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>
55 #include <wrapper/ringbuffer/backend.h>
56 #include <wrapper/ringbuffer/frontend.h>
58 #define METADATA_CACHE_DEFAULT_SIZE 4096
60 static LIST_HEAD(sessions
);
61 static LIST_HEAD(lttng_transport_list
);
63 * Protect the sessions and metadata caches.
65 static DEFINE_MUTEX(sessions_mutex
);
66 static struct kmem_cache
*event_cache
;
68 static void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
69 static void lttng_session_sync_enablers(struct lttng_session
*session
);
70 static void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
72 static void _lttng_event_destroy(struct lttng_event
*event
);
73 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
74 static int _lttng_event_unregister(struct lttng_event
*event
);
76 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
77 struct lttng_channel
*chan
,
78 struct lttng_event
*event
);
80 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
82 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
84 void synchronize_trace(void)
87 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
88 #ifdef CONFIG_PREEMPT_RT_FULL
91 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
92 #ifdef CONFIG_PREEMPT_RT
95 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
98 void lttng_lock_sessions(void)
100 mutex_lock(&sessions_mutex
);
103 void lttng_unlock_sessions(void)
105 mutex_unlock(&sessions_mutex
);
109 * Called with sessions lock held.
111 int lttng_session_active(void)
113 struct lttng_session
*iter
;
115 list_for_each_entry(iter
, &sessions
, list
) {
122 struct lttng_session
*lttng_session_create(void)
124 struct lttng_session
*session
;
125 struct lttng_metadata_cache
*metadata_cache
;
128 mutex_lock(&sessions_mutex
);
129 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
132 INIT_LIST_HEAD(&session
->chan
);
133 INIT_LIST_HEAD(&session
->events
);
134 uuid_le_gen(&session
->uuid
);
136 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
139 goto err_free_session
;
140 metadata_cache
->data
= lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE
);
141 if (!metadata_cache
->data
)
143 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
144 kref_init(&metadata_cache
->refcount
);
145 mutex_init(&metadata_cache
->lock
);
146 session
->metadata_cache
= metadata_cache
;
147 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
148 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
149 sizeof(metadata_cache
->uuid
));
150 INIT_LIST_HEAD(&session
->enablers_head
);
151 for (i
= 0; i
< LTTNG_EVENT_HT_SIZE
; i
++)
152 INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
153 list_add(&session
->list
, &sessions
);
154 mutex_unlock(&sessions_mutex
);
158 kfree(metadata_cache
);
162 mutex_unlock(&sessions_mutex
);
166 void metadata_cache_destroy(struct kref
*kref
)
168 struct lttng_metadata_cache
*cache
=
169 container_of(kref
, struct lttng_metadata_cache
, refcount
);
174 void lttng_session_destroy(struct lttng_session
*session
)
176 struct lttng_channel
*chan
, *tmpchan
;
177 struct lttng_event
*event
, *tmpevent
;
178 struct lttng_metadata_stream
*metadata_stream
;
179 struct lttng_enabler
*enabler
, *tmpenabler
;
182 mutex_lock(&sessions_mutex
);
183 ACCESS_ONCE(session
->active
) = 0;
184 list_for_each_entry(chan
, &session
->chan
, list
) {
185 ret
= lttng_syscalls_unregister(chan
);
188 list_for_each_entry(event
, &session
->events
, list
) {
189 ret
= _lttng_event_unregister(event
);
192 synchronize_trace(); /* Wait for in-flight events to complete */
193 list_for_each_entry_safe(enabler
, tmpenabler
,
194 &session
->enablers_head
, node
)
195 lttng_enabler_destroy(enabler
);
196 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
197 _lttng_event_destroy(event
);
198 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
199 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
200 _lttng_channel_destroy(chan
);
202 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
203 _lttng_metadata_channel_hangup(metadata_stream
);
204 if (session
->pid_tracker
)
205 lttng_pid_tracker_destroy(session
->pid_tracker
);
206 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
207 list_del(&session
->list
);
208 mutex_unlock(&sessions_mutex
);
212 int lttng_session_enable(struct lttng_session
*session
)
215 struct lttng_channel
*chan
;
217 mutex_lock(&sessions_mutex
);
218 if (session
->active
) {
223 /* Set transient enabler state to "enabled" */
227 * Snapshot the number of events per channel to know the type of header
230 list_for_each_entry(chan
, &session
->chan
, list
) {
231 if (chan
->header_type
)
232 continue; /* don't change it if session stop/restart */
233 if (chan
->free_event_id
< 31)
234 chan
->header_type
= 1; /* compact */
236 chan
->header_type
= 2; /* large */
239 /* We need to sync enablers with session before activation. */
240 lttng_session_sync_enablers(session
);
242 /* Clear each stream's quiescent state. */
243 list_for_each_entry(chan
, &session
->chan
, list
)
244 lib_ring_buffer_clear_quiescent_channel(chan
->chan
);
246 ACCESS_ONCE(session
->active
) = 1;
247 ACCESS_ONCE(session
->been_active
) = 1;
248 ret
= _lttng_session_metadata_statedump(session
);
250 ACCESS_ONCE(session
->active
) = 0;
253 ret
= lttng_statedump_start(session
);
255 ACCESS_ONCE(session
->active
) = 0;
257 mutex_unlock(&sessions_mutex
);
261 int lttng_session_disable(struct lttng_session
*session
)
264 struct lttng_channel
*chan
;
266 mutex_lock(&sessions_mutex
);
267 if (!session
->active
) {
271 ACCESS_ONCE(session
->active
) = 0;
273 /* Set transient enabler state to "disabled" */
275 lttng_session_sync_enablers(session
);
277 /* Set each stream's quiescent state. */
278 list_for_each_entry(chan
, &session
->chan
, list
)
279 lib_ring_buffer_set_quiescent_channel(chan
->chan
);
281 mutex_unlock(&sessions_mutex
);
285 int lttng_session_metadata_regenerate(struct lttng_session
*session
)
288 struct lttng_channel
*chan
;
289 struct lttng_event
*event
;
290 struct lttng_metadata_cache
*cache
= session
->metadata_cache
;
291 struct lttng_metadata_stream
*stream
;
293 mutex_lock(&sessions_mutex
);
294 if (!session
->active
) {
299 mutex_lock(&cache
->lock
);
300 memset(cache
->data
, 0, cache
->cache_alloc
);
301 cache
->metadata_written
= 0;
303 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
) {
304 stream
->metadata_out
= 0;
305 stream
->metadata_in
= 0;
307 mutex_unlock(&cache
->lock
);
309 session
->metadata_dumped
= 0;
310 list_for_each_entry(chan
