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
 37char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
 38
 39static FILE *config_file;
 40static const char *config_file_name;
 41static int config_linenr;
 42static int config_file_eof;
 43static struct perf_config_set *config_set;
 44
 45const char *config_exclusive_filename;
 46
 47static 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
 73static 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
139static inline int iskeychar(int c)
140{
141	return isalnum(c) || c == '-' || c == '_';
142}
143
144static 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
175static 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
211static 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
231static 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
297static 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
316static 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
331static 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
345static 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
353int 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
366int 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
 
 
 
 
 
 
 
 
 
 
 
 
377static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
378{
379	int ret;
380
381	*is_bool = 1;
382	if (!value)
383		return 1;
384	if (!*value)
385		return 0;
386	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
387		return 1;
388	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
389		return 0;
390	*is_bool = 0;
391	return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
392}
393
394int perf_config_bool(const char *name, const char *value)
395{
396	int discard;
397	return !!perf_config_bool_or_int(name, value, &discard);
398}
399
400static const char *perf_config_dirname(const char *name, const char *value)
401{
402	if (!name)
403		return NULL;
404	return value;
405}
406
407static int perf_buildid_config(const char *var, const char *value)
408{
409	/* same dir for all commands */
410	if (!strcmp(var, "buildid.dir")) {
411		const char *dir = perf_config_dirname(var, value);
412
413		if (!dir) {
414			pr_err("Invalid buildid directory!\n");
415			return -1;
416		}
417		strncpy(buildid_dir, dir, MAXPATHLEN-1);
418		buildid_dir[MAXPATHLEN-1] = '\0';
419	}
420
421	return 0;
422}
423
424static int perf_default_core_config(const char *var __maybe_unused,
425				    const char *value __maybe_unused)
426{
427	if (!strcmp(var, "core.proc-map-timeout"))
428		proc_map_timeout = strtoul(value, NULL, 10);
429
430	/* Add other config variables here. */
431	return 0;
432}
433
434static int perf_ui_config(const char *var, const char *value)
435{
436	/* Add other config variables here. */
437	if (!strcmp(var, "ui.show-headers"))
438		symbol_conf.show_hist_headers = perf_config_bool(var, value);
439
440	return 0;
441}
442
 
 
 
 
 
 
 
 
 
443int perf_default_config(const char *var, const char *value,
444			void *dummy __maybe_unused)
445{
446	if (strstarts(var, "core."))
447		return perf_default_core_config(var, value);
448
449	if (strstarts(var, "hist."))
450		return perf_hist_config(var, value);
451
452	if (strstarts(var, "ui."))
453		return perf_ui_config(var, value);
454
455	if (strstarts(var, "call-graph."))
456		return perf_callchain_config(var, value);
457
458	if (strstarts(var, "llvm."))
459		return perf_llvm_config(var, value);
460
461	if (strstarts(var, "buildid."))
462		return perf_buildid_config(var, value);
 
 
 
