xref: /openbmc/linux/tools/perf/util/config.c (revision 37744fee)
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 "cache.h"
15 #include "callchain.h"
16 #include <subcmd/exec-cmd.h>
17 #include "util/event.h"  /* proc_map_timeout */
18 #include "util/hist.h"  /* perf_hist_config */
19 #include "util/llvm-utils.h"   /* perf_llvm_config */
20 #include "build-id.h"
21 #include "debug.h"
22 #include "config.h"
23 #include "debug.h"
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <linux/string.h>
29 #include <linux/zalloc.h>
30 #include <linux/ctype.h>
31 
32 #define MAXNAME (256)
33 
34 #define DEBUG_CACHE_DIR ".debug"
35 
36 
37 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
38 
39 static FILE *config_file;
40 static const char *config_file_name;
41 static int config_linenr;
42 static int config_file_eof;
43 static struct perf_config_set *config_set;
44 
45 const char *config_exclusive_filename;
46 
47 static int get_next_char(void)
48 {
49 	int c;
50 	FILE *f;
51 
52 	c = '\n';
53 	if ((f = config_file) != NULL) {
54 		c = fgetc(f);
55 		if (c == '\r') {
56 			/* DOS like systems */
57 			c = fgetc(f);
58 			if (c != '\n') {
59 				ungetc(c, f);
60 				c = '\r';
61 			}
62 		}
63 		if (c == '\n')
64 			config_linenr++;
65 		if (c == EOF) {
66 			config_file_eof = 1;
67 			c = '\n';
68 		}
69 	}
70 	return c;
71 }
72 
73 static char *parse_value(void)
74 {
75 	static char value[1024];
76 	int quote = 0, comment = 0, space = 0;
77 	size_t len = 0;
78 
79 	for (;;) {
80 		int c = get_next_char();
81 
82 		if (len >= sizeof(value) - 1)
83 			return NULL;
84 		if (c == '\n') {
85 			if (quote)
86 				return NULL;
87 			value[len] = 0;
88 			return value;
89 		}
90 		if (comment)
91 			continue;
92 		if (isspace(c) && !quote) {
93 			space = 1;
94 			continue;
95 		}
96 		if (!quote) {
97 			if (c == ';' || c == '#') {
98 				comment = 1;
99 				continue;
100 			}
101 		}
102 		if (space) {
103 			if (len)
104 				value[len++] = ' ';
105 			space = 0;
106 		}
107 		if (c == '\\') {
108 			c = get_next_char();
109 			switch (c) {
110 			case '\n':
111 				continue;
112 			case 't':
113 				c = '\t';
114 				break;
115 			case 'b':
116 				c = '\b';
117 				break;
118 			case 'n':
119 				c = '\n';
120 				break;
121 			/* Some characters escape as themselves */
122 			case '\\': case '"':
123 				break;
124 			/* Reject unknown escape sequences */
125 			default:
126 				return NULL;
127 			}
128 			value[len++] = c;
129 			continue;
130 		}
131 		if (c == '"') {
132 			quote = 1-quote;
133 			continue;
134 		}
135 		value[len++] = c;
136 	}
137 }
138 
139 static inline int iskeychar(int c)
140 {
141 	return isalnum(c) || c == '-' || c == '_';
142 }
143 
144 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
145 {
146 	int c;
147 	char *value;
148 
149 	/* Get the full name */
150 	for (;;) {
151 		c = get_next_char();
152 		if (config_file_eof)
153 			break;
154 		if (!iskeychar(c))
155 			break;
156 		name[len++] = c;
157 		if (len >= MAXNAME)
158 			return -1;
159 	}
160 	name[len] = 0;
161 	while (c == ' ' || c == '\t')
162 		c = get_next_char();
163 
164 	value = NULL;
165 	if (c != '\n') {
166 		if (c != '=')
167 			return -1;
168 		value = parse_value();
169 		if (!value)
170 			return -1;
171 	}
172 	return fn(name, value, data);
173 }
174 
175 static int get_extended_base_var(char *name, int baselen, int c)
176 {
177 	do {
178 		if (c == '\n')
179 			return -1;
180 		c = get_next_char();
181 	} while (isspace(c));
182 
183 	/* We require the format to be '[base "extension"]' */
184 	if (c != '"')
185 		return -1;
186 	name[baselen++] = '.';
187 
188 	for (;;) {
189 		int ch = get_next_char();
190 
191 		if (ch == '\n')
192 			return -1;
193 		if (ch == '"')
194 			break;
195 		if (ch == '\\') {
196 			ch = get_next_char();
197 			if (ch == '\n')
198 				return -1;
199 		}
200 		name[baselen++] = ch;
201 		if (baselen > MAXNAME / 2)
202 			return -1;
203 	}
204 
205 	/* Final ']' */
206 	if (get_next_char() != ']')
207 		return -1;
208 	return baselen;
209 }
210 
211 static int get_base_var(char *name)
212 {
213 	int baselen = 0;
214 
215 	for (;;) {
216 		int c = get_next_char();
217 		if (config_file_eof)
218 			return -1;
219 		if (c == ']')
220 			return baselen;
221 		if (isspace(c))
222 			return get_extended_base_var(name, baselen, c);
223 		if (!iskeychar(c) && c != '.')
