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
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <linux/sched.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/utsname.h>
29 #include <linux/err.h>
30 #include <linux/seq_file.h>
31 #include <linux/file.h>
32 #include <linux/anon_inodes.h>
33 #include "wrapper/file.h"
34 #include <linux/jhash.h>
36 #include "wrapper/uuid.h"
37 #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
38 #include "wrapper/random.h"
39 #include "wrapper/tracepoint.h"
40 #include "wrapper/list.h"
41 #include "lttng-kernel-version.h"
42 #include "lttng-events.h"
43 #include "lttng-tracer.h"
44 #include "lttng-abi-old.h"
46 #define METADATA_CACHE_DEFAULT_SIZE 4096
48 static LIST_HEAD(sessions
);
49 static LIST_HEAD(lttng_transport_list
);
51 * Protect the sessions and metadata caches.
53 static DEFINE_MUTEX(sessions_mutex
);
54 static struct kmem_cache
*event_cache
;
56 static void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
57 static void lttng_session_sync_enablers(struct lttng_session
*session
);
58 static void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
60 static void _lttng_event_destroy(struct lttng_event
*event
);
61 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
62 static int _lttng_event_unregister(struct lttng_event
*event
);
64 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
65 struct lttng_channel
*chan
,
66 struct lttng_event
*event
);
68 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
70 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
72 void synchronize_trace(void)
75 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
76 #ifdef CONFIG_PREEMPT_RT_FULL
79 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
80 #ifdef CONFIG_PREEMPT_RT
83 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
86 void lttng_lock_sessions(void)
88 mutex_lock(&sessions_mutex
);
91 void lttng_unlock_sessions(void)
93 mutex_unlock(&sessions_mutex
);
97 * Called with sessions lock held.
99 int lttng_session_active(void)
101 struct lttng_session
*iter
;
103 list_for_each_entry(iter
, &sessions
, list
) {
110 struct lttng_session
*lttng_session_create(void)
112 struct lttng_session
*session
;
113 struct lttng_metadata_cache
*metadata_cache
;
116 mutex_lock(&sessions_mutex
);
117 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
120 INIT_LIST_HEAD(&session
->chan
);
121 INIT_LIST_HEAD(&session
->events
);
122 uuid_le_gen(&session
->uuid
);
124 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
127 goto err_free_session
;
128 metadata_cache
->data
= kzalloc(METADATA_CACHE_DEFAULT_SIZE
,
130 if (!metadata_cache
->data
)
132 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
133 kref_init(&metadata_cache
->refcount
);
134 session
->metadata_cache
= metadata_cache
;
135 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
136 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
137 sizeof(metadata_cache
->uuid
));
138 INIT_LIST_HEAD(&session
->enablers_head
);
139 for (i
= 0; i
< LTTNG_EVENT_HT_SIZE
; i
++)
140 INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
141 list_add(&session
->list
, &sessions
);
142 mutex_unlock(&sessions_mutex
);
146 kfree(metadata_cache
);
150 mutex_unlock(&sessions_mutex
);
154 void metadata_cache_destroy(struct kref
*kref
)
156 struct lttng_metadata_cache
*cache
=
157 container_of(kref
, struct lttng_metadata_cache
, refcount
);
162 void lttng_session_destroy(struct lttng_session
*session
)
164 struct lttng_channel
*chan
, *tmpchan
;
165 struct lttng_event
*event
, *tmpevent
;
166 struct lttng_metadata_stream
*metadata_stream
;
167 struct lttng_enabler
*enabler
, *tmpenabler
;
170 mutex_lock(&sessions_mutex
);
171 ACCESS_ONCE(session
->active
) = 0;
172 list_for_each_entry(chan
, &session
->chan
, list
) {
173 ret
= lttng_syscalls_unregister(chan
);
176 list_for_each_entry(event
, &session
->events
, list
) {
177 ret
= _lttng_event_unregister(event
);
180 synchronize_trace(); /* Wait for in-flight events to complete */
181 list_for_each_entry_safe(enabler
, tmpenabler
,
182 &session
->enablers_head
, node
)
183 lttng_enabler_destroy(enabler
);
184 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
185 _lttng_event_destroy(event
);
186 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
187 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
188 _lttng_channel_destroy(chan
);
190 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
191 _lttng_metadata_channel_hangup(metadata_stream
);
192 if (session
->pid_tracker
)
193 lttng_pid_tracker_destroy(session
->pid_tracker
);
194 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
195 list_del(&session
->list
);
196 mutex_unlock(&sessions_mutex
);
200 int lttng_session_enable(struct lttng_session
*session
)
203 struct lttng_channel
*chan
;
205 mutex_lock(&sessions_mutex
);
206 if (session
->active
) {
211 /* Set transient enabler state to "enabled" */
215 * Snapshot the number of events per channel to know the type of header
218 list_for_each_entry(chan
