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"
48 #include "wrapper/ringbuffer/backend.h"
49 #include "wrapper/ringbuffer/frontend.h"
51 #define METADATA_CACHE_DEFAULT_SIZE 4096
53 static LIST_HEAD(sessions
);
54 static LIST_HEAD(lttng_transport_list
);
56 * Protect the sessions and metadata caches.
58 static DEFINE_MUTEX(sessions_mutex
);
59 static struct kmem_cache
*event_cache
;
61 static void _lttng_event_destroy(struct lttng_event
*event
);
62 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
63 static int _lttng_event_unregister(struct lttng_event
*event
);
65 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
66 struct lttng_channel
*chan
,
67 struct lttng_event
*event
);
69 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
71 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
73 void synchronize_trace(void)
76 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
77 #ifdef CONFIG_PREEMPT_RT_FULL
80 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
81 #ifdef CONFIG_PREEMPT_RT
84 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
87 struct lttng_session
*lttng_session_create(void)
89 struct lttng_session
*session
;
90 struct lttng_metadata_cache
*metadata_cache
;
92 mutex_lock(&sessions_mutex
);
93 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
96 INIT_LIST_HEAD(&session
->chan
);
97 INIT_LIST_HEAD(&session
->events
);
98 uuid_le_gen(&session
->uuid
);
100 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
103 goto err_free_session
;
104 metadata_cache
->data
= lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE
);
105 if (!metadata_cache
->data
)
107 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
108 kref_init(&metadata_cache
->refcount
);
109 mutex_init(&metadata_cache
->lock
);
110 session
->metadata_cache
= metadata_cache
;
111 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
112 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
113 sizeof(metadata_cache
->uuid
));
114 list_add(&session
->list
, &sessions
);
115 mutex_unlock(&sessions_mutex
);
119 kfree(metadata_cache
);
123 mutex_unlock(&sessions_mutex
);
127 void metadata_cache_destroy(struct kref
*kref
)
129 struct lttng_metadata_cache
*cache
=
130 container_of(kref
, struct lttng_metadata_cache
, refcount
);
135 void lttng_session_destroy(struct lttng_session
*session
)
137 struct lttng_channel
*chan
, *tmpchan
;
138 struct lttng_event
*event
, *tmpevent
;
139 struct lttng_metadata_stream
*metadata_stream
;
142 mutex_lock(&sessions_mutex
);
143 ACCESS_ONCE(session
->active
) = 0;
144 list_for_each_entry(chan
, &session
->chan
, list
) {
145 ret
= lttng_syscalls_unregister(chan
);
148 list_for_each_entry(event
, &session
->events
, list
) {
149 ret
= _lttng_event_unregister(event
);
152 synchronize_trace(); /* Wait for in-flight events to complete */
153 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
154 _lttng_event_destroy(event
);
155 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
156 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
157 _lttng_channel_destroy(chan
);
159 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
160 _lttng_metadata_channel_hangup(metadata_stream
);
161 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
162 list_del(&session
->list
);
163 mutex_unlock(&sessions_mutex
);
167 int lttng_session_enable(struct lttng_session
*session
)
170 struct lttng_channel
*chan
;
172 mutex_lock(&sessions_mutex
);
173 if (session
->active
) {
179 * Snapshot the number of events per channel to know the type of header
182 list_for_each_entry(chan
, &session
->chan
, list
) {
183 if (chan
->header_type
)
184 continue; /* don't change it if session stop/restart */
185 if (chan
->free_event_id
< 31)
186 chan
->header_type
= 1; /* compact */
188 chan
->header_type
= 2; /* large */
191 /* Clear each stream's quiescent state. */
192 list_for_each_entry(chan
, &session
->chan
, list
)
193 lib_ring_buffer_clear_quiescent_channel(chan
->chan
);
195 ACCESS_ONCE(session
->active
) = 1;
196 ACCESS_ONCE(session
->been_active
) = 1;
197 ret
= _lttng_session_metadata_statedump(session
);
199 ACCESS_ONCE(session
