GNU Linux-libre 4.19.211-gnu1
[releases.git] / tools / perf / util / trace-event-info.c
1 /*
2  * Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com>
3  *
4  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License (not later!)
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  *
19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
20  */
21 #include "util.h"
22 #include <dirent.h>
23 #include <mntent.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <stdarg.h>
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <sys/wait.h>
31 #include <fcntl.h>
32 #include <unistd.h>
33 #include <errno.h>
34 #include <stdbool.h>
35 #include <linux/list.h>
36 #include <linux/kernel.h>
37
38 #include "../perf.h"
39 #include "trace-event.h"
40 #include <api/fs/tracing_path.h>
41 #include "evsel.h"
42 #include "debug.h"
43
44 #define VERSION "0.6"
45
46 static int output_fd;
47
48
49 int bigendian(void)
50 {
51         unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
52         unsigned int *ptr;
53
54         ptr = (unsigned int *)(void *)str;
55         return *ptr == 0x01020304;
56 }
57
58 /* unfortunately, you can not stat debugfs or proc files for size */
59 static int record_file(const char *file, ssize_t hdr_sz)
60 {
61         unsigned long long size = 0;
62         char buf[BUFSIZ], *sizep;
63         off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
64         int r, fd;
65         int err = -EIO;
66
67         fd = open(file, O_RDONLY);
68         if (fd < 0) {
69                 pr_debug("Can't read '%s'", file);
70                 return -errno;
71         }
72
73         /* put in zeros for file size, then fill true size later */
74         if (hdr_sz) {
75                 if (write(output_fd, &size, hdr_sz) != hdr_sz)
76                         goto out;
77         }
78
79         do {
80                 r = read(fd, buf, BUFSIZ);
81                 if (r > 0) {
82                         size += r;
83                         if (write(output_fd, buf, r) != r)
84                                 goto out;
85                 }
86         } while (r > 0);
87
88         /* ugh, handle big-endian hdr_size == 4 */
89         sizep = (char*)&size;
90         if (bigendian())
91                 sizep += sizeof(u64) - hdr_sz;
92
93         if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
94                 pr_debug("writing file size failed\n");
95                 goto out;
96         }
97
98         err = 0;
99 out:
100         close(fd);
101         return err;
102 }
103
104 static int record_header_files(void)
105 {
106         char *path = get_events_file("header_page");
107         struct stat st;
108         int err = -EIO;
109
110         if (!path) {
111                 pr_debug("can't get tracing/events/header_page");
112                 return -ENOMEM;
113         }
114
115         if (stat(path, &st) < 0) {
116                 pr_debug("can't read '%s'", path);
117                 goto out;
118         }
119
120         if (write(output_fd, "header_page", 12) != 12) {
121                 pr_debug("can't write header_page\n");
122                 goto out;
123         }
124
125         if (record_file(path, 8) < 0) {
126                 pr_debug("can't record header_page file\n");
127                 goto out;
128         }
129
130         put_events_file(path);
131
132         path = get_events_file("header_event");
133         if (!path) {
134                 pr_debug("can't get tracing/events/header_event");
135                 err = -ENOMEM;
136                 goto out;
137         }
138
139         if (stat(path, &st) < 0) {
140                 pr_debug("can't read '%s'", path);
141                 goto out;
142         }
143
144         if (write(output_fd, "header_event", 13) != 13) {
145                 pr_debug("can't write header_event\n");
146                 goto out;
147         }
148
149         if (record_file(path, 8) < 0) {
150                 pr_debug("can't record header_event file\n");
151                 goto out;
152         }
153
154         err = 0;
155 out:
156         put_events_file(path);
157         return err;
158 }
159
160 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
161 {
162         while (tps) {
163                 if (!strcmp(sys, tps->name))
164                         return true;
165                 tps = tps->next;
166         }
167
168         return false;
169 }
170
171 #define for_each_event(dir, dent, tps)                          \
172         while ((dent = readdir(dir)))                           \
173                 if (dent->d_type == DT_DIR &&                   \
174                     (strcmp(dent->d_name, ".")) &&              \
175                     (strcmp(dent->d_name, "..")))               \
176
177 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
178 {
179         struct dirent *dent;
180         struct stat st;
181         char *format;
182         DIR *dir;
183         int count = 0;
184         int ret;
185         int err;
186
187         dir = opendir(sys);
188         if (!dir) {
189                 pr_debug("can't read directory '%s'", sys);
190                 return -errno;
191         }
192
193         for_each_event(dir, dent, tps) {
194                 if (!name_in_tp_list(dent->d_name, tps))
195                         continue;
196
197                 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
198                         err = -ENOMEM;
199                         goto out;
200                 }
201                 ret = stat(format, &st);
202                 free(format);
203                 if (ret < 0)
204                         continue;
205                 count++;
206         }
207
208         if (write(output_fd, &count, 4) != 4) {
209                 err = -EIO;
210                 pr_debug("can't write count\n");
211                 goto out;
212         }
213
214         rewinddir(dir);
215         for_each_event(dir, dent, tps) {
