Commit | Line | Data |
---|---|---|
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 | ||
6c1c0768 | 18 | #define _LGPL_SOURCE |
7b395890 | 19 | #include <fcntl.h> |
20fe2104 DG |
20 | #include <stdlib.h> |
21 | #include <stdio.h> | |
f34daff7 | 22 | #include <string.h> |
8c0faa1d | 23 | #include <unistd.h> |
77c7c900 | 24 | #include <inttypes.h> |
20fe2104 | 25 | |
990570ed | 26 | #include <common/common.h> |
db758600 | 27 | #include <common/kernel-ctl/kernel-ctl.h> |
c052142c | 28 | #include <common/kernel-ctl/kernel-ioctl.h> |
42224349 | 29 | #include <common/sessiond-comm/sessiond-comm.h> |
1e307fab | 30 | |
2f77fc4b | 31 | #include "consumer.h" |
4771f025 | 32 | #include "kernel.h" |
6dc3064a | 33 | #include "kernel-consumer.h" |
096102bd | 34 | #include "kern-modules.h" |
834978fd | 35 | #include "utils.h" |
20fe2104 | 36 | |
e1f3997a JD |
37 | /* |
38 | * Key used to reference a channel between the sessiond and the consumer. This | |
39 | * is only read and updated with the session_list lock held. | |
40 | */ | |
41 | static uint64_t next_kernel_channel_key; | |
42 | ||
d65106b1 | 43 | /* |
050349bb | 44 | * Add context on a kernel channel. |
df3c77c8 JG |
45 | * |
46 | * Assumes the ownership of ctx. | |
d65106b1 DG |
47 | */ |
48 | int kernel_add_channel_context(struct ltt_kernel_channel *chan, | |
645328ae | 49 | struct ltt_kernel_context *ctx) |
d65106b1 DG |
50 | { |
51 | int ret; | |
52 | ||
0525e9ae DG |
53 | assert(chan); |
54 | assert(ctx); | |
55 | ||
d65106b1 | 56 | DBG("Adding context to channel %s", chan->channel->name); |
645328ae | 57 | ret = kernctl_add_context(chan->fd, &ctx->ctx); |
d65106b1 | 58 | if (ret < 0) { |
32af2c95 | 59 | switch (-ret) { |
1ae5e83e JD |
60 | case ENOSYS: |
61 | /* Exists but not available for this kernel */ | |
62 | ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE; | |
63 | goto error; | |
64 | case EEXIST: | |
b579acd9 DG |
65 | /* If EEXIST, we just ignore the error */ |
66 | ret = 0; | |
1ae5e83e JD |
67 | goto end; |
68 | default: | |
69 | PERROR("add context ioctl"); | |
70 | ret = LTTNG_ERR_KERN_CONTEXT_FAIL; | |
71 | goto error; | |
b579acd9 | 72 | } |
d65106b1 | 73 | } |
21ed98c1 | 74 | ret = 0; |
d65106b1 | 75 | |
1ae5e83e | 76 | end: |
645328ae | 77 | cds_list_add_tail(&ctx->list, &chan->ctx_list); |
ba985c3a | 78 | ctx->in_list = true; |
df3c77c8 | 79 | ctx = NULL; |
d65106b1 | 80 | error: |
df3c77c8 JG |
81 | if (ctx) { |
82 | trace_kernel_destroy_context(ctx); | |
83 | } | |
d65106b1 DG |
84 | return ret; |
85 | } | |
86 | ||
20fe2104 | 87 | /* |
050349bb DG |
88 | * Create a new kernel session, register it to the kernel tracer and add it to |
89 | * the session daemon session. | |
20fe2104 | 90 | */ |
8c0faa1d | 91 | int kernel_create_session(struct ltt_session *session, int tracer_fd) |
20fe2104 DG |
92 | { |
93 | int ret; | |
94 | struct ltt_kernel_session *lks; | |
95 | ||
0525e9ae DG |
96 | assert(session); |
97 | ||
54012638 | 98 | /* Allocate data structure */ |
dec56f6c | 99 | lks = trace_kernel_create_session(); |
20fe2104 | 100 | if (lks == NULL) { |
54012638 | 101 | ret = -1; |
20fe2104 DG |
102 | goto error; |
103 | } | |
104 | ||
54012638 | 105 | /* Kernel tracer session creation */ |
20fe2104 DG |
106 | ret = kernctl_create_session(tracer_fd); |
107 | if (ret < 0) { | |
df0f840b | 108 | PERROR("ioctl kernel create session"); |
20fe2104 DG |
109 | goto error; |
110 | } | |
111 | ||
20fe2104 | 112 | lks->fd = ret; |
7b395890 DG |
113 | /* Prevent fd duplication after execlp() */ |
114 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); | |
115 | if (ret < 0) { | |
df0f840b | 116 | PERROR("fcntl session fd"); |
7b395890 DG |
117 | } |
118 | ||
53632229 | 119 | lks->id = session->id; |
3bd1e081 | 120 | lks->consumer_fds_sent = 0; |
8c0faa1d | 121 | session->kernel_session = lks; |
8c0faa1d DG |
122 | |
123 | DBG("Kernel session created (fd: %d)", lks->fd); | |
20fe2104 DG |
124 | |
125 | return 0; | |
126 | ||
127 | error: | |
5f62c685 DG |
128 | if (lks) { |
129 | trace_kernel_destroy_session(lks); | |
130 | } | |
20fe2104 DG |
131 | return ret; |
132 | } | |
133 | ||
134 | /* | |
050349bb DG |
135 | * Create a kernel channel, register it to the kernel tracer and add it to the |
136 | * kernel session. | |
20fe2104 | 137 | */ |
050349bb | 138 | int kernel_create_channel(struct ltt_kernel_session *session, |
fdd9eb17 | 139 | struct lttng_channel *chan) |
20fe2104 DG |
140 | { |
141 | int ret; | |
142 | struct ltt_kernel_channel *lkc; | |
20fe2104 | 143 | |
0525e9ae DG |
144 | assert(session); |
145 | assert(chan); | |
0525e9ae | 146 | |
54012638 | 147 | /* Allocate kernel channel */ |
fdd9eb17 | 148 | lkc = trace_kernel_create_channel(chan); |
