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_channel_enable(struct lttng_channel
*channel
)
289 mutex_lock(&sessions_mutex
);
290 if (channel
->channel_type
== METADATA_CHANNEL
) {
294 if (channel
->enabled
) {
298 /* Set transient enabler state to "enabled" */
300 lttng_session_sync_enablers(channel
->session
);
301 /* Set atomically the state to "enabled" */
302 ACCESS_ONCE(channel
->enabled
) = 1;
304 mutex_unlock(&sessions_mutex
);
308 int lttng_channel_disable(struct lttng_channel
*channel
)
312 mutex_lock(&sessions_mutex
);
313 if (channel
->channel_type
== METADATA_CHANNEL
) {
317 if (!channel
->enabled
) {
321 /* Set atomically the state to "disabled" */
322 ACCESS_ONCE(channel
->enabled
) = 0;
323 /* Set transient enabler state to "enabled" */
325 lttng_session_sync_enablers(channel
->session
);
327 mutex_unlock(&sessions_mutex
);
331 int lttng_event_enable(struct lttng_event
*event
)
335 mutex_lock(&sessions_mutex
);
336 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
340 if (event
->enabled
) {
344 switch (event
->instrumentation
) {
345 case LTTNG_KERNEL_TRACEPOINT
:
346 case LTTNG_KERNEL_SYSCALL
:
349 case LTTNG_KERNEL_KPROBE
:
350 case LTTNG_KERNEL_FUNCTION
:
351 case LTTNG_KERNEL_NOOP
:
352 ACCESS_ONCE(event
->enabled
) = 1;
354 case LTTNG_KERNEL_KRETPROBE
:
355 ret
= lttng_kretprobes_event_enable_state(event
, 1);
362 mutex_unlock(&sessions_mutex
);
366 int lttng_event_disable(struct lttng_event
*event
)
370 mutex_lock(&sessions_mutex
);
371 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
375 if (!event
->enabled
) {
379 switch (event
->instrumentation
) {
380 case LTTNG_KERNEL_TRACEPOINT
:
381 case LTTNG_KERNEL_SYSCALL
:
384 case LTTNG_KERNEL_KPROBE
:
385 case LTTNG_KERNEL_FUNCTION
:
386 case LTTNG_KERNEL_NOOP
:
387 ACCESS_ONCE(event
->enabled
) = 0;
389 case LTTNG_KERNEL_KRETPROBE
:
390 ret
= lttng_kretprobes_event_enable_state(event
, 0);
397 mutex_unlock(&sessions_mutex
);
401 static struct lttng_transport
*lttng_transport_find(const char *name
)
403 struct lttng_transport
*transport
;
405 list_for_each_entry(transport
, <tng_transport_list
, node
) {
406 if (!strcmp(transport
->name
, name
))
412 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
413 const char *transport_name
,
415 size_t subbuf_size
, size_t num_subbuf
,
416 unsigned int switch_timer_interval
,
417 unsigned int read_timer_interval
,
418 enum channel_type channel_type
)
420 struct lttng_channel
*chan
;
421 struct lttng_transport
*transport
= NULL
;
423 mutex_lock(&sessions_mutex
);
424 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
425 goto active
; /* Refuse to add channel to active session */
426 transport
= lttng_transport_find(transport_name
);
428 printk(KERN_WARNING
"LTTng transport %s not found\n",
432 if (!try_module_get(transport
->owner
)) {
433 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
436 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
439 chan
->session
= session
;
440 chan
->id
= session
->free_chan_id
++;
441 chan
->ops
= &transport
->ops
;
443 * Note: the channel creation op already writes into the packet
444 * headers. Therefore the "chan" information used as input
445 * should be already accessible.
447 chan
->chan
= transport
->ops
.channel_create(transport_name
,
448 chan
, buf_addr
, subbuf_size
, num_subbuf
,
449 switch_timer_interval
, read_timer_interval
);
454 chan
->transport
= transport
;
455 chan
->channel_type
= channel_type
;
456 list_add(&chan
->list
, &session
->chan
);
457 mutex_unlock(&sessions_mutex
);
464 module_put(transport
->owner
);
467 mutex_unlock(&sessions_mutex
);
472 * Only used internally at session destruction for per-cpu channels, and
473 * when metadata channel is released.
474 * Needs to be called with sessions mutex held.
477 void _lttng_channel_destroy(struct lttng_channel
*chan
)
479 chan
->ops
->channel_destroy(chan
->chan
);
480 module_put(chan
->transport
->owner
);
481 list_del(&chan
->list
);
482 lttng_destroy_context(chan
->ctx
);
486 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
488 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
490 /* Protect the metadata cache with the sessions_mutex. */
491 mutex_lock(&sessions_mutex
);
492 _lttng_channel_destroy(chan
);
493 mutex_unlock(&sessions_mutex
);
495 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
498 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
500 stream
->finalized
= 1;
501 wake_up_interruptible(&stream
->read_wait
);
505 * Supports event creation while tracing session is active.
506 * Needs to be called with sessions mutex held.
