2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <common/common.h>
27 #include <common/kernel-ctl/kernel-ctl.h>
28 #include <common/kernel-ctl/kernel-ioctl.h>
29 #include <common/sessiond-comm/sessiond-comm.h>
33 #include "kernel-consumer.h"
34 #include "kern-modules.h"
38 * Add context on a kernel channel.
40 * Assumes the ownership of ctx.
42 int kernel_add_channel_context(struct ltt_kernel_channel
*chan
,
43 struct ltt_kernel_context
*ctx
)
50 DBG("Adding context to channel %s", chan
->channel
->name
);
51 ret
= kernctl_add_context(chan
->fd
, &ctx
->ctx
);
55 /* Exists but not available for this kernel */
56 ret
= LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE
;
59 /* If EEXIST, we just ignore the error */
63 PERROR("add context ioctl");
64 ret
= LTTNG_ERR_KERN_CONTEXT_FAIL
;
70 cds_list_add_tail(&ctx
->list
, &chan
->ctx_list
);
75 trace_kernel_destroy_context(ctx
);
81 * Create a new kernel session, register it to the kernel tracer and add it to
82 * the session daemon session.
84 int kernel_create_session(struct ltt_session
*session
, int tracer_fd
)
87 struct ltt_kernel_session
*lks
;
91 /* Allocate data structure */
92 lks
= trace_kernel_create_session();
98 /* Kernel tracer session creation */
99 ret
= kernctl_create_session(tracer_fd
);
101 PERROR("ioctl kernel create session");
106 /* Prevent fd duplication after execlp() */
107 ret
= fcntl(lks
->fd
, F_SETFD
, FD_CLOEXEC
);
109 PERROR("fcntl session fd");
112 lks
->id
= session
->id
;
113 lks
->consumer_fds_sent
= 0;
114 session
->kernel_session
= lks
;
116 DBG("Kernel session created (fd: %d)", lks
->fd
);
122 trace_kernel_destroy_session(lks
);
128 * Create a kernel channel, register it to the kernel tracer and add it to the
131 int kernel_create_channel(struct ltt_kernel_session
*session
,
132 struct lttng_channel
*chan
)
135 struct ltt_kernel_channel
*lkc
;
140 /* Allocate kernel channel */
141 lkc
= trace_kernel_create_channel(chan
);
146 DBG3("Kernel create channel %s with attr: %d, %" PRIu64
", %" PRIu64
", %u, %u, %d, %d",
147 chan
->name
, lkc
->channel
->attr
.overwrite
,
148 lkc
->channel
->attr
.subbuf_size
, lkc
->channel
->attr
.num_subbuf
,
149 lkc
->channel
->attr
.switch_timer_interval
, lkc
->channel
->attr
.read_timer_interval
,
150 lkc
->channel
->attr
.live_timer_interval
, lkc
->channel
->attr
.output
);
152 /* Kernel tracer channel creation */
153 ret
= kernctl_create_channel(session
->fd
, &lkc
->channel
->attr
);
155 PERROR("ioctl kernel create channel");
159 /* Setup the channel fd */
161 /* Prevent fd duplication after execlp() */
162 ret
= fcntl(lkc
->fd
, F_SETFD
, FD_CLOEXEC
);
164 PERROR("fcntl session fd");
167 /* Add channel to session */
168 cds_list_add(&lkc
->list
, &session
->channel_list
.head
);
169 session
->channel_count
++;
170 lkc
->session
= session
;
172 DBG("Kernel channel %s created (fd: %d)", lkc
->channel
->name
, lkc
->fd
);
185 * Create a kernel event, enable it to the kernel tracer and add it to the
186 * channel event list of the kernel session.
187 * We own filter_expression and filter.
