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 * Mimic system calls for:
24 * - session creation, returns an object descriptor or failure.
25 * - channel creation, returns an object descriptor or failure.
26 * - Operates on a session object descriptor
27 * - Takes all channel options as parameters.
28 * - stream get, returns an object descriptor or failure.
29 * - Operates on a channel object descriptor.
30 * - stream notifier get, returns an object descriptor or failure.
31 * - Operates on a channel object descriptor.
32 * - event creation, returns an object descriptor or failure.
33 * - Operates on a channel object descriptor
34 * - Takes an event name as parameter
35 * - Takes an instrumentation source as parameter
36 * - e.g. tracepoints, dynamic_probes...
37 * - Takes instrumentation source specific arguments.
41 #include <lttng/ust-abi.h>
42 #include <lttng/ust-error.h>
43 #include <urcu/compiler.h>
44 #include <urcu/list.h>
45 #include <lttng/ust-events.h>
46 #include <lttng/ust-version.h>
47 #include <lttng/tracepoint.h>
48 #include "tracepoint-internal.h"
49 #include <usterr-signal-safe.h>
51 #include "lttng-tracer.h"
52 #include "../libringbuffer/shm.h"
53 #include "../libringbuffer/frontend_types.h"
55 #define OBJ_NAME_LEN 16
57 static int lttng_ust_abi_close_in_progress
;
60 int lttng_abi_tracepoint_list(void *owner
);
62 int lttng_abi_tracepoint_field_list(void *owner
);
65 * Object descriptor table. Should be protected from concurrent access
69 struct lttng_ust_obj
{
73 const struct lttng_ust_objd_ops
*ops
;
75 int owner_ref
; /* has ref from owner */
77 char name
[OBJ_NAME_LEN
];
79 int freelist_next
; /* offset freelist. end is -1. */
83 struct lttng_ust_objd_table
{
84 struct lttng_ust_obj
*array
;
85 unsigned int len
, allocated_len
;
86 int freelist_head
; /* offset freelist head. end is -1 */
89 static struct lttng_ust_objd_table objd_table
= {
94 int objd_alloc(void *private_data
, const struct lttng_ust_objd_ops
*ops
,
95 void *owner
, const char *name
)
97 struct lttng_ust_obj
*obj
;
99 if (objd_table
.freelist_head
!= -1) {
100 obj
= &objd_table
.array
[objd_table
.freelist_head
];
101 objd_table
.freelist_head
= obj
->u
.freelist_next
;
105 if (objd_table
.len
>= objd_table
.allocated_len
) {
106 unsigned int new_allocated_len
, old_allocated_len
;
107 struct lttng_ust_obj
*new_table
, *old_table
;
109 old_allocated_len
= objd_table
.allocated_len
;
110 old_table
= objd_table
.array
;
111 if (!old_allocated_len
)
112 new_allocated_len
= 1;
114 new_allocated_len
= old_allocated_len
<< 1;
115 new_table
= zmalloc(sizeof(struct lttng_ust_obj
) * new_allocated_len
);
118 memcpy(new_table
, old_table
,
119 sizeof(struct lttng_ust_obj
) * old_allocated_len
);
