7327c3cb2262ddf4337b46c08f2d02160f1136e7
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
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.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <getopt.h>
21 #include <grp.h>
22 #include <limits.h>
23 #include <pthread.h>
24 #include <semaphore.h>
25 #include <signal.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sys/mman.h>
30 #include <sys/mount.h>
31 #include <sys/resource.h>
32 #include <sys/socket.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35 #include <sys/wait.h>
36 #include <urcu/futex.h>
37 #include <urcu/uatomic.h>
38 #include <unistd.h>
39 #include <config.h>
40
41 #include <common/common.h>
42 #include <common/compat/poll.h>
43 #include <common/compat/socket.h>
44 #include <common/defaults.h>
45 #include <common/kernel-consumer/kernel-consumer.h>
46 #include <common/ust-consumer/ust-consumer.h>
47
48 #include "lttng-sessiond.h"
49 #include "channel.h"
50 #include "context.h"
51 #include "event.h"
52 #include "futex.h"
53 #include "kernel.h"
54 #include "modprobe.h"
55 #include "shm.h"
56 #include "ust-ctl.h"
57 #include "utils.h"
58 #include "fd-limit.h"
59
60 #define CONSUMERD_FILE "lttng-consumerd"
61
62 struct consumer_data {
63 enum lttng_consumer_type type;
64
65 pthread_t thread; /* Worker thread interacting with the consumer */
66 sem_t sem;
67
68 /* Mutex to control consumerd pid assignation */
69 pthread_mutex_t pid_mutex;
70 pid_t pid;
71
72 int err_sock;
73 int cmd_sock;
74
75 /* consumer error and command Unix socket path */
76 char err_unix_sock_path[PATH_MAX];
77 char cmd_unix_sock_path[PATH_MAX];
78 };
79
80 /* Const values */
81 const char default_home_dir[] = DEFAULT_HOME_DIR;
82 const char default_tracing_group[] = DEFAULT_TRACING_GROUP;
83 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
84 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
85
86 const char *progname;
87 const char *opt_tracing_group;
88 static int opt_sig_parent;
89 static int opt_verbose_consumer;
90 static int opt_daemon;
91 static int opt_no_kernel;
92 static int is_root; /* Set to 1 if the daemon is running as root */
93 static pid_t ppid; /* Parent PID for --sig-parent option */
94 static char *rundir;
95
96 /* Consumer daemon specific control data */
97 static struct consumer_data kconsumer_data = {
98 .type = LTTNG_CONSUMER_KERNEL,
99 .err_unix_sock_path = DEFAULT_KCONSUMERD_ERR_SOCK_PATH,
100 .cmd_unix_sock_path = DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
101 .err_sock = -1,
102 .cmd_sock = -1,
103 };
104 static struct consumer_data ustconsumer64_data = {
105 .type = LTTNG_CONSUMER64_UST,
106 .err_unix_sock_path = DEFAULT_USTCONSUMERD64_ERR_SOCK_PATH,
107 .cmd_unix_sock_path = DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH,
108 .err_sock = -1,
109 .cmd_sock = -1,
110 };
111 static struct consumer_data ustconsumer32_data = {
112 .type = LTTNG_CONSUMER32_UST,
113 .err_unix_sock_path = DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH,
114 .cmd_unix_sock_path = DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH,
115 .err_sock = -1,
116 .cmd_sock = -1,
117 };
118
119 static int dispatch_thread_exit;
120
121 /* Global application Unix socket path */
122 static char apps_unix_sock_path[PATH_MAX];
123 /* Global client Unix socket path */
124 static char client_unix_sock_path[PATH_MAX];
125 /* global wait shm path for UST */
126 static char wait_shm_path[PATH_MAX];
127
128 /* Sockets and FDs */
129 static int client_sock = -1;
130 static int apps_sock = -1;
131 static int kernel_tracer_fd = -1;
132 static int kernel_poll_pipe[2] = { -1, -1 };
133
134 /*
135 * Quit pipe for all threads. This permits a single cancellation point
136 * for all threads when receiving an event on the pipe.
137 */
138 static int thread_quit_pipe[2] = { -1, -1 };
139
140 /*
141 * This pipe is used to inform the thread managing application communication
142 * that a command is queued and ready to be processed.
143 */
144 static int apps_cmd_pipe[2] = { -1, -1 };
145
146 /* Pthread, Mutexes and Semaphores */
147 static pthread_t apps_thread;
148 static pthread_t reg_apps_thread;
149 static pthread_t client_thread;
150 static pthread_t kernel_thread;
151 static pthread_t dispatch_thread;
152
153
154 /*
155 * UST registration command queue. This queue is tied with a futex and uses a N
156 * wakers / 1 waiter implemented and detailed in futex.c/.h
157 *
158 * The thread_manage_apps and thread_dispatch_ust_registration interact with
159 * this queue and the wait/wake scheme.
160 */
161 static struct ust_cmd_queue ust_cmd_queue;
162
163 /*
164 * Pointer initialized before thread creation.
165 *
166 * This points to the tracing session list containing the session count and a
167 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
168 * MUST NOT be taken if you call a public function in session.c.
169 *
170 * The lock is nested inside the structure: session_list_ptr->lock. Please use
171 * session_lock_list and session_unlock_list for lock acquisition.
172 */
173 static struct ltt_session_list *session_list_ptr;
174
175 int ust_consumerd64_fd = -1;
176 int ust_consumerd32_fd = -1;
177
178 static const char *consumerd32_bin = CONFIG_CONSUMERD32_BIN;
179 static const char *consumerd64_bin = CONFIG_CONSUMERD64_BIN;
180 static const char *consumerd32_libdir = CONFIG_CONSUMERD32_LIBDIR;
181 static const char *consumerd64_libdir = CONFIG_CONSUMERD64_LIBDIR;
182
183 /*
184 * Consumer daemon state which is changed when spawning it, killing it or in
185 * case of a fatal error.
186 */
187 enum consumerd_state {
188 CONSUMER_STARTED = 1,
189 CONSUMER_STOPPED = 2,
190 CONSUMER_ERROR = 3,
191 };
192
193 /*
194 * This consumer daemon state is used to validate if a client command will be
195 * able to reach the consumer. If not, the client is informed. For instance,
196 * doing a "lttng start" when the consumer state is set to ERROR will return an
197 * error to the client.
198 *
199 * The following example shows a possible race condition of this scheme:
200 *
201 * consumer thread error happens
202 * client cmd arrives
203 * client cmd checks state -> still OK
204 * consumer thread exit, sets error
205 * client cmd try to talk to consumer
206 * ...
207 *
208 * However, since the consumer is a different daemon, we have no way of making
209 * sure the command will reach it safely even with this state flag. This is why
210 * we consider that up to the state validation during command processing, the
211 * command is safe. After that, we can not guarantee the correctness of the
212 * client request vis-a-vis the consumer.
213 */
214 static enum consumerd_state ust_consumerd_state;
215 static enum consumerd_state kernel_consumerd_state;
216
217 static
218 void setup_consumerd_path(void)
219 {
220 const char *bin, *libdir;
221
222 /*
223 * Allow INSTALL_BIN_PATH to be used as a target path for the
224 * native architecture size consumer if CONFIG_CONSUMER*_PATH
225 * has not been defined.
226 */
227 #if (CAA_BITS_PER_LONG == 32)
228 if (!consumerd32_bin[0]) {
229 consumerd32_bin = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
230 }
231 if (!consumerd32_libdir[0]) {
232 consumerd32_libdir = INSTALL_LIB_PATH;
233 }
234 #elif (CAA_BITS_PER_LONG == 64)
235 if (!consumerd64_bin[0]) {
236 consumerd64_bin = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
237 }
238 if (!consumerd64_libdir[0]) {
239 consumerd64_libdir = INSTALL_LIB_PATH;
240 }
241 #else
242 #error "Unknown bitness"
243 #endif
244
245 /*
246 * runtime env. var. overrides the build default.
247 */
248 bin = getenv("LTTNG_CONSUMERD32_BIN");
249 if (bin) {
250 consumerd32_bin = bin;
251 }
252 bin = getenv("LTTNG_CONSUMERD64_BIN");
253 if (bin) {
254 consumerd64_bin = bin;
255 }
256 libdir = getenv("LTTNG_CONSUMERD32_LIBDIR");
257 if (libdir) {
258 consumerd32_libdir = libdir;
259 }
260 libdir = getenv("LTTNG_CONSUMERD64_LIBDIR");
261 if (libdir) {
262 consumerd64_libdir = libdir;
263 }
264 }
265
266 /*
267 * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
268 */
269 static int create_thread_poll_set(struct lttng_poll_event *events,
270 unsigned int size)
271 {
272 int ret;
273
274 if (events == NULL || size == 0) {
275 ret = -1;
276 goto error;
277 }
278
279 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
280 if (ret < 0) {
281 goto error;
282 }
283
284 /* Add quit pipe */
285 ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
286 if (ret < 0) {
287 goto error;
288 }
289
290 return 0;
291
292 error:
293 return ret;
294 }
295
296 /*
297 * Check if the thread quit pipe was triggered.
298 *
299 * Return 1 if it was triggered else 0;
300 */
301 static int check_thread_quit_pipe(int fd, uint32_t events)
302 {
303 if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
304 return 1;
305 }
306
307 return 0;
308 }
309
310 /*
311 * Return group ID of the tracing group or -1 if not found.
312 */
313 static gid_t allowed_group(void)
314 {
315 struct group *grp;
316
317 if (opt_tracing_group) {
318 grp = getgrnam(opt_tracing_group);
319 } else {
320 grp = getgrnam(default_tracing_group);
321 }
322 if (!grp) {
323 return -1;
324 } else {
325 return grp->gr_gid;
326 }
327 }
328
329 /*
330 * Init thread quit pipe.
331 *
332 * Return -1 on error or 0 if all pipes are created.
333 */
334 static int init_thread_quit_pipe(void)
335 {
336 int ret, i;
337
338 ret = pipe(thread_quit_pipe);
339 if (ret < 0) {
340 PERROR("thread quit pipe");
341 goto error;
342 }
343
344 for (i = 0; i < 2; i++) {
345 ret = fcntl(thread_quit_pipe[i], F_SETFD, FD_CLOEXEC);
346 if (ret < 0) {
347 PERROR("fcntl");
348 goto error;
349 }
350 }
351
352 error:
353 return ret;
354 }
355
356 /*
357 * Complete teardown of a kernel session. This free all data structure related
358 * to a kernel session and update counter.
359 */
360 static void teardown_kernel_session(struct ltt_session *session)
361 {
362 if (!session->kernel_session) {
363 DBG3("No kernel session when tearing down session");
364 return;
365 }
366
367 DBG("Tearing down kernel session");
368
369 /*
370 * If a custom kernel consumer was registered, close the socket before
371 * tearing down the complete kernel session structure
372 */
373 if (kconsumer_data.cmd_sock >= 0 &&
374 session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
375 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
376 }
377
378 trace_kernel_destroy_session(session->kernel_session);
379 }
380
381 /*
382 * Complete teardown of all UST sessions. This will free everything on his path
383 * and destroy the core essence of all ust sessions :)
384 */
385 static void teardown_ust_session(struct ltt_session *session)
386 {
387 int ret;
388
389 if (!session->ust_session) {
390 DBG3("No UST session when tearing down session");
391 return;
392 }
393
394 DBG("Tearing down UST session(s)");
395
396 ret = ust_app_destroy_trace_all(session->ust_session);
397 if (ret) {
398 ERR("Error in ust_app_destroy_trace_all");
399 }
400
401 trace_ust_destroy_session(session->ust_session);
402 }
403
404 /*
405 * Stop all threads by closing the thread quit pipe.
406 */
407 static void stop_threads(void)
408 {
409 int ret;
410
411 /* Stopping all threads */
412 DBG("Terminating all threads");
413 ret = notify_thread_pipe(thread_quit_pipe[1]);
414 if (ret < 0) {
415 ERR("write error on thread quit pipe");
416 }
417
418 /* Dispatch thread */
419 dispatch_thread_exit = 1;
420 futex_nto1_wake(&ust_cmd_queue.futex);
421 }
422
423 /*
424 * Cleanup the daemon
425 */
426 static void cleanup(void)
427 {
428 int ret, i;
429 char *cmd;
430 struct ltt_session *sess, *stmp;
431
432 DBG("Cleaning up");
433
434 DBG("Removing %s directory", rundir);
435 ret = asprintf(&cmd, "rm -rf %s", rundir);
436 if (ret < 0) {
437 ERR("asprintf failed. Something is really wrong!");
438 }
439
440 /* Remove lttng run directory */
441 ret = system(cmd);
442 if (ret < 0) {
443 ERR("Unable to clean %s", rundir);
444 }
445 free(cmd);
446
447 DBG("Cleaning up all sessions");
448
449 /* Destroy session list mutex */
450 if (session_list_ptr != NULL) {
451 pthread_mutex_destroy(&session_list_ptr->lock);
452
453 /* Cleanup ALL session */
454 cds_list_for_each_entry_safe(sess, stmp,
455 &session_list_ptr->head, list) {
456 teardown_kernel_session(sess);
457 teardown_ust_session(sess);
458 free(sess);
459 }
460 }
461
462 DBG("Closing all UST sockets");
463 ust_app_clean_list();
464
465 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
466
467 if (is_root && !opt_no_kernel) {
468 DBG2("Closing kernel fd");
469 if (kernel_tracer_fd >= 0) {
470 ret = close(kernel_tracer_fd);
471 if (ret) {
472 PERROR("close");
473 }
474 }
475 DBG("Unloading kernel modules");
476 modprobe_remove_lttng_all();
477 }
478
479 /*
480 * Closing all pipes used for communication between threads.