->active
) = 0;
202 ret
= lttng_statedump_start(session
);
204 ACCESS_ONCE(session
->active
) = 0;
206 mutex_unlock(&sessions_mutex
);
210 int lttng_session_disable(struct lttng_session
*session
)
213 struct lttng_channel
*chan
;
215 mutex_lock(&sessions_mutex
);
216 if (!session
->active
) {
220 ACCESS_ONCE(session
->active
) = 0;
222 /* Set each stream's quiescent state. */
223 list_for_each_entry(chan
, &session
->chan
, list
)
224 lib_ring_buffer_set_quiescent_channel(chan
->chan
);
227 mutex_unlock(&sessions_mutex
);
231 int lttng_channel_enable(struct lttng_channel
*channel
)
235 if (channel
->channel_type
== METADATA_CHANNEL
)
237 old
= xchg(&channel
->enabled
, 1);
243 int lttng_channel_disable(struct lttng_channel
*channel
)
247 if (channel
->channel_type
== METADATA_CHANNEL
)
249 old
= xchg(&channel
->enabled
, 0);
255 int lttng_event_enable(struct lttng_event
*event
)
259 if (event
->chan
->channel_type
== METADATA_CHANNEL
)
261 old
= xchg(&event
->enabled
, 1);
267 int lttng_event_disable(struct lttng_event
*event
)
271 if (event
->chan
->channel_type
== METADATA_CHANNEL
)
273 old
= xchg(&event
->enabled
, 0);
279 static struct lttng_transport
*lttng_transport_find(const char *name
)
281 struct lttng_transport
*transport
;
283 list_for_each_entry(transport
, <tng_transport_list
, node
) {
284 if (!strcmp(transport
->name
, name
))
290 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
291 const char *transport_name
,
293 size_t subbuf_size
, size_t num_subbuf
,
294 unsigned int switch_timer_interval
,
295 unsigned int read_timer_interval
,
296 enum channel_type channel_type
)
298 struct lttng_channel
*chan
;
299 struct lttng_transport
*transport
= NULL
;
301 mutex_lock(&sessions_mutex
);
302 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
303 goto active
; /* Refuse to add channel to active session */
304 transport
= lttng_transport_find(transport_name
);
306 printk(KERN_WARNING
"LTTng transport %s not found\n",
310 if (!try_module_get(transport
->owner
)) {
311 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
314 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
317 chan
->session
= session
;
318 chan
->id
= session
->free_chan_id
++;
319 chan
->ops
= &transport
->ops
;
321 * Note: the channel creation op already writes into the packet
322 * headers. Therefore the "chan" information used as input
323 * should be already accessible.
325 chan
->chan
= transport
->ops
.channel_create(transport_name
,
326 chan
, buf_addr
, subbuf_size
, num_subbuf
,
327 switch_timer_interval
, read_timer_interval
);
331 chan
->transport
= transport
;
332 chan
->channel_type
= channel_type
;
333 list_add(&chan
->list
, &session
->chan
);
334 mutex_unlock(&sessions_mutex
);
341 module_put(transport
->owner
);
344 mutex_unlock(&sessions_mutex
);
349 * Only used internally at session destruction for per-cpu channels, and
350 * when metadata channel is released.
351 * Needs to be called with sessions mutex held.
354 void _lttng_channel_destroy(struct lttng_channel
*chan
)
356 chan
->ops
->channel_destroy(chan
->chan
);
357 module_put(chan
->transport
->owner
);
358 list_del(&chan
->list
);
359 lttng_destroy_context(chan
->ctx
);
363 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
365 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
367 /* Protect the metadata cache with the sessions_mutex. */
368 mutex_lock(&sessions_mutex
);
369 _lttng_channel_destroy(chan
);
370 mutex_unlock(&sessions_mutex
);
372 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
375 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
377 stream
->finalized
= 1;
378 wake_up_interruptible(&stream
->read_wait
);
382 * Supports event creation while tracing session is active.
384 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
385 struct lttng_kernel_event
*event_param
,
387 const struct lttng_event_desc
*internal_desc
)
389 struct lttng_event
*event
;
392 mutex_lock(&sessions_mutex
);
393 if (chan
->free_event_id
== -1U) {
398 * This is O(n^2) (for each event, the loop is called at event
399 * creation). Might require a hash if we have lots of events.