463
464	/* Add other config variables here. */
465	return 0;
466}
467
468static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
469{
470	int ret;
471	FILE *f = fopen(filename, "r");
472
473	ret = -1;
474	if (f) {
475		config_file = f;
476		config_file_name = filename;
477		config_linenr = 1;
478		config_file_eof = 0;
479		ret = perf_parse_file(fn, data);
480		fclose(f);
481		config_file_name = NULL;
482	}
483	return ret;
484}
485
486const char *perf_etc_perfconfig(void)
487{
488	static const char *system_wide;
489	if (!system_wide)
490		system_wide = system_path(ETC_PERFCONFIG);
491	return system_wide;
492}
493
494static int perf_env_bool(const char *k, int def)
495{
496	const char *v = getenv(k);
497	return v ? perf_config_bool(k, v) : def;
498}
499
500static int perf_config_system(void)
501{
502	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
503}
504
505static int perf_config_global(void)
506{
507	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
508}
509
510static struct perf_config_section *find_section(struct list_head *sections,
511						const char *section_name)
512{
513	struct perf_config_section *section;
514
515	list_for_each_entry(section, sections, node)
516		if (!strcmp(section->name, section_name))
517			return section;
518
519	return NULL;
520}
521
522static struct perf_config_item *find_config_item(const char *name,
523						 struct perf_config_section *section)
524{
525	struct perf_config_item *item;
526
527	list_for_each_entry(item, &section->items, node)
528		if (!strcmp(item->name, name))
529			return item;
530
531	return NULL;
532}
533
534static struct perf_config_section *add_section(struct list_head *sections,
535					       const char *section_name)
536{
537	struct perf_config_section *section = zalloc(sizeof(*section));
538
539	if (!section)
540		return NULL;
541
542	INIT_LIST_HEAD(&section->items);
543	section->name = strdup(section_name);
544	if (!section->name) {
545		pr_debug("%s: strdup failed\n", __func__);
546		free(section);
547		return NULL;
548	}
549
550	list_add_tail(&section->node, sections);
551	return section;
552}
553
554static struct perf_config_item *add_config_item(struct perf_config_section *section,
555						const char *name)
556{
557	struct perf_config_item *item = zalloc(sizeof(*item));
558
559	if (!item)
560		return NULL;
561
562	item->name = strdup(name);
563	if (!item->name) {
564		pr_debug("%s: strdup failed\n", __func__);
565		free(item);
566		return NULL;
567	}
568
569	list_add_tail(&item->node, &section->items);
570	return item;
571}
572
573static int set_value(struct perf_config_item *item, const char *value)
574{
575	char *val = strdup(value);
576
577	if (!val)
578		return -1;
579
580	zfree(&item->value);
581	item->value = val;
582	return 0;
583}
584
585static int collect_config(const char *var, const char *value,
586			  void *perf_config_set)
587{
588	int ret = -1;
589	char *ptr, *key;
590	char *section_name, *name;
591	struct perf_config_section *section = NULL;
592	struct perf_config_item *item = NULL;
593	struct perf_config_set *set = perf_config_set;
594	struct list_head *sections;
595
596	if (set == NULL)
597		return -1;
598
599	sections = &set->sections;
600	key = ptr = strdup(var);
601	if (!key) {
602		pr_debug("%s: strdup failed\n", __func__);
603		return -1;
604	}
605
606	section_name = strsep(&ptr, ".");
607	name = ptr;
608	if (name == NULL || value == NULL)
609		goto out_free;
610
611	section = find_section(sections, section_name);
612	if (!section) {
613		section = add_section(sections, section_name);
614		if (!section)
615			goto out_free;
616	}
617
618	item = find_config_item(name, section);
619	if (!item) {
620		item = add_config_item(section, name);
621		if (!item)
622			goto out_free;
623	}
624
625	/* perf_config_set can contain both user and system config items.
626	 * So we should know where each value is from.
627	 * The classification would be needed when a particular config file
628	 * is overwrited by setting feature i.e. set_config().
629	 */
630	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
631		section->from_system_config = true;
632		item->from_system_config = true;
633	} else {
634		section->from_system_config = false;
635		item->from_system_config = false;
636	}
637
638	ret = set_value(item, value);
639
640out_free:
641	free(key);
642	return ret;
643}
644
645int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
646			     const char *var, const char *value)
647{
648	config_file_name = file_name;
649	return collect_config(var, value, set);
650}
651
