2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; only version 2
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26 #include <semaphore.h>
32 #include <sys/mount.h>
34 #include <sys/socket.h>
36 #include <sys/types.h>
38 #include <sys/resource.h>
41 #include <urcu/list.h> /* URCU list library (-lurcu) */
42 #include <lttng/lttng.h>
45 #include "liblttsessiondcomm.h"
46 #include "ltt-sessiond.h"
48 #include "kernel-ctl.h"
51 #include "traceable-app.h"
52 #include "lttng-kconsumerd.h"
56 const char default_home_dir
[] = DEFAULT_HOME_DIR
;
57 const char default_tracing_group
[] = LTTNG_DEFAULT_TRACING_GROUP
;
58 const char default_ust_sock_dir
[] = DEFAULT_UST_SOCK_DIR
;
59 const char default_global_apps_pipe
[] = DEFAULT_GLOBAL_APPS_PIPE
;
62 int opt_verbose
; /* Not static for lttngerr.h */
63 int opt_quiet
; /* Not static for lttngerr.h */
66 const char *opt_tracing_group
;
67 static int opt_sig_parent
;
68 static int opt_daemon
;
69 static int is_root
; /* Set to 1 if the daemon is running as root */
70 static pid_t ppid
; /* Parent PID for --sig-parent option */
71 static pid_t kconsumerd_pid
;
72 static struct pollfd
*kernel_pollfd
;
74 static char apps_unix_sock_path
[PATH_MAX
]; /* Global application Unix socket path */
75 static char client_unix_sock_path
[PATH_MAX
]; /* Global client Unix socket path */
76 static char kconsumerd_err_unix_sock_path
[PATH_MAX
]; /* kconsumerd error Unix socket path */
77 static char kconsumerd_cmd_unix_sock_path
[PATH_MAX
]; /* kconsumerd command Unix socket path */
80 static int client_sock
;
82 static int kconsumerd_err_sock
;
83 static int kconsumerd_cmd_sock
;
84 static int kernel_tracer_fd
;
85 static int kernel_poll_pipe
[2];
88 * Quit pipe for all threads. This permits a single cancellation point
89 * for all threads when receiving an event on the pipe.
91 static int thread_quit_pipe
[2];
93 /* Pthread, Mutexes and Semaphores */
94 static pthread_t kconsumerd_thread
;
95 static pthread_t apps_thread
;
96 static pthread_t client_thread
;
97 static pthread_t kernel_thread
;
98 static sem_t kconsumerd_sem
;
100 static pthread_mutex_t kconsumerd_pid_mutex
; /* Mutex to control kconsumerd pid assignation */
102 static int modprobe_remove_kernel_modules(void);
105 * Pointer initialized before thread creation.
107 * This points to the tracing session list containing the session count and a
108 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
109 * MUST NOT be taken if you call a public function in session.c.
111 * The lock is nested inside the structure: session_list_ptr->lock. Please use
112 * lock_session_list and unlock_session_list for lock acquisition.
114 static struct ltt_session_list
*session_list_ptr
;
119 * Return -1 on error or 0 if all pipes are created.
121 static int init_thread_quit_pipe(void)
125 ret
= pipe2(thread_quit_pipe
, O_CLOEXEC
);
127 perror("thread quit pipe");
136 * Complete teardown of a kernel session. This free all data structure related
137 * to a kernel session and update counter.
139 static void teardown_kernel_session(struct ltt_session
*session
)
141 if (session
->kernel_session
!= NULL
) {
142 DBG("Tearing down kernel session");
143 trace_destroy_kernel_session(session
->kernel_session
);
144 /* Extra precaution */
145 session
->kernel_session
= NULL
;
152 static void cleanup()
156 struct ltt_session
*sess
, *stmp
;
161 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
162 "Matthew, BEET driven development works!%c[%dm",
163 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
166 /* Stopping all threads */
167 DBG("Terminating all threads");
168 close(thread_quit_pipe
[0]);
169 close(thread_quit_pipe
[1]);
171 DBG("Removing %s directory", LTTNG_RUNDIR
);
172 ret
= asprintf(&cmd
, "rm -rf " LTTNG_RUNDIR
);
174 ERR("asprintf failed. Something is really wrong!");
177 /* Remove lttng run directory */
180 ERR("Unable to clean " LTTNG_RUNDIR
);
183 DBG("Cleaning up all session");
185 /* Destroy session list mutex */
186 if (session_list_ptr
!= NULL
) {
187 pthread_mutex_destroy(&session_list_ptr
->lock
);
189 /* Cleanup ALL session */
190 cds_list_for_each_entry_safe(sess
, stmp
, &session_list_ptr
->head
, list
) {
191 teardown_kernel_session(sess
);
192 // TODO complete session cleanup (including UST)
196 pthread_mutex_destroy(&kconsumerd_pid_mutex
);
198 DBG("Closing kernel fd");
199 close(kernel_tracer_fd
);
201 DBG("Unloading kernel modules");
202 modprobe_remove_kernel_modules();
206 * Send data on a unix socket using the liblttsessiondcomm API.
208 * Return lttcomm error code.
210 static int send_unix_sock(int sock
, void *buf
, size_t len
)
212 /* Check valid length */
217 return lttcomm_send_unix_sock(sock
, buf
, len
);
221 * Free memory of a command context structure.
223 static void clean_command_ctx(struct command_ctx
**cmd_ctx
)
225 DBG("Clean command context structure");
227 if ((*cmd_ctx
)->llm
) {
228 free((*cmd_ctx
)->llm
);
230 if ((*cmd_ctx
)->lsm
) {
231 free((*cmd_ctx
)->lsm
);
239 * Send all stream fds of kernel channel to the consumer.
241 static int send_kconsumerd_channel_fds(int sock
, struct ltt_kernel_channel
*channel
)
245 struct ltt_kernel_stream
*stream
;
246 struct lttcomm_kconsumerd_header lkh
;
247 struct lttcomm_kconsumerd_msg lkm
;
249 DBG("Sending fds of channel %s to kernel consumer", channel
->channel
->name
);
251 nb_fd
= channel
->stream_count
;
254 lkh
.payload_size
= nb_fd
* sizeof(struct lttcomm_kconsumerd_msg
);
255 lkh
.cmd_type
= ADD_STREAM
;
257 DBG("Sending kconsumerd header");
259 ret
= lttcomm_send_unix_sock(sock
, &lkh
, sizeof(struct lttcomm_kconsumerd_header
));
261 perror("send kconsumerd header");
265 cds_list_for_each_entry(stream
, &channel
->stream_list
.head
, list
) {
266 if (stream
->fd
!= 0) {
268 lkm
.state
= stream
->state
;
269 lkm
.max_sb_size
= channel
->channel
->attr
.subbuf_size
;
270 strncpy(lkm
.path_name
, stream
->pathname
, PATH_MAX
);
272 DBG("Sending fd %d to kconsumerd", lkm
.fd
);
274 ret
= lttcomm_send_fds_unix_sock(sock
, &lkm
, &lkm
.fd
, 1, sizeof(lkm
));
276 perror("send kconsumerd fd");
282 DBG("Kconsumerd channel fds sent");
291 * Send all stream fds of the kernel session to the consumer.
293 static int send_kconsumerd_fds(int sock
, struct ltt_kernel_session
*session
)
296 struct ltt_kernel_channel
*chan
;
297 struct lttcomm_kconsumerd_header lkh
;
298 struct lttcomm_kconsumerd_msg lkm
;
301 lkh
.payload_size
= sizeof(struct lttcomm_kconsumerd_msg
);
302 lkh
.cmd_type
= ADD_STREAM
;
304 DBG("Sending kconsumerd header for metadata");
306 ret
= lttcomm_send_unix_sock(sock
, &lkh
, sizeof(struct lttcomm_kconsumerd_header
));
308 perror("send kconsumerd header");
312 DBG("Sending metadata stream fd");
314 if (session
->metadata_stream_fd
!= 0) {
315 /* Send metadata stream fd first */
316 lkm
.fd
= session
->metadata_stream_fd
;
317 lkm
.state
= ACTIVE_FD
;
318 lkm
.max_sb_size
= session
->metadata
->conf
->attr
.subbuf_size
;
319 strncpy(lkm
.path_name
, session
->metadata
->pathname
, PATH_MAX
);
321 ret
= lttcomm_send_fds_unix_sock(sock
, &lkm
, &lkm
.fd
, 1, sizeof(lkm
));
323 perror("send kconsumerd fd");
328 cds_list_for_each_entry(chan
, &session
->channel_list
.head
, list
) {
329 ret
= send_kconsumerd_channel_fds(sock
, chan
);
335 DBG("Kconsumerd fds (metadata and channel streams) sent");
345 * Return a socket connected to the libust communication socket of the
346 * application identified by the pid.
