2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; only version 2
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 #include <semaphore.h>
33 #include <sys/mount.h>
35 #include <sys/socket.h>
37 #include <sys/types.h>
39 #include <sys/resource.h>
42 #include <urcu/list.h> /* URCU list library (-lurcu) */
43 #include <lttng/lttng.h>
44 #include <lttng-sessiond-comm.h>
47 #include "ltt-sessiond.h"
49 #include "kernel-ctl.h"
52 #include "traceable-app.h"
53 #include "lttng-kconsumerd.h"
57 const char default_home_dir
[] = DEFAULT_HOME_DIR
;
58 const char default_tracing_group
[] = LTTNG_DEFAULT_TRACING_GROUP
;
59 const char default_ust_sock_dir
[] = DEFAULT_UST_SOCK_DIR
;
60 const char default_global_apps_pipe
[] = DEFAULT_GLOBAL_APPS_PIPE
;
63 int opt_verbose
; /* Not static for lttngerr.h */
64 int opt_verbose_kconsumerd
; /* Not static for lttngerr.h */
65 int opt_quiet
; /* Not static for lttngerr.h */
68 const char *opt_tracing_group
;
69 static int opt_sig_parent
;
70 static int opt_daemon
;
71 static int is_root
; /* Set to 1 if the daemon is running as root */
72 static pid_t ppid
; /* Parent PID for --sig-parent option */
73 static pid_t kconsumerd_pid
;
74 static struct pollfd
*kernel_pollfd
;
76 static char apps_unix_sock_path
[PATH_MAX
]; /* Global application Unix socket path */
77 static char client_unix_sock_path
[PATH_MAX
]; /* Global client Unix socket path */
78 static char kconsumerd_err_unix_sock_path
[PATH_MAX
]; /* kconsumerd error Unix socket path */
79 static char kconsumerd_cmd_unix_sock_path
[PATH_MAX
]; /* kconsumerd command Unix socket path */
82 static int client_sock
;
84 static int kconsumerd_err_sock
;
85 static int kconsumerd_cmd_sock
;
86 static int kernel_tracer_fd
;
87 static int kernel_poll_pipe
[2];
90 * Quit pipe for all threads. This permits a single cancellation point
91 * for all threads when receiving an event on the pipe.
93 static int thread_quit_pipe
[2];
95 /* Pthread, Mutexes and Semaphores */
96 static pthread_t kconsumerd_thread
;
97 static pthread_t apps_thread
;
98 static pthread_t client_thread
;
99 static pthread_t kernel_thread
;
100 static sem_t kconsumerd_sem
;
102 static pthread_mutex_t kconsumerd_pid_mutex
; /* Mutex to control kconsumerd pid assignation */
104 static int modprobe_remove_kernel_modules(void);
107 * Pointer initialized before thread creation.
109 * This points to the tracing session list containing the session count and a
110 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
111 * MUST NOT be taken if you call a public function in session.c.
113 * The lock is nested inside the structure: session_list_ptr->lock. Please use
114 * lock_session_list and unlock_session_list for lock acquisition.
116 static struct ltt_session_list
*session_list_ptr
;
118 static gid_t
allowed_group(void)
122 if (opt_tracing_group
) {
123 grp
= getgrnam(opt_tracing_group
);
125 grp
= getgrnam(default_tracing_group
);
137 * Return -1 on error or 0 if all pipes are created.
139 static int init_thread_quit_pipe(void)
143 ret
= pipe2(thread_quit_pipe
, O_CLOEXEC
);
145 perror("thread quit pipe");
154 * Complete teardown of a kernel session. This free all data structure related
155 * to a kernel session and update counter.
157 static void teardown_kernel_session(struct ltt_session
*session
)
159 if (session
->kernel_session
!= NULL
) {
160 DBG("Tearing down kernel session");
161 trace_destroy_kernel_session(session
->kernel_session
);
162 /* Extra precaution */
163 session
->kernel_session
= NULL
;
167 static void stop_threads(void)
169 /* Stopping all threads */
170 DBG("Terminating all threads");
171 close(thread_quit_pipe
[0]);
172 close(thread_quit_pipe
[1]);
178 static void cleanup(void)
182 struct ltt_session
*sess
, *stmp
;
187 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
188 "Matthew, BEET driven development works!%c[%dm",
189 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
192 DBG("Removing %s directory", LTTNG_RUNDIR
);
193 ret
= asprintf(&cmd
, "rm -rf " LTTNG_RUNDIR
);
195 ERR("asprintf failed. Something is really wrong!");
198 /* Remove lttng run directory */
201 ERR("Unable to clean " LTTNG_RUNDIR
);
204 DBG("Cleaning up all session");
206 /* Destroy session list mutex */
207 if (session_list_ptr
!= NULL
) {
208 pthread_mutex_destroy(&session_list_ptr
->lock
);
210 /* Cleanup ALL session */
211 cds_list_for_each_entry_safe(sess
, stmp
, &session_list_ptr
->head
, list
) {
212 teardown_kernel_session(sess
);
213 // TODO complete session cleanup (including UST)
217 pthread_mutex_destroy(&kconsumerd_pid_mutex
);
219 DBG("Closing kernel fd");
220 close(kernel_tracer_fd
);
222 DBG("Unloading kernel modules");
223 modprobe_remove_kernel_modules();
227 * Send data on a unix socket using the liblttsessiondcomm API.
229 * Return lttcomm error code.
231 static int send_unix_sock(int sock
, void *buf
, size_t len
)
233 /* Check valid length */
238 return lttcomm_send_unix_sock(sock
, buf
, len
);
242 * Free memory of a command context structure.
244 static void clean_command_ctx(struct command_ctx
**cmd_ctx
)
246 DBG("Clean command context structure");
248 if ((*cmd_ctx
)->llm
) {
249 free((*cmd_ctx
)->llm
);
251 if ((*cmd_ctx
)->lsm
) {
252 free((*cmd_ctx
)->lsm
);
260 * Send all stream fds of kernel channel to the consumer.
262 static int send_kconsumerd_channel_fds(int sock
, struct ltt_kernel_channel
*channel
)
266 struct ltt_kernel_stream
*stream
;
267 struct lttcomm_kconsumerd_header lkh
;
268 struct lttcomm_kconsumerd_msg lkm
;
270 DBG("Sending fds of channel %s to kernel consumer", channel
->channel
->name
);
272 nb_fd
= channel
->stream_count
;
275 lkh
.payload_size
= nb_fd
* sizeof(struct lttcomm_kconsumerd_msg
);
276 lkh
.cmd_type
= ADD_STREAM
;
278 DBG("Sending kconsumerd header");
280 ret
= lttcomm_send_unix_sock(sock
, &lkh
, sizeof(struct lttcomm_kconsumerd_header
));
282 perror("send kconsumerd header");
286 cds_list_for_each_entry(stream
, &channel
->stream_list
.head
, list
) {
287 if (stream
->fd
!= 0) {
289 lkm
.state
= stream
->state
;
290 lkm
.max_sb_size
= channel
->channel
->attr
.subbuf_size
;
291 lkm
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
292 strncpy(lkm
.path_name
, stream
->pathname
, PATH_MAX
);
293 lkm
.path_name
[PATH_MAX
- 1] = '\0';
295 DBG("Sending fd %d to kconsumerd", lkm
.fd
);
297 ret
= lttcomm_send_fds_unix_sock(sock
, &lkm
, &lkm
.fd
, 1, sizeof(lkm
));
299 perror("send kconsumerd fd");
305 DBG("Kconsumerd channel fds sent");
314 * Send all stream fds of the kernel session to the consumer.
316 static int send_kconsumerd_fds(int sock
, struct ltt_kernel_session
*session
)
319 struct ltt_kernel_channel
*chan
;
320 struct lttcomm_kconsumerd_header lkh
;
321 struct lttcomm_kconsumerd_msg lkm
;
324 lkh
.payload_size
= sizeof(struct lttcomm_kconsumerd_msg
);
325 lkh
.cmd_type
= ADD_STREAM
;
327 DBG("Sending kconsumerd header for metadata");
329 ret
= lttcomm_send_unix_sock(sock
, &lkh
, sizeof(struct lttcomm_kconsumerd_header
));
331 perror("send kconsumerd header");
335 DBG("Sending metadata stream fd");
337 if (session
->metadata_stream_fd
!= 0) {
338 /* Send metadata stream fd first */
339 lkm
.fd
= session
->metadata_stream_fd
;
340 lkm
.state
= ACTIVE_FD
;
341 lkm
.max_sb_size
= session
->metadata
->conf
->attr
.subbuf_size
;
342 lkm
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
343 strncpy(lkm
.path_name
, session
->metadata
->pathname
, PATH_MAX
);
344 lkm
.path_name
[PATH_MAX
- 1] = '\0';
346 ret
= lttcomm_send_fds_unix_sock(sock
, &lkm
, &lkm
.fd
, 1, sizeof(lkm
));
348 perror("send kconsumerd fd");
353 cds_list_for_each_entry(chan
, &session
->channel_list
.head
, list
) {
354 ret
= send_kconsumerd_channel_fds(sock
, chan
);
360 DBG("Kconsumerd fds (metadata and channel streams) sent");
370 * Return a socket connected to the libust communication socket of the
371 * application identified by the pid.
