tracectl.c: add description comment
[ust.git] / libust / tracectl.c
1 /* Copyright (C) 2009 Pierre-Marc Fournier
2 *
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
7 *
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17
18 /* This file contains the implementation of the UST listener thread, which
19 * receives trace control commands. It also coordinates the initialization of
20 * libust.
21 */
22
23 #define _GNU_SOURCE
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <stdint.h>
27 #include <pthread.h>
28 #include <signal.h>
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <sys/un.h>
32 #include <fcntl.h>
33 #include <poll.h>
34 #include <regex.h>
35 #include <urcu/uatomic_arch.h>
36
37 #include <ust/marker.h>
38 #include <ust/tracectl.h>
39 #include "tracer.h"
40 #include "usterr.h"
41 #include "ustcomm.h"
42 #include "buffers.h"
43 #include "marker-control.h"
44 #include "multipoll.h"
45
46 #define USTSIGNAL SIGIO
47
48 #define MAX_MSG_SIZE (100)
49 #define MSG_NOTIF 1
50 #define MSG_REGISTER_NOTIF 2
51
52 /* This should only be accessed by the constructor, before the creation
53 * of the listener, and then only by the listener.
54 */
55 s64 pidunique = -1LL;
56
57 extern struct chan_info_struct chan_infos[];
58
59 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
60
61 static struct ustcomm_app ustcomm_app;
62
63 struct tracecmd { /* no padding */
64 uint32_t size;
65 uint16_t command;
66 };
67
68 /* volatile because shared between the listener and the main thread */
69 int buffers_to_export = 0;
70
71 struct trctl_msg {
72 /* size: the size of all the fields except size itself */
73 uint32_t size;
74 uint16_t type;
75 /* Only the necessary part of the payload is transferred. It
76 * may even be none of it.
77 */
78 char payload[94];
79 };
80
81 struct consumer_channel {
82 int fd;
83 struct ltt_channel_struct *chan;
84 };
85
86 struct blocked_consumer {
87 int fd_consumer;
88 int fd_producer;
89 int tmp_poll_idx;
90
91 /* args to ustcomm_send_reply */
92 struct ustcomm_server server;
93 struct ustcomm_source src;
94
95 /* args to ust_buffers_get_subbuf */
96 struct ust_buffer *buf;
97
98 struct list_head list;
99 };
100
101 static long long make_pidunique(void)
102 {
103 s64 retval;
104 struct timeval tv;
105
106 gettimeofday(&tv, NULL);
107
108 retval = tv.tv_sec;
109 retval <<= 32;
110 retval |= tv.tv_usec;
111
112 return retval;
113 }
114
115 static void print_markers(FILE *fp)
116 {
117 struct marker_iter iter;
118
119 lock_markers();
120 marker_iter_reset(&iter);
121 marker_iter_start(&iter);
122
123 while(iter.marker) {
124 fprintf(fp, "marker: %s/%s %d \"%s\" %p\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format, iter.marker->location);
125 marker_iter_next(&iter);
126 }
127 unlock_markers();
128 }
129
130 static int init_socket(void);
131
132 /* Ask the daemon to collect a trace called trace_name and being
133 * produced by this pid.
134 *
135 * The trace must be at least allocated. (It can also be started.)
136 * This is because _ltt_trace_find is used.
137 */
138
139 static void inform_consumer_daemon(const char *trace_name)
140 {
141 int i,j;
142 struct ust_trace *trace;
143 pid_t pid = getpid();
144 int result;
145
146 ltt_lock_traces();
147
148 trace = _ltt_trace_find(trace_name);
149 if(trace == NULL) {
150 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
151 goto finish;
152 }
153
154 for(i=0; i < trace->nr_channels; i++) {
155 if(trace->channels[i].request_collection) {
156 /* iterate on all cpus */
157 for(j=0; j<trace->channels[i].n_cpus; j++) {
158 char *buf;
159 asprintf(&buf, "%s_%d", trace->channels[i].channel_name, j);
160 result = ustcomm_request_consumer(pid, buf);
161 if(result == -1) {
162 WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
163 /* continue even if fail */
164 }
165 free(buf);
166 STORE_SHARED(buffers_to_export, LOAD_SHARED(buffers_to_export)+1);
167 }
168 }
169 }
170
171 finish:
172 ltt_unlock_traces();
173 }
174
175 int process_blkd_consumer_act(void *priv, int fd, short events)
176 {
177 int result;
178 long consumed_old = 0;
179 char *reply;
180 struct blocked_consumer *bc = (struct blocked_consumer *) priv;
181 char inbuf;
182
183 result = read(bc->fd_producer, &inbuf, 1);
184 if(result == -1) {
185 PERROR("read");
186 return -1;
187 }
188 if(result == 0) {
189 int res;
190 DBG("listener: got messsage that a buffer ended");
191
192 res = close(bc->fd_producer);
193 if(res == -1) {
194 PERROR("close");
195 }
196
197 list_del(&bc->list);
198
199 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
200 if(result < 0) {
201 ERR("ustcomm_send_reply failed");
202 return -1;
203 }
204
205 return 0;
206 }
207
208 result = ust_buffers_get_subbuf(bc->buf, &consumed_old);
209 if(result == -EAGAIN) {
210 WARN("missed buffer?");
211 return 0;
212 }
213 else if(result < 0) {
214 ERR("ust_buffers_get_subbuf: error: %s", strerror(-result));
215 }
216 asprintf(&reply, "%s %ld", "OK", consumed_old);
217 result = ustcomm_send_reply(&bc->server, reply, &bc->src);
218 if(result < 0) {
