1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com>
4 */
5 #include <dirent.h>
6 #include <mntent.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <stdarg.h>
11 #include <sys/types.h>
12 #include <sys/stat.h>
13 #include <sys/wait.h>
14 #include <fcntl.h>
15 #include <unistd.h>
16 #include <errno.h>
17 #include <stdbool.h>
18 #include <linux/list.h>
19 #include <linux/kernel.h>
20 #include <linux/zalloc.h>
21 #include <internal/lib.h> // page_size
22 #include <sys/param.h>
23
24 #include "trace-event.h"
25 #include "tracepoint.h"
26 #include <api/fs/tracing_path.h>
27 #include "evsel.h"
28 #include "debug.h"
29 #include "util.h"
30
31 #define VERSION "0.6"
32 #define MAX_EVENT_LENGTH 512
33
34 static int output_fd;
35
36 struct tracepoint_path {
37 char *system;
38 char *name;
39 struct tracepoint_path *next;
40 };
41
42 /* unfortunately, you can not stat debugfs or proc files for size */
record_file(const char * file,ssize_t hdr_sz)43 static int record_file(const char *file, ssize_t hdr_sz)
44 {
45 unsigned long long size = 0;
46 char buf[BUFSIZ], *sizep;
47 off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
48 int r, fd;
49 int err = -EIO;
50
51 fd = open(file, O_RDONLY);
52 if (fd < 0) {
53 pr_debug("Can't read '%s'", file);
54 return -errno;
55 }
56
57 /* put in zeros for file size, then fill true size later */
58 if (hdr_sz) {
59 if (write(output_fd, &size, hdr_sz) != hdr_sz)
60 goto out;
61 }
62
63 do {
64 r = read(fd, buf, BUFSIZ);
65 if (r > 0) {
66 size += r;
67 if (write(output_fd, buf, r) != r)
68 goto out;
69 }
70 } while (r > 0);
71
72 /* ugh, handle big-endian hdr_size == 4 */
73 sizep = (char*)&size;
74 if (host_is_bigendian())
75 sizep += sizeof(u64) - hdr_sz;
76
77 if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
78 pr_debug("writing file size failed\n");
79 goto out;
80 }
81
82 err = 0;
83 out:
84 close(fd);
85 return err;
86 }
87
record_header_files(void)88 static int record_header_files(void)
89 {
90 char *path = get_events_file("header_page");
91 struct stat st;
92 int err = -EIO;
93
94 if (!path) {
95 pr_debug("can't get tracing/events/header_page");
96 return -ENOMEM;
97 }
98
99 if (stat(path, &st) < 0) {
100 pr_debug("can't read '%s'", path);
101 goto out;
102 }
103
104 if (write(output_fd, "header_page", 12) != 12) {
105 pr_debug("can't write header_page\n");
106 goto out;
107 }
108
109 if (record_file(path, 8) < 0) {
110 pr_debug("can't record header_page file\n");
111 goto out;
112 }
113
114 put_events_file(path);
115
116 path = get_events_file("header_event");
117 if (!path) {
118 pr_debug("can't get tracing/events/header_event");
119 err = -ENOMEM;
120 goto out;
121 }
122
123 if (stat(path, &st) < 0) {
124 pr_debug("can't read '%s'", path);
125 goto out;
126 }
127
128 if (write(output_fd, "header_event", 13) != 13) {
129 pr_debug("can't write header_event\n");
130 goto out;
131 }
132
133 if (record_file(path, 8) < 0) {
134 pr_debug("can't record header_event file\n");
135 goto out;
136 }
137
138 err = 0;
139 out:
140 put_events_file(path);
141 return err;
142 }
143
name_in_tp_list(char * sys,struct tracepoint_path * tps)144 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
145 {
146 while (tps) {
147 if (!strcmp(sys, tps->name))
148 return true;
149 tps = tps->next;
150 }
151
152 return false;
153 }
154
155 #define for_each_event_tps(dir, dent, tps) \
156 while ((dent = readdir(dir))) \
157 if (dent->d_type == DT_DIR && \
158 (strcmp(dent->d_name, ".")) && \
159 (strcmp(dent->d_name, ".."))) \
160
copy_event_system(const char * sys,struct tracepoint_path * tps)161 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