348 * If the pid is not found in the traceable list, return -1 to indicate error.
350 static int ust_connect_app(pid_t pid
)
353 struct ltt_traceable_app
*lta
;
355 DBG("Connect to application pid %d", pid
);
357 lta
= find_app_by_pid(pid
);
360 DBG("Application pid %d not found", pid
);
364 sock
= ustctl_connect_pid(lta
->pid
);
366 ERR("Fail connecting to the PID %d", pid
);
371 #endif /* DISABLED */
374 * Notify apps by writing 42 to a named pipe using name. Every applications
375 * waiting for a ltt-sessiond will be notified and re-register automatically to
376 * the session daemon.
378 * Return open or write error value.
380 static int notify_apps(const char *name
)
385 DBG("Notify the global application pipe");
387 /* Try opening the global pipe */
388 fd
= open(name
, O_WRONLY
);
393 /* Notify by writing on the pipe */
394 ret
= write(fd
, "42", 2);
404 * Setup the outgoing data buffer for the response (llm) by allocating the
405 * right amount of memory and copying the original information from the lsm
408 * Return total size of the buffer pointed by buf.
410 static int setup_lttng_msg(struct command_ctx
*cmd_ctx
, size_t size
)
416 cmd_ctx
->llm
= malloc(sizeof(struct lttcomm_lttng_msg
) + buf_size
);
417 if (cmd_ctx
->llm
== NULL
) {
423 /* Copy common data */
424 cmd_ctx
->llm
->cmd_type
= cmd_ctx
->lsm
->cmd_type
;
425 cmd_ctx
->llm
->pid
= cmd_ctx
->lsm
->domain
.attr
.pid
;
427 cmd_ctx
->llm
->data_size
= size
;
428 cmd_ctx
->lttng_msg_size
= sizeof(struct lttcomm_lttng_msg
) + buf_size
;
437 * Update the kernel pollfd set of all channel fd available over all tracing
438 * session. Add the wakeup pipe at the end of the set.
440 static int update_kernel_pollfd(void)
444 * The wakup pipe and the quit pipe are needed so the number of fds starts
445 * at 2 for those pipes.
447 unsigned int nb_fd
= 2;
448 struct ltt_session
*session
;
449 struct ltt_kernel_channel
*channel
;
451 DBG("Updating kernel_pollfd");
453 /* Get the number of channel of all kernel session */
455 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
456 lock_session(session
);
457 if (session
->kernel_session
== NULL
) {
458 unlock_session(session
);
461 nb_fd
+= session
->kernel_session
->channel_count
;
462 unlock_session(session
);
465 DBG("Resizing kernel_pollfd to size %d", nb_fd
);
467 kernel_pollfd
= realloc(kernel_pollfd
, nb_fd
* sizeof(struct pollfd
));
468 if (kernel_pollfd
== NULL
) {
469 perror("malloc kernel_pollfd");
473 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
474 lock_session(session
);
475 if (session
->kernel_session
== NULL
) {
476 unlock_session(session
);
480 ERR("To much channel for kernel_pollfd size");
481 unlock_session(session
);
484 cds_list_for_each_entry(channel
, &session
->kernel_session
->channel_list
.head
, list
) {
485 kernel_pollfd
[i
].fd
= channel
->fd
;
486 kernel_pollfd
[i
].events
= POLLIN
| POLLRDNORM
;
489 unlock_session(session
);
491 unlock_session_list();
493 /* Adding wake up pipe */
494 kernel_pollfd
[nb_fd
- 2].fd
= kernel_poll_pipe
[0];
495 kernel_pollfd
[nb_fd
- 2].events
= POLLIN
;
497 /* Adding the quit pipe */
498 kernel_pollfd
[nb_fd
- 1].fd
= thread_quit_pipe
[0];
503 unlock_session_list();
508 * Find the channel fd from 'fd' over all tracing session. When found, check
509 * for new channel stream and send those stream fds to the kernel consumer.
511 * Useful for CPU hotplug feature.
513 static int update_kernel_stream(int fd
)
516 struct ltt_session
*session
;
517 struct ltt_kernel_channel
*channel
;
519 DBG("Updating kernel streams for channel fd %d", fd
);
522 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
523 lock_session(session
);
524 if (session
->kernel_session
== NULL
) {
525 unlock_session(session
);
528 cds_list_for_each_entry(channel
, &session
->kernel_session
->channel_list
.head
, list
) {
529 if (channel
->fd
== fd
) {
530 DBG("Channel found, updating kernel streams");
531 ret
= kernel_open_channel_stream(channel
);
536 * Have we already sent fds to the consumer? If yes, it means that
537 * tracing is started so it is safe to send our updated stream fds.
539 if (session
->kernel_session
->kconsumer_fds_sent
== 1) {
540 ret
= send_kconsumerd_channel_fds(kconsumerd_cmd_sock
, channel
);
548 unlock_session(session
);
552 unlock_session_list();
554 unlock_session(session
);
560 * This thread manage event coming from the kernel.
562 * Features supported in this thread:
565 static void *thread_manage_kernel(void *data
)
567 int ret
, i
, nb_fd
= 0;
569 int update_poll_flag
= 1;
571 DBG("Thread manage kernel started");
574 if (update_poll_flag
== 1) {
575 nb_fd
= update_kernel_pollfd();
579 update_poll_flag
= 0;
582 DBG("Polling on %d fds", nb_fd
);
584 /* Poll infinite value of time */
585 ret
= poll(kernel_pollfd
, nb_fd
, -1);
587 perror("poll kernel thread");
589 } else if (ret
== 0) {
590 /* Should not happen since timeout is infinite */
594 /* Thread quit pipe has been closed. Killing thread. */
595 if (kernel_pollfd
[nb_fd
- 1].revents
== POLLNVAL
) {
599 DBG("Kernel poll event triggered");
602 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
605 switch (kernel_pollfd
[nb_fd
- 2].revents
) {
607 ret
= read(kernel_poll_pipe
[0], &tmp
, 1);
608 update_poll_flag
= 1;
616 for (i
= 0; i
< nb_fd
; i
++) {
617 switch (kernel_pollfd
[i
].revents
) {
619 * New CPU detected by the kernel. Adding kernel stream to kernel
620 * session and updating the kernel consumer
622 case POLLIN
| POLLRDNORM
:
623 ret
= update_kernel_stream(kernel_pollfd
[i
].fd
);
633 DBG("Kernel thread dying");
638 close(kernel_poll_pipe
[0]);
639 close(kernel_poll_pipe
[1]);
644 * This thread manage the kconsumerd error sent back to the session daemon.
