xref: /openbmc/linux/tools/perf/util/pmu.c (revision e8f6f3b4)
1 #include <linux/list.h>
2 #include <sys/types.h>
3 #include <unistd.h>
4 #include <stdio.h>
5 #include <stdbool.h>
6 #include <stdarg.h>
7 #include <dirent.h>
8 #include <api/fs/fs.h>
9 #include <locale.h>
10 #include "util.h"
11 #include "pmu.h"
12 #include "parse-events.h"
13 #include "cpumap.h"
14 
15 struct perf_pmu_format {
16 	char *name;
17 	int value;
18 	DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
19 	struct list_head list;
20 };
21 
22 #define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"
23 
24 int perf_pmu_parse(struct list_head *list, char *name);
25 extern FILE *perf_pmu_in;
26 
27 static LIST_HEAD(pmus);
28 
29 /*
30  * Parse & process all the sysfs attributes located under
31  * the directory specified in 'dir' parameter.
32  */
33 int perf_pmu__format_parse(char *dir, struct list_head *head)
34 {
35 	struct dirent *evt_ent;
36 	DIR *format_dir;
37 	int ret = 0;
38 
39 	format_dir = opendir(dir);
40 	if (!format_dir)
41 		return -EINVAL;
42 
43 	while (!ret && (evt_ent = readdir(format_dir))) {
44 		char path[PATH_MAX];
45 		char *name = evt_ent->d_name;
46 		FILE *file;
47 
48 		if (!strcmp(name, ".") || !strcmp(name, ".."))
49 			continue;
50 
51 		snprintf(path, PATH_MAX, "%s/%s", dir, name);
52 
53 		ret = -EINVAL;
54 		file = fopen(path, "r");
55 		if (!file)
56 			break;
57 
58 		perf_pmu_in = file;
59 		ret = perf_pmu_parse(head, name);
60 		fclose(file);
61 	}
62 
63 	closedir(format_dir);
64 	return ret;
65 }
66 
67 /*
68  * Reading/parsing the default pmu format definition, which should be
69  * located at:
70  * /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
71  */
72 static int pmu_format(const char *name, struct list_head *format)
73 {
74 	struct stat st;
75 	char path[PATH_MAX];
76 	const char *sysfs = sysfs__mountpoint();
77 
78 	if (!sysfs)
79 		return -1;
80 
81 	snprintf(path, PATH_MAX,
82 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);
83 
84 	if (stat(path, &st) < 0)
85 		return 0;	/* no error if format does not exist */
86 
87 	if (perf_pmu__format_parse(path, format))
88 		return -1;
89 
90 	return 0;
91 }
92 
93 static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *name)
94 {
95 	struct stat st;
96 	ssize_t sret;
97 	char scale[128];
98 	int fd, ret = -1;
99 	char path[PATH_MAX];
100 	const char *lc;
101 
102 	snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);
103 
104 	fd = open(path, O_RDONLY);
105 	if (fd == -1)
106 		return -1;
107 
108 	if (fstat(fd, &st) < 0)
109 		goto error;
110 
111 	sret = read(fd, scale, sizeof(scale)-1);
112 	if (sret < 0)
113 		goto error;
114 
115 	scale[sret] = '\0';
116 	/*
117 	 * save current locale
118 	 */
119 	lc = setlocale(LC_NUMERIC, NULL);
120 
121 	/*
122 	 * force to C locale to ensure kernel
123 	 * scale string is converted correctly.
124 	 * kernel uses default C locale.
