Add debug output to sessiond's kernel consumer selection
[lttng-tools.git] / 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 it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; only version 2 of the License.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <grp.h>
23 #include <limits.h>
24 #include <pthread.h>
25 #include <semaphore.h>
26 #include <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sys/mman.h>
31 #include <sys/mount.h>
32 #include <sys/resource.h>
33 #include <sys/socket.h>
34 #include <sys/stat.h>
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 #include <urcu/futex.h>
38 #include <unistd.h>
39 #include <config.h>
40
41 #include <lttng-consumerd.h>
42 #include <lttng-ht.h>
43 #include <lttng-sessiond-comm.h>
44 #include <lttng/lttng-consumer.h>
45
46 #include <lttngerr.h>
47 #include <runas.h>
48
49 #include "channel.h"
50 #include "compat/poll.h"
51 #include "context.h"
52 #include "event.h"
53 #include "futex.h"
54 #include "kernel.h"
55 #include "lttng-sessiond.h"
56 #include "shm.h"
57 #include "ust-app.h"
58 #include "ust-ctl.h"
59 #include "utils.h"
60
61 #define CONSUMERD_FILE "lttng-consumerd"
62
63 struct consumer_data {
64 enum lttng_consumer_type type;
65
66 pthread_t thread; /* Worker thread interacting with the consumer */
67 sem_t sem;
68
69 /* Mutex to control consumerd pid assignation */
70 pthread_mutex_t pid_mutex;
71 pid_t pid;
72
73 int err_sock;
74 int cmd_sock;
75
76 /* consumer error and command Unix socket path */
77 char err_unix_sock_path[PATH_MAX];
78 char cmd_unix_sock_path[PATH_MAX];
79 };
80
81 /* Const values */
82 const char default_home_dir[] = DEFAULT_HOME_DIR;
83 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
84 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
85 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
86
87 /* Variables */
88 int opt_verbose; /* Not static for lttngerr.h */
89 int opt_verbose_consumer; /* Not static for lttngerr.h */
90 int opt_quiet; /* Not static for lttngerr.h */
91
92 const char *progname;
93 const char *opt_tracing_group;
94 static int opt_sig_parent;
95 static int opt_daemon;
96 static int opt_no_kernel;
97 static int is_root; /* Set to 1 if the daemon is running as root */
98 static pid_t ppid; /* Parent PID for --sig-parent option */
99 static char *rundir;
100
101 /* Consumer daemon specific control data */
102 static struct consumer_data kconsumer_data = {
103 .type = LTTNG_CONSUMER_KERNEL,
104 .err_unix_sock_path = KCONSUMERD_ERR_SOCK_PATH,
105 .cmd_unix_sock_path = KCONSUMERD_CMD_SOCK_PATH,
106 };
107 static struct consumer_data ustconsumer64_data = {
108 .type = LTTNG_CONSUMER64_UST,
109 .err_unix_sock_path = USTCONSUMERD64_ERR_SOCK_PATH,
110 .cmd_unix_sock_path = USTCONSUMERD64_CMD_SOCK_PATH,
111 };
112 static struct consumer_data ustconsumer32_data = {
113 .type = LTTNG_CONSUMER32_UST,
114 .err_unix_sock_path = USTCONSUMERD32_ERR_SOCK_PATH,
115 .cmd_unix_sock_path = USTCONSUMERD32_CMD_SOCK_PATH,
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;
129 static int apps_sock;
130 static int kernel_tracer_fd;
131 static int kernel_poll_pipe[2];
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];
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];
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 =
178 __stringify(CONFIG_CONSUMERD32_BIN);
179 static const char *consumerd64_bin =
180 __stringify(CONFIG_CONSUMERD64_BIN);
181 static const char *consumerd32_libdir =
182 __stringify(CONFIG_CONSUMERD32_LIBDIR);
183 static const char *consumerd64_libdir =
184 __stringify(CONFIG_CONSUMERD64_LIBDIR);
185
186 static
187 void setup_consumerd_path(void)
188 {
189 const char *bin, *libdir;
190
191 /*
192 * Allow INSTALL_BIN_PATH to be used as a target path for the
193 * native architecture size consumer if CONFIG_CONSUMER*_PATH
194 * has not been defined.
195 */
196 #if (CAA_BITS_PER_LONG == 32)
197 if (!consumerd32_bin[0]) {
198 consumerd32_bin = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
199 }
200 if (!consumerd32_libdir[0]) {
201 consumerd32_libdir = INSTALL_LIB_PATH;
202 }
203 #elif (CAA_BITS_PER_LONG == 64)
204 if (!consumerd64_bin[0]) {
205 consumerd64_bin = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
206 }
207 if (!consumerd64_libdir[0]) {
208 consumerd64_libdir = INSTALL_LIB_PATH;
209 }
210 #else
211 #error "Unknown bitness"
212 #endif
213
214 /*
215 * runtime env. var. overrides the build default.
216 */
217 bin = getenv("LTTNG_CONSUMERD32_BIN");
218 if (bin) {
219 consumerd32_bin = bin;
220 }
221 bin = getenv("LTTNG_CONSUMERD64_BIN");
222 if (bin) {
223 consumerd64_bin = bin;
224 }
225 libdir = getenv("LTTNG_TOOLS_CONSUMERD32_LIBDIR");
226 if (libdir) {
227 consumerd32_libdir = libdir;
228 }
229 libdir = getenv("LTTNG_TOOLS_CONSUMERD64_LIBDIR");
230 if (libdir) {
231 consumerd64_libdir = libdir;
232 }
233 }
234
235 /*
236 * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
237 */
238 static int create_thread_poll_set(struct lttng_poll_event *events,
239 unsigned int size)
240 {
241 int ret;
242
243 if (events == NULL || size == 0) {
244 ret = -1;
245 goto error;
246 }
247
248 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
249 if (ret < 0) {
250 goto error;
251 }
252
253 /* Add quit pipe */
254 ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
255 if (ret < 0) {
256 goto error;
257 }
258
259 return 0;
260
261 error:
262 return ret;
263 }
264
265 /*
266 * Check if the thread quit pipe was triggered.
267 *
268 * Return 1 if it was triggered else 0;
269 */
270 static int check_thread_quit_pipe(int fd, uint32_t events)
271 {
272 if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
273 return 1;
274 }
275
276 return 0;
277 }
278
279 /*
280 * Remove modules in reverse load order.
281 */
282 static int modprobe_remove_kernel_modules(void)
283 {
284 int ret = 0, i;
285 char modprobe[256];
286
287 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
288 ret = snprintf(modprobe, sizeof(modprobe),
289 "/sbin/modprobe -r -q %s",
290 kernel_modules_list[i].name);
291 if (ret < 0) {
292 perror("snprintf modprobe -r");
293 goto error;
294 }
295 modprobe[sizeof(modprobe) - 1] = '\0';
296 ret = system(modprobe);
297 if (ret == -1) {
298 ERR("Unable to launch modprobe -r for module %s",
299 kernel_modules_list[i].name);
300 } else if (kernel_modules_list[i].required
301 && WEXITSTATUS(ret) != 0) {
302 ERR("Unable to remove module %s",
303 kernel_modules_list[i].name);
304 } else {
305 DBG("Modprobe removal successful %s",
306 kernel_modules_list[i].name);
307 }
308 }
309
310 error:
311 return ret;
312 }
313
314 /*
315 * Return group ID of the tracing group or -1 if not found.
316 */
317 static gid_t allowed_group(void)
318 {
319 struct group *grp;
320
321 if (opt_tracing_group) {
322 grp = getgrnam(opt_tracing_group);
323 } else {
324 grp = getgrnam(default_tracing_group);
325 }
326 if (!grp) {
327 return -1;
328 } else {
329 return grp->gr_gid;
330 }
331 }
332
333 /*
334 * Init thread quit pipe.
335 *
336 * Return -1 on error or 0 if all pipes are created.
337 */
338 static int init_thread_quit_pipe(void)
339 {
340 int ret;
341
342 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
343 if (ret < 0) {
344 perror("thread quit pipe");
345 goto error;
346 }
347
348 error:
349 return ret;
350 }
351
352 /*
353 * Complete teardown of a kernel session. This free all data structure related
354 * to a kernel session and update counter.
355 */
356 static void teardown_kernel_session(struct ltt_session *session)
357 {
358 if (!session->kernel_session) {
359 DBG3("No kernel session when tearingdown session");
360 return;
361 }
362
363 DBG("Tearing down kernel session");
364
365 /*
366 * If a custom kernel consumer was registered, close the socket before
367 * tearing down the complete kernel session structure
368 */
369 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
370 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
371 }
372
373 trace_kernel_destroy_session(session->kernel_session);
374 }
375
376 /*
377 * Complete teardown of all UST sessions. This will free everything on his path
378 * and destroy the core essence of all ust sessions :)
379 */
380 static void teardown_ust_session(struct ltt_session *session)
381 {
382 int ret;
383
384 if (!session->ust_session) {
385 DBG3("No UST session when tearingdown session");
386 return;
387 }
388
389 DBG("Tearing down UST session(s)");
390
391 ret = ust_app_destroy_trace_all(session->ust_session);
392 if (ret) {
393 ERR("Error in ust_app_destroy_trace_all");
394 }
395
396 trace_ust_destroy_session(session->ust_session);
397 }
398
399 /*
400 * Stop all threads by closing the thread quit pipe.
401 */
402 static void stop_threads(void)
403 {
404 int ret;
405
406 /* Stopping all threads */
407 DBG("Terminating all threads");
408 ret = notify_thread_pipe(thread_quit_pipe[1]);
409 if (ret < 0) {
410 ERR("write error on thread quit pipe");
411 }
412
413 /* Dispatch thread */
414 dispatch_thread_exit = 1;
415 futex_nto1_wake(&ust_cmd_queue.futex);
416 }
417
418 /*
419 * Cleanup the daemon
420 */
421 static void cleanup(void)
422 {
423 int ret;
424 char *cmd;
425 struct ltt_session *sess, *stmp;
426
427 DBG("Cleaning up");
428
429 DBG("Removing %s directory", rundir);
430 ret = asprintf(&cmd, "rm -rf %s", rundir);
431 if (ret < 0) {
432 ERR("asprintf failed. Something is really wrong!");
433 }
434
435 /* Remove lttng run directory */
436 ret = system(cmd);
437 if (ret < 0) {
438 ERR("Unable to clean %s", rundir);
439 }
440 free(cmd);
441
442 DBG("Cleaning up all session");
443
444 /* Destroy session list mutex */
445 if (session_list_ptr != NULL) {
446 pthread_mutex_destroy(&session_list_ptr->lock);
447
448 /* Cleanup ALL session */
449 cds_list_for_each_entry_safe(sess, stmp,
450 &session_list_ptr->head, list) {
451 teardown_kernel_session(sess);
452 teardown_ust_session(sess);
453 free(sess);
454 }
455 }
456
457 DBG("Closing all UST sockets");
458 ust_app_clean_list();
459
460 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
461
462 if (is_root && !opt_no_kernel) {
463 DBG2("Closing kernel fd");
464 close(kernel_tracer_fd);
465 DBG("Unloading kernel modules");
466 modprobe_remove_kernel_modules();
467 }
468
469 close(thread_quit_pipe[0]);
470 close(thread_quit_pipe[1]);
471
472 /* <fun> */
473 DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
474 "Matthew, BEET driven development works!%c[%dm",
475 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
476 /* </fun> */
477 }
478
479 /*
480 * Send data on a unix socket using the liblttsessiondcomm API.
481 *
482 * Return lttcomm error code.
