tools/perf/util/symbol.c

   1 #include <dirent.h>
   2 #include <errno.h>
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <sys/param.h>
   9 #include <fcntl.h>
  10 #include <unistd.h>
  11 #include <inttypes.h>
  12 #include "build-id.h"
  13 #include "util.h"
  14 #include "debug.h"
  15 #include "machine.h"
  16 #include "symbol.h"
  17 #include "strlist.h"
  18
  19 #include <elf.h>
  20 #include <limits.h>
  21 #include <sys/utsname.h>
  22
  23 #ifndef KSYM_NAME_LEN
  24 #define KSYM_NAME_LEN 256
  25 #endif
  26
  27 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
  28                                 symbol_filter_t filter);
  29 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
  30                         symbol_filter_t filter);
  31 int vmlinux_path__nr_entries;
  32 char **vmlinux_path;
  33
  34 struct symbol_conf symbol_conf = {
  35         .exclude_other    = true,
  36         .use_modules      = true,
  37         .try_vmlinux_path = true,
  38         .annotate_src     = true,
  39         .symfs            = "",
  40 };
  41
  42 static enum dso_binary_type binary_type_symtab[] = {
  43         DSO_BINARY_TYPE__KALLSYMS,
  44         DSO_BINARY_TYPE__GUEST_KALLSYMS,
  45         DSO_BINARY_TYPE__JAVA_JIT,
  46         DSO_BINARY_TYPE__DEBUGLINK,
  47         DSO_BINARY_TYPE__BUILD_ID_CACHE,
  48         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
  49         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
  50         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
  51         DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
  52         DSO_BINARY_TYPE__GUEST_KMODULE,
  53         DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
  54         DSO_BINARY_TYPE__NOT_FOUND,
  55 };
  56
  57 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
  58
  59 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
  60 {
  61         symbol_type = toupper(symbol_type);
  62
  63         switch (map_type) {
  64         case MAP__FUNCTION:
  65                 return symbol_type == 'T' || symbol_type == 'W';
  66         case MAP__VARIABLE:
  67                 return symbol_type == 'D';
  68         default:
  69                 return false;
  70         }
  71 }
  72
  73 static int prefix_underscores_count(const char *str)
  74 {
  75         const char *tail = str;
  76
  77         while (*tail == '_')
  78                 tail++;
  79
  80         return tail - str;
  81 }
  82
  83 #define SYMBOL_A 0
  84 #define SYMBOL_B 1
  85
  86 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
  87 {
  88         s64 a;
  89         s64 b;
  90
  91         /* Prefer a symbol with non zero length */
  92         a = syma->end - syma->start;
  93         b = symb->end - symb->start;
  94         if ((b == 0) && (a > 0))
  95                 return SYMBOL_A;
  96         else if ((a == 0) && (b > 0))
  97                 return SYMBOL_B;
  98
  99         /* Prefer a non weak symbol over a weak one */
 100         a = syma->binding == STB_WEAK;
 101         b = symb->binding == STB_WEAK;
 102         if (b && !a)
 103                 return SYMBOL_A;
 104         if (a && !b)
 105                 return SYMBOL_B;
 106
 107         /* Prefer a global symbol over a non global one */
 108         a = syma->binding == STB_GLOBAL;
 109         b = symb->binding == STB_GLOBAL;
 110         if (a && !b)
 111                 return SYMBOL_A;
 112         if (b && !a)
 113                 return SYMBOL_B;
 114
 115         /* Prefer a symbol with less underscores */
 116         a = prefix_underscores_count(syma->name);
 117         b = prefix_underscores_count(symb->name);
 118         if (b > a)
 119                 return SYMBOL_A;
 120         else if (a > b)
 121                 return SYMBOL_B;
 122
 123         /* If all else fails, choose the symbol with the longest name */
 124         if (strlen(syma->name) >= strlen(symb->name))
 125                 return SYMBOL_A;
 126         else
 127                 return SYMBOL_B;
 128 }
 129
 130 void symbols__fixup_duplicate(struct rb_root *symbols)
 131 {
 132         struct rb_node *nd;
 133         struct symbol *curr, *next;
 134
 135         nd = rb_first(symbols);
 136
 137         while (nd) {
 138                 curr = rb_entry(nd, struct symbol, rb_node);
 139 again:
 140                 nd = rb_next(&curr->rb_node);
 141                 next = rb_entry(nd, struct symbol, rb_node);
 142
 143                 if (!nd)
 144                         break;
 145
 146                 if (curr->start != next->start)
 147                         continue;
 148
 149                 if (choose_best_symbol(curr, next) == SYMBOL_A) {
 150                         rb_erase(&next->rb_node, symbols);
 151                         goto again;
 152                 } else {
 153                         nd = rb_next(&curr->rb_node);
 154                         rb_erase(&curr->rb_node, symbols);
 155                 }
 156         }
 157 }
 158
 159 void symbols__fixup_end(struct rb_root *symbols)
 160 {
 161         struct rb_node *nd, *prevnd = rb_first(symbols);
 162         struct symbol *curr, *prev;
 163
 164         if (prevnd == NULL)
 165                 return;
 166
 167         curr = rb_entry(prevnd, struct symbol, rb_node);
 168
 169         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 170                 prev = curr;
 171                 curr = rb_entry(nd, struct symbol, rb_node);
 172
 173                 if (prev->end == prev->start && prev->end != curr->start)
 174                         prev->end = curr->start - 1;
 175         }
 176
 177         /* Last entry */
 178         if (curr->end == curr->start)
 179                 curr->end = roundup(curr->start, 4096);
 180 }
 181
 182 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
 183 {
 184         struct map *prev, *curr;
 185         struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
 186
 187         if (prevnd == NULL)
 188                 return;
 189
 190         curr = rb_entry(prevnd, struct map, rb_node);
 191
 192         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 193                 prev = curr;
 194                 curr = rb_entry(nd, struct map, rb_node);
 195                 prev->end = curr->start - 1;
 196         }
 197
 198         /*
 199          * We still haven't the actual symbols, so guess the
 200          * last map final address.
