Pileus Git - ~andy/linux/blob - 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         .use_modules      = true,
  36         .try_vmlinux_path = true,
  37         .annotate_src     = true,
  38         .demangle         = 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__OPENEMBEDDED_DEBUGINFO,
  55         DSO_BINARY_TYPE__NOT_FOUND,
  56 };
  57
  58 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
  59
  60 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
  61 {
  62         symbol_type = toupper(symbol_type);
  63
  64         switch (map_type) {
  65         case MAP__FUNCTION:
  66                 return symbol_type == 'T' || symbol_type == 'W';
  67         case MAP__VARIABLE:
  68                 return symbol_type == 'D';
  69         default:
  70                 return false;
  71         }
  72 }
  73
  74 static int prefix_underscores_count(const char *str)
  75 {
  76         const char *tail = str;
  77
  78         while (*tail == '_')
  79                 tail++;
  80
  81         return tail - str;
  82 }
  83
  84 #define SYMBOL_A 0
  85 #define SYMBOL_B 1
  86
  87 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
  88 {
  89         s64 a;
  90         s64 b;
  91         size_t na, nb;
  92
  93         /* Prefer a symbol with non zero length */
  94         a = syma->end - syma->start;
  95         b = symb->end - symb->start;
  96         if ((b == 0) && (a > 0))
  97                 return SYMBOL_A;
  98         else if ((a == 0) && (b > 0))
  99                 return SYMBOL_B;
 100
 101         /* Prefer a non weak symbol over a weak one */
 102         a = syma->binding == STB_WEAK;
 103         b = symb->binding == STB_WEAK;
 104         if (b && !a)
 105                 return SYMBOL_A;
 106         if (a && !b)
 107                 return SYMBOL_B;
 108
 109         /* Prefer a global symbol over a non global one */
 110         a = syma->binding == STB_GLOBAL;
 111         b = symb->binding == STB_GLOBAL;
 112         if (a && !b)
 113                 return SYMBOL_A;
 114         if (b && !a)
 115                 return SYMBOL_B;
 116
 117         /* Prefer a symbol with less underscores */
 118         a = prefix_underscores_count(syma->name);
 119         b = prefix_underscores_count(symb->name);
 120         if (b > a)
 121                 return SYMBOL_A;
 122         else if (a > b)
 123                 return SYMBOL_B;
 124
 125         /* Choose the symbol with the longest name */
 126         na = strlen(syma->name);
 127         nb = strlen(symb->name);
 128         if (na > nb)
 129                 return SYMBOL_A;
 130         else if (na < nb)
 131                 return SYMBOL_B;
 132
 133         /* Avoid "SyS" kernel syscall aliases */
 134         if (na >= 3 && !strncmp(syma->name, "SyS", 3))
 135                 return SYMBOL_B;
 136         if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
 137                 return SYMBOL_B;
 138
 139         return SYMBOL_A;
 140 }
 141
 142 void symbols__fixup_duplicate(struct rb_root *symbols)
 143 {
 144         struct rb_node *nd;
 145         struct symbol *curr, *next;
 146
 147         nd = rb_first(symbols);
 148
 149         while (nd) {
 150                 curr = rb_entry(nd, struct symbol, rb_node);
 151 again:
 152                 nd = rb_next(&curr->rb_node);
 153                 next = rb_entry(nd, struct symbol, rb_node);
 154
 155                 if (!nd)
 156                         break;
 157
 158                 if (curr->start != next->start)
 159                         continue;
 160
 161                 if (choose_best_symbol(curr, next) == SYMBOL_A) {
 162                         rb_erase(&next->rb_node, symbols);
 163                         symbol__delete(next);
 164                         goto again;
 165                 } else {
 166                         nd = rb_next(&curr->rb_node);
 167                         rb_erase(&curr->rb_node, symbols);
 168                         symbol__delete(curr);
 169                 }
 170         }
 171 }
 172
 173 void symbols__fixup_end(struct rb_root *symbols)
 174 {
 175         struct rb_node *nd, *prevnd = rb_first(symbols);
 176         struct symbol *curr, *prev;
 177
 178         if (prevnd == NULL)
 179                 return;
 180
 181         curr = rb_entry(prevnd, struct symbol, rb_node);
 182
 183         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 184                 prev = curr;
 185                 curr = rb_entry(nd, struct symbol, rb_node);
 186
 187                 if (prev->end == prev->start && prev->end != curr->start)
 188                         prev->end = curr->start - 1;
 189         }
 190
 191         /* Last entry */
 192         if (curr->end == curr->start)
 193                 curr->end = roundup(curr->start, 4096);
 194 }
 195
 196 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
 197 {
 198         struct map *prev, *curr;
 199         struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
 200
 201         if (prevnd == NULL)
 202                 return;
 203
 204         curr = rb_entry(prevnd, struct map, rb_node);
 205
 206         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 207                 prev = curr;
 208                 curr = rb_entry(nd, struct map, rb_node);
 209                 prev->end = curr->start - 1;
 210         }
 211
 212         /*
 213          * We still haven't the actual symbols, so guess the
 214          * last map final address.