54012638 | 149 | if (lkc == NULL) { |
20fe2104 DG |
150 | goto error; |
151 | } | |
152 | ||
ecc48a90 | 153 | DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d", |
fdd9eb17 | 154 | chan->name, lkc->channel->attr.overwrite, |
173af62f DG |
155 | lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf, |
156 | lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval, | |
ecc48a90 | 157 | lkc->channel->attr.live_timer_interval, lkc->channel->attr.output); |
173af62f | 158 | |
54012638 | 159 | /* Kernel tracer channel creation */ |
f3ed775e | 160 | ret = kernctl_create_channel(session->fd, &lkc->channel->attr); |
20fe2104 | 161 | if (ret < 0) { |
df0f840b | 162 | PERROR("ioctl kernel create channel"); |
20fe2104 DG |
163 | goto error; |
164 | } | |
165 | ||
54012638 | 166 | /* Setup the channel fd */ |
20fe2104 | 167 | lkc->fd = ret; |
7b395890 DG |
168 | /* Prevent fd duplication after execlp() */ |
169 | ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC); | |
170 | if (ret < 0) { | |
df0f840b | 171 | PERROR("fcntl session fd"); |
7b395890 DG |
172 | } |
173 | ||
54012638 | 174 | /* Add channel to session */ |
8c0faa1d DG |
175 | cds_list_add(&lkc->list, &session->channel_list.head); |
176 | session->channel_count++; | |
fb5f35b6 | 177 | lkc->session = session; |
e1f3997a | 178 | lkc->key = ++next_kernel_channel_key; |
20fe2104 | 179 | |
e1f3997a JD |
180 | DBG("Kernel channel %s created (fd: %d, key: %" PRIu64 ")", |
181 | lkc->channel->name, lkc->fd, lkc->key); | |
20fe2104 DG |
182 | |
183 | return 0; | |
184 | ||
185 | error: | |
5f62c685 DG |
186 | if (lkc) { |
187 | free(lkc->channel); | |
188 | free(lkc); | |
189 | } | |
54012638 | 190 | return -1; |
20fe2104 | 191 | } |
f34daff7 DG |
192 | |
193 | /* | |
050349bb DG |
194 | * Create a kernel event, enable it to the kernel tracer and add it to the |
195 | * channel event list of the kernel session. | |
49d21f93 | 196 | * We own filter_expression and filter. |
f34daff7 | 197 | */ |
050349bb | 198 | int kernel_create_event(struct lttng_event *ev, |
00a62084 MD |
199 | struct ltt_kernel_channel *channel, |
200 | char *filter_expression, | |
201 | struct lttng_filter_bytecode *filter) | |
f34daff7 DG |
202 | { |
203 | int ret; | |
204 | struct ltt_kernel_event *event; | |
f34daff7 | 205 | |
0525e9ae DG |
206 | assert(ev); |
207 | assert(channel); | |
208 | ||
a969e101 | 209 | /* We pass ownership of filter_expression and filter */ |
00a62084 MD |
210 | event = trace_kernel_create_event(ev, filter_expression, |
211 | filter); | |
54012638 | 212 | if (event == NULL) { |
d87bfb32 | 213 | ret = -1; |
f34daff7 DG |
214 | goto error; |
215 | } | |
216 | ||
f3ed775e DG |
217 | ret = kernctl_create_event(channel->fd, event->event); |
218 | if (ret < 0) { | |
32af2c95 | 219 | switch (-ret) { |
bd29c13d DG |
220 | case EEXIST: |
221 | break; | |
222 | case ENOSYS: | |
223 | WARN("Event type not implemented"); | |
224 | break; | |
8197a339 DG |
225 | case ENOENT: |
226 | WARN("Event %s not found!", ev->name); | |
227 | break; | |
bd29c13d | 228 | default: |
d87bfb32 DG |
229 | PERROR("create event ioctl"); |
230 | } | |
e953ef25 | 231 | goto free_event; |
8c0faa1d | 232 | } |
f34daff7 | 233 | |
d0ae4ea8 | 234 | event->type = ev->type; |
f3ed775e | 235 | event->fd = ret; |
7b395890 DG |
236 | /* Prevent fd duplication after execlp() */ |
237 | ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC); | |
238 | if (ret < 0) { | |
df0f840b | 239 | PERROR("fcntl session fd"); |
7b395890 DG |
240 | } |
241 | ||
00a62084 MD |
242 | if (filter) { |
243 | ret = kernctl_filter(event->fd, filter); | |
244 | if (ret) { | |
245 | goto filter_error; | |
246 | } | |
247 | } | |
248 | ||
249 | ret = kernctl_enable(event->fd); | |
250 | if (ret < 0) { | |
32af2c95 | 251 | switch (-ret) { |
00a62084 MD |
252 | case EEXIST: |
253 | ret = LTTNG_ERR_KERN_EVENT_EXIST; | |
254 | break; | |
255 | default: | |
256 | PERROR("enable kernel event"); | |
257 | break; | |
258 | } | |
259 | goto enable_error; | |
260 | } | |
261 | ||
f3ed775e DG |
262 | /* Add event to event list */ |
263 | cds_list_add(&event->list, &channel->events_list.head); | |
cbbbb275 DG |
264 | channel->event_count++; |
265 | ||
e953ef25 DG |
266 | DBG("Event %s created (fd: %d)", ev->name, event->fd); |
267 | ||
268 | return 0; | |
269 | ||
00a62084 MD |
270 | enable_error: |
271 | filter_error: | |
272 | { | |
273 | int closeret; | |
274 | ||
275 | closeret = close(event->fd); | |
276 | if (closeret) { | |
277 | PERROR("close event fd"); | |
278 | } | |
279 | } | |
e953ef25 DG |
280 | free_event: |
281 | free(event); | |
282 | error: | |
d87bfb32 | 283 | return ret; |
e953ef25 DG |
284 | } |
285 | ||
26cc6b4e | 286 | /* |
050349bb | 287 | * Disable a kernel channel. |