483 */
484 static int send_unix_sock(int sock, void *buf, size_t len)
485 {
486 /* Check valid length */
487 if (len <= 0) {
488 return -1;
489 }
490
491 return lttcomm_send_unix_sock(sock, buf, len);
492 }
493
494 /*
495 * Free memory of a command context structure.
496 */
497 static void clean_command_ctx(struct command_ctx **cmd_ctx)
498 {
499 DBG("Clean command context structure");
500 if (*cmd_ctx) {
501 if ((*cmd_ctx)->llm) {
502 free((*cmd_ctx)->llm);
503 }
504 if ((*cmd_ctx)->lsm) {
505 free((*cmd_ctx)->lsm);
506 }
507 free(*cmd_ctx);
508 *cmd_ctx = NULL;
509 }
510 }
511
512 /*
513 * Send all stream fds of kernel channel to the consumer.
514 */
515 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
516 int sock, struct ltt_kernel_channel *channel,
517 uid_t uid, gid_t gid)
518 {
519 int ret;
520 struct ltt_kernel_stream *stream;
521 struct lttcomm_consumer_msg lkm;
522
523 DBG("Sending streams of channel %s to kernel consumer",
524 channel->channel->name);
525
526 /* Send channel */
527 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
528 lkm.u.channel.channel_key = channel->fd;
529 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
530 lkm.u.channel.mmap_len = 0; /* for kernel */
531 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
532 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
533 if (ret < 0) {
534 perror("send consumer channel");
535 goto error;
536 }
537
538 /* Send streams */
539 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
540 if (!stream->fd) {
541 continue;
542 }
543 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
544 lkm.u.stream.channel_key = channel->fd;
545 lkm.u.stream.stream_key = stream->fd;
546 lkm.u.stream.state = stream->state;
547 lkm.u.stream.output = channel->channel->attr.output;
548 lkm.u.stream.mmap_len = 0; /* for kernel */
549 lkm.u.stream.uid = uid;
550 lkm.u.stream.gid = gid;
551 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
552 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
553 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
554 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
555 if (ret < 0) {
556 perror("send consumer stream");
557 goto error;
558 }
559 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
560 if (ret < 0) {
561 perror("send consumer stream ancillary data");
562 goto error;
563 }
564 }
565
566 DBG("consumer channel streams sent");
567
568 return 0;
569
570 error:
571 return ret;
572 }
573
574 /*
575 * Send all stream fds of the kernel session to the consumer.
576 */
577 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
578 struct ltt_kernel_session *session)
579 {
580 int ret;
581 struct ltt_kernel_channel *chan;
582 struct lttcomm_consumer_msg lkm;
583 int sock = session->consumer_fd;
584
585 DBG("Sending metadata stream fd");
586
587 /* Extra protection. It's NOT supposed to be set to 0 at this point */
588 if (session->consumer_fd == 0) {
589 session->consumer_fd = consumer_data->cmd_sock;
590 }
591
592 if (session->metadata_stream_fd != 0) {
593 /* Send metadata channel fd */
594 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
595 lkm.u.channel.channel_key = session->metadata->fd;
596 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
597 lkm.u.channel.mmap_len = 0; /* for kernel */
598 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
599 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
600 if (ret < 0) {
601 perror("send consumer channel");
602 goto error;
603 }
604
605 /* Send metadata stream fd */
606 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
607 lkm.u.stream.channel_key = session->metadata->fd;
608 lkm.u.stream.stream_key = session->metadata_stream_fd;
609 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
610 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
611 lkm.u.stream.mmap_len = 0; /* for kernel */
612 lkm.u.stream.uid = session->uid;
613 lkm.u.stream.gid = session->gid;
614 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
615 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
616 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
617 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
618 if (ret < 0) {
619 perror("send consumer stream");
620 goto error;
621 }
622 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
623 if (ret < 0) {
624 perror("send consumer stream");
625 goto error;
626 }
627 }
628
629 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
630 ret = send_kconsumer_channel_streams(consumer_data, sock, chan,
631 session->uid, session->gid);
632 if (ret < 0) {
633 goto error;
634 }
635 }
636
637 DBG("consumer fds (metadata and channel streams) sent");
638
639 return 0;
640
641 error:
642 return ret;
643 }
644
645 /*
646 * Notify UST applications using the shm mmap futex.
647 */
648 static int notify_ust_apps(int active)
649 {
650 char *wait_shm_mmap;
651
652 DBG("Notifying applications of session daemon state: %d", active);
653
654 /* See shm.c for this call implying mmap, shm and futex calls */
655 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
656 if (wait_shm_mmap == NULL) {
657 goto error;
658 }
659
660 /* Wake waiting process */
661 futex_wait_update((int32_t *) wait_shm_mmap, active);
662
663 /* Apps notified successfully */
664 return 0;
665
666 error:
667 return -1;
668 }
669
670 /*
671 * Setup the outgoing data buffer for the response (llm) by allocating the
672 * right amount of memory and copying the original information from the lsm
673 * structure.
674 *
675 * Return total size of the buffer pointed by buf.
676 */
677 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
678 {
679 int ret, buf_size;
680
681 buf_size = size;
682
683 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
684 if (cmd_ctx->llm == NULL) {
685 perror("zmalloc");
686 ret = -ENOMEM;
687 goto error;
688 }
689
690 /* Copy common data */
691 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
692 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
693
694 cmd_ctx->llm->data_size = size;
695 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
696
697 return buf_size;
698
699 error:
700 return ret;
701 }
702
703 /*
704 * Update the kernel poll set of all channel fd available over all tracing
705 * session. Add the wakeup pipe at the end of the set.
706 */
707 static int update_kernel_poll(struct lttng_poll_event *events)
708 {
709 int ret;
710 struct ltt_session *session;
711 struct ltt_kernel_channel *channel;
712
713 DBG("Updating kernel poll set");
714
715 session_lock_list();
716 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
717 session_lock(session);
718 if (session->kernel_session == NULL) {
719 session_unlock(session);
720 continue;
721 }
722
723 cds_list_for_each_entry(channel,
724 &session->kernel_session->channel_list.head, list) {
725 /* Add channel fd to the kernel poll set */
726 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
727 if (ret < 0) {
728 session_unlock(session);
729 goto error;
730 }
731 DBG("Channel fd %d added to kernel set", channel->fd);
732 }
733 session_unlock(session);
734 }
735 session_unlock_list();
736
737 return 0;
738
739 error:
740 session_unlock_list();
741 return -1;
742 }
743
744 /*
745 * Find the channel fd from 'fd' over all tracing session. When found, check
746 * for new channel stream and send those stream fds to the kernel consumer.
747 *
748 * Useful for CPU hotplug feature.
749 */
750 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
751 {
752 int ret = 0;
753 struct ltt_session *session;
754 struct ltt_kernel_channel *channel;
755
756 DBG("Updating kernel streams for channel fd %d", fd);
757
758 session_lock_list();
759 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
760 session_lock(session);
761 if (session->kernel_session == NULL) {
762 session_unlock(session);
763 continue;
764 }
765
766 /* This is not suppose to be 0 but this is an extra security check */
767 if (session->kernel_session->consumer_fd == 0) {
768 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
769 }
770
771 cds_list_for_each_entry(channel,
772 &session->kernel_session->channel_list.head, list) {
773 if (channel->fd == fd) {
774 DBG("Channel found, updating kernel streams");
775 ret = kernel_open_channel_stream(channel);
776 if (ret < 0) {
777 goto error;
778 }
779
780 /*
781 * Have we already sent fds to the consumer? If yes, it means
782 * that tracing is started so it is safe to send our updated
783 * stream fds.
784 */
785 if (session->kernel_session->consumer_fds_sent == 1) {
786 ret = send_kconsumer_channel_streams(consumer_data,
787 session->kernel_session->consumer_fd, channel,
788 session->uid, session->gid);
789 if (ret < 0) {
790 goto error;
791 }
792 }
793 goto error;
794 }
795 }
796 session_unlock(session);
797 }
798 session_unlock_list();
799 return ret;
800
801 error:
802 session_unlock(session);
803 session_unlock_list();
804 return ret;
805 }
806
807 /*
808 * For each tracing session, update newly registered apps.
809 */
810 static void update_ust_app(int app_sock)
811 {
812 struct ltt_session *sess, *stmp;
813
814 /* For all tracing session(s) */
815 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
816 if (sess->ust_session) {
817 ust_app_global_update(sess->ust_session, app_sock);
818 }
819 }
820 }
821
822 /*
823 * This thread manage event coming from the kernel.
824 *
825 * Features supported in this thread:
826 * -) CPU Hotplug
827 */
828 static void *thread_manage_kernel(void *data)
829 {
830 int ret, i, pollfd, update_poll_flag = 1;
831 uint32_t revents, nb_fd;
832 char tmp;
833 struct lttng_poll_event events;
834
835 DBG("Thread manage kernel started");
836
837 ret = create_thread_poll_set(&events, 2);
838 if (ret < 0) {
839 goto error;
840 }
841
842 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
843 if (ret < 0) {
844 goto error;
845 }
846
847 while (1) {
848 if (update_poll_flag == 1) {
849 /*
850 * Reset number of fd in the poll set. Always 2 since there is the thread
851 * quit pipe and the kernel pipe.
852 */
853 events.nb_fd = 2;
854
855 ret = update_kernel_poll(&events);
856 if (ret < 0) {
857 goto error;
858 }
859 update_poll_flag = 0;
860 }
861
862 nb_fd = LTTNG_POLL_GETNB(&events);
863
864 DBG("Thread kernel polling on %d fds", nb_fd);
865
866 /* Zeroed the poll events */
867 lttng_poll_reset(&events);
868
869 /* Poll infinite value of time */
870 ret = lttng_poll_wait(&events, -1);
871 if (ret < 0) {
872 goto error;
873 } else if (ret == 0) {
874 /* Should not happen since timeout is infinite */
875 ERR("Return value of poll is 0 with an infinite timeout.\n"
876 "This should not have happened! Continuing...");
877 continue;
878 }
879
880 for (i = 0; i < nb_fd; i++) {
881 /* Fetch once the poll data */
882 revents = LTTNG_POLL_GETEV(&events, i);
883 pollfd = LTTNG_POLL_GETFD(&events, i);
884
885 /* Thread quit pipe has been closed. Killing thread. */
886 ret = check_thread_quit_pipe(pollfd, revents);
887 if (ret) {
888 goto error;
889 }
890
891 /* Check for data on kernel pipe */
892 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
893 ret = read(kernel_poll_pipe[0], &tmp, 1);
894 update_poll_flag = 1;
895 continue;
896 } else {
897 /*
898 * New CPU detected by the kernel. Adding kernel stream to
899 * kernel session and updating the kernel consumer
900 */
901 if (revents & LPOLLIN) {
902 ret = update_kernel_stream(&kconsumer_data, pollfd);
903 if (ret < 0) {
904 continue;
905 }
906 break;
907 /*
908 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
909 * and unregister kernel stream at this point.
910 */
911 }
912 }
913 }
914 }
915
916 error:
917 DBG("Kernel thread dying");
918 close(kernel_poll_pipe[0]);
919 close(kernel_poll_pipe[1]);
920
921 lttng_poll_clean(&events);
922
923 return NULL;
924 }
925
926 /*
927 * This thread manage the consumer error sent back to the session daemon.
928 */
929 static void *thread_manage_consumer(void *data)
930 {
931 int sock = 0, i, ret, pollfd;
932 uint32_t revents, nb_fd;
933 enum lttcomm_return_code code;
934 struct lttng_poll_event events;
935 struct consumer_data *consumer_data = data;
936
937 DBG("[thread] Manage consumer started");
938
939 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
940 if (ret < 0) {
941 goto error;
942 }
943
944 /*
945 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
946 * Nothing more will be added to this poll set.
