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 <symbol/kallsyms.h>
  22 #include <sys/utsname.h>
  23
  24 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
  25                                 symbol_filter_t filter);
  26 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
  27                         symbol_filter_t filter);
  28 int vmlinux_path__nr_entries;
  29 char **vmlinux_path;
  30
  31 struct symbol_conf symbol_conf = {
  32         .use_modules      = true,
  33         .try_vmlinux_path = true,
  34         .annotate_src     = true,
  35         .demangle         = true,
  36         .symfs            = "",
  37 };
  38
  39 static enum dso_binary_type binary_type_symtab[] = {
  40         DSO_BINARY_TYPE__KALLSYMS,
  41         DSO_BINARY_TYPE__GUEST_KALLSYMS,
  42         DSO_BINARY_TYPE__JAVA_JIT,
  43         DSO_BINARY_TYPE__DEBUGLINK,
  44         DSO_BINARY_TYPE__BUILD_ID_CACHE,
  45         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
  46         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
  47         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
  48         DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
  49         DSO_BINARY_TYPE__GUEST_KMODULE,
  50         DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
  51         DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
  52         DSO_BINARY_TYPE__NOT_FOUND,
  53 };
  54
  55 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
  56
  57 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
  58 {
  59         symbol_type = toupper(symbol_type);
  60
  61         switch (map_type) {
  62         case MAP__FUNCTION:
  63                 return symbol_type == 'T' || symbol_type == 'W';
  64         case MAP__VARIABLE:
  65                 return symbol_type == 'D';
  66         default:
  67                 return false;
  68         }
  69 }
  70
  71 static int prefix_underscores_count(const char *str)
  72 {
  73         const char *tail = str;
  74
  75         while (*tail == '_')
  76                 tail++;
  77
  78         return tail - str;
  79 }
  80
  81 #define SYMBOL_A 0
  82 #define SYMBOL_B 1
  83
  84 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
  85 {
  86         s64 a;
  87         s64 b;
  88         size_t na, nb;
  89
  90         /* Prefer a symbol with non zero length */
  91         a = syma->end - syma->start;
  92         b = symb->end - symb->start;
  93         if ((b == 0) && (a > 0))
  94                 return SYMBOL_A;
  95         else if ((a == 0) && (b > 0))
  96                 return SYMBOL_B;
  97
  98         /* Prefer a non weak symbol over a weak one */
  99         a = syma->binding == STB_WEAK;
 100         b = symb->binding == STB_WEAK;
 101         if (b && !a)
 102                 return SYMBOL_A;
 103         if (a && !b)
 104                 return SYMBOL_B;
 105
 106         /* Prefer a global symbol over a non global one */
 107         a = syma->binding == STB_GLOBAL;
 108         b = symb->binding == STB_GLOBAL;
 109         if (a && !b)
 110                 return SYMBOL_A;
 111         if (b && !a)
 112                 return SYMBOL_B;
 113
 114         /* Prefer a symbol with less underscores */
 115         a = prefix_underscores_count(syma->name);
 116         b = prefix_underscores_count(symb->name);
 117         if (b > a)
 118                 return SYMBOL_A;
 119         else if (a > b)
 120                 return SYMBOL_B;
 121
 122         /* Choose the symbol with the longest name */
 123         na = strlen(syma->name);
 124         nb = strlen(symb->name);
 125         if (na > nb)
 126                 return SYMBOL_A;
 127         else if (na < nb)
 128                 return SYMBOL_B;
 129
 130         /* Avoid "SyS" kernel syscall aliases */
 131         if (na >= 3 && !strncmp(syma->name, "SyS", 3))
 132                 return SYMBOL_B;
 133         if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
 134                 return SYMBOL_B;
 135
 136         return SYMBOL_A;
 137 }
 138
 139 void symbols__fixup_duplicate(struct rb_root *symbols)
 140 {
 141         struct rb_node *nd;
 142         struct symbol *curr, *next;
 143
 144         nd = rb_first(symbols);
 145
 146         while (nd) {
 147                 curr = rb_entry(nd, struct symbol, rb_node);
 148 again:
 149                 nd = rb_next(&curr->rb_node);
 150                 next = rb_entry(nd, struct symbol, rb_node);
 151
 152                 if (!nd)
 153                         break;
 154
 155                 if (curr->start != next->start)
 156                         continue;
 157
 158                 if (choose_best_symbol(curr, next) == SYMBOL_A) {
 159                         rb_erase(&next->rb_node, symbols);
 160                         symbol__delete(next);
 161                         goto again;
 162                 } else {
 163                         nd = rb_next(&curr->rb_node);
 164                         rb_erase(&curr->rb_node, symbols);
 165                         symbol__delete(curr);
 166                 }
 167         }
 168 }
 169
 170 void symbols__fixup_end(struct rb_root *symbols)
 171 {
 172         struct rb_node *nd, *prevnd = rb_first(symbols);
 173         struct symbol *curr, *prev;
 174
 175         if (prevnd == NULL)
 176                 return;
 177
 178         curr = rb_entry(prevnd, struct symbol, rb_node);
 179
 180         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 181                 prev = curr;
 182                 curr = rb_entry(nd, struct symbol, rb_node);
 183
 184                 if (prev->end == prev->start && prev->end != curr->start)
 185                         prev->end = curr->start - 1;
 186         }
 187
 188         /* Last entry */
 189         if (curr->end == curr->start)
 190                 curr->end = roundup(curr->start, 4096);
 191 }
 192
 193 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
 194 {
 195         struct map *prev, *curr;
 196         struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
 197
 198         if (prevnd == NULL)
 199                 return;
 200
 201         curr = rb_entry(prevnd, struct map, rb_node);
 202
 203         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 204                 prev = curr;
 205                 curr = rb_entry(nd, struct map, rb_node);
 206                 prev->end = curr->start - 1;
 207         }
 208
 209         /*
 210          * We still haven't the actual symbols, so guess the
 211          * last map final address.
