4 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * Holds LTTng per-session event registry.
8 * Dual LGPL v2.1/GPL v2 license.
11 #include <linux/module.h>
12 #include <linux/list.h>
13 #include <linux/mutex.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/jiffies.h>
17 #include "wrapper/uuid.h"
18 #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
19 #include "ltt-events.h"
20 #include "ltt-tracer.h"
22 static LIST_HEAD(sessions
);
23 static LIST_HEAD(ltt_transport_list
);
24 static DEFINE_MUTEX(sessions_mutex
);
25 static struct kmem_cache
*event_cache
;
27 static void _ltt_event_destroy(struct ltt_event
*event
);
28 static void _ltt_channel_destroy(struct ltt_channel
*chan
);
29 static int _ltt_event_unregister(struct ltt_event
*event
);
31 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
32 struct ltt_channel
*chan
,
33 struct ltt_event
*event
);
35 int _ltt_session_metadata_statedump(struct ltt_session
*session
);
37 void synchronize_trace(void)
40 #ifdef CONFIG_PREEMPT_RT
45 struct ltt_session
*ltt_session_create(void)
47 struct ltt_session
*session
;
49 mutex_lock(&sessions_mutex
);
50 session
= kzalloc(sizeof(struct ltt_session
), GFP_KERNEL
);
53 INIT_LIST_HEAD(&session
->chan
);
54 INIT_LIST_HEAD(&session
->events
);
55 uuid_le_gen(&session
->uuid
);
56 list_add(&session
->list
, &sessions
);
57 mutex_unlock(&sessions_mutex
);
61 void ltt_session_destroy(struct ltt_session
*session
)
63 struct ltt_channel
*chan
, *tmpchan
;
64 struct ltt_event
*event
, *tmpevent
;
67 mutex_lock(&sessions_mutex
);
68 ACCESS_ONCE(session
->active
) = 0;
69 list_for_each_entry(chan
, &session
->chan
, list
) {
70 ret
= lttng_syscalls_unregister(chan
);
73 list_for_each_entry(event
, &session
->events
, list
) {
74 ret
= _ltt_event_unregister(event
);
77 synchronize_trace(); /* Wait for in-flight events to complete */
78 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
79 _ltt_event_destroy(event
);
80 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
)
81 _ltt_channel_destroy(chan
);
82 list_del(&session
->list
);
83 mutex_unlock(&sessions_mutex
);
87 int ltt_session_enable(struct ltt_session
*session
)
90 struct ltt_channel
*chan
;
92 mutex_lock(&sessions_mutex
);
93 if (session
->active
) {
99 * Snapshot the number of events per channel to know the type of header
102 list_for_each_entry(chan
, &session
->chan
, list
) {
103 if (chan
->header_type
)
104 continue; /* don't change it if session stop/restart */
105 if (chan
->free_event_id
< 31)
106 chan
->header_type
= 1; /* compact */
108 chan
->header_type
= 2; /* large */
111 ACCESS_ONCE(session
->active
) = 1;
112 ACCESS_ONCE(session
->been_active
) = 1;
113 ret
= _ltt_session_metadata_statedump(session
);
115 ACCESS_ONCE(session
->active
) = 0;
117 mutex_unlock(&sessions_mutex
);
121 int ltt_session_disable(struct ltt_session
*session
)
125 mutex_lock(&sessions_mutex
);
126 if (!session
->active
) {
130 ACCESS_ONCE(session
->active
) = 0;
132 mutex_unlock(&sessions_mutex
);
136 int ltt_channel_enable(struct ltt_channel
*channel
)
140 if (channel
== channel
->session
->metadata
)
142 old
= xchg(&channel
->enabled
, 1);
148 int ltt_channel_disable(struct ltt_channel
*channel
)
152 if (channel
== channel
->session
->metadata
)
154 old
= xchg(&channel
->enabled
, 0);
160 int ltt_event_enable(struct ltt_event
*event
)
164 if (event
->chan
== event
->chan
->session
->metadata
)
166 old
= xchg(&event
->enabled
, 1);
172 int ltt_event_disable(struct ltt_event
*event
)
176 if (event
->chan
== event
->chan
->session
->metadata
)
178 old
= xchg(&event
->enabled
, 0);
184 static struct ltt_transport
*ltt_transport_find(const char *name
)
186 struct ltt_transport
*transport
;
188 list_for_each_entry(transport
, <t_transport_list
, node
) {
189 if (!strcmp(transport
->name
, name
))
195 struct ltt_channel
*ltt_channel_create(struct ltt_session
*session
,
196 const char *transport_name
,
198 size_t subbuf_size
, size_t num_subbuf
,
199 unsigned int switch_timer_interval
,
200 unsigned int read_timer_interval
)
202 struct ltt_channel
*chan
;
203 struct ltt_transport
*transport
= NULL
;
205 mutex_lock(&sessions_mutex
);
206 if (session
->been_active
)
207 goto active
; /* Refuse to add channel to active session */
208 transport
= ltt_transport_find(transport_name
);
210 printk(KERN_WARNING
"LTTng transport %s not found\n",
214 if (!try_module_get(transport
->owner
)) {
215 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
218 chan
= kzalloc(sizeof(struct ltt_channel
), GFP_KERNEL
);
221 chan
->session
= session
;
222 chan
->id
= session
->free_chan_id
++;
224 * Note: the channel creation op already writes into the packet
225 * headers. Therefore the "chan" information used as input
226 * should be already accessible.
