Fix: relayd metadata size
[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c
CommitLineData
20fe2104
DG
1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
d14d33bf
AM
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
20fe2104
DG
7 *
8 * This program 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
11 * GNU General Public License for more details.
12 *
d14d33bf
AM
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20fe2104
DG
16 */
17
8c0faa1d 18#define _GNU_SOURCE
20fe2104 19#include <errno.h>
7b395890 20#include <fcntl.h>
20fe2104
DG
21#include <stdlib.h>
22#include <stdio.h>
f34daff7 23#include <string.h>
8c0faa1d 24#include <unistd.h>
20fe2104 25
990570ed 26#include <common/common.h>
db758600 27#include <common/kernel-ctl/kernel-ctl.h>
42224349 28#include <common/sessiond-comm/sessiond-comm.h>
1e307fab 29
4771f025 30#include "kernel.h"
096102bd 31#include "kern-modules.h"
20fe2104 32
d65106b1 33/*
050349bb 34 * Add context on a kernel channel.
d65106b1
DG
35 */
36int kernel_add_channel_context(struct ltt_kernel_channel *chan,
37 struct lttng_kernel_context *ctx)
38{
39 int ret;
40
41 DBG("Adding context to channel %s", chan->channel->name);
42 ret = kernctl_add_context(chan->fd, ctx);
43 if (ret < 0) {
b579acd9 44 if (errno != EEXIST) {
df0f840b 45 PERROR("add context ioctl");
b579acd9
DG
46 } else {
47 /* If EEXIST, we just ignore the error */
48 ret = 0;
49 }
d65106b1
DG
50 goto error;
51 }
52
ba7f0ae5 53 chan->ctx = zmalloc(sizeof(struct lttng_kernel_context));
d65106b1 54 if (chan->ctx == NULL) {
df0f840b 55 PERROR("zmalloc event context");
d65106b1
DG
56 goto error;
57 }
58
59 memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
60
61 return 0;
62
63error:
64 return ret;
65}
66
67/*
050349bb 68 * Add context on a kernel event.
d65106b1
DG
69 */
70int kernel_add_event_context(struct ltt_kernel_event *event,
71 struct lttng_kernel_context *ctx)
72{
73 int ret;
74
75 DBG("Adding context to event %s", event->event->name);
76 ret = kernctl_add_context(event->fd, ctx);
77 if (ret < 0) {
df0f840b 78 PERROR("add context ioctl");
d65106b1
DG
79 goto error;
80 }
81
ba7f0ae5 82 event->ctx = zmalloc(sizeof(struct lttng_kernel_context));
d65106b1 83 if (event->ctx == NULL) {
df0f840b 84 PERROR("zmalloc event context");
d65106b1
DG
85 goto error;
86 }
87
88 memcpy(event->ctx, ctx, sizeof(struct lttng_kernel_context));
89
90 return 0;
91
92error:
93 return ret;
94}
95
20fe2104 96/*
050349bb
DG
97 * Create a new kernel session, register it to the kernel tracer and add it to
98 * the session daemon session.
20fe2104 99 */
8c0faa1d 100int kernel_create_session(struct ltt_session *session, int tracer_fd)
20fe2104
DG
101{
102 int ret;
103 struct ltt_kernel_session *lks;
104
54012638 105 /* Allocate data structure */
f9815039 106 lks = trace_kernel_create_session(session->path);
20fe2104 107 if (lks == NULL) {
54012638 108 ret = -1;
20fe2104
DG
109 goto error;
110 }
111
54012638 112 /* Kernel tracer session creation */
20fe2104
DG
113 ret = kernctl_create_session(tracer_fd);
114 if (ret < 0) {
df0f840b 115 PERROR("ioctl kernel create session");
20fe2104
DG
116 goto error;
117 }
118
20fe2104 119 lks->fd = ret;
7b395890
DG
120 /* Prevent fd duplication after execlp() */
121 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
122 if (ret < 0) {
df0f840b 123 PERROR("fcntl session fd");
7b395890
DG
124 }
125
3bd1e081 126 lks->consumer_fds_sent = 0;
8c0faa1d 127 session->kernel_session = lks;
8c0faa1d
DG
128
129 DBG("Kernel session created (fd: %d)", lks->fd);
20fe2104
DG
130
131 return 0;
132
133error:
134 return ret;
135}
136
137/*
050349bb
DG
138 * Create a kernel channel, register it to the kernel tracer and add it to the
139 * kernel session.
