xref: /openbmc/linux/tools/perf/util/config.c (revision ece550b5) 
1 /*
2  * config.c
3  *
4  * Helper functions for parsing config items.
5  * Originally copied from GIT source.
6  *
7  * Copyright (C) Linus Torvalds, 2005
8  * Copyright (C) Johannes Schindelin, 2005
9  *
10  */
11 #include <errno.h>
12 #include <sys/param.h>
13 #include "util.h"
14 #include "cache.h"
15 #include <subcmd/exec-cmd.h>
16 #include "util/hist.h"  /* perf_hist_config */
17 #include "util/llvm-utils.h"   /* perf_llvm_config */
18 #include "config.h"
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <unistd.h>
22 #include <linux/string.h>
23 
24 #include "sane_ctype.h"
25 
26 #define MAXNAME (256)
27 
28 #define DEBUG_CACHE_DIR ".debug"
29 
30 
31 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
32 
33 static FILE *config_file;
34 static const char *config_file_name;
35 static int config_linenr;
36 static int config_file_eof;
37 static struct perf_config_set *config_set;
38 
39 const char *config_exclusive_filename;
40 
41 static int get_next_char(void)
42 {
43 	int c;
44 	FILE *f;
45 
46 	c = '\n';
47 	if ((f = config_file) != NULL) {
48 		c = fgetc(f);
49 		if (c == '\r') {
50 			/* DOS like systems */
51 			c = fgetc(f);
52 			if (c != '\n') {
53 				ungetc(c, f);
54 				c = '\r';
55 			}
56 		}
57 		if (c == '\n')
58 			config_linenr++;
59 		if (c == EOF) {
60 			config_file_eof = 1;
61 			c = '\n';
62 		}
63 	}
64 	return c;
65 }
66 
67 static char *parse_value(void)
68 {
69 	static char value[1024];
70 	int quote = 0, comment = 0, space = 0;
71 	size_t len = 0;
72 
73 	for (;;) {
74 		int c = get_next_char();
75 
76 		if (len >= sizeof(value) - 1)
77 			return NULL;
78 		if (c == '\n') {
79 			if (quote)
80 				return NULL;
81 			value[len] = 0;
82 			return value;
83 		}
84 		if (comment)
85 			continue;
86 		if (isspace(c) && !quote) {
87 			space = 1;
88 			continue;
89 		}
90 		if (!quote) {
91 			if (c == ';' || c == '#') {
92 				comment = 1;
93 				continue;
94 			}
95 		}
96 		if (space) {
97 			if (len)
98 				value[len++] = ' ';
99 			space = 0;
100 		}
101 		if (c == '\\') {
102 			c = get_next_char();
103 			switch (c) {
104 			case '\n':
105 				continue;
106 			case 't':
107 				c = '\t';
108 				break;
109 			case 'b':
110 				c = '\b';
111 				break;
112 			case 'n':
113 				c = '\n';
114 				break;
115 			/* Some characters escape as themselves */
116 			case '\\': case '"':
117 				break;
118 			/* Reject unknown escape sequences */
119 			default:
120 				return NULL;
121 			}
122 			value[len++] = c;
123 			continue;
124 		}
125 		if (c == '"') {
126 			quote = 1-quote;
127 			continue;
128 		}
129 		value[len++] = c;
130 	}
131 }
132 
133 static inline int iskeychar(int c)
134 {
135 	return isalnum(c) || c == '-' || c == '_';
136 }
137 
138 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
139 {
140 	int c;
141 	char *value;
142 
143 	/* Get the full name */
144 	for (;;) {
145 		c = get_next_char();
146 		if (config_file_eof)
147 			break;
148 		if (!iskeychar(c))
149 			break;
150 		name[len++] = c;
151 		if (len >= MAXNAME)
152 			return -1;
153 	}
154 	name[len] = 0;
155 	while (c == ' ' || c == '\t')
156 		c = get_next_char();
157 
158 	value = NULL;
159 	if (c != '\n') {
160 		if (c != '=')
161 			return -1;
162 		value = parse_value();
163 		if (!value)
164 			return -1;
165 	}
166 	return fn(name, value, data);
167 }
168 
169 static int get_extended_base_var(char *name, int baselen, int c)
170 {
171 	do {
172 		if (c == '\n')
173 			return -1;
174 		c = get_next_char();
175 	} while (isspace(c));
176 
177 	/* We require the format to be '[base "extension"]' */
178 	if (c != '"')
179 		return -1;
180 	name[baselen++] = '.';
181 
182 	for (;;) {
183 		int ch = get_next_char();
184 
185 		if (ch == '\n')
186 			return -1;
187 		if (ch == '"')
188 			break;
189 		if (ch == '\\') {
190 			ch = get_next_char();
191 			if (ch == '\n')
192 				return -1;
193 		}
194 		name[baselen++] = ch;
195 		if (baselen > MAXNAME / 2)
196 			return -1;
197 	}
198 
199 	/* Final ']' */
200 	if (get_next_char() != ']')
201 		return -1;
202 	return baselen;
203 }
204 
205 static int get_base_var(char *name)
206 {
207 	int baselen = 0;
208 
209 	for (;;) {
210 		int c = get_next_char();
211 		if (config_file_eof)
212 			return -1;
213 		if (c == ']')
214 			return baselen;
215 		if (isspace(c))
216 			return get_extended_base_var(name, baselen, c);
217 		if (!iskeychar(c) && c != '.')