121 objd_table
.array
= new_table
;
122 objd_table
.allocated_len
= new_allocated_len
;
124 obj
= &objd_table
.array
[objd_table
.len
];
127 obj
->u
.s
.private_data
= private_data
;
129 obj
->u
.s
.f_count
= 2; /* count == 1 : object is allocated */
130 /* count == 2 : allocated + hold ref */
131 obj
->u
.s
.owner_ref
= 1; /* One owner reference */
132 obj
->u
.s
.owner
= owner
;
133 strncpy(obj
->u
.s
.name
, name
, OBJ_NAME_LEN
);
134 obj
->u
.s
.name
[OBJ_NAME_LEN
- 1] = '\0';
135 return obj
- objd_table
.array
;
139 struct lttng_ust_obj
*_objd_get(int id
)
141 if (id
>= objd_table
.len
)
143 if (!objd_table
.array
[id
].u
.s
.f_count
)
145 return &objd_table
.array
[id
];
149 void *objd_private(int id
)
151 struct lttng_ust_obj
*obj
= _objd_get(id
);
153 return obj
->u
.s
.private_data
;
157 void objd_set_private(int id
, void *private_data
)
159 struct lttng_ust_obj
*obj
= _objd_get(id
);
161 obj
->u
.s
.private_data
= private_data
;
164 const struct lttng_ust_objd_ops
*objd_ops(int id
)
166 struct lttng_ust_obj
*obj
= _objd_get(id
);
174 void objd_free(int id
)
176 struct lttng_ust_obj
*obj
= _objd_get(id
);
179 obj
->u
.freelist_next
= objd_table
.freelist_head
;
180 objd_table
.freelist_head
= obj
- objd_table
.array
;
181 assert(obj
->u
.s
.f_count
== 1);
182 obj
->u
.s
.f_count
= 0; /* deallocated */
186 void objd_ref(int id
)
188 struct lttng_ust_obj
*obj
= _objd_get(id
);
193 int lttng_ust_objd_unref(int id
, int is_owner
)
195 struct lttng_ust_obj
*obj
= _objd_get(id
);
199 if (obj
->u
.s
.f_count
== 1) {
200 ERR("Reference counting error\n");
204 if (!obj
->u
.s
.owner_ref
) {
205 ERR("Error decrementing owner reference");
208 obj
->u
.s
.owner_ref
--;
210 if ((--obj
->u
.s
.f_count
) == 1) {
211 const struct lttng_ust_objd_ops
*ops
= objd_ops(id
);
221 void objd_table_destroy(void)
225 for (i
= 0; i
< objd_table
.allocated_len
; i
++) {
226 struct lttng_ust_obj
*obj
;
231 if (!obj
->u
.s
.owner_ref
)
232 continue; /* only unref owner ref. */
233 (void) lttng_ust_objd_unref(i
, 1);
235 free(objd_table
.array
);
236 objd_table
.array
= NULL
;
238 objd_table
.allocated_len
= 0;
239 objd_table
.freelist_head
= -1;
242 const char *lttng_ust_obj_get_name(int id
)
244 struct lttng_ust_obj
*obj
= _objd_get(id
);
248 return obj
->u
.s
.name
;
251 void lttng_ust_objd_table_owner_cleanup(void *owner
)
255 for (i
= 0; i
< objd_table
.allocated_len
; i
++) {
256 struct lttng_ust_obj
*obj
;
262 continue; /* skip root handles */
263 if (!obj
->u
.s
.owner_ref
)
264 continue; /* only unref owner ref. */
265 if (obj
->u
.s
.owner
== owner
)
266 (void) lttng_ust_objd_unref(i
, 1);
271 * This is LTTng's own personal way to create an ABI for sessiond.
272 * We send commands over a socket.