 212          */
 213         curr->end = ~0ULL;
 214 }
 215
 216 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
 217 {
 218         size_t namelen = strlen(name) + 1;
 219         struct symbol *sym = calloc(1, (symbol_conf.priv_size +
 220                                         sizeof(*sym) + namelen));
 221         if (sym == NULL)
 222                 return NULL;
 223
 224         if (symbol_conf.priv_size)
 225                 sym = ((void *)sym) + symbol_conf.priv_size;
 226
 227         sym->start   = start;
 228         sym->end     = len ? start + len - 1 : start;
 229         sym->binding = binding;
 230         sym->namelen = namelen - 1;
 231
 232         pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
 233                   __func__, name, start, sym->end);
 234         memcpy(sym->name, name, namelen);
 235
 236         return sym;
 237 }
 238
 239 void symbol__delete(struct symbol *sym)
 240 {
 241         free(((void *)sym) - symbol_conf.priv_size);
 242 }
 243
 244 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
 245 {
 246         return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
 247                        sym->start, sym->end,
 248                        sym->binding == STB_GLOBAL ? 'g' :
 249                        sym->binding == STB_LOCAL  ? 'l' : 'w',
 250                        sym->name);
 251 }
 252
 253 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 254                                     const struct addr_location *al, FILE *fp)
 255 {
 256         unsigned long offset;
 257         size_t length;
 258
 259         if (sym && sym->name) {
 260                 length = fprintf(fp, "%s", sym->name);
 261                 if (al) {
 262                         if (al->addr < sym->end)
 263                                 offset = al->addr - sym->start;
 264                         else
 265                                 offset = al->addr - al->map->start - sym->start;
 266                         length += fprintf(fp, "+0x%lx", offset);
 267                 }
 268                 return length;
 269         } else
 270                 return fprintf(fp, "[unknown]");
 271 }
 272
 273 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
 274 {
 275         return symbol__fprintf_symname_offs(sym, NULL, fp);
 276 }
 277
 278 void symbols__delete(struct rb_root *symbols)
 279 {
 280         struct symbol *pos;
 281         struct rb_node *next = rb_first(symbols);
 282
 283         while (next) {
 284                 pos = rb_entry(next, struct symbol, rb_node);
 285                 next = rb_next(&pos->rb_node);
 286                 rb_erase(&pos->rb_node, symbols);
 287                 symbol__delete(pos);
 288         }
 289 }
 290
 291 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
 292 {
 293         struct rb_node **p = &symbols->rb_node;
 294         struct rb_node *parent = NULL;
 295         const u64 ip = sym->start;
 296         struct symbol *s;
 297
 298         while (*p != NULL) {
 299                 parent = *p;
 300                 s = rb_entry(parent, struct symbol, rb_node);
 301                 if (ip < s->start)
 302                         p = &(*p)->rb_left;
 303                 else
 304                         p = &(*p)->rb_right;
 305         }
 306         rb_link_node(&sym->rb_node, parent, p);
 307         rb_insert_color(&sym->rb_node, symbols);
 308 }
 309
 310 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
 311 {
 312         struct rb_node *n;
 313
 314         if (symbols == NULL)
 315                 return NULL;
 316
 317         n = symbols->rb_node;
 318
 319         while (n) {
 320                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
 321
 322                 if (ip < s->start)
 323                         n = n->rb_left;
 324                 else if (ip > s->end)
 325                         n = n->rb_right;
 326                 else
 327                         return s;
 328         }
 329
 330         return NULL;
 331 }
 332
 333 static struct symbol *symbols__first(struct rb_root *symbols)
 334 {
 335         struct rb_node *n = rb_first(symbols);
 336
 337         if (n)
 338                 return rb_entry(n, struct symbol, rb_node);
 339
 340         return NULL;
 341 }
 342
 343 struct symbol_name_rb_node {
 344         struct rb_node  rb_node;
 345         struct symbol   sym;
 346 };
 347
 348 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
 349 {
 350         struct rb_node **p = &symbols->rb_node;
 351         struct rb_node *parent = NULL;
 352         struct symbol_name_rb_node *symn, *s;
 353
 354         symn = container_of(sym, struct symbol_name_rb_node, sym);
 355
 356         while (*p != NULL) {
 357                 parent = *p;
 358                 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
 359                 if (strcmp(sym->name, s->sym.name) < 0)
 360                         p = &(*p)->rb_left;
 361                 else
 362                         p = &(*p)->rb_right;
 363         }
 364         rb_link_node(&symn->rb_node, parent, p);
 365         rb_insert_color(&symn->rb_node, symbols);
 366 }
 367
 368 static void symbols__sort_by_name(struct rb_root *symbols,
 369                                   struct rb_root *source)
 370 {
 371         struct rb_node *nd;
 372
 373         for (nd = rb_first(source); nd; nd = rb_next(nd)) {
 374                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 375                 symbols__insert_by_name(symbols, pos);
 376         }
 377 }
 378
 379 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
 380                                             const char *name)
 381 {
 382         struct rb_node *n;
 383
 384         if (symbols == NULL)
 385                 return NULL;
 386
 387         n = symbols->rb_node;
 388
 389         while (n) {
 390                 struct symbol_name_rb_node *s;
 391                 int cmp;
 392
 393                 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
 394                 cmp = strcmp(name, s->sym.name);
 395
 396                 if (cmp < 0)
 397                         n = n->rb_left;
 398                 else if (cmp > 0)
 399                         n = n->rb_right;
 400                 else
 401                         return &s->sym;
 402         }
 403
 404         return NULL;
 405 }
 406
 407 struct symbol *dso__find_symbol(struct dso *dso,
 408                                 enum map_type type, u64 addr)
 409 {
 410         return symbols__find(&dso->symbols[type], addr);
 411 }
 412
 413 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
 414 {
 415         return symbols__first(&dso->symbols[type]);
 416 }
 417
 418 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
 419                                         const char *name)
 420 {
 421         return symbols__find_by_name(&dso->symbol_names[type], name);
 422 }
 423
 424 void dso__sort_by_name(struct dso *dso, enum map_type type)
 425 {
 426         dso__set_sorted_by_name(dso, type);
 427         return symbols__sort_by_name(&dso->symbol_names[type],
 428                                      &dso->symbols[type]);
 429 }
 430
 431 size_t dso__fprintf_symbols_by_name(struct dso *dso,
 432                                     enum map_type type, FILE *fp)
 433 {
 434         size_t ret = 0;
 435         struct rb_node *nd;
 436         struct symbol_name_rb_node *pos;
 437
 438         for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
 439                 pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
 440                 fprintf(fp, "%s\n", pos->sym.name);
 441         }
 442
 443         return ret;
 444 }
 445
 446 int modules__parse(const char *filename, void *arg,
 447                    int (*process_module)(void *arg, const char *name,
 448                                          u64 start))
 449 {
 450         char *line = NULL;
 451         size_t n;
 452         FILE *file;
 453         int err = 0;
 454
 455         file = fopen(filename, "r");
 456         if (file == NULL)
 457                 return -1;
 458
 459         while (1) {
 460                 char name[PATH_MAX];
 461                 u64 start;
 462                 char *sep;
 463                 ssize_t line_len;
 464
 465                 line_len = getline(&line, &n, file);
 466                 if (line_len < 0) {
 467                         if (feof(file))
 468                                 break;
 469                         err = -1;
 470                         goto out;
 471                 }
 472
 473                 if (!line) {
 474                         err = -1;
 475                         goto out;
 476                 }
 477
 478                 line[--line_len] = '\0'; /* \n */
 479
 480                 sep = strrchr(line, 'x');
 481                 if (sep == NULL)
 482                         continue;
 483
 484                 hex2u64(sep + 1, &start);
 485
 486                 sep = strchr(line, ' ');
 487                 if (sep == NULL)
 488                         continue;
 489
 490                 *sep = '\0';
 491
 492                 scnprintf(name, sizeof(name), "[%s]", line);
 493
 494                 err = process_module(arg, name, start);
 495                 if (err)
 496                         break;
 497         }
 498 out:
 499         free(line);
 500         fclose(file);
 501         return err;
 502 }
 503
 504 struct process_kallsyms_args {
 505         struct map *map;
 506         struct dso *dso;
 507 };
 508
 509 bool symbol__is_idle(struct symbol *sym)
 510 {
 511         const char * const idle_symbols[] = {
 512                 "cpu_idle",
 513                 "intel_idle",
 514                 "default_idle",
 515                 "native_safe_halt",
 516                 "enter_idle",
 517                 "exit_idle",
 518                 "mwait_idle",
 519                 "mwait_idle_with_hints",
 520                 "poll_idle",
 521                 "ppc64_runlatch_off",
 522                 "pseries_dedicated_idle_sleep",
 523                 NULL
 524         };
 525
 526         int i;
 527
 528         if (!sym)
 529                 return false;
 530
 531         for (i = 0; idle_symbols[i]; i++) {
 532                 if (!strcmp(idle_symbols[i], sym->name))
 533                         return true;
 534         }
 535
 536         return false;
 537 }
 538
 539 static int map__process_kallsym_symbol(void *arg, const char *name,
 540                                        char type, u64 start)
 541 {
 542         struct symbol *sym;
 543         struct process_kallsyms_args *a = arg;
 544         struct rb_root *root = &a->dso->symbols[a->map->type];
 545
 546         if (!symbol_type__is_a(type, a->map->type))
 547                 return 0;
 548
 549         /*
 550          * module symbols are not sorted so we add all
 551          * symbols, setting length to 0, and rely on
 552          * symbols__fixup_end() to fix it up.