20fe2104 140 */
050349bb
DG
141int kernel_create_channel(struct ltt_kernel_session *session,
142 struct lttng_channel *chan, char *path)
20fe2104
DG
143{
144 int ret;
145 struct ltt_kernel_channel *lkc;
20fe2104 146
54012638 147 /* Allocate kernel channel */
62499ad6 148 lkc = trace_kernel_create_channel(chan, path);
54012638 149 if (lkc == NULL) {
20fe2104
DG
150 goto error;
151 }
152
54012638 153 /* Kernel tracer channel creation */
f3ed775e 154 ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
20fe2104 155 if (ret < 0) {
df0f840b 156 PERROR("ioctl kernel create channel");
20fe2104
DG
157 goto error;
158 }
159
54012638 160 /* Setup the channel fd */
20fe2104 161 lkc->fd = ret;
7b395890
DG
162 /* Prevent fd duplication after execlp() */
163 ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC);
164 if (ret < 0) {
df0f840b 165 PERROR("fcntl session fd");
7b395890
DG
166 }
167
54012638 168 /* Add channel to session */
8c0faa1d
DG
169 cds_list_add(&lkc->list, &session->channel_list.head);
170 session->channel_count++;
20fe2104 171
00e2e675 172 DBG("Kernel channel %s created (fd: %d)", lkc->channel->name, lkc->fd);
20fe2104
DG
173
174 return 0;
175
176error:
54012638 177 return -1;
20fe2104 178}
f34daff7
DG
179
180/*
050349bb
DG
181 * Create a kernel event, enable it to the kernel tracer and add it to the
182 * channel event list of the kernel session.
f34daff7 183 */
050349bb
DG
184int kernel_create_event(struct lttng_event *ev,
185 struct ltt_kernel_channel *channel)
f34daff7
DG
186{
187 int ret;
188 struct ltt_kernel_event *event;
f34daff7 189
62499ad6 190 event = trace_kernel_create_event(ev);
54012638 191 if (event == NULL) {
d87bfb32 192 ret = -1;
f34daff7
DG
193 goto error;
194 }
195
f3ed775e
DG
196 ret = kernctl_create_event(channel->fd, event->event);
197 if (ret < 0) {
bd29c13d
DG
198 switch (errno) {
199 case EEXIST:
200 break;
201 case ENOSYS:
202 WARN("Event type not implemented");
203 break;
204 default:
d87bfb32
DG
205 PERROR("create event ioctl");
206 }
207 ret = -errno;
e953ef25 208 goto free_event;
8c0faa1d 209 }
f34daff7 210
5f822d0a 211 /*
2c425ff7 212 * LTTNG_KERNEL_SYSCALL event creation will return 0 on success.
5f822d0a
DG
213 */
214 if (ret == 0 && event->event->instrumentation == LTTNG_KERNEL_SYSCALL) {
215 DBG2("Kernel event syscall creation success");
87eb4ab8
MD
216 /*
217 * We use fd == -1 to ensure that we never trigger a close of fd
218 * 0.
219 */
220 event->fd = -1;
2c425ff7 221 goto add_list;
5f822d0a
DG
222 }
223
f3ed775e 224 event->fd = ret;
7b395890
DG
225 /* Prevent fd duplication after execlp() */
226 ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
227 if (ret < 0) {
df0f840b 228 PERROR("fcntl session fd");
7b395890
DG
229 }
230
2c425ff7 231add_list:
f3ed775e
DG
232 /* Add event to event list */
233 cds_list_add(&event->list, &channel->events_list.head);
cbbbb275
DG
234 channel->event_count++;
235
e953ef25
DG
236 DBG("Event %s created (fd: %d)", ev->name, event->fd);
237
238 return 0;
239
240free_event:
241 free(event);
242error:
d87bfb32 243 return ret;
e953ef25
DG
244}
245
26cc6b4e 246/*
050349bb 247 * Disable a kernel channel.
26cc6b4e
DG
248 */
249int kernel_disable_channel(struct ltt_kernel_channel *chan)
250{
251 int ret;
252
253 ret = kernctl_disable(chan->fd);
254 if (ret < 0) {
df0f840b 255 PERROR("disable chan ioctl");
26cc6b4e
DG
256 ret = errno;
257 goto error;
258 }
259
260 chan->enabled = 0;
261 DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
262
263 return 0;
264
265error:
266 return ret;
267}
268
d36b8583 269/*
050349bb 270 * Enable a kernel channel.
d36b8583
DG
271 */
272int kernel_enable_channel(struct ltt_kernel_channel *chan)
273{
274 int ret;
275
276 ret = kernctl_enable(chan->fd);
54d01ffb 277 if (ret < 0 && errno != EEXIST) {
df0f840b 278 PERROR("Enable kernel chan");
d36b8583
DG
279 goto error;
280 }
281
282 chan->enabled = 1;
283 DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
284
285 return 0;
286
287error:
288 return ret;
289}
290
19e70852 291/*
050349bb 292 * Enable a kernel event.