275 static const struct lttng_ust_objd_ops lttng_ops
;
276 static const struct lttng_ust_objd_ops lttng_session_ops
;
277 static const struct lttng_ust_objd_ops lttng_channel_ops
;
278 static const struct lttng_ust_objd_ops lttng_enabler_ops
;
279 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops
;
280 static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops
;
282 int lttng_abi_create_root_handle(void)
286 /* root handles have NULL owners */
287 root_handle
= objd_alloc(NULL
, <tng_ops
, NULL
, "root");
292 int lttng_is_channel_ready(struct lttng_channel
*lttng_chan
)
294 struct channel
*chan
;
295 unsigned int nr_streams
, exp_streams
;
297 chan
= lttng_chan
->chan
;
298 nr_streams
= channel_handle_get_nr_streams(lttng_chan
->handle
);
299 exp_streams
= chan
->nr_streams
;
300 return nr_streams
== exp_streams
;
304 int lttng_abi_create_session(void *owner
)
306 struct lttng_session
*session
;
307 int session_objd
, ret
;
309 session
= lttng_session_create();
312 session_objd
= objd_alloc(session
, <tng_session_ops
, owner
, "session");
313 if (session_objd
< 0) {
317 session
->objd
= session_objd
;
318 session
->owner
= owner
;
322 lttng_session_destroy(session
);
327 long lttng_abi_tracer_version(int objd
,
328 struct lttng_ust_tracer_version
*v
)
330 v
->major
= LTTNG_UST_MAJOR_VERSION
;
331 v
->minor
= LTTNG_UST_MINOR_VERSION
;
332 v
->patchlevel
= LTTNG_UST_PATCHLEVEL_VERSION
;
337 long lttng_abi_add_context(int objd
,
338 struct lttng_ust_context
*context_param
,
339 union ust_args
*uargs
,
340 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
342 return lttng_attach_context(context_param
, uargs
, ctx
, session
);
346 * lttng_cmd - lttng control through socket commands
348 * @objd: the object descriptor
351 * @uargs: UST arguments (internal)
354 * This descriptor implements lttng commands:
356 * Returns a LTTng trace session object descriptor
357 * LTTNG_UST_TRACER_VERSION
358 * Returns the LTTng kernel tracer version
359 * LTTNG_UST_TRACEPOINT_LIST
360 * Returns a file descriptor listing available tracepoints
361 * LTTNG_UST_TRACEPOINT_FIELD_LIST
362 * Returns a file descriptor listing available tracepoint fields
363 * LTTNG_UST_WAIT_QUIESCENT
364 * Returns after all previously running probes have completed
366 * The returned session will be deleted when its file descriptor is closed.
369 long lttng_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
370 union ust_args
*uargs
, void *owner
)
373 case LTTNG_UST_SESSION
:
374 return lttng_abi_create_session(owner
);
375 case LTTNG_UST_TRACER_VERSION
:
376 return lttng_abi_tracer_version(objd
,
377 (struct lttng_ust_tracer_version
*) arg
);
378 case LTTNG_UST_TRACEPOINT_LIST
:
379 return lttng_abi_tracepoint_list(owner
);
380 case LTTNG_UST_TRACEPOINT_FIELD_LIST
:
381 return lttng_abi_tracepoint_field_list(owner
);
382 case LTTNG_UST_WAIT_QUIESCENT
:
390 static const struct lttng_ust_objd_ops lttng_ops
= {
394 int lttng_abi_map_channel(int session_objd
,
395 struct lttng_ust_channel
*ust_chan
,
396 union ust_args
*uargs
,
399 struct lttng_session
*session
= objd_private(session_objd
);
400 const char *transport_name
;
401 const struct lttng_transport
*transport
;
402 const char *chan_name
;
404 struct lttng_ust_shm_handle
*channel_handle
;
405 struct lttng_channel
*lttng_chan
;
406 struct channel
*chan
;
407 struct lttng_ust_lib_ring_buffer_config
*config
;
412 enum lttng_ust_chan_type type
;
414 chan_data
= uargs
->channel
.chan_data