, &session
->chan
, list
) {
311 chan
->metadata_dumped
= 0;
314 list_for_each_entry(event
, &session
->events
, list
) {
315 event
->metadata_dumped
= 0;
318 ret
= _lttng_session_metadata_statedump(session
);
321 mutex_unlock(&sessions_mutex
);
327 int lttng_channel_enable(struct lttng_channel
*channel
)
331 mutex_lock(&sessions_mutex
);
332 if (channel
->channel_type
== METADATA_CHANNEL
) {
336 if (channel
->enabled
) {
340 /* Set transient enabler state to "enabled" */
342 lttng_session_sync_enablers(channel
->session
);
343 /* Set atomically the state to "enabled" */
344 ACCESS_ONCE(channel
->enabled
) = 1;
346 mutex_unlock(&sessions_mutex
);
350 int lttng_channel_disable(struct lttng_channel
*channel
)
354 mutex_lock(&sessions_mutex
);
355 if (channel
->channel_type
== METADATA_CHANNEL
) {
359 if (!channel
->enabled
) {
363 /* Set atomically the state to "disabled" */
364 ACCESS_ONCE(channel
->enabled
) = 0;
365 /* Set transient enabler state to "enabled" */
367 lttng_session_sync_enablers(channel
->session
);
369 mutex_unlock(&sessions_mutex
);
373 int lttng_event_enable(struct lttng_event
*event
)
377 mutex_lock(&sessions_mutex
);
378 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
382 if (event
->enabled
) {
386 switch (event
->instrumentation
) {
387 case LTTNG_KERNEL_TRACEPOINT
:
388 case LTTNG_KERNEL_SYSCALL
:
391 case LTTNG_KERNEL_KPROBE
:
392 case LTTNG_KERNEL_FUNCTION
:
393 case LTTNG_KERNEL_NOOP
:
394 ACCESS_ONCE(event
->enabled
) = 1;
396 case LTTNG_KERNEL_KRETPROBE
:
397 ret
= lttng_kretprobes_event_enable_state(event
, 1);
404 mutex_unlock(&sessions_mutex
);
408 int lttng_event_disable(struct lttng_event
*event
)
412 mutex_lock(&sessions_mutex
);
413 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
417 if (!event
->enabled
) {
421 switch (event
->instrumentation
) {
422 case LTTNG_KERNEL_TRACEPOINT
:
423 case LTTNG_KERNEL_SYSCALL
:
426 case LTTNG_KERNEL_KPROBE
:
427 case LTTNG_KERNEL_FUNCTION
:
428 case LTTNG_KERNEL_NOOP
:
429 ACCESS_ONCE(event
->enabled
) = 0;
431 case LTTNG_KERNEL_KRETPROBE
:
432 ret
= lttng_kretprobes_event_enable_state(event
, 0);
439 mutex_unlock(&sessions_mutex
);
443 static struct lttng_transport
*lttng_transport_find(const char *name
)
445 struct lttng_transport
*transport
;
447 list_for_each_entry(transport
, <tng_transport_list
, node
) {
448 if (!strcmp(transport
->name
, name
))
454 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
455 const char *transport_name
,
457 size_t subbuf_size
, size_t num_subbuf
,
458 unsigned int switch_timer_interval
,
459 unsigned int read_timer_interval
,
460 enum channel_type channel_type
)
462 struct lttng_channel
*chan
;
463 struct lttng_transport
*transport
= NULL
;
465 mutex_lock(&sessions_mutex
);
466 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
467 goto active
; /* Refuse to add channel to active session */
468 transport
= lttng_transport_find(transport_name
);
470 printk(KERN_WARNING
"LTTng transport %s not found\n",
474 if (!try_module_get(transport
->owner
)) {
475 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
478 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
481 chan
->session
= session
;
482 chan
->id
= session
->free_chan_id
++;
483 chan
->ops
= &transport
->ops
;
485 * Note: the channel creation op already writes into the packet
486 * headers. Therefore the "chan" information used as input
487 * should be already accessible.
489 chan
->chan
= transport
->ops
.channel_create(transport_name
,
490 chan
, buf_addr
, subbuf_size
, num_subbuf
,
491 switch_timer_interval
, read_timer_interval
);
496 chan
->transport
= transport
;
497 chan
->channel_type
= channel_type
;
498 list_add(&chan
->list
, &session
->chan
);
499 mutex_unlock(&sessions_mutex
);
506 module_put(transport
->owner
);
509 mutex_unlock(&sessions_mutex
);
514 * Only used internally at session destruction for per-cpu channels, and
515 * when metadata channel is released.
516 * Needs to be called with sessions mutex held.
519 void _lttng_channel_destroy(struct lttng_channel
*chan
)
521 chan
->ops
->channel_destroy(chan
->chan
);
522 module_put(chan
->transport
->owner
);
523 list_del(&chan
->list
);
524 lttng_destroy_context(chan
->ctx
);
528 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
530 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
532 /* Protect the metadata cache with the sessions_mutex. */
533 mutex_lock(&sessions_mutex
);
534 _lttng_channel_destroy(chan
);
535 mutex_unlock(&sessions_mutex
);
537 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
540 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
542 stream
->finalized
= 1;
543 wake_up_interruptible(&stream
->read_wait
);
547 * Supports event creation while tracing session is active.
548 * Needs to be called with sessions mutex held.
550 struct lttng_event
*_lttng_event_create(struct lttng_channel
*chan
,
551 struct lttng_kernel_event
*event_param
,
553 const struct lttng_event_desc
*event_desc
,
554 enum lttng_kernel_instrumentation itype
)
556 struct lttng_session
*session
= chan
->session
;
557 struct lttng_event
*event
;
558 const char *event_name
;
559 struct hlist_head
*head
;
564 if (chan
->free_event_id
== -1U) {
570 case LTTNG_KERNEL_TRACEPOINT
:
571 event_name
= event_desc
->name
;
573 case LTTNG_KERNEL_KPROBE
:
574 case LTTNG_KERNEL_KRETPROBE
:
575 case LTTNG_KERNEL_FUNCTION
:
576 case LTTNG_KERNEL_NOOP
:
577 case LTTNG_KERNEL_SYSCALL
:
578 event_name
= event_param
->name
;
585 name_len
= strlen(event_name
);
586 hash
= jhash(event_name
, name_len
, 0);
587 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
588 lttng_hlist_for_each_entry(event
, head
, hlist
) {
589 WARN_ON_ONCE(!event
->desc
);
590 if (!strncmp(event
->desc
->name
, event_name
,
591 LTTNG_KERNEL_SYM_NAME_LEN
- 1)
592 && chan
== event
->chan
) {
598 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
604 event
->filter
= filter
;
605 event
->id
= chan
->free_event_id
++;
606 event
->instrumentation
= itype
;
607 event
->evtype
= LTTNG_TYPE_EVENT
;
608 INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
609 INIT_LIST_HEAD(&event
->enablers_ref_head
);
612 case LTTNG_KERNEL_TRACEPOINT
:
613 /* Event will be enabled by enabler sync. */
615 event
->registered
= 0;
616 event
->desc
= lttng_event_get(event_name
);
621 /* Populate lttng_event structure before event registration. */
624 case LTTNG_KERNEL_KPROBE
:
626 * Needs to be explicitly enabled after creation, since
627 * we may want to apply filters.
