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
24 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
25 * overrides a function with a define.
27 #include "wrapper/page_alloc.h"
29 #include <linux/module.h>
30 #include <linux/mutex.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/jiffies.h>
34 #include <linux/utsname.h>
35 #include <linux/err.h>
36 #include <linux/seq_file.h>
37 #include <linux/file.h>
38 #include <linux/anon_inodes.h>
39 #include <wrapper/file.h>
40 #include <linux/jhash.h>
41 #include <linux/uaccess.h>
42 #include <linux/vmalloc.h>
44 #include <wrapper/uuid.h>
45 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
46 #include <wrapper/random.h>
47 #include <wrapper/tracepoint.h>
48 #include <wrapper/list.h>
49 #include <lttng-kernel-version.h>
50 #include <lttng-events.h>
51 #include <lttng-tracer.h>
52 #include <lttng-abi-old.h>
53 #include <lttng-endian.h>
54 #include <wrapper/vzalloc.h>
56 #define METADATA_CACHE_DEFAULT_SIZE 4096
58 static LIST_HEAD(sessions
);
59 static LIST_HEAD(lttng_transport_list
);
61 * Protect the sessions and metadata caches.
63 static DEFINE_MUTEX(sessions_mutex
);
64 static struct kmem_cache
*event_cache
;
66 static void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
67 static void lttng_session_sync_enablers(struct lttng_session
*session
);
68 static void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
70 static void _lttng_event_destroy(struct lttng_event
*event
);
71 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
72 static int _lttng_event_unregister(struct lttng_event
*event
);
74 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
75 struct lttng_channel
*chan
,
76 struct lttng_event
*event
);
78 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
80 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
82 int _lttng_field_statedump(struct lttng_session
*session
,
83 const struct lttng_event_field
*field
,
86 void synchronize_trace(void)
89 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
90 #ifdef CONFIG_PREEMPT_RT_FULL
93 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
94 #ifdef CONFIG_PREEMPT_RT
97 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
100 void lttng_lock_sessions(void)
102 mutex_lock(&sessions_mutex
);
105 void lttng_unlock_sessions(void)
107 mutex_unlock(&sessions_mutex
);
111 * Called with sessions lock held.
113 int lttng_session_active(void)
115 struct lttng_session
*iter
;
117 list_for_each_entry(iter
, &sessions
, list
) {
124 struct lttng_session
*lttng_session_create(void)
126 struct lttng_session
*session
;
127 struct lttng_metadata_cache
*metadata_cache
;
130 mutex_lock(&sessions_mutex
);
131 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
134 INIT_LIST_HEAD(&session
->chan
);
135 INIT_LIST_HEAD(&session
->events
);
136 uuid_le_gen(&session
->uuid
);
138 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
141 goto err_free_session
;
142 metadata_cache
->data
= lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE
);
143 if (!metadata_cache
->data
)
145 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
146 kref_init(&metadata_cache
->refcount
);
147 mutex_init(&metadata_cache
->lock
);
148 session
->metadata_cache
= metadata_cache
;
149 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
150 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
151 sizeof(metadata_cache
->uuid
));
152 INIT_LIST_HEAD(&session
->enablers_head
);
153 for (i
= 0; i
< LTTNG_EVENT_HT_SIZE
; i
++)
154 INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
155 list_add(&session
->list
, &sessions
);
156 mutex_unlock(&sessions_mutex
);
160 kfree(metadata_cache
);
164 mutex_unlock(&sessions_mutex
);
168 void metadata_cache_destroy(struct kref
*kref
)
170 struct lttng_metadata_cache
*cache
=
171 container_of(kref
, struct lttng_metadata_cache
, refcount
);
176 void lttng_session_destroy(struct lttng_session
*session
)
178 struct lttng_channel
*chan
, *tmpchan
;
179 struct lttng_event
*event
, *tmpevent
;
180 struct lttng_metadata_stream
*metadata_stream
;
181 struct lttng_enabler
*enabler
, *tmpenabler
;
184 mutex_lock(&sessions_mutex
);
185 ACCESS_ONCE(session
->active
) = 0;
186 list_for_each_entry(chan
, &session
->chan
, list
) {
187 ret
= lttng_syscalls_unregister(chan
);
190 list_for_each_entry(event
, &session
->events
, list
) {
191 ret
= _lttng_event_unregister(event
);
194 synchronize_trace(); /* Wait for in-flight events to complete */
195 list_for_each_entry_safe(enabler
, tmpenabler
,
196 &session
->enablers_head
, node
)
197 lttng_enabler_destroy(enabler
);
198 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
199 _lttng_event_destroy(event
);
200 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
201 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
202 _lttng_channel_destroy(chan
);
204 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
205 _lttng_metadata_channel_hangup(metadata_stream
);
206 if (session
->pid_tracker
)
207 lttng_pid_tracker_destroy(session
->pid_tracker
);
208 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
209 list_del(&session
->list
);
210 mutex_unlock(&sessions_mutex
);
214 int lttng_session_enable(struct lttng_session
*session
)
217 struct lttng_channel
*chan
;
219 mutex_lock(&sessions_mutex
);
220 if (session
->active
) {
225 /* Set transient enabler state to "enabled" */
229 * Snapshot the number of events per channel to know the type of header
232 list_for_each_entry(chan
, &session
->chan
, list
) {
233 if (chan
->header_type
)
234 continue; /* don't change it if session stop/restart */
235 if (chan
->free_event_id
< 31)
236 chan
->header_type
= 1; /* compact */
238 chan
->header_type
= 2; /* large */
241 /* We need to sync enablers with session before activation. */
242 lttng_session_sync_enablers(session
);
244 ACCESS_ONCE(session
->active
) = 1;
245 ACCESS_ONCE(session
->been_active
) = 1;
246 ret
= _lttng_session_metadata_statedump(session
);
248 ACCESS_ONCE(session
->active
) = 0;
251 ret
= lttng_statedump_start(session
);
253 ACCESS_ONCE(session
->active
) = 0;
255 mutex_unlock(&sessions_mutex
);
259 int lttng_session_disable(struct lttng_session
*session
)
263 mutex_lock(&sessions_mutex
);
264 if (!session
->active
) {
268 ACCESS_ONCE(session
->active
) = 0;
270 /* Set transient enabler state to "disabled" */
272 lttng_session_sync_enablers(session
);
274 mutex_unlock(&sessions_mutex
);
278 int lttng_session_metadata_regenerate(struct lttng_session
*session
)
281 struct lttng_channel
*chan
;
282 struct lttng_event
*event
;
283 struct lttng_metadata_cache
*cache
= session
->metadata_cache
;
284 struct lttng_metadata_stream
*stream
;
286 mutex_lock(&sessions_mutex
);
287 if (!session
->active
) {
292 mutex_lock(&cache
->lock
);
293 memset(cache
->data