, &session
->chan
, list
) {
219 if (chan
->header_type
)
220 continue; /* don't change it if session stop/restart */
221 if (chan
->free_event_id
< 31)
222 chan
->header_type
= 1; /* compact */
224 chan
->header_type
= 2; /* large */
227 /* We need to sync enablers with session before activation. */
228 lttng_session_sync_enablers(session
);
230 ACCESS_ONCE(session
->active
) = 1;
231 ACCESS_ONCE(session
->been_active
) = 1;
232 ret
= _lttng_session_metadata_statedump(session
);
234 ACCESS_ONCE(session
->active
) = 0;
237 ret
= lttng_statedump_start(session
);
239 ACCESS_ONCE(session
->active
) = 0;
241 mutex_unlock(&sessions_mutex
);
245 int lttng_session_disable(struct lttng_session
*session
)
249 mutex_lock(&sessions_mutex
);
250 if (!session
->active
) {
254 ACCESS_ONCE(session
->active
) = 0;
256 /* Set transient enabler state to "disabled" */
258 lttng_session_sync_enablers(session
);
260 mutex_unlock(&sessions_mutex
);
264 int lttng_channel_enable(struct lttng_channel
*channel
)
268 mutex_lock(&sessions_mutex
);
269 if (channel
->channel_type
== METADATA_CHANNEL
) {
273 if (channel
->enabled
) {
277 /* Set transient enabler state to "enabled" */
279 lttng_session_sync_enablers(channel
->session
);
280 /* Set atomically the state to "enabled" */
281 ACCESS_ONCE(channel
->enabled
) = 1;
283 mutex_unlock(&sessions_mutex
);
287 int lttng_channel_disable(struct lttng_channel
*channel
)
291 mutex_lock(&sessions_mutex
);
292 if (channel
->channel_type
== METADATA_CHANNEL
) {
296 if (!channel
->enabled
) {
300 /* Set atomically the state to "disabled" */
301 ACCESS_ONCE(channel
->enabled
) = 0;
302 /* Set transient enabler state to "enabled" */
304 lttng_session_sync_enablers(channel
->session
);
306 mutex_unlock(&sessions_mutex
);
310 int lttng_event_enable(struct lttng_event
*event
)
314 mutex_lock(&sessions_mutex
);
315 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
319 if (event
->enabled
) {
323 ACCESS_ONCE(event
->enabled
) = 1;
324 lttng_session_sync_enablers(event
->chan
->session
);
326 mutex_unlock(&sessions_mutex
);
330 int lttng_event_disable(struct lttng_event
*event
)
334 mutex_lock(&sessions_mutex
);
335 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
339 if (!event
->enabled
) {
343 ACCESS_ONCE(event
->enabled
) = 0;
344 lttng_session_sync_enablers(event
->chan
->session
);
346 mutex_unlock(&sessions_mutex
);
350 static struct lttng_transport
*lttng_transport_find(const char *name
)
352 struct lttng_transport
*transport
;
354 list_for_each_entry(transport
, <tng_transport_list
, node
) {
355 if (!strcmp(transport
->name
, name
))
361 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
362 const char *transport_name
,
364 size_t subbuf_size
, size_t num_subbuf
,
365 unsigned int switch_timer_interval
,
366 unsigned int read_timer_interval
,
367 enum channel_type channel_type
)
369 struct lttng_channel
*chan
;
370 struct lttng_transport
*transport
= NULL
;
372 mutex_lock(&sessions_mutex
);
373 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
374 goto active
; /* Refuse to add channel to active session */
375 transport
= lttng_transport_find(transport_name
);
377 printk(KERN_WARNING
"LTTng transport %s not found\n",
381 if (!try_module_get(transport
->owner
)) {
382 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
385 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
388 chan
->session
= session
;
389 chan
->id
= session
->free_chan_id
++;
390 chan
->ops
= &transport
->ops
;
392 * Note: the channel creation op already writes into the packet
393 * headers. Therefore the "chan" information used as input
394 * should be already accessible.
396 chan
->chan
= transport
->ops
.channel_create(transport_name
,
397 chan
, buf_addr
, subbuf_size
, num_subbuf
,
398 switch_timer_interval
, read_timer_interval
);
403 chan
->transport
= transport
;
404 chan
->channel_type
= channel_type
;
405 list_add(&chan
->list
, &session
->chan
);
406 mutex_unlock(&sessions_mutex
);
413 module_put(transport
->owner
);
416 mutex_unlock(&sessions_mutex
);
421 * Only used internally at session destruction for per-cpu channels, and
422 * when metadata channel is released.
423 * Needs to be called with sessions mutex held.
426 void _lttng_channel_destroy(struct lttng_channel
*chan
)
428 chan
->ops
->channel_destroy(chan
->chan
);
429 module_put(chan
->transport
->owner
);
430 list_del(&chan
->list
);
431 lttng_destroy_context(chan
->ctx
);
435 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
437 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
439 /* Protect the metadata cache with the sessions_mutex. */
440 mutex_lock(&sessions_mutex
);
441 _lttng_channel_destroy(chan
);
442 mutex_unlock(&sessions_mutex
);
444 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
447 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
449 stream
->finalized
= 1;
450 wake_up_interruptible(&stream
->read_wait
);
454 * Supports event creation while tracing session is active.
455 * Needs to be called with sessions mutex held.