481 */
482 for (i = 0; i < 2; i++) {
483 if (kernel_poll_pipe[i] >= 0) {
484 ret = close(kernel_poll_pipe[i]);
485 if (ret) {
486 PERROR("close");
487 }
488 }
489 }
490 for (i = 0; i < 2; i++) {
491 if (thread_quit_pipe[i] >= 0) {
492 ret = close(thread_quit_pipe[i]);
493 if (ret) {
494 PERROR("close");
495 }
496 }
497 }
498 for (i = 0; i < 2; i++) {
499 if (apps_cmd_pipe[i] >= 0) {
500 ret = close(apps_cmd_pipe[i]);
501 if (ret) {
502 PERROR("close");
503 }
504 }
505 }
506
507 /* <fun> */
508 DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
509 "Matthew, BEET driven development works!%c[%dm",
510 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
511 /* </fun> */
512 }
513
514 /*
515 * Send data on a unix socket using the liblttsessiondcomm API.
516 *
517 * Return lttcomm error code.
518 */
519 static int send_unix_sock(int sock, void *buf, size_t len)
520 {
521 /* Check valid length */
522 if (len <= 0) {
523 return -1;
524 }
525
526 return lttcomm_send_unix_sock(sock, buf, len);
527 }
528
529 /*
530 * Free memory of a command context structure.
531 */
532 static void clean_command_ctx(struct command_ctx **cmd_ctx)
533 {
534 DBG("Clean command context structure");
535 if (*cmd_ctx) {
536 if ((*cmd_ctx)->llm) {
537 free((*cmd_ctx)->llm);
538 }
539 if ((*cmd_ctx)->lsm) {
540 free((*cmd_ctx)->lsm);
541 }
542 free(*cmd_ctx);
543 *cmd_ctx = NULL;
544 }
545 }
546
547 /*
548 * Send all stream fds of kernel channel to the consumer.
549 */
550 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
551 int sock, struct ltt_kernel_channel *channel,
552 uid_t uid, gid_t gid)
553 {
554 int ret;
555 struct ltt_kernel_stream *stream;
556 struct lttcomm_consumer_msg lkm;
557
558 DBG("Sending streams of channel %s to kernel consumer",
559 channel->channel->name);
560
561 /* Send channel */
562 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
563 lkm.u.channel.channel_key = channel->fd;
564 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
565 lkm.u.channel.mmap_len = 0; /* for kernel */
566 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
567 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
568 if (ret < 0) {
569 PERROR("send consumer channel");
570 goto error;
571 }
572
573 /* Send streams */
574 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
575 if (!stream->fd) {
576 continue;
577 }
578 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
579 lkm.u.stream.channel_key = channel->fd;
580 lkm.u.stream.stream_key = stream->fd;
581 lkm.u.stream.state = stream->state;
582 lkm.u.stream.output = channel->channel->attr.output;
583 lkm.u.stream.mmap_len = 0; /* for kernel */
584 lkm.u.stream.uid = uid;
585 lkm.u.stream.gid = gid;
586 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
587 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
588 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
589 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
590 if (ret < 0) {
591 PERROR("send consumer stream");
592 goto error;
593 }
594 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
595 if (ret < 0) {
596 PERROR("send consumer stream ancillary data");
597 goto error;
598 }
599 }
600
601 DBG("consumer channel streams sent");
602
603 return 0;
604
605 error:
606 return ret;
607 }
608
609 /*
610 * Send all stream fds of the kernel session to the consumer.
611 */
612 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
613 struct ltt_kernel_session *session)
614 {
615 int ret;
616 struct ltt_kernel_channel *chan;
617 struct lttcomm_consumer_msg lkm;
618 int sock = session->consumer_fd;
619
620 DBG("Sending metadata stream fd");
621
622 /* Extra protection. It's NOT supposed to be set to -1 at this point */
623 if (session->consumer_fd < 0) {
624 session->consumer_fd = consumer_data->cmd_sock;
625 }
626
627 if (session->metadata_stream_fd >= 0) {
628 /* Send metadata channel fd */
629 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
630 lkm.u.channel.channel_key = session->metadata->fd;
631 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
632 lkm.u.channel.mmap_len = 0; /* for kernel */
633 DBG("Sending metadata channel %d to consumer", lkm.u.channel.channel_key);
634 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
635 if (ret < 0) {
636 PERROR("send consumer channel");
637 goto error;
638 }
639
640 /* Send metadata stream fd */
641 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
642 lkm.u.stream.channel_key = session->metadata->fd;
643 lkm.u.stream.stream_key = session->metadata_stream_fd;
644 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
645 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
646 lkm.u.stream.mmap_len = 0; /* for kernel */
647 lkm.u.stream.uid = session->uid;
648 lkm.u.stream.gid = session->gid;
649 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
650 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
651 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
652 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
653 if (ret < 0) {
654 PERROR("send consumer stream");
655 goto error;
656 }
657 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
658 if (ret < 0) {
659 PERROR("send consumer stream");
660 goto error;
661 }
662 }
663
664 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
665 ret = send_kconsumer_channel_streams(consumer_data, sock, chan,
666 session->uid, session->gid);
667 if (ret < 0) {
668 goto error;
669 }
670 }
671
672 DBG("consumer fds (metadata and channel streams) sent");
673
674 return 0;
675
676 error:
677 return ret;
678 }
679
680 /*
681 * Notify UST applications using the shm mmap futex.
682 */
683 static int notify_ust_apps(int active)
684 {
685 char *wait_shm_mmap;
686
687 DBG("Notifying applications of session daemon state: %d", active);
688
689 /* See shm.c for this call implying mmap, shm and futex calls */
690 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
691 if (wait_shm_mmap == NULL) {
692 goto error;
693 }
694
695 /* Wake waiting process */
696 futex_wait_update((int32_t *) wait_shm_mmap, active);
697
698 /* Apps notified successfully */
699 return 0;
700
701 error:
702 return -1;
703 }
704
705 /*
706 * Setup the outgoing data buffer for the response (llm) by allocating the
707 * right amount of memory and copying the original information from the lsm
708 * structure.
709 *
710 * Return total size of the buffer pointed by buf.
711 */
712 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
713 {
714 int ret, buf_size;
715
716 buf_size = size;
717
718 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
719 if (cmd_ctx->llm == NULL) {
720 PERROR("zmalloc");
721 ret = -ENOMEM;
722 goto error;
723 }
724
725 /* Copy common data */
726 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
727 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
728
729 cmd_ctx->llm->data_size = size;
730 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
731
732 return buf_size;
733
734 error:
735 return ret;
736 }
737
738 /*
739 * Update the kernel poll set of all channel fd available over all tracing
740 * session. Add the wakeup pipe at the end of the set.
741 */
742 static int update_kernel_poll(struct lttng_poll_event *events)
743 {
744 int ret;
745 struct ltt_session *session;
746 struct ltt_kernel_channel *channel;
747
748 DBG("Updating kernel poll set");
749
750 session_lock_list();
751 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
752 session_lock(session);
753 if (session->kernel_session == NULL) {
754 session_unlock(session);
755 continue;
756 }
757
758 cds_list_for_each_entry(channel,
759 &session->kernel_session->channel_list.head, list) {
760 /* Add channel fd to the kernel poll set */
761 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
762 if (ret < 0) {
763 session_unlock(session);
764 goto error;
765 }
766 DBG("Channel fd %d added to kernel set", channel->fd);
767 }
768 session_unlock(session);
769 }
770 session_unlock_list();
771
772 return 0;
773
774 error:
775 session_unlock_list();
776 return -1;
777 }
778
779 /*
780 * Find the channel fd from 'fd' over all tracing session. When found, check
781 * for new channel stream and send those stream fds to the kernel consumer.
782 *
783 * Useful for CPU hotplug feature.
784 */
785 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
786 {
787 int ret = 0;
788 struct ltt_session *session;
789 struct ltt_kernel_channel *channel;
790
791 DBG("Updating kernel streams for channel fd %d", fd);
792
793 session_lock_list();
794 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
795 session_lock(session);
796 if (session->kernel_session == NULL) {
797 session_unlock(session);
798 continue;
799 }
800
801 /* This is not suppose to be -1 but this is an extra security check */
802 if (session->kernel_session->consumer_fd < 0) {
803 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
804 }
805
806 cds_list_for_each_entry(channel,
807 &session->kernel_session->channel_list.head, list) {
808 if (channel->fd == fd) {
809 DBG("Channel found, updating kernel streams");
810 ret = kernel_open_channel_stream(channel);
811 if (ret < 0) {
812 goto error;
813 }
814
815 /*
816 * Have we already sent fds to the consumer? If yes, it means
817 * that tracing is started so it is safe to send our updated
818 * stream fds.
819 */
820 if (session->kernel_session->consumer_fds_sent == 1) {
821 ret = send_kconsumer_channel_streams(consumer_data,
822 session->kernel_session->consumer_fd, channel,
823 session->uid, session->gid);
824 if (ret < 0) {
825 goto error;
826 }
827 }
828 goto error;
829 }
830 }
831 session_unlock(session);
832 }
833 session_unlock_list();
834 return ret;
835
836 error:
837 session_unlock(session);
838 session_unlock_list();
839 return ret;
840 }
841
842 /*
843 * For each tracing session, update newly registered apps.
844 */
845 static void update_ust_app(int app_sock)
846 {
847 struct ltt_session *sess, *stmp;
848
849 session_lock_list();
850
851 /* For all tracing session(s) */
852 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
853 session_lock(sess);
854 if (sess->ust_session) {
855 ust_app_global_update(sess->ust_session, app_sock);
856 }
857 session_unlock(sess);
858 }
859
860 session_unlock_list();
861 }
862
863 /*
864 * This thread manage event coming from the kernel.
865 *
866 * Features supported in this thread:
867 * -) CPU Hotplug
868 */
869 static void *thread_manage_kernel(void *data)
870 {
871 int ret, i, pollfd, update_poll_flag = 1;
872 uint32_t revents, nb_fd;
873 char tmp;
874 struct lttng_poll_event events;
875
876 DBG("Thread manage kernel started");
877
878 ret = create_thread_poll_set(&events, 2);
879 if (ret < 0) {
880 goto error_poll_create;
881 }
882
883 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
884 if (ret < 0) {
885 goto error;
886 }
887
888 while (1) {
889 if (update_poll_flag == 1) {
890 /*
891 * Reset number of fd in the poll set. Always 2 since there is the thread
892 * quit pipe and the kernel pipe.
893 */
894 events.nb_fd = 2;
895
896 ret = update_kernel_poll(&events);
897 if (ret < 0) {
898 goto error;
899 }
900 update_poll_flag = 0;
901 }
902
903 nb_fd = LTTNG_POLL_GETNB(&events);
904
905 DBG("Thread kernel polling on %d fds", nb_fd);
906
907 /* Zeroed the poll events */
908 lttng_poll_reset(&events);
909
910 /* Poll infinite value of time */
911 restart:
912 ret = lttng_poll_wait(&events, -1);
913 if (ret < 0) {
914 /*
915 * Restart interrupted system call.
916 */
917 if (errno == EINTR) {
918 goto restart;
919 }
920 goto error;
921 } else if (ret == 0) {
922 /* Should not happen since timeout is infinite */
923 ERR("Return value of poll is 0 with an infinite timeout.\n"
924 "This should not have happened! Continuing...");
925 continue;
926 }
927
928 for (i = 0; i < nb_fd; i++) {
929 /* Fetch once the poll data */
930 revents = LTTNG_POLL_GETEV(&events, i);
931 pollfd = LTTNG_POLL_GETFD(&events, i);
932
933 /* Thread quit pipe has been closed. Killing thread. */
934 ret = check_thread_quit_pipe(pollfd, revents);
935 if (ret) {
936 goto error;
937 }
938
939 /* Check for data on kernel pipe */
940 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
941 ret = read(kernel_poll_pipe[0], &tmp, 1);
942 update_poll_flag = 1;
943 continue;
944 } else {
945 /*
946 * New CPU detected by the kernel. Adding kernel stream to
947 * kernel session and updating the kernel consumer
948 */
949 if (revents & LPOLLIN) {
950 ret = update_kernel_stream(&kconsumer_data, pollfd);
951 if (ret < 0) {
952 continue;
953 }
954 break;
955 /*
956 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
957 * and unregister kernel stream at this point.
958 */
959 }
960 }
961 }
962 }
963
964 error:
965 lttng_poll_clean(&events);
966 error_poll_create:
967 DBG("Kernel thread dying");
968 return NULL;
969 }
970
971 /*
972 * This thread manage the consumer error sent back to the session daemon.
973 */
974 static void *thread_manage_consumer(void *data)
975 {
976 int sock = -1, i, ret, pollfd;
977 uint32_t revents, nb_fd;
978 enum lttcomm_return_code code;
979 struct lttng_poll_event events;
980 struct consumer_data *consumer_data = data;
981
982 DBG("[thread] Manage consumer started");
983
984 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
985 if (ret < 0) {
986 goto error_listen;
987 }
988
989 /*
990 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
991 * Nothing more will be added to this poll set.
