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/list.h>
25 #include <linux/mutex.h>
26 #include <linux/sched.h>
27 #include <linux/slab.h>
28 #include <linux/jiffies.h>
29 #include <linux/utsname.h>
30 #include "wrapper/uuid.h"
31 #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
32 #include "wrapper/random.h"
33 #include "wrapper/tracepoint.h"
34 #include "lttng-kernel-version.h"
35 #include "lttng-events.h"
36 #include "lttng-tracer.h"
37 #include "lttng-abi-old.h"
39 #define METADATA_CACHE_DEFAULT_SIZE 4096
41 static LIST_HEAD(sessions
);
42 static LIST_HEAD(lttng_transport_list
);
44 * Protect the sessions and metadata caches.
46 static DEFINE_MUTEX(sessions_mutex
);
47 static struct kmem_cache
*event_cache
;
49 static void _lttng_event_destroy(struct lttng_event
*event
);
50 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
51 static int _lttng_event_unregister(struct lttng_event
*event
);
53 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
54 struct lttng_channel
*chan
,
55 struct lttng_event
*event
);
57 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
59 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
61 void synchronize_trace(void)
64 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
65 #ifdef CONFIG_PREEMPT_RT_FULL
68 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
69 #ifdef CONFIG_PREEMPT_RT
72 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
75 struct lttng_session
*lttng_session_create(void)
77 struct lttng_session
*session
;
78 struct lttng_metadata_cache
*metadata_cache
;
80 mutex_lock(&sessions_mutex
);
81 session
= kzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
84 INIT_LIST_HEAD(&session
->chan
);
85 INIT_LIST_HEAD(&session
->events
);
86 uuid_le_gen(&session
->uuid
);
88 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
91 goto err_free_session
;
92 metadata_cache
->data
= kzalloc(METADATA_CACHE_DEFAULT_SIZE
,
94 if (!metadata_cache
->data
)
96 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
97 kref_init(&metadata_cache
->refcount
);
98 session
->metadata_cache
= metadata_cache
;
99 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
100 list_add(&session
->list
, &sessions
);
101 mutex_unlock(&sessions_mutex
);
105 kfree(metadata_cache
);
109 mutex_unlock(&sessions_mutex
);
113 void metadata_cache_destroy(struct kref
*kref
)
115 struct lttng_metadata_cache
*cache
=
116 container_of(kref
, struct lttng_metadata_cache
, refcount
);
121 void lttng_session_destroy(struct lttng_session
*session
)
123 struct lttng_channel
*chan
, *tmpchan
;
124 struct lttng_event
*event
, *tmpevent
;
125 struct lttng_metadata_stream
*metadata_stream
;
128 mutex_lock(&sessions_mutex
);
129 ACCESS_ONCE(session
->active
) = 0;
130 list_for_each_entry(chan
, &session
->chan
, list
) {
131 ret
= lttng_syscalls_unregister(chan
);
134 list_for_each_entry(event
, &session
->events
, list
) {
135 ret
= _lttng_event_unregister(event
);
138 synchronize_trace(); /* Wait for in-flight events to complete */
139 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
140 _lttng_event_destroy(event
);
141 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
142 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
143 _lttng_channel_destroy(chan
);
145 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
146 _lttng_metadata_channel_hangup(metadata_stream
);
147 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
148 list_del(&session
->list
);
149 mutex_unlock(&sessions_mutex
);
153 int lttng_session_enable(struct lttng_session
*session
)
156 struct lttng_channel
*chan
;
158 mutex_lock(&sessions_mutex
);
159 if (session
->active
) {
165 * Snapshot the number of events per channel to know the type of header
168 list_for_each_entry(chan
, &session
->chan
, list
) {
169 if (chan
->header_type
)
170 continue; /* don't change it if session stop/restart */