219 ERR("ustcomm_send_reply failed");
220 free(reply);
221 return -1;
222 }
223 free(reply);
224
225 list_del(&bc->list);
226
227 return 0;
228 }
229
230 void blocked_consumers_add_to_mp(struct mpentries *ent)
231 {
232 struct blocked_consumer *bc;
233
234 list_for_each_entry(bc, &blocked_consumers, list) {
235 multipoll_add(ent, bc->fd_producer, POLLIN, process_blkd_consumer_act, bc, NULL);
236 }
237
238 }
239
240 void seperate_channel_cpu(const char *channel_and_cpu, char **channel, int *cpu)
241 {
242 const char *sep;
243
244 sep = rindex(channel_and_cpu, '_');
245 if(sep == NULL) {
246 *cpu = -1;
247 sep = channel_and_cpu + strlen(channel_and_cpu);
248 }
249 else {
250 *cpu = atoi(sep+1);
251 }
252
253 asprintf(channel, "%.*s", (int)(sep-channel_and_cpu), channel_and_cpu);
254 }
255
256 static int do_cmd_get_shmid(const char *recvbuf, struct ustcomm_source *src)
257 {
258 int retval = 0;
259 struct ust_trace *trace;
260 char trace_name[] = "auto";
261 int i;
262 char *channel_and_cpu;
263 int found = 0;
264 int result;
265 char *ch_name;
266 int ch_cpu;
267
268 DBG("get_shmid");
269
270 channel_and_cpu = nth_token(recvbuf, 1);
271 if(channel_and_cpu == NULL) {
272 ERR("cannot parse channel");
273 goto end;
274 }
275
276 seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
277 if(ch_cpu == -1) {
278 ERR("problem parsing channel name");
279 goto free_short_chan_name;
280 }
281
282 ltt_lock_traces();
283 trace = _ltt_trace_find(trace_name);
284 ltt_unlock_traces();
285
286 if(trace == NULL) {
287 ERR("cannot find trace!");
288 retval = -1;
289 goto free_short_chan_name;
290 }
291
292 for(i=0; i<trace->nr_channels; i++) {
293 struct ust_channel *channel = &trace->channels[i];
294 struct ust_buffer *buf = channel->buf[ch_cpu];
295
296 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
297 char *reply;
298
299 // DBG("the shmid for the requested channel is %d", buf->shmid);
300 // DBG("the shmid for its buffer structure is %d", channel->buf_struct_shmids);
301 asprintf(&reply, "%d %d", buf->shmid, channel->buf_struct_shmids[ch_cpu]);
302
303 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
304 if(result) {
305 ERR("ustcomm_send_reply failed");
306 free(reply);
307 retval = -1;
308 goto free_short_chan_name;
309 }
310
311 free(reply);
312
313 found = 1;
314 break;
315 }
316 }
317
318 if(!found) {
319 ERR("channel not found (%s)", channel_and_cpu);
320 }
321
322 free_short_chan_name:
323 free(ch_name);
324
325 end:
326 return retval;
327 }
328
329 static int do_cmd_get_n_subbufs(const char *recvbuf, struct ustcomm_source *src)
330 {
331 int retval = 0;
332 struct ust_trace *trace;
333 char trace_name[] = "auto";
334 int i;
335 char *channel_and_cpu;
336 int found = 0;
337 int result;
338 char *ch_name;
339 int ch_cpu;
340
341 DBG("get_n_subbufs");
342
343 channel_and_cpu = nth_token(recvbuf, 1);
344 if(channel_and_cpu == NULL) {
345 ERR("cannot parse channel");
346 goto end;
347 }
348
349 seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
350 if(ch_cpu == -1) {
351 ERR("problem parsing channel name");
352 goto free_short_chan_name;
353 }
354
355 ltt_lock_traces();
356 trace = _ltt_trace_find(trace_name);
357 ltt_unlock_traces();
358
359 if(trace == NULL) {
360 ERR("cannot find trace!");
361 retval = -1;
362 goto free_short_chan_name;
363 }
364
365 for(i=0; i<trace->nr_channels; i++) {
366 struct ust_channel *channel = &trace->channels[i];
367
368 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
369 char *reply;
370
371 DBG("the n_subbufs for the requested channel is %d", channel->subbuf_cnt);
372 asprintf(&reply, "%d", channel->subbuf_cnt);
373
374 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
375 if(result) {
376 ERR("ustcomm_send_reply failed");
377 free(reply);
378 retval = -1;
379 goto free_short_chan_name;
380 }
381
382 free(reply);
383 found = 1;
384 break;
385 }
386 }
387 if(found == 0) {
388 ERR("unable to find channel");
389 }
390
391 free_short_chan_name:
392 free(ch_name);
393
394 end:
395 return retval;
396 }
397
398 static int do_cmd_get_subbuf_size(const char *recvbuf, struct ustcomm_source *src)
399 {
400 int retval = 0;
401 struct ust_trace *trace;
402 char trace_name[] = "auto";
403 int i;
404 char *channel_and_cpu;
405 int found = 0;
406 int result;
407 char *ch_name;
408 int ch_cpu;
409
410 DBG("get_subbuf_size");
411
412 channel_and_cpu = nth_token(recvbuf, 1);
413 if(channel_and_cpu == NULL) {
414 ERR("cannot parse channel");
415 goto end;
416 }
417
418 seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
419 if(ch_cpu == -1) {
420 ERR("problem parsing channel name");
421 goto free_short_chan_name;
422 }
423
424 ltt_lock_traces();
425 trace = _ltt_trace_find(trace_name);
426 ltt_unlock_traces();
427
428 if(trace == NULL) {
429 ERR("cannot find trace!");
430 retval = -1;
431 goto free_short_chan_name;
432 }
433
434 for(i=0; i<trace->nr_channels; i++) {
435 struct ust_channel *channel = &trace->channels[i];
436
437 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
438 char *reply;
439