26cc6b4e DG |
288 | */ |
289 | int kernel_disable_channel(struct ltt_kernel_channel *chan) | |
290 | { | |
291 | int ret; | |
292 | ||
0525e9ae DG |
293 | assert(chan); |
294 | ||
26cc6b4e DG |
295 | ret = kernctl_disable(chan->fd); |
296 | if (ret < 0) { | |
df0f840b | 297 | PERROR("disable chan ioctl"); |
26cc6b4e DG |
298 | goto error; |
299 | } | |
300 | ||
301 | chan->enabled = 0; | |
e1f3997a JD |
302 | DBG("Kernel channel %s disabled (fd: %d, key: %" PRIu64 ")", |
303 | chan->channel->name, chan->fd, chan->key); | |
26cc6b4e DG |
304 | |
305 | return 0; | |
306 | ||
307 | error: | |
308 | return ret; | |
309 | } | |
310 | ||
d36b8583 | 311 | /* |
050349bb | 312 | * Enable a kernel channel. |
d36b8583 DG |
313 | */ |
314 | int kernel_enable_channel(struct ltt_kernel_channel *chan) | |
315 | { | |
316 | int ret; | |
317 | ||
0525e9ae DG |
318 | assert(chan); |
319 | ||
d36b8583 | 320 | ret = kernctl_enable(chan->fd); |
32af2c95 | 321 | if (ret < 0 && ret != -EEXIST) { |
df0f840b | 322 | PERROR("Enable kernel chan"); |
d36b8583 DG |
323 | goto error; |
324 | } | |
325 | ||
326 | chan->enabled = 1; | |
e1f3997a JD |
327 | DBG("Kernel channel %s enabled (fd: %d, key: %" PRIu64 ")", |
328 | chan->channel->name, chan->fd, chan->key); | |
d36b8583 DG |
329 | |
330 | return 0; | |
331 | ||
332 | error: | |
333 | return ret; | |
334 | } | |
335 | ||
19e70852 | 336 | /* |
050349bb | 337 | * Enable a kernel event. |
19e70852 DG |
338 | */ |
339 | int kernel_enable_event(struct ltt_kernel_event *event) | |
340 | { | |
341 | int ret; | |
342 | ||
0525e9ae DG |
343 | assert(event); |
344 | ||
19e70852 | 345 | ret = kernctl_enable(event->fd); |
42224349 | 346 | if (ret < 0) { |
32af2c95 | 347 | switch (-ret) { |
42224349 | 348 | case EEXIST: |
f73fabfd | 349 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
42224349 DG |
350 | break; |
351 | default: | |
352 | PERROR("enable kernel event"); | |
353 | break; | |
354 | } | |
19e70852 DG |
355 | goto error; |
356 | } | |
357 | ||
358 | event->enabled = 1; | |
359 | DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd); | |
360 | ||
361 | return 0; | |
362 | ||
363 | error: | |
d36b8583 | 364 | return ret; |
19e70852 DG |
365 | } |
366 | ||
e953ef25 | 367 | /* |
050349bb | 368 | * Disable a kernel event. |
e953ef25 | 369 | */ |
19e70852 | 370 | int kernel_disable_event(struct ltt_kernel_event *event) |
e953ef25 DG |
371 | { |
372 | int ret; | |
19e70852 | 373 | |
0525e9ae DG |
374 | assert(event); |
375 | ||
19e70852 | 376 | ret = kernctl_disable(event->fd); |
42224349 | 377 | if (ret < 0) { |
32af2c95 | 378 | switch (-ret) { |
42224349 | 379 | case EEXIST: |
f73fabfd | 380 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
42224349 DG |
381 | break; |
382 | default: | |
383 | PERROR("disable kernel event"); | |
384 | break; | |
385 | } | |
19e70852 | 386 | goto error; |
e953ef25 | 387 | } |
f3ed775e | 388 | |
19e70852 DG |
389 | event->enabled = 0; |
390 | DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd); | |
391 | ||
f34daff7 DG |
392 | return 0; |
393 | ||
394 | error: | |
d36b8583 | 395 | return ret; |
f34daff7 | 396 | } |
aaf26714 | 397 | |
6e911cad | 398 | |
ccf10263 MD |
399 | int kernel_track_pid(struct ltt_kernel_session *session, int pid) |
400 | { | |
7c493d31 MD |
401 | int ret; |
402 | ||
ccf10263 MD |
403 | DBG("Kernel track PID %d for session id %" PRIu64 ".", |
404 | pid, session->id); | |
7c493d31 MD |
405 | ret = kernctl_track_pid(session->fd, pid); |
406 | if (!ret) { | |
407 | return LTTNG_OK; | |
408 | } | |
32af2c95 | 409 | switch (-ret) { |
7c493d31 MD |
410 | case EINVAL: |
411 | return LTTNG_ERR_INVALID; | |
412 | case ENOMEM: | |
413 | return LTTNG_ERR_NOMEM; | |
414 | case EEXIST: | |
415 | return LTTNG_ERR_PID_TRACKED; | |
416 | default: | |
417 | return LTTNG_ERR_UNK; | |
418 | } | |
ccf10263 MD |
419 | } |
420 | ||
421 | int kernel_untrack_pid(struct ltt_kernel_session *session, int pid) | |
422 | { | |
7c493d31 MD |
423 | int ret; |
424 | ||
ccf10263 MD |
425 | DBG("Kernel untrack PID %d for session id %" PRIu64 ".", |
426 | pid, session->id); | |
7c493d31 MD |
427 | ret = kernctl_untrack_pid(session->fd, pid); |
428 | if (!ret) { | |
429 | return LTTNG_OK; | |
430 | } | |
32af2c95 | 431 | switch (-ret) { |
7c493d31 MD |
432 | case EINVAL: |
433 | return LTTNG_ERR_INVALID; | |
434 | case ENOMEM: | |
435 | return LTTNG_ERR_NOMEM; | |
436 | case ENOENT: | |
437 | return LTTNG_ERR_PID_NOT_TRACKED; | |
438 | default: | |
439 | return LTTNG_ERR_UNK; | |
440 | } | |
ccf10263 MD |
441 | } |
442 | ||
a5dfbb9d MD |
443 | ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session, |
444 | int **_pids) | |
445 | { | |
446 | int fd, ret; | |
447 | int pid; | |
