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-statedump.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
,
104 loglevel
= TRACE_DEFAULT
;
106 case LTTNG_UST_LOGLEVEL_RANGE
:
107 if (loglevel
<= req_loglevel
108 || (req_loglevel
== -1 && loglevel
<= TRACE_DEBUG
))
112 case LTTNG_UST_LOGLEVEL_SINGLE
:
113 if (loglevel
== req_loglevel
114 || (req_loglevel
== -1 && loglevel
<= TRACE_DEBUG
))
118 case LTTNG_UST_LOGLEVEL_ALL
:
120 if (loglevel
<= TRACE_DEBUG
)
127 void synchronize_trace(void)
132 struct lttng_session
*lttng_session_create(void)
134 struct lttng_session
*session
;
137 session
= zmalloc(sizeof(struct lttng_session
));
140 CDS_INIT_LIST_HEAD(&session
->chan_head
);
141 CDS_INIT_LIST_HEAD(&session
->events_head
);
142 CDS_INIT_LIST_HEAD(&session
->enablers_head
);
143 for (i
= 0; i
< LTTNG_UST_EVENT_HT_SIZE
; i
++)
144 CDS_INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
145 cds_list_add(&session
->node
, &sessions
);
150 * Only used internally at session destruction.
153 void _lttng_channel_unmap(struct lttng_channel
*lttng_chan
)
155 struct channel
*chan
;
156 struct lttng_ust_shm_handle
*handle
;
158 cds_list_del(<tng_chan
->node
);
159 lttng_destroy_context(lttng_chan
->ctx
);
160 chan
= lttng_chan
->chan
;
161 handle
= lttng_chan
->handle
;
163 * note: lttng_chan is private data contained within handle. It
164 * will be freed along with the handle.
166 channel_destroy(chan
, handle
, 0);
170 void register_event(struct lttng_event
*event
)
173 const struct lttng_event_desc
*desc
;
175 assert(event
->registered
== 0);
177 ret
= __tracepoint_probe_register(desc
->name
,
178 desc
->probe_callback
,
179 event
, desc
->signature
);
182 event
->registered
= 1;
186 void unregister_event(struct lttng_event
*event
)
189 const struct lttng_event_desc
*desc
;
191 assert(event
->registered
== 1);
193 ret
= __tracepoint_probe_unregister(desc
->name
,
194 desc
->probe_callback
,
198 event
->registered
= 0;
202 * Only used internally at session destruction.
205 void _lttng_event_unregister(struct lttng_event
*event
)
207 if (event
->registered
)
208 unregister_event(event
);
211 void lttng_session_destroy(struct lttng_session
*session
)
213 struct lttng_channel
*chan
, *tmpchan
;
214 struct lttng_event
*event
, *tmpevent
;
215 struct lttng_enabler
*enabler
, *tmpenabler
;
217 CMM_ACCESS_ONCE(session
->active
) = 0;
218 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
219 _lttng_event_unregister(event
);
221 synchronize_trace(); /* Wait for in-flight events to complete */
222 cds_list_for_each_entry_safe(enabler
, tmpenabler
,
223 &session
->enablers_head
, node
)
224 lttng_enabler_destroy(enabler
);
225 cds_list_for_each_entry_safe(event
, tmpevent
,
226 &session
->events_head
, node
)
227 _lttng_event_destroy(event
);
228 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan_head
, node
)
229 _lttng_channel_unmap(chan
);
230 cds_list_del(&session
->node
);
234 int lttng_session_enable(struct lttng_session
*session
)
237 struct lttng_channel
*chan
;
240 if (session
->active
) {
245 notify_socket
= lttng_get_notify_socket(session
->owner
);
246 if (notify_socket
< 0)
247 return notify_socket
;
249 /* Set transient enabler state to "enabled" */
253 * Snapshot the number of events per channel to know the type of header
256 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
257 const struct lttng_ctx
*ctx
;
258 const struct lttng_ctx_field
*fields
= NULL
;
259 size_t nr_fields
= 0;
262 /* don't change it if session stop/restart */
263 if (chan
->header_type