, 0, cache
->cache_alloc
);
294 cache
->metadata_written
= 0;
296 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
) {
297 stream
->metadata_out
= 0;
298 stream
->metadata_in
= 0;
300 mutex_unlock(&cache
->lock
);
302 session
->metadata_dumped
= 0;
303 list_for_each_entry(chan
, &session
->chan
, list
) {
304 chan
->metadata_dumped
= 0;
307 list_for_each_entry(event
, &session
->events
, list
) {
308 event
->metadata_dumped
= 0;
311 ret
= _lttng_session_metadata_statedump(session
);
314 mutex_unlock(&sessions_mutex
);
320 int lttng_channel_enable(struct lttng_channel
*channel
)
324 mutex_lock(&sessions_mutex
);
325 if (channel
->channel_type
== METADATA_CHANNEL
) {
329 if (channel
->enabled
) {
333 /* Set transient enabler state to "enabled" */
335 lttng_session_sync_enablers(channel
->session
);
336 /* Set atomically the state to "enabled" */
337 ACCESS_ONCE(channel
->enabled
) = 1;
339 mutex_unlock(&sessions_mutex
);
343 int lttng_channel_disable(struct lttng_channel
*channel
)
347 mutex_lock(&sessions_mutex
);
348 if (channel
->channel_type
== METADATA_CHANNEL
) {
352 if (!channel
->enabled
) {
356 /* Set atomically the state to "disabled" */
357 ACCESS_ONCE(channel
->enabled
) = 0;
358 /* Set transient enabler state to "enabled" */
360 lttng_session_sync_enablers(channel
->session
);
362 mutex_unlock(&sessions_mutex
);
366 int lttng_event_enable(struct lttng_event
*event
)
370 mutex_lock(&sessions_mutex
);
371 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
375 if (event
->enabled
) {
379 switch (event
->instrumentation
) {
380 case LTTNG_KERNEL_TRACEPOINT
:
381 case LTTNG_KERNEL_SYSCALL
:
384 case LTTNG_KERNEL_KPROBE
:
385 case LTTNG_KERNEL_FUNCTION
:
386 case LTTNG_KERNEL_NOOP
:
387 ACCESS_ONCE(event
->enabled
) = 1;
389 case LTTNG_KERNEL_KRETPROBE
:
390 ret
= lttng_kretprobes_event_enable_state(event
, 1);
397 mutex_unlock(&sessions_mutex
);
401 int lttng_event_disable(struct lttng_event
*event
)
405 mutex_lock(&sessions_mutex
);
406 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
410 if (!event
->enabled
) {
414 switch (event
->instrumentation
) {
415 case LTTNG_KERNEL_TRACEPOINT
:
416 case LTTNG_KERNEL_SYSCALL
:
419 case LTTNG_KERNEL_KPROBE
:
420 case LTTNG_KERNEL_FUNCTION
:
421 case LTTNG_KERNEL_NOOP
:
422 ACCESS_ONCE(event
->enabled
) = 0;
424 case LTTNG_KERNEL_KRETPROBE
:
425 ret
= lttng_kretprobes_event_enable_state(event
, 0);
432 mutex_unlock(&sessions_mutex
);
436 static struct lttng_transport
*lttng_transport_find(const char *name
)
438 struct lttng_transport
*transport
;
440 list_for_each_entry(transport
, <tng_transport_list
, node
) {
441 if (!strcmp(transport
->name
, name
))
447 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
448 const char *transport_name
,
450 size_t subbuf_size
, size_t num_subbuf
,
451 unsigned int switch_timer_interval
,
452 unsigned int read_timer_interval
,
453 enum channel_type channel_type
)
455 struct lttng_channel
*chan
;
456 struct lttng_transport
*transport
= NULL
;
458 mutex_lock(&sessions_mutex
);
459 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
460 goto active
; /* Refuse to add channel to active session */
461 transport
= lttng_transport_find(transport_name
);
463 printk(KERN_WARNING
"LTTng transport %s not found\n",
467 if (!try_module_get(transport
->owner
)) {
468 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
471 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
474 chan
->session
= session
;
475 chan
->id
= session
->free_chan_id
++;
476 chan
->ops
= &transport
->ops
;
478 * Note: the channel creation op already writes into the packet
479 * headers. Therefore the "chan" information used as input
480 * should be already accessible.
482 chan
->chan
= transport
->ops
.channel_create(transport_name
,
483 chan
, buf_addr
, subbuf_size
, num_subbuf
,
484 switch_timer_interval
, read_timer_interval
);
489 chan
->transport
= transport
;
490 chan
->channel_type
= channel_type
;
491 list_add(&chan
->list
, &session
->chan
);
492 mutex_unlock(&sessions_mutex
);
499 module_put(transport
->owner
);
502 mutex_unlock(&sessions_mutex
);
507 * Only used internally at session destruction for per-cpu channels, and
508 * when metadata channel is released.
509 * Needs to be called with sessions mutex held.
512 void _lttng_channel_destroy(struct lttng_channel
*chan
)
514 chan
->ops
->channel_destroy(chan
->chan
);
515 module_put(chan
->transport
->owner
);
516 list_del(&chan
->list
);
517 lttng_destroy_context(chan
->ctx
);
521 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
523 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
525 /* Protect the metadata cache with the sessions_mutex. */
526 mutex_lock(&sessions_mutex
);
527 _lttng_channel_destroy(chan
);
528 mutex_unlock(&sessions_mutex
);
530 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
533 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
535 stream
->finalized
= 1;
536 wake_up_interruptible(&stream
->read_wait
);
540 * Supports event creation while tracing session is active.
541 * Needs to be called with sessions mutex held.
543 struct lttng_event
*_lttng_event_create(struct lttng_channel
*chan
,
544 struct lttng_kernel_event
*event_param
,
546 const struct lttng_event_desc
*event_desc
,
547 enum lttng_kernel_instrumentation itype
)
549 struct lttng_session
*session
= chan
->session
;
550 struct lttng_event
*event
;
551 const char *event_name
;
552 struct hlist_head
*head
;
557 if (chan
->free_event_id
== -1U) {
563 case LTTNG_KERNEL_TRACEPOINT
:
564 event_name
= event_desc
->name
;
566 case LTTNG_KERNEL_KPROBE
:
567 case LTTNG_KERNEL_KRETPROBE
:
568 case LTTNG_KERNEL_FUNCTION
:
569 case LTTNG_KERNEL_NOOP
:
570 case LTTNG_KERNEL_SYSCALL
:
571 event_name
= event_param
->name
;
578 name_len
= strlen(event_name
);
579 hash
= jhash(event_name
, name_len
, 0);
580 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
581 lttng_hlist_for_each_entry(event
, head
, hlist
) {
582 WARN_ON_ONCE(!event
->desc
);
583 if (!strncmp(event
->desc
->name
, event_name
,
584 LTTNG_KERNEL_SYM_NAME_LEN
- 1)
585 && chan
== event
->chan
) {
591 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
597 event
->filter
= filter
;
598 event
->id
= chan
->free_event_id
++;
599 event
->instrumentation
= itype
;
600 event
->evtype
= LTTNG_TYPE_EVENT
;
601 INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
602 INIT_LIST_HEAD(&event
->enablers_ref_head
);
605 case LTTNG_KERNEL_TRACEPOINT
:
606 /* Event will be enabled by enabler sync. */
608 event
->registered
= 0;
609 event
->desc
= lttng_event_get(event_name
);
614 /* Populate lttng_event structure before event registration. */
617 case LTTNG_KERNEL_KPROBE
:
619 * Needs to be explicitly enabled after creation, since
620 * we may want to apply filters.