 201          */
 202         curr->end = ~0ULL;
 203 }
 204
 205 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
 206 {
 207         size_t namelen = strlen(name) + 1;
 208         struct symbol *sym = calloc(1, (symbol_conf.priv_size +
 209                                         sizeof(*sym) + namelen));
 210         if (sym == NULL)
 211                 return NULL;
 212
 213         if (symbol_conf.priv_size)
 214                 sym = ((void *)sym) + symbol_conf.priv_size;
 215
 216         sym->start   = start;
 217         sym->end     = len ? start + len - 1 : start;
 218         sym->binding = binding;
 219         sym->namelen = namelen - 1;
 220
 221         pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
 222                   __func__, name, start, sym->end);
 223         memcpy(sym->name, name, namelen);
 224
 225         return sym;
 226 }
 227
 228 void symbol__delete(struct symbol *sym)
 229 {
 230         free(((void *)sym) - symbol_conf.priv_size);
 231 }
 232
 233 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
 234 {
 235         return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
 236                        sym->start, sym->end,
 237                        sym->binding == STB_GLOBAL ? 'g' :
 238                        sym->binding == STB_LOCAL  ? 'l' : 'w',
 239                        sym->name);
 240 }
 241
 242 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 243                                     const struct addr_location *al, FILE *fp)
 244 {
 245         unsigned long offset;
 246         size_t length;
 247
 248         if (sym && sym->name) {
 249                 length = fprintf(fp, "%s", sym->name);
 250                 if (al) {
 251                         offset = al->addr - sym->start;
 252                         length += fprintf(fp, "+0x%lx", offset);
 253                 }
 254                 return length;
 255         } else
 256                 return fprintf(fp, "[unknown]");
 257 }
 258
 259 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
 260 {
 261         return symbol__fprintf_symname_offs(sym, NULL, fp);
 262 }
 263
 264 void symbols__delete(struct rb_root *symbols)
 265 {
 266         struct symbol *pos;
 267         struct rb_node *next = rb_first(symbols);
 268
 269         while (next) {
 270                 pos = rb_entry(next, struct symbol, rb_node);
 271                 next = rb_next(&pos->rb_node);
 272                 rb_erase(&pos->rb_node, symbols);
 273                 symbol__delete(pos);
 274         }
 275 }
 276
 277 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
 278 {
 279         struct rb_node **p = &symbols->rb_node;
 280         struct rb_node *parent = NULL;
 281         const u64 ip = sym->start;
 282         struct symbol *s;
 283
 284         while (*p != NULL) {
 285                 parent = *p;
 286                 s = rb_entry(parent, struct symbol, rb_node);
 287                 if (ip < s->start)
 288                         p = &(*p)->rb_left;
 289                 else
 290                         p = &(*p)->rb_right;
 291         }
 292         rb_link_node(&sym->rb_node, parent, p);
 293         rb_insert_color(&sym->rb_node, symbols);
 294 }
 295
 296 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
 297 {
 298         struct rb_node *n;
 299
 300         if (symbols == NULL)
 301                 return NULL;
 302
 303         n = symbols->rb_node;
 304
 305         while (n) {
 306                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
 307
 308                 if (ip < s->start)
 309                         n = n->rb_left;
 310                 else if (ip > s->end)
 311                         n = n->rb_right;
 312                 else
 313                         return s;
 314         }
 315
 316         return NULL;
 317 }
 318
 319 struct symbol_name_rb_node {
 320         struct rb_node  rb_node;
 321         struct symbol   sym;
 322 };
 323
 324 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
 325 {
 326         struct rb_node **p = &symbols->rb_node;
 327         struct rb_node *parent = NULL;
 328         struct symbol_name_rb_node *symn, *s;
 329
 330         symn = container_of(sym, struct symbol_name_rb_node, sym);
 331
 332         while (*p != NULL) {
 333                 parent = *p;
 334                 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
 335                 if (strcmp(sym->name, s->sym.name) < 0)
 336                         p = &(*p)->rb_left;
 337                 else
 338                         p = &(*p)->rb_right;
 339         }
 340         rb_link_node(&symn->rb_node, parent, p);
 341         rb_insert_color(&symn->rb_node, symbols);
 342 }
 343
 344 static void symbols__sort_by_name(struct rb_root *symbols,
 345                                   struct rb_root *source)
