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/list.h>
31 #include <linux/mutex.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/jiffies.h>
35 #include <linux/utsname.h>
36 #include <linux/err.h>
37 #include <linux/vmalloc.h>
39 #include "wrapper/uuid.h"
40 #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
41 #include "wrapper/random.h"
42 #include "wrapper/tracepoint.h"
43 #include "lttng-kernel-version.h"
44 #include "lttng-events.h"
45 #include "lttng-tracer.h"
46 #include "lttng-abi-old.h"
47 #include "wrapper/vzalloc.h"
49 #define METADATA_CACHE_DEFAULT_SIZE 4096
51 static LIST_HEAD(sessions
);
52 static LIST_HEAD(lttng_transport_list
);
54 * Protect the sessions and metadata caches.
56 static DEFINE_MUTEX(sessions_mutex
);
57 static struct kmem_cache
*event_cache
;
59 static void _lttng_event_destroy(struct lttng_event
*event
);
60 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
61 static int _lttng_event_unregister(struct lttng_event
*event
);
63 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
64 struct lttng_channel
*chan
,
65 struct lttng_event
*event
);
67 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
69 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
71 void synchronize_trace(void)
74 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
75 #ifdef CONFIG_PREEMPT_RT_FULL
78 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
79 #ifdef CONFIG_PREEMPT_RT
82 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
85 struct lttng_session
*lttng_session_create(void)
87 struct lttng_session
*session
;
88 struct lttng_metadata_cache
*metadata_cache
;
90 mutex_lock(&sessions_mutex
);
91 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
94 INIT_LIST_HEAD(&session
->chan
);
95 INIT_LIST_HEAD(&session
->events
);
96 uuid_le_gen(&session
->uuid
);
98 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
101 goto err_free_session
;
102 metadata_cache
->data
= lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE
);
103 if (!metadata_cache
->data
)
105 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
106 kref_init(&metadata_cache
->refcount
);
107 mutex_init(&metadata_cache
->lock
);
108 session
->metadata_cache
= metadata_cache
;
109 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
110 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
111 sizeof(metadata_cache
->uuid
));
112 list_add(&session
->list
, &sessions
);
113 mutex_unlock(&sessions_mutex
);
117 kfree(metadata_cache
);
121 mutex_unlock(&sessions_mutex
);
125 void metadata_cache_destroy(struct kref
*kref
)
127 struct lttng_metadata_cache
*cache
=
128 container_of(kref
, struct lttng_metadata_cache
, refcount
);
133 void lttng_session_destroy(struct lttng_session
*session
)
135 struct lttng_channel
*chan
, *tmpchan
;
136 struct lttng_event
*event
, *tmpevent
;
137 struct lttng_metadata_stream
*metadata_stream
;
140 mutex_lock(&sessions_mutex
);
141 ACCESS_ONCE(session
->active
) = 0;
142 list_for_each_entry(chan
, &session
->chan
, list
) {
143 ret
= lttng_syscalls_unregister(chan
);
146 list_for_each_entry(event
, &session
->events
, list
) {
147 ret
= _lttng_event_unregister(event
);
150 synchronize_trace(); /* Wait for in-flight events to complete */
151 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
152 _lttng_event_destroy(event
);
153 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
154 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
155 _lttng_channel_destroy(chan
);
157 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
158 _lttng_metadata_channel_hangup(metadata_stream
);
159 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
160 list_del(&session
->list
);
161 mutex_unlock(&sessions_mutex
);
165 int lttng_session_enable(struct lttng_session
*session
)
168 struct lttng_channel
*chan
;
170 mutex_lock(&sessions_mutex
);
171 if (session
->active
) {
177 * Snapshot the number of events per channel to know the type of header
180 list_for_each_entry(chan
, &session
->chan
, list
) {
181 if (chan
->header_type
)
182 continue; /* don't change it if session stop/restart */
183 if (chan
->free_event_id
< 31)
184 chan
->header_type