373 * If the pid is not found in the traceable list, return -1 to indicate error.
375 static int ust_connect_app(pid_t pid
)
378 struct ltt_traceable_app
*lta
;
380 DBG("Connect to application pid %d", pid
);
382 lta
= find_app_by_pid(pid
);
385 DBG("Application pid %d not found", pid
);
389 sock
= ustctl_connect_pid(lta
->pid
);
391 ERR("Fail connecting to the PID %d", pid
);
396 #endif /* DISABLED */
399 * Notify apps by writing 42 to a named pipe using name. Every applications
400 * waiting for a ltt-sessiond will be notified and re-register automatically to
401 * the session daemon.
403 * Return open or write error value.
405 static int notify_apps(const char *name
)
410 DBG("Notify the global application pipe");
412 /* Try opening the global pipe */
413 fd
= open(name
, O_WRONLY
);
418 /* Notify by writing on the pipe */
419 ret
= write(fd
, "42", 2);
429 * Setup the outgoing data buffer for the response (llm) by allocating the
430 * right amount of memory and copying the original information from the lsm
433 * Return total size of the buffer pointed by buf.
435 static int setup_lttng_msg(struct command_ctx
*cmd_ctx
, size_t size
)
441 cmd_ctx
->llm
= malloc(sizeof(struct lttcomm_lttng_msg
) + buf_size
);
442 if (cmd_ctx
->llm
== NULL
) {
448 /* Copy common data */
449 cmd_ctx
->llm
->cmd_type
= cmd_ctx
->lsm
->cmd_type
;
450 cmd_ctx
->llm
->pid
= cmd_ctx
->lsm
->domain
.attr
.pid
;
452 cmd_ctx
->llm
->data_size
= size
;
453 cmd_ctx
->lttng_msg_size
= sizeof(struct lttcomm_lttng_msg
) + buf_size
;
462 * Update the kernel pollfd set of all channel fd available over all tracing
463 * session. Add the wakeup pipe at the end of the set.
465 static int update_kernel_pollfd(void)
469 * The wakup pipe and the quit pipe are needed so the number of fds starts
470 * at 2 for those pipes.
472 unsigned int nb_fd
= 2;
473 struct ltt_session
*session
;
474 struct ltt_kernel_channel
*channel
;
476 DBG("Updating kernel_pollfd");
478 /* Get the number of channel of all kernel session */
480 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
481 lock_session(session
);
482 if (session
->kernel_session
== NULL
) {
483 unlock_session(session
);
486 nb_fd
+= session
->kernel_session
->channel_count
;
487 unlock_session(session
);
490 DBG("Resizing kernel_pollfd to size %d", nb_fd
);
492 kernel_pollfd
= realloc(kernel_pollfd
, nb_fd
* sizeof(struct pollfd
));
493 if (kernel_pollfd
== NULL
) {
494 perror("malloc kernel_pollfd");
498 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
499 lock_session(session
);
500 if (session
->kernel_session
== NULL
) {
501 unlock_session(session
);
505 ERR("To much channel for kernel_pollfd size");
506 unlock_session(session
);
509 cds_list_for_each_entry(channel
, &session
->kernel_session
->channel_list
.head
, list
) {
510 kernel_pollfd
[i
].fd
= channel
->fd
;
511 kernel_pollfd
[i
].events
= POLLIN
| POLLRDNORM
;
514 unlock_session(session
);
516 unlock_session_list();
518 /* Adding wake up pipe */
519 kernel_pollfd
[nb_fd
- 2].fd
= kernel_poll_pipe
[0];
520 kernel_pollfd
[nb_fd
- 2].events
= POLLIN
;
522 /* Adding the quit pipe */
523 kernel_pollfd
[nb_fd
- 1].fd
= thread_quit_pipe
[0];
528 unlock_session_list();
533 * Find the channel fd from 'fd' over all tracing session. When found, check
534 * for new channel stream and send those stream fds to the kernel consumer.
536 * Useful for CPU hotplug feature.
538 static int update_kernel_stream(int fd
)
541 struct ltt_session
*session
;
542 struct ltt_kernel_channel
*channel
;
544 DBG("Updating kernel streams for channel fd %d", fd
);
547 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
548 lock_session(session
);
549 if (session
->kernel_session
== NULL
) {
550 unlock_session(session
);
553 cds_list_for_each_entry(channel
, &session
->kernel_session
->channel_list
.head
, list
) {
554 if (channel
->fd
== fd
) {
555 DBG("Channel found, updating kernel streams");
556 ret
= kernel_open_channel_stream(channel
);
561 * Have we already sent fds to the consumer? If yes, it means that
562 * tracing is started so it is safe to send our updated stream fds.
564 if (session
->kernel_session
->kconsumer_fds_sent
== 1) {
565 ret
= send_kconsumerd_channel_fds(kconsumerd_cmd_sock
, channel
);
573 unlock_session(session
);
577 unlock_session_list();
579 unlock_session(session
);
585 * This thread manage event coming from the kernel.
587 * Features supported in this thread:
590 static void *thread_manage_kernel(void *data
)
592 int ret
, i
, nb_fd
= 0;
594 int update_poll_flag
= 1;
596 DBG("Thread manage kernel started");
599 if (update_poll_flag
== 1) {
600 nb_fd
= update_kernel_pollfd();
604 update_poll_flag
= 0;
607 DBG("Polling on %d fds", nb_fd
);
609 /* Poll infinite value of time */
610 ret
= poll(kernel_pollfd
, nb_fd
, -1);
612 perror("poll kernel thread");
614 } else if (ret
== 0) {
615 /* Should not happen since timeout is infinite */
619 /* Thread quit pipe has been closed. Killing thread. */
620 if (kernel_pollfd
[nb_fd
- 1].revents
== POLLNVAL
) {
624 DBG("Kernel poll event triggered");
627 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
630 switch (kernel_pollfd
[nb_fd
- 2].revents
) {
632 ret
= read(kernel_poll_pipe
[0], &tmp
, 1);
633 update_poll_flag
= 1;
641 for (i
= 0; i
< nb_fd
; i
++) {
642 switch (kernel_pollfd
[i
].revents
) {
644 * New CPU detected by the kernel. Adding kernel stream to kernel
645 * session and updating the kernel consumer
647 case POLLIN
| POLLRDNORM
:
648 ret
= update_kernel_stream(kernel_pollfd
[i
].fd
);
658 DBG("Kernel thread dying");
663 close(kernel_poll_pipe
[0]);
664 close(kernel_poll_pipe
[1]);
669 * This thread manage the kconsumerd error sent back to the session daemon.