125 	 */
126 	setlocale(LC_NUMERIC, "C");
127 
128 	alias->scale = strtod(scale, NULL);
129 
130 	/* restore locale */
131 	setlocale(LC_NUMERIC, lc);
132 
133 	ret = 0;
134 error:
135 	close(fd);
136 	return ret;
137 }
138 
139 static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, char *dir, char *name)
140 {
141 	char path[PATH_MAX];
142 	ssize_t sret;
143 	int fd;
144 
145 	snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
146 
147 	fd = open(path, O_RDONLY);
148 	if (fd == -1)
149 		return -1;
150 
151 		sret = read(fd, alias->unit, UNIT_MAX_LEN);
152 	if (sret < 0)
153 		goto error;
154 
155 	close(fd);
156 
157 	alias->unit[sret] = '\0';
158 
159 	return 0;
160 error:
161 	close(fd);
162 	alias->unit[0] = '\0';
163 	return -1;
164 }
165 
166 static int
167 perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, char *dir, char *name)
168 {
169 	char path[PATH_MAX];
170 	int fd;
171 
172 	snprintf(path, PATH_MAX, "%s/%s.per-pkg", dir, name);
173 
174 	fd = open(path, O_RDONLY);
175 	if (fd == -1)
176 		return -1;
177 
178 	close(fd);
179 
180 	alias->per_pkg = true;
181 	return 0;
182 }
183 
184 static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
185 				    char *dir, char *name)
186 {
187 	char path[PATH_MAX];
188 	int fd;
189 
190 	snprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);
191 
192 	fd = open(path, O_RDONLY);
193 	if (fd == -1)
194 		return -1;
195 
196 	alias->snapshot = true;
197 	close(fd);
198 	return 0;
199 }
200 
201 static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
202 {
203 	struct perf_pmu_alias *alias;
204 	char buf[256];
205 	int ret;
206 
207 	ret = fread(buf, 1, sizeof(buf), file);
208 	if (ret == 0)
209 		return -EINVAL;
210 	buf[ret] = 0;
211 
212 	alias = malloc(sizeof(*alias));
213 	if (!alias)
214 		return -ENOMEM;
215 
216 	INIT_LIST_HEAD(&alias->terms);
217 	alias->scale = 1.0;
218 	alias->unit[0] = '\0';
219 	alias->per_pkg = false;
220 
221 	ret = parse_events_terms(&alias->terms, buf);
222 	if (ret) {
223 		free(alias);
224 		return ret;
225 	}
226 
227 	alias->name = strdup(name);
228 	/*
229 	 * load unit name and scale if available
230 	 */
231 	perf_pmu__parse_unit(alias, dir, name);
232 	perf_pmu__parse_scale(alias, dir, name);
233 	perf_pmu__parse_per_pkg(alias, dir, name);
234 	perf_pmu__parse_snapshot(alias, dir, name);
235 
236 	list_add_tail(&alias->list, list);
237 
238 	return 0;
239 }
240 
241 static inline bool pmu_alias_info_file(char *name)
242 {
243 	size_t len;
244 
245 	len = strlen(name);
246 	if (len > 5 && !strcmp(name + len - 5, ".unit"))
247 		return true;
248 	if (len > 6 && !strcmp(name + len - 6, ".scale"))
249 		return true;
250 	if (len > 8 && !strcmp(name + len - 8, ".per-pkg"))
251 		return true;
252 	if (len > 9 && !strcmp(name + len - 9, ".snapshot"))
253 		return true;
254 
255 	return false;
256 }
257 
258 /*
259  * Process all the sysfs attributes located under the directory
260  * specified in 'dir' parameter.
261  */
262 static int pmu_aliases_parse(char *dir, struct list_head *head)
263 {
264 	struct dirent *evt_ent;
265 	DIR *event_dir;
266 	int ret = 0;
267 
268 	event_dir = opendir(dir);
269 	if (!event_dir)
270 		return -EINVAL;
271 
272 	while (!ret && (evt_ent = readdir(event_dir))) {
273 		char path[PATH_MAX];
274 		char *name = evt_ent->d_name;
275 		FILE *file;
276 
277 		if (!strcmp(name, ".") || !strcmp(name, ".."))
