mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-17 10:30:20 +00:00
649ad05add
1999-02-03 Ulrich Drepper <drepper@cygnus.com> * elf/dlsym.c (dlsym_doit): If no symbol for RTLD_NEXT is found initialize ref element of args object so that dlsym does not dump a core. * elf/dlvsym.c (dlvsym_doit): Likewise.
116 lines
3.4 KiB
C
116 lines
3.4 KiB
C
/* Look up a versioned symbol in a shared object loaded by `dlopen'.
|
|
Copyright (C) 1995, 1996, 1997, 1998, 1999 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 <dlfcn.h>
|
|
#include <setjmp.h>
|
|
#include <stddef.h>
|
|
#include <elf/ldsodefs.h>
|
|
|
|
#include <dl-hash.h>
|
|
|
|
struct dlvsym_args
|
|
{
|
|
/* The arguments to dlvsym_doit. */
|
|
void *handle;
|
|
const char *name;
|
|
struct r_found_version version;
|
|
ElfW(Addr) caller;
|
|
/* The return values of dlvsym_doit. */
|
|
ElfW(Addr) loadbase;
|
|
const ElfW(Sym) *ref;
|
|
};
|
|
|
|
|
|
static void
|
|
dlvsym_doit (void *a)
|
|
{
|
|
struct dlvsym_args *args = (struct dlvsym_args *)a;
|
|
args->ref = NULL;
|
|
|
|
if (args->handle == RTLD_DEFAULT)
|
|
/* Search the global scope. */
|
|
args->loadbase = _dl_lookup_versioned_symbol (args->name, &args->ref,
|
|
_dl_global_scope,
|
|
NULL, &args->version, 0);
|
|
else if (args->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 (args->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;
|
|
|
|
args->loadbase = _dl_lookup_versioned_symbol_skip (args->name,
|
|
&args->ref,
|
|
l->l_local_scope,
|
|
NULL, &args->version,
|
|
match);
|
|
|
|
if (args->loadbase == 0)
|
|
{
|
|
/* This means that no such symbol is defined. In this case we
|
|
have to provide a phony Elfxx_Sym entry since the value is
|
|
referenced in `dlsym'. */
|
|
static const ElfW(Sym) null_result;
|
|
|
|
args->ref = &null_result;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Search the scope of the given object. */
|
|
struct link_map *map = args->handle;
|
|
args->loadbase = _dl_lookup_versioned_symbol (args->name, &args->ref,
|
|
map->l_local_scope,
|
|
map->l_name,
|
|
&args->version, 0);
|
|
}
|
|
}
|
|
|
|
void *
|
|
__dlvsym (void *handle, const char *name, const char *version_str)
|
|
{
|
|
struct dlvsym_args args;
|
|
|
|
args.handle = handle;
|
|
args.name = name;
|
|
args.caller = (ElfW(Addr)) __builtin_return_address (0);
|
|
|
|
/* Compute hash value to the version string. */
|
|
args.version.name = version_str;
|
|
args.version.hidden = 1;
|
|
args.version.hash = _dl_elf_hash (version_str);
|
|
/* We don't have a specific file where the symbol can be found. */
|
|
args.version.filename = NULL;
|
|
|
|
return (_dlerror_run (dlvsym_doit, &args)
|
|
? NULL : (void *) (args.loadbase + args.ref->st_value));
|
|
}
|
|
weak_alias (__dlvsym, dlvsym)
|