992 */
993 ret = create_thread_poll_set(&events, 2);
994 if (ret < 0) {
995 goto error_poll;
996 }
997
998 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
999 if (ret < 0) {
1000 goto error;
1001 }
1002
1003 nb_fd = LTTNG_POLL_GETNB(&events);
1004
1005 /* Inifinite blocking call, waiting for transmission */
1006 restart:
1007 ret = lttng_poll_wait(&events, -1);
1008 if (ret < 0) {
1009 /*
1010 * Restart interrupted system call.
1011 */
1012 if (errno == EINTR) {
1013 goto restart;
1014 }
1015 goto error;
1016 }
1017
1018 for (i = 0; i < nb_fd; i++) {
1019 /* Fetch once the poll data */
1020 revents = LTTNG_POLL_GETEV(&events, i);
1021 pollfd = LTTNG_POLL_GETFD(&events, i);
1022
1023 /* Thread quit pipe has been closed. Killing thread. */
1024 ret = check_thread_quit_pipe(pollfd, revents);
1025 if (ret) {
1026 goto error;
1027 }
1028
1029 /* Event on the registration socket */
1030 if (pollfd == consumer_data->err_sock) {
1031 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1032 ERR("consumer err socket poll error");
1033 goto error;
1034 }
1035 }
1036 }
1037
1038 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
1039 if (sock < 0) {
1040 goto error;
1041 }
1042
1043 DBG2("Receiving code from consumer err_sock");
1044
1045 /* Getting status code from kconsumerd */
1046 ret = lttcomm_recv_unix_sock(sock, &code,
1047 sizeof(enum lttcomm_return_code));
1048 if (ret <= 0) {
1049 goto error;
1050 }
1051
1052 if (code == CONSUMERD_COMMAND_SOCK_READY) {
1053 consumer_data->cmd_sock =
1054 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
1055 if (consumer_data->cmd_sock < 0) {
1056 sem_post(&consumer_data->sem);
1057 PERROR("consumer connect");
1058 goto error;
1059 }
1060 /* Signal condition to tell that the kconsumerd is ready */
1061 sem_post(&consumer_data->sem);
1062 DBG("consumer command socket ready");
1063 } else {
1064 ERR("consumer error when waiting for SOCK_READY : %s",
1065 lttcomm_get_readable_code(-code));
1066 goto error;
1067 }
1068
1069 /* Remove the kconsumerd error sock since we've established a connexion */
1070 ret = lttng_poll_del(&events, consumer_data->err_sock);
1071 if (ret < 0) {
1072 goto error;
1073 }
1074
1075 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
1076 if (ret < 0) {
1077 goto error;
1078 }
1079
1080 /* Update number of fd */
1081 nb_fd = LTTNG_POLL_GETNB(&events);
1082
1083 /* Inifinite blocking call, waiting for transmission */
1084 restart_poll:
1085 ret = lttng_poll_wait(&events, -1);
1086 if (ret < 0) {
1087 /*
1088 * Restart interrupted system call.
1089 */
1090 if (errno == EINTR) {
1091 goto restart_poll;
1092 }
1093 goto error;
1094 }
1095
1096 for (i = 0; i < nb_fd; i++) {
1097 /* Fetch once the poll data */
1098 revents = LTTNG_POLL_GETEV(&events, i);
1099 pollfd = LTTNG_POLL_GETFD(&events, i);
1100
1101 /* Thread quit pipe has been closed. Killing thread. */
1102 ret = check_thread_quit_pipe(pollfd, revents);
1103 if (ret) {
1104 goto error;
1105 }
1106
1107 /* Event on the kconsumerd socket */
1108 if (pollfd == sock) {
1109 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1110 ERR("consumer err socket second poll error");
1111 goto error;
1112 }
1113 }
1114 }
1115
1116 /* Wait for any kconsumerd error */
1117 ret = lttcomm_recv_unix_sock(sock, &code,
1118 sizeof(enum lttcomm_return_code));
1119 if (ret <= 0) {
1120 ERR("consumer closed the command socket");
1121 goto error;
1122 }
1123
1124 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
1125
1126 error:
1127 /* Immediately set the consumerd state to stopped */
1128 if (consumer_data->type == LTTNG_CONSUMER_KERNEL) {
1129 uatomic_set(&kernel_consumerd_state, CONSUMER_ERROR);
1130 } else if (consumer_data->type == LTTNG_CONSUMER64_UST ||
1131 consumer_data->type == LTTNG_CONSUMER32_UST) {
1132 uatomic_set(&ust_consumerd_state, CONSUMER_ERROR);
1133 } else {
1134 /* Code flow error... */
1135 assert(0);
1136 }
1137
1138 if (consumer_data->err_sock >= 0) {
1139 ret = close(consumer_data->err_sock);
1140 if (ret) {
1141 PERROR("close");
1142 }
1143 }
1144 if (consumer_data->cmd_sock >= 0) {
1145 ret = close(consumer_data->cmd_sock);
1146 if (ret) {
1147 PERROR("close");
1148 }
1149 }
1150 if (sock >= 0) {
1151 ret = close(sock);
1152 if (ret) {
1153 PERROR("close");
1154 }
1155 }
1156
1157 unlink(consumer_data->err_unix_sock_path);
1158 unlink(consumer_data->cmd_unix_sock_path);
1159 consumer_data->pid = 0;
1160
1161 lttng_poll_clean(&events);
1162 error_poll:
1163 error_listen:
1164 DBG("consumer thread cleanup completed");
1165
1166 return NULL;
1167 }
1168
1169 /*
1170 * This thread manage application communication.
1171 */
1172 static void *thread_manage_apps(void *data)
1173 {
1174 int i, ret, pollfd;
1175 uint32_t revents, nb_fd;
1176 struct ust_command ust_cmd;
1177 struct lttng_poll_event events;
1178
1179 DBG("[thread] Manage application started");
1180
1181 rcu_register_thread();
1182 rcu_thread_online();
1183
1184 ret = create_thread_poll_set(&events, 2);
1185 if (ret < 0) {
1186 goto error_poll_create;
1187 }
1188
1189 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1190 if (ret < 0) {
1191 goto error;
1192 }
1193
1194 while (1) {
1195 /* Zeroed the events structure */
1196 lttng_poll_reset(&events);
1197
1198 nb_fd = LTTNG_POLL_GETNB(&events);
1199
1200 DBG("Apps thread polling on %d fds", nb_fd);
1201
1202 /* Inifinite blocking call, waiting for transmission */
1203 restart:
1204 ret = lttng_poll_wait(&events, -1);
1205 if (ret < 0) {
1206 /*
1207 * Restart interrupted system call.
1208 */
1209 if (errno == EINTR) {
1210 goto restart;
1211 }
1212 goto error;
1213 }
1214
1215 for (i = 0; i < nb_fd; i++) {
1216 /* Fetch once the poll data */
1217 revents = LTTNG_POLL_GETEV(&events, i);
1218 pollfd = LTTNG_POLL_GETFD(&events, i);
1219
1220 /* Thread quit pipe has been closed. Killing thread. */
1221 ret = check_thread_quit_pipe(pollfd, revents);
1222 if (ret) {
1223 goto error;
1224 }
1225
1226 /* Inspect the apps cmd pipe */
1227 if (pollfd == apps_cmd_pipe[0]) {
1228 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1229 ERR("Apps command pipe error");
1230 goto error;
1231 } else if (revents & LPOLLIN) {
1232 /* Empty pipe */
1233 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1234 if (ret < 0 || ret < sizeof(ust_cmd)) {
1235 PERROR("read apps cmd pipe");
1236 goto error;
1237 }
1238
1239 /* Register applicaton to the session daemon */
1240 ret = ust_app_register(&ust_cmd.reg_msg,
1241 ust_cmd.sock);
1242 if (ret == -ENOMEM) {
1243 goto error;
1244 } else if (ret < 0) {
1245 break;
1246 }
1247
1248 /*
1249 * Validate UST version compatibility.
1250 */
1251 ret = ust_app_validate_version(ust_cmd.sock);
1252 if (ret >= 0) {
1253 /*
1254 * Add channel(s) and event(s) to newly registered apps
1255 * from lttng global UST domain.
1256 */
1257 update_ust_app(ust_cmd.sock);
1258 }
1259
1260 ret = ust_app_register_done(ust_cmd.sock);
1261 if (ret < 0) {
1262 /*
1263 * If the registration is not possible, we simply
1264 * unregister the apps and continue
1265 */
1266 ust_app_unregister(ust_cmd.sock);
1267 } else {
1268 /*
1269 * We just need here to monitor the close of the UST
1270 * socket and poll set monitor those by default.
1271 * Listen on POLLIN (even if we never expect any
1272 * data) to ensure that hangup wakes us.
1273 */
1274 ret = lttng_poll_add(&events, ust_cmd.sock, LPOLLIN);
1275 if (ret < 0) {
1276 goto error;
1277 }
1278
1279 DBG("Apps with sock %d added to poll set",
1280 ust_cmd.sock);
1281 }
1282
1283 break;
1284 }
1285 } else {
1286 /*
1287 * At this point, we know that a registered application made
1288 * the event at poll_wait.
1289 */
1290 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1291 /* Removing from the poll set */
1292 ret = lttng_poll_del(&events, pollfd);
1293 if (ret < 0) {
1294 goto error;
1295 }
1296
1297 /* Socket closed on remote end. */
1298 ust_app_unregister(pollfd);
1299 break;
1300 }
1301 }
1302 }
1303 }
1304
1305 error:
1306 lttng_poll_clean(&events);
1307 error_poll_create:
1308 DBG("Application communication apps thread cleanup complete");
1309 rcu_thread_offline();
1310 rcu_unregister_thread();
1311 return NULL;
1312 }
1313
1314 /*
1315 * Dispatch request from the registration threads to the application
1316 * communication thread.
1317 */
1318 static void *thread_dispatch_ust_registration(void *data)
1319 {
1320 int ret;
1321 struct cds_wfq_node *node;
1322 struct ust_command *ust_cmd = NULL;
1323
1324 DBG("[thread] Dispatch UST command started");
1325
1326 while (!dispatch_thread_exit) {
1327 /* Atomically prepare the queue futex */
1328 futex_nto1_prepare(&ust_cmd_queue.futex);
1329
1330 do {
1331 /* Dequeue command for registration */
1332 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1333 if (node == NULL) {
1334 DBG("Woken up but nothing in the UST command queue");
1335 /* Continue thread execution */
1336 break;
1337 }
1338
1339 ust_cmd = caa_container_of(node, struct ust_command, node);
1340
1341 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1342 " gid:%d sock:%d name:%s (version %d.%d)",
1343 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1344 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1345 ust_cmd->sock, ust_cmd->reg_msg.name,
1346 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1347 /*
1348 * Inform apps thread of the new application registration. This
1349 * call is blocking so we can be assured that the data will be read
1350 * at some point in time or wait to the end of the world :)
1351 */
1352 ret = write(apps_cmd_pipe[1], ust_cmd,
1353 sizeof(struct ust_command));
1354 if (ret < 0) {
1355 PERROR("write apps cmd pipe");
1356 if (errno == EBADF) {
1357 /*
1358 * We can't inform the application thread to process
1359 * registration. We will exit or else application
1360 * registration will not occur and tracing will never
1361 * start.
1362 */
1363 goto error;
1364 }
1365 }
1366 free(ust_cmd);
1367 } while (node != NULL);
1368
1369 /* Futex wait on queue. Blocking call on futex() */
1370 futex_nto1_wait(&ust_cmd_queue.futex);
1371 }
1372
1373 error:
1374 DBG("Dispatch thread dying");
1375 return NULL;
1376 }
1377
1378 /*
1379 * This thread manage application registration.
1380 */
1381 static void *thread_registration_apps(void *data)
1382 {
1383 int sock = -1, i, ret, pollfd;
1384 uint32_t revents, nb_fd;
1385 struct lttng_poll_event events;
1386 /*
1387 * Get allocated in this thread, enqueued to a global queue, dequeued and
1388 * freed in the manage apps thread.
1389 */
1390 struct ust_command *ust_cmd = NULL;
1391
1392 DBG("[thread] Manage application registration started");
1393
1394 ret = lttcomm_listen_unix_sock(apps_sock);
1395 if (ret < 0) {
1396 goto error_listen;
1397 }
1398
1399 /*
1400 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1401 * more will be added to this poll set.
1402 */
1403 ret = create_thread_poll_set(&events, 2);
1404 if (ret < 0) {
1405 goto error_create_poll;
1406 }
1407
1408 /* Add the application registration socket */
1409 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1410 if (ret < 0) {
1411 goto error_poll_add;
1412 }
1413
1414 /* Notify all applications to register */
1415 ret = notify_ust_apps(1);
1416 if (ret < 0) {
1417 ERR("Failed to notify applications or create the wait shared memory.\n"
1418 "Execution continues but there might be problem for already\n"
1419 "running applications that wishes to register.");
1420 }
1421
1422 while (1) {
1423 DBG("Accepting application registration");
1424
1425 nb_fd = LTTNG_POLL_GETNB(&events);
1426
1427 /* Inifinite blocking call, waiting for transmission */
1428 restart:
1429 ret = lttng_poll_wait(&events, -1);
1430 if (ret < 0) {
1431 /*
1432 * Restart interrupted system call.