630 event
->registered
= 1;
632 * Populate lttng_event structure before event
636 ret
= lttng_kprobes_register(event_name
,
637 event_param
->u
.kprobe
.symbol_name
,
638 event_param
->u
.kprobe
.offset
,
639 event_param
->u
.kprobe
.addr
,
645 ret
= try_module_get(event
->desc
->owner
);
648 case LTTNG_KERNEL_KRETPROBE
:
650 struct lttng_event
*event_return
;
652 /* kretprobe defines 2 events */
654 * Needs to be explicitly enabled after creation, since
655 * we may want to apply filters.
658 event
->registered
= 1;
660 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
665 event_return
->chan
= chan
;
666 event_return
->filter
= filter
;
667 event_return
->id
= chan
->free_event_id
++;
668 event_return
->enabled
= 0;
669 event_return
->registered
= 1;
670 event_return
->instrumentation
= itype
;
672 * Populate lttng_event structure before kretprobe registration.
675 ret
= lttng_kretprobes_register(event_name
,
676 event_param
->u
.kretprobe
.symbol_name
,
677 event_param
->u
.kretprobe
.offset
,
678 event_param
->u
.kretprobe
.addr
,
679 event
, event_return
);
681 kmem_cache_free(event_cache
, event_return
);
685 /* Take 2 refs on the module: one per event. */
686 ret
= try_module_get(event
->desc
->owner
);
688 ret
= try_module_get(event
->desc
->owner
);
690 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
692 WARN_ON_ONCE(ret
> 0);
694 kmem_cache_free(event_cache
, event_return
);
695 module_put(event
->desc
->owner
);
696 module_put(event
->desc
->owner
);
697 goto statedump_error
;
699 list_add(&event_return
->list
, &chan
->session
->events
);
702 case LTTNG_KERNEL_FUNCTION
:
704 * Needs to be explicitly enabled after creation, since
705 * we may want to apply filters.
708 event
->registered
= 1;
710 * Populate lttng_event structure before event
714 ret
= lttng_ftrace_register(event_name
,
715 event_param
->u
.ftrace
.symbol_name
,
720 ret
= try_module_get(event
->desc
->owner
);
723 case LTTNG_KERNEL_NOOP
:
724 case LTTNG_KERNEL_SYSCALL
:
726 * Needs to be explicitly enabled after creation, since
727 * we may want to apply filters.
730 event
->registered
= 0;
731 event
->desc
= event_desc
;
742 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
743 WARN_ON_ONCE(ret
> 0);
745 goto statedump_error
;
747 hlist_add_head(&event
->hlist
, head
);
748 list_add(&event
->list
, &chan
->session
->events
);
752 /* If a statedump error occurs, events will not be readable. */
754 kmem_cache_free(event_cache
, event
);
762 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
763 struct lttng_kernel_event
*event_param
,
765 const struct lttng_event_desc
*event_desc
,
766 enum lttng_kernel_instrumentation itype
)
768 struct lttng_event
*event
;
770 mutex_lock(&sessions_mutex
);
771 event
= _lttng_event_create(chan
, event_param
, filter
, event_desc
,
773 mutex_unlock(&sessions_mutex
);
777 /* Only used for tracepoints for now. */
779 void register_event(struct lttng_event
*event
)
781 const struct lttng_event_desc
*desc
;
784 if (event
->registered
)
788 switch (event
->instrumentation
) {
789 case LTTNG_KERNEL_TRACEPOINT
:
790 ret
= lttng_wrapper_tracepoint_probe_register(desc
->kname
,
791 desc
->probe_callback
,
794 case LTTNG_KERNEL_SYSCALL
:
795 ret
= lttng_syscall_filter_enable(event
->chan
,
798 case LTTNG_KERNEL_KPROBE
:
799 case LTTNG_KERNEL_KRETPROBE
:
800 case LTTNG_KERNEL_FUNCTION
:
801 case LTTNG_KERNEL_NOOP
:
808 event
->registered
= 1;
812 * Only used internally at session destruction.
814 int _lttng_event_unregister(struct lttng_event
*event
)
816 const struct lttng_event_desc
*desc
;
819 if (!event
->registered
)
823 switch (event
->instrumentation
) {
824 case LTTNG_KERNEL_TRACEPOINT
:
825 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
826 event
->desc
->probe_callback
,
829 case LTTNG_KERNEL_KPROBE
:
830 lttng_kprobes_unregister(event
);
833 case LTTNG_KERNEL_KRETPROBE
:
834 lttng_kretprobes_unregister(event
);
837 case LTTNG_KERNEL_FUNCTION
:
838 lttng_ftrace_unregister(event
);
841 case LTTNG_KERNEL_SYSCALL
:
842 ret
= lttng_syscall_filter_disable(event
->chan
,
845 case LTTNG_KERNEL_NOOP
:
852 event
->registered
= 0;
857 * Only used internally at session destruction.
