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 <lk/debugfs.h>
42 #include "evsel.h"
43 
44 #define VERSION "0.5"
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;
107 	struct stat st;
108 	int err = -EIO;
109 
110 	path = get_tracing_file("events/header_page");
111 	if (!path) {
112 		pr_debug("can't get tracing/events/header_page");
113 		return -ENOMEM;
114 	}
115 
116 	if (stat(path, &st) < 0) {
117 		pr_debug("can't read '%s'", path);
118 		goto out;
119 	}
120 
121 	if (write(output_fd, "header_page", 12) != 12) {
122 		pr_debug("can't write header_page\n");
123 		goto out;
124 	}
125 
126 	if (record_file(path, 8) < 0) {
127 		pr_debug("can't record header_page file\n");
128 		goto out;
129 	}
130 
131 	put_tracing_file(path);
132 
133 	path = get_tracing_file("events/header_event");
134 	if (!path) {
135 		pr_debug("can't get tracing/events/header_event");
136 		err = -ENOMEM;
137 		goto out;
138 	}
139 
140 	if (stat(path, &st) < 0) {
141 		pr_debug("can't read '%s'", path);
142 		goto out;
143 	}
144 
145 	if (write(output_fd, "header_event", 13) != 13) {
146 		pr_debug("can't write header_event\n");
147 		goto out;
148 	}
149 
150 	if (record_file(path, 8) < 0) {
151 		pr_debug("can't record header_event file\n");
152 		goto out;
153 	}
154 
155 	err = 0;
156 out:
157 	put_tracing_file(path);
158 	return err;
159 }
160 
161 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
162 {
163 	while (tps) {
164 		if (!strcmp(sys, tps->name))
165 			return true;
166 		tps = tps->next;
167 	}
168 
169 	return false;
170 }
171 
172 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
173 {
174 	struct dirent *dent;
175 	struct stat st;
176 	char *format;
177 	DIR *dir;
178 	int count = 0;
179 	int ret;
180 	int err;
181 
182 	dir = opendir(sys);
183 	if (!dir) {
184 		pr_debug("can't read directory '%s'", sys);
185 		return -errno;
186 	}
187 
188 	while ((dent = readdir(dir))) {
189 		if (dent->d_type != DT_DIR ||
190 		    strcmp(dent->d_name, ".") == 0 ||
191 		    strcmp(dent->d_name, "..") == 0 ||
192 		    !name_in_tp_list(dent->d_name, tps))
193 			continue;
194 		format = malloc(strlen(sys) + strlen(dent->d_name) + 10);
195 		if (!format) {
196 			err = -ENOMEM;
197 			goto out;
198 		}
199 		sprintf(format, "%s/%s/format", sys, dent->d_name);
200 		ret = stat(format, &st);
201 		free(format);
202 		if (ret < 0)
203 			continue;
204 		count++;
205 	}
206 
207 	if (write(output_fd, &count, 4) != 4) {
208 		err = -EIO;
209 		pr_debug("can't write count\n");
210 		goto out;
211 	}
212 
213 	rewinddir(dir);
214 	while ((dent = readdir(dir))) {
215 		if (dent->d_type != DT_DIR ||
216 		    strcmp(dent->d_name, ".") == 0 ||
217 		    strcmp(dent->d_name, "..") == 0 ||
218 		    !name_in_tp_list(dent->d_name, tps))
219 			continue;
220 		format = malloc(strlen(sys) + strlen(dent->d_name) + 10);
221 		if (!format) {
222 			err = -ENOMEM;
223 			goto out;
224 		}
225 		sprintf(format, "%s/%s/format", sys, dent->d_name);
226 		ret = stat(format, &st);
227 
228 		if (ret >= 0) {
229 			err = record_file(format, 8);
230 			if (err) {
231 				free(format);
232 				goto out;
233 			}
234 		}
235 		free(format);
236 	}
237 	err = 0;
238 out:
239 	closedir(dir);
240 	return err;
241 }
242 
243 static int record_ftrace_files(struct tracepoint_path *tps)
244 {
245 	char *path;
246 	int ret;
247 
248 	path = get_tracing_file("events/ftrace");
249 	if (!path) {
250 		pr_debug("can't get tracing/events/ftrace");
251 		return -ENOMEM;
252 	}
253 