224 			return -1;
225 		if (baselen > MAXNAME / 2)
226 			return -1;
227 		name[baselen++] = tolower(c);
228 	}
229 }
230 
231 static int perf_parse_file(config_fn_t fn, void *data)
232 {
233 	int comment = 0;
234 	int baselen = 0;
235 	static char var[MAXNAME];
236 
237 	/* U+FEFF Byte Order Mark in UTF8 */
238 	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
239 	const unsigned char *bomptr = utf8_bom;
240 
241 	for (;;) {
242 		int line, c = get_next_char();
243 
244 		if (bomptr && *bomptr) {
245 			/* We are at the file beginning; skip UTF8-encoded BOM
246 			 * if present. Sane editors won't put this in on their
247 			 * own, but e.g. Windows Notepad will do it happily. */
248 			if ((unsigned char) c == *bomptr) {
249 				bomptr++;
250 				continue;
251 			} else {
252 				/* Do not tolerate partial BOM. */
253 				if (bomptr != utf8_bom)
254 					break;
255 				/* No BOM at file beginning. Cool. */
256 				bomptr = NULL;
257 			}
258 		}
259 		if (c == '\n') {
260 			if (config_file_eof)
261 				return 0;
262 			comment = 0;
263 			continue;
264 		}
265 		if (comment || isspace(c))
266 			continue;
267 		if (c == '#' || c == ';') {
268 			comment = 1;
269 			continue;
270 		}
271 		if (c == '[') {
272 			baselen = get_base_var(var);
273 			if (baselen <= 0)
274 				break;
275 			var[baselen++] = '.';
276 			var[baselen] = 0;
277 			continue;
278 		}
279 		if (!isalpha(c))
280 			break;
281 		var[baselen] = tolower(c);
282 
283 		/*
284 		 * The get_value function might or might not reach the '\n',
285 		 * so saving the current line number for error reporting.
286 		 */
287 		line = config_linenr;
288 		if (get_value(fn, data, var, baselen+1) < 0) {
289 			config_linenr = line;
290 			break;
291 		}
292 	}
293 	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
294 	return -1;
295 }
296 
297 static int parse_unit_factor(const char *end, unsigned long *val)
298 {
299 	if (!*end)
300 		return 1;
301 	else if (!strcasecmp(end, "k")) {
302 		*val *= 1024;
303 		return 1;
304 	}
305 	else if (!strcasecmp(end, "m")) {
306 		*val *= 1024 * 1024;
307 		return 1;
308 	}
309 	else if (!strcasecmp(end, "g")) {
310 		*val *= 1024 * 1024 * 1024;
311 		return 1;
312 	}
313 	return 0;
314 }
315 
316 static int perf_parse_llong(const char *value, long long *ret)
317 {
318 	if (value && *value) {
319 		char *end;
320 		long long val = strtoll(value, &end, 0);
321 		unsigned long factor = 1;
322 
323 		if (!parse_unit_factor(end, &factor))
324 			return 0;
325 		*ret = val * factor;
326 		return 1;
327 	}
328 	return 0;
329 }
330 
331 static int perf_parse_long(const char *value, long *ret)
332 {
333 	if (value && *value) {
334 		char *end;
335 		long val = strtol(value, &end, 0);
336 		unsigned long factor = 1;
337 		if (!parse_unit_factor(end, &factor))
338 			return 0;
339 		*ret = val * factor;
340 		return 1;
341 	}
342 	return 0;
343 }
344 
345 static void bad_config(const char *name)
346 {
347 	if (config_file_name)
348 		pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
349 	else