162 {
163 struct dirent *dent;
164 struct stat st;
165 char *format;
166 DIR *dir;
167 int count = 0;
168 int ret;
169 int err;
170
171 dir = opendir(sys);
172 if (!dir) {
173 pr_debug("can't read directory '%s'", sys);
174 return -errno;
175 }
176
177 for_each_event_tps(dir, dent, tps) {
178 if (!name_in_tp_list(dent->d_name, tps))
179 continue;
180
181 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
182 err = -ENOMEM;
183 goto out;
184 }
185 ret = stat(format, &st);
186 free(format);
187 if (ret < 0)
188 continue;
189 count++;
190 }
191
192 if (write(output_fd, &count, 4) != 4) {
193 err = -EIO;
194 pr_debug("can't write count\n");
195 goto out;
196 }
197
198 rewinddir(dir);
199 for_each_event_tps(dir, dent, tps) {
200 if (!name_in_tp_list(dent->d_name, tps))
201 continue;
202
203 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
204 err = -ENOMEM;
205 goto out;
206 }
207 ret = stat(format, &st);
208
209 if (ret >= 0) {
210 err = record_file(format, 8);
211 if (err) {
212 free(format);
213 goto out;
214 }
215 }
216 free(format);
217 }
218 err = 0;
219 out:
220 closedir(dir);
221 return err;
222 }
223
record_ftrace_files(struct tracepoint_path * tps)224 static int record_ftrace_files(struct tracepoint_path *tps)
225 {
226 char *path;
227 int ret;
228
229 path = get_events_file("ftrace");
230 if (!path) {
231 pr_debug("can't get tracing/events/ftrace");
232 return -ENOMEM;
233 }
234
235 ret = copy_event_system(path, tps);
236
237 put_tracing_file(path);
238
239 return ret;
240 }
241
system_in_tp_list(char * sys,struct tracepoint_path * tps)242 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
243 {
244 while (tps) {
245 if (!strcmp(sys, tps->system))
246 return true;
247 tps = tps->next;
248 }
249
250 return false;
251 }
252
record_event_files(struct tracepoint_path * tps)253 static int record_event_files(struct tracepoint_path *tps)
254 {
255 struct dirent *dent;
256 struct stat st;
257 char *path;
258 char *sys;
259 DIR *dir;
260 int count = 0;
261 int ret;
262 int err;
263
264 path = get_tracing_file("events");
265 if (!path) {
266 pr_debug("can't get tracing/events");
267 return -ENOMEM;
268 }
269
270 dir = opendir(path);
271 if (!dir) {
272 err = -errno;
273 pr_debug("can't read directory '%s'", path);
274 goto out;
275 }
276
277 for_each_event_tps(dir, dent, tps) {
278 if (strcmp(dent->d_name, "ftrace") == 0 ||
279 !system_in_tp_list(dent->d_name, tps))
280 continue;
281
282 count++;
283 }
284
285 if (write(output_fd, &count, 4) != 4) {
286 err = -EIO;
287 pr_debug("can't write count\n");
288 goto out;
289 }
290
291 rewinddir(dir);
292 for_each_event_tps(dir, dent, tps) {
293 if (strcmp(dent->d_name, "ftrace") == 0 ||
294 !system_in_tp_list(dent->d_name, tps))
295 continue;
296
297 if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
298 err = -ENOMEM;
299 goto out;
300 }
301 ret = stat(sys, &st);
302 if (ret >= 0) {
303 ssize_t size = strlen(dent->d_name) + 1;
304
305 if (write(output_fd, dent->d_name, size) != size ||
306 copy_event_system(sys, tps) < 0) {
307 err = -EIO;
308 free(sys);
309 goto out;
310 }
311 }
312 free(sys);
313 }
314 err = 0;
315 out:
316 if (dir)
317 closedir(dir);
318 put_tracing_file(path);
319
320 return err;
321 }
322
record_proc_kallsyms(void)323 static int record_proc_kallsyms(void)
324 {
325 unsigned long long size = 0;
326 /*
327 * Just to keep older perf.data file parsers happy, record a zero
328 * sized kallsyms file, i.e. do the same thing that was done when
329 * /proc/kallsyms (or something specified via --kallsyms, in a
330 * different path) couldn't be read.
