libelf/gelf_update_rel.c

/* Update REL relocation information at given index.
   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
   Written by Ulrich Drepper <drepper@redhat.com>, 2000.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, version 2.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <gelf.h>
#include <stdlib.h>

#include "libelfP.h"


int
gelf_update_rel (Elf_Data *dst, int ndx, GElf_Rel *src)
{
  Elf_Data_Scn *data_scn = (Elf_Data_Scn *) dst;
  Elf_Scn *scn;
  int result = 0;

  if (dst == NULL)
    return 0;

  if (unlikely (ndx < 0))
    {
      __libelf_seterrno (ELF_E_INVALID_INDEX);
      return 0;
    }

  if (unlikely (data_scn->d.d_type != ELF_T_REL))
    {
      /* The type of the data better should match.  */
      __libelf_seterrno (ELF_E_DATA_MISMATCH);
      return 0;
    }

  scn = data_scn->s;
  rwlock_wrlock (scn->elf->lock);

  if (scn->elf->class == ELFCLASS32)
    {
      Elf32_Rel *rel;

      /* There is the possibility that the values in the input are
	 too large.  */
      if (unlikely (src->r_offset > 0xffffffffull)
	  || unlikely (GELF_R_SYM (src->r_info) > 0xffffff)
	  || unlikely (GELF_R_TYPE (src->r_info) > 0xff))
	{
	  __libelf_seterrno (ELF_E_INVALID_DATA);
	  goto out;
	}

      /* Check whether we have to resize the data buffer.  */
      if (unlikely ((ndx + 1) * sizeof (Elf32_Rel) > data_scn->d.d_size))
	{
	  __libelf_seterrno (ELF_E_INVALID_INDEX);
	  goto out;
	}

      rel = &((Elf32_Rel *) data_scn->d.d_buf)[ndx];

      rel->r_offset = src->r_offset;
      rel->r_info = ELF32_R_INFO (GELF_R_SYM (src->r_info),
				  GELF_R_TYPE (src->r_info));
    }
  else
    {
      /* Check whether we have to resize the data buffer.  */
      if (unlikely ((ndx + 1) * sizeof (Elf64_Rel) > data_scn->d.d_size))
	{
	  __libelf_seterrno (ELF_E_INVALID_INDEX);
	  goto out;
	}

      ((Elf64_Rel *) data_scn->d.d_buf)[ndx] = *src;
    }

  result = 1;

  /* Mark the section as modified.  */
  scn->flags |= ELF_F_DIRTY;

 out:
  rwlock_unlock (scn->elf->lock);

  return result;
}