218 			return -1;
219 		if (baselen > MAXNAME / 2)
220 			return -1;
221 		name[baselen++] = tolower(c);
222 	}
223 }
224 
225 static int perf_parse_file(config_fn_t fn, void *data)
226 {
227 	int comment = 0;
228 	int baselen = 0;
229 	static char var[MAXNAME];
230 
231 	/* U+FEFF Byte Order Mark in UTF8 */
232 	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
233 	const unsigned char *bomptr = utf8_bom;
234 
235 	for (;;) {
236 		int line, c = get_next_char();
237 
238 		if (bomptr && *bomptr) {
239 			/* We are at the file beginning; skip UTF8-encoded BOM
240 			 * if present. Sane editors won't put this in on their
241 			 * own, but e.g. Windows Notepad will do it happily. */
242 			if ((unsigned char) c == *bomptr) {
243 				bomptr++;
244 				continue;
245 			} else {
246 				/* Do not tolerate partial BOM. */
247 				if (bomptr != utf8_bom)
248 					break;
249 				/* No BOM at file beginning. Cool. */
250 				bomptr = NULL;
251 			}
252 		}
253 		if (c == '\n') {
254 			if (config_file_eof)
255 				return 0;
256 			comment = 0;
257 			continue;
258 		}
259 		if (comment || isspace(c))
260 			continue;
261 		if (c == '#' || c == ';') {
262 			comment = 1;
263 			continue;
264 		}
265 		if (c == '[') {
266 			baselen = get_base_var(var);
267 			if (baselen <= 0)
268 				break;
269 			var[baselen++] = '.';
270 			var[baselen] = 0;
271 			continue;
272 		}
273 		if (!isalpha(c))
274 			break;
275 		var[baselen] = tolower(c);
276 
277 		/*
278 		 * The get_value function might or might not reach the '\n',
279 		 * so saving the current line number for error reporting.
280 		 */
281 		line = config_linenr;
282 		if (get_value(fn, data, var, baselen+1) < 0) {
283 			config_linenr = line;
284 			break;
285 		}
286 	}
287 	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
288 	return -1;
289 }
290 
291 static int parse_unit_factor(const char *end, unsigned long *val)
292 {
293 	if (!*end)
294 		return 1;
295 	else if (!strcasecmp(end, "k")) {
296 		*val *= 1024;
297 		return 1;
298 	}
299 	else if (!strcasecmp(end, "m")) {
300 		*val *= 1024 * 1024;
301 		return 1;
302 	}
303 	else if (!strcasecmp(end, "g")) {
304 		*val *= 1024 * 1024 * 1024;
305 		return 1;
306 	}
307 	return 0;
308 }
309 
310 static int perf_parse_llong(const char *value, long long *ret)
311 {
312 	if (value && *value) {
313 		char *end;
314 		long long val = strtoll(value, &end, 0);
315 		unsigned long factor = 1;
316 
317 		if (!parse_unit_factor(end, &factor))
318 			return 0;
319 		*ret = val * factor;
320 		return 1;
321 	}
322 	return 0;
323 }
324 
325 static int perf_parse_long(const char *value, long *ret)
326 {
327 	if (value && *value) {
328 		char *end;
329 		long val = strtol(value, &end, 0);
330 		unsigned long factor = 1;
331 		if (!parse_unit_factor(end, &factor))
332 			return 0;
333 		*ret = val * factor;
334 		return 1;
335 	}
336 	return 0;
