tools/perf/util/config.c

   1 /*
   2  * config.c
   3  *
   4  * Helper functions for parsing config items.
   5  * Originally copied from GIT source.
   6  *
   7  * Copyright (C) Linus Torvalds, 2005
   8  * Copyright (C) Johannes Schindelin, 2005
   9  *
  10  */
  11 #include <errno.h>
  12 #include <sys/param.h>
  13 #include "util.h"
  14 #include "cache.h"
  15 #include <subcmd/exec-cmd.h>
  16 #include "util/hist.h"  /* perf_hist_config */
  17 #include "util/llvm-utils.h"   /* perf_llvm_config */
  18 #include "config.h"
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <unistd.h>
  22
  23 #include "sane_ctype.h"
  24
  25 #define MAXNAME (256)
  26
  27 #define DEBUG_CACHE_DIR ".debug"
  28
  29
  30 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
  31
  32 static FILE *config_file;
  33 static const char *config_file_name;
  34 static int config_linenr;
  35 static int config_file_eof;
  36 static struct perf_config_set *config_set;
  37
  38 const char *config_exclusive_filename;
  39
  40 static int get_next_char(void)
  41 {
  42         int c;
  43         FILE *f;
  44
  45         c = '\n';
  46         if ((f = config_file) != NULL) {
  47                 c = fgetc(f);
  48                 if (c == '\r') {
  49                         /* DOS like systems */
  50                         c = fgetc(f);
  51                         if (c != '\n') {
  52                                 ungetc(c, f);
  53                                 c = '\r';
  54                         }
  55                 }
  56                 if (c == '\n')
  57                         config_linenr++;
  58                 if (c == EOF) {
  59                         config_file_eof = 1;
  60                         c = '\n';
  61                 }
  62         }
  63         return c;
  64 }
  65
  66 static char *parse_value(void)
  67 {
  68         static char value[1024];
  69         int quote = 0, comment = 0, space = 0;
  70         size_t len = 0;
  71
  72         for (;;) {
  73                 int c = get_next_char();
  74
  75                 if (len >= sizeof(value) - 1)
  76                         return NULL;
  77                 if (c == '\n') {
  78                         if (quote)
  79                                 return NULL;
  80                         value[len] = 0;
  81                         return value;
  82                 }
  83                 if (comment)
  84                         continue;
  85                 if (isspace(c) && !quote) {
  86                         space = 1;
  87                         continue;
  88                 }
  89                 if (!quote) {
  90                         if (c == ';' || c == '#') {
  91                                 comment = 1;
  92                                 continue;
  93                         }
  94                 }
  95                 if (space) {
  96                         if (len)
  97                                 value[len++] = ' ';
  98                         space = 0;
  99                 }
 100                 if (c == '\\') {
 101                         c = get_next_char();
 102                         switch (c) {
 103                         case '\n':
 104                                 continue;
 105                         case 't':
 106                                 c = '\t';
 107                                 break;
 108                         case 'b':
 109                                 c = '\b';
 110                                 break;
 111                         case 'n':
 112                                 c = '\n';
 113                                 break;
 114                         /* Some characters escape as themselves */
 115                         case '\\': case '"':
 116                                 break;
 117                         /* Reject unknown escape sequences */
 118                         default:
 119                                 return NULL;
 120                         }
 121                         value[len++] = c;
 122                         continue;
 123                 }
 124                 if (c == '"') {
 125                         quote = 1-quote;
 126                         continue;
 127                 }
 128                 value[len++] = c;
 129         }
 130 }
 131
 132 static inline int iskeychar(int c)
 133 {
 134         return isalnum(c) || c == '-' || c == '_';
 135 }
 136
 137 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 138 {
 139         int c;
 140         char *value;
 141
 142         /* Get the full name */
 143         for (;;) {
 144                 c = get_next_char();
 145                 if (config_file_eof)
 146                         break;
 147                 if (!iskeychar(c))
 148                         break;
 149                 name[len++] = c;
 150                 if (len >= MAXNAME)
 151                         return -1;
 152         }
 153         name[len] = 0;
 154         while (c == ' ' || c == '\t')
 155                 c = get_next_char();
 156
 157         value = NULL;
 158         if (c != '\n') {
 159                 if (c != '=')
 160                         return -1;
 161                 value = parse_value();
 162                 if (!value)
 163                         return -1;
 164         }
 165         return fn(name, value, data);
 166 }
 167
 168 static int get_extended_base_var(char *name, int baselen, int c)
 169 {
 170         do {
 171                 if (c == '\n')
 172                         return -1;
 173                 c = get_next_char();
 174         } while (isspace(c));
 175
 176         /* We require the format to be '[base "extension"]' */
 177         if (c != '"')
 178                 return -1;
 179         name[baselen++] = '.';
 180
 181         for (;;) {
 182                 int ch = get_next_char();
 183
 184                 if (ch == '\n')
 185                         return -1;
 186                 if (ch == '"')
 187                         break;
 188                 if (ch == '\\') {
 189                         ch = get_next_char();
 190                         if (ch == '\n')
 191                                 return -1;
 192                 }
 193                 name[baselen++] = ch;
 194                 if (baselen > MAXNAME / 2)
 195                         return -1;
 196         }
 197
 198         /* Final ']' */
 199         if (get_next_char() != ']')
 200                 return -1;
 201         return baselen;
 202 }
 203
 204 static int get_base_var(char *name)
 205 {
 206         int baselen = 0;
 207
 208         for (;;) {
 209                 int c = get_next_char();
 210                 if (config_file_eof)
 211                         return -1;
 212                 if (c == ']')
 213                         return baselen;
 214                 if (isspace(c))
 215                         return get_extended_base_var(name, baselen, c);
 216                 if (!iskeychar(c) && c != '.')
