lib/libelf/gelf_rela.c

   1 /*-
   2  * Copyright (c) 2006,2008 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 <sys/cdefs.h>
  28
  29 #include <assert.h>
  30 #include <gelf.h>
  31
  32 #include "_libelf.h"
  33
  34 LIBELF_VCSID("$Id$");
  35
  36 GElf_Rela *
  37 gelf_getrela(Elf_Data *d, int ndx, GElf_Rela *dst)
  38 {
  39         int ec;
  40         Elf *e;
  41         Elf_Scn *scn;
  42         Elf32_Rela *rela32;
  43         Elf64_Rela *rela64;
  44         size_t msz;
  45         uint32_t sh_type;
  46
  47         if (d == NULL || ndx < 0 || dst == NULL ||
  48             (scn = d->d_scn) == NULL ||
  49             (e = scn->s_elf) == 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_RELA) {
  63                 LIBELF_SET_ERROR(ARGUMENT, 0);
  64                 return (NULL);
  65         }
  66
  67         msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
  68
  69         assert(msz > 0);
  70
  71         if (msz * ndx >= d->d_size) {
  72                 LIBELF_SET_ERROR(ARGUMENT, 0);
  73                 return (NULL);
  74         }
  75
  76         if (ec == ELFCLASS32) {
  77                 rela32 = (Elf32_Rela *) d->d_buf + ndx;
  78
  79                 dst->r_offset = (Elf64_Addr) rela32->r_offset;
  80                 dst->r_info   = ELF64_R_INFO(
  81                     (Elf64_Xword) ELF32_R_SYM(rela32->r_info),
  82                     ELF32_R_TYPE(rela32->r_info));
  83                 dst->r_addend = (Elf64_Sxword) rela32->r_addend;
  84
  85         } else {
  86
  87                 rela64 = (Elf64_Rela *) d->d_buf + ndx;
  88
  89                 *dst = *rela64;
  90         }
  91
  92         return (dst);
  93 }
  94
  95 int
  96 gelf_update_rela(Elf_Data *d, int ndx, GElf_Rela *dr)
  97 {
  98         int ec;
  99         Elf *e;
 100         Elf_Scn *scn;
 101         Elf32_Rela *rela32;
 102         Elf64_Rela *rela64;
 103         size_t msz;
 104         uint32_t sh_type;
 105
 106         if (d == NULL || ndx < 0 || dr == NULL ||
 107             (scn = d->d_scn) == NULL ||
 108             (e = scn->s_elf) == NULL) {
 109                 LIBELF_SET_ERROR(ARGUMENT, 0);
 110                 return (0);
 111         }
 112
 113         ec = e->e_class;
 114         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 115
 116         if (ec == ELFCLASS32)
 117                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 118         else
 119                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 120
 121         if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
 122                 LIBELF_SET_ERROR(ARGUMENT, 0);
 123                 return (0);
 124         }
 125
 126         msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
 127         assert(msz > 0);
 128
 129         if (msz * ndx >= d->d_size) {
 130                 LIBELF_SET_ERROR(ARGUMENT, 0);
 131                 return (0);
 132         }
 133
 134         if (ec == ELFCLASS32) {
 135                 rela32 = (Elf32_Rela *) d->d_buf + ndx;
 136
 137                 LIBELF_COPY_U32(rela32, dr, r_offset);
 138
 139                 if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
 140                     ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
 141                         LIBELF_SET_ERROR(RANGE, 0);
 142                         return (0);
 143                 }
 144                 rela32->r_info = ELF32_R_INFO(ELF64_R_SYM(dr->r_info),
 145                     ELF64_R_TYPE(dr->r_info));
 146
 147                 LIBELF_COPY_S32(rela32, dr, r_addend);
 148         } else {
 149                 rela64 = (Elf64_Rela *) d->d_buf + ndx;
 150
 151                 *rela64 = *dr;
 152         }
 153
 154         return (1);
 155 }