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[lttng-tools.git] / ltt-sessiond / kernel-ctl.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; only version 2
7 * of the License.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <stdlib.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <unistd.h>
26
27 #include "lttngerr.h"
28 #include "libkernelctl.h"
29 #include "kernel-ctl.h"
30
31 /*
32 * kernel_add_channel_context
33 *
34 * Add context on a kernel channel.
35 */
36 int 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) {
44 perror("add context ioctl");
45 goto error;
46 }
47
48 chan->ctx = malloc(sizeof(struct lttng_kernel_context));
49 if (chan->ctx == NULL) {
50 perror("malloc event context");
51 goto error;
52 }
53
54 memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
55
56 return 0;
57
58 error:
59 return ret;
60 }
61
62 /*
63 * kernel_add_event_context
64 *
65 * Add context on a kernel event.
66 */
67 int kernel_add_event_context(struct ltt_kernel_event *event,
68 struct lttng_kernel_context *ctx)
69 {
70 int ret;
71
72 DBG("Adding context to event %s", event->event->name);
73 ret = kernctl_add_context(event->fd, ctx);
74 if (ret < 0) {
75 perror("add context ioctl");
76 goto error;
77 }
78
79 event->ctx = malloc(sizeof(struct lttng_kernel_context));
80 if (event->ctx == NULL) {
81 perror("malloc event context");
82 goto error;
83 }
84
85 memcpy(event->ctx, ctx, sizeof(struct lttng_kernel_context));
86
87 return 0;
88
89 error:
90 return ret;
91 }
92
93 /*
94 * kernel_create_session
95 *
96 * Create a new kernel session, register it to the kernel tracer and add it to
97 * the session daemon session.
98 */
99 int kernel_create_session(struct ltt_session *session, int tracer_fd)
100 {
101 int ret;
102 struct ltt_kernel_session *lks;
103
104 /* Allocate data structure */
105 lks = trace_create_kernel_session();
106 if (lks == NULL) {
107 ret = -1;
108 goto error;
109 }
110
111 /* Kernel tracer session creation */
112 ret = kernctl_create_session(tracer_fd);
113 if (ret < 0) {
114 perror("ioctl kernel create session");
115 goto error;
116 }
117
118 lks->fd = ret;
119 /* Prevent fd duplication after execlp() */
120 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
121 if (ret < 0) {
122 perror("fcntl session fd");
123 }
124
125 lks->kconsumer_fds_sent = 0;
126 session->kernel_session = lks;
127
128 DBG("Kernel session created (fd: %d)", lks->fd);
129
130 return 0;
131
132 error:
133 return ret;
134 }
135
136 /*
137 * kernel_create_channel
138 *
139 * Create a kernel channel, register it to the kernel tracer and add it to the
140 * kernel session.
141 */
142 int kernel_create_channel(struct ltt_kernel_session *session, struct lttng_channel *chan, char *path)
143 {
144 int ret;
145 struct ltt_kernel_channel *lkc;
146
147 /* Allocate kernel channel */
148 lkc = trace_create_kernel_channel(chan, path);
149 if (lkc == NULL) {
150 goto error;
151 }
152
153 /* Kernel tracer channel creation */
154 ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
155 if (ret < 0) {
156 perror("ioctl kernel create channel");
157 goto error;
158 }
159
160 /* Setup the channel fd */
161 lkc->fd = ret;
162 /* Prevent fd duplication after execlp() */
163 ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC);
164 if (ret < 0) {
165 perror("fcntl session fd");
166 }
167
168 /* Add channel to session */
169 cds_list_add(&lkc->list, &session->channel_list.head);
170 session->channel_count++;
171
172 DBG("Kernel channel %s created (fd: %d and path: %s)",
173 lkc->channel->name, lkc->fd, lkc->pathname);
174
175 return 0;
176
177 error:
178 return -1;
179 }
180
181 /*
182 * kernel_create_event
183 *
184 * Create a kernel event, enable it to the kernel tracer and add it to the
185 * channel event list of the kernel session.
186 */
187 int kernel_create_event(struct lttng_event *ev, struct ltt_kernel_channel *channel)
188 {
189 int ret;
190 struct ltt_kernel_event *event;
191
192 event = trace_create_kernel_event(ev);
193 if (event == NULL) {
194 goto error;
195 }
196
197 ret = kernctl_create_event(channel->fd, event->event);
198 if (ret < 0) {
199 perror("create event ioctl");
200 goto free_event;
201 }
202
203 event->fd = ret;
204 /* Prevent fd duplication after execlp() */
205 ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
206 if (ret < 0) {
207 perror("fcntl session fd");
208 }
209
210 /* Add event to event list */
211 cds_list_add(&event->list, &channel->events_list.head);
212 DBG("Event %s created (fd: %d)", ev->name, event->fd);
213
214 return 0;
215
216 free_event:
217 free(event);
218 error:
219 return -1;
220 }
221
222 /*
223 * kernel_disable_channel
224 *
225 * Disable a kernel channel.