278 			continue;
279 
280 		/*
281 		 * skip info files parsed in perf_pmu__new_alias()
282 		 */
283 		if (pmu_alias_info_file(name))
284 			continue;
285 
286 		snprintf(path, PATH_MAX, "%s/%s", dir, name);
287 
288 		ret = -EINVAL;
289 		file = fopen(path, "r");
290 		if (!file)
291 			break;
292 
293 		ret = perf_pmu__new_alias(head, dir, name, file);
294 		fclose(file);
295 	}
296 
297 	closedir(event_dir);
298 	return ret;
299 }
300 
301 /*
302  * Reading the pmu event aliases definition, which should be located at:
303  * /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
304  */
305 static int pmu_aliases(const char *name, struct list_head *head)
306 {
307 	struct stat st;
308 	char path[PATH_MAX];
309 	const char *sysfs = sysfs__mountpoint();
310 
311 	if (!sysfs)
312 		return -1;
313 
314 	snprintf(path, PATH_MAX,
315 		 "%s/bus/event_source/devices/%s/events", sysfs, name);
316 
317 	if (stat(path, &st) < 0)
318 		return 0;	 /* no error if 'events' does not exist */
319 
320 	if (pmu_aliases_parse(path, head))
321 		return -1;
322 
323 	return 0;
324 }
325 
326 static int pmu_alias_terms(struct perf_pmu_alias *alias,
327 			   struct list_head *terms)
328 {
329 	struct parse_events_term *term, *cloned;
330 	LIST_HEAD(list);
331 	int ret;
332 
333 	list_for_each_entry(term, &alias->terms, list) {
334 		ret = parse_events_term__clone(&cloned, term);
335 		if (ret) {
336 			parse_events__free_terms(&list);
337 			return ret;
338 		}
339 		list_add_tail(&cloned->list, &list);
340 	}
341 	list_splice(&list, terms);
342 	return 0;
343 }
344 
345 /*
346  * Reading/parsing the default pmu type value, which should be
347  * located at:
348  * /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
349  */
350 static int pmu_type(const char *name, __u32 *type)
351 {
352 	struct stat st;
353 	char path[PATH_MAX];
354 	FILE *file;
355 	int ret = 0;
356 	const char *sysfs = sysfs__mountpoint();
357 
358 	if (!sysfs)
359 		return -1;
360 
361 	snprintf(path, PATH_MAX,
362 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name);
363 
364 	if (stat(path, &st) < 0)
365 		return -1;
366 
367 	file = fopen(path, "r");
368 	if (!file)
369 		return -EINVAL;
370 
371 	if (1 != fscanf(file, "%u", type))
372 		ret = -1;
373 
374 	fclose(file);
375 	return ret;
376 }
377 
378 /* Add all pmus in sysfs to pmu list: */
379 static void pmu_read_sysfs(void)
380 {
381 	char path[PATH_MAX];
382 	DIR *dir;
383 	struct dirent *dent;
384 	const char *sysfs = sysfs__mountpoint();
385 
386 	if (!sysfs)
387 		return;
388 
389 	snprintf(path, PATH_MAX,
390 		 "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
391 
392 	dir = opendir(path);
393 	if (!dir)
394 		return;
395 
396 	while ((dent = readdir(dir))) {
397 		if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
398 			continue;
399 		/* add to static LIST_HEAD(pmus): */
400 		perf_pmu__find(dent->d_name);
401 	}
402 
403 	closedir(dir);
404 }
405 
406 static struct cpu_map *pmu_cpumask(const char *name)
407 {
408 	struct stat st;
409 	char path[PATH_MAX];
410 	FILE *file;
411 	struct cpu_map *cpus;
412 	const char *sysfs = sysfs__mountpoint();
413 
414 	if (!sysfs)
415 		return NULL;
416 
417 	snprintf(path, PATH_MAX,
418 		 "%s/bus/event_source/devices/%s/cpumask", sysfs, name);
419 
420 	if (stat(path, &st) < 0)
421 		return NULL;
422 
423 	file = fopen(path, "r");
424 	if (!file)
425 		return NULL;
426 
427 	cpus = cpu_map__read(file);
428 	fclose(file);
429 	return cpus;
430 }
431 
432 struct perf_event_attr *__attribute__((weak))
433 perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
434 {
435 	return NULL;
436 }
437 
438 static struct perf_pmu *pmu_lookup(const char *name)
439 {
440 	struct perf_pmu *pmu;
441 	LIST_HEAD(format);
442 	LIST_HEAD(aliases);
443 	__u32 type;
444 
445 	/*
446 	 * The pmu data we store & need consists of the pmu
447 	 * type value and format definitions. Load both right
448 	 * now.
449 	 */
450 	if (pmu_format(name, &format))
451 		return NULL;
452 
453 	if (pmu_aliases(name, &aliases))
454 		return NULL;
455 
456 	if (pmu_type(name, &type))
457 		return NULL;
458 
459 	pmu = zalloc(sizeof(*pmu));
460 	if (!pmu)
461 		return NULL;
462 
463 	pmu->cpus = pmu_cpumask(name);
464 
465 	INIT_LIST_HEAD(&pmu->format);
466 	INIT_LIST_HEAD(&pmu->aliases);
467 	list_splice(&format, &pmu->format);
468 	list_splice(&aliases, &pmu->aliases);
469 	pmu->name = strdup(name);
470 	pmu->type = type;
471 	list_add_tail(&pmu->list, &pmus);
472 
473 	pmu->default_config = perf_pmu__get_default_config(pmu);
474 
475 	return pmu;
476 }
477 
478 static struct perf_pmu *pmu_find(const char *name)
479 {
480 	struct perf_pmu *pmu;
481 
482 	list_for_each_entry(pmu, &pmus, list)
483 		if (!strcmp(pmu->name, name))
484 			return pmu;
485 
486 	return NULL;
487 }
488 
489 struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
490 {
491 	/*
492 	 * pmu iterator: If pmu is NULL, we start at the begin,
493 	 * otherwise return the next pmu. Returns NULL on end.
