brk.S revision 87006 
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
37#if defined(SYSLIBC_RCS) && !defined(lint)
38	.text
39	.asciz "$FreeBSD: head/lib/libc/amd64/sys/brk.S 87006 2001-11-27 20:51:26Z jhb $"
40#endif /* SYSLIBC_RCS and not lint */
41
42#include "SYS.h"
43
44	.globl	HIDENAME(curbrk)
45	.globl	HIDENAME(minbrk)
46ENTRY(_brk)
47	jmp	ok
48
49ENTRY(brk)
50#ifdef PIC
51	movl	4(%esp),%eax
52	PIC_PROLOGUE
53	movl	PIC_GOT(HIDENAME(curbrk)),%edx	# set up GOT addressing
54	movl	PIC_GOT(HIDENAME(minbrk)),%ecx	#
55	PIC_EPILOGUE
56	cmpl	%eax,(%ecx)
57	jbe	ok
58	movl	(%ecx),%eax
59	movl	%eax,4(%esp)
60ok:
61	mov	$SYS_break,%eax
62	KERNCALL
63	jb	err
64	movl	4(%esp),%eax
65	movl	%eax,(%edx)
66	movl	$0,%eax
67	ret
68err:
69	PIC_PROLOGUE
70	jmp	PIC_PLT(HIDENAME(cerror))
71
72#else
73
74	movl	4(%esp),%eax
75	cmpl	%eax,HIDENAME(minbrk)
76	jbe	ok
77	movl	HIDENAME(minbrk),%eax
78	movl	%eax,4(%esp)
79ok:
80	mov	$SYS_break,%eax
81	KERNCALL
82	jb	err
83	movl	4(%esp),%eax
84	movl	%eax,HIDENAME(curbrk)
85	movl	$0,%eax
86	ret
87err:
88	jmp	HIDENAME(cerror)
89#endif
90