440 DBG("the subbuf_size for the requested channel is %zd", channel->subbuf_size);
441 asprintf(&reply, "%zd", channel->subbuf_size);
442
443 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
444 if(result) {
445 ERR("ustcomm_send_reply failed");
446 free(reply);
447 retval = -1;
448 goto free_short_chan_name;
449 }
450
451 free(reply);
452 found = 1;
453 break;
454 }
455 }
456 if(found == 0) {
457 ERR("unable to find channel");
458 }
459
460 free_short_chan_name:
461 free(ch_name);
462
463 end:
464 return retval;
465 }
466
467 /* Return the power of two which is equal or higher to v */
468
469 static unsigned int pow2_higher_or_eq(unsigned int v)
470 {
471 int hb = fls(v);
472 int hbm1 = hb-1;
473 int retval = 1<<(hb-1);
474
475 if(v-retval == 0)
476 return retval;
477 else
478 return retval<<1;
479 }
480
481 static int do_cmd_set_subbuf_size(const char *recvbuf, struct ustcomm_source *src)
482 {
483 char *channel_slash_size;
484 char ch_name[256]="";
485 unsigned int size, power;
486 int retval = 0;
487 struct ust_trace *trace;
488 char trace_name[] = "auto";
489 int i;
490 int found = 0;
491
492 DBG("set_subbuf_size");
493
494 channel_slash_size = nth_token(recvbuf, 1);
495 sscanf(channel_slash_size, "%255[^/]/%u", ch_name, &size);
496
497 if(ch_name == NULL) {
498 ERR("cannot parse channel");
499 goto end;
500 }
501
502 power = pow2_higher_or_eq(size);
503 power = max_t(unsigned int, 2u, power);
504 if (power != size)
505 WARN("using the next power of two for buffer size = %u\n", power);
506
507 ltt_lock_traces();
508 trace = _ltt_trace_find_setup(trace_name);
509 if(trace == NULL) {
510 ERR("cannot find trace!");
511 retval = -1;
512 goto end;
513 }
514
515 for(i = 0; i < trace->nr_channels; i++) {
516 struct ust_channel *channel = &trace->channels[i];
517
518 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
519
520 channel->subbuf_size = power;
521 DBG("the set_subbuf_size for the requested channel is %zd", channel->subbuf_size);
522
523 found = 1;
524 break;
525 }
526 }
527 if(found == 0) {
528 ERR("unable to find channel");
529 }
530
531 end:
532 ltt_unlock_traces();
533 return retval;
534 }
535
536 static int do_cmd_set_subbuf_num(const char *recvbuf, struct ustcomm_source *src)
537 {
538 char *channel_slash_num;
539 char ch_name[256]="";
540 unsigned int num;
541 int retval = 0;
542 struct ust_trace *trace;
543 char trace_name[] = "auto";
544 int i;
545 int found = 0;
546
547 DBG("set_subbuf_num");
548
549 channel_slash_num = nth_token(recvbuf, 1);
550 sscanf(channel_slash_num, "%255[^/]/%u", ch_name, &num);
551
552 if(ch_name == NULL) {
553 ERR("cannot parse channel");
554 goto end;
555 }
556 if (num < 2) {
557 ERR("subbuffer count should be greater than 2");
558 goto end;
559 }
560
561 ltt_lock_traces();
562 trace = _ltt_trace_find_setup(trace_name);
563 if(trace == NULL) {
564 ERR("cannot find trace!");
565 retval = -1;
566 goto end;
567 }
568
569 for(i = 0; i < trace->nr_channels; i++) {
570 struct ust_channel *channel = &trace->channels[i];
571
572 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
573
574 channel->subbuf_cnt = num;
575 DBG("the set_subbuf_cnt for the requested channel is %zd", channel->subbuf_cnt);
576
577 found = 1;
578 break;
579 }
580 }
581 if(found == 0) {
582 ERR("unable to find channel");
583 }
584
585 end:
586 ltt_unlock_traces();
587 return retval;
588 }
589
590 static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
591 {
592 int retval = 0;
593 struct ust_trace *trace;
594 char trace_name[] = "auto";
595 int i;
596 char *channel_and_cpu;
597 int found = 0;
598 char *ch_name;
599 int ch_cpu;
600
601 DBG("get_subbuf");
602
603 channel_and_cpu = nth_token(recvbuf, 1);
604 if(channel_and_cpu == NULL) {
605 ERR("cannot parse channel");
606 goto end;
607 }
608
609 seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
610 if(ch_cpu == -1) {
611 ERR("problem parsing channel name");
612 goto free_short_chan_name;
613 }
614
615 ltt_lock_traces();
616 trace = _ltt_trace_find(trace_name);
617
618 if(trace == NULL) {
619 int result;
620
621 DBG("Cannot find trace. It was likely destroyed by the user.");
622 result = ustcomm_send_reply(&ustcomm_app.server, "NOTFOUND", src);
623 if(result) {
624 ERR("ustcomm_send_reply failed");
625 retval = -1;
626 goto unlock_traces;
627 }
628
629 goto unlock_traces;
630 }
631
632 for(i=0; i<trace->nr_channels; i++) {
633 struct ust_channel *channel = &trace->channels[i];
634
635 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
636 struct ust_buffer *buf = channel->buf[ch_cpu];
637 struct blocked_consumer *bc;
638
639 found = 1;
640
641 bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
642 if(bc == NULL) {
643 ERR("malloc returned NULL");
644 goto unlock_traces;
645 }
646 bc->fd_consumer = src->fd;
647 bc->fd_producer = buf->data_ready_fd_read;
648 bc->buf = buf;
649 bc->src = *src;
650 bc->server = ustcomm_app.server;
651
652 list_add(&bc->list, &blocked_consumers);
653
654 /* Being here is the proof the daemon has mapped the buffer in its
655 * memory. We may now decrement buffers_to_export.