646 static void *thread_manage_kconsumerd(void *data
)
649 enum lttcomm_return_code code
;
650 struct pollfd pollfd
[2];
652 DBG("[thread] Manage kconsumerd started");
654 ret
= lttcomm_listen_unix_sock(kconsumerd_err_sock
);
659 /* First fd is always the quit pipe */
660 pollfd
[0].fd
= thread_quit_pipe
[0];
663 pollfd
[1].fd
= kconsumerd_err_sock
;
664 pollfd
[1].events
= POLLIN
;
666 /* Inifinite blocking call, waiting for transmission */
667 ret
= poll(pollfd
, 2, -1);
669 perror("poll kconsumerd thread");
673 /* Thread quit pipe has been closed. Killing thread. */
674 if (pollfd
[0].revents
== POLLNVAL
) {
676 } else if (pollfd
[1].revents
== POLLERR
) {
677 ERR("Kconsumerd err socket poll error");
681 sock
= lttcomm_accept_unix_sock(kconsumerd_err_sock
);
686 /* Getting status code from kconsumerd */
687 ret
= lttcomm_recv_unix_sock(sock
, &code
, sizeof(enum lttcomm_return_code
));
692 if (code
== KCONSUMERD_COMMAND_SOCK_READY
) {
693 kconsumerd_cmd_sock
= lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path
);
694 if (kconsumerd_cmd_sock
< 0) {
695 sem_post(&kconsumerd_sem
);
696 perror("kconsumerd connect");
699 /* Signal condition to tell that the kconsumerd is ready */
700 sem_post(&kconsumerd_sem
);
701 DBG("Kconsumerd command socket ready");
703 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
704 lttcomm_get_readable_code(-code
));
708 /* Wait for any kconsumerd error */
709 ret
= lttcomm_recv_unix_sock(sock
, &code
, sizeof(enum lttcomm_return_code
));
711 ERR("Kconsumerd closed the command socket");
715 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code
));
718 DBG("Kconsumerd thread dying");
719 if (kconsumerd_err_sock
) {
720 close(kconsumerd_err_sock
);
722 if (kconsumerd_cmd_sock
) {
723 close(kconsumerd_cmd_sock
);
729 unlink(kconsumerd_err_unix_sock_path
);
730 unlink(kconsumerd_cmd_unix_sock_path
);
737 * This thread manage the application socket communication
739 static void *thread_manage_apps(void *data
)
742 struct pollfd pollfd
[2];
744 /* TODO: Something more elegant is needed but fine for now */
745 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
746 * for 32-bit vs 64-bit compat processes. */
747 /* replicate in ust with version number */
749 int reg
; /* 1:register, 0:unregister */
754 DBG("[thread] Manage apps started");
756 ret
= lttcomm_listen_unix_sock(apps_sock
);
761 /* First fd is always the quit pipe */
762 pollfd
[0].fd
= thread_quit_pipe
[0];
765 pollfd
[1].fd
= apps_sock
;
766 pollfd
[1].events
= POLLIN
;
768 /* Notify all applications to register */
769 notify_apps(default_global_apps_pipe
);
772 DBG("Accepting application registration");
774 /* Inifinite blocking call, waiting for transmission */
775 ret
= poll(pollfd
, 2, -1);
777 perror("poll apps thread");
781 /* Thread quit pipe has been closed. Killing thread. */
782 if (pollfd
[0].revents
== POLLNVAL
) {
784 } else if (pollfd
[1].revents
== POLLERR
) {
785 ERR("Apps socket poll error");
789 sock
= lttcomm_accept_unix_sock(apps_sock
);
795 * Basic recv here to handle the very simple data
796 * that the libust send to register (reg_msg).
798 ret
= recv(sock
, ®_msg
, sizeof(reg_msg
), 0);
804 /* Add application to the global traceable list */
805 if (reg_msg
.reg
== 1) {
807 ret
= register_traceable_app(reg_msg
.pid
, reg_msg
.uid
);
809 /* register_traceable_app only return an error with
810 * ENOMEM. At this point, we better stop everything.
816 unregister_traceable_app(reg_msg
.pid
);
821 DBG("Apps thread dying");
829 unlink(apps_unix_sock_path
);
834 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
835 * exec or it will fails.
837 static int spawn_kconsumerd_thread(void)
841 /* Setup semaphore */
842 sem_init(&kconsumerd_sem
, 0, 0);
844 ret
= pthread_create(&kconsumerd_thread
, NULL
, thread_manage_kconsumerd
, (void *) NULL
);
846 perror("pthread_create kconsumerd");
850 /* Wait for the kconsumerd thread to be ready */
851 sem_wait(&kconsumerd_sem
);
853 if (kconsumerd_pid
== 0) {
854 ERR("Kconsumerd did not start");
861 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
866 * Fork and exec a kernel consumer daemon (kconsumerd).
868 * Return pid if successful else -1.
870 static pid_t
spawn_kconsumerd(void)
874 const char *verbosity
;
876 DBG("Spawning kconsumerd");
883 if (opt_verbose
> 1) {
884 verbosity
= "--verbose";
886 verbosity
= "--quiet";
888 execl(INSTALL_BIN_PATH
"/ltt-kconsumerd", "ltt-kconsumerd", verbosity
, NULL
);
890 perror("kernel start consumer exec");
893 } else if (pid
> 0) {
897 perror("kernel start consumer fork");
907 * Spawn the kconsumerd daemon and session daemon thread.
909 static int start_kconsumerd(void)
913 pthread_mutex_lock(&kconsumerd_pid_mutex
);
914 if (kconsumerd_pid
!= 0) {
915 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
919 ret
= spawn_kconsumerd();
921 ERR("Spawning kconsumerd failed");
922 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
923 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
927 /* Setting up the global kconsumerd_pid */
928 kconsumerd_pid
= ret
;
929 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
931 DBG("Kconsumerd pid %d", ret
);
933 DBG("Spawning kconsumerd thread");
934 ret
= spawn_kconsumerd_thread();
936 ERR("Fatal error spawning kconsumerd thread");
948 * modprobe_kernel_modules
950 static int modprobe_kernel_modules(void)
955 for (i
= 0; i
< ARRAY_SIZE(kernel_modules_list
); i
++) {
956 ret
= snprintf(modprobe
, sizeof(modprobe
),
957 "/sbin/modprobe %s%s",
958 kernel_modules_list
[i
].required
? "" : "--quiet ",
959 kernel_modules_list
[i
].name
);
961 perror("snprintf modprobe");
964 modprobe
[sizeof(modprobe
) - 1] = '\0';
965 ret
= system(modprobe
);
967 ERR("Unable to launch modprobe for module %s",
968 kernel_modules_list
[i
].name
);
969 } else if (kernel_modules_list
[i
].required
970 && WEXITSTATUS(ret
) != 0) {
971 ERR("Unable to load module %s",
972 kernel_modules_list
[i
].name
);
974 DBG("Modprobe successfully %s",
975 kernel_modules_list
[i
].name
);
984 * modprobe_remove_kernel_modules
985 * Remove modules in reverse load order.
987 static int modprobe_remove_kernel_modules(void)
992 for (i
= ARRAY_SIZE(kernel_modules_list
) - 1; i
>= 0; i
--) {
993 ret
= snprintf(modprobe
, sizeof(modprobe
),
994 "/sbin/modprobe --remove --quiet %s",
995 kernel_modules_list
[i
].name
);
997 perror("snprintf modprobe --remove");
1000 modprobe
[sizeof(modprobe
) - 1] = '\0';
1001 ret
= system(modprobe
);
1003 ERR("Unable to launch modprobe --remove for module %s",
1004 kernel_modules_list
[i
].name
);
1005 } else if (kernel_modules_list
[i
].required
1006 && WEXITSTATUS(ret
) != 0) {
1007 ERR("Unable to remove module %s",
1008 kernel_modules_list
[i
].name
);
1010 DBG("Modprobe removal successful %s",
1011 kernel_modules_list
[i
].name
);
1022 static int mount_debugfs(char *path
)
1025 char *type
= "debugfs";
1027 ret
= mkdir_recursive(path
, S_IRWXU
| S_IRWXG
);
1032 ret
= mount(type
, path
, type
, 0, NULL
);
1034 perror("mount debugfs");
1038 DBG("Mounted debugfs successfully at %s", path
);
1045 * Setup necessary data for kernel tracer action.
