4 * Holds LTTng per-session event registry.
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include <urcu/list.h>
26 #include <urcu/hlist.h>
35 #include <lttng/ust-endian.h>
39 #include <urcu/compiler.h>
40 #include <urcu/uatomic.h>
41 #include <urcu/arch.h>
43 #include <lttng/tracepoint.h>
44 #include <lttng/ust-events.h>
46 #include <usterr-signal-safe.h>
48 #include <lttng/ust-ctl.h>
52 #include "lttng-ust-uuid.h"
54 #include "tracepoint-internal.h"
55 #include "lttng-tracer.h"
56 #include "lttng-tracer-core.h"
57 #include "lttng-ust-baddr.h"
59 #include "../libringbuffer/shm.h"
63 * All operations within this file are called by the communication
64 * thread, under ust_lock protection.
67 static CDS_LIST_HEAD(sessions
);
69 struct cds_list_head
*_lttng_get_sessions(void)
74 static void _lttng_event_destroy(struct lttng_event
*event
);
77 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
79 void lttng_session_sync_enablers(struct lttng_session
*session
);
81 void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
84 * Called with ust lock held.
86 int lttng_session_active(void)
88 struct lttng_session
*iter
;
90 cds_list_for_each_entry(iter
, &sessions
, node
) {
98 int lttng_loglevel_match(int loglevel
,
99 unsigned int has_loglevel
,
100 enum lttng_ust_loglevel_type req_type
,
103 if (req_type
== LTTNG_UST_LOGLEVEL_ALL
)
106 loglevel
= TRACE_DEFAULT
;
108 case LTTNG_UST_LOGLEVEL_RANGE
:
109 if (loglevel
<= req_loglevel
|| req_loglevel
== -1)
113 case LTTNG_UST_LOGLEVEL_SINGLE
:
114 if (loglevel
== req_loglevel
|| req_loglevel
== -1)
118 case LTTNG_UST_LOGLEVEL_ALL
:
124 void synchronize_trace(void)
129 struct lttng_session
*lttng_session_create(void)
131 struct lttng_session
*session
;
134 session
= zmalloc(sizeof(struct lttng_session
));
137 CDS_INIT_LIST_HEAD(&session
->chan_head
);
138 CDS_INIT_LIST_HEAD(&session
->events_head
);
139 CDS_INIT_LIST_HEAD(&session
->enablers_head
);
140 for (i
= 0; i
< LTTNG_UST_EVENT_HT_SIZE
; i
++)
141 CDS_INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
142 cds_list_add(&session
->node
, &sessions
);
147 * Only used internally at session destruction.
150 void _lttng_channel_unmap(struct lttng_channel
*lttng_chan
)
152 struct channel
*chan
;
153 struct lttng_ust_shm_handle
*handle
;
155 cds_list_del(<tng_chan
->node
);
156 lttng_destroy_context(lttng_chan
->ctx
);
157 chan
= lttng_chan
->chan
;
158 handle
= lttng_chan
->handle
;
160 * note: lttng_chan is private data contained within handle. It
161 * will be freed along with the handle.
163 channel_destroy(chan
, handle
, 0);
167 void register_event(struct lttng_event
*event
)
170 const struct lttng_event_desc
*desc
;
172 assert(event
->registered
== 0);
174 ret
= __tracepoint_probe_register(desc
->name
,
175 desc
->probe_callback
,
176 event
, desc
->signature
);
179 event
->registered
= 1;
183 void unregister_event(struct lttng_event
*event
)
186 const struct lttng_event_desc
*desc
;
188 assert(event
->registered
== 1);
190 ret
= __tracepoint_probe_unregister(desc
->name
,
191 desc
->probe_callback
,
195 event
->registered
= 0;
199 * Only used internally at session destruction.
