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