508 struct lttng_event
*_lttng_event_create(struct lttng_channel
*chan
,
509 struct lttng_kernel_event
*event_param
,
511 const struct lttng_event_desc
*event_desc
,
512 enum lttng_kernel_instrumentation itype
)
514 struct lttng_session
*session
= chan
->session
;
515 struct lttng_event
*event
;
516 const char *event_name
;
517 struct hlist_head
*head
;
522 if (chan
->free_event_id
== -1U) {
528 case LTTNG_KERNEL_TRACEPOINT
:
529 event_name
= event_desc
->name
;
531 case LTTNG_KERNEL_KPROBE
:
532 case LTTNG_KERNEL_KRETPROBE
:
533 case LTTNG_KERNEL_FUNCTION
:
534 case LTTNG_KERNEL_NOOP
:
535 case LTTNG_KERNEL_SYSCALL
:
536 event_name
= event_param
->name
;
543 name_len
= strlen(event_name
);
544 hash
= jhash(event_name
, name_len
, 0);
545 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
546 lttng_hlist_for_each_entry(event
, head
, hlist
) {
547 WARN_ON_ONCE(!event
->desc
);
548 if (!strncmp(event
->desc
->name
, event_name
,
549 LTTNG_KERNEL_SYM_NAME_LEN
- 1)
550 && chan
== event
->chan
) {
556 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
562 event
->filter
= filter
;
563 event
->id
= chan
->free_event_id
++;
564 event
->instrumentation
= itype
;
565 event
->evtype
= LTTNG_TYPE_EVENT
;
566 INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
567 INIT_LIST_HEAD(&event
->enablers_ref_head
);
570 case LTTNG_KERNEL_TRACEPOINT
:
571 /* Event will be enabled by enabler sync. */
573 event
->registered
= 0;
574 event
->desc
= lttng_event_get(event_name
);
579 /* Populate lttng_event structure before event registration. */
582 case LTTNG_KERNEL_KPROBE
:
584 * Needs to be explicitly enabled after creation, since
585 * we may want to apply filters.
588 event
->registered
= 1;
590 * Populate lttng_event structure before event
594 ret
= lttng_kprobes_register(event_name
,
595 event_param
->u
.kprobe
.symbol_name
,
596 event_param
->u
.kprobe
.offset
,
597 event_param
->u
.kprobe
.addr
,
603 ret
= try_module_get(event
->desc
->owner
);
606 case LTTNG_KERNEL_KRETPROBE
:
608 struct lttng_event
*event_return
;
610 /* kretprobe defines 2 events */
612 * Needs to be explicitly enabled after creation, since
613 * we may want to apply filters.
616 event
->registered
= 1;
618 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
623 event_return
->chan
= chan
;
624 event_return
->filter
= filter
;
625 event_return
->id
= chan
->free_event_id
++;
626 event_return
->enabled
= 0;
627 event_return
->registered
= 1;
628 event_return
->instrumentation
= itype
;
630 * Populate lttng_event structure before kretprobe registration.
633 ret
= lttng_kretprobes_register(event_name
,
634 event_param
->u
.kretprobe
.symbol_name
,
635 event_param
->u
.kretprobe
.offset
,
636 event_param
->u
.kretprobe
.addr
,
637 event
, event_return
);
639 kmem_cache_free(event_cache
, event_return
);
643 /* Take 2 refs on the module: one per event. */
644 ret
= try_module_get(event
->desc
->owner
);
646 ret
= try_module_get(event
->desc
->owner
);
648 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
650 WARN_ON_ONCE(ret
> 0);
652 kmem_cache_free(event_cache
, event_return
);
653 module_put(event
->desc
->owner
);
654 module_put(event
->desc
->owner
);
655 goto statedump_error
;
657 list_add(&event_return
->list
, &chan
->session
->events
);
660 case LTTNG_KERNEL_FUNCTION
:
662 * Needs to be explicitly enabled after creation, since
663 * we may want to apply filters.
666 event
->registered
= 1;
668 * Populate lttng_event structure before event
672 ret
= lttng_ftrace_register(event_name
,
673 event_param
->u
.ftrace
.symbol_name
,
678 ret
= try_module_get(event
->desc
->owner
);
681 case LTTNG_KERNEL_NOOP
:
682 case LTTNG_KERNEL_SYSCALL
:
684 * Needs to be explicitly enabled after creation, since
685 * we may want to apply filters.
688 event
->registered
= 0;
689 event
->desc
= event_desc
;
700 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
701 WARN_ON_ONCE(ret
> 0);
703 goto statedump_error
;
705 hlist_add_head(&event
->hlist
, head
);
706 list_add(&event
->list
, &chan
->session
->events
);
710 /* If a statedump error occurs, events will not be readable. */
712 kmem_cache_free(event_cache
, event
);
720 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
721 struct lttng_kernel_event
*event_param
,
723 const struct lttng_event_desc
*event_desc
,
724 enum lttng_kernel_instrumentation itype
)
726 struct lttng_event
*event
;
728 mutex_lock(&sessions_mutex
);
729 event
= _lttng_event_create(chan
, event_param
, filter
, event_desc
,
731 mutex_unlock(&sessions_mutex
);
735 /* Only used for tracepoints for now. */
737 void register_event(struct lttng_event
*event
)
739 const struct lttng_event_desc
*desc
;
742 if (event
->registered
)
746 switch (event
->instrumentation
) {
747 case LTTNG_KERNEL_TRACEPOINT
:
748 ret
= lttng_wrapper_tracepoint_probe_register(desc
->kname
,
749 desc
->probe_callback
,
752 case LTTNG_KERNEL_SYSCALL
:
753 ret
= lttng_syscall_filter_enable(event
->chan
,
756 case LTTNG_KERNEL_KPROBE
:
757 case LTTNG_KERNEL_KRETPROBE
:
758 case LTTNG_KERNEL_FUNCTION
:
759 case LTTNG_KERNEL_NOOP
:
766 event
->registered
= 1;
770 * Only used internally at session destruction.
