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 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
340 return lttng_attach_context(context_param
, ctx
, session
);
344 * lttng_cmd - lttng control through socket commands
346 * @objd: the object descriptor
349 * @uargs: UST arguments (internal)
352 * This descriptor implements lttng commands:
354 * Returns a LTTng trace session object descriptor
355 * LTTNG_UST_TRACER_VERSION
356 * Returns the LTTng kernel tracer version
357 * LTTNG_UST_TRACEPOINT_LIST
358 * Returns a file descriptor listing available tracepoints
359 * LTTNG_UST_TRACEPOINT_FIELD_LIST
360 * Returns a file descriptor listing available tracepoint fields
361 * LTTNG_UST_WAIT_QUIESCENT
362 * Returns after all previously running probes have completed
364 * The returned session will be deleted when its file descriptor is closed.
367 long lttng_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
368 union ust_args
*uargs
, void *owner
)
371 case LTTNG_UST_SESSION
:
372 return lttng_abi_create_session(owner
);
373 case LTTNG_UST_TRACER_VERSION
:
374 return lttng_abi_tracer_version(objd
,
375 (struct lttng_ust_tracer_version
*) arg
);
376 case LTTNG_UST_TRACEPOINT_LIST
:
377 return lttng_abi_tracepoint_list(owner
);
378 case LTTNG_UST_TRACEPOINT_FIELD_LIST
:
379 return lttng_abi_tracepoint_field_list(owner
);
380 case LTTNG_UST_WAIT_QUIESCENT
:
388 static const struct lttng_ust_objd_ops lttng_ops
= {
392 int lttng_abi_map_channel(int session_objd
,
393 struct lttng_ust_channel
*ust_chan
,
394 union ust_args
*uargs
,
397 struct lttng_session
*session
= objd_private(session_objd
);
398 const char *transport_name
;
399 const struct lttng_transport
*transport
;
400 const char *chan_name
;
402 struct lttng_ust_shm_handle
*channel_handle
;
403 struct lttng_channel
*lttng_chan
;
404 struct channel
*chan
;
405 struct lttng_ust_lib_ring_buffer_config
*config
;
410 enum lttng_ust_chan_type type
;
412 chan_data
= uargs
->channel
.chan_data
;
413 wakeup_fd
= uargs
->channel
.wakeup_fd
;
415 type
= ust_chan
->type
;
418 case LTTNG_UST_CHAN_PER_CPU
:
425 if (session
->been_active
) {
427 goto active
; /* Refuse to add channel to active session */
430 channel_handle
= channel_handle_create(chan_data
, len
, wakeup_fd
);
431 if (!channel_handle
) {
436 chan
= shmp(channel_handle
, channel_handle
->chan
);
438 chan
->handle
= channel_handle
;
439 config
= &chan
->backend
.config
;
440 lttng_chan
= channel_get_private(chan
);
446 /* Lookup transport name */
448 case LTTNG_UST_CHAN_PER_CPU
:
449 if (config
->output
== RING_BUFFER_MMAP
) {
450 if (config
->mode
== RING_BUFFER_OVERWRITE
) {
451 if (config
->wakeup
== RING_BUFFER_WAKEUP_BY_WRITER
) {
452 transport_name
= "relay-overwrite-mmap";
454 transport_name
= "relay-overwrite-rt-mmap";
457 if (config
->wakeup
== RING_BUFFER_WAKEUP_BY_WRITER
) {
458 transport_name
= "relay-discard-mmap";
460 transport_name
= "relay-discard-rt-mmap";
467 chan_name
= "channel";
473 transport
= lttng_transport_find(transport_name
);
475 DBG("LTTng transport %s not found\n",
481 chan_objd
= objd_alloc(NULL
, <tng_channel_ops
, owner
, chan_name
);
487 /* Initialize our lttng chan */
488 lttng_chan
->chan
= chan
;
489 lttng_chan
->tstate
= 1;
490 lttng_chan
->enabled
= 1;
491 lttng_chan
->ctx
= NULL
;
492 lttng_chan
->session
= session
;
493 lttng_chan
->ops
= &transport
->ops
;
494 memcpy(<tng_chan
->chan
->backend
.config
,
495 transport
->client_config
,
496 sizeof(lttng_chan
->chan
->backend
.config
));
497 cds_list_add(<tng_chan
->node
, &session
->chan_head
);
498 lttng_chan
->header_type
= 0;
499 lttng_chan
->handle
= channel_handle
;
500 lttng_chan
->type
= type
;
503 * We tolerate no failure path after channel creation. It will stay
504 * invariant for the rest of the session.
506 objd_set_private(chan_objd
, lttng_chan
);
507 lttng_chan
->objd
= chan_objd
;
508 /* The channel created holds a reference on the session */
509 objd_ref(session_objd
);
512 /* error path after channel was created */
517 channel_destroy(chan
, channel_handle
, 0);
521 * error path before channel creation (owning chan_data and
530 close_ret
= close(wakeup_fd
);
540 * lttng_session_cmd - lttng session object command
545 * @uargs: UST arguments (internal)
548 * This descriptor implements lttng commands:
550 * Returns a LTTng channel object descriptor
552 * Enables tracing for a session (weak enable)
554 * Disables tracing for a session (strong disable)
556 * The returned channel will be deleted when its file descriptor is closed.