171 if (chan
->free_event_id
< 31)
172 chan
->header_type
= 1; /* compact */
174 chan
->header_type
= 2; /* large */
177 ACCESS_ONCE(session
->active
) = 1;
178 ACCESS_ONCE(session
->been_active
) = 1;
179 ret
= _lttng_session_metadata_statedump(session
);
181 ACCESS_ONCE(session
->active
) = 0;
184 ret
= lttng_statedump_start(session
);
186 ACCESS_ONCE(session
->active
) = 0;
188 mutex_unlock(&sessions_mutex
);
192 int lttng_session_disable(struct lttng_session
*session
)
196 mutex_lock(&sessions_mutex
);
197 if (!session
->active
) {
201 ACCESS_ONCE(session
->active
) = 0;
203 mutex_unlock(&sessions_mutex
);
207 int lttng_channel_enable(struct lttng_channel
*channel
)
211 if (channel
->channel_type
== METADATA_CHANNEL
)
213 old
= xchg(&channel
->enabled
, 1);
219 int lttng_channel_disable(struct lttng_channel
*channel
)
223 if (channel
->channel_type
== METADATA_CHANNEL
)
225 old
= xchg(&channel
->enabled
, 0);
231 int lttng_event_enable(struct lttng_event
*event
)
235 if (event
->chan
->channel_type
== METADATA_CHANNEL
)
237 old
= xchg(&event
->enabled
, 1);
243 int lttng_event_disable(struct lttng_event
*event
)
247 if (event
->chan
->channel_type
== METADATA_CHANNEL
)
249 old
= xchg(&event
->enabled
, 0);
255 static struct lttng_transport
*lttng_transport_find(const char *name
)
257 struct lttng_transport
*transport
;
259 list_for_each_entry(transport
, <tng_transport_list
, node
) {
260 if (!strcmp(transport
->name
, name
))
266 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
267 const char *transport_name
,
269 size_t subbuf_size
, size_t num_subbuf
,
270 unsigned int switch_timer_interval
,
271 unsigned int read_timer_interval
,
272 enum channel_type channel_type
)
274 struct lttng_channel
*chan
;
275 struct lttng_transport
*transport
= NULL
;
277 mutex_lock(&sessions_mutex
);
278 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
279 goto active
; /* Refuse to add channel to active session */
280 transport
= lttng_transport_find(transport_name
);
282 printk(KERN_WARNING
"LTTng transport %s not found\n",
286 if (!try_module_get(transport
->owner
)) {
287 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
290 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
293 chan
->session
= session
;
294 chan
->id
= session
->free_chan_id
++;
296 * Note: the channel creation op already writes into the packet
297 * headers. Therefore the "chan" information used as input
298 * should be already accessible.
300 chan
->chan
= transport
->ops
.channel_create(transport_name
,
301 chan
, buf_addr
, subbuf_size
, num_subbuf
,
302 switch_timer_interval
, read_timer_interval
);
306 chan
->ops
= &transport
->ops
;
307 chan
->transport
= transport
;
308 chan
->channel_type
= channel_type
;
309 list_add(&chan
->list
, &session
->chan
);
310 mutex_unlock(&sessions_mutex
);
317 module_put(transport
->owner
);
320 mutex_unlock(&sessions_mutex
);
325 * Only used internally at session destruction for per-cpu channels, and
326 * when metadata channel is released.
327 * Needs to be called with sessions mutex held.
330 void _lttng_channel_destroy(struct lttng_channel
*chan
)
332 chan
->ops
->channel_destroy(chan
->chan
);
333 module_put(chan
->transport
->owner
);
334 list_del(&chan
->list
);
335 lttng_destroy_context(chan
->ctx
);
339 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
341 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
343 /* Protect the metadata cache with the sessions_mutex. */
344 mutex_lock(&sessions_mutex
);
345 _lttng_channel_destroy(chan
);
346 mutex_unlock(&sessions_mutex
);
348 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
351 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
353 stream
->finalized
= 1;
354 wake_up_interruptible(&stream
->read_wait
);
358 * Supports event creation while tracing session is active.
