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 "wrapper/vzalloc.h"
55 #define METADATA_CACHE_DEFAULT_SIZE 4096
57 static LIST_HEAD(sessions
);
58 static LIST_HEAD(lttng_transport_list
);
60 * Protect the sessions and metadata caches.
62 static DEFINE_MUTEX(sessions_mutex
);
63 static struct kmem_cache
*event_cache
;
65 static void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
66 static void lttng_session_sync_enablers(struct lttng_session
*session
);
67 static void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
69 static void _lttng_event_destroy(struct lttng_event
*event
);
70 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
71 static int _lttng_event_unregister(struct lttng_event
*event
);
73 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
74 struct lttng_channel
*chan
,
75 struct lttng_event
*event
);
77 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
79 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
81 void synchronize_trace(void)
84 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
85 #ifdef CONFIG_PREEMPT_RT_FULL
88 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
89 #ifdef CONFIG_PREEMPT_RT
92 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
95 void lttng_lock_sessions(void)
97 mutex_lock(&sessions_mutex
);
100 void lttng_unlock_sessions(void)
102 mutex_unlock(&sessions_mutex
);
106 * Called with sessions lock held.
108 int lttng_session_active(void)
110 struct lttng_session
*iter
;
112 list_for_each_entry(iter
, &sessions
, list
) {
119 struct lttng_session
*lttng_session_create(void)
121 struct lttng_session
*session
;
122 struct lttng_metadata_cache
*metadata_cache
;
125 mutex_lock(&sessions_mutex
);
126 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
129 INIT_LIST_HEAD(&session
->chan
);
130 INIT_LIST_HEAD(&session
->events
);
131 uuid_le_gen(&session
->uuid
);
133 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
136 goto err_free_session
;
137 metadata_cache
->data
= lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE
);
138 if (!metadata_cache
->data
)
140 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
141 kref_init(&metadata_cache
->refcount
);
142 mutex_init(&metadata_cache
->lock
);
143 session
->metadata_cache
= metadata_cache
;
144 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
145 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
146 sizeof(metadata_cache
->uuid
));
147 INIT_LIST_HEAD(&session
->enablers_head
);
148 for (i
= 0; i
< LTTNG_EVENT_HT_SIZE
; i
++)
149 INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
150 list_add(&session
->list
, &sessions
);
151 mutex_unlock(&sessions_mutex
);
155 kfree(metadata_cache
);
159 mutex_unlock(&sessions_mutex
);
163 void metadata_cache_destroy(struct kref
*kref
)
165 struct lttng_metadata_cache
*cache
=
166 container_of(kref
, struct lttng_metadata_cache
, refcount
);
171 void lttng_session_destroy(struct lttng_session
*session
)
173 struct lttng_channel
*chan
, *tmpchan
;
174 struct lttng_event
*event
, *tmpevent
;
175 struct lttng_metadata_stream
*metadata_stream
;
176 struct lttng_enabler
*enabler
, *tmpenabler
;
179 mutex_lock(&sessions_mutex
);
180 ACCESS_ONCE(session
->active
) = 0;
181 list_for_each_entry(chan
, &session
->chan
, list
) {
182 ret
= lttng_syscalls_unregister(chan
);
185 list_for_each_entry(event
, &session
->events
, list
) {
186 ret
= _lttng_event_unregister(event
);
189 synchronize_trace(); /* Wait for in-flight events to complete */
190 list_for_each_entry_safe(enabler
, tmpenabler
,
191 &session
->enablers_head
, node
)
192 lttng_enabler_destroy(enabler
);
193 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
194 _lttng_event_destroy(event
);
195 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
196 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
197 _lttng_channel_destroy(chan
);
199 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
200 _lttng_metadata_channel_hangup(metadata_stream
);
201 if (session
->pid_tracker
)
202 lttng_pid_tracker_destroy(session
->pid_tracker
);
203 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
204 list_del(&session
->list
);
205 mutex_unlock(&sessions_mutex
);
209 int lttng_session_enable(struct lttng_session
*session
)
212 struct lttng_channel
*chan
;
214 mutex_lock(&sessions_mutex
);
215 if (session
->active
) {
220 /* Set transient enabler state to "enabled" */
224 * Snapshot the number of events per channel to know the type of header
227 list_for_each_entry(chan
, &session
->chan
, list
) {
228 if (chan
->header_type
)
229 continue; /* don't change it if session stop/restart */
230 if (chan
->free_event_id
< 31)
231 chan
->header_type
= 1; /* compact */
233 chan
->header_type
= 2; /* large */
236 /* We need to sync enablers with session before activation. */
237 lttng_session_sync_enablers(session
);
239 ACCESS_ONCE(session
->active
) = 1;
240 ACCESS_ONCE(session
->been_active
) = 1;
241 ret
= _lttng_session_metadata_statedump(session
);
243 ACCESS_ONCE(session
->active
) = 0;
246 ret
= lttng_statedump_start(session
);
248 ACCESS_ONCE(session
->active
) = 0;
250 mutex_unlock(&sessions_mutex
);
254 int lttng_session_disable(struct lttng_session
*session
)
258 mutex_lock(&sessions_mutex
);
259 if (!session
->active
) {
263 ACCESS_ONCE(session
->active
) = 0;
265 /* Set transient enabler state to "disabled" */
267 lttng_session_sync_enablers(session
);
269 mutex_unlock(&sessions_mutex
);
273 int lttng_channel_enable(struct lttng_channel
*channel
)
277 mutex_lock(&sessions_mutex
);
278 if (channel
->channel_type
== METADATA_CHANNEL
) {
282 if (channel
->enabled
) {
286 /* Set transient enabler state to "enabled" */
288 lttng_session_sync_enablers(channel
->session
);
289 /* Set atomically the state to "enabled" */
290 ACCESS_ONCE(channel
->enabled
) = 1;
292 mutex_unlock(&sessions_mutex