254 	ret = copy_event_system(path, tps);
255 
256 	put_tracing_file(path);
257 
258 	return ret;
259 }
260 
261 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
262 {
263 	while (tps) {
264 		if (!strcmp(sys, tps->system))
265 			return true;
266 		tps = tps->next;
267 	}
268 
269 	return false;
270 }
271 
272 static int record_event_files(struct tracepoint_path *tps)
273 {
274 	struct dirent *dent;
275 	struct stat st;
276 	char *path;
277 	char *sys;
278 	DIR *dir;
279 	int count = 0;
280 	int ret;
281 	int err;
282 
283 	path = get_tracing_file("events");
284 	if (!path) {
285 		pr_debug("can't get tracing/events");
286 		return -ENOMEM;
287 	}
288 
289 	dir = opendir(path);
290 	if (!dir) {
291 		err = -errno;
292 		pr_debug("can't read directory '%s'", path);
293 		goto out;
294 	}
295 
296 	while ((dent = readdir(dir))) {
297 		if (dent->d_type != DT_DIR ||
298 		    strcmp(dent->d_name, ".") == 0 ||
299 		    strcmp(dent->d_name, "..") == 0 ||
300 		    strcmp(dent->d_name, "ftrace") == 0 ||
301 		    !system_in_tp_list(dent->d_name, tps))
302 			continue;
303 		count++;
304 	}
305 
306 	if (write(output_fd, &count, 4) != 4) {
307 		err = -EIO;
308 		pr_debug("can't write count\n");
309 		goto out;
310 	}
311 
312 	rewinddir(dir);
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 		    strcmp(dent->d_name, "ftrace") == 0 ||
318 		    !system_in_tp_list(dent->d_name, tps))
319 			continue;
320 		sys = malloc(strlen(path) + strlen(dent->d_name) + 2);
321 		if (!sys) {
322 			err = -ENOMEM;
323 			goto out;
324 		}
325 		sprintf(sys, "%s/%s", path, dent->d_name);
326 		ret = stat(sys, &st);
327 		if (ret >= 0) {
328 			ssize_t size = strlen(dent->d_name) + 1;
329 
330 			if (write(output_fd, dent->d_name, size) != size ||
331 			    copy_event_system(sys, tps) < 0) {
332 				err = -EIO;
333 				free(sys);
334 				goto out;
335 			}
336 		}
337 		free(sys);
338 	}
339 	err = 0;
340 out:
341 	closedir(dir);
342 	put_tracing_file(path);
343 
344 	return err;
345 }
346 
347 static int record_proc_kallsyms(void)
348 {
349 	unsigned int size;
350 	const char *path = "/proc/kallsyms";
351 	struct stat st;
352 	int ret, err = 0;
353 
354 	ret = stat(path, &st);
355 	if (ret < 0) {
356 		/* not found */
357 		size = 0;
358 		if (write(output_fd, &size, 4) != 4)
359 			err = -EIO;
360 		return err;
361 	}
362 	return record_file(path, 4);
363 }
364 
365 static int record_ftrace_printk(void)
366 {
367 	unsigned int size;
368 	char *path;
369 	struct stat st;
370 	int ret, err = 0;
371 
372 	path = get_tracing_file("printk_formats");
373 	if (!path) {
374 		pr_debug("can't get tracing/printk_formats");
375 		return -ENOMEM;
376 	}
377 
378 	ret = stat(path, &st);
379 	if (ret < 0) {
380 		/* not found */
381 		size = 0;
382 		if (write(output_fd, &size, 4) != 4)
383 			err = -EIO;
384 		goto out;
385 	}
386 	err = record_file(path, 4);
387 
388 out:
389 	put_tracing_file(path);
390 	return err;
391 }
392 
393 static void
394 put_tracepoints_path(struct tracepoint_path *tps)
395 {
396 	while (tps) {
397 		struct tracepoint_path *t = tps;
398 
399 		tps = tps->next;
400 		free(t->name);
401 		free(t->system);
402 		free(t);
403 	}
404 }
405 
406 static struct tracepoint_path *
407 get_tracepoints_path(struct list_head *pattrs)
408 {
409 	struct tracepoint_path path, *ppath = &path;
410 	struct perf_evsel *pos;
411 	int nr_tracepoints = 0;
412 
413 	list_for_each_entry(pos, pattrs, node) {
414 		if (pos->attr.type != PERF_TYPE_TRACEPOINT)
415 			continue;
