xref: /linux/tools/perf/util/util.c (revision 64af4e0da419ef9e9db0d34a3b5836adbf90a5e8)
1 #include "../perf.h"
2 #include "util.h"
3 #include "debug.h"
4 #include <api/fs/fs.h>
5 #include <sys/mman.h>
6 #include <sys/utsname.h>
7 #ifdef HAVE_BACKTRACE_SUPPORT
8 #include <execinfo.h>
9 #endif
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <errno.h>
14 #include <limits.h>
15 #include <byteswap.h>
16 #include <linux/kernel.h>
17 #include <unistd.h>
18 #include "callchain.h"
19 
20 struct callchain_param	callchain_param = {
21 	.mode	= CHAIN_GRAPH_ABS,
22 	.min_percent = 0.5,
23 	.order  = ORDER_CALLEE,
24 	.key	= CCKEY_FUNCTION,
25 	.value	= CCVAL_PERCENT,
26 };
27 
28 /*
29  * XXX We need to find a better place for these things...
30  */
31 unsigned int page_size;
32 int cacheline_size;
33 
34 bool test_attr__enabled;
35 
36 bool perf_host  = true;
37 bool perf_guest = false;
38 
39 void event_attr_init(struct perf_event_attr *attr)
40 {
41 	if (!perf_host)
42 		attr->exclude_host  = 1;
43 	if (!perf_guest)
44 		attr->exclude_guest = 1;
45 	/* to capture ABI version */
46 	attr->size = sizeof(*attr);
47 }
48 
49 int mkdir_p(char *path, mode_t mode)
50 {
51 	struct stat st;
52 	int err;
53 	char *d = path;
54 
55 	if (*d != '/')
56 		return -1;
57 
58 	if (stat(path, &st) == 0)
59 		return 0;
60 
61 	while (*++d == '/');
62 
63 	while ((d = strchr(d, '/'))) {
64 		*d = '\0';
65 		err = stat(path, &st) && mkdir(path, mode);
66 		*d++ = '/';
67 		if (err)
68 			return -1;
69 		while (*d == '/')
70 			++d;
71 	}
72 	return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
73 }
74 
75 int rm_rf(char *path)
76 {
77 	DIR *dir;
78 	int ret = 0;
79 	struct dirent *d;
80 	char namebuf[PATH_MAX];
81 
82 	dir = opendir(path);
83 	if (dir == NULL)
84 		return 0;
85 
86 	while ((d = readdir(dir)) != NULL && !ret) {
87 		struct stat statbuf;
88 
89 		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
90 			continue;
91 
92 		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
93 			  path, d->d_name);
94 
95 		ret = stat(namebuf, &statbuf);
96 		if (ret < 0) {
97 			pr_debug("stat failed: %s\n", namebuf);
98 			break;
99 		}
100 
101 		if (S_ISREG(statbuf.st_mode))
102 			ret = unlink(namebuf);
103 		else if (S_ISDIR(statbuf.st_mode))
104 			ret = rm_rf(namebuf);
105 		else {
106 			pr_debug("unknown file: %s\n", namebuf);
107 			ret = -1;
108 		}
109 	}
110 	closedir(dir);
111 
112 	if (ret < 0)
113 		return ret;
114 
115 	return rmdir(path);
116 }
117 
118 static int slow_copyfile(const char *from, const char *to)
119 {
120 	int err = -1;
121 	char *line = NULL;
122 	size_t n;
123 	FILE *from_fp = fopen(from, "r"), *to_fp;
124 
125 	if (from_fp == NULL)
126 		goto out;
127 
128 	to_fp = fopen(to, "w");
129 	if (to_fp == NULL)
130 		goto out_fclose_from;
131 
132 	while (getline(&line, &n, from_fp) > 0)
133 		if (fputs(line, to_fp) == EOF)
134 			goto out_fclose_to;
135 	err = 0;
136 out_fclose_to:
137 	fclose(to_fp);
138 	free(line);
139 out_fclose_from:
140 	fclose(from_fp);
141 out:
142 	return err;
143 }
144 
145 int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
146 {
147 	void *ptr;
148 	loff_t pgoff;
149 
150 	pgoff = off_in & ~(page_size - 1);
151 	off_in -= pgoff;
152 