947 */
948 ret = create_thread_poll_set(&events, 2);
949 if (ret < 0) {
950 goto error;
951 }
952
953 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
954 if (ret < 0) {
955 goto error;
956 }
957
958 nb_fd = LTTNG_POLL_GETNB(&events);
959
960 /* Inifinite blocking call, waiting for transmission */
961 ret = lttng_poll_wait(&events, -1);
962 if (ret < 0) {
963 goto error;
964 }
965
966 for (i = 0; i < nb_fd; i++) {
967 /* Fetch once the poll data */
968 revents = LTTNG_POLL_GETEV(&events, i);
969 pollfd = LTTNG_POLL_GETFD(&events, i);
970
971 /* Thread quit pipe has been closed. Killing thread. */
972 ret = check_thread_quit_pipe(pollfd, revents);
973 if (ret) {
974 goto error;
975 }
976
977 /* Event on the registration socket */
978 if (pollfd == consumer_data->err_sock) {
979 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
980 ERR("consumer err socket poll error");
981 goto error;
982 }
983 }
984 }
985
986 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
987 if (sock < 0) {
988 goto error;
989 }
990
991 DBG2("Receiving code from consumer err_sock");
992
993 /* Getting status code from kconsumerd */
994 ret = lttcomm_recv_unix_sock(sock, &code,
995 sizeof(enum lttcomm_return_code));
996 if (ret <= 0) {
997 goto error;
998 }
999
1000 if (code == CONSUMERD_COMMAND_SOCK_READY) {
1001 consumer_data->cmd_sock =
1002 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
1003 if (consumer_data->cmd_sock < 0) {
1004 sem_post(&consumer_data->sem);
1005 PERROR("consumer connect");
1006 goto error;
1007 }
1008 /* Signal condition to tell that the kconsumerd is ready */
1009 sem_post(&consumer_data->sem);
1010 DBG("consumer command socket ready");
1011 } else {
1012 ERR("consumer error when waiting for SOCK_READY : %s",
1013 lttcomm_get_readable_code(-code));
1014 goto error;
1015 }
1016
1017 /* Remove the kconsumerd error sock since we've established a connexion */
1018 ret = lttng_poll_del(&events, consumer_data->err_sock);
1019 if (ret < 0) {
1020 goto error;
1021 }
1022
1023 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
1024 if (ret < 0) {
1025 goto error;
1026 }
1027
1028 /* Update number of fd */
1029 nb_fd = LTTNG_POLL_GETNB(&events);
1030
1031 /* Inifinite blocking call, waiting for transmission */
1032 ret = lttng_poll_wait(&events, -1);
1033 if (ret < 0) {
1034 goto error;
1035 }
1036
1037 for (i = 0; i < nb_fd; i++) {
1038 /* Fetch once the poll data */
1039 revents = LTTNG_POLL_GETEV(&events, i);
1040 pollfd = LTTNG_POLL_GETFD(&events, i);
1041
1042 /* Thread quit pipe has been closed. Killing thread. */
1043 ret = check_thread_quit_pipe(pollfd, revents);
1044 if (ret) {
1045 goto error;
1046 }
1047
1048 /* Event on the kconsumerd socket */
1049 if (pollfd == sock) {
1050 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1051 ERR("consumer err socket second poll error");
1052 goto error;
1053 }
1054 }
1055 }
1056
1057 /* Wait for any kconsumerd error */
1058 ret = lttcomm_recv_unix_sock(sock, &code,
1059 sizeof(enum lttcomm_return_code));
1060 if (ret <= 0) {
1061 ERR("consumer closed the command socket");
1062 goto error;
1063 }
1064
1065 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
1066
1067 error:
1068 DBG("consumer thread dying");
1069 close(consumer_data->err_sock);
1070 close(consumer_data->cmd_sock);
1071 close(sock);
1072
1073 unlink(consumer_data->err_unix_sock_path);
1074 unlink(consumer_data->cmd_unix_sock_path);
1075 consumer_data->pid = 0;
1076
1077 lttng_poll_clean(&events);
1078
1079 return NULL;
1080 }
1081
1082 /*
1083 * This thread manage application communication.
1084 */
1085 static void *thread_manage_apps(void *data)
1086 {
1087 int i, ret, pollfd;
1088 uint32_t revents, nb_fd;
1089 struct ust_command ust_cmd;
1090 struct lttng_poll_event events;
1091
1092 DBG("[thread] Manage application started");
1093
1094 rcu_register_thread();
1095 rcu_thread_online();
1096
1097 ret = create_thread_poll_set(&events, 2);
1098 if (ret < 0) {
1099 goto error;
1100 }
1101
1102 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1103 if (ret < 0) {
1104 goto error;
1105 }
1106
1107 while (1) {
1108 /* Zeroed the events structure */
1109 lttng_poll_reset(&events);
1110
1111 nb_fd = LTTNG_POLL_GETNB(&events);
1112
1113 DBG("Apps thread polling on %d fds", nb_fd);
1114
1115 /* Inifinite blocking call, waiting for transmission */
1116 ret = lttng_poll_wait(&events, -1);
1117 if (ret < 0) {
1118 goto error;
1119 }
1120
1121 for (i = 0; i < nb_fd; i++) {
1122 /* Fetch once the poll data */
1123 revents = LTTNG_POLL_GETEV(&events, i);
1124 pollfd = LTTNG_POLL_GETFD(&events, i);
1125
1126 /* Thread quit pipe has been closed. Killing thread. */
1127 ret = check_thread_quit_pipe(pollfd, revents);
1128 if (ret) {
1129 goto error;
1130 }
1131
1132 /* Inspect the apps cmd pipe */
1133 if (pollfd == apps_cmd_pipe[0]) {
1134 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1135 ERR("Apps command pipe error");
1136 goto error;
1137 } else if (revents & LPOLLIN) {
1138 /* Empty pipe */
1139 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1140 if (ret < 0 || ret < sizeof(ust_cmd)) {
1141 perror("read apps cmd pipe");
1142 goto error;
1143 }
1144
1145 /* Register applicaton to the session daemon */
1146 ret = ust_app_register(&ust_cmd.reg_msg,
1147 ust_cmd.sock);
1148 if (ret == -ENOMEM) {
1149 goto error;
1150 } else if (ret < 0) {
1151 break;
1152 }
1153
1154 /*
1155 * Add channel(s) and event(s) to newly registered apps
1156 * from lttng global UST domain.
1157 */
1158 update_ust_app(ust_cmd.sock);
1159
1160 ret = ust_app_register_done(ust_cmd.sock);
1161 if (ret < 0) {
1162 /*
1163 * If the registration is not possible, we simply
1164 * unregister the apps and continue
1165 */
1166 ust_app_unregister(ust_cmd.sock);
1167 } else {
1168 /*
1169 * We just need here to monitor the close of the UST
1170 * socket and poll set monitor those by default.
1171 */
1172 ret = lttng_poll_add(&events, ust_cmd.sock, 0);
1173 if (ret < 0) {
1174 goto error;
1175 }
1176
1177 DBG("Apps with sock %d added to poll set",
1178 ust_cmd.sock);
1179 }
1180
1181 break;
1182 }
1183 } else {
1184 /*
1185 * At this point, we know that a registered application made
1186 * the event at poll_wait.
1187 */
1188 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1189 /* Removing from the poll set */
1190 ret = lttng_poll_del(&events, pollfd);
1191 if (ret < 0) {
1192 goto error;
1193 }
1194
1195 /* Socket closed on remote end. */
1196 ust_app_unregister(pollfd);
1197 break;
1198 }
1199 }
1200 }
1201 }
1202
1203 error:
1204 DBG("Application communication apps dying");
1205 close(apps_cmd_pipe[0]);
1206 close(apps_cmd_pipe[1]);
1207
1208 lttng_poll_clean(&events);
1209
1210 rcu_thread_offline();
1211 rcu_unregister_thread();
1212 return NULL;
1213 }
1214
1215 /*
1216 * Dispatch request from the registration threads to the application
1217 * communication thread.
1218 */
1219 static void *thread_dispatch_ust_registration(void *data)
1220 {
1221 int ret;
1222 struct cds_wfq_node *node;
1223 struct ust_command *ust_cmd = NULL;
1224
1225 DBG("[thread] Dispatch UST command started");
1226
1227 while (!dispatch_thread_exit) {
1228 /* Atomically prepare the queue futex */
1229 futex_nto1_prepare(&ust_cmd_queue.futex);
1230
1231 do {
1232 /* Dequeue command for registration */
1233 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1234 if (node == NULL) {
1235 DBG("Woken up but nothing in the UST command queue");
1236 /* Continue thread execution */
1237 break;
1238 }
1239
1240 ust_cmd = caa_container_of(node, struct ust_command, node);
1241
1242 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1243 " gid:%d sock:%d name:%s (version %d.%d)",
1244 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1245 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1246 ust_cmd->sock, ust_cmd->reg_msg.name,
1247 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1248 /*
1249 * Inform apps thread of the new application registration. This
1250 * call is blocking so we can be assured that the data will be read
1251 * at some point in time or wait to the end of the world :)
1252 */
1253 ret = write(apps_cmd_pipe[1], ust_cmd,
1254 sizeof(struct ust_command));
1255 if (ret < 0) {
1256 perror("write apps cmd pipe");
1257 if (errno == EBADF) {
1258 /*
1259 * We can't inform the application thread to process
1260 * registration. We will exit or else application
1261 * registration will not occur and tracing will never
1262 * start.
1263 */
1264 goto error;
1265 }
1266 }
1267 free(ust_cmd);
1268 } while (node != NULL);
1269
1270 /* Futex wait on queue. Blocking call on futex() */
1271 futex_nto1_wait(&ust_cmd_queue.futex);
1272 }
1273
1274 error:
1275 DBG("Dispatch thread dying");
1276 return NULL;
1277 }
1278
1279 /*
1280 * This thread manage application registration.
1281 */
1282 static void *thread_registration_apps(void *data)
1283 {
1284 int sock = 0, i, ret, pollfd;
1285 uint32_t revents, nb_fd;
1286 struct lttng_poll_event events;
1287 /*
1288 * Get allocated in this thread, enqueued to a global queue, dequeued and
1289 * freed in the manage apps thread.
1290 */
1291 struct ust_command *ust_cmd = NULL;
1292
1293 DBG("[thread] Manage application registration started");
1294
1295 ret = lttcomm_listen_unix_sock(apps_sock);
1296 if (ret < 0) {
1297 goto error;
1298 }
1299
1300 /*
1301 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1302 * more will be added to this poll set.