656 */
657 if(uatomic_read(&buf->consumed) == 0) {
658 DBG("decrementing buffers_to_export");
659 STORE_SHARED(buffers_to_export, LOAD_SHARED(buffers_to_export)-1);
660 }
661
662 break;
663 }
664 }
665 if(found == 0) {
666 ERR("unable to find channel");
667 }
668
669 unlock_traces:
670 ltt_unlock_traces();
671
672 free_short_chan_name:
673 free(ch_name);
674
675 end:
676 return retval;
677 }
678
679 static int do_cmd_put_subbuffer(const char *recvbuf, struct ustcomm_source *src)
680 {
681 int retval = 0;
682 struct ust_trace *trace;
683 char trace_name[] = "auto";
684 int i;
685 char *channel_and_cpu;
686 int found = 0;
687 int result;
688 char *ch_name;
689 int ch_cpu;
690 long consumed_old;
691 char *consumed_old_str;
692 char *endptr;
693 char *reply = NULL;
694
695 DBG("put_subbuf");
696
697 channel_and_cpu = strdup(nth_token(recvbuf, 1));
698 if(channel_and_cpu == NULL) {
699 ERR("cannot parse channel");
700 retval = -1;
701 goto end;
702 }
703
704 consumed_old_str = strdup(nth_token(recvbuf, 2));
705 if(consumed_old_str == NULL) {
706 ERR("cannot parse consumed_old");
707 retval = -1;
708 goto free_channel_and_cpu;
709 }
710 consumed_old = strtol(consumed_old_str, &endptr, 10);
711 if(*endptr != '\0') {
712 ERR("invalid value for consumed_old");
713 retval = -1;
714 goto free_consumed_old_str;
715 }
716
717 seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
718 if(ch_cpu == -1) {
719 ERR("problem parsing channel name");
720 retval = -1;
721 goto free_short_chan_name;
722 }
723
724 ltt_lock_traces();
725 trace = _ltt_trace_find(trace_name);
726
727 if(trace == NULL) {
728 DBG("Cannot find trace. It was likely destroyed by the user.");
729 result = ustcomm_send_reply(&ustcomm_app.server, "NOTFOUND", src);
730 if(result) {
731 ERR("ustcomm_send_reply failed");
732 retval = -1;
733 goto unlock_traces;
734 }
735
736 goto unlock_traces;
737 }
738
739 for(i=0; i<trace->nr_channels; i++) {
740 struct ust_channel *channel = &trace->channels[i];
741
742 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
743 struct ust_buffer *buf = channel->buf[ch_cpu];
744
745 found = 1;
746
747 result = ust_buffers_put_subbuf(buf, consumed_old);
748 if(result < 0) {
749 WARN("ust_buffers_put_subbuf: error (subbuf=%s)", channel_and_cpu);
750 asprintf(&reply, "%s", "ERROR");
751 }
752 else {
753 DBG("ust_buffers_put_subbuf: success (subbuf=%s)", channel_and_cpu);
754 asprintf(&reply, "%s", "OK");
755 }
756
757 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
758 if(result) {
759 ERR("ustcomm_send_reply failed");
760 free(reply);
761 retval = -1;
762 goto unlock_traces;
763 }
764
765 free(reply);
766 break;
767 }
768 }
769 if(found == 0) {
770 ERR("unable to find channel");
771 }
772
773 unlock_traces:
774 ltt_unlock_traces();
775 free_short_chan_name:
776 free(ch_name);
777 free_consumed_old_str:
778 free(consumed_old_str);
779 free_channel_and_cpu:
780 free(channel_and_cpu);
781
782 end:
783 return retval;
784 }
785
786 static void listener_cleanup(void *ptr)
787 {
788 ustcomm_fini_app(&ustcomm_app, 0);
789 }
790
791 int process_client_cmd(char *recvbuf, struct ustcomm_source *src)
792 {
793 int result;
794 char trace_name[] = "auto";
795 char trace_type[] = "ustrelay";
796 int len;
797
798 DBG("received a message! it's: %s", recvbuf);
799 len = strlen(recvbuf);
800
801 if(!strcmp(recvbuf, "print_markers")) {
802 print_markers(stderr);
803 }
804 else if(!strcmp(recvbuf, "list_markers")) {
805 char *ptr;
806 size_t size;
807 FILE *fp;
808
809 fp = open_memstream(&ptr, &size);
810 print_markers(fp);
811 fclose(fp);
812
813 result = ustcomm_send_reply(&ustcomm_app.server, ptr, src);
814
815 free(ptr);
816 }
817 else if(!strcmp(recvbuf, "start")) {
818 /* start is an operation that setups the trace, allocates it and starts it */
819 result = ltt_trace_setup(trace_name);
820 if(result < 0) {
821 ERR("ltt_trace_setup failed");
822 return -1;
823 }
824
825 result = ltt_trace_set_type(trace_name, trace_type);
826 if(result < 0) {
827 ERR("ltt_trace_set_type failed");
828 return -1;
829 }
830
831 result = ltt_trace_alloc(trace_name);
832 if(result < 0) {
833 ERR("ltt_trace_alloc failed");
834 return -1;
835 }
836
837 inform_consumer_daemon(trace_name);
838
839 result = ltt_trace_start(trace_name);
840 if(result < 0) {
841 ERR("ltt_trace_start failed");
842 return -1;
843 }
844 }
845 else if(!strcmp(recvbuf, "trace_setup")) {
846 DBG("trace setup");
847
848 result = ltt_trace_setup(trace_name);
849 if(result < 0) {
850 ERR("ltt_trace_setup failed");