772 int _lttng_event_unregister(struct lttng_event
*event
)
774 const struct lttng_event_desc
*desc
;
777 if (!event
->registered
)
781 switch (event
->instrumentation
) {
782 case LTTNG_KERNEL_TRACEPOINT
:
783 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
784 event
->desc
->probe_callback
,
787 case LTTNG_KERNEL_KPROBE
:
788 lttng_kprobes_unregister(event
);
791 case LTTNG_KERNEL_KRETPROBE
:
792 lttng_kretprobes_unregister(event
);
795 case LTTNG_KERNEL_FUNCTION
:
796 lttng_ftrace_unregister(event
);
799 case LTTNG_KERNEL_SYSCALL
:
800 ret
= lttng_syscall_filter_disable(event
->chan
,
803 case LTTNG_KERNEL_NOOP
:
810 event
->registered
= 0;
815 * Only used internally at session destruction.
818 void _lttng_event_destroy(struct lttng_event
*event
)
820 switch (event
->instrumentation
) {
821 case LTTNG_KERNEL_TRACEPOINT
:
822 lttng_event_put(event
->desc
);
824 case LTTNG_KERNEL_KPROBE
:
825 module_put(event
->desc
->owner
);
826 lttng_kprobes_destroy_private(event
);
828 case LTTNG_KERNEL_KRETPROBE
:
829 module_put(event
->desc
->owner
);
830 lttng_kretprobes_destroy_private(event
);
832 case LTTNG_KERNEL_FUNCTION
:
833 module_put(event
->desc
->owner
);
834 lttng_ftrace_destroy_private(event
);
836 case LTTNG_KERNEL_NOOP
:
837 case LTTNG_KERNEL_SYSCALL
:
842 list_del(&event
->list
);
843 lttng_destroy_context(event
->ctx
);
844 kmem_cache_free(event_cache
, event
);
847 int lttng_session_track_pid(struct lttng_session
*session
, int pid
)
853 mutex_lock(&sessions_mutex
);
855 /* track all pids: destroy tracker. */
856 if (session
->pid_tracker
) {
857 struct lttng_pid_tracker
*lpf
;
859 lpf
= session
->pid_tracker
;
860 rcu_assign_pointer(session
->pid_tracker
, NULL
);
862 lttng_pid_tracker_destroy(lpf
);
866 if (!session
->pid_tracker
) {
867 struct lttng_pid_tracker
*lpf
;
869 lpf
= lttng_pid_tracker_create();
874 ret
= lttng_pid_tracker_add(lpf
, pid
);
875 rcu_assign_pointer(session
->pid_tracker
, lpf
);
877 ret
= lttng_pid_tracker_add(session
->pid_tracker
, pid
);
881 mutex_unlock(&sessions_mutex
);
885 int lttng_session_untrack_pid(struct lttng_session
*session
, int pid
)
891 mutex_lock(&sessions_mutex
);
893 /* untrack all pids: replace by empty tracker. */
894 struct lttng_pid_tracker
*old_lpf
= session
->pid_tracker
;
895 struct lttng_pid_tracker
*lpf
;
897 lpf
= lttng_pid_tracker_create();
902 rcu_assign_pointer(session
->pid_tracker
, lpf
);
905 lttng_pid_tracker_destroy(old_lpf
);
908 if (!session
->pid_tracker
) {
912 ret
= lttng_pid_tracker_del(session
->pid_tracker
, pid
);
915 mutex_unlock(&sessions_mutex
);
920 void *pid_list_start(struct seq_file
*m
, loff_t
*pos
)
922 struct lttng_session
*session
= m
->private;
923 struct lttng_pid_tracker
*lpf
;
924 struct lttng_pid_hash_node
*e
;
927 mutex_lock(&sessions_mutex
);
928 lpf
= session
->pid_tracker
;
930 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
931 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
933 lttng_hlist_for_each_entry(e
, head
, hlist
) {
939 /* PID tracker disabled. */
940 if (iter
>= *pos
&& iter
== 0) {
941 return session
; /* empty tracker */
949 /* Called with sessions_mutex held. */
951 void *pid_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
953 struct lttng_session
*session
= m
->private;
954 struct lttng_pid_tracker
*lpf
;
955 struct lttng_pid_hash_node
*e
;
959 lpf
= session
->pid_tracker
;
961 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
962 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
964 lttng_hlist_for_each_entry(e
, head
, hlist
) {
970 /* PID tracker disabled. */
971 if (iter
>= *ppos
&& iter
== 0)
972 return session
; /* empty tracker */
981 void pid_list_stop(struct seq_file
*m
, void *p
)
983 mutex_unlock(&sessions_mutex
);
987 int pid_list_show(struct seq_file
*m
, void *p
)
991 if (p
== m
->private) {
992 /* Tracker disabled. */
995 const struct lttng_pid_hash_node
*e
= p
;
997 pid
= lttng_pid_tracker_get_node_pid(e
);
999 seq_printf(m
, "process { pid = %d; };\n", pid
);
1004 const struct seq_operations lttng_tracker_pids_list_seq_ops
= {
1005 .start
= pid_list_start
,
1006 .next
= pid_list_next
,
1007 .stop
= pid_list_stop
,
1008 .show
= pid_list_show
,
1012 int lttng_tracker_pids_list_open(struct inode
*inode
, struct file
*file
)
1014 return seq_open(file
, <tng_tracker_pids_list_seq_ops
);
1018 int lttng_tracker_pids_list_release(struct inode
*inode
, struct file
*file
)
1020 struct seq_file
*m
= file
->private_data
;
1021 struct lttng_session
*session
= m
->private;
1024 WARN_ON_ONCE(!session
);
1025 ret
= seq_release(inode
, file
);
1026 if (!ret
&& session
)
1027 fput(session
->file
);
1031 const struct file_operations lttng_tracker_pids_list_fops
= {
1032 .owner
= THIS_MODULE
,
1033 .open
= lttng_tracker_pids_list_open
,
1035 .llseek
= seq_lseek
,
1036 .release
= lttng_tracker_pids_list_release
,
1039 int lttng_session_list_tracker_pids(struct lttng_session
*session
)
1041 struct file
*tracker_pids_list_file
;
1045 file_fd
= lttng_get_unused_fd();
1051 tracker_pids_list_file
= anon_inode_getfile("[lttng_tracker_pids_list]",
1052 <tng_tracker_pids_list_fops
,
1054 if (IS_ERR(tracker_pids_list_file
)) {
1055 ret
= PTR_ERR(tracker_pids_list_file
);
1058 if (atomic_long_add_unless(&session
->file
->f_count
,
1059 1, INT_MAX
) == INT_MAX
) {
1060 goto refcount_error
;
1062 ret
= lttng_tracker_pids_list_fops
.open(NULL
, tracker_pids_list_file
);
1065 m
= tracker_pids_list_file
->private_data
;
1066 m
->private = session
;
1067 fd_install(file_fd
, tracker_pids_list_file
);
1072 atomic_long_dec(&session
->file
->f_count
);
1074 fput(tracker_pids_list_file
);
1076 put_unused_fd(file_fd
);
1082 * Enabler management.
