mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-12 06:10:10 +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
53 lines
2.0 KiB
C
53 lines
2.0 KiB
C
/* _Fork implementation. Linux version.
|
|
Copyright (C) 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/>. */
|
|
|
|
#include <arch-fork.h>
|
|
#include <pthreadP.h>
|
|
|
|
/* Pointer to the fork generation counter in the thread library. */
|
|
extern unsigned long int *__fork_generation_pointer attribute_hidden;
|
|
|
|
pid_t
|
|
_Fork (void)
|
|
{
|
|
pid_t pid = arch_fork (&THREAD_SELF->tid);
|
|
if (pid == 0)
|
|
{
|
|
struct pthread *self = THREAD_SELF;
|
|
|
|
/* Initialize the robust mutex list setting in the kernel which has
|
|
been reset during the fork. We do not check for errors because if
|
|
it fails here, it must have failed at process startup as well and
|
|
nobody could have used robust mutexes.
|
|
Before we do that, we have to clear the list of robust mutexes
|
|
because we do not inherit ownership of mutexes from the parent.
|
|
We do not have to set self->robust_head.futex_offset since we do
|
|
inherit the correct value from the parent. We do not need to clear
|
|
the pending operation because it must have been zero when fork was
|
|
called. */
|
|
#if __PTHREAD_MUTEX_HAVE_PREV
|
|
self->robust_prev = &self->robust_head;
|
|
#endif
|
|
self->robust_head.list = &self->robust_head;
|
|
INTERNAL_SYSCALL_CALL (set_robust_list, &self->robust_head,
|
|
sizeof (struct robust_list_head));
|
|
}
|
|
return pid;
|
|
}
|
|
libc_hidden_def (_Fork)
|