 553          */
 554         sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
 555         if (sym == NULL)
 556                 return -ENOMEM;
 557         /*
 558          * We will pass the symbols to the filter later, in
 559          * map__split_kallsyms, when we have split the maps per module
 560          */
 561         symbols__insert(root, sym);
 562
 563         return 0;
 564 }
 565
 566 /*
 567  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 568  * so that we can in the next step set the symbol ->end address and then
 569  * call kernel_maps__split_kallsyms.
 570  */
 571 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
 572                                   struct map *map)
 573 {
 574         struct process_kallsyms_args args = { .map = map, .dso = dso, };
 575         return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
 576 }
 577
 578 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
 579                                          symbol_filter_t filter)
 580 {
 581         struct map_groups *kmaps = map__kmap(map)->kmaps;
 582         struct map *curr_map;
 583         struct symbol *pos;
 584         int count = 0, moved = 0;
 585         struct rb_root *root = &dso->symbols[map->type];
 586         struct rb_node *next = rb_first(root);
 587
 588         while (next) {
 589                 char *module;
 590
 591                 pos = rb_entry(next, struct symbol, rb_node);
 592                 next = rb_next(&pos->rb_node);
 593
 594                 module = strchr(pos->name, '\t');
 595                 if (module)
 596                         *module = '\0';
 597
 598                 curr_map = map_groups__find(kmaps, map->type, pos->start);
 599
 600                 if (!curr_map || (filter && filter(curr_map, pos))) {
 601                         rb_erase(&pos->rb_node, root);
 602                         symbol__delete(pos);
 603                 } else {
 604                         pos->start -= curr_map->start - curr_map->pgoff;
 605                         if (pos->end)
 606                                 pos->end -= curr_map->start - curr_map->pgoff;
 607                         if (curr_map != map) {
 608                                 rb_erase(&pos->rb_node, root);
 609                                 symbols__insert(
 610                                         &curr_map->dso->symbols[curr_map->type],
 611                                         pos);
 612                                 ++moved;
 613                         } else {
 614                                 ++count;
 615                         }
 616                 }
 617         }
 618
 619         /* Symbols have been adjusted */
 620         dso->adjust_symbols = 1;
 621
 622         return count + moved;
 623 }
 624
 625 /*
 626  * Split the symbols into maps, making sure there are no overlaps, i.e. the
 627  * kernel range is broken in several maps, named [kernel].N, as we don't have
 628  * the original ELF section names vmlinux have.
 629  */
 630 static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
 631                                symbol_filter_t filter)
 632 {
 633         struct map_groups *kmaps = map__kmap(map)->kmaps;
 634         struct machine *machine = kmaps->machine;
 635         struct map *curr_map = map;
 636         struct symbol *pos;
 637         int count = 0, moved = 0;
 638         struct rb_root *root = &dso->symbols[map->type];
 639         struct rb_node *next = rb_first(root);
 640         int kernel_range = 0;
 641
 642         while (next) {
 643                 char *module;
 644
 645                 pos = rb_entry(next, struct symbol, rb_node);
 646                 next = rb_next(&pos->rb_node);
 647
 648                 module = strchr(pos->name, '\t');
 649                 if (module) {
 650                         if (!symbol_conf.use_modules)
 651                                 goto discard_symbol;
 652
 653                         *module++ = '\0';
 654
 655                         if (strcmp(curr_map->dso->short_name, module)) {
 656                                 if (curr_map != map &&
 657                                     dso->kernel == DSO_TYPE_GUEST_KERNEL &&
 658                                     machine__is_default_guest(machine)) {
 659                                         /*
 660                                          * We assume all symbols of a module are
 661                                          * continuous in * kallsyms, so curr_map
 662                                          * points to a module and all its
 663                                          * symbols are in its kmap. Mark it as
 664                                          * loaded.
 665                                          */
 666                                         dso__set_loaded(curr_map->dso,
 667                                                         curr_map->type);
 668                                 }
 669
 670                                 curr_map = map_groups__find_by_name(kmaps,
 671                                                         map->type, module);
 672                                 if (curr_map == NULL) {
 673                                         pr_debug("%s/proc/{kallsyms,modules} "
 674                                                  "inconsistency while looking "
 675                                                  "for \"%s\" module!\n",
 676                                                  machine->root_dir, module);
 677                                         curr_map = map;
 678                                         goto discard_symbol;
 679                                 }
 680
 681                                 if (curr_map->dso->loaded &&
 682                                     !machine__is_default_guest(machine))
 683                                         goto discard_symbol;
 684                         }
 685                         /*
 686                          * So that we look just like we get from .ko files,
 687                          * i.e. not prelinked, relative to map->start.