216                 if (!name_in_tp_list(dent->d_name, tps))
217                         continue;
218
219                 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
220                         err = -ENOMEM;
221                         goto out;
222                 }
223                 ret = stat(format, &st);
224
225                 if (ret >= 0) {
226                         err = record_file(format, 8);
227                         if (err) {
228                                 free(format);
229                                 goto out;
230                         }
231                 }
232                 free(format);
233         }
234         err = 0;
235 out:
236         closedir(dir);
237         return err;
238 }
239
240 static int record_ftrace_files(struct tracepoint_path *tps)
241 {
242         char *path;
243         int ret;
244
245         path = get_events_file("ftrace");
246         if (!path) {
247                 pr_debug("can't get tracing/events/ftrace");
248                 return -ENOMEM;
249         }
250
251         ret = copy_event_system(path, tps);
252
253         put_tracing_file(path);
254
255         return ret;
256 }
257
258 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
259 {
260         while (tps) {
261                 if (!strcmp(sys, tps->system))
262                         return true;
263                 tps = tps->next;
264         }
265
266         return false;
267 }
268
269 static int record_event_files(struct tracepoint_path *tps)
270 {
271         struct dirent *dent;
272         struct stat st;
273         char *path;
274         char *sys;
275         DIR *dir;
276         int count = 0;
277         int ret;
278         int err;
279
280         path = get_tracing_file("events");
281         if (!path) {
282                 pr_debug("can't get tracing/events");
283                 return -ENOMEM;
284         }
285
286         dir = opendir(path);
287         if (!dir) {
288                 err = -errno;
289                 pr_debug("can't read directory '%s'", path);
290                 goto out;
291         }
292
293         for_each_event(dir, dent, tps) {
294                 if (strcmp(dent->d_name, "ftrace") == 0 ||
295                     !system_in_tp_list(dent->d_name, tps))
296                         continue;
297
298                 count++;
299         }
300
301         if (write(output_fd, &count, 4) != 4) {
302                 err = -EIO;
303                 pr_debug("can't write count\n");
304                 goto out;
305         }
306
307         rewinddir(dir);
308         for_each_event(dir, dent, tps) {
309                 if (strcmp(dent->d_name, "ftrace") == 0 ||
310                     !system_in_tp_list(dent->d_name, tps))
311                         continue;
312
313                 if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
314                         err = -ENOMEM;
315                         goto out;
316                 }
317                 ret = stat(sys, &st);
318                 if (ret >= 0) {
319                         ssize_t size = strlen(dent->d_name) + 1;
320
321                         if (write(output_fd, dent->d_name, size) != size ||
322                             copy_event_system(sys, tps) < 0) {
323                                 err = -EIO;
324                                 free(sys);
325                                 goto out;
326                         }
327                 }
328                 free(sys);
329         }
330         err = 0;
331 out:
332         closedir(dir);
333         put_tracing_file(path);
334
335         return err;
336 }
337
338 static int record_proc_kallsyms(void)
339 {
340         unsigned long long size = 0;
341         /*
342          * Just to keep older perf.data file parsers happy, record a zero
343          * sized kallsyms file, i.e. do the same thing that was done when
344          * /proc/kallsyms (or something specified via --kallsyms, in a
345          * different path) couldn't be read.
346          */
347         return write(output_fd, &size, 4) != 4 ? -EIO : 0;
348 }
349
350 static int record_ftrace_printk(void)
351 {
352         unsigned int size;
353         char *path;
354         struct stat st;
355         int ret, err = 0;
356
357         path = get_tracing_file("printk_formats");
358         if (!path) {
359                 pr_debug("can't get tracing/printk_formats");
360                 return -ENOMEM;
361         }
362
363         ret = stat(path, &st);
364         if (ret < 0) {
365                 /* not found */
366                 size = 0;
367                 if (write(output_fd, &size, 4) != 4)
368                         err = -EIO;
369                 goto out;
370         }
371         err = record_file(path, 4);
372
373 out:
374         put_tracing_file(path);
375         return err;
376 }
377
378 static int record_saved_cmdline(void)
379 {
380         unsigned long long size;
381         char *path;
382         struct stat st;
383         int ret, err = 0;
384
385         path = get_tracing_file("saved_cmdlines");
386         if (!path) {
387                 pr_debug("can't get tracing/saved_cmdline");
388                 return -ENOMEM;
389         }
390
391         ret = stat(path, &st);
392         if (ret < 0) {
393                 /* not found */
394                 size = 0;
395                 if (write(output_fd, &size, 8) != 8)
396                         err = -EIO;
397                 goto out;
398         }
399         err = record_file(path, 8);
400
401 out:
402         put_tracing_file(path);
403         return err;
404 }
405
406 static void
407 put_tracepoints_path(struct tracepoint_path *tps)
408 {
409         while (tps) {
410                 struct tracepoint_path *t = tps;
411
412                 tps = tps->next;
413                 zfree(&t->name);
414                 zfree(&t->system);
415                 free(t);
416         }