1433 */
1434 if (errno == EINTR) {
1435 goto restart;
1436 }
1437 goto error;
1438 }
1439
1440 for (i = 0; i < nb_fd; i++) {
1441 /* Fetch once the poll data */
1442 revents = LTTNG_POLL_GETEV(&events, i);
1443 pollfd = LTTNG_POLL_GETFD(&events, i);
1444
1445 /* Thread quit pipe has been closed. Killing thread. */
1446 ret = check_thread_quit_pipe(pollfd, revents);
1447 if (ret) {
1448 goto error;
1449 }
1450
1451 /* Event on the registration socket */
1452 if (pollfd == apps_sock) {
1453 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1454 ERR("Register apps socket poll error");
1455 goto error;
1456 } else if (revents & LPOLLIN) {
1457 sock = lttcomm_accept_unix_sock(apps_sock);
1458 if (sock < 0) {
1459 goto error;
1460 }
1461
1462 /* Create UST registration command for enqueuing */
1463 ust_cmd = zmalloc(sizeof(struct ust_command));
1464 if (ust_cmd == NULL) {
1465 PERROR("ust command zmalloc");
1466 goto error;
1467 }
1468
1469 /*
1470 * Using message-based transmissions to ensure we don't
1471 * have to deal with partially received messages.
1472 */
1473 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
1474 if (ret < 0) {
1475 ERR("Exhausted file descriptors allowed for applications.");
1476 free(ust_cmd);
1477 ret = close(sock);
1478 if (ret) {
1479 PERROR("close");
1480 }
1481 sock = -1;
1482 continue;
1483 }
1484 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1485 sizeof(struct ust_register_msg));
1486 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1487 if (ret < 0) {
1488 PERROR("lttcomm_recv_unix_sock register apps");
1489 } else {
1490 ERR("Wrong size received on apps register");
1491 }
1492 free(ust_cmd);
1493 ret = close(sock);
1494 if (ret) {
1495 PERROR("close");
1496 }
1497 lttng_fd_put(LTTNG_FD_APPS, 1);
1498 sock = -1;
1499 continue;
1500 }
1501
1502 ust_cmd->sock = sock;
1503 sock = -1;
1504
1505 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1506 " gid:%d sock:%d name:%s (version %d.%d)",
1507 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1508 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1509 ust_cmd->sock, ust_cmd->reg_msg.name,
1510 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1511
1512 /*
1513 * Lock free enqueue the registration request. The red pill
1514 * has been taken! This apps will be part of the *system*.
1515 */
1516 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1517
1518 /*
1519 * Wake the registration queue futex. Implicit memory
1520 * barrier with the exchange in cds_wfq_enqueue.
1521 */
1522 futex_nto1_wake(&ust_cmd_queue.futex);
1523 }
1524 }
1525 }
1526 }
1527
1528 error:
1529 /* Notify that the registration thread is gone */
1530 notify_ust_apps(0);
1531
1532 if (apps_sock >= 0) {
1533 ret = close(apps_sock);
1534 if (ret) {
1535 PERROR("close");
1536 }
1537 }
1538 if (sock >= 0) {
1539 ret = close(sock);
1540 if (ret) {
1541 PERROR("close");
1542 }
1543 lttng_fd_put(LTTNG_FD_APPS, 1);
1544 }
1545 unlink(apps_unix_sock_path);
1546
1547 error_poll_add:
1548 lttng_poll_clean(&events);
1549 error_listen:
1550 error_create_poll:
1551 DBG("UST Registration thread cleanup complete");
1552
1553 return NULL;
1554 }
1555
1556 /*
1557 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1558 * exec or it will fails.
1559 */
1560 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1561 {
1562 int ret;
1563 struct timespec timeout;
1564
1565 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1566 timeout.tv_nsec = 0;
1567
1568 /* Setup semaphore */
1569 ret = sem_init(&consumer_data->sem, 0, 0);
1570 if (ret < 0) {
1571 PERROR("sem_init consumer semaphore");
1572 goto error;
1573 }
1574
1575 ret = pthread_create(&consumer_data->thread, NULL,
1576 thread_manage_consumer, consumer_data);
1577 if (ret != 0) {
1578 PERROR("pthread_create consumer");
1579 ret = -1;
1580 goto error;
1581 }
1582
1583 /* Get time for sem_timedwait absolute timeout */
1584 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1585 if (ret < 0) {
1586 PERROR("clock_gettime spawn consumer");
1587 /* Infinite wait for the kconsumerd thread to be ready */
1588 ret = sem_wait(&consumer_data->sem);
1589 } else {
1590 /* Normal timeout if the gettime was successful */
1591 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1592 ret = sem_timedwait(&consumer_data->sem, &timeout);
1593 }
1594
1595 if (ret < 0) {
1596 if (errno == ETIMEDOUT) {
1597 /*
1598 * Call has timed out so we kill the kconsumerd_thread and return
1599 * an error.
1600 */
1601 ERR("The consumer thread was never ready. Killing it");
1602 ret = pthread_cancel(consumer_data->thread);
1603 if (ret < 0) {
1604 PERROR("pthread_cancel consumer thread");
1605 }
1606 } else {
1607 PERROR("semaphore wait failed consumer thread");
1608 }
1609 goto error;
1610 }
1611
1612 pthread_mutex_lock(&consumer_data->pid_mutex);
1613 if (consumer_data->pid == 0) {
1614 ERR("Kconsumerd did not start");
1615 pthread_mutex_unlock(&consumer_data->pid_mutex);
1616 goto error;
1617 }
1618 pthread_mutex_unlock(&consumer_data->pid_mutex);
1619
1620 return 0;
1621
1622 error:
1623 return ret;
1624 }
1625
1626 /*
1627 * Join consumer thread
1628 */
1629 static int join_consumer_thread(struct consumer_data *consumer_data)
1630 {
1631 void *status;
1632 int ret;
1633
1634 if (consumer_data->pid != 0) {
1635 ret = kill(consumer_data->pid, SIGTERM);
1636 if (ret) {
1637 ERR("Error killing consumer daemon");
1638 return ret;
1639 }
1640 return pthread_join(consumer_data->thread, &status);
1641 } else {
1642 return 0;
1643 }
1644 }
1645
1646 /*
1647 * Fork and exec a consumer daemon (consumerd).
1648 *
1649 * Return pid if successful else -1.
1650 */
1651 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1652 {
1653 int ret;
1654 pid_t pid;
1655 const char *consumer_to_use;
1656 const char *verbosity;
1657 struct stat st;
1658
1659 DBG("Spawning consumerd");
1660
1661 pid = fork();
1662 if (pid == 0) {
1663 /*
1664 * Exec consumerd.
1665 */
1666 if (opt_verbose_consumer) {
1667 verbosity = "--verbose";
1668 } else {
1669 verbosity = "--quiet";
1670 }
1671 switch (consumer_data->type) {
1672 case LTTNG_CONSUMER_KERNEL:
1673 /*
1674 * Find out which consumerd to execute. We will first try the
1675 * 64-bit path, then the sessiond's installation directory, and
1676 * fallback on the 32-bit one,
1677 */
1678 DBG3("Looking for a kernel consumer at these locations:");
1679 DBG3(" 1) %s", consumerd64_bin);
1680 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, CONSUMERD_FILE);
1681 DBG3(" 3) %s", consumerd32_bin);
1682 if (stat(consumerd64_bin, &st) == 0) {
1683 DBG3("Found location #1");
1684 consumer_to_use = consumerd64_bin;
1685 } else if (stat(INSTALL_BIN_PATH "/" CONSUMERD_FILE, &st) == 0) {
1686 DBG3("Found location #2");
1687 consumer_to_use = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
1688 } else if (stat(consumerd32_bin, &st) == 0) {
1689 DBG3("Found location #3");
1690 consumer_to_use = consumerd32_bin;
1691 } else {
1692 DBG("Could not find any valid consumerd executable");
1693 break;
1694 }
1695 DBG("Using kernel consumer at: %s", consumer_to_use);
1696 execl(consumer_to_use,
1697 "lttng-consumerd", verbosity, "-k",
1698 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1699 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1700 NULL);
1701 break;
1702 case LTTNG_CONSUMER64_UST:
1703 {
1704 char *tmpnew = NULL;
1705
1706 if (consumerd64_libdir[0] != '\0') {
1707 char *tmp;
1708 size_t tmplen;
1709
1710 tmp = getenv("LD_LIBRARY_PATH");
1711 if (!tmp) {
1712 tmp = "";
1713 }
1714 tmplen = strlen("LD_LIBRARY_PATH=")
1715 + strlen(consumerd64_libdir) + 1 /* : */ + strlen(tmp);
1716 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1717 if (!tmpnew) {
1718 ret = -ENOMEM;
1719 goto error;
1720 }
1721 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1722 strcat(tmpnew, consumerd64_libdir);
1723 if (tmp[0] != '\0') {
1724 strcat(tmpnew, ":");
1725 strcat(tmpnew, tmp);
1726 }
1727 ret = putenv(tmpnew);
1728 if (ret) {
1729 ret = -errno;
1730 goto error;
1731 }
1732 }
1733 DBG("Using 64-bit UST consumer at: %s", consumerd64_bin);
1734 ret = execl(consumerd64_bin, "lttng-consumerd", verbosity, "-u",
1735 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1736 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1737 NULL);
1738 if (consumerd64_libdir[0] != '\0') {
1739 free(tmpnew);
1740 }
1741 if (ret) {
1742 goto error;
1743 }
1744 break;
1745 }
1746 case LTTNG_CONSUMER32_UST:
1747 {
1748 char *tmpnew = NULL;
1749
1750 if (consumerd32_libdir[0] != '\0') {
1751 char *tmp;
1752 size_t tmplen;
1753
1754 tmp = getenv("LD_LIBRARY_PATH");
1755 if (!tmp) {
1756 tmp = "";
1757 }
1758 tmplen = strlen("LD_LIBRARY_PATH=")
1759 + strlen(consumerd32_libdir) + 1 /* : */ + strlen(tmp);
1760 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1761 if (!tmpnew) {
1762 ret = -ENOMEM;
1763 goto error;
1764 }
1765 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1766 strcat(tmpnew, consumerd32_libdir);
1767 if (tmp[0] != '\0') {
1768 strcat(tmpnew, ":");
1769 strcat(tmpnew, tmp);
1770 }
1771 ret = putenv(tmpnew);
1772 if (ret) {
1773 ret = -errno;
1774 goto error;
1775 }
1776 }
1777 DBG("Using 32-bit UST consumer at: %s", consumerd32_bin);
1778 ret = execl(consumerd32_bin, "lttng-consumerd", verbosity, "-u",
1779 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1780 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1781 NULL);
1782 if (consumerd32_libdir[0] != '\0') {
1783 free(tmpnew);
1784 }
1785 if (ret) {
1786 goto error;
1787 }
1788 break;
1789 }
1790 default:
1791 PERROR("unknown consumer type");
1792 exit(EXIT_FAILURE);
1793 }
1794 if (errno != 0) {
1795 PERROR("kernel start consumer exec");
1796 }
1797 exit(EXIT_FAILURE);
1798 } else if (pid > 0) {
1799 ret = pid;
1800 } else {
1801 PERROR("start consumer fork");
1802 ret = -errno;
1803 }
1804 error:
1805 return ret;
1806 }
1807
1808 /*
1809 * Spawn the consumerd daemon and session daemon thread.
1810 */
1811 static int start_consumerd(struct consumer_data *consumer_data)
1812 {
1813 int ret;
1814
1815 pthread_mutex_lock(&consumer_data->pid_mutex);
1816 if (consumer_data->pid != 0) {
1817 pthread_mutex_unlock(&consumer_data->pid_mutex);
1818 goto end;
1819 }
1820
1821 ret = spawn_consumerd(consumer_data);
1822 if (ret < 0) {
1823 ERR("Spawning consumerd failed");
1824 pthread_mutex_unlock(&consumer_data->pid_mutex);
1825 goto error;
1826 }
1827
1828 /* Setting up the consumer_data pid */
1829 consumer_data->pid = ret;
1830 DBG2("Consumer pid %d", consumer_data->pid);
1831 pthread_mutex_unlock(&consumer_data->pid_mutex);
1832
1833 DBG2("Spawning consumer control thread");
1834 ret = spawn_consumer_thread(consumer_data);
1835 if (ret < 0) {
1836 ERR("Fatal error spawning consumer control thread");
1837 goto error;
1838 }
1839
1840 end:
1841 return 0;
1842
1843 error:
1844 return ret;
1845 }
1846
1847 /*
1848 * Check version of the lttng-modules.
1849 */
1850 static int validate_lttng_modules_version(void)
1851 {
1852 return kernel_validate_version(kernel_tracer_fd);
1853 }
1854
1855 /*
1856 * Setup necessary data for kernel tracer action.
