2727692a |
1 | /* libltt |
2 | * |
3 | * Linux Trace Toolkit Netlink Control Library |
4 | * |
c928825d |
5 | * Controls the ltt-control kernel module through debugfs. |
2727692a |
6 | * |
7 | * Copyright 2005 - |
8 | * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
9 | * |
10 | * |
11 | * This program is free software; you can redistribute it and/or modify |
12 | * it under the terms of the GNU General Public License as published by |
13 | * the Free Software Foundation; either version 2 of the License, or |
14 | * (at your option) any later version. |
15 | * |
16 | * This program is distributed in the hope that it will be useful, |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
10e8a188 |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
2727692a |
19 | * GNU General Public License for more details. |
c928825d |
20 | * |
2727692a |
21 | */ |
22 | |
23 | #ifdef HAVE_CONFIG_H |
24 | #include <config.h> |
25 | #endif |
26 | |
27 | #include <liblttctl/lttctl.h> |
28 | #include <errno.h> |
29 | #include <stdio.h> |
2727692a |
30 | #include <string.h> |
c928825d |
31 | #include <dirent.h> |
32 | #include <limits.h> |
33 | #include <fcntl.h> |
34 | #include <stdlib.h> |
2727692a |
35 | |
c928825d |
36 | #define MAX_CHANNEL (256) |
2727692a |
37 | |
c928825d |
38 | static char debugfsmntdir[PATH_MAX]; |
2727692a |
39 | |
c928825d |
40 | static int initdebugfsmntdir(void) |
2727692a |
41 | { |
354b34fd |
42 | return getdebugfsmntdir(debugfsmntdir); |
43 | } |
2727692a |
44 | |
354b34fd |
45 | /* |
46 | * This function must called posterior to initdebugfsmntdir(), |
47 | * because it need to use debugfsmntdir[] which is inited in initdebugfsmntdir() |
48 | */ |
49 | static int initmodule(void) |
50 | { |
51 | char controldirname[PATH_MAX]; |
52 | DIR *dir; |
53 | int tryload_done = 0; |
54 | |
55 | sprintf(controldirname, "%s/ltt/control/", debugfsmntdir); |
56 | |
57 | check_again: |
58 | /* |
59 | * Check ltt control's debugfs dir |
60 | * |
61 | * We don't check is ltt-trace-control module exist, because it maybe |
62 | * compiled into kernel. |
63 | */ |
64 | dir = opendir(controldirname); |
65 | if (dir) { |
66 | closedir(dir); |
67 | return 0; |
c928825d |
68 | } |
2727692a |
69 | |
354b34fd |
70 | if (!tryload_done) { |
71 | system("modprobe ltt-trace-control"); |
72 | tryload_done = 1; |
73 | goto check_again; |
2727692a |
74 | } |
354b34fd |
75 | |
76 | return -ENOENT; |
c928825d |
77 | } |
78 | |
79 | int lttctl_init(void) |
80 | { |
81 | int ret; |
354b34fd |
82 | |
c928825d |
83 | |
84 | ret = initdebugfsmntdir(); |
85 | if (ret) { |
354b34fd |
86 | fprintf(stderr, "Get debugfs mount point failed\n"); |
c928825d |
87 | return 1; |
2727692a |
88 | } |
2727692a |
89 | |
354b34fd |
90 | ret = initmodule(); |
91 | if (ret) { |
92 | fprintf(stderr, "Control module seems not work\n"); |
93 | return 1; |
c928825d |
94 | } |
2727692a |
95 | |
c928825d |
96 | return 0; |
97 | } |
2727692a |
98 | |
c928825d |
99 | int lttctl_destroy(void) |
2727692a |
100 | { |
c928825d |
101 | return 0; |
2727692a |
102 | } |
103 | |
c928825d |
104 | static int lttctl_sendop(const char *fname, const char *op) |
2727692a |
105 | { |
c928825d |
