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/stat.h" /* perf_stat__set_big_num */
20 #include "util/evsel.h" /* evsel__hw_names, evsel__use_bpf_counters */
21 #include "util/srcline.h" /* addr2line_timeout_ms */
22 #include "build-id.h"
23 #include "debug.h"
24 #include "config.h"
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <stdlib.h>
28 #include <unistd.h>
29 #include <linux/string.h>
30 #include <linux/zalloc.h>
31 #include <linux/ctype.h>
32
33 #define MAXNAME (256)
34
35 #define DEBUG_CACHE_DIR ".debug"
36
37
38 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
39
40 static FILE *config_file;
41 static const char *config_file_name;
42 static int config_linenr;
43 static int config_file_eof;
44 static struct perf_config_set *config_set;
45
46 const char *config_exclusive_filename;
47
48 static int get_next_char(void)
49 {
50 int c;
51 FILE *f;
52
53 c = '\n';
54 if ((f = config_file) != NULL) {
55 c = fgetc(f);
56 if (c == '\r') {
57 /* DOS like systems */
58 c = fgetc(f);
59 if (c != '\n') {
60 ungetc(c, f);
61 c = '\r';
62 }
63 }
64 if (c == '\n')
65 config_linenr++;
66 if (c == EOF) {
67 config_file_eof = 1;
68 c = '\n';
69 }
70 }
71 return c;
72 }
73
74 static char *parse_value(void)
75 {
76 static char value[1024];
77 int quote = 0, comment = 0, space = 0;
78 size_t len = 0;
79
80 for (;;) {
81 int c = get_next_char();
82
83 if (len >= sizeof(value) - 1)
84 return NULL;
85 if (c == '\n') {
86 if (quote)
87 return NULL;
88 value[len] = 0;
89 return value;
90 }
91 if (comment)
92 continue;
93 if (isspace(c) && !quote) {
94 space = 1;
95 continue;
96 }
97 if (!quote) {
98 if (c == ';' || c == '#') {
99 comment = 1;
100 continue;
101 }
102 }
103 if (space) {
104 if (len)
105 value[len++] = ' ';
106 space = 0;
107 }
108 if (c == '\\') {
109 c = get_next_char();
110 switch (c) {
111 case '\n':
112 continue;
113 case 't':
114 c = '\t';
115 break;
116 case 'b':
117 c = '\b';
118 break;
119 case 'n':
120 c = '\n';
121 break;
122 /* Some characters escape as themselves */
123 case '\\': case '"':
124 break;
125 /* Reject unknown escape sequences */
126 default:
127 return NULL;
128 }
129 value[len++] = c;
130 continue;
131 }
132 if (c == '"') {
133 quote = 1-quote;
134 continue;
135 }
136 value[len++] = c;
137 }
138 }
139
140 static inline int iskeychar(int c)
141 {
142 return isalnum(c) || c == '-' || c == '_';
143 }
144
145 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
146 {
147 int c;
148 char *value;
149
150 /* Get the full name */
151 for (;;) {
152 c = get_next_char();
153 if (config_file_eof)
154 break;
155 if (!iskeychar(c))
156 break;
157 name[len++] = c;
158 if (len >= MAXNAME)
159 return -1;
160 }
161 name[len] = 0;
162 while (c == ' ' || c == '\t')
163 c = get_next_char();
164
165 value = NULL;
166 if (c != '\n') {
167 if (c != '=')
168 return -1;
169 value = parse_value();
170 if (!value)
171 return -1;
172 }
173 return fn(name, value, data);
174 }
175
176 static int get_extended_base_var(char *name, int baselen, int c)
177 {
178 do {
179 if (c == '\n')
180 return -1;
181 c = get_next_char();
182 } while (isspace(c));
183
184 /* We require the format to be '[base "extension"]' */
185 if (c != '"')
186 return -1;
187 name[baselen++] = '.';
188
189 for (;;) {
190 int ch = get_next_char();
191
192 if (ch == '\n')
193 return -1;
194 if (ch == '"')
195 break;
196 if (ch == '\\') {
197 ch = get_next_char();
198 if (ch == '\n')
199 return -1;
200 }
201 name[baselen++] = ch;
202 if (baselen > MAXNAME / 2)
203 return -1;
204 }
205
206 /* Final ']' */
207 if (get_next_char() != ']')
208 return -1;
209 return baselen;
210 }
211
212 static int get_base_var(char *name)
213 {
214 int baselen = 0;
215
216 for (;;) {
217 int c = get_next_char();
218 if (config_file_eof)
219 return -1;
220 if (c == ']')
221 return baselen;
222 if (isspace(c))
223 return get_extended_base_var(name, baselen, c);
224 if (!iskeychar(c) && c != '.')