 217                         return -1;
 218                 if (baselen > MAXNAME / 2)
 219                         return -1;
 220                 name[baselen++] = tolower(c);
 221         }
 222 }
 223
 224 static int perf_parse_file(config_fn_t fn, void *data)
 225 {
 226         int comment = 0;
 227         int baselen = 0;
 228         static char var[MAXNAME];
 229
 230         /* U+FEFF Byte Order Mark in UTF8 */
 231         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 232         const unsigned char *bomptr = utf8_bom;
 233
 234         for (;;) {
 235                 int line, c = get_next_char();
 236
 237                 if (bomptr && *bomptr) {
 238                         /* We are at the file beginning; skip UTF8-encoded BOM
 239                          * if present. Sane editors won't put this in on their
 240                          * own, but e.g. Windows Notepad will do it happily. */
 241                         if ((unsigned char) c == *bomptr) {
 242                                 bomptr++;
 243                                 continue;
 244                         } else {
 245                                 /* Do not tolerate partial BOM. */
 246                                 if (bomptr != utf8_bom)
 247                                         break;
 248                                 /* No BOM at file beginning. Cool. */
 249                                 bomptr = NULL;
 250                         }
 251                 }
 252                 if (c == '\n') {
 253                         if (config_file_eof)
 254                                 return 0;
 255                         comment = 0;
 256                         continue;
 257                 }
 258                 if (comment || isspace(c))
 259                         continue;
 260                 if (c == '#' || c == ';') {
 261                         comment = 1;
 262                         continue;
 263                 }
 264                 if (c == '[') {
 265                         baselen = get_base_var(var);
 266                         if (baselen <= 0)
 267                                 break;
 268                         var[baselen++] = '.';
 269                         var[baselen] = 0;
 270                         continue;
 271                 }
 272                 if (!isalpha(c))
 273                         break;
 274                 var[baselen] = tolower(c);
 275
 276                 /*
 277                  * The get_value function might or might not reach the '\n',
 278                  * so saving the current line number for error reporting.
 279                  */
 280                 line = config_linenr;
 281                 if (get_value(fn, data, var, baselen+1) < 0) {
 282                         config_linenr = line;
 283                         break;
 284                 }
 285         }
 286         pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
 287         return -1;
 288 }
 289
 290 static int parse_unit_factor(const char *end, unsigned long *val)
 291 {
 292         if (!*end)
 293                 return 1;
 294         else if (!strcasecmp(end, "k")) {
 295                 *val *= 1024;
 296                 return 1;
 297         }
 298         else if (!strcasecmp(end, "m")) {
 299                 *val *= 1024 * 1024;
 300                 return 1;
 301         }
 302         else if (!strcasecmp(end, "g")) {
 303                 *val *= 1024 * 1024 * 1024;
 304                 return 1;
 305         }
 306         return 0;
 307 }
 308
 309 static int perf_parse_llong(const char *value, long long *ret)
 310 {
 311         if (value && *value) {
 312                 char *end;
 313                 long long val = strtoll(value, &end, 0);
 314                 unsigned long factor = 1;
 315
 316                 if (!parse_unit_factor(end, &factor))
 317                         return 0;
 318                 *ret = val * factor;
 319                 return 1;
 320         }
 321         return 0;
 322 }
 323
 324 static int perf_parse_long(const char *value, long *ret)