401 list_for_each_entry(event
, &chan
->session
->events
, list
) {
402 if (!strcmp(event
->desc
->name
, event_param
->name
)) {
404 * Allow events with the same name to appear in
405 * different channels.
407 if (event
->chan
== chan
) {
413 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
419 event
->filter
= filter
;
420 event
->id
= chan
->free_event_id
++;
422 event
->instrumentation
= event_param
->instrumentation
;
423 /* Populate lttng_event structure before tracepoint registration. */
425 switch (event_param
->instrumentation
) {
426 case LTTNG_KERNEL_TRACEPOINT
:
427 event
->desc
= lttng_event_get(event_param
->name
);
432 ret
= lttng_wrapper_tracepoint_probe_register(event
->desc
->kname
,
433 event
->desc
->probe_callback
,
440 case LTTNG_KERNEL_KPROBE
:
441 ret
= lttng_kprobes_register(event_param
->name
,
442 event_param
->u
.kprobe
.symbol_name
,
443 event_param
->u
.kprobe
.offset
,
444 event_param
->u
.kprobe
.addr
,
450 ret
= try_module_get(event
->desc
->owner
);
453 case LTTNG_KERNEL_KRETPROBE
:
455 struct lttng_event
*event_return
;
457 /* kretprobe defines 2 events */
459 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
464 event_return
->chan
= chan
;
465 event_return
->filter
= filter
;
466 event_return
->id
= chan
->free_event_id
++;
467 event_return
->enabled
= 1;
468 event_return
->instrumentation
= event_param
->instrumentation
;
470 * Populate lttng_event structure before kretprobe registration.
473 ret
= lttng_kretprobes_register(event_param
->name
,
474 event_param
->u
.kretprobe
.symbol_name
,
475 event_param
->u
.kretprobe
.offset
,
476 event_param
->u
.kretprobe
.addr
,
477 event
, event_return
);
479 kmem_cache_free(event_cache
, event_return
);
483 /* Take 2 refs on the module: one per event. */
484 ret
= try_module_get(event
->desc
->owner
);
486 ret
= try_module_get(event
->desc
->owner
);
488 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
490 WARN_ON_ONCE(ret
> 0);
492 kmem_cache_free(event_cache
, event_return
);
493 module_put(event
->desc
->owner
);
494 module_put(event
->desc
->owner
);
495 goto statedump_error
;
497 list_add(&event_return
->list
, &chan
->session
->events
);
500 case LTTNG_KERNEL_FUNCTION
:
501 ret
= lttng_ftrace_register(event_param
->name
,
502 event_param
->u
.ftrace
.symbol_name
,
507 ret
= try_module_get(event
->desc
->owner
);
510 case LTTNG_KERNEL_NOOP
:
511 event
->desc
= internal_desc
;
522 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
523 WARN_ON_ONCE(ret
> 0);
525 goto statedump_error
;
527 list_add(&event
->list
, &chan
->session
->events
);
528 mutex_unlock(&sessions_mutex
);
532 /* If a statedump error occurs, events will not be readable. */
534 kmem_cache_free(event_cache
, event
);
538 mutex_unlock(&sessions_mutex
);
543 * Only used internally at session destruction.
545 int _lttng_event_unregister(struct lttng_event
*event
)
549 switch (event
->instrumentation
) {
550 case LTTNG_KERNEL_TRACEPOINT
:
551 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
552 event
->desc
->probe_callback
,
557 case LTTNG_KERNEL_KPROBE
:
558 lttng_kprobes_unregister(event
);
561 case LTTNG_KERNEL_KRETPROBE
:
562 lttng_kretprobes_unregister(event
);
565 case LTTNG_KERNEL_FUNCTION
:
566 lttng_ftrace_unregister(event
);
569 case LTTNG_KERNEL_NOOP
:
579 * Only used internally at session destruction.
