xref: /openbmc/linux/tools/perf/util/config.c (revision 5b628549)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * config.c
4  *
5  * Helper functions for parsing config items.
6  * Originally copied from GIT source.
7  *
8  * Copyright (C) Linus Torvalds, 2005
9  * Copyright (C) Johannes Schindelin, 2005
10  *
11  */
12 #include <errno.h>
13 #include <sys/param.h>
14 #include "util.h"
15 #include "cache.h"
16 #include "callchain.h"
17 #include <subcmd/exec-cmd.h>
18 #include "util/event.h"  /* proc_map_timeout */
19 #include "util/hist.h"  /* perf_hist_config */
20 #include "util/llvm-utils.h"   /* perf_llvm_config */
21 #include "config.h"
22 #include <sys/types.h>
23 #include <sys/stat.h>
24 #include <unistd.h>
25 #include <linux/string.h>
26 
27 #include "sane_ctype.h"
28 
29 #define MAXNAME (256)
30 
31 #define DEBUG_CACHE_DIR ".debug"
32 
33 
34 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
35 
36 static FILE *config_file;
37 static const char *config_file_name;
38 static int config_linenr;
39 static int config_file_eof;
40 static struct perf_config_set *config_set;
41 
42 const char *config_exclusive_filename;
43 
44 static int get_next_char(void)
45 {
46 	int c;
47 	FILE *f;
48 
49 	c = '\n';
50 	if ((f = config_file) != NULL) {
51 		c = fgetc(f);
52 		if (c == '\r') {
53 			/* DOS like systems */
54 			c = fgetc(f);
55 			if (c != '\n') {
56 				ungetc(c, f);
57 				c = '\r';
58 			}
59 		}
60 		if (c == '\n')
61 			config_linenr++;
62 		if (c == EOF) {
63 			config_file_eof = 1;
64 			c = '\n';
65 		}
66 	}
67 	return c;
68 }
69 
70 static char *parse_value(void)
71 {
72 	static char value[1024];
73 	int quote = 0, comment = 0, space = 0;
74 	size_t len = 0;
75 
76 	for (;;) {
77 		int c = get_next_char();
78 
79 		if (len >= sizeof(value) - 1)
80 			return NULL;
81 		if (c == '\n') {
82 			if (quote)
83 				return NULL;
84 			value[len] = 0;
85 			return value;
86 		}
87 		if (comment)
88 			continue;
89 		if (isspace(c) && !quote) {
90 			space = 1;
91 			continue;
92 		}
93 		if (!quote) {
94 			if (c == ';' || c == '#') {
95 				comment = 1;
96 				continue;
97 			}
98 		}
99 		if (space) {
100 			if (len)
101 				value[len++] = ' ';
102 			space = 0;
103 		}
104 		if (c == '\\') {
105 			c = get_next_char();
106 			switch (c) {
107 			case '\n':
108 				continue;
109 			case 't':
110 				c = '\t';
111 				break;
112 			case 'b':
113 				c = '\b';
114 				break;
115 			case 'n':
116 				c = '\n';
117 				break;
118 			/* Some characters escape as themselves */
119 			case '\\': case '"':
120 				break;
121 			/* Reject unknown escape sequences */
122 			default:
123 				return NULL;
124 			}
125 			value[len++] = c;
126 			continue;
127 		}
128 		if (c == '"') {
129 			quote = 1-quote;
130 			continue;
131 		}
132 		value[len++] = c;
133 	}
134 }
135 
136 static inline int iskeychar(int c)
137 {
138 	return isalnum(c) || c == '-' || c == '_';
139 }
140 
141 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
142 {
143 	int c;
144 	char *value;
145 
146 	/* Get the full name */
147 	for (;;) {
148 		c = get_next_char();
149 		if (config_file_eof)
150 			break;
151 		if (!iskeychar(c))
152 			break;
153 		name[len++] = c;
154 		if (len >= MAXNAME)
155 			return -1;
156 	}
157 	name[len] = 0;
158 	while (c == ' ' || c == '\t')
159 		c = get_next_char();
160 
161 	value = NULL;
162 	if (c != '\n') {
163 		if (c != '=')
164 			return -1;
165 		value = parse_value();
166 		if (!value)
167 			return -1;
168 	}
169 	return fn(name, value, data);
170 }
171 
172 static int get_extended_base_var(char *name, int baselen, int c)
173 {
174 	do {
175 		if (c == '\n')
176 			return -1;
177 		c = get_next_char();
178 	} while (isspace(c));
179 
180 	/* We require the format to be '[base "extension"]' */
181 	if (c != '"')
182 		return -1;
183 	name[baselen++] = '.';
184 
185 	for (;;) {
186 		int ch = get_next_char();
187 
188 		if (ch == '\n')
189 			return -1;
190 		if (ch == '"')
191 			break;
192 		if (ch == '\\') {
193 			ch = get_next_char();
194 			if (ch == '\n')
195 				return -1;
196 		}
197 		name[baselen++] = ch;
198 		if (baselen > MAXNAME / 2)
199 			return -1;
200 	}
201 
202 	/* Final ']' */
203 	if (get_next_char() != ']')
204 		return -1;
205 	return baselen;
206 }
207 
208 static int get_base_var(char *name)
209 {
210 	int baselen = 0;
211 
212 	for (;;) {
213 		int c = get_next_char();
214 		if (config_file_eof)
215 			return -1;
216 		if (c == ']')
217 			return baselen;
218 		if (isspace(c))
219 			return get_extended_base_var(name, baselen, c);
220 		if (!iskeychar(c) && c != '.')