623 event
->registered
= 1;
625 * Populate lttng_event structure before event
629 ret
= lttng_kprobes_register(event_name
,
630 event_param
->u
.kprobe
.symbol_name
,
631 event_param
->u
.kprobe
.offset
,
632 event_param
->u
.kprobe
.addr
,
638 ret
= try_module_get(event
->desc
->owner
);
641 case LTTNG_KERNEL_KRETPROBE
:
643 struct lttng_event
*event_return
;
645 /* kretprobe defines 2 events */
647 * Needs to be explicitly enabled after creation, since
648 * we may want to apply filters.
651 event
->registered
= 1;
653 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
658 event_return
->chan
= chan
;
659 event_return
->filter
= filter
;
660 event_return
->id
= chan
->free_event_id
++;
661 event_return
->enabled
= 0;
662 event_return
->registered
= 1;
663 event_return
->instrumentation
= itype
;
665 * Populate lttng_event structure before kretprobe registration.
668 ret
= lttng_kretprobes_register(event_name
,
669 event_param
->u
.kretprobe
.symbol_name
,
670 event_param
->u
.kretprobe
.offset
,
671 event_param
->u
.kretprobe
.addr
,
672 event
, event_return
);
674 kmem_cache_free(event_cache
, event_return
);
678 /* Take 2 refs on the module: one per event. */
679 ret
= try_module_get(event
->desc
->owner
);
681 ret
= try_module_get(event
->desc
->owner
);
683 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
685 WARN_ON_ONCE(ret
> 0);
687 kmem_cache_free(event_cache
, event_return
);
688 module_put(event
->desc
->owner
);
689 module_put(event
->desc
->owner
);
690 goto statedump_error
;
692 list_add(&event_return
->list
, &chan
->session
->events
);
695 case LTTNG_KERNEL_FUNCTION
:
697 * Needs to be explicitly enabled after creation, since
698 * we may want to apply filters.
701 event
->registered
= 1;
703 * Populate lttng_event structure before event
707 ret
= lttng_ftrace_register(event_name
,
708 event_param
->u
.ftrace
.symbol_name
,
713 ret
= try_module_get(event
->desc
->owner
);
716 case LTTNG_KERNEL_NOOP
:
717 case LTTNG_KERNEL_SYSCALL
:
719 * Needs to be explicitly enabled after creation, since
720 * we may want to apply filters.
723 event
->registered
= 0;
724 event
->desc
= event_desc
;
735 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
736 WARN_ON_ONCE(ret
> 0);
738 goto statedump_error
;
740 hlist_add_head(&event
->hlist
, head
);
741 list_add(&event
->list
, &chan
->session
->events
);
745 /* If a statedump error occurs, events will not be readable. */
747 kmem_cache_free(event_cache
, event
);
755 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
756 struct lttng_kernel_event
*event_param
,
758 const struct lttng_event_desc
*event_desc
,
759 enum lttng_kernel_instrumentation itype
)
761 struct lttng_event
*event
;
763 mutex_lock(&sessions_mutex
);
764 event
= _lttng_event_create(chan
, event_param
, filter
, event_desc
,
766 mutex_unlock(&sessions_mutex
);
770 /* Only used for tracepoints for now. */
772 void register_event(struct lttng_event
*event
)
774 const struct lttng_event_desc
*desc
;
777 if (event
->registered
)
781 switch (event
->instrumentation
) {
782 case LTTNG_KERNEL_TRACEPOINT
:
783 ret
= lttng_wrapper_tracepoint_probe_register(desc
->kname
,
784 desc
->probe_callback
,
787 case LTTNG_KERNEL_SYSCALL
:
788 ret
= lttng_syscall_filter_enable(event
->chan
,
791 case LTTNG_KERNEL_KPROBE
:
792 case LTTNG_KERNEL_KRETPROBE
:
793 case LTTNG_KERNEL_FUNCTION
:
794 case LTTNG_KERNEL_NOOP
:
801 event
->registered
= 1;
805 * Only used internally at session destruction.
807 int _lttng_event_unregister(struct lttng_event
*event
)
809 const struct lttng_event_desc
*desc
;
812 if (!event
->registered
)
816 switch (event
->instrumentation
) {
817 case LTTNG_KERNEL_TRACEPOINT
:
818 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
819 event
->desc
->probe_callback
,
822 case LTTNG_KERNEL_KPROBE
:
823 lttng_kprobes_unregister(event
);
826 case LTTNG_KERNEL_KRETPROBE
:
827 lttng_kretprobes_unregister(event
);
830 case LTTNG_KERNEL_FUNCTION
:
831 lttng_ftrace_unregister(event
);
834 case LTTNG_KERNEL_SYSCALL
:
835 ret
= lttng_syscall_filter_disable(event
->chan
,
838 case LTTNG_KERNEL_NOOP
:
845 event
->registered
= 0;
850 * Only used internally at session destruction.
853 void _lttng_event_destroy(struct lttng_event
*event
)
855 switch (event
->instrumentation
) {
856 case LTTNG_KERNEL_TRACEPOINT
:
857 lttng_event_put(event
->desc
);
859 case LTTNG_KERNEL_KPROBE
:
860 module_put(event
->desc
->owner
);
861 lttng_kprobes_destroy_private(event
);
863 case LTTNG_KERNEL_KRETPROBE
:
864 module_put(event
->desc
->owner
);
865 lttng_kretprobes_destroy_private(event
);
867 case LTTNG_KERNEL_FUNCTION
:
868 module_put(event
->desc
->owner
);
869 lttng_ftrace_destroy_private(event
);
871 case LTTNG_KERNEL_NOOP
:
872 case LTTNG_KERNEL_SYSCALL
:
877 list_del(&event
->list
);
878 lttng_destroy_context(event
->ctx
);
879 kmem_cache_free(event_cache
, event
);
882 int lttng_session_track_pid(struct lttng_session
*session
, int pid
)
888 mutex_lock(&sessions_mutex
);
890 /* track all pids: destroy tracker. */
891 if (session
->pid_tracker
) {
892 struct lttng_pid_tracker
*lpf
;
894 lpf
= session
->pid_tracker
;
895 rcu_assign_pointer(session
->pid_tracker
, NULL
);
897 lttng_pid_tracker_destroy(lpf
);
901 if (!session
->pid_tracker
) {
902 struct lttng_pid_tracker
*lpf
;
904 lpf
= lttng_pid_tracker_create();
909 ret
= lttng_pid_tracker_add(lpf
, pid
);
910 rcu_assign_pointer(session
->pid_tracker
, lpf
);
912 ret
= lttng_pid_tracker_add(session
->pid_tracker
, pid
);
916 mutex_unlock(&sessions_mutex
);
920 int lttng_session_untrack_pid(struct lttng_session
*session
, int pid
)
926 mutex_lock(&sessions_mutex
);
928 /* untrack all pids: replace by empty tracker. */
929 struct lttng_pid_tracker
*old_lpf
= session
->pid_tracker
;
930 struct lttng_pid_tracker
*lpf
;
932 lpf
= lttng_pid_tracker_create();
937 rcu_assign_pointer(session
->pid_tracker
, lpf
);
940 lttng_pid_tracker_destroy(old_lpf
);
943 if (!session
->pid_tracker
) {
947 ret
= lttng_pid_tracker_del(session
->pid_tracker
, pid
);
950 mutex_unlock(&sessions_mutex
);
955 void *pid_list_start(struct seq_file
*m
, loff_t
*pos
)
957 struct lttng_session
*session
= m
->private;
958 struct lttng_pid_tracker
*lpf
;
959 struct lttng_pid_hash_node
*e
;
962 mutex_lock(&sessions_mutex