 688                          */
 689                         pos->start = curr_map->map_ip(curr_map, pos->start);
 690                         pos->end   = curr_map->map_ip(curr_map, pos->end);
 691                 } else if (curr_map != map) {
 692                         char dso_name[PATH_MAX];
 693                         struct dso *ndso;
 694
 695                         if (delta) {
 696                                 /* Kernel was relocated at boot time */
 697                                 pos->start -= delta;
 698                                 pos->end -= delta;
 699                         }
 700
 701                         if (count == 0) {
 702                                 curr_map = map;
 703                                 goto filter_symbol;
 704                         }
 705
 706                         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 707                                 snprintf(dso_name, sizeof(dso_name),
 708                                         "[guest.kernel].%d",
 709                                         kernel_range++);
 710                         else
 711                                 snprintf(dso_name, sizeof(dso_name),
 712                                         "[kernel].%d",
 713                                         kernel_range++);
 714
 715                         ndso = dso__new(dso_name);
 716                         if (ndso == NULL)
 717                                 return -1;
 718
 719                         ndso->kernel = dso->kernel;
 720
 721                         curr_map = map__new2(pos->start, ndso, map->type);
 722                         if (curr_map == NULL) {
 723                                 dso__delete(ndso);
 724                                 return -1;
 725                         }
 726
 727                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 728                         map_groups__insert(kmaps, curr_map);
 729                         ++kernel_range;
 730                 } else if (delta) {
 731                         /* Kernel was relocated at boot time */
 732                         pos->start -= delta;
 733                         pos->end -= delta;
 734                 }
 735 filter_symbol:
 736                 if (filter && filter(curr_map, pos)) {
 737 discard_symbol:         rb_erase(&pos->rb_node, root);
 738                         symbol__delete(pos);
 739                 } else {
 740                         if (curr_map != map) {
 741                                 rb_erase(&pos->rb_node, root);
 742                                 symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
 743                                 ++moved;
 744                         } else
 745                                 ++count;
 746                 }
 747         }
 748
 749         if (curr_map != map &&
 750             dso->kernel == DSO_TYPE_GUEST_KERNEL &&
 751             machine__is_default_guest(kmaps->machine)) {
 752                 dso__set_loaded(curr_map->dso, curr_map->type);
 753         }
 754
 755         return count + moved;
 756 }
 757
 758 bool symbol__restricted_filename(const char *filename,
 759                                  const char *restricted_filename)
 760 {
 761         bool restricted = false;
 762
 763         if (symbol_conf.kptr_restrict) {
 764                 char *r = realpath(filename, NULL);
 765
 766                 if (r != NULL) {
 767                         restricted = strcmp(r, restricted_filename) == 0;
 768                         free(r);
 769                         return restricted;
 770                 }
 771         }
 772
 773         return restricted;
 774 }
 775
 776 struct module_info {
 777         struct rb_node rb_node;
 778         char *name;
 779         u64 start;
 780 };
 781
 782 static void add_module(struct module_info *mi, struct rb_root *modules)
 783 {
 784         struct rb_node **p = &modules->rb_node;
 785         struct rb_node *parent = NULL;
 786         struct module_info *m;
 787
 788         while (*p != NULL) {
 789                 parent = *p;
 790                 m = rb_entry(parent, struct module_info, rb_node);
 791                 if (strcmp(mi->name, m->name) < 0)
 792                         p = &(*p)->rb_left;
 793                 else
 794                         p = &(*p)->rb_right;
 795         }
 796         rb_link_node(&mi->rb_node, parent, p);
 797         rb_insert_color(&mi->rb_node, modules);
 798 }
 799
 800 static void delete_modules(struct rb_root *modules)
 801 {
 802         struct module_info *mi;
 803         struct rb_node *next = rb_first(modules);
 804
 805         while (next) {
 806                 mi = rb_entry(next, struct module_info, rb_node);
 807                 next = rb_next(&mi->rb_node);
 808                 rb_erase(&mi->rb_node, modules);
 809                 zfree(&mi->name);
 810                 free(mi);
 811         }
 812 }
 813
 814 static struct module_info *find_module(const char *name,
 815                                        struct rb_root *modules)
 816 {
 817         struct rb_node *n = modules->rb_node;
 818
 819         while (n) {
 820                 struct module_info *m;
 821                 int cmp;
 822
 823                 m = rb_entry(n, struct module_info, rb_node);
 824                 cmp = strcmp(name, m->name);
 825                 if (cmp < 0)
 826                         n = n->rb_left;
 827                 else if (cmp > 0)
 828                         n = n->rb_right;
 829                 else
 830                         return m;
 831         }
 832
 833         return NULL;
 834 }
 835
 836 static int __read_proc_modules(void *arg, const char *name, u64 start)
 837 {
 838         struct rb_root *modules = arg;
 839         struct module_info *mi;
 840
 841         mi = zalloc(sizeof(struct module_info));
 842         if (!mi)
 843                 return -ENOMEM;
 844
 845         mi->name = strdup(name);
 846         mi->start = start;
 847
 848         if (!mi->name) {
 849                 free(mi);
 850                 return -ENOMEM;
 851         }
 852
 853         add_module(mi, modules);
 854
 855         return 0;
 856 }
 857
 858 static int read_proc_modules(const char *filename, struct rb_root *modules)
 859 {
 860         if (symbol__restricted_filename(filename, "/proc/modules"))
 861                 return -1;
 862
 863         if (modules__parse(filename, modules, __read_proc_modules)) {
 864                 delete_modules(modules);
 865                 return -1;
 866         }
 867
 868         return 0;
 869 }
 870
 871 int compare_proc_modules(const char *from, const char *to)
 872 {
 873         struct rb_root from_modules = RB_ROOT;
 874         struct rb_root to_modules = RB_ROOT;
 875         struct rb_node *from_node, *to_node;
 876         struct module_info *from_m, *to_m;
 877         int ret = -1;
 878
 879         if (read_proc_modules(from, &from_modules))
 880                 return -1;
 881
 882         if (read_proc_modules(to, &to_modules))
 883                 goto out_delete_from;
 884
 885         from_node = rb_first(&from_modules);
 886         to_node = rb_first(&to_modules);
 887         while (from_node) {
 888                 if (!to_node)
 889                         break;
 890
 891                 from_m = rb_entry(from_node, struct module_info, rb_node);
 892                 to_m = rb_entry(to_node, struct module_info, rb_node);
 893
 894                 if (from_m->start != to_m->start ||
 895                     strcmp(from_m->name, to_m->name))
 896                         break;
 897
 898                 from_node = rb_next(from_node);
 899                 to_node = rb_next(to_node);
 900         }
 901
 902         if (!from_node && !to_node)
 903                 ret = 0;
 904
 905         delete_modules(&to_modules);
 906 out_delete_from:
 907         delete_modules(&from_modules);
 908
 909         return ret;
 910 }
 911
 912 static int do_validate_kcore_modules(const char *filename, struct map *map,
 913                                   struct map_groups *kmaps)
 914 {
 915         struct rb_root modules = RB_ROOT;
 916         struct map *old_map;
 917         int err;
 918
 919         err = read_proc_modules(filename, &modules);
 920         if (err)
 921                 return err;
 922
 923         old_map = map_groups__first(kmaps, map->type);
 924         while (old_map) {
 925                 struct map *next = map_groups__next(old_map);
 926                 struct module_info *mi;
 927
 928                 if (old_map == map || old_map->start == map->start) {
 929                         /* The kernel map */
 930                         old_map = next;
 931                         continue;
 932                 }
 933
 934                 /* Module must be in memory at the same address */
 935                 mi = find_module(old_map->dso->short_name, &modules);
 936                 if (!mi || mi->start != old_map->start) {
 937                         err = -EINVAL;
 938                         goto out;
 939                 }
 940
 941                 old_map = next;
 942         }
 943 out:
 944         delete_modules(&modules);
 945         return err;
 946 }
 947
 948 /*
 949  * If kallsyms is referenced by name then we look for filename in the same
 950  * directory.