202 void _lttng_event_unregister(struct lttng_event
*event
)
204 if (event
->registered
)
205 unregister_event(event
);
208 void lttng_session_destroy(struct lttng_session
*session
)
210 struct lttng_channel
*chan
, *tmpchan
;
211 struct lttng_event
*event
, *tmpevent
;
212 struct lttng_enabler
*enabler
, *tmpenabler
;
214 CMM_ACCESS_ONCE(session
->active
) = 0;
215 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
216 _lttng_event_unregister(event
);
218 synchronize_trace(); /* Wait for in-flight events to complete */
219 cds_list_for_each_entry_safe(enabler
, tmpenabler
,
220 &session
->enablers_head
, node
)
221 lttng_enabler_destroy(enabler
);
222 cds_list_for_each_entry_safe(event
, tmpevent
,
223 &session
->events_head
, node
)
224 _lttng_event_destroy(event
);
225 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan_head
, node
)
226 _lttng_channel_unmap(chan
);
227 cds_list_del(&session
->node
);
231 int lttng_session_enable(struct lttng_session
*session
)
234 struct lttng_channel
*chan
;
237 if (session
->active
) {
242 notify_socket
= lttng_get_notify_socket(session
->owner
);
243 if (notify_socket
< 0)
244 return notify_socket
;
246 /* Set transient enabler state to "enabled" */
248 /* We need to sync enablers with session before activation. */
249 lttng_session_sync_enablers(session
);
252 * Snapshot the number of events per channel to know the type of header
255 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
256 const struct lttng_ctx
*ctx
;
257 const struct lttng_ctx_field
*fields
= NULL
;
258 size_t nr_fields
= 0;
261 /* don't change it if session stop/restart */
262 if (chan
->header_type
)
266 nr_fields
= ctx
->nr_fields
;
267 fields
= ctx
->fields
;
269 ret
= ustcomm_register_channel(notify_socket
,
277 DBG("Error (%d) registering channel to sessiond", ret
);
280 if (chan_id
!= chan
->id
) {
281 DBG("Error: channel registration id (%u) does not match id assigned at creation (%u)",
287 /* Set atomically the state to "active" */
288 CMM_ACCESS_ONCE(session
->active
) = 1;
289 CMM_ACCESS_ONCE(session
->been_active
) = 1;
291 session
->statedump_pending
= 1;
292 lttng_ust_sockinfo_session_enabled(session
->owner
);
297 int lttng_session_disable(struct lttng_session
*session
)
301 if (!session
->active
) {
305 /* Set atomically the state to "inactive" */
306 CMM_ACCESS_ONCE(session
->active
) = 0;
308 /* Set transient enabler state to "disabled" */
310 lttng_session_sync_enablers(session
);
315 int lttng_channel_enable(struct lttng_channel
*channel
)
319 if (channel
->enabled
) {
323 /* Set transient enabler state to "enabled" */
325 lttng_session_sync_enablers(channel
->session
);
326 /* Set atomically the state to "enabled" */
327 CMM_ACCESS_ONCE(channel
->enabled
) = 1;
332 int lttng_channel_disable(struct lttng_channel
*channel
)
336 if (!channel
->enabled
) {
340 /* Set atomically the state to "disabled" */
341 CMM_ACCESS_ONCE(channel
->enabled
) = 0;
342 /* Set transient enabler state to "enabled" */
344 lttng_session_sync_enablers(channel
->session
);
350 * Supports event creation while tracing session is active.
353 int lttng_event_create(const struct lttng_event_desc
*desc
,
354 struct lttng_channel
*chan
)
356 const char *event_name
= desc
->name
;
357 struct lttng_event
*event
;
358 struct lttng_session
*session
= chan
->session
;
359 struct cds_hlist_head
*head
;
360 struct cds_hlist_node
*node
;
362 size_t name_len
= strlen(event_name
);
364 int notify_socket
, loglevel
;
367 hash
= jhash(event_name
, name_len
, 0);
368 head
= &chan
->session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
369 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
371 if (!strncmp(event
->desc
->name
, desc
->name
,
372 LTTNG_UST_SYM_NAME_LEN
- 1)
373 && chan
== event
->chan
) {
379 notify_socket
= lttng_get_notify_socket(session
->owner
);
380 if (notify_socket
< 0) {
386 * Check if loglevel match. Refuse to connect event if not.