);
963 lpf
= session
->pid_tracker
;
965 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
966 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
968 lttng_hlist_for_each_entry(e
, head
, hlist
) {
974 /* PID tracker disabled. */
975 if (iter
>= *pos
&& iter
== 0) {
976 return session
; /* empty tracker */
984 /* Called with sessions_mutex held. */
986 void *pid_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
988 struct lttng_session
*session
= m
->private;
989 struct lttng_pid_tracker
*lpf
;
990 struct lttng_pid_hash_node
*e
;
994 lpf
= session
->pid_tracker
;
996 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
997 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
999 lttng_hlist_for_each_entry(e
, head
, hlist
) {
1000 if (iter
++ >= *ppos
)
1005 /* PID tracker disabled. */
1006 if (iter
>= *ppos
&& iter
== 0)
1007 return session
; /* empty tracker */
1016 void pid_list_stop(struct seq_file
*m
, void *p
)
1018 mutex_unlock(&sessions_mutex
);
1022 int pid_list_show(struct seq_file
*m
, void *p
)
1026 if (p
== m
->private) {
1027 /* Tracker disabled. */
1030 const struct lttng_pid_hash_node
*e
= p
;
1032 pid
= lttng_pid_tracker_get_node_pid(e
);
1034 seq_printf(m
, "process { pid = %d; };\n", pid
);
1039 const struct seq_operations lttng_tracker_pids_list_seq_ops
= {
1040 .start
= pid_list_start
,
1041 .next
= pid_list_next
,
1042 .stop
= pid_list_stop
,
1043 .show
= pid_list_show
,
1047 int lttng_tracker_pids_list_open(struct inode
*inode
, struct file
*file
)
1049 return seq_open(file
, <tng_tracker_pids_list_seq_ops
);
1053 int lttng_tracker_pids_list_release(struct inode
*inode
, struct file
*file
)
1055 struct seq_file
*m
= file
->private_data
;
1056 struct lttng_session
*session
= m
->private;
1059 WARN_ON_ONCE(!session
);
1060 ret
= seq_release(inode
, file
);
1061 if (!ret
&& session
)
1062 fput(session
->file
);
1066 const struct file_operations lttng_tracker_pids_list_fops
= {
1067 .owner
= THIS_MODULE
,
1068 .open
= lttng_tracker_pids_list_open
,
1070 .llseek
= seq_lseek
,
1071 .release
= lttng_tracker_pids_list_release
,
1074 int lttng_session_list_tracker_pids(struct lttng_session
*session
)
1076 struct file
*tracker_pids_list_file
;
1080 file_fd
= lttng_get_unused_fd();
1086 tracker_pids_list_file
= anon_inode_getfile("[lttng_tracker_pids_list]",
1087 <tng_tracker_pids_list_fops
,
1089 if (IS_ERR(tracker_pids_list_file
)) {
1090 ret
= PTR_ERR(tracker_pids_list_file
);
1093 if (atomic_long_add_unless(&session
->file
->f_count
,
1094 1, INT_MAX
) == INT_MAX
) {
1095 goto refcount_error
;
1097 ret
= lttng_tracker_pids_list_fops
.open(NULL
, tracker_pids_list_file
);
1100 m
= tracker_pids_list_file
->private_data
;
1101 m
->private = session
;
1102 fd_install(file_fd
, tracker_pids_list_file
);
1107 atomic_long_dec(&session
->file
->f_count
);
1109 fput(tracker_pids_list_file
);
1111 put_unused_fd(file_fd
);
1117 * Enabler management.
1120 int lttng_match_enabler_wildcard(const char *desc_name
,
1123 /* Compare excluding final '*' */
1124 if (strncmp(desc_name
, name
, strlen(name
) - 1))
1130 int lttng_match_enabler_name(const char *desc_name
,
1133 if (strcmp(desc_name
, name
))
1139 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
1140 struct lttng_enabler
*enabler
)
1142 const char *desc_name
, *enabler_name
;
1144 enabler_name
= enabler
->event_param
.name
;
1145 switch (enabler
->event_param
.instrumentation
) {
1146 case LTTNG_KERNEL_TRACEPOINT
:
1147 desc_name
= desc
->name
;
1149 case LTTNG_KERNEL_SYSCALL
:
1150 desc_name
= desc
->name
;
1151 if (!strncmp(desc_name
, "compat_", strlen("compat_")))
1152 desc_name
+= strlen("compat_");
1153 if (!strncmp(desc_name
, "syscall_exit_",
1154 strlen("syscall_exit_"))) {
1155 desc_name
+= strlen("syscall_exit_");
1156 } else if (!strncmp(desc_name
, "syscall_entry_",
1157 strlen("syscall_entry_"))) {
1158 desc_name
+= strlen("syscall_entry_");
1168 switch (enabler
->type
) {
1169 case LTTNG_ENABLER_WILDCARD
:
1170 return lttng_match_enabler_wildcard(desc_name
, enabler_name
);
1171 case LTTNG_ENABLER_NAME
:
1172 return lttng_match_enabler_name(desc_name
, enabler_name
);
1179 int lttng_event_match_enabler(struct lttng_event
*event
,
1180 struct lttng_enabler
*enabler
)
1182 if (enabler
->event_param
.instrumentation
!= event
->instrumentation
)
1184 if (lttng_desc_match_enabler(event
->desc
, enabler
)
1185 && event
->chan
== enabler
->chan
)
1192 struct lttng_enabler_ref
*lttng_event_enabler_ref(struct lttng_event
*event
,
1193 struct lttng_enabler
*enabler
)
1195 struct lttng_enabler_ref
*enabler_ref
;
1197 list_for_each_entry(enabler_ref
,
1198 &event
->enablers_ref_head
, node
) {
1199 if (enabler_ref
->ref
== enabler
)
1206 void lttng_create_tracepoint_if_missing(struct lttng_enabler
*enabler
)
1208 struct lttng_session
*session
= enabler
->chan
->session
;
1209 struct lttng_probe_desc
*probe_desc
;
1210 const struct lttng_event_desc
*desc
;
1212 struct list_head
*probe_list
;
1214 probe_list
= lttng_get_probe_list_head();
1216 * For each probe event, if we find that a probe event matches
1217 * our enabler, create an associated lttng_event if not
1220 list_for_each_entry(probe_desc
, probe_list
, head
) {
1221 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
1223 struct hlist_head
*head
;
1224 const char *event_name
;
1227 struct lttng_event
*event
;
1229 desc
= probe_desc
->event_desc
[i
];
1230 if (!lttng_desc_match_enabler(desc
, enabler
))
1232 event_name
= desc
->name
;
1233 name_len
= strlen(event_name
);
1236 * Check if already created.
1238 hash
= jhash(event_name
, name_len
, 0);
1239 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
1240 lttng_hlist_for_each_entry(event
, head
, hlist
) {
1241 if (event
->desc
== desc
1242 && event
->chan
== enabler
->chan
)
1249 * We need to create an event for this
1252 event
= _lttng_event_create(enabler
->chan
,
1254 LTTNG_KERNEL_TRACEPOINT
);
1256 printk(KERN_INFO
"Unable to create event %s\n",
1257 probe_desc
->event_desc
[i
]->name
);
1264 void lttng_create_syscall_if_missing(struct lttng_enabler
*enabler
)
1268 ret
= lttng_syscalls_register(enabler
->chan
, NULL
);
1273 * Create struct lttng_event if it is missing and present in the list of
1274 * tracepoint probes.
