tools/bpf/resolve_btfids/main.c

   1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
   2
   3 /*
   4  * resolve_btfids scans Elf object for .BTF_ids section and resolves
   5  * its symbols with BTF ID values.
   6  *
   7  * Each symbol points to 4 bytes data and is expected to have
   8  * following name syntax:
   9  *
  10  * __BTF_ID__<type>__<symbol>[__<id>]
  11  *
  12  * type is:
  13  *
  14  *   func    - lookup BTF_KIND_FUNC symbol with <symbol> name
  15  *             and store its ID into the data:
  16  *
  17  *             __BTF_ID__func__vfs_close__1:
  18  *             .zero 4
  19  *
  20  *   struct  - lookup BTF_KIND_STRUCT symbol with <symbol> name
  21  *             and store its ID into the data:
  22  *
  23  *             __BTF_ID__struct__sk_buff__1:
  24  *             .zero 4
  25  *
  26  *   union   - lookup BTF_KIND_UNION symbol with <symbol> name
  27  *             and store its ID into the data:
  28  *
  29  *             __BTF_ID__union__thread_union__1:
  30  *             .zero 4
  31  *
  32  *   typedef - lookup BTF_KIND_TYPEDEF symbol with <symbol> name
  33  *             and store its ID into the data:
  34  *
  35  *             __BTF_ID__typedef__pid_t__1:
  36  *             .zero 4
  37  *
  38  *   set     - store symbol size into first 4 bytes and sort following
  39  *             ID list
  40  *
  41  *             __BTF_ID__set__list:
  42  *             .zero 4
  43  *             list:
  44  *             __BTF_ID__func__vfs_getattr__3:
  45  *             .zero 4
  46  *             __BTF_ID__func__vfs_fallocate__4:
  47  *             .zero 4
  48  */
  49
  50 #define  _GNU_SOURCE
  51 #include <stdio.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54 #include <stdlib.h>
  55 #include <libelf.h>
  56 #include <gelf.h>
  57 #include <sys/stat.h>
  58 #include <fcntl.h>
  59 #include <errno.h>
  60 #include <linux/rbtree.h>
  61 #include <linux/zalloc.h>
  62 #include <linux/err.h>
  63 #include <btf.h>
  64 #include <libbpf.h>
  65 #include <parse-options.h>
  66
  67 #define BTF_IDS_SECTION ".BTF_ids"
  68 #define BTF_ID          "__BTF_ID__"
  69
  70 #define BTF_STRUCT      "struct"
  71 #define BTF_UNION       "union"
  72 #define BTF_TYPEDEF     "typedef"
  73 #define BTF_FUNC        "func"
  74 #define BTF_SET         "set"
  75
  76 #define ADDR_CNT        100
  77
  78 struct btf_id {
  79         struct rb_node   rb_node;
  80         char            *name;
  81         union {
  82                 int      id;
  83                 int      cnt;
  84         };
  85         int              addr_cnt;
  86         Elf64_Addr       addr[ADDR_CNT];
  87 };
  88
  89 struct object {
  90         const char *path;
  91         const char *btf;
  92
  93         struct {
  94                 int              fd;
  95                 Elf             *elf;
  96                 Elf_Data        *symbols;
  97                 Elf_Data        *idlist;
  98                 int              symbols_shndx;
  99                 int              idlist_shndx;
 100                 size_t           strtabidx;
 101                 unsigned long    idlist_addr;
 102         } efile;
 103
 104         struct rb_root  sets;
 105         struct rb_root  structs;
 106         struct rb_root  unions;
 107         struct rb_root  typedefs;
 108         struct rb_root  funcs;
 109
 110         int nr_funcs;
 111         int nr_structs;
 112         int nr_unions;
 113         int nr_typedefs;
 114 };
 115
 116 static int verbose;
 117
 118 int eprintf(int level, int var, const char *fmt, ...)
