate
)
4195 struct lttng_ht_iter iter
;
4196 struct ust_app
*app
;
4200 cds_lfht_for_each_entry(ust_app_ht
->ht
, &iter
.iter
, app
, pid_n
.node
) {
4201 if (!app
->compatible
) {
4203 * TODO: In time, we should notice the caller of this error by
4204 * telling him that this is a version error.
4209 health_code_update();
4211 ret
= ustctl_calibrate(app
->sock
, calibrate
);
4215 /* Means that it's not implemented on the tracer side. */
4219 DBG2("Calibrate app PID %d returned with error %d",
4226 DBG("UST app global domain calibration finished");
4230 health_code_update();
4236 * Receive registration and populate the given msg structure.
4238 * On success return 0 else a negative value returned by the ustctl call.
4240 int ust_app_recv_registration(int sock
, struct ust_register_msg
*msg
)
4243 uint32_t pid
, ppid
, uid
, gid
;
4247 ret
= ustctl_recv_reg_msg(sock
, &msg
->type
, &msg
->major
, &msg
->minor
,
4248 &pid
, &ppid
, &uid
, &gid
,
4249 &msg
->bits_per_long
,
4250 &msg
->uint8_t_alignment
,
4251 &msg
->uint16_t_alignment
,
4252 &msg
->uint32_t_alignment
,
4253 &msg
->uint64_t_alignment
,
4254 &msg
->long_alignment
,
4261 case LTTNG_UST_ERR_EXITING
:
4262 DBG3("UST app recv reg message failed. Application died");
4264 case LTTNG_UST_ERR_UNSUP_MAJOR
:
4265 ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
4266 msg
->major
, msg
->minor
, LTTNG_UST_ABI_MAJOR_VERSION
,
4267 LTTNG_UST_ABI_MINOR_VERSION
);
4270 ERR("UST app recv reg message failed with ret %d", ret
);
4275 msg
->pid
= (pid_t
) pid
;
4276 msg
->ppid
= (pid_t
) ppid
;
4277 msg
->uid
= (uid_t
) uid
;
4278 msg
->gid
= (gid_t
) gid
;
4285 * Return a ust app channel object using the application object and the channel
4286 * object descriptor has a key. If not found, NULL is returned. A RCU read side
4287 * lock MUST be acquired before calling this function.
4289 static struct ust_app_channel
*find_channel_by_objd(struct ust_app
*app
,
4292 struct lttng_ht_node_ulong
*node
;
4293 struct lttng_ht_iter iter
;
4294 struct ust_app_channel
*ua_chan
= NULL
;
4298 lttng_ht_lookup(app
->ust_objd
, (void *)((unsigned long) objd
), &iter
);
4299 node
= lttng_ht_iter_get_node_ulong(&iter
);
4301 DBG2("UST app channel find by objd %d not found", objd
);
4305 ua_chan
= caa_container_of(node
, struct ust_app_channel
, ust_objd_node
);
4312 * Reply to a register channel notification from an application on the notify
4313 * socket. The channel metadata is also created.
4315 * The session UST registry lock is acquired in this function.
4317 * On success 0 is returned else a negative value.