 346 {
 347         struct rb_node *nd;
 348
 349         for (nd = rb_first(source); nd; nd = rb_next(nd)) {
 350                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 351                 symbols__insert_by_name(symbols, pos);
 352         }
 353 }
 354
 355 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
 356                                             const char *name)
 357 {
 358         struct rb_node *n;
 359
 360         if (symbols == NULL)
 361                 return NULL;
 362
 363         n = symbols->rb_node;
 364
 365         while (n) {
 366                 struct symbol_name_rb_node *s;
 367                 int cmp;
 368
 369                 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
 370                 cmp = strcmp(name, s->sym.name);
 371
 372                 if (cmp < 0)
 373                         n = n->rb_left;
 374                 else if (cmp > 0)
 375                         n = n->rb_right;
 376                 else
 377                         return &s->sym;
 378         }
 379
 380         return NULL;
 381 }
 382
 383 struct symbol *dso__find_symbol(struct dso *dso,
 384                                 enum map_type type, u64 addr)
 385 {
 386         return symbols__find(&dso->symbols[type], addr);
 387 }
 388
 389 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
 390                                         const char *name)
 391 {
 392         return symbols__find_by_name(&dso->symbol_names[type], name);
 393 }
 394
 395 void dso__sort_by_name(struct dso *dso, enum map_type type)
 396 {
 397         dso__set_sorted_by_name(dso, type);
 398         return symbols__sort_by_name(&dso->symbol_names[type],
 399                                      &dso->symbols[type]);
 400 }
 401
 402 size_t dso__fprintf_symbols_by_name(struct dso *dso,
 403                                     enum map_type type, FILE *fp)
 404 {
 405         size_t ret = 0;
 406         struct rb_node *nd;
 407         struct symbol_name_rb_node *pos;
 408
 409         for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
 410                 pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
 411                 fprintf(fp, "%s\n", pos->sym.name);
 412         }
 413
 414         return ret;
 415 }
 416
 417 int kallsyms__parse(const char *filename, void *arg,
 418                     int (*process_symbol)(void *arg, const char *name,
 419                                           char type, u64 start))
 420 {
 421         char *line = NULL;
 422         size_t n;
 423         int err = -1;
 424         FILE *file = fopen(filename, "r");
 425
 426         if (file == NULL)
 427                 goto out_failure;
 428
 429         err = 0;
 430
 431         while (!feof(file)) {
 432                 u64 start;
 433                 int line_len, len;
 434                 char symbol_type;
 435                 char *symbol_name;
 436
 437                 line_len = getline(&line, &n, file);
 438                 if (line_len < 0 || !line)
 439                         break;
 440
 441                 line[--line_len] = '\0'; /* \n */
 442
 443                 len = hex2u64(line, &start);
 444
 445                 len++;
 446                 if (len + 2 >= line_len)
 447                         continue;
 448
 449                 symbol_type = line[len];
 450                 len += 2;
 451                 symbol_name = line + len;
 452                 len = line_len - len;
 453
 454                 if (len >= KSYM_NAME_LEN) {
 455                         err = -1;
 456                         break;
 457                 }
 458
 459                 err = process_symbol(arg, symbol_name,
 460                                      symbol_type, start);
 461                 if (err)
 462                         break;
 463         }
 464
 465         free(line);
 466         fclose(file);
 467         return err;
 468
 469 out_failure:
 470         return -1;
 471 }
 472
 473 struct process_kallsyms_args {
 474         struct map *map;
 475         struct dso *dso;
 476 };
 477
 478 static u8 kallsyms2elf_type(char type)
 479 {
 480         if (type == 'W')
 481                 return STB_WEAK;
 482
 483         return isupper(type) ? STB_GLOBAL : STB_LOCAL;
 484 }
 485
 486 static int map__process_kallsym_symbol(void *arg, const char *name,
 487                                        char type, u64 start)
 488 {
 489         struct symbol *sym;
 490         struct process_kallsyms_args *a = arg;
 491         struct rb_root *root = &a->dso->symbols[a->map->type];
 492
 493         if (!symbol_type__is_a(type, a->map->type))
 494                 return 0;
 495
 496         /*
 497          * module symbols are not sorted so we add all
 498          * symbols, setting length to 0, and rely on
 499          * symbols__fixup_end() to fix it up.