 215          */
 216         curr->end = ~0ULL;
 217 }
 218
 219 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
 220 {
 221         size_t namelen = strlen(name) + 1;
 222         struct symbol *sym = calloc(1, (symbol_conf.priv_size +
 223                                         sizeof(*sym) + namelen));
 224         if (sym == NULL)
 225                 return NULL;
 226
 227         if (symbol_conf.priv_size)
 228                 sym = ((void *)sym) + symbol_conf.priv_size;
 229
 230         sym->start   = start;
 231         sym->end     = len ? start + len - 1 : start;
 232         sym->binding = binding;
 233         sym->namelen = namelen - 1;
 234
 235         pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
 236                   __func__, name, start, sym->end);
 237         memcpy(sym->name, name, namelen);
 238
 239         return sym;
 240 }
 241
 242 void symbol__delete(struct symbol *sym)
 243 {
 244         free(((void *)sym) - symbol_conf.priv_size);
 245 }
 246
 247 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
 248 {
 249         return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
 250                        sym->start, sym->end,
 251                        sym->binding == STB_GLOBAL ? 'g' :
 252                        sym->binding == STB_LOCAL  ? 'l' : 'w',
 253                        sym->name);
 254 }
 255
 256 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 257                                     const struct addr_location *al, FILE *fp)
 258 {
 259         unsigned long offset;
 260         size_t length;
 261
 262         if (sym && sym->name) {
 263                 length = fprintf(fp, "%s", sym->name);
 264                 if (al) {
 265                         if (al->addr < sym->end)
 266                                 offset = al->addr - sym->start;
 267                         else
 268                                 offset = al->addr - al->map->start - sym->start;
 269                         length += fprintf(fp, "+0x%lx", offset);
 270                 }
 271                 return length;
 272         } else
 273                 return fprintf(fp, "[unknown]");
 274 }
 275
 276 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
 277 {
 278         return symbol__fprintf_symname_offs(sym, NULL, fp);
 279 }
 280
 281 void symbols__delete(struct rb_root *symbols)
 282 {
 283         struct symbol *pos;
 284         struct rb_node *next = rb_first(symbols);
 285
 286         while (next) {
 287                 pos = rb_entry(next, struct symbol, rb_node);
 288                 next = rb_next(&pos->rb_node);
 289                 rb_erase(&pos->rb_node, symbols);
 290                 symbol__delete(pos);
 291         }
 292 }
 293
 294 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
 295 {
 296         struct rb_node **p = &symbols->rb_node;
 297         struct rb_node *parent = NULL;
 298         const u64 ip = sym->start;
 299         struct symbol *s;
 300
 301         while (*p != NULL) {
 302                 parent = *p;
 303                 s = rb_entry(parent, struct symbol, rb_node);
 304                 if (ip < s->start)
 305                         p = &(*p)->rb_left;
 306                 else
 307                         p = &(*p)->rb_right;
 308         }
 309         rb_link_node(&sym->rb_node, parent, p);
 310         rb_insert_color(&sym->rb_node, symbols);
 311 }
 312
 313 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
 314 {
 315         struct rb_node *n;
 316
 317         if (symbols == NULL)
 318                 return NULL;
 319
 320         n = symbols->rb_node;
 321
 322         while (n) {
 323                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
 324
 325                 if (ip < s->start)
 326                         n = n->rb_left;
 327                 else if (ip > s->end)
 328                         n = n->rb_right;
 329                 else
 330                         return s;
 331         }
 332
 333         return NULL;
 334 }
 335
 336 static struct symbol *symbols__first(struct rb_root *symbols)
 337 {
 338         struct rb_node *n = rb_first(symbols);
 339
 340         if (n)
 341                 return rb_entry(n, struct symbol, rb_node);
 342
 343         return NULL;
 344 }
 345
 346 struct symbol_name_rb_node {
 347         struct rb_node  rb_node;
 348         struct symbol   sym;
 349 };
 350
 351 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
 352 {
 353         struct rb_node **p = &symbols->rb_node;
 354         struct rb_node *parent = NULL;
 355         struct symbol_name_rb_node *symn, *s;
 356
 357         symn = container_of(sym, struct symbol_name_rb_node, sym);
 358
 359         while (*p != NULL) {
 360                 parent = *p;
 361                 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
 362                 if (strcmp(sym->name, s->sym.name) < 0)
 363                         p = &(*p)->rb_left;
 364                 else
 365                         p = &(*p)->rb_right;
 366         }
 367         rb_link_node(&symn->rb_node, parent, p);
 368         rb_insert_color(&symn->rb_node, symbols);
 369 }
 370
 371 static void symbols__sort_by_name(struct rb_root *symbols,
 372                                   struct rb_root *source)
 373 {
 374         struct rb_node *nd;
 375
 376         for (nd = rb_first(source); nd; nd = rb_next(nd)) {
 377                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 378                 symbols__insert_by_name(symbols, pos);
 379         }
 380 }
 381
 382 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
 383                                             const char *name)
 384 {
 385         struct rb_node *n;
 386
 387         if (symbols == NULL)
 388                 return NULL;
 389
 390         n = symbols->rb_node;
 391
 392         while (n) {
 393                 struct symbol_name_rb_node *s;
 394                 int cmp;
 395
 396                 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
 397                 cmp = strcmp(name, s->sym.name);
 398
 399                 if (cmp < 0)
 400                         n = n->rb_left;
 401                 else if (cmp > 0)
 402                         n = n->rb_right;
 403                 else
 404                         return &s->sym;
 405         }
 406
 407         return NULL;
 408 }
 409
 410 struct symbol *dso__find_symbol(struct dso *dso,
 411                                 enum map_type type, u64 addr)
 412 {
 413         return symbols__find(&dso->symbols[type], addr);
 414 }
 415
 416 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
 417 {
 418         return symbols__first(&dso->symbols[type]);
 419 }
 420
 421 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
 422                                         const char *name)
 423 {
 424         return symbols__find_by_name(&dso->symbol_names[type], name);
 425 }
 426
 427 void dso__sort_by_name(struct dso *dso, enum map_type type)
 428 {
 429         dso__set_sorted_by_name(dso, type);
 430         return symbols__sort_by_name(&dso->symbol_names[type],
 431                                      &dso->symbols[type]);
 432 }
 433
 434 size_t dso__fprintf_symbols_by_name(struct dso *dso,
 435                                     enum map_type type, FILE *fp)
 436 {
 437         size_t ret = 0;
 438         struct rb_node *nd;
 439         struct symbol_name_rb_node *pos;
 440
 441         for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
 442                 pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
 443                 fprintf(fp, "%s\n", pos->sym.name);
 444         }
 445
 446         return ret;
 447 }
 448
 449 int kallsyms__parse(const char *filename, void *arg,
 450                     int (*process_symbol)(void *arg, const char *name,
 451                                           char type, u64 start))
 452 {
 453         char *line = NULL;
 454         size_t n;
 455         int err = -1;
 456         FILE *file = fopen(filename, "r");
 457
 458         if (file == NULL)
 459                 goto out_failure;
 460
 461         err = 0;
 462
 463         while (!feof(file)) {
 464                 u64 start;
 465                 int line_len, len;
 466                 char symbol_type;
 467                 char *symbol_name;
 468
 469                 line_len = getline(&line, &n, file);
 470                 if (line_len < 0 || !line)
 471                         break;
 472
 473                 line[--line_len] = '\0'; /* \n */
 474
 475                 len = hex2u64(line, &start);
 476
 477                 len++;
 478                 if (len + 2 >= line_len)
 479                         continue;
 480
 481                 symbol_type = line[len];
 482                 len += 2;
 483                 symbol_name = line + len;
 484                 len = line_len - len;
 485
 486                 if (len >= KSYM_NAME_LEN) {
 487                         err = -1;
 488                         break;
 489                 }
 490
 491                 err = process_symbol(arg, symbol_name,