)
267 nr_fields
= ctx
->nr_fields
;
268 fields
= ctx
->fields
;
270 ret
= ustcomm_register_channel(notify_socket
,
278 DBG("Error (%d) registering channel to sessiond", ret
);
281 if (chan_id
!= chan
->id
) {
282 DBG("Error: channel registration id (%u) does not match id assigned at creation (%u)",
288 /* We need to sync enablers with session before activation. */
289 lttng_session_sync_enablers(session
);
291 /* Set atomically the state to "active" */
292 CMM_ACCESS_ONCE(session
->active
) = 1;
293 CMM_ACCESS_ONCE(session
->been_active
) = 1;
295 session
->statedump_pending
= 1;
296 lttng_ust_sockinfo_session_enabled(session
->owner
);
301 int lttng_session_disable(struct lttng_session
*session
)
305 if (!session
->active
) {
309 /* Set atomically the state to "inactive" */
310 CMM_ACCESS_ONCE(session
->active
) = 0;
312 /* Set transient enabler state to "disabled" */
314 lttng_session_sync_enablers(session
);
319 int lttng_channel_enable(struct lttng_channel
*channel
)
323 if (channel
->enabled
) {
327 /* Set transient enabler state to "enabled" */
329 lttng_session_sync_enablers(channel
->session
);
330 /* Set atomically the state to "enabled" */
331 CMM_ACCESS_ONCE(channel
->enabled
) = 1;
336 int lttng_channel_disable(struct lttng_channel
*channel
)
340 if (!channel
->enabled
) {
344 /* Set atomically the state to "disabled" */
345 CMM_ACCESS_ONCE(channel
->enabled
) = 0;
346 /* Set transient enabler state to "enabled" */
348 lttng_session_sync_enablers(channel
->session
);
354 * Supports event creation while tracing session is active.
357 int lttng_event_create(const struct lttng_event_desc
*desc
,
358 struct lttng_channel
*chan
)
360 const char *event_name
= desc
->name
;
361 struct lttng_event
*event
;
362 struct lttng_session
*session
= chan
->session
;
363 struct cds_hlist_head
*head
;
364 struct cds_hlist_node
*node
;
366 size_t name_len
= strlen(event_name
);
368 int notify_socket
, loglevel
;
371 hash
= jhash(event_name
, name_len
, 0);
372 head
= &chan
->session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
373 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
375 if (!strncmp(event
->desc
->name
, desc
->name
,
376 LTTNG_UST_SYM_NAME_LEN
- 1)
377 && chan
== event
->chan
) {
383 notify_socket
= lttng_get_notify_socket(session
->owner
);
384 if (notify_socket
< 0) {
390 * Check if loglevel match. Refuse to connect event if not.
392 event
= zmalloc(sizeof(struct lttng_event
));
399 /* Event will be enabled by enabler sync. */
401 event
->registered
= 0;
402 CDS_INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
403 CDS_INIT_LIST_HEAD(&event
->enablers_ref_head
);
407 loglevel
= *(*event
->desc
->loglevel
);
409 loglevel
= TRACE_DEFAULT
;
410 if (desc
->u
.ext
.model_emf_uri
)
411 uri
= *(desc
->u
.ext
.model_emf_uri
);
415 /* Fetch event ID from sessiond */
416 ret
= ustcomm_register_event(notify_socket
,
427 DBG("Error (%d) registering event to sessiond", ret
);
428 goto sessiond_register_error
;
431 /* Populate lttng_event structure before tracepoint registration. */
433 cds_list_add(&event
->node
, &chan
->session
->events_head
);
434 cds_hlist_add_head(&event
->hlist
, head
);
437 sessiond_register_error
:
446 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
447 struct lttng_enabler
*enabler
)
450 unsigned int has_loglevel
= 0;
452 assert(enabler
->type
== LTTNG_ENABLER_WILDCARD
);
453 /* Compare excluding final '*' */
454 if (strncmp(desc
->name
, enabler
->event_param
.name
,
455 strlen(enabler
->event_param
.name
) - 1))
457 if (desc