228 chan
->chan
= transport
->ops
.channel_create("[lttng]", chan
, buf_addr
,
229 subbuf_size
, num_subbuf
, switch_timer_interval
,
230 read_timer_interval
);
234 chan
->ops
= &transport
->ops
;
235 chan
->transport
= transport
;
236 list_add(&chan
->list
, &session
->chan
);
237 mutex_unlock(&sessions_mutex
);
244 module_put(transport
->owner
);
247 mutex_unlock(&sessions_mutex
);
252 * Only used internally at session destruction.
255 void _ltt_channel_destroy(struct ltt_channel
*chan
)
257 chan
->ops
->channel_destroy(chan
->chan
);
258 module_put(chan
->transport
->owner
);
259 list_del(&chan
->list
);
260 lttng_destroy_context(chan
->ctx
);
265 * Supports event creation while tracing session is active.
267 struct ltt_event
*ltt_event_create(struct ltt_channel
*chan
,
268 struct lttng_kernel_event
*event_param
,
271 struct ltt_event
*event
;
274 mutex_lock(&sessions_mutex
);
275 if (chan
->free_event_id
== -1UL)
278 * This is O(n^2) (for each event, the loop is called at event
279 * creation). Might require a hash if we have lots of events.
281 list_for_each_entry(event
, &chan
->session
->events
, list
)
282 if (!strcmp(event
->desc
->name
, event_param
->name
))
284 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
288 event
->filter
= filter
;
289 event
->id
= chan
->free_event_id
++;
291 event
->instrumentation
= event_param
->instrumentation
;
292 /* Populate ltt_event structure before tracepoint registration. */
294 switch (event_param
->instrumentation
) {
295 case LTTNG_KERNEL_TRACEPOINT
:
296 event
->desc
= ltt_event_get(event_param
->name
);
299 ret
= tracepoint_probe_register(event_param
->name
,
300 event
->desc
->probe_callback
,
305 case LTTNG_KERNEL_KPROBE
:
306 ret
= lttng_kprobes_register(event_param
->name
,
307 event_param
->u
.kprobe
.symbol_name
,
308 event_param
->u
.kprobe
.offset
,
309 event_param
->u
.kprobe
.addr
,
313 ret
= try_module_get(event
->desc
->owner
);
316 case LTTNG_KERNEL_KRETPROBE
:
318 struct ltt_event
*event_return
;
320 /* kretprobe defines 2 events */
322 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
325 event_return
->chan
= chan
;
326 event_return
->filter
= filter
;
327 event_return
->id
= chan
->free_event_id
++;
328 event_return
->enabled
= 1;
329 event_return
->instrumentation
= event_param
->instrumentation
;
331 * Populate ltt_event structure before kretprobe registration.