 951  */
 952 static bool filename_from_kallsyms_filename(char *filename,
 953                                             const char *base_name,
 954                                             const char *kallsyms_filename)
 955 {
 956         char *name;
 957
 958         strcpy(filename, kallsyms_filename);
 959         name = strrchr(filename, '/');
 960         if (!name)
 961                 return false;
 962
 963         name += 1;
 964
 965         if (!strcmp(name, "kallsyms")) {
 966                 strcpy(name, base_name);
 967                 return true;
 968         }
 969
 970         return false;
 971 }
 972
 973 static int validate_kcore_modules(const char *kallsyms_filename,
 974                                   struct map *map)
 975 {
 976         struct map_groups *kmaps = map__kmap(map)->kmaps;
 977         char modules_filename[PATH_MAX];
 978
 979         if (!filename_from_kallsyms_filename(modules_filename, "modules",
 980                                              kallsyms_filename))
 981                 return -EINVAL;
 982
 983         if (do_validate_kcore_modules(modules_filename, map, kmaps))
 984                 return -EINVAL;
 985
 986         return 0;
 987 }
 988
 989 static int validate_kcore_addresses(const char *kallsyms_filename,
 990                                     struct map *map)
 991 {
 992         struct kmap *kmap = map__kmap(map);
 993
 994         if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
 995                 u64 start;
 996
 997                 start = kallsyms__get_function_start(kallsyms_filename,
 998                                                      kmap->ref_reloc_sym->name);
 999                 if (start != kmap->ref_reloc_sym->addr)
1000                         return -EINVAL;
1001         }
1002
1003         return validate_kcore_modules(kallsyms_filename, map);
1004 }
1005
1006 struct kcore_mapfn_data {
1007         struct dso *dso;
1008         enum map_type type;
1009         struct list_head maps;
1010 };
1011
1012 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1013 {
1014         struct kcore_mapfn_data *md = data;
1015         struct map *map;
1016
1017         map = map__new2(start, md->dso, md->type);
1018         if (map == NULL)
1019                 return -ENOMEM;
1020
1021         map->end = map->start + len;
1022         map->pgoff = pgoff;
1023
1024         list_add(&map->node, &md->maps);
1025
1026         return 0;
1027 }
1028
1029 static int dso__load_kcore(struct dso *dso, struct map *map,
1030                            const char *kallsyms_filename)
1031 {
1032         struct map_groups *kmaps = map__kmap(map)->kmaps;
1033         struct machine *machine = kmaps->machine;
1034         struct kcore_mapfn_data md;
1035         struct map *old_map, *new_map, *replacement_map = NULL;
1036         bool is_64_bit;
1037         int err, fd;
1038         char kcore_filename[PATH_MAX];
1039         struct symbol *sym;
1040
1041         /* This function requires that the map is the kernel map */
1042         if (map != machine->vmlinux_maps[map->type])
1043                 return -EINVAL;
1044
1045         if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1046                                              kallsyms_filename))
1047                 return -EINVAL;
1048
1049         /* Modules and kernel must be present at their original addresses */
1050         if (validate_kcore_addresses(kallsyms_filename, map))
1051                 return -EINVAL;
1052
1053         md.dso = dso;
1054         md.type = map->type;
1055         INIT_LIST_HEAD(&md.maps);
1056
1057         fd = open(kcore_filename, O_RDONLY);
1058         if (fd < 0)
1059                 return -EINVAL;
1060
1061         /* Read new maps into temporary lists */
1062         err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1063                               &is_64_bit);
1064         if (err)
1065                 goto out_err;
1066
1067         if (list_empty(&md.maps)) {
1068                 err = -EINVAL;
1069                 goto out_err;
1070         }
1071
1072         /* Remove old maps */
1073         old_map = map_groups__first(kmaps, map->type);
1074         while (old_map) {
1075                 struct map *next = map_groups__next(old_map);
1076
1077                 if (old_map != map)
1078                         map_groups__remove(kmaps, old_map);
1079                 old_map = next;
1080         }
1081
1082         /* Find the kernel map using the first symbol */
1083         sym = dso__first_symbol(dso, map->type);
1084         list_for_each_entry(new_map, &md.maps, node) {
1085                 if (sym && sym->start >= new_map->start &&
1086                     sym->start < new_map->end) {
1087                         replacement_map = new_map;
1088                         break;
1089                 }
1090         }
1091
1092         if (!replacement_map)
1093                 replacement_map = list_entry(md.maps.next, struct map, node);
1094
1095         /* Add new maps */
1096         while (!list_empty(&md.maps)) {
1097                 new_map = list_entry(md.maps.next, struct map, node);
1098                 list_del(&new_map->node);
1099                 if (new_map == replacement_map) {
1100                         map->start      = new_map->start;
1101                         map->end        = new_map->end;
1102                         map->pgoff      = new_map->pgoff;
1103                         map->map_ip     = new_map->map_ip;
1104                         map->unmap_ip   = new_map->unmap_ip;
1105                         map__delete(new_map);
1106                         /* Ensure maps are correctly ordered */
1107                         map_groups__remove(kmaps, map);
1108                         map_groups__insert(kmaps, map);
1109                 } else {
1110                         map_groups__insert(kmaps, new_map);
1111                 }
1112         }
1113
1114         /*
1115          * Set the data type and long name so that kcore can be read via
1116          * dso__data_read_addr().