494 	 */
495 	if (!pmu) {
496 		pmu_read_sysfs();
497 		pmu = list_prepare_entry(pmu, &pmus, list);
498 	}
499 	list_for_each_entry_continue(pmu, &pmus, list)
500 		return pmu;
501 	return NULL;
502 }
503 
504 struct perf_pmu *perf_pmu__find(const char *name)
505 {
506 	struct perf_pmu *pmu;
507 
508 	/*
509 	 * Once PMU is loaded it stays in the list,
510 	 * so we keep us from multiple reading/parsing
511 	 * the pmu format definitions.
512 	 */
513 	pmu = pmu_find(name);
514 	if (pmu)
515 		return pmu;
516 
517 	return pmu_lookup(name);
518 }
519 
520 static struct perf_pmu_format *
521 pmu_find_format(struct list_head *formats, char *name)
522 {
523 	struct perf_pmu_format *format;
524 
525 	list_for_each_entry(format, formats, list)
526 		if (!strcmp(format->name, name))
527 			return format;
528 
529 	return NULL;
530 }
531 
532 /*
533  * Sets value based on the format definition (format parameter)
534  * and unformated value (value parameter).
535  */
536 static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
537 			     bool zero)
538 {
539 	unsigned long fbit, vbit;
540 
541 	for (fbit = 0, vbit = 0; fbit < PERF_PMU_FORMAT_BITS; fbit++) {
542 
543 		if (!test_bit(fbit, format))
544 			continue;
545 
546 		if (value & (1llu << vbit++))
547 			*v |= (1llu << fbit);
548 		else if (zero)
549 			*v &= ~(1llu << fbit);
550 	}
551 }
552 
553 /*
554  * Setup one of config[12] attr members based on the
555  * user input data - term parameter.
556  */
557 static int pmu_config_term(struct list_head *formats,
558 			   struct perf_event_attr *attr,
559 			   struct parse_events_term *term,
560 			   bool zero)
561 {
562 	struct perf_pmu_format *format;
563 	__u64 *vp;
564 
565 	/*
566 	 * Support only for hardcoded and numnerial terms.
567 	 * Hardcoded terms should be already in, so nothing
568 	 * to be done for them.
569 	 */
570 	if (parse_events__is_hardcoded_term(term))
571 		return 0;
572 
573 	if (term->type_val != PARSE_EVENTS__TERM_TYPE_NUM)
574 		return -EINVAL;
575 
576 	format = pmu_find_format(formats, term->config);
577 	if (!format)
578 		return -EINVAL;
579 
580 	switch (format->value) {
581 	case PERF_PMU_FORMAT_VALUE_CONFIG:
582 		vp = &attr->config;
583 		break;
584 	case PERF_PMU_FORMAT_VALUE_CONFIG1:
585 		vp = &attr->config1;
586 		break;
587 	case PERF_PMU_FORMAT_VALUE_CONFIG2:
588 		vp = &attr->config2;
589 		break;
590 	default:
591 		return -EINVAL;
592 	}
593 
594 	/*
595 	 * XXX If we ever decide to go with string values for
596 	 * non-hardcoded terms, here's the place to translate
597 	 * them into value.
