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 "util/stat.h" /* perf_stat__set_big_num */ 21 #include "build-id.h" 22 #include "debug.h" 23 #include "config.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 static int perf_stat_config(const char *var, const char *value) 456 { 457 if (!strcmp(var, "stat.big-num")) 458 perf_stat__set_big_num(perf_config_bool(var, value)); 459 460 /* Add other config variables here. */ 461 return 0; 462 } 463 464 int perf_default_config(const char *var, const char *value, 465 void *dummy __maybe_unused) 466 { 467 if (strstarts(var, "core.")) 468 return perf_default_core_config(var, value); 469 470 if (strstarts(var, "hist.")) 471 return perf_hist_config(var, value); 472 473 if (strstarts(var, "ui.")) 474 return perf_ui_config(var, value); 475 476 if (strstarts(var, "call-graph.")) 477 return perf_callchain_config(var, value); 478 479 if (strstarts(var, "llvm.")) 480 return perf_llvm_config(var, value); 481 482 if (strstarts(var, "buildid.")) 483 return perf_buildid_config(var, value); 484 485 if (strstarts(var, "stat.")) 486 return perf_stat_config(var, value); 487 488 /* Add other config variables here. */ 489 return 0; 490 } 491 492 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data) 493 { 494 int ret; 495 FILE *f = fopen(filename, "r"); 496 497 ret = -1; 498 if (f) { 499 config_file = f; 500 config_file_name = filename; 501 config_linenr = 1; 502 config_file_eof = 0; 503 ret = perf_parse_file(fn, data); 504 fclose(f); 505 config_file_name = NULL; 506 } 507 return ret; 508 } 509 510 const char *perf_etc_perfconfig(void) 511 { 512 static const char *system_wide; 513 if (!system_wide) 514 system_wide = system_path(ETC_PERFCONFIG); 515 return system_wide; 516 } 517 518 static int perf_env_bool(const char *k, int def) 519 { 520 const char *v = getenv(k); 521 return v ? perf_config_bool(k, v) : def; 522 } 523 524 int perf_config_system(void) 525 { 526 return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0); 527 } 528 529 int perf_config_global(void) 530 { 531 return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0); 532 } 533 534 static char *home_perfconfig(void) 535 { 536 const char *home = NULL; 537 char *config; 538 struct stat st; 539 540 home = getenv("HOME"); 541 542 /* 543 * Skip reading user config if: 544 * - there is no place to read it from (HOME) 545 * - we are asked not to (PERF_CONFIG_NOGLOBAL=1) 546 */ 547 if (!home || !*home || !perf_config_global()) 548 return NULL; 549 550 config = strdup(mkpath("%s/.perfconfig", home)); 551 if (config == NULL) { 552 pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home); 553 return NULL; 554 } 555 556 if (stat(config, &st) < 0) 557 goto out_free; 558 559 if (st.st_uid && (st.st_uid != geteuid())) { 560 pr_warning("File %s not owned by current user or root, ignoring it.", config); 561 goto out_free; 562 } 563 564 if (st.st_size) 565 return config; 566 567 out_free: 568 free(config); 569 return NULL; 570 } 571 572 const char *perf_home_perfconfig(void) 573 { 574 static const char *config; 575 static bool failed; 576 577 config = failed ? NULL : home_perfconfig(); 578 if (!config) 579 failed = true; 580 581 return config; 582 } 583 584 static struct perf_config_section *find_section(struct list_head *sections, 585 const char *section_name) 586 { 587 struct perf_config_section *section; 588 589 list_for_each_entry(section, sections, node) 590 if (!strcmp(section->name, section_name)) 591 return section; 592 593 return NULL; 594 } 595 596 static struct perf_config_item *find_config_item(const char *name, 597 struct perf_config_section *section) 598 { 599 struct perf_config_item *item; 