860 void _lttng_event_destroy(struct lttng_event
*event
)
862 switch (event
->instrumentation
) {
863 case LTTNG_KERNEL_TRACEPOINT
:
864 lttng_event_put(event
->desc
);
866 case LTTNG_KERNEL_KPROBE
:
867 module_put(event
->desc
->owner
);
868 lttng_kprobes_destroy_private(event
);
870 case LTTNG_KERNEL_KRETPROBE
:
871 module_put(event
->desc
->owner
);
872 lttng_kretprobes_destroy_private(event
);
874 case LTTNG_KERNEL_FUNCTION
:
875 module_put(event
->desc
->owner
);
876 lttng_ftrace_destroy_private(event
);
878 case LTTNG_KERNEL_NOOP
:
879 case LTTNG_KERNEL_SYSCALL
:
884 list_del(&event
->list
);
885 lttng_destroy_context(event
->ctx
);
886 kmem_cache_free(event_cache
, event
);
889 int lttng_session_track_pid(struct lttng_session
*session
, int pid
)
895 mutex_lock(&sessions_mutex
);
897 /* track all pids: destroy tracker. */
898 if (session
->pid_tracker
) {
899 struct lttng_pid_tracker
*lpf
;
901 lpf
= session
->pid_tracker
;
902 rcu_assign_pointer(session
->pid_tracker
, NULL
);
904 lttng_pid_tracker_destroy(lpf
);
908 if (!session
->pid_tracker
) {
909 struct lttng_pid_tracker
*lpf
;
911 lpf
= lttng_pid_tracker_create();
916 ret
= lttng_pid_tracker_add(lpf
, pid
);
917 rcu_assign_pointer(session
->pid_tracker
, lpf
);
919 ret
= lttng_pid_tracker_add(session
->pid_tracker
, pid
);
923 mutex_unlock(&sessions_mutex
);
927 int lttng_session_untrack_pid(struct lttng_session
*session
, int pid
)
933 mutex_lock(&sessions_mutex
);
935 /* untrack all pids: replace by empty tracker. */
936 struct lttng_pid_tracker
*old_lpf
= session
->pid_tracker
;
937 struct lttng_pid_tracker
*lpf
;
939 lpf
= lttng_pid_tracker_create();
944 rcu_assign_pointer(session
->pid_tracker
, lpf
);
947 lttng_pid_tracker_destroy(old_lpf
);
950 if (!session
->pid_tracker
) {
954 ret
= lttng_pid_tracker_del(session
->pid_tracker
, pid
);
957 mutex_unlock(&sessions_mutex
);
962 void *pid_list_start(struct seq_file
*m
, loff_t
*pos
)
964 struct lttng_session
*session
= m
->private;
965 struct lttng_pid_tracker
*lpf
;
966 struct lttng_pid_hash_node
*e
;
969 mutex_lock(&sessions_mutex
);
970 lpf
= session
->pid_tracker
;
972 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
973 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
975 lttng_hlist_for_each_entry(e
, head
, hlist
) {
981 /* PID tracker disabled. */
982 if (iter
>= *pos
&& iter
== 0) {
983 return session
; /* empty tracker */
991 /* Called with sessions_mutex held. */
993 void *pid_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
995 struct lttng_session
*session
= m
->private;
996 struct lttng_pid_tracker
*lpf
;
997 struct lttng_pid_hash_node
*e
;
1001 lpf
= session
->pid_tracker
;
1003 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
1004 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
1006 lttng_hlist_for_each_entry(e
, head
, hlist
) {
1007 if (iter
++ >= *ppos
)
1012 /* PID tracker disabled. */
1013 if (iter
>= *ppos
&& iter
== 0)
1014 return session
; /* empty tracker */
1023 void pid_list_stop(struct seq_file
*m
, void *p
)
1025 mutex_unlock(&sessions_mutex
);
1029 int pid_list_show(struct seq_file
*m
, void *p
)
1033 if (p
== m
->private) {
1034 /* Tracker disabled. */
1037 const struct lttng_pid_hash_node
*e
= p
;
1039 pid
= lttng_pid_tracker_get_node_pid(e
);
1041 seq_printf(m
, "process { pid = %d; };\n", pid
);
1046 const struct seq_operations lttng_tracker_pids_list_seq_ops
= {
1047 .start
= pid_list_start
,
1048 .next
= pid_list_next
,
1049 .stop
= pid_list_stop
,
1050 .show
= pid_list_show
,
1054 int lttng_tracker_pids_list_open(struct inode
*inode
, struct file
*file
)
1056 return seq_open(file
, <tng_tracker_pids_list_seq_ops
);
1060 int lttng_tracker_pids_list_release(struct inode
*inode
, struct file
*file
)
1062 struct seq_file
*m
= file
->private_data
;
1063 struct lttng_session
*session
= m
->private;
1066 WARN_ON_ONCE(!session
);
1067 ret
= seq_release(inode
, file
);
1068 if (!ret
&& session
)
1069 fput(session
->file
);
1073 const struct file_operations lttng_tracker_pids_list_fops
= {
1074 .owner
= THIS_MODULE
,
1075 .open
= lttng_tracker_pids_list_open
,
1077 .llseek
= seq_lseek
,
1078 .release
= lttng_tracker_pids_list_release
,
1081 int lttng_session_list_tracker_pids(struct lttng_session
*session
)
1083 struct file
*tracker_pids_list_file
;
1087 file_fd
= lttng_get_unused_fd();
1093 tracker_pids_list_file
= anon_inode_getfile("[lttng_tracker_pids_list]",
1094 <tng_tracker_pids_list_fops
,
1096 if (IS_ERR(tracker_pids_list_file
)) {
1097 ret
= PTR_ERR(tracker_pids_list_file
);
1100 if (atomic_long_add_unless(&session
->file
->f_count
,
1101 1, INT_MAX
) == INT_MAX
) {
1102 goto refcount_error
;
1104 ret
= lttng_tracker_pids_list_fops
.open(NULL
, tracker_pids_list_file
);
1107 m
= tracker_pids_list_file
->private_data
;
1108 m
->private = session
;
1109 fd_install(file_fd
, tracker_pids_list_file
);
1114 atomic_long_dec(&session
->file
->f_count
);
1116 fput(tracker_pids_list_file
);
1118 put_unused_fd(file_fd
);
1124 * Enabler management.
1127 int lttng_match_enabler_wildcard(const char *desc_name
,
1130 /* Compare excluding final '*' */
1131 if (strncmp(desc_name
, name
, strlen(name
) - 1))
1137 int lttng_match_enabler_name(const char *desc_name
,
1140 if (strcmp(desc_name
, name
))
1146 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
1147 struct lttng_enabler
*enabler
)
1149 const char *desc_name
, *enabler_name
;
1151 enabler_name
= enabler
->event_param
.name
;
1152 switch (enabler
->event_param
.instrumentation
) {
1153 case LTTNG_KERNEL_TRACEPOINT
:
1154 desc_name
= desc
->name
;
1156 case LTTNG_KERNEL_SYSCALL
:
1157 desc_name
= desc
->name
;
1158 if (!strncmp(desc_name
, "compat_", strlen("compat_")))
1159 desc_name
+= strlen("compat_");
1160 if (!strncmp(desc_name
, "syscall_exit_",
1161 strlen("syscall_exit_"))) {
1162 desc_name
+= strlen("syscall_exit_");
1163 } else if (!strncmp(desc_name
, "syscall_entry_",
1164 strlen("syscall_entry_"))) {
1165 desc_name
+= strlen("syscall_entry_");
1175 switch (enabler
->type
) {
1176 case LTTNG_ENABLER_WILDCARD
:
1177 return lttng_match_enabler_wildcard(desc_name
, enabler_name
);
1178 case LTTNG_ENABLER_NAME
:
1179 return lttng_match_enabler_name(desc_name
, enabler_name
);
1186 int lttng_event_match_enabler(struct lttng_event
*event
,
1187 struct lttng_enabler
*enabler
)
1189 if (enabler
->event_param
.instrumentation
!= event
->instrumentation
)
1191 if (lttng_desc_match_enabler(event
->desc
, enabler
)
1192 && event
->chan
== enabler
->chan
)
1199 struct lttng_enabler_ref
*lttng_event_enabler_ref(struct lttng_event
*event
,
1200 struct lttng_enabler
*enabler
)
1202 struct lttng_enabler_ref
*enabler_ref
;
1204 list_for_each_entry(enabler_ref
,
1205 &event
->enablers_ref_head
, node
) {
1206 if (enabler_ref
->ref
== enabler
)
1213 void lttng_create_tracepoint_if_missing(struct lttng_enabler
*enabler
)
1215 struct lttng_session
*session
= enabler
->chan
->session
;
1216 struct lttng_probe_desc
*probe_desc
;
1217 const struct lttng_event_desc
*desc
;
1219 struct list_head
*probe_list
;
1221 probe_list
= lttng_get_probe_list_head();
1223 * For each probe event, if we find that a probe event matches
1224 * our enabler, create an associated lttng_event if not
1227 list_for_each_entry(probe_desc
, probe_list
, head
) {
1228 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
1230 struct hlist_head
*head
;
1231 const char *event_name
;
1234 struct lttng_event
*event
;
1236 desc
= probe_desc
->event_desc
[i
];
1237 if (!lttng_desc_match_enabler(desc
, enabler
))
1239 event_name
= desc
->name
;
1240 name_len
= strlen(event_name
);
1243 * Check if already created.