337 }
338 
339 static void bad_config(const char *name)
340 {
341 	if (config_file_name)
342 		pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
343 	else
344 		pr_warning("bad config value for '%s', ignoring...\n", name);
345 }
346 
347 int perf_config_u64(u64 *dest, const char *name, const char *value)
348 {
349 	long long ret = 0;
350 
351 	if (!perf_parse_llong(value, &ret)) {
352 		bad_config(name);
353 		return -1;
354 	}
355 
356 	*dest = ret;
357 	return 0;
358 }
359 
360 int perf_config_int(int *dest, const char *name, const char *value)
361 {
362 	long ret = 0;
363 	if (!perf_parse_long(value, &ret)) {
364 		bad_config(name);
365 		return -1;
366 	}
367 	*dest = ret;
368 	return 0;
369 }
370 
371 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
372 {
373 	int ret;
374 
375 	*is_bool = 1;
376 	if (!value)
377 		return 1;
378 	if (!*value)
379 		return 0;
380 	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
381 		return 1;
382 	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
383 		return 0;
384 	*is_bool = 0;
385 	return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
386 }
387 
388 int perf_config_bool(const char *name, const char *value)
389 {
390 	int discard;
391 	return !!perf_config_bool_or_int(name, value, &discard);
392 }
393 
394 static const char *perf_config_dirname(const char *name, const char *value)
395 {
396 	if (!name)
397 		return NULL;
398 	return value;
399 }
400 
401 static int perf_buildid_config(const char *var, const char *value)
402 {
403 	/* same dir for all commands */
404 	if (!strcmp(var, "buildid.dir")) {
405 		const char *dir = perf_config_dirname(var, value);
406 
407 		if (!dir) {
408 			pr_err("Invalid buildid directory!\n");
409 			return -1;
410 		}
411 		strncpy(buildid_dir, dir, MAXPATHLEN-1);
412 		buildid_dir[MAXPATHLEN-1] = '\0';
413 	}
414 
415 	return 0;
416 }
417 
418 static int perf_default_core_config(const char *var __maybe_unused,
419 				    const char *value __maybe_unused)
420 {
421 	/* Add other config variables here. */
422 	return 0;
423 }
424 
425 static int perf_ui_config(const char *var, const char *value)
426 {
427 	/* Add other config variables here. */
428 	if (!strcmp(var, "ui.show-headers"))
429 		symbol_conf.show_hist_headers = perf_config_bool(var, value);
430 
431 	return 0;
432 }
433 
434 int perf_default_config(const char *var, const char *value,
435 			void *dummy __maybe_unused)
436 {
437 	if (strstarts(var, "core."))
438 		return perf_default_core_config(var, value);
439 
440 	if (strstarts(var, "hist."))
441 		return perf_hist_config(var, value);
442 
443 	if (strstarts(var, "ui."))
444 		return perf_ui_config(var, value);
445 
446 	if (strstarts(var, "call-graph."))
447 		return perf_callchain_config(var, value);
448 
449 	if (strstarts(var, "llvm."))
450 		return perf_llvm_config(var, value);
451 
452 	if (strstarts(var, "buildid."))