);
296 int lttng_channel_disable(struct lttng_channel
*channel
)
300 mutex_lock(&sessions_mutex
);
301 if (channel
->channel_type
== METADATA_CHANNEL
) {
305 if (!channel
->enabled
) {
309 /* Set atomically the state to "disabled" */
310 ACCESS_ONCE(channel
->enabled
) = 0;
311 /* Set transient enabler state to "enabled" */
313 lttng_session_sync_enablers(channel
->session
);
315 mutex_unlock(&sessions_mutex
);
319 int lttng_event_enable(struct lttng_event
*event
)
323 mutex_lock(&sessions_mutex
);
324 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
328 if (event
->enabled
) {
332 switch (event
->instrumentation
) {
333 case LTTNG_KERNEL_TRACEPOINT
:
334 case LTTNG_KERNEL_SYSCALL
:
337 case LTTNG_KERNEL_KPROBE
:
338 case LTTNG_KERNEL_FUNCTION
:
339 case LTTNG_KERNEL_NOOP
:
340 ACCESS_ONCE(event
->enabled
) = 1;
342 case LTTNG_KERNEL_KRETPROBE
:
343 ret
= lttng_kretprobes_event_enable_state(event
, 1);
350 mutex_unlock(&sessions_mutex
);
354 int lttng_event_disable(struct lttng_event
*event
)
358 mutex_lock(&sessions_mutex
);
359 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
363 if (!event
->enabled
) {
367 switch (event
->instrumentation
) {
368 case LTTNG_KERNEL_TRACEPOINT
:
369 case LTTNG_KERNEL_SYSCALL
:
372 case LTTNG_KERNEL_KPROBE
:
373 case LTTNG_KERNEL_FUNCTION
:
374 case LTTNG_KERNEL_NOOP
:
375 ACCESS_ONCE(event
->enabled
) = 0;
377 case LTTNG_KERNEL_KRETPROBE
:
378 ret
= lttng_kretprobes_event_enable_state(event
, 0);
385 mutex_unlock(&sessions_mutex
);
389 static struct lttng_transport
*lttng_transport_find(const char *name
)
391 struct lttng_transport
*transport
;
393 list_for_each_entry(transport
, <tng_transport_list
, node
) {
394 if (!strcmp(transport
->name
, name
))
400 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
401 const char *transport_name
,
403 size_t subbuf_size
, size_t num_subbuf
,
404 unsigned int switch_timer_interval
,
405 unsigned int read_timer_interval
,
406 enum channel_type channel_type
)
408 struct lttng_channel
*chan
;
409 struct lttng_transport
*transport
= NULL
;
411 mutex_lock(&sessions_mutex
);
412 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
413 goto active
; /* Refuse to add channel to active session */
414 transport
= lttng_transport_find(transport_name
);
416 printk(KERN_WARNING
"LTTng transport %s not found\n",
420 if (!try_module_get(transport
->owner
)) {
421 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
424 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
427 chan
->session
= session
;
428 chan
->id
= session
->free_chan_id
++;
429 chan
->ops
= &transport
->ops
;
431 * Note: the channel creation op already writes into the packet
432 * headers. Therefore the "chan" information used as input
433 * should be already accessible.
435 chan
->chan
= transport
->ops
.channel_create(transport_name
,
436 chan
, buf_addr
, subbuf_size
, num_subbuf
,
437 switch_timer_interval
, read_timer_interval
);
442 chan
->transport
= transport
;
443 chan
->channel_type
= channel_type
;
444 list_add(&chan
->list
, &session
->chan
);
445 mutex_unlock(&sessions_mutex
);
452 module_put(transport
->owner
);
455 mutex_unlock(&sessions_mutex
);
460 * Only used internally at session destruction for per-cpu channels, and
461 * when metadata channel is released.
462 * Needs to be called with sessions mutex held.
465 void _lttng_channel_destroy(struct lttng_channel
*chan
)
467 chan
->ops
->channel_destroy(chan
->chan
);
468 module_put(chan
->transport
->owner
);
469 list_del(&chan
->list
);
470 lttng_destroy_context(chan
->ctx
);
474 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
476 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
478 /* Protect the metadata cache with the sessions_mutex. */
479 mutex_lock(&sessions_mutex
);
480 _lttng_channel_destroy(chan
);
481 mutex_unlock(&sessions_mutex
);
483 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
486 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
488 stream
->finalized
= 1;
489 wake_up_interruptible(&stream
->read_wait
);
493 * Supports event creation while tracing session is active.
494 * Needs to be called with sessions mutex held.
496 struct lttng_event
*_lttng_event_create(struct lttng_channel
*chan
,
497 struct lttng_kernel_event
*event_param
,
499 const struct lttng_event_desc
*event_desc
,
500 enum lttng_kernel_instrumentation itype
)
502 struct lttng_session
*session
= chan
->session
;
503 struct lttng_event
*event
;
504 const char *event_name
;
505 struct hlist_head
*head
;
510 if (chan
->free_event_id
== -1U) {
516 case LTTNG_KERNEL_TRACEPOINT
:
517 event_name
= event_desc
->name
;
519 case LTTNG_KERNEL_KPROBE
:
520 case LTTNG_KERNEL_KRETPROBE
:
521 case LTTNG_KERNEL_FUNCTION
:
522 case LTTNG_KERNEL_NOOP
:
523 case LTTNG_KERNEL_SYSCALL
:
524 event_name
= event_param
->name
;
531 name_len
= strlen(event_name
);
532 hash
= jhash(event_name
, name_len
, 0);
533 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
534 lttng_hlist_for_each_entry(event
, head
, hlist
) {
535 WARN_ON_ONCE(!event
->desc
);
536 if (!strncmp(event
->desc
->name
, event_name
,
537 LTTNG_KERNEL_SYM_NAME_LEN
- 1)
538 && chan
== event
->chan
) {
544 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
550 event
->filter
= filter
;
551 event
->id
= chan
->free_event_id
++;
552 event
->instrumentation
= itype
;
553 event
->evtype
= LTTNG_TYPE_EVENT
;
554 INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
555 INIT_LIST_HEAD(&event
->enablers_ref_head
);
558 case LTTNG_KERNEL_TRACEPOINT
:
559 /* Event will be enabled by enabler sync. */
561 event
->registered
= 0;
562 event
->desc
= lttng_event_get(event_name
);
567 /* Populate lttng_event structure before event registration. */
570 case LTTNG_KERNEL_KPROBE
:
572 * Needs to be explicitly enabled after creation, since
573 * we may want to apply filters.