1245 hash
= jhash(event_name
, name_len
, 0);
1246 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
1247 lttng_hlist_for_each_entry(event
, head
, hlist
) {
1248 if (event
->desc
== desc
1249 && event
->chan
== enabler
->chan
)
1256 * We need to create an event for this
1259 event
= _lttng_event_create(enabler
->chan
,
1261 LTTNG_KERNEL_TRACEPOINT
);
1263 printk(KERN_INFO
"Unable to create event %s\n",
1264 probe_desc
->event_desc
[i
]->name
);
1271 void lttng_create_syscall_if_missing(struct lttng_enabler
*enabler
)
1275 ret
= lttng_syscalls_register(enabler
->chan
, NULL
);
1280 * Create struct lttng_event if it is missing and present in the list of
1281 * tracepoint probes.
1282 * Should be called with sessions mutex held.
1285 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
1287 switch (enabler
->event_param
.instrumentation
) {
1288 case LTTNG_KERNEL_TRACEPOINT
:
1289 lttng_create_tracepoint_if_missing(enabler
);
1291 case LTTNG_KERNEL_SYSCALL
:
1292 lttng_create_syscall_if_missing(enabler
);
1301 * Create events associated with an enabler (if not already present),
1302 * and add backward reference from the event to the enabler.
1303 * Should be called with sessions mutex held.
1306 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
1308 struct lttng_session
*session
= enabler
->chan
->session
;
1309 struct lttng_event
*event
;
1311 /* First ensure that probe events are created for this enabler. */
1312 lttng_create_event_if_missing(enabler
);
1314 /* For each event matching enabler in session event list. */
1315 list_for_each_entry(event
, &session
->events
, list
) {
1316 struct lttng_enabler_ref
*enabler_ref
;
1318 if (!lttng_event_match_enabler(event
, enabler
))
1320 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
1323 * If no backward ref, create it.
1324 * Add backward ref from event to enabler.
1326 enabler_ref
= kzalloc(sizeof(*enabler_ref
), GFP_KERNEL
);
1329 enabler_ref
->ref
= enabler
;
1330 list_add(&enabler_ref
->node
,
1331 &event
->enablers_ref_head
);
1335 * Link filter bytecodes if not linked yet.
1337 lttng_enabler_event_link_bytecode(event
, enabler
);
1339 /* TODO: merge event context. */
1345 * Called at module load: connect the probe on all enablers matching
1347 * Called with sessions lock held.
1349 int lttng_fix_pending_events(void)
1351 struct lttng_session
*session
;
1353 list_for_each_entry(session
, &sessions
, list
)
1354 lttng_session_lazy_sync_enablers(session
);
1358 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1359 struct lttng_kernel_event
*event_param
,
1360 struct lttng_channel
*chan
)
1362 struct lttng_enabler
*enabler
;
1364 enabler
= kzalloc(sizeof(*enabler
), GFP_KERNEL
);
1367 enabler
->type
= type
;
1368 INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1369 memcpy(&enabler
->event_param
, event_param
,
1370 sizeof(enabler
->event_param
));
1371 enabler
->chan
= chan
;
1373 enabler
->enabled
= 0;
1374 enabler
->evtype
= LTTNG_TYPE_ENABLER
;
1375 mutex_lock(&sessions_mutex
);
1376 list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1377 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1378 mutex_unlock(&sessions_mutex
);
1382 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1384 mutex_lock(&sessions_mutex
);
1385 enabler
->enabled
= 1;
1386 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1387 mutex_unlock(&sessions_mutex
);
1391 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1393 mutex_lock(&sessions_mutex
);
1394 enabler
->enabled
= 0;
1395 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1396 mutex_unlock(&sessions_mutex
);
1400 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1401 struct lttng_kernel_filter_bytecode __user
*bytecode
)
1403 struct lttng_filter_bytecode_node
*bytecode_node
;
1404 uint32_t bytecode_len
;
1407 ret
= get_user(bytecode_len
, &bytecode
->len
);
1410 bytecode_node
= kzalloc(sizeof(*bytecode_node
) + bytecode_len
,
1414 ret
= copy_from_user(&bytecode_node
->bc
, bytecode
,
1415 sizeof(*bytecode
) + bytecode_len
);
1418 bytecode_node
->enabler
= enabler
;
1419 /* Enforce length based on allocated size */
1420 bytecode_node
->bc
.len
= bytecode_len
;
1421 list_add_tail(&bytecode_node
->node
, &enabler
->filter_bytecode_head
);
1422 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1426 kfree(bytecode_node
);
1430 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1431 struct lttng_kernel_context
*context_param
)
1437 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1439 struct lttng_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1441 /* Destroy filter bytecode */
1442 list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1443 &enabler
->filter_bytecode_head
, node
) {
1447 /* Destroy contexts */
1448 lttng_destroy_context(enabler
->ctx
);
1450 list_del(&enabler
->node
);
1455 * lttng_session_sync_enablers should be called just before starting a
1457 * Should be called with sessions mutex held.
1460 void lttng_session_sync_enablers(struct lttng_session
*session
)
1462 struct lttng_enabler
*enabler
;
1463 struct lttng_event
*event
;
1465 list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1466 lttng_enabler_ref_events(enabler
);
1468 * For each event, if at least one of its enablers is enabled,
1469 * and its channel and session transient states are enabled, we
1470 * enable the event, else we disable it.