453 		return perf_buildid_config(var, value);
454 
455 	/* Add other config variables here. */
456 	return 0;
457 }
458 
459 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
460 {
461 	int ret;
462 	FILE *f = fopen(filename, "r");
463 
464 	ret = -1;
465 	if (f) {
466 		config_file = f;
467 		config_file_name = filename;
468 		config_linenr = 1;
469 		config_file_eof = 0;
470 		ret = perf_parse_file(fn, data);
471 		fclose(f);
472 		config_file_name = NULL;
473 	}
474 	return ret;
475 }
476 
477 const char *perf_etc_perfconfig(void)
478 {
479 	static const char *system_wide;
480 	if (!system_wide)
481 		system_wide = system_path(ETC_PERFCONFIG);
482 	return system_wide;
483 }
484 
485 static int perf_env_bool(const char *k, int def)
486 {
487 	const char *v = getenv(k);
488 	return v ? perf_config_bool(k, v) : def;
489 }
490 
491 static int perf_config_system(void)
492 {
493 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
494 }
495 
496 static int perf_config_global(void)
497 {
498 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
499 }
500 
501 static struct perf_config_section *find_section(struct list_head *sections,
502 						const char *section_name)
503 {
504 	struct perf_config_section *section;
505 
506 	list_for_each_entry(section, sections, node)
507 		if (!strcmp(section->name, section_name))
508 			return section;
509 
510 	return NULL;
511 }
512 
513 static struct perf_config_item *find_config_item(const char *name,
514 						 struct perf_config_section *section)
515 {
516 	struct perf_config_item *item;
517 
518 	list_for_each_entry(item, &section->items, node)
519 		if (!strcmp(item->name, name))
520 			return item;
521 
522 	return NULL;
523 }
524 
525 static struct perf_config_section *add_section(struct list_head *sections,
526 					       const char *section_name)
527 {
528 	struct perf_config_section *section = zalloc(sizeof(*section));
529 
530 	if (!section)
531 		return NULL;
532 
533 	INIT_LIST_HEAD(&section->items);
534 	section->name = strdup(section_name);
535 	if (!section->name) {
536 		pr_debug("%s: strdup failed\n", __func__);
537 		free(section);
538 		return NULL;
539 	}
540 
541 	list_add_tail(&section->node, sections);
542 	return section;
543 }
544 
545 static struct perf_config_item *add_config_item(struct perf_config_section *section,
546 						const char *name)
547 {
548 	struct perf_config_item *item = zalloc(sizeof(*item));
549 
550 	if (!item)
551 		return NULL;
552 
553 	item->name = strdup(name);
554 	if (!item->name) {
555 		pr_debug("%s: strdup failed\n", __func__);
556 		free(item);
557 		return NULL;
558 	}
559 
560 	list_add_tail(&item->node, &section->items);
561 	return item;
562 }
563 
564 static int set_value(struct perf_config_item *item, const char *value)
565 {
566 	char *val = strdup(value);
567 
568 	if (!val)
569 		return -1;
570 
571 	zfree(&item->value);
572 	item->value = val;
573 	return 0;
574 }
575 
576 static int collect_config(const char *var, const char *value,
577 			  void *perf_config_set)
578 {
579 	int ret = -1;
580 	char *ptr, *key;
581 	char *section_name, *name;
582 	struct perf_config_section *section = NULL;
583 	struct perf_config_item *item = NULL;
584 	struct perf_config_set *set = perf_config_set;
585 	struct list_head *sections;
586 
587 	if (set == NULL)
588 		return -1;
589 
590 	sections = &set->sections;
591 	key = ptr = strdup(var);
592 	if (!key) {
593 		pr_debug("%s: strdup failed\n", __func__);
594 		return -1;
595 	}
596 
597 	section_name = strsep(&ptr, ".");
598 	name = ptr;
599 	if (name == NULL || value == NULL)
600 		goto out_free;
601 
602 	section = find_section(sections, section_name);
603 	if (!section) {
604 		section = add_section(sections, section_name);
605 		if (!section)
606 			goto out_free;
607 	}
608 
609 	item = find_config_item(name, section);
610 	if (!item) {
611 		item = add_config_item(section, name);
612 		if (!item)
613 			goto out_free;
614 	}
615 
616 	/* perf_config_set can contain both user and system config items.
617 	 * So we should know where each value is from.
618 	 * The classification would be needed when a particular config file
619 	 * is overwrited by setting feature i.e. set_config().