851 return -1;
852 }
853
854 result = ltt_trace_set_type(trace_name, trace_type);
855 if(result < 0) {
856 ERR("ltt_trace_set_type failed");
857 return -1;
858 }
859 }
860 else if(!strcmp(recvbuf, "trace_alloc")) {
861 DBG("trace alloc");
862
863 result = ltt_trace_alloc(trace_name);
864 if(result < 0) {
865 ERR("ltt_trace_alloc failed");
866 return -1;
867 }
868 inform_consumer_daemon(trace_name);
869 }
870 else if(!strcmp(recvbuf, "trace_create")) {
871 DBG("trace create");
872
873 result = ltt_trace_setup(trace_name);
874 if(result < 0) {
875 ERR("ltt_trace_setup failed");
876 return -1;
877 }
878
879 result = ltt_trace_set_type(trace_name, trace_type);
880 if(result < 0) {
881 ERR("ltt_trace_set_type failed");
882 return -1;
883 }
884 }
885 else if(!strcmp(recvbuf, "trace_start")) {
886 DBG("trace start");
887
888 result = ltt_trace_alloc(trace_name);
889 if(result < 0) {
890 ERR("ltt_trace_alloc failed");
891 return -1;
892 }
893 if(!result) {
894 inform_consumer_daemon(trace_name);
895 }
896
897 result = ltt_trace_start(trace_name);
898 if(result < 0) {
899 ERR("ltt_trace_start failed");
900 return -1;
901 }
902 }
903 else if(!strcmp(recvbuf, "trace_stop")) {
904 DBG("trace stop");
905
906 result = ltt_trace_stop(trace_name);
907 if(result < 0) {
908 ERR("ltt_trace_stop failed");
909 return -1;
910 }
911 }
912 else if(!strcmp(recvbuf, "trace_destroy")) {
913
914 DBG("trace destroy");
915
916 result = ltt_trace_destroy(trace_name, 0);
917 if(result < 0) {
918 ERR("ltt_trace_destroy failed");
919 return -1;
920 }
921 }
922 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
923 do_cmd_get_shmid(recvbuf, src);
924 }
925 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
926 do_cmd_get_n_subbufs(recvbuf, src);
927 }
928 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
929 do_cmd_get_subbuf_size(recvbuf, src);
930 }
931 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
932 char *libfile;
933
934 libfile = nth_token(recvbuf, 1);
935
936 DBG("load_probe_lib loading %s", libfile);
937
938 free(libfile);
939 }
940 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
941 do_cmd_get_subbuffer(recvbuf, src);
942 }
943 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
944 do_cmd_put_subbuffer(recvbuf, src);
945 }
946 else if(nth_token_is(recvbuf, "set_subbuf_size", 0) == 1) {
947 do_cmd_set_subbuf_size(recvbuf, src);
948 }
949 else if(nth_token_is(recvbuf, "set_subbuf_num", 0) == 1) {
950 do_cmd_set_subbuf_num(recvbuf, src);
951 }
952 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
953 char *channel_slash_name = nth_token(recvbuf, 1);
954 char channel_name[256]="";
955 char marker_name[256]="";
956
957 result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
958
959 if(channel_name == NULL || marker_name == NULL) {
960 WARN("invalid marker name");
961 goto next_cmd;
962 }
963
964 result = ltt_marker_connect(channel_name, marker_name, "default");
965 if(result < 0) {
966 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
967 }
968 }
969 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
970 char *channel_slash_name = nth_token(recvbuf, 1);
971 char *marker_name;
972 char *channel_name;
973
974 result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
975
976 if(marker_name == NULL) {
977 }
978
979 result = ltt_marker_disconnect(channel_name, marker_name, "default");
980 if(result < 0) {
981 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
982 }
983 }
984 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
985 char *reply;
986
987 asprintf(&reply, "%lld", pidunique);
988
989 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
990 if(result) {
991 ERR("listener: get_pidunique: ustcomm_send_reply failed");
992 goto next_cmd;
993 }
994
995 free(reply);
996 }
997 else {
998 ERR("unable to parse message: %s", recvbuf);
999 }
1000
1001 next_cmd:
1002
1003 return 0;
1004 }
1005
1006 void *listener_main(void *p)
1007 {
1008 int result;
1009
1010 DBG("LISTENER");
1011
1012 pthread_cleanup_push(listener_cleanup, NULL);
1013
1014 for(;;) {
1015 struct mpentries mpent;
1016
1017 multipoll_init(&mpent);
1018
1019 blocked_consumers_add_to_mp(&mpent);
1020 ustcomm_mp_add_app_clients(&mpent, &ustcomm_app, process_client_cmd);
1021
1022 result = multipoll_poll(&mpent, -1);
1023 if(result == -1) {
1024 ERR("error in multipoll_poll");
1025 }
1026
1027 multipoll_destroy(&mpent);
1028 }
1029
1030 pthread_cleanup_pop(1);
1031 }
1032
1033 /* These should only be accessed in the parent thread,
1034 * not the listener.