1085 int lttng_match_enabler_wildcard(const char *desc_name
,
1088 /* Compare excluding final '*' */
1089 if (strncmp(desc_name
, name
, strlen(name
) - 1))
1095 int lttng_match_enabler_name(const char *desc_name
,
1098 if (strcmp(desc_name
, name
))
1104 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
1105 struct lttng_enabler
*enabler
)
1107 const char *desc_name
, *enabler_name
;
1109 enabler_name
= enabler
->event_param
.name
;
1110 switch (enabler
->event_param
.instrumentation
) {
1111 case LTTNG_KERNEL_TRACEPOINT
:
1112 desc_name
= desc
->name
;
1114 case LTTNG_KERNEL_SYSCALL
:
1115 desc_name
= desc
->name
;
1116 if (!strncmp(desc_name
, "compat_", strlen("compat_")))
1117 desc_name
+= strlen("compat_");
1118 if (!strncmp(desc_name
, "syscall_exit_",
1119 strlen("syscall_exit_"))) {
1120 desc_name
+= strlen("syscall_exit_");
1121 } else if (!strncmp(desc_name
, "syscall_entry_",
1122 strlen("syscall_entry_"))) {
1123 desc_name
+= strlen("syscall_entry_");
1133 switch (enabler
->type
) {
1134 case LTTNG_ENABLER_WILDCARD
:
1135 return lttng_match_enabler_wildcard(desc_name
, enabler_name
);
1136 case LTTNG_ENABLER_NAME
:
1137 return lttng_match_enabler_name(desc_name
, enabler_name
);
1144 int lttng_event_match_enabler(struct lttng_event
*event
,
1145 struct lttng_enabler
*enabler
)
1147 if (enabler
->event_param
.instrumentation
!= event
->instrumentation
)
1149 if (lttng_desc_match_enabler(event
->desc
, enabler
)
1150 && event
->chan
== enabler
->chan
)
1157 struct lttng_enabler_ref
*lttng_event_enabler_ref(struct lttng_event
*event
,
1158 struct lttng_enabler
*enabler
)
1160 struct lttng_enabler_ref
*enabler_ref
;
1162 list_for_each_entry(enabler_ref
,
1163 &event
->enablers_ref_head
, node
) {
1164 if (enabler_ref
->ref
== enabler
)
1171 void lttng_create_tracepoint_if_missing(struct lttng_enabler
*enabler
)
1173 struct lttng_session
*session
= enabler
->chan
->session
;
1174 struct lttng_probe_desc
*probe_desc
;
1175 const struct lttng_event_desc
*desc
;
1177 struct list_head
*probe_list
;
1179 probe_list
= lttng_get_probe_list_head();
1181 * For each probe event, if we find that a probe event matches
1182 * our enabler, create an associated lttng_event if not
1185 list_for_each_entry(probe_desc
, probe_list
, head
) {
1186 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
1188 struct hlist_head
*head
;
1189 const char *event_name
;
1192 struct lttng_event
*event
;
1194 desc
= probe_desc
->event_desc
[i
];
1195 if (!lttng_desc_match_enabler(desc
, enabler
))
1197 event_name
= desc
->name
;
1198 name_len
= strlen(event_name
);
1201 * Check if already created.
1203 hash
= jhash(event_name
, name_len
, 0);
1204 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
1205 lttng_hlist_for_each_entry(event
, head
, hlist
) {
1206 if (event
->desc
== desc
1207 && event
->chan
== enabler
->chan
)
1214 * We need to create an event for this
1217 event
= _lttng_event_create(enabler
->chan
,
1219 LTTNG_KERNEL_TRACEPOINT
);
1221 printk(KERN_INFO
"Unable to create event %s\n",
1222 probe_desc
->event_desc
[i
]->name
);
1229 void lttng_create_syscall_if_missing(struct lttng_enabler
*enabler
)
1233 ret
= lttng_syscalls_register(enabler
->chan
, NULL
);
1238 * Create struct lttng_event if it is missing and present in the list of
1239 * tracepoint probes.
1240 * Should be called with sessions mutex held.
1243 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
1245 switch (enabler
->event_param
.instrumentation
) {
1246 case LTTNG_KERNEL_TRACEPOINT
:
1247 lttng_create_tracepoint_if_missing(enabler
);
1249 case LTTNG_KERNEL_SYSCALL
:
1250 lttng_create_syscall_if_missing(enabler
);
1259 * Create events associated with an enabler (if not already present),
1260 * and add backward reference from the event to the enabler.
1261 * Should be called with sessions mutex held.