582 void _lttng_event_destroy(struct lttng_event
*event
)
584 switch (event
->instrumentation
) {
585 case LTTNG_KERNEL_TRACEPOINT
:
586 lttng_event_put(event
->desc
);
588 case LTTNG_KERNEL_KPROBE
:
589 module_put(event
->desc
->owner
);
590 lttng_kprobes_destroy_private(event
);
592 case LTTNG_KERNEL_KRETPROBE
:
593 module_put(event
->desc
->owner
);
594 lttng_kretprobes_destroy_private(event
);
596 case LTTNG_KERNEL_FUNCTION
:
597 module_put(event
->desc
->owner
);
598 lttng_ftrace_destroy_private(event
);
600 case LTTNG_KERNEL_NOOP
:
605 list_del(&event
->list
);
606 lttng_destroy_context(event
->ctx
);
607 kmem_cache_free(event_cache
, event
);
611 * Serialize at most one packet worth of metadata into a metadata
613 * We grab the metadata cache mutex to get exclusive access to our metadata
614 * buffer and to the metadata cache. Exclusive access to the metadata buffer
615 * allows us to do racy operations such as looking for remaining space left in
616 * packet and write, since mutual exclusion protects us from concurrent writes.
617 * Mutual exclusion on the metadata cache allow us to read the cache content
618 * without racing against reallocation of the cache by updates.
619 * Returns the number of bytes written in the channel, 0 if no data
620 * was written and a negative value on error.
622 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
623 struct channel
*chan
)
625 struct lib_ring_buffer_ctx ctx
;
627 size_t len
, reserve_len
;
630 * Ensure we support mutiple get_next / put sequences followed by
631 * put_next. The metadata cache lock protects reading the metadata
632 * cache. It can indeed be read concurrently by "get_next_subbuf" and
633 * "flush" operations on the buffer invoked by different processes.
634 * Moreover, since the metadata cache memory can be reallocated, we
635 * need to have exclusive access against updates even though we only
638 mutex_lock(&stream
->metadata_cache
->lock
);
639 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
640 if (stream
->metadata_in
!= stream
->metadata_out
)
643 len
= stream
->metadata_cache
->metadata_written
-
647 reserve_len
= min_t(size_t,
648 stream
->transport
->ops
.packet_avail_size(chan
),
650 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
653 * If reservation failed, return an error to the caller.
655 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
657 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
660 stream
->transport
->ops
.event_write(&ctx
,
661 stream
->metadata_cache
->data
+ stream
->metadata_in
,
663 stream
->transport
->ops
.event_commit(&ctx
);
664 stream
->metadata_in
+= reserve_len
;
668 mutex_unlock(&stream
->metadata_cache
->lock
);
673 * Write the metadata to the metadata cache.
674 * Must be called with sessions_mutex held.
675 * The metadata cache lock protects us from concurrent read access from
676 * thread outputting metadata content to ring buffer.
678 int lttng_metadata_printf(struct lttng_session
*session
,
679 const char *fmt
, ...)
684 struct lttng_metadata_stream
*stream
;
686 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
689 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
695 mutex_lock(&session
->metadata_cache
->lock
);
696 if (session
->metadata_cache
->metadata_written
+ len
>
697 session
->metadata_cache
->cache_alloc
) {
698 char *tmp_cache_realloc
;
699 unsigned int tmp_cache_alloc_size
;
701 tmp_cache_alloc_size
= max_t(unsigned int,
702 session
->metadata_cache
->cache_alloc
+ len
,
703 session
->metadata_cache
->cache_alloc
<< 1);
704 tmp_cache_realloc
= lttng_vzalloc(tmp_cache_alloc_size
);
705 if (!tmp_cache_realloc
)
707 if (session
->metadata_cache
->data
) {
708 memcpy(tmp_cache_realloc
,
709 session
->metadata_cache
->data
,
710 session
->metadata_cache
->cache_alloc
);
711 vfree(session
->metadata_cache
->data
);
714 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
715 session
->metadata_cache
->data
= tmp_cache_realloc
;
717 memcpy(session
->metadata_cache
->data
+
718 session
->metadata_cache
->metadata_written
,
720 session
->metadata_cache
->metadata_written
+= len
;
721 mutex_unlock(&session
->metadata_cache
->lock
);
724 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
725 wake_up_interruptible(&stream
->read_wait
);
730 mutex_unlock(&session
->metadata_cache
->lock
);
736 * Must be called with sessions_mutex held.