559 long lttng_session_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
560 union ust_args
*uargs
, void *owner
)
562 struct lttng_session
*session
= objd_private(objd
);
565 case LTTNG_UST_CHANNEL
:
566 return lttng_abi_map_channel(objd
,
567 (struct lttng_ust_channel
*) arg
,
569 case LTTNG_UST_SESSION_START
:
570 case LTTNG_UST_ENABLE
:
571 return lttng_session_enable(session
);
572 case LTTNG_UST_SESSION_STOP
:
573 case LTTNG_UST_DISABLE
:
574 return lttng_session_disable(session
);
581 * Called when the last file reference is dropped.
583 * Big fat note: channels and events are invariant for the whole session after
584 * their creation. So this session destruction also destroys all channel and
585 * event structures specific to this session (they are not destroyed when their
586 * individual file is released).
589 int lttng_release_session(int objd
)
591 struct lttng_session
*session
= objd_private(objd
);
594 lttng_session_destroy(session
);
601 static const struct lttng_ust_objd_ops lttng_session_ops
= {
602 .release
= lttng_release_session
,
603 .cmd
= lttng_session_cmd
,
607 long lttng_tracepoint_list_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
608 union ust_args
*uargs
, void *owner
)
610 struct lttng_ust_tracepoint_list
*list
= objd_private(objd
);
611 struct lttng_ust_tracepoint_iter
*tp
=
612 (struct lttng_ust_tracepoint_iter
*) arg
;
613 struct lttng_ust_tracepoint_iter
*iter
;
616 case LTTNG_UST_TRACEPOINT_LIST_GET
:
618 iter
= lttng_ust_tracepoint_list_get_iter_next(list
);
620 return -LTTNG_UST_ERR_NOENT
;
621 memcpy(tp
, iter
, sizeof(*tp
));
630 int lttng_abi_tracepoint_list(void *owner
)
633 struct lttng_ust_tracepoint_list
*list
;
635 list_objd
= objd_alloc(NULL
, <tng_tracepoint_list_ops
, owner
, "tp_list");
640 list
= zmalloc(sizeof(*list
));
645 objd_set_private(list_objd
, list
);
647 /* populate list by walking on all registered probes. */
648 ret
= lttng_probes_get_event_list(list
);
660 err
= lttng_ust_objd_unref(list_objd
, 1);
668 int lttng_release_tracepoint_list(int objd
)
670 struct lttng_ust_tracepoint_list
*list
= objd_private(objd
);
673 lttng_probes_prune_event_list(list
);
681 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops
= {
682 .release
= lttng_release_tracepoint_list
,
683 .cmd
= lttng_tracepoint_list_cmd
,
687 long lttng_tracepoint_field_list_cmd(int objd
, unsigned int cmd
,
688 unsigned long arg
, union ust_args
*uargs
, void *owner
)
690 struct lttng_ust_field_list
*list
= objd_private(objd
);
691 struct lttng_ust_field_iter
*tp
= &uargs
->field_list
.entry
;
692 struct lttng_ust_field_iter
*iter
;
695 case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET
:
697 iter
= lttng_ust_field_list_get_iter_next(list
);
699 return -LTTNG_UST_ERR_NOENT
;
700 memcpy(tp
, iter
, sizeof(*tp
));
709 int lttng_abi_tracepoint_field_list(void *owner
)
712 struct lttng_ust_field_list
*list
;
714 list_objd
= objd_alloc(NULL
, <tng_tracepoint_field_list_ops
, owner
,
720 list
= zmalloc(sizeof(*list
));
725 objd_set_private(list_objd
, list
);
727 /* populate list by walking on all registered probes. */
728 ret
= lttng_probes_get_field_list(list
);
740 err
= lttng_ust_objd_unref(list_objd
, 1);
748 int lttng_release_tracepoint_field_list(int objd
)
750 struct lttng_ust_field_list
*list
= objd_private(objd
);
753 lttng_probes_prune_field_list(list
);
761 static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops
= {
762 .release
= lttng_release_tracepoint_field_list
,
763 .cmd
= lttng_tracepoint_field_list_cmd
,
767 int lttng_abi_map_stream(int channel_objd
, struct lttng_ust_stream
*info
,
768 union ust_args
*uargs
, void *owner
)
770 struct lttng_channel
*channel
= objd_private(channel_objd
);
773 ret
= channel_handle_add_stream(channel
->handle
,
774 uargs
->stream
.shm_fd
, uargs
->stream
.wakeup_fd
,
775 info
->stream_nr
, info
->len
);
777 goto error_add_stream
;
786 int lttng_abi_create_enabler(int channel_objd
,
787 struct lttng_ust_event
*event_param
,
789 enum lttng_enabler_type type
)
791 struct lttng_channel
*channel
= objd_private(channel_objd
);
792 struct lttng_enabler
*enabler
;
795 event_param
->name
[LTTNG_UST_SYM_NAME_LEN
- 1] = '\0';
796 event_objd
= objd_alloc(NULL
, <tng_enabler_ops
, owner
, "enabler");
797 if (event_objd
< 0) {
802 * We tolerate no failure path after event creation. It will stay
803 * invariant for the rest of the session.
