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.
40 #include <lttng/ust-abi.h>
41 #include <lttng/ust-error.h>
42 #include <urcu/compiler.h>
43 #include <urcu/list.h>
44 #include <lttng/ust-events.h>
45 #include <lttng/ust-version.h>
46 #include <lttng/tracepoint.h>
47 #include "tracepoint-internal.h"
48 #include <usterr-signal-safe.h>
50 #include "lttng-tracer.h"
51 #include "../libringbuffer/shm.h"
52 #include "../libringbuffer/frontend_types.h"
54 #define OBJ_NAME_LEN 16
56 static int lttng_ust_abi_close_in_progress
;
59 int lttng_abi_tracepoint_list(void *owner
);
61 int lttng_abi_tracepoint_field_list(void *owner
);
64 * Object descriptor table. Should be protected from concurrent access
68 struct lttng_ust_obj
{
72 const struct lttng_ust_objd_ops
*ops
;
74 int owner_ref
; /* has ref from owner */
76 char name
[OBJ_NAME_LEN
];
78 int freelist_next
; /* offset freelist. end is -1. */
82 struct lttng_ust_objd_table
{
83 struct lttng_ust_obj
*array
;
84 unsigned int len
, allocated_len
;
85 int freelist_head
; /* offset freelist head. end is -1 */
88 static struct lttng_ust_objd_table objd_table
= {
93 int objd_alloc(void *private_data
, const struct lttng_ust_objd_ops
*ops
,
94 void *owner
, const char *name
)
96 struct lttng_ust_obj
*obj
;
98 if (objd_table
.freelist_head
!= -1) {
99 obj
= &objd_table
.array
[objd_table
.freelist_head
];
100 objd_table
.freelist_head
= obj
->u
.freelist_next
;
104 if (objd_table
.len
>= objd_table
.allocated_len
) {
105 unsigned int new_allocated_len
, old_allocated_len
;
106 struct lttng_ust_obj
*new_table
, *old_table
;
108 old_allocated_len
= objd_table
.allocated_len
;
109 old_table
= objd_table
.array
;
110 if (!old_allocated_len
)
111 new_allocated_len
= 1;
113 new_allocated_len
= old_allocated_len
<< 1;
114 new_table
= zmalloc(sizeof(struct lttng_ust_obj
) * new_allocated_len
);
117 memcpy(new_table
, old_table
,
118 sizeof(struct lttng_ust_obj
) * old_allocated_len
);
120 objd_table
.array
= new_table
;
121 objd_table
.allocated_len
= new_allocated_len
;
123 obj
= &objd_table
.array
[objd_table
.len
];
126 obj
->u
.s
.private_data
= private_data
;
128 obj
->u
.s
.f_count
= 2; /* count == 1 : object is allocated */
129 /* count == 2 : allocated + hold ref */
130 obj
->u
.s
.owner_ref
= 1; /* One owner reference */
131 obj
->u
.s
.owner
= owner
;
132 strncpy(obj
->u
.s
.name
, name
, OBJ_NAME_LEN
);
133 obj
->u
.s
.name
[OBJ_NAME_LEN
- 1] = '\0';
134 return obj
- objd_table
.array
;
138 struct lttng_ust_obj
*_objd_get(int id
)
140 if (id
>= objd_table
.len
)
142 if (!objd_table
.array
[id
].u
.s
.f_count
)
144 return &objd_table
.array
[id
];
148 void *objd_private(int id
)
150 struct lttng_ust_obj
*obj
= _objd_get(id
);
152 return obj
->u
.s
.private_data
;
156 void objd_set_private(int id
, void *private_data
)
158 struct lttng_ust_obj
*obj
= _objd_get(id
);
160 obj
->u
.s
.private_data
= private_data
;
163 const struct lttng_ust_objd_ops
*objd_ops(int id
)
165 struct lttng_ust_obj
*obj
= _objd_get(id
);
173 void objd_free(int id
)
175 struct lttng_ust_obj
*obj
= _objd_get(id
);
178 obj
->u
.freelist_next
= objd_table
.freelist_head
;
179 objd_table
.freelist_head
= obj
- objd_table
.array
;
180 assert(obj
->u
.s
.f_count
== 1);
181 obj
->u
.s
.f_count
= 0; /* deallocated */
185 void objd_ref(int id
)
187 struct lttng_ust_obj
*obj
= _objd_get(id
);
192 int lttng_ust_objd_unref(int id
, int is_owner
)
194 struct lttng_ust_obj
*obj
= _objd_get(id
);
198 if (obj
->u
.s
.f_count
== 1) {
199 ERR("Reference counting error\n");