1857 */
1858 static int init_kernel_tracer(void)
1859 {
1860 int ret;
1861
1862 /* Modprobe lttng kernel modules */
1863 ret = modprobe_lttng_control();
1864 if (ret < 0) {
1865 goto error;
1866 }
1867
1868 /* Open debugfs lttng */
1869 kernel_tracer_fd = open(module_proc_lttng, O_RDWR);
1870 if (kernel_tracer_fd < 0) {
1871 DBG("Failed to open %s", module_proc_lttng);
1872 ret = -1;
1873 goto error_open;
1874 }
1875
1876 /* Validate kernel version */
1877 ret = validate_lttng_modules_version();
1878 if (ret < 0) {
1879 goto error_version;
1880 }
1881
1882 ret = modprobe_lttng_data();
1883 if (ret < 0) {
1884 goto error_modules;
1885 }
1886
1887 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1888 return 0;
1889
1890 error_version:
1891 modprobe_remove_lttng_control();
1892 ret = close(kernel_tracer_fd);
1893 if (ret) {
1894 PERROR("close");
1895 }
1896 kernel_tracer_fd = -1;
1897 return LTTCOMM_KERN_VERSION;
1898
1899 error_modules:
1900 ret = close(kernel_tracer_fd);
1901 if (ret) {
1902 PERROR("close");
1903 }
1904
1905 error_open:
1906 modprobe_remove_lttng_control();
1907
1908 error:
1909 WARN("No kernel tracer available");
1910 kernel_tracer_fd = -1;
1911 if (!is_root) {
1912 return LTTCOMM_NEED_ROOT_SESSIOND;
1913 } else {
1914 return LTTCOMM_KERN_NA;
1915 }
1916 }
1917
1918 /*
1919 * Init tracing by creating trace directory and sending fds kernel consumer.
1920 */
1921 static int init_kernel_tracing(struct ltt_kernel_session *session)
1922 {
1923 int ret = 0;
1924
1925 if (session->consumer_fds_sent == 0) {
1926 /*
1927 * Assign default kernel consumer socket if no consumer assigned to the
1928 * kernel session. At this point, it's NOT supposed to be -1 but this is
1929 * an extra security check.
1930 */
1931 if (session->consumer_fd < 0) {
1932 session->consumer_fd = kconsumer_data.cmd_sock;
1933 }
1934
1935 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1936 if (ret < 0) {
1937 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1938 goto error;
1939 }
1940
1941 session->consumer_fds_sent = 1;
1942 }
1943
1944 error:
1945 return ret;
1946 }
1947
1948 /*
1949 * Create an UST session and add it to the session ust list.
1950 */
1951 static int create_ust_session(struct ltt_session *session,
1952 struct lttng_domain *domain)
1953 {
1954 struct ltt_ust_session *lus = NULL;
1955 int ret;
1956
1957 switch (domain->type) {
1958 case LTTNG_DOMAIN_UST:
1959 break;
1960 default:
1961 ret = LTTCOMM_UNKNOWN_DOMAIN;
1962 goto error;
1963 }
1964
1965 DBG("Creating UST session");
1966
1967 lus = trace_ust_create_session(session->path, session->id, domain);
1968 if (lus == NULL) {
1969 ret = LTTCOMM_UST_SESS_FAIL;
1970 goto error;
1971 }
1972
1973 ret = run_as_mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1974 session->uid, session->gid);
1975 if (ret < 0) {
1976 if (ret != -EEXIST) {
1977 ERR("Trace directory creation error");
1978 ret = LTTCOMM_UST_SESS_FAIL;
1979 goto error;
1980 }
1981 }
1982
1983 /* The domain type dictate different actions on session creation */
1984 switch (domain->type) {
1985 case LTTNG_DOMAIN_UST:
1986 /* No ustctl for the global UST domain */
1987 break;
1988 default:
1989 ERR("Unknown UST domain on create session %d", domain->type);
1990 goto error;
1991 }
1992 lus->uid = session->uid;
1993 lus->gid = session->gid;
1994 session->ust_session = lus;
1995
1996 return LTTCOMM_OK;
1997
1998 error:
1999 free(lus);
2000 return ret;
2001 }
2002
2003 /*
2004 * Create a kernel tracer session then create the default channel.
2005 */
2006 static int create_kernel_session(struct ltt_session *session)
2007 {
2008 int ret;
2009
2010 DBG("Creating kernel session");
2011
2012 ret = kernel_create_session(session, kernel_tracer_fd);
2013 if (ret < 0) {
2014 ret = LTTCOMM_KERN_SESS_FAIL;
2015 goto error;
2016 }
2017
2018 /* Set kernel consumer socket fd */
2019 if (kconsumer_data.cmd_sock >= 0) {
2020 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
2021 }
2022
2023 ret = run_as_mkdir_recursive(session->kernel_session->trace_path,
2024 S_IRWXU | S_IRWXG, session->uid, session->gid);
2025 if (ret < 0) {
2026 if (ret != -EEXIST) {
2027 ERR("Trace directory creation error");
2028 goto error;
2029 }
2030 }
2031 session->kernel_session->uid = session->uid;
2032 session->kernel_session->gid = session->gid;
2033
2034 error:
2035 return ret;
2036 }
2037
2038 /*
2039 * Check if the UID or GID match the session. Root user has access to all
2040 * sessions.
2041 */
2042 static int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
2043 {
2044 if (uid != session->uid && gid != session->gid && uid != 0) {
2045 return 0;
2046 } else {
2047 return 1;
2048 }
2049 }
2050
2051 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
2052 {
2053 unsigned int i = 0;
2054 struct ltt_session *session;
2055
2056 DBG("Counting number of available session for UID %d GID %d",
2057 uid, gid);
2058 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
2059 /*
2060 * Only list the sessions the user can control.
2061 */
2062 if (!session_access_ok(session, uid, gid)) {
2063 continue;
2064 }
2065 i++;
2066 }
2067 return i;
2068 }
2069
2070 /*
2071 * Using the session list, filled a lttng_session array to send back to the
2072 * client for session listing.
2073 *
2074 * The session list lock MUST be acquired before calling this function. Use
2075 * session_lock_list() and session_unlock_list().
2076 */
2077 static void list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2078 gid_t gid)
2079 {
2080 unsigned int i = 0;
2081 struct ltt_session *session;
2082
2083 DBG("Getting all available session for UID %d GID %d",
2084 uid, gid);
2085 /*
2086 * Iterate over session list and append data after the control struct in
2087 * the buffer.
2088 */
2089 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
2090 /*
2091 * Only list the sessions the user can control.
2092 */
2093 if (!session_access_ok(session, uid, gid)) {
2094 continue;
2095 }
2096 strncpy(sessions[i].path, session->path, PATH_MAX);
2097 sessions[i].path[PATH_MAX - 1] = '\0';
2098 strncpy(sessions[i].name, session->name, NAME_MAX);
2099 sessions[i].name[NAME_MAX - 1] = '\0';
2100 sessions[i].enabled = session->enabled;
2101 i++;
2102 }
2103 }
2104
2105 /*
2106 * Fill lttng_channel array of all channels.
2107 */
2108 static void list_lttng_channels(int domain, struct ltt_session *session,
2109 struct lttng_channel *channels)
2110 {
2111 int i = 0;
2112 struct ltt_kernel_channel *kchan;
2113
2114 DBG("Listing channels for session %s", session->name);
2115
2116 switch (domain) {
2117 case LTTNG_DOMAIN_KERNEL:
2118 /* Kernel channels */
2119 if (session->kernel_session != NULL) {
2120 cds_list_for_each_entry(kchan,
2121 &session->kernel_session->channel_list.head, list) {
2122 /* Copy lttng_channel struct to array */
2123 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
2124 channels[i].enabled = kchan->enabled;
2125 i++;
2126 }
2127 }
2128 break;
2129 case LTTNG_DOMAIN_UST:
2130 {
2131 struct lttng_ht_iter iter;
2132 struct ltt_ust_channel *uchan;
2133
2134 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
2135 &iter.iter, uchan, node.node) {
2136 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
2137 channels[i].attr.overwrite = uchan->attr.overwrite;
2138 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
2139 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
2140 channels[i].attr.switch_timer_interval =
2141 uchan->attr.switch_timer_interval;
2142 channels[i].attr.read_timer_interval =
2143 uchan->attr.read_timer_interval;
2144 channels[i].enabled = uchan->enabled;
2145 switch (uchan->attr.output) {
2146 case LTTNG_UST_MMAP:
2147 default:
2148 channels[i].attr.output = LTTNG_EVENT_MMAP;
2149 break;
2150 }
2151 i++;
2152 }
2153 break;
2154 }
2155 default:
2156 break;
2157 }
2158 }
2159
2160 /*
2161 * Create a list of ust global domain events.
2162 */
2163 static int list_lttng_ust_global_events(char *channel_name,
2164 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
2165 {
2166 int i = 0, ret = 0;
2167 unsigned int nb_event = 0;
2168 struct lttng_ht_iter iter;
2169 struct lttng_ht_node_str *node;
2170 struct ltt_ust_channel *uchan;
2171 struct ltt_ust_event *uevent;
2172 struct lttng_event *tmp;
2173
2174 DBG("Listing UST global events for channel %s", channel_name);
2175
2176 rcu_read_lock();
2177
2178 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
2179 node = lttng_ht_iter_get_node_str(&iter);
2180 if (node == NULL) {
2181 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
2182 goto error;
2183 }
2184
2185 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
2186
2187 nb_event += lttng_ht_get_count(uchan->events);
2188
2189 if (nb_event == 0) {
2190 ret = nb_event;
2191 goto error;
2192 }
2193
2194 DBG3("Listing UST global %d events", nb_event);
2195
2196 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
2197 if (tmp == NULL) {
2198 ret = -LTTCOMM_FATAL;
2199 goto error;
2200 }
2201
2202 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
2203 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
2204 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2205 tmp[i].enabled = uevent->enabled;
2206 switch (uevent->attr.instrumentation) {
2207 case LTTNG_UST_TRACEPOINT:
2208 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
2209 break;
2210 case LTTNG_UST_PROBE:
2211 tmp[i].type = LTTNG_EVENT_PROBE;
2212 break;
2213 case LTTNG_UST_FUNCTION:
2214 tmp[i].type = LTTNG_EVENT_FUNCTION;
2215 break;
2216 }
2217 tmp[i].loglevel = uevent->attr.loglevel;
2218 switch (uevent->attr.loglevel_type) {
2219 case LTTNG_UST_LOGLEVEL_ALL:
2220 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2221 break;
2222 case LTTNG_UST_LOGLEVEL_RANGE:
2223 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
2224 break;
2225 case LTTNG_UST_LOGLEVEL_SINGLE:
2226 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
2227 break;
2228 }
2229 i++;
2230 }
2231
2232 ret = nb_event;
2233 *events = tmp;
2234
2235 error:
2236 rcu_read_unlock();
2237 return ret;
2238 }
2239
2240 /*
2241 * Fill lttng_event array of all kernel events in the channel.
