1 /* Copyright (C) 2009 Pierre-Marc Fournier
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library 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 GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 /* This file contains the implementation of the UST listener thread, which
19 * receives trace control commands. It also coordinates the initialization of
29 #include <sys/epoll.h>
31 #include <sys/types.h>
32 #include <sys/socket.h>
36 #include <urcu/uatomic_arch.h>
37 #include <urcu/list.h>
39 #include <ust/marker.h>
40 #include <ust/tracepoint.h>
41 #include <ust/tracectl.h>
42 #include <ust/clock.h>
47 #include "marker-control.h"
49 /* This should only be accessed by the constructor, before the creation
50 * of the listener, and then only by the listener.
54 /* The process pid is used to detect a non-traceable fork
55 * and allow the non-traceable fork to be ignored
56 * by destructor sequences in libust
58 static pid_t processpid
= 0;
60 static struct ustcomm_header _receive_header
;
61 static struct ustcomm_header
*receive_header
= &_receive_header
;
62 static char receive_buffer
[USTCOMM_BUFFER_SIZE
];
63 static char send_buffer
[USTCOMM_BUFFER_SIZE
];
68 * Listener thread data vs fork() protection mechanism. Ensures that no listener
69 * thread mutexes and data structures are being concurrently modified or held by
70 * other threads when fork() is executed.
72 static pthread_mutex_t listener_thread_data_mutex
= PTHREAD_MUTEX_INITIALIZER
;
74 /* Mutex protecting listen_sock. Nests inside listener_thread_data_mutex. */
75 static pthread_mutex_t listen_sock_mutex
= PTHREAD_MUTEX_INITIALIZER
;
76 static struct ustcomm_sock
*listen_sock
;
78 extern struct chan_info_struct chan_infos
[];
80 static struct cds_list_head open_buffers_list
= CDS_LIST_HEAD_INIT(open_buffers_list
);
82 static struct cds_list_head ust_socks
= CDS_LIST_HEAD_INIT(ust_socks
);
84 /* volatile because shared between the listener and the main thread */
85 int buffers_to_export
= 0;
89 static long long make_pidunique(void)
94 gettimeofday(&tv
, NULL
);
103 static void print_markers(FILE *fp
)
105 struct marker_iter iter
;
108 marker_iter_reset(&iter
);
109 marker_iter_start(&iter
);
111 while (iter
.marker
) {
112 fprintf(fp
, "marker: %s/%s %d \"%s\" %p\n",
113 (*iter
.marker
)->channel
,
114 (*iter
.marker
)->name
,
115 (int)imv_read((*iter
.marker
)->state
),
116 (*iter
.marker
)->format
,
117 (*iter
.marker
)->location
);
118 marker_iter_next(&iter
);
123 static void print_trace_events(FILE *fp
)
125 struct trace_event_iter iter
;
128 trace_event_iter_reset(&iter
);
129 trace_event_iter_start(&iter
);
131 while (iter
.trace_event
) {
132 fprintf(fp
, "trace_event: %s\n", (*iter
.trace_event
)->name
);
133 trace_event_iter_next(&iter
);
135 unlock_trace_events();
138 static int connect_ustconsumer(void)
141 char default_daemon_path
[] = SOCK_DIR
"/ustconsumer";
142 char *explicit_daemon_path
, *daemon_path
;
144 explicit_daemon_path
= getenv("UST_DAEMON_SOCKET");
145 if (explicit_daemon_path
) {
146 daemon_path
= explicit_daemon_path
;
148 daemon_path
= default_daemon_path
;
151 DBG("Connecting to daemon_path %s", daemon_path
);
153 result
= ustcomm_connect_path(daemon_path
, &fd
);
155 WARN("connect_ustconsumer failed, daemon_path: %s",
164 static void request_buffer_consumer(int sock
,
169 struct ustcomm_header send_header
, recv_header
;
170 struct ustcomm_buffer_info buf_inf
;
173 result
= ustcomm_pack_buffer_info(&send_header
,
180 ERR("failed to pack buffer info message %s_%d",
185 buf_inf
.pid
= getpid();
186 send_header
.command
= CONSUME_BUFFER
;
188 result
= ustcomm_req(sock
, &send_header
, (char *) &buf_inf
,
191 PERROR("request for buffer consumer failed, is the daemon online?");
197 /* Ask the daemon to collect a trace called trace_name and being
198 * produced by this pid.
200 * The trace must be at least allocated. (It can also be started.)
201 * This is because _ltt_trace_find is used.