739 int _lttng_field_statedump(struct lttng_session
*session
,
740 const struct lttng_event_field
*field
)
744 switch (field
->type
.atype
) {
746 ret
= lttng_metadata_printf(session
,
747 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
748 field
->type
.u
.basic
.integer
.size
,
749 field
->type
.u
.basic
.integer
.alignment
,
750 field
->type
.u
.basic
.integer
.signedness
,
751 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
753 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
756 field
->type
.u
.basic
.integer
.base
,
758 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
760 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
765 ret
= lttng_metadata_printf(session
,
767 field
->type
.u
.basic
.enumeration
.name
,
772 const struct lttng_basic_type
*elem_type
;
774 elem_type
= &field
->type
.u
.array
.elem_type
;
775 ret
= lttng_metadata_printf(session
,
776 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
777 elem_type
->u
.basic
.integer
.size
,
778 elem_type
->u
.basic
.integer
.alignment
,
779 elem_type
->u
.basic
.integer
.signedness
,
780 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
782 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
785 elem_type
->u
.basic
.integer
.base
,
787 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
789 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
791 field
->name
, field
->type
.u
.array
.length
);
796 const struct lttng_basic_type
*elem_type
;
797 const struct lttng_basic_type
*length_type
;
799 elem_type
= &field
->type
.u
.sequence
.elem_type
;
800 length_type
= &field
->type
.u
.sequence
.length_type
;
801 ret
= lttng_metadata_printf(session
,
802 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
803 length_type
->u
.basic
.integer
.size
,
804 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
805 length_type
->u
.basic
.integer
.signedness
,
806 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
808 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
811 length_type
->u
.basic
.integer
.base
,
813 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
815 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
821 ret
= lttng_metadata_printf(session
,
822 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
823 elem_type
->u
.basic
.integer
.size
,
824 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
825 elem_type
->u
.basic
.integer
.signedness
,
826 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
828 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
831 elem_type
->u
.basic
.integer
.base
,
833 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
835 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
843 /* Default encoding is UTF8 */
844 ret
= lttng_metadata_printf(session
,
846 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
847 " { encoding = ASCII; }" : "",
858 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
859 struct lttng_ctx
*ctx
)
866 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
867 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
869 ret
= _lttng_field_statedump(session
, &field
->event_field
);
877 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
878 struct lttng_event
*event
)
880 const struct lttng_event_desc
*desc
= event
->desc
;
884 for (i
= 0; i
< desc
->nr_fields
; i
++) {
885 const struct lttng_event_field
*field
= &desc
->fields
[i
];
887 ret
= _lttng_field_statedump(session
, field
);
895 * Must be called with sessions_mutex held.
898 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
899 struct lttng_channel
*chan
,
900 struct lttng_event
*event
)
904 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
906 if (chan
->channel_type
== METADATA_CHANNEL
)
909 ret
= lttng_metadata_printf(session
,
913 " stream_id = %u;\n",
921 ret
= lttng_metadata_printf(session
,
922 " context := struct {\n");
926 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
930 ret
= lttng_metadata_printf(session
,
936 ret
= lttng_metadata_printf(session
,
937 " fields := struct {\n"
942 ret
= _lttng_fields_metadata_statedump(session
, event
);
947 * LTTng space reservation can only reserve multiples of the
950 ret
= lttng_metadata_printf(session
,
956 event
->metadata_dumped
= 1;
963 * Must be called with sessions_mutex held.
966 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
967 struct lttng_channel
*chan
)
971 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
974 if (chan
->channel_type
== METADATA_CHANNEL
)
977 WARN_ON_ONCE(!chan
->header_type
);
978 ret
= lttng_metadata_printf(session
,
981 " event.header := %s;\n"
982 " packet.context := struct packet_context;\n",
984 chan
->header_type
== 1 ? "struct event_header_compact" :
985 "struct event_header_large");
990 ret
= lttng_metadata_printf(session
,
991 " event.context := struct {\n");
995 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
999 ret
= lttng_metadata_printf(session
,
1005 ret
= lttng_metadata_printf(session
,
1008 chan
->metadata_dumped
= 1;
1014 * Must be called with sessions_mutex held.