 492                                      symbol_type, start);
 493                 if (err)
 494                         break;
 495         }
 496
 497         free(line);
 498         fclose(file);
 499         return err;
 500
 501 out_failure:
 502         return -1;
 503 }
 504
 505 int modules__parse(const char *filename, void *arg,
 506                    int (*process_module)(void *arg, const char *name,
 507                                          u64 start))
 508 {
 509         char *line = NULL;
 510         size_t n;
 511         FILE *file;
 512         int err = 0;
 513
 514         file = fopen(filename, "r");
 515         if (file == NULL)
 516                 return -1;
 517
 518         while (1) {
 519                 char name[PATH_MAX];
 520                 u64 start;
 521                 char *sep;
 522                 ssize_t line_len;
 523
 524                 line_len = getline(&line, &n, file);
 525                 if (line_len < 0) {
 526                         if (feof(file))
 527                                 break;
 528                         err = -1;
 529                         goto out;
 530                 }
 531
 532                 if (!line) {
 533                         err = -1;
 534                         goto out;
 535                 }
 536
 537                 line[--line_len] = '\0'; /* \n */
 538
 539                 sep = strrchr(line, 'x');
 540                 if (sep == NULL)
 541                         continue;
 542
 543                 hex2u64(sep + 1, &start);
 544
 545                 sep = strchr(line, ' ');
 546                 if (sep == NULL)
 547                         continue;
 548
 549                 *sep = '\0';
 550
 551                 scnprintf(name, sizeof(name), "[%s]", line);
 552
 553                 err = process_module(arg, name, start);
 554                 if (err)
 555                         break;
 556         }
 557 out:
 558         free(line);
 559         fclose(file);
 560         return err;
 561 }
 562
 563 struct process_kallsyms_args {
 564         struct map *map;
 565         struct dso *dso;
 566 };
 567
 568 static u8 kallsyms2elf_type(char type)
 569 {
 570         if (type == 'W')
 571                 return STB_WEAK;
 572
 573         return isupper(type) ? STB_GLOBAL : STB_LOCAL;
 574 }
 575
 576 static int map__process_kallsym_symbol(void *arg, const char *name,
 577                                        char type, u64 start)
 578 {
 579         struct symbol *sym;
 580         struct process_kallsyms_args *a = arg;
 581         struct rb_root *root = &a->dso->symbols[a->map->type];
 582
 583         if (!symbol_type__is_a(type, a->map->type))
 584                 return 0;
 585
 586         /*
 587          * module symbols are not sorted so we add all
 588          * symbols, setting length to 0, and rely on
 589          * symbols__fixup_end() to fix it up.
 590          */
 591         sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
 592         if (sym == NULL)
 593                 return -ENOMEM;
 594         /*
 595          * We will pass the symbols to the filter later, in
 596          * map__split_kallsyms, when we have split the maps per module
 597          */
 598         symbols__insert(root, sym);
 599
 600         return 0;
 601 }
 602
 603 /*
 604  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 605  * so that we can in the next step set the symbol ->end address and then
 606  * call kernel_maps__split_kallsyms.
 607  */
 608 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
 609                                   struct map *map)
 610 {
 611         struct process_kallsyms_args args = { .map = map, .dso = dso, };
 612         return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
 613 }
 614
 615 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
 616                                          symbol_filter_t filter)
 617 {
 618         struct map_groups *kmaps = map__kmap(map)->kmaps;
 619         struct map *curr_map;
 620         struct symbol *pos;
 621         int count = 0, moved = 0;
 622         struct rb_root *root = &dso->symbols[map->type];
 623         struct rb_node *next = rb_first(root);
 624
 625         while (next) {
 626                 char *module;
 627
 628                 pos = rb_entry(next, struct symbol, rb_node);
 629                 next = rb_next(&pos->rb_node);
 630
 631                 module = strchr(pos->name, '\t');
 632                 if (module)
 633                         *module = '\0';
 634
 635                 curr_map = map_groups__find(kmaps, map->type, pos->start);
 636
 637                 if (!curr_map || (filter && filter(curr_map, pos))) {
 638                         rb_erase(&pos->rb_node, root);
 639                         symbol__delete(pos);
 640                 } else {
 641                         pos->start -= curr_map->start - curr_map->pgoff;
 642                         if (pos->end)
 643                                 pos->end -= curr_map->start - curr_map->pgoff;
 644                         if (curr_map != map) {
 645                                 rb_erase(&pos->rb_node, root);
 646                                 symbols__insert(
 647                                         &curr_map->dso->symbols[curr_map->type],
 648                                         pos);
 649                                 ++moved;
 650                         } else {
 651                                 ++count;
 652                         }
 653                 }
 654         }
 655
 656         /* Symbols have been adjusted */
 657         dso->adjust_symbols = 1;
 658
 659         return count + moved;
 660 }
 661
 662 /*
 663  * Split the symbols into maps, making sure there are no overlaps, i.e. the
 664  * kernel range is broken in several maps, named [kernel].N, as we don't have
 665  * the original ELF section names vmlinux have.
 666  */
 667 static int dso__split_kallsyms(struct dso *dso, struct map *map,
 668                                symbol_filter_t filter)
 669 {
 670         struct map_groups *kmaps = map__kmap(map)->kmaps;
 671         struct machine *machine = kmaps->machine;
 672         struct map *curr_map = map;
 673         struct symbol *pos;
 674         int count = 0, moved = 0;
 675         struct rb_root *root = &dso->symbols[map->type];
 676         struct rb_node *next = rb_first(root);
 677         int kernel_range = 0;
 678
 679         while (next) {
 680                 char *module;
 681
 682                 pos = rb_entry(next, struct symbol, rb_node);
 683                 next = rb_next(&pos->rb_node);
 684
 685                 module = strchr(pos->name, '\t');
 686                 if (module) {
 687                         if (!symbol_conf.use_modules)
 688                                 goto discard_symbol;
 689
 690                         *module++ = '\0';
 691
 692                         if (strcmp(curr_map->dso->short_name, module)) {
 693                                 if (curr_map != map &&
 694                                     dso->kernel == DSO_TYPE_GUEST_KERNEL &&
 695                                     machine__is_default_guest(machine)) {
 696                                         /*
 697                                          * We assume all symbols of a module are
 698                                          * continuous in * kallsyms, so curr_map
 699                                          * points to a module and all its
 700                                          * symbols are in its kmap. Mark it as
 701                                          * loaded.
 702                                          */
 703                                         dso__set_loaded(curr_map->dso,
 704                                                         curr_map->type);
 705                                 }
 706
 707                                 curr_map = map_groups__find_by_name(kmaps,
 708                                                         map->type, module);
 709                                 if (curr_map == NULL) {
 710                                         pr_debug("%s/proc/{kallsyms,modules} "
 711                                                  "inconsistency while looking "
 712                                                  "for \"%s\" module!\n",
 713                                                  machine->root_dir, module);
 714                                         curr_map = map;
 715                                         goto discard_symbol;
 716                                 }
 717
 718                                 if (curr_map->dso->loaded &&
 719                                     !machine__is_default_guest(machine))
 720                                         goto discard_symbol;
 721                         }
 722                         /*
 723                          * So that we look just like we get from .ko files,
 724                          * i.e. not prelinked, relative to map->start.
