xref: /openbmc/linux/tools/perf/util/config.c (revision 020c5260)
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 
23 #include "sane_ctype.h"
24 
25 #define MAXNAME (256)
26 
27 #define DEBUG_CACHE_DIR ".debug"
28 
29 
30 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
31 
32 static FILE *config_file;
33 static const char *config_file_name;
34 static int config_linenr;
35 static int config_file_eof;
36 static struct perf_config_set *config_set;
37 
38 const char *config_exclusive_filename;
39 
40 static int get_next_char(void)
41 {
42 	int c;
43 	FILE *f;
44 
45 	c = '\n';
46 	if ((f = config_file) != NULL) {
47 		c = fgetc(f);
48 		if (c == '\r') {
49 			/* DOS like systems */
50 			c = fgetc(f);
51 			if (c != '\n') {
52 				ungetc(c, f);
53 				c = '\r';
54 			}
55 		}
56 		if (c == '\n')
57 			config_linenr++;
58 		if (c == EOF) {
59 			config_file_eof = 1;
60 			c = '\n';
61 		}
62 	}
63 	return c;
64 }
65 
66 static char *parse_value(void)
67 {
68 	static char value[1024];
69 	int quote = 0, comment = 0, space = 0;
70 	size_t len = 0;
71 
72 	for (;;) {
73 		int c = get_next_char();
74 
75 		if (len >= sizeof(value) - 1)
76 			return NULL;
77 		if (c == '\n') {
78 			if (quote)
79 				return NULL;
80 			value[len] = 0;
81 			return value;
82 		}
83 		if (comment)
84 			continue;
85 		if (isspace(c) && !quote) {
86 			space = 1;
87 			continue;
88 		}
89 		if (!quote) {
90 			if (c == ';' || c == '#') {
91 				comment = 1;
92 				continue;
93 			}
94 		}
95 		if (space) {
96 			if (len)
97 				value[len++] = ' ';
98 			space = 0;
99 		}
100 		if (c == '\\') {
101 			c = get_next_char();
102 			switch (c) {
103 			case '\n':
104 				continue;
105 			case 't':
106 				c = '\t';
107 				break;
108 			case 'b':
109 				c = '\b';
110 				break;
111 			case 'n':
112 				c = '\n';
113 				break;
114 			/* Some characters escape as themselves */
115 			case '\\': case '"':
116 				break;
117 			/* Reject unknown escape sequences */
118 			default:
119 				return NULL;
120 			}
121 			value[len++] = c;
122 			continue;
123 		}
124 		if (c == '"') {
125 			quote = 1-quote;
126 			continue;
127 		}
128 		value[len++] = c;
129 	}
130 }
131 
132 static inline int iskeychar(int c)
133 {
134 	return isalnum(c) || c == '-' || c == '_';
135 }
136 
137 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
138 {
139 	int c;
140 	char *value;
141 
142 	/* Get the full name */
143 	for (;;) {
144 		c = get_next_char();
145 		if (config_file_eof)
146 			break;
147 		if (!iskeychar(c))
148 			break;
149 		name[len++] = c;
150 		if (len >= MAXNAME)
151 			return -1;
152 	}
153 	name[len] = 0;
154 	while (c == ' ' || c == '\t')
155 		c = get_next_char();
156 
157 	value = NULL;
158 	if (c != '\n') {
159 		if (c != '=')
160 			return -1;
161 		value = parse_value();
162 		if (!value)
163 			return -1;
164 	}
165 	return fn(name, value, data);
166 }
167 
168 static int get_extended_base_var(char *name, int baselen, int c)
169 {
170 	do {
171 		if (c == '\n')
172 			return -1;
173 		c = get_next_char();
174 	} while (isspace(c));
175 
176 	/* We require the format to be '[base "extension"]' */
177 	if (c != '"')
178 		return -1;
179 	name[baselen++] = '.';
180 
181 	for (;;) {
182 		int ch = get_next_char();
183 
184 		if (ch == '\n')
185 			return -1;
186 		if (ch == '"')
187 			break;
188 		if (ch == '\\') {
189 			ch = get_next_char();
190 			if (ch == '\n')
191 				return -1;
192 		}
193 		name[baselen++] = ch;
194 		if (baselen > MAXNAME / 2)
195 			return -1;
196 	}
197 
198 	/* Final ']' */
199 	if (get_next_char() != ']')
200 		return -1;
201 	return baselen;
202 }
203 
204 static int get_base_var(char *name)
205 {
206 	int baselen = 0;
207 
208 	for (;;) {
209 		int c = get_next_char();
210 		if (config_file_eof)
211 			return -1;
212 		if (c == ']')
213 			return baselen;
214 		if (isspace(c))
215 			return get_extended_base_var(name, baselen, c);
216 		if (!iskeychar(c) && c != '.')
