xref: /netbsd-src/lib/libc/arch/i386/sys/brk.S (revision 38023541164cff097d5fadec63134189b1453b8c)
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 *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
37 *	$Id: brk.S,v 1.2 1993/10/21 02:19:26 jtc Exp $
38 */
39
40#if defined(SYSLIBC_SCCS) && !defined(lint)
41	.text
42	.asciz "$Id: brk.S,v 1.2 1993/10/21 02:19:26 jtc Exp $"
43#endif /* SYSLIBC_SCCS and not lint */
44
45#include "SYS.h"
46
47#define	SYS_brk		17
48
49	.globl	curbrk
50	.globl	minbrk
51ENTRY(_brk)
52	jmp	ok
53
54ENTRY(brk)
55#ifdef PIC
56	movl	4(%esp),%eax
57	PIC_PROLOGUE
58	movl	%edx,PIC_GOT(curbrk)	# set up GOT addressing
59	movl	%ecx,PIC_GOT(minbrk)	#
60	cmpl	%eax,(%ecx)
61	PIC_EPILOGUE
62	jl	ok
63	movl	(%ecx),%eax
64	movl	%eax,4(%esp)
65ok:
66	lea	SYS_brk,%eax
67	LCALL(7,0)
68	jb	err
69	movl	4(%esp),%eax
70	movl	%eax,(%edx)
71	movl	$0,%eax
72	ret
73err:
74	jmp	PIC_PLT(cerror)
75
76#else
77
78	movl	4(%esp),%eax
79	cmpl	%eax,minbrk
80	jl	ok
81	movl	minbrk,%eax
82	movl	%eax,4(%esp)
83ok:
84	lea	SYS_brk,%eax
85	LCALL(7,0)
86	jb	err
87	movl	4(%esp),%eax
88	movl	%eax,curbrk
89	movl	$0,%eax
90	ret
91err:
92	jmp	cerror
93#endif
94