448 | ssize_t nbmem, count = 0; | |
449 | FILE *fp; | |
450 | int *pids; | |
451 | ||
452 | fd = kernctl_list_tracker_pids(session->fd); | |
453 | if (fd < 0) { | |
454 | PERROR("kernel tracker pids list"); | |
455 | goto error; | |
456 | } | |
457 | ||
458 | fp = fdopen(fd, "r"); | |
459 | if (fp == NULL) { | |
460 | PERROR("kernel tracker pids list fdopen"); | |
461 | goto error_fp; | |
462 | } | |
463 | ||
464 | nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE; | |
465 | pids = zmalloc(sizeof(*pids) * nbmem); | |
466 | if (pids == NULL) { | |
467 | PERROR("alloc list pids"); | |
468 | count = -ENOMEM; | |
469 | goto end; | |
470 | } | |
471 | ||
472 | while (fscanf(fp, "process { pid = %u; };\n", &pid) == 1) { | |
473 | if (count >= nbmem) { | |
474 | int *new_pids; | |
475 | size_t new_nbmem; | |
476 | ||
477 | new_nbmem = nbmem << 1; | |
478 | DBG("Reallocating pids list from %zu to %zu entries", | |
479 | nbmem, new_nbmem); | |
480 | new_pids = realloc(pids, new_nbmem * sizeof(*new_pids)); | |
481 | if (new_pids == NULL) { | |
482 | PERROR("realloc list events"); | |
483 | free(pids); | |
484 | count = -ENOMEM; | |
485 | goto end; | |
486 | } | |
487 | /* Zero the new memory */ | |
488 | memset(new_pids + nbmem, 0, | |
489 | (new_nbmem - nbmem) * sizeof(*new_pids)); | |
490 | nbmem = new_nbmem; | |
491 | pids = new_pids; | |
492 | } | |
493 | pids[count++] = pid; | |
494 | } | |
495 | ||
496 | *_pids = pids; | |
497 | DBG("Kernel list tracker pids done (%zd pids)", count); | |
498 | end: | |
499 | ret = fclose(fp); /* closes both fp and fd */ | |
500 | if (ret) { | |
501 | PERROR("fclose"); | |
502 | } | |
503 | return count; | |
504 | ||
505 | error_fp: | |
506 | ret = close(fd); | |
507 | if (ret) { | |
508 | PERROR("close"); | |
509 | } | |
510 | error: | |
511 | return -1; | |
512 | } | |
513 | ||
aaf26714 | 514 | /* |
050349bb DG |
515 | * Create kernel metadata, open from the kernel tracer and add it to the |
516 | * kernel session. | |
aaf26714 | 517 | */ |
a4b92340 | 518 | int kernel_open_metadata(struct ltt_kernel_session *session) |
aaf26714 DG |
519 | { |
520 | int ret; | |
74024a21 | 521 | struct ltt_kernel_metadata *lkm = NULL; |
aaf26714 | 522 | |
0525e9ae DG |
523 | assert(session); |
524 | ||
54012638 | 525 | /* Allocate kernel metadata */ |
a4b92340 | 526 | lkm = trace_kernel_create_metadata(); |
54012638 | 527 | if (lkm == NULL) { |
aaf26714 DG |
528 | goto error; |
529 | } | |
530 | ||
54012638 | 531 | /* Kernel tracer metadata creation */ |
f3ed775e | 532 | ret = kernctl_open_metadata(session->fd, &lkm->conf->attr); |
aaf26714 | 533 | if (ret < 0) { |
74024a21 | 534 | goto error_open; |
aaf26714 DG |
535 | } |
536 | ||
8c0faa1d | 537 | lkm->fd = ret; |
d40f0359 | 538 | lkm->key = ++next_kernel_channel_key; |
7b395890 DG |
539 | /* Prevent fd duplication after execlp() */ |
540 | ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC); | |
541 | if (ret < 0) { | |
df0f840b | 542 | PERROR("fcntl session fd"); |
7b395890 DG |
543 | } |
544 | ||
aaf26714 | 545 | session->metadata = lkm; |
8c0faa1d | 546 | |
00e2e675 | 547 | DBG("Kernel metadata opened (fd: %d)", lkm->fd); |
8c0faa1d DG |
548 | |
549 | return 0; | |
550 | ||
74024a21 DG |
551 | error_open: |
552 | trace_kernel_destroy_metadata(lkm); | |
8c0faa1d | 553 | error: |
54012638 | 554 | return -1; |
8c0faa1d DG |
555 | } |
556 | ||
557 | /* | |
050349bb | 558 | * Start tracing session. |
8c0faa1d DG |
559 | */ |
560 | int kernel_start_session(struct ltt_kernel_session *session) | |
561 | { | |
562 | int ret; | |
563 | ||
0525e9ae DG |
564 | assert(session); |
565 | ||
8c0faa1d DG |
566 | ret = kernctl_start_session(session->fd); |
567 | if (ret < 0) { | |
df0f840b | 568 | PERROR("ioctl start session"); |
8c0faa1d DG |
569 | goto error; |
570 | } | |
571 | ||
572 | DBG("Kernel session started"); | |
573 | ||
574 | return 0; | |
575 | ||
576 | error: | |
577 | return ret; | |
578 | } | |
579 | ||
f3ed775e | 580 | /* |
050349bb | 581 | * Make a kernel wait to make sure in-flight probe have completed. |
f3ed775e DG |
582 | */ |
583 | void kernel_wait_quiescent(int fd) | |
584 | { | |
585 | int ret; | |
586 | ||
587 | DBG("Kernel quiescent wait on %d", fd); | |
588 | ||
589 | ret = kernctl_wait_quiescent(fd); | |
590 | if (ret < 0) { | |
df0f840b | 591 | PERROR("wait quiescent ioctl"); |
f3ed775e DG |
592 | ERR("Kernel quiescent wait failed"); |
593 | } | |
594 | } | |
595 | ||
596 | /* | |
f3ed775e DG |
597 | * Force flush buffer of metadata. |
598 | */ | |
599 | int kernel_metadata_flush_buffer(int fd) | |
600 | { | |
601 | int ret; | |
602 | ||
169d2cb7 DG |
603 | DBG("Kernel flushing metadata buffer on fd %d", fd); |
604 | ||
f3ed775e DG |
605 | ret = kernctl_buffer_flush(fd); |
