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/* Look up a versioned symbol in a shared object loaded by `dlopen'.
Copyright (C) 1995-2022 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
<https://www.gnu.org/licenses/>. */
#include <dlfcn.h>
#include <ldsodefs.h>
#include <shlib-compat.h>
#include <stddef.h>
struct dlvsym_args
{
/* The arguments to dlvsym_doit. */
void *handle;
const char *name;
const char *version;
void *who;
/* The return values of dlvsym_doit. */
void *sym;
};
static void
dlvsym_doit (void *a)
{
struct dlvsym_args *args = (struct dlvsym_args *) a;
args->sym = _dl_vsym (args->handle, args->name, args->version, args->who);
}
static void *
dlvsym_implementation (void *handle, const char *name, const char *version,
void *dl_caller)
{
struct dlvsym_args args;
args.who = dl_caller;
args.handle = handle;
args.name = name;
args.version = version;
/* Protect against concurrent loads and unloads. */
__rtld_lock_lock_recursive (GL(dl_load_lock));
void *result = (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);
__rtld_lock_unlock_recursive (GL(dl_load_lock));
return result;
}
#ifdef SHARED
void *
___dlvsym (void *handle, const char *name, const char *version)
{
if (GLRO (dl_dlfcn_hook) != NULL)
return GLRO (dl_dlfcn_hook)->dlvsym (handle, name, version,
RETURN_ADDRESS (0));
else
return dlvsym_implementation (handle, name, version, RETURN_ADDRESS (0));
}
versioned_symbol (libc, ___dlvsym, dlvsym, GLIBC_2_34);
# if OTHER_SHLIB_COMPAT (libdl, GLIBC_2_1, GLIBC_2_34)
compat_symbol (libdl, ___dlvsym, dlvsym, GLIBC_2_1);
# endif
#else /* !SHARED */
/* Also used with _dlfcn_hook. */
void *
__dlvsym (void *handle, const char *name, const char *version, void *dl_caller)
{
return dlvsym_implementation (handle, name, version, dl_caller);
}
void *
___dlvsym (void *handle, const char *name, const char *version)
{
return __dlvsym (handle, name, version, RETURN_ADDRESS (0));
}
weak_alias (___dlvsym, dlvsym)
#endif /* !SHARED */
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