360 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
361 struct lttng_kernel_event
*event_param
,
363 const struct lttng_event_desc
*internal_desc
)
365 struct lttng_event
*event
;
368 mutex_lock(&sessions_mutex
);
369 if (chan
->free_event_id
== -1U)
372 * This is O(n^2) (for each event, the loop is called at event
373 * creation). Might require a hash if we have lots of events.
375 list_for_each_entry(event
, &chan
->session
->events
, list
)
376 if (!strcmp(event
->desc
->name
, event_param
->name
))
378 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
382 event
->filter
= filter
;
383 event
->id
= chan
->free_event_id
++;
385 event
->instrumentation
= event_param
->instrumentation
;
386 /* Populate lttng_event structure before tracepoint registration. */
388 switch (event_param
->instrumentation
) {
389 case LTTNG_KERNEL_TRACEPOINT
:
390 event
->desc
= lttng_event_get(event_param
->name
);
393 ret
= kabi_2635_tracepoint_probe_register(event_param
->name
,
394 event
->desc
->probe_callback
,
399 case LTTNG_KERNEL_KPROBE
:
400 ret
= lttng_kprobes_register(event_param
->name
,
401 event_param
->u
.kprobe
.symbol_name
,
402 event_param
->u
.kprobe
.offset
,
403 event_param
->u
.kprobe
.addr
,
407 ret
= try_module_get(event
->desc
->owner
);
410 case LTTNG_KERNEL_KRETPROBE
:
412 struct lttng_event
*event_return
;
414 /* kretprobe defines 2 events */
416 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
419 event_return
->chan
= chan
;
420 event_return
->filter
= filter
;
421 event_return
->id
= chan
->free_event_id
++;
422 event_return
->enabled
= 1;
423 event_return
->instrumentation
= event_param
->instrumentation
;
425 * Populate lttng_event structure before kretprobe registration.
428 ret
= lttng_kretprobes_register(event_param
->name
,
429 event_param
->u
.kretprobe
.symbol_name
,
430 event_param
->u
.kretprobe
.offset
,
431 event_param
->u
.kretprobe
.addr
,
432 event
, event_return
);
434 kmem_cache_free(event_cache
, event_return
);
437 /* Take 2 refs on the module: one per event. */
438 ret
= try_module_get(event
->desc
->owner
);
440 ret
= try_module_get(event
->desc
->owner
);
442 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
445 kmem_cache_free(event_cache
, event_return
);
446 module_put(event
->desc
->owner
);
447 module_put(event
->desc
->owner
);
448 goto statedump_error
;
450 list_add(&event_return
->list
, &chan
->session
->events
);
453 case LTTNG_KERNEL_FUNCTION
:
454 ret
= lttng_ftrace_register(event_param
->name
,
455 event_param
->u
.ftrace
.symbol_name
,
459 ret
= try_module_get(event
->desc
->owner
);
462 case LTTNG_KERNEL_NOOP
:
463 event
->desc
= internal_desc
;
471 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
473 goto statedump_error
;
474 list_add(&event
->list
, &chan
->session
->events
);
475 mutex_unlock(&sessions_mutex
);
479 /* If a statedump error occurs, events will not be readable. */
481 kmem_cache_free(event_cache
, event
);
485 mutex_unlock(&sessions_mutex
);
490 * Only used internally at session destruction.
492 int _lttng_event_unregister(struct lttng_event
*event
)
496 switch (event
->instrumentation
) {
497 case LTTNG_KERNEL_TRACEPOINT
:
498 ret
= kabi_2635_tracepoint_probe_unregister(event
->desc
->name
,
499 event
->desc
->probe_callback
,
504 case LTTNG_KERNEL_KPROBE
:
505 lttng_kprobes_unregister(event
);
508 case LTTNG_KERNEL_KRETPROBE
:
509 lttng_kretprobes_unregister(event
);
512 case LTTNG_KERNEL_FUNCTION
:
513 lttng_ftrace_unregister(event
);
516 case LTTNG_KERNEL_NOOP
:
526 * Only used internally at session destruction.