1275 * Should be called with sessions mutex held.
1278 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
1280 switch (enabler
->event_param
.instrumentation
) {
1281 case LTTNG_KERNEL_TRACEPOINT
:
1282 lttng_create_tracepoint_if_missing(enabler
);
1284 case LTTNG_KERNEL_SYSCALL
:
1285 lttng_create_syscall_if_missing(enabler
);
1294 * Create events associated with an enabler (if not already present),
1295 * and add backward reference from the event to the enabler.
1296 * Should be called with sessions mutex held.
1299 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
1301 struct lttng_session
*session
= enabler
->chan
->session
;
1302 struct lttng_event
*event
;
1304 /* First ensure that probe events are created for this enabler. */
1305 lttng_create_event_if_missing(enabler
);
1307 /* For each event matching enabler in session event list. */
1308 list_for_each_entry(event
, &session
->events
, list
) {
1309 struct lttng_enabler_ref
*enabler_ref
;
1311 if (!lttng_event_match_enabler(event
, enabler
))
1313 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
1316 * If no backward ref, create it.
1317 * Add backward ref from event to enabler.
1319 enabler_ref
= kzalloc(sizeof(*enabler_ref
), GFP_KERNEL
);
1322 enabler_ref
->ref
= enabler
;
1323 list_add(&enabler_ref
->node
,
1324 &event
->enablers_ref_head
);
1328 * Link filter bytecodes if not linked yet.
1330 lttng_enabler_event_link_bytecode(event
, enabler
);
1332 /* TODO: merge event context. */
1338 * Called at module load: connect the probe on all enablers matching
1340 * Called with sessions lock held.
1342 int lttng_fix_pending_events(void)
1344 struct lttng_session
*session
;
1346 list_for_each_entry(session
, &sessions
, list
)
1347 lttng_session_lazy_sync_enablers(session
);
1351 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1352 struct lttng_kernel_event
*event_param
,
1353 struct lttng_channel
*chan
)
1355 struct lttng_enabler
*enabler
;
1357 enabler
= kzalloc(sizeof(*enabler
), GFP_KERNEL
);
1360 enabler
->type
= type
;
1361 INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1362 memcpy(&enabler
->event_param
, event_param
,
1363 sizeof(enabler
->event_param
));
1364 enabler
->chan
= chan
;
1366 enabler
->enabled
= 0;
1367 enabler
->evtype
= LTTNG_TYPE_ENABLER
;
1368 mutex_lock(&sessions_mutex
);
1369 list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1370 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1371 mutex_unlock(&sessions_mutex
);
1375 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1377 mutex_lock(&sessions_mutex
);
1378 enabler
->enabled
= 1;
1379 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1380 mutex_unlock(&sessions_mutex
);
1384 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1386 mutex_lock(&sessions_mutex
);
1387 enabler
->enabled
= 0;
1388 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1389 mutex_unlock(&sessions_mutex
);
1393 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1394 struct lttng_kernel_filter_bytecode __user
*bytecode
)
1396 struct lttng_filter_bytecode_node
*bytecode_node
;
1397 uint32_t bytecode_len
;
1400 ret
= get_user(bytecode_len
, &bytecode
->len
);
1403 bytecode_node
= kzalloc(sizeof(*bytecode_node
) + bytecode_len
,
1407 ret
= copy_from_user(&bytecode_node
->bc
, bytecode
,
1408 sizeof(*bytecode
) + bytecode_len
);
1411 bytecode_node
->enabler
= enabler
;
1412 /* Enforce length based on allocated size */
1413 bytecode_node
->bc
.len
= bytecode_len
;
1414 list_add_tail(&bytecode_node
->node
, &enabler
->filter_bytecode_head
);
1415 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1419 kfree(bytecode_node
);
1423 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1424 struct lttng_kernel_context
*context_param
)
1430 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1432 struct lttng_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1434 /* Destroy filter bytecode */
1435 list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1436 &enabler
->filter_bytecode_head
, node
) {
1440 /* Destroy contexts */
1441 lttng_destroy_context(enabler
->ctx
);
1443 list_del(&enabler
->node
);
1448 * lttng_session_sync_enablers should be called just before starting a
1450 * Should be called with sessions mutex held.
1453 void lttng_session_sync_enablers(struct lttng_session
*session
)
1455 struct lttng_enabler
*enabler
;
1456 struct lttng_event
*event
;
1458 list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1459 lttng_enabler_ref_events(enabler
);
1461 * For each event, if at least one of its enablers is enabled,
1462 * and its channel and session transient states are enabled, we
1463 * enable the event, else we disable it.
1465 list_for_each_entry(event
, &session
->events
, list
) {
1466 struct lttng_enabler_ref
*enabler_ref
;
1467 struct lttng_bytecode_runtime
*runtime
;
1468 int enabled
= 0, has_enablers_without_bytecode
= 0;
1470 switch (event
->instrumentation
) {
1471 case LTTNG_KERNEL_TRACEPOINT
:
1472 case LTTNG_KERNEL_SYSCALL
:
1474 list_for_each_entry(enabler_ref
,
1475 &event
->enablers_ref_head
, node
) {
1476 if (enabler_ref
->ref
->enabled
) {
1483 /* Not handled with lazy sync. */
1487 * Enabled state is based on union of enablers, with
1488 * intesection of session and channel transient enable
1491 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
1493 ACCESS_ONCE(event
->enabled
) = enabled
;
1495 * Sync tracepoint registration with event enabled
1499 register_event(event
);
1501 _lttng_event_unregister(event
);
1504 /* Check if has enablers without bytecode enabled */
1505 list_for_each_entry(enabler_ref
,
1506 &event
->enablers_ref_head
, node
) {
1507 if (enabler_ref
->ref
->enabled
1508 && list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1509 has_enablers_without_bytecode
= 1;
1513 event
->has_enablers_without_bytecode
=
1514 has_enablers_without_bytecode
;
1516 /* Enable filters */
1517 list_for_each_entry(runtime
,
1518 &event
->bytecode_runtime_head
, node
)
1519 lttng_filter_sync_state(runtime
);
1524 * Apply enablers to session events, adding events to session if need
1525 * be. It is required after each modification applied to an active
1526 * session, and right before session "start".
1527 * "lazy" sync means we only sync if required.
1528 * Should be called with sessions mutex held.
1531 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1533 /* We can skip if session is not active */
1534 if (!session
->active
)
1536 lttng_session_sync_enablers(session
);
1540 * Serialize at most one packet worth of metadata into a metadata
1542 * We grab the metadata cache mutex to get exclusive access to our metadata
1543 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1544 * allows us to do racy operations such as looking for remaining space left in
1545 * packet and write, since mutual exclusion protects us from concurrent writes.
1546 * Mutual exclusion on the metadata cache allow us to read the cache content
1547 * without racing against reallocation of the cache by updates.
1548 * Returns the number of bytes written in the channel, 0 if no data
1549 * was written and a negative value on error.
1551 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
1552 struct channel
*chan
)
1554 struct lib_ring_buffer_ctx ctx
;
1556 size_t len
, reserve_len
;
1559 * Ensure we support mutiple get_next / put sequences followed by
1560 * put_next. The metadata cache lock protects reading the metadata
1561 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1562 * "flush" operations on the buffer invoked by different processes.