4319 static int reply_ust_register_channel(int sock
, int sobjd
, int cobjd
,
4320 size_t nr_fields
, struct ustctl_field
*fields
)
4322 int ret
, ret_code
= 0;
4323 uint32_t chan_id
, reg_count
;
4324 uint64_t chan_reg_key
;
4325 enum ustctl_channel_header type
;
4326 struct ust_app
*app
;
4327 struct ust_app_channel
*ua_chan
;
4328 struct ust_app_session
*ua_sess
;
4329 struct ust_registry_session
*registry
;
4330 struct ust_registry_channel
*chan_reg
;
4334 /* Lookup application. If not found, there is a code flow error. */
4335 app
= find_app_by_notify_sock(sock
);
4337 DBG("Application socket %d is being teardown. Abort event notify",
4340 goto error_rcu_unlock
;
4343 /* Lookup channel by UST object descriptor. Should always be found. */
4344 ua_chan
= find_channel_by_objd(app
, cobjd
);
4346 assert(ua_chan
->session
);
4347 ua_sess
= ua_chan
->session
;
4349 /* Get right session registry depending on the session buffer type. */
4350 registry
= get_session_registry(ua_sess
);
4353 /* Depending on the buffer type, a different channel key is used. */
4354 if (ua_sess
->buffer_type
== LTTNG_BUFFER_PER_UID
) {
4355 chan_reg_key
= ua_chan
->tracing_channel_id
;
4357 chan_reg_key
= ua_chan
->key
;
4360 pthread_mutex_lock(®istry
->lock
);
4362 chan_reg
= ust_registry_channel_find(registry
, chan_reg_key
);
4365 if (!chan_reg
->register_done
) {
4366 reg_count
= ust_registry_get_event_count(chan_reg
);
4367 if (reg_count
< 31) {
4368 type
= USTCTL_CHANNEL_HEADER_COMPACT
;
4370 type
= USTCTL_CHANNEL_HEADER_LARGE
;
4373 chan_reg
->nr_ctx_fields
= nr_fields
;
4374 chan_reg
->ctx_fields
= fields
;
4375 chan_reg
->header_type
= type
;
4377 /* Get current already assigned values. */
4378 type
= chan_reg
->header_type
;
4380 /* Channel id is set during the object creation. */
4381 chan_id
= chan_reg
->chan_id
;
4383 /* Append to metadata */
4384 if (!chan_reg
->metadata_dumped
) {
4385 ret_code
= ust_metadata_channel_statedump(registry
, chan_reg
);
4387 ERR("Error appending channel metadata (errno = %d)", ret_code
);
4393 DBG3("UST app replying to register channel key %" PRIu64
4394 " with id %u, type: %d, ret: %d", chan_reg_key
, chan_id
, type
,
4397 ret
= ustctl_reply_register_channel(sock
, chan_id
, type
, ret_code
);
4399 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
4400 ERR("UST app reply channel failed with ret %d", ret
);
4402 DBG3("UST app reply channel failed. Application died");
4407 /* This channel registry registration is completed. */
4408 chan_reg
->register_done
= 1;
4411 pthread_mutex_unlock(®istry
->lock
);
4418 * Add event to the UST channel registry. When the event is added to the
4419 * registry, the metadata is also created. Once done, this replies to the
4420 * application with the appropriate error code.
4422 * The session UST registry lock is acquired in the function.
4424 * On success 0 is returned else a negative value.
4426 static int add_event_ust_registry(int sock
, int sobjd
, int cobjd
, char *name
,
4427 char *sig
, size_t nr_fields
, struct ustctl_field
*fields
, int loglevel
,
4428 char *model_emf_uri
)
4431 uint32_t event_id
= 0;
4432 uint64_t chan_reg_key
;
4433 struct ust_app
*app
;
4434 struct ust_app_channel
*ua_chan
;
4435 struct ust_app_session
*ua_sess
;
4436 struct ust_registry_session
*registry
;
4440 /* Lookup application. If not found, there is a code flow error. */
4441 app
= find_app_by_notify_sock(sock
);
4443 DBG("Application socket %d is being teardown. Abort event notify",
4446 goto error_rcu_unlock
;
4449 /* Lookup channel by UST object descriptor. Should always be found. */
4450 ua_chan
= find_channel_by_objd(app
, cobjd
);
4452 assert(ua_chan
->session
);
4453 ua_sess
= ua_chan
->session
;
4455 registry
= get_session_registry(ua_sess
);
4458 if (ua_sess
->buffer_type
== LTTNG_BUFFER_PER_UID
) {
4459 chan_reg_key
= ua_chan
->tracing_channel_id
;
4461 chan_reg_key
= ua_chan
->key
;
4464 pthread_mutex_lock(®istry
->lock
);
4466 ret_code
= ust_registry_create_event(registry
, chan_reg_key
,
4467 sobjd
, cobjd
, name
, sig
, nr_fields
, fields
, loglevel
,
4468 model_emf_uri
, ua_sess
->buffer_type
, &event_id
);
4471 * The return value is returned to ustctl so in case of an error, the
4472 * application can be notified. In case of an error, it's important not to
4473 * return a negative error or else the application will get closed.
4475 ret
= ustctl_reply_register_event(sock
, event_id
, ret_code
);
4477 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
4478 ERR("UST app reply event failed with ret %d", ret
);
4480 DBG3("UST app reply event failed. Application died");
4483 * No need to wipe the create event since the application socket will
4484 * get close on error hence cleaning up everything by itself.