106 | int fd; |
107 | |
108 | if (!fname) { |
109 | fprintf(stderr, "%s: args invalid\n", __func__); |
110 | return 1; |
111 | } |
112 | |
113 | fd = open(fname, O_WRONLY); |
114 | if (fd == -1) { |
115 | fprintf(stderr, "%s: open %s failed: %s\n", __func__, fname, |
116 | strerror(errno)); |
117 | return errno; |
118 | } |
119 | |
120 | if (write(fd, op, strlen(op)) == -1) { |
121 | fprintf(stderr, "%s: write %s to %s failed: %s\n", __func__, op, |
122 | fname, strerror(errno)); |
123 | close(fd); |
124 | return 1; |
125 | } |
2727692a |
126 | |
c928825d |
127 | close(fd); |
128 | |
129 | return 0; |
130 | } |
2727692a |
131 | |
132 | /* |
c928825d |
133 | * check is trace exist(check debugfsmntdir too) |
134 | * expect: |
135 | * 0: expect that trace not exist |
136 | * !0: expect that trace exist |
137 | * |
138 | * ret: |
139 | * 0: check pass |
140 | * 1: check failed |
141 | * -ERRNO: error happened (no check) |
2727692a |
142 | */ |
c928825d |
143 | static int lttctl_check_trace(const char *name, int expect) |
2727692a |
144 | { |
c928825d |
145 | char tracedirname[PATH_MAX]; |
146 | DIR *dir; |
147 | int exist; |
2727692a |
148 | |
c928825d |
149 | if (!name) { |
150 | fprintf(stderr, "%s: args invalid\n", __func__); |
151 | return -EINVAL; |
2727692a |
152 | } |
c928825d |
153 | |
154 | if (!debugfsmntdir[0]) { |
155 | fprintf(stderr, "%s: debugfsmntdir not valid\n", __func__); |
156 | return -EINVAL; |
157 | } |
158 | |
159 | sprintf(tracedirname, "%s/ltt/control/%s", debugfsmntdir, name); |
160 | |
161 | dir = opendir(tracedirname); |
162 | if (dir) { |
163 | exist = 1; |
164 | } else { |
165 | if (errno != ENOENT) { |
166 | fprintf(stderr, "%s: %s\n", __func__, strerror(errno)); |
167 | return -EINVAL; |
168 | } |
169 | exist = 0; |
170 | } |
171 | |
172 | closedir(dir); |
173 | |
174 | if (!expect != !exist) { |
175 | if (exist) |
176 | fprintf(stderr, "Trace %s already exist\n", name); |
177 | else |
178 | fprintf(stderr, "Trace %s not exist\n", name); |
179 | return 1; |
180 | } |
181 | |
182 | return 0; |
2727692a |
183 | } |
184 | |
185 | /* |
c928825d |
186 | * get channel list of a trace |
187 | * don't include metadata channel when metadata is 0 |
188 | * |
189 | * return number of channel on success |
190 | * return negative number on fail |
191 | * Caller must free channellist. |
2727692a |
192 | */ |
c928825d |
193 | static int lttctl_get_channellist(const char *tracename, |
194 | char ***channellist, int metadata) |
2727692a |
195 | { |
c928825d |
196 | char tracedirname[PATH_MAX]; |
197 | struct dirent *dirent; |
198 | DIR *dir; |
199 | char **list = NULL, **old_list; |
200 | int nr_chan = 0; |
201 | |
202 | sprintf(tracedirname, "%s/ltt/control/%s/channel", debugfsmntdir, |
203 | tracename); |
204 | |
205 | dir = opendir(tracedirname); |
206 | if (!dir) { |
207 | nr_chan = -ENOENT; |
208 | goto error; |
209 | } |
210 | |
211 | for (;;) { |
212 | dirent = readdir(dir); |
213 | if (!dirent) |
214 | break; |
215 | if (!strcmp(dirent->d_name, ".") |
216 | || !strcmp(dirent->d_name, "..")) |
217 | continue; |
218 | if (!metadata && !strcmp(dirent->d_name, "metadata")) |
219 | continue; |
220 | old_list = list; |