457 struct lttng_event
*_lttng_event_create(struct lttng_channel
*chan
,
458 struct lttng_kernel_event
*event_param
,
460 const struct lttng_event_desc
*event_desc
,
461 enum lttng_kernel_instrumentation itype
)
463 struct lttng_session
*session
= chan
->session
;
464 struct lttng_event
*event
;
465 const char *event_name
;
466 struct hlist_head
*head
;
471 if (chan
->free_event_id
== -1U) {
477 case LTTNG_KERNEL_TRACEPOINT
:
478 event_name
= event_desc
->name
;
480 case LTTNG_KERNEL_KPROBE
:
481 case LTTNG_KERNEL_KRETPROBE
:
482 case LTTNG_KERNEL_FUNCTION
:
483 case LTTNG_KERNEL_NOOP
:
484 event_name
= event_param
->name
;
491 name_len
= strlen(event_name
);
492 hash
= jhash(event_name
, name_len
, 0);
493 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
494 hlist_for_each_entry(event
, head
, hlist
) {
495 WARN_ON_ONCE(!event
->desc
);
496 if (!strncmp(event
->desc
->name
, event_name
,
497 LTTNG_KERNEL_SYM_NAME_LEN
- 1)
498 && chan
== event
->chan
) {
504 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
510 event
->filter
= filter
;
511 event
->id
= chan
->free_event_id
++;
512 event
->instrumentation
= itype
;
513 event
->evtype
= LTTNG_TYPE_EVENT
;
514 INIT_LIST_HEAD(&event
->enablers_ref_head
);
517 case LTTNG_KERNEL_TRACEPOINT
:
518 /* Event will be enabled by enabler sync. */
520 event
->registered
= 0;
521 event
->desc
= lttng_event_get(event_name
);
526 /* Populate lttng_event structure before event registration. */
529 case LTTNG_KERNEL_KPROBE
:
531 event
->registered
= 1;
533 * Populate lttng_event structure before event
537 ret
= lttng_kprobes_register(event_name
,
538 event_param
->u
.kprobe
.symbol_name
,
539 event_param
->u
.kprobe
.offset
,
540 event_param
->u
.kprobe
.addr
,
546 ret
= try_module_get(event
->desc
->owner
);
549 case LTTNG_KERNEL_KRETPROBE
:
551 struct lttng_event
*event_return
;
553 /* kretprobe defines 2 events */
555 event
->registered
= 1;
557 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
562 event_return
->chan
= chan
;
563 event_return
->filter
= filter
;
564 event_return
->id
= chan
->free_event_id
++;
565 event_return
->enabled
= 1;
566 event_return
->registered
= 1;
567 event_return
->instrumentation
= itype
;
569 * Populate lttng_event structure before kretprobe registration.
572 ret
= lttng_kretprobes_register(event_name
,
573 event_param
->u
.kretprobe
.symbol_name
,
574 event_param
->u
.kretprobe
.offset
,
575 event_param
->u
.kretprobe
.addr
,
576 event
, event_return
);
578 kmem_cache_free(event_cache
, event_return
);
582 /* Take 2 refs on the module: one per event. */
583 ret
= try_module_get(event
->desc
->owner
);
585 ret
= try_module_get(event
->desc
->owner
);
587 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
589 WARN_ON_ONCE(ret
> 0);
591 kmem_cache_free(event_cache
, event_return
);
592 module_put(event
->desc
->owner
);
593 module_put(event
->desc
->owner
);
594 goto statedump_error
;
596 list_add(&event_return
->list
, &chan
->session
->events
);
599 case LTTNG_KERNEL_FUNCTION
:
601 event
->registered
= 1;
603 * Populate lttng_event structure before event
607 ret
= lttng_ftrace_register(event_name
,
608 event_param
->u
.ftrace
.symbol_name
,
613 ret
= try_module_get(event
->desc
->owner
);
616 case LTTNG_KERNEL_NOOP
:
618 event
->registered
= 0;
619 event
->desc
= event_desc
;
630 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
631 WARN_ON_ONCE(ret
> 0);
633 goto statedump_error
;
635 hlist_add_head(&event
->hlist
, head
);
636 list_add(&event
->list
, &chan
->session
->events
);
637 mutex_unlock(&sessions_mutex
);
641 /* If a statedump error occurs, events will not be readable. */
643 kmem_cache_free(event_cache
, event
);
651 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
652 struct lttng_kernel_event
*event_param
,
654 const struct lttng_event_desc
*event_desc
,
655 enum lttng_kernel_instrumentation itype
)
657 struct lttng_event
*event
;
659 mutex_lock(&sessions_mutex
);
660 event
= _lttng_event_create(chan
, event_param
, filter
, event_desc
,
662 mutex_unlock(&sessions_mutex
);
666 /* Only used for tracepoints for now. */
668 void register_event(struct lttng_event
*event
)
670 const struct lttng_event_desc
*desc
;
673 WARN_ON_ONCE(event
->instrumentation
!= LTTNG_KERNEL_TRACEPOINT
);
674 if (event
->registered
)
677 ret
= lttng_wrapper_tracepoint_probe_register(desc
->kname
,
678 desc
->probe_callback
, event
);
680 event
->registered
= 1;
684 * Only used internally at session destruction.
686 int _lttng_event_unregister(struct lttng_event
*event
)
690 if (!event
->registered
)
693 switch (event
->instrumentation
) {
694 case LTTNG_KERNEL_TRACEPOINT
:
695 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
696 event
->desc
->probe_callback
,
701 case LTTNG_KERNEL_KPROBE
:
702 lttng_kprobes_unregister(event
);
705 case LTTNG_KERNEL_KRETPROBE
:
706 lttng_kretprobes_unregister(event
);
709 case LTTNG_KERNEL_FUNCTION
:
710 lttng_ftrace_unregister(event
);
713 case LTTNG_KERNEL_NOOP
:
720 event
->registered
= 0;
725 * Only used internally at session destruction.