1035 */
1036 static volatile sig_atomic_t have_listener = 0;
1037 static pthread_t listener_thread;
1038
1039 void create_listener(void)
1040 {
1041 int result;
1042 sigset_t sig_all_blocked;
1043 sigset_t orig_parent_mask;
1044
1045 if(have_listener) {
1046 WARN("not creating listener because we already had one");
1047 return;
1048 }
1049
1050 /* A new thread created by pthread_create inherits the signal mask
1051 * from the parent. To avoid any signal being received by the
1052 * listener thread, we block all signals temporarily in the parent,
1053 * while we create the listener thread.
1054 */
1055
1056 sigfillset(&sig_all_blocked);
1057
1058 result = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask);
1059 if(result) {
1060 PERROR("pthread_sigmask: %s", strerror(result));
1061 }
1062
1063 result = pthread_create(&listener_thread, NULL, listener_main, NULL);
1064 if(result == -1) {
1065 PERROR("pthread_create");
1066 }
1067
1068 /* Restore original signal mask in parent */
1069 result = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL);
1070 if(result) {
1071 PERROR("pthread_sigmask: %s", strerror(result));
1072 }
1073
1074 have_listener = 1;
1075 }
1076
1077 static int init_socket(void)
1078 {
1079 return ustcomm_init_app(getpid(), &ustcomm_app);
1080 }
1081
1082 #define AUTOPROBE_DISABLED 0
1083 #define AUTOPROBE_ENABLE_ALL 1
1084 #define AUTOPROBE_ENABLE_REGEX 2
1085 static int autoprobe_method = AUTOPROBE_DISABLED;
1086 static regex_t autoprobe_regex;
1087
1088 static void auto_probe_connect(struct marker *m)
1089 {
1090 int result;
1091
1092 char* concat_name = NULL;
1093 const char *probe_name = "default";
1094
1095 if(autoprobe_method == AUTOPROBE_DISABLED) {
1096 return;
1097 }
1098 else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
1099 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
1100 if(result == -1) {
1101 ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
1102 m->channel, m->name);
1103 return;
1104 }
1105 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
1106 free(concat_name);
1107 return;
1108 }
1109 free(concat_name);
1110 }
1111
1112 result = ltt_marker_connect(m->channel, m->name, probe_name);
1113 if(result && result != -EEXIST)
1114 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
1115
1116 DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
1117
1118 }
1119
1120 static void __attribute__((constructor)) init()
1121 {
1122 int result;
1123 char* autoprobe_val = NULL;
1124 char* subbuffer_size_val = NULL;
1125 char* subbuffer_count_val = NULL;
1126 unsigned int subbuffer_size;
1127 unsigned int subbuffer_count;
1128 unsigned int power;
1129
1130 /* Assign the pidunique, to be able to differentiate the processes with same
1131 * pid, (before and after an exec).
1132 */
1133 pidunique = make_pidunique();
1134
1135 DBG("Tracectl constructor");
1136
1137 result = init_socket();
1138 if(result == -1) {
1139 ERR("init_socket error");
1140 return;
1141 }
1142
1143 create_listener();
1144
1145 autoprobe_val = getenv("UST_AUTOPROBE");
1146 if(autoprobe_val) {
1147 struct marker_iter iter;
1148
1149 DBG("Autoprobe enabled.");
1150
1151 /* Ensure markers are initialized */
1152 //init_markers();
1153
1154 /* Ensure marker control is initialized, for the probe */
1155 init_marker_control();
1156
1157 /* first, set the callback that will connect the
1158 * probe on new markers
1159 */
1160 if(autoprobe_val[0] == '/') {
1161 result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
1162 if (result) {
1163 char regexerr[150];
1164
1165 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
1166 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
1167 /* don't crash the application just for this */
1168 }
1169 else {
1170 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
1171 }
1172 }
1173 else {
1174 /* just enable all instrumentation */
1175 autoprobe_method = AUTOPROBE_ENABLE_ALL;
1176 }
1177
1178 marker_set_new_marker_cb(auto_probe_connect);
1179
1180 /* Now, connect the probes that were already registered. */
1181 marker_iter_reset(&iter);
1182 marker_iter_start(&iter);
1183
1184 DBG("now iterating on markers already registered");
1185 while(iter.marker) {
1186 DBG("now iterating on marker %s", iter.marker->name);
1187 auto_probe_connect(iter.marker);
1188 marker_iter_next(&iter);
1189 }
1190 }
1191
1192 if(getenv("UST_OVERWRITE")) {
1193 int val = atoi(getenv("UST_OVERWRITE"));
1194 if(val == 0 || val == 1) {
1195 STORE_SHARED(ust_channels_overwrite_by_default, val);
1196 }
1197 else {
1198 WARN("invalid value for UST_OVERWRITE");
1199 }
1200 }
1201
1202 if(getenv("UST_AUTOCOLLECT")) {
1203 int val = atoi(getenv("UST_AUTOCOLLECT"));
1204 if(val == 0 || val == 1) {
1205 STORE_SHARED(ust_channels_request_collection_by_default, val);
1206 }
1207 else {
1208 WARN("invalid value for UST_AUTOCOLLECT");
1209 }
1210 }
1211
1212 subbuffer_size_val = getenv("UST_SUBBUF_SIZE");
1213 if(subbuffer_size_val) {
1214 sscanf(subbuffer_size_val, "%u", &subbuffer_size);
