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 "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, &section->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(&section->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(&section->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, &section->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, &section->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(&section->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(&section->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         const char *value;
 916         va_list args;
 917         int ret;
 918 };
 919
 920 static int perf_config_scan_cb(const char *var, const char *value, void *data)
 921 {
 922         struct perf_config_scan_data *d = data;
 923
 924         if (!strcmp(var, d->name))
 925                 d->ret = vsscanf(value, d->fmt, d->args);
 926
 927         return 0;
 928 }
 929
 930 int perf_config_scan(const char *name, const char *fmt, ...)
 931 {
 932         struct perf_config_scan_data d = {
 933                 .name = name,
 934                 .fmt = fmt,
 935         };
 936
 937         va_start(d.args, fmt);
 938         perf_config(perf_config_scan_cb, &d);
 939         va_end(d.args);
 940
 941         return d.ret;
 942 }
 943
 944 static int perf_config_get_cb(const char *var, const char *value, void *data)
 945 {
 946         struct perf_config_scan_data *d = data;
 947
 948         if (!strcmp(var, d->name))
 949                 d->value = value;
 950
 951         return 0;
 952 }
 953
 954 const char *perf_config_get(const char *name)
 955 {
 956         struct perf_config_scan_data d = {
 957                 .name = name,
 958                 .value = NULL,
 959         };
 960
 961         perf_config(perf_config_get_cb, &d);
 962         return d.value;
 963 }