 725                          */
 726                         pos->start = curr_map->map_ip(curr_map, pos->start);
 727                         pos->end   = curr_map->map_ip(curr_map, pos->end);
 728                 } else if (curr_map != map) {
 729                         char dso_name[PATH_MAX];
 730                         struct dso *ndso;
 731
 732                         if (count == 0) {
 733                                 curr_map = map;
 734                                 goto filter_symbol;
 735                         }
 736
 737                         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 738                                 snprintf(dso_name, sizeof(dso_name),
 739                                         "[guest.kernel].%d",
 740                                         kernel_range++);
 741                         else
 742                                 snprintf(dso_name, sizeof(dso_name),
 743                                         "[kernel].%d",
 744                                         kernel_range++);
 745
 746                         ndso = dso__new(dso_name);
 747                         if (ndso == NULL)
 748                                 return -1;
 749
 750                         ndso->kernel = dso->kernel;
 751
 752                         curr_map = map__new2(pos->start, ndso, map->type);
 753                         if (curr_map == NULL) {
 754                                 dso__delete(ndso);
 755                                 return -1;
 756                         }
 757
 758                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 759                         map_groups__insert(kmaps, curr_map);
 760                         ++kernel_range;
 761                 }
 762 filter_symbol:
 763                 if (filter && filter(curr_map, pos)) {
 764 discard_symbol:         rb_erase(&pos->rb_node, root);
 765                         symbol__delete(pos);
 766                 } else {
 767                         if (curr_map != map) {
 768                                 rb_erase(&pos->rb_node, root);
 769                                 symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
 770                                 ++moved;
 771                         } else
 772                                 ++count;
 773                 }
 774         }
 775
 776         if (curr_map != map &&
 777             dso->kernel == DSO_TYPE_GUEST_KERNEL &&
 778             machine__is_default_guest(kmaps->machine)) {
 779                 dso__set_loaded(curr_map->dso, curr_map->type);
 780         }
 781
 782         return count + moved;
 783 }
 784
 785 bool symbol__restricted_filename(const char *filename,
 786                                  const char *restricted_filename)
 787 {
 788         bool restricted = false;
 789
 790         if (symbol_conf.kptr_restrict) {
 791                 char *r = realpath(filename, NULL);
 792
 793                 if (r != NULL) {
 794                         restricted = strcmp(r, restricted_filename) == 0;
 795                         free(r);
 796                         return restricted;
 797                 }
 798         }
 799
 800         return restricted;
 801 }
 802
 803 struct module_info {
 804         struct rb_node rb_node;
 805         char *name;
 806         u64 start;
 807 };
 808
 809 static void add_module(struct module_info *mi, struct rb_root *modules)
 810 {
 811         struct rb_node **p = &modules->rb_node;
 812         struct rb_node *parent = NULL;
 813         struct module_info *m;
 814
 815         while (*p != NULL) {
 816                 parent = *p;
 817                 m = rb_entry(parent, struct module_info, rb_node);
 818                 if (strcmp(mi->name, m->name) < 0)
 819                         p = &(*p)->rb_left;
 820                 else
 821                         p = &(*p)->rb_right;
 822         }
 823         rb_link_node(&mi->rb_node, parent, p);
 824         rb_insert_color(&mi->rb_node, modules);
 825 }
 826
 827 static void delete_modules(struct rb_root *modules)
 828 {
 829         struct module_info *mi;
 830         struct rb_node *next = rb_first(modules);
 831
 832         while (next) {
 833                 mi = rb_entry(next, struct module_info, rb_node);
 834                 next = rb_next(&mi->rb_node);
 835                 rb_erase(&mi->rb_node, modules);
 836                 free(mi->name);
 837                 free(mi);
 838         }
 839 }
 840
 841 static struct module_info *find_module(const char *name,
 842                                        struct rb_root *modules)
 843 {
 844         struct rb_node *n = modules->rb_node;
 845
 846         while (n) {
 847                 struct module_info *m;
 848                 int cmp;
 849
 850                 m = rb_entry(n, struct module_info, rb_node);
 851                 cmp = strcmp(name, m->name);
 852                 if (cmp < 0)
 853                         n = n->rb_left;
 854                 else if (cmp > 0)
 855                         n = n->rb_right;
 856                 else
 857                         return m;
 858         }
 859
 860         return NULL;
 861 }
 862
 863 static int __read_proc_modules(void *arg, const char *name, u64 start)
 864 {
 865         struct rb_root *modules = arg;
 866         struct module_info *mi;
 867
 868         mi = zalloc(sizeof(struct module_info));
 869         if (!mi)
 870                 return -ENOMEM;
 871
 872         mi->name = strdup(name);
 873         mi->start = start;
 874
 875         if (!mi->name) {
 876                 free(mi);
 877                 return -ENOMEM;
 878         }
 879
 880         add_module(mi, modules);
 881
 882         return 0;
 883 }
 884
 885 static int read_proc_modules(const char *filename, struct rb_root *modules)
 886 {
 887         if (symbol__restricted_filename(filename, "/proc/modules"))
 888                 return -1;
 889
 890         if (modules__parse(filename, modules, __read_proc_modules)) {
 891                 delete_modules(modules);
 892                 return -1;
 893         }
 894
 895         return 0;
 896 }
 897
 898 int compare_proc_modules(const char *from, const char *to)
 899 {
 900         struct rb_root from_modules = RB_ROOT;
 901         struct rb_root to_modules = RB_ROOT;
 902         struct rb_node *from_node, *to_node;
 903         struct module_info *from_m, *to_m;
 904         int ret = -1;
 905
 906         if (read_proc_modules(from, &from_modules))
 907                 return -1;
 908
 909         if (read_proc_modules(to, &to_modules))
 910                 goto out_delete_from;
 911
 912         from_node = rb_first(&from_modules);
 913         to_node = rb_first(&to_modules);
 914         while (from_node) {
 915                 if (!to_node)
 916                         break;
 917
 918                 from_m = rb_entry(from_node, struct module_info, rb_node);
 919                 to_m = rb_entry(to_node, struct module_info, rb_node);
 920
 921                 if (from_m->start != to_m->start ||
 922                     strcmp(from_m->name, to_m->name))
 923                         break;
 924
 925                 from_node = rb_next(from_node);
 926                 to_node = rb_next(to_node);
 927         }
 928
 929         if (!from_node && !to_node)
 930                 ret = 0;
 931
 932         delete_modules(&to_modules);
 933 out_delete_from:
 934         delete_modules(&from_modules);
 935
 936         return ret;
 937 }
 938
 939 static int do_validate_kcore_modules(const char *filename, struct map *map,
 940                                   struct map_groups *kmaps)
 941 {
 942         struct rb_root modules = RB_ROOT;
 943         struct map *old_map;
 944         int err;
 945
 946         err = read_proc_modules(filename, &modules);
 947         if (err)
 948                 return err;
 949
 950         old_map = map_groups__first(kmaps, map->type);
 951         while (old_map) {
 952                 struct map *next = map_groups__next(old_map);
 953                 struct module_info *mi;
 954
 955                 if (old_map == map || old_map->start == map->start) {
 956                         /* The kernel map */
 957                         old_map = next;
 958                         continue;
 959                 }
 960
 961                 /* Module must be in memory at the same address */
 962                 mi = find_module(old_map->dso->short_name, &modules);
 963                 if (!mi || mi->start != old_map->start) {
 964                         err = -EINVAL;
 965                         goto out;
 966                 }
 967
 968                 old_map = next;
 969         }
 970 out:
 971         delete_modules(&modules);
 972         return err;
 973 }
 974
 975 /*
 976  * If kallsyms is referenced by name then we look for filename in the same
 977  * directory.