203 if (!obj
->u
.s
.owner_ref
) {
204 ERR("Error decrementing owner reference");
207 obj
->u
.s
.owner_ref
--;
209 if ((--obj
->u
.s
.f_count
) == 1) {
210 const struct lttng_ust_objd_ops
*ops
= objd_ops(id
);
220 void objd_table_destroy(void)
224 for (i
= 0; i
< objd_table
.allocated_len
; i
++) {
225 struct lttng_ust_obj
*obj
;
230 if (!obj
->u
.s
.owner_ref
)
231 continue; /* only unref owner ref. */
232 (void) lttng_ust_objd_unref(i
, 1);
234 free(objd_table
.array
);
235 objd_table
.array
= NULL
;
237 objd_table
.allocated_len
= 0;
238 objd_table
.freelist_head
= -1;
241 const char *lttng_ust_obj_get_name(int id
)
243 struct lttng_ust_obj
*obj
= _objd_get(id
);
247 return obj
->u
.s
.name
;
250 void lttng_ust_objd_table_owner_cleanup(void *owner
)
254 for (i
= 0; i
< objd_table
.allocated_len
; i
++) {
255 struct lttng_ust_obj
*obj
;
261 continue; /* skip root handles */
262 if (!obj
->u
.s
.owner_ref
)
263 continue; /* only unref owner ref. */
264 if (obj
->u
.s
.owner
== owner
)
265 (void) lttng_ust_objd_unref(i
, 1);
270 * This is LTTng's own personal way to create an ABI for sessiond.
271 * We send commands over a socket.
274 static const struct lttng_ust_objd_ops lttng_ops
;
275 static const struct lttng_ust_objd_ops lttng_session_ops
;
276 static const struct lttng_ust_objd_ops lttng_channel_ops
;
277 static const struct lttng_ust_objd_ops lttng_enabler_ops
;
278 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops
;
279 static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops
;
281 int lttng_abi_create_root_handle(void)
285 /* root handles have NULL owners */
286 root_handle
= objd_alloc(NULL
, <tng_ops
, NULL
, "root");
291 int lttng_is_channel_ready(struct lttng_channel
*lttng_chan
)
293 struct channel
*chan
;
294 unsigned int nr_streams
, exp_streams
;
296 chan
= lttng_chan
->chan
;
297 nr_streams
= channel_handle_get_nr_streams(lttng_chan
->handle
);
298 exp_streams
= chan
->nr_streams
;
299 return nr_streams
== exp_streams
;
303 int lttng_abi_create_session(void *owner
)
305 struct lttng_session
*session
;
306 int session_objd
, ret
;
308 session
= lttng_session_create();
311 session_objd
= objd_alloc(session
, <tng_session_ops
, owner
, "session");
312 if (session_objd
< 0) {
316 session
->objd
= session_objd
;
317 session
->owner
= owner
;
321 lttng_session_destroy(session
);
326 long lttng_abi_tracer_version(int objd
,
327 struct lttng_ust_tracer_version
*v
)
329 v
->major
= LTTNG_UST_MAJOR_VERSION
;
330 v
->minor
= LTTNG_UST_MINOR_VERSION
;
331 v
->patchlevel
= LTTNG_UST_PATCHLEVEL_VERSION
;
336 long lttng_abi_add_context(int objd
,
337 struct lttng_ust_context
*context_param
,
338 union ust_args
*uargs
,
339 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
341 return lttng_attach_context(context_param
, uargs
, ctx
, session
);
345 * lttng_cmd - lttng control through socket commands
347 * @objd: the object descriptor
350 * @uargs: UST arguments (internal)
353 * This descriptor implements lttng commands:
355 * Returns a LTTng trace session object descriptor
356 * LTTNG_UST_TRACER_VERSION
357 * Returns the LTTng kernel tracer version
358 * LTTNG_UST_TRACEPOINT_LIST
359 * Returns a file descriptor listing available tracepoints
360 * LTTNG_UST_TRACEPOINT_FIELD_LIST
361 * Returns a file descriptor listing available tracepoint fields
362 * LTTNG_UST_WAIT_QUIESCENT
363 * Returns after all previously running probes have completed
365 * The returned session will be deleted when its file descriptor is closed.