 119 {
 120         va_list args;
 121         int ret;
 122
 123         if (var >= level) {
 124                 va_start(args, fmt);
 125                 ret = vfprintf(stderr, fmt, args);
 126                 va_end(args);
 127         }
 128         return ret;
 129 }
 130
 131 #ifndef pr_fmt
 132 #define pr_fmt(fmt) fmt
 133 #endif
 134
 135 #define pr_debug(fmt, ...) \
 136         eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__)
 137 #define pr_debugN(n, fmt, ...) \
 138         eprintf(n, verbose, pr_fmt(fmt), ##__VA_ARGS__)
 139 #define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__)
 140 #define pr_err(fmt, ...) \
 141         eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
 142 #define pr_info(fmt, ...) \
 143         eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
 144
 145 static bool is_btf_id(const char *name)
 146 {
 147         return name && !strncmp(name, BTF_ID, sizeof(BTF_ID) - 1);
 148 }
 149
 150 static struct btf_id *btf_id__find(struct rb_root *root, const char *name)
 151 {
 152         struct rb_node *p = root->rb_node;
 153         struct btf_id *id;
 154         int cmp;
 155
 156         while (p) {
 157                 id = rb_entry(p, struct btf_id, rb_node);
 158                 cmp = strcmp(id->name, name);
 159                 if (cmp < 0)
 160                         p = p->rb_left;
 161                 else if (cmp > 0)
 162                         p = p->rb_right;
 163                 else
 164                         return id;
 165         }
 166         return NULL;
 167 }
 168
 169 static struct btf_id*
 170 btf_id__add(struct rb_root *root, char *name, bool unique)
 171 {
 172         struct rb_node **p = &root->rb_node;
 173         struct rb_node *parent = NULL;
 174         struct btf_id *id;
 175         int cmp;
 176
 177         while (*p != NULL) {
 178                 parent = *p;
 179                 id = rb_entry(parent, struct btf_id, rb_node);
 180                 cmp = strcmp(id->name, name);
 181                 if (cmp < 0)
 182                         p = &(*p)->rb_left;
 183                 else if (cmp > 0)
 184                         p = &(*p)->rb_right;
 185                 else
 186                         return unique ? NULL : id;
 187         }
 188
 189         id = zalloc(sizeof(*id));
 190         if (id) {
 191                 pr_debug("adding symbol %s\n", name);
 192                 id->name = name;
 193                 rb_link_node(&id->rb_node, parent, p);
 194                 rb_insert_color(&id->rb_node, root);
 195         }
 196         return id;
 197 }
 198
 199 static char *get_id(const char *prefix_end)
 200 {
 201         /*
 202          * __BTF_ID__func__vfs_truncate__0
 203          * prefix_end =  ^
 204          * pos        =    ^
 205          */
 206         int len = strlen(prefix_end);
 207         int pos = sizeof("__") - 1;
 208         char *p, *id;
 209
 210         if (pos >= len)
 211                 return NULL;
 212
 213         id = strdup(prefix_end + pos);
 214         if (id) {
 215                 /*
 216                  * __BTF_ID__func__vfs_truncate__0
 217                  * id =            ^
 218                  *
 219                  * cut the unique id part
 220                  */
 221                 p = strrchr(id, '_');
 222                 p--;
 223                 if (*p != '_') {
 224                         free(id);
 225                         return NULL;
 226                 }
 227                 *p = '\0';
 228         }
 229         return id;
 230 }
 231
 232 static struct btf_id *add_set(struct object *obj, char *name)
 233 {
 234         /*
 235          * __BTF_ID__set__name
 236          * name =    ^
 237          * id   =         ^
 238          */
 239         char *id = name + sizeof(BTF_SET "__") - 1;
 240         int len = strlen(name);
 241
 242         if (id >= name + len) {
 243                 pr_err("FAILED to parse set name: %s\n", name);
 244                 return NULL;
 245         }
 246
 247         return btf_id__add(&obj->sets, id, true);
 248 }
 249
 250 static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
 251 {
 252         char *id;
 253
 254         id = get_id(name + size);
 255         if (!id) {
 256                 pr_err("FAILED to parse symbol name: %s\n", name);
 257                 return NULL;
 258         }
 259
 260         return btf_id__add(root, id, false);
 261 }
 262
 263 /* Older libelf.h and glibc elf.h might not yet define the ELF compression types. */
 264 #ifndef SHF_COMPRESSED
 265 #define SHF_COMPRESSED (1 << 11) /* Section with compressed data. */
 266 #endif
 267
 268 /*
 269  * The data of compressed section should be aligned to 4
 270  * (for 32bit) or 8 (for 64 bit) bytes. The binutils ld
 271  * sets sh_addralign to 1, which makes libelf fail with
 272  * misaligned section error during the update:
 273  *    FAILED elf_update(WRITE): invalid section alignment
 274  *
 275  * While waiting for ld fix, we fix the compressed sections
 276  * sh_addralign value manualy.