1303 */
1304 ret = create_thread_poll_set(&events, 2);
1305 if (ret < 0) {
1306 goto error;
1307 }
1308
1309 /* Add the application registration socket */
1310 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1311 if (ret < 0) {
1312 goto error;
1313 }
1314
1315 /* Notify all applications to register */
1316 ret = notify_ust_apps(1);
1317 if (ret < 0) {
1318 ERR("Failed to notify applications or create the wait shared memory.\n"
1319 "Execution continues but there might be problem for already\n"
1320 "running applications that wishes to register.");
1321 }
1322
1323 while (1) {
1324 DBG("Accepting application registration");
1325
1326 nb_fd = LTTNG_POLL_GETNB(&events);
1327
1328 /* Inifinite blocking call, waiting for transmission */
1329 ret = lttng_poll_wait(&events, -1);
1330 if (ret < 0) {
1331 goto error;
1332 }
1333
1334 for (i = 0; i < nb_fd; i++) {
1335 /* Fetch once the poll data */
1336 revents = LTTNG_POLL_GETEV(&events, i);
1337 pollfd = LTTNG_POLL_GETFD(&events, i);
1338
1339 /* Thread quit pipe has been closed. Killing thread. */
1340 ret = check_thread_quit_pipe(pollfd, revents);
1341 if (ret) {
1342 goto error;
1343 }
1344
1345 /* Event on the registration socket */
1346 if (pollfd == apps_sock) {
1347 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1348 ERR("Register apps socket poll error");
1349 goto error;
1350 } else if (revents & LPOLLIN) {
1351 sock = lttcomm_accept_unix_sock(apps_sock);
1352 if (sock < 0) {
1353 goto error;
1354 }
1355
1356 /* Create UST registration command for enqueuing */
1357 ust_cmd = zmalloc(sizeof(struct ust_command));
1358 if (ust_cmd == NULL) {
1359 perror("ust command zmalloc");
1360 goto error;
1361 }
1362
1363 /*
1364 * Using message-based transmissions to ensure we don't
1365 * have to deal with partially received messages.
1366 */
1367 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1368 sizeof(struct ust_register_msg));
1369 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1370 if (ret < 0) {
1371 perror("lttcomm_recv_unix_sock register apps");
1372 } else {
1373 ERR("Wrong size received on apps register");
1374 }
1375 free(ust_cmd);
1376 close(sock);
1377 continue;
1378 }
1379
1380 ust_cmd->sock = sock;
1381
1382 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1383 " gid:%d sock:%d name:%s (version %d.%d)",
1384 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1385 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1386 ust_cmd->sock, ust_cmd->reg_msg.name,
1387 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1388
1389 /*
1390 * Lock free enqueue the registration request. The red pill
1391 * has been taken! This apps will be part of the *system*.
1392 */
1393 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1394
1395 /*
1396 * Wake the registration queue futex. Implicit memory
1397 * barrier with the exchange in cds_wfq_enqueue.
1398 */
1399 futex_nto1_wake(&ust_cmd_queue.futex);
1400 }
1401 }
1402 }
1403 }
1404
1405 error:
1406 DBG("UST Registration thread dying");
1407
1408 /* Notify that the registration thread is gone */
1409 notify_ust_apps(0);
1410
1411 close(apps_sock);
1412 close(sock);
1413 unlink(apps_unix_sock_path);
1414
1415 lttng_poll_clean(&events);
1416
1417 return NULL;
1418 }
1419
1420 /*
1421 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1422 * exec or it will fails.
1423 */
1424 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1425 {
1426 int ret;
1427 struct timespec timeout;
1428
1429 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1430 timeout.tv_nsec = 0;
1431
1432 /* Setup semaphore */
1433 ret = sem_init(&consumer_data->sem, 0, 0);
1434 if (ret < 0) {
1435 PERROR("sem_init consumer semaphore");
1436 goto error;
1437 }
1438
1439 ret = pthread_create(&consumer_data->thread, NULL,
1440 thread_manage_consumer, consumer_data);
1441 if (ret != 0) {
1442 PERROR("pthread_create consumer");
1443 ret = -1;
1444 goto error;
1445 }
1446
1447 /* Get time for sem_timedwait absolute timeout */
1448 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1449 if (ret < 0) {
1450 PERROR("clock_gettime spawn consumer");
1451 /* Infinite wait for the kconsumerd thread to be ready */
1452 ret = sem_wait(&consumer_data->sem);
1453 } else {
1454 /* Normal timeout if the gettime was successful */
1455 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1456 ret = sem_timedwait(&consumer_data->sem, &timeout);
1457 }
1458
1459 if (ret < 0) {
1460 if (errno == ETIMEDOUT) {
1461 /*
1462 * Call has timed out so we kill the kconsumerd_thread and return
1463 * an error.
1464 */
1465 ERR("The consumer thread was never ready. Killing it");
1466 ret = pthread_cancel(consumer_data->thread);
1467 if (ret < 0) {
1468 PERROR("pthread_cancel consumer thread");
1469 }
1470 } else {
1471 PERROR("semaphore wait failed consumer thread");
1472 }
1473 goto error;
1474 }
1475
1476 pthread_mutex_lock(&consumer_data->pid_mutex);
1477 if (consumer_data->pid == 0) {
1478 ERR("Kconsumerd did not start");
1479 pthread_mutex_unlock(&consumer_data->pid_mutex);
1480 goto error;
1481 }
1482 pthread_mutex_unlock(&consumer_data->pid_mutex);
1483
1484 return 0;
1485
1486 error:
1487 return ret;
1488 }
1489
1490 /*
1491 * Join consumer thread
1492 */
1493 static int join_consumer_thread(struct consumer_data *consumer_data)
1494 {
1495 void *status;
1496 int ret;
1497
1498 if (consumer_data->pid != 0) {
1499 ret = kill(consumer_data->pid, SIGTERM);
1500 if (ret) {
1501 ERR("Error killing consumer daemon");
1502 return ret;
1503 }
1504 return pthread_join(consumer_data->thread, &status);
1505 } else {
1506 return 0;
1507 }
1508 }
1509
1510 /*
1511 * Fork and exec a consumer daemon (consumerd).
1512 *
1513 * Return pid if successful else -1.
1514 */
1515 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1516 {
1517 int ret;
1518 pid_t pid;
1519 const char *consumer_to_use;
1520 const char *verbosity;
1521 struct stat st;
1522
1523 DBG("Spawning consumerd");
1524
1525 pid = fork();
1526 if (pid == 0) {
1527 /*
1528 * Exec consumerd.
1529 */
1530 if (opt_verbose_consumer) {
1531 verbosity = "--verbose";
1532 } else {
1533 verbosity = "--quiet";
1534 }
1535 switch (consumer_data->type) {
1536 case LTTNG_CONSUMER_KERNEL:
1537 /*
1538 * Find out which consumerd to execute. We will
1539 * first try the 64-bit path, then the
1540 * sessiond's installation directory, and
1541 * fallback on the 32-bit one,
1542 */
1543 DBG3("Looking for a kernel consumer at these locations:");
1544 DBG3(" 1) %s", consumerd64_bin);
1545 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, CONSUMERD_FILE);
1546 DBG3(" 3) %s", consumerd32_bin);
1547 if (stat(consumerd64_bin, &st) == 0) {
1548 DBG3("Found location #1");
1549 consumer_to_use = consumerd64_bin;
1550 } else if (stat(INSTALL_BIN_PATH "/" CONSUMERD_FILE, &st) == 0) {
1551 DBG3("Found location #2");
1552 consumer_to_use = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
1553 } else if (stat(consumerd32_bin, &st) == 0) {
1554 DBG3("Found location #3");
1555 consumer_to_use = consumerd32_bin;
1556 } else {
1557 DBG("Could not find any valid consumerd executable");
1558 break;
1559 }
1560 DBG("Using kernel consumer at: %s", consumer_to_use);
1561 execl(consumer_to_use,
1562 "lttng-consumerd", verbosity, "-k",
1563 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1564 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1565 NULL);
1566 break;
1567 case LTTNG_CONSUMER64_UST:
1568 {
1569 char *tmpnew = NULL;
1570
1571 if (consumerd64_libdir[0] != '\0') {
1572 char *tmp;
1573 size_t tmplen;
1574
1575 tmp = getenv("LD_LIBRARY_PATH");
1576 if (!tmp) {
1577 tmp = "";
1578 }
1579 tmplen = strlen("LD_LIBRARY_PATH=")
1580 + strlen(consumerd64_libdir) + 1 /* : */ + strlen(tmp);
1581 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1582 if (!tmpnew) {
1583 ret = -ENOMEM;
1584 goto error;
1585 }
1586 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1587 strcat(tmpnew, consumerd64_libdir);
1588 if (tmp[0] != '\0') {
1589 strcat(tmpnew, ":");
1590 strcat(tmpnew, tmp);
1591 }
1592 ret = putenv(tmpnew);
1593 if (ret) {
1594 ret = -errno;
1595 goto error;
1596 }
1597 }
1598 DBG("Using 64-bit UST consumer at: %s", consumerd64_bin);
1599 ret = execl(consumerd64_bin, "lttng-consumerd", verbosity, "-u",
1600 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1601 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1602 NULL);
1603 if (consumerd64_libdir[0] != '\0') {
1604 free(tmpnew);
1605 }
1606 if (ret) {
1607 goto error;
1608 }
1609 break;
1610 }
1611 case LTTNG_CONSUMER32_UST:
1612 {
1613 char *tmpnew = NULL;
1614
1615 if (consumerd32_libdir[0] != '\0') {
1616 char *tmp;
1617 size_t tmplen;
1618
1619 tmp = getenv("LD_LIBRARY_PATH");
1620 if (!tmp) {
1621 tmp = "";
1622 }
1623 tmplen = strlen("LD_LIBRARY_PATH=")
1624 + strlen(consumerd32_libdir) + 1 /* : */ + strlen(tmp);
1625 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1626 if (!tmpnew) {
1627 ret = -ENOMEM;
1628 goto error;
1629 }
1630 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1631 strcat(tmpnew, consumerd32_libdir);
1632 if (tmp[0] != '\0') {
1633 strcat(tmpnew, ":");
1634 strcat(tmpnew, tmp);
1635 }
1636 ret = putenv(tmpnew);
1637 if (ret) {
1638 ret = -errno;
1639 goto error;
1640 }
1641 }
1642 DBG("Using 32-bit UST consumer at: %s", consumerd32_bin);
1643 ret = execl(consumerd32_bin, "lttng-consumerd", verbosity, "-u",
1644 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1645 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1646 NULL);
1647 if (consumerd32_libdir[0] != '\0') {
1648 free(tmpnew);
1649 }
1650 if (ret) {
1651 goto error;
1652 }
1653 break;
1654 }
1655 default:
1656 perror("unknown consumer type");
1657 exit(EXIT_FAILURE);
1658 }
1659 if (errno != 0) {
1660 perror("kernel start consumer exec");
1661 }
1662 exit(EXIT_FAILURE);
1663 } else if (pid > 0) {
1664 ret = pid;
1665 } else {
1666 perror("start consumer fork");
1667 ret = -errno;
1668 }
1669 error:
1670 return ret;
1671 }
1672
1673 /*
1674 * Spawn the consumerd daemon and session daemon thread.