225 return -1;
226 if (baselen > MAXNAME / 2)
227 return -1;
228 name[baselen++] = tolower(c);
229 }
230 }
231
232 static int perf_parse_file(config_fn_t fn, void *data)
233 {
234 int comment = 0;
235 int baselen = 0;
236 static char var[MAXNAME];
237
238 /* U+FEFF Byte Order Mark in UTF8 */
239 static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
240 const unsigned char *bomptr = utf8_bom;
241
242 for (;;) {
243 int line, c = get_next_char();
244
245 if (bomptr && *bomptr) {
246 /* We are at the file beginning; skip UTF8-encoded BOM
247 * if present. Sane editors won't put this in on their
248 * own, but e.g. Windows Notepad will do it happily. */
249 if ((unsigned char) c == *bomptr) {
250 bomptr++;
251 continue;
252 } else {
253 /* Do not tolerate partial BOM. */
254 if (bomptr != utf8_bom)
255 break;
256 /* No BOM at file beginning. Cool. */
257 bomptr = NULL;
258 }
259 }
260 if (c == '\n') {
261 if (config_file_eof)
262 return 0;
263 comment = 0;
264 continue;
265 }
266 if (comment || isspace(c))
267 continue;
268 if (c == '#' || c == ';') {
269 comment = 1;
270 continue;
271 }
272 if (c == '[') {
273 baselen = get_base_var(var);
274 if (baselen <= 0)
275 break;
276 var[baselen++] = '.';
277 var[baselen] = 0;
278 continue;
279 }
280 if (!isalpha(c))
281 break;
282 var[baselen] = tolower(c);
283
284 /*
285 * The get_value function might or might not reach the '\n',
286 * so saving the current line number for error reporting.
287 */
288 line = config_linenr;
289 if (get_value(fn, data, var, baselen+1) < 0) {
290 config_linenr = line;
291 break;
292 }
293 }
294 pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
295 return -1;
296 }
297
298 static int parse_unit_factor(const char *end, unsigned long *val)
299 {
300 if (!*end)
301 return 1;
302 else if (!strcasecmp(end, "k")) {
303 *val *= 1024;
304 return 1;
305 }
306 else if (!strcasecmp(end, "m")) {
307 *val *= 1024 * 1024;
308 return 1;
309 }
310 else if (!strcasecmp(end, "g")) {
311 *val *= 1024 * 1024 * 1024;
312 return 1;
313 }
314 return 0;
315 }
316
317 static int perf_parse_llong(const char *value, long long *ret)
318 {
319 if (value && *value) {
320 char *end;
321 long long val = strtoll(value, &end, 0);
322 unsigned long factor = 1;
323
324 if (!parse_unit_factor(end, &factor))
325 return 0;
326 *ret = val * factor;
327 return 1;
328 }
329 return 0;
330 }
331
332 static int perf_parse_long(const char *value, long *ret)
333 {
334 if (value && *value) {
335 char *end;
336 long val = strtol(value, &end, 0);
337 unsigned long factor = 1;
338 if (!parse_unit_factor(end, &factor))
339 return 0;
340 *ret = val * factor;
341 return 1;
342 }
343 return 0;
344 }
345
346 static void bad_config(const char *name)
347 {
348 if (config_file_name)
349 pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
350 else
351 pr_warning("bad config value for '%s', ignoring...\n", name);
352 }
353
354 int perf_config_u64(u64 *dest, const char *name, const char *value)
355 {
356 long long ret = 0;
357
358 if (!perf_parse_llong(value, &ret)) {
359 bad_config(name);
360 return -1;
361 }
362
363 *dest = ret;
364 return 0;
365 }
366
367 int perf_config_int(int *dest, const char *name, const char *value)
368 {
369 long ret = 0;
370 if (!perf_parse_long(value, &ret)) {
371 bad_config(name);
372 return -1;
373 }
374 *dest = ret;
375 return 0;
376 }
377
378 int perf_config_u8(u8 *dest, const char *name, const char *value)
379 {
380 long ret = 0;
381
382 if (!perf_parse_long(value, &ret)) {
383 bad_config(name);
384 return -1;
385 }
386 *dest = ret;
387 return 0;
388 }
389
390 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
391 {
392 int ret;
393
394 *is_bool = 1;
395 if (!value)
396 return 1;
397 if (!*value)
398 return 0;
399 if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
400 return 1;
401 if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
402 return 0;
403 *is_bool = 0;
404 return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
405 }
406
407 int perf_config_bool(const char *name, const char *value)
408 {
409 int discard;
410 return !!perf_config_bool_or_int(name, value, &discard);
411 }
412
413 static const char *perf_config_dirname(const char *name, const char *value)
414 {
415 if (!name)
416 return NULL;
417 return value;
418 }
419
420 static int perf_buildid_config(const char *var, const char *value)
421 {
422 /* same dir for all commands */
423 if (!strcmp(var, "buildid.dir")) {
424 const char *dir = perf_config_dirname(var, value);
425
426 if (!dir) {
427 pr_err("Invalid buildid directory!\n");
428 return -1;
429 }
430 strncpy(buildid_dir, dir, MAXPATHLEN-1);
431 buildid_dir[MAXPATHLEN-1] = '\0';
