xref: /openbmc/linux/tools/perf/util/trace-event-info.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 #define _GNU_SOURCE
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 <pthread.h>
32 #include <fcntl.h>
33 #include <unistd.h>
34 #include <ctype.h>
35 #include <errno.h>
36 #include <stdbool.h>
37 #include <linux/list.h>
38 #include <linux/kernel.h>
39 
40 #include "../perf.h"
41 #include "trace-event.h"
42 #include "debugfs.h"
43 #include "evsel.h"
44 
45 #define VERSION "0.5"
46 
47 #define _STR(x) #x
48 #define STR(x) _STR(x)
49 #define MAX_PATH 256
50 
51 #define TRACE_CTRL	"tracing_on"
52 #define TRACE		"trace"
53 #define AVAILABLE	"available_tracers"
54 #define CURRENT		"current_tracer"
55 #define ITER_CTRL	"trace_options"
56 #define MAX_LATENCY	"tracing_max_latency"
57 
58 unsigned int page_size;
59 
60 static const char *output_file = "trace.info";
61 static int output_fd;
62 
63 struct event_list {
64 	struct event_list *next;
65 	const char *event;
66 };
67 
68 struct events {
69 	struct events *sibling;
70 	struct events *children;
71 	struct events *next;
72 	char *name;
73 };
74 
75 
76 
77 static void die(const char *fmt, ...)
78 {
79 	va_list ap;
80 	int ret = errno;
81 
82 	if (errno)
83 		perror("trace-cmd");
84 	else
85 		ret = -1;
86 
87 	va_start(ap, fmt);
88 	fprintf(stderr, "  ");
89 	vfprintf(stderr, fmt, ap);
90 	va_end(ap);
91 
92 	fprintf(stderr, "\n");
93 	exit(ret);
94 }
95 
96 void *malloc_or_die(unsigned int size)
97 {
98 	void *data;
99 
100 	data = malloc(size);
101 	if (!data)
102 		die("malloc");
103 	return data;
104 }
105 
106 static const char *find_debugfs(void)
107 {
108 	const char *path = debugfs_mount(NULL);
109 
110 	if (!path)
111 		die("Your kernel not support debugfs filesystem");
112 
113 	return path;
114 }
115 
116 /*
117  * Finds the path to the debugfs/tracing
118  * Allocates the string and stores it.
119  */
120 static const char *find_tracing_dir(void)
121 {
122 	static char *tracing;
123 	static int tracing_found;
124 	const char *debugfs;
125 
126 	if (tracing_found)
127 		return tracing;
128 
129 	debugfs = find_debugfs();
130 
131 	tracing = malloc_or_die(strlen(debugfs) + 9);
132 
133 	sprintf(tracing, "%s/tracing", debugfs);
134 
135 	tracing_found = 1;
136 	return tracing;
137 }
138 
139 static char *get_tracing_file(const char *name)
140 {
141 	const char *tracing;
142 	char *file;
143 
144 	tracing = find_tracing_dir();
145 	if (!tracing)
146 		return NULL;
147 
148 	file = malloc_or_die(strlen(tracing) + strlen(name) + 2);
149 
150 	sprintf(file, "%s/%s", tracing, name);
151 	return file;
152 }
153 
154 static void put_tracing_file(char *file)
155 {
156 	free(file);
157 }
158 
159 static ssize_t calc_data_size;
160 
161 static ssize_t write_or_die(const void *buf, size_t len)
162 {
163 	int ret;
164 
165 	if (calc_data_size) {
166 		calc_data_size += len;
167 		return len;
168 	}
169 
170 	ret = write(output_fd, buf, len);
171 	if (ret < 0)
172 		die("writing to '%s'", output_file);
173 
174 	return ret;
175 }
176 
177 int bigendian(void)
178 {
179 	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
180 	unsigned int *ptr;
181 
182 	ptr = (unsigned int *)(void *)str;
183 	return *ptr == 0x01020304;
184 }
185 
186 static unsigned long long copy_file_fd(int fd)
187 {
188 	unsigned long long size = 0;
189 	char buf[BUFSIZ];
190 	int r;
191 
192 	do {
193 		r = read(fd, buf, BUFSIZ);
194 		if (r > 0) {
195 			size += r;
196 			write_or_die(buf, r);
197 		}
198 	} while (r > 0);
199 
200 	return size;
201 }
202 
203 static unsigned long long copy_file(const char *file)
204 {
205 	unsigned long long size = 0;
206 	int fd;
207 
208 	fd = open(file, O_RDONLY);
209 	if (fd < 0)
210 		die("Can't read '%s'", file);
211 	size = copy_file_fd(fd);
212 	close(fd);
213 
214 	return size;
215 }
216 
217 static unsigned long get_size_fd(int fd)
218 {
219 	unsigned long long size = 0;
220 	char buf[BUFSIZ];
221 	int r;
222 
223 	do {
224 		r = read(fd, buf, BUFSIZ);
225 		if (r > 0)
226 			size += r;
227 	} while (r > 0);