1675 */
1676 static int start_consumerd(struct consumer_data *consumer_data)
1677 {
1678 int ret;
1679
1680 pthread_mutex_lock(&consumer_data->pid_mutex);
1681 if (consumer_data->pid != 0) {
1682 pthread_mutex_unlock(&consumer_data->pid_mutex);
1683 goto end;
1684 }
1685
1686 ret = spawn_consumerd(consumer_data);
1687 if (ret < 0) {
1688 ERR("Spawning consumerd failed");
1689 pthread_mutex_unlock(&consumer_data->pid_mutex);
1690 goto error;
1691 }
1692
1693 /* Setting up the consumer_data pid */
1694 consumer_data->pid = ret;
1695 DBG2("Consumer pid %d", consumer_data->pid);
1696 pthread_mutex_unlock(&consumer_data->pid_mutex);
1697
1698 DBG2("Spawning consumer control thread");
1699 ret = spawn_consumer_thread(consumer_data);
1700 if (ret < 0) {
1701 ERR("Fatal error spawning consumer control thread");
1702 goto error;
1703 }
1704
1705 end:
1706 return 0;
1707
1708 error:
1709 return ret;
1710 }
1711
1712 /*
1713 * modprobe_kernel_modules
1714 */
1715 static int modprobe_kernel_modules(void)
1716 {
1717 int ret = 0, i;
1718 char modprobe[256];
1719
1720 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1721 ret = snprintf(modprobe, sizeof(modprobe),
1722 "/sbin/modprobe %s%s",
1723 kernel_modules_list[i].required ? "" : "-q ",
1724 kernel_modules_list[i].name);
1725 if (ret < 0) {
1726 perror("snprintf modprobe");
1727 goto error;
1728 }
1729 modprobe[sizeof(modprobe) - 1] = '\0';
1730 ret = system(modprobe);
1731 if (ret == -1) {
1732 ERR("Unable to launch modprobe for module %s",
1733 kernel_modules_list[i].name);
1734 } else if (kernel_modules_list[i].required
1735 && WEXITSTATUS(ret) != 0) {
1736 ERR("Unable to load module %s",
1737 kernel_modules_list[i].name);
1738 } else {
1739 DBG("Modprobe successfully %s",
1740 kernel_modules_list[i].name);
1741 }
1742 }
1743
1744 error:
1745 return ret;
1746 }
1747
1748 /*
1749 * mount_debugfs
1750 */
1751 static int mount_debugfs(char *path)
1752 {
1753 int ret;
1754 char *type = "debugfs";
1755
1756 ret = mkdir_recursive_run_as(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1757 if (ret < 0) {
1758 PERROR("Cannot create debugfs path");
1759 goto error;
1760 }
1761
1762 ret = mount(type, path, type, 0, NULL);
1763 if (ret < 0) {
1764 PERROR("Cannot mount debugfs");
1765 goto error;
1766 }
1767
1768 DBG("Mounted debugfs successfully at %s", path);
1769
1770 error:
1771 return ret;
1772 }
1773
1774 /*
1775 * Setup necessary data for kernel tracer action.
1776 */
1777 static void init_kernel_tracer(void)
1778 {
1779 int ret;
1780 char *proc_mounts = "/proc/mounts";
1781 char line[256];
1782 char *debugfs_path = NULL, *lttng_path = NULL;
1783 FILE *fp;
1784
1785 /* Detect debugfs */
1786 fp = fopen(proc_mounts, "r");
1787 if (fp == NULL) {
1788 ERR("Unable to probe %s", proc_mounts);
1789 goto error;
1790 }
1791
1792 while (fgets(line, sizeof(line), fp) != NULL) {
1793 if (strstr(line, "debugfs") != NULL) {
1794 /* Remove first string */
1795 strtok(line, " ");
1796 /* Dup string here so we can reuse line later on */
1797 debugfs_path = strdup(strtok(NULL, " "));
1798 DBG("Got debugfs path : %s", debugfs_path);
1799 break;
1800 }
1801 }
1802
1803 fclose(fp);
1804
1805 /* Mount debugfs if needded */
1806 if (debugfs_path == NULL) {
1807 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1808 if (ret < 0) {
1809 perror("asprintf debugfs path");
1810 goto error;
1811 }
1812 ret = mount_debugfs(debugfs_path);
1813 if (ret < 0) {
1814 perror("Cannot mount debugfs");
1815 goto error;
1816 }
1817 }
1818
1819 /* Modprobe lttng kernel modules */
1820 ret = modprobe_kernel_modules();
1821 if (ret < 0) {
1822 goto error;
1823 }
1824
1825 /* Setup lttng kernel path */
1826 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1827 if (ret < 0) {
1828 perror("asprintf lttng path");
1829 goto error;
1830 }
1831
1832 /* Open debugfs lttng */
1833 kernel_tracer_fd = open(lttng_path, O_RDWR);
1834 if (kernel_tracer_fd < 0) {
1835 DBG("Failed to open %s", lttng_path);
1836 goto error;
1837 }
1838
1839 free(lttng_path);
1840 free(debugfs_path);
1841 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1842 return;
1843
1844 error:
1845 if (lttng_path) {
1846 free(lttng_path);
1847 }
1848 if (debugfs_path) {
1849 free(debugfs_path);
1850 }
1851 WARN("No kernel tracer available");
1852 kernel_tracer_fd = 0;
1853 return;
1854 }
1855
1856 /*
1857 * Init tracing by creating trace directory and sending fds kernel consumer.
1858 */
1859 static int init_kernel_tracing(struct ltt_kernel_session *session)
1860 {
1861 int ret = 0;
1862
1863 if (session->consumer_fds_sent == 0) {
1864 /*
1865 * Assign default kernel consumer socket if no consumer assigned to the
1866 * kernel session. At this point, it's NOT suppose to be 0 but this is
1867 * an extra security check.
1868 */
1869 if (session->consumer_fd == 0) {
1870 session->consumer_fd = kconsumer_data.cmd_sock;
1871 }
1872
1873 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1874 if (ret < 0) {
1875 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1876 goto error;
1877 }
1878
1879 session->consumer_fds_sent = 1;
1880 }
1881
1882 error:
1883 return ret;
1884 }
1885
1886 /*
1887 * Create an UST session and add it to the session ust list.
1888 */
1889 static int create_ust_session(struct ltt_session *session,
1890 struct lttng_domain *domain)
1891 {
1892 struct ltt_ust_session *lus = NULL;
1893 int ret;
1894
1895 switch (domain->type) {
1896 case LTTNG_DOMAIN_UST:
1897 break;
1898 default:
1899 ret = LTTCOMM_UNKNOWN_DOMAIN;
1900 goto error;
1901 }
1902
1903 DBG("Creating UST session");
1904
1905 lus = trace_ust_create_session(session->path, session->id, domain);
1906 if (lus == NULL) {
1907 ret = LTTCOMM_UST_SESS_FAIL;
1908 goto error;
1909 }
1910
1911 ret = mkdir_recursive_run_as(lus->pathname, S_IRWXU | S_IRWXG,
1912 session->uid, session->gid);
1913 if (ret < 0) {
1914 if (ret != -EEXIST) {
1915 ERR("Trace directory creation error");
1916 ret = LTTCOMM_UST_SESS_FAIL;
1917 goto error;
1918 }
1919 }
1920
1921 /* The domain type dictate different actions on session creation */
1922 switch (domain->type) {
1923 case LTTNG_DOMAIN_UST:
1924 /* No ustctl for the global UST domain */
1925 break;
1926 default:
1927 ERR("Unknown UST domain on create session %d", domain->type);
1928 goto error;
1929 }
1930 lus->uid = session->uid;
1931 lus->gid = session->gid;
1932 session->ust_session = lus;
1933
1934 return LTTCOMM_OK;
1935
1936 error:
1937 free(lus);
1938 return ret;
1939 }
1940
1941 /*
1942 * Create a kernel tracer session then create the default channel.
1943 */
1944 static int create_kernel_session(struct ltt_session *session)
1945 {
1946 int ret;
1947
1948 DBG("Creating kernel session");
1949
1950 ret = kernel_create_session(session, kernel_tracer_fd);
1951 if (ret < 0) {
1952 ret = LTTCOMM_KERN_SESS_FAIL;
1953 goto error;
1954 }
1955
1956 /* Set kernel consumer socket fd */
1957 if (kconsumer_data.cmd_sock) {
1958 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1959 }
1960
1961 ret = mkdir_recursive_run_as(session->kernel_session->trace_path,
1962 S_IRWXU | S_IRWXG, session->uid, session->gid);
1963 if (ret < 0) {
1964 if (ret != -EEXIST) {
1965 ERR("Trace directory creation error");
1966 goto error;
1967 }
1968 }
1969 session->kernel_session->uid = session->uid;
1970 session->kernel_session->gid = session->gid;
1971
1972 error:
1973 return ret;
1974 }
1975
1976 /*
1977 * Check if the UID or GID match the session. Root user has access to
1978 * all sessions.
1979 */
1980 static int session_access_ok(struct ltt_session *session,
1981 uid_t uid, gid_t gid)
1982 {
1983 if (uid != session->uid && gid != session->gid
1984 && uid != 0) {
1985 return 0;
1986 } else {
1987 return 1;
1988 }
1989 }
1990
1991 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
1992 {
1993 unsigned int i = 0;
1994 struct ltt_session *session;
1995
1996 DBG("Counting number of available session for UID %d GID %d",
1997 uid, gid);
1998 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1999 /*
2000 * Only list the sessions the user can control.
2001 */
2002 if (!session_access_ok(session, uid, gid)) {
2003 continue;
2004 }
2005 i++;
2006 }
2007 return i;
2008 }
2009
2010 /*
2011 * Using the session list, filled a lttng_session array to send back to the
2012 * client for session listing.
2013 *
2014 * The session list lock MUST be acquired before calling this function. Use
2015 * session_lock_list() and session_unlock_list().
2016 */
2017 static void list_lttng_sessions(struct lttng_session *sessions,
2018 uid_t uid, gid_t gid)
2019 {
2020 unsigned int i = 0;
2021 struct ltt_session *session;
2022
2023 DBG("Getting all available session for UID %d GID %d",
2024 uid, gid);
2025 /*
2026 * Iterate over session list and append data after the control struct in
2027 * the buffer.
2028 */
2029 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
2030 /*
2031 * Only list the sessions the user can control.
2032 */
2033 if (!session_access_ok(session, uid, gid)) {
2034 continue;
2035 }
2036 strncpy(sessions[i].path, session->path, PATH_MAX);
2037 sessions[i].path[PATH_MAX - 1] = '\0';
2038 strncpy(sessions[i].name, session->name, NAME_MAX);
2039 sessions[i].name[NAME_MAX - 1] = '\0';
2040 sessions[i].enabled = session->enabled;
2041 i++;
2042 }
2043 }
2044
2045 /*
2046 * Fill lttng_channel array of all channels.
2047 */
2048 static void list_lttng_channels(int domain, struct ltt_session *session,
2049 struct lttng_channel *channels)
2050 {
2051 int i = 0;
2052 struct ltt_kernel_channel *kchan;
2053
2054 DBG("Listing channels for session %s", session->name);
2055
2056 switch (domain) {
2057 case LTTNG_DOMAIN_KERNEL:
2058 /* Kernel channels */
2059 if (session->kernel_session != NULL) {
2060 cds_list_for_each_entry(kchan,
2061 &session->kernel_session->channel_list.head, list) {
2062 /* Copy lttng_channel struct to array */
2063 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
2064 channels[i].enabled = kchan->enabled;
2065 i++;
2066 }
2067 }
2068 break;
2069 case LTTNG_DOMAIN_UST:
2070 {
2071 struct lttng_ht_iter iter;
2072 struct ltt_ust_channel *uchan;
2073
2074 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
2075 &iter.iter, uchan, node.node) {
2076 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
2077 channels[i].attr.overwrite = uchan->attr.overwrite;
2078 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
2079 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
2080 channels[i].attr.switch_timer_interval =
2081 uchan->attr.switch_timer_interval;
2082 channels[i].attr.read_timer_interval =
2083 uchan->attr.read_timer_interval;
2084 channels[i].enabled = uchan->enabled;
2085 switch (uchan->attr.output) {
2086 case LTTNG_UST_MMAP:
2087 default:
2088 channels[i].attr.output = LTTNG_EVENT_MMAP;
2089 break;
2090 }
2091 i++;
2092 }
2093 break;
2094 }
2095 default:
2096 break;
2097 }
2098 }
2099
2100 /*
2101 * Create a list of ust global domain events.