334 ret
= lttng_kretprobes_register(event_param
->name
,
335 event_param
->u
.kretprobe
.symbol_name
,
336 event_param
->u
.kretprobe
.offset
,
337 event_param
->u
.kretprobe
.addr
,
338 event
, event_return
);
340 kmem_cache_free(event_cache
, event_return
);
343 /* Take 2 refs on the module: one per event. */
344 ret
= try_module_get(event
->desc
->owner
);
346 ret
= try_module_get(event
->desc
->owner
);
348 ret
= _ltt_event_metadata_statedump(chan
->session
, chan
,
351 kmem_cache_free(event_cache
, event_return
);
352 module_put(event
->desc
->owner
);
353 module_put(event
->desc
->owner
);
354 goto statedump_error
;
356 list_add(&event_return
->list
, &chan
->session
->events
);
359 case LTTNG_KERNEL_FUNCTION
:
360 ret
= lttng_ftrace_register(event_param
->name
,
361 event_param
->u
.ftrace
.symbol_name
,
365 ret
= try_module_get(event
->desc
->owner
);
368 case LTTNG_KERNEL_NOOP
:
373 ret
= _ltt_event_metadata_statedump(chan
->session
, chan
, event
);
375 goto statedump_error
;
376 list_add(&event
->list
, &chan
->session
->events
);
377 mutex_unlock(&sessions_mutex
);
381 WARN_ON_ONCE(tracepoint_probe_unregister(event_param
->name
,
382 event
->desc
->probe_callback
,
384 ltt_event_put(event
->desc
);
386 kmem_cache_free(event_cache
, event
);
390 mutex_unlock(&sessions_mutex
);
395 * Only used internally at session destruction.
397 int _ltt_event_unregister(struct ltt_event
*event
)
401 switch (event
->instrumentation
) {
402 case LTTNG_KERNEL_TRACEPOINT
:
403 ret
= tracepoint_probe_unregister(event
->desc
->name
,
404 event
->desc
->probe_callback
,
409 case LTTNG_KERNEL_KPROBE
:
410 lttng_kprobes_unregister(event
);
413 case LTTNG_KERNEL_KRETPROBE
:
414 lttng_kretprobes_unregister(event
);
417 case LTTNG_KERNEL_FUNCTION
:
418 lttng_ftrace_unregister(event
);
428 * Only used internally at session destruction.
431 void _ltt_event_destroy(struct ltt_event
*event
)
433 switch (event
->instrumentation
) {
434 case LTTNG_KERNEL_TRACEPOINT
:
435 ltt_event_put(event
->desc
);
437 case LTTNG_KERNEL_KPROBE
:
438 module_put(event
->desc
->owner
);
439 lttng_kprobes_destroy_private(event
);
441 case LTTNG_KERNEL_KRETPROBE
:
442 module_put(event
->desc
->owner
);
443 lttng_kretprobes_destroy_private(event
);
445 case LTTNG_KERNEL_FUNCTION
:
446 module_put(event
->desc
->owner
);
447 lttng_ftrace_destroy_private(event
);
452 list_del(&event
->list
);
453 lttng_destroy_context(event
->ctx
);
454 kmem_cache_free(event_cache
, event
);
458 * We have exclusive access to our metadata buffer (protected by the
459 * sessions_mutex), so we can do racy operations such as looking for
460 * remaining space left in packet and write, since mutual exclusion
461 * protects us from concurrent writes.
463 int lttng_metadata_printf(struct ltt_session
*session
,
464 const char *fmt
, ...)
466 struct lib_ring_buffer_ctx ctx
;
467 struct ltt_channel
*chan
= session
->metadata
;
469 int ret
= 0, waitret
;
470 size_t len
, reserve_len
, pos
;
473 WARN_ON_ONCE(!ACCESS_ONCE(session
->active
));
476 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
484 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
485 reserve_len
= min_t(size_t,
486 chan
->ops
->packet_avail_size(chan
->chan
),
488 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
491 * We don't care about metadata buffer's records lost
492 * count, because we always retry here. Report error if
493 * we need to bail out after timeout or being
496 waitret
= wait_event_interruptible_timeout(*chan
->ops
->get_writer_buf_wait_queue(chan
->chan
, -1),
498 ret
= chan
->ops
->event_reserve(&ctx
, 0);
499 ret
!= -ENOBUFS
|| !ret
;
501 msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC
));
502 if (!waitret
|| waitret
== -ERESTARTSYS
|| ret
) {
503 printk(KERN_WARNING
"LTTng: Failure to write metadata to buffers (%s)\n",
504 waitret
== -ERESTARTSYS
? "interrupted" :
505 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
506 if (waitret
== -ERESTARTSYS
)
510 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
511 chan
->ops
->event_commit(&ctx
);
519 int _ltt_field_statedump(struct ltt_session
*session
,
520 const struct lttng_event_field
*field
)
524 switch (field
->type
.atype
) {
526 ret
= lttng_metadata_printf(session
,
527 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n",
528 field
->type
.u
.basic
.integer
.size
,
529 field
->type
.u
.basic
.integer
.alignment
,
530 field
->type
.u
.basic
.integer
.signedness
,
531 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
533 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
536 field
->type
.u
.basic
.integer
.base
,
538 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