19e70852
DG
293 */
294int kernel_enable_event(struct ltt_kernel_event *event)
295{
296 int ret;
297
298 ret = kernctl_enable(event->fd);
42224349
DG
299 if (ret < 0) {
300 switch (errno) {
301 case EEXIST:
302 ret = LTTCOMM_KERN_EVENT_EXIST;
303 break;
304 default:
305 PERROR("enable kernel event");
306 break;
307 }
19e70852
DG
308 goto error;
309 }
310
311 event->enabled = 1;
312 DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd);
313
314 return 0;
315
316error:
d36b8583 317 return ret;
19e70852
DG
318}
319
e953ef25 320/*
050349bb 321 * Disable a kernel event.
e953ef25 322 */
19e70852 323int kernel_disable_event(struct ltt_kernel_event *event)
e953ef25
DG
324{
325 int ret;
19e70852
DG
326
327 ret = kernctl_disable(event->fd);
42224349
DG
328 if (ret < 0) {
329 switch (errno) {
330 case EEXIST:
331 ret = LTTCOMM_KERN_EVENT_EXIST;
332 break;
333 default:
334 PERROR("disable kernel event");
335 break;
336 }
19e70852 337 goto error;
e953ef25 338 }
f3ed775e 339
19e70852
DG
340 event->enabled = 0;
341 DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
342
f34daff7
DG
343 return 0;
344
345error:
d36b8583 346 return ret;
f34daff7 347}
aaf26714
DG
348
349/*
050349bb
DG
350 * Create kernel metadata, open from the kernel tracer and add it to the
351 * kernel session.
aaf26714 352 */
58a97671 353int kernel_open_metadata(struct ltt_kernel_session *session, char *path)
aaf26714
DG
354{
355 int ret;
356 struct ltt_kernel_metadata *lkm;
aaf26714 357
54012638 358 /* Allocate kernel metadata */
62499ad6 359 lkm = trace_kernel_create_metadata(path);
54012638 360 if (lkm == NULL) {
aaf26714
DG
361 goto error;
362 }
363
54012638 364 /* Kernel tracer metadata creation */
f3ed775e 365 ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
aaf26714
DG
366 if (ret < 0) {
367 goto error;
368 }
369
8c0faa1d 370 lkm->fd = ret;
7b395890
DG
371 /* Prevent fd duplication after execlp() */
372 ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
373 if (ret < 0) {
df0f840b 374 PERROR("fcntl session fd");
7b395890
DG
375 }
376
aaf26714 377 session->metadata = lkm;
8c0faa1d 378
00e2e675 379 DBG("Kernel metadata opened (fd: %d)", lkm->fd);
8c0faa1d
DG
380
381 return 0;
382
383error:
54012638 384 return -1;
8c0faa1d
DG
385}
386
387/*
050349bb 388 * Start tracing session.
8c0faa1d
DG
389 */
390int kernel_start_session(struct ltt_kernel_session *session)
391{
392 int ret;
393
394 ret = kernctl_start_session(session->fd);
395 if (ret < 0) {
df0f840b 396 PERROR("ioctl start session");
8c0faa1d
DG
397 goto error;
398 }
399
400 DBG("Kernel session started");
401
402 return 0;
403
404error:
405 return ret;
406}
407
f3ed775e 408/*
050349bb 409 * Make a kernel wait to make sure in-flight probe have completed.
f3ed775e
DG
410 */
411void kernel_wait_quiescent(int fd)
412{
413 int ret;
414
415 DBG("Kernel quiescent wait on %d", fd);
416
417 ret = kernctl_wait_quiescent(fd);
418 if (ret < 0) {
df0f840b 419 PERROR("wait quiescent ioctl");
f3ed775e
DG
420 ERR("Kernel quiescent wait failed");
421 }
422}
423
d0254c7c 424/*
050349bb 425 * Kernel calibrate
d0254c7c
MD
426 */
427int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
428{
429 int ret;
430
431 ret = kernctl_calibrate(fd, calibrate);
432 if (ret < 0) {
df0f840b 433 PERROR("calibrate ioctl");
d0254c7c
MD
434 return -1;
435 }
436
437 return 0;
438}
439
440
f3ed775e 441/*
f3ed775e
DG
442 * Force flush buffer of metadata.