2102 */
2103 static int list_lttng_ust_global_events(char *channel_name,
2104 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
2105 {
2106 int i = 0, ret = 0;
2107 unsigned int nb_event = 0;
2108 struct lttng_ht_iter iter;
2109 struct lttng_ht_node_str *node;
2110 struct ltt_ust_channel *uchan;
2111 struct ltt_ust_event *uevent;
2112 struct lttng_event *tmp;
2113
2114 DBG("Listing UST global events for channel %s", channel_name);
2115
2116 rcu_read_lock();
2117
2118 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
2119 node = lttng_ht_iter_get_node_str(&iter);
2120 if (node == NULL) {
2121 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
2122 goto error;
2123 }
2124
2125 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
2126
2127 nb_event += lttng_ht_get_count(uchan->events);
2128
2129 if (nb_event == 0) {
2130 ret = nb_event;
2131 goto error;
2132 }
2133
2134 DBG3("Listing UST global %d events", nb_event);
2135
2136 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
2137 if (tmp == NULL) {
2138 ret = -LTTCOMM_FATAL;
2139 goto error;
2140 }
2141
2142 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
2143 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
2144 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2145 tmp[i].enabled = uevent->enabled;
2146 switch (uevent->attr.instrumentation) {
2147 case LTTNG_UST_TRACEPOINT:
2148 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
2149 break;
2150 case LTTNG_UST_PROBE:
2151 tmp[i].type = LTTNG_EVENT_PROBE;
2152 break;
2153 case LTTNG_UST_FUNCTION:
2154 tmp[i].type = LTTNG_EVENT_FUNCTION;
2155 break;
2156 case LTTNG_UST_TRACEPOINT_LOGLEVEL:
2157 tmp[i].type = LTTNG_EVENT_TRACEPOINT_LOGLEVEL;
2158 break;
2159 }
2160 i++;
2161 }
2162
2163 ret = nb_event;
2164 *events = tmp;
2165
2166 error:
2167 rcu_read_unlock();
2168 return ret;
2169 }
2170
2171 /*
2172 * Fill lttng_event array of all kernel events in the channel.
2173 */
2174 static int list_lttng_kernel_events(char *channel_name,
2175 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
2176 {
2177 int i = 0, ret;
2178 unsigned int nb_event;
2179 struct ltt_kernel_event *event;
2180 struct ltt_kernel_channel *kchan;
2181
2182 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
2183 if (kchan == NULL) {
2184 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2185 goto error;
2186 }
2187
2188 nb_event = kchan->event_count;
2189
2190 DBG("Listing events for channel %s", kchan->channel->name);
2191
2192 if (nb_event == 0) {
2193 ret = nb_event;
2194 goto error;
2195 }
2196
2197 *events = zmalloc(nb_event * sizeof(struct lttng_event));
2198 if (*events == NULL) {
2199 ret = LTTCOMM_FATAL;
2200 goto error;
2201 }
2202
2203 /* Kernel channels */
2204 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
2205 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
2206 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2207 (*events)[i].enabled = event->enabled;
2208 switch (event->event->instrumentation) {
2209 case LTTNG_KERNEL_TRACEPOINT:
2210 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
2211 break;
2212 case LTTNG_KERNEL_KPROBE:
2213 case LTTNG_KERNEL_KRETPROBE:
2214 (*events)[i].type = LTTNG_EVENT_PROBE;
2215 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
2216 sizeof(struct lttng_kernel_kprobe));
2217 break;
2218 case LTTNG_KERNEL_FUNCTION:
2219 (*events)[i].type = LTTNG_EVENT_FUNCTION;
2220 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
2221 sizeof(struct lttng_kernel_function));
2222 break;
2223 case LTTNG_KERNEL_NOOP:
2224 (*events)[i].type = LTTNG_EVENT_NOOP;
2225 break;
2226 case LTTNG_KERNEL_SYSCALL:
2227 (*events)[i].type = LTTNG_EVENT_SYSCALL;
2228 break;
2229 case LTTNG_KERNEL_ALL:
2230 assert(0);
2231 break;
2232 }
2233 i++;
2234 }
2235
2236 return nb_event;
2237
2238 error:
2239 return ret;
2240 }
2241
2242 /*
2243 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
2244 */
2245 static int cmd_disable_channel(struct ltt_session *session,
2246 int domain, char *channel_name)
2247 {
2248 int ret;
2249 struct ltt_ust_session *usess;
2250
2251 usess = session->ust_session;
2252
2253 switch (domain) {
2254 case LTTNG_DOMAIN_KERNEL:
2255 {
2256 ret = channel_kernel_disable(session->kernel_session,
2257 channel_name);
2258 if (ret != LTTCOMM_OK) {
2259 goto error;
2260 }
2261
2262 kernel_wait_quiescent(kernel_tracer_fd);
2263 break;
2264 }
2265 case LTTNG_DOMAIN_UST:
2266 {
2267 struct ltt_ust_channel *uchan;
2268 struct lttng_ht *chan_ht;
2269
2270 chan_ht = usess->domain_global.channels;
2271
2272 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
2273 if (uchan == NULL) {
2274 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2275 goto error;
2276 }
2277
2278 ret = channel_ust_disable(usess, domain, uchan);
2279 if (ret != LTTCOMM_OK) {
2280 goto error;
2281 }
2282 break;
2283 }
2284 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2285 case LTTNG_DOMAIN_UST_EXEC_NAME:
2286 case LTTNG_DOMAIN_UST_PID:
2287 ret = LTTCOMM_NOT_IMPLEMENTED;
2288 goto error;
2289 default:
2290 ret = LTTCOMM_UNKNOWN_DOMAIN;
2291 goto error;
2292 }
2293
2294 ret = LTTCOMM_OK;
2295
2296 error:
2297 return ret;
2298 }
2299
2300 /*
2301 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2302 */
2303 static int cmd_enable_channel(struct ltt_session *session,
2304 int domain, struct lttng_channel *attr)
2305 {
2306 int ret;
2307 struct ltt_ust_session *usess = session->ust_session;
2308 struct lttng_ht *chan_ht;
2309
2310 DBG("Enabling channel %s for session %s", attr->name, session->name);
2311
2312 switch (domain) {
2313 case LTTNG_DOMAIN_KERNEL:
2314 {
2315 struct ltt_kernel_channel *kchan;
2316
2317 kchan = trace_kernel_get_channel_by_name(attr->name,
2318 session->kernel_session);
2319 if (kchan == NULL) {
2320 ret = channel_kernel_create(session->kernel_session,
2321 attr, kernel_poll_pipe[1]);
2322 } else {
2323 ret = channel_kernel_enable(session->kernel_session, kchan);
2324 }
2325
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
2337 chan_ht = usess->domain_global.channels;
2338
2339 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
2340 if (uchan == NULL) {
2341 ret = channel_ust_create(usess, domain, attr);
2342 } else {
2343 ret = channel_ust_enable(usess, domain, uchan);
2344 }
2345 break;
2346 }
2347 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2348 case LTTNG_DOMAIN_UST_EXEC_NAME:
2349 case LTTNG_DOMAIN_UST_PID:
2350 ret = LTTCOMM_NOT_IMPLEMENTED;
2351 goto error;
2352 default:
2353 ret = LTTCOMM_UNKNOWN_DOMAIN;
2354 goto error;
2355 }
2356
2357 error:
2358 return ret;
2359 }
2360
2361 /*
2362 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2363 */
2364 static int cmd_disable_event(struct ltt_session *session, int domain,
2365 char *channel_name, char *event_name)
2366 {
2367 int ret;
2368
2369 switch (domain) {
2370 case LTTNG_DOMAIN_KERNEL:
2371 {
2372 struct ltt_kernel_channel *kchan;
2373 struct ltt_kernel_session *ksess;
2374
2375 ksess = session->kernel_session;
2376
2377 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2378 if (kchan == NULL) {
2379 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2380 goto error;
2381 }
2382
2383 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
2384 if (ret != LTTCOMM_OK) {
2385 goto error;
2386 }
2387
2388 kernel_wait_quiescent(kernel_tracer_fd);
2389 break;
2390 }
2391 case LTTNG_DOMAIN_UST:
2392 {
2393 struct ltt_ust_channel *uchan;
2394 struct ltt_ust_session *usess;
2395
2396 usess = session->ust_session;
2397
2398 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2399 channel_name);
2400 if (uchan == NULL) {
2401 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2402 goto error;
2403 }
2404
2405 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
2406 if (ret != LTTCOMM_OK) {
2407 goto error;
2408 }
2409
2410 DBG3("Disable UST event %s in channel %s completed", event_name,
2411 channel_name);
2412 break;
2413 }
2414 case LTTNG_DOMAIN_UST_EXEC_NAME:
2415 case LTTNG_DOMAIN_UST_PID:
2416 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2417 default:
2418 ret = LTTCOMM_NOT_IMPLEMENTED;
2419 goto error;
2420 }
2421
2422 ret = LTTCOMM_OK;
2423
2424 error:
2425 return ret;
2426 }
2427
2428 /*
2429 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2430 */
2431 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2432 char *channel_name)
2433 {
2434 int ret;
2435
2436 switch (domain) {
2437 case LTTNG_DOMAIN_KERNEL:
2438 {
2439 struct ltt_kernel_session *ksess;
2440 struct ltt_kernel_channel *kchan;
2441
2442 ksess = session->kernel_session;
2443
2444 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2445 if (kchan == NULL) {
2446 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2447 goto error;
2448 }
2449
2450 ret = event_kernel_disable_all(ksess, kchan);
2451 if (ret != LTTCOMM_OK) {
2452 goto error;
2453 }
2454
2455 kernel_wait_quiescent(kernel_tracer_fd);
2456 break;
2457 }
2458 case LTTNG_DOMAIN_UST:
2459 {
2460 struct ltt_ust_session *usess;
2461 struct ltt_ust_channel *uchan;
2462
2463 usess = session->ust_session;
2464
2465 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2466 channel_name);
2467 if (uchan == NULL) {
2468 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2469 goto error;
2470 }
2471
2472 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
2473 if (ret != 0) {
2474 goto error;
2475 }
2476
2477 DBG3("Disable all UST events in channel %s completed", channel_name);
2478
2479 break;
2480 }
2481 case LTTNG_DOMAIN_UST_EXEC_NAME:
2482 case LTTNG_DOMAIN_UST_PID:
2483 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2484 default:
2485 ret = LTTCOMM_NOT_IMPLEMENTED;
2486 goto error;
2487 }
2488
2489 ret = LTTCOMM_OK;
2490
2491 error:
2492 return ret;
2493 }
2494
2495 /*
2496 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2497 */
2498 static int cmd_add_context(struct ltt_session *session, int domain,
2499 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2500 {
2501 int ret;
2502
2503 switch (domain) {
2504 case LTTNG_DOMAIN_KERNEL:
2505 /* Add kernel context to kernel tracer */
2506 ret = context_kernel_add(session->kernel_session, ctx,
2507 event_name, channel_name);
2508 if (ret != LTTCOMM_OK) {
2509 goto error;
2510 }
2511 break;
2512 case LTTNG_DOMAIN_UST:
2513 {
2514 struct ltt_ust_session *usess = session->ust_session;
2515
2516 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
2517 if (ret != LTTCOMM_OK) {
2518 goto error;
2519 }
2520 break;
2521 }
2522 case LTTNG_DOMAIN_UST_EXEC_NAME:
2523 case LTTNG_DOMAIN_UST_PID:
2524 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2525 default:
2526 ret = LTTCOMM_NOT_IMPLEMENTED;
2527 goto error;
2528 }
2529
2530 ret = LTTCOMM_OK;
2531
2532 error:
2533 return ret;
2534 }
2535
2536 /*
2537 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2538 *
2539 * TODO: currently, both events and loglevels are kept within the same
2540 * namespace for UST global registry/app registery, so if an event
2541 * happen to have the same name as the loglevel (very unlikely though),
2542 * and an attempt is made to enable/disable both in the same session,
2543 * the first to be created will be the only one allowed to exist.