226 */
227 int kernel_disable_channel(struct ltt_kernel_channel *chan)
228 {
229 int ret;
230
231 ret = kernctl_disable(chan->fd);
232 if (ret < 0) {
233 perror("disable chan ioctl");
234 ret = errno;
235 goto error;
236 }
237
238 chan->enabled = 0;
239 DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
240
241 return 0;
242
243 error:
244 return ret;
245 }
246
247 /*
248 * kernel_enable_channel
249 *
250 * Enable a kernel channel.
251 */
252 int kernel_enable_channel(struct ltt_kernel_channel *chan)
253 {
254 int ret;
255
256 ret = kernctl_enable(chan->fd);
257 if (ret < 0) {
258 perror("enable chan ioctl");
259 ret = errno;
260 goto error;
261 }
262
263 chan->enabled = 1;
264 DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
265
266 return 0;
267
268 error:
269 return ret;
270 }
271
272 /*
273 * kernel_enable_event
274 *
275 * Enable a kernel event.
276 */
277 int kernel_enable_event(struct ltt_kernel_event *event)
278 {
279 int ret;
280
281 ret = kernctl_enable(event->fd);
282 if (ret < 0) {
283 perror("enable event ioctl");
284 if (errno == EEXIST) {
285 ret = -EEXIST;
286 }
287 goto error;
288 }
289
290 event->enabled = 1;
291 DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd);
292
293 return 0;
294
295 error:
296 return ret;
297 }
298
299 /*
300 * kernel_disable_event
301 *
302 * Disable a kernel event.
303 */
304 int kernel_disable_event(struct ltt_kernel_event *event)
305 {
306 int ret;
307
308 ret = kernctl_disable(event->fd);
309 if (ret < 0) {
310 perror("disable event ioctl");
311 goto error;
312 }
313
314 event->enabled = 0;
315 DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
316
317 return 0;
318
319 error:
320 return ret;
321 }
322
323 /*
324 * kernel_open_metadata
325 *
326 * Create kernel metadata, open from the kernel tracer and add it to the
327 * kernel session.
328 */
329 int kernel_open_metadata(struct ltt_kernel_session *session, char *path)
330 {
331 int ret;
332 struct ltt_kernel_metadata *lkm;
333
334 /* Allocate kernel metadata */
335 lkm = trace_create_kernel_metadata(path);
336 if (lkm == NULL) {
337 goto error;
338 }
339
340 /* Kernel tracer metadata creation */
341 ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
342 if (ret < 0) {
343 goto error;
344 }
345
346 lkm->fd = ret;
347 /* Prevent fd duplication after execlp() */
348 ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
349 if (ret < 0) {
350 perror("fcntl session fd");
351 }
352
353 session->metadata = lkm;
354
355 DBG("Kernel metadata opened (fd: %d and path: %s)", lkm->fd, lkm->pathname);
356
357 return 0;
358
359 error:
360 return -1;
361 }
362
363 /*
364 * kernel_start_session
365 *
366 * Start tracing session.
367 */
368 int kernel_start_session(struct ltt_kernel_session *session)
369 {
370 int ret;
371
372 ret = kernctl_start_session(session->fd);
373 if (ret < 0) {
374 perror("ioctl start session");
375 goto error;
376 }
377
378 DBG("Kernel session started");
379
380 return 0;
381
382 error:
383 return ret;
384 }
385
386 /*
387 * kernel_wait_quiescent
388 *
389 * Make a kernel wait to make sure in-flight probe have completed.
390 */
391 void kernel_wait_quiescent(int fd)
392 {
393 int ret;
394
395 DBG("Kernel quiescent wait on %d", fd);
396
397 ret = kernctl_wait_quiescent(fd);
398 if (ret < 0) {
399 perror("wait quiescent ioctl");
400 ERR("Kernel quiescent wait failed");
401 }
402 }
403
404 /*
405 * kernel_metadata_flush_buffer
406 *
407 * Force flush buffer of metadata.
408 */
409 int kernel_metadata_flush_buffer(int fd)
410 {
411 int ret;
412
413 ret = kernctl_buffer_flush(fd);
414 if (ret < 0) {
415 ERR("Fail to flush metadata buffers %d (ret: %d", fd, ret);
416 }
417
418 return 0;
419 }
420
421 /*
422 * kernel_flush_buffer
423 *
424 * Force flush buffer for channel.
