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 closedir(dir);
317 put_tracing_file(path);
318
319 return err;
320 }
321
record_proc_kallsyms(void)322 static int record_proc_kallsyms(void)
323 {
324 unsigned long long size = 0;
325 /*
326 * Just to keep older perf.data file parsers happy, record a zero
327 * sized kallsyms file, i.e. do the same thing that was done when
328 * /proc/kallsyms (or something specified via --kallsyms, in a
329 * different path) couldn't be read.
330 */
331 return write(output_fd, &size, 4) != 4 ? -EIO : 0;
332 }
333
record_ftrace_printk(void)334 static int record_ftrace_printk(void)
335 {
336 unsigned int size;
337 char *path;
338 struct stat st;
339 int ret, err = 0;
340
341 path = get_tracing_file("printk_formats");
342 if (!path) {
343 pr_debug("can't get tracing/printk_formats");
344 return -ENOMEM;
345 }
346
347 ret = stat(path, &st);
348 if (ret < 0) {
349 /* not found */
350 size = 0;
351 if (write(output_fd, &size, 4) != 4)
352 err = -EIO;
353 goto out;
354 }
355 err = record_file(path, 4);
356
357 out:
358 put_tracing_file(path);
359 return err;
360 }
361
record_saved_cmdline(void)362 static int record_saved_cmdline(void)
363 {
364 unsigned long long size;
365 char *path;
366 struct stat st;
367 int ret, err = 0;
368
369 path = get_tracing_file("saved_cmdlines");
370 if (!path) {
371 pr_debug("can't get tracing/saved_cmdline");
372 return -ENOMEM;
373 }
374
375 ret = stat(path, &st);
376 if (ret < 0) {
377 /* not found */
378 size = 0;
379 if (write(output_fd, &size, 8) != 8)
380 err = -EIO;
381 goto out;
382 }
383 err = record_file(path, 8);
384
385 out:
386 put_tracing_file(path);
387 return err;
388 }
389
390 static void
put_tracepoints_path(struct tracepoint_path * tps)391 put_tracepoints_path(struct tracepoint_path *tps)
392 {
393 while (tps) {
394 struct tracepoint_path *t = tps;
395
396 tps = tps->next;
397 zfree(&t->name);
398 zfree(&t->system);
399 free(t);
400 }
401 }
402
tracepoint_id_to_path(u64 config)403 static struct tracepoint_path *tracepoint_id_to_path(u64 config)
404 {
405 struct tracepoint_path *path = NULL;
406 DIR *sys_dir, *evt_dir;
407 struct dirent *sys_dirent, *evt_dirent;
408 char id_buf[24];
409 int fd;
410 u64 id;
411 char evt_path[MAXPATHLEN];
412 char *dir_path;
413
414 sys_dir = tracing_events__opendir();
415 if (!sys_dir)
416 return NULL;
417
418 for_each_subsystem(sys_dir, sys_dirent) {
419 dir_path = get_events_file(sys_dirent->d_name);
420 if (!dir_path)
421 continue;
422 evt_dir = opendir(dir_path);
423 if (!evt_dir)
424 goto next;
425
426 for_each_event(dir_path, evt_dir, evt_dirent) {
427
428 scnprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path,
429 evt_dirent->d_name);
430 fd = open(evt_path, O_RDONLY);
431 if (fd < 0)
432 continue;
433 if (read(fd, id_buf, sizeof(id_buf)) < 0) {
434 close(fd);
435 continue;
436 }
437 close(fd);
438 id = atoll(id_buf);
439 if (id == config) {
440 put_events_file(dir_path);
441 closedir(evt_dir);
442 closedir(sys_dir);
443 path = zalloc(sizeof(*path));
444 if (!path)
445 return NULL;
446 if (asprintf(&path->system, "%.*s",
447 MAX_EVENT_LENGTH, sys_dirent->d_name) < 0) {
448 free(path);
449 return NULL;
450 }
451 if (asprintf(&path->name, "%.*s",
452 MAX_EVENT_LENGTH, evt_dirent->d_name) < 0) {
453 zfree(&path->system);
454 free(path);
455 return NULL;
456 }
457 return path;
458 }
459 }
460 closedir(evt_dir);
461 next:
462 put_events_file(dir_path);
463 }
464
465 closedir(sys_dir);
466 return NULL;
467 }
468
tracepoint_id_to_name(u64 config)469 char *tracepoint_id_to_name(u64 config)
470 {
471 struct tracepoint_path *path = tracepoint_id_to_path(config);
472 char *buf = NULL;
473
474 if (path && asprintf(&buf, "%s:%s", path->system, path->name) < 0)
475 buf = NULL;
476
477 put_tracepoints_path(path);
478 return buf;
479 }
480
tracepoint_name_to_path(const char * name)481 static struct tracepoint_path *tracepoint_name_to_path(const char *name)
482 {
483 struct tracepoint_path *path = zalloc(sizeof(*path));
484 char *str = strchr(name, ':');
485
486 if (path == NULL || str == NULL) {
487 free(path);
488 return NULL;
489 }
490
491 path->system = strndup(name, str - name);
492 path->name = strdup(str+1);
493
494 if (path->system == NULL || path->name == NULL) {
495 zfree(&path->system);
496 zfree(&path->name);
497 zfree(&path);
498 }
499
500 return path;
501 }
502
503 static struct tracepoint_path *
