glibc/elf/dynamic-link.h

/* Inline functions for dynamic linking.
   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <elf.h>
#include <dl-machine.h>
#include <assert.h>


/* Global read-only variable defined in rtld.c which is nonzero if we
   shall give more warning messages.  */
extern int _dl_verbose __attribute__ ((unused));


/* Read the dynamic section at DYN and fill in INFO with indices DT_*.  */

static inline void __attribute__ ((unused))
elf_get_dynamic_info (ElfW(Dyn) *dyn,
		      ElfW(Dyn) *info[DT_NUM + DT_PROCNUM + DT_VERSIONTAGNUM
				     + DT_EXTRANUM])
{
  unsigned int i;

  for (i = 0; i < DT_NUM + DT_PROCNUM + DT_VERSIONTAGNUM + DT_EXTRANUM; ++i)
    info[i] = NULL;

  if (! dyn)
    return;

  while (dyn->d_tag != DT_NULL)
    {
      if (dyn->d_tag < DT_NUM)
	info[dyn->d_tag] = dyn;
      else if (dyn->d_tag >= DT_LOPROC &&
	       dyn->d_tag < DT_LOPROC + DT_PROCNUM)
	info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
      else if ((Elf32_Word) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
	info[DT_VERSIONTAGIDX (dyn->d_tag) + DT_NUM + DT_PROCNUM] = dyn;
      else if ((Elf32_Word) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
	info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_PROCNUM
	     + DT_VERSIONTAGNUM] = dyn;
      else
	assert (! "bad dynamic tag");
      dyn++;
    }

  if (info[DT_RELA])
    assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
  if (info[DT_REL])
    assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
  if (info[DT_PLTREL])
    assert (info[DT_PLTREL]->d_un.d_val == DT_REL ||
	    info[DT_PLTREL]->d_un.d_val == DT_RELA);
}

#ifdef RESOLVE

/* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
   These functions are almost identical, so we use cpp magic to avoid
   duplicating their code.  It cannot be done in a more general function
   because we must be able to completely inline.  */

#if ! ELF_MACHINE_NO_REL
#include "do-rel.h"
#define ELF_DYNAMIC_DO_REL(map, lazy)					      \
  if ((map)->l_info[DT_REL])						      \
    elf_dynamic_do_rel ((map), DT_REL, DT_RELSZ, 0);			      \
  if ((map)->l_info[DT_PLTREL] &&					      \
      (map)->l_info[DT_PLTREL]->d_un.d_val == DT_REL)			      \
    elf_dynamic_do_rel ((map), DT_JMPREL, DT_PLTRELSZ, (lazy));
#else
#define ELF_DYNAMIC_DO_REL(map, lazy) /* Nothing to do.  */
#endif

#if ! ELF_MACHINE_NO_RELA
#define DO_RELA
#include "do-rel.h"
#define ELF_DYNAMIC_DO_RELA(map, lazy)					      \
  if ((map)->l_info[DT_RELA])						      \
    elf_dynamic_do_rela ((map), DT_RELA, DT_RELASZ, 0);			      \
  if ((map)->l_info[DT_PLTREL] &&					      \
      (map)->l_info[DT_PLTREL]->d_un.d_val == DT_RELA)			      \
    elf_dynamic_do_rela ((map), DT_JMPREL, DT_PLTRELSZ, (lazy));
#else
#define ELF_DYNAMIC_DO_RELA(map, lazy) /* Nothing to do.  */
#endif

/* This can't just be an inline function because GCC is too dumb
   to inline functions containing inlines themselves.  */
#define ELF_DYNAMIC_RELOCATE(map, lazy)				\
  do {								\
    int edr_lazy = elf_machine_runtime_setup((map), (lazy));	\
    ELF_DYNAMIC_DO_REL ((map), edr_lazy);			\
    ELF_DYNAMIC_DO_RELA ((map), edr_lazy);			\
  } while (0)

#endif