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/* vfork ABI-compatibility entry points for libpthread.
Copyright (C) 2014-2016 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 <unistd.h>
#include <shlib-compat.h>
/* libpthread used to have its own vfork implementation that differed
from libc's only in having a pointless micro-optimization. There
is no longer any use to having a separate copy in libpthread, but
the historical ABI requires it. For static linking, there is no
need to provide anything here--the libc version will be linked in.
For shared library ABI compatibility, there must be __vfork and
vfork symbols in libpthread.so; so we define them using IFUNC to
redirect to the libc function. */
/* Note! If the architecture doesn't support IFUNC, then we need an
alternate target-specific mechanism to implement this. So we just
assume IFUNC here and require that the target override this file
if necessary.
If the architecture can assume all supported versions of gcc will
produce a tail-call to __libc_vfork, consider including the version
in sysdeps/unix/sysv/linux/aarch64/pt-vfork.c. */
#if !HAVE_IFUNC
# error "must write pt-vfork for this machine or get IFUNC support"
#endif
#if (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \
|| SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20))
extern __typeof (vfork) __libc_vfork; /* Defined in libc. */
static __typeof (vfork) *
__attribute__ ((used))
vfork_resolve (void)
{
return &__libc_vfork;
}
# ifdef HAVE_ASM_SET_DIRECTIVE
# define DEFINE_VFORK(name) \
asm (".set " #name ", vfork_resolve\n" \
".globl " #name "\n" \
".type " #name ", %gnu_indirect_function");
# else
# define DEFINE_VFORK(name) \
asm (#name " = vfork_resolve\n" \
".globl " #name "\n" \
".type " #name ", %gnu_indirect_function");
# endif
#endif
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20)
DEFINE_VFORK (vfork_ifunc)
compat_symbol (libpthread, vfork_ifunc, vfork, GLIBC_2_0);
#endif
#if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)
DEFINE_VFORK (__vfork_ifunc)
compat_symbol (libpthread, __vfork_ifunc, __vfork, GLIBC_2_1_2);
#endif
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