204 static void inform_consumer_daemon(const char *trace_name
)
207 struct ust_trace
*trace
;
210 sock
= connect_ustconsumer();
215 DBG("Connected to ustconsumer");
219 trace
= _ltt_trace_find(trace_name
);
221 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name
);
225 for (i
=0; i
< trace
->nr_channels
; i
++) {
226 if (trace
->channels
[i
].request_collection
) {
227 /* iterate on all cpus */
228 for (j
=0; j
<trace
->channels
[i
].n_cpus
; j
++) {
229 ch_name
= trace
->channels
[i
].channel_name
;
230 request_buffer_consumer(sock
, trace_name
,
232 CMM_STORE_SHARED(buffers_to_export
,
233 CMM_LOAD_SHARED(buffers_to_export
)+1);
244 static struct ust_channel
*find_channel(const char *ch_name
,
245 struct ust_trace
*trace
)
249 for (i
=0; i
<trace
->nr_channels
; i
++) {
250 if (!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
251 return &trace
->channels
[i
];
258 static int get_buffer_shmid_pipe_fd(const char *trace_name
, const char *ch_name
,
261 int *buf_struct_shmid
,
264 struct ust_trace
*trace
;
265 struct ust_channel
*channel
;
266 struct ust_buffer
*buf
;
268 DBG("get_buffer_shmid_pipe_fd");
271 trace
= _ltt_trace_find(trace_name
);
275 ERR("cannot find trace!");
279 channel
= find_channel(ch_name
, trace
);
281 ERR("cannot find channel %s!", ch_name
);
285 buf
= channel
->buf
[ch_cpu
];
287 *buf_shmid
= buf
->shmid
;
288 *buf_struct_shmid
= channel
->buf_struct_shmids
[ch_cpu
];
289 *buf_pipe_fd
= buf
->data_ready_fd_read
;
294 static int get_subbuf_num_size(const char *trace_name
, const char *ch_name
,
297 struct ust_trace
*trace
;
298 struct ust_channel
*channel
;
300 DBG("get_subbuf_size");
303 trace
= _ltt_trace_find(trace_name
);
307 ERR("cannot find trace!");
311 channel
= find_channel(ch_name
, trace
);
313 ERR("unable to find channel");
317 *num
= channel
->subbuf_cnt
;
318 *size
= channel
->subbuf_size
;
323 /* Return the power of two which is equal or higher to v */
325 static unsigned int pow2_higher_or_eq(unsigned int v
)
328 int retval
= 1<<(hb
-1);
336 static int set_subbuf_size(const char *trace_name
, const char *ch_name
,
341 struct ust_trace
*trace
;
342 struct ust_channel
*channel
;
344 DBG("set_subbuf_size");
346 power
= pow2_higher_or_eq(size
);
347 power
= max_t(unsigned int, 2u, power
);
349 WARN("using the next power of two for buffer size = %u\n", power
);
353 trace
= _ltt_trace_find_setup(trace_name
);
355 ERR("cannot find trace!");
360 channel
= find_channel(ch_name
, trace
);
362 ERR("unable to find channel");
367 channel
->subbuf_size
= power
;
368 DBG("the set_subbuf_size for the requested channel is %zu", channel
->subbuf_size
);
376 static int set_subbuf_num(const char *trace_name
, const char *ch_name
,
379 struct ust_trace
*trace
;
380 struct ust_channel
*channel
;
383 DBG("set_subbuf_num");
386 ERR("subbuffer count should be greater than 2");
391 trace
= _ltt_trace_find_setup(trace_name
);
393 ERR("cannot find trace!");
398 channel
= find_channel(ch_name
, trace
);
400 ERR("unable to find channel");
405 channel
->subbuf_cnt
= num
;
406 DBG("the set_subbuf_cnt for the requested channel is %u", channel
->subbuf_cnt
);
413 static int get_subbuffer(const char *trace_name
, const char *ch_name
,
414 int ch_cpu
, long *consumed_old
)
417 struct ust_trace
*trace
;
418 struct ust_channel
*channel
;
419 struct ust_buffer
*buf
;
426 trace
= _ltt_trace_find(trace_name
);
429 DBG("Cannot find trace. It was likely destroyed by the user.");
434 channel
= find_channel(ch_name
, trace
);
436 ERR("unable to find channel");
441 buf
= channel
->buf
[ch_cpu
];
443 retval
= ust_buffers_get_subbuf(buf
, consumed_old
);
445 WARN("missed buffer?");
455 static int notify_buffer_mapped(const char *trace_name
,
460 struct ust_trace
*trace
;
461 struct ust_channel
*channel
;
462 struct ust_buffer
*buf
;
464 DBG("get_buffer_fd");
467 trace
= _ltt_trace_find(trace_name
);
471 DBG("Cannot find trace. It was likely destroyed by the user.");
475 channel
= find_channel(ch_name
, trace
);
478 ERR("unable to find channel");
482 buf
= channel
->buf
[ch_cpu
];
484 /* Being here is the proof the daemon has mapped the buffer in its
485 * memory. We may now decrement buffers_to_export.