529 void _lttng_event_destroy(struct lttng_event
*event
)
531 switch (event
->instrumentation
) {
532 case LTTNG_KERNEL_TRACEPOINT
:
533 lttng_event_put(event
->desc
);
535 case LTTNG_KERNEL_KPROBE
:
536 module_put(event
->desc
->owner
);
537 lttng_kprobes_destroy_private(event
);
539 case LTTNG_KERNEL_KRETPROBE
:
540 module_put(event
->desc
->owner
);
541 lttng_kretprobes_destroy_private(event
);
543 case LTTNG_KERNEL_FUNCTION
:
544 module_put(event
->desc
->owner
);
545 lttng_ftrace_destroy_private(event
);
547 case LTTNG_KERNEL_NOOP
:
552 list_del(&event
->list
);
553 lttng_destroy_context(event
->ctx
);
554 kmem_cache_free(event_cache
, event
);
558 * Serialize at most one packet worth of metadata into a metadata
560 * We have exclusive access to our metadata buffer (protected by the
561 * sessions_mutex), so we can do racy operations such as looking for
562 * remaining space left in packet and write, since mutual exclusion
563 * protects us from concurrent writes.
565 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
566 struct channel
*chan
)
568 struct lib_ring_buffer_ctx ctx
;
570 size_t len
, reserve_len
;
573 * Ensure we support mutiple get_next / put sequences followed
576 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
577 if (stream
->metadata_in
!= stream
->metadata_out
)
580 len
= stream
->metadata_cache
->metadata_written
-
584 reserve_len
= min_t(size_t,
585 stream
->transport
->ops
.packet_avail_size(chan
),
587 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
590 * If reservation failed, return an error to the caller.
592 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
594 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
597 stream
->transport
->ops
.event_write(&ctx
,
598 stream
->metadata_cache
->data
+ stream
->metadata_in
,
600 stream
->transport
->ops
.event_commit(&ctx
);
601 stream
->metadata_in
+= reserve_len
;
609 * Write the metadata to the metadata cache.
610 * Must be called with sessions_mutex held.
612 int lttng_metadata_printf(struct lttng_session
*session
,
613 const char *fmt
, ...)
618 struct lttng_metadata_stream
*stream
;
620 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
623 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
629 if (session
->metadata_cache
->metadata_written
+ len
>
630 session
->metadata_cache
->cache_alloc
) {
631 char *tmp_cache_realloc
;
632 unsigned int tmp_cache_alloc_size
;
634 tmp_cache_alloc_size
= max_t(unsigned int,
635 session
->metadata_cache
->cache_alloc
+ len
,
636 session
->metadata_cache
->cache_alloc
<< 1);
637 tmp_cache_realloc
= krealloc(session
->metadata_cache
->data
,
638 tmp_cache_alloc_size
, GFP_KERNEL
);
639 if (!tmp_cache_realloc
)
641 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
642 session
->metadata_cache
->data
= tmp_cache_realloc
;
644 memcpy(session
->metadata_cache
->data
+
645 session
->metadata_cache
->metadata_written
,
647 session
->metadata_cache
->metadata_written
+= len
;
650 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
651 wake_up_interruptible(&stream
->read_wait
);
661 * Must be called with sessions_mutex held.