598 	 */
599 	pmu_format_value(format->bits, term->val.num, vp, zero);
600 	return 0;
601 }
602 
603 int perf_pmu__config_terms(struct list_head *formats,
604 			   struct perf_event_attr *attr,
605 			   struct list_head *head_terms,
606 			   bool zero)
607 {
608 	struct parse_events_term *term;
609 
610 	list_for_each_entry(term, head_terms, list)
611 		if (pmu_config_term(formats, attr, term, zero))
612 			return -EINVAL;
613 
614 	return 0;
615 }
616 
617 /*
618  * Configures event's 'attr' parameter based on the:
619  * 1) users input - specified in terms parameter
620  * 2) pmu format definitions - specified by pmu parameter
621  */
622 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
623 		     struct list_head *head_terms)
624 {
625 	bool zero = !!pmu->default_config;
626 
627 	attr->type = pmu->type;
628 	return perf_pmu__config_terms(&pmu->format, attr, head_terms, zero);
629 }
630 
631 static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
632 					     struct parse_events_term *term)
633 {
634 	struct perf_pmu_alias *alias;
635 	char *name;
636 
637 	if (parse_events__is_hardcoded_term(term))
638 		return NULL;
639 
640 	if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
641 		if (term->val.num != 1)
642 			return NULL;
643 		if (pmu_find_format(&pmu->format, term->config))
644 			return NULL;
645 		name = term->config;
646 	} else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
647 		if (strcasecmp(term->config, "event"))
648 			return NULL;
649 		name = term->val.str;
650 	} else {
651 		return NULL;
652 	}
653 
654 	list_for_each_entry(alias, &pmu->aliases, list) {
655 		if (!strcasecmp(alias->name, name))
656 			return alias;
657 	}
658 	return NULL;
659 }
660 
661 
662 static int check_info_data(struct perf_pmu_alias *alias,
663 			   struct perf_pmu_info *info)
664 {
665 	/*
666 	 * Only one term in event definition can
667 	 * define unit, scale and snapshot, fail
668 	 * if there's more than one.
669 	 */
670 	if ((info->unit && alias->unit) ||
671 	    (info->scale && alias->scale) ||
672 	    (info->snapshot && alias->snapshot))
673 		return -EINVAL;
674 
675 	if (alias->unit)
676 		info->unit = alias->unit;
677 
678 	if (alias->scale)
679 		info->scale = alias->scale;
680 
681 	if (alias->snapshot)
682 		info->snapshot = alias->snapshot;
683 
684 	return 0;
685 }
686 
687 /*
688  * Find alias in the terms list and replace it with the terms
689  * defined for the alias
690  */
691 int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
692 			  struct perf_pmu_info *info)
693 {
694 	struct parse_events_term *term, *h;
695 	struct perf_pmu_alias *alias;
696 	int ret;
697 
698 	info->per_pkg = false;
699 
700 	/*
701 	 * Mark unit and scale as not set
702 	 * (different from default values, see below)
703 	 */
704 	info->unit     = NULL;
705 	info->scale    = 0.0;
706 	info->snapshot = false;
707 
708 	list_for_each_entry_safe(term, h, head_terms, list) {
709 		alias = pmu_find_alias(pmu, term);
710 		if (!alias)
711 			continue;
712 		ret = pmu_alias_terms(alias, &term->list);
713 		if (ret)
714 			return ret;
715 
716 		ret = check_info_data(alias, info);
717 		if (ret)
718 			return ret;
719 
720 		if (alias->per_pkg)
721 			info->per_pkg = true;
722 
723 		list_del(&term->list);
724 		free(term);
725 	}
726 
727 	/*
728 	 * if no unit or scale foundin aliases, then
729 	 * set defaults as for evsel
730 	 * unit cannot left to NULL
731 	 */
732 	if (info->unit == NULL)
733 		info->unit   = "";
734 
735 	if (info->scale == 0.0)
736 		info->scale  = 1.0;
737 
738 	return 0;
739 }
740 
741 int perf_pmu__new_format(struct list_head *list, char *name,
742 			 int config, unsigned long *bits)
743 {
744 	struct perf_pmu_format *format;
745 
746 	format = zalloc(sizeof(*format));
747 	if (!format)
748 		return -ENOMEM;
749 
750 	format->name = strdup(name);
751 	format->value = config;
752 	memcpy(format->bits, bits, sizeof(format->bits));
753 
754 	list_add_tail(&format->list, list);
