minix/lib/nbsd_libc/arch/hppa/sys/__vfork14.S
Gianluca Guida b6cbf7203b Import unmodified NetBSD libc in trunk
This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is 
split between lib/nbsd_libc and common/lib/libc.
2011-02-14 19:36:03 +00:00

66 lines
2.6 KiB
ArmAsm

/* $NetBSD: __vfork14.S,v 1.5 2008/04/28 20:22:56 martin Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Fredette.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/errno.h>
#include "SYS.h"
ENTRY(__vfork14, 0)
/*
* NB: __vfork14 is a tricky syscall. We can't save
* any values on the stack, because the stack will be
* trashed by the child, leaving garbage for when the
* parent returns.
*
* So we must save values in registers, specifically,
* registers that the kernel is willing to preserve
* across the syscall. Normally, this would be callee-
* saved registers, with the kernel being the callee,
* but the problem is that we, too, are a callee, and
* would have to save that very same register somewhere,
* because *our* caller is counting on us to do so.
*
* What we need is a normally caller-saved register,
* that the kernel is willing to save for us. The
* syscall entry code in locore.S has been modified
* to do just this for the t4 register.
*/
.import __cerror, code
copy %rp, %t4
ldil L%SYSCALLGATE, %r1
ble 4(%sr7, %r1)
ldi SYS___vfork14, %t1
comb,<> %r0, %t1, __cerror
copy %t4, %rp
addi -1, %ret1, %ret1
bv %r0(%rp)
and %ret0, %ret1, %ret0
EXIT(__vfork14)