664 int _lttng_field_statedump(struct lttng_session
*session
,
665 const struct lttng_event_field
*field
)
669 switch (field
->type
.atype
) {
671 ret
= lttng_metadata_printf(session
,
672 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
673 field
->type
.u
.basic
.integer
.size
,
674 field
->type
.u
.basic
.integer
.alignment
,
675 field
->type
.u
.basic
.integer
.signedness
,
676 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
678 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
681 field
->type
.u
.basic
.integer
.base
,
683 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
685 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
690 ret
= lttng_metadata_printf(session
,
692 field
->type
.u
.basic
.enumeration
.name
,
697 const struct lttng_basic_type
*elem_type
;
699 elem_type
= &field
->type
.u
.array
.elem_type
;
700 ret
= lttng_metadata_printf(session
,
701 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
702 elem_type
->u
.basic
.integer
.size
,
703 elem_type
->u
.basic
.integer
.alignment
,
704 elem_type
->u
.basic
.integer
.signedness
,
705 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
707 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
710 elem_type
->u
.basic
.integer
.base
,
712 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
714 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
716 field
->name
, field
->type
.u
.array
.length
);
721 const struct lttng_basic_type
*elem_type
;
722 const struct lttng_basic_type
*length_type
;
724 elem_type
= &field
->type
.u
.sequence
.elem_type
;
725 length_type
= &field
->type
.u
.sequence
.length_type
;
726 ret
= lttng_metadata_printf(session
,
727 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
728 length_type
->u
.basic
.integer
.size
,
729 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
730 length_type
->u
.basic
.integer
.signedness
,
731 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
733 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
736 length_type
->u
.basic
.integer
.base
,
738 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
740 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
746 ret
= lttng_metadata_printf(session
,
747 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
748 elem_type
->u
.basic
.integer
.size
,
749 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
750 elem_type
->u
.basic
.integer
.signedness
,
751 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
753 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
756 elem_type
->u
.basic
.integer
.base
,
758 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
760 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
768 /* Default encoding is UTF8 */
769 ret
= lttng_metadata_printf(session
,
771 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
772 " { encoding = ASCII; }" : "",
783 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
784 struct lttng_ctx
*ctx
)
791 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
792 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
794 ret
= _lttng_field_statedump(session
, &field
->event_field
);
802 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
803 struct lttng_event
*event
)
805 const struct lttng_event_desc
*desc
= event
->desc
;
809 for (i
= 0; i
< desc
->nr_fields
; i
++) {
810 const struct lttng_event_field
*field
= &desc
->fields
[i
];
812 ret
= _lttng_field_statedump(session
, field
);
820 * Must be called with sessions_mutex held.
823 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
824 struct lttng_channel
*chan
,
825 struct lttng_event
*event
)
829 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
831 if (chan
->channel_type
== METADATA_CHANNEL
)
834 ret
= lttng_metadata_printf(session
,
838 " stream_id = %u;\n",
846 ret
= lttng_metadata_printf(session
,
847 " context := struct {\n");
851 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
855 ret
= lttng_metadata_printf(session
,
861 ret
= lttng_metadata_printf(session
,
862 " fields := struct {\n"
867 ret
= _lttng_fields_metadata_statedump(session
, event
);
872 * LTTng space reservation can only reserve multiples of the
875 ret
= lttng_metadata_printf(session
,
881 event
->metadata_dumped
= 1;
888 * Must be called with sessions_mutex held.
891 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
892 struct lttng_channel
*chan
)
896 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
899 if (chan
->channel_type
== METADATA_CHANNEL
)
902 WARN_ON_ONCE(!chan
->header_type
);
903 ret
= lttng_metadata_printf(session
,
906 " event.header := %s;\n"
907 " packet.context := struct packet_context;\n",
909 chan
->header_type
== 1 ? "struct event_header_compact" :
910 "struct event_header_large");
915 ret
= lttng_metadata_printf(session
,
916 " event.context := struct {\n");
920 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
924 ret
= lttng_metadata_printf(session
,
930 ret
= lttng_metadata_printf(session
,
933 chan
->metadata_dumped
= 1;
939 * Must be called with sessions_mutex held.