388 event
= zmalloc(sizeof(struct lttng_event
));
395 /* Event will be enabled by enabler sync. */
397 event
->registered
= 0;
398 CDS_INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
399 CDS_INIT_LIST_HEAD(&event
->enablers_ref_head
);
403 loglevel
= *(*event
->desc
->loglevel
);
405 loglevel
= TRACE_DEFAULT
;
406 if (desc
->u
.ext
.model_emf_uri
)
407 uri
= *(desc
->u
.ext
.model_emf_uri
);
411 /* Fetch event ID from sessiond */
412 ret
= ustcomm_register_event(notify_socket
,
423 DBG("Error (%d) registering event to sessiond", ret
);
424 goto sessiond_register_error
;
427 /* Populate lttng_event structure before tracepoint registration. */
429 cds_list_add(&event
->node
, &chan
->session
->events_head
);
430 cds_hlist_add_head(&event
->hlist
, head
);
433 sessiond_register_error
:
442 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
443 struct lttng_enabler
*enabler
)
446 unsigned int has_loglevel
= 0;
448 assert(enabler
->type
== LTTNG_ENABLER_WILDCARD
);
449 /* Compare excluding final '*' */
450 if (strncmp(desc
->name
, enabler
->event_param
.name
,
451 strlen(enabler
->event_param
.name
) - 1))
453 if (desc
->loglevel
) {
454 loglevel
= *(*desc
->loglevel
);
457 if (!lttng_loglevel_match(loglevel
,
459 enabler
->event_param
.loglevel_type
,
460 enabler
->event_param
.loglevel
))
466 int lttng_desc_match_event_enabler(const struct lttng_event_desc
*desc
,
467 struct lttng_enabler
*enabler
)
470 unsigned int has_loglevel
= 0;
472 assert(enabler
->type
== LTTNG_ENABLER_EVENT
);
473 if (strcmp(desc
->name
, enabler
->event_param
.name
))
475 if (desc
->loglevel
) {
476 loglevel
= *(*desc
->loglevel
);
479 if (!lttng_loglevel_match(loglevel
,
481 enabler
->event_param
.loglevel_type
,
482 enabler
->event_param
.loglevel
))
488 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
489 struct lttng_enabler
*enabler
)
491 struct lttng_ust_excluder_node
*excluder
;
493 /* If event matches with an excluder, return 'does not match' */
494 cds_list_for_each_entry(excluder
, &enabler
->excluder_head
, node
) {
497 for (count
= 0; count
< excluder
->excluder
.count
; count
++) {
501 excluder_name
= (char *) (excluder
->excluder
.names
)
502 + count
* LTTNG_UST_SYM_NAME_LEN
;
503 len
= strnlen(excluder_name
, LTTNG_UST_SYM_NAME_LEN
);
504 if (len
> 0 && excluder_name
[len
- 1] == '*') {
505 found
= !strncmp(desc
->name
, excluder_name
,
508 found
= !strncmp(desc
->name
, excluder_name
,
509 LTTNG_UST_SYM_NAME_LEN
- 1);
516 switch (enabler
->type
) {
517 case LTTNG_ENABLER_WILDCARD
:
518 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
519 case LTTNG_ENABLER_EVENT
:
520 return lttng_desc_match_event_enabler(desc
, enabler
);
527 int lttng_event_match_enabler(struct lttng_event
*event
,
528 struct lttng_enabler
*enabler
)
530 if (lttng_desc_match_enabler(event
->desc
, enabler
)
531 && event
->chan
== enabler
->chan
)
538 struct lttng_enabler_ref
* lttng_event_enabler_ref(struct lttng_event
*event
,
539 struct lttng_enabler
*enabler
)
541 struct lttng_enabler_ref
*enabler_ref
;
543 cds_list_for_each_entry(enabler_ref
,
544 &event
->enablers_ref_head
, node
) {
545 if (enabler_ref
->ref
== enabler
)
552 * Create struct lttng_event if it is missing and present in the list of
556 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
558 struct lttng_session
*session
= enabler
->chan
->session
;
559 struct lttng_probe_desc
*probe_desc
;
560 const struct lttng_event_desc
*desc
;
561 struct lttng_event
*event
;
563 struct cds_list_head
*probe_list
;
565 probe_list
= lttng_get_probe_list_head();
567 * For each probe event, if we find that a probe event matches
568 * our enabler, create an associated lttng_event if not
571 cds_list_for_each_entry(probe_desc
, probe_list
, head
) {
572 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
574 struct cds_hlist_head
*head
;
575 struct cds_hlist_node
*node
;
576 const char *event_name
;
580 desc
= probe_desc
->event_desc
[i
];
581 if (!lttng_desc_match_enabler(desc
, enabler
))
583 event_name
= desc
->name
;
584 name_len
= strlen(event_name
);
587 * Check if already created.