 500          */
 501         sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
 502         if (sym == NULL)
 503                 return -ENOMEM;
 504         /*
 505          * We will pass the symbols to the filter later, in
 506          * map__split_kallsyms, when we have split the maps per module
 507          */
 508         symbols__insert(root, sym);
 509
 510         return 0;
 511 }
 512
 513 /*
 514  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 515  * so that we can in the next step set the symbol ->end address and then
 516  * call kernel_maps__split_kallsyms.
 517  */
 518 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
 519                                   struct map *map)
 520 {
 521         struct process_kallsyms_args args = { .map = map, .dso = dso, };
 522         return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
 523 }
 524
 525 /*
 526  * Split the symbols into maps, making sure there are no overlaps, i.e. the
 527  * kernel range is broken in several maps, named [kernel].N, as we don't have
 528  * the original ELF section names vmlinux have.
 529  */
 530 static int dso__split_kallsyms(struct dso *dso, struct map *map,
 531                                symbol_filter_t filter)
 532 {
 533         struct map_groups *kmaps = map__kmap(map)->kmaps;
 534         struct machine *machine = kmaps->machine;
 535         struct map *curr_map = map;
 536         struct symbol *pos;
 537         int count = 0, moved = 0;
 538         struct rb_root *root = &dso->symbols[map->type];
 539         struct rb_node *next = rb_first(root);
 540         int kernel_range = 0;
 541
 542         while (next) {
 543                 char *module;
 544
 545                 pos = rb_entry(next, struct symbol, rb_node);
 546                 next = rb_next(&pos->rb_node);
 547
 548                 module = strchr(pos->name, '\t');
 549                 if (module) {
 550                         if (!symbol_conf.use_modules)
 551                                 goto discard_symbol;
 552
 553                         *module++ = '\0';
 554
 555                         if (strcmp(curr_map->dso->short_name, module)) {
 556                                 if (curr_map != map &&
 557                                     dso->kernel == DSO_TYPE_GUEST_KERNEL &&
 558                                     machine__is_default_guest(machine)) {
 559                                         /*
 560                                          * We assume all symbols of a module are
 561                                          * continuous in * kallsyms, so curr_map
 562                                          * points to a module and all its
 563                                          * symbols are in its kmap. Mark it as
 564                                          * loaded.
 565                                          */
 566                                         dso__set_loaded(curr_map->dso,
 567                                                         curr_map->type);
 568                                 }
 569
 570                                 curr_map = map_groups__find_by_name(kmaps,
 571                                                         map->type, module);
 572                                 if (curr_map == NULL) {
 573                                         pr_debug("%s/proc/{kallsyms,modules} "
 574                                                  "inconsistency while looking "
 575                                                  "for \"%s\" module!\n",
 576                                                  machine->root_dir, module);
 577                                         curr_map = map;
 578                                         goto discard_symbol;
 579                                 }
 580
 581                                 if (curr_map->dso->loaded &&
 582                                     !machine__is_default_guest(machine))
 583                                         goto discard_symbol;
 584                         }
 585                         /*
 586                          * So that we look just like we get from .ko files,
 587                          * i.e. not prelinked, relative to map->start.
 588                          */
 589                         pos->start = curr_map->map_ip(curr_map, pos->start);
 590                         pos->end   = curr_map->map_ip(curr_map, pos->end);
 591                 } else if (curr_map != map) {
 592                         char dso_name[PATH_MAX];
 593                         struct dso *ndso;
 594
 595                         if (count == 0) {
 596                                 curr_map = map;
 597                                 goto filter_symbol;
 598                         }
 599
 600                         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 601                                 snprintf(dso_name, sizeof(dso_name),
 602                                         "[guest.kernel].%d",
 603                                         kernel_range++);
 604                         else
 605                                 snprintf(dso_name, sizeof(dso_name),
 606                                         "[kernel].%d",
 607                                         kernel_range++);
 608
 609                         ndso = dso__new(dso_name);
 610                         if (ndso == NULL)
 611                                 return -1;
 612
 613                         ndso->kernel = dso->kernel;
 614
 615                         curr_map = map__new2(pos->start, ndso, map->type);
 616                         if (curr_map == NULL) {
 617                                 dso__delete(ndso);
 618                                 return -1;
 619                         }
 620
 621                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 622                         map_groups__insert(kmaps, curr_map);
 623                         ++kernel_range;
 624                 }
 625 filter_symbol:
 626                 if (filter && filter(curr_map, pos)) {
