1/*-
2 * Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org>
3 * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu>
4 * All rights reserved.
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 AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <machine/asm.h>
29__FBSDID("$FreeBSD$");
30
31/*
32 * With thanks to John Dyson for the original version of this.
33 */
34
35#include <SYS.h>
36
37/*
38 *              %edi   %rsi        %rdx       %rcx
39 * rfork_thread(flags, stack_addr, start_fnc, start_arg);
40 *
41 * flags:		Flags to rfork system call.  See rfork(2).
42 * stack_addr:		Top of stack for thread.
43 * start_fnc:		Address of thread function to call in child.
44 * start_arg:		Argument to pass to the thread function in child.
45 */
46
47ENTRY(rfork_thread)
48	pushq	%rbx
49	pushq	%r12
50	movq	%rdx, %rbx
51	movq	%rcx, %r12
52
53	/*
54	 * Prepare and execute the thread creation syscall
55	 */
56	movq	$SYS_rfork, %rax
57	KERNCALL
58	jb 	2f
59
60	/*
61	 * Check to see if we are in the parent or child
62	 */
63	cmpl	$0, %edx
64	jnz	1f
65	popq	%r12
66	popq	%rbx
67	ret
68
69	/*
70	 * If we are in the child (new thread), then
71	 * set-up the call to the internal subroutine.  If it
72	 * returns, then call __exit.
73	 */
741:
75	movq	%rsi, %rsp
76	movq	%r12, %rdi
77	call	*%rbx
78	movl	%eax, %edi
79
80	/*
81	 * Exit system call
82	 */
83#ifdef SYS_exit
84	movq	$SYS_exit, %rax
85#else
86	movq	$SYS_sys_exit, %rax
87#endif
88	KERNCALL
89
90	/*
91	 * Branch here if the thread creation fails:
92	 */
932:
94	popq	%r12
95	popq	%rbx
96	jmp	HIDENAME(cerror)
97END(rfork_thread)
98
99	.section .note.GNU-stack,"",%progbits
100