606 | if (ret < 0) { | |
00e2e675 | 607 | ERR("Fail to flush metadata buffers %d (ret: %d)", fd, ret); |
f3ed775e DG |
608 | } |
609 | ||
610 | return 0; | |
611 | } | |
612 | ||
613 | /* | |
050349bb | 614 | * Force flush buffer for channel. |
f3ed775e DG |
615 | */ |
616 | int kernel_flush_buffer(struct ltt_kernel_channel *channel) | |
617 | { | |
618 | int ret; | |
619 | struct ltt_kernel_stream *stream; | |
620 | ||
0525e9ae DG |
621 | assert(channel); |
622 | ||
f3ed775e DG |
623 | DBG("Flush buffer for channel %s", channel->channel->name); |
624 | ||
625 | cds_list_for_each_entry(stream, &channel->stream_list.head, list) { | |
626 | DBG("Flushing channel stream %d", stream->fd); | |
627 | ret = kernctl_buffer_flush(stream->fd); | |
628 | if (ret < 0) { | |
df0f840b | 629 | PERROR("ioctl"); |
f3ed775e DG |
630 | ERR("Fail to flush buffer for stream %d (ret: %d)", |
631 | stream->fd, ret); | |
632 | } | |
633 | } | |
634 | ||
635 | return 0; | |
636 | } | |
637 | ||
8c0faa1d | 638 | /* |
050349bb | 639 | * Stop tracing session. |
8c0faa1d DG |
640 | */ |
641 | int kernel_stop_session(struct ltt_kernel_session *session) | |
642 | { | |
643 | int ret; | |
644 | ||
0525e9ae DG |
645 | assert(session); |
646 | ||
8c0faa1d DG |
647 | ret = kernctl_stop_session(session->fd); |
648 | if (ret < 0) { | |
649 | goto error; | |
650 | } | |
651 | ||
652 | DBG("Kernel session stopped"); | |
653 | ||
654 | return 0; | |
655 | ||
656 | error: | |
657 | return ret; | |
658 | } | |
659 | ||
660 | /* | |
050349bb DG |
661 | * Open stream of channel, register it to the kernel tracer and add it |
662 | * to the stream list of the channel. | |
8c0faa1d | 663 | * |
1cfb4b98 MD |
664 | * Note: given that the streams may appear in random order wrt CPU |
665 | * number (e.g. cpu hotplug), the index value of the stream number in | |
666 | * the stream name is not necessarily linked to the CPU number. | |
667 | * | |
050349bb | 668 | * Return the number of created stream. Else, a negative value. |
8c0faa1d | 669 | */ |
f3ed775e | 670 | int kernel_open_channel_stream(struct ltt_kernel_channel *channel) |
8c0faa1d | 671 | { |
1cfb4b98 | 672 | int ret; |
8c0faa1d DG |
673 | struct ltt_kernel_stream *lks; |
674 | ||
0525e9ae DG |
675 | assert(channel); |
676 | ||
5a47c6a2 | 677 | while ((ret = kernctl_create_stream(channel->fd)) >= 0) { |
1cfb4b98 MD |
678 | lks = trace_kernel_create_stream(channel->channel->name, |
679 | channel->stream_count); | |
8c0faa1d | 680 | if (lks == NULL) { |
799e2c4f MD |
681 | ret = close(ret); |
682 | if (ret) { | |
683 | PERROR("close"); | |
684 | } | |
8c0faa1d DG |
685 | goto error; |
686 | } | |
687 | ||
688 | lks->fd = ret; | |
7b395890 DG |
689 | /* Prevent fd duplication after execlp() */ |
690 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); | |
691 | if (ret < 0) { | |
df0f840b | 692 | PERROR("fcntl session fd"); |
7b395890 DG |
693 | } |
694 | ||
1624d5b7 JD |
695 | lks->tracefile_size = channel->channel->attr.tracefile_size; |
696 | lks->tracefile_count = channel->channel->attr.tracefile_count; | |
697 | ||
1cfb4b98 | 698 | /* Add stream to channel stream list */ |
8c0faa1d DG |
699 | cds_list_add(&lks->list, &channel->stream_list.head); |
700 | channel->stream_count++; | |
8c0faa1d | 701 | |
00e2e675 DG |
702 | DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd, |
703 | lks->state); | |
54012638 | 704 | } |
8c0faa1d DG |
705 | |
706 | return channel->stream_count; | |
707 | ||
708 | error: | |
54012638 | 709 | return -1; |
8c0faa1d DG |
710 | } |
711 | ||
712 | /* | |
050349bb | 713 | * Open the metadata stream and set it to the kernel session. |
8c0faa1d | 714 | */ |
f3ed775e | 715 | int kernel_open_metadata_stream(struct ltt_kernel_session *session) |
8c0faa1d DG |
716 | { |
717 | int ret; | |
718 | ||
0525e9ae DG |
719 | assert(session); |
720 | ||
8c0faa1d DG |
721 | ret = kernctl_create_stream(session->metadata->fd); |
722 | if (ret < 0) { | |
df0f840b | 723 | PERROR("kernel create metadata stream"); |
8c0faa1d DG |
724 | goto error; |
725 | } | |
726 | ||
727 | DBG("Kernel metadata stream created (fd: %d)", ret); | |
728 | session->metadata_stream_fd = ret; | |
7b395890 DG |
729 | /* Prevent fd duplication after execlp() */ |
730 | ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC); | |
731 | if (ret < 0) { | |
df0f840b | 732 | PERROR("fcntl session fd"); |
7b395890 | 733 | } |
aaf26714 DG |
734 | |
735 | return 0; | |
736 | ||
737 | error: | |
54012638 | 738 | return -1; |
aaf26714 | 739 | } |
2ef84c95 DG |
740 | |
741 | /* | |
9f19cc17 | 742 | * Get the event list from the kernel tracer and return the number of elements. |
2ef84c95 | 743 | */ |
9f19cc17 | 744 | ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events) |