228 
229 	lseek(fd, 0, SEEK_SET);
230 
231 	return size;
232 }
233 
234 static unsigned long get_size(const char *file)
235 {
236 	unsigned long long size = 0;
237 	int fd;
238 
239 	fd = open(file, O_RDONLY);
240 	if (fd < 0)
241 		die("Can't read '%s'", file);
242 	size = get_size_fd(fd);
243 	close(fd);
244 
245 	return size;
246 }
247 
248 static void read_header_files(void)
249 {
250 	unsigned long long size, check_size;
251 	char *path;
252 	int fd;
253 
254 	path = get_tracing_file("events/header_page");
255 	fd = open(path, O_RDONLY);
256 	if (fd < 0)
257 		die("can't read '%s'", path);
258 
259 	/* unfortunately, you can not stat debugfs files for size */
260 	size = get_size_fd(fd);
261 
262 	write_or_die("header_page", 12);
263 	write_or_die(&size, 8);
264 	check_size = copy_file_fd(fd);
265 	close(fd);
266 
267 	if (size != check_size)
268 		die("wrong size for '%s' size=%lld read=%lld",
269 		    path, size, check_size);
270 	put_tracing_file(path);
271 
272 	path = get_tracing_file("events/header_event");
273 	fd = open(path, O_RDONLY);
274 	if (fd < 0)
275 		die("can't read '%s'", path);
276 
277 	size = get_size_fd(fd);
278 
279 	write_or_die("header_event", 13);
280 	write_or_die(&size, 8);
281 	check_size = copy_file_fd(fd);
282 	if (size != check_size)
283 		die("wrong size for '%s'", path);
284 	put_tracing_file(path);
285 	close(fd);
286 }
287 
288 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
289 {
290 	while (tps) {
291 		if (!strcmp(sys, tps->name))
292 			return true;
293 		tps = tps->next;
294 	}
295 
296 	return false;
297 }
298 
299 static void copy_event_system(const char *sys, struct tracepoint_path *tps)
300 {
301 	unsigned long long size, check_size;
302 	struct dirent *dent;
303 	struct stat st;
304 	char *format;
305 	DIR *dir;
306 	int count = 0;
307 	int ret;
308 
309 	dir = opendir(sys);
310 	if (!dir)
311 		die("can't read directory '%s'", sys);
312 
313 	while ((dent = readdir(dir))) {
314 		if (dent->d_type != DT_DIR ||
315 		    strcmp(dent->d_name, ".") == 0 ||
316 		    strcmp(dent->d_name, "..") == 0 ||
317 		    !name_in_tp_list(dent->d_name, tps))
318 			continue;
319 		format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
320 		sprintf(format, "%s/%s/format", sys, dent->d_name);
321 		ret = stat(format, &st);
322 		free(format);
323 		if (ret < 0)
324 			continue;
325 		count++;
326 	}
327 
328 	write_or_die(&count, 4);
329 
330 	rewinddir(dir);
331 	while ((dent = readdir(dir))) {
332 		if (dent->d_type != DT_DIR ||
333 		    strcmp(dent->d_name, ".") == 0 ||
334 		    strcmp(dent->d_name, "..") == 0 ||
335 		    !name_in_tp_list(dent->d_name, tps))
336 			continue;
337 		format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
338 		sprintf(format, "%s/%s/format", sys, dent->d_name);
339 		ret = stat(format, &st);
340 
341 		if (ret >= 0) {
342 			/* unfortunately, you can not stat debugfs files for size */
343 			size = get_size(format);
344 			write_or_die(&size, 8);
345 			check_size = copy_file(format);
346 			if (size != check_size)
347 				die("error in size of file '%s'", format);
348 		}
349 
350 		free(format);
351 	}
352 	closedir(dir);
353 }
354 
355 static void read_ftrace_files(struct tracepoint_path *tps)
356 {
357 	char *path;
358 
359 	path = get_tracing_file("events/ftrace");
360 
361 	copy_event_system(path, tps);
362 
363 	put_tracing_file(path);
364 }
365 
366 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
367 {
368 	while (tps) {
369 		if (!strcmp(sys, tps->system))
370 			return true;
371 		tps = tps->next;
372 	}
373 
374 	return false;
375 }
376 
377 static void read_event_files(struct tracepoint_path *tps)
378 {
379 	struct dirent *dent;
380 	struct stat st;
381 	char *path;
382 	char *sys;
383 	DIR *dir;
384 	int count = 0;
385 	int ret;
386 
387 	path = get_tracing_file("events");
388 
389 	dir = opendir(path);
390 	if (!dir)
391 		die("can't read directory '%s'", path);
392 
393 	while ((dent = readdir(dir))) {
394 		if (dent->d_type != DT_DIR ||
395 		    strcmp(dent->d_name, ".") == 0 ||