576 event
->registered
= 1;
578 * Populate lttng_event structure before event
582 ret
= lttng_kprobes_register(event_name
,
583 event_param
->u
.kprobe
.symbol_name
,
584 event_param
->u
.kprobe
.offset
,
585 event_param
->u
.kprobe
.addr
,
591 ret
= try_module_get(event
->desc
->owner
);
594 case LTTNG_KERNEL_KRETPROBE
:
596 struct lttng_event
*event_return
;
598 /* kretprobe defines 2 events */
600 * Needs to be explicitly enabled after creation, since
601 * we may want to apply filters.
604 event
->registered
= 1;
606 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
611 event_return
->chan
= chan
;
612 event_return
->filter
= filter
;
613 event_return
->id
= chan
->free_event_id
++;
614 event_return
->enabled
= 0;
615 event_return
->registered
= 1;
616 event_return
->instrumentation
= itype
;
618 * Populate lttng_event structure before kretprobe registration.
621 ret
= lttng_kretprobes_register(event_name
,
622 event_param
->u
.kretprobe
.symbol_name
,
623 event_param
->u
.kretprobe
.offset
,
624 event_param
->u
.kretprobe
.addr
,
625 event
, event_return
);
627 kmem_cache_free(event_cache
, event_return
);
631 /* Take 2 refs on the module: one per event. */
632 ret
= try_module_get(event
->desc
->owner
);
634 ret
= try_module_get(event
->desc
->owner
);
636 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
638 WARN_ON_ONCE(ret
> 0);
640 kmem_cache_free(event_cache
, event_return
);
641 module_put(event
->desc
->owner
);
642 module_put(event
->desc
->owner
);
643 goto statedump_error
;
645 list_add(&event_return
->list
, &chan
->session
->events
);
648 case LTTNG_KERNEL_FUNCTION
:
650 * Needs to be explicitly enabled after creation, since
651 * we may want to apply filters.
654 event
->registered
= 1;
656 * Populate lttng_event structure before event
660 ret
= lttng_ftrace_register(event_name
,
661 event_param
->u
.ftrace
.symbol_name
,
666 ret
= try_module_get(event
->desc
->owner
);
669 case LTTNG_KERNEL_NOOP
:
670 case LTTNG_KERNEL_SYSCALL
:
672 * Needs to be explicitly enabled after creation, since
673 * we may want to apply filters.
676 event
->registered
= 0;
677 event
->desc
= event_desc
;
688 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
689 WARN_ON_ONCE(ret
> 0);
691 goto statedump_error
;
693 hlist_add_head(&event
->hlist
, head
);
694 list_add(&event
->list
, &chan
->session
->events
);
698 /* If a statedump error occurs, events will not be readable. */
700 kmem_cache_free(event_cache
, event
);
708 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
709 struct lttng_kernel_event
*event_param
,
711 const struct lttng_event_desc
*event_desc
,
712 enum lttng_kernel_instrumentation itype
)
714 struct lttng_event
*event
;
716 mutex_lock(&sessions_mutex
);
717 event
= _lttng_event_create(chan
, event_param
, filter
, event_desc
,
719 mutex_unlock(&sessions_mutex
);
723 /* Only used for tracepoints for now. */
725 void register_event(struct lttng_event
*event
)
727 const struct lttng_event_desc
*desc
;
730 if (event
->registered
)
734 switch (event
->instrumentation
) {
735 case LTTNG_KERNEL_TRACEPOINT
:
736 ret
= lttng_wrapper_tracepoint_probe_register(desc
->kname
,
737 desc
->probe_callback
,
740 case LTTNG_KERNEL_SYSCALL
:
741 ret
= lttng_syscall_filter_enable(event
->chan
,
744 case LTTNG_KERNEL_KPROBE
:
745 case LTTNG_KERNEL_KRETPROBE
:
746 case LTTNG_KERNEL_FUNCTION
:
747 case LTTNG_KERNEL_NOOP
:
754 event
->registered
= 1;
758 * Only used internally at session destruction.
760 int _lttng_event_unregister(struct lttng_event
*event
)
762 const struct lttng_event_desc
*desc
;
765 if (!event
->registered
)
769 switch (event
->instrumentation
) {
770 case LTTNG_KERNEL_TRACEPOINT
:
771 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
772 event
->desc
->probe_callback
,
775 case LTTNG_KERNEL_KPROBE
:
776 lttng_kprobes_unregister(event
);
779 case LTTNG_KERNEL_KRETPROBE
:
780 lttng_kretprobes_unregister(event
);
783 case LTTNG_KERNEL_FUNCTION
:
784 lttng_ftrace_unregister(event
);
787 case LTTNG_KERNEL_SYSCALL
:
788 ret
= lttng_syscall_filter_disable(event
->chan
,
791 case LTTNG_KERNEL_NOOP
:
798 event
->registered
= 0;
803 * Only used internally at session destruction.