= 1; /* compact */
186 chan
->header_type
= 2; /* large */
189 ACCESS_ONCE(session
->active
) = 1;
190 ACCESS_ONCE(session
->been_active
) = 1;
191 ret
= _lttng_session_metadata_statedump(session
);
193 ACCESS_ONCE(session
->active
) = 0;
196 ret
= lttng_statedump_start(session
);
198 ACCESS_ONCE(session
->active
) = 0;
200 mutex_unlock(&sessions_mutex
);
204 int lttng_session_disable(struct lttng_session
*session
)
208 mutex_lock(&sessions_mutex
);
209 if (!session
->active
) {
213 ACCESS_ONCE(session
->active
) = 0;
215 mutex_unlock(&sessions_mutex
);
219 int lttng_channel_enable(struct lttng_channel
*channel
)
223 if (channel
->channel_type
== METADATA_CHANNEL
)
225 old
= xchg(&channel
->enabled
, 1);
231 int lttng_channel_disable(struct lttng_channel
*channel
)
235 if (channel
->channel_type
== METADATA_CHANNEL
)
237 old
= xchg(&channel
->enabled
, 0);
243 int lttng_event_enable(struct lttng_event
*event
)
247 if (event
->chan
->channel_type
== METADATA_CHANNEL
)
249 old
= xchg(&event
->enabled
, 1);
255 int lttng_event_disable(struct lttng_event
*event
)
259 if (event
->chan
->channel_type
== METADATA_CHANNEL
)
261 old
= xchg(&event
->enabled
, 0);
267 static struct lttng_transport
*lttng_transport_find(const char *name
)
269 struct lttng_transport
*transport
;
271 list_for_each_entry(transport
, <tng_transport_list
, node
) {
272 if (!strcmp(transport
->name
, name
))
278 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
279 const char *transport_name
,
281 size_t subbuf_size
, size_t num_subbuf
,
282 unsigned int switch_timer_interval
,
283 unsigned int read_timer_interval
,
284 enum channel_type channel_type
)
286 struct lttng_channel
*chan
;
287 struct lttng_transport
*transport
= NULL
;
289 mutex_lock(&sessions_mutex
);
290 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
291 goto active
; /* Refuse to add channel to active session */
292 transport
= lttng_transport_find(transport_name
);
294 printk(KERN_WARNING
"LTTng transport %s not found\n",
298 if (!try_module_get(transport
->owner
)) {
299 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
302 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
305 chan
->session
= session
;
306 chan
->id
= session
->free_chan_id
++;
307 chan
->ops
= &transport
->ops
;
309 * Note: the channel creation op already writes into the packet
310 * headers. Therefore the "chan" information used as input
311 * should be already accessible.
313 chan
->chan
= transport
->ops
.channel_create(transport_name
,
314 chan
, buf_addr
, subbuf_size
, num_subbuf
,
315 switch_timer_interval
, read_timer_interval
);
319 chan
->transport
= transport
;
320 chan
->channel_type
= channel_type
;
321 list_add(&chan
->list
, &session
->chan
);
322 mutex_unlock(&sessions_mutex
);
329 module_put(transport
->owner
);
332 mutex_unlock(&sessions_mutex
);
337 * Only used internally at session destruction for per-cpu channels, and
338 * when metadata channel is released.
339 * Needs to be called with sessions mutex held.
342 void _lttng_channel_destroy(struct lttng_channel
*chan
)
344 chan
->ops
->channel_destroy(chan
->chan
);
345 module_put(chan
->transport
->owner
);
346 list_del(&chan
->list
);
347 lttng_destroy_context(chan
->ctx
);
351 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
353 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
355 /* Protect the metadata cache with the sessions_mutex. */
356 mutex_lock(&sessions_mutex
);
357 _lttng_channel_destroy(chan
);
358 mutex_unlock(&sessions_mutex
);
360 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
363 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
365 stream
->finalized
= 1;
366 wake_up_interruptible(&stream
->read_wait
);
370 * Supports event creation while tracing session is active.
372 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
373 struct lttng_kernel_event
*event_param
,
375 const struct lttng_event_desc
*internal_desc
)
377 struct lttng_event
*event
;
380 mutex_lock(&sessions_mutex
);
381 if (chan
->free_event_id
== -1U) {
386 * This is O(n^2) (for each event, the loop is called at event
387 * creation). Might require a hash if we have lots of events.