 325 {
 326         if (value && *value) {
 327                 char *end;
 328                 long val = strtol(value, &end, 0);
 329                 unsigned long factor = 1;
 330                 if (!parse_unit_factor(end, &factor))
 331                         return 0;
 332                 *ret = val * factor;
 333                 return 1;
 334         }
 335         return 0;
 336 }
 337
 338 static void bad_config(const char *name)
 339 {
 340         if (config_file_name)
 341                 pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
 342         else
 343                 pr_warning("bad config value for '%s', ignoring...\n", name);
 344 }
 345
 346 int perf_config_u64(u64 *dest, const char *name, const char *value)
 347 {
 348         long long ret = 0;
 349
 350         if (!perf_parse_llong(value, &ret)) {
 351                 bad_config(name);
 352                 return -1;
 353         }
 354
 355         *dest = ret;
 356         return 0;
 357 }
 358
 359 int perf_config_int(int *dest, const char *name, const char *value)
 360 {
 361         long ret = 0;
 362         if (!perf_parse_long(value, &ret)) {
 363                 bad_config(name);
 364                 return -1;
 365         }
 366         *dest = ret;
 367         return 0;
 368 }
 369
 370 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
 371 {
 372         int ret;
 373
 374         *is_bool = 1;
 375         if (!value)
 376                 return 1;
 377         if (!*value)
 378                 return 0;
 379         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 380                 return 1;
 381         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 382                 return 0;
 383         *is_bool = 0;
 384         return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
 385 }
 386
 387 int perf_config_bool(const char *name, const char *value)
 388 {
 389         int discard;
 390         return !!perf_config_bool_or_int(name, value, &discard);
 391 }
 392
 393 static const char *perf_config_dirname(const char *name, const char *value)
 394 {
 395         if (!name)
 396                 return NULL;
 397         return value;
 398 }
 399
 400 static int perf_buildid_config(const char *var, const char *value)
 401 {
 402         /* same dir for all commands */
 403         if (!strcmp(var, "buildid.dir")) {
 404                 const char *dir = perf_config_dirname(var, value);
 405
 406                 if (!dir) {
 407                         pr_err("Invalid buildid directory!\n");
 408                         return -1;
 409                 }
 410                 strncpy(buildid_dir, dir, MAXPATHLEN-1);
 411                 buildid_dir[MAXPATHLEN-1] = '\0';
 412         }
 413
 414         return 0;
 415 }
 416
 417 static int perf_default_core_config(const char *var __maybe_unused,
 418                                     const char *value __maybe_unused)
 419 {
 420         /* Add other config variables here. */
 421         return 0;
 422 }
 423
 424 static int perf_ui_config(const char *var, const char *value)
 425 {
 426         /* Add other config variables here. */
 427         if (!strcmp(var, "ui.show-headers"))
 428                 symbol_conf.show_hist_headers = perf_config_bool(var, value);
 429
 430         return 0;
 431 }
 432
 433 int perf_default_config(const char *var, const char *value,
 434                         void *dummy __maybe_unused)
 435 {
 436         if (!prefixcmp(var, "core."))
 437                 return perf_default_core_config(var, value);
 438
 439         if (!prefixcmp(var, "hist."))
 440                 return perf_hist_config(var, value);
 441
 442         if (!prefixcmp(var, "ui."))
 443                 return perf_ui_config(var, value);
 444
 445         if (!prefixcmp(var, "call-graph."))
 446                 return perf_callchain_config(var, value);
 447
 448         if (!prefixcmp(var, "llvm."))
 449                 return perf_llvm_config(var, value);
 450
 451         if (!prefixcmp(var, "buildid."))
