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 <pthread.h>
32 #include <fcntl.h>
33 #include <unistd.h>
34 #include <errno.h>
35 #include <stdbool.h>
36 #include <linux/list.h>
37 #include <linux/kernel.h>
38 
39 #include "../perf.h"
40 #include "trace-event.h"
41 #include <api/fs/debugfs.h>
42 #include "evsel.h"
43 #include "debug.h"
44 
45 #define VERSION "0.5"
46 
47 static int output_fd;
48 
49 
50 int bigendian(void)
51 {
52 	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
53 	unsigned int *ptr;
54 
55 	ptr = (unsigned int *)(void *)str;
56 	return *ptr == 0x01020304;
57 }
58 
59 /* unfortunately, you can not stat debugfs or proc files for size */
60 static int record_file(const char *file, ssize_t hdr_sz)
61 {
62 	unsigned long long size = 0;
63 	char buf[BUFSIZ], *sizep;
64 	off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
65 	int r, fd;
66 	int err = -EIO;
67 
68 	fd = open(file, O_RDONLY);
69 	if (fd < 0) {
70 		pr_debug("Can't read '%s'", file);
71 		return -errno;
72 	}
73 
74 	/* put in zeros for file size, then fill true size later */
75 	if (hdr_sz) {
76 		if (write(output_fd, &size, hdr_sz) != hdr_sz)
77 			goto out;
78 	}
79 
80 	do {
81 		r = read(fd, buf, BUFSIZ);
82 		if (r > 0) {
83 			size += r;
84 			if (write(output_fd, buf, r) != r)
85 				goto out;
86 		}
87 	} while (r > 0);
88 
89 	/* ugh, handle big-endian hdr_size == 4 */
90 	sizep = (char*)&size;
91 	if (bigendian())
92 		sizep += sizeof(u64) - hdr_sz;
93 
94 	if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
95 		pr_debug("writing file size failed\n");
96 		goto out;
97 	}
98 
99 	err = 0;
100 out:
101 	close(fd);
102 	return err;
103 }
104 
105 static int record_header_files(void)
106 {
107 	char *path;
108 	struct stat st;
109 	int err = -EIO;
110 
111 	path = get_tracing_file("events/header_page");
112 	if (!path) {
113 		pr_debug("can't get tracing/events/header_page");
114 		return -ENOMEM;
115 	}
116 
117 	if (stat(path, &st) < 0) {
118 		pr_debug("can't read '%s'", path);
119 		goto out;
120 	}
121 
122 	if (write(output_fd, "header_page", 12) != 12) {
123 		pr_debug("can't write header_page\n");
124 		goto out;
125 	}
126 
127 	if (record_file(path, 8) < 0) {
128 		pr_debug("can't record header_page file\n");
129 		goto out;
130 	}
131 
132 	put_tracing_file(path);
133 
134 	path = get_tracing_file("events/header_event");
135 	if (!path) {
136 		pr_debug("can't get tracing/events/header_event");
137 		err = -ENOMEM;
138 		goto out;
139 	}
140 
141 	if (stat(path, &st) < 0) {
142 		pr_debug("can't read '%s'", path);
143 		goto out;
144 	}
145 
146 	if (write(output_fd, "header_event", 13) != 13) {
147 		pr_debug("can't write header_event\n");
148 		goto out;
149 	}
150 
151 	if (record_file(path, 8) < 0) {
152 		pr_debug("can't record header_event file\n");
153 		goto out;
154 	}
155 
156 	err = 0;
157 out:
158 	put_tracing_file(path);
159 	return err;
160 }
161 
162 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
163 {
164 	while (tps) {
165 		if (!strcmp(sys, tps->name))
166 			return true;
167 		tps = tps->next;
168 	}
169 
170 	return false;
171 }
172 
173 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
174 {
175 	struct dirent *dent;
176 	struct stat st;
177 	char *format;
178 	DIR *dir;
179 	int count = 0;
180 	int ret;
181 	int err;
182 
183 	dir = opendir(sys);
184 	if (!dir) {
185 		pr_debug("can't read directory '%s'", sys);
186 		return -errno;
187 	}
188 
189 	while ((dent = readdir(dir))) {
190 		if (dent->d_type != DT_DIR ||
191 		    strcmp(dent->d_name, ".") == 0 ||
192 		    strcmp(dent->d_name, "..") == 0 ||
193 		    !name_in_tp_list(dent->d_name, tps))
194 			continue;
195 		if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
