mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 07:20:11 +00:00
9a75654037
The Linux nptl implementation is used as base for generic fork implementation to handle the internal locks and mutexes. The system specific bits are moved a new internal _Fork symbol. (This new implementation will be used to provide a async-signal-safe _Fork now that POSIX has clarified that fork might not be async-signal-safe [1]). For Hurd it means that the __nss_database_fork_prepare_parent and __nss_database_fork_subprocess will be run in a slight different order. [1] https://austingroupbugs.net/view.php?id=62
60 lines
2.2 KiB
C
60 lines
2.2 KiB
C
/* arch_fork definition for Linux fork implementation.
|
|
Copyright (C) 2014-2021 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/>. */
|
|
|
|
#ifndef __ARCH_FORK_H
|
|
#define __ARCH_FORK_H
|
|
|
|
#include <sysdep.h>
|
|
#include <sched.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
|
|
/* Call the clone syscall with fork semantic. The CTID address is used
|
|
to store the child thread ID at its locationm, to erase it in child memory
|
|
when the child exits, and do a wakeup on the futex at that address.
|
|
|
|
The architecture with non-default kernel abi semantic should correctlly
|
|
override it with one of the supported calling convention (check generic
|
|
kernel-features.h for the clone abi variants). */
|
|
static inline pid_t
|
|
arch_fork (void *ctid)
|
|
{
|
|
const int flags = CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD;
|
|
long int ret;
|
|
#ifdef __ASSUME_CLONE_BACKWARDS
|
|
# ifdef INLINE_CLONE_SYSCALL
|
|
ret = INLINE_CLONE_SYSCALL (flags, 0, NULL, 0, ctid);
|
|
# else
|
|
ret = INLINE_SYSCALL_CALL (clone, flags, 0, NULL, 0, ctid);
|
|
# endif
|
|
#elif defined(__ASSUME_CLONE_BACKWARDS2)
|
|
ret = INLINE_SYSCALL_CALL (clone, 0, flags, NULL, ctid, 0);
|
|
#elif defined(__ASSUME_CLONE_BACKWARDS3)
|
|
ret = INLINE_SYSCALL_CALL (clone, flags, 0, 0, NULL, ctid, 0);
|
|
#elif defined(__ASSUME_CLONE2)
|
|
ret = INLINE_SYSCALL_CALL (clone2, flags, 0, 0, NULL, ctid, 0);
|
|
#elif defined(__ASSUME_CLONE_DEFAULT)
|
|
ret = INLINE_SYSCALL_CALL (clone, flags, 0, NULL, ctid, 0);
|
|
#else
|
|
# error "Undefined clone variant"
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
#endif /* __ARCH_FORK_H */
|