396 		    strcmp(dent->d_name, "..") == 0 ||
397 		    strcmp(dent->d_name, "ftrace") == 0 ||
398 		    !system_in_tp_list(dent->d_name, tps))
399 			continue;
400 		count++;
401 	}
402 
403 	write_or_die(&count, 4);
404 
405 	rewinddir(dir);
406 	while ((dent = readdir(dir))) {
407 		if (dent->d_type != DT_DIR ||
408 		    strcmp(dent->d_name, ".") == 0 ||
409 		    strcmp(dent->d_name, "..") == 0 ||
410 		    strcmp(dent->d_name, "ftrace") == 0 ||
411 		    !system_in_tp_list(dent->d_name, tps))
412 			continue;
413 		sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
414 		sprintf(sys, "%s/%s", path, dent->d_name);
415 		ret = stat(sys, &st);
416 		if (ret >= 0) {
417 			write_or_die(dent->d_name, strlen(dent->d_name) + 1);
418 			copy_event_system(sys, tps);
419 		}
420 		free(sys);
421 	}
422 
423 	closedir(dir);
424 	put_tracing_file(path);
425 }
426 
427 static void read_proc_kallsyms(void)
428 {
429 	unsigned int size, check_size;
430 	const char *path = "/proc/kallsyms";
431 	struct stat st;
432 	int ret;
433 
434 	ret = stat(path, &st);
435 	if (ret < 0) {
436 		/* not found */
437 		size = 0;
438 		write_or_die(&size, 4);
439 		return;
440 	}
441 	size = get_size(path);
442 	write_or_die(&size, 4);
443 	check_size = copy_file(path);
444 	if (size != check_size)
445 		die("error in size of file '%s'", path);
446 
447 }
448 
449 static void read_ftrace_printk(void)
450 {
451 	unsigned int size, check_size;
452 	char *path;
453 	struct stat st;
454 	int ret;
455 
456 	path = get_tracing_file("printk_formats");
457 	ret = stat(path, &st);
458 	if (ret < 0) {
459 		/* not found */
460 		size = 0;
461 		write_or_die(&size, 4);
462 		goto out;
463 	}
464 	size = get_size(path);
465 	write_or_die(&size, 4);
466 	check_size = copy_file(path);
467 	if (size != check_size)
468 		die("error in size of file '%s'", path);
469 out:
470 	put_tracing_file(path);
471 }
472 
473 static struct tracepoint_path *
474 get_tracepoints_path(struct list_head *pattrs)
475 {
476 	struct tracepoint_path path, *ppath = &path;
477 	struct perf_evsel *pos;
478 	int nr_tracepoints = 0;
479 
480 	list_for_each_entry(pos, pattrs, node) {
481 		if (pos->attr.type != PERF_TYPE_TRACEPOINT)
482 			continue;
483 		++nr_tracepoints;
484 		ppath->next = tracepoint_id_to_path(pos->attr.config);
485 		if (!ppath->next)
486 			die("%s\n", "No memory to alloc tracepoints list");
487 		ppath = ppath->next;
488 	}
489 
490 	return nr_tracepoints > 0 ? path.next : NULL;
491 }
492 
493 bool have_tracepoints(struct list_head *pattrs)
494 {
495 	struct perf_evsel *pos;
496 
497 	list_for_each_entry(pos, pattrs, node)
498 		if (pos->attr.type == PERF_TYPE_TRACEPOINT)
499 			return true;
500 
501 	return false;
502 }
503 
504 int read_tracing_data(int fd, struct list_head *pattrs)
505 {
506 	char buf[BUFSIZ];
507 	struct tracepoint_path *tps = get_tracepoints_path(pattrs);
508 
509 	/*
510 	 * What? No tracepoints? No sense writing anything here, bail out.
511 	 */
512 	if (tps == NULL)
513 		return -1;
514 
515 	output_fd = fd;
516 
517 	buf[0] = 23;
518 	buf[1] = 8;
519 	buf[2] = 68;
520 	memcpy(buf + 3, "tracing", 7);
521 
522 	write_or_die(buf, 10);
523 
524 	write_or_die(VERSION, strlen(VERSION) + 1);
525 
526 	/* save endian */
527 	if (bigendian())
528 		buf[0] = 1;
529 	else
530 		buf[0] = 0;
531 
532 	write_or_die(buf, 1);
533 
534 	/* save size of long */
535 	buf[0] = sizeof(long);
536 	write_or_die(buf, 1);
537 
538 	/* save page_size */
539 	page_size = sysconf(_SC_PAGESIZE);
540 	write_or_die(&page_size, 4);
541 
542 	read_header_files();
543 	read_ftrace_files(tps);
544 	read_event_files(tps);
545 	read_proc_kallsyms();
546 	read_ftrace_printk();
547 
548 	return 0;
549 }
550 
551 ssize_t read_tracing_data_size(int fd, struct list_head *pattrs)
552 {
553 	ssize_t size;
554 	int err = 0;
555 
556 	calc_data_size = 1;
557 	err = read_tracing_data(fd, pattrs);
558 	size = calc_data_size - 1;
559 	calc_data_size = 0;
560 
561 	if (err < 0)
562 		return err;
563 
564 	return size;
565 }
566