1563 * Moreover, since the metadata cache memory can be reallocated, we
1564 * need to have exclusive access against updates even though we only
1567 mutex_lock(&stream
->metadata_cache
->lock
);
1568 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
1569 if (stream
->metadata_in
!= stream
->metadata_out
)
1572 /* Metadata regenerated, change the version. */
1573 if (stream
->metadata_cache
->version
!= stream
->version
)
1574 stream
->version
= stream
->metadata_cache
->version
;
1576 len
= stream
->metadata_cache
->metadata_written
-
1577 stream
->metadata_in
;
1580 reserve_len
= min_t(size_t,
1581 stream
->transport
->ops
.packet_avail_size(chan
),
1583 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
1586 * If reservation failed, return an error to the caller.
1588 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
1590 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
1593 stream
->transport
->ops
.event_write(&ctx
,
1594 stream
->metadata_cache
->data
+ stream
->metadata_in
,
1596 stream
->transport
->ops
.event_commit(&ctx
);
1597 stream
->metadata_in
+= reserve_len
;
1601 mutex_unlock(&stream
->metadata_cache
->lock
);
1606 * Write the metadata to the metadata cache.
1607 * Must be called with sessions_mutex held.
1608 * The metadata cache lock protects us from concurrent read access from
1609 * thread outputting metadata content to ring buffer.
1611 int lttng_metadata_printf(struct lttng_session
*session
,
1612 const char *fmt
, ...)
1617 struct lttng_metadata_stream
*stream
;
1619 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
1622 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
1628 mutex_lock(&session
->metadata_cache
->lock
);
1629 if (session
->metadata_cache
->metadata_written
+ len
>
1630 session
->metadata_cache
->cache_alloc
) {
1631 char *tmp_cache_realloc
;
1632 unsigned int tmp_cache_alloc_size
;
1634 tmp_cache_alloc_size
= max_t(unsigned int,
1635 session
->metadata_cache
->cache_alloc
+ len
,
1636 session
->metadata_cache
->cache_alloc
<< 1);
1637 tmp_cache_realloc
= lttng_vzalloc(tmp_cache_alloc_size
);
1638 if (!tmp_cache_realloc
)
1640 if (session
->metadata_cache
->data
) {
1641 memcpy(tmp_cache_realloc
,
1642 session
->metadata_cache
->data
,
1643 session
->metadata_cache
->cache_alloc
);
1644 vfree(session
->metadata_cache
->data
);
1647 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
1648 session
->metadata_cache
->data
= tmp_cache_realloc
;
1650 memcpy(session
->metadata_cache
->data
+
1651 session
->metadata_cache
->metadata_written
,
1653 session
->metadata_cache
->metadata_written
+= len
;
1654 mutex_unlock(&session
->metadata_cache
->lock
);
1657 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
1658 wake_up_interruptible(&stream
->read_wait
);
1663 mutex_unlock(&session
->metadata_cache
->lock
);
1669 int print_tabs(struct lttng_session
*session
, size_t nesting
)
1673 for (i
= 0; i
< nesting
; i
++) {
1676 ret
= lttng_metadata_printf(session
, " ");
1685 * Must be called with sessions_mutex held.
1688 int _lttng_struct_type_statedump(struct lttng_session
*session
,
1689 const struct lttng_type
*type
,
1693 uint32_t i
, nr_fields
;
1695 ret
= print_tabs(session
, nesting
);
1698 ret
= lttng_metadata_printf(session
,
1702 nr_fields
= type
->u
._struct
.nr_fields
;
1703 for (i
= 0; i
< nr_fields
; i
++) {
1704 const struct lttng_event_field
*iter_field
;
1706 iter_field
= &type
->u
._struct
.fields
[i
];
1707 ret
= _lttng_field_statedump(session
, iter_field
, nesting
+ 1);
1711 ret
= print_tabs(session
, nesting
);
1714 ret
= lttng_metadata_printf(session
,
1720 * Must be called with sessions_mutex held.
1723 int _lttng_struct_statedump(struct lttng_session
*session
,
1724 const struct lttng_event_field
*field
,
1729 ret
= _lttng_struct_type_statedump(session
,
1730 &field
->type
, nesting
);
1733 ret
= lttng_metadata_printf(session
,
1740 * Must be called with sessions_mutex held.
1743 int _lttng_variant_type_statedump(struct lttng_session
*session
,
1744 const struct lttng_type
*type
,
1748 uint32_t i
, nr_choices
;
1750 ret
= print_tabs(session
, nesting
);
1753 ret
= lttng_metadata_printf(session
,
1754 "variant <_%s> {\n",
1755 type
->u
.variant
.tag_name
);
1758 nr_choices
= type
->u
.variant
.nr_choices
;
1759 for (i
= 0; i
< nr_choices
; i
++) {
1760 const struct lttng_event_field
*iter_field
;
1762 iter_field
= &type
->u
.variant
.choices
[i
];
1763 ret
= _lttng_field_statedump(session
, iter_field
, nesting
+ 1);
1767 ret
= print_tabs(session
, nesting
);
1770 ret
= lttng_metadata_printf(session
,
1776 * Must be called with sessions_mutex held.
1779 int _lttng_variant_statedump(struct lttng_session
*session
,
1780 const struct lttng_event_field
*field
,
1785 ret
= _lttng_variant_type_statedump(session
,
1786 &field
->type
, nesting
);
1789 ret
= lttng_metadata_printf(session
,
1796 * Must be called with sessions_mutex held.
1799 int _lttng_array_compound_statedump(struct lttng_session
*session
,
1800 const struct lttng_event_field
*field
,
1804 const struct lttng_type
*elem_type
;
1806 /* Only array of structures and variants are currently supported. */
1807 elem_type
= field
->type
.u
.array_compound
.elem_type
;
1808 switch (elem_type
->atype
) {
1810 ret
= _lttng_struct_type_statedump(session
, elem_type
, nesting
);
1815 ret
= _lttng_variant_type_statedump(session
, elem_type
, nesting
);
1822 ret
= lttng_metadata_printf(session
,
1825 field
->type
.u
.array_compound
.length
);
1830 * Must be called with sessions_mutex held.
1833 int _lttng_sequence_compound_statedump(struct lttng_session
*session
,
1834 const struct lttng_event_field
*field
,
1838 const char *length_name
;
1839 const struct lttng_type
*elem_type
;
1841 length_name
= field
->type
.u
.sequence_compound
.length_name
;
1843 /* Only array of structures and variants are currently supported. */
1844 elem_type
= field
->type
.u
.sequence_compound
.elem_type
;
1845 switch (elem_type
->atype
) {
1847 ret
= _lttng_struct_type_statedump(session
, elem_type
, nesting
);
1852 ret
= _lttng_variant_type_statedump(session
, elem_type
, nesting
);
1859 ret
= lttng_metadata_printf(session
,
1867 * Must be called with sessions_mutex held.