 277  */
 278 static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
 279 {
 280         int expected = gelf_getclass(elf) == ELFCLASS32 ? 4 : 8;
 281
 282         if (!(sh->sh_flags & SHF_COMPRESSED))
 283                 return 0;
 284
 285         if (sh->sh_addralign == expected)
 286                 return 0;
 287
 288         pr_debug2(" - fixing wrong alignment sh_addralign %u, expected %u\n",
 289                   sh->sh_addralign, expected);
 290
 291         sh->sh_addralign = expected;
 292
 293         if (gelf_update_shdr(scn, sh) == 0) {
 294                 printf("FAILED cannot update section header: %s\n",
 295                         elf_errmsg(-1));
 296                 return -1;
 297         }
 298         return 0;
 299 }
 300
 301 static int elf_collect(struct object *obj)
 302 {
 303         Elf_Scn *scn = NULL;
 304         size_t shdrstrndx;
 305         int idx = 0;
 306         Elf *elf;
 307         int fd;
 308
 309         fd = open(obj->path, O_RDWR, 0666);
 310         if (fd == -1) {
 311                 pr_err("FAILED cannot open %s: %s\n",
 312                         obj->path, strerror(errno));
 313                 return -1;
 314         }
 315
 316         elf_version(EV_CURRENT);
 317
 318         elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL);
 319         if (!elf) {
 320                 pr_err("FAILED cannot create ELF descriptor: %s\n",
 321                         elf_errmsg(-1));
 322                 return -1;
 323         }
 324
 325         obj->efile.fd  = fd;
 326         obj->efile.elf = elf;
 327
 328         elf_flagelf(elf, ELF_C_SET, ELF_F_LAYOUT);
 329
 330         if (elf_getshdrstrndx(elf, &shdrstrndx) != 0) {
 331                 pr_err("FAILED cannot get shdr str ndx\n");
 332                 return -1;
 333         }
 334
 335         /*
 336          * Scan all the elf sections and look for save data
 337          * from .BTF_ids section and symbols.
 338          */
 339         while ((scn = elf_nextscn(elf, scn)) != NULL) {
 340                 Elf_Data *data;
 341                 GElf_Shdr sh;
 342                 char *name;
 343
 344                 idx++;
 345                 if (gelf_getshdr(scn, &sh) != &sh) {
 346                         pr_err("FAILED get section(%d) header\n", idx);
 347                         return -1;
 348                 }
 349
 350                 name = elf_strptr(elf, shdrstrndx, sh.sh_name);
 351                 if (!name) {
 352                         pr_err("FAILED get section(%d) name\n", idx);
 353                         return -1;
 354                 }
 355
 356                 data = elf_getdata(scn, 0);
 357                 if (!data) {
 358                         pr_err("FAILED to get section(%d) data from %s\n",
 359                                 idx, name);
 360                         return -1;
 361                 }
 362
 363                 pr_debug2("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
 364                           idx, name, (unsigned long) data->d_size,
 365                           (int) sh.sh_link, (unsigned long) sh.sh_flags,
 366                           (int) sh.sh_type);
 367
 368                 if (sh.sh_type == SHT_SYMTAB) {
 369                         obj->efile.symbols       = data;
 370                         obj->efile.symbols_shndx = idx;
 371                         obj->efile.strtabidx     = sh.sh_link;
 372                 } else if (!strcmp(name, BTF_IDS_SECTION)) {
 373                         obj->efile.idlist       = data;
 374                         obj->efile.idlist_shndx = idx;
 375                         obj->efile.idlist_addr  = sh.sh_addr;
 376                 }
 377
 378                 if (compressed_section_fix(elf, scn, &sh))
 379                         return -1;
 380         }
 381
 382         return 0;
 383 }
 384
 385 static int symbols_collect(struct object *obj)
 386 {
 387         Elf_Scn *scn = NULL;
 388         int n, i, err = 0;
 389         GElf_Shdr sh;
 390         char *name;
 391
 392         scn = elf_getscn(obj->efile.elf, obj->efile.symbols_shndx);
 393         if (!scn)
 394                 return -1;
 395
 396         if (gelf_getshdr(scn, &sh) != &sh)
 397                 return -1;
 398
 399         n = sh.sh_size / sh.sh_entsize;
 400
 401         /*
 402          * Scan symbols and look for the ones starting with
 403          * __BTF_ID__* over .BTF_ids section.