540 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
545 ret
= lttng_metadata_printf(session
,
547 field
->type
.u
.basic
.enumeration
.name
,
552 const struct lttng_basic_type
*elem_type
;
554 elem_type
= &field
->type
.u
.array
.elem_type
;
555 ret
= lttng_metadata_printf(session
,
556 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n",
557 elem_type
->u
.basic
.integer
.size
,
558 elem_type
->u
.basic
.integer
.alignment
,
559 elem_type
->u
.basic
.integer
.signedness
,
560 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
562 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
565 elem_type
->u
.basic
.integer
.base
,
567 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
569 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
571 field
->name
, field
->type
.u
.array
.length
);
576 const struct lttng_basic_type
*elem_type
;
577 const struct lttng_basic_type
*length_type
;
579 elem_type
= &field
->type
.u
.sequence
.elem_type
;
580 length_type
= &field
->type
.u
.sequence
.length_type
;
581 ret
= lttng_metadata_printf(session
,
582 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
583 length_type
->u
.basic
.integer
.size
,
584 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
585 length_type
->u
.basic
.integer
.signedness
,
586 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
588 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
591 length_type
->u
.basic
.integer
.base
,
593 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
595 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
601 ret
= lttng_metadata_printf(session
,
602 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n",
603 elem_type
->u
.basic
.integer
.size
,
604 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
605 elem_type
->u
.basic
.integer
.signedness
,
606 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
608 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
611 elem_type
->u
.basic
.integer
.base
,
613 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
615 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
623 /* Default encoding is UTF8 */
624 ret
= lttng_metadata_printf(session
,
626 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
627 " { encoding = ASCII; }" : "",
638 int _ltt_context_metadata_statedump(struct ltt_session
*session
,
639 struct lttng_ctx
*ctx
)
646 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
647 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
649 ret
= _ltt_field_statedump(session
, &field
->event_field
);
657 int _ltt_fields_metadata_statedump(struct ltt_session
*session
,
658 struct ltt_event
*event
)
660 const struct lttng_event_desc
*desc
= event
->desc
;
664 for (i
= 0; i
< desc
->nr_fields
; i
++) {
665 const struct lttng_event_field
*field
= &desc
->fields
[i
];
667 ret
= _ltt_field_statedump(session
, field
);
675 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
676 struct ltt_channel
*chan
,
677 struct ltt_event
*event
)
681 if (event
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
683 if (chan
== session
->metadata
)
686 ret
= lttng_metadata_printf(session
,
690 " stream_id = %u;\n",
698 ret
= lttng_metadata_printf(session
,
699 " context := struct {\n");
703 ret
= _ltt_context_metadata_statedump(session
, event
->ctx
);
707 ret
= lttng_metadata_printf(session
,
713 ret
= lttng_metadata_printf(session
,
714 " fields := struct {\n"
719 ret
= _ltt_fields_metadata_statedump(session
, event
);
724 * LTTng space reservation can only reserve multiples of the
727 ret
= lttng_metadata_printf(session
,
733 event
->metadata_dumped
= 1;
740 int _ltt_channel_metadata_statedump(struct ltt_session
*session
,
741 struct ltt_channel
*chan
)
745 if (chan
->metadata_dumped
|| !ACCESS_ONCE(session
->active
))
747 if (chan
== session
->metadata
)
750 WARN_ON_ONCE(!chan
->header_type
);
751 ret
= lttng_metadata_printf(session
,
754 " event.header := %s;\n"
755 " packet.context := struct packet_context;\n",
757 chan
->header_type
== 1 ? "struct event_header_compact" :
758 "struct event_header_large");
763 ret
= lttng_metadata_printf(session
,
764 " event.context := struct {\n");
768 ret
= _ltt_context_metadata_statedump(session
, chan
->ctx
);
772 ret
= lttng_metadata_printf(session
,
778 ret
= lttng_metadata_printf(session
,
781 chan
->metadata_dumped
= 1;
787 int _ltt_stream_packet_context_declare(struct ltt_session
*session
)
789 return lttng_metadata_printf(session
,
790 "struct packet_context {\n"
791 " uint64_t timestamp_begin;\n"
792 " uint64_t timestamp_end;\n"
793 " uint32_t events_discarded;\n"
794 " uint32_t content_size;\n"
795 " uint32_t packet_size;\n"
796 " uint32_t cpu_id;\n"
804 * id 31 is reserved to indicate an extended header.