1870 int _lttng_field_statedump(struct lttng_session
*session
,
1871 const struct lttng_event_field
*field
,
1876 switch (field
->type
.atype
) {
1878 ret
= print_tabs(session
, nesting
);
1881 ret
= lttng_metadata_printf(session
,
1882 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
1883 field
->type
.u
.basic
.integer
.size
,
1884 field
->type
.u
.basic
.integer
.alignment
,
1885 field
->type
.u
.basic
.integer
.signedness
,
1886 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
1888 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1891 field
->type
.u
.basic
.integer
.base
,
1892 #if __BYTE_ORDER == __BIG_ENDIAN
1893 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1895 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1900 ret
= print_tabs(session
, nesting
);
1903 ret
= lttng_metadata_printf(session
,
1905 field
->type
.u
.basic
.enumeration
.name
,
1910 const struct lttng_basic_type
*elem_type
;
1912 elem_type
= &field
->type
.u
.array
.elem_type
;
1913 if (field
->type
.u
.array
.elem_alignment
) {
1914 ret
= print_tabs(session
, nesting
);
1917 ret
= lttng_metadata_printf(session
,
1918 "struct { } align(%u) _%s_padding;\n",
1919 field
->type
.u
.array
.elem_alignment
* CHAR_BIT
,
1924 ret
= print_tabs(session
, nesting
);
1927 ret
= lttng_metadata_printf(session
,
1928 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
1929 elem_type
->u
.basic
.integer
.size
,
1930 elem_type
->u
.basic
.integer
.alignment
,
1931 elem_type
->u
.basic
.integer
.signedness
,
1932 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1934 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1937 elem_type
->u
.basic
.integer
.base
,
1938 #if __BYTE_ORDER == __BIG_ENDIAN
1939 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1941 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1943 field
->name
, field
->type
.u
.array
.length
);
1946 case atype_sequence
:
1948 const struct lttng_basic_type
*elem_type
;
1949 const struct lttng_basic_type
*length_type
;
1951 elem_type
= &field
->type
.u
.sequence
.elem_type
;
1952 length_type
= &field
->type
.u
.sequence
.length_type
;
1953 ret
= print_tabs(session
, nesting
);
1956 ret
= lttng_metadata_printf(session
,
1957 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
1958 length_type
->u
.basic
.integer
.size
,
1959 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
1960 length_type
->u
.basic
.integer
.signedness
,
1961 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1963 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1966 length_type
->u
.basic
.integer
.base
,
1967 #if __BYTE_ORDER == __BIG_ENDIAN
1968 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1970 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1976 if (field
->type
.u
.sequence
.elem_alignment
) {
1977 ret
= print_tabs(session
, nesting
);
1980 ret
= lttng_metadata_printf(session
,
1981 "struct { } align(%u) _%s_padding;\n",
1982 field
->type
.u
.sequence
.elem_alignment
* CHAR_BIT
,
1987 ret
= print_tabs(session
, nesting
);
1990 ret
= lttng_metadata_printf(session
,
1991 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
1992 elem_type
->u
.basic
.integer
.size
,
1993 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
1994 elem_type
->u
.basic
.integer
.signedness
,
1995 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1997 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
2000 elem_type
->u
.basic
.integer
.base
,
2001 #if __BYTE_ORDER == __BIG_ENDIAN
2002 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
2004 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
2012 /* Default encoding is UTF8 */
2013 ret
= print_tabs(session
, nesting
);
2016 ret
= lttng_metadata_printf(session
,
2018 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
2019 " { encoding = ASCII; }" : "",
2023 ret
= _lttng_struct_statedump(session
, field
, nesting
);
2025 case atype_array_compound
:
2026 ret
= _lttng_array_compound_statedump(session
, field
, nesting
);
2028 case atype_sequence_compound
:
2029 ret
= _lttng_sequence_compound_statedump(session
, field
, nesting
);
2032 ret
= _lttng_variant_statedump(session
, field
, nesting
);
2043 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
2044 struct lttng_ctx
*ctx
)
2051 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
2052 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
2054 ret
= _lttng_field_statedump(session
, &field
->event_field
, 2);
2062 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
2063 struct lttng_event
*event
)
2065 const struct lttng_event_desc
*desc
= event
->desc
;
2069 for (i
= 0; i
< desc
->nr_fields
; i
++) {
2070 const struct lttng_event_field
*field
= &desc
->fields
[i
];
2072 ret
= _lttng_field_statedump(session
, field
, 2);
2080 * Must be called with sessions_mutex held.
2083 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
2084 struct lttng_channel
*chan
,
2085 struct lttng_event
*event
)
2089 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
2091 if (chan
->channel_type
== METADATA_CHANNEL
)
2094 ret
= lttng_metadata_printf(session
,
2098 " stream_id = %u;\n",
2106 ret
= lttng_metadata_printf(session
,
2107 " context := struct {\n");
2111 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
2115 ret
= lttng_metadata_printf(session
,
2121 ret
= lttng_metadata_printf(session
,
2122 " fields := struct {\n"
2127 ret
= _lttng_fields_metadata_statedump(session
, event
);
2132 * LTTng space reservation can only reserve multiples of the
2135 ret
= lttng_metadata_printf(session
,
2141 event
->metadata_dumped
= 1;
2148 * Must be called with sessions_mutex held.
2151 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
2152 struct lttng_channel
*chan
)
2156 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
2159 if (chan
->channel_type
== METADATA_CHANNEL
)
2162 WARN_ON_ONCE(!chan
->header_type
);
2163 ret
= lttng_metadata_printf(session
,
2166 " event.header := %s;\n"
2167 " packet.context := struct packet_context;\n",
2169 chan
->header_type
== 1 ? "struct event_header_compact" :
2170 "struct event_header_large");
2175 ret
= lttng_metadata_printf(session
,
2176 " event.context := struct {\n");
2180 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
2184 ret
= lttng_metadata_printf(session
,
2190 ret
= lttng_metadata_printf(session
,
2193 chan
->metadata_dumped
= 1;
2199 * Must be called with sessions_mutex held.
2202 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
2204 return lttng_metadata_printf(session
,
2205 "struct packet_context {\n"
2206 " uint64_clock_monotonic_t timestamp_begin;\n"
2207 " uint64_clock_monotonic_t timestamp_end;\n"
2208 " uint64_t content_size;\n"
2209 " uint64_t packet_size;\n"
2210 " uint64_t packet_seq_num;\n"
2211 " unsigned long events_discarded;\n"
2212 " uint32_t cpu_id;\n"
2219 * id: range: 0 - 30.
2220 * id 31 is reserved to indicate an extended header.
2223 * id: range: 0 - 65534.
2224 * id 65535 is reserved to indicate an extended header.
2226 * Must be called with sessions_mutex held.
2229 int _lttng_event_header_declare(struct lttng_session
*session
)
2231 return lttng_metadata_printf(session
,
2232 "struct event_header_compact {\n"
2233 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2236 " uint27_clock_monotonic_t timestamp;\n"
2240 " uint64_clock_monotonic_t timestamp;\n"
2245 "struct event_header_large {\n"
2246 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2249 " uint32_clock_monotonic_t timestamp;\n"
2253 " uint64_clock_monotonic_t timestamp;\n"
2257 lttng_alignof(uint32_t) * CHAR_BIT
,
2258 lttng_alignof(uint16_t) * CHAR_BIT
2263 * Approximation of NTP time of day to clock monotonic correlation,
2264 * taken at start of trace.
2265 * Yes, this is only an approximation. Yes, we can (and will) do better
2266 * in future versions.
2267 * This function may return a negative offset. It may happen if the
2268 * system sets the REALTIME clock to 0 after boot.