 404          */
 405         for (i = 0; !err && i < n; i++) {
 406                 char *tmp, *prefix;
 407                 struct btf_id *id;
 408                 GElf_Sym sym;
 409                 int err = -1;
 410
 411                 if (!gelf_getsym(obj->efile.symbols, i, &sym))
 412                         return -1;
 413
 414                 if (sym.st_shndx != obj->efile.idlist_shndx)
 415                         continue;
 416
 417                 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
 418                                   sym.st_name);
 419
 420                 if (!is_btf_id(name))
 421                         continue;
 422
 423                 /*
 424                  * __BTF_ID__TYPE__vfs_truncate__0
 425                  * prefix =  ^
 426                  */
 427                 prefix = name + sizeof(BTF_ID) - 1;
 428
 429                 /* struct */
 430                 if (!strncmp(prefix, BTF_STRUCT, sizeof(BTF_STRUCT) - 1)) {
 431                         obj->nr_structs++;
 432                         id = add_symbol(&obj->structs, prefix, sizeof(BTF_STRUCT) - 1);
 433                 /* union  */
 434                 } else if (!strncmp(prefix, BTF_UNION, sizeof(BTF_UNION) - 1)) {
 435                         obj->nr_unions++;
 436                         id = add_symbol(&obj->unions, prefix, sizeof(BTF_UNION) - 1);
 437                 /* typedef */
 438                 } else if (!strncmp(prefix, BTF_TYPEDEF, sizeof(BTF_TYPEDEF) - 1)) {
 439                         obj->nr_typedefs++;
 440                         id = add_symbol(&obj->typedefs, prefix, sizeof(BTF_TYPEDEF) - 1);
 441                 /* func */
 442                 } else if (!strncmp(prefix, BTF_FUNC, sizeof(BTF_FUNC) - 1)) {
 443                         obj->nr_funcs++;
 444                         id = add_symbol(&obj->funcs, prefix, sizeof(BTF_FUNC) - 1);
 445                 /* set */
 446                 } else if (!strncmp(prefix, BTF_SET, sizeof(BTF_SET) - 1)) {
 447                         id = add_set(obj, prefix);
 448                         /*
 449                          * SET objects store list's count, which is encoded
 450                          * in symbol's size, together with 'cnt' field hence
 451                          * that - 1.
 452                          */
 453                         if (id)
 454                                 id->cnt = sym.st_size / sizeof(int) - 1;
 455                 } else {
 456                         pr_err("FAILED unsupported prefix %s\n", prefix);
 457                         return -1;
 458                 }
 459
 460                 if (!id)
 461                         return -ENOMEM;
 462
 463                 if (id->addr_cnt >= ADDR_CNT) {
 464                         pr_err("FAILED symbol %s crossed the number of allowed lists\n",
 465                                 id->name);
 466                         return -1;
 467                 }
 468                 id->addr[id->addr_cnt++] = sym.st_value;
 469         }
 470
 471         return 0;
 472 }
 473
 474 static int symbols_resolve(struct object *obj)
 475 {
 476         int nr_typedefs = obj->nr_typedefs;
 477         int nr_structs  = obj->nr_structs;
 478         int nr_unions   = obj->nr_unions;
 479         int nr_funcs    = obj->nr_funcs;
 480         int err, type_id;
 481         struct btf *btf;
 482         __u32 nr_types;
 483
 484         btf = btf__parse(obj->btf ?: obj->path, NULL);
 485         err = libbpf_get_error(btf);
 486         if (err) {
 487                 pr_err("FAILED: load BTF from %s: %s\n",
 488                         obj->path, strerror(-err));
 489                 return -1;
 490         }
 491
 492         err = -1;
 493         nr_types = btf__get_nr_types(btf);
 494
 495         /*
 496          * Iterate all the BTF types and search for collected symbol IDs.