671 static void *thread_manage_kconsumerd(void *data
)
674 enum lttcomm_return_code code
;
675 struct pollfd pollfd
[2];
677 DBG("[thread] Manage kconsumerd started");
679 ret
= lttcomm_listen_unix_sock(kconsumerd_err_sock
);
684 /* First fd is always the quit pipe */
685 pollfd
[0].fd
= thread_quit_pipe
[0];
688 pollfd
[1].fd
= kconsumerd_err_sock
;
689 pollfd
[1].events
= POLLIN
;
691 /* Inifinite blocking call, waiting for transmission */
692 ret
= poll(pollfd
, 2, -1);
694 perror("poll kconsumerd thread");
698 /* Thread quit pipe has been closed. Killing thread. */
699 if (pollfd
[0].revents
== POLLNVAL
) {
701 } else if (pollfd
[1].revents
== POLLERR
) {
702 ERR("Kconsumerd err socket poll error");
706 sock
= lttcomm_accept_unix_sock(kconsumerd_err_sock
);
711 /* Getting status code from kconsumerd */
712 ret
= lttcomm_recv_unix_sock(sock
, &code
, sizeof(enum lttcomm_return_code
));
717 if (code
== KCONSUMERD_COMMAND_SOCK_READY
) {
718 kconsumerd_cmd_sock
= lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path
);
719 if (kconsumerd_cmd_sock
< 0) {
720 sem_post(&kconsumerd_sem
);
721 perror("kconsumerd connect");
724 /* Signal condition to tell that the kconsumerd is ready */
725 sem_post(&kconsumerd_sem
);
726 DBG("Kconsumerd command socket ready");
728 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
729 lttcomm_get_readable_code(-code
));
733 /* Wait for any kconsumerd error */
734 ret
= lttcomm_recv_unix_sock(sock
, &code
, sizeof(enum lttcomm_return_code
));
736 ERR("Kconsumerd closed the command socket");
740 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code
));
743 DBG("Kconsumerd thread dying");
744 if (kconsumerd_err_sock
) {
745 close(kconsumerd_err_sock
);
747 if (kconsumerd_cmd_sock
) {
748 close(kconsumerd_cmd_sock
);
754 unlink(kconsumerd_err_unix_sock_path
);
755 unlink(kconsumerd_cmd_unix_sock_path
);
762 * This thread manage the application socket communication
764 static void *thread_manage_apps(void *data
)
767 struct pollfd pollfd
[2];
769 /* TODO: Something more elegant is needed but fine for now */
770 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
771 * for 32-bit vs 64-bit compat processes. */
772 /* replicate in ust with version number */
774 int reg
; /* 1:register, 0:unregister */
779 DBG("[thread] Manage apps started");
781 ret
= lttcomm_listen_unix_sock(apps_sock
);
786 /* First fd is always the quit pipe */
787 pollfd
[0].fd
= thread_quit_pipe
[0];
790 pollfd
[1].fd
= apps_sock
;
791 pollfd
[1].events
= POLLIN
;
793 /* Notify all applications to register */
794 notify_apps(default_global_apps_pipe
);
797 DBG("Accepting application registration");
799 /* Inifinite blocking call, waiting for transmission */
800 ret
= poll(pollfd
, 2, -1);
802 perror("poll apps thread");
806 /* Thread quit pipe has been closed. Killing thread. */
807 if (pollfd
[0].revents
== POLLNVAL
) {
809 } else if (pollfd
[1].revents
== POLLERR
) {
810 ERR("Apps socket poll error");
814 sock
= lttcomm_accept_unix_sock(apps_sock
);
820 * Basic recv here to handle the very simple data
821 * that the libust send to register (reg_msg).
823 ret
= recv(sock
, ®_msg
, sizeof(reg_msg
), 0);
829 /* Add application to the global traceable list */
830 if (reg_msg
.reg
== 1) {
832 ret
= register_traceable_app(reg_msg
.pid
, reg_msg
.uid
);
834 /* register_traceable_app only return an error with
835 * ENOMEM. At this point, we better stop everything.
841 unregister_traceable_app(reg_msg
.pid
);
846 DBG("Apps thread dying");
854 unlink(apps_unix_sock_path
);
859 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
860 * exec or it will fails.
862 static int spawn_kconsumerd_thread(void)
866 /* Setup semaphore */
867 sem_init(&kconsumerd_sem
, 0, 0);
869 ret
= pthread_create(&kconsumerd_thread
, NULL
, thread_manage_kconsumerd
, (void *) NULL
);
871 perror("pthread_create kconsumerd");
875 /* Wait for the kconsumerd thread to be ready */
876 sem_wait(&kconsumerd_sem
);
878 if (kconsumerd_pid
== 0) {
879 ERR("Kconsumerd did not start");
886 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
890 static int join_kconsumerd_thread(void)
895 if (kconsumerd_pid
!= 0) {
896 ret
= kill(kconsumerd_pid
, SIGTERM
);
898 ERR("Error killing kconsumerd");
901 return pthread_join(kconsumerd_thread
, &status
);
908 * Fork and exec a kernel consumer daemon (kconsumerd).
910 * Return pid if successful else -1.
912 static pid_t
spawn_kconsumerd(void)
916 const char *verbosity
;
918 DBG("Spawning kconsumerd");
925 if (opt_verbose
> 1 || opt_verbose_kconsumerd
) {
926 verbosity
= "--verbose";
928 verbosity
= "--quiet";
930 execl(INSTALL_BIN_PATH
"/ltt-kconsumerd", "ltt-kconsumerd", verbosity
, NULL
);
932 perror("kernel start consumer exec");
935 } else if (pid
> 0) {
939 perror("kernel start consumer fork");
949 * Spawn the kconsumerd daemon and session daemon thread.
951 static int start_kconsumerd(void)
955 pthread_mutex_lock(&kconsumerd_pid_mutex
);
956 if (kconsumerd_pid
!= 0) {
957 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
961 ret
= spawn_kconsumerd();
963 ERR("Spawning kconsumerd failed");
964 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
965 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
969 /* Setting up the global kconsumerd_pid */
970 kconsumerd_pid
= ret
;
971 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
973 DBG("Kconsumerd pid %d", ret
);
975 DBG("Spawning kconsumerd thread");
976 ret
= spawn_kconsumerd_thread();
978 ERR("Fatal error spawning kconsumerd thread");
990 * modprobe_kernel_modules
992 static int modprobe_kernel_modules(void)
997 for (i
= 0; i
< ARRAY_SIZE(kernel_modules_list
); i
++) {
998 ret
= snprintf(modprobe
, sizeof(modprobe
),
999 "/sbin/modprobe %s%s",
1000 kernel_modules_list
[i
].required
? "" : "--quiet ",
1001 kernel_modules_list
[i
].name
);
1003 perror("snprintf modprobe");
1006 modprobe
[sizeof(modprobe
) - 1] = '\0';
1007 ret
= system(modprobe
);
1009 ERR("Unable to launch modprobe for module %s",
1010 kernel_modules_list
[i
].name
);
1011 } else if (kernel_modules_list
[i
].required
1012 && WEXITSTATUS(ret
) != 0) {
1013 ERR("Unable to load module %s",
1014 kernel_modules_list
[i
].name
);
1016 DBG("Modprobe successfully %s",
1017 kernel_modules_list
[i
].name
);
1026 * modprobe_remove_kernel_modules
1027 * Remove modules in reverse load order.
1029 static int modprobe_remove_kernel_modules(void)
1034 for (i
= ARRAY_SIZE(kernel_modules_list
) - 1; i
>= 0; i
--) {
1035 ret
= snprintf(modprobe
, sizeof(modprobe
),
1036 "/sbin/modprobe --remove --quiet %s",
1037 kernel_modules_list
[i
].name
);
1039 perror("snprintf modprobe --remove");
1042 modprobe
[sizeof(modprobe
) - 1] = '\0';
1043 ret
= system(modprobe
);
1045 ERR("Unable to launch modprobe --remove for module %s",
1046 kernel_modules_list
[i
].name
);
1047 } else if (kernel_modules_list
[i
].required
1048 && WEXITSTATUS(ret
) != 0) {
1049 ERR("Unable to remove module %s",
1050 kernel_modules_list
[i
].name
);
1052 DBG("Modprobe removal successful %s",
1053 kernel_modules_list
[i
].name
);
1064 static int mount_debugfs(char *path
)
1067 char *type
= "debugfs";
1069 ret
= mkdir_recursive(path
, S_IRWXU
| S_IRWXG
, geteuid(), getegid());
1074 ret
= mount(type
, path
, type
, 0, NULL
);
1076 perror("mount debugfs");
1080 DBG("Mounted debugfs successfully at %s", path
);
1087 * Setup necessary data for kernel tracer action.
