glibc/nptl/pt-fork.c
2015-02-06 10:53:07 -08:00

73 lines
2.3 KiB
C

/* ABI compatibility for 'fork' symbol in libpthread ABI.
Copyright (C) 2002-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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 once had its own fork, though there was no apparent reason
for it. There is no use in having a separate symbol 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 __fork and fork symbols in
libpthread.so; so we define them using IFUNC to redirect to the libc
function. */
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
# if HAVE_IFUNC
static __typeof (fork) *
__attribute__ ((used))
fork_resolve (void)
{
return &__libc_fork;
}
# ifdef HAVE_ASM_SET_DIRECTIVE
# define DEFINE_FORK(name) \
asm (".set " #name ", fork_resolve\n" \
".globl " #name "\n" \
".type " #name ", %gnu_indirect_function");
# else
# define DEFINE_FORK(name) \
asm (#name " = fork_resolve\n" \
".globl " #name "\n" \
".type " #name ", %gnu_indirect_function");
# endif
# else /* !HAVE_IFUNC */
static pid_t __attribute__ ((used))
fork_compat (void)
{
return __libc_fork ();
}
# define DEFINE_FORK(name) strong_alias (fork_compat, name)
# endif /* HAVE_IFUNC */
DEFINE_FORK (fork_ifunc)
compat_symbol (libpthread, fork_ifunc, fork, GLIBC_2_0);
DEFINE_FORK (__fork_ifunc)
compat_symbol (libpthread, __fork_ifunc, __fork, GLIBC_2_0);
#endif