->loglevel
) {
458 loglevel
= *(*desc
->loglevel
);
461 if (!lttng_loglevel_match(loglevel
,
463 enabler
->event_param
.loglevel_type
,
464 enabler
->event_param
.loglevel
))
470 int lttng_desc_match_event_enabler(const struct lttng_event_desc
*desc
,
471 struct lttng_enabler
*enabler
)
474 unsigned int has_loglevel
= 0;
476 assert(enabler
->type
== LTTNG_ENABLER_EVENT
);
477 if (strcmp(desc
->name
, enabler
->event_param
.name
))
479 if (desc
->loglevel
) {
480 loglevel
= *(*desc
->loglevel
);
483 if (!lttng_loglevel_match(loglevel
,
485 enabler
->event_param
.loglevel_type
,
486 enabler
->event_param
.loglevel
))
492 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
493 struct lttng_enabler
*enabler
)
495 struct lttng_ust_excluder_node
*excluder
;
497 /* If event matches with an excluder, return 'does not match' */
498 cds_list_for_each_entry(excluder
, &enabler
->excluder_head
, node
) {
501 for (count
= 0; count
< excluder
->excluder
.count
; count
++) {
505 excluder_name
= (char *) (excluder
->excluder
.names
)
506 + count
* LTTNG_UST_SYM_NAME_LEN
;
507 len
= strnlen(excluder_name
, LTTNG_UST_SYM_NAME_LEN
);
508 if (len
> 0 && excluder_name
[len
- 1] == '*') {
509 found
= !strncmp(desc
->name
, excluder_name
,
512 found
= !strncmp(desc
->name
, excluder_name
,
513 LTTNG_UST_SYM_NAME_LEN
- 1);
520 switch (enabler
->type
) {
521 case LTTNG_ENABLER_WILDCARD
:
522 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
523 case LTTNG_ENABLER_EVENT
:
524 return lttng_desc_match_event_enabler(desc
, enabler
);
531 int lttng_event_match_enabler(struct lttng_event
*event
,
532 struct lttng_enabler
*enabler
)
534 if (lttng_desc_match_enabler(event
->desc
, enabler
)
535 && event
->chan
== enabler
->chan
)
542 struct lttng_enabler_ref
* lttng_event_enabler_ref(struct lttng_event
*event
,
543 struct lttng_enabler
*enabler
)
545 struct lttng_enabler_ref
*enabler_ref
;
547 cds_list_for_each_entry(enabler_ref
,
548 &event
->enablers_ref_head
, node
) {
549 if (enabler_ref
->ref
== enabler
)
556 * Create struct lttng_event if it is missing and present in the list of
560 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
562 struct lttng_session
*session
= enabler
->chan
->session
;
563 struct lttng_probe_desc
*probe_desc
;
564 const struct lttng_event_desc
*desc
;
565 struct lttng_event
*event
;
567 struct cds_list_head
*probe_list
;
569 probe_list
= lttng_get_probe_list_head();
571 * For each probe event, if we find that a probe event matches
572 * our enabler, create an associated lttng_event if not
575 cds_list_for_each_entry(probe_desc
, probe_list
, head
) {
576 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
578 struct cds_hlist_head
*head
;
579 struct cds_hlist_node
*node
;
580 const char *event_name
;
584 desc
= probe_desc
->event_desc
[i
];
585 if (!lttng_desc_match_enabler(desc
, enabler
))
587 event_name
= desc
->name
;
588 name_len
= strlen(event_name
);
591 * Check if already created.
593 hash
= jhash(event_name
, name_len
, 0);
594 head
= &session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
595 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
596 if (event
->desc
== desc
597 && event
->chan
== enabler
->chan
)
604 * We need to create an event for this
607 ret
= lttng_event_create(probe_desc
->event_desc
[i
],
610 DBG("Unable to create event %s, error %d\n",
611 probe_desc
->event_desc
[i
]->name
, ret
);
618 * Create events associated with an enabler (if not already present),
619 * and add backward reference from the event to the enabler.
