/* ELF symbol resolve functions for VDSO objects.

   Copyright (C) 2005-2018 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 Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include "config.h"

#include <ldsodefs.h>

void *

_dl_vdso_vsym (const char *name, const struct r_found_version *vers)

{

  struct link_map *map = GLRO (dl_sysinfo_map);

  void *value = NULL;

  if (map != NULL)

    {

      /* Use a WEAK REF so we don't error out if the symbol is not found.  */

      ElfW (Sym) wsym;

      memset (&wsym, 0, sizeof (ElfW (Sym)));

      wsym.st_info = (unsigned char) ELFW (ST_INFO (STB_WEAK, STT_NOTYPE));

      /* Search the scope of the vdso map.  */

      const ElfW (Sym) *ref = &wsy;;

      lookup_t result = GLRO (dl_lookup_symbol_x) (name, map, &ref,

						   map->l_local_scope,

						   vers, 0, 0, NULL);

      if (ref != NULL)

	value = DL_SYMBOL_ADDRESS (result, ref);

    }

  return value;

}