806 void _lttng_event_destroy(struct lttng_event
*event
)
808 switch (event
->instrumentation
) {
809 case LTTNG_KERNEL_TRACEPOINT
:
810 lttng_event_put(event
->desc
);
812 case LTTNG_KERNEL_KPROBE
:
813 module_put(event
->desc
->owner
);
814 lttng_kprobes_destroy_private(event
);
816 case LTTNG_KERNEL_KRETPROBE
:
817 module_put(event
->desc
->owner
);
818 lttng_kretprobes_destroy_private(event
);
820 case LTTNG_KERNEL_FUNCTION
:
821 module_put(event
->desc
->owner
);
822 lttng_ftrace_destroy_private(event
);
824 case LTTNG_KERNEL_NOOP
:
825 case LTTNG_KERNEL_SYSCALL
:
830 list_del(&event
->list
);
831 lttng_destroy_context(event
->ctx
);
832 kmem_cache_free(event_cache
, event
);
835 int lttng_session_track_pid(struct lttng_session
*session
, int pid
)
841 mutex_lock(&sessions_mutex
);
843 /* track all pids: destroy tracker. */
844 if (session
->pid_tracker
) {
845 struct lttng_pid_tracker
*lpf
;
847 lpf
= session
->pid_tracker
;
848 rcu_assign_pointer(session
->pid_tracker
, NULL
);
850 lttng_pid_tracker_destroy(lpf
);
854 if (!session
->pid_tracker
) {
855 struct lttng_pid_tracker
*lpf
;
857 lpf
= lttng_pid_tracker_create();
862 ret
= lttng_pid_tracker_add(lpf
, pid
);
863 rcu_assign_pointer(session
->pid_tracker
, lpf
);
865 ret
= lttng_pid_tracker_add(session
->pid_tracker
, pid
);
869 mutex_unlock(&sessions_mutex
);
873 int lttng_session_untrack_pid(struct lttng_session
*session
, int pid
)
879 mutex_lock(&sessions_mutex
);
881 /* untrack all pids: replace by empty tracker. */
882 struct lttng_pid_tracker
*old_lpf
= session
->pid_tracker
;
883 struct lttng_pid_tracker
*lpf
;
885 lpf
= lttng_pid_tracker_create();
890 rcu_assign_pointer(session
->pid_tracker
, lpf
);
893 lttng_pid_tracker_destroy(old_lpf
);
896 if (!session
->pid_tracker
) {
900 ret
= lttng_pid_tracker_del(session
->pid_tracker
, pid
);
903 mutex_unlock(&sessions_mutex
);
908 void *pid_list_start(struct seq_file
*m
, loff_t
*pos
)
910 struct lttng_session
*session
= m
->private;
911 struct lttng_pid_tracker
*lpf
;
912 struct lttng_pid_hash_node
*e
;
915 mutex_lock(&sessions_mutex
);
916 lpf
= session
->pid_tracker
;
918 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
919 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
921 lttng_hlist_for_each_entry(e
, head
, hlist
) {
927 /* PID tracker disabled. */
928 if (iter
>= *pos
&& iter
== 0) {
929 return session
; /* empty tracker */
937 /* Called with sessions_mutex held. */
939 void *pid_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
941 struct lttng_session
*session
= m
->private;
942 struct lttng_pid_tracker
*lpf
;
943 struct lttng_pid_hash_node
*e
;
947 lpf
= session
->pid_tracker
;
949 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
950 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
952 lttng_hlist_for_each_entry(e
, head
, hlist
) {
958 /* PID tracker disabled. */
959 if (iter
>= *ppos
&& iter
== 0)
960 return session
; /* empty tracker */
969 void pid_list_stop(struct seq_file
*m
, void *p
)
971 mutex_unlock(&sessions_mutex
);
975 int pid_list_show(struct seq_file
*m
, void *p
)
979 if (p
== m
->private) {
980 /* Tracker disabled. */
983 const struct lttng_pid_hash_node
*e
= p
;
985 pid
= lttng_pid_tracker_get_node_pid(e
);
987 seq_printf(m
, "process { pid = %d; };\n", pid
);
992 const struct seq_operations lttng_tracker_pids_list_seq_ops
= {
993 .start
= pid_list_start
,
994 .next
= pid_list_next
,
995 .stop
= pid_list_stop
,
996 .show
= pid_list_show
,
1000 int lttng_tracker_pids_list_open(struct inode
*inode
, struct file
*file
)
1002 return seq_open(file
, <tng_tracker_pids_list_seq_ops
);
1006 int lttng_tracker_pids_list_release(struct inode
*inode
, struct file
*file
)
1008 struct seq_file
*m
= file
->private_data
;
1009 struct lttng_session
*session
= m
->private;
1012 WARN_ON_ONCE(!session
);
1013 ret
= seq_release(inode
, file
);
1014 if (!ret
&& session
)
1015 fput(session
->file
);
1019 const struct file_operations lttng_tracker_pids_list_fops
= {
1020 .owner
= THIS_MODULE
,
1021 .open
= lttng_tracker_pids_list_open
,
1023 .llseek
= seq_lseek
,
1024 .release
= lttng_tracker_pids_list_release
,
1027 int lttng_session_list_tracker_pids(struct lttng_session
*session
)
1029 struct file
*tracker_pids_list_file
;
1033 file_fd
= lttng_get_unused_fd();
1039 tracker_pids_list_file
= anon_inode_getfile("[lttng_tracker_pids_list]",
1040 <tng_tracker_pids_list_fops
,
1042 if (IS_ERR(tracker_pids_list_file
)) {
1043 ret
= PTR_ERR(tracker_pids_list_file
);
1046 if (atomic_long_add_unless(&session
->file
->f_count
,
1047 1, INT_MAX
) == INT_MAX
) {
1048 goto refcount_error
;
1050 ret
= lttng_tracker_pids_list_fops
.open(NULL
, tracker_pids_list_file
);
1053 m
= tracker_pids_list_file
->private_data
;
1054 m
->private = session
;
1055 fd_install(file_fd
, tracker_pids_list_file
);
1060 atomic_long_dec(&session
->file
->f_count
);
1062 fput(tracker_pids_list_file
);
1064 put_unused_fd(file_fd
);
1070 * Enabler management.
1073 int lttng_match_enabler_wildcard(const char *desc_name
,
1076 /* Compare excluding final '*' */
1077 if (strncmp(desc_name
, name
, strlen(name
) - 1))
1083 int lttng_match_enabler_name(const char *desc_name
,
1086 if (strcmp(desc_name
, name
))
1092 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
1093 struct lttng_enabler
*enabler
)
1095 const char *desc_name
, *enabler_name
;
1097 enabler_name
= enabler
->event_param
.name
;
1098 switch (enabler
->event_param
.instrumentation
) {
1099 case LTTNG_KERNEL_TRACEPOINT
:
1100 desc_name
= desc
->name
;
1102 case LTTNG_KERNEL_SYSCALL
:
1103 desc_name
= desc
->name
;
1104 if (!strncmp(desc_name
, "compat_", strlen("compat_")))
1105 desc_name
+= strlen("compat_");
1106 if (!strncmp(desc_name
, "syscall_exit_",
1107 strlen("syscall_exit_"))) {
1108 desc_name
+= strlen("syscall_exit_");
1109 } else if (!strncmp(desc_name
, "syscall_entry_",
1110 strlen("syscall_entry_"))) {
1111 desc_name
+= strlen("syscall_entry_");
1121 switch (enabler
->type
) {
1122 case LTTNG_ENABLER_WILDCARD
:
1123 return lttng_match_enabler_wildcard(desc_name
, enabler_name
);
1124 case LTTNG_ENABLER_NAME
:
1125 return lttng_match_enabler_name(desc_name
, enabler_name
);
1132 int lttng_event_match_enabler(struct lttng_event
*event
,
1133 struct lttng_enabler
*enabler
)
1135 if (enabler
->event_param
.instrumentation
!= event
->instrumentation
)
1137 if (lttng_desc_match_enabler(event
->desc
, enabler
)
1138 && event
->chan
== enabler
->chan
)
1145 struct lttng_enabler_ref
*lttng_event_enabler_ref(struct lttng_event
*event
,
1146 struct lttng_enabler
*enabler
)
1148 struct lttng_enabler_ref
*enabler_ref
;
1150 list_for_each_entry(enabler_ref
,
1151 &event
->enablers_ref_head
, node
) {
1152 if (enabler_ref
->ref
== enabler
)
1159 void lttng_create_tracepoint_if_missing(struct lttng_enabler
*enabler
)
1161 struct lttng_session
*session
= enabler
->chan
->session
;
1162 struct lttng_probe_desc
*probe_desc
;
1163 const struct lttng_event_desc
*desc
;
1165 struct list_head
*probe_list
;
1167 probe_list
= lttng_get_probe_list_head();
1169 * For each probe event, if we find that a probe event matches
1170 * our enabler, create an associated lttng_event if not
1173 list_for_each_entry(probe_desc
, probe_list
, head
) {
1174 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
1176 struct hlist_head
*head
;
1177 const char *event_name
;
1180 struct lttng_event
*event
;
1182 desc
= probe_desc
->event_desc
[i
];
1183 if (!lttng_desc_match_enabler(desc
, enabler
))
1185 event_name
= desc
->name
;
1186 name_len
= strlen(event_name
);
1189 * Check if already created.