1047 static void init_kernel_tracer(void)
1050 char *proc_mounts
= "/proc/mounts";
1052 char *debugfs_path
= NULL
, *lttng_path
;
1055 /* Detect debugfs */
1056 fp
= fopen(proc_mounts
, "r");
1058 ERR("Unable to probe %s", proc_mounts
);
1062 while (fgets(line
, sizeof(line
), fp
) != NULL
) {
1063 if (strstr(line
, "debugfs") != NULL
) {
1064 /* Remove first string */
1066 /* Dup string here so we can reuse line later on */
1067 debugfs_path
= strdup(strtok(NULL
, " "));
1068 DBG("Got debugfs path : %s", debugfs_path
);
1075 /* Mount debugfs if needded */
1076 if (debugfs_path
== NULL
) {
1077 ret
= asprintf(&debugfs_path
, "/mnt/debugfs");
1079 perror("asprintf debugfs path");
1082 ret
= mount_debugfs(debugfs_path
);
1088 /* Modprobe lttng kernel modules */
1089 ret
= modprobe_kernel_modules();
1094 /* Setup lttng kernel path */
1095 ret
= asprintf(<tng_path
, "%s/lttng", debugfs_path
);
1097 perror("asprintf lttng path");
1101 /* Open debugfs lttng */
1102 kernel_tracer_fd
= open(lttng_path
, O_RDWR
);
1103 if (kernel_tracer_fd
< 0) {
1104 DBG("Failed to open %s", lttng_path
);
1110 DBG("Kernel tracer fd %d", kernel_tracer_fd
);
1120 WARN("No kernel tracer available");
1121 kernel_tracer_fd
= 0;
1126 * Start tracing by creating trace directory and sending FDs to the kernel
1129 static int start_kernel_trace(struct ltt_kernel_session
*session
)
1133 if (session
->kconsumer_fds_sent
== 0) {
1134 ret
= send_kconsumerd_fds(kconsumerd_cmd_sock
, session
);
1136 ERR("Send kconsumerd fds failed");
1137 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
1141 session
->kconsumer_fds_sent
= 1;
1149 * Notify kernel thread to update it's pollfd.
1151 static int notify_kernel_pollfd(void)
1155 /* Inform kernel thread of the new kernel channel */
1156 ret
= write(kernel_poll_pipe
[1], "!", 1);
1158 perror("write kernel poll pipe");
1165 * Allocate a channel structure and fill it.
1167 static struct lttng_channel
*init_default_channel(char *name
)
1169 struct lttng_channel
*chan
;
1171 chan
= malloc(sizeof(struct lttng_channel
));
1173 perror("init channel malloc");
1177 if (snprintf(chan
->name
, NAME_MAX
, "%s", name
) < 0) {
1178 perror("snprintf channel name");
1182 chan
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
1183 chan
->attr
.subbuf_size
= DEFAULT_CHANNEL_SUBBUF_SIZE
;
1184 chan
->attr
.num_subbuf
= DEFAULT_CHANNEL_SUBBUF_NUM
;
1185 chan
->attr
.switch_timer_interval
= DEFAULT_CHANNEL_SWITCH_TIMER
;
1186 chan
->attr
.read_timer_interval
= DEFAULT_CHANNEL_READ_TIMER
;
1187 chan
->attr
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
1194 * Create a kernel tracer session then create the default channel.
1196 static int create_kernel_session(struct ltt_session
*session
)
1200 DBG("Creating kernel session");
1202 ret
= kernel_create_session(session
, kernel_tracer_fd
);
1204 ret
= LTTCOMM_KERN_SESS_FAIL
;
1208 ret
= mkdir_recursive(session
->path
, S_IRWXU
| S_IRWXG
);
1210 if (ret
!= EEXIST
) {
1211 ERR("Trace directory creation error");
1221 * Using the session list, filled a lttng_session array to send back to the
1222 * client for session listing.
1224 * The session list lock MUST be acquired before calling this function. Use
1225 * lock_session_list() and unlock_session_list().
1227 static void list_lttng_sessions(struct lttng_session
*sessions
)
1230 struct ltt_session
*session
;
1232 DBG("Getting all available session");
1234 * Iterate over session list and append data after the control struct in
1237 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
1238 strncpy(sessions
[i
].path
, session
->path
, PATH_MAX
);
1239 strncpy(sessions
[i
].name
, session
->name
, NAME_MAX
);
1245 * Fill lttng_channel array of all channels.
1247 static void list_lttng_channels(struct ltt_session
*session
,
1248 struct lttng_channel
*channels
)
1251 struct ltt_kernel_channel
*kchan
;
1253 DBG("Listing channels for session %s", session
->name
);
1255 /* Kernel channels */
1256 if (session
->kernel_session
!= NULL
) {
1257 cds_list_for_each_entry(kchan
, &session
->kernel_session
->channel_list
.head
, list
) {
1258 /* Copy lttng_channel struct to array */
1259 memcpy(&channels
[i
], kchan
->channel
, sizeof(struct lttng_channel
));
1260 channels
[i
].enabled
= kchan
->enabled
;
1265 /* TODO: Missing UST listing */
1269 * Fill lttng_event array of all events in the channel.
1271 static void list_lttng_events(struct ltt_kernel_channel
*kchan
,
1272 struct lttng_event
*events
)
1275 * TODO: This is ONLY kernel. Need UST support.
1278 struct ltt_kernel_event
*event
;
1280 DBG("Listing events for channel %s", kchan
->channel
->name
);
1282 /* Kernel channels */
1283 cds_list_for_each_entry(event
, &kchan
->events_list
.head
, list
) {
1284 strncpy(events
[i
].name
, event
->event
->name
, LTTNG_SYMBOL_NAME_LEN
);
1285 events
[i
].enabled
= event
->enabled
;
1286 switch (event
->event
->instrumentation
) {
1287 case LTTNG_KERNEL_TRACEPOINT
:
1288 events
[i
].type
= LTTNG_EVENT_TRACEPOINT
;
1290 case LTTNG_KERNEL_KPROBE
:
1291 case LTTNG_KERNEL_KRETPROBE
:
1292 events
[i
].type
= LTTNG_EVENT_PROBE
;
1293 memcpy(&events
[i
].attr
.probe
, &event
->event
->u
.kprobe
,
1294 sizeof(struct lttng_kernel_kprobe
));
1296 case LTTNG_KERNEL_FUNCTION
:
1297 events
[i
].type
= LTTNG_EVENT_FUNCTION
;
1298 memcpy(&events
[i
].attr
.ftrace
, &event
->event
->u
.ftrace
,
1299 sizeof(struct lttng_kernel_function
));
1307 * Process the command requested by the lttng client within the command
1308 * context structure. This function make sure that the return structure (llm)
1309 * is set and ready for transmission before returning.
1311 * Return any error encountered or 0 for success.
1313 static int process_client_msg(struct command_ctx
*cmd_ctx
)
1315 int ret
= LTTCOMM_OK
;
1317 DBG("Processing client command %d", cmd_ctx
->lsm
->cmd_type
);
1319 /* Listing commands don't need a session */
1320 switch (cmd_ctx
->lsm
->cmd_type
) {
1321 case LTTNG_CREATE_SESSION
:
1322 case LTTNG_LIST_SESSIONS
:
1323 case LTTNG_LIST_TRACEPOINTS
:
1324 case LTTNG_CALIBRATE
:
1327 DBG("Getting session %s by name", cmd_ctx
->lsm
->session
.name
);
1328 cmd_ctx
->session
= find_session_by_name(cmd_ctx
->lsm
->session
.name
);
1329 if (cmd_ctx
->session
== NULL
) {
1330 /* If session name not found */
1331 if (cmd_ctx
->lsm
->session
.name
!= NULL
) {
1332 ret
= LTTCOMM_SESS_NOT_FOUND
;
1333 } else { /* If no session name specified */
1334 ret
= LTTCOMM_SELECT_SESS
;
1338 /* Acquire lock for the session */
1339 lock_session(cmd_ctx
->session
);
1345 * Check domain type for specific "pre-action".
