libelf/gelf_update_symshndx.c

/* Update symbol information and section index in symbol table at the
   given index.
   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
   This file is part of Red Hat elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 2000.

   Red Hat elfutils 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 of the License.

   Red Hat elfutils 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 Red Hat elfutils; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.

   In addition, as a special exception, Red Hat, Inc. gives You the
   additional right to link the code of Red Hat elfutils with code licensed
   under any Open Source Initiative certified open source license
   (http://www.opensource.org/licenses/index.php) which requires the
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   this exception must only link to the code of Red Hat elfutils through
   those well defined interfaces identified in the file named EXCEPTION
   found in the source code files (the "Approved Interfaces").  The files
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   Red Hat's grant of this exception is conditioned upon your not adding
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   code used in conjunction with Red Hat elfutils except the Non-GPL Code
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   exception to your version of the file, but you are not obligated to do
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   this file solely under the GPL without exception.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
   Open Invention Network licensees cross-license their patents.  No patent
   license is granted, either expressly or impliedly, by designation as an
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#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

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

#include "libelfP.h"


int
gelf_update_symshndx (symdata, shndxdata, ndx, src, srcshndx)
     Elf_Data *symdata;
     Elf_Data *shndxdata;
     int ndx;
     GElf_Sym *src;
     Elf32_Word srcshndx;
{
  Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata;
  Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata;
  Elf_Scn *scn;
  Elf32_Word *shndx = NULL;
  int result = 0;

  if (symdata == NULL)
    return 0;

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

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

  scn = symdata_scn->s;
  /* We simply have to believe the user that the two sections belong to
     the same ELF file.  */
  rwlock_wrlock (scn->elf->lock);

  /* The user is not required to pass a data descriptor for an extended
     section index table.  */
  if (shndxdata_scn != NULL)
    {
      if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size))
	{
	  __libelf_seterrno (ELF_E_INVALID_INDEX);
	  goto out;
	}

      shndx = &((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx];
    }
  /* But if s/he does not the extended sectio index must be zero.  */
  else if (unlikely (srcshndx != 0))
    {
      __libelf_seterrno (ELF_E_INVALID_INDEX);
      goto out;
    }

  if (scn->elf->class == ELFCLASS32)
    {
      Elf32_Sym *sym;

      /* There is the possibility that the values in the input are
	 too large.  */
      if (unlikely (src->st_value > 0xffffffffull)
	  || unlikely (src->st_size > 0xffffffffull))
	{
	  __libelf_seterrno (ELF_E_INVALID_DATA);
	  goto out;
	}

      /* Check whether we have to resize the data buffer.  */
      if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > symdata_scn->d.d_size))
	{
	  __libelf_seterrno (ELF_E_INVALID_INDEX);
	  goto out;
	}

      sym = &((Elf32_Sym *) symdata_scn->d.d_buf)[ndx];

#define COPY(name) \
      sym->name = src->name
      COPY (st_name);
      COPY (st_value);
      COPY (st_size);
      /* Please note that we can simply copy the `st_info' element since
	 the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
	 for the 64 bit variant.  */
      COPY (st_info);
      COPY (st_other);
      COPY (st_shndx);
    }
  else
    {
      /* Check whether we have to resize the data buffer.  */
      if (unlikely ((ndx + 1) * sizeof (Elf64_Sym) > symdata_scn->d.d_size))
	{
	  __libelf_seterrno (ELF_E_INVALID_INDEX);
	  goto out;
	}

      ((Elf64_Sym *) symdata_scn->d.d_buf)[ndx] = *src;
    }

  /* Now we can store the section index.  */
  if (shndx != NULL)
    *shndx = srcshndx;

  result = 1;

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

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

  return result;
}