622 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
624 struct lttng_session
*session
= enabler
->chan
->session
;
625 struct lttng_event
*event
;
627 /* First ensure that probe events are created for this enabler. */
628 lttng_create_event_if_missing(enabler
);
630 /* For each event matching enabler in session event list. */
631 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
632 struct lttng_enabler_ref
*enabler_ref
;
634 if (!lttng_event_match_enabler(event
, enabler
))
637 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
640 * If no backward ref, create it.
641 * Add backward ref from event to enabler.
643 enabler_ref
= zmalloc(sizeof(*enabler_ref
));
646 enabler_ref
->ref
= enabler
;
647 cds_list_add(&enabler_ref
->node
,
648 &event
->enablers_ref_head
);
652 * Link filter bytecodes if not linked yet.
654 lttng_enabler_event_link_bytecode(event
, enabler
);
656 /* TODO: merge event context. */
662 * Called at library load: connect the probe on all enablers matching
664 * Called with session mutex held.
666 int lttng_fix_pending_events(void)
668 struct lttng_session
*session
;
670 cds_list_for_each_entry(session
, &sessions
, node
) {
671 lttng_session_lazy_sync_enablers(session
);
677 * For each session of the owner thread, execute pending statedump.
678 * Only dump state for the sessions owned by the caller thread, because
679 * we don't keep ust_lock across the entire iteration.
681 void lttng_handle_pending_statedump(void *owner
)
683 struct lttng_session
*session
;
685 /* Execute state dump */
686 do_lttng_ust_statedump(owner
);
688 /* Clear pending state dump */
692 cds_list_for_each_entry(session
, &sessions
, node
) {
693 if (session
->owner
!= owner
)
695 if (!session
->statedump_pending
)
697 session
->statedump_pending
= 0;
705 * Only used internally at session destruction.
708 void _lttng_event_destroy(struct lttng_event
*event
)
710 struct lttng_enabler_ref
*enabler_ref
, *tmp_enabler_ref
;
712 cds_list_del(&event
->node
);
713 lttng_destroy_context(event
->ctx
);
714 lttng_free_event_filter_runtime(event
);
715 /* Free event enabler refs */
716 cds_list_for_each_entry_safe(enabler_ref
, tmp_enabler_ref
,
717 &event
->enablers_ref_head
, node
)
722 void lttng_ust_events_exit(void)
724 struct lttng_session
*session
, *tmpsession
;
726 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, node
)
727 lttng_session_destroy(session
);
731 * Enabler management.
733 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
734 struct lttng_ust_event
*event_param
,
735 struct lttng_channel
*chan
)
737 struct lttng_enabler
*enabler
;
739 enabler
= zmalloc(sizeof(*enabler
));
742 enabler
->type
= type
;
743 CDS_INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
744 CDS_INIT_LIST_HEAD(&enabler
->excluder_head
);
745 memcpy(&enabler
->event_param
, event_param
,
746 sizeof(enabler
->event_param
));
747 enabler
->chan
= chan
;
749 enabler
->enabled
= 0;
750 cds_list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
751 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
755 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
757 enabler
->enabled
= 1;
758 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
762 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
764 enabler
->enabled
= 0;
765 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
769 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
770 struct lttng_ust_filter_bytecode_node
*bytecode
)
772 bytecode
->enabler
= enabler
;
773 cds_list_add_tail(&bytecode
->node
, &enabler
->filter_bytecode_head
);
774 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
778 int lttng_enabler_attach_exclusion(struct lttng_enabler
*enabler
,
779 struct lttng_ust_excluder_node
*excluder
)
781 excluder
->enabler
= enabler
;
782 cds_list_add_tail(&excluder
->node
, &enabler
->excluder_head
);
783 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
787 int lttng_attach_context(struct lttng_ust_context
*context_param
,
788 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
791 * We cannot attach a context after trace has been started for a
792 * session because the metadata does not allow expressing this
793 * information outside of the original channel scope.