600 601 list_for_each_entry(item, §ion->items, node) 602 if (!strcmp(item->name, name)) 603 return item; 604 605 return NULL; 606 } 607 608 static struct perf_config_section *add_section(struct list_head *sections, 609 const char *section_name) 610 { 611 struct perf_config_section *section = zalloc(sizeof(*section)); 612 613 if (!section) 614 return NULL; 615 616 INIT_LIST_HEAD(§ion->items); 617 section->name = strdup(section_name); 618 if (!section->name) { 619 pr_debug("%s: strdup failed\n", __func__); 620 free(section); 621 return NULL; 622 } 623 624 list_add_tail(§ion->node, sections); 625 return section; 626 } 627 628 static struct perf_config_item *add_config_item(struct perf_config_section *section, 629 const char *name) 630 { 631 struct perf_config_item *item = zalloc(sizeof(*item)); 632 633 if (!item) 634 return NULL; 635 636 item->name = strdup(name); 637 if (!item->name) { 638 pr_debug("%s: strdup failed\n", __func__); 639 free(item); 640 return NULL; 641 } 642 643 list_add_tail(&item->node, §ion->items); 644 return item; 645 } 646 647 static int set_value(struct perf_config_item *item, const char *value) 648 { 649 char *val = strdup(value); 650 651 if (!val) 652 return -1; 653 654 zfree(&item->value); 655 item->value = val; 656 return 0; 657 } 658 659 static int collect_config(const char *var, const char *value, 660 void *perf_config_set) 661 { 662 int ret = -1; 663 char *ptr, *key; 664 char *section_name, *name; 665 struct perf_config_section *section = NULL; 666 struct perf_config_item *item = NULL; 667 struct perf_config_set *set = perf_config_set; 668 struct list_head *sections; 669 670 if (set == NULL) 671 return -1; 672 673 sections = &set->sections; 674 key = ptr = strdup(var); 675 if (!key) { 676 pr_debug("%s: strdup failed\n", __func__); 677 return -1; 678 } 679 680 section_name = strsep(&ptr, "."); 681 name = ptr; 682 if (name == NULL || value == NULL) 683 goto out_free; 684 685 section = find_section(sections, section_name); 686 if (!section) { 687 section = add_section(sections, section_name); 688 if (!section) 689 goto out_free; 690 } 691 692 item = find_config_item(name, section); 693 if (!item) { 694 item = add_config_item(section, name); 695 if (!item) 696 goto out_free; 697 } 698 699 /* perf_config_set can contain both user and system config items. 700 * So we should know where each value is from. 701 * The classification would be needed when a particular config file 702 * is overwrited by setting feature i.e. set_config(). 703 */ 704 if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) { 705 section->from_system_config = true; 706 item->from_system_config = true; 707 } else { 708 section->from_system_config = false; 709 item->from_system_config = false; 710 } 711 712 ret = set_value(item, value); 713 714 out_free: 715 free(key); 716 return ret; 717 } 718 719 int perf_config_set__collect(struct perf_config_set *set, const char *file_name, 720 const char *var, const char *value) 721 { 722 config_file_name = file_name; 723 return collect_config(var, value, set); 724 } 725 726 static int perf_config_set__init(struct perf_config_set *set) 727 { 728 int ret = -1; 729 730 /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */ 731 if (config_exclusive_filename) 732 return perf_config_from_file(collect_config, config_exclusive_filename, set); 733 if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) { 734 if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0) 735 goto out; 736 } 737 if (perf_config_global() && perf_home_perfconfig()) { 738 if (perf_config_from_file(collect_config, perf_home_perfconfig(), set) < 0) 739 goto out; 740 } 741 742 out: 743 return