2ef84c95 | 745 | { |
53efb85a | 746 | int fd, ret; |
9f19cc17 DG |
747 | char *event; |
748 | size_t nbmem, count = 0; | |
2ef84c95 | 749 | FILE *fp; |
9f19cc17 | 750 | struct lttng_event *elist; |
2ef84c95 | 751 | |
0525e9ae DG |
752 | assert(events); |
753 | ||
2ef84c95 DG |
754 | fd = kernctl_tracepoint_list(tracer_fd); |
755 | if (fd < 0) { | |
df0f840b | 756 | PERROR("kernel tracepoint list"); |
2ef84c95 DG |
757 | goto error; |
758 | } | |
759 | ||
760 | fp = fdopen(fd, "r"); | |
761 | if (fp == NULL) { | |
df0f840b | 762 | PERROR("kernel tracepoint list fdopen"); |
61b73b12 | 763 | goto error_fp; |
2ef84c95 DG |
764 | } |
765 | ||
766 | /* | |
767 | * Init memory size counter | |
768 | * See kernel-ctl.h for explanation of this value | |
769 | */ | |
6725fe19 | 770 | nbmem = KERNEL_EVENT_INIT_LIST_SIZE; |
ba7f0ae5 | 771 | elist = zmalloc(sizeof(struct lttng_event) * nbmem); |
3b870559 MD |
772 | if (elist == NULL) { |
773 | PERROR("alloc list events"); | |
774 | count = -ENOMEM; | |
775 | goto end; | |
776 | } | |
2ef84c95 | 777 | |
53efb85a | 778 | while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) { |
6725fe19 | 779 | if (count >= nbmem) { |
3b870559 | 780 | struct lttng_event *new_elist; |
53efb85a | 781 | size_t new_nbmem; |
3b870559 | 782 | |
53efb85a MD |
783 | new_nbmem = nbmem << 1; |
784 | DBG("Reallocating event list from %zu to %zu bytes", | |
785 | nbmem, new_nbmem); | |
786 | new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event)); | |
3b870559 | 787 | if (new_elist == NULL) { |
df0f840b | 788 | PERROR("realloc list events"); |
3b870559 MD |
789 | free(event); |
790 | free(elist); | |
61b73b12 MD |
791 | count = -ENOMEM; |
792 | goto end; | |
2ef84c95 | 793 | } |
53efb85a MD |
794 | /* Zero the new memory */ |
795 | memset(new_elist + nbmem, 0, | |
796 | (new_nbmem - nbmem) * sizeof(struct lttng_event)); | |
797 | nbmem = new_nbmem; | |
3b870559 | 798 | elist = new_elist; |
2ef84c95 | 799 | } |
99497cd0 MD |
800 | strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN); |
801 | elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
67b9d018 | 802 | elist[count].enabled = -1; |
9f19cc17 | 803 | count++; |
3b870559 | 804 | free(event); |
2ef84c95 DG |
805 | } |
806 | ||
9f19cc17 | 807 | *events = elist; |
ced2f820 | 808 | DBG("Kernel list events done (%zu events)", count); |
61b73b12 | 809 | end: |
799e2c4f MD |
810 | ret = fclose(fp); /* closes both fp and fd */ |
811 | if (ret) { | |
812 | PERROR("fclose"); | |
813 | } | |
9f19cc17 | 814 | return count; |
2ef84c95 | 815 | |
61b73b12 | 816 | error_fp: |
799e2c4f MD |
817 | ret = close(fd); |
818 | if (ret) { | |
819 | PERROR("close"); | |
820 | } | |
2ef84c95 DG |
821 | error: |
822 | return -1; | |
823 | } | |
096102bd DG |
824 | |
825 | /* | |
826 | * Get kernel version and validate it. | |
827 | */ | |
88076e89 JD |
828 | int kernel_validate_version(int tracer_fd, |
829 | struct lttng_kernel_tracer_version *version, | |
830 | struct lttng_kernel_tracer_abi_version *abi_version) | |
096102bd DG |
831 | { |
832 | int ret; | |
096102bd | 833 | |
88076e89 | 834 | ret = kernctl_tracer_version(tracer_fd, version); |
096102bd | 835 | if (ret < 0) { |
521dd134 | 836 | ERR("Failed to retrieve the lttng-modules version"); |
096102bd DG |
837 | goto error; |
838 | } | |
839 | ||
840 | /* Validate version */ | |
88076e89 | 841 | if (version->major != VERSION_MAJOR) { |
c052142c | 842 | ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)", |
88076e89 | 843 | version->major, VERSION_MAJOR); |
096102bd | 844 | goto error_version; |
096102bd | 845 | } |
88076e89 | 846 | ret = kernctl_tracer_abi_version(tracer_fd, abi_version); |
c052142c | 847 | if (ret < 0) { |
521dd134 | 848 | ERR("Failed to retrieve lttng-modules ABI version"); |
c052142c MD |
849 | goto error; |
850 | } | |
88076e89 | 851 | if (abi_version->major != LTTNG_MODULES_ABI_MAJOR_VERSION) { |
521dd134 | 852 | ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)", |
88076e89 | 853 | abi_version->major, abi_version->minor, |
c052142c MD |
854 | LTTNG_MODULES_ABI_MAJOR_VERSION); |
855 | goto error; | |
856 | } | |
857 | DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)", | |
88076e89 JD |
858 | version->major, version->minor, |
859 | abi_version->major, abi_version->minor); | |
096102bd DG |
860 | return 0; |
861 | ||
862 | error_version: | |
096102bd DG |
863 | ret = -1; |
864 | ||
865 | error: | |
521dd134 | 866 | ERR("Kernel tracer version check failed; kernel tracing will not be available"); |
096102bd DG |
867 | return ret; |
868 | } | |
335a95b7 MD |
869 | |
870 | /* | |
871 | * Kernel work-arounds called at the start of sessiond main(). | |
872 | */ | |