942 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
944 return lttng_metadata_printf(session
,
945 "struct packet_context {\n"
946 " uint64_clock_monotonic_t timestamp_begin;\n"
947 " uint64_clock_monotonic_t timestamp_end;\n"
948 " uint64_t content_size;\n"
949 " uint64_t packet_size;\n"
950 " unsigned long events_discarded;\n"
951 " uint32_t cpu_id;\n"
959 * id 31 is reserved to indicate an extended header.
962 * id: range: 0 - 65534.
963 * id 65535 is reserved to indicate an extended header.
965 * Must be called with sessions_mutex held.
968 int _lttng_event_header_declare(struct lttng_session
*session
)
970 return lttng_metadata_printf(session
,
971 "struct event_header_compact {\n"
972 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
975 " uint27_clock_monotonic_t timestamp;\n"
979 " uint64_clock_monotonic_t timestamp;\n"
984 "struct event_header_large {\n"
985 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
988 " uint32_clock_monotonic_t timestamp;\n"
992 " uint64_clock_monotonic_t timestamp;\n"
996 lttng_alignof(uint32_t) * CHAR_BIT
,
997 lttng_alignof(uint16_t) * CHAR_BIT
1002 * Approximation of NTP time of day to clock monotonic correlation,
1003 * taken at start of trace.
1004 * Yes, this is only an approximation. Yes, we can (and will) do better
1005 * in future versions.
1008 uint64_t measure_clock_offset(void)
1010 uint64_t offset
, monotonic
[2], realtime
;
1011 struct timespec rts
= { 0, 0 };
1012 unsigned long flags
;
1014 /* Disable interrupts to increase correlation precision. */
1015 local_irq_save(flags
);
1016 monotonic
[0] = trace_clock_read64();
1017 getnstimeofday(&rts
);
1018 monotonic
[1] = trace_clock_read64();
1019 local_irq_restore(flags
);
1021 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1022 realtime
= (uint64_t) rts
.tv_sec
* NSEC_PER_SEC
;
1023 realtime
+= rts
.tv_nsec
;
1024 offset
= realtime
- offset
;
1029 * Output metadata into this session's metadata buffers.
1030 * Must be called with sessions_mutex held.
1033 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1035 unsigned char *uuid_c
= session
->uuid
.b
;
1036 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
1037 struct lttng_channel
*chan
;
1038 struct lttng_event
*event
;
1041 if (!ACCESS_ONCE(session
->active
))
1043 if (session
->metadata_dumped
)
1046 snprintf(uuid_s
, sizeof(uuid_s
),
1047 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1048 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1049 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1050 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1051 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1053 ret
= lttng_metadata_printf(session
,
1054 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1055 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1056 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1057 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1058 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1059 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1060 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1066 " byte_order = %s;\n"
1067 " packet.header := struct {\n"
1068 " uint32_t magic;\n"
1069 " uint8_t uuid[16];\n"
1070 " uint32_t stream_id;\n"
1073 lttng_alignof(uint8_t) * CHAR_BIT
,
1074 lttng_alignof(uint16_t) * CHAR_BIT
,
1075 lttng_alignof(uint32_t) * CHAR_BIT
,
1076 lttng_alignof(uint64_t) * CHAR_BIT
,
1077 sizeof(unsigned long) * CHAR_BIT
,
1078 lttng_alignof(unsigned long) * CHAR_BIT
,
1091 ret
= lttng_metadata_printf(session
,
1093 " hostname = \"%s\";\n"
1094 " domain = \"kernel\";\n"
1095 " sysname = \"%s\";\n"
1096 " kernel_release = \"%s\";\n"
1097 " kernel_version = \"%s\";\n"
1098 " tracer_name = \"lttng-modules\";\n"