432 }
433
434 return 0;
435 }
436
437 static int perf_default_core_config(const char *var, const char *value)
438 {
439 if (!strcmp(var, "core.proc-map-timeout"))
440 proc_map_timeout = strtoul(value, NULL, 10);
441
442 if (!strcmp(var, "core.addr2line-timeout"))
443 addr2line_timeout_ms = strtoul(value, NULL, 10);
444
445 /* Add other config variables here. */
446 return 0;
447 }
448
449 static int perf_ui_config(const char *var, const char *value)
450 {
451 /* Add other config variables here. */
452 if (!strcmp(var, "ui.show-headers"))
453 symbol_conf.show_hist_headers = perf_config_bool(var, value);
454
455 return 0;
456 }
457
458 static int perf_stat_config(const char *var, const char *value)
459 {
460 if (!strcmp(var, "stat.big-num"))
461 perf_stat__set_big_num(perf_config_bool(var, value));
462
463 if (!strcmp(var, "stat.no-csv-summary"))
464 perf_stat__set_no_csv_summary(perf_config_bool(var, value));
465
466 if (!strcmp(var, "stat.bpf-counter-events"))
467 evsel__bpf_counter_events = strdup(value);
468
469 /* Add other config variables here. */
470 return 0;
471 }
472
473 int perf_default_config(const char *var, const char *value,
474 void *dummy __maybe_unused)
475 {
476 if (strstarts(var, "core."))
477 return perf_default_core_config(var, value);
478
479 if (strstarts(var, "hist."))
480 return perf_hist_config(var, value);
481
482 if (strstarts(var, "ui."))
483 return perf_ui_config(var, value);
484
485 if (strstarts(var, "call-graph."))
486 return perf_callchain_config(var, value);
487
488 if (strstarts(var, "buildid."))
489 return perf_buildid_config(var, value);
490
491 if (strstarts(var, "stat."))
492 return perf_stat_config(var, value);
493
494 /* Add other config variables here. */
495 return 0;
496 }
497
498 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
499 {
500 int ret;
501 FILE *f = fopen(filename, "r");
502
503 ret = -1;
504 if (f) {
505 config_file = f;
506 config_file_name = filename;
507 config_linenr = 1;
508 config_file_eof = 0;
509 ret = perf_parse_file(fn, data);
510 fclose(f);
511 config_file_name = NULL;
512 }
513 return ret;
514 }
515
516 const char *perf_etc_perfconfig(void)
517 {
518 static const char *system_wide;
519 if (!system_wide)
520 system_wide = system_path(ETC_PERFCONFIG);
521 return system_wide;
522 }
523
524 static int perf_env_bool(const char *k, int def)
525 {
526 const char *v = getenv(k);
527 return v ? perf_config_bool(k, v) : def;
528 }
529
530 int perf_config_system(void)
531 {
532 return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
533 }
534
535 int perf_config_global(void)
536 {
537 return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
538 }
539
540 static char *home_perfconfig(void)
541 {
542 const char *home = NULL;
543 char *config;
544 struct stat st;
545 char path[PATH_MAX];
546
547 home = getenv("HOME");
548
549 /*
550 * Skip reading user config if:
551 * - there is no place to read it from (HOME)
552 * - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
553 */
554 if (!home || !*home || !perf_config_global())
555 return NULL;
556
557 config = strdup(mkpath(path, sizeof(path), "%s/.perfconfig", home));
558 if (config == NULL) {
559 pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.\n", home);
560 return NULL;
561 }
562
563 if (stat(config, &st) < 0)
564 goto out_free;
565
566 if (st.st_uid && (st.st_uid != geteuid())) {
567 pr_warning("File %s not owned by current user or root, ignoring it.\n", config);
568 goto out_free;
569 }
570
571 if (st.st_size)
572 return config;
573
574 out_free:
575 free(config);
576 return NULL;
577 }
578
579 const char *perf_home_perfconfig(void)
580 {
581 static const char *config;
582 static bool failed;
583
584 if (failed || config)
585 return config;
586
587 config = home_perfconfig();
588 if (!config)
589 failed = true;
590
591 return config;
592 }
593
594 static struct perf_config_section *find_section(struct list_head *sections,
595 const char *section_name)
596 {
597 struct perf_config_section *section;
598
599 list_for_each_entry(section, sections, node)
600 if (!strcmp(section->name, section_name))
601 return section;
602
603 return NULL;
604 }
605
606 static struct perf_config_item *find_config_item(const char *name,
607 struct perf_config_section *section)
608 {
609 struct perf_config_item *item;
610
611 list_for_each_entry(item, §ion->items, node)
612 if (!strcmp(item->name, name))
613 return item;
614
615 return NULL;
616 }
617
618 static struct perf_config_section *add_section(struct list_head *sections,
619 const char *section_name)
620 {
621 struct perf_config_section *section = zalloc(sizeof(*section));
622