873 | int init_kernel_workarounds(void) | |
874 | { | |
8936c33a | 875 | int ret; |
335a95b7 MD |
876 | FILE *fp; |
877 | ||
878 | /* | |
879 | * boot_id needs to be read once before being used concurrently | |
880 | * to deal with a Linux kernel race. A fix is proposed for | |
881 | * upstream, but the work-around is needed for older kernels. | |
882 | */ | |
883 | fp = fopen("/proc/sys/kernel/random/boot_id", "r"); | |
884 | if (!fp) { | |
885 | goto end_boot_id; | |
886 | } | |
887 | while (!feof(fp)) { | |
888 | char buf[37] = ""; | |
889 | ||
8936c33a DG |
890 | ret = fread(buf, 1, sizeof(buf), fp); |
891 | if (ret < 0) { | |
892 | /* Ignore error, we don't really care */ | |
893 | } | |
335a95b7 | 894 | } |
799e2c4f MD |
895 | ret = fclose(fp); |
896 | if (ret) { | |
897 | PERROR("fclose"); | |
898 | } | |
335a95b7 | 899 | end_boot_id: |
335a95b7 MD |
900 | return 0; |
901 | } | |
2f77fc4b DG |
902 | |
903 | /* | |
904 | * Complete teardown of a kernel session. | |
905 | */ | |
906 | void kernel_destroy_session(struct ltt_kernel_session *ksess) | |
907 | { | |
908 | if (ksess == NULL) { | |
909 | DBG3("No kernel session when tearing down session"); | |
910 | return; | |
911 | } | |
912 | ||
913 | DBG("Tearing down kernel session"); | |
914 | ||
07b86b52 | 915 | /* |
15dc512a DG |
916 | * Destroy channels on the consumer if at least one FD has been sent and we |
917 | * are in no output mode because the streams are in *no* monitor mode so we | |
918 | * have to send a command to clean them up or else they leaked. | |
07b86b52 | 919 | */ |
15dc512a | 920 | if (!ksess->output_traces && ksess->consumer_fds_sent) { |
07b86b52 JD |
921 | int ret; |
922 | struct consumer_socket *socket; | |
923 | struct lttng_ht_iter iter; | |
924 | ||
925 | /* For each consumer socket. */ | |
d069d577 | 926 | rcu_read_lock(); |
07b86b52 JD |
927 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
928 | socket, node.node) { | |
929 | struct ltt_kernel_channel *chan; | |
930 | ||
931 | /* For each channel, ask the consumer to destroy it. */ | |
932 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { | |
933 | ret = kernel_consumer_destroy_channel(socket, chan); | |
934 | if (ret < 0) { | |
935 | /* Consumer is probably dead. Use next socket. */ | |
936 | continue; | |
937 | } | |
938 | } | |
939 | } | |
d069d577 | 940 | rcu_read_unlock(); |
07b86b52 JD |
941 | } |
942 | ||
2f77fc4b DG |
943 | /* Close any relayd session */ |
944 | consumer_output_send_destroy_relayd(ksess->consumer); | |
945 | ||
946 | trace_kernel_destroy_session(ksess); | |
947 | } | |
fb5f35b6 DG |
948 | |
949 | /* | |
950 | * Destroy a kernel channel object. It does not do anything on the tracer side. | |
951 | */ | |
952 | void kernel_destroy_channel(struct ltt_kernel_channel *kchan) | |
953 | { | |
954 | struct ltt_kernel_session *ksess = NULL; | |
955 | ||
956 | assert(kchan); | |
957 | assert(kchan->channel); | |
958 | ||
959 | DBG3("Kernel destroy channel %s", kchan->channel->name); | |
960 | ||
961 | /* Update channel count of associated session. */ | |
962 | if (kchan->session) { | |
963 | /* Keep pointer reference so we can update it after the destroy. */ | |
964 | ksess = kchan->session; | |
965 | } | |
966 | ||
967 | trace_kernel_destroy_channel(kchan); | |
968 | ||
969 | /* | |
970 | * At this point the kernel channel is not visible anymore. This is safe | |
971 | * since in order to work on a visible kernel session, the tracing session | |
972 | * lock (ltt_session.lock) MUST be acquired. | |
973 | */ | |
974 | if (ksess) { | |
975 | ksess->channel_count--; | |
976 | } | |
977 | } | |
6dc3064a DG |
978 | |
979 | /* | |
980 | * Take a snapshot for a given kernel session. | |
981 | * | |
2a06df8d | 982 | * Return 0 on success or else return a LTTNG_ERR code. |
6dc3064a DG |
983 | */ |
984 | int kernel_snapshot_record(struct ltt_kernel_session *ksess, | |
d07ceecd MD |
985 | struct snapshot_output *output, int wait, |
986 | uint64_t nb_packets_per_stream) | |
6dc3064a | 987 | { |
2a06df8d | 988 | int err, ret, saved_metadata_fd; |
6dc3064a DG |
989 | struct consumer_socket *socket; |
990 | struct lttng_ht_iter iter; | |
991 | struct ltt_kernel_metadata *saved_metadata; | |
992 | ||
993 | assert(ksess); | |
994 | assert(ksess->consumer); | |
995 | assert(output); | |
996 | ||
997 | DBG("Kernel snapshot record started"); | |
998 | ||
999 | /* Save current metadata since the following calls will change it. */ | |
1000 | saved_metadata = ksess->metadata; | |
1001 | saved_metadata_fd = ksess->metadata_stream_fd; | |
1002 | ||
1003 | rcu_read_lock(); | |
1004 | ||
1005 | ret = kernel_open_metadata(ksess); | |
1006 | if (ret < 0) { | |
1007 | ret = LTTNG_ERR_KERN_META_FAIL; | |
1008 | goto error; | |