221 			return -1;
222 		if (baselen > MAXNAME / 2)
223 			return -1;
224 		name[baselen++] = tolower(c);
225 	}
226 }
227 
228 static int perf_parse_file(config_fn_t fn, void *data)
229 {
230 	int comment = 0;
231 	int baselen = 0;
232 	static char var[MAXNAME];
233 
234 	/* U+FEFF Byte Order Mark in UTF8 */
235 	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
236 	const unsigned char *bomptr = utf8_bom;
237 
238 	for (;;) {
239 		int line, c = get_next_char();
240 
241 		if (bomptr && *bomptr) {
242 			/* We are at the file beginning; skip UTF8-encoded BOM
243 			 * if present. Sane editors won't put this in on their
244 			 * own, but e.g. Windows Notepad will do it happily. */
245 			if ((unsigned char) c == *bomptr) {
246 				bomptr++;
247 				continue;
248 			} else {
249 				/* Do not tolerate partial BOM. */
250 				if (bomptr != utf8_bom)
251 					break;
252 				/* No BOM at file beginning. Cool. */
253 				bomptr = NULL;
254 			}
255 		}
256 		if (c == '\n') {
257 			if (config_file_eof)
258 				return 0;
259 			comment = 0;
260 			continue;
261 		}
262 		if (comment || isspace(c))
263 			continue;
264 		if (c == '#' || c == ';') {
265 			comment = 1;
266 			continue;
267 		}
268 		if (c == '[') {
269 			baselen = get_base_var(var);
270 			if (baselen <= 0)
271 				break;
272 			var[baselen++] = '.';
273 			var[baselen] = 0;
274 			continue;
275 		}
276 		if (!isalpha(c))
277 			break;
278 		var[baselen] = tolower(c);
279 
280 		/*
281 		 * The get_value function might or might not reach the '\n',
282 		 * so saving the current line number for error reporting.
283 		 */
284 		line = config_linenr;
285 		if (get_value(fn, data, var, baselen+1) < 0) {
286 			config_linenr = line;
287 			break;
288 		}
289 	}
290 	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
291 	return -1;
292 }
293 
294 static int parse_unit_factor(const char *end, unsigned long *val)
295 {
296 	if (!*end)
297 		return 1;
298 	else if (!strcasecmp(end, "k")) {
299 		*val *= 1024;
300 		return 1;
301 	}
302 	else if (!strcasecmp(end, "m")) {
303 		*val *= 1024 * 1024;
304 		return 1;
305 	}
306 	else if (!strcasecmp(end, "g")) {
307 		*val *= 1024 * 1024 * 1024;
308 		return 1;
309 	}
310 	return 0;
311 }
312 
313 static int perf_parse_llong(const char *value, long long *ret)
314 {
315 	if (value && *value) {
316 		char *end;
317 		long long val = strtoll(value, &end, 0);
318 		unsigned long factor = 1;
319 
320 		if (!parse_unit_factor(end, &factor))
321 			return 0;
322 		*ret = val * factor;
323 		return 1;
324 	}
325 	return 0;
326 }
327 
328 static int perf_parse_long(const char *value, long *ret)
329 {
330 	if (value && *value) {
331 		char *end;
332 		long val = strtol(value, &end, 0);
333 		unsigned long factor = 1;
334 		if (!parse_unit_factor(end, &factor))
335 			return 0;
336 		*ret = val * factor;
337 		return 1;
338 	}
339 	return 0;
340 }
341 
342 static void bad_config(const char *name)
