sbrk.S revision 114313 
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_SCCS) && !defined(lint)
38	.asciz "@(#)sbrk.s	5.1 (Berkeley) 4/23/90"
39#endif /* SYSLIBC_SCCS and not lint */
40#include <machine/asm.h>
41__FBSDID("$FreeBSD: head/lib/libc/amd64/sys/sbrk.S 114313 2003-04-30 18:16:33Z peter $");
42
43#include "SYS.h"
44
45	.globl	CNAME(_end)
46	.globl	HIDENAME(minbrk)
47	.globl	HIDENAME(curbrk)
48
49	.data
50HIDENAME(minbrk):	.quad	CNAME(_end)
51HIDENAME(curbrk):	.quad	CNAME(_end)
52	.text
53
54ENTRY(sbrk)
55	pushq	%rdi
56	movq	%rdi,%rcx
57	movq	PIC_GOT(HIDENAME(curbrk)),%rax
58	testq	%rcx,%rcx
59	jz	back
60	addq	%rax,%rdi
61	mov	$SYS_break,%eax
62	KERNCALL
63	jb	err
64	movq	PIC_GOT(HIDENAME(curbrk)),%rax
65	movq	0(%rsp), %rcx
66	addq	%rcx,PIC_GOT(HIDENAME(curbrk))
67back:
68	addq	$8, %rsp
69	ret
70err:
71	addq	$8, %rsp
72	jmp	PIC_PLT(HIDENAME(cerror))
73