620 	 */
621 	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
622 		section->from_system_config = true;
623 		item->from_system_config = true;
624 	} else {
625 		section->from_system_config = false;
626 		item->from_system_config = false;
627 	}
628 
629 	ret = set_value(item, value);
630 	return ret;
631 
632 out_free:
633 	free(key);
634 	return -1;
635 }
636 
637 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
638 			     const char *var, const char *value)
639 {
640 	config_file_name = file_name;
641 	return collect_config(var, value, set);
642 }
643 
644 static int perf_config_set__init(struct perf_config_set *set)
645 {
646 	int ret = -1;
647 	const char *home = NULL;
648 	char *user_config;
649 	struct stat st;
650 
651 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
652 	if (config_exclusive_filename)
653 		return perf_config_from_file(collect_config, config_exclusive_filename, set);
654 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
655 		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
656 			goto out;
657 	}
658 
659 	home = getenv("HOME");
660 
661 	/*
662 	 * Skip reading user config if:
663 	 *   - there is no place to read it from (HOME)
664 	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
665 	 */
666 	if (!home || !*home || !perf_config_global())
667 		return 0;
668 
669 	user_config = strdup(mkpath("%s/.perfconfig", home));
670 	if (user_config == NULL) {
671 		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
672 		goto out;
673 	}
674 
675 	if (stat(user_config, &st) < 0) {
676 		if (errno == ENOENT)
677 			ret = 0;
678 		goto out_free;
679 	}
680 
681 	ret = 0;
682 
683 	if (st.st_uid && (st.st_uid != geteuid())) {
684 		pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
685 		goto out_free;
686 	}
687 
688 	if (st.st_size)
689 		ret = perf_config_from_file(collect_config, user_config, set);
690 
691 out_free:
692 	free(user_config);
693 out:
694 	return ret;
695 }
696 
697 struct perf_config_set *perf_config_set__new(void)
698 {
699 	struct perf_config_set *set = zalloc(sizeof(*set));
700 
701 	if (set) {
702 		INIT_LIST_HEAD(&set->sections);
703 		if (perf_config_set__init(set) < 0) {
704 			perf_config_set__delete(set);
705 			set = NULL;
706 		}
707 	}
708 
709 	return set;
710 }
711 
712 int perf_config(config_fn_t fn, void *data)
713 {
714 	int ret = 0;
715 	char key[BUFSIZ];
716 	struct perf_config_section *section;
717 	struct perf_config_item *item;
718 
719 	if (config_set == NULL)
720 		return -1;
721 
722 	perf_config_set__for_each_entry(config_set, section, item) {
723 		char *value = item->value;
724 
725 		if (value) {
726 			scnprintf(key, sizeof(key), "%s.%s",
727 				  section->name, item->name);
728 			ret = fn(key, value, data);
729 			if (ret < 0) {
730 				pr_err("Error: wrong config key-value pair %s=%s\n",
731 				       key, value);
732 				break;
733 			}
734 		}
735 	}
736 
737 	return ret;
738 }
739 
740 void perf_config__init(void)
741 {
742 	if (config_set == NULL)
743 		config_set = perf_config_set__new();
744 }
745 
746 void perf_config__exit(void)
747 {
748 	perf_config_set__delete(config_set);
749 	config_set = NULL;
750 }
751 
752 void perf_config__refresh(void)
753 {
754 	perf_config__exit();
755 	perf_config__init();
756 }
757 
758 static void perf_config_item__delete(struct perf_config_item *item)
759 {
760 	zfree(&item->name);
761 	zfree(&item->value);
762 	free(item);
763 }
764 
765 static void perf_config_section__purge(struct perf_config_section *section)
766 {
767 	struct perf_config_item *item, *tmp;
768 
769 	list_for_each_entry_safe(item, tmp, &section->items, node) {
770 		list_del_init(&item->node);
771 		perf_config_item__delete(item);
772 	}
773 }
774 
775 static void perf_config_section__delete(struct perf_config_section *section)
776 {
777 	perf_config_section__purge(section);
778 	zfree(&section->name);
779 	free(section);
780 }
781 
782 static void perf_config_set__purge(struct perf_config_set *set)
783 {
784 	struct perf_config_section *section, *tmp;
785 
786 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
787 		list_del_init(&section->node);
788 		perf_config_section__delete(section);
789 	}
790 }
791 
792 void perf_config_set__delete(struct perf_config_set *set)
793 {
794 	if (set == NULL)
795 		return;
796 
797 	perf_config_set__purge(set);
798 	free(set);
799 }
800 
801 /*
802  * Call this to report error for your variable that should not
803  * get a boolean value (i.e. "[my] var" means "true").
804  */
805 int config_error_nonbool(const char *var)
806 {
807 	pr_err("Missing value for '%s'", var);
808 	return -1;
809 }
810 
811 void set_buildid_dir(const char *dir)
812 {
813 	if (dir)
814 		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
815 
816 	/* default to $HOME/.debug */
817 	if (buildid_dir[0] == '\0') {
818 		char *home = getenv("HOME");
819 
820 		if (home) {
821 			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
822 				 home, DEBUG_CACHE_DIR);
823 		} else {
824 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
825 		}
826 		buildid_dir[MAXPATHLEN-1] = '\0';
827 	}
828 	/* for communicating with external commands */
829 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
830 }
831