2544 */
2545 static int cmd_enable_event(struct ltt_session *session, int domain,
2546 char *channel_name, struct lttng_event *event)
2547 {
2548 int ret;
2549 struct lttng_channel *attr;
2550 struct ltt_ust_session *usess = session->ust_session;
2551
2552 switch (domain) {
2553 case LTTNG_DOMAIN_KERNEL:
2554 {
2555 struct ltt_kernel_channel *kchan;
2556
2557 kchan = trace_kernel_get_channel_by_name(channel_name,
2558 session->kernel_session);
2559 if (kchan == NULL) {
2560 attr = channel_new_default_attr(domain);
2561 if (attr == NULL) {
2562 ret = LTTCOMM_FATAL;
2563 goto error;
2564 }
2565 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2566
2567 /* This call will notify the kernel thread */
2568 ret = channel_kernel_create(session->kernel_session,
2569 attr, kernel_poll_pipe[1]);
2570 if (ret != LTTCOMM_OK) {
2571 free(attr);
2572 goto error;
2573 }
2574 free(attr);
2575 }
2576
2577 /* Get the newly created kernel channel pointer */
2578 kchan = trace_kernel_get_channel_by_name(channel_name,
2579 session->kernel_session);
2580 if (kchan == NULL) {
2581 /* This sould not happen... */
2582 ret = LTTCOMM_FATAL;
2583 goto error;
2584 }
2585
2586 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2587 event);
2588 if (ret != LTTCOMM_OK) {
2589 goto error;
2590 }
2591
2592 kernel_wait_quiescent(kernel_tracer_fd);
2593 break;
2594 }
2595 case LTTNG_DOMAIN_UST:
2596 {
2597 struct lttng_channel *attr;
2598 struct ltt_ust_channel *uchan;
2599
2600 /* Get channel from global UST domain */
2601 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2602 channel_name);
2603 if (uchan == NULL) {
2604 /* Create default channel */
2605 attr = channel_new_default_attr(domain);
2606 if (attr == NULL) {
2607 ret = LTTCOMM_FATAL;
2608 goto error;
2609 }
2610 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2611 attr->name[NAME_MAX - 1] = '\0';
2612
2613 ret = channel_ust_create(usess, domain, attr);
2614 if (ret != LTTCOMM_OK) {
2615 free(attr);
2616 goto error;
2617 }
2618 free(attr);
2619
2620 /* Get the newly created channel reference back */
2621 uchan = trace_ust_find_channel_by_name(
2622 usess->domain_global.channels, channel_name);
2623 if (uchan == NULL) {
2624 /* Something is really wrong */
2625 ret = LTTCOMM_FATAL;
2626 goto error;
2627 }
2628 }
2629
2630 /* At this point, the session and channel exist on the tracer */
2631 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
2632 if (ret != LTTCOMM_OK) {
2633 goto error;
2634 }
2635 break;
2636 }
2637 case LTTNG_DOMAIN_UST_EXEC_NAME:
2638 case LTTNG_DOMAIN_UST_PID:
2639 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2640 default:
2641 ret = LTTCOMM_NOT_IMPLEMENTED;
2642 goto error;
2643 }
2644
2645 ret = LTTCOMM_OK;
2646
2647 error:
2648 return ret;
2649 }
2650
2651 /*
2652 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2653 */
2654 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2655 char *channel_name, int event_type)
2656 {
2657 int ret;
2658 struct ltt_kernel_channel *kchan;
2659
2660 switch (domain) {
2661 case LTTNG_DOMAIN_KERNEL:
2662 kchan = trace_kernel_get_channel_by_name(channel_name,
2663 session->kernel_session);
2664 if (kchan == NULL) {
2665 /* This call will notify the kernel thread */
2666 ret = channel_kernel_create(session->kernel_session, NULL,
2667 kernel_poll_pipe[1]);
2668 if (ret != LTTCOMM_OK) {
2669 goto error;
2670 }
2671
2672 /* Get the newly created kernel channel pointer */
2673 kchan = trace_kernel_get_channel_by_name(channel_name,
2674 session->kernel_session);
2675 if (kchan == NULL) {
2676 /* This sould not happen... */
2677 ret = LTTCOMM_FATAL;
2678 goto error;
2679 }
2680
2681 }
2682
2683 switch (event_type) {
2684 case LTTNG_EVENT_SYSCALL:
2685 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2686 kchan, kernel_tracer_fd);
2687 break;
2688 case LTTNG_EVENT_TRACEPOINT:
2689 /*
2690 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2691 * events already registered to the channel.
2692 */
2693 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2694 kchan, kernel_tracer_fd);
2695 break;
2696 case LTTNG_EVENT_ALL:
2697 /* Enable syscalls and tracepoints */
2698 ret = event_kernel_enable_all(session->kernel_session,
2699 kchan, kernel_tracer_fd);
2700 break;
2701 default:
2702 ret = LTTCOMM_KERN_ENABLE_FAIL;
2703 goto error;
2704 }
2705
2706 /* Manage return value */
2707 if (ret != LTTCOMM_OK) {
2708 goto error;
2709 }
2710
2711 kernel_wait_quiescent(kernel_tracer_fd);
2712 break;
2713 case LTTNG_DOMAIN_UST:
2714 {
2715 struct lttng_channel *attr;
2716 struct ltt_ust_channel *uchan;
2717 struct ltt_ust_session *usess = session->ust_session;
2718
2719 /* Get channel from global UST domain */
2720 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2721 channel_name);
2722 if (uchan == NULL) {
2723 /* Create default channel */
2724 attr = channel_new_default_attr(domain);
2725 if (attr == NULL) {
2726 ret = LTTCOMM_FATAL;
2727 goto error;
2728 }
2729 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2730 attr->name[NAME_MAX - 1] = '\0';
2731
2732 /* Use the internal command enable channel */
2733 ret = channel_ust_create(usess, domain, attr);
2734 if (ret != LTTCOMM_OK) {
2735 free(attr);
2736 goto error;
2737 }
2738 free(attr);
2739
2740 /* Get the newly created channel reference back */
2741 uchan = trace_ust_find_channel_by_name(
2742 usess->domain_global.channels, channel_name);
2743 if (uchan == NULL) {
2744 /* Something is really wrong */
2745 ret = LTTCOMM_FATAL;
2746 goto error;
2747 }
2748 }
2749
2750 /* At this point, the session and channel exist on the tracer */
2751
2752 switch (event_type) {
2753 case LTTNG_EVENT_ALL:
2754 case LTTNG_EVENT_TRACEPOINT:
2755 ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
2756 if (ret != LTTCOMM_OK) {
2757 goto error;
2758 }
2759 break;
2760 default:
2761 ret = LTTCOMM_UST_ENABLE_FAIL;
2762 goto error;
2763 }
2764
2765 /* Manage return value */
2766 if (ret != LTTCOMM_OK) {
2767 goto error;
2768 }
2769
2770 break;
2771 }
2772 case LTTNG_DOMAIN_UST_EXEC_NAME:
2773 case LTTNG_DOMAIN_UST_PID:
2774 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2775 default:
2776 ret = LTTCOMM_NOT_IMPLEMENTED;
2777 goto error;
2778 }
2779
2780 ret = LTTCOMM_OK;
2781
2782 error:
2783 return ret;
2784 }
2785
2786 /*
2787 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2788 */
2789 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2790 {
2791 int ret;
2792 ssize_t nb_events = 0;
2793
2794 switch (domain) {
2795 case LTTNG_DOMAIN_KERNEL:
2796 nb_events = kernel_list_events(kernel_tracer_fd, events);
2797 if (nb_events < 0) {
2798 ret = LTTCOMM_KERN_LIST_FAIL;
2799 goto error;
2800 }
2801 break;
2802 case LTTNG_DOMAIN_UST:
2803 nb_events = ust_app_list_events(events);
2804 if (nb_events < 0) {
2805 ret = LTTCOMM_UST_LIST_FAIL;
2806 goto error;
2807 }
2808 break;
2809 default:
2810 ret = LTTCOMM_NOT_IMPLEMENTED;
2811 goto error;
2812 }
2813
2814 return nb_events;
2815
2816 error:
2817 /* Return negative value to differentiate return code */
2818 return -ret;
2819 }
2820
2821 /*
2822 * Command LTTNG_START_TRACE processed by the client thread.
2823 */
2824 static int cmd_start_trace(struct ltt_session *session)
2825 {
2826 int ret;
2827 struct ltt_kernel_session *ksession;
2828 struct ltt_ust_session *usess;
2829
2830 /* Short cut */
2831 ksession = session->kernel_session;
2832 usess = session->ust_session;
2833
2834 if (session->enabled) {
2835 ret = LTTCOMM_UST_START_FAIL;
2836 goto error;
2837 }
2838
2839 session->enabled = 1;
2840
2841 /* Kernel tracing */
2842 if (ksession != NULL) {
2843 struct ltt_kernel_channel *kchan;
2844
2845 /* Open kernel metadata */
2846 if (ksession->metadata == NULL) {
2847 ret = kernel_open_metadata(ksession, ksession->trace_path);
2848 if (ret < 0) {
2849 ret = LTTCOMM_KERN_META_FAIL;
2850 goto error;
2851 }
2852 }
2853
2854 /* Open kernel metadata stream */
2855 if (ksession->metadata_stream_fd == 0) {
2856 ret = kernel_open_metadata_stream(ksession);
2857 if (ret < 0) {
2858 ERR("Kernel create metadata stream failed");
2859 ret = LTTCOMM_KERN_STREAM_FAIL;
2860 goto error;
2861 }
2862 }
2863
2864 /* For each channel */
2865 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2866 if (kchan->stream_count == 0) {
2867 ret = kernel_open_channel_stream(kchan);
2868 if (ret < 0) {
2869 ret = LTTCOMM_KERN_STREAM_FAIL;
2870 goto error;
2871 }
2872 /* Update the stream global counter */
2873 ksession->stream_count_global += ret;
2874 }
2875 }
2876
2877 /* Setup kernel consumer socket and send fds to it */
2878 ret = init_kernel_tracing(ksession);
2879 if (ret < 0) {
2880 ret = LTTCOMM_KERN_START_FAIL;
2881 goto error;
2882 }
2883
2884 /* This start the kernel tracing */
2885 ret = kernel_start_session(ksession);
2886 if (ret < 0) {
2887 ret = LTTCOMM_KERN_START_FAIL;
2888 goto error;
2889 }
2890
2891 /* Quiescent wait after starting trace */
2892 kernel_wait_quiescent(kernel_tracer_fd);
2893 }
2894
2895 /* Flag session that trace should start automatically */
2896 if (usess) {
2897 usess->start_trace = 1;
2898
2899 ret = ust_app_start_trace_all(usess);
2900 if (ret < 0) {
2901 ret = LTTCOMM_UST_START_FAIL;
2902 goto error;
2903 }
2904 }
2905
2906 ret = LTTCOMM_OK;
2907
2908 error:
2909 return ret;
2910 }
2911
2912 /*
2913 * Command LTTNG_STOP_TRACE processed by the client thread.