 627 discard_symbol:         rb_erase(&pos->rb_node, root);
 628                         symbol__delete(pos);
 629                 } else {
 630                         if (curr_map != map) {
 631                                 rb_erase(&pos->rb_node, root);
 632                                 symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
 633                                 ++moved;
 634                         } else
 635                                 ++count;
 636                 }
 637         }
 638
 639         if (curr_map != map &&
 640             dso->kernel == DSO_TYPE_GUEST_KERNEL &&
 641             machine__is_default_guest(kmaps->machine)) {
 642                 dso__set_loaded(curr_map->dso, curr_map->type);
 643         }
 644
 645         return count + moved;
 646 }
 647
 648 bool symbol__restricted_filename(const char *filename,
 649                                  const char *restricted_filename)
 650 {
 651         bool restricted = false;
 652
 653         if (symbol_conf.kptr_restrict) {
 654                 char *r = realpath(filename, NULL);
 655
 656                 if (r != NULL) {
 657                         restricted = strcmp(r, restricted_filename) == 0;
 658                         free(r);
 659                         return restricted;
 660                 }
 661         }
 662
 663         return restricted;
 664 }
 665
 666 int dso__load_kallsyms(struct dso *dso, const char *filename,
 667                        struct map *map, symbol_filter_t filter)
 668 {
 669         if (symbol__restricted_filename(filename, "/proc/kallsyms"))
 670                 return -1;
 671
 672         if (dso__load_all_kallsyms(dso, filename, map) < 0)
 673                 return -1;
 674
 675         symbols__fixup_duplicate(&dso->symbols[map->type]);
 676         symbols__fixup_end(&dso->symbols[map->type]);
 677
 678         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 679                 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
 680         else
 681                 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
 682
 683         return dso__split_kallsyms(dso, map, filter);
 684 }
 685
 686 static int dso__load_perf_map(struct dso *dso, struct map *map,
 687                               symbol_filter_t filter)
 688 {
 689         char *line = NULL;
 690         size_t n;
 691         FILE *file;
 692         int nr_syms = 0;
 693
 694         file = fopen(dso->long_name, "r");
 695         if (file == NULL)
 696                 goto out_failure;
 697
 698         while (!feof(file)) {
 699                 u64 start, size;
 700                 struct symbol *sym;
 701                 int line_len, len;
 702
 703                 line_len = getline(&line, &n, file);
 704                 if (line_len < 0)
 705                         break;
 706
 707                 if (!line)
 708                         goto out_failure;
 709
 710                 line[--line_len] = '\0'; /* \n */
 711
 712                 len = hex2u64(line, &start);
 713
 714                 len++;
 715                 if (len + 2 >= line_len)
 716                         continue;
 717
 718                 len += hex2u64(line + len, &size);
 719
 720                 len++;
 721                 if (len + 2 >= line_len)
 722                         continue;
 723
 724                 sym = symbol__new(start, size, STB_GLOBAL, line + len);
 725
 726                 if (sym == NULL)
 727                         goto out_delete_line;
 728
 729                 if (filter && filter(map, sym))
 730                         symbol__delete(sym);
 731                 else {
 732                         symbols__insert(&dso->symbols[map->type], sym);
 733                         nr_syms++;
 734                 }
 735         }
 736
 737         free(line);
 738         fclose(file);
 739
 740         return nr_syms;
 741
 742 out_delete_line:
 743         free(line);
 744 out_failure:
 745         return -1;
 746 }
 747
 748 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 749 {
 750         char *name;
 751         int ret = -1;
 752         u_int i;
 753         struct machine *machine;
 754         char *root_dir = (char *) "";
 755         int ss_pos = 0;
 756         struct symsrc ss_[2];
 757         struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
 758
 759         dso__set_loaded(dso, map->type);
 760
 761         if (dso->kernel == DSO_TYPE_KERNEL)
 762                 return dso__load_kernel_sym(dso, map, filter);
 763         else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 764                 return dso__load_guest_kernel_sym(dso, map, filter);
 765
 766         if (map->groups && map->groups->machine)
 767                 machine = map->groups->machine;
 768         else
 769                 machine = NULL;
 770
 771         dso->adjust_symbols = 0;
 772
 773         if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
 774                 struct stat st;
 775
 776                 if (lstat(dso->name, &st) < 0)
 777                         return -1;
 778
 779                 if (st.st_uid && (st.st_uid != geteuid())) {
 780                         pr_warning("File %s not owned by current user or root, "
 781                                 "ignoring it.\n", dso->name);
 782                         return -1;
 783                 }
 784
 785                 ret = dso__load_perf_map(dso, map, filter);
 786                 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
 787                                              DSO_BINARY_TYPE__NOT_FOUND;
 788                 return ret;
 789         }
 790
 791         if (machine)
 792                 root_dir = machine->root_dir;
 793
 794         name = malloc(PATH_MAX);
 795         if (!name)
 796                 return -1;
 797
 798         /* Iterate over candidate debug images.
 799          * Keep track of "interesting" ones (those which have a symtab, dynsym,
 800          * and/or opd section) for processing.