350 		pr_warning("bad config value for '%s', ignoring...\n", name);
351 }
352 
353 int perf_config_u64(u64 *dest, const char *name, const char *value)
354 {
355 	long long ret = 0;
356 
357 	if (!perf_parse_llong(value, &ret)) {
358 		bad_config(name);
359 		return -1;
360 	}
361 
362 	*dest = ret;
363 	return 0;
364 }
365 
366 int perf_config_int(int *dest, const char *name, const char *value)
367 {
368 	long ret = 0;
369 	if (!perf_parse_long(value, &ret)) {
370 		bad_config(name);
371 		return -1;
372 	}
373 	*dest = ret;
374 	return 0;
375 }
376 
377 int perf_config_u8(u8 *dest, const char *name, const char *value)
378 {
379 	long ret = 0;
380 
381 	if (!perf_parse_long(value, &ret)) {
382 		bad_config(name);
383 		return -1;
384 	}
385 	*dest = ret;
386 	return 0;
387 }
388 
389 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
390 {
391 	int ret;
392 
393 	*is_bool = 1;
394 	if (!value)
395 		return 1;
396 	if (!*value)
397 		return 0;
398 	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
399 		return 1;
400 	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
401 		return 0;
402 	*is_bool = 0;
403 	return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
404 }
405 
406 int perf_config_bool(const char *name, const char *value)
407 {
408 	int discard;
409 	return !!perf_config_bool_or_int(name, value, &discard);
410 }
411 
412 static const char *perf_config_dirname(const char *name, const char *value)
413 {
414 	if (!name)
415 		return NULL;
416 	return value;
417 }
418 
419 static int perf_buildid_config(const char *var, const char *value)
420 {
421 	/* same dir for all commands */
422 	if (!strcmp(var, "buildid.dir")) {
423 		const char *dir = perf_config_dirname(var, value);
424 
425 		if (!dir) {
426 			pr_err("Invalid buildid directory!\n");
427 			return -1;
428 		}
429 		strncpy(buildid_dir, dir, MAXPATHLEN-1);
430 		buildid_dir[MAXPATHLEN-1] = '\0';
431 	}
432 
433 	return 0;
434 }
435 
436 static int perf_default_core_config(const char *var __maybe_unused,
437 				    const char *value __maybe_unused)
438 {
439 	if (!strcmp(var, "core.proc-map-timeout"))
440 		proc_map_timeout = strtoul(value, NULL, 10);
441 
442 	/* Add other config variables here. */
443 	return 0;
444 }
445 
446 static int perf_ui_config(const char *var, const char *value)
447 {
448 	/* Add other config variables here. */
449 	if (!strcmp(var, "ui.show-headers"))
450 		symbol_conf.show_hist_headers = perf_config_bool(var, value);
451 
452 	return 0;
453 }
454 
455 int perf_default_config(const char *var, const char *value,
456 			void *dummy __maybe_unused)
457 {
458 	if (strstarts(var, "core."))
459 		return perf_default_core_config(var, value);
460 
461 	if (strstarts(var, "hist."))
462 		return perf_hist_config(var, value);
463 
464 	if (strstarts(var, "ui."))
465 		return perf_ui_config(var, value);
466 
467 	if (strstarts(var, "call-graph."))
468 		return perf_callchain_config(var, value);
469 
470 	if (strstarts(var, "llvm."))
471 		return perf_llvm_config(var, value);
472 
473 	if (strstarts(var, "buildid."))