;
415 wakeup_fd
= uargs
->channel
.wakeup_fd
;
417 type
= ust_chan
->type
;
420 case LTTNG_UST_CHAN_PER_CPU
:
427 if (session
->been_active
) {
429 goto active
; /* Refuse to add channel to active session */
432 channel_handle
= channel_handle_create(chan_data
, len
, wakeup_fd
);
433 if (!channel_handle
) {
438 chan
= shmp(channel_handle
, channel_handle
->chan
);
440 chan
->handle
= channel_handle
;
441 config
= &chan
->backend
.config
;
442 lttng_chan
= channel_get_private(chan
);
448 /* Lookup transport name */
450 case LTTNG_UST_CHAN_PER_CPU
:
451 if (config
->output
== RING_BUFFER_MMAP
) {
452 if (config
->mode
== RING_BUFFER_OVERWRITE
) {
453 if (config
->wakeup
== RING_BUFFER_WAKEUP_BY_WRITER
) {
454 transport_name
= "relay-overwrite-mmap";
456 transport_name
= "relay-overwrite-rt-mmap";
459 if (config
->wakeup
== RING_BUFFER_WAKEUP_BY_WRITER
) {
460 transport_name
= "relay-discard-mmap";
462 transport_name
= "relay-discard-rt-mmap";
469 chan_name
= "channel";
475 transport
= lttng_transport_find(transport_name
);
477 DBG("LTTng transport %s not found\n",
483 chan_objd
= objd_alloc(NULL
, <tng_channel_ops
, owner
, chan_name
);
489 /* Initialize our lttng chan */
490 lttng_chan
->chan
= chan
;
491 lttng_chan
->tstate
= 1;
492 lttng_chan
->enabled
= 1;
493 lttng_chan
->ctx
= NULL
;
494 lttng_chan
->session
= session
;
495 lttng_chan
->ops
= &transport
->ops
;
496 memcpy(<tng_chan
->chan
->backend
.config
,
497 transport
->client_config
,
498 sizeof(lttng_chan
->chan
->backend
.config
));
499 cds_list_add(<tng_chan
->node
, &session
->chan_head
);
500 lttng_chan
->header_type
= 0;
501 lttng_chan
->handle
= channel_handle
;
502 lttng_chan
->type
= type
;
505 * We tolerate no failure path after channel creation. It will stay
506 * invariant for the rest of the session.
508 objd_set_private(chan_objd
, lttng_chan
);
509 lttng_chan
->objd
= chan_objd
;
510 /* The channel created holds a reference on the session */
511 objd_ref(session_objd
);
514 /* error path after channel was created */
518 channel_destroy(chan
, channel_handle
, 0);
522 * error path before channel creation (owning chan_data and
531 close_ret
= close(wakeup_fd
);
541 * lttng_session_cmd - lttng session object command
546 * @uargs: UST arguments (internal)
549 * This descriptor implements lttng commands:
551 * Returns a LTTng channel object descriptor
553 * Enables tracing for a session (weak enable)
555 * Disables tracing for a session (strong disable)
557 * The returned channel will be deleted when its file descriptor is closed.
560 long lttng_session_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
561 union ust_args
*uargs
, void *owner
)
563 struct lttng_session
*session
= objd_private(objd
);
566 case LTTNG_UST_CHANNEL
:
567 return lttng_abi_map_channel(objd
,
568 (struct lttng_ust_channel
*) arg
,
570 case LTTNG_UST_SESSION_START
:
571 case LTTNG_UST_ENABLE
:
572 return lttng_session_enable(session
);
573 case LTTNG_UST_SESSION_STOP
:
574 case LTTNG_UST_DISABLE
:
575 return lttng_session_disable(session
);
576 case LTTNG_UST_SESSION_STATEDUMP
:
577 return lttng_session_statedump(session
);
584 * Called when the last file reference is dropped.
586 * Big fat note: channels and events are invariant for the whole session after
587 * their creation. So this session destruction also destroys all channel and
588 * event structures specific to this session (they are not destroyed when their
589 * individual file is released).