1089 static void init_kernel_tracer(void)
1092 char *proc_mounts
= "/proc/mounts";
1094 char *debugfs_path
= NULL
, *lttng_path
;
1097 /* Detect debugfs */
1098 fp
= fopen(proc_mounts
, "r");
1100 ERR("Unable to probe %s", proc_mounts
);
1104 while (fgets(line
, sizeof(line
), fp
) != NULL
) {
1105 if (strstr(line
, "debugfs") != NULL
) {
1106 /* Remove first string */
1108 /* Dup string here so we can reuse line later on */
1109 debugfs_path
= strdup(strtok(NULL
, " "));
1110 DBG("Got debugfs path : %s", debugfs_path
);
1117 /* Mount debugfs if needded */
1118 if (debugfs_path
== NULL
) {
1119 ret
= asprintf(&debugfs_path
, "/mnt/debugfs");
1121 perror("asprintf debugfs path");
1124 ret
= mount_debugfs(debugfs_path
);
1130 /* Modprobe lttng kernel modules */
1131 ret
= modprobe_kernel_modules();
1136 /* Setup lttng kernel path */
1137 ret
= asprintf(<tng_path
, "%s/lttng", debugfs_path
);
1139 perror("asprintf lttng path");
1143 /* Open debugfs lttng */
1144 kernel_tracer_fd
= open(lttng_path
, O_RDWR
);
1145 if (kernel_tracer_fd
< 0) {
1146 DBG("Failed to open %s", lttng_path
);
1152 DBG("Kernel tracer fd %d", kernel_tracer_fd
);
1162 WARN("No kernel tracer available");
1163 kernel_tracer_fd
= 0;
1168 * Start tracing by creating trace directory and sending FDs to the kernel
1171 static int start_kernel_trace(struct ltt_kernel_session
*session
)
1175 if (session
->kconsumer_fds_sent
== 0) {
1176 ret
= send_kconsumerd_fds(kconsumerd_cmd_sock
, session
);
1178 ERR("Send kconsumerd fds failed");
1179 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
1183 session
->kconsumer_fds_sent
= 1;
1191 * Notify kernel thread to update it's pollfd.
1193 static int notify_kernel_pollfd(void)
1197 /* Inform kernel thread of the new kernel channel */
1198 ret
= write(kernel_poll_pipe
[1], "!", 1);
1200 perror("write kernel poll pipe");
1207 * Allocate a channel structure and fill it.
1209 static struct lttng_channel
*init_default_channel(char *name
)
1211 struct lttng_channel
*chan
;
1213 chan
= malloc(sizeof(struct lttng_channel
));
1215 perror("init channel malloc");
1219 if (snprintf(chan
->name
, NAME_MAX
, "%s", name
) < 0) {
1220 perror("snprintf channel name");
1224 chan
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
1225 chan
->attr
.subbuf_size
= DEFAULT_CHANNEL_SUBBUF_SIZE
;
1226 chan
->attr
.num_subbuf
= DEFAULT_CHANNEL_SUBBUF_NUM
;
1227 chan
->attr
.switch_timer_interval
= DEFAULT_CHANNEL_SWITCH_TIMER
;
1228 chan
->attr
.read_timer_interval
= DEFAULT_CHANNEL_READ_TIMER
;
1229 chan
->attr
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
1236 * Create a kernel tracer session then create the default channel.
1238 static int create_kernel_session(struct ltt_session
*session
)
1242 DBG("Creating kernel session");
1244 ret
= kernel_create_session(session
, kernel_tracer_fd
);
1246 ret
= LTTCOMM_KERN_SESS_FAIL
;
1250 ret
= asprintf(&session
->kernel_session
->trace_path
, "%s/kernel",
1253 perror("asprintf kernel traces path");
1257 ret
= mkdir_recursive(session
->kernel_session
->trace_path
,
1258 S_IRWXU
| S_IRWXG
, geteuid(), allowed_group());
1260 if (ret
!= -EEXIST
) {
1261 ERR("Trace directory creation error");
1271 * Using the session list, filled a lttng_session array to send back to the
1272 * client for session listing.
1274 * The session list lock MUST be acquired before calling this function. Use
1275 * lock_session_list() and unlock_session_list().
1277 static void list_lttng_sessions(struct lttng_session
*sessions
)
1280 struct ltt_session
*session
;
1282 DBG("Getting all available session");
1284 * Iterate over session list and append data after the control struct in
1287 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
1288 strncpy(sessions
[i
].path
, session
->path
, PATH_MAX
);
1289 sessions
[i
].path
[PATH_MAX
- 1] = '\0';
1290 strncpy(sessions
[i
].name
, session
->name
, NAME_MAX
);
1291 sessions
[i
].name
[NAME_MAX
- 1] = '\0';
1297 * Fill lttng_channel array of all channels.
1299 static void list_lttng_channels(struct ltt_session
*session
,
1300 struct lttng_channel
*channels
)
1303 struct ltt_kernel_channel
*kchan
;
1305 DBG("Listing channels for session %s", session
->name
);
1307 /* Kernel channels */
1308 if (session
->kernel_session
!= NULL
) {
1309 cds_list_for_each_entry(kchan
, &session
->kernel_session
->channel_list
.head
, list
) {
1310 /* Copy lttng_channel struct to array */
1311 memcpy(&channels
[i
], kchan
->channel
, sizeof(struct lttng_channel
));
1312 channels
[i
].enabled
= kchan
->enabled
;
1317 /* TODO: Missing UST listing */
1321 * Fill lttng_event array of all events in the channel.
1323 static void list_lttng_events(struct ltt_kernel_channel
*kchan
,
1324 struct lttng_event
*events
)
1327 * TODO: This is ONLY kernel. Need UST support.
1330 struct ltt_kernel_event
*event
;
1332 DBG("Listing events for channel %s", kchan
->channel
->name
);
1334 /* Kernel channels */
1335 cds_list_for_each_entry(event
, &kchan
->events_list
.head
, list
) {
1336 strncpy(events
[i
].name
, event
->event
->name
, LTTNG_SYMBOL_NAME_LEN
);
1337 events
[i
].name
[LTTNG_SYMBOL_NAME_LEN
- 1] = '\0';
1338 events
[i
].enabled
= event
->enabled
;
1339 switch (event
->event
->instrumentation
) {
1340 case LTTNG_KERNEL_TRACEPOINT
:
1341 events
[i
].type
= LTTNG_EVENT_TRACEPOINT
;
1343 case LTTNG_KERNEL_KPROBE
:
1344 case LTTNG_KERNEL_KRETPROBE
:
1345 events
[i
].type
= LTTNG_EVENT_PROBE
;
1346 memcpy(&events
[i
].attr
.probe
, &event
->event
->u
.kprobe
,
1347 sizeof(struct lttng_kernel_kprobe
));
1349 case LTTNG_KERNEL_FUNCTION
:
1350 events
[i
].type
= LTTNG_EVENT_FUNCTION
;
1351 memcpy(&events
[i
].attr
.ftrace
, &event
->event
->u
.ftrace
,
1352 sizeof(struct lttng_kernel_function
));
1360 * Process the command requested by the lttng client within the command
1361 * context structure. This function make sure that the return structure (llm)
1362 * is set and ready for transmission before returning.
1364 * Return any error encountered or 0 for success.
1366 static int process_client_msg(struct command_ctx
*cmd_ctx
)
1368 int ret
= LTTCOMM_OK
;
1370 DBG("Processing client command %d", cmd_ctx
->lsm
->cmd_type
);
1373 * Commands that DO NOT need a session.
1375 switch (cmd_ctx
->lsm
->cmd_type
) {
1376 case LTTNG_CREATE_SESSION
:
1377 case LTTNG_LIST_SESSIONS
:
1378 case LTTNG_LIST_TRACEPOINTS
:
1379 case LTTNG_CALIBRATE
:
1382 DBG("Getting session %s by name", cmd_ctx
->lsm
->session
.name
);
1383 cmd_ctx
->session
= find_session_by_name(cmd_ctx
->lsm
->session
.name
);
1384 if (cmd_ctx
->session
== NULL
) {
1385 /* If session name not found */
1386 if (cmd_ctx
->lsm
->session
.name
!= NULL
) {
1387 ret
= LTTCOMM_SESS_NOT_FOUND
;
1388 } else { /* If no session name specified */
1389 ret
= LTTCOMM_SELECT_SESS
;
1393 /* Acquire lock for the session */
1394 lock_session(cmd_ctx
->session
);
1400 * Check domain type for specific "pre-action".
