glibc/dlfcn/dlvsym.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

95 lines
2.6 KiB
C

/* 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 (!rtld_active ())
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 */