189 int kernel_create_event(struct lttng_event
*ev
,
190 struct ltt_kernel_channel
*channel
,
191 char *filter_expression
,
192 struct lttng_filter_bytecode
*filter
)
195 struct ltt_kernel_event
*event
;
200 /* We pass ownership of filter_expression and filter */
201 event
= trace_kernel_create_event(ev
, filter_expression
,
208 ret
= kernctl_create_event(channel
->fd
, event
->event
);
214 WARN("Event type not implemented");
217 WARN("Event %s not found!", ev
->name
);
220 PERROR("create event ioctl");
225 event
->type
= ev
->type
;
227 /* Prevent fd duplication after execlp() */
228 ret
= fcntl(event
->fd
, F_SETFD
, FD_CLOEXEC
);
230 PERROR("fcntl session fd");
234 ret
= kernctl_filter(event
->fd
, filter
);
240 ret
= kernctl_enable(event
->fd
);
244 ret
= LTTNG_ERR_KERN_EVENT_EXIST
;
247 PERROR("enable kernel event");
253 /* Add event to event list */
254 cds_list_add(&event
->list
, &channel
->events_list
.head
);
255 channel
->event_count
++;
257 DBG("Event %s created (fd: %d)", ev
->name
, event
->fd
);
266 closeret
= close(event
->fd
);
268 PERROR("close event fd");
278 * Disable a kernel channel.
280 int kernel_disable_channel(struct ltt_kernel_channel
*chan
)
286 ret
= kernctl_disable(chan
->fd
);
288 PERROR("disable chan ioctl");
293 DBG("Kernel channel %s disabled (fd: %d)", chan
->channel
->name
, chan
->fd
);
302 * Enable a kernel channel.
304 int kernel_enable_channel(struct ltt_kernel_channel
*chan
)
310 ret
= kernctl_enable(chan
->fd
);
311 if (ret
< 0 && ret
!= -EEXIST
) {
312 PERROR("Enable kernel chan");
317 DBG("Kernel channel %s enabled (fd: %d)", chan
->channel
->name
, chan
->fd
);
326 * Enable a kernel event.
328 int kernel_enable_event(struct ltt_kernel_event
*event
)
334 ret
= kernctl_enable(event
->fd
);
338 ret
= LTTNG_ERR_KERN_EVENT_EXIST
;
341 PERROR("enable kernel event");
348 DBG("Kernel event %s enabled (fd: %d)", event
->event
->name
, event
->fd
);
357 * Disable a kernel event.
359 int kernel_disable_event(struct ltt_kernel_event
*event
)
365 ret
= kernctl_disable(event
->fd
);
369 ret
= LTTNG_ERR_KERN_EVENT_EXIST
;
372 PERROR("disable kernel event");
379 DBG("Kernel event %s disabled (fd: %d)", event
->event
->name
, event
->fd
);
388 struct lttng_tracker_list
*get_id_tracker_list(struct ltt_kernel_session
*session
,
389 enum lttng_tracker_type tracker_type
)
391 switch (tracker_type
) {
392 case LTTNG_TRACKER_PID
:
393 return session
->tracker_list_pid
;
394 case LTTNG_TRACKER_VPID
:
395 return session
->tracker_list_vpid
;
396 case LTTNG_TRACKER_UID
:
397 return session
->tracker_list_uid
;
398 case LTTNG_TRACKER_VUID
:
399 return session
->tracker_list_vuid
;
400 case LTTNG_TRACKER_GID
:
401 return session
->tracker_list_gid
;
402 case LTTNG_TRACKER_VGID
:
403 return session
->tracker_list_vgid
;
409 int kernel_track_id(enum lttng_tracker_type tracker_type
,
410 struct ltt_kernel_session
*session
,
411 struct lttng_tracker_id
*id
)
414 struct lttng_tracker_list
*tracker_list
;
415 struct lttng_tracker_id
*saved_ids
;
416 ssize_t saved_ids_count