487 if (uatomic_read(&buf
->consumed
) == 0) {
488 DBG("decrementing buffers_to_export");
489 CMM_STORE_SHARED(buffers_to_export
, CMM_LOAD_SHARED(buffers_to_export
)-1);
492 /* The buffer has been exported, ergo, we can add it to the
493 * list of open buffers
495 cds_list_add(&buf
->open_buffers_list
, &open_buffers_list
);
503 static int put_subbuffer(const char *trace_name
, const char *ch_name
,
504 int ch_cpu
, long consumed_old
)
507 struct ust_trace
*trace
;
508 struct ust_channel
*channel
;
509 struct ust_buffer
*buf
;
514 trace
= _ltt_trace_find(trace_name
);
518 DBG("Cannot find trace. It was likely destroyed by the user.");
522 channel
= find_channel(ch_name
, trace
);
525 ERR("unable to find channel");
529 buf
= channel
->buf
[ch_cpu
];
531 retval
= ust_buffers_put_subbuf(buf
, consumed_old
);
533 WARN("ust_buffers_put_subbuf: error (subbuf=%s_%d)",
536 DBG("ust_buffers_put_subbuf: success (subbuf=%s_%d)",
546 static void release_listener_mutex(void *ptr
)
548 pthread_mutex_unlock(&listener_thread_data_mutex
);
551 static void listener_cleanup(void *ptr
)
553 pthread_mutex_lock(&listen_sock_mutex
);
555 ustcomm_del_named_sock(listen_sock
, 0);
558 pthread_mutex_unlock(&listen_sock_mutex
);
561 static void force_subbuf_switch()
563 struct ust_buffer
*buf
;
565 cds_list_for_each_entry(buf
, &open_buffers_list
,
567 ltt_force_switch(buf
, FORCE_FLUSH
);
571 /* Simple commands are those which need only respond with a return value. */
572 static int process_simple_client_cmd(int command
, char *recv_buf
)
579 struct ustcomm_single_field
*sock_msg
;
580 sock_msg
= (struct ustcomm_single_field
*)recv_buf
;
581 result
= ustcomm_unpack_single_field(sock_msg
);
585 return setenv("UST_DAEMON_SOCKET", sock_msg
->field
, 1);
588 case FORCE_SUBBUF_SWITCH
:
589 /* FIXME: return codes? */
590 force_subbuf_switch();
602 static int process_trace_cmd(int command
, char *trace_name
)
605 char trace_type
[] = "ustrelay";
609 /* start is an operation that setups the trace, allocates it and starts it */
610 result
= ltt_trace_setup(trace_name
);
612 ERR("ltt_trace_setup failed");
616 result
= ltt_trace_set_type(trace_name
, trace_type
);
618 ERR("ltt_trace_set_type failed");
622 result
= ltt_trace_alloc(trace_name
);
624 ERR("ltt_trace_alloc failed");
628 inform_consumer_daemon(trace_name
);
630 result
= ltt_trace_start(trace_name
);
632 ERR("ltt_trace_start failed");
640 result
= ltt_trace_setup(trace_name
);
642 ERR("ltt_trace_setup failed");
646 result
= ltt_trace_set_type(trace_name
, trace_type
);
648 ERR("ltt_trace_set_type failed");
656 result
= ltt_trace_alloc(trace_name
);
658 ERR("ltt_trace_alloc failed");
661 inform_consumer_daemon(trace_name
);
668 result
= ltt_trace_setup(trace_name
);
670 ERR("ltt_trace_setup failed");
674 result
= ltt_trace_set_type(trace_name
, trace_type
);
676 ERR("ltt_trace_set_type failed");
684 result
= ltt_trace_alloc(trace_name
);
686 ERR("ltt_trace_alloc failed");
690 inform_consumer_daemon(trace_name
);
693 result
= ltt_trace_start(trace_name
);
695 ERR("ltt_trace_start failed");
703 result
= ltt_trace_stop(trace_name
);
705 ERR("ltt_trace_stop failed");
711 DBG("trace destroy");
713 result
= ltt_trace_destroy(trace_name
, 0);
715 ERR("ltt_trace_destroy failed");
725 static void process_channel_cmd(int sock
, int command
,
726 struct ustcomm_channel_info
*ch_inf
)
728 struct ustcomm_header _reply_header
;
729 struct ustcomm_header
*reply_header
= &_reply_header
;
730 struct ustcomm_channel_info
*reply_msg
=
731 (struct ustcomm_channel_info
*)send_buffer
;
732 int result
, offset
= 0, num
, size
;
734 memset(reply_header
, 0, sizeof(*reply_header
));
737 case GET_SUBBUF_NUM_SIZE
:
738 result
= get_subbuf_num_size(ch_inf