443 */
444int kernel_metadata_flush_buffer(int fd)
445{
446 int ret;
447
448 ret = kernctl_buffer_flush(fd);
449 if (ret < 0) {
00e2e675 450 ERR("Fail to flush metadata buffers %d (ret: %d)", fd, ret);
f3ed775e
DG
451 }
452
453 return 0;
454}
455
456/*
050349bb 457 * Force flush buffer for channel.
f3ed775e
DG
458 */
459int kernel_flush_buffer(struct ltt_kernel_channel *channel)
460{
461 int ret;
462 struct ltt_kernel_stream *stream;
463
464 DBG("Flush buffer for channel %s", channel->channel->name);
465
466 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
467 DBG("Flushing channel stream %d", stream->fd);
468 ret = kernctl_buffer_flush(stream->fd);
469 if (ret < 0) {
df0f840b 470 PERROR("ioctl");
f3ed775e
DG
471 ERR("Fail to flush buffer for stream %d (ret: %d)",
472 stream->fd, ret);
473 }
474 }
475
476 return 0;
477}
478
8c0faa1d 479/*
050349bb 480 * Stop tracing session.
8c0faa1d
DG
481 */
482int kernel_stop_session(struct ltt_kernel_session *session)
483{
484 int ret;
485
486 ret = kernctl_stop_session(session->fd);
487 if (ret < 0) {
488 goto error;
489 }
490
491 DBG("Kernel session stopped");
492
493 return 0;
494
495error:
496 return ret;
497}
498
499/*
050349bb
DG
500 * Open stream of channel, register it to the kernel tracer and add it
501 * to the stream list of the channel.
8c0faa1d 502 *
050349bb 503 * Return the number of created stream. Else, a negative value.
8c0faa1d 504 */
f3ed775e 505int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
8c0faa1d 506{
00e2e675 507 int ret, count = 0;
8c0faa1d
DG
508 struct ltt_kernel_stream *lks;
509
5a47c6a2 510 while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
00e2e675 511 lks = trace_kernel_create_stream(channel->channel->name, count);
8c0faa1d 512 if (lks == NULL) {
799e2c4f
MD
513 ret = close(ret);
514 if (ret) {
515 PERROR("close");
516 }
8c0faa1d
DG
517 goto error;
518 }
519
520 lks->fd = ret;
7b395890
DG
521 /* Prevent fd duplication after execlp() */
522 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
523 if (ret < 0) {
df0f840b 524 PERROR("fcntl session fd");
7b395890
DG
525 }
526
54012638 527 /* Add stream to channe stream list */
8c0faa1d
DG
528 cds_list_add(&lks->list, &channel->stream_list.head);
529 channel->stream_count++;
8c0faa1d 530
00e2e675
DG
531 /* Increment counter which represent CPU number. */
532 count++;
533
534 DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd,
535 lks->state);
54012638 536 }
8c0faa1d
DG
537
538 return channel->stream_count;
539
540error:
54012638 541 return -1;
8c0faa1d
DG
542}
543
544/*
050349bb 545 * Open the metadata stream and set it to the kernel session.
8c0faa1d 546 */
f3ed775e 547int kernel_open_metadata_stream(struct ltt_kernel_session *session)
8c0faa1d
DG
548{
549 int ret;
550
551 ret = kernctl_create_stream(session->metadata->fd);
552 if (ret < 0) {
df0f840b 553 PERROR("kernel create metadata stream");
8c0faa1d
DG
554 goto error;
555 }
556
557 DBG("Kernel metadata stream created (fd: %d)", ret);
558 session->metadata_stream_fd = ret;
7b395890
DG
559 /* Prevent fd duplication after execlp() */
560 ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC);
561 if (ret < 0) {
df0f840b 562 PERROR("fcntl session fd");
7b395890 563 }
aaf26714
DG
564
565 return 0;
566
567error:
54012638 568 return -1;
aaf26714 569}
2ef84c95
DG
570
571/*
9f19cc17 572 * Get the event list from the kernel tracer and return the number of elements.