1264 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
1266 struct lttng_session
*session
= enabler
->chan
->session
;
1267 struct lttng_event
*event
;
1269 /* First ensure that probe events are created for this enabler. */
1270 lttng_create_event_if_missing(enabler
);
1272 /* For each event matching enabler in session event list. */
1273 list_for_each_entry(event
, &session
->events
, list
) {
1274 struct lttng_enabler_ref
*enabler_ref
;
1276 if (!lttng_event_match_enabler(event
, enabler
))
1278 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
1281 * If no backward ref, create it.
1282 * Add backward ref from event to enabler.
1284 enabler_ref
= kzalloc(sizeof(*enabler_ref
), GFP_KERNEL
);
1287 enabler_ref
->ref
= enabler
;
1288 list_add(&enabler_ref
->node
,
1289 &event
->enablers_ref_head
);
1293 * Link filter bytecodes if not linked yet.
1295 lttng_enabler_event_link_bytecode(event
, enabler
);
1297 /* TODO: merge event context. */
1303 * Called at module load: connect the probe on all enablers matching
1305 * Called with sessions lock held.
1307 int lttng_fix_pending_events(void)
1309 struct lttng_session
*session
;
1311 list_for_each_entry(session
, &sessions
, list
)
1312 lttng_session_lazy_sync_enablers(session
);
1316 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1317 struct lttng_kernel_event
*event_param
,
1318 struct lttng_channel
*chan
)
1320 struct lttng_enabler
*enabler
;
1322 enabler
= kzalloc(sizeof(*enabler
), GFP_KERNEL
);
1325 enabler
->type
= type
;
1326 INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1327 memcpy(&enabler
->event_param
, event_param
,
1328 sizeof(enabler
->event_param
));
1329 enabler
->chan
= chan
;
1331 enabler
->enabled
= 0;
1332 enabler
->evtype
= LTTNG_TYPE_ENABLER
;
1333 mutex_lock(&sessions_mutex
);
1334 list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1335 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1336 mutex_unlock(&sessions_mutex
);
1340 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1342 mutex_lock(&sessions_mutex
);
1343 enabler
->enabled
= 1;
1344 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1345 mutex_unlock(&sessions_mutex
);
1349 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1351 mutex_lock(&sessions_mutex
);
1352 enabler
->enabled
= 0;
1353 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1354 mutex_unlock(&sessions_mutex
);
1358 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1359 struct lttng_kernel_filter_bytecode __user
*bytecode
)
1361 struct lttng_filter_bytecode_node
*bytecode_node
;
1362 uint32_t bytecode_len
;
1365 ret
= get_user(bytecode_len
, &bytecode
->len
);
1368 bytecode_node
= kzalloc(sizeof(*bytecode_node
) + bytecode_len
,
1372 ret
= copy_from_user(&bytecode_node
->bc
, bytecode
,
1373 sizeof(*bytecode
) + bytecode_len
);
1376 bytecode_node
->enabler
= enabler
;
1377 /* Enforce length based on allocated size */
1378 bytecode_node
->bc
.len
= bytecode_len
;
1379 list_add_tail(&bytecode_node
->node
, &enabler
->filter_bytecode_head
);
1380 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1384 kfree(bytecode_node
);
1388 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1389 struct lttng_kernel_context
*context_param
)
1395 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1397 struct lttng_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1399 /* Destroy filter bytecode */
1400 list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1401 &enabler
->filter_bytecode_head
, node
) {
1405 /* Destroy contexts */
1406 lttng_destroy_context(enabler
->ctx
);
1408 list_del(&enabler
->node
);
1413 * lttng_session_sync_enablers should be called just before starting a
1415 * Should be called with sessions mutex held.
1418 void lttng_session_sync_enablers(struct lttng_session
*session
)
1420 struct lttng_enabler
*enabler
;
1421 struct lttng_event
*event
;
1423 list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1424 lttng_enabler_ref_events(enabler
);
1426 * For each event, if at least one of its enablers is enabled,
1427 * and its channel and session transient states are enabled, we
1428 * enable the event, else we disable it.
1430 list_for_each_entry(event
, &session
->events
, list
) {
1431 struct lttng_enabler_ref
*enabler_ref
;
1432 struct lttng_bytecode_runtime
*runtime
;
1433 int enabled
= 0, has_enablers_without_bytecode
= 0;
1435 switch (event
->instrumentation
) {
1436 case LTTNG_KERNEL_TRACEPOINT
:
1437 case LTTNG_KERNEL_SYSCALL
:
1439 list_for_each_entry(enabler_ref
,
1440 &event
->enablers_ref_head
, node
) {
1441 if (enabler_ref
->ref
->enabled
) {
1448 /* Not handled with lazy sync. */
1452 * Enabled state is based on union of enablers, with
1453 * intesection of session and channel transient enable
1456 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
1458 ACCESS_ONCE(event
->enabled
) = enabled
;
1460 * Sync tracepoint registration with event enabled
1464 register_event(event
);
1466 _lttng_event_unregister(event
);
1469 /* Check if has enablers without bytecode enabled */
1470 list_for_each_entry(enabler_ref
,
1471 &event
->enablers_ref_head
, node
) {
1472 if (enabler_ref
->ref
->enabled
1473 && list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1474 has_enablers_without_bytecode
= 1;
1478 event
->has_enablers_without_bytecode
=
1479 has_enablers_without_bytecode
;
1481 /* Enable filters */
1482 list_for_each_entry(runtime
,
1483 &event
->bytecode_runtime_head
, node
)
1484 lttng_filter_sync_state(runtime
);
1489 * Apply enablers to session events, adding events to session if need
1490 * be. It is required after each modification applied to an active
1491 * session, and right before session "start".
1492 * "lazy" sync means we only sync if required.
1493 * Should be called with sessions mutex held.
