rfork_thread.S revision 217106 
1239310Sdim/*-
2239310Sdim * Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org>
3239310Sdim * All rights reserved.
4239310Sdim *
5239310Sdim * Redistribution and use in source and binary forms, with or without
6239310Sdim * modification, are permitted provided that the following conditions
7239310Sdim * are met:
8239310Sdim * 1. Redistributions of source code must retain the above copyright
9239310Sdim *    notice, this list of conditions and the following disclaimer.
10239310Sdim * 2. Redistributions in binary form must reproduce the above copyright
11239310Sdim *    notice, this list of conditions and the following disclaimer in the
12239310Sdim *    documentation and/or other materials provided with the distribution.
13239310Sdim *
14239310Sdim * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15239310Sdim * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16239310Sdim * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17239310Sdim * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18239310Sdim * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19239310Sdim * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20249423Sdim * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21249423Sdim * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22239310Sdim * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23263508Sdim * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24239310Sdim * SUCH DAMAGE.
25239310Sdim */
26239310Sdim
27239310Sdim#include <machine/asm.h>
28239310Sdim__FBSDID("$FreeBSD: head/lib/libc/i386/gen/rfork_thread.S 217106 2011-01-07 16:08:40Z kib $");
29249423Sdim
30239310Sdim/*
31239310Sdim * With thanks to John Dyson for the original version of this.
32239310Sdim */
33239310Sdim
34239310Sdim#include <SYS.h>
35239310Sdim
36239310Sdim/*
37239310Sdim *                8      12          16         20
38239310Sdim * rfork_thread(flags, stack_addr, start_fnc, start_arg);
39239310Sdim *
40263508Sdim * flags:		Flags to rfork system call.  See rfork(2).
41263508Sdim * stack_addr:		Top of stack for thread.
42263508Sdim * start_fnc:		Address of thread function to call in child.
43263508Sdim * start_arg:		Argument to pass to the thread function in child.
44263508Sdim */
45263508Sdim
46263508SdimENTRY(rfork_thread)
47263508Sdim	pushl	%ebp
48263508Sdim	movl	%esp, %ebp
49263508Sdim	pushl	%esi
50263508Sdim
51249423Sdim	/*
52263508Sdim	 * Push thread info onto the new thread's stack
53263508Sdim	 */
54263508Sdim	movl	12(%ebp), %esi	# get stack addr
55263508Sdim
56263508Sdim	subl	$4, %esi
57263508Sdim	movl	20(%ebp), %eax	# get start argument
58239310Sdim	movl	%eax, (%esi)
59239310Sdim
60239310Sdim	subl	$4, %esi
61239310Sdim	movl	16(%ebp), %eax	# get start thread address
62239310Sdim	movl	%eax, (%esi)
63249423Sdim
64249423Sdim	/*
65249423Sdim	 * Prepare and execute the thread creation syscall
66249423Sdim	 */
67249423Sdim	pushl	8(%ebp)
68249423Sdim	pushl	$0
69249423Sdim	movl	$SYS_rfork, %eax
70249423Sdim	KERNCALL
71249423Sdim	jb 	2f
72249423Sdim
73239310Sdim	/*
74	 * Check to see if we are in the parent or child
75	 */
76	cmpl	$0, %edx
77	jnz	1f
78	addl	$8, %esp
79	popl	%esi
80	movl	%ebp, %esp
81	popl	%ebp
82	ret
83	.p2align 2
84
85	/*
86	 * If we are in the child (new thread), then
87	 * set-up the call to the internal subroutine.  If it
88	 * returns, then call __exit.
89	 */
901:
91	movl	%esi,%esp
92	popl	%eax
93	call	*%eax
94	addl	$4, %esp
95
96	/*
97	 * Exit system call
98	 */
99	pushl	%eax
100	pushl	$0
101#ifdef SYS_exit
102	movl	$SYS_exit, %eax
103#else
104	movl	$SYS_sys_exit, %eax
105#endif
106	KERNCALL
107
108	/*
109	 * Branch here if the thread creation fails:
110	 */
1112:
112	addl	$8, %esp
113	popl	%esi
114	movl	%ebp, %esp
115	popl	%ebp
116	PIC_PROLOGUE
117	jmp	PIC_PLT(HIDENAME(cerror))
118END(rfork_thread)
119
120	.section .note.GNU-stack,"",%progbits
121