755 	return 0;
756 }
757 
758 void perf_pmu__set_format(unsigned long *bits, long from, long to)
759 {
760 	long b;
761 
762 	if (!to)
763 		to = from;
764 
765 	memset(bits, 0, BITS_TO_BYTES(PERF_PMU_FORMAT_BITS));
766 	for (b = from; b <= to; b++)
767 		set_bit(b, bits);
768 }
769 
770 static char *format_alias(char *buf, int len, struct perf_pmu *pmu,
771 			  struct perf_pmu_alias *alias)
772 {
773 	snprintf(buf, len, "%s/%s/", pmu->name, alias->name);
774 	return buf;
775 }
776 
777 static char *format_alias_or(char *buf, int len, struct perf_pmu *pmu,
778 			     struct perf_pmu_alias *alias)
779 {
780 	snprintf(buf, len, "%s OR %s/%s/", alias->name, pmu->name, alias->name);
781 	return buf;
782 }
783 
784 static int cmp_string(const void *a, const void *b)
785 {
786 	const char * const *as = a;
787 	const char * const *bs = b;
788 	return strcmp(*as, *bs);
789 }
790 
791 void print_pmu_events(const char *event_glob, bool name_only)
792 {
793 	struct perf_pmu *pmu;
794 	struct perf_pmu_alias *alias;
795 	char buf[1024];
796 	int printed = 0;
797 	int len, j;
798 	char **aliases;
799 
800 	pmu = NULL;
801 	len = 0;
802 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
803 		list_for_each_entry(alias, &pmu->aliases, list)
804 			len++;
805 		if (pmu->selectable)
806 			len++;
807 	}
808 	aliases = zalloc(sizeof(char *) * len);
809 	if (!aliases)
810 		goto out_enomem;
811 	pmu = NULL;
812 	j = 0;
813 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
814 		list_for_each_entry(alias, &pmu->aliases, list) {
815 			char *name = format_alias(buf, sizeof(buf), pmu, alias);
816 			bool is_cpu = !strcmp(pmu->name, "cpu");
817 
818 			if (event_glob != NULL &&
819 			    !(strglobmatch(name, event_glob) ||
820 			      (!is_cpu && strglobmatch(alias->name,
821 						       event_glob))))
822 				continue;
823 
824 			if (is_cpu && !name_only)
825 				name = format_alias_or(buf, sizeof(buf), pmu, alias);
826 
827 			aliases[j] = strdup(name);
828 			if (aliases[j] == NULL)
829 				goto out_enomem;
830 			j++;
831 		}
832 		if (pmu->selectable) {
833 			char *s;
834 			if (asprintf(&s, "%s//", pmu->name) < 0)
835 				goto out_enomem;
836 			aliases[j] = s;
837 			j++;
838 		}
839 	}
840 	len = j;
841 	qsort(aliases, len, sizeof(char *), cmp_string);
842 	for (j = 0; j < len; j++) {
843 		if (name_only) {
844 			printf("%s ", aliases[j]);
845 			continue;
846 		}
847 		printf("  %-50s [Kernel PMU event]\n", aliases[j]);
848 		printed++;
849 	}
850 	if (printed)
851 		printf("\n");
852 out_free:
853 	for (j = 0; j < len; j++)
854 		zfree(&aliases[j]);
855 	zfree(&aliases);
856 	return;
857 
858 out_enomem:
859 	printf("FATAL: not enough memory to print PMU events\n");
860 	if (aliases)
861 		goto out_free;
862 }
863 
864 bool pmu_have_event(const char *pname, const char *name)
865 {
866 	struct perf_pmu *pmu;
867 	struct perf_pmu_alias *alias;
868 
869 	pmu = NULL;
870 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
871 		if (strcmp(pname, pmu->name))
872 			continue;
873 		list_for_each_entry(alias, &pmu->aliases, list)
874 			if (!strcmp(alias->name, name))
875 				return true;
876 	}
877 	return false;
878 }
879 
880 static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
881 {
882 	struct stat st;
883 	char path[PATH_MAX];
884 	const char *sysfs;
885 
886 	sysfs = sysfs__mountpoint();
887 	if (!sysfs)
888 		return NULL;
889 
890 	snprintf(path, PATH_MAX,
891 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/%s", sysfs, pmu->name, name);
892 
893 	if (stat(path, &st) < 0)
894 		return NULL;
895 
896 	return fopen(path, "r");
897 }
898 
899 int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt,
900 			...)
901 {
902 	va_list args;
903 	FILE *file;
904 	int ret = EOF;
905 
906 	va_start(args, fmt);
907 	file = perf_pmu__open_file(pmu, name);
908 	if (file) {
909 		ret = vfscanf(file, fmt, args);
910 		fclose(file);
911 	}
912 	va_end(args);
913 	return ret;
914 }
915