343 {
344 	if (config_file_name)
345 		pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
346 	else
347 		pr_warning("bad config value for '%s', ignoring...\n", name);
348 }
349 
350 int perf_config_u64(u64 *dest, const char *name, const char *value)
351 {
352 	long long ret = 0;
353 
354 	if (!perf_parse_llong(value, &ret)) {
355 		bad_config(name);
356 		return -1;
357 	}
358 
359 	*dest = ret;
360 	return 0;
361 }
362 
363 int perf_config_int(int *dest, const char *name, const char *value)
364 {
365 	long ret = 0;
366 	if (!perf_parse_long(value, &ret)) {
367 		bad_config(name);
368 		return -1;
369 	}
370 	*dest = ret;
371 	return 0;
372 }
373 
374 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
375 {
376 	int ret;
377 
378 	*is_bool = 1;
379 	if (!value)
380 		return 1;
381 	if (!*value)
382 		return 0;
383 	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
384 		return 1;
385 	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
386 		return 0;
387 	*is_bool = 0;
388 	return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
389 }
390 
391 int perf_config_bool(const char *name, const char *value)
392 {
393 	int discard;
394 	return !!perf_config_bool_or_int(name, value, &discard);
395 }
396 
397 static const char *perf_config_dirname(const char *name, const char *value)
398 {
399 	if (!name)
400 		return NULL;
401 	return value;
402 }
403 
404 static int perf_buildid_config(const char *var, const char *value)
405 {
406 	/* same dir for all commands */
407 	if (!strcmp(var, "buildid.dir")) {
408 		const char *dir = perf_config_dirname(var, value);
409 
410 		if (!dir) {
411 			pr_err("Invalid buildid directory!\n");
412 			return -1;
413 		}
414 		strncpy(buildid_dir, dir, MAXPATHLEN-1);
415 		buildid_dir[MAXPATHLEN-1] = '\0';
416 	}
417 
418 	return 0;
419 }
420 
421 static int perf_default_core_config(const char *var __maybe_unused,
422 				    const char *value __maybe_unused)
423 {
424 	if (!strcmp(var, "core.proc-map-timeout"))
425 		proc_map_timeout = strtoul(value, NULL, 10);
426 
427 	/* Add other config variables here. */
428 	return 0;
429 }
430 
431 static int perf_ui_config(const char *var, const char *value)
432 {
433 	/* Add other config variables here. */
434 	if (!strcmp(var, "ui.show-headers"))
435 		symbol_conf.show_hist_headers = perf_config_bool(var, value);
436 
437 	return 0;
438 }
439 
440 int perf_default_config(const char *var, const char *value,
441 			void *dummy __maybe_unused)
442 {
443 	if (strstarts(var, "core."))
444 		return perf_default_core_config(var, value);
445 
446 	if (strstarts(var, "hist."))
447 		return perf_hist_config(var, value);
448 
449 	if (strstarts(var, "ui."))
450 		return perf_ui_config(var, value);
451 
452 	if (strstarts(var, "call-graph."))
453 		return perf_callchain_config(var, value);
454 
455 	if (strstarts(var, "llvm."))
456 		return perf_llvm_config(var, value);
457 
458 	if (strstarts(var, "buildid."))