2ef84c95 573 */
9f19cc17 574ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
2ef84c95 575{
799e2c4f 576 int fd, pos, ret;
9f19cc17
DG
577 char *event;
578 size_t nbmem, count = 0;
2ef84c95
DG
579 ssize_t size;
580 FILE *fp;
9f19cc17 581 struct lttng_event *elist;
2ef84c95
DG
582
583 fd = kernctl_tracepoint_list(tracer_fd);
584 if (fd < 0) {
df0f840b 585 PERROR("kernel tracepoint list");
2ef84c95
DG
586 goto error;
587 }
588
589 fp = fdopen(fd, "r");
590 if (fp == NULL) {
df0f840b 591 PERROR("kernel tracepoint list fdopen");
61b73b12 592 goto error_fp;
2ef84c95
DG
593 }
594
595 /*
596 * Init memory size counter
597 * See kernel-ctl.h for explanation of this value
598 */
6725fe19 599 nbmem = KERNEL_EVENT_INIT_LIST_SIZE;
ba7f0ae5 600 elist = zmalloc(sizeof(struct lttng_event) * nbmem);
3b870559
MD
601 if (elist == NULL) {
602 PERROR("alloc list events");
603 count = -ENOMEM;
604 goto end;
605 }
2ef84c95 606
9f19cc17 607 while ((size = fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
6725fe19 608 if (count >= nbmem) {
3b870559
MD
609 struct lttng_event *new_elist;
610
ced2f820 611 DBG("Reallocating event list from %zu to %zu bytes", nbmem,
6725fe19
DG
612 nbmem * 2);
613 /* Double the size */
614 nbmem <<= 1;
3b870559
MD
615 new_elist = realloc(elist, nbmem * sizeof(struct lttng_event));
616 if (new_elist == NULL) {
df0f840b 617 PERROR("realloc list events");
3b870559
MD
618 free(event);
619 free(elist);
61b73b12
MD
620 count = -ENOMEM;
621 goto end;
2ef84c95 622 }
3b870559 623 elist = new_elist;
2ef84c95 624 }
99497cd0
MD
625 strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN);
626 elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
67b9d018 627 elist[count].enabled = -1;
9f19cc17 628 count++;
3b870559 629 free(event);
2ef84c95
DG
630 }
631
9f19cc17 632 *events = elist;
ced2f820 633 DBG("Kernel list events done (%zu events)", count);
61b73b12 634end:
799e2c4f
MD
635 ret = fclose(fp); /* closes both fp and fd */
636 if (ret) {
637 PERROR("fclose");
638 }
9f19cc17 639 return count;
2ef84c95 640
61b73b12 641error_fp:
799e2c4f
MD
642 ret = close(fd);
643 if (ret) {
644 PERROR("close");
645 }
2ef84c95
DG
646error:
647 return -1;
648}
096102bd
DG
649
650/*
651 * Get kernel version and validate it.
652 */
653int kernel_validate_version(int tracer_fd)
654{
655 int ret;
656 struct lttng_kernel_tracer_version version;
657
658 ret = kernctl_tracer_version(tracer_fd, &version);
659 if (ret < 0) {
660 ERR("Failed at getting the lttng-modules version");
661 goto error;
662 }
663
664 /* Validate version */
a62a6556
MD
665 if (version.major != KERN_MODULES_PRE_MAJOR
666 && version.major != KERN_MODULES_MAJOR) {
096102bd 667 goto error_version;
096102bd
DG
668 }
669
a62a6556 670 DBG2("Kernel tracer version validated (major version %d)", version.major);
096102bd
DG
671 return 0;
672
673error_version:
5df0f285 674 ERR("Kernel major version %d is not compatible (supporting <= %d)",
a62a6556 675 version.major, KERN_MODULES_MAJOR)
096102bd
DG
676 ret = -1;
677
678error:
679 return ret;
680}
335a95b7
MD
681
682/*
683 * Kernel work-arounds called at the start of sessiond main().
684 */
685int init_kernel_workarounds(void)
686{
8936c33a 687 int ret;
335a95b7
MD
688 FILE *fp;
689
690 /*
691 * boot_id needs to be read once before being used concurrently
692 * to deal with a Linux kernel race. A fix is proposed for
693 * upstream, but the work-around is needed for older kernels.
694 */
695 fp = fopen("/proc/sys/kernel/random/boot_id", "r");
696 if (!fp) {
697 goto end_boot_id;
698 }
699 while (!feof(fp)) {
700 char buf[37] = "";
701
8936c33a
DG
702 ret = fread(buf, 1, sizeof(buf), fp);
703 if (ret < 0) {
704 /* Ignore error, we don't really care */
705 }
335a95b7 706 }
799e2c4f
MD
707 ret = fclose(fp);
708 if (ret) {
709 PERROR("fclose");
710 }
335a95b7 711end_boot_id:
335a95b7
MD
712 return 0;
713}
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