728 void _lttng_event_destroy(struct lttng_event
*event
)
730 switch (event
->instrumentation
) {
731 case LTTNG_KERNEL_TRACEPOINT
:
732 lttng_event_put(event
->desc
);
734 case LTTNG_KERNEL_KPROBE
:
735 module_put(event
->desc
->owner
);
736 lttng_kprobes_destroy_private(event
);
738 case LTTNG_KERNEL_KRETPROBE
:
739 module_put(event
->desc
->owner
);
740 lttng_kretprobes_destroy_private(event
);
742 case LTTNG_KERNEL_FUNCTION
:
743 module_put(event
->desc
->owner
);
744 lttng_ftrace_destroy_private(event
);
746 case LTTNG_KERNEL_NOOP
:
751 list_del(&event
->list
);
752 lttng_destroy_context(event
->ctx
);
753 kmem_cache_free(event_cache
, event
);
756 int lttng_session_track_pid(struct lttng_session
*session
, int pid
)
762 mutex_lock(&sessions_mutex
);
764 /* track all pids: destroy tracker. */
765 if (session
->pid_tracker
) {
766 struct lttng_pid_tracker
*lpf
;
768 lpf
= session
->pid_tracker
;
769 rcu_assign_pointer(session
->pid_tracker
, NULL
);
771 lttng_pid_tracker_destroy(lpf
);
775 if (!session
->pid_tracker
) {
776 struct lttng_pid_tracker
*lpf
;
778 lpf
= lttng_pid_tracker_create();
783 ret
= lttng_pid_tracker_add(lpf
, pid
);
784 rcu_assign_pointer(session
->pid_tracker
, lpf
);
786 ret
= lttng_pid_tracker_add(session
->pid_tracker
, pid
);
790 mutex_unlock(&sessions_mutex
);
794 int lttng_session_untrack_pid(struct lttng_session
*session
, int pid
)
800 mutex_lock(&sessions_mutex
);
802 /* untrack all pids: replace by empty tracker. */
803 struct lttng_pid_tracker
*old_lpf
= session
->pid_tracker
;
804 struct lttng_pid_tracker
*lpf
;
806 lpf
= lttng_pid_tracker_create();
811 rcu_assign_pointer(session
->pid_tracker
, lpf
);
814 lttng_pid_tracker_destroy(old_lpf
);
817 if (!session
->pid_tracker
) {
821 ret
= lttng_pid_tracker_del(session
->pid_tracker
, pid
);
824 mutex_unlock(&sessions_mutex
);
829 void *pid_list_start(struct seq_file
*m
, loff_t
*pos
)
831 struct lttng_session
*session
= m
->private;
832 struct lttng_pid_tracker
*lpf
;
833 struct lttng_pid_hash_node
*e
;
836 mutex_lock(&sessions_mutex
);
837 lpf
= session
->pid_tracker
;
839 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
840 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
842 lttng_hlist_for_each_entry(e
, head
, hlist
) {
848 /* PID tracker disabled. */
849 if (iter
>= *pos
&& iter
== 0) {
850 return session
; /* empty tracker */
858 /* Called with sessions_mutex held. */
860 void *pid_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
862 struct lttng_session
*session
= m
->private;
863 struct lttng_pid_tracker
*lpf
;
864 struct lttng_pid_hash_node
*e
;
868 lpf
= session
->pid_tracker
;
870 for (i
= 0; i
< LTTNG_PID_TABLE_SIZE
; i
++) {
871 struct hlist_head
*head
= &lpf
->pid_hash
[i
];
873 lttng_hlist_for_each_entry(e
, head
, hlist
) {
879 /* PID tracker disabled. */
880 if (iter
>= *ppos
&& iter
== 0)
881 return session
; /* empty tracker */
890 void pid_list_stop(struct seq_file
*m
, void *p
)
892 mutex_unlock(&sessions_mutex
);
896 int pid_list_show(struct seq_file
*m
, void *p
)
900 if (p
== m
->private) {
901 /* Tracker disabled. */
904 const struct lttng_pid_hash_node
*e
= p
;
906 pid
= lttng_pid_tracker_get_node_pid(e
);
908 seq_printf(m
, "process { pid = %d; };\n", pid
);
913 const struct seq_operations lttng_tracker_pids_list_seq_ops
= {
914 .start
= pid_list_start
,
915 .next
= pid_list_next
,
916 .stop
= pid_list_stop
,
917 .show
= pid_list_show
,
921 int lttng_tracker_pids_list_open(struct inode
*inode
, struct file
*file
)
923 return seq_open(file
, <tng_tracker_pids_list_seq_ops
);
927 int lttng_tracker_pids_list_release(struct inode
*inode
, struct file
*file
)
929 struct seq_file
*m
= file
->private_data
;
930 struct lttng_session
*session
= m
->private;
933 WARN_ON_ONCE(!session
);
934 ret
= seq_release(inode
, file
);
940 const struct file_operations lttng_tracker_pids_list_fops
= {
941 .owner
= THIS_MODULE
,
942 .open
= lttng_tracker_pids_list_open
,
945 .release
= lttng_tracker_pids_list_release
,
948 int lttng_session_list_tracker_pids(struct lttng_session
*session
)
950 struct file
*tracker_pids_list_file
;
954 file_fd
= lttng_get_unused_fd();
960 tracker_pids_list_file
= anon_inode_getfile("[lttng_tracker_pids_list]",
961 <tng_tracker_pids_list_fops
,
963 if (IS_ERR(tracker_pids_list_file
)) {
964 ret
= PTR_ERR(tracker_pids_list_file
);
967 ret
= lttng_tracker_pids_list_fops
.open(NULL
, tracker_pids_list_file
);
970 m
= tracker_pids_list_file
->private_data
;
971 m
->private = session
;
972 fd_install(file_fd
, tracker_pids_list_file
);
973 atomic_long_inc(&session
->file
->f_count
);
978 fput(tracker_pids_list_file
);
980 put_unused_fd(file_fd
);
986 * Enabler management.