217 			return -1;
218 		if (baselen > MAXNAME / 2)
219 			return -1;
220 		name[baselen++] = tolower(c);
221 	}
222 }
223 
224 static int perf_parse_file(config_fn_t fn, void *data)
225 {
226 	int comment = 0;
227 	int baselen = 0;
228 	static char var[MAXNAME];
229 
230 	/* U+FEFF Byte Order Mark in UTF8 */
231 	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
232 	const unsigned char *bomptr = utf8_bom;
233 
234 	for (;;) {
235 		int line, c = get_next_char();
236 
237 		if (bomptr && *bomptr) {
238 			/* We are at the file beginning; skip UTF8-encoded BOM
239 			 * if present. Sane editors won't put this in on their
240 			 * own, but e.g. Windows Notepad will do it happily. */
241 			if ((unsigned char) c == *bomptr) {
242 				bomptr++;
243 				continue;
244 			} else {
245 				/* Do not tolerate partial BOM. */
246 				if (bomptr != utf8_bom)
247 					break;
248 				/* No BOM at file beginning. Cool. */
249 				bomptr = NULL;
250 			}
251 		}
252 		if (c == '\n') {
253 			if (config_file_eof)
254 				return 0;
255 			comment = 0;
256 			continue;
257 		}
258 		if (comment || isspace(c))
259 			continue;
260 		if (c == '#' || c == ';') {
261 			comment = 1;
262 			continue;
263 		}
264 		if (c == '[') {
265 			baselen = get_base_var(var);
266 			if (baselen <= 0)
267 				break;
268 			var[baselen++] = '.';
269 			var[baselen] = 0;
270 			continue;
271 		}
272 		if (!isalpha(c))
273 			break;
274 		var[baselen] = tolower(c);
275 
276 		/*
277 		 * The get_value function might or might not reach the '\n',
278 		 * so saving the current line number for error reporting.
279 		 */
280 		line = config_linenr;
281 		if (get_value(fn, data, var, baselen+1) < 0) {
282 			config_linenr = line;
283 			break;
284 		}
285 	}
286 	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
287 	return -1;
288 }
289 
290 static int parse_unit_factor(const char *end, unsigned long *val)
291 {
292 	if (!*end)
293 		return 1;
294 	else if (!strcasecmp(end, "k")) {
295 		*val *= 1024;
296 		return 1;
297 	}
298 	else if (!strcasecmp(end, "m")) {
299 		*val *= 1024 * 1024;
300 		return 1;
301 	}
302 	else if (!strcasecmp(end, "g")) {
303 		*val *= 1024 * 1024 * 1024;
304 		return 1;
305 	}
306 	return 0;
307 }
308 
309 static int perf_parse_llong(const char *value, long long *ret)
310 {
311 	if (value && *value) {
312 		char *end;
313 		long long val = strtoll(value, &end, 0);
314 		unsigned long factor = 1;
315 
316 		if (!parse_unit_factor(end, &factor))
317 			return 0;
318 		*ret = val * factor;
319 		return 1;
320 	}
321 	return 0;
322 }
323 
324 static int perf_parse_long(const char *value, long *ret)
325 {
326 	if (value && *value) {
327 		char *end;
328 		long val = strtol(value, &end, 0);
329 		unsigned long factor = 1;
330 		if (!parse_unit_factor(end, &factor))
331 			return 0;
332 		*ret = val * factor;
333 		return 1;
334 	}
335 	return 0;
336 }
337 
338 static void die_bad_config(const char *name)
339 {
340 	if (config_file_name)
341 		die("bad config value for '%s' in %s", name, config_file_name);
342 	die("bad config value for '%s'", name);
343 }
344 
345 u64 perf_config_u64(const char *name, const char *value)
346 {
347 	long long ret = 0;
348 
349 	if (!perf_parse_llong(value, &ret))
350 		die_bad_config(name);