2242 */
2243 static int list_lttng_kernel_events(char *channel_name,
2244 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
2245 {
2246 int i = 0, ret;
2247 unsigned int nb_event;
2248 struct ltt_kernel_event *event;
2249 struct ltt_kernel_channel *kchan;
2250
2251 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
2252 if (kchan == NULL) {
2253 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2254 goto error;
2255 }
2256
2257 nb_event = kchan->event_count;
2258
2259 DBG("Listing events for channel %s", kchan->channel->name);
2260
2261 if (nb_event == 0) {
2262 ret = nb_event;
2263 goto error;
2264 }
2265
2266 *events = zmalloc(nb_event * sizeof(struct lttng_event));
2267 if (*events == NULL) {
2268 ret = LTTCOMM_FATAL;
2269 goto error;
2270 }
2271
2272 /* Kernel channels */
2273 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
2274 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
2275 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2276 (*events)[i].enabled = event->enabled;
2277 switch (event->event->instrumentation) {
2278 case LTTNG_KERNEL_TRACEPOINT:
2279 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
2280 break;
2281 case LTTNG_KERNEL_KPROBE:
2282 case LTTNG_KERNEL_KRETPROBE:
2283 (*events)[i].type = LTTNG_EVENT_PROBE;
2284 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
2285 sizeof(struct lttng_kernel_kprobe));
2286 break;
2287 case LTTNG_KERNEL_FUNCTION:
2288 (*events)[i].type = LTTNG_EVENT_FUNCTION;
2289 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
2290 sizeof(struct lttng_kernel_function));
2291 break;
2292 case LTTNG_KERNEL_NOOP:
2293 (*events)[i].type = LTTNG_EVENT_NOOP;
2294 break;
2295 case LTTNG_KERNEL_SYSCALL:
2296 (*events)[i].type = LTTNG_EVENT_SYSCALL;
2297 break;
2298 case LTTNG_KERNEL_ALL:
2299 assert(0);
2300 break;
2301 }
2302 i++;
2303 }
2304
2305 return nb_event;
2306
2307 error:
2308 return ret;
2309 }
2310
2311 /*
2312 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
2313 */
2314 static int cmd_disable_channel(struct ltt_session *session,
2315 int domain, char *channel_name)
2316 {
2317 int ret;
2318 struct ltt_ust_session *usess;
2319
2320 usess = session->ust_session;
2321
2322 switch (domain) {
2323 case LTTNG_DOMAIN_KERNEL:
2324 {
2325 ret = channel_kernel_disable(session->kernel_session,
2326 channel_name);
2327 if (ret != LTTCOMM_OK) {
2328 goto error;
2329 }
2330
2331 kernel_wait_quiescent(kernel_tracer_fd);
2332 break;
2333 }
2334 case LTTNG_DOMAIN_UST:
2335 {
2336 struct ltt_ust_channel *uchan;
2337 struct lttng_ht *chan_ht;
2338
2339 chan_ht = usess->domain_global.channels;
2340
2341 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
2342 if (uchan == NULL) {
2343 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2344 goto error;
2345 }
2346
2347 ret = channel_ust_disable(usess, domain, uchan);
2348 if (ret != LTTCOMM_OK) {
2349 goto error;
2350 }
2351 break;
2352 }
2353 #if 0
2354 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2355 case LTTNG_DOMAIN_UST_EXEC_NAME:
2356 case LTTNG_DOMAIN_UST_PID:
2357 #endif
2358 default:
2359 ret = LTTCOMM_UNKNOWN_DOMAIN;
2360 goto error;
2361 }
2362
2363 ret = LTTCOMM_OK;
2364
2365 error:
2366 return ret;
2367 }
2368
2369 /*
2370 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2371 */
2372 static int cmd_enable_channel(struct ltt_session *session,
2373 int domain, struct lttng_channel *attr)
2374 {
2375 int ret;
2376 struct ltt_ust_session *usess = session->ust_session;
2377 struct lttng_ht *chan_ht;
2378
2379 DBG("Enabling channel %s for session %s", attr->name, session->name);
2380
2381 switch (domain) {
2382 case LTTNG_DOMAIN_KERNEL:
2383 {
2384 struct ltt_kernel_channel *kchan;
2385
2386 kchan = trace_kernel_get_channel_by_name(attr->name,
2387 session->kernel_session);
2388 if (kchan == NULL) {
2389 ret = channel_kernel_create(session->kernel_session,
2390 attr, kernel_poll_pipe[1]);
2391 } else {
2392 ret = channel_kernel_enable(session->kernel_session, kchan);
2393 }
2394
2395 if (ret != LTTCOMM_OK) {
2396 goto error;
2397 }
2398
2399 kernel_wait_quiescent(kernel_tracer_fd);
2400 break;
2401 }
2402 case LTTNG_DOMAIN_UST:
2403 {
2404 struct ltt_ust_channel *uchan;
2405
2406 chan_ht = usess->domain_global.channels;
2407
2408 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
2409 if (uchan == NULL) {
2410 ret = channel_ust_create(usess, domain, attr);
2411 } else {
2412 ret = channel_ust_enable(usess, domain, uchan);
2413 }
2414 break;
2415 }
2416 #if 0
2417 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2418 case LTTNG_DOMAIN_UST_EXEC_NAME:
2419 case LTTNG_DOMAIN_UST_PID:
2420 #endif
2421 default:
2422 ret = LTTCOMM_UNKNOWN_DOMAIN;
2423 goto error;
2424 }
2425
2426 error:
2427 return ret;
2428 }
2429
2430 /*
2431 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2432 */
2433 static int cmd_disable_event(struct ltt_session *session, int domain,
2434 char *channel_name, char *event_name)
2435 {
2436 int ret;
2437
2438 switch (domain) {
2439 case LTTNG_DOMAIN_KERNEL:
2440 {
2441 struct ltt_kernel_channel *kchan;
2442 struct ltt_kernel_session *ksess;
2443
2444 ksess = session->kernel_session;
2445
2446 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2447 if (kchan == NULL) {
2448 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2449 goto error;
2450 }
2451
2452 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
2453 if (ret != LTTCOMM_OK) {
2454 goto error;
2455 }
2456
2457 kernel_wait_quiescent(kernel_tracer_fd);
2458 break;
2459 }
2460 case LTTNG_DOMAIN_UST:
2461 {
2462 struct ltt_ust_channel *uchan;
2463 struct ltt_ust_session *usess;
2464
2465 usess = session->ust_session;
2466
2467 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2468 channel_name);
2469 if (uchan == NULL) {
2470 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2471 goto error;
2472 }
2473
2474 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
2475 if (ret != LTTCOMM_OK) {
2476 goto error;
2477 }
2478
2479 DBG3("Disable UST event %s in channel %s completed", event_name,
2480 channel_name);
2481 break;
2482 }
2483 #if 0
2484 case LTTNG_DOMAIN_UST_EXEC_NAME:
2485 case LTTNG_DOMAIN_UST_PID:
2486 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2487 #endif
2488 default:
2489 ret = LTTCOMM_UND;
2490 goto error;
2491 }
2492
2493 ret = LTTCOMM_OK;
2494
2495 error:
2496 return ret;
2497 }
2498
2499 /*
2500 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2501 */
2502 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2503 char *channel_name)
2504 {
2505 int ret;
2506
2507 switch (domain) {
2508 case LTTNG_DOMAIN_KERNEL:
2509 {
2510 struct ltt_kernel_session *ksess;
2511 struct ltt_kernel_channel *kchan;
2512
2513 ksess = session->kernel_session;
2514
2515 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2516 if (kchan == NULL) {
2517 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2518 goto error;
2519 }
2520
2521 ret = event_kernel_disable_all(ksess, kchan);
2522 if (ret != LTTCOMM_OK) {
2523 goto error;
2524 }
2525
2526 kernel_wait_quiescent(kernel_tracer_fd);
2527 break;
2528 }
2529 case LTTNG_DOMAIN_UST:
2530 {
2531 struct ltt_ust_session *usess;
2532 struct ltt_ust_channel *uchan;
2533
2534 usess = session->ust_session;
2535
2536 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2537 channel_name);
2538 if (uchan == NULL) {
2539 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2540 goto error;
2541 }
2542
2543 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
2544 if (ret != 0) {
2545 goto error;
2546 }
2547
2548 DBG3("Disable all UST events in channel %s completed", channel_name);
2549
2550 break;
2551 }
2552 #if 0
2553 case LTTNG_DOMAIN_UST_EXEC_NAME:
2554 case LTTNG_DOMAIN_UST_PID:
2555 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2556 #endif
2557 default:
2558 ret = LTTCOMM_UND;
2559 goto error;
2560 }
2561
2562 ret = LTTCOMM_OK;
2563
2564 error:
2565 return ret;
2566 }
2567
2568 /*
2569 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2570 */
2571 static int cmd_add_context(struct ltt_session *session, int domain,
2572 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2573 {
2574 int ret;
2575
2576 switch (domain) {
2577 case LTTNG_DOMAIN_KERNEL:
2578 /* Add kernel context to kernel tracer */
2579 ret = context_kernel_add(session->kernel_session, ctx,
2580 event_name, channel_name);
2581 if (ret != LTTCOMM_OK) {
2582 goto error;
2583 }
2584 break;
2585 case LTTNG_DOMAIN_UST:
2586 {
2587 struct ltt_ust_session *usess = session->ust_session;
2588
2589 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
2590 if (ret != LTTCOMM_OK) {
2591 goto error;
2592 }
2593 break;
2594 }
2595 #if 0
2596 case LTTNG_DOMAIN_UST_EXEC_NAME:
2597 case LTTNG_DOMAIN_UST_PID:
2598 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2599 #endif
2600 default:
2601 ret = LTTCOMM_UND;
2602 goto error;
2603 }
2604
2605 ret = LTTCOMM_OK;
2606
2607 error:
2608 return ret;
2609 }
2610
2611 /*
2612 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2613 */
2614 static int cmd_enable_event(struct ltt_session *session, int domain,
2615 char *channel_name, struct lttng_event *event)
2616 {
2617 int ret;
2618 struct lttng_channel *attr;
2619 struct ltt_ust_session *usess = session->ust_session;
2620
2621 switch (domain) {
2622 case LTTNG_DOMAIN_KERNEL:
2623 {
2624 struct ltt_kernel_channel *kchan;
2625
2626 kchan = trace_kernel_get_channel_by_name(channel_name,
2627 session->kernel_session);
2628 if (kchan == NULL) {
2629 attr = channel_new_default_attr(domain);
2630 if (attr == NULL) {
2631 ret = LTTCOMM_FATAL;
2632 goto error;
2633 }
2634 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2635
2636 /* This call will notify the kernel thread */
2637 ret = channel_kernel_create(session->kernel_session,
2638 attr, kernel_poll_pipe[1]);
2639 if (ret != LTTCOMM_OK) {
2640 free(attr);
2641 goto error;
2642 }
2643 free(attr);
2644 }
2645
2646 /* Get the newly created kernel channel pointer */
2647 kchan = trace_kernel_get_channel_by_name(channel_name,
2648 session->kernel_session);
2649 if (kchan == NULL) {
2650 /* This sould not happen... */
2651 ret = LTTCOMM_FATAL;
2652 goto error;
2653 }
2654
2655 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2656 event);
2657 if (ret != LTTCOMM_OK) {
2658 goto error;
2659 }
2660
2661 kernel_wait_quiescent(kernel_tracer_fd);
2662 break;
2663 }
2664 case LTTNG_DOMAIN_UST:
2665 {
2666 struct lttng_channel *attr;
2667 struct ltt_ust_channel *uchan;
2668
2669 /* Get channel from global UST domain */
2670 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2671 channel_name);
2672 if (uchan == NULL) {
2673 /* Create default channel */
2674 attr = channel_new_default_attr(domain);
2675 if (attr == NULL) {
2676 ret = LTTCOMM_FATAL;
2677 goto error;
2678 }
2679 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2680 attr->name[NAME_MAX - 1] = '\0';
2681
2682 ret = channel_ust_create(usess, domain, attr);
2683 if (ret != LTTCOMM_OK) {
2684 free(attr);
2685 goto error;
2686 }
2687 free(attr);
2688
2689 /* Get the newly created channel reference back */
2690 uchan = trace_ust_find_channel_by_name(
2691 usess->domain_global.channels, channel_name);
2692 if (uchan == NULL) {
2693 /* Something is really wrong */
2694 ret = LTTCOMM_FATAL;
2695 goto error;
2696 }
2697 }
2698
2699 /* At this point, the session and channel exist on the tracer */
2700 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
2701 if (ret != LTTCOMM_OK) {
2702 goto error;
2703 }
2704 break;
2705 }
2706 #if 0
2707 case LTTNG_DOMAIN_UST_EXEC_NAME:
2708 case LTTNG_DOMAIN_UST_PID:
2709 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2710 #endif
2711 default:
2712 ret = LTTCOMM_UND;
2713 goto error;
2714 }
2715
2716 ret = LTTCOMM_OK;
2717
2718 error:
2719 return ret;
2720 }
2721
2722 /*
2723 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2724 */
2725 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2726 char *channel_name, int event_type)
2727 {
2728 int ret;
2729 struct ltt_kernel_channel *kchan;
2730
2731 switch (domain) {
2732 case LTTNG_DOMAIN_KERNEL:
2733 kchan = trace_kernel_get_channel_by_name(channel_name,
2734 session->kernel_session);
2735 if (kchan == NULL) {
2736 /* This call will notify the kernel thread */
2737 ret = channel_kernel_create(session->kernel_session, NULL,
2738 kernel_poll_pipe[1]);
2739 if (ret != LTTCOMM_OK) {
2740 goto error;
2741 }
2742
2743 /* Get the newly created kernel channel pointer */
2744 kchan = trace_kernel_get_channel_by_name(channel_name,
2745 session->kernel_session);
2746 if (kchan == NULL) {
2747 /* This sould not happen... */
2748 ret = LTTCOMM_FATAL;
2749 goto error;
2750 }
2751
2752 }
2753
2754 switch (event_type) {
2755 case LTTNG_EVENT_SYSCALL:
2756 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2757 kchan, kernel_tracer_fd);
2758 break;
2759 case LTTNG_EVENT_TRACEPOINT:
2760 /*
2761 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2762 * events already registered to the channel.
2763 */
2764 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2765 kchan, kernel_tracer_fd);
2766 break;
2767 case LTTNG_EVENT_ALL:
2768 /* Enable syscalls and tracepoints */
2769 ret = event_kernel_enable_all(session->kernel_session,
2770 kchan, kernel_tracer_fd);
2771 break;
2772 default:
2773 ret = LTTCOMM_KERN_ENABLE_FAIL;
2774 goto error;
2775 }
2776
2777 /* Manage return value */
2778 if (ret != LTTCOMM_OK) {
2779 goto error;
2780 }
2781
2782 kernel_wait_quiescent(kernel_tracer_fd);
2783 break;
2784 case LTTNG_DOMAIN_UST:
2785 {
2786 struct lttng_channel *attr;
2787 struct ltt_ust_channel *uchan;
2788 struct ltt_ust_session *usess = session->ust_session;
2789
2790 /* Get channel from global UST domain */
2791 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2792 channel_name);
2793 if (uchan == NULL) {
2794 /* Create default channel */
2795 attr = channel_new_default_attr(domain);
2796 if (attr == NULL) {
2797 ret = LTTCOMM_FATAL;
2798 goto error;
2799 }
2800 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2801 attr->name[NAME_MAX - 1] = '\0';
2802
2803 /* Use the internal command enable channel */
2804 ret = channel_ust_create(usess, domain, attr);
2805 if (ret != LTTCOMM_OK) {
2806 free(attr);
2807 goto error;
2808 }
2809 free(attr);
2810
2811 /* Get the newly created channel reference back */
2812 uchan = trace_ust_find_channel_by_name(
2813 usess->domain_global.channels, channel_name);
2814 if (uchan == NULL) {
2815 /* Something is really wrong */
2816 ret = LTTCOMM_FATAL;
2817 goto error;
2818 }
2819 }
2820
2821 /* At this point, the session and channel exist on the tracer */
2822
2823 switch (event_type) {
2824 case LTTNG_EVENT_ALL:
2825 case LTTNG_EVENT_TRACEPOINT:
2826 ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
2827 if (ret != LTTCOMM_OK) {
2828 goto error;
2829 }
2830 break;
2831 default:
2832 ret = LTTCOMM_UST_ENABLE_FAIL;
2833 goto error;
2834 }
2835
2836 /* Manage return value */
2837 if (ret != LTTCOMM_OK) {
2838 goto error;
2839 }
2840
2841 break;
2842 }
2843 #if 0
2844 case LTTNG_DOMAIN_UST_EXEC_NAME:
2845 case LTTNG_DOMAIN_UST_PID:
2846 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2847 #endif
2848 default:
2849 ret = LTTCOMM_UND;
2850 goto error;
2851 }
2852
2853 ret = LTTCOMM_OK;
2854
2855 error:
2856 return ret;
2857 }
2858
2859 /*
2860 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2861 */
2862 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2863 {
2864 int ret;
2865 ssize_t nb_events = 0;
2866
2867 switch (domain) {
2868 case LTTNG_DOMAIN_KERNEL:
2869 nb_events = kernel_list_events(kernel_tracer_fd, events);
2870 if (nb_events < 0) {
2871 ret = LTTCOMM_KERN_LIST_FAIL;
2872 goto error;
2873 }
2874 break;
2875 case LTTNG_DOMAIN_UST:
2876 nb_events = ust_app_list_events(events);
2877 if (nb_events < 0) {
2878 ret = LTTCOMM_UST_LIST_FAIL;
2879 goto error;
2880 }
2881 break;
2882 default:
2883 ret = LTTCOMM_UND;
2884 goto error;
2885 }
2886
2887 return nb_events;
2888
2889 error:
2890 /* Return negative value to differentiate return code */
2891 return -ret;
2892 }
2893
2894 /*
2895 * Command LTTNG_START_TRACE processed by the client thread.