416 		++nr_tracepoints;
417 
418 		if (pos->name) {
419 			ppath->next = tracepoint_name_to_path(pos->name);
420 			if (ppath->next)
421 				goto next;
422 
423 			if (strchr(pos->name, ':') == NULL)
424 				goto try_id;
425 
426 			goto error;
427 		}
428 
429 try_id:
430 		ppath->next = tracepoint_id_to_path(pos->attr.config);
431 		if (!ppath->next) {
432 error:
433 			pr_debug("No memory to alloc tracepoints list\n");
434 			put_tracepoints_path(&path);
435 			return NULL;
436 		}
437 next:
438 		ppath = ppath->next;
439 	}
440 
441 	return nr_tracepoints > 0 ? path.next : NULL;
442 }
443 
444 bool have_tracepoints(struct list_head *pattrs)
445 {
446 	struct perf_evsel *pos;
447 
448 	list_for_each_entry(pos, pattrs, node)
449 		if (pos->attr.type == PERF_TYPE_TRACEPOINT)
450 			return true;
451 
452 	return false;
453 }
454 
455 static int tracing_data_header(void)
456 {
457 	char buf[20];
458 	ssize_t size;
459 
460 	/* just guessing this is someone's birthday.. ;) */
461 	buf[0] = 23;
462 	buf[1] = 8;
463 	buf[2] = 68;
464 	memcpy(buf + 3, "tracing", 7);
465 
466 	if (write(output_fd, buf, 10) != 10)
467 		return -1;
468 
469 	size = strlen(VERSION) + 1;
470 	if (write(output_fd, VERSION, size) != size)
471 		return -1;
472 
473 	/* save endian */
474 	if (bigendian())
475 		buf[0] = 1;
476 	else
477 		buf[0] = 0;
478 
479 	if (write(output_fd, buf, 1) != 1)
480 		return -1;
481 
482 	/* save size of long */
483 	buf[0] = sizeof(long);
484 	if (write(output_fd, buf, 1) != 1)
485 		return -1;
486 
487 	/* save page_size */
488 	if (write(output_fd, &page_size, 4) != 4)
489 		return -1;
490 
491 	return 0;
492 }
493 
494 struct tracing_data *tracing_data_get(struct list_head *pattrs,
495 				      int fd, bool temp)
496 {
497 	struct tracepoint_path *tps;
498 	struct tracing_data *tdata;
499 	int err;
500 
501 	output_fd = fd;
502 
503 	tps = get_tracepoints_path(pattrs);
504 	if (!tps)
505 		return NULL;
506 
507 	tdata = malloc(sizeof(*tdata));
508 	if (!tdata)
509 		return NULL;
510 
511 	tdata->temp = temp;
512 	tdata->size = 0;
513 
514 	if (temp) {
515 		int temp_fd;
516 
517 		snprintf(tdata->temp_file, sizeof(tdata->temp_file),
518 			 "/tmp/perf-XXXXXX");
519 		if (!mkstemp(tdata->temp_file)) {
520 			pr_debug("Can't make temp file");
521 			return NULL;
522 		}
523 
524 		temp_fd = open(tdata->temp_file, O_RDWR);
525 		if (temp_fd < 0) {
526 			pr_debug("Can't read '%s'", tdata->temp_file);
527 			return NULL;
528 		}
529 
530 		/*
531 		 * Set the temp file the default output, so all the
532 		 * tracing data are stored into it.
533 		 */
534 		output_fd = temp_fd;
535 	}
536 
537 	err = tracing_data_header();
538 	if (err)
539 		goto out;
540 	err = record_header_files();
541 	if (err)
542 		goto out;
543 	err = record_ftrace_files(tps);
544 	if (err)
545 		goto out;
546 	err = record_event_files(tps);
547 	if (err)
548 		goto out;
549 	err = record_proc_kallsyms();
550 	if (err)
551 		goto out;
552 	err = record_ftrace_printk();
553 
554 out:
555 	/*
556 	 * All tracing data are stored by now, we can restore
557 	 * the default output file in case we used temp file.
558 	 */
559 	if (temp) {
560 		tdata->size = lseek(output_fd, 0, SEEK_CUR);
561 		close(output_fd);
562 		output_fd = fd;
563 	}
564 
565 	if (err) {
566 		free(tdata);
567 		tdata = NULL;
568 	}
569 
570 	put_tracepoints_path(tps);
571 	return tdata;
572 }
573 
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 
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