989 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
990 struct lttng_enabler
*enabler
)
992 WARN_ON_ONCE(enabler
->type
!= LTTNG_ENABLER_WILDCARD
);
993 /* Compare excluding final '*' */
994 if (strncmp(desc
->name
, enabler
->event_param
.name
,
995 strlen(enabler
->event_param
.name
) - 1))
1001 int lttng_desc_match_name_enabler(const struct lttng_event_desc
*desc
,
1002 struct lttng_enabler
*enabler
)
1004 WARN_ON_ONCE(enabler
->type
!= LTTNG_ENABLER_NAME
);
1005 if (strcmp(desc
->name
, enabler
->event_param
.name
))
1011 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
1012 struct lttng_enabler
*enabler
)
1014 switch (enabler
->type
) {
1015 case LTTNG_ENABLER_WILDCARD
:
1016 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
1017 case LTTNG_ENABLER_NAME
:
1018 return lttng_desc_match_name_enabler(desc
, enabler
);
1025 int lttng_event_match_enabler(struct lttng_event
*event
,
1026 struct lttng_enabler
*enabler
)
1028 if (lttng_desc_match_enabler(event
->desc
, enabler
)
1029 && event
->chan
== enabler
->chan
)
1036 struct lttng_enabler_ref
*lttng_event_enabler_ref(struct lttng_event
*event
,
1037 struct lttng_enabler
*enabler
)
1039 struct lttng_enabler_ref
*enabler_ref
;
1041 list_for_each_entry(enabler_ref
,
1042 &event
->enablers_ref_head
, node
) {
1043 if (enabler_ref
->ref
== enabler
)
1050 * Create struct lttng_event if it is missing and present in the list of
1051 * tracepoint probes.
1052 * Should be called with sessions mutex held.
1055 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
1057 struct lttng_session
*session
= enabler
->chan
->session
;
1058 struct lttng_probe_desc
*probe_desc
;
1059 const struct lttng_event_desc
*desc
;
1061 struct list_head
*probe_list
;
1063 probe_list
= lttng_get_probe_list_head();
1065 * For each probe event, if we find that a probe event matches
1066 * our enabler, create an associated lttng_event if not
1069 list_for_each_entry(probe_desc
, probe_list
, head
) {
1070 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
1072 struct hlist_head
*head
;
1073 const char *event_name
;
1076 struct lttng_event
*event
;
1078 desc
= probe_desc
->event_desc
[i
];
1079 if (!lttng_desc_match_enabler(desc
, enabler
))
1081 event_name
= desc
->name
;
1082 name_len
= strlen(event_name
);
1085 * Check if already created.
1087 hash
= jhash(event_name
, name_len
, 0);
1088 head
= &session
->events_ht
.table
[hash
& (LTTNG_EVENT_HT_SIZE
- 1)];
1089 hlist_for_each_entry(event
, head
, hlist
) {
1090 if (event
->desc
== desc
1091 && event
->chan
== enabler
->chan
)
1098 * We need to create an event for this
1101 event
= _lttng_event_create(enabler
->chan
,
1103 LTTNG_KERNEL_TRACEPOINT
);
1105 printk(KERN_INFO
"Unable to create event %s\n",
1106 probe_desc
->event_desc
[i
]->name
);
1113 * Create events associated with an enabler (if not already present),
1114 * and add backward reference from the event to the enabler.
1115 * Should be called with sessions mutex held.
1118 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
1120 struct lttng_session
*session
= enabler
->chan
->session
;
1121 struct lttng_event
*event
;
1123 /* First ensure that probe events are created for this enabler. */
1124 lttng_create_event_if_missing(enabler
);
1126 /* For each event matching enabler in session event list. */
1127 list_for_each_entry(event
, &session
->events
, list
) {
1128 struct lttng_enabler_ref
*enabler_ref
;
1130 if (!lttng_event_match_enabler(event
, enabler
))
1132 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
1135 * If no backward ref, create it.
1136 * Add backward ref from event to enabler.
1138 enabler_ref
= kzalloc(sizeof(*enabler_ref
), GFP_KERNEL
);
1141 enabler_ref
->ref
= enabler
;
1142 list_add(&enabler_ref
->node
,
1143 &event
->enablers_ref_head
);
1146 /* TODO: merge event context. */
1152 * Called at module load: connect the probe on all enablers matching
1154 * Called with sessions lock held.
1156 int lttng_fix_pending_events(void)
1158 struct lttng_session
*session
;
1160 list_for_each_entry(session
, &sessions
, list
)
1161 lttng_session_lazy_sync_enablers(session
);
1165 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1166 struct lttng_kernel_event
*event_param
,
1167 struct lttng_channel
*chan
)
1169 struct lttng_enabler
*enabler
;
1171 enabler
= kzalloc(sizeof(*enabler
), GFP_KERNEL
);
1174 enabler
->type
= type
;
1175 memcpy(&enabler
->event_param
, event_param
,
1176 sizeof(enabler
->event_param
));
1177 enabler
->chan
= chan
;
1179 enabler
->enabled
= 1;
1180 enabler
->evtype
= LTTNG_TYPE_ENABLER
;
1181 mutex_lock(&sessions_mutex
);
1182 list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1183 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1184 mutex_unlock(&sessions_mutex
);
1188 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1190 mutex_lock(&sessions_mutex
);
1191 enabler
->enabled
= 1;
1192 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1193 mutex_unlock(&sessions_mutex
);
1197 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1199 mutex_lock(&sessions_mutex
);
1200 enabler
->enabled
= 0;
1201 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1202 mutex_unlock(&sessions_mutex
);
1206 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1207 struct lttng_kernel_context
*context_param
)
1213 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1215 /* Destroy contexts */
1216 lttng_destroy_context(enabler
->ctx
);
1218 list_del(&enabler
->node
);
1223 * lttng_session_sync_enablers should be called just before starting a
1225 * Should be called with sessions mutex held.