 801          */
 802         for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
 803                 struct symsrc *ss = &ss_[ss_pos];
 804                 bool next_slot = false;
 805
 806                 enum dso_binary_type symtab_type = binary_type_symtab[i];
 807
 808                 if (dso__binary_type_file(dso, symtab_type,
 809                                           root_dir, name, PATH_MAX))
 810                         continue;
 811
 812                 /* Name is now the name of the next image to try */
 813                 if (symsrc__init(ss, dso, name, symtab_type) < 0)
 814                         continue;
 815
 816                 if (!syms_ss && symsrc__has_symtab(ss)) {
 817                         syms_ss = ss;
 818                         next_slot = true;
 819                 }
 820
 821                 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
 822                         runtime_ss = ss;
 823                         next_slot = true;
 824                 }
 825
 826                 if (next_slot) {
 827                         ss_pos++;
 828
 829                         if (syms_ss && runtime_ss)
 830                                 break;
 831                 }
 832
 833         }
 834
 835         if (!runtime_ss && !syms_ss)
 836                 goto out_free;
 837
 838         if (runtime_ss && !syms_ss) {
 839                 syms_ss = runtime_ss;
 840         }
 841
 842         /* We'll have to hope for the best */
 843         if (!runtime_ss && syms_ss)
 844                 runtime_ss = syms_ss;
 845
 846         if (syms_ss)
 847                 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, 0);
 848         else
 849                 ret = -1;
 850
 851         if (ret > 0) {
 852                 int nr_plt;
 853
 854                 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
 855                 if (nr_plt > 0)
 856                         ret += nr_plt;
 857         }
 858
 859         for (; ss_pos > 0; ss_pos--)
 860                 symsrc__destroy(&ss_[ss_pos - 1]);
 861 out_free:
 862         free(name);
 863         if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
 864                 return 0;
 865         return ret;
 866 }
 867
 868 struct map *map_groups__find_by_name(struct map_groups *mg,
 869                                      enum map_type type, const char *name)
 870 {
 871         struct rb_node *nd;
 872
 873         for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
 874                 struct map *map = rb_entry(nd, struct map, rb_node);
 875
 876                 if (map->dso && strcmp(map->dso->short_name, name) == 0)
 877                         return map;
 878         }
 879
 880         return NULL;
 881 }
 882
 883 int dso__load_vmlinux(struct dso *dso, struct map *map,
 884                       const char *vmlinux, symbol_filter_t filter)
 885 {
 886         int err = -1;
 887         struct symsrc ss;
 888         char symfs_vmlinux[PATH_MAX];
 889         enum dso_binary_type symtab_type;
 890
 891         snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
 892                  symbol_conf.symfs, vmlinux);
 893
 894         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 895                 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
 896         else
 897                 symtab_type = DSO_BINARY_TYPE__VMLINUX;
 898
 899         if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
 900                 return -1;
 901
 902         err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
 903         symsrc__destroy(&ss);
 904
 905         if (err > 0) {
 906                 dso__set_long_name(dso, (char *)vmlinux);
 907                 dso__set_loaded(dso, map->type);
 908                 pr_debug("Using %s for symbols\n", symfs_vmlinux);
 909         }
 910
 911         return err;
 912 }
 913
 914 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
 915                            symbol_filter_t filter)
 916 {
 917         int i, err = 0;
 918         char *filename;
 919
 920         pr_debug("Looking at the vmlinux_path (%d entries long)\n",
 921                  vmlinux_path__nr_entries + 1);
 922
 923         filename = dso__build_id_filename(dso, NULL, 0);
 924         if (filename != NULL) {
 925                 err = dso__load_vmlinux(dso, map, filename, filter);
 926                 if (err > 0) {
 927                         dso->lname_alloc = 1;
 928                         goto out;
 929                 }
 930                 free(filename);
 931         }
 932
 933         for (i = 0; i < vmlinux_path__nr_entries; ++i) {
 934                 err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
 935                 if (err > 0) {
 936                         dso__set_long_name(dso, strdup(vmlinux_path[i]));
 937                         dso->lname_alloc = 1;
 938                         break;
 939                 }
 940         }
 941 out:
 942         return err;
 943 }
 944
 945 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
 946                                 symbol_filter_t filter)
 947 {
 948         int err;
 949         const char *kallsyms_filename = NULL;
 950         char *kallsyms_allocated_filename = NULL;
 951         /*
 952          * Step 1: if the user specified a kallsyms or vmlinux filename, use
 953          * it and only it, reporting errors to the user if it cannot be used.
 954          *
 955          * For instance, try to analyse an ARM perf.data file _without_ a
 956          * build-id, or if the user specifies the wrong path to the right
 957          * vmlinux file, obviously we can't fallback to another vmlinux (a
 958          * x86_86 one, on the machine where analysis is being performed, say),
 959          * or worse, /proc/kallsyms.