1017 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1019 return lttng_metadata_printf(session
,
1020 "struct packet_context {\n"
1021 " uint64_clock_monotonic_t timestamp_begin;\n"
1022 " uint64_clock_monotonic_t timestamp_end;\n"
1023 " uint64_t content_size;\n"
1024 " uint64_t packet_size;\n"
1025 " unsigned long events_discarded;\n"
1026 " uint32_t cpu_id;\n"
1033 * id: range: 0 - 30.
1034 * id 31 is reserved to indicate an extended header.
1037 * id: range: 0 - 65534.
1038 * id 65535 is reserved to indicate an extended header.
1040 * Must be called with sessions_mutex held.
1043 int _lttng_event_header_declare(struct lttng_session
*session
)
1045 return lttng_metadata_printf(session
,
1046 "struct event_header_compact {\n"
1047 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1050 " uint27_clock_monotonic_t timestamp;\n"
1054 " uint64_clock_monotonic_t timestamp;\n"
1059 "struct event_header_large {\n"
1060 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1063 " uint32_clock_monotonic_t timestamp;\n"
1067 " uint64_clock_monotonic_t timestamp;\n"
1071 lttng_alignof(uint32_t) * CHAR_BIT
,
1072 lttng_alignof(uint16_t) * CHAR_BIT
1077 * Approximation of NTP time of day to clock monotonic correlation,
1078 * taken at start of trace.
1079 * Yes, this is only an approximation. Yes, we can (and will) do better
1080 * in future versions.
1083 uint64_t measure_clock_offset(void)
1085 uint64_t offset
, monotonic
[2], realtime
;
1086 struct timespec rts
= { 0, 0 };
1087 unsigned long flags
;
1089 /* Disable interrupts to increase correlation precision. */
1090 local_irq_save(flags
);
1091 monotonic
[0] = trace_clock_read64();
1092 getnstimeofday(&rts
);
1093 monotonic
[1] = trace_clock_read64();
1094 local_irq_restore(flags
);
1096 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1097 realtime
= (uint64_t) rts
.tv_sec
* NSEC_PER_SEC
;
1098 realtime
+= rts
.tv_nsec
;
1099 offset
= realtime
- offset
;
1104 * Output metadata into this session's metadata buffers.
1105 * Must be called with sessions_mutex held.
1108 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1110 unsigned char *uuid_c
= session
->uuid
.b
;
1111 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
1112 struct lttng_channel
*chan
;
1113 struct lttng_event
*event
;
1116 if (!ACCESS_ONCE(session
->active
))
1118 if (session
->metadata_dumped
)
1121 snprintf(uuid_s
, sizeof(uuid_s
),
1122 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1123 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1124 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1125 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1126 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1128 ret
= lttng_metadata_printf(session
,
1129 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1130 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1131 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1132 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1133 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1134 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1135 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1141 " byte_order = %s;\n"
1142 " packet.header := struct {\n"
1143 " uint32_t magic;\n"
1144 " uint8_t uuid[16];\n"
1145 " uint32_t stream_id;\n"
1148 lttng_alignof(uint8_t) * CHAR_BIT
,
1149 lttng_alignof(uint16_t) * CHAR_BIT
,
1150 lttng_alignof(uint32_t) * CHAR_BIT
,
1151 lttng_alignof(uint64_t) * CHAR_BIT
,
1152 sizeof(unsigned long) * CHAR_BIT
,
1153 lttng_alignof(unsigned long) * CHAR_BIT
,
1166 ret
= lttng_metadata_printf(session
,
1168 " hostname = \"%s\";\n"
1169 " domain = \"kernel\";\n"
1170 " sysname = \"%s\";\n"
1171 " kernel_release = \"%s\";\n"
1172 " kernel_version = \"%s\";\n"
1173 " tracer_name = \"lttng-modules\";\n"
1174 " tracer_major = %d;\n"
1175 " tracer_minor = %d;\n"
1176 " tracer_patchlevel = %d;\n"
1178 current
->nsproxy
->uts_ns
->name
.nodename
,
1182 LTTNG_MODULES_MAJOR_VERSION
,
1183 LTTNG_MODULES_MINOR_VERSION