623 if (!section)
624 return NULL;
625
626 INIT_LIST_HEAD(§ion->items);
627 section->name = strdup(section_name);
628 if (!section->name) {
629 pr_debug("%s: strdup failed\n", __func__);
630 free(section);
631 return NULL;
632 }
633
634 list_add_tail(§ion->node, sections);
635 return section;
636 }
637
638 static struct perf_config_item *add_config_item(struct perf_config_section *section,
639 const char *name)
640 {
641 struct perf_config_item *item = zalloc(sizeof(*item));
642
643 if (!item)
644 return NULL;
645
646 item->name = strdup(name);
647 if (!item->name) {
648 pr_debug("%s: strdup failed\n", __func__);
649 free(item);
650 return NULL;
651 }
652
653 list_add_tail(&item->node, §ion->items);
654 return item;
655 }
656
657 static int set_value(struct perf_config_item *item, const char *value)
658 {
659 char *val = strdup(value);
660
661 if (!val)
662 return -1;
663
664 zfree(&item->value);
665 item->value = val;
666 return 0;
667 }
668
669 static int collect_config(const char *var, const char *value,
670 void *perf_config_set)
671 {
672 int ret = -1;
673 char *ptr, *key;
674 char *section_name, *name;
675 struct perf_config_section *section = NULL;
676 struct perf_config_item *item = NULL;
677 struct perf_config_set *set = perf_config_set;
678 struct list_head *sections;
679
680 if (set == NULL)
681 return -1;
682
683 sections = &set->sections;
684 key = ptr = strdup(var);
685 if (!key) {
686 pr_debug("%s: strdup failed\n", __func__);
687 return -1;
688 }
689
690 section_name = strsep(&ptr, ".");
691 name = ptr;
692 if (name == NULL || value == NULL)
693 goto out_free;
694
695 section = find_section(sections, section_name);
696 if (!section) {
697 section = add_section(sections, section_name);
698 if (!section)
699 goto out_free;
700 }
701
702 item = find_config_item(name, section);
703 if (!item) {
704 item = add_config_item(section, name);
705 if (!item)
706 goto out_free;
707 }
708
709 /* perf_config_set can contain both user and system config items.
710 * So we should know where each value is from.
711 * The classification would be needed when a particular config file
712 * is overwritten by setting feature i.e. set_config().
713 */
714 if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
715 section->from_system_config = true;
716 item->from_system_config = true;
717 } else {
718 section->from_system_config = false;
719 item->from_system_config = false;
720 }
721
722 ret = set_value(item, value);
723
724 out_free:
725 free(key);
726 return ret;
727 }
728
729 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
730 const char *var, const char *value)
731 {
732 config_file_name = file_name;
733 return collect_config(var, value, set);
734 }
735
736 static int perf_config_set__init(struct perf_config_set *set)
737 {
738 int ret = -1;
739
740 /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
741 if (config_exclusive_filename)
742 return perf_config_from_file(collect_config, config_exclusive_filename, set);
743 if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
744 if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
745 goto out;
746 }
747 if (perf_config_global() && perf_home_perfconfig()) {
748 if (perf_config_from_file(collect_config, perf_home_perfconfig(), set) < 0)
749 goto out;
750 }
751
752 out:
753 return ret;
754 }
755
756 struct perf_config_set *perf_config_set__new(void)
757 {
758 struct perf_config_set *set = zalloc(sizeof(*set));
759
760 if (set) {
761 INIT_LIST_HEAD(&set->sections);
762 perf_config_set__init(set);
763 }
764
765 return set;
766 }
767
768 struct perf_config_set *perf_config_set__load_file(const char *file)
769 {
770 struct perf_config_set *set = zalloc(sizeof(*set));
771
772 if (set) {
773 INIT_LIST_HEAD(&set->sections);
774 perf_config_from_file(collect_config, file, set);
775 }
776
777 return set;
778 }
779
780 static int perf_config__init(void)
781 {
782 if (config_set == NULL)
783 config_set = perf_config_set__new();
784
785 return config_set == NULL;
786 }
787
788 int perf_config_set(struct perf_config_set *set,
789 config_fn_t fn, void *data)
790 {
791 int ret = 0;
792 char key[BUFSIZ];
793 struct perf_config_section *section;
794 struct perf_config_item *item;
795
796 perf_config_set__for_each_entry(set, section, item) {
797 char *value = item->value;
798
799 if (value) {
800 scnprintf(key, sizeof(key), "%s.%s",
801 section->name, item->name);
802 ret = fn(key, value, data);
803 if (ret < 0) {
804 pr_err("Error in the given config file: wrong config key-value pair %s=%s\n",
805 key, value);
806 /*
807 * Can't be just a 'break', as perf_config_set__for_each_entry()
808 * expands to two nested for() loops.
