sbrk.S revision 21673 
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 *	$FreeBSD: head/lib/libc/amd64/sys/sbrk.S 21673 1997-01-14 07:20:47Z jkh $
37 */
38
39#if defined(SYSLIBC_RCS) && !defined(lint)
40	.text
41	.asciz "$FreeBSD: head/lib/libc/amd64/sys/sbrk.S 21673 1997-01-14 07:20:47Z jkh $"
42#endif /* SYSLIBC_RCS and not lint */
43
44#include "SYS.h"
45
46	.globl	CNAME(end)
47	.globl	HIDENAME(minbrk)
48	.globl	HIDENAME(curbrk)
49
50	.data
51HIDENAME(minbrk):	.long	CNAME(end)
52HIDENAME(curbrk):	.long	CNAME(end)
53	.text
54
55ENTRY(sbrk)
56#ifdef PIC
57	movl	4(%esp),%ecx
58	PIC_PROLOGUE
59	movl	PIC_GOT(HIDENAME(curbrk)),%edx
60	movl	(%edx),%eax
61	PIC_EPILOGUE
62	testl	%ecx,%ecx
63	jz	back
64	addl	%eax,4(%esp)
65	lea	SYS_break,%eax
66	KERNCALL
67	jb	err
68	PIC_PROLOGUE
69	movl	PIC_GOT(HIDENAME(curbrk)),%edx
70	movl	(%edx),%eax
71	addl	%ecx,(%edx)
72	PIC_EPILOGUE
73back:
74	ret
75err:
76	PIC_PROLOGUE
77	jmp	PIC_PLT(HIDENAME(cerror))
78
79#else /* !PIC */
80
81	movl	4(%esp),%ecx
82	movl	HIDENAME(curbrk),%eax
83	testl	%ecx,%ecx
84	jz	back
85	addl	%eax,4(%esp)
86	lea	SYS_break,%eax
87	KERNCALL
88	jb	err
89	movl	HIDENAME(curbrk),%eax
90	addl	%ecx,HIDENAME(curbrk)
91back:
92	ret
93err:
94	jmp	HIDENAME(cerror)
95#endif /* PIC */
96