 497          */
 498         for (type_id = 1; type_id <= nr_types; type_id++) {
 499                 const struct btf_type *type;
 500                 struct rb_root *root;
 501                 struct btf_id *id;
 502                 const char *str;
 503                 int *nr;
 504
 505                 type = btf__type_by_id(btf, type_id);
 506                 if (!type) {
 507                         pr_err("FAILED: malformed BTF, can't resolve type for ID %d\n",
 508                                 type_id);
 509                         goto out;
 510                 }
 511
 512                 if (btf_is_func(type) && nr_funcs) {
 513                         nr   = &nr_funcs;
 514                         root = &obj->funcs;
 515                 } else if (btf_is_struct(type) && nr_structs) {
 516                         nr   = &nr_structs;
 517                         root = &obj->structs;
 518                 } else if (btf_is_union(type) && nr_unions) {
 519                         nr   = &nr_unions;
 520                         root = &obj->unions;
 521                 } else if (btf_is_typedef(type) && nr_typedefs) {
 522                         nr   = &nr_typedefs;
 523                         root = &obj->typedefs;
 524                 } else
 525                         continue;
 526
 527                 str = btf__name_by_offset(btf, type->name_off);
 528                 if (!str) {
 529                         pr_err("FAILED: malformed BTF, can't resolve name for ID %d\n",
 530                                 type_id);
 531                         goto out;
 532                 }
 533
 534                 id = btf_id__find(root, str);
 535                 if (id) {
 536                         if (id->id) {
 537                                 pr_info("WARN: multiple IDs found for '%s': %d, %d - using %d\n",
 538                                         str, id->id, type_id, id->id);
 539                         } else {
 540                                 id->id = type_id;
 541                                 (*nr)--;
 542                         }
 543                 }
 544         }
 545
 546         err = 0;
 547 out:
 548         btf__free(btf);
 549         return err;
 550 }
 551
 552 static int id_patch(struct object *obj, struct btf_id *id)
 553 {
 554         Elf_Data *data = obj->efile.idlist;
 555         int *ptr = data->d_buf;
 556         int i;
 557
 558         if (!id->id) {
 559                 pr_err("FAILED unresolved symbol %s\n", id->name);
 560                 return -EINVAL;
 561         }
 562
 563         for (i = 0; i < id->addr_cnt; i++) {
 564                 unsigned long addr = id->addr[i];
 565                 unsigned long idx = addr - obj->efile.idlist_addr;
 566
 567                 pr_debug("patching addr %5lu: ID %7d [%s]\n",
 568                          idx, id->id, id->name);
 569
 570                 if (idx >= data->d_size) {
 571                         pr_err("FAILED patching index %lu out of bounds %lu\n",
 572                                 idx, data->d_size);
 573                         return -1;
 574                 }
 575
 576                 idx = idx / sizeof(int);
 577                 ptr[idx] = id->id;
 578         }
 579
 580         return 0;
 581 }
 582
 583 static int __symbols_patch(struct object *obj, struct rb_root *root)
 584 {
 585         struct rb_node *next;
 586         struct btf_id *id;
 587
 588         next = rb_first(root);
 589         while (next) {
 590                 id = rb_entry(next, struct btf_id, rb_node);
 591
 592                 if (id_patch(obj, id))
 593                         return -1;
 594
 595                 next = rb_next(next);
 596         }
 597         return 0;
 598 }
 599
 600 static int cmp_id(const void *pa, const void *pb)
 601 {
 602         const int *a = pa, *b = pb;
 603
 604         return *a - *b;
 605 }
 606
 607 static int sets_patch(struct object *obj)
 608 {
 609         Elf_Data *data = obj->efile.idlist;
 610         int *ptr = data->d_buf;
 611         struct rb_node *next;
 612
 613         next = rb_first(&obj->sets);
 614         while (next) {
 615                 unsigned long addr, idx;
 616                 struct btf_id *id;