368 long lttng_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
369 union ust_args
*uargs
, void *owner
)
372 case LTTNG_UST_SESSION
:
373 return lttng_abi_create_session(owner
);
374 case LTTNG_UST_TRACER_VERSION
:
375 return lttng_abi_tracer_version(objd
,
376 (struct lttng_ust_tracer_version
*) arg
);
377 case LTTNG_UST_TRACEPOINT_LIST
:
378 return lttng_abi_tracepoint_list(owner
);
379 case LTTNG_UST_TRACEPOINT_FIELD_LIST
:
380 return lttng_abi_tracepoint_field_list(owner
);
381 case LTTNG_UST_WAIT_QUIESCENT
:
389 static const struct lttng_ust_objd_ops lttng_ops
= {
393 int lttng_abi_map_channel(int session_objd
,
394 struct lttng_ust_channel
*ust_chan
,
395 union ust_args
*uargs
,
398 struct lttng_session
*session
= objd_private(session_objd
);
399 const char *transport_name
;
400 const struct lttng_transport
*transport
;
401 const char *chan_name
;
403 struct lttng_ust_shm_handle
*channel_handle
;
404 struct lttng_channel
*lttng_chan
;
405 struct channel
*chan
;
406 struct lttng_ust_lib_ring_buffer_config
*config
;
411 enum lttng_ust_chan_type type
;
413 chan_data
= uargs
->channel
.chan_data
;
414 wakeup_fd
= uargs
->channel
.wakeup_fd
;
416 type
= ust_chan
->type
;
419 case LTTNG_UST_CHAN_PER_CPU
:
426 if (session
->been_active
) {
428 goto active
; /* Refuse to add channel to active session */
431 channel_handle
= channel_handle_create(chan_data
, len
, wakeup_fd
);
432 if (!channel_handle
) {
437 chan
= shmp(channel_handle
, channel_handle
->chan
);
439 chan
->handle
= channel_handle
;
440 config
= &chan
->backend
.config
;
441 lttng_chan
= channel_get_private(chan
);
447 /* Lookup transport name */
449 case LTTNG_UST_CHAN_PER_CPU
:
450 if (config
->output
== RING_BUFFER_MMAP
) {
451 if (config
->mode
== RING_BUFFER_OVERWRITE
) {
452 if (config
->wakeup
== RING_BUFFER_WAKEUP_BY_WRITER
) {
453 transport_name
= "relay-overwrite-mmap";
455 transport_name
= "relay-overwrite-rt-mmap";
458 if (config
->wakeup
== RING_BUFFER_WAKEUP_BY_WRITER
) {
459 transport_name
= "relay-discard-mmap";
461 transport_name
= "relay-discard-rt-mmap";
468 chan_name
= "channel";
474 transport
= lttng_transport_find(transport_name
);
476 DBG("LTTng transport %s not found\n",
482 chan_objd
= objd_alloc(NULL
, <tng_channel_ops
, owner
, chan_name
);
488 /* Initialize our lttng chan */
489 lttng_chan
->chan
= chan
;
490 lttng_chan
->tstate
= 1;
491 lttng_chan
->enabled
= 1;
492 lttng_chan
->ctx
= NULL
;
493 lttng_chan
->session
= session
;
494 lttng_chan
->ops
= &transport
->ops
;
495 memcpy(<tng_chan
->chan
->backend
.config
,
496 transport
->client_config
,
497 sizeof(lttng_chan
->chan
->backend
.config
));
498 cds_list_add(<tng_chan
->node
, &session
->chan_head
);
499 lttng_chan
->header_type
= 0;
500 lttng_chan
->handle
= channel_handle
;
501 lttng_chan
->type
= type
;
504 * We tolerate no failure path after channel creation. It will stay
505 * invariant for the rest of the session.
507 objd_set_private(chan_objd
, lttng_chan
);
508 lttng_chan
->objd
= chan_objd
;
509 /* The channel created holds a reference on the session */
510 objd_ref(session_objd
);
513 /* 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;