807 * id: range: 0 - 65534.
808 * id 65535 is reserved to indicate an extended header.
811 int _ltt_event_header_declare(struct ltt_session
*session
)
813 return lttng_metadata_printf(session
,
814 "struct event_header_compact {\n"
815 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
818 " uint27_t timestamp;\n"
822 " uint64_t timestamp;\n"
827 "struct event_header_large {\n"
828 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
831 " uint32_t timestamp;\n"
835 " uint64_t timestamp;\n"
839 ltt_alignof(uint32_t) * CHAR_BIT
,
840 ltt_alignof(uint16_t) * CHAR_BIT
845 * Output metadata into this session's metadata buffers.
848 int _ltt_session_metadata_statedump(struct ltt_session
*session
)
850 unsigned char *uuid_c
= session
->uuid
.b
;
851 unsigned char uuid_s
[37];
852 struct ltt_channel
*chan
;
853 struct ltt_event
*event
;
856 if (!ACCESS_ONCE(session
->active
))
858 if (session
->metadata_dumped
)
860 if (!session
->metadata
) {
861 printk(KERN_WARNING
"LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
865 snprintf(uuid_s
, sizeof(uuid_s
),
866 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
867 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
868 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
869 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
870 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
872 ret
= lttng_metadata_printf(session
,
873 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
874 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
875 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
876 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
877 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
878 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
884 " byte_order = %s;\n"
885 " packet.header := struct {\n"
887 " uint8_t uuid[16];\n"
888 " uint32_t stream_id;\n"
891 ltt_alignof(uint8_t) * CHAR_BIT
,
892 ltt_alignof(uint16_t) * CHAR_BIT
,
893 ltt_alignof(uint32_t) * CHAR_BIT
,
894 ltt_alignof(uint64_t) * CHAR_BIT
,
907 ret
= _ltt_stream_packet_context_declare(session
);
911 ret
= _ltt_event_header_declare(session
);
916 list_for_each_entry(chan
, &session
->chan
, list
) {
917 ret
= _ltt_channel_metadata_statedump(session
, chan
);
922 list_for_each_entry(event
, &session
->events
, list
) {
923 ret
= _ltt_event_metadata_statedump(session
, event
->chan
, event
);
927 session
->metadata_dumped
= 1;
933 * ltt_transport_register - LTT transport registration
934 * @transport: transport structure
936 * Registers a transport which can be used as output to extract the data out of
937 * LTTng. The module calling this registration function must ensure that no
938 * trap-inducing code will be executed by the transport functions. E.g.
939 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
940 * is made visible to the transport function. This registration acts as a
941 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
942 * after its registration must it synchronize the TLBs.
944 void ltt_transport_register(struct ltt_transport
*transport
)
947 * Make sure no page fault can be triggered by the module about to be
948 * registered. We deal with this here so we don't have to call
949 * vmalloc_sync_all() in each module's init.
951 wrapper_vmalloc_sync_all();
953 mutex_lock(&sessions_mutex
);
954 list_add_tail(&transport
->node
, <t_transport_list
);
955 mutex_unlock(&sessions_mutex
);
957 EXPORT_SYMBOL_GPL(ltt_transport_register
);
960 * ltt_transport_unregister - LTT transport unregistration
961 * @transport: transport structure
963 void ltt_transport_unregister(struct ltt_transport
*transport
)
965 mutex_lock(&sessions_mutex
);
966 list_del(&transport
->node
);
967 mutex_unlock(&sessions_mutex
);
969 EXPORT_SYMBOL_GPL(ltt_transport_unregister
);
971 static int __init
ltt_events_init(void)
975 event_cache
= KMEM_CACHE(ltt_event
, 0);
978 ret
= ltt_debugfs_abi_init();
983 kmem_cache_destroy(event_cache
);
987 module_init(ltt_events_init
);
989 static void __exit
ltt_events_exit(void)
991 struct ltt_session
*session
, *tmpsession
;
993 ltt_debugfs_abi_exit();
994 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
995 ltt_session_destroy(session
);
996 kmem_cache_destroy(event_cache
);
999 module_exit(ltt_events_exit
);
1001 MODULE_LICENSE("GPL and additional rights");
1002 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
1003 MODULE_DESCRIPTION("LTTng Events");