1191 hash
= jhash(event_name
, name_len
, 0);
1192 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
1193 lttng_hlist_for_each_entry(event
, head
, hlist
) {
1194 if (event
->desc
== desc
1195 && event
->chan
== enabler
->chan
)
1202 * We need to create an event for this
1205 event
= _lttng_event_create(enabler
->chan
,
1207 LTTNG_KERNEL_TRACEPOINT
);
1209 printk(KERN_INFO
"Unable to create event %s\n",
1210 probe_desc
->event_desc
[i
]->name
);
1217 void lttng_create_syscall_if_missing(struct lttng_enabler
*enabler
)
1221 ret
= lttng_syscalls_register(enabler
->chan
, NULL
);
1226 * Create struct lttng_event if it is missing and present in the list of
1227 * tracepoint probes.
1228 * Should be called with sessions mutex held.
1231 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
1233 switch (enabler
->event_param
.instrumentation
) {
1234 case LTTNG_KERNEL_TRACEPOINT
:
1235 lttng_create_tracepoint_if_missing(enabler
);
1237 case LTTNG_KERNEL_SYSCALL
:
1238 lttng_create_syscall_if_missing(enabler
);
1247 * Create events associated with an enabler (if not already present),
1248 * and add backward reference from the event to the enabler.
1249 * Should be called with sessions mutex held.
1252 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
1254 struct lttng_session
*session
= enabler
->chan
->session
;
1255 struct lttng_event
*event
;
1257 /* First ensure that probe events are created for this enabler. */
1258 lttng_create_event_if_missing(enabler
);
1260 /* For each event matching enabler in session event list. */
1261 list_for_each_entry(event
, &session
->events
, list
) {
1262 struct lttng_enabler_ref
*enabler_ref
;
1264 if (!lttng_event_match_enabler(event
, enabler
))
1266 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
1269 * If no backward ref, create it.
1270 * Add backward ref from event to enabler.
1272 enabler_ref
= kzalloc(sizeof(*enabler_ref
), GFP_KERNEL
);
1275 enabler_ref
->ref
= enabler
;
1276 list_add(&enabler_ref
->node
,
1277 &event
->enablers_ref_head
);
1281 * Link filter bytecodes if not linked yet.
1283 lttng_enabler_event_link_bytecode(event
, enabler
);
1285 /* TODO: merge event context. */
1291 * Called at module load: connect the probe on all enablers matching
1293 * Called with sessions lock held.
1295 int lttng_fix_pending_events(void)
1297 struct lttng_session
*session
;
1299 list_for_each_entry(session
, &sessions
, list
)
1300 lttng_session_lazy_sync_enablers(session
);
1304 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1305 struct lttng_kernel_event
*event_param
,
1306 struct lttng_channel
*chan
)
1308 struct lttng_enabler
*enabler
;
1310 enabler
= kzalloc(sizeof(*enabler
), GFP_KERNEL
);
1313 enabler
->type
= type
;
1314 INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1315 memcpy(&enabler
->event_param
, event_param
,
1316 sizeof(enabler
->event_param
));
1317 enabler
->chan
= chan
;
1319 enabler
->enabled
= 0;
1320 enabler
->evtype
= LTTNG_TYPE_ENABLER
;
1321 mutex_lock(&sessions_mutex
);
1322 list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1323 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1324 mutex_unlock(&sessions_mutex
);
1328 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1330 mutex_lock(&sessions_mutex
);
1331 enabler
->enabled
= 1;
1332 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1333 mutex_unlock(&sessions_mutex
);
1337 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1339 mutex_lock(&sessions_mutex
);
1340 enabler
->enabled
= 0;
1341 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1342 mutex_unlock(&sessions_mutex
);
1346 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1347 struct lttng_kernel_filter_bytecode __user
*bytecode
)
1349 struct lttng_filter_bytecode_node
*bytecode_node
;
1350 uint32_t bytecode_len
;
1353 ret
= get_user(bytecode_len
, &bytecode
->len
);
1356 bytecode_node
= kzalloc(sizeof(*bytecode_node
) + bytecode_len
,
1360 ret
= copy_from_user(&bytecode_node
->bc
, bytecode
,
1361 sizeof(*bytecode
) + bytecode_len
);
1364 bytecode_node
->enabler
= enabler
;
1365 /* Enforce length based on allocated size */
1366 bytecode_node
->bc
.len
= bytecode_len
;
1367 list_add_tail(&bytecode_node
->node
, &enabler
->filter_bytecode_head
);
1368 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1372 kfree(bytecode_node
);
1376 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1377 struct lttng_kernel_context
*context_param
)
1383 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1385 struct lttng_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1387 /* Destroy filter bytecode */
1388 list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1389 &enabler
->filter_bytecode_head
, node
) {
1393 /* Destroy contexts */
1394 lttng_destroy_context(enabler
->ctx
);
1396 list_del(&enabler
->node
);
1401 * lttng_session_sync_enablers should be called just before starting a
1403 * Should be called with sessions mutex held.