474 		return perf_buildid_config(var, value);
475 
476 	/* Add other config variables here. */
477 	return 0;
478 }
479 
480 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
481 {
482 	int ret;
483 	FILE *f = fopen(filename, "r");
484 
485 	ret = -1;
486 	if (f) {
487 		config_file = f;
488 		config_file_name = filename;
489 		config_linenr = 1;
490 		config_file_eof = 0;
491 		ret = perf_parse_file(fn, data);
492 		fclose(f);
493 		config_file_name = NULL;
494 	}
495 	return ret;
496 }
497 
498 const char *perf_etc_perfconfig(void)
499 {
500 	static const char *system_wide;
501 	if (!system_wide)
502 		system_wide = system_path(ETC_PERFCONFIG);
503 	return system_wide;
504 }
505 
506 static int perf_env_bool(const char *k, int def)
507 {
508 	const char *v = getenv(k);
509 	return v ? perf_config_bool(k, v) : def;
510 }
511 
512 static int perf_config_system(void)
513 {
514 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
515 }
516 
517 static int perf_config_global(void)
518 {
519 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
520 }
521 
522 static struct perf_config_section *find_section(struct list_head *sections,
523 						const char *section_name)
524 {
525 	struct perf_config_section *section;
526 
527 	list_for_each_entry(section, sections, node)
528 		if (!strcmp(section->name, section_name))
529 			return section;
530 
531 	return NULL;
532 }
533 
534 static struct perf_config_item *find_config_item(const char *name,
535 						 struct perf_config_section *section)
536 {
537 	struct perf_config_item *item;
538 
539 	list_for_each_entry(item, &section->items, node)
540 		if (!strcmp(item->name, name))
541 			return item;
542 
543 	return NULL;
544 }
545 
546 static struct perf_config_section *add_section(struct list_head *sections,
547 					       const char *section_name)
548 {
549 	struct perf_config_section *section = zalloc(sizeof(*section));
550 
551 	if (!section)
552 		return NULL;
553 
554 	INIT_LIST_HEAD(&section->items);
555 	section->name = strdup(section_name);
556 	if (!section->name) {
557 		pr_debug("%s: strdup failed\n", __func__);
558 		free(section);
559 		return NULL;
560 	}
561 
562 	list_add_tail(&section->node, sections);
563 	return section;
564 }
565 
566 static struct perf_config_item *add_config_item(struct perf_config_section *section,
567 						const char *name)
568 {
569 	struct perf_config_item *item = zalloc(sizeof(*item));
570 
571 	if (!item)
572 		return NULL;
573 
574 	item->name = strdup(name);
575 	if (!item->name) {
576 		pr_debug("%s: strdup failed\n", __func__);
577 		free(item);
578 		return NULL;
579 	}
580 
581 	list_add_tail(&item->node, &section->items);
582 	return item;
583 }
584 
585 static int set_value(struct perf_config_item *item, const char *value)
586 {
587 	char *val = strdup(value);
588 
589 	if (!val)
590 		return -1;
591 
592 	zfree(&item->value);
593 	item->value = val;
594 	return 0;
595 }
596 
597 static int collect_config(const char *var, const char *value,
598 			  void *perf_config_set)
599 {
600 	int ret = -1;
601 	char *ptr, *key;
602 	char *section_name, *name;
603 	struct perf_config_section *section = NULL;
604 	struct perf_config_item *item = NULL;
605 	struct perf_config_set *set = perf_config_set;
606 	struct list_head *sections;
607 
608 	if (set == NULL)
609 		return -1;
610 
611 	sections = &set->sections;
612 	key = ptr = strdup(var);
613 	if (!key) {
614 		pr_debug("%s: strdup failed\n", __func__);
615 		return -1;
616 	}
617 
618 	section_name = strsep(&ptr, ".");
619 	name = ptr;
620 	if (name == NULL || value == NULL)
621 		goto out_free;
622 
623 	section = find_section(sections, section_name);
624 	if (!section) {
625 		section = add_section(sections, section_name);
626 		if (!section)
627 			goto out_free;
628 	}
629 
630 	item = find_config_item(name, section);
631 	if (!item) {
632 		item = add_config_item(section, name);
633 		if (!item)
634 			goto out_free;
635 	}
636 
637 	/* perf_config_set can contain both user and system config items.
638 	 * So we should know where each value is from.
639 	 * The classification would be needed when a particular config file
640 	 * is overwrited by setting feature i.e. set_config().
