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
23 #include "trace-event.h"
24 #include <api/fs/tracing_path.h>
25 #include "evsel.h"
26 #include "debug.h"
27
28 #define VERSION "0.6"
29
30 static int output_fd;
31
32
bigendian(void)33 int bigendian(void)
34 {
35 unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
36 unsigned int *ptr;
37
38 ptr = (unsigned int *)(void *)str;
39 return *ptr == 0x01020304;
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 (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
403 static struct tracepoint_path *
get_tracepoints_path(struct list_head * pattrs)404 get_tracepoints_path(struct list_head *pattrs)
405 {
406 struct tracepoint_path path, *ppath = &path;
407 struct evsel *pos;
408 int nr_tracepoints = 0;
409
410 list_for_each_entry(pos, pattrs, core.node) {
411 if (pos->core.attr.type != PERF_TYPE_TRACEPOINT)
412 continue;
413 ++nr_tracepoints;
414
415 if (pos->name) {
416 ppath->next = tracepoint_name_to_path(pos->name);
417 if (ppath->next)
418 goto next;
419
420 if (strchr(pos->name, ':') == NULL)
421 goto try_id;
422
423 goto error;
424 }
425
426 try_id:
427 ppath->next = tracepoint_id_to_path(pos->core.attr.config);
428 if (!ppath->next) {
429 error:
430 pr_debug("No memory to alloc tracepoints list\n");
431 put_tracepoints_path(path.next);
432 return NULL;
433 }
434 next:
435 ppath = ppath->next;
436 }
437
438 return nr_tracepoints > 0 ? path.next : NULL;
439 }
440
have_tracepoints(struct list_head * pattrs)441 bool have_tracepoints(struct list_head *pattrs)
442 {
443 struct evsel *pos;
444
445 list_for_each_entry(pos, pattrs, core.node)
446 if (pos->core.attr.type == PERF_TYPE_TRACEPOINT)
447 return true;
448
449 return false;
450 }
451
tracing_data_header(void)452 static int tracing_data_header(void)
453 {
454 char buf[20];
455 ssize_t size;
456
457 /* just guessing this is someone's birthday.. ;) */
458 buf[0] = 23;
459 buf[1] = 8;
460 buf[2] = 68;
461 memcpy(buf + 3, "tracing", 7);
462
463 if (write(output_fd, buf, 10) != 10)
464 return -1;
465
466 size = strlen(VERSION) + 1;
467 if (write(output_fd, VERSION, size) != size)
468 return -1;
469
470 /* save endian */
471 if (bigendian())
472 buf[0] = 1;
473 else
474 buf[0] = 0;
475
476 if (write(output_fd, buf, 1) != 1)
477 return -1;
478
479 /* save size of long */
480 buf[0] = sizeof(long);
481 if (write(output_fd, buf, 1) != 1)
482 return -1;
483
484 /* save page_size */
485 if (write(output_fd, &page_size, 4) != 4)
486 return -1;
487
488 return 0;
489 }
490
tracing_data_get(struct list_head * pattrs,int fd,bool temp)491 struct tracing_data *tracing_data_get(struct list_head *pattrs,
492 int fd, bool temp)
493 {
494 struct tracepoint_path *tps;
495 struct tracing_data *tdata;
496 int err;
497
498 output_fd = fd;
499
500 tps = get_tracepoints_path(pattrs);
501 if (!tps)
502 return NULL;
503
504 tdata = malloc(sizeof(*tdata));
505 if (!tdata)
506 return NULL;
507
508 tdata->temp = temp;
509 tdata->size = 0;
510
511 if (temp) {
512 int temp_fd;
513
514 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
515 "/tmp/perf-XXXXXX");
516 if (!mkstemp(tdata->temp_file)) {
517 pr_debug("Can't make temp file");
518 free(tdata);
519 return NULL;
520 }
521
522 temp_fd = open(tdata->temp_file, O_RDWR);
523 if (temp_fd < 0) {
524 pr_debug("Can't read '%s'", tdata->temp_file);
525 free(tdata);
526 return NULL;
527 }
528
529 /*
530 * Set the temp file the default output, so all the
531 * tracing data are stored into it.
532 */
533 output_fd = temp_fd;
534 }
535
536 err = tracing_data_header();
537 if (err)
538 goto out;
539 err = record_header_files();
540 if (err)
541 goto out;
542 err = record_ftrace_files(tps);
543 if (err)
544 goto out;
545 err = record_event_files(tps);
546 if (err)
547 goto out;
548 err = record_proc_kallsyms();
549 if (err)
550 goto out;
551 err = record_ftrace_printk();
552 if (err)
553 goto out;
554 err = record_saved_cmdline();
555
556 out:
557 /*
558 * All tracing data are stored by now, we can restore
559 * the default output file in case we used temp file.
560 */
561 if (temp) {
562 tdata->size = lseek(output_fd, 0, SEEK_CUR);
563 close(output_fd);
564 output_fd = fd;
565 }
566
567 if (err)
568 zfree(&tdata);
569
570 put_tracepoints_path(tps);
571 return tdata;
572 }
573
tracing_data_put(struct tracing_data * tdata)574 int tracing_data_put(struct tracing_data *tdata)
575 {
576 int err = 0;
577
578 if (tdata->temp) {
579 err = record_file(tdata->temp_file, 0);
580 unlink(tdata->temp_file);
581 }
582
583 free(tdata);
584 return err;
585 }
586
read_tracing_data(int fd,struct list_head * pattrs)587 int read_tracing_data(int fd, struct list_head *pattrs)
588 {
589 int err;
590 struct tracing_data *tdata;
591
592 /*
593 * We work over the real file, so we can write data
594 * directly, no temp file is needed.
595 */
596 tdata = tracing_data_get(pattrs, fd, false);
597 if (!tdata)
598 return -ENOMEM;
599
600 err = tracing_data_put(tdata);
601 return err;
602 }
603