brk.S revision 5790 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	$Id: brk.S,v 1.1 1994/08/05 01:18:39 wollman Exp $
37 */
38
39#if defined(SYSLIBC_RCS) && !defined(lint)
40	.text
41	.asciz "$Id$"
42#endif /* SYSLIBC_RCS and not lint */
43
44#include "SYS.h"
45
46#define	SYS_brk		17
47
48	.globl	curbrk
49	.globl	minbrk
50ENTRY(_brk)
51	jmp	ok
52
53ENTRY(brk)
54#ifdef PIC
55	movl	4(%esp),%eax
56	PIC_PROLOGUE
57	movl	PIC_GOT(curbrk),%edx	# set up GOT addressing
58	movl	PIC_GOT(minbrk),%ecx	#
59	cmpl	%eax,(%ecx)
60	PIC_EPILOGUE
61	jl	ok
62	movl	(%ecx),%eax
63	movl	%eax,4(%esp)
64ok:
65	lea	SYS_brk,%eax
66	LCALL(7,0)
67	jb	err
68	movl	4(%esp),%eax
69	movl	%eax,(%edx)
70	movl	$0,%eax
71	ret
72err:
73	jmp	PIC_PLT(cerror)
74
75#else
76
77	movl	4(%esp),%eax
78	cmpl	%eax,minbrk
79	jl	ok
80	movl	minbrk,%eax
81	movl	%eax,4(%esp)
82ok:
83	lea	SYS_brk,%eax
84	LCALL(7,0)
85	jb	err
86	movl	4(%esp),%eax
87	movl	%eax,curbrk
88	movl	$0,%eax
89	ret
90err:
91	jmp	cerror
92#endif
93