ret; 744 } 745 746 struct perf_config_set *perf_config_set__new(void) 747 { 748 struct perf_config_set *set = zalloc(sizeof(*set)); 749 750 if (set) { 751 INIT_LIST_HEAD(&set->sections); 752 perf_config_set__init(set); 753 } 754 755 return set; 756 } 757 758 struct perf_config_set *perf_config_set__load_file(const char *file) 759 { 760 struct perf_config_set *set = zalloc(sizeof(*set)); 761 762 if (set) { 763 INIT_LIST_HEAD(&set->sections); 764 perf_config_from_file(collect_config, file, set); 765 } 766 767 return set; 768 } 769 770 static int perf_config__init(void) 771 { 772 if (config_set == NULL) 773 config_set = perf_config_set__new(); 774 775 return config_set == NULL; 776 } 777 778 int perf_config_set(struct perf_config_set *set, 779 config_fn_t fn, void *data) 780 { 781 int ret = 0; 782 char key[BUFSIZ]; 783 struct perf_config_section *section; 784 struct perf_config_item *item; 785 786 perf_config_set__for_each_entry(set, section, item) { 787 char *value = item->value; 788 789 if (value) { 790 scnprintf(key, sizeof(key), "%s.%s", 791 section->name, item->name); 792 ret = fn(key, value, data); 793 if (ret < 0) { 794 pr_err("Error: wrong config key-value pair %s=%s\n", 795 key, value); 796 /* 797 * Can't be just a 'break', as perf_config_set__for_each_entry() 798 * expands to two nested for() loops. 799 */ 800 goto out; 801 } 802 } 803 } 804 out: 805 return ret; 806 } 807 808 int perf_config(config_fn_t fn, void *data) 809 { 810 if (config_set == NULL && perf_config__init()) 811 return -1; 812 813 return perf_config_set(config_set, fn, data); 814 } 815 816 void perf_config__exit(void) 817 { 818 perf_config_set__delete(config_set); 819 config_set = NULL; 820 } 821 822 void perf_config__refresh(void) 823 { 824 perf_config__exit(); 825 perf_config__init(); 826 } 827 828 static void perf_config_item__delete(struct perf_config_item *item) 829 { 830 zfree(&item->name); 831 zfree(&item->value); 832 free(item); 833 } 834 835 static void perf_config_section__purge(struct perf_config_section *section) 836 { 837 struct perf_config_item *item, *tmp; 838 839 list_for_each_entry_safe(item, tmp, §ion->items, node) { 840 list_del_init(&item->node); 841 perf_config_item__delete(item); 842 } 843 } 844 845 static void perf_config_section__delete(struct perf_config_section *section) 846 { 847 perf_config_section__purge(section); 848 zfree(§ion->name); 849 free(section); 850 } 851 852 static void perf_config_set__purge(struct perf_config_set *set) 853 { 854 struct perf_config_section *section, *tmp; 855 856 list_for_each_entry_safe(section, tmp, &set->sections, node) { 857 list_del_init(§ion->node); 858 perf_config_section__delete(section); 859 } 860 } 861 862 void perf_config_set__delete(struct perf_config_set *set) 863 { 864 if (set == NULL) 865 return; 866 867 perf_config_set__purge(set); 868 free(set); 869 } 870 871 /* 872 * Call this to report error for your variable that should not 873 * get a boolean value (i.e. "[my] var" means "true"). 874 */ 875 int config_error_nonbool(const char *var) 876 { 877 pr_err("Missing value for '%s'", var); 878 return -1; 879 } 880 881 void set_buildid_dir(const char *dir) 882 { 883 if (dir) 884 scnprintf(buildid_dir, MAXPATHLEN, "%s", dir); 885 886 /* default to $HOME/.debug */ 887 if (buildid_dir[0] == '\0') { 888 char *home = getenv("HOME"); 889 890 if (home) { 891 snprintf(buildid_dir, MAXPATHLEN, "%s/%s", 892 home, DEBUG_CACHE_DIR); 893 } else { 894 strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1); 895 } 896 buildid_dir[MAXPATHLEN-1] = '\0'; 897 } 898 /* for communicating with external commands */ 899 setenv("PERF_BUILDID_DIR", buildid_dir, 1); 900 } 901