153 	ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
154 	if (ptr == MAP_FAILED)
155 		return -1;
156 
157 	while (size) {
158 		ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
159 		if (ret < 0 && errno == EINTR)
160 			continue;
161 		if (ret <= 0)
162 			break;
163 
164 		size -= ret;
165 		off_in += ret;
166 		off_out -= ret;
167 	}
168 	munmap(ptr, off_in + size);
169 
170 	return size ? -1 : 0;
171 }
172 
173 int copyfile_mode(const char *from, const char *to, mode_t mode)
174 {
175 	int fromfd, tofd;
176 	struct stat st;
177 	int err = -1;
178 	char *tmp = NULL, *ptr = NULL;
179 
180 	if (stat(from, &st))
181 		goto out;
182 
183 	/* extra 'x' at the end is to reserve space for '.' */
184 	if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
185 		tmp = NULL;
186 		goto out;
187 	}
188 	ptr = strrchr(tmp, '/');
189 	if (!ptr)
190 		goto out;
191 	ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
192 	*ptr = '.';
193 
194 	tofd = mkstemp(tmp);
195 	if (tofd < 0)
196 		goto out;
197 
198 	if (fchmod(tofd, mode))
199 		goto out_close_to;
200 
201 	if (st.st_size == 0) { /* /proc? do it slowly... */
202 		err = slow_copyfile(from, tmp);
203 		goto out_close_to;
204 	}
205 
206 	fromfd = open(from, O_RDONLY);
207 	if (fromfd < 0)
208 		goto out_close_to;
209 
210 	err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
211 
212 	close(fromfd);
213 out_close_to:
214 	close(tofd);
215 	if (!err)
216 		err = link(tmp, to);
217 	unlink(tmp);
218 out:
219 	free(tmp);
220 	return err;
221 }
222 
223 int copyfile(const char *from, const char *to)
224 {
225 	return copyfile_mode(from, to, 0755);
226 }
227 
228 unsigned long convert_unit(unsigned long value, char *unit)
229 {
230 	*unit = ' ';
231 
232 	if (value > 1000) {
233 		value /= 1000;
234 		*unit = 'K';
235 	}
236 
237 	if (value > 1000) {
238 		value /= 1000;
239 		*unit = 'M';
240 	}
241 
242 	if (value > 1000) {
243 		value /= 1000;
244 		*unit = 'G';
245 	}
246 
247 	return value;
248 }
249 
250 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
251 {
252 	void *buf_start = buf;
253 	size_t left = n;
254 
255 	while (left) {
256 		ssize_t ret = is_read ? read(fd, buf, left) :
257 					write(fd, buf, left);
258 
259 		if (ret < 0 && errno == EINTR)
260 			continue;
261 		if (ret <= 0)
262 			return ret;
263 
264 		left -= ret;
265 		buf  += ret;
266 	}
267 
268 	BUG_ON((size_t)(buf - buf_start) != n);
269 	return n;
270 }
271 
272 /*
273  * Read exactly 'n' bytes or return an error.
274  */
275 ssize_t readn(int fd, void *buf, size_t n)
276 {
277 	return ion(true, fd, buf, n);
278 }
279 
280 /*
281  * Write exactly 'n' bytes or return an error.
282  */
283 ssize_t writen(int fd, void *buf, size_t n)
284 {
285 	return ion(false, fd, buf, n);
286 }
287 
288 size_t hex_width(u64 v)
289 {
290 	size_t n = 1;
291 
292 	while ((v >>= 4))
293 		++n;
294 
295 	return n;
296 }
297 
298 static int hex(char ch)
299 {
300 	if ((ch >= '0') && (ch <= '9'))
301 		return ch - '0';
302 	if ((ch >= 'a') && (ch <= 'f'))
303 		return ch - 'a' + 10;
304 	if ((ch >= 'A') && (ch <= 'F'))
305 		return ch - 'A' + 10;
306 	return -1;
307 }
308 
309 /*
310  * While we find nice hex chars, build a long_val.
311  * Return number of chars processed.
