xref: /openbsd/lib/libc/arch/powerpc/sys/tfork_thread.S (revision 83762a71)
1/*	$OpenBSD: tfork_thread.S,v 1.11 2023/12/10 16:45:51 deraadt Exp $	*/
2
3/*
4 * Copyright (c) 2005 Tim Wiess <tim@nop.cx>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include "SYS.h"
20
21ENTRY(__tfork_thread)
22	RETGUARD_SETUP(__tfork_thread, %r11, %r12)
23	/* call __tfork */
24	li	%r0, SYS___tfork
2599:	sc
26	PINSYSCALL(SYS___tfork, 99b)
27	cmpwi	%r0, 0
28	bne	1f
29
30	/* check if we are parent or child */
31	cmpwi	%r3, 0
32	bne	9f
33
34	/* child */
35	mtlr	%r5		/* fp */
36	mr	%r3, %r6	/* arg */
37	subi	%r1, %r1, 16	/* fixup sp to get headroom */
38	blrl
39
40	/* child returned, call __threxit */
41	li	%r0, SYS___threxit
4298:	sc
43	PINSYSCALL(SYS___threxit, 98b)
44	.long	0		/* illegal */
45
461:
47	stw	0, R2_OFFSET_ERRNO(%r2)
48	li	%r3, -1
499:
50	RETGUARD_CHECK(__tfork_thread, %r11, %r12)
51	blr
52END(__tfork_thread)
53