 617                 int *base;
 618                 int cnt;
 619
 620                 id   = rb_entry(next, struct btf_id, rb_node);
 621                 addr = id->addr[0];
 622                 idx  = addr - obj->efile.idlist_addr;
 623
 624                 /* sets are unique */
 625                 if (id->addr_cnt != 1) {
 626                         pr_err("FAILED malformed data for set '%s'\n",
 627                                 id->name);
 628                         return -1;
 629                 }
 630
 631                 idx = idx / sizeof(int);
 632                 base = &ptr[idx] + 1;
 633                 cnt = ptr[idx];
 634
 635                 pr_debug("sorting  addr %5lu: cnt %6d [%s]\n",
 636                          (idx + 1) * sizeof(int), cnt, id->name);
 637
 638                 qsort(base, cnt, sizeof(int), cmp_id);
 639
 640                 next = rb_next(next);
 641         }
 642         return 0;
 643 }
 644
 645 static int symbols_patch(struct object *obj)
 646 {
 647         int err;
 648
 649         if (__symbols_patch(obj, &obj->structs)  ||
 650             __symbols_patch(obj, &obj->unions)   ||
 651             __symbols_patch(obj, &obj->typedefs) ||
 652             __symbols_patch(obj, &obj->funcs)    ||
 653             __symbols_patch(obj, &obj->sets))
 654                 return -1;
 655
 656         if (sets_patch(obj))
 657                 return -1;
 658
 659         elf_flagdata(obj->efile.idlist, ELF_C_SET, ELF_F_DIRTY);
 660
 661         err = elf_update(obj->efile.elf, ELF_C_WRITE);
 662         if (err < 0) {
 663                 pr_err("FAILED elf_update(WRITE): %s\n",
 664                         elf_errmsg(-1));
 665         }
 666
 667         pr_debug("update %s for %s\n",
 668                  err >= 0 ? "ok" : "failed", obj->path);
 669         return err < 0 ? -1 : 0;
 670 }
 671
 672 static const char * const resolve_btfids_usage[] = {
 673         "resolve_btfids [<options>] <ELF object>",
 674         NULL
 675 };
 676
 677 int main(int argc, const char **argv)
 678 {
 679         bool no_fail = false;
 680         struct object obj = {
 681                 .efile = {
 682                         .idlist_shndx  = -1,
 683                         .symbols_shndx = -1,
 684                 },
 685                 .structs  = RB_ROOT,
 686                 .unions   = RB_ROOT,
 687                 .typedefs = RB_ROOT,
 688                 .funcs    = RB_ROOT,
 689                 .sets     = RB_ROOT,
 690         };
 691         struct option btfid_options[] = {
 692                 OPT_INCR('v', "verbose", &verbose,
 693                          "be more verbose (show errors, etc)"),
 694                 OPT_STRING(0, "btf", &obj.btf, "BTF data",
 695                            "BTF data"),
 696                 OPT_BOOLEAN(0, "no-fail", &no_fail,
 697                            "do not fail if " BTF_IDS_SECTION " section is not found"),
 698                 OPT_END()
 699         };
 700         int err = -1;
 701
 702         argc = parse_options(argc, argv, btfid_options, resolve_btfids_usage,
 703                              PARSE_OPT_STOP_AT_NON_OPTION);
 704         if (argc != 1)
 705                 usage_with_options(resolve_btfids_usage, btfid_options);
 706
 707         obj.path = argv[0];
 708
 709         if (elf_collect(&obj))
 710                 goto out;
 711
 712         /*
 713          * We did not find .BTF_ids section or symbols section,
 714          * nothing to do..
 715          */
 716         if (obj.efile.idlist_shndx == -1 ||
 717             obj.efile.symbols_shndx == -1) {
 718                 if (no_fail)
 719                         return 0;
 720                 pr_err("FAILED to find needed sections\n");
 721                 return -1;
 722         }
 723
 724         if (symbols_collect(&obj))
 725                 goto out;
 726
 727         if (symbols_resolve(&obj))
 728                 goto out;
 729
 730         if (symbols_patch(&obj))
 731                 goto out;
 732
 733         err = 0;
 734 out:
 735         if (obj.efile.elf)
 736                 elf_end(obj.efile.elf);
 737         close(obj.efile.fd);
 738         return err;
 739 }