417 }
418
419 static struct tracepoint_path *
420 get_tracepoints_path(struct list_head *pattrs)
421 {
422         struct tracepoint_path path, *ppath = &path;
423         struct perf_evsel *pos;
424         int nr_tracepoints = 0;
425
426         list_for_each_entry(pos, pattrs, node) {
427                 if (pos->attr.type != PERF_TYPE_TRACEPOINT)
428                         continue;
429                 ++nr_tracepoints;
430
431                 if (pos->name) {
432                         ppath->next = tracepoint_name_to_path(pos->name);
433                         if (ppath->next)
434                                 goto next;
435
436                         if (strchr(pos->name, ':') == NULL)
437                                 goto try_id;
438
439                         goto error;
440                 }
441
442 try_id:
443                 ppath->next = tracepoint_id_to_path(pos->attr.config);
444                 if (!ppath->next) {
445 error:
446                         pr_debug("No memory to alloc tracepoints list\n");
447                         put_tracepoints_path(&path);
448                         return NULL;
449                 }
450 next:
451                 ppath = ppath->next;
452         }
453
454         return nr_tracepoints > 0 ? path.next : NULL;
455 }
456
457 bool have_tracepoints(struct list_head *pattrs)
458 {
459         struct perf_evsel *pos;
460
461         list_for_each_entry(pos, pattrs, node)
462                 if (pos->attr.type == PERF_TYPE_TRACEPOINT)
463                         return true;
464
465         return false;
466 }
467
468 static int tracing_data_header(void)
469 {
470         char buf[20];
471         ssize_t size;
472
473         /* just guessing this is someone's birthday.. ;) */
474         buf[0] = 23;
475         buf[1] = 8;
476         buf[2] = 68;
477         memcpy(buf + 3, "tracing", 7);
478
479         if (write(output_fd, buf, 10) != 10)
480                 return -1;
481
482         size = strlen(VERSION) + 1;
483         if (write(output_fd, VERSION, size) != size)
484                 return -1;
485
486         /* save endian */
487         if (bigendian())
488                 buf[0] = 1;
489         else
490                 buf[0] = 0;
491
492         if (write(output_fd, buf, 1) != 1)
493                 return -1;
494
495         /* save size of long */
496         buf[0] = sizeof(long);
497         if (write(output_fd, buf, 1) != 1)
498                 return -1;
499
500         /* save page_size */
501         if (write(output_fd, &page_size, 4) != 4)
502                 return -1;
503
504         return 0;
505 }
506
507 struct tracing_data *tracing_data_get(struct list_head *pattrs,
508                                       int fd, bool temp)
509 {
510         struct tracepoint_path *tps;
511         struct tracing_data *tdata;
512         int err;
513
514         output_fd = fd;
515
516         tps = get_tracepoints_path(pattrs);
517         if (!tps)
518                 return NULL;
519
520         tdata = malloc(sizeof(*tdata));
521         if (!tdata)
522                 return NULL;
523
524         tdata->temp = temp;
525         tdata->size = 0;
526
527         if (temp) {
528                 int temp_fd;
529
530                 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
531                          "/tmp/perf-XXXXXX");
532                 if (!mkstemp(tdata->temp_file)) {
533                         pr_debug("Can't make temp file");
534                         free(tdata);
535                         return NULL;
536                 }
537
538                 temp_fd = open(tdata->temp_file, O_RDWR);
539                 if (temp_fd < 0) {
540                         pr_debug("Can't read '%s'", tdata->temp_file);
541                         free(tdata);
542                         return NULL;
543                 }
544
545                 /*
546                  * Set the temp file the default output, so all the
547                  * tracing data are stored into it.
548                  */
549                 output_fd = temp_fd;
550         }
551
552         err = tracing_data_header();
553         if (err)
554                 goto out;
555         err = record_header_files();
556         if (err)
557                 goto out;
558         err = record_ftrace_files(tps);
559         if (err)
560                 goto out;
561         err = record_event_files(tps);
562         if (err)
563                 goto out;
564         err = record_proc_kallsyms();
565         if (err)
566                 goto out;
567         err = record_ftrace_printk();
568         if (err)
569                 goto out;
570         err = record_saved_cmdline();
571
572 out:
573         /*
574          * All tracing data are stored by now, we can restore
575          * the default output file in case we used temp file.
576          */
577         if (temp) {
578                 tdata->size = lseek(output_fd, 0, SEEK_CUR);
579                 close(output_fd);
580                 output_fd = fd;
581         }
582
583         if (err)
584                 zfree(&tdata);
585
586         put_tracepoints_path(tps);
587         return tdata;
588 }
589
590 int tracing_data_put(struct tracing_data *tdata)
591 {
592         int err = 0;
593
594         if (tdata->temp) {
595                 err = record_file(tdata->temp_file, 0);
596                 unlink(tdata->temp_file);
597         }
598
599         free(tdata);
600         return err;
601 }
602
603 int read_tracing_data(int fd, struct list_head *pattrs)
604 {
605         int err;
606         struct tracing_data *tdata;
607
608         /*
609          * We work over the real file, so we can write data
610          * directly, no temp file is needed.
611          */
612         tdata = tracing_data_get(pattrs, fd, false);
613         if (!tdata)
614                 return -ENOMEM;
615
616         err = tracing_data_put(tdata);
617         return err;
618 }