libelf/elf32_newphdr.c

/* Create new ELF program header table.
   Copyright (C) 1999, 2000, 2002 Red Hat, Inc.
   Written by Ulrich Drepper <drepper@redhat.com>, 1998.

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

#include "libelfP.h"

#ifndef LIBELFBITS
# define LIBELFBITS 32
#endif


ElfW2(LIBELFBITS,Phdr) *
elfw2(LIBELFBITS,newphdr) (elf, count)
     Elf *elf;
     size_t count;
{
  ElfW2(LIBELFBITS,Phdr) *result;

  if (elf == NULL)
    return NULL;

  if (unlikely (elf->kind != ELF_K_ELF))
    {
      __libelf_seterrno (ELF_E_INVALID_HANDLE);
      return NULL;
    }

  rwlock_wrlock (elf->lock);

  if (elf->class == 0)
    elf->class = ELFW(ELFCLASS,LIBELFBITS);
  else if (unlikely (elf->class != ELFW(ELFCLASS,LIBELFBITS)))
    {
      __libelf_seterrno (ELF_E_INVALID_CLASS);
      result = NULL;
      goto out;
    }

  if (unlikely (elf->state.ELFW(elf,LIBELFBITS).ehdr == NULL))
    {
      __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
      result = NULL;
      goto out;
    }

  /* A COUNT of zero means remove existing table.  */
  if (count == 0)
    {
      /* Free the old program header.  */
      if (elf->state.ELFW(elf,LIBELFBITS).phdr != NULL)
	{
	  if (elf->state.ELFW(elf,LIBELFBITS).phdr_flags & ELF_F_MALLOCED)
	    free (elf->state.ELFW(elf,LIBELFBITS).phdr);

	  /* Set the pointer to NULL.  */
	  elf->state.ELFW(elf,LIBELFBITS).phdr = NULL;
	  /* Set the `e_phnum' member to the new value.  */
	  elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum = 0;
	  /* Also set the size.  */
	  elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phentsize =
	    sizeof (ElfW2(LIBELFBITS,Phdr));

	  elf->state.ELFW(elf,LIBELFBITS).phdr_flags |= ELF_F_DIRTY;
	  elf->flags |= ELF_F_DIRTY;
	  __libelf_seterrno (ELF_E_NOERROR);
	}

      result = NULL;
    }
  else if (elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum != count
	   || elf->state.ELFW(elf,LIBELFBITS).phdr == NULL)
    {
      /* Allocate a new program header with the appropriate number of
	 elements.  */
      result = (ElfW2(LIBELFBITS,Phdr) *)
	realloc (elf->state.ELFW(elf,LIBELFBITS).phdr,
		 count * sizeof (ElfW2(LIBELFBITS,Phdr)));
      if (result == NULL)
	__libelf_seterrno (ELF_E_NOMEM);
      else
	{
	  /* Now set the result.  */
	  elf->state.ELFW(elf,LIBELFBITS).phdr = result;
	  /* Clear the whole memory.  */
	  memset (result, '\0', count * sizeof (ElfW2(LIBELFBITS,Phdr)));
	  /* Set the `e_phnum' member to the new value.  */
	  elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum = count;
	  /* Also set the size.  */
	  elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phentsize =
	    elf_typesize (LIBELFBITS, ELF_T_PHDR, 1);
	  /* Remember we allocated the array and mark the structure is
	     modified.  */
	  elf->state.ELFW(elf,LIBELFBITS).phdr_flags |=
	    ELF_F_DIRTY | ELF_F_MALLOCED;
	  /* We have to rewrite the entire file if the size of the
	     program header is changed.  */
	  elf->flags |= ELF_F_DIRTY;
	}
    }
  else
    {
      /* We have the same number of entries.  Just clear the array.  */
      assert (elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phentsize
	      == elf_typesize (LIBELFBITS, ELF_T_PHDR, 1));

      /* Mark the structure as modified.  */
      elf->state.ELFW(elf,LIBELFBITS).phdr_flags |= ELF_F_DIRTY;

      result = elf->state.ELFW(elf,LIBELFBITS).phdr;
    }

 out:
  rwlock_unlock (elf->lock);

  return result;
}
INTDEF(elfw2(LIBELFBITS,newphdr))