1347 switch (cmd_ctx
->lsm
->domain
.type
) {
1348 case LTTNG_DOMAIN_KERNEL
:
1349 /* Kernel tracer check */
1350 if (kernel_tracer_fd
== 0) {
1351 init_kernel_tracer();
1352 if (kernel_tracer_fd
== 0) {
1353 ret
= LTTCOMM_KERN_NA
;
1358 /* Need a session for kernel command */
1359 switch (cmd_ctx
->lsm
->cmd_type
) {
1360 case LTTNG_CREATE_SESSION
:
1361 case LTTNG_LIST_SESSIONS
:
1362 case LTTNG_LIST_TRACEPOINTS
:
1363 case LTTNG_CALIBRATE
:
1366 if (cmd_ctx
->session
->kernel_session
== NULL
) {
1367 ret
= create_kernel_session(cmd_ctx
->session
);
1369 ret
= LTTCOMM_KERN_SESS_FAIL
;
1373 /* Start the kernel consumer daemon */
1374 if (kconsumerd_pid
== 0) {
1375 ret
= start_kconsumerd();
1387 /* Process by command type */
1388 switch (cmd_ctx
->lsm
->cmd_type
) {
1389 case LTTNG_ADD_CONTEXT
:
1391 struct lttng_kernel_context kctx
;
1393 /* Setup lttng message with no payload */
1394 ret
= setup_lttng_msg(cmd_ctx
, 0);
1399 switch (cmd_ctx
->lsm
->domain
.type
) {
1400 case LTTNG_DOMAIN_KERNEL
:
1401 /* Create Kernel context */
1402 kctx
.ctx
= cmd_ctx
->lsm
->u
.context
.ctx
.ctx
;
1403 kctx
.u
.perf_counter
.type
= cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.type
;
1404 kctx
.u
.perf_counter
.config
= cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.config
;
1405 strncpy(kctx
.u
.perf_counter
.name
,
1406 cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.name
,
1407 LTTNG_SYMBOL_NAME_LEN
);
1409 /* Add kernel context to kernel tracer. See context.c */
1410 ret
= add_kernel_context(cmd_ctx
->session
->kernel_session
, &kctx
,
1411 cmd_ctx
->lsm
->u
.context
.event_name
,
1412 cmd_ctx
->lsm
->u
.context
.channel_name
);
1413 if (ret
!= LTTCOMM_OK
) {
1418 /* TODO: Userspace tracing */
1419 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1426 case LTTNG_DISABLE_CHANNEL
:
1428 struct ltt_kernel_channel
*kchan
;
1430 /* Setup lttng message with no payload */
1431 ret
= setup_lttng_msg(cmd_ctx
, 0);
1436 switch (cmd_ctx
->lsm
->domain
.type
) {
1437 case LTTNG_DOMAIN_KERNEL
:
1438 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1439 cmd_ctx
->session
->kernel_session
);
1440 if (kchan
== NULL
) {
1441 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1443 } else if (kchan
->enabled
== 1) {
1444 ret
= kernel_disable_channel(kchan
);
1446 if (ret
!= EEXIST
) {
1447 ret
= LTTCOMM_KERN_CHAN_DISABLE_FAIL
;
1452 kernel_wait_quiescent(kernel_tracer_fd
);
1455 /* TODO: Userspace tracing */
1456 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1463 case LTTNG_DISABLE_EVENT
:
1465 struct ltt_kernel_channel
*kchan
;
1466 struct ltt_kernel_event
*kevent
;
1468 /* Setup lttng message with no payload */
1469 ret
= setup_lttng_msg(cmd_ctx
, 0);
1474 switch (cmd_ctx
->lsm
->domain
.type
) {
1475 case LTTNG_DOMAIN_KERNEL
:
1476 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1477 cmd_ctx
->session
->kernel_session
);
1478 if (kchan
== NULL
) {
1479 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1483 kevent
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.disable
.name
, kchan
);
1484 if (kevent
!= NULL
) {
1485 DBG("Disabling kernel event %s for channel %s.", kevent
->event
->name
,
1486 kchan
->channel
->name
);
1487 ret
= kernel_disable_event(kevent
);
1489 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
1494 kernel_wait_quiescent(kernel_tracer_fd
);
1497 /* TODO: Userspace tracing */
1498 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1505 case LTTNG_DISABLE_ALL_EVENT
:
1507 struct ltt_kernel_channel
*kchan
;
1508 struct ltt_kernel_event
*kevent
;
1510 /* Setup lttng message with no payload */
1511 ret
= setup_lttng_msg(cmd_ctx
, 0);
1516 switch (cmd_ctx
->lsm
->domain
.type
) {
1517 case LTTNG_DOMAIN_KERNEL
:
1518 DBG("Disabling all enabled kernel events");
1519 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1520 cmd_ctx
->session
->kernel_session
);
1521 if (kchan
== NULL
) {
1522 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1526 /* For each event in the kernel session */
1527 cds_list_for_each_entry(kevent
, &kchan
->events_list
.head
, list
) {
1528 DBG("Disabling kernel event %s for channel %s.",
1529 kevent
->event
->name
, kchan
->channel
->name
);
1530 ret
= kernel_disable_event(kevent
);
1536 /* Quiescent wait after event disable */
1537 kernel_wait_quiescent(kernel_tracer_fd
);
1540 /* TODO: Userspace tracing */
1541 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1548 case LTTNG_ENABLE_CHANNEL
:
1550 struct ltt_kernel_channel
*kchan
;
1552 /* Setup lttng message with no payload */
1553 ret
= setup_lttng_msg(cmd_ctx
, 0);
1558 switch (cmd_ctx
->lsm
->domain
.type
) {
1559 case LTTNG_DOMAIN_KERNEL
:
1560 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.enable
.channel_name
,
1561 cmd_ctx
->session
->kernel_session
);
1562 if (kchan
== NULL
) {
1563 /* Channel not found, creating it */
1564 DBG("Creating kernel channel");
1566 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1567 &cmd_ctx
->lsm
->u
.channel
.chan
, cmd_ctx
->session
->path
);
1569 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1573 /* Notify kernel thread that there is a new channel */
1574 ret
= notify_kernel_pollfd();
1576 ret
= LTTCOMM_FATAL
;
1579 } else if (kchan
->enabled
== 0) {
1580 ret
= kernel_enable_channel(kchan
);
1582 if (ret
!= EEXIST
) {
1583 ret
= LTTCOMM_KERN_CHAN_ENABLE_FAIL
;
1589 kernel_wait_quiescent(kernel_tracer_fd
);
1592 /* TODO: Userspace tracing */
1593 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1600 case LTTNG_ENABLE_EVENT
:
1603 struct ltt_kernel_channel
*kchan
;
1604 struct ltt_kernel_event
*kevent
;
1605 struct lttng_channel
*chan
;
1607 /* Setup lttng message with no payload */
1608 ret
= setup_lttng_msg(cmd_ctx
, 0);
1613 channel_name
= cmd_ctx
->lsm
->u
.enable
.channel_name
;
1615 switch (cmd_ctx
->lsm
->domain
.type
) {
1616 case LTTNG_DOMAIN_KERNEL
:
1618 kchan
= get_kernel_channel_by_name(channel_name
,
1619 cmd_ctx
->session
->kernel_session
);
1620 if (kchan
== NULL
) {
1621 DBG("Channel not found. Creating channel %s", channel_name
);
1623 chan
= init_default_channel(channel_name
);
1625 ret
= LTTCOMM_FATAL
;
1629 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1630 chan
, cmd_ctx
->session
->path
);
1632 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1636 } while (kchan
== NULL
);
1638 kevent
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.enable
.event
.name
, kchan
);
1639 if (kevent
== NULL
) {
1640 DBG("Creating kernel event %s for channel %s.",
1641 cmd_ctx
->lsm
->u
.enable
.event
.name
, channel_name
);
1642 ret
= kernel_create_event(&cmd_ctx
->lsm
->u
.enable
.event
, kchan
);
1644 DBG("Enabling kernel event %s for channel %s.",
1645 kevent
->event
->name
, channel_name
);
1646 ret
= kernel_enable_event(kevent
);
1647 if (ret
== -EEXIST
) {
1648 ret
= LTTCOMM_KERN_EVENT_EXIST
;
1654 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
1658 kernel_wait_quiescent(kernel_tracer_fd
);
1661 /* TODO: Userspace tracing */
1662 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1668 case LTTNG_ENABLE_ALL_EVENT
:
1672 struct ltt_kernel_channel
*kchan
;
1673 struct ltt_kernel_event
*kevent
;
1674 struct lttng_event
*event_list
;
1675 struct lttng_channel
*chan
;
1677 /* Setup lttng message with no payload */
1678 ret
= setup_lttng_msg(cmd_ctx
, 0);
1683 DBG("Enabling all kernel event");
1685 channel_name
= cmd_ctx
->lsm
->u
.enable
.channel_name
;
1687 switch (cmd_ctx
->lsm
->domain
.type
) {
1688 case LTTNG_DOMAIN_KERNEL
:
1690 kchan
= get_kernel_channel_by_name(channel_name
,
1691 cmd_ctx
->session
->kernel_session
);
1692 if (kchan
== NULL
) {
1693 DBG("Channel not found. Creating channel %s", channel_name
);
1695 chan
= init_default_channel(channel_name
);
1697 ret
= LTTCOMM_FATAL
;
1701 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1702 chan
, cmd_ctx
->session
->path
);
1704 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1708 } while (kchan
== NULL
);
1710 /* For each event in the kernel session */
1711 cds_list_for_each_entry(kevent
, &kchan
->events_list
.head
, list
) {
1712 DBG("Enabling kernel event %s for channel %s.",
1713 kevent
->event
->name
, channel_name
);
1714 ret
= kernel_enable_event(kevent
);
1720 size
= kernel_list_events(kernel_tracer_fd
, &event_list
);
1722 ret
= LTTCOMM_KERN_LIST_FAIL
;
1726 for (i
= 0; i
< size
; i
++) {
1727 kevent
= get_kernel_event_by_name(event_list
[i
].name
, kchan
);
1728 if (kevent
== NULL
) {
1729 /* Default event type for enable all */
1730 event_list
[i
].type
= LTTNG_EVENT_TRACEPOINT
;
1731 /* Enable each single tracepoint event */
1732 ret
= kernel_create_event(&event_list
[i
], kchan
);
1734 /* Ignore error here and continue */
1741 /* Quiescent wait after event enable */
1742 kernel_wait_quiescent(kernel_tracer_fd
);
1745 /* TODO: Userspace tracing */
1746 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1753 case LTTNG_LIST_TRACEPOINTS
:
1755 struct lttng_event
*events
;
1756 ssize_t nb_events
= 0;
1758 switch (cmd_ctx
->lsm
->domain
.type
) {
1759 case LTTNG_DOMAIN_KERNEL
:
1760 DBG("Listing kernel events");
1761 nb_events
= kernel_list_events(kernel_tracer_fd
, &events
);
1762 if (nb_events
< 0) {
1763 ret
= LTTCOMM_KERN_LIST_FAIL
;
1768 /* TODO: Userspace listing */
1769 ret
= LTTCOMM_NOT_IMPLEMENTED
;
1774 * Setup lttng message with payload size set to the event list size in
1775 * bytes and then copy list into the llm payload.