351 	return (u64) ret;
352 }
353 
354 int perf_config_int(const char *name, const char *value)
355 {
356 	long ret = 0;
357 	if (!perf_parse_long(value, &ret))
358 		die_bad_config(name);
359 	return ret;
360 }
361 
362 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
363 {
364 	*is_bool = 1;
365 	if (!value)
366 		return 1;
367 	if (!*value)
368 		return 0;
369 	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
370 		return 1;
371 	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
372 		return 0;
373 	*is_bool = 0;
374 	return perf_config_int(name, value);
375 }
376 
377 int perf_config_bool(const char *name, const char *value)
378 {
379 	int discard;
380 	return !!perf_config_bool_or_int(name, value, &discard);
381 }
382 
383 static const char *perf_config_dirname(const char *name, const char *value)
384 {
385 	if (!name)
386 		return NULL;
387 	return value;
388 }
389 
390 static int perf_buildid_config(const char *var, const char *value)
391 {
392 	/* same dir for all commands */
393 	if (!strcmp(var, "buildid.dir")) {
394 		const char *dir = perf_config_dirname(var, value);
395 
396 		if (!dir) {
397 			pr_err("Invalid buildid directory!\n");
398 			return -1;
399 		}
400 		strncpy(buildid_dir, dir, MAXPATHLEN-1);
401 		buildid_dir[MAXPATHLEN-1] = '\0';
402 	}
403 
404 	return 0;
405 }
406 
407 static int perf_default_core_config(const char *var __maybe_unused,
408 				    const char *value __maybe_unused)
409 {
410 	/* Add other config variables here. */
411 	return 0;
412 }
413 
414 static int perf_ui_config(const char *var, const char *value)
415 {
416 	/* Add other config variables here. */
417 	if (!strcmp(var, "ui.show-headers"))
418 		symbol_conf.show_hist_headers = perf_config_bool(var, value);
419 
420 	return 0;
421 }
422 
423 int perf_default_config(const char *var, const char *value,
424 			void *dummy __maybe_unused)
425 {
426 	if (!prefixcmp(var, "core."))
427 		return perf_default_core_config(var, value);
428 
429 	if (!prefixcmp(var, "hist."))
430 		return perf_hist_config(var, value);
431 
432 	if (!prefixcmp(var, "ui."))
433 		return perf_ui_config(var, value);
434 
435 	if (!prefixcmp(var, "call-graph."))
436 		return perf_callchain_config(var, value);
437 
438 	if (!prefixcmp(var, "llvm."))
439 		return perf_llvm_config(var, value);
440 
441 	if (!prefixcmp(var, "buildid."))
442 		return perf_buildid_config(var, value);
443 
444 	/* Add other config variables here. */
445 	return 0;
446 }
447 
448 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
449 {
450 	int ret;
451 	FILE *f = fopen(filename, "r");
452 
453 	ret = -1;
454 	if (f) {
455 		config_file = f;
456 		config_file_name = filename;
457 		config_linenr = 1;
458 		config_file_eof = 0;
459 		ret = perf_parse_file(fn, data);
460 		fclose(f);
461 		config_file_name = NULL;
462 	}
463 	return ret;
464 }
465 
466 const char *perf_etc_perfconfig(void)
467 {
468 	static const char *system_wide;
469 	if (!system_wide)
470 		system_wide = system_path(ETC_PERFCONFIG);
471 	return system_wide;
472 }
473 
474 static int perf_env_bool(const char *k, int def)
475 {
476 	const char *v = getenv(k);
477 	return v ? perf_config_bool(k, v) : def;
478 }
479 
480 static int perf_config_system(void)
481 {
482 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