331 */
332 return write(output_fd, &size, 4) != 4 ? -EIO : 0;
333 }
334
record_ftrace_printk(void)335 static int record_ftrace_printk(void)
336 {
337 unsigned int size;
338 char *path;
339 struct stat st;
340 int ret, err = 0;
341
342 path = get_tracing_file("printk_formats");
343 if (!path) {
344 pr_debug("can't get tracing/printk_formats");
345 return -ENOMEM;
346 }
347
348 ret = stat(path, &st);
349 if (ret < 0) {
350 /* not found */
351 size = 0;
352 if (write(output_fd, &size, 4) != 4)
353 err = -EIO;
354 goto out;
355 }
356 err = record_file(path, 4);
357
358 out:
359 put_tracing_file(path);
360 return err;
361 }
362
record_saved_cmdline(void)363 static int record_saved_cmdline(void)
364 {
365 unsigned long long size;
366 char *path;
367 struct stat st;
368 int ret, err = 0;
369
370 path = get_tracing_file("saved_cmdlines");
371 if (!path) {
372 pr_debug("can't get tracing/saved_cmdline");
373 return -ENOMEM;
374 }
375
376 ret = stat(path, &st);
377 if (ret < 0) {
378 /* not found */
379 size = 0;
380 if (write(output_fd, &size, 8) != 8)
381 err = -EIO;
382 goto out;
383 }
384 err = record_file(path, 8);
385
386 out:
387 put_tracing_file(path);
388 return err;
389 }
390
391 static void
put_tracepoints_path(struct tracepoint_path * tps)392 put_tracepoints_path(struct tracepoint_path *tps)
393 {
394 while (tps) {
395 struct tracepoint_path *t = tps;
396
397 tps = tps->next;
398 zfree(&t->name);
399 zfree(&t->system);
400 free(t);
401 }
402 }
403
tracepoint_id_to_path(u64 config)404 static struct tracepoint_path *tracepoint_id_to_path(u64 config)
405 {
406 struct tracepoint_path *path = NULL;
407 DIR *sys_dir, *evt_dir;
408 struct dirent *sys_dirent, *evt_dirent;
409 char id_buf[24];
410 int fd;
411 u64 id;
412 char evt_path[MAXPATHLEN];
413 char *dir_path;
414
415 sys_dir = tracing_events__opendir();
416 if (!sys_dir)
417 return NULL;
418
419 for_each_subsystem(sys_dir, sys_dirent) {
420 dir_path = get_events_file(sys_dirent->d_name);
421 if (!dir_path)
422 continue;
423 evt_dir = opendir(dir_path);
424 if (!evt_dir)
425 goto next;
426
427 for_each_event(dir_path, evt_dir, evt_dirent) {
428
429 scnprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path,
430 evt_dirent->d_name);
431 fd = open(evt_path, O_RDONLY);
432 if (fd < 0)
433 continue;
434 if (read(fd, id_buf, sizeof(id_buf)) < 0) {
435 close(fd);
436 continue;
437 }
438 close(fd);
439 id = atoll(id_buf);
440 if (id == config) {
441 put_events_file(dir_path);
442 closedir(evt_dir);
443 closedir(sys_dir);
444 path = zalloc(sizeof(*path));
445 if (!path)
446 return NULL;
447 if (asprintf(&path->system, "%.*s",
448 MAX_EVENT_LENGTH, sys_dirent->d_name) < 0) {
449 free(path);
450 return NULL;
451 }
452 if (asprintf(&path->name, "%.*s",
453 MAX_EVENT_LENGTH, evt_dirent->d_name) < 0) {
454 zfree(&path->system);
455 free(path);
456 return NULL;
457 }
458 return path;
459 }
460 }
461 closedir(evt_dir);
462 next:
463 put_events_file(dir_path);
464 }
465
466 closedir(sys_dir);
467 return NULL;
468 }
469
tracepoint_id_to_name(u64 config)470 char *tracepoint_id_to_name(u64 config)
471 {
472 struct tracepoint_path *path = tracepoint_id_to_path(config);
473 char *buf = NULL;
474
475 if (path && asprintf(&buf, "%s:%s", path->system, path->name) < 0)
476 buf = NULL;
477
478 put_tracepoints_path(path);
479 return buf;
480 }
481
tracepoint_name_to_path(const char * name)482 static struct tracepoint_path *tracepoint_name_to_path(const char *name)
483 {
484 struct tracepoint_path *path = zalloc(sizeof(*path));
485 char *str = strchr(name, ':');
486
487 if (path == NULL || str == NULL) {
488 free(path);
489 return NULL;
490 }
491
492 path->system = strndup(name, str - name);
493 path->name = strdup(str+1);
494
495 if (path->system == NULL || path->name == NULL) {
496 zfree(&path->system);
497 zfree(&path->name);
498 zfree(&path);
499 }
500
501 return path;
502 }
503
504 static struct tracepoint_path *
get_tracepoints_path(struct list_head * pattrs)505 get_tracepoints_path(struct list_head *pattrs)
506 {
507 struct tracepoint_path path, *ppath = &path;
508 struct evsel *pos;
509 int nr_tracepoints = 0;
510
511 list_for_each_entry(pos, pattrs, core.node) {