1215 power = pow2_higher_or_eq(subbuffer_size);
1216 if(power != subbuffer_size)
1217 WARN("using the next power of two for buffer size = %u\n", power);
1218 chan_infos[LTT_CHANNEL_UST].def_subbufsize = power;
1219 }
1220
1221 subbuffer_count_val = getenv("UST_SUBBUF_NUM");
1222 if(subbuffer_count_val) {
1223 sscanf(subbuffer_count_val, "%u", &subbuffer_count);
1224 if(subbuffer_count < 2)
1225 subbuffer_count = 2;
1226 chan_infos[LTT_CHANNEL_UST].def_subbufcount = subbuffer_count;
1227 }
1228
1229 if(getenv("UST_TRACE")) {
1230 char trace_name[] = "auto";
1231 char trace_type[] = "ustrelay";
1232
1233 DBG("starting early tracing");
1234
1235 /* Ensure marker control is initialized */
1236 init_marker_control();
1237
1238 /* Ensure markers are initialized */
1239 init_markers();
1240
1241 /* Ensure buffers are initialized, for the transport to be available.
1242 * We are about to set a trace type and it will fail without this.
1243 */
1244 init_ustrelay_transport();
1245
1246 /* FIXME: When starting early tracing (here), depending on the
1247 * order of constructors, it is very well possible some marker
1248 * sections are not yet registered. Because of this, some
1249 * channels may not be registered. Yet, we are about to ask the
1250 * daemon to collect the channels. Channels which are not yet
1251 * registered will not be collected.
1252 *
1253 * Currently, in LTTng, there is no way to add a channel after
1254 * trace start. The reason for this is that it induces complex
1255 * concurrency issues on the trace structures, which can only
1256 * be resolved using RCU. This has not been done yet. As a
1257 * workaround, we are forcing the registration of the "ust"
1258 * channel here. This is the only channel (apart from metadata)
1259 * that can be reliably used in early tracing.
1260 *
1261 * Non-early tracing does not have this problem and can use
1262 * arbitrary channel names.
1263 */
1264 ltt_channels_register("ust");
1265
1266 result = ltt_trace_setup(trace_name);
1267 if(result < 0) {
1268 ERR("ltt_trace_setup failed");
1269 return;
1270 }
1271
1272 result = ltt_trace_set_type(trace_name, trace_type);
1273 if(result < 0) {
1274 ERR("ltt_trace_set_type failed");
1275 return;
1276 }
1277
1278 result = ltt_trace_alloc(trace_name);
1279 if(result < 0) {
1280 ERR("ltt_trace_alloc failed");
1281 return;
1282 }
1283
1284 result = ltt_trace_start(trace_name);
1285 if(result < 0) {
1286 ERR("ltt_trace_start failed");
1287 return;
1288 }
1289
1290 /* Do this after the trace is started in order to avoid creating confusion
1291 * if the trace fails to start. */
1292 inform_consumer_daemon(trace_name);
1293 }
1294
1295 return;
1296
1297 /* should decrementally destroy stuff if error */
1298
1299 }
1300
1301 /* This is only called if we terminate normally, not with an unhandled signal,
1302 * so we cannot rely on it. However, for now, LTTV requires that the header of
1303 * the last sub-buffer contain a valid end time for the trace. This is done
1304 * automatically only when the trace is properly stopped.
1305 *
1306 * If the traced program crashed, it is always possible to manually add the
1307 * right value in the header, or to open the trace in text mode.
1308 *
1309 * FIXME: Fix LTTV so it doesn't need this.
1310 */
1311
1312 static void destroy_traces(void)
1313 {
1314 int result;
1315
1316 /* if trace running, finish it */
1317
1318 DBG("destructor stopping traces");
1319
1320 result = ltt_trace_stop("auto");
1321 if(result == -1) {
1322 ERR("ltt_trace_stop error");
1323 }
1324
1325 result = ltt_trace_destroy("auto", 0);
1326 if(result == -1) {
1327 ERR("ltt_trace_destroy error");
1328 }
1329 }
1330
1331 static int trace_recording(void)
1332 {
1333 int retval = 0;
1334 struct ust_trace *trace;
1335
1336 ltt_lock_traces();
1337
1338 list_for_each_entry(trace, &ltt_traces.head, list) {
1339 if(trace->active) {
1340 retval = 1;
1341 break;
1342 }
1343 }
1344
1345 ltt_unlock_traces();
1346
1347 return retval;
1348 }
1349
1350 #if 0
1351 static int have_consumer(void)
1352 {
1353 return !list_empty(&blocked_consumers);
1354 }
1355 #endif
1356
1357 int restarting_usleep(useconds_t usecs)
1358 {
1359 struct timespec tv;
1360 int result;
1361
1362 tv.tv_sec = 0;
1363 tv.tv_nsec = usecs * 1000;
1364
1365 do {
1366 result = nanosleep(&tv, &tv);
1367 } while(result == -1 && errno == EINTR);
1368
1369 return result;
1370 }
1371
1372 static void stop_listener()
1373 {
1374 int result;
1375
1376 result = pthread_cancel(listener_thread);
1377 if(result != 0) {
1378 ERR("pthread_cancel: %s", strerror(result));
1379 }
1380 result = pthread_join(listener_thread, NULL);
1381 if(result != 0) {
1382 ERR("pthread_join: %s", strerror(result));
1383 }
1384 }
1385
1386 /* This destructor keeps the process alive for a few seconds in order
1387 * to leave time to ustd to connect to its buffers. This is necessary
1388 * for programs whose execution is very short. It is also useful in all
1389 * programs when tracing is started close to the end of the program
1390 * execution.