483 }
484 
485 static int perf_config_global(void)
486 {
487 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
488 }
489 
490 static struct perf_config_section *find_section(struct list_head *sections,
491 						const char *section_name)
492 {
493 	struct perf_config_section *section;
494 
495 	list_for_each_entry(section, sections, node)
496 		if (!strcmp(section->name, section_name))
497 			return section;
498 
499 	return NULL;
500 }
501 
502 static struct perf_config_item *find_config_item(const char *name,
503 						 struct perf_config_section *section)
504 {
505 	struct perf_config_item *item;
506 
507 	list_for_each_entry(item, &section->items, node)
508 		if (!strcmp(item->name, name))
509 			return item;
510 
511 	return NULL;
512 }
513 
514 static struct perf_config_section *add_section(struct list_head *sections,
515 					       const char *section_name)
516 {
517 	struct perf_config_section *section = zalloc(sizeof(*section));
518 
519 	if (!section)
520 		return NULL;
521 
522 	INIT_LIST_HEAD(&section->items);
523 	section->name = strdup(section_name);
524 	if (!section->name) {
525 		pr_debug("%s: strdup failed\n", __func__);
526 		free(section);
527 		return NULL;
528 	}
529 
530 	list_add_tail(&section->node, sections);
531 	return section;
532 }
533 
534 static struct perf_config_item *add_config_item(struct perf_config_section *section,
535 						const char *name)
536 {
537 	struct perf_config_item *item = zalloc(sizeof(*item));
538 
539 	if (!item)
540 		return NULL;
541 
542 	item->name = strdup(name);
543 	if (!item->name) {
544 		pr_debug("%s: strdup failed\n", __func__);
545 		free(item);
546 		return NULL;
547 	}
548 
549 	list_add_tail(&item->node, &section->items);
550 	return item;
551 }
552 
553 static int set_value(struct perf_config_item *item, const char *value)
554 {
555 	char *val = strdup(value);
556 
557 	if (!val)
558 		return -1;
559 
560 	zfree(&item->value);
561 	item->value = val;
562 	return 0;
563 }
564 
565 static int collect_config(const char *var, const char *value,
566 			  void *perf_config_set)
567 {
568 	int ret = -1;
569 	char *ptr, *key;
570 	char *section_name, *name;
571 	struct perf_config_section *section = NULL;
572 	struct perf_config_item *item = NULL;
573 	struct perf_config_set *set = perf_config_set;
574 	struct list_head *sections;
575 
576 	if (set == NULL)
577 		return -1;
578 
579 	sections = &set->sections;
580 	key = ptr = strdup(var);
581 	if (!key) {
582 		pr_debug("%s: strdup failed\n", __func__);
583 		return -1;
584 	}
585 
586 	section_name = strsep(&ptr, ".");
587 	name = ptr;
588 	if (name == NULL || value == NULL)
589 		goto out_free;
590 
591 	section = find_section(sections, section_name);
592 	if (!section) {
593 		section = add_section(sections, section_name);
594 		if (!section)
595 			goto out_free;
596 	}
597 
598 	item = find_config_item(name, section);
599 	if (!item) {
600 		item = add_config_item(section, name);
601 		if (!item)
602 			goto out_free;
603 	}
604 
605 	/* perf_config_set can contain both user and system config items.
606 	 * So we should know where each value is from.
607 	 * The classification would be needed when a particular config file
608 	 * is overwrited by setting feature i.e. set_config().