 960          *
 961          * If the specified file _has_ a build-id and there is a build-id
 962          * section in the perf.data file, we will still do the expected
 963          * validation in dso__load_vmlinux and will bail out if they don't
 964          * match.
 965          */
 966         if (symbol_conf.kallsyms_name != NULL) {
 967                 kallsyms_filename = symbol_conf.kallsyms_name;
 968                 goto do_kallsyms;
 969         }
 970
 971         if (symbol_conf.vmlinux_name != NULL) {
 972                 err = dso__load_vmlinux(dso, map,
 973                                         symbol_conf.vmlinux_name, filter);
 974                 if (err > 0) {
 975                         dso__set_long_name(dso,
 976                                            strdup(symbol_conf.vmlinux_name));
 977                         dso->lname_alloc = 1;
 978                         goto out_fixup;
 979                 }
 980                 return err;
 981         }
 982
 983         if (vmlinux_path != NULL) {
 984                 err = dso__load_vmlinux_path(dso, map, filter);
 985                 if (err > 0)
 986                         goto out_fixup;
 987         }
 988
 989         /* do not try local files if a symfs was given */
 990         if (symbol_conf.symfs[0] != 0)
 991                 return -1;
 992
 993         /*
 994          * Say the kernel DSO was created when processing the build-id header table,
 995          * we have a build-id, so check if it is the same as the running kernel,
 996          * using it if it is.
 997          */
 998         if (dso->has_build_id) {
 999                 u8 kallsyms_build_id[BUILD_ID_SIZE];
1000                 char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1001
1002                 if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
1003                                          sizeof(kallsyms_build_id)) == 0) {
1004                         if (dso__build_id_equal(dso, kallsyms_build_id)) {
1005                                 kallsyms_filename = "/proc/kallsyms";
1006                                 goto do_kallsyms;
1007                         }
1008                 }
1009                 /*
1010                  * Now look if we have it on the build-id cache in
1011                  * $HOME/.debug/[kernel.kallsyms].
1012                  */
1013                 build_id__sprintf(dso->build_id, sizeof(dso->build_id),
1014                                   sbuild_id);
1015
1016                 if (asprintf(&kallsyms_allocated_filename,
1017                              "%s/.debug/[kernel.kallsyms]/%s",
1018                              getenv("HOME"), sbuild_id) == -1) {
1019                         pr_err("Not enough memory for kallsyms file lookup\n");
1020                         return -1;
1021                 }
1022
1023                 kallsyms_filename = kallsyms_allocated_filename;
1024
1025                 if (access(kallsyms_filename, F_OK)) {
1026                         pr_err("No kallsyms or vmlinux with build-id %s "
1027                                "was found\n", sbuild_id);
1028                         free(kallsyms_allocated_filename);
1029                         return -1;
1030                 }
1031         } else {
1032                 /*
1033                  * Last resort, if we don't have a build-id and couldn't find
1034                  * any vmlinux file, try the running kernel kallsyms table.
1035                  */
1036                 kallsyms_filename = "/proc/kallsyms";
1037         }
1038
1039 do_kallsyms:
1040         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1041         if (err > 0)
1042                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1043         free(kallsyms_allocated_filename);
1044
1045         if (err > 0) {
1046                 dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
1047 out_fixup:
1048                 map__fixup_start(map);
1049                 map__fixup_end(map);
1050         }
1051
1052         return err;
1053 }
1054
1055 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1056                                       symbol_filter_t filter)
1057 {
1058         int err;
1059         const char *kallsyms_filename = NULL;
1060         struct machine *machine;
1061         char path[PATH_MAX];
1062
1063         if (!map->groups) {
1064                 pr_debug("Guest kernel map hasn't the point to groups\n");
1065                 return -1;
1066         }
1067         machine = map->groups->machine;
1068
1069         if (machine__is_default_guest(machine)) {
1070                 /*
1071                  * if the user specified a vmlinux filename, use it and only
1072                  * it, reporting errors to the user if it cannot be used.