1117          */
1118         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1119                 dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1120         else
1121                 dso->binary_type = DSO_BINARY_TYPE__KCORE;
1122         dso__set_long_name(dso, strdup(kcore_filename), true);
1123
1124         close(fd);
1125
1126         if (map->type == MAP__FUNCTION)
1127                 pr_debug("Using %s for kernel object code\n", kcore_filename);
1128         else
1129                 pr_debug("Using %s for kernel data\n", kcore_filename);
1130
1131         return 0;
1132
1133 out_err:
1134         while (!list_empty(&md.maps)) {
1135                 map = list_entry(md.maps.next, struct map, node);
1136                 list_del(&map->node);
1137                 map__delete(map);
1138         }
1139         close(fd);
1140         return -EINVAL;
1141 }
1142
1143 /*
1144  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1145  * delta based on the relocation reference symbol.
1146  */
1147 static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
1148 {
1149         struct kmap *kmap = map__kmap(map);
1150         u64 addr;
1151
1152         if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1153                 return 0;
1154
1155         addr = kallsyms__get_function_start(filename,
1156                                             kmap->ref_reloc_sym->name);
1157         if (!addr)
1158                 return -1;
1159
1160         *delta = addr - kmap->ref_reloc_sym->addr;
1161         return 0;
1162 }
1163
1164 int dso__load_kallsyms(struct dso *dso, const char *filename,
1165                        struct map *map, symbol_filter_t filter)
1166 {
1167         u64 delta = 0;
1168
1169         if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1170                 return -1;
1171
1172         if (dso__load_all_kallsyms(dso, filename, map) < 0)
1173                 return -1;
1174
1175         if (kallsyms__delta(map, filename, &delta))
1176                 return -1;
1177
1178         symbols__fixup_duplicate(&dso->symbols[map->type]);
1179         symbols__fixup_end(&dso->symbols[map->type]);
1180
1181         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1182                 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1183         else
1184                 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1185
1186         if (!dso__load_kcore(dso, map, filename))
1187                 return dso__split_kallsyms_for_kcore(dso, map, filter);
1188         else
1189                 return dso__split_kallsyms(dso, map, delta, filter);
1190 }
1191
1192 static int dso__load_perf_map(struct dso *dso, struct map *map,
1193                               symbol_filter_t filter)
1194 {
1195         char *line = NULL;
1196         size_t n;
1197         FILE *file;
1198         int nr_syms = 0;
1199
1200         file = fopen(dso->long_name, "r");
1201         if (file == NULL)
1202                 goto out_failure;
1203
1204         while (!feof(file)) {
1205                 u64 start, size;
1206                 struct symbol *sym;
1207                 int line_len, len;
1208
1209                 line_len = getline(&line, &n, file);
1210                 if (line_len < 0)
1211                         break;
1212
1213                 if (!line)
1214                         goto out_failure;
1215
1216                 line[--line_len] = '\0'; /* \n */
1217
1218                 len = hex2u64(line, &start);
1219
1220                 len++;
1221                 if (len + 2 >= line_len)
1222                         continue;
1223
1224                 len += hex2u64(line + len, &size);
1225
1226                 len++;
1227                 if (len + 2 >= line_len)
1228                         continue;
1229
1230                 sym = symbol__new(start, size, STB_GLOBAL, line + len);
1231
1232                 if (sym == NULL)
1233                         goto out_delete_line;
1234
1235                 if (filter && filter(map, sym))
1236                         symbol__delete(sym);
1237                 else {
1238                         symbols__insert(&dso->symbols[map->type], sym);
1239                         nr_syms++;
1240                 }
1241         }
1242
1243         free(line);
1244         fclose(file);
1245
1246         return nr_syms;
1247
1248 out_delete_line:
1249         free(line);
1250 out_failure:
1251         return -1;
1252 }
1253
1254 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1255 {
1256         char *name;
1257         int ret = -1;
1258         u_int i;
1259         struct machine *machine;
1260         char *root_dir = (char *) "";
1261         int ss_pos = 0;
1262         struct symsrc ss_[2];
1263         struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1264
1265         dso__set_loaded(dso, map->type);
1266
1267         if (dso->kernel == DSO_TYPE_KERNEL)
1268                 return dso__load_kernel_sym(dso, map, filter);
1269         else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1270                 return dso__load_guest_kernel_sym(dso, map, filter);
1271
1272         if (map->groups && map->groups->machine)
1273                 machine = map->groups->machine;
1274         else
1275                 machine = NULL;
1276
1277         dso->adjust_symbols = 0;
1278
1279         if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1280                 struct stat st;
1281
1282                 if (lstat(dso->name, &st) < 0)
1283                         return -1;
1284
1285                 if (st.st_uid && (st.st_uid != geteuid())) {
1286                         pr_warning("File %s not owned by current user or root, "
1287                                 "ignoring it.\n", dso->name);
1288                         return -1;
1289                 }
1290
1291                 ret = dso__load_perf_map(dso, map, filter);
1292                 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1293                                              DSO_BINARY_TYPE__NOT_FOUND;
1294                 return ret;
1295         }
1296
1297         if (machine)
1298                 root_dir = machine->root_dir;
1299
1300         name = malloc(PATH_MAX);
1301         if (!name)
1302                 return -1;
1303
1304         /* Iterate over candidate debug images.
1305          * Keep track of "interesting" ones (those which have a symtab, dynsym,
1306          * and/or opd section) for processing.