1777 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_event
) * nb_events
);
1783 /* Copy event list into message payload */
1784 memcpy(cmd_ctx
->llm
->payload
, events
,
1785 sizeof(struct lttng_event
) * nb_events
);
1792 case LTTNG_START_TRACE
:
1794 struct ltt_kernel_channel
*chan
;
1796 /* Setup lttng message with no payload */
1797 ret
= setup_lttng_msg(cmd_ctx
, 0);
1802 /* Kernel tracing */
1803 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1804 if (cmd_ctx
->session
->kernel_session
->metadata
== NULL
) {
1805 DBG("Open kernel metadata");
1806 ret
= kernel_open_metadata(cmd_ctx
->session
->kernel_session
,
1807 cmd_ctx
->session
->path
);
1809 ret
= LTTCOMM_KERN_META_FAIL
;
1814 if (cmd_ctx
->session
->kernel_session
->metadata_stream_fd
== 0) {
1815 DBG("Opening kernel metadata stream");
1816 if (cmd_ctx
->session
->kernel_session
->metadata_stream_fd
== 0) {
1817 ret
= kernel_open_metadata_stream(cmd_ctx
->session
->kernel_session
);
1819 ERR("Kernel create metadata stream failed");
1820 ret
= LTTCOMM_KERN_STREAM_FAIL
;
1826 /* For each channel */
1827 cds_list_for_each_entry(chan
,
1828 &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1829 if (chan
->stream_count
== 0) {
1830 ret
= kernel_open_channel_stream(chan
);
1832 ERR("Kernel create channel stream failed");
1833 ret
= LTTCOMM_KERN_STREAM_FAIL
;
1836 /* Update the stream global counter */
1837 cmd_ctx
->session
->kernel_session
->stream_count_global
+= ret
;
1841 DBG("Start kernel tracing");
1842 ret
= kernel_start_session(cmd_ctx
->session
->kernel_session
);
1844 ERR("Kernel start session failed");
1845 ret
= LTTCOMM_KERN_START_FAIL
;
1849 ret
= start_kernel_trace(cmd_ctx
->session
->kernel_session
);
1851 ret
= LTTCOMM_KERN_START_FAIL
;
1855 /* Quiescent wait after starting trace */
1856 kernel_wait_quiescent(kernel_tracer_fd
);
1859 /* TODO: Start all UST traces */
1864 case LTTNG_STOP_TRACE
:
1866 struct ltt_kernel_channel
*chan
;
1867 /* Setup lttng message with no payload */
1868 ret
= setup_lttng_msg(cmd_ctx
, 0);
1874 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1875 DBG("Stop kernel tracing");
1877 ret
= kernel_metadata_flush_buffer(cmd_ctx
->session
->kernel_session
->metadata_stream_fd
);
1879 ERR("Kernel metadata flush failed");
1882 cds_list_for_each_entry(chan
, &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1883 ret
= kernel_flush_buffer(chan
);
1885 ERR("Kernel flush buffer error");
1889 ret
= kernel_stop_session(cmd_ctx
->session
->kernel_session
);
1891 ERR("Kernel stop session failed");
1892 ret
= LTTCOMM_KERN_STOP_FAIL
;
1896 /* Quiescent wait after stopping trace */
1897 kernel_wait_quiescent(kernel_tracer_fd
);
1900 /* TODO : User-space tracer */
1905 case LTTNG_CREATE_SESSION
:
1907 /* Setup lttng message with no payload */
1908 ret
= setup_lttng_msg(cmd_ctx
, 0);
1913 ret
= create_session(cmd_ctx
->lsm
->session
.name
, cmd_ctx
->lsm
->session
.path
);
1915 if (ret
== -EEXIST
) {
1916 ret
= LTTCOMM_EXIST_SESS
;
1918 ret
= LTTCOMM_FATAL
;
1926 case LTTNG_DESTROY_SESSION
:
1928 /* Setup lttng message with no payload */
1929 ret
= setup_lttng_msg(cmd_ctx
, 0);
1934 /* Clean kernel session teardown */
1935 teardown_kernel_session(cmd_ctx
->session
);
1937 ret
= destroy_session(cmd_ctx
->lsm
->session
.name
);
1939 ret
= LTTCOMM_FATAL
;
1944 * Must notify the kernel thread here to update it's pollfd in order to
1945 * remove the channel(s)' fd just destroyed.
1947 ret
= notify_kernel_pollfd();
1949 ret
= LTTCOMM_FATAL
;
1956 case LTTNG_LIST_DOMAINS
:
1960 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1964 nb_dom
+= cmd_ctx
->session
->ust_trace_count
;
1966 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_domain
) * nb_dom
);
1971 ((struct lttng_domain
*)(cmd_ctx
->llm
->payload
))[0].type
=
1972 LTTNG_DOMAIN_KERNEL
;
1974 /* TODO: User-space tracer domain support */
1978 case LTTNG_LIST_CHANNELS
:
1981 * TODO: Only kernel channels are listed here. UST listing
1982 * is needed on lttng-ust 2.0 release.
1985 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1986 nb_chan
+= cmd_ctx
->session
->kernel_session
->channel_count
;
1989 ret
= setup_lttng_msg(cmd_ctx
,
1990 sizeof(struct lttng_channel
) * nb_chan
);
1995 list_lttng_channels(cmd_ctx
->session
,
1996 (struct lttng_channel
*)(cmd_ctx
->llm
->payload
));
2001 case LTTNG_LIST_EVENTS
:
2004 * TODO: Only kernel events are listed here. UST listing
2005 * is needed on lttng-ust 2.0 release.
