libelf/gelf_update_rel.c

   1 /* Update REL relocation information at given index.
   2    Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014 Red Hat, Inc.
   3    This file is part of elfutils.
   4    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
   5
   6    This file is free software; you can redistribute it and/or modify
   7    it under the terms of either
   8
   9      * the GNU Lesser General Public License as published by the Free
  10        Software Foundation; either version 3 of the License, or (at
  11        your option) any later version
  12
  13    or
  14
  15      * the GNU General Public License as published by the Free
  16        Software Foundation; either version 2 of the License, or (at
  17        your option) any later version
  18
  19    or both in parallel, as here.
  20
  21    elfutils is distributed in the hope that it will be useful, but
  22    WITHOUT ANY WARRANTY; without even the implied warranty of
  23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  24    General Public License for more details.
  25
  26    You should have received copies of the GNU General Public License and
  27    the GNU Lesser General Public License along with this program.  If
  28    not, see <http://www.gnu.org/licenses/>.  */
  29
  30 #ifdef HAVE_CONFIG_H
  31 # include <config.h>
  32 #endif
  33
  34 #include <gelf.h>
  35 #include <stdlib.h>
  36
  37 #include "libelfP.h"
  38
  39
  40 int
  41 gelf_update_rel (Elf_Data *dst, int ndx, GElf_Rel *src)
  42 {
  43   Elf_Data_Scn *data_scn = (Elf_Data_Scn *) dst;
  44   Elf_Scn *scn;
  45   int result = 0;
  46
  47   if (dst == NULL)
  48     return 0;
  49
  50   if (unlikely (data_scn->d.d_type != ELF_T_REL))
  51     {
  52       /* The type of the data better should match.  */
  53       __libelf_seterrno (ELF_E_DATA_MISMATCH);
  54       return 0;
  55     }
  56
  57   scn = data_scn->s;
  58   rwlock_wrlock (scn->elf->lock);
  59
  60   if (scn->elf->class == ELFCLASS32)
  61     {
  62       Elf32_Rel *rel;
  63
  64       /* There is the possibility that the values in the input are
  65          too large.  */
  66       if (unlikely (src->r_offset > 0xffffffffull)
  67           || unlikely (GELF_R_SYM (src->r_info) > 0xffffff)
  68           || unlikely (GELF_R_TYPE (src->r_info) > 0xff))
  69         {
  70           __libelf_seterrno (ELF_E_INVALID_DATA);
  71           goto out;
  72         }
  73
  74       /* Check whether we have to resize the data buffer.  */
  75       if (INVALID_NDX (ndx, Elf32_Rel, &data_scn->d))
  76         {
  77           __libelf_seterrno (ELF_E_INVALID_INDEX);
  78           goto out;
  79         }
  80
  81       rel = &((Elf32_Rel *) data_scn->d.d_buf)[ndx];
  82
  83       rel->r_offset = src->r_offset;
  84       rel->r_info = ELF32_R_INFO (GELF_R_SYM (src->r_info),
  85                                   GELF_R_TYPE (src->r_info));
  86     }
  87   else
  88     {
  89       /* Check whether we have to resize the data buffer.  */
  90       if (INVALID_NDX (ndx, Elf64_Rel, &data_scn->d))
  91         {
  92           __libelf_seterrno (ELF_E_INVALID_INDEX);
  93           goto out;
  94         }
  95
  96       ((Elf64_Rel *) data_scn->d.d_buf)[ndx] = *src;
  97     }
  98
  99   result = 1;
 100
 101   /* Mark the section as modified.  */
 102   scn->flags |= ELF_F_DIRTY;
 103
 104  out:
 105   rwlock_unlock (scn->elf->lock);
 106
 107   return result;
 108 }