1496 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1498 /* We can skip if session is not active */
1499 if (!session
->active
)
1501 lttng_session_sync_enablers(session
);
1505 * Serialize at most one packet worth of metadata into a metadata
1507 * We grab the metadata cache mutex to get exclusive access to our metadata
1508 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1509 * allows us to do racy operations such as looking for remaining space left in
1510 * packet and write, since mutual exclusion protects us from concurrent writes.
1511 * Mutual exclusion on the metadata cache allow us to read the cache content
1512 * without racing against reallocation of the cache by updates.
1513 * Returns the number of bytes written in the channel, 0 if no data
1514 * was written and a negative value on error.
1516 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
1517 struct channel
*chan
)
1519 struct lib_ring_buffer_ctx ctx
;
1521 size_t len
, reserve_len
;
1524 * Ensure we support mutiple get_next / put sequences followed by
1525 * put_next. The metadata cache lock protects reading the metadata
1526 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1527 * "flush" operations on the buffer invoked by different processes.
1528 * Moreover, since the metadata cache memory can be reallocated, we
1529 * need to have exclusive access against updates even though we only
1532 mutex_lock(&stream
->metadata_cache
->lock
);
1533 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
1534 if (stream
->metadata_in
!= stream
->metadata_out
)
1537 len
= stream
->metadata_cache
->metadata_written
-
1538 stream
->metadata_in
;
1541 reserve_len
= min_t(size_t,
1542 stream
->transport
->ops
.packet_avail_size(chan
),
1544 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
1547 * If reservation failed, return an error to the caller.
1549 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
1551 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
1554 stream
->transport
->ops
.event_write(&ctx
,
1555 stream
->metadata_cache
->data
+ stream
->metadata_in
,
1557 stream
->transport
->ops
.event_commit(&ctx
);
1558 stream
->metadata_in
+= reserve_len
;
1562 mutex_unlock(&stream
->metadata_cache
->lock
);
1567 * Write the metadata to the metadata cache.
1568 * Must be called with sessions_mutex held.
1569 * The metadata cache lock protects us from concurrent read access from
1570 * thread outputting metadata content to ring buffer.
1572 int lttng_metadata_printf(struct lttng_session
*session
,
1573 const char *fmt
, ...)
1578 struct lttng_metadata_stream
*stream
;
1580 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
1583 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
1589 mutex_lock(&session
->metadata_cache
->lock
);
1590 if (session
->metadata_cache
->metadata_written
+ len
>
1591 session
->metadata_cache
->cache_alloc
) {
1592 char *tmp_cache_realloc
;
1593 unsigned int tmp_cache_alloc_size
;
1595 tmp_cache_alloc_size
= max_t(unsigned int,
1596 session
->metadata_cache
->cache_alloc
+ len
,
1597 session
->metadata_cache
->cache_alloc
<< 1);
1598 tmp_cache_realloc
= lttng_vzalloc(tmp_cache_alloc_size
);
1599 if (!tmp_cache_realloc
)
1601 if (session
->metadata_cache
->data
) {
1602 memcpy(tmp_cache_realloc
,
1603 session
->metadata_cache
->data
,
1604 session
->metadata_cache
->cache_alloc
);
1605 vfree(session
->metadata_cache
->data
);
1608 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
1609 session
->metadata_cache
->data
= tmp_cache_realloc
;
1611 memcpy(session
->metadata_cache
->data
+
1612 session
->metadata_cache
->metadata_written
,
1614 session
->metadata_cache
->metadata_written
+= len
;
1615 mutex_unlock(&session
->metadata_cache
->lock
);
1618 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
1619 wake_up_interruptible(&stream
->read_wait
);
1624 mutex_unlock(&session
->metadata_cache
->lock
);
1630 * Must be called with sessions_mutex held.
1633 int _lttng_field_statedump(struct lttng_session
*session
,
1634 const struct lttng_event_field
*field
)
1638 switch (field
->type
.atype
) {
1640 ret
= lttng_metadata_printf(session
,
1641 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
1642 field
->type
.u
.basic
.integer
.size
,
1643 field
->type
.u
.basic
.integer
.alignment
,
1644 field
->type
.u
.basic
.integer
.signedness
,
1645 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
1647 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1650 field
->type
.u
.basic
.integer
.base
,
1651 #if __BYTE_ORDER == __BIG_ENDIAN
1652 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1654 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1659 ret
= lttng_metadata_printf(session
,
1661 field
->type
.u
.basic
.enumeration
.name
,
1666 const struct lttng_basic_type
*elem_type
;
1668 elem_type
= &field
->type
.u
.array
.elem_type
;
1669 ret
= lttng_metadata_printf(session
,
1670 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
1671 elem_type
->u
.basic
.integer
.size
,
1672 elem_type
->u
.basic
.integer
.alignment
,
1673 elem_type
->u
.basic
.integer
.signedness
,
1674 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1676 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1679 elem_type
->u
.basic
.integer
.base
,
1680 #if __BYTE_ORDER == __BIG_ENDIAN
1681 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1683 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1685 field
->name
, field
->type
.u
.array
.length
);
1688 case atype_sequence
:
1690 const struct lttng_basic_type
*elem_type
;
1691 const struct lttng_basic_type
*length_type
;
1693 elem_type
= &field
->type
.u
.sequence
.elem_type
;
1694 length_type
= &field
->type
.u
.sequence
.length_type
;
1695 ret
= lttng_metadata_printf(session
,
1696 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
1697 length_type
->u
.basic
.integer
.size
,
1698 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
1699 length_type
->u
.basic
.integer
.signedness
,
1700 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1702 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1705 length_type
->u
.basic
.integer
.base
,
1706 #if __BYTE_ORDER == __BIG_ENDIAN
1707 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1709 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1715 ret
= lttng_metadata_printf(session
,
1716 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
1717 elem_type
->u
.basic
.integer
.size
,
1718 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
1719 elem_type
->u
.basic
.integer
.signedness
,
1720 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1722 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1725 elem_type
->u
.basic
.integer
.base
,
1726 #if __BYTE_ORDER == __BIG_ENDIAN
1727 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1729 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1737 /* Default encoding is UTF8 */
1738 ret
= lttng_metadata_printf(session
,
1740 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
1741 " { encoding = ASCII; }" : "",
1752 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
1753 struct lttng_ctx
*ctx
)
1760 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
1761 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
1763 ret
= _lttng_field_statedump(session
, &field
->event_field
);
1771 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
1772 struct lttng_event
*event
)
1774 const struct lttng_event_desc
*desc
= event
->desc
;
1778 for (i
= 0; i
< desc
->nr_fields
; i
++) {
1779 const struct lttng_event_field
*field
= &desc
->fields
[i
];
1781 ret
= _lttng_field_statedump(session
, field
);
1789 * Must be called with sessions_mutex held.