1402 switch (cmd_ctx
->lsm
->domain
.type
) {
1403 case LTTNG_DOMAIN_KERNEL
:
1404 /* Kernel tracer check */
1405 if (kernel_tracer_fd
== 0) {
1406 init_kernel_tracer();
1407 if (kernel_tracer_fd
== 0) {
1408 ret
= LTTCOMM_KERN_NA
;
1413 /* Need a session for kernel command */
1414 switch (cmd_ctx
->lsm
->cmd_type
) {
1415 case LTTNG_CREATE_SESSION
:
1416 case LTTNG_LIST_SESSIONS
:
1417 case LTTNG_LIST_TRACEPOINTS
:
1418 case LTTNG_CALIBRATE
:
1421 if (cmd_ctx
->session
->kernel_session
== NULL
) {
1422 ret
= create_kernel_session(cmd_ctx
->session
);
1424 ret
= LTTCOMM_KERN_SESS_FAIL
;
1428 /* Start the kernel consumer daemon */
1429 if (kconsumerd_pid
== 0) {
1430 ret
= start_kconsumerd();
1442 /* Process by command type */
1443 switch (cmd_ctx
->lsm
->cmd_type
) {
1444 case LTTNG_ADD_CONTEXT
:
1446 struct lttng_kernel_context kctx
;
1448 /* Setup lttng message with no payload */
1449 ret
= setup_lttng_msg(cmd_ctx
, 0);
1454 switch (cmd_ctx
->lsm
->domain
.type
) {
1455 case LTTNG_DOMAIN_KERNEL
:
1456 /* Create Kernel context */
1457 kctx
.ctx
= cmd_ctx
->lsm
->u
.context
.ctx
.ctx
;
1458 kctx
.u
.perf_counter
.type
= cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.type
;
1459 kctx
.u
.perf_counter
.config
= cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.config
;
1460 strncpy(kctx
.u
.perf_counter
.name
,
1461 cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.name
,
1462 LTTNG_SYMBOL_NAME_LEN
);
1463 kctx
.u
.perf_counter
.name
[LTTNG_SYMBOL_NAME_LEN
- 1] = '\0';
1465 /* Add kernel context to kernel tracer. See context.c */
1466 ret
= add_kernel_context(cmd_ctx
->session
->kernel_session
, &kctx
,
1467 cmd_ctx
->lsm
->u
.context
.event_name
,
1468 cmd_ctx
->lsm
->u
.context
.channel_name
);
1469 if (ret
!= LTTCOMM_OK
) {
1474 /* TODO: Userspace tracing */
1475 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1482 case LTTNG_DISABLE_CHANNEL
:
1484 struct ltt_kernel_channel
*kchan
;
1486 /* Setup lttng message with no payload */
1487 ret
= setup_lttng_msg(cmd_ctx
, 0);
1492 switch (cmd_ctx
->lsm
->domain
.type
) {
1493 case LTTNG_DOMAIN_KERNEL
:
1494 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1495 cmd_ctx
->session
->kernel_session
);
1496 if (kchan
== NULL
) {
1497 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1499 } else if (kchan
->enabled
== 1) {
1500 ret
= kernel_disable_channel(kchan
);
1502 if (ret
!= EEXIST
) {
1503 ret
= LTTCOMM_KERN_CHAN_DISABLE_FAIL
;
1508 kernel_wait_quiescent(kernel_tracer_fd
);
1511 /* TODO: Userspace tracing */
1512 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1519 case LTTNG_DISABLE_EVENT
:
1521 struct ltt_kernel_channel
*kchan
;
1522 struct ltt_kernel_event
*kevent
;
1524 /* Setup lttng message with no payload */
1525 ret
= setup_lttng_msg(cmd_ctx
, 0);
1530 switch (cmd_ctx
->lsm
->domain
.type
) {
1531 case LTTNG_DOMAIN_KERNEL
:
1532 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1533 cmd_ctx
->session
->kernel_session
);
1534 if (kchan
== NULL
) {
1535 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1539 kevent
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.disable
.name
, kchan
);
1540 if (kevent
!= NULL
) {
1541 DBG("Disabling kernel event %s for channel %s.", kevent
->event
->name
,
1542 kchan
->channel
->name
);
1543 ret
= kernel_disable_event(kevent
);
1545 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
1550 kernel_wait_quiescent(kernel_tracer_fd
);
1553 /* TODO: Userspace tracing */
1554 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1561 case LTTNG_DISABLE_ALL_EVENT
:
1563 struct ltt_kernel_channel
*kchan
;
1564 struct ltt_kernel_event
*kevent
;
1566 /* Setup lttng message with no payload */
1567 ret
= setup_lttng_msg(cmd_ctx
, 0);
1572 switch (cmd_ctx
->lsm
->domain
.type
) {
1573 case LTTNG_DOMAIN_KERNEL
:
1574 DBG("Disabling all enabled kernel events");
1575 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1576 cmd_ctx
->session
->kernel_session
);
1577 if (kchan
== NULL
) {
1578 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1582 /* For each event in the kernel session */
1583 cds_list_for_each_entry(kevent
, &kchan
->events_list
.head
, list
) {
1584 DBG("Disabling kernel event %s for channel %s.",
1585 kevent
->event
->name
, kchan
->channel
->name
);
1586 ret
= kernel_disable_event(kevent
);
1592 /* Quiescent wait after event disable */
1593 kernel_wait_quiescent(kernel_tracer_fd
);
1596 /* TODO: Userspace tracing */
1597 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1604 case LTTNG_ENABLE_CHANNEL
:
1606 struct ltt_kernel_channel
*kchan
;
1608 /* Setup lttng message with no payload */
1609 ret
= setup_lttng_msg(cmd_ctx
, 0);
1614 switch (cmd_ctx
->lsm
->domain
.type
) {
1615 case LTTNG_DOMAIN_KERNEL
:
1616 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.enable
.channel_name
,
1617 cmd_ctx
->session
->kernel_session
);
1618 if (kchan
== NULL
) {
1619 /* Channel not found, creating it */
1620 DBG("Creating kernel channel");
1622 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1623 &cmd_ctx
->lsm
->u
.channel
.chan
,
1624 cmd_ctx
->session
->kernel_session
->trace_path
);
1626 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1630 /* Notify kernel thread that there is a new channel */
1631 ret
= notify_kernel_pollfd();
1633 ret
= LTTCOMM_FATAL
;
1636 } else if (kchan
->enabled
== 0) {
1637 ret
= kernel_enable_channel(kchan
);
1639 if (ret
!= EEXIST
) {
1640 ret
= LTTCOMM_KERN_CHAN_ENABLE_FAIL
;
1646 kernel_wait_quiescent(kernel_tracer_fd
);
1649 /* TODO: Userspace tracing */
1650 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1657 case LTTNG_ENABLE_EVENT
:
1660 struct ltt_kernel_channel
*kchan
;
1661 struct ltt_kernel_event
*kevent
;
1662 struct lttng_channel
*chan
;
1664 /* Setup lttng message with no payload */
1665 ret
= setup_lttng_msg(cmd_ctx
, 0);
1670 channel_name
= cmd_ctx
->lsm
->u
.enable
.channel_name
;
1672 switch (cmd_ctx
->lsm
->domain
.type
) {
1673 case LTTNG_DOMAIN_KERNEL
:
1675 kchan
= get_kernel_channel_by_name(channel_name
,
1676 cmd_ctx
->session
->kernel_session
);
1677 if (kchan
== NULL
) {
1678 DBG("Channel not found. Creating channel %s", channel_name
);
1680 chan
= init_default_channel(channel_name
);
1682 ret
= LTTCOMM_FATAL
;
1686 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1687 chan
, cmd_ctx
->session
->kernel_session
->trace_path
);
1689 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1693 } while (kchan
== NULL
);
1695 kevent
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.enable
.event
.name
, kchan
);
1696 if (kevent
== NULL
) {
1697 DBG("Creating kernel event %s for channel %s.",
1698 cmd_ctx
->lsm
->u
.enable
.event
.name
, channel_name
);
1699 ret
= kernel_create_event(&cmd_ctx
->lsm
->u
.enable
.event
, kchan
);
1701 DBG("Enabling kernel event %s for channel %s.",
1702 kevent
->event
->name
, channel_name
);
1703 ret
= kernel_enable_event(kevent
);
1704 if (ret
== -EEXIST
) {
1705 ret
= LTTCOMM_KERN_EVENT_EXIST
;
1711 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
1715 kernel_wait_quiescent(kernel_tracer_fd
);
1718 /* TODO: Userspace tracing */
1719 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1725 case LTTNG_ENABLE_ALL_EVENT
:
1729 struct ltt_kernel_channel
*kchan
;
1730 struct ltt_kernel_event
*kevent
;
1731 struct lttng_event
*event_list
;
1732 struct lttng_channel
*chan
;
1734 /* Setup lttng message with no payload */
1735 ret
= setup_lttng_msg(cmd_ctx
, 0);
1740 DBG("Enabling all kernel event");
1742 channel_name
= cmd_ctx
->lsm
->u
.enable
.channel_name
;
1744 switch (cmd_ctx
->lsm
->domain
.type
) {
1745 case LTTNG_DOMAIN_KERNEL
:
1747 kchan
= get_kernel_channel_by_name(channel_name
,
1748 cmd_ctx
->session
->kernel_session
);
1749 if (kchan
== NULL
) {
1750 DBG("Channel not found. Creating channel %s", channel_name
);
1752 chan
= init_default_channel(channel_name
);
1754 ret
= LTTCOMM_FATAL
;
1758 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1759 chan
, cmd_ctx
->session
->kernel_session
->trace_path
);
1761 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1765 } while (kchan
== NULL
);
1767 /* For each event in the kernel session */
1768 cds_list_for_each_entry(kevent
, &kchan
->events_list
.head
, list
) {
1769 DBG("Enabling kernel event %s for channel %s.",
1770 kevent
->event
->name
, channel_name
);
1771 ret
= kernel_enable_event(kevent
);
1777 size
= kernel_list_events(kernel_tracer_fd
, &event_list
);
1779 ret
= LTTCOMM_KERN_LIST_FAIL
;
1783 for (i
= 0; i
< size
; i
++) {
1784 kevent
= get_kernel_event_by_name(event_list
[i
].name
, kchan
);
1785 if (kevent
== NULL
) {
1786 /* Default event type for enable all */
1787 event_list
[i
].type
= LTTNG_EVENT_TRACEPOINT
;
1788 /* Enable each single tracepoint event */
1789 ret
= kernel_create_event(&event_list
[i
], kchan
);
1791 /* Ignore error here and continue */
1798 /* Quiescent wait after event enable */
1799 kernel_wait_quiescent(kernel_tracer_fd
);
1802 /* TODO: Userspace tracing */
1803 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1810 case LTTNG_LIST_TRACEPOINTS
:
1812 struct lttng_event
*events
;
1813 ssize_t nb_events
= 0;
1815 switch (cmd_ctx
->lsm
->domain
.type
) {
1816 case LTTNG_DOMAIN_KERNEL
:
1817 DBG("Listing kernel events");
1818 nb_events
= kernel_list_events(kernel_tracer_fd
, &events
);
1819 if (nb_events
< 0) {
1820 ret
= LTTCOMM_KERN_LIST_FAIL
;
1825 /* TODO: Userspace listing */
1826 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1831 * Setup lttng message with payload size set to the event list size in
1832 * bytes and then copy list into the llm payload.
