xref: /openbsd/lib/libc/arch/i386/sys/sbrk.S (revision 7b36286a)
1/*	$OpenBSD: sbrk.S,v 1.8 2005/08/07 11:30:38 espie Exp $ */
2/*-
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "SYS.h"
35
36	.globl	_end
37	.globl	__curbrk
38
39	.data
40__curbrk:	.long	_end
41	.text
42
43ENTRY(sbrk)
44#ifdef PIC
45	movl	4(%esp),%ecx
46	PIC_PROLOGUE
47	movl	PIC_GOT(__curbrk),%edx
48	PIC_EPILOGUE
49	movl	(%edx),%eax
50	addl	%eax,4(%esp)
51	movl	$(SYS_break),%eax
52	int	$0x80
53	jc	err
54	PIC_PROLOGUE
55	movl	PIC_GOT(__curbrk),%edx
56	PIC_EPILOGUE
57	movl	(%edx),%eax
58	addl	%ecx,(%edx)
59	ret
60err:
61	PIC_PROLOGUE
62	movl	PIC_GOT(CERROR), %ecx
63	PIC_EPILOGUE
64	jmp	*%ecx
65
66#else
67
68	movl	4(%esp),%ecx
69	movl	__curbrk,%eax
70	addl	%eax,4(%esp)
71	movl	$(SYS_break),%eax
72	int	$0x80
73	jc	err
74	movl	__curbrk,%eax
75	addl	%ecx,__curbrk
76	ret
77err:
78	jmp	CERROR
79#endif
80