1228 void lttng_session_sync_enablers(struct lttng_session
*session
)
1230 struct lttng_enabler
*enabler
;
1231 struct lttng_event
*event
;
1233 list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1234 lttng_enabler_ref_events(enabler
);
1236 * For each event, if at least one of its enablers is enabled,
1237 * and its channel and session transient states are enabled, we
1238 * enable the event, else we disable it.
1240 list_for_each_entry(event
, &session
->events
, list
) {
1241 struct lttng_enabler_ref
*enabler_ref
;
1244 if (event
->instrumentation
== LTTNG_KERNEL_TRACEPOINT
) {
1246 list_for_each_entry(enabler_ref
,
1247 &event
->enablers_ref_head
, node
) {
1248 if (enabler_ref
->ref
->enabled
) {
1254 /* Not handled with lazy sync. */
1258 * Enabled state is based on union of enablers, with
1259 * intesection of session and channel transient enable
1262 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
1264 ACCESS_ONCE(event
->enabled
) = enabled
;
1266 * Sync tracepoint registration with event enabled
1270 register_event(event
);
1272 _lttng_event_unregister(event
);
1278 * Apply enablers to session events, adding events to session if need
1279 * be. It is required after each modification applied to an active
1280 * session, and right before session "start".
1281 * "lazy" sync means we only sync if required.
1282 * Should be called with sessions mutex held.
1285 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1287 /* We can skip if session is not active */
1288 if (!session
->active
)
1290 lttng_session_sync_enablers(session
);
1294 * Serialize at most one packet worth of metadata into a metadata
1296 * We have exclusive access to our metadata buffer (protected by the
1297 * sessions_mutex), so we can do racy operations such as looking for
1298 * remaining space left in packet and write, since mutual exclusion
1299 * protects us from concurrent writes.
1300 * Returns the number of bytes written in the channel, 0 if no data
1301 * was written and a negative value on error.
1303 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
1304 struct channel
*chan
)
1306 struct lib_ring_buffer_ctx ctx
;
1308 size_t len
, reserve_len
;
1311 * Ensure we support mutiple get_next / put sequences followed
1312 * by put_next. The metadata stream lock internally protects
1313 * reading the metadata cache. It can indeed be read
1314 * concurrently by "get_next_subbuf" and "flush" operations on
1315 * the buffer invoked by different processes.
1317 mutex_lock(&stream
->lock
);
1318 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
1319 if (stream
->metadata_in
!= stream
->metadata_out
)
1322 len
= stream
->metadata_cache
->metadata_written
-
1323 stream
->metadata_in
;
1326 reserve_len
= min_t(size_t,
1327 stream
->transport
->ops
.packet_avail_size(chan
),
1329 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
1332 * If reservation failed, return an error to the caller.
1334 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
1336 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
1339 stream
->transport
->ops
.event_write(&ctx
,
1340 stream
->metadata_cache
->data
+ stream
->metadata_in
,
1342 stream
->transport
->ops
.event_commit(&ctx
);
1343 stream
->metadata_in
+= reserve_len
;
1347 mutex_unlock(&stream
->lock
);
1352 * Write the metadata to the metadata cache.
1353 * Must be called with sessions_mutex held.
1355 int lttng_metadata_printf(struct lttng_session
*session
,
1356 const char *fmt
, ...)
1361 struct lttng_metadata_stream
*stream
;
1363 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
1366 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
1372 if (session
->metadata_cache
->metadata_written
+ len
>
1373 session
->metadata_cache
->cache_alloc
) {
1374 char *tmp_cache_realloc
;
1375 unsigned int tmp_cache_alloc_size
;
1377 tmp_cache_alloc_size
= max_t(unsigned int,
1378 session
->metadata_cache
->cache_alloc
+ len
,
1379 session
->metadata_cache
->cache_alloc
<< 1);
1380 tmp_cache_realloc
= krealloc(session
->metadata_cache
->data
,
1381 tmp_cache_alloc_size
, GFP_KERNEL
);
1382 if (!tmp_cache_realloc
)
1384 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
1385 session
->metadata_cache
->data
= tmp_cache_realloc
;
1387 memcpy(session
->metadata_cache
->data
+
1388 session
->metadata_cache
->metadata_written
,
1390 session
->metadata_cache
->metadata_written
+= len
;
1393 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
1394 wake_up_interruptible(&stream
->read_wait
);
1404 * Must be called with sessions_mutex held.