1834 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_event
) * nb_events
);
1840 /* Copy event list into message payload */
1841 memcpy(cmd_ctx
->llm
->payload
, events
,
1842 sizeof(struct lttng_event
) * nb_events
);
1849 case LTTNG_START_TRACE
:
1851 struct ltt_kernel_channel
*chan
;
1853 /* Setup lttng message with no payload */
1854 ret
= setup_lttng_msg(cmd_ctx
, 0);
1859 /* Kernel tracing */
1860 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1861 if (cmd_ctx
->session
->kernel_session
->metadata
== NULL
) {
1862 DBG("Open kernel metadata");
1863 ret
= kernel_open_metadata(cmd_ctx
->session
->kernel_session
,
1864 cmd_ctx
->session
->kernel_session
->trace_path
);
1866 ret
= LTTCOMM_KERN_META_FAIL
;
1871 if (cmd_ctx
->session
->kernel_session
->metadata_stream_fd
== 0) {
1872 DBG("Opening kernel metadata stream");
1873 if (cmd_ctx
->session
->kernel_session
->metadata_stream_fd
== 0) {
1874 ret
= kernel_open_metadata_stream(cmd_ctx
->session
->kernel_session
);
1876 ERR("Kernel create metadata stream failed");
1877 ret
= LTTCOMM_KERN_STREAM_FAIL
;
1883 /* For each channel */
1884 cds_list_for_each_entry(chan
,
1885 &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1886 if (chan
->stream_count
== 0) {
1887 ret
= kernel_open_channel_stream(chan
);
1889 ERR("Kernel create channel stream failed");
1890 ret
= LTTCOMM_KERN_STREAM_FAIL
;
1893 /* Update the stream global counter */
1894 cmd_ctx
->session
->kernel_session
->stream_count_global
+= ret
;
1898 DBG("Start kernel tracing");
1899 ret
= kernel_start_session(cmd_ctx
->session
->kernel_session
);
1901 ERR("Kernel start session failed");
1902 ret
= LTTCOMM_KERN_START_FAIL
;
1906 ret
= start_kernel_trace(cmd_ctx
->session
->kernel_session
);
1908 ret
= LTTCOMM_KERN_START_FAIL
;
1912 /* Quiescent wait after starting trace */
1913 kernel_wait_quiescent(kernel_tracer_fd
);
1916 /* TODO: Start all UST traces */
1921 case LTTNG_STOP_TRACE
:
1923 struct ltt_kernel_channel
*chan
;
1924 /* Setup lttng message with no payload */
1925 ret
= setup_lttng_msg(cmd_ctx
, 0);
1931 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1932 DBG("Stop kernel tracing");
1934 ret
= kernel_metadata_flush_buffer(cmd_ctx
->session
->kernel_session
->metadata_stream_fd
);
1936 ERR("Kernel metadata flush failed");
1939 cds_list_for_each_entry(chan
, &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1940 ret
= kernel_flush_buffer(chan
);
1942 ERR("Kernel flush buffer error");
1946 ret
= kernel_stop_session(cmd_ctx
->session
->kernel_session
);
1948 ERR("Kernel stop session failed");
1949 ret
= LTTCOMM_KERN_STOP_FAIL
;
1953 /* Quiescent wait after stopping trace */
1954 kernel_wait_quiescent(kernel_tracer_fd
);
1957 /* TODO : User-space tracer */
1962 case LTTNG_CREATE_SESSION
:
1964 /* Setup lttng message with no payload */
1965 ret
= setup_lttng_msg(cmd_ctx
, 0);
1970 ret
= create_session(cmd_ctx
->lsm
->session
.name
, cmd_ctx
->lsm
->session
.path
);
1972 if (ret
== -EEXIST
) {
1973 ret
= LTTCOMM_EXIST_SESS
;
1975 ret
= LTTCOMM_FATAL
;
1983 case LTTNG_DESTROY_SESSION
:
1985 /* Setup lttng message with no payload */
1986 ret
= setup_lttng_msg(cmd_ctx
, 0);
1991 /* Clean kernel session teardown */
1992 teardown_kernel_session(cmd_ctx
->session
);
1994 ret
= destroy_session(cmd_ctx
->lsm
->session
.name
);
1996 ret
= LTTCOMM_FATAL
;
2001 * Must notify the kernel thread here to update it's pollfd in order to
2002 * remove the channel(s)' fd just destroyed.
2004 ret
= notify_kernel_pollfd();
2006 ret
= LTTCOMM_FATAL
;
2013 case LTTNG_LIST_DOMAINS
:
2017 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
2021 nb_dom
+= cmd_ctx
->session
->ust_trace_count
;
2023 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_domain
) * nb_dom
);
2028 ((struct lttng_domain
*)(cmd_ctx
->llm
->payload
))[0].type
=
2029 LTTNG_DOMAIN_KERNEL
;
2031 /* TODO: User-space tracer domain support */
2035 case LTTNG_LIST_CHANNELS
:
2038 * TODO: Only kernel channels are listed here. UST listing
2039 * is needed on lttng-ust 2.0 release.
2042 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
2043 nb_chan
+= cmd_ctx
->session
->kernel_session
->channel_count
;
2046 ret
= setup_lttng_msg(cmd_ctx
,
2047 sizeof(struct lttng_channel
) * nb_chan
);
2052 list_lttng_channels(cmd_ctx
->session
,
2053 (struct lttng_channel
*)(cmd_ctx
->llm
->payload
));
2058 case LTTNG_LIST_EVENTS
:
2061 * TODO: Only kernel events are listed here. UST listing
2062 * is needed on lttng-ust 2.0 release.