1472 list_for_each_entry(event
, &session
->events
, list
) {
1473 struct lttng_enabler_ref
*enabler_ref
;
1474 struct lttng_bytecode_runtime
*runtime
;
1475 int enabled
= 0, has_enablers_without_bytecode
= 0;
1477 switch (event
->instrumentation
) {
1478 case LTTNG_KERNEL_TRACEPOINT
:
1479 case LTTNG_KERNEL_SYSCALL
:
1481 list_for_each_entry(enabler_ref
,
1482 &event
->enablers_ref_head
, node
) {
1483 if (enabler_ref
->ref
->enabled
) {
1490 /* Not handled with lazy sync. */
1494 * Enabled state is based on union of enablers, with
1495 * intesection of session and channel transient enable
1498 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
1500 ACCESS_ONCE(event
->enabled
) = enabled
;
1502 * Sync tracepoint registration with event enabled
1506 register_event(event
);
1508 _lttng_event_unregister(event
);
1511 /* Check if has enablers without bytecode enabled */
1512 list_for_each_entry(enabler_ref
,
1513 &event
->enablers_ref_head
, node
) {
1514 if (enabler_ref
->ref
->enabled
1515 && list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1516 has_enablers_without_bytecode
= 1;
1520 event
->has_enablers_without_bytecode
=
1521 has_enablers_without_bytecode
;
1523 /* Enable filters */
1524 list_for_each_entry(runtime
,
1525 &event
->bytecode_runtime_head
, node
)
1526 lttng_filter_sync_state(runtime
);
1531 * Apply enablers to session events, adding events to session if need
1532 * be. It is required after each modification applied to an active
1533 * session, and right before session "start".
1534 * "lazy" sync means we only sync if required.
1535 * Should be called with sessions mutex held.
1538 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1540 /* We can skip if session is not active */
1541 if (!session
->active
)
1543 lttng_session_sync_enablers(session
);
1547 * Serialize at most one packet worth of metadata into a metadata
1549 * We grab the metadata cache mutex to get exclusive access to our metadata
1550 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1551 * allows us to do racy operations such as looking for remaining space left in
1552 * packet and write, since mutual exclusion protects us from concurrent writes.
1553 * Mutual exclusion on the metadata cache allow us to read the cache content
1554 * without racing against reallocation of the cache by updates.
1555 * Returns the number of bytes written in the channel, 0 if no data
1556 * was written and a negative value on error.
1558 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
1559 struct channel
*chan
)
1561 struct lib_ring_buffer_ctx ctx
;
1563 size_t len
, reserve_len
;
1566 * Ensure we support mutiple get_next / put sequences followed by
1567 * put_next. The metadata cache lock protects reading the metadata
1568 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1569 * "flush" operations on the buffer invoked by different processes.
1570 * Moreover, since the metadata cache memory can be reallocated, we
1571 * need to have exclusive access against updates even though we only
1574 mutex_lock(&stream
->metadata_cache
->lock
);
1575 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
1576 if (stream
->metadata_in
!= stream
->metadata_out
)
1579 /* Metadata regenerated, change the version. */
1580 if (stream
->metadata_cache
->version
!= stream
->version
)
1581 stream
->version
= stream
->metadata_cache
->version
;
1583 len
= stream
->metadata_cache
->metadata_written
-
1584 stream
->metadata_in
;
1587 reserve_len
= min_t(size_t,
1588 stream
->transport
->ops
.packet_avail_size(chan
),
1590 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
1593 * If reservation failed, return an error to the caller.
1595 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
1597 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
1600 stream
->transport
->ops
.event_write(&ctx
,
1601 stream
->metadata_cache
->data
+ stream
->metadata_in
,
1603 stream
->transport
->ops
.event_commit(&ctx
);
1604 stream
->metadata_in
+= reserve_len
;
1608 mutex_unlock(&stream
->metadata_cache
->lock
);
1613 * Write the metadata to the metadata cache.
1614 * Must be called with sessions_mutex held.
1615 * The metadata cache lock protects us from concurrent read access from
1616 * thread outputting metadata content to ring buffer.
1618 int lttng_metadata_printf(struct lttng_session
*session
,
1619 const char *fmt
, ...)
1624 struct lttng_metadata_stream
*stream
;
1626 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
1629 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
1635 mutex_lock(&session
->metadata_cache
->lock
);
1636 if (session
->metadata_cache
->metadata_written
+ len
>
1637 session
->metadata_cache
->cache_alloc
) {
1638 char *tmp_cache_realloc
;
1639 unsigned int tmp_cache_alloc_size
;
1641 tmp_cache_alloc_size
= max_t(unsigned int,
1642 session
->metadata_cache
->cache_alloc
+ len
,
1643 session
->metadata_cache
->cache_alloc
<< 1);
1644 tmp_cache_realloc
= lttng_vzalloc(tmp_cache_alloc_size
);
1645 if (!tmp_cache_realloc
)
1647 if (session
->metadata_cache
->data
) {
1648 memcpy(tmp_cache_realloc
,
1649 session
->metadata_cache
->data
,
1650 session
->metadata_cache
->cache_alloc
);
1651 vfree(session
->metadata_cache
->data
);
1654 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
1655 session
->metadata_cache
->data
= tmp_cache_realloc
;
1657 memcpy(session
->metadata_cache
->data
+
1658 session
->metadata_cache
->metadata_written
,
1660 session
->metadata_cache
->metadata_written
+= len
;
1661 mutex_unlock(&session
->metadata_cache
->lock
);
1664 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
1665 wake_up_interruptible(&stream
->read_wait
);
1670 mutex_unlock(&session
->metadata_cache
->lock
);
1676 * Must be called with sessions_mutex held.
