ext/libelf/gelf_rel.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_Rel *
  35 gelf_getrel(Elf_Data *d, int ndx, GElf_Rel *dst)
  36 {
  37         int ec;
  38         Elf *e;
  39         Elf_Scn *scn;
  40         Elf32_Rel *rel32;
  41         Elf64_Rel *rel64;
  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_REL) {
  61                 LIBELF_SET_ERROR(ARGUMENT, 0);
  62                 return (NULL);
  63         }
  64
  65         msz = _libelf_msize(ELF_T_REL, 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                 rel32 = (Elf32_Rel *) d->d_buf + ndx;
  76
  77                 dst->r_offset = (Elf64_Addr) rel32->r_offset;
  78                 dst->r_info   = (Elf64_Xword) rel32->r_info;
  79
  80         } else {
  81
  82                 rel64 = (Elf64_Rel *) d->d_buf + ndx;
  83
  84                 *dst = *rel64;
  85         }
  86
  87         return (dst);
  88 }
  89
  90 int
  91 gelf_update_rel(Elf_Data *d, int ndx, GElf_Rel *dr)
  92 {
  93         int ec;
  94         Elf *e;
  95         Elf_Scn *scn;
  96         Elf32_Rel *rel32;
  97         Elf64_Rel *rel64;
  98         size_t msz;
  99         uint32_t sh_type;
 100
 101         if (d == NULL || ndx < 0 || dr == NULL ||
 102             (scn = d->d_scn) == NULL ||
 103             (e = scn->s_elf) == NULL) {
 104                 LIBELF_SET_ERROR(ARGUMENT, 0);
 105                 return (0);
 106         }
 107
 108         ec = e->e_class;
 109         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 110
 111         if (ec == ELFCLASS32)
 112                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 113         else
 114                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 115
 116         if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
 117                 LIBELF_SET_ERROR(ARGUMENT, 0);
 118                 return (0);
 119         }
 120
 121         msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
 122         assert(msz > 0);
 123
 124         if (msz * ndx >= d->d_size) {
 125                 LIBELF_SET_ERROR(ARGUMENT, 0);
 126                 return (0);
 127         }
 128
 129         if (ec == ELFCLASS32) {
 130                 rel32 = (Elf32_Rel *) d->d_buf + ndx;
 131
 132                 LIBELF_COPY_U32(rel32, dr, r_offset);
 133                 LIBELF_COPY_U32(rel32, dr, r_info);
 134         } else {
 135                 rel64 = (Elf64_Rel *) d->d_buf + ndx;
 136
 137                 *rel64 = *dr;
 138         }
 139
 140         return (1);
 141 }