 978  */
 979 static bool filename_from_kallsyms_filename(char *filename,
 980                                             const char *base_name,
 981                                             const char *kallsyms_filename)
 982 {
 983         char *name;
 984
 985         strcpy(filename, kallsyms_filename);
 986         name = strrchr(filename, '/');
 987         if (!name)
 988                 return false;
 989
 990         name += 1;
 991
 992         if (!strcmp(name, "kallsyms")) {
 993                 strcpy(name, base_name);
 994                 return true;
 995         }
 996
 997         return false;
 998 }
 999
1000 static int validate_kcore_modules(const char *kallsyms_filename,
1001                                   struct map *map)
1002 {
1003         struct map_groups *kmaps = map__kmap(map)->kmaps;
1004         char modules_filename[PATH_MAX];
1005
1006         if (!filename_from_kallsyms_filename(modules_filename, "modules",
1007                                              kallsyms_filename))
1008                 return -EINVAL;
1009
1010         if (do_validate_kcore_modules(modules_filename, map, kmaps))
1011                 return -EINVAL;
1012
1013         return 0;
1014 }
1015
1016 struct kcore_mapfn_data {
1017         struct dso *dso;
1018         enum map_type type;
1019         struct list_head maps;
1020 };
1021
1022 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1023 {
1024         struct kcore_mapfn_data *md = data;
1025         struct map *map;
1026
1027         map = map__new2(start, md->dso, md->type);
1028         if (map == NULL)
1029                 return -ENOMEM;
1030
1031         map->end = map->start + len;
1032         map->pgoff = pgoff;
1033
1034         list_add(&map->node, &md->maps);
1035
1036         return 0;
1037 }
1038
1039 static int dso__load_kcore(struct dso *dso, struct map *map,
1040                            const char *kallsyms_filename)
1041 {
1042         struct map_groups *kmaps = map__kmap(map)->kmaps;
1043         struct machine *machine = kmaps->machine;
1044         struct kcore_mapfn_data md;
1045         struct map *old_map, *new_map, *replacement_map = NULL;
1046         bool is_64_bit;
1047         int err, fd;
1048         char kcore_filename[PATH_MAX];
1049         struct symbol *sym;
1050
1051         /* This function requires that the map is the kernel map */
1052         if (map != machine->vmlinux_maps[map->type])
1053                 return -EINVAL;
1054
1055         if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1056                                              kallsyms_filename))
1057                 return -EINVAL;
1058
1059         /* All modules must be present at their original addresses */
1060         if (validate_kcore_modules(kallsyms_filename, map))
1061                 return -EINVAL;
1062
1063         md.dso = dso;
1064         md.type = map->type;
1065         INIT_LIST_HEAD(&md.maps);
1066
1067         fd = open(kcore_filename, O_RDONLY);
1068         if (fd < 0)
1069                 return -EINVAL;
1070
1071         /* Read new maps into temporary lists */
1072         err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1073                               &is_64_bit);
1074         if (err)
1075                 goto out_err;
1076
1077         if (list_empty(&md.maps)) {
1078                 err = -EINVAL;
1079                 goto out_err;
1080         }
1081
1082         /* Remove old maps */
1083         old_map = map_groups__first(kmaps, map->type);
1084         while (old_map) {
1085                 struct map *next = map_groups__next(old_map);
1086
1087                 if (old_map != map)
1088                         map_groups__remove(kmaps, old_map);
1089                 old_map = next;
1090         }
1091
1092         /* Find the kernel map using the first symbol */
1093         sym = dso__first_symbol(dso, map->type);
1094         list_for_each_entry(new_map, &md.maps, node) {
1095                 if (sym && sym->start >= new_map->start &&
1096                     sym->start < new_map->end) {
1097                         replacement_map = new_map;
1098                         break;
1099                 }
1100         }
1101
1102         if (!replacement_map)
1103                 replacement_map = list_entry(md.maps.next, struct map, node);
1104
1105         /* Add new maps */
1106         while (!list_empty(&md.maps)) {
1107                 new_map = list_entry(md.maps.next, struct map, node);
1108                 list_del(&new_map->node);
1109                 if (new_map == replacement_map) {
1110                         map->start      = new_map->start;
1111                         map->end        = new_map->end;
1112                         map->pgoff      = new_map->pgoff;
1113                         map->map_ip     = new_map->map_ip;
1114                         map->unmap_ip   = new_map->unmap_ip;
1115                         map__delete(new_map);
1116                         /* Ensure maps are correctly ordered */
1117                         map_groups__remove(kmaps, map);
1118                         map_groups__insert(kmaps, map);
1119                 } else {
1120                         map_groups__insert(kmaps, new_map);
1121                 }
1122         }
1123
1124         /*
1125          * Set the data type and long name so that kcore can be read via
1126          * dso__data_read_addr().
