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