2064 size_t nb_event
= 0;
2065 struct ltt_kernel_channel
*kchan
= NULL
;
2067 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
2068 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.list
.channel_name
,
2069 cmd_ctx
->session
->kernel_session
);
2070 if (kchan
== NULL
) {
2071 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
2074 nb_event
+= kchan
->event_count
;
2077 ret
= setup_lttng_msg(cmd_ctx
,
2078 sizeof(struct lttng_event
) * nb_event
);
2083 DBG("Listing events (%zu events)", nb_event
);
2085 list_lttng_events(kchan
,
2086 (struct lttng_event
*)(cmd_ctx
->llm
->payload
));
2091 case LTTNG_LIST_SESSIONS
:
2093 lock_session_list();
2095 if (session_list_ptr
->count
== 0) {
2096 ret
= LTTCOMM_NO_SESSION
;
2097 unlock_session_list();
2101 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_session
) *
2102 session_list_ptr
->count
);
2104 unlock_session_list();
2108 /* Filled the session array */
2109 list_lttng_sessions((struct lttng_session
*)(cmd_ctx
->llm
->payload
));
2111 unlock_session_list();
2117 case LTTNG_CALIBRATE
:
2119 /* Setup lttng message with no payload */
2120 ret
= setup_lttng_msg(cmd_ctx
, 0);
2125 switch (cmd_ctx
->lsm
->domain
.type
) {
2126 case LTTNG_DOMAIN_KERNEL
:
2128 struct lttng_kernel_calibrate kcalibrate
;
2130 kcalibrate
.type
= cmd_ctx
->lsm
->u
.calibrate
.type
;
2131 ret
= kernel_calibrate(kernel_tracer_fd
, &kcalibrate
);
2133 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
2139 /* TODO: Userspace tracing */
2140 ret
= LTTCOMM_NOT_IMPLEMENTED
;
2148 /* Undefined command */
2149 ret
= setup_lttng_msg(cmd_ctx
, 0);
2158 /* Set return code */
2159 cmd_ctx
->llm
->ret_code
= ret
;
2161 if (cmd_ctx
->session
) {
2162 unlock_session(cmd_ctx
->session
);
2168 if (cmd_ctx
->llm
== NULL
) {
2169 DBG("Missing llm structure. Allocating one.");
2170 if (setup_lttng_msg(cmd_ctx
, 0) < 0) {
2174 /* Notify client of error */
2175 cmd_ctx
->llm
->ret_code
= ret
;
2178 if (cmd_ctx
->session
) {
2179 unlock_session(cmd_ctx
->session
);
2185 * This thread manage all clients request using the unix client socket for
2188 static void *thread_manage_clients(void *data
)
2191 struct command_ctx
*cmd_ctx
= NULL
;
2192 struct pollfd pollfd
[2];
2194 DBG("[thread] Manage client started");
2196 ret
= lttcomm_listen_unix_sock(client_sock
);
2201 /* First fd is always the quit pipe */
2202 pollfd
[0].fd
= thread_quit_pipe
[0];
2205 pollfd
[1].fd
= client_sock
;
2206 pollfd
[1].events
= POLLIN
;
2208 /* Notify parent pid that we are ready
2209 * to accept command for client side.
2211 if (opt_sig_parent
) {
2212 kill(ppid
, SIGCHLD
);
2216 DBG("Accepting client command ...");
2218 /* Inifinite blocking call, waiting for transmission */
2219 ret
= poll(pollfd
, 2, -1);
2221 perror("poll client thread");
2225 /* Thread quit pipe has been closed. Killing thread. */
2226 if (pollfd
[0].revents
== POLLNVAL
) {
2228 } else if (pollfd
[1].revents
== POLLERR
) {
2229 ERR("Client socket poll error");
2233 sock
= lttcomm_accept_unix_sock(client_sock
);
2238 /* Allocate context command to process the client request */
2239 cmd_ctx
= malloc(sizeof(struct command_ctx
));
2241 /* Allocate data buffer for reception */
2242 cmd_ctx
->lsm
= malloc(sizeof(struct lttcomm_session_msg
));
2243 cmd_ctx
->llm
= NULL
;
2244 cmd_ctx
->session
= NULL
;
2247 * Data is received from the lttng client. The struct
2248 * lttcomm_session_msg (lsm) contains the command and data request of
2251 DBG("Receiving data from client ...");
2252 ret
= lttcomm_recv_unix_sock(sock
, cmd_ctx
->lsm
, sizeof(struct lttcomm_session_msg
));
2257 // TODO: Validate cmd_ctx including sanity check for security purpose.
2260 * This function dispatch the work to the kernel or userspace tracer
2261 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2262 * informations for the client. The command context struct contains
2263 * everything this function may needs.
2265 ret
= process_client_msg(cmd_ctx
);
2267 /* TODO: Inform client somehow of the fatal error. At this point,
2268 * ret < 0 means that a malloc failed (ENOMEM). */
2269 /* Error detected but still accept command */
2270 clean_command_ctx(&cmd_ctx
);
2274 DBG("Sending response (size: %d, retcode: %d)",
2275 cmd_ctx
->lttng_msg_size
, cmd_ctx
->llm
->ret_code
);
2276 ret
= send_unix_sock(sock
, cmd_ctx
->llm
, cmd_ctx
->lttng_msg_size
);
2278 ERR("Failed to send data back to client");
2281 clean_command_ctx(&cmd_ctx
);
2283 /* End of transmission */
2288 DBG("Client thread dying");
2296 unlink(client_unix_sock_path
);
2298 clean_command_ctx(&cmd_ctx
);
2304 * usage function on stderr
2306 static void usage(void)
2308 fprintf(stderr
, "Usage: %s OPTIONS\n\nOptions:\n", progname
);
2309 fprintf(stderr
, " -h, --help Display this usage.\n");
2310 fprintf(stderr
, " -c, --client-sock PATH Specify path for the client unix socket\n");
2311 fprintf(stderr
, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2312 fprintf(stderr
, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2313 fprintf(stderr
, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2314 fprintf(stderr
, " -d, --daemonize Start as a daemon.\n");
2315 fprintf(stderr
, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2316 fprintf(stderr
, " -V, --version Show version number.\n");
2317 fprintf(stderr
, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2318 fprintf(stderr
, " -q, --quiet No output at all.\n");
2319 fprintf(stderr
, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2320 fprintf(stderr
, " --verbose-kconsumerd Verbose mode for kconsumerd. Activate DBG() macro.\n");
2324 * daemon argument parsing
2326 static int parse_args(int argc
, char **argv
)
2330 static struct option long_options
[] = {
2331 { "client-sock", 1, 0, 'c' },
2332 { "apps-sock", 1, 0, 'a' },
2333 { "kconsumerd-cmd-sock", 1, 0, 0 },
2334 { "kconsumerd-err-sock", 1, 0, 0 },
2335 { "daemonize", 0, 0, 'd' },
2336 { "sig-parent", 0, 0, 'S' },
2337 { "help", 0, 0, 'h' },
2338 { "group", 1, 0, 'g' },
2339 { "version", 0, 0, 'V' },
2340 { "quiet", 0, 0, 'q' },
2341 { "verbose", 0, 0, 'v' },
2342 { "verbose-kconsumerd", 0, 0, 'Z' },
2347 int option_index
= 0;
2348 c
= getopt_long(argc
, argv
, "dhqvVS" "a:c:g:s:E:C:Z", long_options
, &option_index
);
2355 fprintf(stderr
, "option %s", long_options
[option_index
].name
);
2357 fprintf(stderr
, " with arg %s\n", optarg
);
2361 snprintf(client_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2364 snprintf(apps_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2370 opt_tracing_group
= strdup(optarg
);
2376 fprintf(stdout
, "%s\n", VERSION
);
2382 snprintf(kconsumerd_err_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2385 snprintf(kconsumerd_cmd_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2391 /* Verbose level can increase using multiple -v */
2395 opt_verbose_kconsumerd
+= 1;
2398 /* Unknown option or other error.
2399 * Error is printed by getopt, just return */
2408 * Creates the two needed socket by the daemon.
2409 * apps_sock - The communication socket for all UST apps.
2410 * client_sock - The communication of the cli tool (lttng).
2412 static int init_daemon_socket(void)
2417 old_umask
= umask(0);
2419 /* Create client tool unix socket */
2420 client_sock
= lttcomm_create_unix_sock(client_unix_sock_path
);
2421 if (client_sock
< 0) {
2422 ERR("Create unix sock failed: %s", client_unix_sock_path
);
2427 /* File permission MUST be 660 */
2428 ret
= chmod(client_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
2430 ERR("Set file permissions failed: %s", client_unix_sock_path
);
2435 /* Create the application unix socket */
2436 apps_sock
= lttcomm_create_unix_sock(apps_unix_sock_path
);
2437 if (apps_sock
< 0) {
2438 ERR("Create unix sock failed: %s", apps_unix_sock_path
);
2443 /* File permission MUST be 666 */
2444 ret
= chmod(apps_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
| S_IWOTH
);
2446 ERR("Set file permissions failed: %s", apps_unix_sock_path
);
2457 * Check if the global socket is available, and if a daemon is answering
2458 * at the other side. If yes, error is returned.