->trace
,
742 reply_header
->result
= result
;
746 reply_msg
->channel
= USTCOMM_POISON_PTR
;
747 reply_msg
->subbuf_num
= num
;
748 reply_msg
->subbuf_size
= size
;
751 reply_header
->size
= COMPUTE_MSG_SIZE(reply_msg
, offset
);
755 reply_header
->result
= set_subbuf_num(ch_inf
->trace
,
760 case SET_SUBBUF_SIZE
:
761 reply_header
->result
= set_subbuf_size(ch_inf
->trace
,
763 ch_inf
->subbuf_size
);
768 if (ustcomm_send(sock
, reply_header
, (char *)reply_msg
) < 0) {
769 ERR("ustcomm_send failed");
773 static void process_buffer_cmd(int sock
, int command
,
774 struct ustcomm_buffer_info
*buf_inf
)
776 struct ustcomm_header _reply_header
;
777 struct ustcomm_header
*reply_header
= &_reply_header
;
778 struct ustcomm_buffer_info
*reply_msg
=
779 (struct ustcomm_buffer_info
*)send_buffer
;
780 int result
, offset
= 0, buf_shmid
, buf_struct_shmid
, buf_pipe_fd
;
783 memset(reply_header
, 0, sizeof(*reply_header
));
786 case GET_BUF_SHMID_PIPE_FD
:
787 result
= get_buffer_shmid_pipe_fd(buf_inf
->trace
,
794 reply_header
->result
= result
;
798 reply_msg
->channel
= USTCOMM_POISON_PTR
;
799 reply_msg
->buf_shmid
= buf_shmid
;
800 reply_msg
->buf_struct_shmid
= buf_struct_shmid
;
802 reply_header
->size
= COMPUTE_MSG_SIZE(reply_msg
, offset
);
803 reply_header
->fd_included
= 1;
805 if (ustcomm_send_fd(sock
, reply_header
, (char *)reply_msg
,
807 ERR("ustcomm_send failed");
811 case NOTIFY_BUF_MAPPED
:
812 reply_header
->result
=
813 notify_buffer_mapped(buf_inf
->trace
,
818 result
= get_subbuffer(buf_inf
->trace
, buf_inf
->channel
,
819 buf_inf
->ch_cpu
, &consumed_old
);
821 reply_header
->result
= result
;
825 reply_msg
->channel
= USTCOMM_POISON_PTR
;
826 reply_msg
->consumed_old
= consumed_old
;
828 reply_header
->size
= COMPUTE_MSG_SIZE(reply_msg
, offset
);
832 result
= put_subbuffer(buf_inf
->trace
, buf_inf
->channel
,
834 buf_inf
->consumed_old
);
835 reply_header
->result
= result
;
840 if (ustcomm_send(sock
, reply_header
, (char *)reply_msg
) < 0) {
841 ERR("ustcomm_send failed");
846 static void process_marker_cmd(int sock
, int command
,
847 struct ustcomm_marker_info
*marker_inf
)
849 struct ustcomm_header _reply_header
;
850 struct ustcomm_header
*reply_header
= &_reply_header
;
853 memset(reply_header
, 0, sizeof(*reply_header
));
858 result
= ltt_marker_connect(marker_inf
->channel
,
862 WARN("could not enable marker; channel=%s,"
870 result
= ltt_marker_disconnect(marker_inf
->channel
,
874 WARN("could not disable marker; channel=%s,"
882 reply_header
->result
= result
;
884 if (ustcomm_send(sock
, reply_header
, NULL
) < 0) {
885 ERR("ustcomm_send failed");
889 static void process_client_cmd(struct ustcomm_header
*recv_header
,
890 char *recv_buf
, int sock
)
893 struct ustcomm_header _reply_header
;
894 struct ustcomm_header
*reply_header
= &_reply_header
;
895 char *send_buf
= send_buffer
;
897 memset(reply_header
, 0, sizeof(*reply_header
));
898 memset(send_buf
, 0, sizeof(send_buffer
));
900 switch(recv_header
->command
) {
901 case GET_SUBBUF_NUM_SIZE
:
903 case SET_SUBBUF_SIZE
:
905 struct ustcomm_channel_info
*ch_inf
;
906 ch_inf
= (struct ustcomm_channel_info
*)recv_buf
;
907 result
= ustcomm_unpack_channel_info(ch_inf
);
909 ERR("couldn't unpack channel info");
910 reply_header
->result
= -EINVAL
;
913 process_channel_cmd(sock
, recv_header
->command
, ch_inf
);
916 case GET_BUF_SHMID_PIPE_FD
:
917 case NOTIFY_BUF_MAPPED
:
921 struct ustcomm_buffer_info
*buf_inf
;
922 buf_inf
= (struct ustcomm_buffer_info
*)recv_buf
;
923 result
= ustcomm_unpack_buffer_info(buf_inf
);
925 ERR("couldn't unpack buffer info");
926 reply_header
->result
= -EINVAL
;
929 process_buffer_cmd(sock
, recv_header
->command
, buf_inf
);