2896 */
2897 static int cmd_start_trace(struct ltt_session *session)
2898 {
2899 int ret;
2900 struct ltt_kernel_session *ksession;
2901 struct ltt_ust_session *usess;
2902
2903 /* Short cut */
2904 ksession = session->kernel_session;
2905 usess = session->ust_session;
2906
2907 if (session->enabled) {
2908 /* Already started. */
2909 ret = LTTCOMM_TRACE_ALREADY_STARTED;
2910 goto error;
2911 }
2912
2913 session->enabled = 1;
2914
2915 /* Kernel tracing */
2916 if (ksession != NULL) {
2917 struct ltt_kernel_channel *kchan;
2918
2919 /* Open kernel metadata */
2920 if (ksession->metadata == NULL) {
2921 ret = kernel_open_metadata(ksession, ksession->trace_path);
2922 if (ret < 0) {
2923 ret = LTTCOMM_KERN_META_FAIL;
2924 goto error;
2925 }
2926 }
2927
2928 /* Open kernel metadata stream */
2929 if (ksession->metadata_stream_fd < 0) {
2930 ret = kernel_open_metadata_stream(ksession);
2931 if (ret < 0) {
2932 ERR("Kernel create metadata stream failed");
2933 ret = LTTCOMM_KERN_STREAM_FAIL;
2934 goto error;
2935 }
2936 }
2937
2938 /* For each channel */
2939 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2940 if (kchan->stream_count == 0) {
2941 ret = kernel_open_channel_stream(kchan);
2942 if (ret < 0) {
2943 ret = LTTCOMM_KERN_STREAM_FAIL;
2944 goto error;
2945 }
2946 /* Update the stream global counter */
2947 ksession->stream_count_global += ret;
2948 }
2949 }
2950
2951 /* Setup kernel consumer socket and send fds to it */
2952 ret = init_kernel_tracing(ksession);
2953 if (ret < 0) {
2954 ret = LTTCOMM_KERN_START_FAIL;
2955 goto error;
2956 }
2957
2958 /* This start the kernel tracing */
2959 ret = kernel_start_session(ksession);
2960 if (ret < 0) {
2961 ret = LTTCOMM_KERN_START_FAIL;
2962 goto error;
2963 }
2964
2965 /* Quiescent wait after starting trace */
2966 kernel_wait_quiescent(kernel_tracer_fd);
2967 }
2968
2969 /* Flag session that trace should start automatically */
2970 if (usess) {
2971 usess->start_trace = 1;
2972
2973 ret = ust_app_start_trace_all(usess);
2974 if (ret < 0) {
2975 ret = LTTCOMM_UST_START_FAIL;
2976 goto error;
2977 }
2978 }
2979
2980 ret = LTTCOMM_OK;
2981
2982 error:
2983 return ret;
2984 }
2985
2986 /*
2987 * Command LTTNG_STOP_TRACE processed by the client thread.
2988 */
2989 static int cmd_stop_trace(struct ltt_session *session)
2990 {
2991 int ret;
2992 struct ltt_kernel_channel *kchan;
2993 struct ltt_kernel_session *ksession;
2994 struct ltt_ust_session *usess;
2995
2996 /* Short cut */
2997 ksession = session->kernel_session;
2998 usess = session->ust_session;
2999
3000 if (!session->enabled) {
3001 ret = LTTCOMM_TRACE_ALREADY_STOPPED;
3002 goto error;
3003 }
3004
3005 session->enabled = 0;
3006
3007 /* Kernel tracer */
3008 if (ksession != NULL) {
3009 DBG("Stop kernel tracing");
3010
3011 /* Flush all buffers before stopping */
3012 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
3013 if (ret < 0) {
3014 ERR("Kernel metadata flush failed");
3015 }
3016
3017 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
3018 ret = kernel_flush_buffer(kchan);
3019 if (ret < 0) {
3020 ERR("Kernel flush buffer error");
3021 }
3022 }
3023
3024 ret = kernel_stop_session(ksession);
3025 if (ret < 0) {
3026 ret = LTTCOMM_KERN_STOP_FAIL;
3027 goto error;
3028 }
3029
3030 kernel_wait_quiescent(kernel_tracer_fd);
3031 }
3032
3033 if (usess) {
3034 usess->start_trace = 0;
3035
3036 ret = ust_app_stop_trace_all(usess);
3037 if (ret < 0) {
3038 ret = LTTCOMM_UST_STOP_FAIL;
3039 goto error;
3040 }
3041 }
3042
3043 ret = LTTCOMM_OK;
3044
3045 error:
3046 return ret;
3047 }
3048
3049 /*
3050 * Command LTTNG_CREATE_SESSION processed by the client thread.
3051 */
3052 static int cmd_create_session(char *name, char *path, lttng_sock_cred *creds)
3053 {
3054 int ret;
3055
3056 ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
3057 LTTNG_SOCK_GET_GID_CRED(creds));
3058 if (ret != LTTCOMM_OK) {
3059 goto error;
3060 }
3061
3062 ret = LTTCOMM_OK;
3063
3064 error:
3065 return ret;
3066 }
3067
3068 /*
3069 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3070 */
3071 static int cmd_destroy_session(struct ltt_session *session, char *name)
3072 {
3073 int ret;
3074
3075 /* Clean kernel session teardown */
3076 teardown_kernel_session(session);
3077 /* UST session teardown */
3078 teardown_ust_session(session);
3079
3080 /*
3081 * Must notify the kernel thread here to update it's poll setin order
3082 * to remove the channel(s)' fd just destroyed.
3083 */
3084 ret = notify_thread_pipe(kernel_poll_pipe[1]);
3085 if (ret < 0) {
3086 PERROR("write kernel poll pipe");
3087 }
3088
3089 ret = session_destroy(session);
3090
3091 return ret;
3092 }
3093
3094 /*
3095 * Command LTTNG_CALIBRATE processed by the client thread.
3096 */
3097 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
3098 {
3099 int ret;
3100
3101 switch (domain) {
3102 case LTTNG_DOMAIN_KERNEL:
3103 {
3104 struct lttng_kernel_calibrate kcalibrate;
3105
3106 kcalibrate.type = calibrate->type;
3107 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
3108 if (ret < 0) {
3109 ret = LTTCOMM_KERN_ENABLE_FAIL;
3110 goto error;
3111 }
3112 break;
3113 }
3114 case LTTNG_DOMAIN_UST:
3115 {
3116 struct lttng_ust_calibrate ucalibrate;
3117
3118 ucalibrate.type = calibrate->type;
3119 ret = ust_app_calibrate_glb(&ucalibrate);
3120 if (ret < 0) {
3121 ret = LTTCOMM_UST_CALIBRATE_FAIL;
3122 goto error;
3123 }
3124 break;
3125 }
3126 default:
3127 ret = LTTCOMM_UND;
3128 goto error;
3129 }
3130
3131 ret = LTTCOMM_OK;
3132
3133 error:
3134 return ret;
3135 }
3136
3137 /*
3138 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3139 */
3140 static int cmd_register_consumer(struct ltt_session *session, int domain,
3141 char *sock_path)
3142 {
3143 int ret, sock;
3144
3145 switch (domain) {
3146 case LTTNG_DOMAIN_KERNEL:
3147 /* Can't register a consumer if there is already one */
3148 if (session->kernel_session->consumer_fds_sent != 0) {
3149 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3150 goto error;
3151 }
3152
3153 sock = lttcomm_connect_unix_sock(sock_path);
3154 if (sock < 0) {
3155 ret = LTTCOMM_CONNECT_FAIL;
3156 goto error;
3157 }
3158
3159 session->kernel_session->consumer_fd = sock;
3160 break;
3161 default:
3162 /* TODO: Userspace tracing */
3163 ret = LTTCOMM_UND;
3164 goto error;
3165 }
3166
3167 ret = LTTCOMM_OK;
3168
3169 error:
3170 return ret;
3171 }
3172
3173 /*
3174 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3175 */
3176 static ssize_t cmd_list_domains(struct ltt_session *session,
3177 struct lttng_domain **domains)
3178 {
3179 int ret, index = 0;
3180 ssize_t nb_dom = 0;
3181
3182 if (session->kernel_session != NULL) {
3183 DBG3("Listing domains found kernel domain");
3184 nb_dom++;
3185 }
3186
3187 if (session->ust_session != NULL) {
3188 DBG3("Listing domains found UST global domain");
3189 nb_dom++;
3190 }
3191
3192 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3193 if (*domains == NULL) {
3194 ret = -LTTCOMM_FATAL;
3195 goto error;
3196 }
3197
3198 if (session->kernel_session != NULL) {
3199 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3200 index++;
3201 }
3202
3203 if (session->ust_session != NULL) {
3204 (*domains)[index].type = LTTNG_DOMAIN_UST;
3205 index++;
3206 }
3207
3208 return nb_dom;
3209
3210 error:
3211 return ret;
3212 }
3213
3214 /*
3215 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3216 */
3217 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
3218 struct lttng_channel **channels)
3219 {
3220 int ret;
3221 ssize_t nb_chan = 0;
3222
3223 switch (domain) {
3224 case LTTNG_DOMAIN_KERNEL:
3225 if (session->kernel_session != NULL) {
3226 nb_chan = session->kernel_session->channel_count;
3227 }
3228 DBG3("Number of kernel channels %zd", nb_chan);
3229 break;
3230 case LTTNG_DOMAIN_UST:
3231 if (session->ust_session != NULL) {
3232 nb_chan = lttng_ht_get_count(
3233 session->ust_session->domain_global.channels);
3234 }
3235 DBG3("Number of UST global channels %zd", nb_chan);
3236 break;
3237 default:
3238 *channels = NULL;
3239 ret = -LTTCOMM_UND;
3240 goto error;
3241 }
3242
3243 if (nb_chan > 0) {
3244 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
3245 if (*channels == NULL) {
3246 ret = -LTTCOMM_FATAL;
3247 goto error;
3248 }
3249
3250 list_lttng_channels(domain, session, *channels);
3251 } else {
3252 *channels = NULL;
3253 }
3254
3255 return nb_chan;
3256
3257 error:
3258 return ret;
3259 }
3260
3261 /*
3262 * Command LTTNG_LIST_EVENTS processed by the client thread.
3263 */
3264 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
3265 char *channel_name, struct lttng_event **events)
3266 {
3267 int ret = 0;
3268 ssize_t nb_event = 0;
3269
3270 switch (domain) {
3271 case LTTNG_DOMAIN_KERNEL:
3272 if (session->kernel_session != NULL) {
3273 nb_event = list_lttng_kernel_events(channel_name,
3274 session->kernel_session, events);
3275 }
3276 break;
3277 case LTTNG_DOMAIN_UST:
3278 {
3279 if (session->ust_session != NULL) {
3280 nb_event = list_lttng_ust_global_events(channel_name,
3281 &session->ust_session->domain_global, events);
3282 }
3283 break;
3284 }
3285 default:
3286 ret = -LTTCOMM_UND;
3287 goto error;
3288 }
3289
3290 ret = nb_event;
3291
3292 error:
3293 return ret;
3294 }
3295
3296 /*
3297 * Process the command requested by the lttng client within the command
3298 * context structure. This function make sure that the return structure (llm)
3299 * is set and ready for transmission before returning.
3300 *
3301 * Return any error encountered or 0 for success.