389 list_for_each_entry(event
, &chan
->session
->events
, list
) {
390 if (!strcmp(event
->desc
->name
, event_param
->name
)) {
395 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
401 event
->filter
= filter
;
402 event
->id
= chan
->free_event_id
++;
404 event
->instrumentation
= event_param
->instrumentation
;
405 /* Populate lttng_event structure before tracepoint registration. */
407 switch (event_param
->instrumentation
) {
408 case LTTNG_KERNEL_TRACEPOINT
:
409 event
->desc
= lttng_event_get(event_param
->name
);
414 ret
= lttng_wrapper_tracepoint_probe_register(event
->desc
->kname
,
415 event
->desc
->probe_callback
,
422 case LTTNG_KERNEL_KPROBE
:
423 ret
= lttng_kprobes_register(event_param
->name
,
424 event_param
->u
.kprobe
.symbol_name
,
425 event_param
->u
.kprobe
.offset
,
426 event_param
->u
.kprobe
.addr
,
432 ret
= try_module_get(event
->desc
->owner
);
435 case LTTNG_KERNEL_KRETPROBE
:
437 struct lttng_event
*event_return
;
439 /* kretprobe defines 2 events */
441 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
446 event_return
->chan
= chan
;
447 event_return
->filter
= filter
;
448 event_return
->id
= chan
->free_event_id
++;
449 event_return
->enabled
= 1;
450 event_return
->instrumentation
= event_param
->instrumentation
;
452 * Populate lttng_event structure before kretprobe registration.
455 ret
= lttng_kretprobes_register(event_param
->name
,
456 event_param
->u
.kretprobe
.symbol_name
,
457 event_param
->u
.kretprobe
.offset
,
458 event_param
->u
.kretprobe
.addr
,
459 event
, event_return
);
461 kmem_cache_free(event_cache
, event_return
);
465 /* Take 2 refs on the module: one per event. */
466 ret
= try_module_get(event
->desc
->owner
);
468 ret
= try_module_get(event
->desc
->owner
);
470 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
472 WARN_ON_ONCE(ret
> 0);
474 kmem_cache_free(event_cache
, event_return
);
475 module_put(event
->desc
->owner
);
476 module_put(event
->desc
->owner
);
477 goto statedump_error
;
479 list_add(&event_return
->list
, &chan
->session
->events
);
482 case LTTNG_KERNEL_FUNCTION
:
483 ret
= lttng_ftrace_register(event_param
->name
,
484 event_param
->u
.ftrace
.symbol_name
,
489 ret
= try_module_get(event
->desc
->owner
);
492 case LTTNG_KERNEL_NOOP
:
493 event
->desc
= internal_desc
;
504 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
505 WARN_ON_ONCE(ret
> 0);
507 goto statedump_error
;
509 list_add(&event
->list
, &chan
->session
->events
);
510 mutex_unlock(&sessions_mutex
);
514 /* If a statedump error occurs, events will not be readable. */
516 kmem_cache_free(event_cache
, event
);
520 mutex_unlock(&sessions_mutex
);
525 * Only used internally at session destruction.
527 int _lttng_event_unregister(struct lttng_event
*event
)
531 switch (event
->instrumentation
) {
532 case LTTNG_KERNEL_TRACEPOINT
:
533 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
534 event
->desc
->probe_callback
,
539 case LTTNG_KERNEL_KPROBE
:
540 lttng_kprobes_unregister(event
);
543 case LTTNG_KERNEL_KRETPROBE
:
544 lttng_kretprobes_unregister(event
);
547 case LTTNG_KERNEL_FUNCTION
:
548 lttng_ftrace_unregister(event
);
551 case LTTNG_KERNEL_NOOP
:
561 * Only used internally at session destruction.
