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/tracing_path.h>
42#include "evsel.h"
43#include "debug.h"
44
45#define VERSION "0.5"
46
47static int output_fd;
48
49
50int 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 */
60static 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;
100out:
101	close(fd);
102	return err;
103}
104
105static 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;
157out:
158	put_tracing_file(path);
159	return err;
160}
161
162static 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
173static 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;
235out:
236	closedir(dir);
237	return err;
238}
239
240static 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
258static 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
269static 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;
335out:
336	closedir(dir);
337	put_tracing_file(path);
338
339	return err;
340}
341
342static 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
354static 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
377out:
378	put_tracing_file(path);
379	return err;
380}
381
382static void
383put_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
395static struct tracepoint_path *
396get_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
418try_id:
419		ppath->next = tracepoint_id_to_path(pos->attr.config);
420		if (!ppath->next) {
421error:
422			pr_debug("No memory to alloc tracepoints list\n");
423			put_tracepoints_path(&path);
424			return NULL;
425		}
426next:
427		ppath = ppath->next;
428	}
429
430	return nr_tracepoints > 0 ? path.next : NULL;
431}
432
433bool 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
444static 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
483struct 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
543out:
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
561int 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
574int 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