glibc/sysdeps/unix/sysv/linux/aarch64/vfork.S
Szabolcs Nagy 1cf59c2603 aarch64: Add GCS support to vfork
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2025-01-20 09:22:41 +00:00

47 lines
1.6 KiB
ArmAsm

/* Copyright (C) 1999-2025 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 <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
/* Clone the calling process, but without copying the whole address space.
The calling process is suspended until the new process exits or is
replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
and the process ID of the new process to the old process. */
ENTRY (__vfork)
mov x0, #0x4111 /* CLONE_VM | CLONE_VFORK | SIGCHLD */
mov x1, sp
DO_CALL (clone, 2)
cmn x0, #4095
b.cs .Lsyscall_error
cbz x0, L(child)
RET
L(child):
/* Return with indirect branch in the child to support GCS.
Compilers insert BTI instruction after vfork() to make
sure return via BR works on systems with BTI. */
br x30
PSEUDO_END (__vfork)
libc_hidden_def (__vfork)
weak_alias (__vfork, vfork)
strong_alias (__vfork, __libc_vfork)