3302 */
3303 static int process_client_msg(struct command_ctx *cmd_ctx)
3304 {
3305 int ret = LTTCOMM_OK;
3306 int need_tracing_session = 1;
3307 int need_domain;
3308
3309 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
3310
3311 switch (cmd_ctx->lsm->cmd_type) {
3312 case LTTNG_CREATE_SESSION:
3313 case LTTNG_DESTROY_SESSION:
3314 case LTTNG_LIST_SESSIONS:
3315 case LTTNG_LIST_DOMAINS:
3316 case LTTNG_START_TRACE:
3317 case LTTNG_STOP_TRACE:
3318 need_domain = 0;
3319 break;
3320 default:
3321 need_domain = 1;
3322 }
3323
3324 if (opt_no_kernel && need_domain
3325 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
3326 if (!is_root) {
3327 ret = LTTCOMM_NEED_ROOT_SESSIOND;
3328 } else {
3329 ret = LTTCOMM_KERN_NA;
3330 }
3331 goto error;
3332 }
3333
3334 /*
3335 * Check for command that don't needs to allocate a returned payload. We do
3336 * this here so we don't have to make the call for no payload at each
3337 * command.
3338 */
3339 switch(cmd_ctx->lsm->cmd_type) {
3340 case LTTNG_LIST_SESSIONS:
3341 case LTTNG_LIST_TRACEPOINTS:
3342 case LTTNG_LIST_DOMAINS:
3343 case LTTNG_LIST_CHANNELS:
3344 case LTTNG_LIST_EVENTS:
3345 break;
3346 default:
3347 /* Setup lttng message with no payload */
3348 ret = setup_lttng_msg(cmd_ctx, 0);
3349 if (ret < 0) {
3350 /* This label does not try to unlock the session */
3351 goto init_setup_error;
3352 }
3353 }
3354
3355 /* Commands that DO NOT need a session. */
3356 switch (cmd_ctx->lsm->cmd_type) {
3357 case LTTNG_CREATE_SESSION:
3358 case LTTNG_CALIBRATE:
3359 case LTTNG_LIST_SESSIONS:
3360 case LTTNG_LIST_TRACEPOINTS:
3361 need_tracing_session = 0;
3362 break;
3363 default:
3364 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
3365 /*
3366 * We keep the session list lock across _all_ commands
3367 * for now, because the per-session lock does not
3368 * handle teardown properly.
3369 */
3370 session_lock_list();
3371 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
3372 if (cmd_ctx->session == NULL) {
3373 if (cmd_ctx->lsm->session.name != NULL) {
3374 ret = LTTCOMM_SESS_NOT_FOUND;
3375 } else {
3376 /* If no session name specified */
3377 ret = LTTCOMM_SELECT_SESS;
3378 }
3379 goto error;
3380 } else {
3381 /* Acquire lock for the session */
3382 session_lock(cmd_ctx->session);
3383 }
3384 break;
3385 }
3386
3387 if (!need_domain) {
3388 goto skip_domain;
3389 }
3390 /*
3391 * Check domain type for specific "pre-action".
3392 */
3393 switch (cmd_ctx->lsm->domain.type) {
3394 case LTTNG_DOMAIN_KERNEL:
3395 if (!is_root) {
3396 ret = LTTCOMM_NEED_ROOT_SESSIOND;
3397 goto error;
3398 }
3399
3400 /* Kernel tracer check */
3401 if (kernel_tracer_fd == -1) {
3402 /* Basically, load kernel tracer modules */
3403 ret = init_kernel_tracer();
3404 if (ret != 0) {
3405 goto error;
3406 }
3407 }
3408
3409 /* Consumer is in an ERROR state. Report back to client */
3410 if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
3411 ret = LTTCOMM_NO_KERNCONSUMERD;
3412 goto error;
3413 }
3414
3415 /* Need a session for kernel command */
3416 if (need_tracing_session) {
3417 if (cmd_ctx->session->kernel_session == NULL) {
3418 ret = create_kernel_session(cmd_ctx->session);
3419 if (ret < 0) {
3420 ret = LTTCOMM_KERN_SESS_FAIL;
3421 goto error;
3422 }
3423 }
3424
3425 /* Start the kernel consumer daemon */
3426 pthread_mutex_lock(&kconsumer_data.pid_mutex);
3427 if (kconsumer_data.pid == 0 &&
3428 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3429 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3430 ret = start_consumerd(&kconsumer_data);
3431 if (ret < 0) {
3432 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3433 goto error;
3434 }
3435 uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
3436 } else {
3437 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3438 }
3439 }
3440
3441 break;
3442 case LTTNG_DOMAIN_UST:
3443 {
3444 /* Consumer is in an ERROR state. Report back to client */
3445 if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
3446 ret = LTTCOMM_NO_USTCONSUMERD;
3447 goto error;
3448 }
3449
3450 if (need_tracing_session) {
3451 if (cmd_ctx->session->ust_session == NULL) {
3452 ret = create_ust_session(cmd_ctx->session,
3453 &cmd_ctx->lsm->domain);
3454 if (ret != LTTCOMM_OK) {
3455 goto error;
3456 }
3457 }
3458 /* Start the UST consumer daemons */
3459 /* 64-bit */
3460 pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
3461 if (consumerd64_bin[0] != '\0' &&
3462 ustconsumer64_data.pid == 0 &&
3463 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3464 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
3465 ret = start_consumerd(&ustconsumer64_data);
3466 if (ret < 0) {
3467 ret = LTTCOMM_UST_CONSUMER64_FAIL;
3468 ust_consumerd64_fd = -EINVAL;
3469 goto error;
3470 }
3471
3472 ust_consumerd64_fd = ustconsumer64_data.cmd_sock;
3473 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
3474 } else {
3475 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
3476 }
3477 /* 32-bit */
3478 if (consumerd32_bin[0] != '\0' &&
3479 ustconsumer32_data.pid == 0 &&
3480 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3481 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
3482 ret = start_consumerd(&ustconsumer32_data);
3483 if (ret < 0) {
3484 ret = LTTCOMM_UST_CONSUMER32_FAIL;
3485 ust_consumerd32_fd = -EINVAL;
3486 goto error;
3487 }
3488
3489 ust_consumerd32_fd = ustconsumer32_data.cmd_sock;
3490 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
3491 } else {
3492 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
3493 }
3494 }
3495 break;
3496 }
3497 default:
3498 break;
3499 }
3500 skip_domain:
3501
3502 /* Validate consumer daemon state when start/stop trace command */
3503 if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
3504 cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
3505 switch (cmd_ctx->lsm->domain.type) {
3506 case LTTNG_DOMAIN_UST:
3507 if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
3508 ret = LTTCOMM_NO_USTCONSUMERD;
3509 goto error;
3510 }
3511 break;
3512 case LTTNG_DOMAIN_KERNEL:
3513 if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
3514 ret = LTTCOMM_NO_KERNCONSUMERD;
3515 goto error;
3516 }
3517 break;
3518 }
3519 }
3520
3521 /*
3522 * Check that the UID or GID match that of the tracing session.
3523 * The root user can interact with all sessions.
3524 */
3525 if (need_tracing_session) {
3526 if (!session_access_ok(cmd_ctx->session,
3527 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
3528 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds))) {
3529 ret = LTTCOMM_EPERM;
3530 goto error;
3531 }
3532 }
3533
3534 /* Process by command type */
3535 switch (cmd_ctx->lsm->cmd_type) {
3536 case LTTNG_ADD_CONTEXT:
3537 {
3538 ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3539 cmd_ctx->lsm->u.context.channel_name,
3540 cmd_ctx->lsm->u.context.event_name,
3541 &cmd_ctx->lsm->u.context.ctx);
3542 break;
3543 }
3544 case LTTNG_DISABLE_CHANNEL:
3545 {
3546 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3547 cmd_ctx->lsm->u.disable.channel_name);
3548 break;
3549 }
3550 case LTTNG_DISABLE_EVENT:
3551 {
3552 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3553 cmd_ctx->lsm->u.disable.channel_name,
3554 cmd_ctx->lsm->u.disable.name);
3555 break;
3556 }
3557 case LTTNG_DISABLE_ALL_EVENT:
3558 {
3559 DBG("Disabling all events");
3560
3561 ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3562 cmd_ctx->lsm->u.disable.channel_name);
3563 break;
3564 }
3565 case LTTNG_ENABLE_CHANNEL:
3566 {
3567 ret = cmd_enable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3568 &cmd_ctx->lsm->u.channel.chan);
3569 break;
3570 }
3571 case LTTNG_ENABLE_EVENT:
3572 {
3573 ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3574 cmd_ctx->lsm->u.enable.channel_name,
3575 &cmd_ctx->lsm->u.enable.event);
3576 break;
3577 }
3578 case LTTNG_ENABLE_ALL_EVENT:
3579 {
3580 DBG("Enabling all events");
3581
3582 ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3583 cmd_ctx->lsm->u.enable.channel_name,
3584 cmd_ctx->lsm->u.enable.event.type);
3585 break;
3586 }
3587 case LTTNG_LIST_TRACEPOINTS:
3588 {
3589 struct lttng_event *events;
3590 ssize_t nb_events;
3591
3592 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
3593 if (nb_events < 0) {
3594 ret = -nb_events;
3595 goto error;
3596 }
3597
3598 /*
3599 * Setup lttng message with payload size set to the event list size in
3600 * bytes and then copy list into the llm payload.
3601 */
3602 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
3603 if (ret < 0) {
3604 free(events);
3605 goto setup_error;
3606 }
3607
3608 /* Copy event list into message payload */
3609 memcpy(cmd_ctx->llm->payload, events,
3610 sizeof(struct lttng_event) * nb_events);
3611
3612 free(events);
3613
3614 ret = LTTCOMM_OK;
3615 break;
3616 }
3617 case LTTNG_START_TRACE:
3618 {
3619 ret = cmd_start_trace(cmd_ctx->session);
3620 break;
3621 }
3622 case LTTNG_STOP_TRACE:
3623 {
3624 ret = cmd_stop_trace(cmd_ctx->session);
3625 break;
3626 }
3627 case LTTNG_CREATE_SESSION:
3628 {
3629 ret = cmd_create_session(cmd_ctx->lsm->session.name,
3630 cmd_ctx->lsm->session.path, &cmd_ctx->creds);
3631 break;
3632 }
3633 case LTTNG_DESTROY_SESSION:
3634 {
3635 ret = cmd_destroy_session(cmd_ctx->session,
3636 cmd_ctx->lsm->session.name);
3637 /*
3638 * Set session to NULL so we do not unlock it after
3639 * free.
3640 */
3641 cmd_ctx->session = NULL;
3642 break;
3643 }
3644 case LTTNG_LIST_DOMAINS:
3645 {
3646 ssize_t nb_dom;
3647 struct lttng_domain *domains;
3648
3649 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
3650 if (nb_dom < 0) {
3651 ret = -nb_dom;
3652 goto error;
3653 }
3654
3655 ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
3656 if (ret < 0) {
3657 goto setup_error;
3658 }
3659
3660 /* Copy event list into message payload */
3661 memcpy(cmd_ctx->llm->payload, domains,
3662 nb_dom * sizeof(struct lttng_domain));
3663
3664 free(domains);
3665
3666 ret = LTTCOMM_OK;
3667 break;
3668 }
3669 case LTTNG_LIST_CHANNELS:
3670 {
3671 size_t nb_chan;
3672 struct lttng_channel *channels;
3673
3674 nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
3675 cmd_ctx->session, &channels);
3676 if (nb_chan < 0) {
3677 ret = -nb_chan;
3678 goto error;
3679 }
3680
3681 ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
3682 if (ret < 0) {
3683 goto setup_error;
3684 }
3685
3686 /* Copy event list into message payload */
3687 memcpy(cmd_ctx->llm->payload, channels,
3688 nb_chan * sizeof(struct lttng_channel));
3689
3690 free(channels);
3691
3692 ret = LTTCOMM_OK;
3693 break;
3694 }
3695 case LTTNG_LIST_EVENTS:
3696 {
3697 ssize_t nb_event;
3698 struct lttng_event *events = NULL;
3699
3700 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type, cmd_ctx->session,
3701 cmd_ctx->lsm->u.list.channel_name, &events);
3702 if (nb_event < 0) {
3703 ret = -nb_event;
3704 goto error;
3705 }
3706
3707 ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
3708 if (ret < 0) {
3709 goto setup_error;
3710 }
3711
3712 /* Copy event list into message payload */
3713 memcpy(cmd_ctx->llm->payload, events,
3714 nb_event * sizeof(struct lttng_event));
3715
3716 free(events);
3717
3718 ret = LTTCOMM_OK;
3719 break;
3720 }
3721 case LTTNG_LIST_SESSIONS:
3722 {
3723 unsigned int nr_sessions;
3724
3725 session_lock_list();
3726 nr_sessions = lttng_sessions_count(
3727 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
3728 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
3729
3730 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * nr_sessions);
3731 if (ret < 0) {
3732 session_unlock_list();
3733 goto setup_error;
3734 }
3735
3736 /* Filled the session array */
3737 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload),
3738 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
3739 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
3740
3741 session_unlock_list();
3742
3743 ret = LTTCOMM_OK;
3744 break;
3745 }
3746 case LTTNG_CALIBRATE:
3747 {
3748 ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
3749 &cmd_ctx->lsm->u.calibrate);
3750 break;
3751 }
3752 case LTTNG_REGISTER_CONSUMER:
3753 {
3754 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3755 cmd_ctx->lsm->u.reg.path);
3756 break;
3757 }
3758 default:
3759 ret = LTTCOMM_UND;
3760 break;
3761 }
3762
3763 error:
3764 if (cmd_ctx->llm == NULL) {
3765 DBG("Missing llm structure. Allocating one.");
3766 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
3767 goto setup_error;
3768 }
3769 }