1127          */
1128         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1129                 dso->data_type = DSO_BINARY_TYPE__GUEST_KCORE;
1130         else
1131                 dso->data_type = DSO_BINARY_TYPE__KCORE;
1132         dso__set_long_name(dso, strdup(kcore_filename));
1133
1134         close(fd);
1135
1136         if (map->type == MAP__FUNCTION)
1137                 pr_debug("Using %s for kernel object code\n", kcore_filename);
1138         else
1139                 pr_debug("Using %s for kernel data\n", kcore_filename);
1140
1141         return 0;
1142
1143 out_err:
1144         while (!list_empty(&md.maps)) {
1145                 map = list_entry(md.maps.next, struct map, node);
1146                 list_del(&map->node);
1147                 map__delete(map);
1148         }
1149         close(fd);
1150         return -EINVAL;
1151 }
1152
1153 int dso__load_kallsyms(struct dso *dso, const char *filename,
1154                        struct map *map, symbol_filter_t filter)
1155 {
1156         if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1157                 return -1;
1158
1159         if (dso__load_all_kallsyms(dso, filename, map) < 0)
1160                 return -1;
1161
1162         symbols__fixup_duplicate(&dso->symbols[map->type]);
1163         symbols__fixup_end(&dso->symbols[map->type]);
1164
1165         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1166                 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1167         else
1168                 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1169
1170         if (!dso__load_kcore(dso, map, filename))
1171                 return dso__split_kallsyms_for_kcore(dso, map, filter);
1172         else
1173                 return dso__split_kallsyms(dso, map, filter);
1174 }
1175
1176 static int dso__load_perf_map(struct dso *dso, struct map *map,
1177                               symbol_filter_t filter)
1178 {
1179         char *line = NULL;
1180         size_t n;
1181         FILE *file;
1182         int nr_syms = 0;
1183
1184         file = fopen(dso->long_name, "r");
1185         if (file == NULL)
1186                 goto out_failure;
1187
1188         while (!feof(file)) {
1189                 u64 start, size;
1190                 struct symbol *sym;
1191                 int line_len, len;
1192
1193                 line_len = getline(&line, &n, file);
1194                 if (line_len < 0)
1195                         break;
1196
1197                 if (!line)
1198                         goto out_failure;
1199
1200                 line[--line_len] = '\0'; /* \n */
1201
1202                 len = hex2u64(line, &start);
1203
1204                 len++;
1205                 if (len + 2 >= line_len)
1206                         continue;
1207
1208                 len += hex2u64(line + len, &size);
1209
1210                 len++;
1211                 if (len + 2 >= line_len)
1212                         continue;
1213
1214                 sym = symbol__new(start, size, STB_GLOBAL, line + len);
1215
1216                 if (sym == NULL)
1217                         goto out_delete_line;
1218
1219                 if (filter && filter(map, sym))
1220                         symbol__delete(sym);
1221                 else {
1222                         symbols__insert(&dso->symbols[map->type], sym);
1223                         nr_syms++;
1224                 }
1225         }
1226
1227         free(line);
1228         fclose(file);
1229
1230         return nr_syms;
1231
1232 out_delete_line:
1233         free(line);
1234 out_failure:
1235         return -1;
1236 }
1237
1238 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1239 {
1240         char *name;
1241         int ret = -1;
1242         u_int i;
1243         struct machine *machine;
1244         char *root_dir = (char *) "";
1245         int ss_pos = 0;
1246         struct symsrc ss_[2];
1247         struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1248
1249         dso__set_loaded(dso, map->type);
1250
1251         if (dso->kernel == DSO_TYPE_KERNEL)
1252                 return dso__load_kernel_sym(dso, map, filter);
1253         else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1254                 return dso__load_guest_kernel_sym(dso, map, filter);
1255
1256         if (map->groups && map->groups->machine)
1257                 machine = map->groups->machine;
1258         else
1259                 machine = NULL;
1260
1261         dso->adjust_symbols = 0;
1262
1263         if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1264                 struct stat st;
1265
1266                 if (lstat(dso->name, &st) < 0)
1267                         return -1;
1268
1269                 if (st.st_uid && (st.st_uid != geteuid())) {
1270                         pr_warning("File %s not owned by current user or root, "
1271                                 "ignoring it.\n", dso->name);
1272                         return -1;
1273                 }
1274
1275                 ret = dso__load_perf_map(dso, map, filter);
1276                 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1277                                              DSO_BINARY_TYPE__NOT_FOUND;
1278                 return ret;
1279         }
1280
1281         if (machine)
1282                 root_dir = machine->root_dir;
1283
1284         name = malloc(PATH_MAX);
1285         if (!name)
1286                 return -1;
1287
1288         /* Iterate over candidate debug images.
1289          * Keep track of "interesting" ones (those which have a symtab, dynsym,
1290          * and/or opd section) for processing.
1291          */
1292         for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1293                 struct symsrc *ss = &ss_[ss_pos];
1294                 bool next_slot = false;
1295
1296                 enum dso_binary_type symtab_type = binary_type_symtab[i];
1297
1298                 if (dso__binary_type_file(dso, symtab_type,
1299                                           root_dir, name, PATH_MAX))
1300                         continue;
1301
1302                 /* Name is now the name of the next image to try */
1303                 if (symsrc__init(ss, dso, name, symtab_type) < 0)
1304                         continue;
1305
1306                 if (!syms_ss && symsrc__has_symtab(ss)) {
1307                         syms_ss = ss;
1308                         next_slot = true;
1309                 }
1310
1311                 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1312                         runtime_ss = ss;
1313                         next_slot = true;
1314                 }
1315
1316                 if (next_slot) {
1317                         ss_pos++;
1318
1319                         if (syms_ss && runtime_ss)
1320                                 break;
1321                 }
1322
1323         }
1324
1325         if (!runtime_ss && !syms_ss)
1326                 goto out_free;
1327
1328         if (runtime_ss && !syms_ss) {
1329                 syms_ss = runtime_ss;
1330         }
1331
1332         /* We'll have to hope for the best */
1333         if (!runtime_ss && syms_ss)
1334                 runtime_ss = syms_ss;
1335
1336         if (syms_ss) {
1337                 int km;
1338
1339                 km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1340                      dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
1341                 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
1342         } else {
1343                 ret = -1;
1344         }
1345
1346         if (ret > 0) {
1347                 int nr_plt;
1348
1349                 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1350                 if (nr_plt > 0)
1351                         ret += nr_plt;
1352         }
1353
1354         for (; ss_pos > 0; ss_pos--)
1355                 symsrc__destroy(&ss_[ss_pos - 1]);
1356 out_free:
1357         free(name);