312  */
313 int hex2u64(const char *ptr, u64 *long_val)
314 {
315 	const char *p = ptr;
316 	*long_val = 0;
317 
318 	while (*p) {
319 		const int hex_val = hex(*p);
320 
321 		if (hex_val < 0)
322 			break;
323 
324 		*long_val = (*long_val << 4) | hex_val;
325 		p++;
326 	}
327 
328 	return p - ptr;
329 }
330 
331 /* Obtain a backtrace and print it to stdout. */
332 #ifdef HAVE_BACKTRACE_SUPPORT
333 void dump_stack(void)
334 {
335 	void *array[16];
336 	size_t size = backtrace(array, ARRAY_SIZE(array));
337 	char **strings = backtrace_symbols(array, size);
338 	size_t i;
339 
340 	printf("Obtained %zd stack frames.\n", size);
341 
342 	for (i = 0; i < size; i++)
343 		printf("%s\n", strings[i]);
344 
345 	free(strings);
346 }
347 #else
348 void dump_stack(void) {}
349 #endif
350 
351 void sighandler_dump_stack(int sig)
352 {
353 	psignal(sig, "perf");
354 	dump_stack();
355 	signal(sig, SIG_DFL);
356 	raise(sig);
357 }
358 
359 int parse_nsec_time(const char *str, u64 *ptime)
360 {
361 	u64 time_sec, time_nsec;
362 	char *end;
363 
364 	time_sec = strtoul(str, &end, 10);
365 	if (*end != '.' && *end != '\0')
366 		return -1;
367 
368 	if (*end == '.') {
369 		int i;
370 		char nsec_buf[10];
371 
372 		if (strlen(++end) > 9)
373 			return -1;
374 
375 		strncpy(nsec_buf, end, 9);
376 		nsec_buf[9] = '\0';
377 
378 		/* make it nsec precision */
379 		for (i = strlen(nsec_buf); i < 9; i++)
380 			nsec_buf[i] = '0';
381 
382 		time_nsec = strtoul(nsec_buf, &end, 10);
383 		if (*end != '\0')
384 			return -1;
385 	} else
386 		time_nsec = 0;
387 
388 	*ptime = time_sec * NSEC_PER_SEC + time_nsec;
389 	return 0;
390 }
391 
392 unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
393 {
394 	struct parse_tag *i = tags;
395 
396 	while (i->tag) {
397 		char *s;
398 
399 		s = strchr(str, i->tag);
400 		if (s) {
401 			unsigned long int value;
402 			char *endptr;
403 
404 			value = strtoul(str, &endptr, 10);
405 			if (s != endptr)
406 				break;
407 
408 			if (value > ULONG_MAX / i->mult)
409 				break;
410 			value *= i->mult;
411 			return value;
412 		}
413 		i++;
414 	}
415 
416 	return (unsigned long) -1;
417 }
418 
419 int get_stack_size(const char *str, unsigned long *_size)
420 {
421 	char *endptr;
422 	unsigned long size;
423 	unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));
424 
425 	size = strtoul(str, &endptr, 0);
426 
427 	do {
428 		if (*endptr)
429 			break;
430 
431 		size = round_up(size, sizeof(u64));
432 		if (!size || size > max_size)
433 			break;
434 
435 		*_size = size;
436 		return 0;
437 
438 	} while (0);
439 
440 	pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
441 	       max_size, str);
442 	return -1;
443 }
444 
445 int parse_callchain_record(const char *arg, struct callchain_param *param)
446 {
447 	char *tok, *name, *saveptr = NULL;
448 	char *buf;
449 	int ret = -1;
450 
451 	/* We need buffer that we know we can write to. */
452 	buf = malloc(strlen(arg) + 1);
453 	if (!buf)
454 		return -ENOMEM;
455 
456 	strcpy(buf, arg);
457 
458 	tok = strtok_r((char *)buf, ",", &saveptr);
459 	name = tok ? : (char *)buf;
460 
461 	do {
462 		/* Framepointer style */
463 		if (!strncmp(name, "fp", sizeof("fp"))) {
464 			if (!strtok_r(NULL, ",", &saveptr)) {
465 				param->record_mode = CALLCHAIN_FP;
466 				ret = 0;
467 			} else
468 				pr_err("callchain: No more arguments "
469 				       "needed for --call-graph fp\n");
470 			break;
471 
472 #ifdef HAVE_DWARF_UNWIND_SUPPORT
473 		/* Dwarf style */
474 		} else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
475 			const unsigned long default_stack_dump_size = 8192;
476 
477 			ret = 0;
478 			param->record_mode = CALLCHAIN_DWARF;
479 			param->dump_size = default_stack_dump_size;
480 
481 			tok = strtok_r(NULL, ",", &saveptr);
482 			if (tok) {
483 				unsigned long size = 0;
484 
485 				ret = get_stack_size(tok, &size);