589 hash
= jhash(event_name
, name_len
, 0);
590 head
= &session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
591 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
592 if (event
->desc
== desc
593 && event
->chan
== enabler
->chan
)
600 * We need to create an event for this
603 ret
= lttng_event_create(probe_desc
->event_desc
[i
],
606 DBG("Unable to create event %s, error %d\n",
607 probe_desc
->event_desc
[i
]->name
, ret
);
614 * Create events associated with an enabler (if not already present),
615 * and add backward reference from the event to the enabler.
618 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
620 struct lttng_session
*session
= enabler
->chan
->session
;
621 struct lttng_event
*event
;
623 /* First ensure that probe events are created for this enabler. */
624 lttng_create_event_if_missing(enabler
);
626 /* For each event matching enabler in session event list. */
627 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
628 struct lttng_enabler_ref
*enabler_ref
;
630 if (!lttng_event_match_enabler(event
, enabler
))
633 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
636 * If no backward ref, create it.
637 * Add backward ref from event to enabler.
639 enabler_ref
= zmalloc(sizeof(*enabler_ref
));
642 enabler_ref
->ref
= enabler
;
643 cds_list_add(&enabler_ref
->node
,
644 &event
->enablers_ref_head
);
648 * Link filter bytecodes if not linked yet.
650 lttng_enabler_event_link_bytecode(event
, enabler
);
652 /* TODO: merge event context. */
658 * Called at library load: connect the probe on all enablers matching
660 * Called with session mutex held.
662 int lttng_fix_pending_events(void)
664 struct lttng_session
*session
;
666 cds_list_for_each_entry(session
, &sessions
, node
) {
667 lttng_session_lazy_sync_enablers(session
);
673 * For each session of the owner thread, execute pending statedump.
674 * Only dump state for the sessions owned by the caller thread, because
675 * we don't keep ust_lock across the entire iteration.
677 void lttng_handle_pending_statedump(void *owner
)
679 struct lttng_session
*session
;
681 /* Execute state dump */
682 lttng_ust_baddr_statedump(owner
);
684 /* Clear pending state dump */
688 cds_list_for_each_entry(session
, &sessions
, node
) {
689 if (session
->owner
!= owner
)
691 if (!session
->statedump_pending
)
693 session
->statedump_pending
= 0;
701 * Only used internally at session destruction.
704 void _lttng_event_destroy(struct lttng_event
*event
)
706 struct lttng_enabler_ref
*enabler_ref
, *tmp_enabler_ref
;
708 cds_list_del(&event
->node
);
709 lttng_destroy_context(event
->ctx
);
710 lttng_free_event_filter_runtime(event
);
711 /* Free event enabler refs */
712 cds_list_for_each_entry_safe(enabler_ref
, tmp_enabler_ref
,
713 &event
->enablers_ref_head
, node
)
718 void lttng_ust_events_exit(void)
720 struct lttng_session
*session
, *tmpsession
;
722 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, node
)
723 lttng_session_destroy(session
);
727 * Enabler management.
729 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
730 struct lttng_ust_event
*event_param
,
731 struct lttng_channel
*chan
)
733 struct lttng_enabler
*enabler
;
735 enabler
= zmalloc(sizeof(*enabler
));
738 enabler
->type
= type
;
739 CDS_INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
740 CDS_INIT_LIST_HEAD(&enabler
->excluder_head
);
741 memcpy(&enabler
->event_param
, event_param
,
742 sizeof(enabler
->event_param
));
743 enabler
->chan
= chan
;
745 enabler
->enabled
= 1;
746 cds_list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
747 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
751 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
753 enabler
->enabled
= 1;
754 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
758 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
760 enabler
->enabled
= 0;
761 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
765 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
766 struct lttng_ust_filter_bytecode_node
*bytecode
)
768 bytecode
->enabler
= enabler
;
769 cds_list_add_tail(&bytecode
->node
, &enabler
->filter_bytecode_head
);
770 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
774 int lttng_enabler_attach_exclusion(struct lttng_enabler
*enabler
,
775 struct lttng_ust_excluder_node
*excluder
)
777 excluder
->enabler
= enabler
;
778 cds_list_add_tail(&excluder
->node
, &enabler
->excluder_head
);
779 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
783 int lttng_attach_context(struct lttng_ust_context
*context_param
,
784 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
787 * We cannot attach a context after trace has been started for a
788 * session because the metadata does not allow expressing this
789 * information outside of the original channel scope.