221 | list = malloc(sizeof(char *) * ++nr_chan); |
222 | memcpy(list, old_list, sizeof(*list) * (nr_chan - 1)); |
223 | free(old_list); |
224 | list[nr_chan - 1] = strdup(dirent->d_name); |
225 | } |
226 | |
227 | closedir(dir); |
228 | |
229 | *channellist = list; |
230 | return nr_chan; |
231 | error: |
232 | free(list); |
233 | *channellist = NULL; |
234 | return nr_chan; |
235 | } |
236 | |
237 | int lttctl_setup_trace(const char *name) |
238 | { |
239 | int ret; |
240 | char ctlfname[PATH_MAX]; |
241 | |
242 | if (!name) { |
243 | fprintf(stderr, "%s: args invalid\n", __func__); |
244 | ret = -EINVAL; |
245 | goto arg_error; |
246 | } |
247 | |
248 | ret = lttctl_check_trace(name, 0); |
249 | if (ret) |
250 | goto arg_error; |
251 | |
252 | sprintf(ctlfname, "%s/ltt/setup_trace", debugfsmntdir); |
253 | |
254 | ret = lttctl_sendop(ctlfname, name); |
255 | if (ret) { |
256 | fprintf(stderr, "Setup trace failed\n"); |
257 | goto op_err; |
2727692a |
258 | } |
c928825d |
259 | |
2727692a |
260 | return 0; |
c928825d |
261 | |
262 | op_err: |
263 | arg_error: |
264 | return ret; |
2727692a |
265 | } |
266 | |
c928825d |
267 | int lttctl_destroy_trace(const char *name) |
268 | { |
269 | int ret; |
270 | char ctlfname[PATH_MAX]; |
271 | |
272 | if (!name) { |
273 | fprintf(stderr, "%s: args invalid\n", __func__); |
274 | ret = -EINVAL; |
275 | goto arg_error; |
276 | } |
277 | |
278 | ret = lttctl_check_trace(name, 1); |
279 | if (ret) |
280 | goto arg_error; |
281 | |
282 | sprintf(ctlfname, "%s/ltt/destroy_trace", debugfsmntdir); |
283 | |
284 | ret = lttctl_sendop(ctlfname, name); |
285 | if (ret) { |
286 | fprintf(stderr, "Destroy trace failed\n"); |
287 | goto op_err; |
288 | } |
289 | |
290 | return 0; |
291 | |
292 | op_err: |
293 | arg_error: |
294 | return ret; |
295 | } |
2727692a |
296 | |
c928825d |
297 | int lttctl_alloc_trace(const char *name) |
2727692a |
298 | { |
c928825d |
299 | int ret; |
300 | char ctlfname[PATH_MAX]; |
301 | |
302 | if (!name) { |
303 | fprintf(stderr, "%s: args invalid\n", __func__); |
304 | ret = -EINVAL; |
305 | goto arg_error; |
306 | } |
307 | |
308 | ret = lttctl_check_trace(name, 1); |
309 | if (ret) |
310 | goto arg_error; |
311 | |
312 | sprintf(ctlfname, "%s/ltt/control/%s/alloc", debugfsmntdir, name); |
313 | |
314 | ret = lttctl_sendop(ctlfname, "1"); |
315 | if (ret) { |
316 | fprintf(stderr, "Allocate trace failed\n"); |
317 | goto op_err; |
318 | } |
319 | |
320 | return 0; |
321 | |
322 | op_err: |
323 | arg_error: |
324 | return ret; |
325 | } |
326 | |
327 | int lttctl_start(const char *name) |
328 | { |
329 | int ret; |
330 | char ctlfname[PATH_MAX]; |
331 | |
332 | if (!name) { |
333 | fprintf(stderr, "%s: args invalid\n", __func__); |
334 | ret = -EINVAL; |
335 | goto arg_error; |
336 | } |
337 | |
338 | ret = lttctl_check_trace(name, 1); |
339 | if (ret) |
340 | goto arg_error; |
341 | |
342 | sprintf(ctlfname, "%s/ltt/control/%s/enabled", debugfsmntdir, name); |
343 | |
344 | ret = lttctl_sendop(ctlfname, "1"); |
345 | if (ret) { |
346 | fprintf(stderr, "Start trace failed\n"); |
347 | goto op_err; |
2727692a |
348 | } |
349 | |
350 | return 0; |
351 | |
c928825d |
352 | op_err: |
353 | arg_error: |