1307          */
1308         for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1309                 struct symsrc *ss = &ss_[ss_pos];
1310                 bool next_slot = false;
1311
1312                 enum dso_binary_type symtab_type = binary_type_symtab[i];
1313
1314                 if (dso__read_binary_type_filename(dso, symtab_type,
1315                                                    root_dir, name, PATH_MAX))
1316                         continue;
1317
1318                 /* Name is now the name of the next image to try */
1319                 if (symsrc__init(ss, dso, name, symtab_type) < 0)
1320                         continue;
1321
1322                 if (!syms_ss && symsrc__has_symtab(ss)) {
1323                         syms_ss = ss;
1324                         next_slot = true;
1325                         if (!dso->symsrc_filename)
1326                                 dso->symsrc_filename = strdup(name);
1327                 }
1328
1329                 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1330                         runtime_ss = ss;
1331                         next_slot = true;
1332                 }
1333
1334                 if (next_slot) {
1335                         ss_pos++;
1336
1337                         if (syms_ss && runtime_ss)
1338                                 break;
1339                 } else {
1340                         symsrc__destroy(ss);
1341                 }
1342
1343         }
1344
1345         if (!runtime_ss && !syms_ss)
1346                 goto out_free;
1347
1348         if (runtime_ss && !syms_ss) {
1349                 syms_ss = runtime_ss;
1350         }
1351
1352         /* We'll have to hope for the best */
1353         if (!runtime_ss && syms_ss)
1354                 runtime_ss = syms_ss;
1355
1356         if (syms_ss) {
1357                 int km;
1358
1359                 km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1360                      dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
1361                 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
1362         } else {
1363                 ret = -1;
1364         }
1365
1366         if (ret > 0) {
1367                 int nr_plt;
1368
1369                 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1370                 if (nr_plt > 0)
1371                         ret += nr_plt;
1372         }
1373
1374         for (; ss_pos > 0; ss_pos--)
1375                 symsrc__destroy(&ss_[ss_pos - 1]);
1376 out_free:
1377         free(name);
1378         if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1379                 return 0;
1380         return ret;
1381 }
1382
1383 struct map *map_groups__find_by_name(struct map_groups *mg,
1384                                      enum map_type type, const char *name)
1385 {
1386         struct rb_node *nd;
1387
1388         for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
1389                 struct map *map = rb_entry(nd, struct map, rb_node);
1390
1391                 if (map->dso && strcmp(map->dso->short_name, name) == 0)
1392                         return map;
1393         }
1394
1395         return NULL;
1396 }
1397
1398 int dso__load_vmlinux(struct dso *dso, struct map *map,
1399                       const char *vmlinux, bool vmlinux_allocated,
1400                       symbol_filter_t filter)
1401 {
1402         int err = -1;
1403         struct symsrc ss;
1404         char symfs_vmlinux[PATH_MAX];
1405         enum dso_binary_type symtab_type;
1406
1407         if (vmlinux[0] == '/')
1408                 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1409         else
1410                 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
1411                          symbol_conf.symfs, vmlinux);
1412
1413         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1414                 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1415         else
1416                 symtab_type = DSO_BINARY_TYPE__VMLINUX;
1417
1418         if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1419                 return -1;
1420
1421         err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1422         symsrc__destroy(&ss);
1423
1424         if (err > 0) {
1425                 if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1426                         dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1427                 else
1428                         dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
1429                 dso__set_long_name(dso, vmlinux, vmlinux_allocated);
1430                 dso__set_loaded(dso, map->type);
1431                 pr_debug("Using %s for symbols\n", symfs_vmlinux);
1432         }
1433
1434         return err;
1435 }
1436
1437 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1438                            symbol_filter_t filter)
1439 {
1440         int i, err = 0;
1441         char *filename;
1442
1443         pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1444                  vmlinux_path__nr_entries + 1);
1445
1446         filename = dso__build_id_filename(dso, NULL, 0);
1447         if (filename != NULL) {
1448                 err = dso__load_vmlinux(dso, map, filename, true, filter);
1449                 if (err > 0)
1450                         goto out;
1451                 free(filename);
1452         }
1453
1454         for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1455                 err = dso__load_vmlinux(dso, map, vmlinux_path[i], false, filter);
1456                 if (err > 0)
1457                         break;
1458         }
1459 out:
1460         return err;
1461 }
1462
1463 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1464 {
1465         char kallsyms_filename[PATH_MAX];
1466         struct dirent *dent;
1467         int ret = -1;
1468         DIR *d;
1469
1470         d = opendir(dir);
1471         if (!d)
1472                 return -1;
1473
1474         while (1) {
1475                 dent = readdir(d);
1476                 if (!dent)
1477                         break;
1478                 if (dent->d_type != DT_DIR)
1479                         continue;
1480                 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1481                           "%s/%s/kallsyms", dir, dent->d_name);
1482                 if (!validate_kcore_addresses(kallsyms_filename, map)) {
1483                         strlcpy(dir, kallsyms_filename, dir_sz);
1484                         ret = 0;
1485                         break;
1486                 }
1487         }
1488
1489         closedir(d);
1490
1491         return ret;
1492 }
1493
1494 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1495 {
1496         u8 host_build_id[BUILD_ID_SIZE];
1497         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1498         bool is_host = false;
1499         char path[PATH_MAX];
1500
1501         if (!dso->has_build_id) {
1502                 /*
1503                  * Last resort, if we don't have a build-id and couldn't find
1504                  * any vmlinux file, try the running kernel kallsyms table.
1505                  */
1506                 goto proc_kallsyms;
1507         }
1508
1509         if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1510                                  sizeof(host_build_id)) == 0)
1511                 is_host = dso__build_id_equal(dso, host_build_id);
1512
1513         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1514
1515         scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
1516                   sbuild_id);
1517
1518         /* Use /proc/kallsyms if possible */
1519         if (is_host) {
1520                 DIR *d;
1521                 int fd;
1522
1523                 /* If no cached kcore go with /proc/kallsyms */
1524                 d = opendir(path);
1525                 if (!d)
1526                         goto proc_kallsyms;
1527                 closedir(d);
1528
1529                 /*
1530                  * Do not check the build-id cache, until we know we cannot use
1531                  * /proc/kcore.
1532                  */
1533                 fd = open("/proc/kcore", O_RDONLY);
1534                 if (fd != -1) {
1535                         close(fd);
1536                         /* If module maps match go with /proc/kallsyms */
1537                         if (!validate_kcore_addresses("/proc/kallsyms", map))
1538                                 goto proc_kallsyms;
1539                 }
1540
1541                 /* Find kallsyms in build-id cache with kcore */
1542                 if (!find_matching_kcore(map, path, sizeof(path)))
1543                         return strdup(path);
1544
1545                 goto proc_kallsyms;
1546         }
1547
1548         /* Find kallsyms in build-id cache with kcore */
1549         if (!find_matching_kcore(map, path, sizeof(path)))
1550                 return strdup(path);
1551
1552         scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1553                   buildid_dir, sbuild_id);
1554
1555         if (access(path, F_OK)) {
1556                 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1557                        sbuild_id);
1558                 return NULL;
1559         }
1560
1561         return strdup(path);
1562
1563 proc_kallsyms:
1564         return strdup("/proc/kallsyms");
1565 }
1566
1567 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1568                                 symbol_filter_t filter)
1569 {
1570         int err;
1571         const char *kallsyms_filename = NULL;
1572         char *kallsyms_allocated_filename = NULL;
1573         /*
1574          * Step 1: if the user specified a kallsyms or vmlinux filename, use
1575          * it and only it, reporting errors to the user if it cannot be used.
1576          *
1577          * For instance, try to analyse an ARM perf.data file _without_ a
1578          * build-id, or if the user specifies the wrong path to the right
1579          * vmlinux file, obviously we can't fallback to another vmlinux (a
1580          * x86_86 one, on the machine where analysis is being performed, say),
1581          * or worse, /proc/kallsyms.
1582          *
1583          * If the specified file _has_ a build-id and there is a build-id
1584          * section in the perf.data file, we will still do the expected
1585          * validation in dso__load_vmlinux and will bail out if they don't
1586          * match.