2007 size_t nb_event
= 0;
2008 struct ltt_kernel_channel
*kchan
= NULL
;
2010 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
2011 kchan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.list
.channel_name
,
2012 cmd_ctx
->session
->kernel_session
);
2013 if (kchan
== NULL
) {
2014 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
2017 nb_event
+= kchan
->event_count
;
2020 ret
= setup_lttng_msg(cmd_ctx
,
2021 sizeof(struct lttng_event
) * nb_event
);
2026 DBG("Listing events (%ld events)", nb_event
);
2028 list_lttng_events(kchan
,
2029 (struct lttng_event
*)(cmd_ctx
->llm
->payload
));
2034 case LTTNG_LIST_SESSIONS
:
2036 lock_session_list();
2038 if (session_list_ptr
->count
== 0) {
2039 ret
= LTTCOMM_NO_SESSION
;
2040 unlock_session_list();
2044 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_session
) *
2045 session_list_ptr
->count
);
2047 unlock_session_list();
2051 /* Filled the session array */
2052 list_lttng_sessions((struct lttng_session
*)(cmd_ctx
->llm
->payload
));
2054 unlock_session_list();
2060 case LTTNG_CALIBRATE
:
2062 /* Setup lttng message with no payload */
2063 ret
= setup_lttng_msg(cmd_ctx
, 0);
2068 switch (cmd_ctx
->lsm
->domain
.type
) {
2069 case LTTNG_DOMAIN_KERNEL
:
2071 struct lttng_kernel_calibrate kcalibrate
;
2073 kcalibrate
.type
= cmd_ctx
->lsm
->u
.calibrate
.type
;
2074 ret
= kernel_calibrate(kernel_tracer_fd
, &kcalibrate
);
2076 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
2082 /* TODO: Userspace tracing */
2083 ret
= LTTCOMM_NOT_IMPLEMENTED
;
2091 /* Undefined command */
2092 ret
= setup_lttng_msg(cmd_ctx
, 0);
2101 /* Set return code */
2102 cmd_ctx
->llm
->ret_code
= ret
;
2104 if (cmd_ctx
->session
) {
2105 unlock_session(cmd_ctx
->session
);
2111 if (cmd_ctx
->llm
== NULL
) {
2112 DBG("Missing llm structure. Allocating one.");
2113 if (setup_lttng_msg(cmd_ctx
, 0) < 0) {
2117 /* Notify client of error */
2118 cmd_ctx
->llm
->ret_code
= ret
;
2121 if (cmd_ctx
->session
) {
2122 unlock_session(cmd_ctx
->session
);
2128 * This thread manage all clients request using the unix client socket for
2131 static void *thread_manage_clients(void *data
)
2134 struct command_ctx
*cmd_ctx
= NULL
;
2135 struct pollfd pollfd
[2];
2137 DBG("[thread] Manage client started");
2139 ret
= lttcomm_listen_unix_sock(client_sock
);
2144 /* First fd is always the quit pipe */
2145 pollfd
[0].fd
= thread_quit_pipe
[0];
2148 pollfd
[1].fd
= client_sock
;
2149 pollfd
[1].events
= POLLIN
;
2151 /* Notify parent pid that we are ready
2152 * to accept command for client side.
2154 if (opt_sig_parent
) {
2155 kill(ppid
, SIGCHLD
);
2159 DBG("Accepting client command ...");
2161 /* Inifinite blocking call, waiting for transmission */
2162 ret
= poll(pollfd
, 2, -1);
2164 perror("poll client thread");
2168 /* Thread quit pipe has been closed. Killing thread. */
2169 if (pollfd
[0].revents
== POLLNVAL
) {
2171 } else if (pollfd
[1].revents
== POLLERR
) {
2172 ERR("Client socket poll error");
2176 sock
= lttcomm_accept_unix_sock(client_sock
);
2181 /* Allocate context command to process the client request */
2182 cmd_ctx
= malloc(sizeof(struct command_ctx
));
2184 /* Allocate data buffer for reception */
2185 cmd_ctx
->lsm
= malloc(sizeof(struct lttcomm_session_msg
));
2186 cmd_ctx
->llm
= NULL
;
2187 cmd_ctx
->session
= NULL
;
2190 * Data is received from the lttng client. The struct
2191 * lttcomm_session_msg (lsm) contains the command and data request of
2194 DBG("Receiving data from client ...");
2195 ret
= lttcomm_recv_unix_sock(sock
, cmd_ctx
->lsm
, sizeof(struct lttcomm_session_msg
));
2200 // TODO: Validate cmd_ctx including sanity check for security purpose.
2203 * This function dispatch the work to the kernel or userspace tracer
2204 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2205 * informations for the client. The command context struct contains
2206 * everything this function may needs.
2208 ret
= process_client_msg(cmd_ctx
);
2210 /* TODO: Inform client somehow of the fatal error. At this point,
2211 * ret < 0 means that a malloc failed (ENOMEM). */
2212 /* Error detected but still accept command */
2213 clean_command_ctx(&cmd_ctx
);
2217 DBG("Sending response (size: %d, retcode: %d)",
2218 cmd_ctx
->lttng_msg_size
, cmd_ctx
->llm
->ret_code
);
2219 ret
= send_unix_sock(sock
, cmd_ctx
->llm
, cmd_ctx
->lttng_msg_size
);
2221 ERR("Failed to send data back to client");
2224 clean_command_ctx(&cmd_ctx
);
2226 /* End of transmission */
2231 DBG("Client thread dying");
2239 unlink(client_unix_sock_path
);
2241 clean_command_ctx(&cmd_ctx
);
2247 * usage function on stderr
2249 static void usage(void)
2251 fprintf(stderr
, "Usage: %s OPTIONS\n\nOptions:\n", progname
);
2252 fprintf(stderr
, " -h, --help Display this usage.\n");
2253 fprintf(stderr
, " -c, --client-sock PATH Specify path for the client unix socket\n");
2254 fprintf(stderr
, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2255 fprintf(stderr
, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2256 fprintf(stderr
, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2257 fprintf(stderr
, " -d, --daemonize Start as a daemon.\n");
2258 fprintf(stderr
, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2259 fprintf(stderr
, " -V, --version Show version number.\n");
2260 fprintf(stderr
, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2261 fprintf(stderr
, " -q, --quiet No output at all.\n");
2262 fprintf(stderr
, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2266 * daemon argument parsing
2268 static int parse_args(int argc
, char **argv
)
2272 static struct option long_options
[] = {
2273 { "client-sock", 1, 0, 'c' },
2274 { "apps-sock", 1, 0, 'a' },
2275 { "kconsumerd-cmd-sock", 1, 0, 0 },
2276 { "kconsumerd-err-sock", 1, 0, 0 },
2277 { "daemonize", 0, 0, 'd' },
2278 { "sig-parent", 0, 0, 'S' },
2279 { "help", 0, 0, 'h' },
2280 { "group", 1, 0, 'g' },
2281 { "version", 0, 0, 'V' },
2282 { "quiet", 0, 0, 'q' },
2283 { "verbose", 0, 0, 'v' },
2288 int option_index
= 0;
2289 c
= getopt_long(argc
, argv
, "dhqvVS" "a:c:g:s:E:C:", long_options
, &option_index
);
2296 fprintf(stderr
, "option %s", long_options
[option_index
].name
);
2298 fprintf(stderr
, " with arg %s\n", optarg
);
2302 snprintf(client_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2305 snprintf(apps_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2311 opt_tracing_group
= strdup(optarg
);
2317 fprintf(stdout
, "%s\n", VERSION
);
2323 snprintf(kconsumerd_err_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2326 snprintf(kconsumerd_cmd_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2332 /* Verbose level can increase using multiple -v */
2336 /* Unknown option or other error.
2337 * Error is printed by getopt, just return */
2346 * Creates the two needed socket by the daemon.
2347 * apps_sock - The communication socket for all UST apps.
2348 * client_sock - The communication of the cli tool (lttng).
2350 static int init_daemon_socket()
2355 old_umask
= umask(0);
2357 /* Create client tool unix socket */
2358 client_sock
= lttcomm_create_unix_sock(client_unix_sock_path
);
2359 if (client_sock
< 0) {
2360 ERR("Create unix sock failed: %s", client_unix_sock_path
);
2365 /* File permission MUST be 660 */
2366 ret
= chmod(client_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
2368 ERR("Set file permissions failed: %s", client_unix_sock_path
);
2373 /* Create the application unix socket */
2374 apps_sock
= lttcomm_create_unix_sock(apps_unix_sock_path
);
2375 if (apps_sock
< 0) {
2376 ERR("Create unix sock failed: %s", apps_unix_sock_path
);
2381 /* File permission MUST be 666 */
2382 ret
= chmod(apps_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
| S_IWOTH
);
2384 ERR("Set file permissions failed: %s", apps_unix_sock_path
);
2395 * Check if the global socket is available. If yes, error is returned.
