ext/libelf/gelf_symshndx.c

   1 /*-
   2  * Copyright (c) 2006 Joseph Koshy
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <limits.h>
  28
  29 #include <assert.h>
  30 #include "gelf.h"
  31
  32 #include "_libelf.h"
  33
  34 GElf_Sym *
  35 gelf_getsymshndx(Elf_Data *d, Elf_Data *id, int ndx, GElf_Sym *dst,
  36     Elf32_Word *shindex)
  37 {
  38         int ec;
  39         Elf *e;
  40         Elf_Scn *scn;
  41         size_t msz;
  42         uint32_t sh_type;
  43
  44         if (gelf_getsym(d, ndx, dst) == 0)
  45                 return (NULL);
  46
  47         if (id == NULL || (scn = id->d_scn) == NULL ||
  48             (e = scn->s_elf) == NULL || (e != d->d_scn->s_elf) ||
  49             shindex == NULL) {
  50                 LIBELF_SET_ERROR(ARGUMENT, 0);
  51                 return (NULL);
  52         }
  53
  54         ec = e->e_class;
  55         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  56
  57         if (ec == ELFCLASS32)
  58                 sh_type = scn->s_shdr.s_shdr32.sh_type;
  59         else
  60                 sh_type = scn->s_shdr.s_shdr64.sh_type;
  61
  62         if (_libelf_xlate_shtype(sh_type) != ELF_T_WORD ||
  63            id->d_type != ELF_T_WORD) {
  64                 LIBELF_SET_ERROR(ARGUMENT, 0);
  65                 return (NULL);
  66         }
  67
  68         msz = _libelf_msize(ELF_T_WORD, ec, e->e_version);
  69
  70         assert(msz > 0);
  71
  72         if (msz * ndx >= id->d_size) {
  73                 LIBELF_SET_ERROR(ARGUMENT, 0);
  74                 return (NULL);
  75         }
  76
  77         *shindex = ((Elf32_Word *) id->d_buf)[ndx];
  78
  79         return (dst);
  80 }
  81
  82 int
  83 gelf_update_symshndx(Elf_Data *d, Elf_Data *id, int ndx, GElf_Sym *gs,
  84     Elf32_Word xindex)
  85 {
  86         int ec;
  87         Elf *e;
  88         Elf_Scn *scn;
  89         size_t msz;
  90         uint32_t sh_type;
  91
  92         if (gelf_update_sym(d, ndx, gs) == 0)
  93                 return (0);
  94
  95         if (id == NULL || (scn = id->d_scn) == NULL ||
  96             (e = scn->s_elf) == NULL || (e != d->d_scn->s_elf)) {
  97                 LIBELF_SET_ERROR(ARGUMENT, 0);
  98                 return (0);
  99         }
 100
 101         ec = e->e_class;
 102         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 103
 104         if (ec == ELFCLASS32)
 105                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 106         else
 107                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 108
 109         if (_libelf_xlate_shtype(sh_type) != ELF_T_WORD ||
 110             d->d_type != ELF_T_WORD) {
 111                 LIBELF_SET_ERROR(ARGUMENT, 0);
 112                 return (0);
 113         }
 114
 115         msz = _libelf_msize(ELF_T_WORD, ec, e->e_version);
 116         assert(msz > 0);
 117
 118         if (msz * ndx >= id->d_size) {
 119                 LIBELF_SET_ERROR(ARGUMENT, 0);
 120                 return (0);
 121         }
 122
 123         *(((Elf32_Word *) id->d_buf) + ndx) = xindex;
 124
 125         return (1);
 126 }