2914 */
2915 static int cmd_stop_trace(struct ltt_session *session)
2916 {
2917 int ret;
2918 struct ltt_kernel_channel *kchan;
2919 struct ltt_kernel_session *ksession;
2920 struct ltt_ust_session *usess;
2921
2922 /* Short cut */
2923 ksession = session->kernel_session;
2924 usess = session->ust_session;
2925
2926 if (!session->enabled) {
2927 ret = LTTCOMM_UST_STOP_FAIL;
2928 goto error;
2929 }
2930
2931 session->enabled = 0;
2932
2933 /* Kernel tracer */
2934 if (ksession != NULL) {
2935 DBG("Stop kernel tracing");
2936
2937 /* Flush all buffers before stopping */
2938 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2939 if (ret < 0) {
2940 ERR("Kernel metadata flush failed");
2941 }
2942
2943 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2944 ret = kernel_flush_buffer(kchan);
2945 if (ret < 0) {
2946 ERR("Kernel flush buffer error");
2947 }
2948 }
2949
2950 ret = kernel_stop_session(ksession);
2951 if (ret < 0) {
2952 ret = LTTCOMM_KERN_STOP_FAIL;
2953 goto error;
2954 }
2955
2956 kernel_wait_quiescent(kernel_tracer_fd);
2957 }
2958
2959 if (usess) {
2960 usess->start_trace = 0;
2961
2962 ret = ust_app_stop_trace_all(usess);
2963 if (ret < 0) {
2964 ret = LTTCOMM_UST_STOP_FAIL;
2965 goto error;
2966 }
2967 }
2968
2969 ret = LTTCOMM_OK;
2970
2971 error:
2972 return ret;
2973 }
2974
2975 /*
2976 * Command LTTNG_CREATE_SESSION processed by the client thread.
2977 */
2978 static int cmd_create_session(char *name, char *path, struct ucred *creds)
2979 {
2980 int ret;
2981
2982 ret = session_create(name, path, creds->uid, creds->gid);
2983 if (ret != LTTCOMM_OK) {
2984 goto error;
2985 }
2986
2987 ret = LTTCOMM_OK;
2988
2989 error:
2990 return ret;
2991 }
2992
2993 /*
2994 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2995 */
2996 static int cmd_destroy_session(struct ltt_session *session, char *name)
2997 {
2998 int ret;
2999
3000 /* Clean kernel session teardown */
3001 teardown_kernel_session(session);
3002 /* UST session teardown */
3003 teardown_ust_session(session);
3004
3005 /*
3006 * Must notify the kernel thread here to update it's poll setin order
3007 * to remove the channel(s)' fd just destroyed.
3008 */
3009 ret = notify_thread_pipe(kernel_poll_pipe[1]);
3010 if (ret < 0) {
3011 perror("write kernel poll pipe");
3012 }
3013
3014 ret = session_destroy(session);
3015
3016 return ret;
3017 }
3018
3019 /*
3020 * Command LTTNG_CALIBRATE processed by the client thread.
3021 */
3022 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
3023 {
3024 int ret;
3025
3026 switch (domain) {
3027 case LTTNG_DOMAIN_KERNEL:
3028 {
3029 struct lttng_kernel_calibrate kcalibrate;
3030
3031 kcalibrate.type = calibrate->type;
3032 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
3033 if (ret < 0) {
3034 ret = LTTCOMM_KERN_ENABLE_FAIL;
3035 goto error;
3036 }
3037 break;
3038 }
3039 default:
3040 /* TODO: Userspace tracing */
3041 ret = LTTCOMM_NOT_IMPLEMENTED;
3042 goto error;
3043 }
3044
3045 ret = LTTCOMM_OK;
3046
3047 error:
3048 return ret;
3049 }
3050
3051 /*
3052 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3053 */
3054 static int cmd_register_consumer(struct ltt_session *session, int domain,
3055 char *sock_path)
3056 {
3057 int ret, sock;
3058
3059 switch (domain) {
3060 case LTTNG_DOMAIN_KERNEL:
3061 /* Can't register a consumer if there is already one */
3062 if (session->kernel_session->consumer_fds_sent != 0) {
3063 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3064 goto error;
3065 }
3066
3067 sock = lttcomm_connect_unix_sock(sock_path);
3068 if (sock < 0) {
3069 ret = LTTCOMM_CONNECT_FAIL;
3070 goto error;
3071 }
3072
3073 session->kernel_session->consumer_fd = sock;
3074 break;
3075 default:
3076 /* TODO: Userspace tracing */
3077 ret = LTTCOMM_NOT_IMPLEMENTED;
3078 goto error;
3079 }
3080
3081 ret = LTTCOMM_OK;
3082
3083 error:
3084 return ret;
3085 }
3086
3087 /*
3088 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3089 */
3090 static ssize_t cmd_list_domains(struct ltt_session *session,
3091 struct lttng_domain **domains)
3092 {
3093 int ret, index = 0;
3094 ssize_t nb_dom = 0;
3095
3096 if (session->kernel_session != NULL) {
3097 DBG3("Listing domains found kernel domain");
3098 nb_dom++;
3099 }
3100
3101 if (session->ust_session != NULL) {
3102 DBG3("Listing domains found UST global domain");
3103 nb_dom++;
3104 }
3105
3106 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3107 if (*domains == NULL) {
3108 ret = -LTTCOMM_FATAL;
3109 goto error;
3110 }
3111
3112 if (session->kernel_session != NULL) {
3113 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3114 index++;
3115 }
3116
3117 if (session->ust_session != NULL) {
3118 (*domains)[index].type = LTTNG_DOMAIN_UST;
3119 index++;
3120 }
3121
3122 return nb_dom;
3123
3124 error:
3125 return ret;
3126 }
3127
3128 /*
3129 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3130 */
3131 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
3132 struct lttng_channel **channels)
3133 {
3134 int ret;
3135 ssize_t nb_chan = 0;
3136
3137 switch (domain) {
3138 case LTTNG_DOMAIN_KERNEL:
3139 if (session->kernel_session != NULL) {
3140 nb_chan = session->kernel_session->channel_count;
3141 }
3142 DBG3("Number of kernel channels %zd", nb_chan);
3143 break;
3144 case LTTNG_DOMAIN_UST:
3145 if (session->ust_session != NULL) {
3146 nb_chan = lttng_ht_get_count(
3147 session->ust_session->domain_global.channels);
3148 }
3149 DBG3("Number of UST global channels %zd", nb_chan);
3150 break;
3151 default:
3152 *channels = NULL;
3153 ret = -LTTCOMM_NOT_IMPLEMENTED;
3154 goto error;
3155 }
3156
3157 if (nb_chan > 0) {
3158 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
3159 if (*channels == NULL) {
3160 ret = -LTTCOMM_FATAL;
3161 goto error;
3162 }
3163
3164 list_lttng_channels(domain, session, *channels);
3165 } else {
3166 *channels = NULL;
3167 }
3168
3169 return nb_chan;
3170
3171 error:
3172 return ret;
3173 }
3174
3175 /*
3176 * Command LTTNG_LIST_EVENTS processed by the client thread.
3177 */
3178 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
3179 char *channel_name, struct lttng_event **events)
3180 {
3181 int ret = 0;
3182 ssize_t nb_event = 0;
3183
3184 switch (domain) {
3185 case LTTNG_DOMAIN_KERNEL:
3186 if (session->kernel_session != NULL) {
3187 nb_event = list_lttng_kernel_events(channel_name,
3188 session->kernel_session, events);
3189 }
3190 break;
3191 case LTTNG_DOMAIN_UST:
3192 {
3193 if (session->ust_session != NULL) {
3194 nb_event = list_lttng_ust_global_events(channel_name,
3195 &session->ust_session->domain_global, events);
3196 }
3197 break;
3198 }
3199 default:
3200 ret = -LTTCOMM_NOT_IMPLEMENTED;
3201 goto error;
3202 }
3203
3204 ret = nb_event;
3205
3206 error:
3207 return ret;
3208 }
3209
3210 /*
3211 * Process the command requested by the lttng client within the command
3212 * context structure. This function make sure that the return structure (llm)
3213 * is set and ready for transmission before returning.
3214 *
3215 * Return any error encountered or 0 for success.
3216 */
3217 static int process_client_msg(struct command_ctx *cmd_ctx)
3218 {
3219 int ret = LTTCOMM_OK;
3220 int need_tracing_session = 1;
3221
3222 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
3223
3224 if (opt_no_kernel && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
3225 ret = LTTCOMM_KERN_NA;
3226 goto error;
3227 }
3228
3229 /*
3230 * Check for command that don't needs to allocate a returned payload. We do
3231 * this here so we don't have to make the call for no payload at each
3232 * command.
3233 */
3234 switch(cmd_ctx->lsm->cmd_type) {
3235 case LTTNG_LIST_SESSIONS:
3236 case LTTNG_LIST_TRACEPOINTS:
3237 case LTTNG_LIST_DOMAINS:
3238 case LTTNG_LIST_CHANNELS:
3239 case LTTNG_LIST_EVENTS:
3240 break;
3241 default:
3242 /* Setup lttng message with no payload */
3243 ret = setup_lttng_msg(cmd_ctx, 0);
3244 if (ret < 0) {
3245 /* This label does not try to unlock the session */
3246 goto init_setup_error;
3247 }
3248 }
3249
3250 /* Commands that DO NOT need a session. */
3251 switch (cmd_ctx->lsm->cmd_type) {
3252 case LTTNG_CALIBRATE:
3253 case LTTNG_CREATE_SESSION:
3254 case LTTNG_LIST_SESSIONS:
3255 case LTTNG_LIST_TRACEPOINTS:
3256 need_tracing_session = 0;
3257 break;
3258 default:
3259 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
3260 session_lock_list();
3261 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
3262 session_unlock_list();
3263 if (cmd_ctx->session == NULL) {
3264 if (cmd_ctx->lsm->session.name != NULL) {
3265 ret = LTTCOMM_SESS_NOT_FOUND;
3266 } else {
3267 /* If no session name specified */
3268 ret = LTTCOMM_SELECT_SESS;
3269 }
3270 goto error;
3271 } else {
3272 /* Acquire lock for the session */
3273 session_lock(cmd_ctx->session);
3274 }
3275 break;
3276 }
3277
3278 /*
3279 * Check domain type for specific "pre-action".
3280 */
3281 switch (cmd_ctx->lsm->domain.type) {
3282 case LTTNG_DOMAIN_KERNEL:
3283 /* Kernel tracer check */
3284 if (kernel_tracer_fd == 0) {
3285 /* Basically, load kernel tracer modules */
3286 init_kernel_tracer();
3287 if (kernel_tracer_fd == 0) {
3288 ret = LTTCOMM_KERN_NA;
3289 goto error;
3290 }
3291 }
3292
3293 /* Need a session for kernel command */
3294 if (need_tracing_session) {
3295 if (cmd_ctx->session->kernel_session == NULL) {
3296 ret = create_kernel_session(cmd_ctx->session);
3297 if (ret < 0) {
3298 ret = LTTCOMM_KERN_SESS_FAIL;
3299 goto error;
3300 }
3301 }
3302
3303 /* Start the kernel consumer daemon */
3304 pthread_mutex_lock(&kconsumer_data.pid_mutex);
3305 if (kconsumer_data.pid == 0 &&
3306 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3307 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3308 ret = start_consumerd(&kconsumer_data);
3309 if (ret < 0) {
3310 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3311 goto error;
3312 }
3313 } else {
3314 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3315 }
3316 }
3317 break;
3318 case LTTNG_DOMAIN_UST:
3319 {
3320 if (need_tracing_session) {
3321 if (cmd_ctx->session->ust_session == NULL) {
3322 ret = create_ust_session(cmd_ctx->session,
3323 &cmd_ctx->lsm->domain);
3324 if (ret != LTTCOMM_OK) {
3325 goto error;
3326 }
3327 }
3328 /* Start the UST consumer daemons */
3329 /* 64-bit */
3330 pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
3331 if (consumerd64_bin[0] != '\0' &&
3332 ustconsumer64_data.pid == 0 &&
3333 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3334 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);