[thirdparty/glibc.git] / elf / dlvsym.c

/* Look up a versioned symbol in a shared object loaded by `dlopen'.
   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 <stddef.h>
#include <link.h>
#include <dlfcn.h>
#include <setjmp.h>

#include <dl-hash.h>

void *
__dlvsym (void *handle, const char *name, const char *version_str)
{
  ElfW(Addr) caller = (ElfW(Addr)) __builtin_return_address (0);
  ElfW(Addr) loadbase;
  struct r_found_version version;
  const ElfW(Sym) *ref = NULL;
  void doit (void)
    {
      if (handle == NULL)
	/* Search the global scope.  */
	loadbase = _dl_lookup_versioned_symbol
	  (name, &ref, &(_dl_global_scope ?: _dl_default_scope)[2], NULL,
	   &version, 0);
      else if (handle == RTLD_NEXT)
	{
	  struct link_map *l, *match;

	  /* Find the highest-addressed object that CALLER is not below.  */
	  match = NULL;
	  for (l = _dl_loaded; l; l = l->l_next)
	    if (caller >= l->l_addr && (!match || match->l_addr < l->l_addr))
	      match = l;

	  if (! match)
	    _dl_signal_error (0, NULL, _("\
RTLD_NEXT used in code not dynamically loaded"));

	  l = match;
	  while (l->l_loader)
	    l = l->l_loader;

	  loadbase = _dl_lookup_versioned_symbol_skip
	    (name, &ref, &_dl_loaded, NULL, &version, l, 0);
	}
      else
	{
	  /* Search the scope of the given object.  */
	  struct link_map *map = handle;
	  struct link_map *mapscope[2] = { map, NULL };
	  loadbase = _dl_lookup_versioned_symbol
	    (name, &ref, mapscope, map->l_name, &version, 0);
	}
    }

  /* Compute hash value to the version string.  */
  version.name = version_str;
  version.hash = _dl_elf_hash (version_str);
  /* We don't have a specific file where the symbol can be found.  */
  version.filename = NULL;

  return _dlerror_run (doit) ? NULL : (void *) (loadbase + ref->st_value);
}
weak_alias (__dlvsym, dlvsym)
Commit	Line	Data
1fb05e3d	1	/* Look up a versioned symbol in a shared object loaded by `dlopen'.
c84142e8 UD	2	Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Library General Public License as
	7	published by the Free Software Foundation; either version 2 of the
	8	License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Library General Public License for more details.
	14
	15	You should have received a copy of the GNU Library General Public
	16	License along with the GNU C Library; see the file COPYING.LIB. If not,
	17	write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	18	Boston, MA 02111-1307, USA. */
	19
	20	#include <stddef.h>
	21	#include <link.h>
	22	#include <dlfcn.h>
	23	#include <setjmp.h>
	24
1fb05e3d	25	#include <dl-hash.h>
c84142e8 UD	26
c84142e8 UD	27	void *
1fb05e3d	28	__dlvsym (void handle, const char name, const char *version_str)
c84142e8 UD	29	{
	30	ElfW(Addr) caller = (ElfW(Addr)) __builtin_return_address (0);
	31	ElfW(Addr) loadbase;
1fb05e3d	32	struct r_found_version version;
c84142e8 UD	33	const ElfW(Sym) *ref = NULL;
	34	void doit (void)
	35	{
	36	if (handle == NULL)
	37	/* Search the global scope. */
	38	loadbase = _dl_lookup_versioned_symbol
	39	(name, &ref, &(_dl_global_scope ?: _dl_default_scope)[2], NULL,
1fb05e3d	40	&version, 0);
c84142e8 UD	41	else if (handle == RTLD_NEXT)
	42	{
	43	struct link_map l, match;
	44
	45	/* Find the highest-addressed object that CALLER is not below. */
	46	match = NULL;
	47	for (l = _dl_loaded; l; l = l->l_next)
	48	if (caller >= l->l_addr && (!match \|\| match->l_addr < l->l_addr))
	49	match = l;
	50
	51	if (! match)
	52	_dl_signal_error (0, NULL, _("\
	53	RTLD_NEXT used in code not dynamically loaded"));
	54
	55	l = match;
	56	while (l->l_loader)
	57	l = l->l_loader;
	58
	59	loadbase = _dl_lookup_versioned_symbol_skip
1fb05e3d	60	(name, &ref, &_dl_loaded, NULL, &version, l, 0);
c84142e8 UD	61	}
	62	else
	63	{
	64	/* Search the scope of the given object. */
	65	struct link_map *map = handle;
	66	struct link_map *mapscope[2] = { map, NULL };
	67	loadbase = _dl_lookup_versioned_symbol
1fb05e3d	68	(name, &ref, mapscope, map->l_name, &version, 0);
c84142e8 UD	69	}
	70	}
	71
1fb05e3d UD	72	/* Compute hash value to the version string. */
	73	version.name = version_str;
	74	version.hash = _dl_elf_hash (version_str);
	75	/* We don't have a specific file where the symbol can be found. */
	76	version.filename = NULL;
	77
c84142e8 UD	78	return _dlerror_run (doit) ? NULL : (void *) (loadbase + ref->st_value);
	79	}
	80	weak_alias (__dlvsym, dlvsym)