1792 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
1793 struct lttng_channel
*chan
,
1794 struct lttng_event
*event
)
1798 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1800 if (chan
->channel_type
== METADATA_CHANNEL
)
1803 ret
= lttng_metadata_printf(session
,
1807 " stream_id = %u;\n",
1815 ret
= lttng_metadata_printf(session
,
1816 " context := struct {\n");
1820 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
1824 ret
= lttng_metadata_printf(session
,
1830 ret
= lttng_metadata_printf(session
,
1831 " fields := struct {\n"
1836 ret
= _lttng_fields_metadata_statedump(session
, event
);
1841 * LTTng space reservation can only reserve multiples of the
1844 ret
= lttng_metadata_printf(session
,
1850 event
->metadata_dumped
= 1;
1857 * Must be called with sessions_mutex held.
1860 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
1861 struct lttng_channel
*chan
)
1865 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1868 if (chan
->channel_type
== METADATA_CHANNEL
)
1871 WARN_ON_ONCE(!chan
->header_type
);
1872 ret
= lttng_metadata_printf(session
,
1875 " event.header := %s;\n"
1876 " packet.context := struct packet_context;\n",
1878 chan
->header_type
== 1 ? "struct event_header_compact" :
1879 "struct event_header_large");
1884 ret
= lttng_metadata_printf(session
,
1885 " event.context := struct {\n");
1889 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
1893 ret
= lttng_metadata_printf(session
,
1899 ret
= lttng_metadata_printf(session
,
1902 chan
->metadata_dumped
= 1;
1908 * Must be called with sessions_mutex held.
1911 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1913 return lttng_metadata_printf(session
,
1914 "struct packet_context {\n"
1915 " uint64_clock_monotonic_t timestamp_begin;\n"
1916 " uint64_clock_monotonic_t timestamp_end;\n"
1917 " uint64_t content_size;\n"
1918 " uint64_t packet_size;\n"
1919 " unsigned long events_discarded;\n"
1920 " uint32_t cpu_id;\n"
1927 * id: range: 0 - 30.
1928 * id 31 is reserved to indicate an extended header.
1931 * id: range: 0 - 65534.
1932 * id 65535 is reserved to indicate an extended header.
1934 * Must be called with sessions_mutex held.
1937 int _lttng_event_header_declare(struct lttng_session
*session
)
1939 return lttng_metadata_printf(session
,
1940 "struct event_header_compact {\n"
1941 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1944 " uint27_clock_monotonic_t timestamp;\n"
1948 " uint64_clock_monotonic_t timestamp;\n"
1953 "struct event_header_large {\n"
1954 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1957 " uint32_clock_monotonic_t timestamp;\n"
1961 " uint64_clock_monotonic_t timestamp;\n"
1965 lttng_alignof(uint32_t) * CHAR_BIT
,
1966 lttng_alignof(uint16_t) * CHAR_BIT
1971 * Approximation of NTP time of day to clock monotonic correlation,
1972 * taken at start of trace.
1973 * Yes, this is only an approximation. Yes, we can (and will) do better
1974 * in future versions.
1975 * Return 0 if offset is negative. It may happen if the system sets
1976 * the REALTIME clock to 0 after boot.
1979 uint64_t measure_clock_offset(void)
1981 uint64_t monotonic_avg
, monotonic
[2], realtime
;
1983 struct timespec rts
= { 0, 0 };
1984 unsigned long flags
;
1986 /* Disable interrupts to increase correlation precision. */
1987 local_irq_save(flags
);
1988 monotonic
[0] = trace_clock_read64();
1989 getnstimeofday(&rts
);
1990 monotonic
[1] = trace_clock_read64();
1991 local_irq_restore(flags
);
1993 monotonic_avg
= (monotonic
[0] + monotonic
[1]) >> 1;
1994 realtime
= (uint64_t) rts
.tv_sec
* NSEC_PER_SEC
;
1995 realtime
+= rts
.tv_nsec
;
1996 offset
= (int64_t) realtime
- monotonic_avg
;
2003 * Output metadata into this session's metadata buffers.
2004 * Must be called with sessions_mutex held.