,
1184 LTTNG_MODULES_PATCHLEVEL_VERSION
1189 ret
= lttng_metadata_printf(session
,
1197 if (!trace_clock_uuid(clock_uuid_s
)) {
1198 ret
= lttng_metadata_printf(session
,
1199 " uuid = \"%s\";\n",
1206 ret
= lttng_metadata_printf(session
,
1207 " description = \"Monotonic Clock\";\n"
1208 " freq = %llu; /* Frequency, in Hz */\n"
1209 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1212 (unsigned long long) trace_clock_freq(),
1213 (unsigned long long) measure_clock_offset()
1218 ret
= lttng_metadata_printf(session
,
1219 "typealias integer {\n"
1220 " size = 27; align = 1; signed = false;\n"
1221 " map = clock.monotonic.value;\n"
1222 "} := uint27_clock_monotonic_t;\n"
1224 "typealias integer {\n"
1225 " size = 32; align = %u; signed = false;\n"
1226 " map = clock.monotonic.value;\n"
1227 "} := uint32_clock_monotonic_t;\n"
1229 "typealias integer {\n"
1230 " size = 64; align = %u; signed = false;\n"
1231 " map = clock.monotonic.value;\n"
1232 "} := uint64_clock_monotonic_t;\n\n",
1233 lttng_alignof(uint32_t) * CHAR_BIT
,
1234 lttng_alignof(uint64_t) * CHAR_BIT
1239 ret
= _lttng_stream_packet_context_declare(session
);
1243 ret
= _lttng_event_header_declare(session
);
1248 list_for_each_entry(chan
, &session
->chan
, list
) {
1249 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1254 list_for_each_entry(event
, &session
->events
, list
) {
1255 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1259 session
->metadata_dumped
= 1;
1265 * lttng_transport_register - LTT transport registration
1266 * @transport: transport structure
1268 * Registers a transport which can be used as output to extract the data out of
1269 * LTTng. The module calling this registration function must ensure that no
1270 * trap-inducing code will be executed by the transport functions. E.g.
1271 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
1272 * is made visible to the transport function. This registration acts as a
1273 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
1274 * after its registration must it synchronize the TLBs.
1276 void lttng_transport_register(struct lttng_transport
*transport
)
1279 * Make sure no page fault can be triggered by the module about to be
1280 * registered. We deal with this here so we don't have to call
1281 * vmalloc_sync_all() in each module's init.
1283 wrapper_vmalloc_sync_all();
1285 mutex_lock(&sessions_mutex
);
1286 list_add_tail(&transport
->node
, <tng_transport_list
);
1287 mutex_unlock(&sessions_mutex
);
1289 EXPORT_SYMBOL_GPL(lttng_transport_register
);
1292 * lttng_transport_unregister - LTT transport unregistration
1293 * @transport: transport structure
1295 void lttng_transport_unregister(struct lttng_transport
*transport
)
1297 mutex_lock(&sessions_mutex
);
1298 list_del(&transport
->node
);
1299 mutex_unlock(&sessions_mutex
);
1301 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
1303 static int __init
lttng_events_init(void)
1307 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
1310 ret
= wrapper_get_pfnblock_flags_mask_init();
1313 ret
= lttng_tracepoint_init();
1316 event_cache
= KMEM_CACHE(lttng_event
, 0);
1321 ret
= lttng_abi_init();
1324 ret
= lttng_logger_init();
1332 kmem_cache_destroy(event_cache
);
1334 lttng_tracepoint_exit();
1338 module_init(lttng_events_init
);
1340 static void __exit
lttng_events_exit(void)
1342 struct lttng_session
*session
, *tmpsession
;
1344 lttng_logger_exit();
1346 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
1347 lttng_session_destroy(session
);
1348 kmem_cache_destroy(event_cache
);
1349 lttng_tracepoint_exit();
1352 module_exit(lttng_events_exit
);
1354 MODULE_LICENSE("GPL and additional rights");
1355 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
1356 MODULE_DESCRIPTION("LTTng Events");
1357 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
1358 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
1359 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
1360 LTTNG_MODULES_EXTRAVERSION
);