196 			err = -ENOMEM;
197 			goto out;
198 		}
199 		ret = stat(format, &st);
200 		free(format);
201 		if (ret < 0)
202 			continue;
203 		count++;
204 	}
205 
206 	if (write(output_fd, &count, 4) != 4) {
207 		err = -EIO;
208 		pr_debug("can't write count\n");
209 		goto out;
210 	}
211 
212 	rewinddir(dir);
213 	while ((dent = readdir(dir))) {
214 		if (dent->d_type != DT_DIR ||
215 		    strcmp(dent->d_name, ".") == 0 ||
216 		    strcmp(dent->d_name, "..") == 0 ||
217 		    !name_in_tp_list(dent->d_name, tps))
218 			continue;
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_tracing_file("events/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 	while ((dent = readdir(dir))) {
294 		if (dent->d_type != DT_DIR ||
295 		    strcmp(dent->d_name, ".") == 0 ||
296 		    strcmp(dent->d_name, "..") == 0 ||
297 		    strcmp(dent->d_name, "ftrace") == 0 ||
298 		    !system_in_tp_list(dent->d_name, tps))
299 			continue;
300 		count++;
301 	}
302 
303 	if (write(output_fd, &count, 4) != 4) {
304 		err = -EIO;
305 		pr_debug("can't write count\n");
306 		goto out;
307 	}
308 
309 	rewinddir(dir);
310 	while ((dent = readdir(dir))) {
311 		if (dent->d_type != DT_DIR ||
312 		    strcmp(dent->d_name, ".") == 0 ||
313 		    strcmp(dent->d_name, "..") == 0 ||
314 		    strcmp(dent->d_name, "ftrace") == 0 ||
315 		    !system_in_tp_list(dent->d_name, tps))
316 			continue;
317 		if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
318 			err = -ENOMEM;
319 			goto out;
320 		}
321 		ret = stat(sys, &st);
322 		if (ret >= 0) {
323 			ssize_t size = strlen(dent->d_name) + 1;
324 
325 			if (write(output_fd, dent->d_name, size) != size ||
326 			    copy_event_system(sys, tps) < 0) {
327 				err = -EIO;
328 				free(sys);
329 				goto out;
330 			}
331 		}
332 		free(sys);
333 	}
334 	err = 0;
335 out:
336 	closedir(dir);
337 	put_tracing_file(path);
338 
339 	return err;
340 }
341 
342 static int record_proc_kallsyms(void)
343 {
344 	unsigned long long size = 0;
345 	/*
346 	 * Just to keep older perf.data file parsers happy, record a zero
347 	 * sized kallsyms file, i.e. do the same thing that was done when
348 	 * /proc/kallsyms (or something specified via --kallsyms, in a
349 	 * different path) couldn't be read.
350 	 */
351 	return write(output_fd, &size, 4) != 4 ? -EIO : 0;
352 }
353 
354 static int record_ftrace_printk(void)
355 {
356 	unsigned int size;
357 	char *path;
358 	struct stat st;
359 	int ret, err = 0;
360 
361 	path = get_tracing_file("printk_formats");
362 	if (!path) {
363 		pr_debug("can't get tracing/printk_formats");
364 		return -ENOMEM;
365 	}
366 
367 	ret = stat(path, &st);
368 	if (ret < 0) {
369 		/* not found */
370 		size = 0;
371 		if (write(output_fd, &size, 4) != 4)
372 			err = -EIO;
373 		goto out;
374 	}
375 	err = record_file(path, 4);
376 
377 out:
378 	put_tracing_file(path);
379 	return err;
380 }
381 
382 static void
383 put_tracepoints_path(struct tracepoint_path *tps)
384 {
385 	while (tps) {
386 		struct tracepoint_path *t = tps;
387 
388 		tps = tps->next;
389 		zfree(&t->name);
390 		zfree(&t->system);
391 		free(t);
392 	}
393 }
394 
395 static struct tracepoint_path *
396 get_tracepoints_path(struct list_head *pattrs)
397 {
398 	struct tracepoint_path path, *ppath = &path;
399 	struct perf_evsel *pos;
400 	int nr_tracepoints = 0;
401 
402 	list_for_each_entry(pos, pattrs, node) {
403 		if (pos->attr.type != PERF_TYPE_TRACEPOINT)
404 			continue;
405 		++nr_tracepoints;
406 
407 		if (pos->name) {
408 			ppath->next = tracepoint_name_to_path(pos->name);
409 			if (ppath->next)
410 				goto next;
411 
412 			if (strchr(pos->name, ':') == NULL)
413 				goto try_id;
414 
415 			goto error;
416 		}
417 
418 try_id:
419 		ppath->next = tracepoint_id_to_path(pos->attr.config);
420 		if (!ppath->next) {
421 error:
422 			pr_debug("No memory to alloc tracepoints list\n");
423 			put_tracepoints_path(&path);
424 			return NULL;
425 		}
426 next:
427 		ppath = ppath->next;
428 	}
429 
430 	return nr_tracepoints > 0 ? path.next : NULL;
431 }
432 
433 bool have_tracepoints(struct list_head *pattrs)
434 {
435 	struct perf_evsel *pos;
436 
437 	list_for_each_entry(pos, pattrs, node)
438 		if (pos->attr.type == PERF_TYPE_TRACEPOINT)
439 			return true;
440 
441 	return false;
442 }
443 
444 static int tracing_data_header(void)
445 {
446 	char buf[20];
447 	ssize_t size;
448 
449 	/* just guessing this is someone's birthday.. ;) */
450 	buf[0] = 23;
451 	buf[1] = 8;
452 	buf[2] = 68;
453 	memcpy(buf + 3, "tracing", 7);
454 
455 	if (write(output_fd, buf, 10) != 10)
456 		return -1;
457 
458 	size = strlen(VERSION) + 1;
459 	if (write(output_fd, VERSION, size) != size)
460 		return -1;
461 
462 	/* save endian */
463 	if (bigendian())
464 		buf[0] = 1;
465 	else
466 		buf[0] = 0;
467 
468 	if (write(output_fd, buf, 1) != 1)
469 		return -1;
470 
471 	/* save size of long */
472 	buf[0] = sizeof(long);
473 	if (write(output_fd, buf, 1) != 1)
474 		return -1;
475 
476 	/* save page_size */
477 	if (write(output_fd, &page_size, 4) != 4)
478 		return -1;
479 
480 	return 0;
481 }
482 
483 struct tracing_data *tracing_data_get(struct list_head *pattrs,
484 				      int fd, bool temp)
485 {
486 	struct tracepoint_path *tps;
487 	struct tracing_data *tdata;
488 	int err;
489 
490 	output_fd = fd;
491 
492 	tps = get_tracepoints_path(pattrs);
493 	if (!tps)
494 		return NULL;
495 
496 	tdata = malloc(sizeof(*tdata));
497 	if (!tdata)
498 		return NULL;
499 
500 	tdata->temp = temp;
501 	tdata->size = 0;
502 
503 	if (temp) {
504 		int temp_fd;
505 
506 		snprintf(tdata->temp_file, sizeof(tdata->temp_file),
507 			 "/tmp/perf-XXXXXX");
508 		if (!mkstemp(tdata->temp_file)) {
509 			pr_debug("Can't make temp file");
510 			return NULL;
511 		}
512 
513 		temp_fd = open(tdata->temp_file, O_RDWR);
514 		if (temp_fd < 0) {
515 			pr_debug("Can't read '%s'", tdata->temp_file);
516 			return NULL;
517 		}
518 
519 		/*
520 		 * Set the temp file the default output, so all the
521 		 * tracing data are stored into it.
522 		 */
523 		output_fd = temp_fd;
524 	}
525 
526 	err = tracing_data_header();
527 	if (err)
528 		goto out;
529 	err = record_header_files();
530 	if (err)
531 		goto out;
532 	err = record_ftrace_files(tps);
533 	if (err)
534 		goto out;
535 	err = record_event_files(tps);
536 	if (err)
537 		goto out;
538 	err = record_proc_kallsyms();
539 	if (err)
540 		goto out;
541 	err = record_ftrace_printk();
542 
543 out:
544 	/*
545 	 * All tracing data are stored by now, we can restore
546 	 * the default output file in case we used temp file.
547 	 */
548 	if (temp) {
549 		tdata->size = lseek(output_fd, 0, SEEK_CUR);
550 		close(output_fd);
551 		output_fd = fd;
552 	}
553 
554 	if (err)
555 		zfree(&tdata);
556 
557 	put_tracepoints_path(tps);
558 	return tdata;
559 }
560 
561 int tracing_data_put(struct tracing_data *tdata)
562 {
563 	int err = 0;
564 
565 	if (tdata->temp) {
566 		err = record_file(tdata->temp_file, 0);
567 		unlink(tdata->temp_file);
568 	}
569 
570 	free(tdata);
571 	return err;
572 }
573 
574 int read_tracing_data(int fd, struct list_head *pattrs)
575 {
576 	int err;
577 	struct tracing_data *tdata;
578 
579 	/*
580 	 * We work over the real file, so we can write data
581 	 * directly, no temp file is needed.
582 	 */
583 	tdata = tracing_data_get(pattrs, fd, false);
584 	if (!tdata)
585 		return -ENOMEM;
586 
587 	err = tracing_data_put(tdata);
588 	return err;
589 }
590