2460 static int check_existing_daemon(void)
2462 if (access(client_unix_sock_path
, F_OK
) < 0 &&
2463 access(apps_unix_sock_path
, F_OK
) < 0)
2465 /* Is there anybody out there ? */
2466 if (lttng_session_daemon_alive())
2473 * Set the tracing group gid onto the client socket.
2475 * Race window between mkdir and chown is OK because we are going from more
2476 * permissive (root.root) to les permissive (root.tracing).
2478 static int set_permissions(void)
2483 gid
= allowed_group();
2486 WARN("No tracing group detected");
2489 ERR("Missing tracing group. Aborting execution.");
2495 /* Set lttng run dir */
2496 ret
= chown(LTTNG_RUNDIR
, 0, gid
);
2498 ERR("Unable to set group on " LTTNG_RUNDIR
);
2502 /* lttng client socket path */
2503 ret
= chown(client_unix_sock_path
, 0, gid
);
2505 ERR("Unable to set group on %s", client_unix_sock_path
);
2509 /* kconsumerd error socket path */
2510 ret
= chown(kconsumerd_err_unix_sock_path
, 0, gid
);
2512 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path
);
2516 DBG("All permissions are set");
2523 * Create the pipe used to wake up the kernel thread.
2525 static int create_kernel_poll_pipe(void)
2527 return pipe2(kernel_poll_pipe
, O_CLOEXEC
);
2531 * Create the lttng run directory needed for all global sockets and pipe.
2533 static int create_lttng_rundir(void)
2537 ret
= mkdir(LTTNG_RUNDIR
, S_IRWXU
| S_IRWXG
);
2539 if (errno
!= EEXIST
) {
2540 ERR("Unable to create " LTTNG_RUNDIR
);
2552 * Setup sockets and directory needed by the kconsumerd communication with the
2555 static int set_kconsumerd_sockets(void)
2559 if (strlen(kconsumerd_err_unix_sock_path
) == 0) {
2560 snprintf(kconsumerd_err_unix_sock_path
, PATH_MAX
, KCONSUMERD_ERR_SOCK_PATH
);
2563 if (strlen(kconsumerd_cmd_unix_sock_path
) == 0) {
2564 snprintf(kconsumerd_cmd_unix_sock_path
, PATH_MAX
, KCONSUMERD_CMD_SOCK_PATH
);
2567 ret
= mkdir(KCONSUMERD_PATH
, S_IRWXU
| S_IRWXG
);
2569 if (errno
!= EEXIST
) {
2570 ERR("Failed to create " KCONSUMERD_PATH
);
2576 /* Create the kconsumerd error unix socket */
2577 kconsumerd_err_sock
= lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path
);
2578 if (kconsumerd_err_sock
< 0) {
2579 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path
);
2584 /* File permission MUST be 660 */
2585 ret
= chmod(kconsumerd_err_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
2587 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path
);
2597 * Signal handler for the daemon
2599 * Simply stop all worker threads, leaving main() return gracefully
2600 * after joining all threads and calling cleanup().
2602 static void sighandler(int sig
)
2606 DBG("SIGPIPE catched");
2609 DBG("SIGINT catched");
2613 DBG("SIGTERM catched");
2622 * Setup signal handler for :
2623 * SIGINT, SIGTERM, SIGPIPE
2625 static int set_signal_handler(void)
2628 struct sigaction sa
;
2631 if ((ret
= sigemptyset(&sigset
)) < 0) {
2632 perror("sigemptyset");
2636 sa
.sa_handler
= sighandler
;
2637 sa
.sa_mask
= sigset
;
2639 if ((ret
= sigaction(SIGTERM
, &sa
, NULL
)) < 0) {
2640 perror("sigaction");
2644 if ((ret
= sigaction(SIGINT
, &sa
, NULL
)) < 0) {
2645 perror("sigaction");
2649 if ((ret
= sigaction(SIGPIPE
, &sa
, NULL
)) < 0) {
2650 perror("sigaction");
2654 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2660 * Set open files limit to unlimited. This daemon can open a large number of
2661 * file descriptors in order to consumer multiple kernel traces.
2663 static void set_ulimit(void)
2668 /* The kernel does not allowed an infinite limit for open files */
2669 lim
.rlim_cur
= 65535;
2670 lim
.rlim_max
= 65535;
2672 ret
= setrlimit(RLIMIT_NOFILE
, &lim
);
2674 perror("failed to set open files limit");
2681 int main(int argc
, char **argv
)
2685 const char *home_path
;
2687 /* Create thread quit pipe */
2688 if ((ret
= init_thread_quit_pipe()) < 0) {
2692 /* Parse arguments */
2694 if ((ret
= parse_args(argc
, argv
) < 0)) {
2707 /* Check if daemon is UID = 0 */
2708 is_root
= !getuid();
2711 ret
= create_lttng_rundir();
2716 if (strlen(apps_unix_sock_path
) == 0) {
2717 snprintf(apps_unix_sock_path
, PATH_MAX
,
2718 DEFAULT_GLOBAL_APPS_UNIX_SOCK
);
2721 if (strlen(client_unix_sock_path
) == 0) {
2722 snprintf(client_unix_sock_path
, PATH_MAX
,
2723 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
);
2726 home_path
= get_home_dir();
2727 if (home_path
== NULL
) {
2728 /* TODO: Add --socket PATH option */
2729 ERR("Can't get HOME directory for sockets creation.");
2734 if (strlen(apps_unix_sock_path
) == 0) {
2735 snprintf(apps_unix_sock_path
, PATH_MAX
,
2736 DEFAULT_HOME_APPS_UNIX_SOCK
, home_path
);
2739 /* Set the cli tool unix socket path */
2740 if (strlen(client_unix_sock_path
) == 0) {
2741 snprintf(client_unix_sock_path
, PATH_MAX
,
2742 DEFAULT_HOME_CLIENT_UNIX_SOCK
, home_path
);
2746 DBG("Client socket path %s", client_unix_sock_path
);
2747 DBG("Application socket path %s", apps_unix_sock_path
);
2750 * See if daemon already exist.
2752 if ((ret
= check_existing_daemon()) < 0) {
2753 ERR("Already running daemon.\n");
2755 * We do not goto exit because we must not cleanup()
2756 * because a daemon is already running.
2761 /* After this point, we can safely call cleanup() so goto error is used */
2764 * These actions must be executed as root. We do that *after* setting up
2765 * the sockets path because we MUST make the check for another daemon using
2766 * those paths *before* trying to set the kernel consumer sockets and init
2770 ret
= set_kconsumerd_sockets();
2775 /* Setup kernel tracer */
2776 init_kernel_tracer();
2778 /* Set ulimit for open files */
2782 if ((ret
= set_signal_handler()) < 0) {
2786 /* Setup the needed unix socket */
2787 if ((ret
= init_daemon_socket()) < 0) {
2791 /* Set credentials to socket */
2792 if (is_root
&& ((ret
= set_permissions()) < 0)) {
2796 /* Get parent pid if -S, --sig-parent is specified. */
2797 if (opt_sig_parent
) {
2801 /* Setup the kernel pipe for waking up the kernel thread */
2802 if ((ret
= create_kernel_poll_pipe()) < 0) {
2807 * Get session list pointer. This pointer MUST NOT be free().
2808 * This list is statically declared in session.c
2810 session_list_ptr
= get_session_list();
2812 /* Create thread to manage the client socket */
2813 ret
= pthread_create(&client_thread
, NULL
, thread_manage_clients
, (void *) NULL
);
2815 perror("pthread_create");
2819 /* Create thread to manage application socket */
2820 ret
= pthread_create(&apps_thread
, NULL
, thread_manage_apps
, (void *) NULL
);
2822 perror("pthread_create");
2826 /* Create kernel thread to manage kernel event */
2827 ret
= pthread_create(&kernel_thread
, NULL
, thread_manage_kernel
, (void *) NULL
);
2829 perror("pthread_create");
2833 ret
= pthread_join(kernel_thread
, &status
);
2835 perror("pthread_join");
2836 goto error
; /* join error, exit without cleanup */
2840 ret
= pthread_join(apps_thread
, &status
);
2842 perror("pthread_join");
2843 goto error
; /* join error, exit without cleanup */
2847 ret
= pthread_join(client_thread
, &status
);
2849 perror("pthread_join");
2850 goto error
; /* join error, exit without cleanup */
2853 ret
= join_kconsumerd_thread();
2855 perror("join_kconsumerd");
2856 goto error
; /* join error, exit without cleanup */
2862 * cleanup() is called when no other thread is running.