, i
;
418 ret
= lttng_tracker_id_lookup_string(tracker_type
,
420 if (ret
!= LTTNG_OK
) {
424 tracker_list
= get_id_tracker_list(session
, tracker_type
);
426 return LTTNG_ERR_INVALID
;
428 /* Save list for restore on error. */
429 saved_ids_count
= lttng_tracker_id_get_list(tracker_list
, &saved_ids
);
430 if (saved_ids_count
< 0) {
431 return LTTNG_ERR_INVALID
;
434 ret
= lttng_tracker_list_add(tracker_list
, id
);
435 if (ret
!= LTTNG_OK
) {
439 switch (tracker_type
) {
440 case LTTNG_TRACKER_PID
:
441 DBG("Kernel track PID %d for session id %" PRIu64
".",
443 ret
= kernctl_track_pid(session
->fd
, value
);
449 case LTTNG_TRACKER_VPID
:
450 DBG("Kernel track VPID %d for session id %" PRIu64
".",
452 ret
= kernctl_track_id(session
->fd
, LTTNG_TRACKER_VPID
, value
);
458 case LTTNG_TRACKER_UID
:
459 DBG("Kernel track UID %d for session id %" PRIu64
".",
461 ret
= kernctl_track_id(session
->fd
, LTTNG_TRACKER_UID
, value
);
467 case LTTNG_TRACKER_GID
:
468 DBG("Kernel track GID %d for session id %" PRIu64
".",
470 ret
= kernctl_track_id(session
->fd
, LTTNG_TRACKER_GID
, value
);
476 case LTTNG_TRACKER_VUID
:
477 DBG("Kernel track VUID %d for session id %" PRIu64
".",
479 ret
= kernctl_track_id(session
->fd
, LTTNG_TRACKER_VUID
, value
);
485 case LTTNG_TRACKER_VGID
:
486 DBG("Kernel track VGID %d for session id %" PRIu64
".",
488 ret
= kernctl_track_id(session
->fd
, LTTNG_TRACKER_VGID
, value
);
498 /* Error handling. */
501 ret
= LTTNG_ERR_INVALID
;
504 ret
= LTTNG_ERR_NOMEM
;
507 ret
= LTTNG_ERR_ID_TRACKED
;
513 if (lttng_tracker_id_set_list(tracker_list
, saved_ids
, saved_ids_count
) != LTTNG_OK
) {
514 ERR("Error on tracker add error handling.\n");
517 for (i
= 0; i
< saved_ids_count
; i
++) {
518 free(saved_ids
[i
].string
);
524 int kernel_untrack_id(enum lttng_tracker_type tracker_type
,
525 struct ltt_kernel_session
*session
,
526 struct lttng_tracker_id
*id
)
529 struct lttng_tracker_list
*tracker_list
;
530 struct lttng_tracker_id
*saved_ids
;
531 ssize_t saved_ids_count
, i
;
533 ret
= lttng_tracker_id_lookup_string(tracker_type
,
535 if (ret
!= LTTNG_OK
) {
539 tracker_list
= get_id_tracker_list(session
, tracker_type
);
541 return LTTNG_ERR_INVALID
;
543 /* Save list for restore on error. */
544 saved_ids_count
= lttng_tracker_id_get_list(tracker_list
, &saved_ids
);
545 if (saved_ids_count
< 0) {
546 return LTTNG_ERR_INVALID
;
548 /* Remove from list. */
549 ret
= lttng_tracker_list_remove(tracker_list
, id
);
550 if (ret
!= LTTNG_OK
) {
554 switch (tracker_type
) {
555 case LTTNG_TRACKER_PID
:
556 DBG("Kernel untrack PID %d for session id %" PRIu64
".",
558 ret
= kernctl_untrack_pid(session
->fd
, value
);
564 case LTTNG_TRACKER_VPID
:
565 DBG("Kernel untrack VPID %d for session id %" PRIu64
".",
567 ret
= kernctl_untrack_id(session
->fd
, LTTNG_TRACKER_VPID
, value
);
573 case LTTNG_TRACKER_UID
:
574 DBG("Kernel untrack UID %d for session id %" PRIu64
".",
576 ret
= kernctl_untrack_id(session
->fd
, LTTNG_TRACKER_UID
, value
);
582 case LTTNG_TRACKER_GID
:
583 DBG("Kernel untrack GID %d for session id %" PRIu64
".",
585 ret
= kernctl_untrack_id(session
->fd
, LTTNG_TRACKER_GID
, value
);
591 case LTTNG_TRACKER_VUID
:
592 DBG("Kernel untrack VUID %d for session id %" PRIu64
".",
594 ret
= kernctl_untrack_id(session
->fd
, LTTNG_TRACKER_VUID
, value
);
600 case LTTNG_TRACKER_VGID
:
601 DBG("Kernel untrack VGID %d for session id %" PRIu64
".",
603 ret
= kernctl_untrack_id(session
->fd
, LTTNG_TRACKER_VGID
, value
);
614 /* Error handling. */
617 ret
= LTTNG_ERR_INVALID
;
620 ret
= LTTNG_ERR_NOMEM
;
623 ret
= LTTNG_ERR_ID_TRACKED
;
630 if (lttng_tracker_id_set_list(tracker_list
, saved_ids
, saved_ids_count
) != LTTNG_OK
) {
631 ERR("Error on tracker remove error handling.\n");
634 for (i
= 0; i
< saved_ids_count
; i
++) {
635 free(saved_ids
[i
].string
);
642 * Called with session lock held.
644 ssize_t
kernel_list_tracker_ids(enum lttng_tracker_type tracker_type
,
645 struct ltt_kernel_session
*session
,
646 struct lttng_tracker_id
**_ids
)
648 struct lttng_tracker_list
*tracker_list
;
650 tracker_list
= get_id_tracker_list(session
, tracker_type
);
652 return -LTTNG_ERR_INVALID
;
654 return lttng_tracker_id_get_list(tracker_list
, _ids
);
658 * Create kernel metadata, open from the kernel tracer and add it to the
661 int kernel_open_metadata(struct ltt_kernel_session
*session
)
664 struct ltt_kernel_metadata
*lkm
= NULL
;
668 /* Allocate kernel metadata */
669 lkm
= trace_kernel_create_metadata();
674 /* Kernel tracer metadata creation */
675 ret
= kernctl_open_metadata(session
->fd
, &lkm
->conf
->attr
);
681 /* Prevent fd duplication after execlp() */
682 ret
= fcntl(lkm
->fd
, F_SETFD
, FD_CLOEXEC
);
684 PERROR("fcntl session fd");
687 session
->metadata
= lkm
;
689 DBG("Kernel metadata opened (fd: %d)", lkm
->fd
);
694 trace_kernel_destroy_metadata(lkm
);
700 * Start tracing session.
702 int kernel_start_session(struct ltt_kernel_session
*session
)
708 ret
= kernctl_start_session(session
->fd
);
710 PERROR("ioctl start session");
714 DBG("Kernel session started");
723 * Make a kernel wait to make sure in-flight probe have completed.
725 void kernel_wait_quiescent(int fd
)
729 DBG("Kernel quiescent wait on %d", fd
);
731 ret
= kernctl_wait_quiescent(fd
);
733 PERROR("wait quiescent ioctl");
734 ERR("Kernel quiescent wait failed");
739 * Force flush buffer of metadata.
741 int kernel_metadata_flush_buffer(int fd
)
745 DBG("Kernel flushing metadata buffer on fd %d", fd
);
747 ret
= kernctl_buffer_flush(fd
);
749 ERR("Fail to flush metadata buffers %d (ret: %d)", fd
, ret
);
756 * Force flush buffer for channel.
758 int kernel_flush_buffer(struct ltt_kernel_channel
*channel
)
761 struct ltt_kernel_stream
*stream
;
765 DBG("Flush buffer for channel %s", channel
->channel
->name
);
767 cds_list_for_each_entry(stream
, &channel
->stream_list
.head
, list
) {
768 DBG("Flushing channel stream %d", stream
->fd
);
769 ret
= kernctl_buffer_flush(stream
->fd
);
772 ERR("Fail to flush buffer for stream %d (ret: %d)",
781 * Stop tracing session.
