xref: /openbsd/lib/libc/arch/i386/sys/sbrk.S (revision 9b7c3dbb)
1/*	$OpenBSD: sbrk.S,v 1.12 2016/05/07 19:05:21 guenther 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	.hidden	__curbrk
39
40	.data
41__curbrk:	.long	_end
42	END(__curbrk)
43	.type	__curbrk,@object
44	.text
45
46	.weak	sbrk
47
48ENTRY(sbrk)
49#ifdef __PIC__
50	movl	4(%esp),%ecx
51	PIC_PROLOGUE
52	movl	PIC_GOT(__curbrk),%edx
53	PIC_EPILOGUE
54	movl	(%edx),%eax
55	addl	%eax,4(%esp)
56	movl	$(SYS_break),%eax
57	int	$0x80
58	jc	2f
59	PIC_PROLOGUE
60	movl	PIC_GOT(__curbrk),%edx
61	PIC_EPILOGUE
62	movl	(%edx),%eax
63	addl	%ecx,(%edx)
64
65#else
66
67	movl	4(%esp),%ecx
68	movl	__curbrk,%eax
69	addl	%eax,4(%esp)
70	movl	$(SYS_break),%eax
71	int	$0x80
72	jc	2f
73	movl	__curbrk,%eax
74	addl	%ecx,__curbrk
75#endif
76	ret
772:
78	SET_ERRNO()
79	ret
80END(sbrk)
81