512 if (pos->core.attr.type != PERF_TYPE_TRACEPOINT)
513 continue;
514 ++nr_tracepoints;
515
516 if (pos->name) {
517 ppath->next = tracepoint_name_to_path(pos->name);
518 if (ppath->next)
519 goto next;
520
521 if (strchr(pos->name, ':') == NULL)
522 goto try_id;
523
524 goto error;
525 }
526
527 try_id:
528 ppath->next = tracepoint_id_to_path(pos->core.attr.config);
529 if (!ppath->next) {
530 error:
531 pr_debug("No memory to alloc tracepoints list\n");
532 put_tracepoints_path(path.next);
533 return NULL;
534 }
535 next:
536 ppath = ppath->next;
537 }
538
539 return nr_tracepoints > 0 ? path.next : NULL;
540 }
541
have_tracepoints(struct list_head * pattrs)542 bool have_tracepoints(struct list_head *pattrs)
543 {
544 struct evsel *pos;
545
546 list_for_each_entry(pos, pattrs, core.node)
547 if (pos->core.attr.type == PERF_TYPE_TRACEPOINT)
548 return true;
549
550 return false;
551 }
552
tracing_data_header(void)553 static int tracing_data_header(void)
554 {
555 char buf[20];
556 ssize_t size;
557
558 /* just guessing this is someone's birthday.. ;) */
559 buf[0] = 23;
560 buf[1] = 8;
561 buf[2] = 68;
562 memcpy(buf + 3, "tracing", 7);
563
564 if (write(output_fd, buf, 10) != 10)
565 return -1;
566
567 size = strlen(VERSION) + 1;
568 if (write(output_fd, VERSION, size) != size)
569 return -1;
570
571 /* save endian */
572 if (host_is_bigendian())
573 buf[0] = 1;
574 else
575 buf[0] = 0;
576
577 if (write(output_fd, buf, 1) != 1)
578 return -1;
579
580 /* save size of long */
581 buf[0] = sizeof(long);
582 if (write(output_fd, buf, 1) != 1)
583 return -1;
584
585 /* save page_size */
586 if (write(output_fd, &page_size, 4) != 4)
587 return -1;
588
589 return 0;
590 }
591
tracing_data_get(struct list_head * pattrs,int fd,bool temp)592 struct tracing_data *tracing_data_get(struct list_head *pattrs,
593 int fd, bool temp)
594 {
595 struct tracepoint_path *tps;
596 struct tracing_data *tdata;
597 int err;
598
599 output_fd = fd;
600
601 tps = get_tracepoints_path(pattrs);
602 if (!tps)
603 return NULL;
604
605 tdata = malloc(sizeof(*tdata));
606 if (!tdata)
607 return NULL;
608
609 tdata->temp = temp;
610 tdata->size = 0;
611
612 if (temp) {
613 int temp_fd;
614
615 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
616 "/tmp/perf-XXXXXX");
617 if (!mkstemp(tdata->temp_file)) {
618 pr_debug("Can't make temp file");
619 free(tdata);
620 return NULL;
621 }
622
623 temp_fd = open(tdata->temp_file, O_RDWR);
624 if (temp_fd < 0) {
625 pr_debug("Can't read '%s'", tdata->temp_file);
626 free(tdata);
627 return NULL;
628 }
629
630 /*
631 * Set the temp file the default output, so all the
632 * tracing data are stored into it.
633 */
634 output_fd = temp_fd;
635 }
636
637 err = tracing_data_header();
638 if (err)
639 goto out;
640 err = record_header_files();
641 if (err)
642 goto out;
643 err = record_ftrace_files(tps);
644 if (err)
645 goto out;
646 err = record_event_files(tps);
647 if (err)
648 goto out;
649 err = record_proc_kallsyms();
650 if (err)
651 goto out;
652 err = record_ftrace_printk();
653 if (err)
654 goto out;
655 err = record_saved_cmdline();
656
657 out:
658 /*
659 * All tracing data are stored by now, we can restore
660 * the default output file in case we used temp file.
661 */
662 if (temp) {
663 tdata->size = lseek(output_fd, 0, SEEK_CUR);
664 close(output_fd);
665 output_fd = fd;
666 }
667
668 if (err)
669 zfree(&tdata);
670
671 put_tracepoints_path(tps);
672 return tdata;
673 }
674
tracing_data_put(struct tracing_data * tdata)675 int tracing_data_put(struct tracing_data *tdata)
676 {
677 int err = 0;
678
679 if (tdata->temp) {
680 err = record_file(tdata->temp_file, 0);
681 unlink(tdata->temp_file);
682 }
683
684 free(tdata);
685 return err;
686 }
687
read_tracing_data(int fd,struct list_head * pattrs)688 int read_tracing_data(int fd, struct list_head *pattrs)
689 {
690 int err;
691 struct tracing_data *tdata;
692
693 /*
694 * We work over the real file, so we can write data
695 * directly, no temp file is needed.
696 */
697 tdata = tracing_data_get(pattrs, fd, false);
698 if (!tdata)
699 return -ENOMEM;
700
701 err = tracing_data_put(tdata);
702 return err;
703 }
704