609 	 */
610 	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
611 		section->from_system_config = true;
612 		item->from_system_config = true;
613 	} else {
614 		section->from_system_config = false;
615 		item->from_system_config = false;
616 	}
617 
618 	ret = set_value(item, value);
619 	return ret;
620 
621 out_free:
622 	free(key);
623 	return -1;
624 }
625 
626 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
627 			     const char *var, const char *value)
628 {
629 	config_file_name = file_name;
630 	return collect_config(var, value, set);
631 }
632 
633 static int perf_config_set__init(struct perf_config_set *set)
634 {
635 	int ret = -1;
636 	const char *home = NULL;
637 	char *user_config;
638 	struct stat st;
639 
640 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
641 	if (config_exclusive_filename)
642 		return perf_config_from_file(collect_config, config_exclusive_filename, set);
643 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
644 		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
645 			goto out;
646 	}
647 
648 	home = getenv("HOME");
649 
650 	/*
651 	 * Skip reading user config if:
652 	 *   - there is no place to read it from (HOME)
653 	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
654 	 */
655 	if (!home || !*home || !perf_config_global())
656 		return 0;
657 
658 	user_config = strdup(mkpath("%s/.perfconfig", home));
659 	if (user_config == NULL) {
660 		warning("Not enough memory to process %s/.perfconfig, "
661 			"ignoring it.", home);
662 		goto out;
663 	}
664 
665 	if (stat(user_config, &st) < 0) {
666 		if (errno == ENOENT)
667 			ret = 0;
668 		goto out_free;
669 	}
670 
671 	ret = 0;
672 
673 	if (st.st_uid && (st.st_uid != geteuid())) {
674 		warning("File %s not owned by current user or root, "
675 			"ignoring it.", user_config);
676 		goto out_free;
677 	}
678 
679 	if (st.st_size)
680 		ret = perf_config_from_file(collect_config, user_config, set);
681 
682 out_free:
683 	free(user_config);
684 out:
685 	return ret;
686 }
687 
688 struct perf_config_set *perf_config_set__new(void)
689 {
690 	struct perf_config_set *set = zalloc(sizeof(*set));
691 
692 	if (set) {
693 		INIT_LIST_HEAD(&set->sections);
694 		if (perf_config_set__init(set) < 0) {
695 			perf_config_set__delete(set);
696 			set = NULL;
697 		}
698 	}
699 
700 	return set;
701 }
702 
703 int perf_config(config_fn_t fn, void *data)
704 {
705 	int ret = 0;
706 	char key[BUFSIZ];
707 	struct perf_config_section *section;
708 	struct perf_config_item *item;
709 
710 	if (config_set == NULL)
711 		return -1;
712 
713 	perf_config_set__for_each_entry(config_set, section, item) {
714 		char *value = item->value;
715 
716 		if (value) {
717 			scnprintf(key, sizeof(key), "%s.%s",
718 				  section->name, item->name);
719 			ret = fn(key, value, data);
720 			if (ret < 0) {
721 				pr_err("Error: wrong config key-value pair %s=%s\n",
722 				       key, value);
723 				break;
724 			}
725 		}
726 	}
727 
728 	return ret;
729 }
730 
731 void perf_config__init(void)
732 {
733 	if (config_set == NULL)
734 		config_set = perf_config_set__new();
735 }
736 
737 void perf_config__exit(void)
738 {
739 	perf_config_set__delete(config_set);
740 	config_set = NULL;
741 }
742 
743 void perf_config__refresh(void)
744 {
745 	perf_config__exit();
746 	perf_config__init();
747 }
748 
749 static void perf_config_item__delete(struct perf_config_item *item)
750 {
751 	zfree(&item->name);
752 	zfree(&item->value);
753 	free(item);
754 }
755 
756 static void perf_config_section__purge(struct perf_config_section *section)
757 {
758 	struct perf_config_item *item, *tmp;
759 
760 	list_for_each_entry_safe(item, tmp, &section->items, node) {
761 		list_del_init(&item->node);
762 		perf_config_item__delete(item);
763 	}
764 }
765 
766 static void perf_config_section__delete(struct perf_config_section *section)
767 {
768 	perf_config_section__purge(section);
769 	zfree(&section->name);
770 	free(section);
771 }
772 
773 static void perf_config_set__purge(struct perf_config_set *set)
774 {
775 	struct perf_config_section *section, *tmp;
776 
777 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
778 		list_del_init(&section->node);
779 		perf_config_section__delete(section);
780 	}
781 }
782 
783 void perf_config_set__delete(struct perf_config_set *set)
784 {
785 	if (set == NULL)
786 		return;
787 
788 	perf_config_set__purge(set);
789 	free(set);
790 }
791 
792 /*
793  * Call this to report error for your variable that should not
794  * get a boolean value (i.e. "[my] var" means "true").
795  */
796 int config_error_nonbool(const char *var)
797 {
798 	return error("Missing value for '%s'", var);
799 }
800 
801 void set_buildid_dir(const char *dir)
802 {
803 	if (dir)
804 		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
805 
806 	/* default to $HOME/.debug */
807 	if (buildid_dir[0] == '\0') {
808 		char *home = getenv("HOME");
809 
810 		if (home) {
811 			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
812 				 home, DEBUG_CACHE_DIR);
813 		} else {
814 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
815 		}
816 		buildid_dir[MAXPATHLEN-1] = '\0';
817 	}
818 	/* for communicating with external commands */
819 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
820 }
821