1679 int _lttng_field_statedump(struct lttng_session
*session
,
1680 const struct lttng_event_field
*field
)
1684 switch (field
->type
.atype
) {
1686 ret
= lttng_metadata_printf(session
,
1687 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
1688 field
->type
.u
.basic
.integer
.size
,
1689 field
->type
.u
.basic
.integer
.alignment
,
1690 field
->type
.u
.basic
.integer
.signedness
,
1691 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
1693 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1696 field
->type
.u
.basic
.integer
.base
,
1697 #if __BYTE_ORDER == __BIG_ENDIAN
1698 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1700 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1705 ret
= lttng_metadata_printf(session
,
1707 field
->type
.u
.basic
.enumeration
.name
,
1712 const struct lttng_basic_type
*elem_type
;
1714 elem_type
= &field
->type
.u
.array
.elem_type
;
1715 if (field
->type
.u
.array
.elem_alignment
) {
1716 ret
= lttng_metadata_printf(session
,
1717 " struct { } align(%u) _%s_padding;\n",
1718 field
->type
.u
.array
.elem_alignment
* CHAR_BIT
,
1723 ret
= lttng_metadata_printf(session
,
1724 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
1725 elem_type
->u
.basic
.integer
.size
,
1726 elem_type
->u
.basic
.integer
.alignment
,
1727 elem_type
->u
.basic
.integer
.signedness
,
1728 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1730 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1733 elem_type
->u
.basic
.integer
.base
,
1734 #if __BYTE_ORDER == __BIG_ENDIAN
1735 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1737 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1739 field
->name
, field
->type
.u
.array
.length
);
1742 case atype_sequence
:
1744 const struct lttng_basic_type
*elem_type
;
1745 const struct lttng_basic_type
*length_type
;
1747 elem_type
= &field
->type
.u
.sequence
.elem_type
;
1748 length_type
= &field
->type
.u
.sequence
.length_type
;
1749 ret
= lttng_metadata_printf(session
,
1750 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
1751 length_type
->u
.basic
.integer
.size
,
1752 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
1753 length_type
->u
.basic
.integer
.signedness
,
1754 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1756 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1759 length_type
->u
.basic
.integer
.base
,
1760 #if __BYTE_ORDER == __BIG_ENDIAN
1761 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1763 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1769 if (field
->type
.u
.sequence
.elem_alignment
) {
1770 ret
= lttng_metadata_printf(session
,
1771 " struct { } align(%u) _%s_padding;\n",
1772 field
->type
.u
.sequence
.elem_alignment
* CHAR_BIT
,
1777 ret
= lttng_metadata_printf(session
,
1778 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
1779 elem_type
->u
.basic
.integer
.size
,
1780 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
1781 elem_type
->u
.basic
.integer
.signedness
,
1782 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1784 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1787 elem_type
->u
.basic
.integer
.base
,
1788 #if __BYTE_ORDER == __BIG_ENDIAN
1789 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1791 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1799 /* Default encoding is UTF8 */
1800 ret
= lttng_metadata_printf(session
,
1802 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
1803 " { encoding = ASCII; }" : "",
1814 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
1815 struct lttng_ctx
*ctx
)
1822 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
1823 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
1825 ret
= _lttng_field_statedump(session
, &field
->event_field
);
1833 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
1834 struct lttng_event
*event
)
1836 const struct lttng_event_desc
*desc
= event
->desc
;
1840 for (i
= 0; i
< desc
->nr_fields
; i
++) {
1841 const struct lttng_event_field
*field
= &desc
->fields
[i
];
1843 ret
= _lttng_field_statedump(session
, field
);
1851 * Must be called with sessions_mutex held.
1854 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
1855 struct lttng_channel
*chan
,
1856 struct lttng_event
*event
)
1860 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1862 if (chan
->channel_type
== METADATA_CHANNEL
)
1865 ret
= lttng_metadata_printf(session
,
1869 " stream_id = %u;\n",
1877 ret
= lttng_metadata_printf(session
,
1878 " context := struct {\n");
1882 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
1886 ret
= lttng_metadata_printf(session
,
1892 ret
= lttng_metadata_printf(session
,
1893 " fields := struct {\n"
1898 ret
= _lttng_fields_metadata_statedump(session
, event
);
1903 * LTTng space reservation can only reserve multiples of the
1906 ret
= lttng_metadata_printf(session
,
1912 event
->metadata_dumped
= 1;
1919 * Must be called with sessions_mutex held.
1922 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
1923 struct lttng_channel
*chan
)
1927 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1930 if (chan
->channel_type
== METADATA_CHANNEL
)
1933 WARN_ON_ONCE(!chan
->header_type
);
1934 ret
= lttng_metadata_printf(session
,
1937 " event.header := %s;\n"
1938 " packet.context := struct packet_context;\n",
1940 chan
->header_type
== 1 ? "struct event_header_compact" :
1941 "struct event_header_large");
1946 ret
= lttng_metadata_printf(session
,
1947 " event.context := struct {\n");
1951 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
1955 ret
= lttng_metadata_printf(session
,
1961 ret
= lttng_metadata_printf(session
,
1964 chan
->metadata_dumped
= 1;
1970 * Must be called with sessions_mutex held.
1973 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1975 return lttng_metadata_printf(session
,
1976 "struct packet_context {\n"
1977 " uint64_clock_monotonic_t timestamp_begin;\n"
1978 " uint64_clock_monotonic_t timestamp_end;\n"
1979 " uint64_t content_size;\n"
1980 " uint64_t packet_size;\n"
1981 " uint64_t packet_seq_num;\n"
1982 " unsigned long events_discarded;\n"
1983 " uint32_t cpu_id;\n"
1990 * id: range: 0 - 30.
1991 * id 31 is reserved to indicate an extended header.
1994 * id: range: 0 - 65534.
1995 * id 65535 is reserved to indicate an extended header.
1997 * Must be called with sessions_mutex held.
2000 int _lttng_event_header_declare(struct lttng_session
*session
)
2002 return lttng_metadata_printf(session
,
2003 "struct event_header_compact {\n"
2004 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2007 " uint27_clock_monotonic_t timestamp;\n"
2011 " uint64_clock_monotonic_t timestamp;\n"
2016 "struct event_header_large {\n"
2017 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2020 " uint32_clock_monotonic_t timestamp;\n"
2024 " uint64_clock_monotonic_t timestamp;\n"
2028 lttng_alignof(uint32_t) * CHAR_BIT
,
2029 lttng_alignof(uint16_t) * CHAR_BIT
2034 * Approximation of NTP time of day to clock monotonic correlation,
2035 * taken at start of trace.
2036 * Yes, this is only an approximation. Yes, we can (and will) do better
2037 * in future versions.
2038 * This function may return a negative offset. It may happen if the
2039 * system sets the REALTIME clock to 0 after boot.
2042 int64_t measure_clock_offset(void)
2044 uint64_t monotonic_avg
, monotonic
[2], realtime
;
2045 uint64_t tcf
= trace_clock_freq();
2047 struct timespec rts
= { 0, 0 };
2048 unsigned long flags
;
2050 /* Disable interrupts to increase correlation precision. */
2051 local_irq_save(flags
);
2052 monotonic
[0] = trace_clock_read64();
2053 getnstimeofday(&rts
);
2054 monotonic
[1] = trace_clock_read64();
2055 local_irq_restore(flags
);
2057 monotonic_avg
= (monotonic
[0] + monotonic
[1]) >> 1;
2058 realtime
= (uint64_t) rts
.tv_sec
* tcf
;
2059 if (tcf
== NSEC_PER_SEC
) {
2060 realtime
+= rts
.tv_nsec
;
2062 uint64_t n
= rts
.tv_nsec
* tcf
;
2064 do_div(n
, NSEC_PER_SEC
);
2067 offset
= (int64_t) realtime
- monotonic_avg
;
2072 * Output metadata into this session's metadata buffers.