1391 *
1392 * FIXME: For now, this only works for the first trace created in a
1393 * process.
1394 */
1395
1396 static void __attribute__((destructor)) keepalive()
1397 {
1398 if(trace_recording() && LOAD_SHARED(buffers_to_export)) {
1399 int total = 0;
1400 DBG("Keeping process alive for consumer daemon...");
1401 while(LOAD_SHARED(buffers_to_export)) {
1402 const int interv = 200000;
1403 restarting_usleep(interv);
1404 total += interv;
1405
1406 if(total >= 3000000) {
1407 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1408 break;
1409 }
1410 }
1411 DBG("Finally dying...");
1412 }
1413
1414 destroy_traces();
1415
1416 /* Ask the listener to stop and clean up. */
1417 stop_listener();
1418 }
1419
1420 void ust_potential_exec(void)
1421 {
1422 trace_mark(ust, potential_exec, MARK_NOARGS);
1423
1424 DBG("test");
1425
1426 keepalive();
1427 }
1428
1429 /* Notify ust that there was a fork. This needs to be called inside
1430 * the new process, anytime a process whose memory is not shared with
1431 * the parent is created. If this function is not called, the events
1432 * of the new process will not be collected.
1433 *
1434 * Signals should be disabled before the fork and reenabled only after
1435 * this call in order to guarantee tracing is not started before ust_fork()
1436 * sanitizes the new process.
1437 */
1438
1439 static void ust_fork(void)
1440 {
1441 struct blocked_consumer *bc;
1442 struct blocked_consumer *deletable_bc = NULL;
1443 int result;
1444
1445 /* FIXME: technically, the locks could have been taken before the fork */
1446 DBG("ust: forking");
1447
1448 /* break lock if necessary */
1449 ltt_unlock_traces();
1450
1451 ltt_trace_stop("auto");
1452 ltt_trace_destroy("auto", 1);
1453 /* Delete all active connections */
1454 ustcomm_close_all_connections(&ustcomm_app.server);
1455
1456 /* Delete all blocked consumers */
1457 list_for_each_entry(bc, &blocked_consumers, list) {
1458 result = close(bc->fd_producer);
1459 if(result == -1) {
1460 PERROR("close");
1461 }
1462 free(deletable_bc);
1463 deletable_bc = bc;
1464 list_del(&bc->list);
1465 }
1466
1467 /* free app, keeping socket file */
1468 ustcomm_fini_app(&ustcomm_app, 1);
1469
1470 STORE_SHARED(buffers_to_export, 0);
1471 have_listener = 0;
1472 init_socket();
1473 create_listener();
1474 ltt_trace_setup("auto");
1475 result = ltt_trace_set_type("auto", "ustrelay");
1476 if(result < 0) {
1477 ERR("ltt_trace_set_type failed");
1478 return;
1479 }
1480
1481 ltt_trace_alloc("auto");
1482 ltt_trace_start("auto");
1483 inform_consumer_daemon("auto");
1484 }
1485
1486 void ust_before_fork(ust_fork_info_t *fork_info)
1487 {
1488 /* Disable signals. This is to avoid that the child
1489 * intervenes before it is properly setup for tracing. It is
1490 * safer to disable all signals, because then we know we are not
1491 * breaking anything by restoring the original mask.
1492 */
1493 sigset_t all_sigs;
1494 int result;
1495
1496 /* FIXME:
1497 - only do this if tracing is active
1498 */
1499
1500 /* Disable signals */
1501 sigfillset(&all_sigs);
1502 result = sigprocmask(SIG_BLOCK, &all_sigs, &fork_info->orig_sigs);
1503 if(result == -1) {
1504 PERROR("sigprocmask");
1505 return;
1506 }
1507 }
1508
1509 /* Don't call this function directly in a traced program */
1510 static void ust_after_fork_common(ust_fork_info_t *fork_info)
1511 {
1512 int result;
1513
1514 /* Restore signals */
1515 result = sigprocmask(SIG_SETMASK, &fork_info->orig_sigs, NULL);
1516 if(result == -1) {
1517 PERROR("sigprocmask");
1518 return;
1519 }
1520 }
1521
1522 void ust_after_fork_parent(ust_fork_info_t *fork_info)
1523 {
1524 /* Reenable signals */
1525 ust_after_fork_common(fork_info);
1526 }
1527
1528 void ust_after_fork_child(ust_fork_info_t *fork_info)
1529 {
1530 /* First sanitize the child */
1531 ust_fork();
1532
1533 /* Then reenable interrupts */
1534 ust_after_fork_common(fork_info);
1535 }
1536
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