459 		return perf_buildid_config(var, value);
460 
461 	/* Add other config variables here. */
462 	return 0;
463 }
464 
465 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
466 {
467 	int ret;
468 	FILE *f = fopen(filename, "r");
469 
470 	ret = -1;
471 	if (f) {
472 		config_file = f;
473 		config_file_name = filename;
474 		config_linenr = 1;
475 		config_file_eof = 0;
476 		ret = perf_parse_file(fn, data);
477 		fclose(f);
478 		config_file_name = NULL;
479 	}
480 	return ret;
481 }
482 
483 const char *perf_etc_perfconfig(void)
484 {
485 	static const char *system_wide;
486 	if (!system_wide)
487 		system_wide = system_path(ETC_PERFCONFIG);
488 	return system_wide;
489 }
490 
491 static int perf_env_bool(const char *k, int def)
492 {
493 	const char *v = getenv(k);
494 	return v ? perf_config_bool(k, v) : def;
495 }
496 
497 static int perf_config_system(void)
498 {
499 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
500 }
501 
502 static int perf_config_global(void)
503 {
504 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
505 }
506 
507 static struct perf_config_section *find_section(struct list_head *sections,
508 						const char *section_name)
509 {
510 	struct perf_config_section *section;
511 
512 	list_for_each_entry(section, sections, node)
513 		if (!strcmp(section->name, section_name))
514 			return section;
515 
516 	return NULL;
517 }
518 
519 static struct perf_config_item *find_config_item(const char *name,
520 						 struct perf_config_section *section)
521 {
522 	struct perf_config_item *item;
523 
524 	list_for_each_entry(item, &section->items, node)
525 		if (!strcmp(item->name, name))
526 			return item;
527 
528 	return NULL;
529 }
530 
531 static struct perf_config_section *add_section(struct list_head *sections,
532 					       const char *section_name)
533 {
534 	struct perf_config_section *section = zalloc(sizeof(*section));
535 
536 	if (!section)
537 		return NULL;
538 
539 	INIT_LIST_HEAD(&section->items);
540 	section->name = strdup(section_name);
541 	if (!section->name) {
542 		pr_debug("%s: strdup failed\n", __func__);
543 		free(section);
544 		return NULL;
545 	}
546 
547 	list_add_tail(&section->node, sections);
548 	return section;
549 }
550 
551 static struct perf_config_item *add_config_item(struct perf_config_section *section,
552 						const char *name)
553 {
554 	struct perf_config_item *item = zalloc(sizeof(*item));
555 
556 	if (!item)
557 		return NULL;
558 
559 	item->name = strdup(name);
560 	if (!item->name) {
561 		pr_debug("%s: strdup failed\n", __func__);
562 		free(item);
563 		return NULL;
564 	}
565 
566 	list_add_tail(&item->node, &section->items);
567 	return item;
568 }
569 
570 static int set_value(struct perf_config_item *item, const char *value)
571 {
572 	char *val = strdup(value);
573 
574 	if (!val)
575 		return -1;
576 
577 	zfree(&item->value);
578 	item->value = val;
579 	return 0;
580 }
581 
582 static int collect_config(const char *var, const char *value,
583 			  void *perf_config_set)
584 {
585 	int ret = -1;
586 	char *ptr, *key;
587 	char *section_name, *name;
588 	struct perf_config_section *section = NULL;
589 	struct perf_config_item *item = NULL;
590 	struct perf_config_set *set = perf_config_set;
591 	struct list_head *sections;
592 
593 	if (set == NULL)
594 		return -1;
595 
596 	sections = &set->sections;
597 	key = ptr = strdup(var);
598 	if (!key) {
599 		pr_debug("%s: strdup failed\n", __func__);
600 		return -1;
601 	}
602 
603 	section_name = strsep(&ptr, ".");
604 	name = ptr;
605 	if (name == NULL || value == NULL)
606 		goto out_free;
607 
608 	section = find_section(sections, section_name);
609 	if (!section) {
610 		section = add_section(sections, section_name);
611 		if (!section)
612 			goto out_free;
613 	}
614 
615 	item = find_config_item(name, section);
616 	if (!item) {
617 		item = add_config_item(section, name);
618 		if (!item)
619 			goto out_free;
620 	}
621 
622 	/* perf_config_set can contain both user and system config items.
623 	 * So we should know where each value is from.
624 	 * The classification would be needed when a particular config file
625 	 * is overwrited by setting feature i.e. set_config().