 452                 return perf_buildid_config(var, value);
 453
 454         /* Add other config variables here. */
 455         return 0;
 456 }
 457
 458 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
 459 {
 460         int ret;
 461         FILE *f = fopen(filename, "r");
 462
 463         ret = -1;
 464         if (f) {
 465                 config_file = f;
 466                 config_file_name = filename;
 467                 config_linenr = 1;
 468                 config_file_eof = 0;
 469                 ret = perf_parse_file(fn, data);
 470                 fclose(f);
 471                 config_file_name = NULL;
 472         }
 473         return ret;
 474 }
 475
 476 const char *perf_etc_perfconfig(void)
 477 {
 478         static const char *system_wide;
 479         if (!system_wide)
 480                 system_wide = system_path(ETC_PERFCONFIG);
 481         return system_wide;
 482 }
 483
 484 static int perf_env_bool(const char *k, int def)
 485 {
 486         const char *v = getenv(k);
 487         return v ? perf_config_bool(k, v) : def;
 488 }
 489
 490 static int perf_config_system(void)
 491 {
 492         return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
 493 }
 494
 495 static int perf_config_global(void)
 496 {
 497         return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 498 }
 499
 500 static struct perf_config_section *find_section(struct list_head *sections,
 501                                                 const char *section_name)
 502 {
 503         struct perf_config_section *section;
 504
 505         list_for_each_entry(section, sections, node)
 506                 if (!strcmp(section->name, section_name))
 507                         return section;
 508
 509         return NULL;
 510 }
 511
 512 static struct perf_config_item *find_config_item(const char *name,
 513                                                  struct perf_config_section *section)
 514 {
 515         struct perf_config_item *item;
 516
 517         list_for_each_entry(item, &section->items, node)
 518                 if (!strcmp(item->name, name))
 519                         return item;
 520
 521         return NULL;
 522 }
 523
 524 static struct perf_config_section *add_section(struct list_head *sections,
 525                                                const char *section_name)
 526 {
 527         struct perf_config_section *section = zalloc(sizeof(*section));
 528
 529         if (!section)
 530                 return NULL;
 531
 532         INIT_LIST_HEAD(&section->items);
 533         section->name = strdup(section_name);
 534         if (!section->name) {
 535                 pr_debug("%s: strdup failed\n", __func__);
 536                 free(section);
 537                 return NULL;
 538         }
 539
 540         list_add_tail(&section->node, sections);
 541         return section;
 542 }
 543
 544 static struct perf_config_item *add_config_item(struct perf_config_section *section,
 545                                                 const char *name)
 546 {
 547         struct perf_config_item *item = zalloc(sizeof(*item));
 548
 549         if (!item)
 550                 return NULL;
 551
 552         item->name = strdup(name);
 553         if (!item->name) {
 554                 pr_debug("%s: strdup failed\n", __func__);
 555                 free(item);
 556                 return NULL;
 557         }
 558
 559         list_add_tail(&item->node, &section->items);
 560         return item;
 561 }
 562
 563 static int set_value(struct perf_config_item *item, const char *value)
 564 {
 565         char *val = strdup(value);
 566
 567         if (!val)
 568                 return -1;
 569
 570         zfree(&item->value);
 571         item->value = val;
 572         return 0;
 573 }
 574
 575 static int collect_config(const char *var, const char *value,
 576                           void *perf_config_set)
 577 {
 578         int ret = -1;
 579         char *ptr, *key;
 580         char *section_name, *name;
 581         struct perf_config_section *section = NULL;
 582         struct perf_config_item *item = NULL;
 583         struct perf_config_set *set = perf_config_set;
 584         struct list_head *sections;
 585
 586         if (set == NULL)
 587                 return -1;
 588
 589         sections = &set->sections;
 590         key = ptr = strdup(var);
 591         if (!key) {
 592                 pr_debug("%s: strdup failed\n", __func__);
 593                 return -1;
 594         }
 595
 596         section_name = strsep(&ptr, ".");
 597         name = ptr;
 598         if (name == NULL || value == NULL)
 599                 goto out_free;
 600
 601         section = find_section(sections, section_name);
 602         if (!section) {
 603                 section = add_section(sections, section_name);
 604                 if (!section)
 605                         goto out_free;
 606         }
 607
 608         item = find_config_item(name, section);
 609         if (!item) {
 610                 item = add_config_item(section, name);
 611                 if (!item)
 612                         goto out_free;
 613         }
 614
 615         /* perf_config_set can contain both user and system config items.
 616          * So we should know where each value is from.
 617          * The classification would be needed when a particular config file
 618          * is overwrited by setting feature i.e. set_config().