783 int kernel_stop_session(struct ltt_kernel_session
*session
)
789 ret
= kernctl_stop_session(session
->fd
);
794 DBG("Kernel session stopped");
803 * Open stream of channel, register it to the kernel tracer and add it
804 * to the stream list of the channel.
806 * Note: given that the streams may appear in random order wrt CPU
807 * number (e.g. cpu hotplug), the index value of the stream number in
808 * the stream name is not necessarily linked to the CPU number.
810 * Return the number of created stream. Else, a negative value.
812 int kernel_open_channel_stream(struct ltt_kernel_channel
*channel
)
815 struct ltt_kernel_stream
*lks
;
819 while ((ret
= kernctl_create_stream(channel
->fd
)) >= 0) {
820 lks
= trace_kernel_create_stream(channel
->channel
->name
,
821 channel
->stream_count
);
831 /* Prevent fd duplication after execlp() */
832 ret
= fcntl(lks
->fd
, F_SETFD
, FD_CLOEXEC
);
834 PERROR("fcntl session fd");
837 lks
->tracefile_size
= channel
->channel
->attr
.tracefile_size
;
838 lks
->tracefile_count
= channel
->channel
->attr
.tracefile_count
;
840 /* Add stream to channel stream list */
841 cds_list_add(&lks
->list
, &channel
->stream_list
.head
);
842 channel
->stream_count
++;
844 DBG("Kernel stream %s created (fd: %d, state: %d)", lks
->name
, lks
->fd
,
848 return channel
->stream_count
;
855 * Open the metadata stream and set it to the kernel session.
857 int kernel_open_metadata_stream(struct ltt_kernel_session
*session
)
863 ret
= kernctl_create_stream(session
->metadata
->fd
);
865 PERROR("kernel create metadata stream");
869 DBG("Kernel metadata stream created (fd: %d)", ret
);
870 session
->metadata_stream_fd
= ret
;
871 /* Prevent fd duplication after execlp() */
872 ret
= fcntl(session
->metadata_stream_fd
, F_SETFD
, FD_CLOEXEC
);
874 PERROR("fcntl session fd");
884 * Get the event list from the kernel tracer and return the number of elements.
886 ssize_t
kernel_list_events(int tracer_fd
, struct lttng_event
**events
)
890 size_t nbmem
, count
= 0;
892 struct lttng_event
*elist
;
896 fd
= kernctl_tracepoint_list(tracer_fd
);
898 PERROR("kernel tracepoint list");
902 fp
= fdopen(fd
, "r");
904 PERROR("kernel tracepoint list fdopen");
909 * Init memory size counter
910 * See kernel-ctl.h for explanation of this value
912 nbmem
= KERNEL_EVENT_INIT_LIST_SIZE
;
913 elist
= zmalloc(sizeof(struct lttng_event
) * nbmem
);
915 PERROR("alloc list events");
920 while (fscanf(fp
, "event { name = %m[^;]; };\n", &event
) == 1) {
921 if (count
>= nbmem
) {
922 struct lttng_event
*new_elist
;
925 new_nbmem
= nbmem
<< 1;
926 DBG("Reallocating event list from %zu to %zu bytes",
928 new_elist
= realloc(elist
, new_nbmem
* sizeof(struct lttng_event
));
929 if (new_elist
== NULL
) {
930 PERROR("realloc list events");
936 /* Zero the new memory */
937 memset(new_elist
+ nbmem
, 0,
938 (new_nbmem
- nbmem
) * sizeof(struct lttng_event
));
942 strncpy(elist
[count
].name
, event
, LTTNG_SYMBOL_NAME_LEN
);
943 elist
[count
].name
[LTTNG_SYMBOL_NAME_LEN
- 1] = '\0';
944 elist
[count
].enabled
= -1;
950 DBG("Kernel list events done (%zu events)", count
);
952 ret
= fclose(fp
); /* closes both fp and fd */
968 * Get kernel version and validate it.