2271 int64_t measure_clock_offset(void)
2273 uint64_t monotonic_avg
, monotonic
[2], realtime
;
2274 uint64_t tcf
= trace_clock_freq();
2276 struct timespec rts
= { 0, 0 };
2277 unsigned long flags
;
2279 /* Disable interrupts to increase correlation precision. */
2280 local_irq_save(flags
);
2281 monotonic
[0] = trace_clock_read64();
2282 getnstimeofday(&rts
);
2283 monotonic
[1] = trace_clock_read64();
2284 local_irq_restore(flags
);
2286 monotonic_avg
= (monotonic
[0] + monotonic
[1]) >> 1;
2287 realtime
= (uint64_t) rts
.tv_sec
* tcf
;
2288 if (tcf
== NSEC_PER_SEC
) {
2289 realtime
+= rts
.tv_nsec
;
2291 uint64_t n
= rts
.tv_nsec
* tcf
;
2293 do_div(n
, NSEC_PER_SEC
);
2296 offset
= (int64_t) realtime
- monotonic_avg
;
2301 * Output metadata into this session's metadata buffers.
2302 * Must be called with sessions_mutex held.
2305 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
2307 unsigned char *uuid_c
= session
->uuid
.b
;
2308 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
2309 struct lttng_channel
*chan
;
2310 struct lttng_event
*event
;
2313 if (!ACCESS_ONCE(session
->active
))
2315 if (session
->metadata_dumped
)
2318 snprintf(uuid_s
, sizeof(uuid_s
),
2319 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2320 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
2321 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
2322 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
2323 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
2325 ret
= lttng_metadata_printf(session
,
2326 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2327 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2328 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2329 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2330 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2331 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2332 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2338 " byte_order = %s;\n"
2339 " packet.header := struct {\n"
2340 " uint32_t magic;\n"
2341 " uint8_t uuid[16];\n"
2342 " uint32_t stream_id;\n"
2343 " uint64_t stream_instance_id;\n"
2346 lttng_alignof(uint8_t) * CHAR_BIT
,
2347 lttng_alignof(uint16_t) * CHAR_BIT
,
2348 lttng_alignof(uint32_t) * CHAR_BIT
,
2349 lttng_alignof(uint64_t) * CHAR_BIT
,
2350 sizeof(unsigned long) * CHAR_BIT
,
2351 lttng_alignof(unsigned long) * CHAR_BIT
,
2355 #if __BYTE_ORDER == __BIG_ENDIAN
2364 ret
= lttng_metadata_printf(session
,
2366 " hostname = \"%s\";\n"
2367 " domain = \"kernel\";\n"
2368 " sysname = \"%s\";\n"
2369 " kernel_release = \"%s\";\n"
2370 " kernel_version = \"%s\";\n"
2371 " tracer_name = \"lttng-modules\";\n"
2372 " tracer_major = %d;\n"
2373 " tracer_minor = %d;\n"
2374 " tracer_patchlevel = %d;\n"
2376 current
->nsproxy
->uts_ns
->name
.nodename
,
2380 LTTNG_MODULES_MAJOR_VERSION
,
2381 LTTNG_MODULES_MINOR_VERSION
,
2382 LTTNG_MODULES_PATCHLEVEL_VERSION
2387 ret
= lttng_metadata_printf(session
,
2389 " name = \"%s\";\n",
2395 if (!trace_clock_uuid(clock_uuid_s
)) {
2396 ret
= lttng_metadata_printf(session
,
2397 " uuid = \"%s\";\n",
2404 ret
= lttng_metadata_printf(session
,
2405 " description = \"%s\";\n"
2406 " freq = %llu; /* Frequency, in Hz */\n"
2407 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2410 trace_clock_description(),
2411 (unsigned long long) trace_clock_freq(),
2412 (long long) measure_clock_offset()
2417 ret
= lttng_metadata_printf(session
,
2418 "typealias integer {\n"
2419 " size = 27; align = 1; signed = false;\n"
2420 " map = clock.%s.value;\n"
2421 "} := uint27_clock_monotonic_t;\n"
2423 "typealias integer {\n"
2424 " size = 32; align = %u; signed = false;\n"
2425 " map = clock.%s.value;\n"
2426 "} := uint32_clock_monotonic_t;\n"
2428 "typealias integer {\n"
2429 " size = 64; align = %u; signed = false;\n"
2430 " map = clock.%s.value;\n"
2431 "} := uint64_clock_monotonic_t;\n\n",
2433 lttng_alignof(uint32_t) * CHAR_BIT
,
2435 lttng_alignof(uint64_t) * CHAR_BIT
,
2441 ret
= _lttng_stream_packet_context_declare(session
);
2445 ret
= _lttng_event_header_declare(session
);
2450 list_for_each_entry(chan
, &session
->chan
, list
) {
2451 ret
= _lttng_channel_metadata_statedump(session
, chan
);
2456 list_for_each_entry(event
, &session
->events
, list
) {
2457 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
2461 session
->metadata_dumped
= 1;
2467 * lttng_transport_register - LTT transport registration
2468 * @transport: transport structure
2470 * Registers a transport which can be used as output to extract the data out of
2471 * LTTng. The module calling this registration function must ensure that no
2472 * trap-inducing code will be executed by the transport functions. E.g.
2473 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
2474 * is made visible to the transport function. This registration acts as a
2475 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
2476 * after its registration must it synchronize the TLBs.
2478 void lttng_transport_register(struct lttng_transport
*transport
)
2481 * Make sure no page fault can be triggered by the module about to be
2482 * registered. We deal with this here so we don't have to call
2483 * vmalloc_sync_all() in each module's init.
2485 wrapper_vmalloc_sync_all();
2487 mutex_lock(&sessions_mutex
);
2488 list_add_tail(&transport
->node
, <tng_transport_list
);
2489 mutex_unlock(&sessions_mutex
);
2491 EXPORT_SYMBOL_GPL(lttng_transport_register
);
2494 * lttng_transport_unregister - LTT transport unregistration
2495 * @transport: transport structure
2497 void lttng_transport_unregister(struct lttng_transport
*transport
)
2499 mutex_lock(&sessions_mutex
);
2500 list_del(&transport
->node
);
2501 mutex_unlock(&sessions_mutex
);
2503 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
2505 static int __init
lttng_events_init(void)
2509 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
2512 ret
= wrapper_get_pfnblock_flags_mask_init();
2515 ret
= wrapper_get_pageblock_flags_mask_init();
2518 ret
= lttng_probes_init();
2521 ret
= lttng_context_init();
2524 ret
= lttng_tracepoint_init();
2527 event_cache
= KMEM_CACHE(lttng_event
, 0);
2532 ret
= lttng_abi_init();
2535 ret
= lttng_logger_init();
2543 kmem_cache_destroy(event_cache
);
2545 lttng_tracepoint_exit();
2547 lttng_context_exit();
2551 module_init(lttng_events_init
);
2553 static void __exit
lttng_events_exit(void)
2555 struct lttng_session
*session
, *tmpsession
;
2557 lttng_logger_exit();
2559 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
2560 lttng_session_destroy(session
);
2561 kmem_cache_destroy(event_cache
);
2562 lttng_tracepoint_exit();
2563 lttng_context_exit();
2566 module_exit(lttng_events_exit
);
2568 MODULE_LICENSE("GPL and additional rights");
2569 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
2570 MODULE_DESCRIPTION("LTTng Events");
2571 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
2572 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
2573 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
2574 LTTNG_MODULES_EXTRAVERSION
);