1358         if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1359                 return 0;
1360         return ret;
1361 }
1362
1363 struct map *map_groups__find_by_name(struct map_groups *mg,
1364                                      enum map_type type, const char *name)
1365 {
1366         struct rb_node *nd;
1367
1368         for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
1369                 struct map *map = rb_entry(nd, struct map, rb_node);
1370
1371                 if (map->dso && strcmp(map->dso->short_name, name) == 0)
1372                         return map;
1373         }
1374
1375         return NULL;
1376 }
1377
1378 int dso__load_vmlinux(struct dso *dso, struct map *map,
1379                       const char *vmlinux, symbol_filter_t filter)
1380 {
1381         int err = -1;
1382         struct symsrc ss;
1383         char symfs_vmlinux[PATH_MAX];
1384         enum dso_binary_type symtab_type;
1385
1386         if (vmlinux[0] == '/')
1387                 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1388         else
1389                 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
1390                          symbol_conf.symfs, vmlinux);
1391
1392         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1393                 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1394         else
1395                 symtab_type = DSO_BINARY_TYPE__VMLINUX;
1396
1397         if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1398                 return -1;
1399
1400         err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1401         symsrc__destroy(&ss);
1402
1403         if (err > 0) {
1404                 if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1405                         dso->data_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1406                 else
1407                         dso->data_type = DSO_BINARY_TYPE__VMLINUX;
1408                 dso__set_long_name(dso, (char *)vmlinux);
1409                 dso__set_loaded(dso, map->type);
1410                 pr_debug("Using %s for symbols\n", symfs_vmlinux);
1411         }
1412
1413         return err;
1414 }
1415
1416 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1417                            symbol_filter_t filter)
1418 {
1419         int i, err = 0;
1420         char *filename;
1421
1422         pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1423                  vmlinux_path__nr_entries + 1);
1424
1425         filename = dso__build_id_filename(dso, NULL, 0);
1426         if (filename != NULL) {
1427                 err = dso__load_vmlinux(dso, map, filename, filter);
1428                 if (err > 0) {
1429                         dso->lname_alloc = 1;
1430                         goto out;
1431                 }
1432                 free(filename);
1433         }
1434
1435         for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1436                 err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
1437                 if (err > 0) {
1438                         dso__set_long_name(dso, strdup(vmlinux_path[i]));
1439                         dso->lname_alloc = 1;
1440                         break;
1441                 }
1442         }
1443 out:
1444         return err;
1445 }
1446
1447 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1448 {
1449         char kallsyms_filename[PATH_MAX];
1450         struct dirent *dent;
1451         int ret = -1;
1452         DIR *d;
1453
1454         d = opendir(dir);
1455         if (!d)
1456                 return -1;
1457
1458         while (1) {
1459                 dent = readdir(d);
1460                 if (!dent)
1461                         break;
1462                 if (dent->d_type != DT_DIR)
1463                         continue;
1464                 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1465                           "%s/%s/kallsyms", dir, dent->d_name);
1466                 if (!validate_kcore_modules(kallsyms_filename, map)) {
1467                         strlcpy(dir, kallsyms_filename, dir_sz);
1468                         ret = 0;
1469                         break;
1470                 }
1471         }
1472
1473         closedir(d);
1474
1475         return ret;
1476 }
1477
1478 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1479 {
1480         u8 host_build_id[BUILD_ID_SIZE];
1481         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1482         bool is_host = false;
1483         char path[PATH_MAX];
1484
1485         if (!dso->has_build_id) {
1486                 /*
1487                  * Last resort, if we don't have a build-id and couldn't find
1488                  * any vmlinux file, try the running kernel kallsyms table.
1489                  */
1490                 goto proc_kallsyms;
1491         }
1492
1493         if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1494                                  sizeof(host_build_id)) == 0)
1495                 is_host = dso__build_id_equal(dso, host_build_id);
1496
1497         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1498
1499         /* Use /proc/kallsyms if possible */
1500         if (is_host) {
1501                 DIR *d;
1502                 int fd;
1503
1504                 /* If no cached kcore go with /proc/kallsyms */
1505                 scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s",
1506                           buildid_dir, sbuild_id);
1507                 d = opendir(path);
1508                 if (!d)
1509                         goto proc_kallsyms;
1510                 closedir(d);
1511
1512                 /*
1513                  * Do not check the build-id cache, until we know we cannot use
1514                  * /proc/kcore.
1515                  */
1516                 fd = open("/proc/kcore", O_RDONLY);
1517                 if (fd != -1) {
1518                         close(fd);
1519                         /* If module maps match go with /proc/kallsyms */
1520                         if (!validate_kcore_modules("/proc/kallsyms", map))
1521                                 goto proc_kallsyms;
1522                 }
1523
1524                 /* Find kallsyms in build-id cache with kcore */
1525                 if (!find_matching_kcore(map, path, sizeof(path)))
1526                         return strdup(path);
1527
1528                 goto proc_kallsyms;
1529         }
1530
1531         scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1532                   buildid_dir, sbuild_id);
1533
1534         if (access(path, F_OK)) {
1535                 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1536                        sbuild_id);
1537                 return NULL;
1538         }
1539
1540         return strdup(path);
1541
1542 proc_kallsyms:
1543         return strdup("/proc/kallsyms");
1544 }
1545
1546 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1547                                 symbol_filter_t filter)
1548 {
1549         int err;
1550         const char *kallsyms_filename = NULL;
1551         char *kallsyms_allocated_filename = NULL;
1552         /*
1553          * Step 1: if the user specified a kallsyms or vmlinux filename, use
1554          * it and only it, reporting errors to the user if it cannot be used.
1555          *
1556          * For instance, try to analyse an ARM perf.data file _without_ a
1557          * build-id, or if the user specifies the wrong path to the right
1558          * vmlinux file, obviously we can't fallback to another vmlinux (a
1559          * x86_86 one, on the machine where analysis is being performed, say),
1560          * or worse, /proc/kallsyms.
1561          *
1562          * If the specified file _has_ a build-id and there is a build-id
1563          * section in the perf.data file, we will still do the expected
1564          * validation in dso__load_vmlinux and will bail out if they don't
1565          * match.