935 struct ustcomm_marker_info
*marker_inf
;
936 marker_inf
= (struct ustcomm_marker_info
*)recv_buf
;
937 result
= ustcomm_unpack_marker_info(marker_inf
);
939 ERR("couldn't unpack marker info");
940 reply_header
->result
= -EINVAL
;
943 process_marker_cmd(sock
, recv_header
->command
, marker_inf
);
952 fp
= open_memstream(&ptr
, &size
);
954 ERR("opening memstream failed");
960 reply_header
->size
= size
+ 1; /* Include final \0 */
962 result
= ustcomm_send(sock
, reply_header
, ptr
);
967 PERROR("failed to send markers list");
972 case LIST_TRACE_EVENTS
:
978 fp
= open_memstream(&ptr
, &size
);
980 ERR("opening memstream failed");
983 print_trace_events(fp
);
986 reply_header
->size
= size
+ 1; /* Include final \0 */
988 result
= ustcomm_send(sock
, reply_header
, ptr
);
993 ERR("list_trace_events failed");
1003 /* FIXME: No functionality at all... */
1006 DBG("load_probe_lib loading %s", libfile
);
1012 struct ustcomm_pidunique
*pid_msg
;
1013 pid_msg
= (struct ustcomm_pidunique
*)send_buf
;
1015 pid_msg
->pidunique
= pidunique
;
1016 reply_header
->size
= sizeof(pid_msg
);
1023 struct ustcomm_single_field
*sock_msg
;
1024 char *sock_path_env
;
1026 sock_msg
= (struct ustcomm_single_field
*)send_buf
;
1028 sock_path_env
= getenv("UST_DAEMON_SOCKET");
1030 if (!sock_path_env
) {
1031 result
= ustcomm_pack_single_field(reply_header
,
1033 SOCK_DIR
"/ustconsumer");
1036 result
= ustcomm_pack_single_field(reply_header
,
1040 reply_header
->result
= result
;
1052 struct ustcomm_single_field
*trace_inf
=
1053 (struct ustcomm_single_field
*)recv_buf
;
1055 result
= ustcomm_unpack_single_field(trace_inf
);
1057 ERR("couldn't unpack trace info");
1058 reply_header
->result
= -EINVAL
;
1062 reply_header
->result
=
1063 process_trace_cmd(recv_header
->command
,
1069 reply_header
->result
=
1070 process_simple_client_cmd(recv_header
->command
,
1079 ustcomm_send(sock
, reply_header
, send_buf
);
1082 #define MAX_EVENTS 10
1084 void *listener_main(void *p
)
1086 struct ustcomm_sock
*epoll_sock
;
1087 struct epoll_event events
[MAX_EVENTS
];
1088 struct sockaddr addr
;
1089 int accept_fd
, nfds
, result
, i
, addr_size
;
1093 pthread_cleanup_push(listener_cleanup
, NULL
);
1096 nfds
= epoll_wait(epoll_fd
, events
, MAX_EVENTS
, -1);
1098 PERROR("listener_main: epoll_wait failed");
1102 for (i
= 0; i
< nfds
; i
++) {
1103 pthread_mutex_lock(&listener_thread_data_mutex
);
1104 pthread_cleanup_push(release_listener_mutex
, NULL
);
1105 epoll_sock
= (struct ustcomm_sock
*)events
[i
].data
.ptr
;
1106 if (epoll_sock
== listen_sock
) {
1107 addr_size
= sizeof(struct sockaddr
);
1108 accept_fd
= accept(epoll_sock
->fd
,
1110 (socklen_t
*)&addr_size
);
1111 if (accept_fd
== -1) {
1112 PERROR("listener_main: accept failed");
1115 ustcomm_init_sock(accept_fd
, epoll_fd
,
1118 memset(receive_header
, 0,
1119 sizeof(*receive_header
));
1120 memset(receive_buffer
, 0,
1121 sizeof(receive_buffer
));
1122 result
= ustcomm_recv(epoll_sock
->fd
,
1126 ustcomm_del_sock(epoll_sock
, 0);
1128 process_client_cmd(receive_header
,
1133 pthread_cleanup_pop(1); /* release listener mutex */
1137 pthread_cleanup_pop(1);
1140 /* These should only be accessed in the parent thread,
1143 static volatile sig_atomic_t have_listener
= 0;
1144 static pthread_t listener_thread
;
1146 void create_listener(void)
1149 sigset_t sig_all_blocked
;
1150 sigset_t orig_parent_mask
;
1152 if (have_listener
) {
1153 WARN("not creating listener because we already had one");
1157 /* A new thread created by pthread_create inherits the signal mask
1158 * from the parent. To avoid any signal being received by the
1159 * listener thread, we block all signals temporarily in the parent,
1160 * while we create the listener thread.