1406 void lttng_session_sync_enablers(struct lttng_session
*session
)
1408 struct lttng_enabler
*enabler
;
1409 struct lttng_event
*event
;
1411 list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1412 lttng_enabler_ref_events(enabler
);
1414 * For each event, if at least one of its enablers is enabled,
1415 * and its channel and session transient states are enabled, we
1416 * enable the event, else we disable it.
1418 list_for_each_entry(event
, &session
->events
, list
) {
1419 struct lttng_enabler_ref
*enabler_ref
;
1420 struct lttng_bytecode_runtime
*runtime
;
1421 int enabled
= 0, has_enablers_without_bytecode
= 0;
1423 switch (event
->instrumentation
) {
1424 case LTTNG_KERNEL_TRACEPOINT
:
1425 case LTTNG_KERNEL_SYSCALL
:
1427 list_for_each_entry(enabler_ref
,
1428 &event
->enablers_ref_head
, node
) {
1429 if (enabler_ref
->ref
->enabled
) {
1436 /* Not handled with lazy sync. */
1440 * Enabled state is based on union of enablers, with
1441 * intesection of session and channel transient enable
1444 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
1446 ACCESS_ONCE(event
->enabled
) = enabled
;
1448 * Sync tracepoint registration with event enabled
1452 register_event(event
);
1454 _lttng_event_unregister(event
);
1457 /* Check if has enablers without bytecode enabled */
1458 list_for_each_entry(enabler_ref
,
1459 &event
->enablers_ref_head
, node
) {
1460 if (enabler_ref
->ref
->enabled
1461 && list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1462 has_enablers_without_bytecode
= 1;
1466 event
->has_enablers_without_bytecode
=
1467 has_enablers_without_bytecode
;
1469 /* Enable filters */
1470 list_for_each_entry(runtime
,
1471 &event
->bytecode_runtime_head
, node
)
1472 lttng_filter_sync_state(runtime
);
1477 * Apply enablers to session events, adding events to session if need
1478 * be. It is required after each modification applied to an active
1479 * session, and right before session "start".
1480 * "lazy" sync means we only sync if required.
1481 * Should be called with sessions mutex held.
1484 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1486 /* We can skip if session is not active */
1487 if (!session
->active
)
1489 lttng_session_sync_enablers(session
);
1493 * Serialize at most one packet worth of metadata into a metadata
1495 * We grab the metadata cache mutex to get exclusive access to our metadata
1496 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1497 * allows us to do racy operations such as looking for remaining space left in
1498 * packet and write, since mutual exclusion protects us from concurrent writes.
1499 * Mutual exclusion on the metadata cache allow us to read the cache content
1500 * without racing against reallocation of the cache by updates.
1501 * Returns the number of bytes written in the channel, 0 if no data
1502 * was written and a negative value on error.
1504 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
1505 struct channel
*chan
)
1507 struct lib_ring_buffer_ctx ctx
;
1509 size_t len
, reserve_len
;
1512 * Ensure we support mutiple get_next / put sequences followed by
1513 * put_next. The metadata cache lock protects reading the metadata
1514 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1515 * "flush" operations on the buffer invoked by different processes.
1516 * Moreover, since the metadata cache memory can be reallocated, we
1517 * need to have exclusive access against updates even though we only
1520 mutex_lock(&stream
->metadata_cache
->lock
);
1521 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
1522 if (stream
->metadata_in
!= stream
->metadata_out
)
1525 len
= stream
->metadata_cache
->metadata_written
-
1526 stream
->metadata_in
;
1529 reserve_len
= min_t(size_t,
1530 stream
->transport
->ops
.packet_avail_size(chan
),
1532 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
1535 * If reservation failed, return an error to the caller.
1537 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
1539 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
1542 stream
->transport
->ops
.event_write(&ctx
,
1543 stream
->metadata_cache
->data
+ stream
->metadata_in
,
1545 stream
->transport
->ops
.event_commit(&ctx
);
1546 stream
->metadata_in
+= reserve_len
;
1550 mutex_unlock(&stream
->metadata_cache
->lock
);
1555 * Write the metadata to the metadata cache.
1556 * Must be called with sessions_mutex held.
1557 * The metadata cache lock protects us from concurrent read access from
1558 * thread outputting metadata content to ring buffer.
1560 int lttng_metadata_printf(struct lttng_session
*session
,
1561 const char *fmt
, ...)
1566 struct lttng_metadata_stream
*stream
;
1568 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
1571 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
1577 mutex_lock(&session
->metadata_cache
->lock
);
1578 if (session
->metadata_cache
->metadata_written
+ len
>
1579 session
->metadata_cache
->cache_alloc
) {
1580 char *tmp_cache_realloc
;
1581 unsigned int tmp_cache_alloc_size
;
1583 tmp_cache_alloc_size
= max_t(unsigned int,
1584 session
->metadata_cache
->cache_alloc
+ len
,
1585 session
->metadata_cache
->cache_alloc
<< 1);
1586 tmp_cache_realloc
= lttng_vzalloc(tmp_cache_alloc_size
);
1587 if (!tmp_cache_realloc
)
1589 if (session
->metadata_cache
->data
) {
1590 memcpy(tmp_cache_realloc
,
1591 session
->metadata_cache
->data
,
1592 session
->metadata_cache
->cache_alloc
);
1593 vfree(session
->metadata_cache
->data
);
1596 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
1597 session
->metadata_cache
->data
= tmp_cache_realloc
;
1599 memcpy(session
->metadata_cache
->data
+
1600 session
->metadata_cache
->metadata_written
,
1602 session
->metadata_cache
->metadata_written
+= len
;
1603 mutex_unlock(&session
->metadata_cache
->lock
);
1606 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
1607 wake_up_interruptible(&stream
->read_wait
);
1612 mutex_unlock(&session
->metadata_cache
->lock
);
1618 * Must be called with sessions_mutex held.