1009 | } | |
1010 | ||
1011 | ret = kernel_open_metadata_stream(ksess); | |
1012 | if (ret < 0) { | |
1013 | ret = LTTNG_ERR_KERN_META_FAIL; | |
1014 | goto error_open_stream; | |
1015 | } | |
1016 | ||
1017 | /* Send metadata to consumer and snapshot everything. */ | |
1018 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, | |
1019 | socket, node.node) { | |
1020 | struct consumer_output *saved_output; | |
1021 | struct ltt_kernel_channel *chan; | |
6dc3064a DG |
1022 | |
1023 | /* | |
1024 | * Temporarly switch consumer output for our snapshot output. As long | |
1025 | * as the session lock is taken, this is safe. | |
1026 | */ | |
1027 | saved_output = ksess->consumer; | |
1028 | ksess->consumer = output->consumer; | |
1029 | ||
1030 | pthread_mutex_lock(socket->lock); | |
1031 | /* This stream must not be monitored by the consumer. */ | |
07b86b52 | 1032 | ret = kernel_consumer_add_metadata(socket, ksess, 0); |
6dc3064a | 1033 | pthread_mutex_unlock(socket->lock); |
07b86b52 | 1034 | /* Put back the saved consumer output into the session. */ |
6dc3064a DG |
1035 | ksess->consumer = saved_output; |
1036 | if (ret < 0) { | |
1037 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; | |
1038 | goto error_consumer; | |
1039 | } | |
1040 | ||
1041 | /* For each channel, ask the consumer to snapshot it. */ | |
1042 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { | |
0a28e553 | 1043 | ret = consumer_snapshot_channel(socket, chan->key, output, 0, |
5c786ded JD |
1044 | ksess->uid, ksess->gid, |
1045 | DEFAULT_KERNEL_TRACE_DIR, wait, | |
d07ceecd | 1046 | nb_packets_per_stream); |
6dc3064a DG |
1047 | if (ret < 0) { |
1048 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; | |
2a06df8d DG |
1049 | (void) kernel_consumer_destroy_metadata(socket, |
1050 | ksess->metadata); | |
6dc3064a DG |
1051 | goto error_consumer; |
1052 | } | |
1053 | } | |
1054 | ||
1055 | /* Snapshot metadata, */ | |
d40f0359 | 1056 | ret = consumer_snapshot_channel(socket, ksess->metadata->key, output, |
5c786ded | 1057 | 1, ksess->uid, ksess->gid, |
d07ceecd | 1058 | DEFAULT_KERNEL_TRACE_DIR, wait, 0); |
6dc3064a DG |
1059 | if (ret < 0) { |
1060 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; | |
1061 | goto error_consumer; | |
1062 | } | |
07b86b52 JD |
1063 | |
1064 | /* | |
1065 | * The metadata snapshot is done, ask the consumer to destroy it since | |
1066 | * it's not monitored on the consumer side. | |
1067 | */ | |
1068 | (void) kernel_consumer_destroy_metadata(socket, ksess->metadata); | |
6dc3064a DG |
1069 | } |
1070 | ||
fac41e72 DG |
1071 | ret = LTTNG_OK; |
1072 | ||
6dc3064a DG |
1073 | error_consumer: |
1074 | /* Close newly opened metadata stream. It's now on the consumer side. */ | |
2a06df8d DG |
1075 | err = close(ksess->metadata_stream_fd); |
1076 | if (err < 0) { | |
6dc3064a DG |
1077 | PERROR("close snapshot kernel"); |
1078 | } | |
1079 | ||
1080 | error_open_stream: | |
1081 | trace_kernel_destroy_metadata(ksess->metadata); | |
1082 | error: | |
1083 | /* Restore metadata state.*/ | |
1084 | ksess->metadata = saved_metadata; | |
1085 | ksess->metadata_stream_fd = saved_metadata_fd; | |
1086 | ||
1087 | rcu_read_unlock(); | |
1088 | return ret; | |
1089 | } | |
834978fd DG |
1090 | |
1091 | /* | |
1092 | * Get the syscall mask array from the kernel tracer. | |
1093 | * | |
1094 | * Return 0 on success else a negative value. In both case, syscall_mask should | |
1095 | * be freed. | |
1096 | */ | |
1097 | int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits) | |
1098 | { | |
1099 | assert(syscall_mask); | |
1100 | assert(nr_bits); | |
1101 | ||
1102 | return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits); | |
1103 | } | |
6e21424e JR |
1104 | |
1105 | /* | |
1106 | * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi | |
1107 | * version number. | |
1108 | * | |
1109 | * Return 1 on success, 0 when feature is not supported, negative value in case | |
1110 | * of errors. | |
1111 | */ | |
1112 | int kernel_supports_ring_buffer_snapshot_sample_positions(int tracer_fd) | |
1113 | { | |
1114 | int ret = 0; // Not supported by default | |
1115 | struct lttng_kernel_tracer_abi_version abi; | |
1116 | ||
1117 | ret = kernctl_tracer_abi_version(tracer_fd, &abi); | |
1118 | if (ret < 0) { | |
1119 | ERR("Failed to retrieve lttng-modules ABI version"); | |
1120 | goto error; | |
1121 | } | |
1122 | ||
1123 | /* | |
1124 | * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3 | |
1125 | */ | |
1126 | if (abi.major >= 2 && abi.minor >= 3) { | |
1127 | /* Supported */ | |
1128 | ret = 1; | |
1129 | } else { | |
1130 | /* Not supported */ | |
1131 | ret = 0; | |
1132 | } | |
1133 | error: | |
1134 | return ret; | |
1135 | } |