1099 " tracer_major = %d;\n"
1100 " tracer_minor = %d;\n"
1101 " tracer_patchlevel = %d;\n"
1103 current
->nsproxy
->uts_ns
->name
.nodename
,
1107 LTTNG_MODULES_MAJOR_VERSION
,
1108 LTTNG_MODULES_MINOR_VERSION
,
1109 LTTNG_MODULES_PATCHLEVEL_VERSION
1114 ret
= lttng_metadata_printf(session
,
1122 if (!trace_clock_uuid(clock_uuid_s
)) {
1123 ret
= lttng_metadata_printf(session
,
1124 " uuid = \"%s\";\n",
1131 ret
= lttng_metadata_printf(session
,
1132 " description = \"Monotonic Clock\";\n"
1133 " freq = %llu; /* Frequency, in Hz */\n"
1134 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1137 (unsigned long long) trace_clock_freq(),
1138 (unsigned long long) measure_clock_offset()
1143 ret
= lttng_metadata_printf(session
,
1144 "typealias integer {\n"
1145 " size = 27; align = 1; signed = false;\n"
1146 " map = clock.monotonic.value;\n"
1147 "} := uint27_clock_monotonic_t;\n"
1149 "typealias integer {\n"
1150 " size = 32; align = %u; signed = false;\n"
1151 " map = clock.monotonic.value;\n"
1152 "} := uint32_clock_monotonic_t;\n"
1154 "typealias integer {\n"
1155 " size = 64; align = %u; signed = false;\n"
1156 " map = clock.monotonic.value;\n"
1157 "} := uint64_clock_monotonic_t;\n\n",
1158 lttng_alignof(uint32_t) * CHAR_BIT
,
1159 lttng_alignof(uint64_t) * CHAR_BIT
1164 ret
= _lttng_stream_packet_context_declare(session
);
1168 ret
= _lttng_event_header_declare(session
);
1173 list_for_each_entry(chan
, &session
->chan
, list
) {
1174 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1179 list_for_each_entry(event
, &session
->events
, list
) {
1180 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1184 session
->metadata_dumped
= 1;
1190 * lttng_transport_register - LTT transport registration
1191 * @transport: transport structure
1193 * Registers a transport which can be used as output to extract the data out of
1194 * LTTng. The module calling this registration function must ensure that no
1195 * trap-inducing code will be executed by the transport functions. E.g.
1196 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
1197 * is made visible to the transport function. This registration acts as a
1198 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
1199 * after its registration must it synchronize the TLBs.
1201 void lttng_transport_register(struct lttng_transport
*transport
)
1204 * Make sure no page fault can be triggered by the module about to be
1205 * registered. We deal with this here so we don't have to call
1206 * vmalloc_sync_all() in each module's init.
1208 wrapper_vmalloc_sync_all();
1210 mutex_lock(&sessions_mutex
);
1211 list_add_tail(&transport
->node
, <tng_transport_list
);
1212 mutex_unlock(&sessions_mutex
);
1214 EXPORT_SYMBOL_GPL(lttng_transport_register
);
1217 * lttng_transport_unregister - LTT transport unregistration
1218 * @transport: transport structure
1220 void lttng_transport_unregister(struct lttng_transport
*transport
)
1222 mutex_lock(&sessions_mutex
);
1223 list_del(&transport
->node
);
1224 mutex_unlock(&sessions_mutex
);
1226 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
1228 static int __init
lttng_events_init(void)
1232 event_cache
= KMEM_CACHE(lttng_event
, 0);
1235 ret
= lttng_abi_init();
1240 kmem_cache_destroy(event_cache
);
1244 module_init(lttng_events_init
);
1246 static void __exit
lttng_events_exit(void)
1248 struct lttng_session
*session
, *tmpsession
;
1251 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
1252 lttng_session_destroy(session
);
1253 kmem_cache_destroy(event_cache
);
1256 module_exit(lttng_events_exit
);
1258 MODULE_LICENSE("GPL and additional rights");
1259 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
1260 MODULE_DESCRIPTION("LTTng Events");