354 | return ret; |
2727692a |
355 | } |
356 | |
c928825d |
357 | int lttctl_pause(const char *name) |
2727692a |
358 | { |
c928825d |
359 | int ret; |
360 | char ctlfname[PATH_MAX]; |
361 | |
362 | if (!name) { |
363 | fprintf(stderr, "%s: args invalid\n", __func__); |
364 | ret = -EINVAL; |
365 | goto arg_error; |
366 | } |
367 | |
368 | ret = lttctl_check_trace(name, 1); |
369 | if (ret) |
370 | goto arg_error; |
371 | |
372 | sprintf(ctlfname, "%s/ltt/control/%s/enabled", debugfsmntdir, name); |
373 | |
374 | ret = lttctl_sendop(ctlfname, "0"); |
375 | if (ret) { |
376 | fprintf(stderr, "Pause trace failed\n"); |
377 | goto op_err; |
2727692a |
378 | } |
379 | |
380 | return 0; |
381 | |
c928825d |
382 | op_err: |
383 | arg_error: |
384 | return ret; |
385 | } |
386 | |
387 | int lttctl_set_trans(const char *name, const char *trans) |
388 | { |
389 | int ret; |
390 | char ctlfname[PATH_MAX]; |
391 | |
392 | if (!name) { |
393 | fprintf(stderr, "%s: args invalid\n", __func__); |
394 | ret = -EINVAL; |
395 | goto arg_error; |
396 | } |
397 | |
398 | ret = lttctl_check_trace(name, 1); |
399 | if (ret) |
400 | goto arg_error; |
401 | |
402 | sprintf(ctlfname, "%s/ltt/control/%s/trans", debugfsmntdir, name); |
2727692a |
403 | |
c928825d |
404 | ret = lttctl_sendop(ctlfname, trans); |
405 | if (ret) { |
406 | fprintf(stderr, "Set transport failed\n"); |
407 | goto op_err; |
408 | } |
409 | |
410 | return 0; |
411 | |
412 | op_err: |
413 | arg_error: |
414 | return ret; |
2727692a |
415 | } |
416 | |
c928825d |
417 | static int __lttctl_set_channel_enable(const char *name, const char *channel, |
418 | int enable) |
2727692a |
419 | { |
c928825d |
420 | int ret; |
421 | char ctlfname[PATH_MAX]; |
2727692a |
422 | |
c928825d |
423 | sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/enable", debugfsmntdir, |
424 | name, channel); |
2727692a |
425 | |
c928825d |
426 | ret = lttctl_sendop(ctlfname, enable ? "1" : "0"); |
427 | if (ret) |
428 | fprintf(stderr, "Set channel's enable mode failed\n"); |
2727692a |
429 | |
c928825d |
430 | return ret; |
431 | } |
432 | int lttctl_set_channel_enable(const char *name, const char *channel, |
433 | int enable) |
434 | { |
435 | int ret; |
2727692a |
436 | |
c928825d |
437 | if (!name || !channel) { |
438 | fprintf(stderr, "%s: args invalid\n", __func__); |
439 | ret = -EINVAL; |
440 | goto arg_error; |
441 | } |
2727692a |
442 | |
c928825d |
443 | ret = lttctl_check_trace(name, 1); |
444 | if (ret) |
445 | goto arg_error; |
446 | |
447 | if (strcmp(channel, "all")) { |
448 | ret = __lttctl_set_channel_enable(name, channel, enable); |
449 | if (ret) |
450 | goto op_err; |
451 | } else { |
452 | char **channellist; |
453 | int n_channel; |
454 | |
455 | /* Don't allow set enable state for metadata channel */ |
456 | n_channel = lttctl_get_channellist(name, &channellist, 0); |
457 | if (n_channel < 0) { |
458 | fprintf(stderr, "%s: lttctl_get_channellist failed\n", |
459 | __func__); |
460 | ret = -ENOENT; |
461 | goto op_err; |
462 | } |
2727692a |
463 | |
c928825d |
464 | for (; n_channel > 0; n_channel--) { |
465 | ret = __lttctl_set_channel_enable(name, |
466 | channellist[n_channel - 1], enable); |