564 void _lttng_event_destroy(struct lttng_event
*event
)
566 switch (event
->instrumentation
) {
567 case LTTNG_KERNEL_TRACEPOINT
:
568 lttng_event_put(event
->desc
);
570 case LTTNG_KERNEL_KPROBE
:
571 module_put(event
->desc
->owner
);
572 lttng_kprobes_destroy_private(event
);
574 case LTTNG_KERNEL_KRETPROBE
:
575 module_put(event
->desc
->owner
);
576 lttng_kretprobes_destroy_private(event
);
578 case LTTNG_KERNEL_FUNCTION
:
579 module_put(event
->desc
->owner
);
580 lttng_ftrace_destroy_private(event
);
582 case LTTNG_KERNEL_NOOP
:
587 list_del(&event
->list
);
588 lttng_destroy_context(event
->ctx
);
589 kmem_cache_free(event_cache
, event
);
593 * Serialize at most one packet worth of metadata into a metadata
595 * We grab the metadata cache mutex to get exclusive access to our metadata
596 * buffer and to the metadata cache. Exclusive access to the metadata buffer
597 * allows us to do racy operations such as looking for remaining space left in
598 * packet and write, since mutual exclusion protects us from concurrent writes.
599 * Mutual exclusion on the metadata cache allow us to read the cache content
600 * without racing against reallocation of the cache by updates.
601 * Returns the number of bytes written in the channel, 0 if no data
602 * was written and a negative value on error.
604 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
605 struct channel
*chan
)
607 struct lib_ring_buffer_ctx ctx
;
609 size_t len
, reserve_len
;
612 * Ensure we support mutiple get_next / put sequences followed by
613 * put_next. The metadata cache lock protects reading the metadata
614 * cache. It can indeed be read concurrently by "get_next_subbuf" and
615 * "flush" operations on the buffer invoked by different processes.
616 * Moreover, since the metadata cache memory can be reallocated, we
617 * need to have exclusive access against updates even though we only
620 mutex_lock(&stream
->metadata_cache
->lock
);
621 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
622 if (stream
->metadata_in
!= stream
->metadata_out
)
625 len
= stream
->metadata_cache
->metadata_written
-
629 reserve_len
= min_t(size_t,
630 stream
->transport
->ops
.packet_avail_size(chan
),
632 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
635 * If reservation failed, return an error to the caller.
637 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
639 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
642 stream
->transport
->ops
.event_write(&ctx
,
643 stream
->metadata_cache
->data
+ stream
->metadata_in
,
645 stream
->transport
->ops
.event_commit(&ctx
);
646 stream
->metadata_in
+= reserve_len
;
650 mutex_unlock(&stream
->metadata_cache
->lock
);
655 * Write the metadata to the metadata cache.
656 * Must be called with sessions_mutex held.
657 * The metadata cache lock protects us from concurrent read access from
658 * thread outputting metadata content to ring buffer.
660 int lttng_metadata_printf(struct lttng_session
*session
,
661 const char *fmt
, ...)
666 struct lttng_metadata_stream
*stream
;
668 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
671 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
677 mutex_lock(&session
->metadata_cache
->lock
);
678 if (session
->metadata_cache
->metadata_written
+ len
>
679 session
->metadata_cache
->cache_alloc
) {
680 char *tmp_cache_realloc
;
681 unsigned int tmp_cache_alloc_size
;
683 tmp_cache_alloc_size
= max_t(unsigned int,
684 session
->metadata_cache
->cache_alloc
+ len
,
685 session
->metadata_cache
->cache_alloc
<< 1);
686 tmp_cache_realloc
= lttng_vzalloc(tmp_cache_alloc_size
);
687 if (!tmp_cache_realloc
)
689 if (session
->metadata_cache
->data
) {
690 memcpy(tmp_cache_realloc
,
691 session
->metadata_cache
->data
,
692 session
->metadata_cache
->cache_alloc
);
693 vfree(session
->metadata_cache
->data
);
696 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
697 session
->metadata_cache
->data
= tmp_cache_realloc
;
699 memcpy(session
->metadata_cache
->data
+
700 session
->metadata_cache
->metadata_written
,
702 session
->metadata_cache
->metadata_written
+= len
;
703 mutex_unlock(&session
->metadata_cache
->lock
);
706 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
707 wake_up_interruptible(&stream
->read_wait
);
712 mutex_unlock(&session
->metadata_cache
->lock
);
718 * Must be called with sessions_mutex held.