425 */
426 int kernel_flush_buffer(struct ltt_kernel_channel *channel)
427 {
428 int ret;
429 struct ltt_kernel_stream *stream;
430
431 DBG("Flush buffer for channel %s", channel->channel->name);
432
433 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
434 DBG("Flushing channel stream %d", stream->fd);
435 ret = kernctl_buffer_flush(stream->fd);
436 if (ret < 0) {
437 perror("ioctl");
438 ERR("Fail to flush buffer for stream %d (ret: %d)",
439 stream->fd, ret);
440 }
441 }
442
443 return 0;
444 }
445
446 /*
447 * kernel_stop_session
448 *
449 * Stop tracing session.
450 */
451 int kernel_stop_session(struct ltt_kernel_session *session)
452 {
453 int ret;
454
455 ret = kernctl_stop_session(session->fd);
456 if (ret < 0) {
457 goto error;
458 }
459
460 DBG("Kernel session stopped");
461
462 return 0;
463
464 error:
465 return ret;
466 }
467
468 /*
469 * kernel_open_channel_stream
470 *
471 * Open stream of channel, register it to the kernel tracer and add it
472 * to the stream list of the channel.
473 *
474 * Return the number of created stream. Else, a negative value.
475 */
476 int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
477 {
478 int ret;
479 struct ltt_kernel_stream *lks;
480
481 while ((ret = kernctl_create_stream(channel->fd)) > 0) {
482 lks = trace_create_kernel_stream();
483 if (lks == NULL) {
484 close(ret);
485 goto error;
486 }
487
488 lks->fd = ret;
489 /* Prevent fd duplication after execlp() */
490 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
491 if (ret < 0) {
492 perror("fcntl session fd");
493 }
494
495 ret = asprintf(&lks->pathname, "%s/%s_%d",
496 channel->pathname, channel->channel->name, channel->stream_count);
497 if (ret < 0) {
498 perror("asprintf kernel create stream");
499 goto error;
500 }
501
502 /* Add stream to channe stream list */
503 cds_list_add(&lks->list, &channel->stream_list.head);
504 channel->stream_count++;
505
506 DBG("Kernel stream %d created (fd: %d, state: %d, path: %s)",
507 channel->stream_count, lks->fd, lks->state, lks->pathname);
508 }
509
510 return channel->stream_count;
511
512 error:
513 return -1;
514 }
515
516 /*
517 * kernel_open_metadata_stream
518 *
519 * Open the metadata stream and set it to the kernel session.
520 */
521 int kernel_open_metadata_stream(struct ltt_kernel_session *session)
522 {
523 int ret;
524
525 ret = kernctl_create_stream(session->metadata->fd);
526 if (ret < 0) {
527 perror("kernel create metadata stream");
528 goto error;
529 }
530
531 DBG("Kernel metadata stream created (fd: %d)", ret);
532 session->metadata_stream_fd = ret;
533 /* Prevent fd duplication after execlp() */
534 ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC);
535 if (ret < 0) {
536 perror("fcntl session fd");
537 }
538
539 return 0;
540
541 error:
542 return -1;
543 }
544
545 /*
546 * kernel_list_events
547 *
548 * Get the event list from the kernel tracer and return that list in the CTF
549 * format.
550 */
551 ssize_t kernel_list_events(int tracer_fd, char **list)
552 {
553 int fd;
554 char *buf, *line = NULL;
555 size_t nb, nbmem, total = 0;
556 ssize_t size;
557 FILE *fp;
558
559 fd = kernctl_tracepoint_list(tracer_fd);
560 if (fd < 0) {
561 perror("kernel tracepoint list");
562 goto error;
563 }
564
565 fp = fdopen(fd, "r");
566 if (fp == NULL) {
567 perror("kernel tracepoint list fdopen");
568 goto error;
569 }
570
571 /*
572 * Init memory size counter
573 * See kernel-ctl.h for explanation of this value
574 */
575 nbmem = KERNEL_EVENT_LIST_SIZE;
576 buf = malloc(nbmem);
577
578 while ((size = getline(&line, &nb, fp)) != -1) {
579 if (total + size > nbmem) {
580 DBG("Reallocating event list from %zd to %zd bytes", nbmem,
581 total + size + KERNEL_EVENT_LIST_SIZE);
582 /* Adding the default size again */
583 nbmem = total + size + KERNEL_EVENT_LIST_SIZE;
584 buf = realloc(buf, nbmem);
585 if (buf == NULL) {
586 perror("realloc list events");
587 goto error;
588 }
589 }
590 memcpy(buf + total, line, size);
591 total += size;
592 }
593
594 *list = buf;
595
596 DBG("Kernel list events done");
597
598 return total;
599
600 error:
601 return -1;
602 }
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