contrib/elftoolchain/libelf/gelf_rel.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 <assert.h>
  28 #include <gelf.h>
  29 #include <limits.h>
  30 #include <stdint.h>
  31
  32 #include "_libelf.h"
  33
  34 ELFTC_VCSID("$Id: gelf_rel.c 3177 2015-03-30 18:19:41Z emaste $");
  35
  36 GElf_Rel *
  37 gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
  38 {
  39         int ec;
  40         Elf *e;
  41         size_t msz;
  42         Elf_Scn *scn;
  43         uint32_t sh_type;
  44         Elf32_Rel *rel32;
  45         Elf64_Rel *rel64;
  46         struct _Libelf_Data *d;
  47
  48         d = (struct _Libelf_Data *) ed;
  49
  50         if (d == NULL || ndx < 0 || dst == NULL ||
  51             (scn = d->d_scn) == NULL ||
  52             (e = scn->s_elf) == NULL) {
  53                 LIBELF_SET_ERROR(ARGUMENT, 0);
  54                 return (NULL);
  55         }
  56
  57         ec = e->e_class;
  58         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  59
  60         if (ec == ELFCLASS32)
  61                 sh_type = scn->s_shdr.s_shdr32.sh_type;
  62         else
  63                 sh_type = scn->s_shdr.s_shdr64.sh_type;
  64
  65         if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
  66                 LIBELF_SET_ERROR(ARGUMENT, 0);
  67                 return (NULL);
  68         }
  69
  70         msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
  71
  72         assert(msz > 0);
  73         assert(ndx >= 0);
  74
  75         if (msz * (size_t) ndx >= d->d_data.d_size) {
  76                 LIBELF_SET_ERROR(ARGUMENT, 0);
  77                 return (NULL);
  78         }
  79
  80         if (ec == ELFCLASS32) {
  81                 rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
  82
  83                 dst->r_offset = (Elf64_Addr) rel32->r_offset;
  84                 dst->r_info   = ELF64_R_INFO(
  85                     (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
  86                     ELF32_R_TYPE(rel32->r_info));
  87
  88         } else {
  89
  90                 rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
  91
  92                 *dst = *rel64;
  93         }
  94
  95         return (dst);
  96 }
  97
  98 int
  99 gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
 100 {
 101         int ec;
 102         Elf *e;
 103         size_t msz;
 104         Elf_Scn *scn;
 105         uint32_t sh_type;
 106         Elf32_Rel *rel32;
 107         Elf64_Rel *rel64;
 108         struct _Libelf_Data *d;
 109
 110         d = (struct _Libelf_Data *) ed;
 111
 112         if (d == NULL || ndx < 0 || dr == NULL ||
 113             (scn = d->d_scn) == NULL ||
 114             (e = scn->s_elf) == NULL) {
 115                 LIBELF_SET_ERROR(ARGUMENT, 0);
 116                 return (0);
 117         }
 118
 119         ec = e->e_class;
 120         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 121
 122         if (ec == ELFCLASS32)
 123                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 124         else
 125                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 126
 127         if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
 128                 LIBELF_SET_ERROR(ARGUMENT, 0);
 129                 return (0);
 130         }
 131
 132         msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
 133
 134         assert(msz > 0);
 135         assert(ndx >= 0);
 136
 137         if (msz * (size_t) ndx >= d->d_data.d_size) {
 138                 LIBELF_SET_ERROR(ARGUMENT, 0);
 139                 return (0);
 140         }
 141
 142         if (ec == ELFCLASS32) {
 143                 rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
 144
 145                 LIBELF_COPY_U32(rel32, dr, r_offset);
 146
 147                 if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
 148                     ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
 149                         LIBELF_SET_ERROR(RANGE, 0);
 150                         return (0);
 151                 }
 152                 rel32->r_info = ELF32_R_INFO(
 153                         (Elf32_Word) ELF64_R_SYM(dr->r_info),
 154                         (Elf32_Word) ELF64_R_TYPE(dr->r_info));
 155         } else {
 156                 rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
 157
 158                 *rel64 = *dr;
 159         }
 160
 161         return (1);
 162 }