721 int _lttng_field_statedump(struct lttng_session
*session
,
722 const struct lttng_event_field
*field
)
726 switch (field
->type
.atype
) {
728 ret
= lttng_metadata_printf(session
,
729 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
730 field
->type
.u
.basic
.integer
.size
,
731 field
->type
.u
.basic
.integer
.alignment
,
732 field
->type
.u
.basic
.integer
.signedness
,
733 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
735 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
738 field
->type
.u
.basic
.integer
.base
,
740 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
742 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
747 ret
= lttng_metadata_printf(session
,
749 field
->type
.u
.basic
.enumeration
.name
,
754 const struct lttng_basic_type
*elem_type
;
756 elem_type
= &field
->type
.u
.array
.elem_type
;
757 ret
= lttng_metadata_printf(session
,
758 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
759 elem_type
->u
.basic
.integer
.size
,
760 elem_type
->u
.basic
.integer
.alignment
,
761 elem_type
->u
.basic
.integer
.signedness
,
762 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
764 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
767 elem_type
->u
.basic
.integer
.base
,
769 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
771 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
773 field
->name
, field
->type
.u
.array
.length
);
778 const struct lttng_basic_type
*elem_type
;
779 const struct lttng_basic_type
*length_type
;
781 elem_type
= &field
->type
.u
.sequence
.elem_type
;
782 length_type
= &field
->type
.u
.sequence
.length_type
;
783 ret
= lttng_metadata_printf(session
,
784 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
785 length_type
->u
.basic
.integer
.size
,
786 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
787 length_type
->u
.basic
.integer
.signedness
,
788 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
790 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
793 length_type
->u
.basic
.integer
.base
,
795 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
797 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
803 ret
= lttng_metadata_printf(session
,
804 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
805 elem_type
->u
.basic
.integer
.size
,
806 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
807 elem_type
->u
.basic
.integer
.signedness
,
808 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
810 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
813 elem_type
->u
.basic
.integer
.base
,
815 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
817 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
825 /* Default encoding is UTF8 */
826 ret
= lttng_metadata_printf(session
,
828 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
829 " { encoding = ASCII; }" : "",
840 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
841 struct lttng_ctx
*ctx
)
848 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
849 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
851 ret
= _lttng_field_statedump(session
, &field
->event_field
);
859 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
860 struct lttng_event
*event
)
862 const struct lttng_event_desc
*desc
= event
->desc
;
866 for (i
= 0; i
< desc
->nr_fields
; i
++) {
867 const struct lttng_event_field
*field
= &desc
->fields
[i
];
869 ret
= _lttng_field_statedump(session
, field
);
877 * Must be called with sessions_mutex held.
880 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
881 struct lttng_channel
*chan
,
882 struct lttng_event
*event
)
886 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
888 if (chan
->channel_type
== METADATA_CHANNEL
)
891 ret
= lttng_metadata_printf(session
,
895 " stream_id = %u;\n",
903 ret
= lttng_metadata_printf(session
,
904 " context := struct {\n");
908 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
912 ret
= lttng_metadata_printf(session
,
918 ret
= lttng_metadata_printf(session
,
919 " fields := struct {\n"
924 ret
= _lttng_fields_metadata_statedump(session
, event
);
929 * LTTng space reservation can only reserve multiples of the
932 ret
= lttng_metadata_printf(session
,
938 event
->metadata_dumped
= 1;
945 * Must be called with sessions_mutex held.
948 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
949 struct lttng_channel
*chan
)
953 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
956 if (chan
->channel_type
== METADATA_CHANNEL
)
959 WARN_ON_ONCE(!chan
->header_type
);
960 ret
= lttng_metadata_printf(session
,
963 " event.header := %s;\n"
964 " packet.context := struct packet_context;\n",
966 chan
->header_type
== 1 ? "struct event_header_compact" :
967 "struct event_header_large");
972 ret
= lttng_metadata_printf(session
,
973 " event.context := struct {\n");
977 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
981 ret
= lttng_metadata_printf(session
,
987 ret
= lttng_metadata_printf(session
,
990 chan
->metadata_dumped
= 1;
996 * Must be called with sessions_mutex held.
