xref: /openbsd/lib/libc/arch/powerpc/sys/tfork_thread.S (revision d415bd75)
1/*	$OpenBSD: tfork_thread.S,v 1.10 2020/11/28 19:49:30 gkoehler 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
25	sc
26	cmpwi	%r0, 0
27	bne	1f
28
29	/* check if we are parent or child */
30	cmpwi	%r3, 0
31	bne	9f
32
33	/* child */
34	mtlr	%r5		/* fp */
35	mr	%r3, %r6	/* arg */
36	subi	%r1, %r1, 16	/* fixup sp to get headroom */
37	blrl
38
39	/* child returned, call __threxit */
40	li	%r0, SYS___threxit
41	sc
42	.long	0		/* illegal */
43
441:
45	stw	0, R2_OFFSET_ERRNO(%r2)
46	li	%r3, -1
479:
48	RETGUARD_CHECK(__tfork_thread, %r11, %r12)
49	blr
50END(__tfork_thread)
51