ARC: Linux Syscall Interface

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

sysdeps/unix/sysv/linux/arc/vfork.S

@@ -0,0 +1,42 @@
+/* vfork for ARC Linux.
+   Copyright (C) 2020 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 <sys/syscall.h>
+#include <sysdep.h>
+#include <tcb-offsets.h>
+#define _SIGNAL_H
+#include <bits/signum-arch.h>       /* For SIGCHLD */
+
+#define CLONE_VM		0x00000100
+#define CLONE_VFORK		0x00004000
+#define CLONE_FLAGS_FOR_VFORK	(CLONE_VM|CLONE_VFORK|SIGCHLD)
+
+ENTRY (__vfork)
+	mov	r0, CLONE_FLAGS_FOR_VFORK
+	mov_s	r1, sp
+	mov	r8, __NR_clone
+	ARC_TRAP_INSN
+
+	cmp	r0, 0
+	jge	[blink]	; child continues
+
+	b   __syscall_error
+PSEUDO_END (__vfork)
+libc_hidden_def (__vfork)
+
+weak_alias (__vfork, vfork)