1163 sigfillset(&sig_all_blocked
);
1165 result
= pthread_sigmask(SIG_SETMASK
, &sig_all_blocked
, &orig_parent_mask
);
1167 PERROR("pthread_sigmask: %s", strerror(result
));
1170 result
= pthread_create(&listener_thread
, NULL
, listener_main
, NULL
);
1172 PERROR("pthread_create");
1175 /* Restore original signal mask in parent */
1176 result
= pthread_sigmask(SIG_SETMASK
, &orig_parent_mask
, NULL
);
1178 PERROR("pthread_sigmask: %s", strerror(result
));
1184 #define AUTOPROBE_DISABLED 0
1185 #define AUTOPROBE_ENABLE_ALL 1
1186 #define AUTOPROBE_ENABLE_REGEX 2
1187 static int autoprobe_method
= AUTOPROBE_DISABLED
;
1188 static regex_t autoprobe_regex
;
1190 static void auto_probe_connect(struct marker
*m
)
1194 char* concat_name
= NULL
;
1195 const char *probe_name
= "default";
1197 if (autoprobe_method
== AUTOPROBE_DISABLED
) {
1199 } else if (autoprobe_method
== AUTOPROBE_ENABLE_REGEX
) {
1200 result
= asprintf(&concat_name
, "%s/%s", m
->channel
, m
->name
);
1202 ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
1203 m
->channel
, m
->name
);
1206 if (regexec(&autoprobe_regex
, concat_name
, 0, NULL
, 0)) {
1213 result
= ltt_marker_connect(m
->channel
, m
->name
, probe_name
);
1214 if (result
&& result
!= -EEXIST
)
1215 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m
->channel
, m
->name
, -result
);
1217 DBG("auto connected marker %s (addr: %p) %s to probe default", m
->channel
, m
, m
->name
);
1221 static struct ustcomm_sock
* init_app_socket(int epoll_fd
)
1225 struct ustcomm_sock
*sock
;
1227 result
= asprintf(&name
, "%s/%d", SOCK_DIR
, (int)getpid());
1229 ERR("string overflow allocating socket name, "
1230 "UST thread bailing");
1234 result
= ensure_dir_exists(SOCK_DIR
);
1236 ERR("Unable to create socket directory %s, UST thread bailing",
1241 sock
= ustcomm_init_named_socket(name
, epoll_fd
);
1243 ERR("Error initializing named socket (%s). Check that directory"
1244 "exists and that it is writable. UST thread bailing", name
);
1256 static void __attribute__((constructor
)) init()
1260 char* autoprobe_val
= NULL
;
1261 char* subbuffer_size_val
= NULL
;
1262 char* subbuffer_count_val
= NULL
;
1263 unsigned int subbuffer_size
;
1264 unsigned int subbuffer_count
;
1267 /* Assign the pidunique, to be able to differentiate the processes with same
1268 * pid, (before and after an exec).
1270 pidunique
= make_pidunique();
1271 processpid
= getpid();
1273 DBG("Tracectl constructor");
1276 epoll_fd
= epoll_create(MAX_EVENTS
);
1277 if (epoll_fd
== -1) {
1278 ERR("epoll_create failed, tracing shutting down");
1282 /* Create the socket */
1283 listen_sock
= init_app_socket(epoll_fd
);
1285 ERR("failed to create application socket,"
1286 " tracing shutting down");
1292 /* Get clock the clock source type */
1294 /* Default clock source */
1295 ust_clock_source
= CLOCK_TRACE
;
1296 if (clock_gettime(ust_clock_source
, &ts
) != 0) {
1297 ust_clock_source
= CLOCK_MONOTONIC
;
1298 DBG("UST traces will not be synchronized with LTTng traces");
1301 autoprobe_val
= getenv("UST_AUTOPROBE");
1302 if (autoprobe_val
) {
1303 struct marker_iter iter
;
1305 DBG("Autoprobe enabled.");
1307 /* Ensure markers are initialized */
1310 /* Ensure marker control is initialized, for the probe */
1311 init_marker_control();
1313 /* first, set the callback that will connect the
1314 * probe on new markers
1316 if (autoprobe_val
[0] == '/') {
1317 result
= regcomp(&autoprobe_regex
, autoprobe_val
+1, 0);
1321 regerror(result
, &autoprobe_regex
, regexerr
, sizeof(regexerr
));
1322 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val
, regexerr
);
1323 /* don't crash the application just for this */
1325 autoprobe_method
= AUTOPROBE_ENABLE_REGEX
;
1328 /* just enable all instrumentation */
1329 autoprobe_method
= AUTOPROBE_ENABLE_ALL
;
1332 marker_set_new_marker_cb(auto_probe_connect
);
1334 /* Now, connect the probes that were already registered. */
1335 marker_iter_reset(&iter
);
1336 marker_iter_start(&iter
);
1338 DBG("now iterating on markers already registered");
1339 while (iter
.marker
) {
1340 DBG("now iterating on marker %s", (*iter
.marker
)->name
);
1341 auto_probe_connect(*iter
.marker
);
1342 marker_iter_next(&iter
);
1346 if (getenv("UST_OVERWRITE")) {
1347 int val
= atoi(getenv("UST_OVERWRITE"));
1348 if (val
== 0 || val
== 1) {
1349 CMM_STORE_SHARED(ust_channels_overwrite_by_default
, val
);
1351 WARN("invalid value for UST_OVERWRITE");
1355 if (getenv("UST_AUTOCOLLECT")) {
1356 int val
= atoi(getenv("UST_AUTOCOLLECT"));
1357 if (val
== 0 || val
== 1) {
1358 CMM_STORE_SHARED(ust_channels_request_collection_by_default
, val
);
1360 WARN("invalid value for UST_AUTOCOLLECT");
1364 subbuffer_size_val
= getenv("UST_SUBBUF_SIZE");
1365 if (subbuffer_size_val
) {
1366 sscanf(subbuffer_size_val
, "%u", &subbuffer_size
);
1367 power
= pow2_higher_or_eq(subbuffer_size
);
1368 if (power
!= subbuffer_size
)
1369 WARN("using the next power of two for buffer size = %u\n", power
);
1370 chan_infos
[LTT_CHANNEL_UST
].def_subbufsize
= power
;
1373 subbuffer_count_val
= getenv("UST_SUBBUF_NUM");
1374 if (subbuffer_count_val
) {
1375 sscanf(subbuffer_count_val
, "%u", &subbuffer_count
);
1376 if (subbuffer_count
< 2)
1377 subbuffer_count
= 2;
1378 chan_infos
[LTT_CHANNEL_UST
].def_subbufcount
= subbuffer_count
;
1381 if (getenv("UST_TRACE")) {
1382 char trace_name
[] = "auto";
1383 char trace_type
[] = "ustrelay";
1385 DBG("starting early tracing");
1387 /* Ensure marker control is initialized */
1388 init_marker_control();
1390 /* Ensure markers are initialized */
1393 /* Ensure buffers are initialized, for the transport to be available.