1073                  * Or use file guest_kallsyms inputted by user on commandline
1074                  */
1075                 if (symbol_conf.default_guest_vmlinux_name != NULL) {
1076                         err = dso__load_vmlinux(dso, map,
1077                                 symbol_conf.default_guest_vmlinux_name, filter);
1078                         goto out_try_fixup;
1079                 }
1080
1081                 kallsyms_filename = symbol_conf.default_guest_kallsyms;
1082                 if (!kallsyms_filename)
1083                         return -1;
1084         } else {
1085                 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1086                 kallsyms_filename = path;
1087         }
1088
1089         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1090         if (err > 0)
1091                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1092
1093 out_try_fixup:
1094         if (err > 0) {
1095                 if (kallsyms_filename != NULL) {
1096                         machine__mmap_name(machine, path, sizeof(path));
1097                         dso__set_long_name(dso, strdup(path));
1098                 }
1099                 map__fixup_start(map);
1100                 map__fixup_end(map);
1101         }
1102
1103         return err;
1104 }
1105
1106 static void vmlinux_path__exit(void)
1107 {
1108         while (--vmlinux_path__nr_entries >= 0) {
1109                 free(vmlinux_path[vmlinux_path__nr_entries]);
1110                 vmlinux_path[vmlinux_path__nr_entries] = NULL;
1111         }
1112
1113         free(vmlinux_path);
1114         vmlinux_path = NULL;
1115 }
1116
1117 static int vmlinux_path__init(void)
1118 {
1119         struct utsname uts;
1120         char bf[PATH_MAX];
1121
1122         vmlinux_path = malloc(sizeof(char *) * 5);
1123         if (vmlinux_path == NULL)
1124                 return -1;
1125
1126         vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1127         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1128                 goto out_fail;
1129         ++vmlinux_path__nr_entries;
1130         vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1131         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1132                 goto out_fail;
1133         ++vmlinux_path__nr_entries;
1134
1135         /* only try running kernel version if no symfs was given */
1136         if (symbol_conf.symfs[0] != 0)
1137                 return 0;
1138
1139         if (uname(&uts) < 0)
1140                 return -1;
1141
1142         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1143         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1144         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1145                 goto out_fail;
1146         ++vmlinux_path__nr_entries;
1147         snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1148         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1149         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1150                 goto out_fail;
1151         ++vmlinux_path__nr_entries;
1152         snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1153                  uts.release);
1154         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1155         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1156                 goto out_fail;
1157         ++vmlinux_path__nr_entries;
1158
1159         return 0;
1160
1161 out_fail:
1162         vmlinux_path__exit();
1163         return -1;
1164 }
1165
1166 static int setup_list(struct strlist **list, const char *list_str,
1167                       const char *list_name)
1168 {
1169         if (list_str == NULL)
1170                 return 0;
1171
1172         *list = strlist__new(true, list_str);
1173         if (!*list) {
1174                 pr_err("problems parsing %s list\n", list_name);
1175                 return -1;
1176         }
1177         return 0;
1178 }
1179
1180 static bool symbol__read_kptr_restrict(void)
1181 {
1182         bool value = false;
1183
1184         if (geteuid() != 0) {
1185                 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1186                 if (fp != NULL) {
1187                         char line[8];
1188
1189                         if (fgets(line, sizeof(line), fp) != NULL)
1190                                 value = atoi(line) != 0;
1191
1192                         fclose(fp);
1193                 }
1194         }
1195
1196         return value;
1197 }
1198
1199 int symbol__init(void)
1200 {
1201         const char *symfs;
1202
1203         if (symbol_conf.initialized)
1204                 return 0;
1205
1206         symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1207
1208         symbol__elf_init();
1209
1210         if (symbol_conf.sort_by_name)
1211                 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1212                                           sizeof(struct symbol));
1213
1214         if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1215                 return -1;
1216
1217         if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1218                 pr_err("'.' is the only non valid --field-separator argument\n");
1219                 return -1;
1220         }
1221
1222         if (setup_list(&symbol_conf.dso_list,
1223                        symbol_conf.dso_list_str, "dso") < 0)
1224                 return -1;
1225
1226         if (setup_list(&symbol_conf.comm_list,
1227                        symbol_conf.comm_list_str, "comm") < 0)
1228                 goto out_free_dso_list;
1229
1230         if (setup_list(&symbol_conf.sym_list,
1231                        symbol_conf.sym_list_str, "symbol") < 0)
1232                 goto out_free_comm_list;
1233
1234         /*
1235          * A path to symbols of "/" is identical to ""
1236          * reset here for simplicity.
1237          */
1238         symfs = realpath(symbol_conf.symfs, NULL);
1239         if (symfs == NULL)
1240                 symfs = symbol_conf.symfs;
1241         if (strcmp(symfs, "/") == 0)
1242                 symbol_conf.symfs = "";
1243         if (symfs != symbol_conf.symfs)
1244                 free((void *)symfs);
1245
1246         symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
1247
1248         symbol_conf.initialized = true;
1249         return 0;
1250
1251 out_free_comm_list:
1252         strlist__delete(symbol_conf.comm_list);
1253 out_free_dso_list:
1254         strlist__delete(symbol_conf.dso_list);
1255         return -1;
1256 }
1257
1258 void symbol__exit(void)
1259 {
1260         if (!symbol_conf.initialized)
1261                 return;
1262         strlist__delete(symbol_conf.sym_list);
1263         strlist__delete(symbol_conf.dso_list);
1264         strlist__delete(symbol_conf.comm_list);
1265         vmlinux_path__exit();
1266         symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1267         symbol_conf.initialized = false;
1268 }