2397 static int check_existing_daemon()
2401 ret
= access(client_unix_sock_path
, F_OK
);
2403 ret
= access(apps_unix_sock_path
, F_OK
);
2410 * Set the tracing group gid onto the client socket.
2412 * Race window between mkdir and chown is OK because we are going from more
2413 * permissive (root.root) to les permissive (root.tracing).
2415 static int set_permissions(void)
2420 /* Decide which group name to use */
2421 (opt_tracing_group
!= NULL
) ?
2422 (grp
= getgrnam(opt_tracing_group
)) :
2423 (grp
= getgrnam(default_tracing_group
));
2427 WARN("No tracing group detected");
2430 ERR("Missing tracing group. Aborting execution.");
2436 /* Set lttng run dir */
2437 ret
= chown(LTTNG_RUNDIR
, 0, grp
->gr_gid
);
2439 ERR("Unable to set group on " LTTNG_RUNDIR
);
2443 /* lttng client socket path */
2444 ret
= chown(client_unix_sock_path
, 0, grp
->gr_gid
);
2446 ERR("Unable to set group on %s", client_unix_sock_path
);
2450 /* kconsumerd error socket path */
2451 ret
= chown(kconsumerd_err_unix_sock_path
, 0, grp
->gr_gid
);
2453 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path
);
2457 DBG("All permissions are set");
2464 * Create the pipe used to wake up the kernel thread.
2466 static int create_kernel_poll_pipe(void)
2468 return pipe2(kernel_poll_pipe
, O_CLOEXEC
);
2472 * Create the lttng run directory needed for all global sockets and pipe.
2474 static int create_lttng_rundir(void)
2478 ret
= mkdir(LTTNG_RUNDIR
, S_IRWXU
| S_IRWXG
);
2480 if (errno
!= EEXIST
) {
2481 ERR("Unable to create " LTTNG_RUNDIR
);
2493 * Setup sockets and directory needed by the kconsumerd communication with the
2496 static int set_kconsumerd_sockets(void)
2500 if (strlen(kconsumerd_err_unix_sock_path
) == 0) {
2501 snprintf(kconsumerd_err_unix_sock_path
, PATH_MAX
, KCONSUMERD_ERR_SOCK_PATH
);
2504 if (strlen(kconsumerd_cmd_unix_sock_path
) == 0) {
2505 snprintf(kconsumerd_cmd_unix_sock_path
, PATH_MAX
, KCONSUMERD_CMD_SOCK_PATH
);
2508 ret
= mkdir(KCONSUMERD_PATH
, S_IRWXU
| S_IRWXG
);
2510 if (errno
!= EEXIST
) {
2511 ERR("Failed to create " KCONSUMERD_PATH
);
2517 /* Create the kconsumerd error unix socket */
2518 kconsumerd_err_sock
= lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path
);
2519 if (kconsumerd_err_sock
< 0) {
2520 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path
);
2525 /* File permission MUST be 660 */
2526 ret
= chmod(kconsumerd_err_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
2528 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path
);
2538 * Signal handler for the daemon
2540 static void sighandler(int sig
)
2544 DBG("SIGPIPE catched");
2547 DBG("SIGINT catched");
2551 DBG("SIGTERM catched");
2562 * Setup signal handler for :
2563 * SIGINT, SIGTERM, SIGPIPE
2565 static int set_signal_handler(void)
2568 struct sigaction sa
;
2571 if ((ret
= sigemptyset(&sigset
)) < 0) {
2572 perror("sigemptyset");
2576 sa
.sa_handler
= sighandler
;
2577 sa
.sa_mask
= sigset
;
2579 if ((ret
= sigaction(SIGTERM
, &sa
, NULL
)) < 0) {
2580 perror("sigaction");
2584 if ((ret
= sigaction(SIGINT
, &sa
, NULL
)) < 0) {
2585 perror("sigaction");
2589 if ((ret
= sigaction(SIGPIPE
, &sa
, NULL
)) < 0) {
2590 perror("sigaction");
2594 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2600 * Set open files limit to unlimited. This daemon can open a large number of
2601 * file descriptors in order to consumer multiple kernel traces.
2603 static void set_ulimit(void)
2608 /* The kernel does not allowed an infinite limit for open files */
2609 lim
.rlim_cur
= 65535;
2610 lim
.rlim_max
= 65535;
2612 ret
= setrlimit(RLIMIT_NOFILE
, &lim
);
2614 perror("failed to set open files limit");
2621 int main(int argc
, char **argv
)
2625 const char *home_path
;
2627 /* Create thread quit pipe */
2628 if (init_thread_quit_pipe() < 0) {
2632 /* Parse arguments */
2634 if ((ret
= parse_args(argc
, argv
) < 0)) {
2647 /* Check if daemon is UID = 0 */
2648 is_root
= !getuid();
2651 ret
= create_lttng_rundir();
2656 if (strlen(apps_unix_sock_path
) == 0) {
2657 snprintf(apps_unix_sock_path
, PATH_MAX
,
2658 DEFAULT_GLOBAL_APPS_UNIX_SOCK
);
2661 if (strlen(client_unix_sock_path
) == 0) {
2662 snprintf(client_unix_sock_path
, PATH_MAX
,
2663 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
);
2666 home_path
= get_home_dir();
2667 if (home_path
== NULL
) {
2668 /* TODO: Add --socket PATH option */
2669 ERR("Can't get HOME directory for sockets creation.");
2673 if (strlen(apps_unix_sock_path
) == 0) {
2674 snprintf(apps_unix_sock_path
, PATH_MAX
,
2675 DEFAULT_HOME_APPS_UNIX_SOCK
, home_path
);
2678 /* Set the cli tool unix socket path */
2679 if (strlen(client_unix_sock_path
) == 0) {
2680 snprintf(client_unix_sock_path
, PATH_MAX
,
2681 DEFAULT_HOME_CLIENT_UNIX_SOCK
, home_path
);
2685 DBG("Client socket path %s", client_unix_sock_path
);
2686 DBG("Application socket path %s", apps_unix_sock_path
);
2689 * See if daemon already exist. If any of the two socket needed by the
2690 * daemon are present, this test fails. However, if the daemon is killed
2691 * with a SIGKILL, those unix socket must be unlinked by hand.
2693 if ((ret
= check_existing_daemon()) == 0) {
2694 ERR("Already running daemon.\n");
2696 * We do not goto error because we must not cleanup() because a daemon
2697 * is already running.
2702 /* After this point, we can safely call cleanup() so goto error is used */
2705 * These actions must be executed as root. We do that *after* setting up
2706 * the sockets path because we MUST make the check for another daemon using
2707 * those paths *before* trying to set the kernel consumer sockets and init
2711 ret
= set_kconsumerd_sockets();
2716 /* Setup kernel tracer */
2717 init_kernel_tracer();
2719 /* Set ulimit for open files */
2723 if (set_signal_handler() < 0) {
2727 /* Setup the needed unix socket */
2728 if (init_daemon_socket() < 0) {
2732 /* Set credentials to socket */
2733 if (is_root
&& (set_permissions() < 0)) {
2737 /* Get parent pid if -S, --sig-parent is specified. */
2738 if (opt_sig_parent
) {
2742 /* Setup the kernel pipe for waking up the kernel thread */
2743 if (create_kernel_poll_pipe() < 0) {
2748 * Get session list pointer. This pointer MUST NOT be free().
2749 * This list is statically declared in session.c
2751 session_list_ptr
= get_session_list();
2754 /* Create thread to manage the client socket */
2755 ret
= pthread_create(&client_thread
, NULL
, thread_manage_clients
, (void *) NULL
);
2757 perror("pthread_create");
2761 /* Create thread to manage application socket */
2762 ret
= pthread_create(&apps_thread
, NULL
, thread_manage_apps
, (void *) NULL
);
2764 perror("pthread_create");
2768 /* Create kernel thread to manage kernel event */
2769 ret
= pthread_create(&kernel_thread
, NULL
, thread_manage_kernel
, (void *) NULL
);
2771 perror("pthread_create");
2775 ret
= pthread_join(client_thread
, &status
);
2777 perror("pthread_join");