1621 int _lttng_field_statedump(struct lttng_session
*session
,
1622 const struct lttng_event_field
*field
)
1626 switch (field
->type
.atype
) {
1628 ret
= lttng_metadata_printf(session
,
1629 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
1630 field
->type
.u
.basic
.integer
.size
,
1631 field
->type
.u
.basic
.integer
.alignment
,
1632 field
->type
.u
.basic
.integer
.signedness
,
1633 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
1635 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1638 field
->type
.u
.basic
.integer
.base
,
1640 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1642 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1647 ret
= lttng_metadata_printf(session
,
1649 field
->type
.u
.basic
.enumeration
.name
,
1654 const struct lttng_basic_type
*elem_type
;
1656 elem_type
= &field
->type
.u
.array
.elem_type
;
1657 ret
= lttng_metadata_printf(session
,
1658 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
1659 elem_type
->u
.basic
.integer
.size
,
1660 elem_type
->u
.basic
.integer
.alignment
,
1661 elem_type
->u
.basic
.integer
.signedness
,
1662 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1664 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1667 elem_type
->u
.basic
.integer
.base
,
1669 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1671 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1673 field
->name
, field
->type
.u
.array
.length
);
1676 case atype_sequence
:
1678 const struct lttng_basic_type
*elem_type
;
1679 const struct lttng_basic_type
*length_type
;
1681 elem_type
= &field
->type
.u
.sequence
.elem_type
;
1682 length_type
= &field
->type
.u
.sequence
.length_type
;
1683 ret
= lttng_metadata_printf(session
,
1684 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
1685 length_type
->u
.basic
.integer
.size
,
1686 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
1687 length_type
->u
.basic
.integer
.signedness
,
1688 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1690 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1693 length_type
->u
.basic
.integer
.base
,
1695 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1697 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1703 ret
= lttng_metadata_printf(session
,
1704 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
1705 elem_type
->u
.basic
.integer
.size
,
1706 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
1707 elem_type
->u
.basic
.integer
.signedness
,
1708 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1710 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1713 elem_type
->u
.basic
.integer
.base
,
1715 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1717 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1725 /* Default encoding is UTF8 */
1726 ret
= lttng_metadata_printf(session
,
1728 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
1729 " { encoding = ASCII; }" : "",
1740 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
1741 struct lttng_ctx
*ctx
)
1748 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
1749 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
1751 ret
= _lttng_field_statedump(session
, &field
->event_field
);
1759 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
1760 struct lttng_event
*event
)
1762 const struct lttng_event_desc
*desc
= event
->desc
;
1766 for (i
= 0; i
< desc
->nr_fields
; i
++) {
1767 const struct lttng_event_field
*field
= &desc
->fields
[i
];
1769 ret
= _lttng_field_statedump(session
, field
);
1777 * Must be called with sessions_mutex held.
1780 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
1781 struct lttng_channel
*chan
,
1782 struct lttng_event
*event
)
1786 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1788 if (chan
->channel_type
== METADATA_CHANNEL
)
1791 ret
= lttng_metadata_printf(session
,
1795 " stream_id = %u;\n",
1803 ret
= lttng_metadata_printf(session
,
1804 " context := struct {\n");
1808 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
1812 ret
= lttng_metadata_printf(session
,
1818 ret
= lttng_metadata_printf(session
,
1819 " fields := struct {\n"
1824 ret
= _lttng_fields_metadata_statedump(session
, event
);
1829 * LTTng space reservation can only reserve multiples of the
1832 ret
= lttng_metadata_printf(session
,
1838 event
->metadata_dumped
= 1;
1845 * Must be called with sessions_mutex held.
1848 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
1849 struct lttng_channel
*chan
)
1853 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1856 if (chan
->channel_type
== METADATA_CHANNEL
)
1859 WARN_ON_ONCE(!chan
->header_type
);
1860 ret
= lttng_metadata_printf(session
,
1863 " event.header := %s;\n"
1864 " packet.context := struct packet_context;\n",
1866 chan
->header_type
== 1 ? "struct event_header_compact" :
1867 "struct event_header_large");
1872 ret
= lttng_metadata_printf(session
,
1873 " event.context := struct {\n");
1877 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
1881 ret
= lttng_metadata_printf(session
,
1887 ret
= lttng_metadata_printf(session
,
1890 chan
->metadata_dumped
= 1;
1896 * Must be called with sessions_mutex held.
1899 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1901 return lttng_metadata_printf(session
,
1902 "struct packet_context {\n"
1903 " uint64_clock_monotonic_t timestamp_begin;\n"
1904 " uint64_clock_monotonic_t timestamp_end;\n"
1905 " uint64_t content_size;\n"
1906 " uint64_t packet_size;\n"
1907 " unsigned long events_discarded;\n"
1908 " uint32_t cpu_id;\n"
1915 * id: range: 0 - 30.
1916 * id 31 is reserved to indicate an extended header.
1919 * id: range: 0 - 65534.
1920 * id 65535 is reserved to indicate an extended header.
1922 * Must be called with sessions_mutex held.
1925 int _lttng_event_header_declare(struct lttng_session
*session
)
1927 return lttng_metadata_printf(session
,
1928 "struct event_header_compact {\n"
1929 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1932 " uint27_clock_monotonic_t timestamp;\n"
1936 " uint64_clock_monotonic_t timestamp;\n"
1941 "struct event_header_large {\n"
1942 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1945 " uint32_clock_monotonic_t timestamp;\n"
1949 " uint64_clock_monotonic_t timestamp;\n"
1953 lttng_alignof(uint32_t) * CHAR_BIT
,
1954 lttng_alignof(uint16_t) * CHAR_BIT
1959 * Approximation of NTP time of day to clock monotonic correlation,
1960 * taken at start of trace.
1961 * Yes, this is only an approximation. Yes, we can (and will) do better
1962 * in future versions.
1965 uint64_t measure_clock_offset(void)
1967 uint64_t offset
, monotonic
[2], realtime
;
1968 struct timespec rts
= { 0, 0 };
1969 unsigned long flags
;
1971 /* Disable interrupts to increase correlation precision. */
1972 local_irq_save(flags
);
1973 monotonic
[0] = trace_clock_read64();
1974 getnstimeofday(&rts
);
1975 monotonic
[1] = trace_clock_read64();
1976 local_irq_restore(flags
);
1978 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1979 realtime
= (uint64_t) rts
.tv_sec
* NSEC_PER_SEC
;
1980 realtime
+= rts
.tv_nsec
;
1981 offset
= realtime
- offset
;
1986 * Output metadata into this session's metadata buffers.
