ext/libelf/gelf_rela.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_Rela *
  35 gelf_getrela(Elf_Data *d, int ndx, GElf_Rela *dst)
  36 {
  37         int ec;
  38         Elf *e;
  39         Elf_Scn *scn;
  40         Elf32_Rela *rela32;
  41         Elf64_Rela *rela64;
  42         size_t msz;
  43         uint32_t sh_type;
  44
  45         if (d == NULL || ndx < 0 || dst == NULL ||
  46             (scn = d->d_scn) == NULL ||
  47             (e = scn->s_elf) == NULL) {
  48                 LIBELF_SET_ERROR(ARGUMENT, 0);
  49                 return (NULL);
  50         }
  51
  52         ec = e->e_class;
  53         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  54
  55         if (ec == ELFCLASS32)
  56                 sh_type = scn->s_shdr.s_shdr32.sh_type;
  57         else
  58                 sh_type = scn->s_shdr.s_shdr64.sh_type;
  59
  60         if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
  61                 LIBELF_SET_ERROR(ARGUMENT, 0);
  62                 return (NULL);
  63         }
  64
  65         msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
  66
  67         assert(msz > 0);
  68
  69         if (msz * ndx >= d->d_size) {
  70                 LIBELF_SET_ERROR(ARGUMENT, 0);
  71                 return (NULL);
  72         }
  73
  74         if (ec == ELFCLASS32) {
  75                 rela32 = (Elf32_Rela *) d->d_buf + ndx;
  76
  77                 dst->r_offset = (Elf64_Addr) rela32->r_offset;
  78                 dst->r_info   = (Elf64_Xword) rela32->r_info;
  79                 dst->r_addend = (Elf64_Sxword) rela32->r_addend;
  80
  81         } else {
  82
  83                 rela64 = (Elf64_Rela *) d->d_buf + ndx;
  84
  85                 *dst = *rela64;
  86         }
  87
  88         return (dst);
  89 }
  90
  91 int
  92 gelf_update_rela(Elf_Data *d, int ndx, GElf_Rela *dr)
  93 {
  94         int ec;
  95         Elf *e;
  96         Elf_Scn *scn;
  97         Elf32_Rela *rela32;
  98         Elf64_Rela *rela64;
  99         size_t msz;
 100         uint32_t sh_type;
 101
 102         if (d == NULL || ndx < 0 || dr == NULL ||
 103             (scn = d->d_scn) == NULL ||
 104             (e = scn->s_elf) == NULL) {
 105                 LIBELF_SET_ERROR(ARGUMENT, 0);
 106                 return (0);
 107         }
 108
 109         ec = e->e_class;
 110         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 111
 112         if (ec == ELFCLASS32)
 113                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 114         else
 115                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 116
 117         if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
 118                 LIBELF_SET_ERROR(ARGUMENT, 0);
 119                 return (0);
 120         }
 121
 122         msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
 123         assert(msz > 0);
 124
 125         if (msz * ndx >= d->d_size) {
 126                 LIBELF_SET_ERROR(ARGUMENT, 0);
 127                 return (0);
 128         }
 129
 130         if (ec == ELFCLASS32) {
 131                 rela32 = (Elf32_Rela *) d->d_buf + ndx;
 132
 133                 LIBELF_COPY_U32(rela32, dr, r_offset);
 134                 LIBELF_COPY_U32(rela32, dr, r_info);
 135                 LIBELF_COPY_S32(rela32, dr, r_addend);
 136         } else {
 137                 rela64 = (Elf64_Rela *) d->d_buf + ndx;
 138
 139                 *rela64 = *dr;
 140         }
 141
 142         return (1);
 143 }