999 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1001 return lttng_metadata_printf(session
,
1002 "struct packet_context {\n"
1003 " uint64_clock_monotonic_t timestamp_begin;\n"
1004 " uint64_clock_monotonic_t timestamp_end;\n"
1005 " uint64_t content_size;\n"
1006 " uint64_t packet_size;\n"
1007 " unsigned long events_discarded;\n"
1008 " uint32_t cpu_id;\n"
1015 * id: range: 0 - 30.
1016 * id 31 is reserved to indicate an extended header.
1019 * id: range: 0 - 65534.
1020 * id 65535 is reserved to indicate an extended header.
1022 * Must be called with sessions_mutex held.
1025 int _lttng_event_header_declare(struct lttng_session
*session
)
1027 return lttng_metadata_printf(session
,
1028 "struct event_header_compact {\n"
1029 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1032 " uint27_clock_monotonic_t timestamp;\n"
1036 " uint64_clock_monotonic_t timestamp;\n"
1041 "struct event_header_large {\n"
1042 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1045 " uint32_clock_monotonic_t timestamp;\n"
1049 " uint64_clock_monotonic_t timestamp;\n"
1053 lttng_alignof(uint32_t) * CHAR_BIT
,
1054 lttng_alignof(uint16_t) * CHAR_BIT
1059 * Approximation of NTP time of day to clock monotonic correlation,
1060 * taken at start of trace.
1061 * Yes, this is only an approximation. Yes, we can (and will) do better
1062 * in future versions.
1065 uint64_t measure_clock_offset(void)
1067 uint64_t offset
, monotonic
[2], realtime
;
1068 struct timespec rts
= { 0, 0 };
1069 unsigned long flags
;
1071 /* Disable interrupts to increase correlation precision. */
1072 local_irq_save(flags
);
1073 monotonic
[0] = trace_clock_read64();
1074 getnstimeofday(&rts
);
1075 monotonic
[1] = trace_clock_read64();
1076 local_irq_restore(flags
);
1078 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1079 realtime
= (uint64_t) rts
.tv_sec
* NSEC_PER_SEC
;
1080 realtime
+= rts
.tv_nsec
;
1081 offset
= realtime
- offset
;
1086 * Output metadata into this session's metadata buffers.
1087 * Must be called with sessions_mutex held.
1090 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1092 unsigned char *uuid_c
= session
->uuid
.b
;
1093 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
1094 struct lttng_channel
*chan
;
1095 struct lttng_event
*event
;
1098 if (!ACCESS_ONCE(session
->active
))
1100 if (session
->metadata_dumped
)
1103 snprintf(uuid_s
, sizeof(uuid_s
),
1104 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1105 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1106 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1107 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1108 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1110 ret
= lttng_metadata_printf(session
,
1111 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1112 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1113 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1114 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1115 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1116 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1117 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1123 " byte_order = %s;\n"
1124 " packet.header := struct {\n"
1125 " uint32_t magic;\n"
1126 " uint8_t uuid[16];\n"
1127 " uint32_t stream_id;\n"
1130 lttng_alignof(uint8_t) * CHAR_BIT
,
1131 lttng_alignof(uint16_t) * CHAR_BIT
,
1132 lttng_alignof(uint32_t) * CHAR_BIT
,
1133 lttng_alignof(uint64_t) * CHAR_BIT
,
1134 sizeof(unsigned long) * CHAR_BIT
,
1135 lttng_alignof(unsigned long) * CHAR_BIT
,
1148 ret
= lttng_metadata_printf(session
,
1150 " hostname = \"%s\";\n"
1151 " domain = \"kernel\";\n"
1152 " sysname = \"%s\";\n"
1153 " kernel_release = \"%s\";\n"
1154 " kernel_version = \"%s\";\n"
1155 " tracer_name = \"lttng-modules\";\n"
1156 " tracer_major = %d;\n"
1157 " tracer_minor = %d;\n"
1158 " tracer_patchlevel = %d;\n"
1160 current
->nsproxy
->uts_ns
->name
.nodename
,
1164 LTTNG_MODULES_MAJOR_VERSION
,
1165 LTTNG_MODULES_MINOR_VERSION