2007 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
2009 unsigned char *uuid_c
= session
->uuid
.b
;
2010 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
2011 struct lttng_channel
*chan
;
2012 struct lttng_event
*event
;
2015 if (!ACCESS_ONCE(session
->active
))
2017 if (session
->metadata_dumped
)
2020 snprintf(uuid_s
, sizeof(uuid_s
),
2021 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2022 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
2023 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
2024 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
2025 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
2027 ret
= lttng_metadata_printf(session
,
2028 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2029 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2030 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2031 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2032 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2033 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2034 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2040 " byte_order = %s;\n"
2041 " packet.header := struct {\n"
2042 " uint32_t magic;\n"
2043 " uint8_t uuid[16];\n"
2044 " uint32_t stream_id;\n"
2047 lttng_alignof(uint8_t) * CHAR_BIT
,
2048 lttng_alignof(uint16_t) * CHAR_BIT
,
2049 lttng_alignof(uint32_t) * CHAR_BIT
,
2050 lttng_alignof(uint64_t) * CHAR_BIT
,
2051 sizeof(unsigned long) * CHAR_BIT
,
2052 lttng_alignof(unsigned long) * CHAR_BIT
,
2056 #if __BYTE_ORDER == __BIG_ENDIAN
2065 ret
= lttng_metadata_printf(session
,
2067 " hostname = \"%s\";\n"
2068 " domain = \"kernel\";\n"
2069 " sysname = \"%s\";\n"
2070 " kernel_release = \"%s\";\n"
2071 " kernel_version = \"%s\";\n"
2072 " tracer_name = \"lttng-modules\";\n"
2073 " tracer_major = %d;\n"
2074 " tracer_minor = %d;\n"
2075 " tracer_patchlevel = %d;\n"
2077 current
->nsproxy
->uts_ns
->name
.nodename
,
2081 LTTNG_MODULES_MAJOR_VERSION
,
2082 LTTNG_MODULES_MINOR_VERSION
,
2083 LTTNG_MODULES_PATCHLEVEL_VERSION
2088 ret
= lttng_metadata_printf(session
,
2096 if (!trace_clock_uuid(clock_uuid_s
)) {
2097 ret
= lttng_metadata_printf(session
,
2098 " uuid = \"%s\";\n",
2105 ret
= lttng_metadata_printf(session
,
2106 " description = \"Monotonic Clock\";\n"
2107 " freq = %llu; /* Frequency, in Hz */\n"
2108 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2111 (unsigned long long) trace_clock_freq(),
2112 (unsigned long long) measure_clock_offset()
2117 ret
= lttng_metadata_printf(session
,
2118 "typealias integer {\n"
2119 " size = 27; align = 1; signed = false;\n"
2120 " map = clock.monotonic.value;\n"
2121 "} := uint27_clock_monotonic_t;\n"
2123 "typealias integer {\n"
2124 " size = 32; align = %u; signed = false;\n"
2125 " map = clock.monotonic.value;\n"
2126 "} := uint32_clock_monotonic_t;\n"
2128 "typealias integer {\n"
2129 " size = 64; align = %u; signed = false;\n"
2130 " map = clock.monotonic.value;\n"
2131 "} := uint64_clock_monotonic_t;\n\n",
2132 lttng_alignof(uint32_t) * CHAR_BIT
,
2133 lttng_alignof(uint64_t) * CHAR_BIT
2138 ret
= _lttng_stream_packet_context_declare(session
);
2142 ret
= _lttng_event_header_declare(session
);
2147 list_for_each_entry(chan
, &session
->chan
, list
) {
2148 ret
= _lttng_channel_metadata_statedump(session
, chan
);
2153 list_for_each_entry(event
, &session
->events
, list
) {
2154 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
2158 session
->metadata_dumped
= 1;
2164 * lttng_transport_register - LTT transport registration
2165 * @transport: transport structure
2167 * Registers a transport which can be used as output to extract the data out of
2168 * LTTng. The module calling this registration function must ensure that no
2169 * trap-inducing code will be executed by the transport functions. E.g.
2170 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
2171 * is made visible to the transport function. This registration acts as a
2172 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
2173 * after its registration must it synchronize the TLBs.
2175 void lttng_transport_register(struct lttng_transport
*transport
)
2178 * Make sure no page fault can be triggered by the module about to be
2179 * registered. We deal with this here so we don't have to call
2180 * vmalloc_sync_all() in each module's init.
2182 wrapper_vmalloc_sync_all();
2184 mutex_lock(&sessions_mutex
);
2185 list_add_tail(&transport
->node
, <tng_transport_list
);
2186 mutex_unlock(&sessions_mutex
);
2188 EXPORT_SYMBOL_GPL(lttng_transport_register
);
2191 * lttng_transport_unregister - LTT transport unregistration
2192 * @transport: transport structure
2194 void lttng_transport_unregister(struct lttng_transport
*transport
)
2196 mutex_lock(&sessions_mutex
);
2197 list_del(&transport
->node
);
2198 mutex_unlock(&sessions_mutex
);
2200 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
2202 static int __init
lttng_events_init(void)
2206 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
2209 ret
= wrapper_get_pfnblock_flags_mask_init();
2212 ret
= wrapper_get_pageblock_flags_mask_init();
2215 ret
= lttng_context_init();
2218 ret
= lttng_tracepoint_init();
2221 event_cache
= KMEM_CACHE(lttng_event
, 0);
2226 ret
= lttng_abi_init();
2229 ret
= lttng_logger_init();
2237 kmem_cache_destroy(event_cache
);
2239 lttng_tracepoint_exit();
2241 lttng_context_exit();
2245 module_init(lttng_events_init
);
2247 static void __exit
lttng_events_exit(void)
2249 struct lttng_session
*session
, *tmpsession
;
2251 lttng_logger_exit();
2253 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
2254 lttng_session_destroy(session
);
2255 kmem_cache_destroy(event_cache
);
2256 lttng_tracepoint_exit();
2257 lttng_context_exit();
2260 module_exit(lttng_events_exit
);
2262 MODULE_LICENSE("GPL and additional rights");
2263 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
2264 MODULE_DESCRIPTION("LTTng Events");
2265 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
2266 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
2267 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
2268 LTTNG_MODULES_EXTRAVERSION
);