 619          */
 620         if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
 621                 section->from_system_config = true;
 622                 item->from_system_config = true;
 623         } else {
 624                 section->from_system_config = false;
 625                 item->from_system_config = false;
 626         }
 627
 628         ret = set_value(item, value);
 629         return ret;
 630
 631 out_free:
 632         free(key);
 633         return -1;
 634 }
 635
 636 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
 637                              const char *var, const char *value)
 638 {
 639         config_file_name = file_name;
 640         return collect_config(var, value, set);
 641 }
 642
 643 static int perf_config_set__init(struct perf_config_set *set)
 644 {
 645         int ret = -1;
 646         const char *home = NULL;
 647         char *user_config;
 648         struct stat st;
 649
 650         /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 651         if (config_exclusive_filename)
 652                 return perf_config_from_file(collect_config, config_exclusive_filename, set);
 653         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
 654                 if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
 655                         goto out;
 656         }
 657
 658         home = getenv("HOME");
 659
 660         /*
 661          * Skip reading user config if:
 662          *   - there is no place to read it from (HOME)
 663          *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
 664          */
 665         if (!home || !*home || !perf_config_global())
 666                 return 0;
 667
 668         user_config = strdup(mkpath("%s/.perfconfig", home));
 669         if (user_config == NULL) {
 670                 pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
 671                 goto out;
 672         }
 673
 674         if (stat(user_config, &st) < 0) {
 675                 if (errno == ENOENT)
 676                         ret = 0;
 677                 goto out_free;
 678         }
 679
 680         ret = 0;
 681
 682         if (st.st_uid && (st.st_uid != geteuid())) {
 683                 pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
 684                 goto out_free;
 685         }
 686
 687         if (st.st_size)
 688                 ret = perf_config_from_file(collect_config, user_config, set);
 689
 690 out_free:
 691         free(user_config);
 692 out:
 693         return ret;
 694 }
 695
 696 struct perf_config_set *perf_config_set__new(void)
 697 {
 698         struct perf_config_set *set = zalloc(sizeof(*set));
 699
 700         if (set) {
 701                 INIT_LIST_HEAD(&set->sections);
 702                 if (perf_config_set__init(set) < 0) {
 703                         perf_config_set__delete(set);
 704                         set = NULL;
 705                 }
 706         }
 707
 708         return set;
 709 }
 710
 711 int perf_config(config_fn_t fn, void *data)
 712 {
 713         int ret = 0;
 714         char key[BUFSIZ];
 715         struct perf_config_section *section;
 716         struct perf_config_item *item;
 717
 718         if (config_set == NULL)
 719                 return -1;
 720
 721         perf_config_set__for_each_entry(config_set, section, item) {
 722                 char *value = item->value;
 723
 724                 if (value) {
 725                         scnprintf(key, sizeof(key), "%s.%s",
 726                                   section->name, item->name);
 727                         ret = fn(key, value, data);
 728                         if (ret < 0) {
 729                                 pr_err("Error: wrong config key-value pair %s=%s\n",
 730                                        key, value);
 731                                 break;
 732                         }
 733                 }
 734         }
 735
 736         return ret;
 737 }
 738
 739 void perf_config__init(void)
 740 {
 741         if (config_set == NULL)
 742                 config_set = perf_config_set__new();
 743 }
 744
 745 void perf_config__exit(void)
 746 {
 747         perf_config_set__delete(config_set);
 748         config_set = NULL;
 749 }
 750
 751 void perf_config__refresh(void)
 752 {
 753         perf_config__exit();
 754         perf_config__init();
 755 }
 756
 757 static void perf_config_item__delete(struct perf_config_item *item)
 758 {
 759         zfree(&item->name);
 760         zfree(&item->value);
 761         free(item);
 762 }
 763
 764 static void perf_config_section__purge(struct perf_config_section *section)
 765 {
 766         struct perf_config_item *item, *tmp;
 767
 768         list_for_each_entry_safe(item, tmp, &section->items, node) {
 769                 list_del_init(&item->node);
 770                 perf_config_item__delete(item);
 771         }
 772 }
 773
 774 static void perf_config_section__delete(struct perf_config_section *section)
 775 {
 776         perf_config_section__purge(section);
 777         zfree(&section->name);
 778         free(section);
 779 }
 780
 781 static void perf_config_set__purge(struct perf_config_set *set)
 782 {
 783         struct perf_config_section *section, *tmp;
 784
 785         list_for_each_entry_safe(section, tmp, &set->sections, node) {
 786                 list_del_init(&section->node);
 787                 perf_config_section__delete(section);
 788         }
 789 }
 790
 791 void perf_config_set__delete(struct perf_config_set *set)
 792 {
 793         if (set == NULL)
 794                 return;
 795
 796         perf_config_set__purge(set);
 797         free(set);
 798 }
 799
 800 /*
 801  * Call this to report error for your variable that should not
 802  * get a boolean value (i.e. "[my] var" means "true").
 803  */
 804 int config_error_nonbool(const char *var)
 805 {
 806         pr_err("Missing value for '%s'", var);
 807         return -1;
 808 }
 809
 810 void set_buildid_dir(const char *dir)
 811 {
 812         if (dir)
 813                 scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
 814
 815         /* default to $HOME/.debug */
 816         if (buildid_dir[0] == '\0') {
 817                 char *home = getenv("HOME");
 818
 819                 if (home) {
 820                         snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
 821                                  home, DEBUG_CACHE_DIR);
 822                 } else {
 823                         strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
 824                 }
 825                 buildid_dir[MAXPATHLEN-1] = '\0';
 826         }
 827         /* for communicating with external commands */
 828         setenv("PERF_BUILDID_DIR", buildid_dir, 1);
 829 }