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/* $OpenBSD: tfork_thread.S,v 1.1 2012/03/22 00:44:56 guenther Exp $ */
/*
* Copyright (c) 2005, Miodrag Vallat
*
* 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 AUTHOR ``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 AUTHOR 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.h"
/*
* int __tfork_thread(const struct __tfork *param, void *stack, void (*func)(void *), void *arg);
*/
ENTRY(__tfork_thread, R2|R3|R4)
/*
* Save thread creation arguments into registers.
*/
movl 8(ap), r2 /* stack */
movl 12(ap), r3 /* func */
movl 16(ap), r4 /* arg */
__DO_SYSCALL(__tfork)
jcs 9f
cmpl r0, $0
beql 1f
/*
* In parent process: just return.
*/
ret
1:
/*
* In child process: switch stack, invoke function, then exit.
* Note that since we can not pass a register to calls, we need
* to waste 4 bytes of stack in every thread.
*/
movl r2, sp /* stack */
pushl r3 /* func */
pushl r4 /* arg */
calls $1, *4(sp) /* func */
__DO_SYSCALL(__threxit)
9:
/*
* system call failed.
*/
jmp _C_LABEL(_cerror)
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