1407 int _lttng_field_statedump(struct lttng_session
*session
,
1408 const struct lttng_event_field
*field
)
1412 switch (field
->type
.atype
) {
1414 ret
= lttng_metadata_printf(session
,
1415 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
1416 field
->type
.u
.basic
.integer
.size
,
1417 field
->type
.u
.basic
.integer
.alignment
,
1418 field
->type
.u
.basic
.integer
.signedness
,
1419 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
1421 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1424 field
->type
.u
.basic
.integer
.base
,
1426 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1428 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1433 ret
= lttng_metadata_printf(session
,
1435 field
->type
.u
.basic
.enumeration
.name
,
1440 const struct lttng_basic_type
*elem_type
;
1442 elem_type
= &field
->type
.u
.array
.elem_type
;
1443 ret
= lttng_metadata_printf(session
,
1444 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
1445 elem_type
->u
.basic
.integer
.size
,
1446 elem_type
->u
.basic
.integer
.alignment
,
1447 elem_type
->u
.basic
.integer
.signedness
,
1448 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1450 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1453 elem_type
->u
.basic
.integer
.base
,
1455 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1457 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1459 field
->name
, field
->type
.u
.array
.length
);
1462 case atype_sequence
:
1464 const struct lttng_basic_type
*elem_type
;
1465 const struct lttng_basic_type
*length_type
;
1467 elem_type
= &field
->type
.u
.sequence
.elem_type
;
1468 length_type
= &field
->type
.u
.sequence
.length_type
;
1469 ret
= lttng_metadata_printf(session
,
1470 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
1471 length_type
->u
.basic
.integer
.size
,
1472 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
1473 length_type
->u
.basic
.integer
.signedness
,
1474 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1476 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1479 length_type
->u
.basic
.integer
.base
,
1481 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1483 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1489 ret
= lttng_metadata_printf(session
,
1490 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
1491 elem_type
->u
.basic
.integer
.size
,
1492 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
1493 elem_type
->u
.basic
.integer
.signedness
,
1494 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
1496 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
1499 elem_type
->u
.basic
.integer
.base
,
1501 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
1503 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
1511 /* Default encoding is UTF8 */
1512 ret
= lttng_metadata_printf(session
,
1514 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
1515 " { encoding = ASCII; }" : "",
1526 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
1527 struct lttng_ctx
*ctx
)
1534 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
1535 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
1537 ret
= _lttng_field_statedump(session
, &field
->event_field
);
1545 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
1546 struct lttng_event
*event
)
1548 const struct lttng_event_desc
*desc
= event
->desc
;
1552 for (i
= 0; i
< desc
->nr_fields
; i
++) {
1553 const struct lttng_event_field
*field
= &desc
->fields
[i
];
1555 ret
= _lttng_field_statedump(session
, field
);
1563 * Must be called with sessions_mutex held.
1566 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
1567 struct lttng_channel
*chan
,
1568 struct lttng_event
*event
)
1572 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1574 if (chan
->channel_type
== METADATA_CHANNEL
)
1577 ret
= lttng_metadata_printf(session
,
1581 " stream_id = %u;\n",
1589 ret
= lttng_metadata_printf(session
,
1590 " context := struct {\n");
1594 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
1598 ret
= lttng_metadata_printf(session
,
1604 ret
= lttng_metadata_printf(session
,
1605 " fields := struct {\n"
1610 ret
= _lttng_fields_metadata_statedump(session
, event
);
1615 * LTTng space reservation can only reserve multiples of the
1618 ret
= lttng_metadata_printf(session
,
1624 event
->metadata_dumped
= 1;
1631 * Must be called with sessions_mutex held.
1634 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
1635 struct lttng_channel
*chan
)
1639 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
1642 if (chan
->channel_type
== METADATA_CHANNEL
)
1645 WARN_ON_ONCE(!chan
->header_type
);
1646 ret
= lttng_metadata_printf(session
,
1649 " event.header := %s;\n"
1650 " packet.context := struct packet_context;\n",
1652 chan
->header_type
== 1 ? "struct event_header_compact" :
1653 "struct event_header_large");
1658 ret
= lttng_metadata_printf(session
,
1659 " event.context := struct {\n");
1663 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
1667 ret
= lttng_metadata_printf(session
,
1673 ret
= lttng_metadata_printf(session
,
1676 chan
->metadata_dumped
= 1;
1682 * Must be called with sessions_mutex held.
1685 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1687 return lttng_metadata_printf(session
,
1688 "struct packet_context {\n"
1689 " uint64_clock_monotonic_t timestamp_begin;\n"
1690 " uint64_clock_monotonic_t timestamp_end;\n"
1691 " uint64_t content_size;\n"
1692 " uint64_t packet_size;\n"
1693 " unsigned long events_discarded;\n"
1694 " uint32_t cpu_id;\n"
1701 * id: range: 0 - 30.
1702 * id 31 is reserved to indicate an extended header.
1705 * id: range: 0 - 65534.
1706 * id 65535 is reserved to indicate an extended header.
1708 * Must be called with sessions_mutex held.
1711 int _lttng_event_header_declare(struct lttng_session
*session
)
1713 return lttng_metadata_printf(session
,
1714 "struct event_header_compact {\n"
1715 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1718 " uint27_clock_monotonic_t timestamp;\n"
1722 " uint64_clock_monotonic_t timestamp;\n"
1727 "struct event_header_large {\n"
1728 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1731 " uint32_clock_monotonic_t timestamp;\n"
1735 " uint64_clock_monotonic_t timestamp;\n"
1739 lttng_alignof(uint32_t) * CHAR_BIT
,
1740 lttng_alignof(uint16_t) * CHAR_BIT
1745 * Approximation of NTP time of day to clock monotonic correlation,
1746 * taken at start of trace.
1747 * Yes, this is only an approximation. Yes, we can (and will) do better
1748 * in future versions.
1751 uint64_t measure_clock_offset(void)
1753 uint64_t offset
, monotonic
[2], realtime
;
1754 struct timespec rts
= { 0, 0 };
1755 unsigned long flags
;
1757 /* Disable interrupts to increase correlation precision. */
1758 local_irq_save(flags
);
1759 monotonic
[0] = trace_clock_read64();
1760 getnstimeofday(&rts
);
1761 monotonic
[1] = trace_clock_read64();
1762 local_irq_restore(flags
);
1764 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1765 realtime
= (uint64_t) rts
.tv_sec
* NSEC_PER_SEC
;
1766 realtime
+= rts
.tv_nsec
;
1767 offset
= realtime
- offset
;
1772 * Output metadata into this session's metadata buffers.
1773 * Must be called with sessions_mutex held.