970 int kernel_validate_version(int tracer_fd
)
973 struct lttng_kernel_tracer_version version
;
974 struct lttng_kernel_tracer_abi_version abi_version
;
976 ret
= kernctl_tracer_version(tracer_fd
, &version
);
978 ERR("Failed to retrieve the lttng-modules version");
982 /* Validate version */
983 if (version
.major
!= VERSION_MAJOR
) {
984 ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)",
985 version
.major
, VERSION_MAJOR
);
988 ret
= kernctl_tracer_abi_version(tracer_fd
, &abi_version
);
990 ERR("Failed to retrieve lttng-modules ABI version");
993 if (abi_version
.major
!= LTTNG_MODULES_ABI_MAJOR_VERSION
) {
994 ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)",
995 abi_version
.major
, abi_version
.minor
,
996 LTTNG_MODULES_ABI_MAJOR_VERSION
);
999 DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)",
1000 version
.major
, version
.minor
,
1001 abi_version
.major
, abi_version
.minor
);
1008 ERR("Kernel tracer version check failed; kernel tracing will not be available");
1013 * Kernel work-arounds called at the start of sessiond main().
1015 int init_kernel_workarounds(void)
1021 * boot_id needs to be read once before being used concurrently
1022 * to deal with a Linux kernel race. A fix is proposed for
1023 * upstream, but the work-around is needed for older kernels.
1025 fp
= fopen("/proc/sys/kernel/random/boot_id", "r");
1032 ret
= fread(buf
, 1, sizeof(buf
), fp
);
1034 /* Ignore error, we don't really care */
1046 * Complete teardown of a kernel session.
1048 void kernel_destroy_session(struct ltt_kernel_session
*ksess
)
1050 if (ksess
== NULL
) {
1051 DBG3("No kernel session when tearing down session");
1055 DBG("Tearing down kernel session");
1058 * Destroy channels on the consumer if at least one FD has been sent and we
1059 * are in no output mode because the streams are in *no* monitor mode so we
1060 * have to send a command to clean them up or else they leaked.
1062 if (!ksess
->output_traces
&& ksess
->consumer_fds_sent
) {
1064 struct consumer_socket
*socket
;
1065 struct lttng_ht_iter iter
;
1067 /* For each consumer socket. */
1069 cds_lfht_for_each_entry(ksess
->consumer
->socks
->ht
, &iter
.iter
,
1070 socket
, node
.node
) {
1071 struct ltt_kernel_channel
*chan
;
1073 /* For each channel, ask the consumer to destroy it. */
1074 cds_list_for_each_entry(chan
, &ksess
->channel_list
.head
, list
) {
1075 ret
= kernel_consumer_destroy_channel(socket
, chan
);
1077 /* Consumer is probably dead. Use next socket. */
1085 /* Close any relayd session */
1086 consumer_output_send_destroy_relayd(ksess
->consumer
);
1088 trace_kernel_destroy_session(ksess
);
1092 * Destroy a kernel channel object. It does not do anything on the tracer side.
1094 void kernel_destroy_channel(struct ltt_kernel_channel
*kchan
)
1096 struct ltt_kernel_session
*ksess
= NULL
;
1099 assert(kchan
->channel
);
1101 DBG3("Kernel destroy channel %s", kchan
->channel
->name
);
1103 /* Update channel count of associated session. */
1104 if (kchan
->session
) {
1105 /* Keep pointer reference so we can update it after the destroy. */
1106 ksess
= kchan
->session
;
1109 trace_kernel_destroy_channel(kchan
);
1112 * At this point the kernel channel is not visible anymore. This is safe
1113 * since in order to work on a visible kernel session, the tracing session
1114 * lock (ltt_session.lock) MUST be acquired.
1117 ksess
->channel_count
--;
1122 * Take a snapshot for a given kernel session.
1124 * Return 0 on success or else return a LTTNG_ERR code.