626 	 */
627 	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
628 		section->from_system_config = true;
629 		item->from_system_config = true;
630 	} else {
631 		section->from_system_config = false;
632 		item->from_system_config = false;
633 	}
634 
635 	ret = set_value(item, value);
636 	return ret;
637 
638 out_free:
639 	free(key);
640 	return -1;
641 }
642 
643 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
644 			     const char *var, const char *value)
645 {
646 	config_file_name = file_name;
647 	return collect_config(var, value, set);
648 }
649 
650 static int perf_config_set__init(struct perf_config_set *set)
651 {
652 	int ret = -1;
653 	const char *home = NULL;
654 	char *user_config;
655 	struct stat st;
656 
657 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
658 	if (config_exclusive_filename)
659 		return perf_config_from_file(collect_config, config_exclusive_filename, set);
660 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
661 		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
662 			goto out;
663 	}
664 
665 	home = getenv("HOME");
666 
667 	/*
668 	 * Skip reading user config if:
669 	 *   - there is no place to read it from (HOME)
670 	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
671 	 */
672 	if (!home || !*home || !perf_config_global())
673 		return 0;
674 
675 	user_config = strdup(mkpath("%s/.perfconfig", home));
676 	if (user_config == NULL) {
677 		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
678 		goto out;
679 	}
680 
681 	if (stat(user_config, &st) < 0) {
682 		if (errno == ENOENT)
683 			ret = 0;
684 		goto out_free;
685 	}
686 
687 	ret = 0;
688 
689 	if (st.st_uid && (st.st_uid != geteuid())) {
690 		pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
691 		goto out_free;
692 	}
693 
694 	if (st.st_size)
695 		ret = perf_config_from_file(collect_config, user_config, set);
696 
697 out_free:
698 	free(user_config);
699 out:
700 	return ret;
701 }
702 
703 struct perf_config_set *perf_config_set__new(void)
704 {
705 	struct perf_config_set *set = zalloc(sizeof(*set));
706 
707 	if (set) {
708 		INIT_LIST_HEAD(&set->sections);
709 		perf_config_set__init(set);
710 	}
711 
712 	return set;
713 }
714 
715 static int perf_config__init(void)
716 {
717 	if (config_set == NULL)
718 		config_set = perf_config_set__new();
719 
720 	return config_set == NULL;
721 }
722 
723 int perf_config(config_fn_t fn, void *data)
724 {
725 	int ret = 0;
726 	char key[BUFSIZ];
727 	struct perf_config_section *section;
728 	struct perf_config_item *item;
729 
730 	if (config_set == NULL && perf_config__init())
731 		return -1;
732 
733 	perf_config_set__for_each_entry(config_set, section, item) {
734 		char *value = item->value;
735 
736 		if (value) {
737 			scnprintf(key, sizeof(key), "%s.%s",
738 				  section->name, item->name);
739 			ret = fn(key, value, data);
740 			if (ret < 0) {
741 				pr_err("Error: wrong config key-value pair %s=%s\n",
742 				       key, value);
743 				break;
744 			}
745 		}
746 	}
747 
748 	return ret;
749 }
750 
751 void perf_config__exit(void)
752 {
753 	perf_config_set__delete(config_set);
754 	config_set = NULL;
755 }
756 
757 void perf_config__refresh(void)
758 {
759 	perf_config__exit();
760 	perf_config__init();
761 }
762 
763 static void perf_config_item__delete(struct perf_config_item *item)
764 {
765 	zfree(&item->name);
766 	zfree(&item->value);
767 	free(item);
768 }
769 
770 static void perf_config_section__purge(struct perf_config_section *section)
771 {
772 	struct perf_config_item *item, *tmp;
773 
774 	list_for_each_entry_safe(item, tmp, &section->items, node) {
775 		list_del_init(&item->node);
776 		perf_config_item__delete(item);
777 	}
778 }
779 
780 static void perf_config_section__delete(struct perf_config_section *section)
781 {
782 	perf_config_section__purge(section);
783 	zfree(&section->name);
784 	free(section);
785 }
786 
787 static void perf_config_set__purge(struct perf_config_set *set)
788 {
789 	struct perf_config_section *section, *tmp;
790 
791 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
792 		list_del_init(&section->node);
793 		perf_config_section__delete(section);
794 	}
795 }
796 
797 void perf_config_set__delete(struct perf_config_set *set)
798 {
799 	if (set == NULL)
800 		return;
801 
802 	perf_config_set__purge(set);
803 	free(set);
804 }
805 
806 /*
807  * Call this to report error for your variable that should not
808  * get a boolean value (i.e. "[my] var" means "true").
809  */
810 int config_error_nonbool(const char *var)
811 {
812 	pr_err("Missing value for '%s'", var);
813 	return -1;
814 }
815 
816 void set_buildid_dir(const char *dir)
817 {
818 	if (dir)
819 		scnprintf(buildid_dir, MAXPATHLEN, "%s", dir);
820 
821 	/* default to $HOME/.debug */
822 	if (buildid_dir[0] == '\0') {
823 		char *home = getenv("HOME");
824 
825 		if (home) {
826 			snprintf(buildid_dir, MAXPATHLEN, "%s/%s",
827 				 home, DEBUG_CACHE_DIR);
828 		} else {
829 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
830 		}
831 		buildid_dir[MAXPATHLEN-1] = '\0';
832 	}
833 	/* for communicating with external commands */
834 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
835 }
836