1776 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1778 unsigned char *uuid_c
= session
->uuid
.b
;
1779 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
1780 struct lttng_channel
*chan
;
1781 struct lttng_event
*event
;
1784 if (!ACCESS_ONCE(session
->active
))
1786 if (session
->metadata_dumped
)
1789 snprintf(uuid_s
, sizeof(uuid_s
),
1790 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1791 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1792 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1793 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1794 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1796 ret
= lttng_metadata_printf(session
,
1797 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1798 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1799 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1800 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1801 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1802 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1803 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1809 " byte_order = %s;\n"
1810 " packet.header := struct {\n"
1811 " uint32_t magic;\n"
1812 " uint8_t uuid[16];\n"
1813 " uint32_t stream_id;\n"
1816 lttng_alignof(uint8_t) * CHAR_BIT
,
1817 lttng_alignof(uint16_t) * CHAR_BIT
,
1818 lttng_alignof(uint32_t) * CHAR_BIT
,
1819 lttng_alignof(uint64_t) * CHAR_BIT
,
1820 sizeof(unsigned long) * CHAR_BIT
,
1821 lttng_alignof(unsigned long) * CHAR_BIT
,
1834 ret
= lttng_metadata_printf(session
,
1836 " hostname = \"%s\";\n"
1837 " domain = \"kernel\";\n"
1838 " sysname = \"%s\";\n"
1839 " kernel_release = \"%s\";\n"
1840 " kernel_version = \"%s\";\n"
1841 " tracer_name = \"lttng-modules\";\n"
1842 " tracer_major = %d;\n"
1843 " tracer_minor = %d;\n"
1844 " tracer_patchlevel = %d;\n"
1846 current
->nsproxy
->uts_ns
->name
.nodename
,
1850 LTTNG_MODULES_MAJOR_VERSION
,
1851 LTTNG_MODULES_MINOR_VERSION
,
1852 LTTNG_MODULES_PATCHLEVEL_VERSION
1857 ret
= lttng_metadata_printf(session
,
1865 if (!trace_clock_uuid(clock_uuid_s
)) {
1866 ret
= lttng_metadata_printf(session
,
1867 " uuid = \"%s\";\n",
1874 ret
= lttng_metadata_printf(session
,
1875 " description = \"Monotonic Clock\";\n"
1876 " freq = %llu; /* Frequency, in Hz */\n"
1877 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1880 (unsigned long long) trace_clock_freq(),
1881 (unsigned long long) measure_clock_offset()
1886 ret
= lttng_metadata_printf(session
,
1887 "typealias integer {\n"
1888 " size = 27; align = 1; signed = false;\n"
1889 " map = clock.monotonic.value;\n"
1890 "} := uint27_clock_monotonic_t;\n"
1892 "typealias integer {\n"
1893 " size = 32; align = %u; signed = false;\n"
1894 " map = clock.monotonic.value;\n"
1895 "} := uint32_clock_monotonic_t;\n"
1897 "typealias integer {\n"
1898 " size = 64; align = %u; signed = false;\n"
1899 " map = clock.monotonic.value;\n"
1900 "} := uint64_clock_monotonic_t;\n\n",
1901 lttng_alignof(uint32_t) * CHAR_BIT
,
1902 lttng_alignof(uint64_t) * CHAR_BIT
1907 ret
= _lttng_stream_packet_context_declare(session
);
1911 ret
= _lttng_event_header_declare(session
);
1916 list_for_each_entry(chan
, &session
->chan
, list
) {
1917 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1922 list_for_each_entry(event
, &session
->events
, list
) {
1923 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1927 session
->metadata_dumped
= 1;
1933 * lttng_transport_register - LTT transport registration
1934 * @transport: transport structure
1936 * Registers a transport which can be used as output to extract the data out of
1937 * LTTng. The module calling this registration function must ensure that no
1938 * trap-inducing code will be executed by the transport functions. E.g.
1939 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
1940 * is made visible to the transport function. This registration acts as a
1941 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
1942 * after its registration must it synchronize the TLBs.
1944 void lttng_transport_register(struct lttng_transport
*transport
)
1947 * Make sure no page fault can be triggered by the module about to be
1948 * registered. We deal with this here so we don't have to call
1949 * vmalloc_sync_all() in each module's init.
1951 wrapper_vmalloc_sync_all();
1953 mutex_lock(&sessions_mutex
);
1954 list_add_tail(&transport
->node
, <tng_transport_list
);
1955 mutex_unlock(&sessions_mutex
);
1957 EXPORT_SYMBOL_GPL(lttng_transport_register
);
1960 * lttng_transport_unregister - LTT transport unregistration
1961 * @transport: transport structure
1963 void lttng_transport_unregister(struct lttng_transport
*transport
)
1965 mutex_lock(&sessions_mutex
);
1966 list_del(&transport
->node
);
1967 mutex_unlock(&sessions_mutex
);
1969 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
1971 static int __init
lttng_events_init(void)
1975 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
1979 ret
= lttng_tracepoint_init();
1982 event_cache
= KMEM_CACHE(lttng_event
, 0);
1987 ret
= lttng_abi_init();
1990 ret
= lttng_logger_init();
1998 kmem_cache_destroy(event_cache
);
2000 lttng_tracepoint_exit();
2004 module_init(lttng_events_init
);
2006 static void __exit
lttng_events_exit(void)
2008 struct lttng_session
*session
, *tmpsession
;
2010 lttng_logger_exit();
2012 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
2013 lttng_session_destroy(session
);
2014 kmem_cache_destroy(event_cache
);
2015 lttng_tracepoint_exit();
2018 module_exit(lttng_events_exit
);
2020 MODULE_LICENSE("GPL and additional rights");
2021 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
2022 MODULE_DESCRIPTION("LTTng Events");
2023 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
2024 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
2025 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
2026 LTTNG_MODULES_EXTRAVERSION
);