805 enabler
= lttng_enabler_create(type
, event_param
, channel
);
810 objd_set_private(event_objd
, enabler
);
811 /* The event holds a reference on the channel */
812 objd_ref(channel_objd
);
819 err
= lttng_ust_objd_unref(event_objd
, 1);
827 * lttng_channel_cmd - lttng control through object descriptors
829 * @objd: the object descriptor
832 * @uargs: UST arguments (internal)
835 * This object descriptor implements lttng commands:
837 * Returns an event stream object descriptor or failure.
838 * (typically, one event stream records events from one CPU)
840 * Returns an event object descriptor or failure.
842 * Prepend a context field to each event in the channel
844 * Enable recording for events in this channel (weak enable)
846 * Disable recording for events in this channel (strong disable)
848 * Channel and event file descriptors also hold a reference on the session.
851 long lttng_channel_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
852 union ust_args
*uargs
, void *owner
)
854 struct lttng_channel
*channel
= objd_private(objd
);
856 if (cmd
!= LTTNG_UST_STREAM
) {
858 * Check if channel received all streams.
860 if (!lttng_is_channel_ready(channel
))
865 case LTTNG_UST_STREAM
:
867 struct lttng_ust_stream
*stream
;
869 stream
= (struct lttng_ust_stream
*) arg
;
870 /* stream used as output */
871 return lttng_abi_map_stream(objd
, stream
, uargs
, owner
);
873 case LTTNG_UST_EVENT
:
875 struct lttng_ust_event
*event_param
=
876 (struct lttng_ust_event
*) arg
;
877 if (event_param
->name
[strlen(event_param
->name
) - 1] == '*') {
878 /* If ends with wildcard, create wildcard. */
879 return lttng_abi_create_enabler(objd
, event_param
,
880 owner
, LTTNG_ENABLER_WILDCARD
);
882 return lttng_abi_create_enabler(objd
, event_param
,
883 owner
, LTTNG_ENABLER_EVENT
);
886 case LTTNG_UST_CONTEXT
:
887 return lttng_abi_add_context(objd
,
888 (struct lttng_ust_context
*) arg
,
889 &channel
->ctx
, channel
->session
);
890 case LTTNG_UST_ENABLE
:
891 return lttng_channel_enable(channel
);
892 case LTTNG_UST_DISABLE
:
893 return lttng_channel_disable(channel
);
894 case LTTNG_UST_FLUSH_BUFFER
:
895 return channel
->ops
->flush_buffer(channel
->chan
, channel
->handle
);
902 int lttng_channel_release(int objd
)
904 struct lttng_channel
*channel
= objd_private(objd
);
907 return lttng_ust_objd_unref(channel
->session
->objd
, 0);
911 static const struct lttng_ust_objd_ops lttng_channel_ops
= {
912 .release
= lttng_channel_release
,
913 .cmd
= lttng_channel_cmd
,
917 * lttng_enabler_cmd - lttng control through object descriptors
919 * @objd: the object descriptor
922 * @uargs: UST arguments (internal)
925 * This object descriptor implements lttng commands:
927 * Prepend a context field to each record of events of this
930 * Enable recording for this enabler
932 * Disable recording for this enabler
934 * Attach a filter to an enabler.
935 * LTTNG_UST_EXCLUSION
936 * Attach exclusions to an enabler.
939 long lttng_enabler_cmd(int objd
, unsigned int cmd
, unsigned long arg
,
940 union ust_args
*uargs
, void *owner
)
942 struct lttng_enabler
*enabler
= objd_private(objd
);
945 case LTTNG_UST_CONTEXT
:
946 return lttng_enabler_attach_context(enabler
,
947 (struct lttng_ust_context
*) arg
);
948 case LTTNG_UST_ENABLE
:
949 return lttng_enabler_enable(enabler
);
950 case LTTNG_UST_DISABLE
:
951 return lttng_enabler_disable(enabler
);
952 case LTTNG_UST_FILTER
:
956 ret
= lttng_enabler_attach_bytecode(enabler
,
957 (struct lttng_ust_filter_bytecode_node
*) arg
);
962 case LTTNG_UST_EXCLUSION
:
964 return lttng_enabler_attach_exclusion(enabler
,
965 (struct lttng_ust_excluder_node
*) arg
);
973 int lttng_enabler_release(int objd
)
975 struct lttng_enabler
*enabler
= objd_private(objd
);
978 return lttng_ust_objd_unref(enabler
->chan
->objd
, 0);
982 static const struct lttng_ust_objd_ops lttng_enabler_ops
= {
983 .release
= lttng_enabler_release
,
984 .cmd
= lttng_enabler_cmd
,
987 void lttng_ust_abi_exit(void)
989 lttng_ust_abi_close_in_progress
= 1;
991 objd_table_destroy();
993 lttng_ust_abi_close_in_progress
= 0;