4489 DBG3("UST registry event %s with id %" PRId32
" added successfully",
4493 pthread_mutex_unlock(®istry
->lock
);
4500 * Handle application notification through the given notify socket.
4502 * Return 0 on success or else a negative value.
4504 int ust_app_recv_notify(int sock
)
4507 enum ustctl_notify_cmd cmd
;
4509 DBG3("UST app receiving notify from sock %d", sock
);
4511 ret
= ustctl_recv_notify(sock
, &cmd
);
4513 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
4514 ERR("UST app recv notify failed with ret %d", ret
);
4516 DBG3("UST app recv notify failed. Application died");
4522 case USTCTL_NOTIFY_CMD_EVENT
:
4524 int sobjd
, cobjd
, loglevel
;
4525 char name
[LTTNG_UST_SYM_NAME_LEN
], *sig
, *model_emf_uri
;
4527 struct ustctl_field
*fields
;
4529 DBG2("UST app ustctl register event received");
4531 ret
= ustctl_recv_register_event(sock
, &sobjd
, &cobjd
, name
, &loglevel
,
4532 &sig
, &nr_fields
, &fields
, &model_emf_uri
);
4534 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
4535 ERR("UST app recv event failed with ret %d", ret
);
4537 DBG3("UST app recv event failed. Application died");
4542 /* Add event to the UST registry coming from the notify socket. */
4543 ret
= add_event_ust_registry(sock
, sobjd
, cobjd
, name
, sig
, nr_fields
,
4544 fields
, loglevel
, model_emf_uri
);
4551 case USTCTL_NOTIFY_CMD_CHANNEL
:
4555 struct ustctl_field
*fields
;
4557 DBG2("UST app ustctl register channel received");
4559 ret
= ustctl_recv_register_channel(sock
, &sobjd
, &cobjd
, &nr_fields
,
4562 if (ret
!= -EPIPE
&& ret
!= -LTTNG_UST_ERR_EXITING
) {
4563 ERR("UST app recv channel failed with ret %d", ret
);
4565 DBG3("UST app recv channel failed. Application died");
4570 ret
= reply_ust_register_channel(sock
, sobjd
, cobjd
, nr_fields
,
4579 /* Should NEVER happen. */
4588 * Once the notify socket hangs up, this is called. First, it tries to find the
4589 * corresponding application. On failure, the call_rcu to close the socket is
4590 * executed. If an application is found, it tries to delete it from the notify
4591 * socket hash table. Whathever the result, it proceeds to the call_rcu.
4593 * Note that an object needs to be allocated here so on ENOMEM failure, the
4594 * call RCU is not done but the rest of the cleanup is.
4596 void ust_app_notify_sock_unregister(int sock
)
4599 struct lttng_ht_iter iter
;
4600 struct ust_app
*app
;
4601 struct ust_app_notify_sock_obj
*obj
;
4607 obj
= zmalloc(sizeof(*obj
));
4610 * An ENOMEM is kind of uncool. If this strikes we continue the
4611 * procedure but the call_rcu will not be called. In this case, we
4612 * accept the fd leak rather than possibly creating an unsynchronized
4613 * state between threads.
4615 * TODO: The notify object should be created once the notify socket is
4616 * registered and stored independantely from the ust app object. The
4617 * tricky part is to synchronize the teardown of the application and
4618 * this notify object. Let's keep that in mind so we can avoid this
4619 * kind of shenanigans with ENOMEM in the teardown path.
4626 DBG("UST app notify socket unregister %d", sock
);
4629 * Lookup application by notify socket. If this fails, this means that the
4630 * hash table delete has already been done by the application
4631 * unregistration process so we can safely close the notify socket in a
4634 app
= find_app_by_notify_sock(sock
);
4639 iter
.iter
.node
= &app
->notify_sock_n
.node
;
4642 * Whatever happens here either we fail or succeed, in both cases we have
4643 * to close the socket after a grace period to continue to the call RCU
4644 * here. If the deletion is successful, the application is not visible
4645 * anymore by other threads and is it fails it means that it was already
4646 * deleted from the hash table so either way we just have to close the
4649 (void) lttng_ht_del(ust_app_ht_by_notify_sock
, &iter
);
4655 * Close socket after a grace period to avoid for the socket to be reused
4656 * before the application object is freed creating potential race between
4657 * threads trying to add unique in the global hash table.
4660 call_rcu(&obj
->head
, close_notify_sock_rcu
);