/* $NetBSD: __clone.S,v 1.3 2015/03/27 23:23:14 matt Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe.
*
* 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"
#if defined(SYSLIBC_SCCS) && !defined(lint)
RCSID("$NetBSD: __clone.S,v 1.3 2015/03/27 23:23:14 matt Exp $");
#endif /* SYSLIBC_SCCS and not lint */
/*
* int __clone(int (*fn)(void *), void *stack, int flags, void *arg);
*/
ENTRY(__clone)
/*
* Sanity checks: func and stack may not be NULL.
*/
mv t0, a0 /* we need a0 for return value */
li a0, EINVAL
beqz t0, 8f
beqz a1, 8f
/*
* We need to be able to get at the func and arg arguments
* in the child. Luckily, we have a convenient place to
* do this: the child's stack.
*/
addi a1, a1, -CALLFRAME_SIZ
REG_S t0, 0(a1)
REG_S a3, SZREG(a1)
/*
* The system call expects (flags, stack).
*/
mv a0, a2
SYSTRAP(__clone)
# a1 (rv[1]) == 0, parent, child pid in a0
8: JUMP_TO_CERROR() /* error */
bnez a1, 9f /* success */
ret # parent return
/* NOTREACHED */
9: /*
* Child: Fetch the function and argument from the new stack and create
a frame so that the child can be safely called.
*
* There are already register slots on the stack from above.
* They already include the o32 argument save area. The
* highest is unused. a1 should equal sp now.
*/
REG_L t0, 0(sp)
REG_L a0, SZREG(sp)
REG_S zero, CALLFRAME_RA(sp) /* make sure stack frame ends */
/* Call the clone's entry point. */
jalr t0
/* Pass the return value to _exit. */
tail _C_LABEL(_exit)