1394 * We are about to set a trace type and it will fail without this.
1396 init_ustrelay_transport();
1398 /* FIXME: When starting early tracing (here), depending on the
1399 * order of constructors, it is very well possible some marker
1400 * sections are not yet registered. Because of this, some
1401 * channels may not be registered. Yet, we are about to ask the
1402 * daemon to collect the channels. Channels which are not yet
1403 * registered will not be collected.
1405 * Currently, in LTTng, there is no way to add a channel after
1406 * trace start. The reason for this is that it induces complex
1407 * concurrency issues on the trace structures, which can only
1408 * be resolved using RCU. This has not been done yet. As a
1409 * workaround, we are forcing the registration of the "ust"
1410 * channel here. This is the only channel (apart from metadata)
1411 * that can be reliably used in early tracing.
1413 * Non-early tracing does not have this problem and can use
1414 * arbitrary channel names.
1416 ltt_channels_register("ust");
1418 result
= ltt_trace_setup(trace_name
);
1420 ERR("ltt_trace_setup failed");
1424 result
= ltt_trace_set_type(trace_name
, trace_type
);
1426 ERR("ltt_trace_set_type failed");
1430 result
= ltt_trace_alloc(trace_name
);
1432 ERR("ltt_trace_alloc failed");
1436 result
= ltt_trace_start(trace_name
);
1438 ERR("ltt_trace_start failed");
1442 /* Do this after the trace is started in order to avoid creating confusion
1443 * if the trace fails to start. */
1444 inform_consumer_daemon(trace_name
);
1449 /* should decrementally destroy stuff if error */
1453 /* This is only called if we terminate normally, not with an unhandled signal,
1454 * so we cannot rely on it. However, for now, LTTV requires that the header of
1455 * the last sub-buffer contain a valid end time for the trace. This is done
1456 * automatically only when the trace is properly stopped.
1458 * If the traced program crashed, it is always possible to manually add the
1459 * right value in the header, or to open the trace in text mode.
1461 * FIXME: Fix LTTV so it doesn't need this.
1464 static void destroy_traces(void)
1468 /* if trace running, finish it */
1470 DBG("destructor stopping traces");
1472 result
= ltt_trace_stop("auto");
1474 ERR("ltt_trace_stop error");
1477 result
= ltt_trace_destroy("auto", 0);
1479 ERR("ltt_trace_destroy error");
1483 static int trace_recording(void)
1486 struct ust_trace
*trace
;
1490 cds_list_for_each_entry(trace
, <t_traces
.head
, list
) {
1491 if (trace
->active
) {
1497 ltt_unlock_traces();
1502 int restarting_usleep(useconds_t usecs
)
1508 tv
.tv_nsec
= usecs
* 1000;
1511 result
= nanosleep(&tv
, &tv
);
1512 } while (result
== -1 && errno
== EINTR
);
1517 static void stop_listener(void)
1524 result
= pthread_cancel(listener_thread
);
1526 ERR("pthread_cancel: %s", strerror(result
));
1528 result
= pthread_join(listener_thread
, NULL
);
1530 ERR("pthread_join: %s", strerror(result
));
1534 /* This destructor keeps the process alive for a few seconds in order
1535 * to leave time for ustconsumer to connect to its buffers. This is necessary
1536 * for programs whose execution is very short. It is also useful in all
1537 * programs when tracing is started close to the end of the program
1540 * FIXME: For now, this only works for the first trace created in a
1544 static void __attribute__((destructor
)) keepalive()
1546 if (processpid
!= getpid()) {
1550 if (trace_recording() && CMM_LOAD_SHARED(buffers_to_export
)) {
1552 DBG("Keeping process alive for consumer daemon...");
1553 while (CMM_LOAD_SHARED(buffers_to_export
)) {
1554 const int interv
= 200000;
1555 restarting_usleep(interv
);
1558 if (total
>= 3000000) {
1559 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1563 DBG("Finally dying...");
1568 /* Ask the listener to stop and clean up. */
1572 void ust_potential_exec(void)
1574 trace_mark(ust
, potential_exec
, MARK_NOARGS
);
1581 /* Notify ust that there was a fork. This needs to be called inside
1582 * the new process, anytime a process whose memory is not shared with
1583 * the parent is created. If this function is not called, the events
1584 * of the new process will not be collected.
