1/*	$OpenBSD: tfork_thread.S,v 1.5 2022/12/08 01:25:43 guenther Exp $	*/
2
3/*
4 * Copyright (c) 2005, Miodrag Vallat
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "SYS.h"
29
30/*
31 * int __tfork_thread(const struct __tfork *param, size_t psize, void (*func)(void *), void *arg);
32 */
33FRAMESZ=4*REGSZ
34GPOFF=FRAMESZ-2*REGSZ
35LEAF(__tfork_thread, FRAMESZ)
36	/* a0 = param, a1 = psize, a2 = func, a3 = arg */
37	PTR_SUBU sp, FRAMESZ
38	SETUP_GP64(GPOFF, __tfork_thread)
39	.set	reorder
40
41	move	t1, a3		/* arg */
42
43	__DO_SYSCALL(__tfork)
44	bnez	a3, 9f
45
46	beqz	v0, 1f
47
48	RESTORE_GP64
49	PTR_ADDU sp, FRAMESZ
50
51	/*
52	 * In parent process: just return.
53	 */
54	j	ra
55
561:
57	/*
58	 * In child process: invoke function, then exit.
59	 */
60
61	move	t9, a2		/* func */
62	move	a0, t1		/* arg */
63	move	v0, zero
64	jal	ra, t9
65
66	move	a0, zero
67	__DO_SYSCALL(__threxit)
68	teq	zero, zero, 0x52
69
709:
71	/*
72	 * System call failure.
73	 */
74	LA	t9, CERROR
75
76	RESTORE_GP64
77	PTR_ADDU sp, FRAMESZ
78	jr	t9
79END(__tfork_thread)
80