1587          */
1588         if (symbol_conf.kallsyms_name != NULL) {
1589                 kallsyms_filename = symbol_conf.kallsyms_name;
1590                 goto do_kallsyms;
1591         }
1592
1593         if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1594                 return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name,
1595                                          false, filter);
1596         }
1597
1598         if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1599                 err = dso__load_vmlinux_path(dso, map, filter);
1600                 if (err > 0)
1601                         return err;
1602         }
1603
1604         /* do not try local files if a symfs was given */
1605         if (symbol_conf.symfs[0] != 0)
1606                 return -1;
1607
1608         kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1609         if (!kallsyms_allocated_filename)
1610                 return -1;
1611
1612         kallsyms_filename = kallsyms_allocated_filename;
1613
1614 do_kallsyms:
1615         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1616         if (err > 0)
1617                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1618         free(kallsyms_allocated_filename);
1619
1620         if (err > 0 && !dso__is_kcore(dso)) {
1621                 dso__set_long_name(dso, "[kernel.kallsyms]", false);
1622                 map__fixup_start(map);
1623                 map__fixup_end(map);
1624         }
1625
1626         return err;
1627 }
1628
1629 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1630                                       symbol_filter_t filter)
1631 {
1632         int err;
1633         const char *kallsyms_filename = NULL;
1634         struct machine *machine;
1635         char path[PATH_MAX];
1636
1637         if (!map->groups) {
1638                 pr_debug("Guest kernel map hasn't the point to groups\n");
1639                 return -1;
1640         }
1641         machine = map->groups->machine;
1642
1643         if (machine__is_default_guest(machine)) {
1644                 /*
1645                  * if the user specified a vmlinux filename, use it and only
1646                  * it, reporting errors to the user if it cannot be used.
1647                  * Or use file guest_kallsyms inputted by user on commandline
1648                  */
1649                 if (symbol_conf.default_guest_vmlinux_name != NULL) {
1650                         err = dso__load_vmlinux(dso, map,
1651                                                 symbol_conf.default_guest_vmlinux_name,
1652                                                 false, filter);
1653                         return err;
1654                 }
1655
1656                 kallsyms_filename = symbol_conf.default_guest_kallsyms;
1657                 if (!kallsyms_filename)
1658                         return -1;
1659         } else {
1660                 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1661                 kallsyms_filename = path;
1662         }
1663
1664         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1665         if (err > 0)
1666                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1667         if (err > 0 && !dso__is_kcore(dso)) {
1668                 machine__mmap_name(machine, path, sizeof(path));
1669                 dso__set_long_name(dso, strdup(path), true);
1670                 map__fixup_start(map);
1671                 map__fixup_end(map);
1672         }
1673
1674         return err;
1675 }
1676
1677 static void vmlinux_path__exit(void)
1678 {
1679         while (--vmlinux_path__nr_entries >= 0)
1680                 zfree(&vmlinux_path[vmlinux_path__nr_entries]);
1681
1682         zfree(&vmlinux_path);
1683 }
1684
1685 static int vmlinux_path__init(void)
1686 {
1687         struct utsname uts;
1688         char bf[PATH_MAX];
1689
1690         vmlinux_path = malloc(sizeof(char *) * 5);
1691         if (vmlinux_path == NULL)
1692                 return -1;
1693
1694         vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1695         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1696                 goto out_fail;
1697         ++vmlinux_path__nr_entries;
1698         vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1699         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1700                 goto out_fail;
1701         ++vmlinux_path__nr_entries;
1702
1703         /* only try running kernel version if no symfs was given */
1704         if (symbol_conf.symfs[0] != 0)
1705                 return 0;
1706
1707         if (uname(&uts) < 0)
1708                 return -1;
1709
1710         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1711         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1712         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1713                 goto out_fail;
1714         ++vmlinux_path__nr_entries;
1715         snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1716         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1717         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1718                 goto out_fail;
1719         ++vmlinux_path__nr_entries;
1720         snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1721                  uts.release);
1722         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1723         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1724                 goto out_fail;
1725         ++vmlinux_path__nr_entries;
1726
1727         return 0;
1728
1729 out_fail:
1730         vmlinux_path__exit();
1731         return -1;
1732 }
1733
1734 int setup_list(struct strlist **list, const char *list_str,
1735                       const char *list_name)
1736 {
1737         if (list_str == NULL)
1738                 return 0;
1739
1740         *list = strlist__new(true, list_str);
1741         if (!*list) {
1742                 pr_err("problems parsing %s list\n", list_name);
1743                 return -1;
1744         }
1745         return 0;
1746 }
1747
1748 static bool symbol__read_kptr_restrict(void)
1749 {
1750         bool value = false;
1751
1752         if (geteuid() != 0) {
1753                 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1754                 if (fp != NULL) {
1755                         char line[8];
1756
1757                         if (fgets(line, sizeof(line), fp) != NULL)
1758                                 value = atoi(line) != 0;
1759
1760                         fclose(fp);
1761                 }
1762         }
1763
1764         return value;
1765 }
1766
1767 int symbol__init(void)
1768 {
1769         const char *symfs;
1770
1771         if (symbol_conf.initialized)
1772                 return 0;
1773
1774         symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1775
1776         symbol__elf_init();
1777
1778         if (symbol_conf.sort_by_name)
1779                 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1780                                           sizeof(struct symbol));
1781
1782         if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1783                 return -1;
1784
1785         if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1786                 pr_err("'.' is the only non valid --field-separator argument\n");
1787                 return -1;
1788         }
1789
1790         if (setup_list(&symbol_conf.dso_list,
1791                        symbol_conf.dso_list_str, "dso") < 0)
1792                 return -1;
1793
1794         if (setup_list(&symbol_conf.comm_list,
1795                        symbol_conf.comm_list_str, "comm") < 0)
1796                 goto out_free_dso_list;
1797
1798         if (setup_list(&symbol_conf.sym_list,
1799                        symbol_conf.sym_list_str, "symbol") < 0)
1800                 goto out_free_comm_list;
1801
1802         /*
1803          * A path to symbols of "/" is identical to ""
1804          * reset here for simplicity.
1805          */
1806         symfs = realpath(symbol_conf.symfs, NULL);
1807         if (symfs == NULL)
1808                 symfs = symbol_conf.symfs;
1809         if (strcmp(symfs, "/") == 0)
1810                 symbol_conf.symfs = "";
1811         if (symfs != symbol_conf.symfs)
1812                 free((void *)symfs);
1813
1814         symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
1815
1816         symbol_conf.initialized = true;
1817         return 0;
1818
1819 out_free_comm_list:
1820         strlist__delete(symbol_conf.comm_list);
1821 out_free_dso_list:
1822         strlist__delete(symbol_conf.dso_list);
1823         return -1;
1824 }
1825
1826 void symbol__exit(void)
1827 {
1828         if (!symbol_conf.initialized)
1829                 return;
1830         strlist__delete(symbol_conf.sym_list);
1831         strlist__delete(symbol_conf.dso_list);
1832         strlist__delete(symbol_conf.comm_list);
1833         vmlinux_path__exit();
1834         symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1835         symbol_conf.initialized = false;
1836 }