lib/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 <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_Rel *
  37 gelf_getrel(Elf_Data *d, int ndx, GElf_Rel *dst)
  38 {
  39         int ec;
  40         Elf *e;
  41         Elf_Scn *scn;
  42         Elf32_Rel *rel32;
  43         Elf64_Rel *rel64;
  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_REL) {
  63                 LIBELF_SET_ERROR(ARGUMENT, 0);
  64                 return (NULL);
  65         }
  66
  67         msz = _libelf_msize(ELF_T_REL, 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                 rel32 = (Elf32_Rel *) d->d_buf + ndx;
  78
  79                 dst->r_offset = (Elf64_Addr) rel32->r_offset;
  80                 dst->r_info   = ELF64_R_INFO(
  81                     (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
  82                     ELF32_R_TYPE(rel32->r_info));
  83
  84         } else {
  85
  86                 rel64 = (Elf64_Rel *) d->d_buf + ndx;
  87
  88                 *dst = *rel64;
  89         }
  90
  91         return (dst);
  92 }
  93
  94 int
  95 gelf_update_rel(Elf_Data *d, int ndx, GElf_Rel *dr)
  96 {
  97         int ec;
  98         Elf *e;
  99         Elf_Scn *scn;
 100         Elf32_Rel *rel32;
 101         Elf64_Rel *rel64;
 102         size_t msz;
 103         uint32_t sh_type;
 104
 105         if (d == NULL || ndx < 0 || dr == NULL ||
 106             (scn = d->d_scn) == NULL ||
 107             (e = scn->s_elf) == NULL) {
 108                 LIBELF_SET_ERROR(ARGUMENT, 0);
 109                 return (0);
 110         }
 111
 112         ec = e->e_class;
 113         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 114
 115         if (ec == ELFCLASS32)
 116                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 117         else
 118                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 119
 120         if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
 121                 LIBELF_SET_ERROR(ARGUMENT, 0);
 122                 return (0);
 123         }
 124
 125         msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
 126         assert(msz > 0);
 127
 128         if (msz * ndx >= d->d_size) {
 129                 LIBELF_SET_ERROR(ARGUMENT, 0);
 130                 return (0);
 131         }
 132
 133         if (ec == ELFCLASS32) {
 134                 rel32 = (Elf32_Rel *) d->d_buf + ndx;
 135
 136                 LIBELF_COPY_U32(rel32, dr, r_offset);
 137
 138                 if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
 139                     ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
 140                         LIBELF_SET_ERROR(RANGE, 0);
 141                         return (0);
 142                 }
 143                 rel32->r_info = ELF32_R_INFO(ELF64_R_SYM(dr->r_info),
 144                     ELF64_R_TYPE(dr->r_info));
 145         } else {
 146                 rel64 = (Elf64_Rel *) d->d_buf + ndx;
 147
 148                 *rel64 = *dr;
 149         }
 150
 151         return (1);
 152 }