592 int lttng_release_session(int objd
)
594 struct lttng_session
*session
= objd_private(objd
);
597 lttng_session_destroy(session
);
604 static const struct lttng_ust_objd_ops lttng_session_ops
= {
605 .release
= lttng_release_session
,
606 .cmd
= lttng_session_cmd
,
610 long lttng_tracepoint_list_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
611 union ust_args
*uargs
, void *owner
)
613 struct lttng_ust_tracepoint_list
*list
= objd_private(objd
);
614 struct lttng_ust_tracepoint_iter
*tp
=
615 (struct lttng_ust_tracepoint_iter
*) arg
;
616 struct lttng_ust_tracepoint_iter
*iter
;
619 case LTTNG_UST_TRACEPOINT_LIST_GET
:
621 iter
= lttng_ust_tracepoint_list_get_iter_next(list
);
623 return -LTTNG_UST_ERR_NOENT
;
624 memcpy(tp
, iter
, sizeof(*tp
));
633 int lttng_abi_tracepoint_list(void *owner
)
636 struct lttng_ust_tracepoint_list
*list
;
638 list_objd
= objd_alloc(NULL
, <tng_tracepoint_list_ops
, owner
, "tp_list");
643 list
= zmalloc(sizeof(*list
));
648 objd_set_private(list_objd
, list
);
650 /* populate list by walking on all registered probes. */
651 ret
= lttng_probes_get_event_list(list
);
663 err
= lttng_ust_objd_unref(list_objd
, 1);
671 int lttng_release_tracepoint_list(int objd
)
673 struct lttng_ust_tracepoint_list
*list
= objd_private(objd
);
676 lttng_probes_prune_event_list(list
);
684 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops
= {
685 .release
= lttng_release_tracepoint_list
,
686 .cmd
= lttng_tracepoint_list_cmd
,
690 long lttng_tracepoint_field_list_cmd(int objd
, unsigned int cmd
,
691 unsigned long arg
, union ust_args
*uargs
, void *owner
)
693 struct lttng_ust_field_list
*list
= objd_private(objd
);
694 struct lttng_ust_field_iter
*tp
= &uargs
->field_list
.entry
;
695 struct lttng_ust_field_iter
*iter
;
698 case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET
:
700 iter
= lttng_ust_field_list_get_iter_next(list
);
702 return -LTTNG_UST_ERR_NOENT
;
703 memcpy(tp
, iter
, sizeof(*tp
));
712 int lttng_abi_tracepoint_field_list(void *owner
)
715 struct lttng_ust_field_list
*list
;
717 list_objd
= objd_alloc(NULL
, <tng_tracepoint_field_list_ops
, owner
,
723 list
= zmalloc(sizeof(*list
));
728 objd_set_private(list_objd
, list
);
730 /* populate list by walking on all registered probes. */
731 ret
= lttng_probes_get_field_list(list
);
743 err
= lttng_ust_objd_unref(list_objd
, 1);
751 int lttng_release_tracepoint_field_list(int objd
)
753 struct lttng_ust_field_list
*list
= objd_private(objd
);
756 lttng_probes_prune_field_list(list
);
764 static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops
= {
765 .release
= lttng_release_tracepoint_field_list
,
766 .cmd
= lttng_tracepoint_field_list_cmd
,
770 int lttng_abi_map_stream(int channel_objd
, struct lttng_ust_stream
*info
,
771 union ust_args
*uargs
, void *owner
)
773 struct lttng_channel
*channel
= objd_private(channel_objd
);
776 ret
= channel_handle_add_stream(channel
->handle
,
777 uargs
->stream
.shm_fd
, uargs
->stream
.wakeup_fd
,
778 info
->stream_nr
, info
->len
);
780 goto error_add_stream
;
789 int lttng_abi_create_enabler(int channel_objd
,
790 struct lttng_ust_event
*event_param
,
792 enum lttng_enabler_type type
)
794 struct lttng_channel
*channel
= objd_private(channel_objd
);
795 struct lttng_enabler
*enabler
;
798 event_param
->name
[LTTNG_UST_SYM_NAME_LEN
- 1] = '\0';
799 event_objd
= objd_alloc(NULL
, <tng_enabler_ops
, owner
, "enabler");
800 if (event_objd
< 0) {
805 * We tolerate no failure path after event creation. It will stay
806 * invariant for the rest of the session.
808 enabler
= lttng_enabler_create(type
, event_param
, channel
);
813 objd_set_private(event_objd
, enabler
);
814 /* The event holds a reference on the channel */
815 objd_ref(channel_objd
);
822 err
= lttng_ust_objd_unref(event_objd
, 1);
830 * lttng_channel_cmd - lttng control through object descriptors
832 * @objd: the object descriptor
835 * @uargs: UST arguments (internal)
838 * This object descriptor implements lttng commands:
840 * Returns an event stream object descriptor or failure.
841 * (typically, one event stream records events from one CPU)
843 * Returns an event object descriptor or failure.
845 * Prepend a context field to each event in the channel
847 * Enable recording for events in this channel (weak enable)
849 * Disable recording for events in this channel (strong disable)
851 * Channel and event file descriptors also hold a reference on the session.