,
1166 LTTNG_MODULES_PATCHLEVEL_VERSION
1171 ret
= lttng_metadata_printf(session
,
1179 if (!trace_clock_uuid(clock_uuid_s
)) {
1180 ret
= lttng_metadata_printf(session
,
1181 " uuid = \"%s\";\n",
1188 ret
= lttng_metadata_printf(session
,
1189 " description = \"Monotonic Clock\";\n"
1190 " freq = %llu; /* Frequency, in Hz */\n"
1191 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1194 (unsigned long long) trace_clock_freq(),
1195 (unsigned long long) measure_clock_offset()
1200 ret
= lttng_metadata_printf(session
,
1201 "typealias integer {\n"
1202 " size = 27; align = 1; signed = false;\n"
1203 " map = clock.monotonic.value;\n"
1204 "} := uint27_clock_monotonic_t;\n"
1206 "typealias integer {\n"
1207 " size = 32; align = %u; signed = false;\n"
1208 " map = clock.monotonic.value;\n"
1209 "} := uint32_clock_monotonic_t;\n"
1211 "typealias integer {\n"
1212 " size = 64; align = %u; signed = false;\n"
1213 " map = clock.monotonic.value;\n"
1214 "} := uint64_clock_monotonic_t;\n\n",
1215 lttng_alignof(uint32_t) * CHAR_BIT
,
1216 lttng_alignof(uint64_t) * CHAR_BIT
1221 ret
= _lttng_stream_packet_context_declare(session
);
1225 ret
= _lttng_event_header_declare(session
);
1230 list_for_each_entry(chan
, &session
->chan
, list
) {
1231 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1236 list_for_each_entry(event
, &session
->events
, list
) {
1237 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1241 session
->metadata_dumped
= 1;
1247 * lttng_transport_register - LTT transport registration
1248 * @transport: transport structure
1250 * Registers a transport which can be used as output to extract the data out of
1251 * LTTng. The module calling this registration function must ensure that no
1252 * trap-inducing code will be executed by the transport functions. E.g.
1253 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
1254 * is made visible to the transport function. This registration acts as a
1255 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
1256 * after its registration must it synchronize the TLBs.
1258 void lttng_transport_register(struct lttng_transport
*transport
)
1261 * Make sure no page fault can be triggered by the module about to be
1262 * registered. We deal with this here so we don't have to call
1263 * vmalloc_sync_all() in each module's init.
1265 wrapper_vmalloc_sync_all();
1267 mutex_lock(&sessions_mutex
);
1268 list_add_tail(&transport
->node
, <tng_transport_list
);
1269 mutex_unlock(&sessions_mutex
);
1271 EXPORT_SYMBOL_GPL(lttng_transport_register
);
1274 * lttng_transport_unregister - LTT transport unregistration
1275 * @transport: transport structure
1277 void lttng_transport_unregister(struct lttng_transport
*transport
)
1279 mutex_lock(&sessions_mutex
);
1280 list_del(&transport
->node
);
1281 mutex_unlock(&sessions_mutex
);
1283 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
1285 static int __init
lttng_events_init(void)
1289 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
1292 ret
= wrapper_get_pfnblock_flags_mask_init();
1295 ret
= lttng_tracepoint_init();
1298 event_cache
= KMEM_CACHE(lttng_event
, 0);
1303 ret
= lttng_abi_init();
1306 ret
= lttng_logger_init();
1314 kmem_cache_destroy(event_cache
);
1316 lttng_tracepoint_exit();
1320 module_init(lttng_events_init
);
1322 static void __exit
lttng_events_exit(void)
1324 struct lttng_session
*session
, *tmpsession
;
1326 lttng_logger_exit();
1328 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
1329 lttng_session_destroy(session
);
1330 kmem_cache_destroy(event_cache
);
1331 lttng_tracepoint_exit();
1334 module_exit(lttng_events_exit
);
1336 MODULE_LICENSE("GPL and additional rights");
1337 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
1338 MODULE_DESCRIPTION("LTTng Events");
1339 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
1340 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
1341 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
1342 LTTNG_MODULES_EXTRAVERSION
);