652static int perf_config_set__init(struct perf_config_set *set)
653{
654	int ret = -1;
655	const char *home = NULL;
656	char *user_config;
657	struct stat st;
658
659	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
660	if (config_exclusive_filename)
661		return perf_config_from_file(collect_config, config_exclusive_filename, set);
662	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
663		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
664			goto out;
665	}
666
667	home = getenv("HOME");
668
669	/*
670	 * Skip reading user config if:
671	 *   - there is no place to read it from (HOME)
672	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
673	 */
674	if (!home || !*home || !perf_config_global())
675		return 0;
676
677	user_config = strdup(mkpath("%s/.perfconfig", home));
678	if (user_config == NULL) {
679		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
680		goto out;
681	}
682
683	if (stat(user_config, &st) < 0) {
684		if (errno == ENOENT)
685			ret = 0;
686		goto out_free;
687	}
688
689	ret = 0;
690
691	if (st.st_uid && (st.st_uid != geteuid())) {
692		pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
693		goto out_free;
694	}
695
696	if (st.st_size)
697		ret = perf_config_from_file(collect_config, user_config, set);
698
699out_free:
700	free(user_config);
701out:
702	return ret;
703}
704
705struct perf_config_set *perf_config_set__new(void)
706{
707	struct perf_config_set *set = zalloc(sizeof(*set));
708
709	if (set) {
710		INIT_LIST_HEAD(&set->sections);
711		perf_config_set__init(set);
712	}
713
714	return set;
715}
716
717static int perf_config__init(void)
718{
719	if (config_set == NULL)
720		config_set = perf_config_set__new();
721
722	return config_set == NULL;
723}
724
725int perf_config(config_fn_t fn, void *data)
726{
727	int ret = 0;
728	char key[BUFSIZ];
729	struct perf_config_section *section;
730	struct perf_config_item *item;
731
732	if (config_set == NULL && perf_config__init())
733		return -1;
734
735	perf_config_set__for_each_entry(config_set, section, item) {
736		char *value = item->value;
737
738		if (value) {
739			scnprintf(key, sizeof(key), "%s.%s",
740				  section->name, item->name);
741			ret = fn(key, value, data);
742			if (ret < 0) {
743				pr_err("Error: wrong config key-value pair %s=%s\n",
744				       key, value);
745				/*
746				 * Can't be just a 'break', as perf_config_set__for_each_entry()
747				 * expands to two nested for() loops.
748				 */
749				goto out;
750			}
751		}
752	}
753out:
754	return ret;
755}
756
757void perf_config__exit(void)
758{
759	perf_config_set__delete(config_set);
760	config_set = NULL;
761}
762
763void perf_config__refresh(void)
764{
765	perf_config__exit();
766	perf_config__init();
767}
768
769static void perf_config_item__delete(struct perf_config_item *item)
770{
771	zfree(&item->name);
772	zfree(&item->value);
773	free(item);
774}
775
776static void perf_config_section__purge(struct perf_config_section *section)
777{
778	struct perf_config_item *item, *tmp;
779
780	list_for_each_entry_safe(item, tmp, &section->items, node) {
781		list_del_init(&item->node);
782		perf_config_item__delete(item);
783	}
784}
785
786static void perf_config_section__delete(struct perf_config_section *section)
787{
788	perf_config_section__purge(section);
789	zfree(&section->name);
790	free(section);
791}
792
793static void perf_config_set__purge(struct perf_config_set *set)
794{
795	struct perf_config_section *section, *tmp;
796
797	list_for_each_entry_safe(section, tmp, &set->sections, node) {
798		list_del_init(&section->node);
799		perf_config_section__delete(section);
800	}
801}
802
803void perf_config_set__delete(struct perf_config_set *set)
804{
805	if (set == NULL)
806		return;
807
808	perf_config_set__purge(set);
809	free(set);
810}
811
812/*
813 * Call this to report error for your variable that should not
814 * get a boolean value (i.e. "[my] var" means "true").
815 */
816int config_error_nonbool(const char *var)
817{
818	pr_err("Missing value for '%s'", var);
819	return -1;
820}
821
822void set_buildid_dir(const char *dir)
823{
824	if (dir)
825		scnprintf(buildid_dir, MAXPATHLEN, "%s", dir);
826
827	/* default to $HOME/.debug */
828	if (buildid_dir[0] == '\0') {
829		char *home = getenv("HOME");
830
831		if (home) {
832			snprintf(buildid_dir, MAXPATHLEN, "%s/%s",
833				 home, DEBUG_CACHE_DIR);
834		} else {
835			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
836		}
837		buildid_dir[MAXPATHLEN-1] = '\0';
838	}
839	/* for communicating with external commands */
840	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
841}