get_tracepoints_path(struct list_head * pattrs)504 get_tracepoints_path(struct list_head *pattrs)
505 {
506 struct tracepoint_path path, *ppath = &path;
507 struct evsel *pos;
508 int nr_tracepoints = 0;
509
510 list_for_each_entry(pos, pattrs, core.node) {
511 if (pos->core.attr.type != PERF_TYPE_TRACEPOINT)
512 continue;
513 ++nr_tracepoints;
514
515 if (pos->name) {
516 ppath->next = tracepoint_name_to_path(pos->name);
517 if (ppath->next)
518 goto next;
519
520 if (strchr(pos->name, ':') == NULL)
521 goto try_id;
522
523 goto error;
524 }
525
526 try_id:
527 ppath->next = tracepoint_id_to_path(pos->core.attr.config);
528 if (!ppath->next) {
529 error:
530 pr_debug("No memory to alloc tracepoints list\n");
531 put_tracepoints_path(path.next);
532 return NULL;
533 }
534 next:
535 ppath = ppath->next;
536 }
537
538 return nr_tracepoints > 0 ? path.next : NULL;
539 }
540
have_tracepoints(struct list_head * pattrs)541 bool have_tracepoints(struct list_head *pattrs)
542 {
543 struct evsel *pos;
544
545 list_for_each_entry(pos, pattrs, core.node)
546 if (pos->core.attr.type == PERF_TYPE_TRACEPOINT)
547 return true;
548
549 return false;
550 }
551
tracing_data_header(void)552 static int tracing_data_header(void)
553 {
554 char buf[20];
555 ssize_t size;
556
557 /* just guessing this is someone's birthday.. ;) */
558 buf[0] = 23;
559 buf[1] = 8;
560 buf[2] = 68;
561 memcpy(buf + 3, "tracing", 7);
562
563 if (write(output_fd, buf, 10) != 10)
564 return -1;
565
566 size = strlen(VERSION) + 1;
567 if (write(output_fd, VERSION, size) != size)
568 return -1;
569
570 /* save endian */
571 if (host_is_bigendian())
572 buf[0] = 1;
573 else
574 buf[0] = 0;
575
576 if (write(output_fd, buf, 1) != 1)
577 return -1;
578
579 /* save size of long */
580 buf[0] = sizeof(long);
581 if (write(output_fd, buf, 1) != 1)
582 return -1;
583
584 /* save page_size */
585 if (write(output_fd, &page_size, 4) != 4)
586 return -1;
587
588 return 0;
589 }
590
tracing_data_get(struct list_head * pattrs,int fd,bool temp)591 struct tracing_data *tracing_data_get(struct list_head *pattrs,
592 int fd, bool temp)
593 {
594 struct tracepoint_path *tps;
595 struct tracing_data *tdata;
596 int err;
597
598 output_fd = fd;
599
600 tps = get_tracepoints_path(pattrs);
601 if (!tps)
602 return NULL;
603
604 tdata = malloc(sizeof(*tdata));
605 if (!tdata)
606 return NULL;
607
608 tdata->temp = temp;
609 tdata->size = 0;
610
611 if (temp) {
612 int temp_fd;
613
614 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
615 "/tmp/perf-XXXXXX");
616 if (!mkstemp(tdata->temp_file)) {
617 pr_debug("Can't make temp file");
618 free(tdata);
619 return NULL;
620 }
621
622 temp_fd = open(tdata->temp_file, O_RDWR);
623 if (temp_fd < 0) {
624 pr_debug("Can't read '%s'", tdata->temp_file);
625 free(tdata);
626 return NULL;
627 }
628
629 /*
630 * Set the temp file the default output, so all the
631 * tracing data are stored into it.
632 */
633 output_fd = temp_fd;
634 }
635
636 err = tracing_data_header();
637 if (err)
638 goto out;
639 err = record_header_files();
640 if (err)
641 goto out;
642 err = record_ftrace_files(tps);
643 if (err)
644 goto out;
645 err = record_event_files(tps);
646 if (err)
647 goto out;
648 err = record_proc_kallsyms();
649 if (err)
650 goto out;
651 err = record_ftrace_printk();
652 if (err)
653 goto out;
654 err = record_saved_cmdline();
655
656 out:
657 /*
658 * All tracing data are stored by now, we can restore
659 * the default output file in case we used temp file.
660 */
661 if (temp) {
662 tdata->size = lseek(output_fd, 0, SEEK_CUR);
663 close(output_fd);
664 output_fd = fd;
665 }
666
667 if (err)
668 zfree(&tdata);
669
670 put_tracepoints_path(tps);
671 return tdata;
672 }
673
tracing_data_put(struct tracing_data * tdata)674 int tracing_data_put(struct tracing_data *tdata)
675 {
676 int err = 0;
677
678 if (tdata->temp) {
679 err = record_file(tdata->temp_file, 0);
680 unlink(tdata->temp_file);
681 }
682
683 free(tdata);
684 return err;
685 }
686
read_tracing_data(int fd,struct list_head * pattrs)687 int read_tracing_data(int fd, struct list_head *pattrs)
688 {
689 int err;
690 struct tracing_data *tdata;
691
692 /*
693 * We work over the real file, so we can write data
694 * directly, no temp file is needed.
695 */
696 tdata = tracing_data_get(pattrs, fd, false);
697 if (!tdata)
698 return -ENOMEM;
699
700 err = tracing_data_put(tdata);
701 return err;
702 }
703