libelf/elf_readall.c

/* Read all of the file associated with the descriptor.
   Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
   Contributed 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 <unistd.h>

#include "libelfP.h"
#include "common.h"


static void
set_address (Elf *elf, size_t offset)
{
  if (elf->kind == ELF_K_AR)
    {
      Elf *child = elf->state.ar.children;

      while (child != NULL)
	{
	  if (child->map_address == NULL)
	    {
	      child->map_address = elf->map_address;
	      child->start_offset -= offset;
	      if (child->kind == ELF_K_AR)
		child->state.ar.offset -= offset;

	      set_address (child, offset);
	    }

	  child = child->next;
	}
    }
}


char *
__libelf_readall (elf)
     Elf *elf;
{
  /* Get the file.  */
  rwlock_wrlock (elf->lock);

  if (elf->map_address == NULL && unlikely (elf->fildes == -1))
    {
      __libelf_seterrno (ELF_E_INVALID_HANDLE);
      rwlock_unlock (elf->lock);
      return NULL;
    }

  /* If the file is not mmap'ed and not previously loaded, do it now.  */
  if (elf->map_address == NULL)
    {
      char *mem;

      /* If this is an archive and we have derived descriptors get the
	 locks for all of them.  */
      libelf_acquire_all (elf);

      /* Allocate all the memory we need.  */
      mem = (char *) malloc (elf->maximum_size);
      if (mem != NULL)
	{
	  /* Read the file content.  */
	  if ((size_t) pread (elf->fildes, mem, elf->maximum_size,
			      elf->start_offset) != elf->maximum_size)
	    {
	      /* Something went wrong.  */
	      __libelf_seterrno (ELF_E_READ_ERROR);
	      free (mem);
	    }
	  else
	    {
	      /* Remember the address.  */
	      elf->map_address = mem;

	      /* Also remember that we allocated the memory.  */
	      elf->flags |= ELF_F_MALLOCED;

	      /* Propagate the information down to all children and
		 their children.  */
	      set_address (elf, elf->start_offset);

	      /* Correct the own offsets.  */
	      if (elf->kind == ELF_K_AR)
		elf->state.ar.offset -= elf->start_offset;
	      elf->start_offset = 0;
	    }
	}
      else
	__libelf_seterrno (ELF_E_NOMEM);

      /* Free the locks on the children.  */
      libelf_release_all (elf);
    }

  rwlock_unlock (elf->lock);

  return (char *) elf->map_address;
}