641 	 */
642 	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
643 		section->from_system_config = true;
644 		item->from_system_config = true;
645 	} else {
646 		section->from_system_config = false;
647 		item->from_system_config = false;
648 	}
649 
650 	ret = set_value(item, value);
651 
652 out_free:
653 	free(key);
654 	return ret;
655 }
656 
657 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
658 			     const char *var, const char *value)
659 {
660 	config_file_name = file_name;
661 	return collect_config(var, value, set);
662 }
663 
664 static int perf_config_set__init(struct perf_config_set *set)
665 {
666 	int ret = -1;
667 	const char *home = NULL;
668 	char *user_config;
669 	struct stat st;
670 
671 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
672 	if (config_exclusive_filename)
673 		return perf_config_from_file(collect_config, config_exclusive_filename, set);
674 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
675 		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
676 			goto out;
677 	}
678 
679 	home = getenv("HOME");
680 
681 	/*
682 	 * Skip reading user config if:
683 	 *   - there is no place to read it from (HOME)
684 	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
685 	 */
686 	if (!home || !*home || !perf_config_global())
687 		return 0;
688 
689 	user_config = strdup(mkpath("%s/.perfconfig", home));
690 	if (user_config == NULL) {
691 		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
692 		goto out;
693 	}
694 
695 	if (stat(user_config, &st) < 0) {
696 		if (errno == ENOENT)
697 			ret = 0;
698 		goto out_free;
699 	}
700 
701 	ret = 0;
702 
703 	if (st.st_uid && (st.st_uid != geteuid())) {
704 		pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
705 		goto out_free;
706 	}
707 
708 	if (st.st_size)
709 		ret = perf_config_from_file(collect_config, user_config, set);
710 
711 out_free:
712 	free(user_config);
713 out:
714 	return ret;
715 }
716 
717 struct perf_config_set *perf_config_set__new(void)
718 {
719 	struct perf_config_set *set = zalloc(sizeof(*set));
720 
721 	if (set) {
722 		INIT_LIST_HEAD(&set->sections);
723 		perf_config_set__init(set);
724 	}
725 
726 	return set;
727 }
728 
729 static int perf_config__init(void)
730 {
731 	if (config_set == NULL)
732 		config_set = perf_config_set__new();
733 
734 	return config_set == NULL;
735 }
736 
737 int perf_config(config_fn_t fn, void *data)
738 {
739 	int ret = 0;
740 	char key[BUFSIZ];
741 	struct perf_config_section *section;
742 	struct perf_config_item *item;
743 
744 	if (config_set == NULL && perf_config__init())
745 		return -1;
746 
747 	perf_config_set__for_each_entry(config_set, section, item) {
748 		char *value = item->value;
749 
750 		if (value) {
751 			scnprintf(key, sizeof(key), "%s.%s",
752 				  section->name, item->name);
753 			ret = fn(key, value, data);
754 			if (ret < 0) {
755 				pr_err("Error: wrong config key-value pair %s=%s\n",
756 				       key, value);
757 				/*
758 				 * Can't be just a 'break', as perf_config_set__for_each_entry()
759 				 * expands to two nested for() loops.
760 				 */
761 				goto out;
762 			}
763 		}
764 	}
765 out:
766 	return ret;
767 }
768 
769 void perf_config__exit(void)
770 {
771 	perf_config_set__delete(config_set);
772 	config_set = NULL;
773 }
774 
775 void perf_config__refresh(void)
776 {
777 	perf_config__exit();
778 	perf_config__init();
779 }
780 
781 static void perf_config_item__delete(struct perf_config_item *item)
782 {
783 	zfree(&item->name);
784 	zfree(&item->value);
785 	free(item);
786 }
787 
788 static void perf_config_section__purge(struct perf_config_section *section)
789 {
790 	struct perf_config_item *item, *tmp;
791 
792 	list_for_each_entry_safe(item, tmp, &section->items, node) {
793 		list_del_init(&item->node);
794 		perf_config_item__delete(item);
795 	}
796 }
797 
798 static void perf_config_section__delete(struct perf_config_section *section)
799 {
800 	perf_config_section__purge(section);
801 	zfree(&section->name);
802 	free(section);
803 }
804 
805 static void perf_config_set__purge(struct perf_config_set *set)
806 {
807 	struct perf_config_section *section, *tmp;
808 
809 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
810 		list_del_init(&section->node);
811 		perf_config_section__delete(section);
812 	}
813 }
814 
815 void perf_config_set__delete(struct perf_config_set *set)
816 {
817 	if (set == NULL)
818 		return;
819 
820 	perf_config_set__purge(set);
821 	free(set);
822 }
823 
824 /*
825  * Call this to report error for your variable that should not
826  * get a boolean value (i.e. "[my] var" means "true").
827  */
828 int config_error_nonbool(const char *var)
829 {
830 	pr_err("Missing value for '%s'", var);
831 	return -1;
832 }
833 
834 void set_buildid_dir(const char *dir)
835 {
836 	if (dir)
837 		scnprintf(buildid_dir, MAXPATHLEN, "%s", dir);
838 
839 	/* default to $HOME/.debug */
840 	if (buildid_dir[0] == '\0') {
841 		char *home = getenv("HOME");
842 
843 		if (home) {
844 			snprintf(buildid_dir, MAXPATHLEN, "%s/%s",
845 				 home, DEBUG_CACHE_DIR);
846 		} else {
847 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
848 		}
849 		buildid_dir[MAXPATHLEN-1] = '\0';
850 	}
851 	/* for communicating with external commands */
852 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
853 }
854