486 				param->dump_size = size;
487 			}
488 #endif /* HAVE_DWARF_UNWIND_SUPPORT */
489 		} else if (!strncmp(name, "lbr", sizeof("lbr"))) {
490 			if (!strtok_r(NULL, ",", &saveptr)) {
491 				param->record_mode = CALLCHAIN_LBR;
492 				ret = 0;
493 			} else
494 				pr_err("callchain: No more arguments "
495 					"needed for --call-graph lbr\n");
496 			break;
497 		} else {
498 			pr_err("callchain: Unknown --call-graph option "
499 			       "value: %s\n", arg);
500 			break;
501 		}
502 
503 	} while (0);
504 
505 	free(buf);
506 	return ret;
507 }
508 
509 int filename__read_str(const char *filename, char **buf, size_t *sizep)
510 {
511 	size_t size = 0, alloc_size = 0;
512 	void *bf = NULL, *nbf;
513 	int fd, n, err = 0;
514 	char sbuf[STRERR_BUFSIZE];
515 
516 	fd = open(filename, O_RDONLY);
517 	if (fd < 0)
518 		return -errno;
519 
520 	do {
521 		if (size == alloc_size) {
522 			alloc_size += BUFSIZ;
523 			nbf = realloc(bf, alloc_size);
524 			if (!nbf) {
525 				err = -ENOMEM;
526 				break;
527 			}
528 
529 			bf = nbf;
530 		}
531 
532 		n = read(fd, bf + size, alloc_size - size);
533 		if (n < 0) {
534 			if (size) {
535 				pr_warning("read failed %d: %s\n", errno,
536 					 strerror_r(errno, sbuf, sizeof(sbuf)));
537 				err = 0;
538 			} else
539 				err = -errno;
540 
541 			break;
542 		}
543 
544 		size += n;
545 	} while (n > 0);
546 
547 	if (!err) {
548 		*sizep = size;
549 		*buf   = bf;
550 	} else
551 		free(bf);
552 
553 	close(fd);
554 	return err;
555 }
556 
557 const char *get_filename_for_perf_kvm(void)
558 {
559 	const char *filename;
560 
561 	if (perf_host && !perf_guest)
562 		filename = strdup("perf.data.host");
563 	else if (!perf_host && perf_guest)
564 		filename = strdup("perf.data.guest");
565 	else
566 		filename = strdup("perf.data.kvm");
567 
568 	return filename;
569 }
570 
571 int perf_event_paranoid(void)
572 {
573 	int value;
574 
575 	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
576 		return INT_MAX;
577 
578 	return value;
579 }
580 
581 void mem_bswap_32(void *src, int byte_size)
582 {
583 	u32 *m = src;
584 	while (byte_size > 0) {
585 		*m = bswap_32(*m);
586 		byte_size -= sizeof(u32);
587 		++m;
588 	}
589 }
590 
591 void mem_bswap_64(void *src, int byte_size)
592 {
593 	u64 *m = src;
594 
595 	while (byte_size > 0) {
596 		*m = bswap_64(*m);
597 		byte_size -= sizeof(u64);
598 		++m;
599 	}
600 }
601 
602 bool find_process(const char *name)
603 {
604 	size_t len = strlen(name);
605 	DIR *dir;
606 	struct dirent *d;
607 	int ret = -1;
608 
609 	dir = opendir(procfs__mountpoint());
610 	if (!dir)
611 		return false;
612 
613 	/* Walk through the directory. */
614 	while (ret && (d = readdir(dir)) != NULL) {
615 		char path[PATH_MAX];
616 		char *data;
617 		size_t size;
618 
619 		if ((d->d_type != DT_DIR) ||
620 		     !strcmp(".", d->d_name) ||
621 		     !strcmp("..", d->d_name))
622 			continue;
623 
624 		scnprintf(path, sizeof(path), "%s/%s/comm",
625 			  procfs__mountpoint(), d->d_name);
626 
627 		if (filename__read_str(path, &data, &size))
628 			continue;
629 
630 		ret = strncmp(name, data, len);
631 		free(data);
632 	}
633 
634 	closedir(dir);
635 	return ret ? false : true;
636 }
637 
638 int
639 fetch_kernel_version(unsigned int *puint, char *str,
640 		     size_t str_size)
641 {
642 	struct utsname utsname;
643 	int version, patchlevel, sublevel, err;
644 
645 	if (uname(&utsname))
646 		return -1;
647 
648 	if (str && str_size) {
649 		strncpy(str, utsname.release, str_size);
650 		str[str_size - 1] = '\0';
651 	}
652 
653 	err = sscanf(utsname.release, "%d.%d.%d",
654 		     &version, &patchlevel, &sublevel);
655 
656 	if (err != 3) {
657 		pr_debug("Unablt to get kernel version from uname '%s'\n",
658 			 utsname.release);
659 		return -1;
660 	}
661 
662 	if (puint)
663 		*puint = (version << 16) + (patchlevel << 8) + sublevel;
664 	return 0;
665 }
666