2073 * Must be called with sessions_mutex held.
2076 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
2078 unsigned char *uuid_c
= session
->uuid
.b
;
2079 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
2080 struct lttng_channel
*chan
;
2081 struct lttng_event
*event
;
2084 if (!ACCESS_ONCE(session
->active
))
2086 if (session
->metadata_dumped
)
2089 snprintf(uuid_s
, sizeof(uuid_s
),
2090 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2091 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
2092 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
2093 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
2094 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
2096 ret
= lttng_metadata_printf(session
,
2097 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2098 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2099 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2100 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2101 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2102 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2103 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2109 " byte_order = %s;\n"
2110 " packet.header := struct {\n"
2111 " uint32_t magic;\n"
2112 " uint8_t uuid[16];\n"
2113 " uint32_t stream_id;\n"
2114 " uint64_t stream_instance_id;\n"
2117 lttng_alignof(uint8_t) * CHAR_BIT
,
2118 lttng_alignof(uint16_t) * CHAR_BIT
,
2119 lttng_alignof(uint32_t) * CHAR_BIT
,
2120 lttng_alignof(uint64_t) * CHAR_BIT
,
2121 sizeof(unsigned long) * CHAR_BIT
,
2122 lttng_alignof(unsigned long) * CHAR_BIT
,
2126 #if __BYTE_ORDER == __BIG_ENDIAN
2135 ret
= lttng_metadata_printf(session
,
2137 " hostname = \"%s\";\n"
2138 " domain = \"kernel\";\n"
2139 " sysname = \"%s\";\n"
2140 " kernel_release = \"%s\";\n"
2141 " kernel_version = \"%s\";\n"
2142 " tracer_name = \"lttng-modules\";\n"
2143 " tracer_major = %d;\n"
2144 " tracer_minor = %d;\n"
2145 " tracer_patchlevel = %d;\n"
2147 current
->nsproxy
->uts_ns
->name
.nodename
,
2151 LTTNG_MODULES_MAJOR_VERSION
,
2152 LTTNG_MODULES_MINOR_VERSION
,
2153 LTTNG_MODULES_PATCHLEVEL_VERSION
2158 ret
= lttng_metadata_printf(session
,
2160 " name = \"%s\";\n",
2166 if (!trace_clock_uuid(clock_uuid_s
)) {
2167 ret
= lttng_metadata_printf(session
,
2168 " uuid = \"%s\";\n",
2175 ret
= lttng_metadata_printf(session
,
2176 " description = \"%s\";\n"
2177 " freq = %llu; /* Frequency, in Hz */\n"
2178 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2181 trace_clock_description(),
2182 (unsigned long long) trace_clock_freq(),
2183 (long long) measure_clock_offset()
2188 ret
= lttng_metadata_printf(session
,
2189 "typealias integer {\n"
2190 " size = 27; align = 1; signed = false;\n"
2191 " map = clock.%s.value;\n"
2192 "} := uint27_clock_monotonic_t;\n"
2194 "typealias integer {\n"
2195 " size = 32; align = %u; signed = false;\n"
2196 " map = clock.%s.value;\n"
2197 "} := uint32_clock_monotonic_t;\n"
2199 "typealias integer {\n"
2200 " size = 64; align = %u; signed = false;\n"
2201 " map = clock.%s.value;\n"
2202 "} := uint64_clock_monotonic_t;\n\n",
2204 lttng_alignof(uint32_t) * CHAR_BIT
,
2206 lttng_alignof(uint64_t) * CHAR_BIT
,
2212 ret
= _lttng_stream_packet_context_declare(session
);
2216 ret
= _lttng_event_header_declare(session
);
2221 list_for_each_entry(chan
, &session
->chan
, list
) {
2222 ret
= _lttng_channel_metadata_statedump(session
, chan
);
2227 list_for_each_entry(event
, &session
->events
, list
) {
2228 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
2232 session
->metadata_dumped
= 1;
2238 * lttng_transport_register - LTT transport registration
2239 * @transport: transport structure
2241 * Registers a transport which can be used as output to extract the data out of
2242 * LTTng. The module calling this registration function must ensure that no
2243 * trap-inducing code will be executed by the transport functions. E.g.
2244 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
2245 * is made visible to the transport function. This registration acts as a
2246 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
2247 * after its registration must it synchronize the TLBs.
2249 void lttng_transport_register(struct lttng_transport
*transport
)
2252 * Make sure no page fault can be triggered by the module about to be
2253 * registered. We deal with this here so we don't have to call
2254 * vmalloc_sync_all() in each module's init.
2256 wrapper_vmalloc_sync_all();
2258 mutex_lock(&sessions_mutex
);
2259 list_add_tail(&transport
->node
, <tng_transport_list
);
2260 mutex_unlock(&sessions_mutex
);
2262 EXPORT_SYMBOL_GPL(lttng_transport_register
);
2265 * lttng_transport_unregister - LTT transport unregistration
2266 * @transport: transport structure
2268 void lttng_transport_unregister(struct lttng_transport
*transport
)
2270 mutex_lock(&sessions_mutex
);
2271 list_del(&transport
->node
);
2272 mutex_unlock(&sessions_mutex
);
2274 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
2276 static int __init
lttng_events_init(void)
2280 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
2283 ret
= wrapper_get_pfnblock_flags_mask_init();
2286 ret
= wrapper_get_pageblock_flags_mask_init();
2289 ret
= lttng_context_init();
2292 ret
= lttng_tracepoint_init();
2295 event_cache
= KMEM_CACHE(lttng_event
, 0);
2300 ret
= lttng_abi_init();
2303 ret
= lttng_logger_init();
2311 kmem_cache_destroy(event_cache
);
2313 lttng_tracepoint_exit();
2315 lttng_context_exit();
2319 module_init(lttng_events_init
);
2321 static void __exit
lttng_events_exit(void)
2323 struct lttng_session
*session
, *tmpsession
;
2325 lttng_logger_exit();
2327 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
2328 lttng_session_destroy(session
);
2329 kmem_cache_destroy(event_cache
);
2330 lttng_tracepoint_exit();
2331 lttng_context_exit();
2334 module_exit(lttng_events_exit
);
2336 MODULE_LICENSE("GPL and additional rights");
2337 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
2338 MODULE_DESCRIPTION("LTTng Events");
2339 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
2340 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
2341 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
2342 LTTNG_MODULES_EXTRAVERSION
);