1586 * Signals should be disabled before the fork and reenabled only after
1587 * this call in order to guarantee tracing is not started before ust_fork()
1588 * sanitizes the new process.
1591 static void ust_fork(void)
1593 struct ust_buffer
*buf
, *buf_tmp
;
1594 struct ustcomm_sock
*sock
, *sock_tmp
;
1595 struct ust_trace
*trace
, *trace_tmp
;
1598 /* FIXME: technically, the locks could have been taken before the fork */
1599 DBG("ust: forking");
1601 /* Get the pid of the new process */
1602 processpid
= getpid();
1605 * FIXME: This could be prettier, we loop over the list twice and
1606 * following good locking practice should lock around the loop
1608 cds_list_for_each_entry_safe(trace
, trace_tmp
, <t_traces
.head
, list
) {
1609 ltt_trace_stop(trace
->trace_name
);
1612 /* Delete all active connections, but leave them in the epoll set */
1613 cds_list_for_each_entry_safe(sock
, sock_tmp
, &ust_socks
, list
) {
1614 ustcomm_del_sock(sock
, 1);
1617 /* Delete all blocked consumers */
1618 cds_list_for_each_entry_safe(buf
, buf_tmp
, &open_buffers_list
,
1619 open_buffers_list
) {
1620 cds_list_del(&buf
->open_buffers_list
);
1624 * FIXME: This could be prettier, we loop over the list twice and
1625 * following good locking practice should lock around the loop
1627 cds_list_for_each_entry_safe(trace
, trace_tmp
, <t_traces
.head
, list
) {
1628 ltt_trace_destroy(trace
->trace_name
, 1);
1631 /* Clean up the listener socket and epoll, keeping the socket file */
1633 ustcomm_del_named_sock(listen_sock
, 1);
1638 /* Re-start the launch sequence */
1639 CMM_STORE_SHARED(buffers_to_export
, 0);
1643 epoll_fd
= epoll_create(MAX_EVENTS
);
1644 if (epoll_fd
== -1) {
1645 ERR("epoll_create failed, tracing shutting down");
1649 /* Create the socket */
1650 listen_sock
= init_app_socket(epoll_fd
);
1652 ERR("failed to create application socket,"
1653 " tracing shutting down");
1657 ltt_trace_setup("auto");
1658 result
= ltt_trace_set_type("auto", "ustrelay");
1660 ERR("ltt_trace_set_type failed");
1664 ltt_trace_alloc("auto");
1665 ltt_trace_start("auto");
1666 inform_consumer_daemon("auto");
1669 void ust_before_fork(ust_fork_info_t
*fork_info
)
1671 /* Disable signals. This is to avoid that the child
1672 * intervenes before it is properly setup for tracing. It is
1673 * safer to disable all signals, because then we know we are not
1674 * breaking anything by restoring the original mask.
1680 - only do this if tracing is active
1683 /* Disable signals */
1684 sigfillset(&all_sigs
);
1685 result
= sigprocmask(SIG_BLOCK
, &all_sigs
, &fork_info
->orig_sigs
);
1687 PERROR("sigprocmask");
1692 * Take the fork lock to make sure we are not in the middle of
1693 * something in the listener thread.
1695 pthread_mutex_lock(&listener_thread_data_mutex
);
1697 * Hold listen_sock_mutex to protect from listen_sock teardown.
1699 pthread_mutex_lock(&listen_sock_mutex
);
1700 rcu_bp_before_fork();
1703 /* Don't call this function directly in a traced program */
1704 static void ust_after_fork_common(ust_fork_info_t
*fork_info
)
1708 pthread_mutex_unlock(&listen_sock_mutex
);
1709 pthread_mutex_unlock(&listener_thread_data_mutex
);
1711 /* Restore signals */
1712 result
= sigprocmask(SIG_SETMASK
, &fork_info
->orig_sigs
, NULL
);
1714 PERROR("sigprocmask");
1719 void ust_after_fork_parent(ust_fork_info_t
*fork_info
)
1721 rcu_bp_after_fork_parent();
1722 /* Release mutexes and reenable signals */
1723 ust_after_fork_common(fork_info
);
1726 void ust_after_fork_child(ust_fork_info_t
*fork_info
)
1728 /* Release urcu mutexes */
1729 rcu_bp_after_fork_child();
1731 /* Sanitize the child */
1734 /* Then release mutexes and reenable signals */
1735 ust_after_fork_common(fork_info
);