795 if (session
->been_active
)
798 switch (context_param
->ctx
) {
799 case LTTNG_UST_CONTEXT_PTHREAD_ID
:
800 return lttng_add_pthread_id_to_ctx(ctx
);
801 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER
:
803 struct lttng_ust_perf_counter_ctx
*perf_ctx_param
;
805 perf_ctx_param
= &context_param
->u
.perf_counter
;
806 return lttng_add_perf_counter_to_ctx(
807 perf_ctx_param
->type
,
808 perf_ctx_param
->config
,
809 perf_ctx_param
->name
,
812 case LTTNG_UST_CONTEXT_VTID
:
813 return lttng_add_vtid_to_ctx(ctx
);
814 case LTTNG_UST_CONTEXT_VPID
:
815 return lttng_add_vpid_to_ctx(ctx
);
816 case LTTNG_UST_CONTEXT_PROCNAME
:
817 return lttng_add_procname_to_ctx(ctx
);
818 case LTTNG_UST_CONTEXT_IP
:
819 return lttng_add_ip_to_ctx(ctx
);
820 case LTTNG_UST_CONTEXT_CPU_ID
:
821 return lttng_add_cpu_id_to_ctx(ctx
);
827 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
828 struct lttng_ust_context
*context_param
)
830 #if 0 // disabled for now.
831 struct lttng_session
*session
= enabler
->chan
->session
;
834 ret
= lttng_attach_context(context_param
, &enabler
->ctx
,
838 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
844 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
846 struct lttng_ust_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
847 struct lttng_ust_excluder_node
*excluder_node
, *tmp_excluder_node
;
849 /* Destroy filter bytecode */
850 cds_list_for_each_entry_safe(filter_node
, tmp_filter_node
,
851 &enabler
->filter_bytecode_head
, node
) {
855 /* Destroy excluders */
856 cds_list_for_each_entry_safe(excluder_node
, tmp_excluder_node
,
857 &enabler
->excluder_head
, node
) {
861 /* Destroy contexts */
862 lttng_destroy_context(enabler
->ctx
);
864 cds_list_del(&enabler
->node
);
869 * lttng_session_sync_enablers should be called just before starting a
873 void lttng_session_sync_enablers(struct lttng_session
*session
)
875 struct lttng_enabler
*enabler
;
876 struct lttng_event
*event
;
878 cds_list_for_each_entry(enabler
, &session
->enablers_head
, node
)
879 lttng_enabler_ref_events(enabler
);
881 * For each event, if at least one of its enablers is enabled,
882 * and its channel and session transient states are enabled, we
883 * enable the event, else we disable it.
885 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
886 struct lttng_enabler_ref
*enabler_ref
;
887 struct lttng_bytecode_runtime
*runtime
;
888 int enabled
= 0, has_enablers_without_bytecode
= 0;
891 cds_list_for_each_entry(enabler_ref
,
892 &event
->enablers_ref_head
, node
) {
893 if (enabler_ref
->ref
->enabled
) {
899 * Enabled state is based on union of enablers, with
900 * intesection of session and channel transient enable
903 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
905 CMM_STORE_SHARED(event
->enabled
, enabled
);
907 * Sync tracepoint registration with event enabled
911 if (!event
->registered
)
912 register_event(event
);
914 if (event
->registered
)
915 unregister_event(event
);
918 /* Check if has enablers without bytecode enabled */
919 cds_list_for_each_entry(enabler_ref
,
920 &event
->enablers_ref_head
, node
) {
921 if (enabler_ref
->ref
->enabled
922 && cds_list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
923 has_enablers_without_bytecode
= 1;
927 event
->has_enablers_without_bytecode
=
928 has_enablers_without_bytecode
;
931 cds_list_for_each_entry(runtime
,
932 &event
->bytecode_runtime_head
, node
) {
933 lttng_filter_sync_state(runtime
);
939 * Apply enablers to session events, adding events to session if need
940 * be. It is required after each modification applied to an active
941 * session, and right before session "start".
942 * "lazy" sync means we only sync if required.
945 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
947 /* We can skip if session is not active */
948 if (!session
->active
)
950 lttng_session_sync_enablers(session
);