1126 int kernel_snapshot_record(struct ltt_kernel_session
*ksess
,
1127 struct snapshot_output
*output
, int wait
,
1128 uint64_t nb_packets_per_stream
)
1130 int err
, ret
, saved_metadata_fd
;
1131 struct consumer_socket
*socket
;
1132 struct lttng_ht_iter iter
;
1133 struct ltt_kernel_metadata
*saved_metadata
;
1136 assert(ksess
->consumer
);
1139 DBG("Kernel snapshot record started");
1141 /* Save current metadata since the following calls will change it. */
1142 saved_metadata
= ksess
->metadata
;
1143 saved_metadata_fd
= ksess
->metadata_stream_fd
;
1147 ret
= kernel_open_metadata(ksess
);
1149 ret
= LTTNG_ERR_KERN_META_FAIL
;
1153 ret
= kernel_open_metadata_stream(ksess
);
1155 ret
= LTTNG_ERR_KERN_META_FAIL
;
1156 goto error_open_stream
;
1159 /* Send metadata to consumer and snapshot everything. */
1160 cds_lfht_for_each_entry(ksess
->consumer
->socks
->ht
, &iter
.iter
,
1161 socket
, node
.node
) {
1162 struct consumer_output
*saved_output
;
1163 struct ltt_kernel_channel
*chan
;
1166 * Temporarly switch consumer output for our snapshot output. As long
1167 * as the session lock is taken, this is safe.
1169 saved_output
= ksess
->consumer
;
1170 ksess
->consumer
= output
->consumer
;
1172 pthread_mutex_lock(socket
->lock
);
1173 /* This stream must not be monitored by the consumer. */
1174 ret
= kernel_consumer_add_metadata(socket
, ksess
, 0);
1175 pthread_mutex_unlock(socket
->lock
);
1176 /* Put back the saved consumer output into the session. */
1177 ksess
->consumer
= saved_output
;
1179 ret
= LTTNG_ERR_KERN_CONSUMER_FAIL
;
1180 goto error_consumer
;
1183 /* For each channel, ask the consumer to snapshot it. */
1184 cds_list_for_each_entry(chan
, &ksess
->channel_list
.head
, list
) {
1185 ret
= consumer_snapshot_channel(socket
, chan
->fd
, output
, 0,
1186 ksess
->uid
, ksess
->gid
,
1187 DEFAULT_KERNEL_TRACE_DIR
, wait
,
1188 nb_packets_per_stream
);
1190 ret
= LTTNG_ERR_KERN_CONSUMER_FAIL
;
1191 (void) kernel_consumer_destroy_metadata(socket
,
1193 goto error_consumer
;
1197 /* Snapshot metadata, */
1198 ret
= consumer_snapshot_channel(socket
, ksess
->metadata
->fd
, output
,
1199 1, ksess
->uid
, ksess
->gid
,
1200 DEFAULT_KERNEL_TRACE_DIR
, wait
, 0);
1202 ret
= LTTNG_ERR_KERN_CONSUMER_FAIL
;
1203 goto error_consumer
;
1207 * The metadata snapshot is done, ask the consumer to destroy it since
1208 * it's not monitored on the consumer side.
1210 (void) kernel_consumer_destroy_metadata(socket
, ksess
->metadata
);
1216 /* Close newly opened metadata stream. It's now on the consumer side. */
1217 err
= close(ksess
->metadata_stream_fd
);
1219 PERROR("close snapshot kernel");
1223 trace_kernel_destroy_metadata(ksess
->metadata
);
1225 /* Restore metadata state.*/
1226 ksess
->metadata
= saved_metadata
;
1227 ksess
->metadata_stream_fd
= saved_metadata_fd
;
1234 * Get the syscall mask array from the kernel tracer.
1236 * Return 0 on success else a negative value. In both case, syscall_mask should
1239 int kernel_syscall_mask(int chan_fd
, char **syscall_mask
, uint32_t *nr_bits
)
1241 assert(syscall_mask
);
1244 return kernctl_syscall_mask(chan_fd
, syscall_mask
, nr_bits
);