1987 * Must be called with sessions_mutex held.
1990 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1992 unsigned char *uuid_c
= session
->uuid
.b
;
1993 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
1994 struct lttng_channel
*chan
;
1995 struct lttng_event
*event
;
1998 if (!ACCESS_ONCE(session
->active
))
2000 if (session
->metadata_dumped
)
2003 snprintf(uuid_s
, sizeof(uuid_s
),
2004 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2005 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
2006 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
2007 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
2008 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
2010 ret
= lttng_metadata_printf(session
,
2011 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2012 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2013 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2014 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2015 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2016 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2017 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2023 " byte_order = %s;\n"
2024 " packet.header := struct {\n"
2025 " uint32_t magic;\n"
2026 " uint8_t uuid[16];\n"
2027 " uint32_t stream_id;\n"
2030 lttng_alignof(uint8_t) * CHAR_BIT
,
2031 lttng_alignof(uint16_t) * CHAR_BIT
,
2032 lttng_alignof(uint32_t) * CHAR_BIT
,
2033 lttng_alignof(uint64_t) * CHAR_BIT
,
2034 sizeof(unsigned long) * CHAR_BIT
,
2035 lttng_alignof(unsigned long) * CHAR_BIT
,
2048 ret
= lttng_metadata_printf(session
,
2050 " hostname = \"%s\";\n"
2051 " domain = \"kernel\";\n"
2052 " sysname = \"%s\";\n"
2053 " kernel_release = \"%s\";\n"
2054 " kernel_version = \"%s\";\n"
2055 " tracer_name = \"lttng-modules\";\n"
2056 " tracer_major = %d;\n"
2057 " tracer_minor = %d;\n"
2058 " tracer_patchlevel = %d;\n"
2060 current
->nsproxy
->uts_ns
->name
.nodename
,
2064 LTTNG_MODULES_MAJOR_VERSION
,
2065 LTTNG_MODULES_MINOR_VERSION
,
2066 LTTNG_MODULES_PATCHLEVEL_VERSION
2071 ret
= lttng_metadata_printf(session
,
2079 if (!trace_clock_uuid(clock_uuid_s
)) {
2080 ret
= lttng_metadata_printf(session
,
2081 " uuid = \"%s\";\n",
2088 ret
= lttng_metadata_printf(session
,
2089 " description = \"Monotonic Clock\";\n"
2090 " freq = %llu; /* Frequency, in Hz */\n"
2091 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2094 (unsigned long long) trace_clock_freq(),
2095 (unsigned long long) measure_clock_offset()
2100 ret
= lttng_metadata_printf(session
,
2101 "typealias integer {\n"
2102 " size = 27; align = 1; signed = false;\n"
2103 " map = clock.monotonic.value;\n"
2104 "} := uint27_clock_monotonic_t;\n"
2106 "typealias integer {\n"
2107 " size = 32; align = %u; signed = false;\n"
2108 " map = clock.monotonic.value;\n"
2109 "} := uint32_clock_monotonic_t;\n"
2111 "typealias integer {\n"
2112 " size = 64; align = %u; signed = false;\n"
2113 " map = clock.monotonic.value;\n"
2114 "} := uint64_clock_monotonic_t;\n\n",
2115 lttng_alignof(uint32_t) * CHAR_BIT
,
2116 lttng_alignof(uint64_t) * CHAR_BIT
2121 ret
= _lttng_stream_packet_context_declare(session
);
2125 ret
= _lttng_event_header_declare(session
);
2130 list_for_each_entry(chan
, &session
->chan
, list
) {
2131 ret
= _lttng_channel_metadata_statedump(session
, chan
);
2136 list_for_each_entry(event
, &session
->events
, list
) {
2137 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
2141 session
->metadata_dumped
= 1;
2147 * lttng_transport_register - LTT transport registration
2148 * @transport: transport structure
2150 * Registers a transport which can be used as output to extract the data out of
2151 * LTTng. The module calling this registration function must ensure that no
2152 * trap-inducing code will be executed by the transport functions. E.g.
2153 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
2154 * is made visible to the transport function. This registration acts as a
2155 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
2156 * after its registration must it synchronize the TLBs.
2158 void lttng_transport_register(struct lttng_transport
*transport
)
2161 * Make sure no page fault can be triggered by the module about to be
2162 * registered. We deal with this here so we don't have to call
2163 * vmalloc_sync_all() in each module's init.
2165 wrapper_vmalloc_sync_all();
2167 mutex_lock(&sessions_mutex
);
2168 list_add_tail(&transport
->node
, <tng_transport_list
);
2169 mutex_unlock(&sessions_mutex
);
2171 EXPORT_SYMBOL_GPL(lttng_transport_register
);
2174 * lttng_transport_unregister - LTT transport unregistration
2175 * @transport: transport structure
2177 void lttng_transport_unregister(struct lttng_transport
*transport
)
2179 mutex_lock(&sessions_mutex
);
2180 list_del(&transport
->node
);
2181 mutex_unlock(&sessions_mutex
);
2183 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
2185 static int __init
lttng_events_init(void)
2189 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
2192 ret
= wrapper_get_pfnblock_flags_mask_init();
2195 ret
= lttng_context_init();
2198 ret
= lttng_tracepoint_init();
2201 event_cache
= KMEM_CACHE(lttng_event
, 0);
2206 ret
= lttng_abi_init();
2209 ret
= lttng_logger_init();
2217 kmem_cache_destroy(event_cache
);
2219 lttng_tracepoint_exit();
2221 lttng_context_exit();
2225 module_init(lttng_events_init
);
2227 static void __exit
lttng_events_exit(void)
2229 struct lttng_session
*session
, *tmpsession
;
2231 lttng_logger_exit();
2233 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
2234 lttng_session_destroy(session
);
2235 kmem_cache_destroy(event_cache
);
2236 lttng_tracepoint_exit();
2237 lttng_context_exit();
2240 module_exit(lttng_events_exit
);
2242 MODULE_LICENSE("GPL and additional rights");
2243 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
2244 MODULE_DESCRIPTION("LTTng Events");
2245 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
2246 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
2247 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
2248 LTTNG_MODULES_EXTRAVERSION
);