tools/perf/util/config.c

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