467 | if (ret) |
468 | goto op_err; |
469 | } |
470 | free(channellist); |
2727692a |
471 | } |
472 | |
473 | return 0; |
474 | |
c928825d |
475 | op_err: |
476 | arg_error: |
477 | return ret; |
478 | } |
479 | |
480 | static int __lttctl_set_channel_overwrite(const char *name, const char *channel, |
481 | int overwrite) |
482 | { |
483 | int ret; |
484 | char ctlfname[PATH_MAX]; |
485 | |
486 | sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/overwrite", |
487 | debugfsmntdir, name, channel); |
488 | |
489 | ret = lttctl_sendop(ctlfname, overwrite ? "1" : "0"); |
490 | if (ret) |
491 | fprintf(stderr, "Set channel's overwrite mode failed\n"); |
492 | |
493 | return ret; |
494 | } |
495 | int lttctl_set_channel_overwrite(const char *name, const char *channel, |
496 | int overwrite) |
497 | { |
498 | int ret; |
499 | |
500 | if (!name || !channel) { |
501 | fprintf(stderr, "%s: args invalid\n", __func__); |
502 | ret = -EINVAL; |
503 | goto arg_error; |
504 | } |
505 | |
506 | ret = lttctl_check_trace(name, 1); |
507 | if (ret) |
508 | goto arg_error; |
509 | |
510 | if (strcmp(channel, "all")) { |
511 | ret = __lttctl_set_channel_overwrite(name, channel, overwrite); |
512 | if (ret) |
513 | goto op_err; |
514 | } else { |
515 | char **channellist; |
516 | int n_channel; |
517 | |
518 | /* Don't allow set overwrite for metadata channel */ |
519 | n_channel = lttctl_get_channellist(name, &channellist, 0); |
520 | if (n_channel < 0) { |
521 | fprintf(stderr, "%s: lttctl_get_channellist failed\n", |
522 | __func__); |
523 | ret = -ENOENT; |
524 | goto op_err; |
525 | } |
526 | |
527 | for (; n_channel > 0; n_channel--) { |
528 | ret = __lttctl_set_channel_overwrite(name, |
529 | channellist[n_channel - 1], overwrite); |
530 | if (ret) |
531 | goto op_err; |
532 | } |
533 | free(channellist); |
534 | } |
535 | |
536 | return 0; |
2727692a |
537 | |
c928825d |
538 | op_err: |
539 | arg_error: |
540 | return ret; |
2727692a |
541 | } |
542 | |
c928825d |
543 | static int __lttctl_set_channel_subbuf_num(const char *name, |
544 | const char *channel, unsigned subbuf_num) |
545 | { |
546 | int ret; |
547 | char ctlfname[PATH_MAX]; |
548 | char opstr[32]; |
549 | |
550 | sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/subbuf_num", |
551 | debugfsmntdir, name, channel); |
552 | |
553 | sprintf(opstr, "%u", subbuf_num); |
554 | |
555 | ret = lttctl_sendop(ctlfname, opstr); |
556 | if (ret) |
557 | fprintf(stderr, "Set channel's subbuf number failed\n"); |
558 | |
559 | return ret; |
560 | } |
561 | int lttctl_set_channel_subbuf_num(const char *name, const char *channel, |
562 | unsigned subbuf_num) |
2727692a |
563 | { |
c928825d |
564 | int ret; |
565 | |
566 | if (!name || !channel) { |
567 | fprintf(stderr, "%s: args invalid\n", __func__); |
568 | ret = -EINVAL; |
569 | goto arg_error; |
570 | } |
571 | |
572 | ret = lttctl_check_trace(name, 1); |
573 | if (ret) |
574 | goto arg_error; |
575 | |
576 | if (strcmp(channel, "all")) { |
577 | ret = __lttctl_set_channel_subbuf_num(name, channel, |
578 | subbuf_num); |
579 | if (ret) |
580 | goto op_err; |
581 | } else { |
582 | char **channellist; |
583 | int n_channel; |
584 | |