1566          */
1567         if (symbol_conf.kallsyms_name != NULL) {
1568                 kallsyms_filename = symbol_conf.kallsyms_name;
1569                 goto do_kallsyms;
1570         }
1571
1572         if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1573                 err = dso__load_vmlinux(dso, map,
1574                                         symbol_conf.vmlinux_name, filter);
1575                 if (err > 0) {
1576                         dso__set_long_name(dso,
1577                                            strdup(symbol_conf.vmlinux_name));
1578                         dso->lname_alloc = 1;
1579                         return err;
1580                 }
1581                 return err;
1582         }
1583
1584         if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1585                 err = dso__load_vmlinux_path(dso, map, filter);
1586                 if (err > 0)
1587                         return err;
1588         }
1589
1590         /* do not try local files if a symfs was given */
1591         if (symbol_conf.symfs[0] != 0)
1592                 return -1;
1593
1594         kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1595         if (!kallsyms_allocated_filename)
1596                 return -1;
1597
1598         kallsyms_filename = kallsyms_allocated_filename;
1599
1600 do_kallsyms:
1601         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1602         if (err > 0)
1603                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1604         free(kallsyms_allocated_filename);
1605
1606         if (err > 0 && !dso__is_kcore(dso)) {
1607                 dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
1608                 map__fixup_start(map);
1609                 map__fixup_end(map);
1610         }
1611
1612         return err;
1613 }
1614
1615 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1616                                       symbol_filter_t filter)
1617 {
1618         int err;
1619         const char *kallsyms_filename = NULL;
1620         struct machine *machine;
1621         char path[PATH_MAX];
1622
1623         if (!map->groups) {
1624                 pr_debug("Guest kernel map hasn't the point to groups\n");
1625                 return -1;
1626         }
1627         machine = map->groups->machine;
1628
1629         if (machine__is_default_guest(machine)) {
1630                 /*
1631                  * if the user specified a vmlinux filename, use it and only
1632                  * it, reporting errors to the user if it cannot be used.
1633                  * Or use file guest_kallsyms inputted by user on commandline
1634                  */
1635                 if (symbol_conf.default_guest_vmlinux_name != NULL) {
1636                         err = dso__load_vmlinux(dso, map,
1637                                 symbol_conf.default_guest_vmlinux_name, filter);
1638                         return err;
1639                 }
1640
1641                 kallsyms_filename = symbol_conf.default_guest_kallsyms;
1642                 if (!kallsyms_filename)
1643                         return -1;
1644         } else {
1645                 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1646                 kallsyms_filename = path;
1647         }
1648
1649         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1650         if (err > 0)
1651                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1652         if (err > 0 && !dso__is_kcore(dso)) {
1653                 machine__mmap_name(machine, path, sizeof(path));
1654                 dso__set_long_name(dso, strdup(path));
1655                 map__fixup_start(map);
1656                 map__fixup_end(map);
1657         }
1658
1659         return err;
1660 }
1661
1662 static void vmlinux_path__exit(void)
1663 {
1664         while (--vmlinux_path__nr_entries >= 0) {
1665                 free(vmlinux_path[vmlinux_path__nr_entries]);
1666                 vmlinux_path[vmlinux_path__nr_entries] = NULL;
1667         }
1668
1669         free(vmlinux_path);
1670         vmlinux_path = NULL;
1671 }
1672
1673 static int vmlinux_path__init(void)
1674 {
1675         struct utsname uts;
1676         char bf[PATH_MAX];
1677
1678         vmlinux_path = malloc(sizeof(char *) * 5);
1679         if (vmlinux_path == NULL)
1680                 return -1;
1681
1682         vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1683         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1684                 goto out_fail;
1685         ++vmlinux_path__nr_entries;
1686         vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1687         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1688                 goto out_fail;
1689         ++vmlinux_path__nr_entries;
1690
1691         /* only try running kernel version if no symfs was given */
1692         if (symbol_conf.symfs[0] != 0)
1693                 return 0;
1694
1695         if (uname(&uts) < 0)
1696                 return -1;
1697
1698         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1699         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1700         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1701                 goto out_fail;
1702         ++vmlinux_path__nr_entries;
1703         snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1704         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1705         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1706                 goto out_fail;
1707         ++vmlinux_path__nr_entries;
1708         snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1709                  uts.release);
1710         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1711         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1712                 goto out_fail;
1713         ++vmlinux_path__nr_entries;
1714
1715         return 0;
1716
1717 out_fail:
1718         vmlinux_path__exit();
1719         return -1;
1720 }
1721
1722 static int setup_list(struct strlist **list, const char *list_str,
1723                       const char *list_name)
1724 {
1725         if (list_str == NULL)
1726                 return 0;
1727
1728         *list = strlist__new(true, list_str);
1729         if (!*list) {
1730                 pr_err("problems parsing %s list\n", list_name);
1731                 return -1;
1732         }
1733         return 0;
1734 }
1735
1736 static bool symbol__read_kptr_restrict(void)
1737 {
1738         bool value = false;
1739
1740         if (geteuid() != 0) {
1741                 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1742                 if (fp != NULL) {
1743                         char line[8];
1744
1745                         if (fgets(line, sizeof(line), fp) != NULL)
1746                                 value = atoi(line) != 0;
1747
1748                         fclose(fp);
1749                 }
1750         }
1751
1752         return value;
1753 }
1754
1755 int symbol__init(void)
1756 {
1757         const char *symfs;
1758
1759         if (symbol_conf.initialized)
1760                 return 0;
1761
1762         symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1763
1764         symbol__elf_init();
1765
1766         if (symbol_conf.sort_by_name)
1767                 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1768                                           sizeof(struct symbol));
1769
1770         if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1771                 return -1;
1772
1773         if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1774                 pr_err("'.' is the only non valid --field-separator argument\n");
1775                 return -1;
1776         }
1777
1778         if (setup_list(&symbol_conf.dso_list,
1779                        symbol_conf.dso_list_str, "dso") < 0)
1780                 return -1;
1781
1782         if (setup_list(&symbol_conf.comm_list,
1783                        symbol_conf.comm_list_str, "comm") < 0)
1784                 goto out_free_dso_list;
1785
1786         if (setup_list(&symbol_conf.sym_list,
1787                        symbol_conf.sym_list_str, "symbol") < 0)
1788                 goto out_free_comm_list;
1789
1790         /*
1791          * A path to symbols of "/" is identical to ""
1792          * reset here for simplicity.
1793          */
1794         symfs = realpath(symbol_conf.symfs, NULL);
1795         if (symfs == NULL)
1796                 symfs = symbol_conf.symfs;
1797         if (strcmp(symfs, "/") == 0)
1798                 symbol_conf.symfs = "";
1799         if (symfs != symbol_conf.symfs)
1800                 free((void *)symfs);
1801
1802         symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
1803
1804         symbol_conf.initialized = true;
1805         return 0;
1806
1807 out_free_comm_list:
1808         strlist__delete(symbol_conf.comm_list);
1809 out_free_dso_list:
1810         strlist__delete(symbol_conf.dso_list);
1811         return -1;
1812 }
1813
1814 void symbol__exit(void)
1815 {
1816         if (!symbol_conf.initialized)
1817                 return;
1818         strlist__delete(symbol_conf.sym_list);
1819         strlist__delete(symbol_conf.dso_list);
1820         strlist__delete(symbol_conf.comm_list);
1821         vmlinux_path__exit();
1822         symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1823         symbol_conf.initialized = false;
1824 }