854 long lttng_channel_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
855 union ust_args
*uargs
, void *owner
)
857 struct lttng_channel
*channel
= objd_private(objd
);
859 if (cmd
!= LTTNG_UST_STREAM
) {
861 * Check if channel received all streams.
863 if (!lttng_is_channel_ready(channel
))
868 case LTTNG_UST_STREAM
:
870 struct lttng_ust_stream
*stream
;
872 stream
= (struct lttng_ust_stream
*) arg
;
873 /* stream used as output */
874 return lttng_abi_map_stream(objd
, stream
, uargs
, owner
);
876 case LTTNG_UST_EVENT
:
878 struct lttng_ust_event
*event_param
=
879 (struct lttng_ust_event
*) arg
;
880 if (event_param
->name
[strlen(event_param
->name
) - 1] == '*') {
881 /* If ends with wildcard, create wildcard. */
882 return lttng_abi_create_enabler(objd
, event_param
,
883 owner
, LTTNG_ENABLER_WILDCARD
);
885 return lttng_abi_create_enabler(objd
, event_param
,
886 owner
, LTTNG_ENABLER_EVENT
);
889 case LTTNG_UST_CONTEXT
:
890 return lttng_abi_add_context(objd
,
891 (struct lttng_ust_context
*) arg
, uargs
,
892 &channel
->ctx
, channel
->session
);
893 case LTTNG_UST_ENABLE
:
894 return lttng_channel_enable(channel
);
895 case LTTNG_UST_DISABLE
:
896 return lttng_channel_disable(channel
);
897 case LTTNG_UST_FLUSH_BUFFER
:
898 return channel
->ops
->flush_buffer(channel
->chan
, channel
->handle
);
905 int lttng_channel_release(int objd
)
907 struct lttng_channel
*channel
= objd_private(objd
);
910 return lttng_ust_objd_unref(channel
->session
->objd
, 0);
914 static const struct lttng_ust_objd_ops lttng_channel_ops
= {
915 .release
= lttng_channel_release
,
916 .cmd
= lttng_channel_cmd
,
920 * lttng_enabler_cmd - lttng control through object descriptors
922 * @objd: the object descriptor
925 * @uargs: UST arguments (internal)
928 * This object descriptor implements lttng commands:
930 * Prepend a context field to each record of events of this
933 * Enable recording for this enabler
935 * Disable recording for this enabler
937 * Attach a filter to an enabler.
938 * LTTNG_UST_EXCLUSION
939 * Attach exclusions to an enabler.
942 long lttng_enabler_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
943 union ust_args
*uargs
, void *owner
)
945 struct lttng_enabler
*enabler
= objd_private(objd
);
948 case LTTNG_UST_CONTEXT
:
949 return lttng_enabler_attach_context(enabler
,
950 (struct lttng_ust_context
*) arg
);
951 case LTTNG_UST_ENABLE
:
952 return lttng_enabler_enable(enabler
);
953 case LTTNG_UST_DISABLE
:
954 return lttng_enabler_disable(enabler
);
955 case LTTNG_UST_FILTER
:
959 ret
= lttng_enabler_attach_bytecode(enabler
,
960 (struct lttng_ust_filter_bytecode_node
*) arg
);
965 case LTTNG_UST_EXCLUSION
:
967 return lttng_enabler_attach_exclusion(enabler
,
968 (struct lttng_ust_excluder_node
*) arg
);
976 int lttng_enabler_release(int objd
)
978 struct lttng_enabler
*enabler
= objd_private(objd
);
981 return lttng_ust_objd_unref(enabler
->chan
->objd
, 0);
985 static const struct lttng_ust_objd_ops lttng_enabler_ops
= {
986 .release
= lttng_enabler_release
,
987 .cmd
= lttng_enabler_cmd
,
990 void lttng_ust_abi_exit(void)
992 lttng_ust_abi_close_in_progress
= 1;
994 objd_table_destroy();
996 lttng_ust_abi_close_in_progress
= 0;