791 if (session
->been_active
)
794 switch (context_param
->ctx
) {
795 case LTTNG_UST_CONTEXT_PTHREAD_ID
:
796 return lttng_add_pthread_id_to_ctx(ctx
);
797 case LTTNG_UST_CONTEXT_VTID
:
798 return lttng_add_vtid_to_ctx(ctx
);
799 case LTTNG_UST_CONTEXT_VPID
:
800 return lttng_add_vpid_to_ctx(ctx
);
801 case LTTNG_UST_CONTEXT_PROCNAME
:
802 return lttng_add_procname_to_ctx(ctx
);
803 case LTTNG_UST_CONTEXT_IP
:
804 return lttng_add_ip_to_ctx(ctx
);
810 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
811 struct lttng_ust_context
*context_param
)
813 #if 0 // disabled for now.
814 struct lttng_session
*session
= enabler
->chan
->session
;
817 ret
= lttng_attach_context(context_param
, &enabler
->ctx
,
821 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
827 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
829 struct lttng_ust_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
830 struct lttng_ust_excluder_node
*excluder_node
, *tmp_excluder_node
;
832 /* Destroy filter bytecode */
833 cds_list_for_each_entry_safe(filter_node
, tmp_filter_node
,
834 &enabler
->filter_bytecode_head
, node
) {
838 /* Destroy excluders */
839 cds_list_for_each_entry_safe(excluder_node
, tmp_excluder_node
,
840 &enabler
->excluder_head
, node
) {
844 /* Destroy contexts */
845 lttng_destroy_context(enabler
->ctx
);
847 cds_list_del(&enabler
->node
);
852 * lttng_session_sync_enablers should be called just before starting a
856 void lttng_session_sync_enablers(struct lttng_session
*session
)
858 struct lttng_enabler
*enabler
;
859 struct lttng_event
*event
;
861 cds_list_for_each_entry(enabler
, &session
->enablers_head
, node
)
862 lttng_enabler_ref_events(enabler
);
864 * For each event, if at least one of its enablers is enabled,
865 * and its channel and session transient states are enabled, we
866 * enable the event, else we disable it.
868 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
869 struct lttng_enabler_ref
*enabler_ref
;
870 struct lttng_bytecode_runtime
*runtime
;
871 int enabled
= 0, has_enablers_without_bytecode
= 0;
874 cds_list_for_each_entry(enabler_ref
,
875 &event
->enablers_ref_head
, node
) {
876 if (enabler_ref
->ref
->enabled
) {
882 * Enabled state is based on union of enablers, with
883 * intesection of session and channel transient enable
886 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
888 CMM_STORE_SHARED(event
->enabled
, enabled
);
890 * Sync tracepoint registration with event enabled
894 if (!event
->registered
)
895 register_event(event
);
897 if (event
->registered
)
898 unregister_event(event
);
901 /* Check if has enablers without bytecode enabled */
902 cds_list_for_each_entry(enabler_ref
,
903 &event
->enablers_ref_head
, node
) {
904 if (enabler_ref
->ref
->enabled
905 && cds_list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
906 has_enablers_without_bytecode
= 1;
910 event
->has_enablers_without_bytecode
=
911 has_enablers_without_bytecode
;
914 cds_list_for_each_entry(runtime
,
915 &event
->bytecode_runtime_head
, node
) {
916 lttng_filter_sync_state(runtime
);
922 * Apply enablers to session events, adding events to session if need
923 * be. It is required after each modification applied to an active
924 * session, and right before session "start".
925 * "lazy" sync means we only sync if required.
928 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
930 /* We can skip if session is not active */
931 if (!session
->active
)
933 lttng_session_sync_enablers(session
);