585 | /* allow set subbuf_num for metadata channel */ |
586 | n_channel = lttctl_get_channellist(name, &channellist, 1); |
587 | if (n_channel < 0) { |
588 | fprintf(stderr, "%s: lttctl_get_channellist failed\n", |
589 | __func__); |
590 | ret = -ENOENT; |
591 | goto op_err; |
592 | } |
593 | |
594 | for (; n_channel > 0; n_channel--) { |
595 | ret = __lttctl_set_channel_subbuf_num(name, |
596 | channellist[n_channel - 1], subbuf_num); |
597 | if (ret) |
598 | goto op_err; |
599 | } |
600 | free(channellist); |
2727692a |
601 | } |
602 | |
603 | return 0; |
604 | |
c928825d |
605 | op_err: |
606 | arg_error: |
607 | return ret; |
608 | } |
609 | |
610 | static int __lttctl_set_channel_subbuf_size(const char *name, |
611 | const char *channel, unsigned subbuf_size) |
612 | { |
613 | int ret; |
614 | char ctlfname[PATH_MAX]; |
615 | char opstr[32]; |
616 | |
617 | sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/subbuf_size", |
618 | debugfsmntdir, name, channel); |
619 | |
620 | sprintf(opstr, "%u", subbuf_size); |
621 | |
622 | ret = lttctl_sendop(ctlfname, opstr); |
623 | if (ret) |
624 | fprintf(stderr, "Set channel's subbuf size failed\n"); |
2727692a |
625 | } |
c928825d |
626 | int lttctl_set_channel_subbuf_size(const char *name, const char *channel, |
627 | unsigned subbuf_size) |
628 | { |
629 | int ret; |
2727692a |
630 | |
c928825d |
631 | if (!name || !channel) { |
632 | fprintf(stderr, "%s: args invalid\n", __func__); |
633 | ret = -EINVAL; |
634 | goto arg_error; |
635 | } |
636 | |
637 | ret = lttctl_check_trace(name, 1); |
638 | if (ret) |
639 | goto arg_error; |
640 | |
641 | if (strcmp(channel, "all")) { |
642 | ret = __lttctl_set_channel_subbuf_size(name, channel, |
643 | subbuf_size); |
644 | if (ret) |
645 | goto op_err; |
646 | } else { |
647 | char **channellist; |
648 | int n_channel; |
649 | |
650 | /* allow set subbuf_size for metadata channel */ |
651 | n_channel = lttctl_get_channellist(name, &channellist, 1); |
652 | if (n_channel < 0) { |
653 | fprintf(stderr, "%s: lttctl_get_channellist failed\n", |
654 | __func__); |
655 | ret = -ENOENT; |
656 | goto op_err; |
657 | } |
658 | |
659 | for (; n_channel > 0; n_channel--) { |
660 | ret = __lttctl_set_channel_subbuf_size(name, |
661 | channellist[n_channel - 1], subbuf_size); |
662 | if (ret) |
663 | goto op_err; |
664 | } |
665 | free(channellist); |
666 | } |
667 | |
668 | return 0; |
669 | |
670 | op_err: |
671 | arg_error: |
672 | return ret; |
673 | } |
354b34fd |
674 | |
675 | int getdebugfsmntdir(char *mntdir) |
676 | { |
677 | char mnt_dir[PATH_MAX]; |
678 | char mnt_type[PATH_MAX]; |
679 | int trymount_done = 0; |
680 | |
681 | FILE *fp = fopen("/proc/mounts", "r"); |
682 | if (!fp) |
683 | return -EINVAL; |
684 | |
685 | find_again: |
686 | while (1) { |
687 | if (fscanf(fp, "%*s %s %s %*s %*s %*s", mnt_dir, mnt_type) <= 0) |
688 | break; |
689 | |
690 | if (!strcmp(mnt_type, "debugfs")) { |
691 | strcpy(mntdir, mnt_dir); |
692 | return 0; |
693 | } |
694 | } |
695 | |
696 | if (!trymount_done) { |
697 | mount("debugfs", "/sys/kernel/debug/", "debugfs", 0, NULL); |
698 | trymount_done = 1; |
699 | goto find_again; |
700 | } |
701 | |
702 | return -ENOENT; |
703 | } |