brk.S revision 165903 
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 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#if defined(SYSLIBC_SCCS) && !defined(lint)
34	.asciz "@(#)brk.s	5.2 (Berkeley) 12/17/90"
35#endif /* SYSLIBC_SCCS and not lint */
36#include <machine/asm.h>
37__FBSDID("$FreeBSD: head/lib/libc/amd64/sys/brk.S 165903 2007-01-09 00:28:16Z imp $");
38
39#include "SYS.h"
40
41	.globl	HIDENAME(curbrk)
42	.globl	HIDENAME(minbrk)
43ENTRY(_brk)
44	pushq	%rdi
45	jmp	ok
46
47ENTRY(brk)
48	pushq	%rdi
49	movq	%rdi,%rax
50#ifdef PIC
51	movq	PIC_GOT(HIDENAME(minbrk)),%rdx
52	cmpq	%rax,(%rdx)
53#else
54	cmpq	%rax,HIDENAME(minbrk)(%rip)
55#endif
56	jbe	ok
57#ifdef PIC
58	movq	(%rdx),%rdi
59#else
60	movq	HIDENAME(minbrk)(%rip),%rdi
61#endif
62ok:
63	movq	$SYS_break,%rax
64	KERNCALL
65	jb	err
66	movq	0(%rsp),%rax
67#ifdef PIC
68	movq	PIC_GOT(HIDENAME(curbrk)),%rdx
69	movq	%rax,(%rdx)
70#else
71	movq	%rax,HIDENAME(curbrk)(%rip)
72#endif
73	movq	$0,%rax
74	popq	%rdi
75	ret
76err:
77	addq	$8, %rsp
78#ifdef PIC
79	movq	PIC_GOT(HIDENAME(cerror)),%rdx
80	jmp	*%rdx
81#else
82	jmp	HIDENAME(cerror)
83#endif
84