809 */
810 goto out;
811 }
812 }
813 }
814 out:
815 return ret;
816 }
817
818 int perf_config(config_fn_t fn, void *data)
819 {
820 if (config_set == NULL && perf_config__init())
821 return -1;
822
823 return perf_config_set(config_set, fn, data);
824 }
825
826 void perf_config__exit(void)
827 {
828 perf_config_set__delete(config_set);
829 config_set = NULL;
830 }
831
832 void perf_config__refresh(void)
833 {
834 perf_config__exit();
835 perf_config__init();
836 }
837
838 static void perf_config_item__delete(struct perf_config_item *item)
839 {
840 zfree(&item->name);
841 zfree(&item->value);
842 free(item);
843 }
844
845 static void perf_config_section__purge(struct perf_config_section *section)
846 {
847 struct perf_config_item *item, *tmp;
848
849 list_for_each_entry_safe(item, tmp, §ion->items, node) {
850 list_del_init(&item->node);
851 perf_config_item__delete(item);
852 }
853 }
854
855 static void perf_config_section__delete(struct perf_config_section *section)
856 {
857 perf_config_section__purge(section);
858 zfree(§ion->name);
859 free(section);
860 }
861
862 static void perf_config_set__purge(struct perf_config_set *set)
863 {
864 struct perf_config_section *section, *tmp;
865
866 list_for_each_entry_safe(section, tmp, &set->sections, node) {
867 list_del_init(§ion->node);
868 perf_config_section__delete(section);
869 }
870 }
871
872 void perf_config_set__delete(struct perf_config_set *set)
873 {
874 if (set == NULL)
875 return;
876
877 perf_config_set__purge(set);
878 free(set);
879 }
880
881 /*
882 * Call this to report error for your variable that should not
883 * get a boolean value (i.e. "[my] var" means "true").
884 */
885 int config_error_nonbool(const char *var)
886 {
887 pr_err("Missing value for '%s'", var);
888 return -1;
889 }
890
891 void set_buildid_dir(const char *dir)
892 {
893 if (dir)
894 scnprintf(buildid_dir, MAXPATHLEN, "%s", dir);
895
896 /* default to $HOME/.debug */
897 if (buildid_dir[0] == '\0') {
898 char *home = getenv("HOME");
899
900 if (home) {
901 snprintf(buildid_dir, MAXPATHLEN, "%s/%s",
902 home, DEBUG_CACHE_DIR);
903 } else {
904 strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
905 }
906 buildid_dir[MAXPATHLEN-1] = '\0';
907 }
908 /* for communicating with external commands */
909 setenv("PERF_BUILDID_DIR", buildid_dir, 1);
910 }
911
912 struct perf_config_scan_data {
913 const char *name;
914 const char *fmt;
915 va_list args;
916 int ret;
917 };
918
919 static int perf_config_scan_cb(const char *var, const char *value, void *data)
920 {
921 struct perf_config_scan_data *d = data;
922
923 if (!strcmp(var, d->name))
924 d->ret = vsscanf(value, d->fmt, d->args);
925
926 return 0;
927 }
928
929 int perf_config_scan(const char *name, const char *fmt, ...)
930 {
931 struct perf_config_scan_data d = {
932 .name = name,
933 .fmt = fmt,
934 };
935
936 va_start(d.args, fmt);
937 perf_config(perf_config_scan_cb, &d);
938 va_end(d.args);
939
940 return d.ret;
941 }
942
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