1/*	$OpenBSD: brk.S,v 1.13 2023/01/11 01:55:17 mortimer Exp $	*/
2/*	$NetBSD: brk.S,v 1.2 2002/06/03 18:30:33 fvdl Exp $	*/
3
4/*-
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
36 */
37
38#include <machine/asm.h>
39
40#include "SYS.h"
41
42	.globl	_end
43	.globl	__curbrk
44
45	.data
46__minbrk:
47	.quad	_end
48	END(__minbrk)
49	.type	__minbrk,@object
50
51ENTRY_NB(brk)
52	RETGUARD_SETUP(brk, r11);
53	RETGUARD_PUSH(r11);
54	cmpq	%rdi,__minbrk(%rip)
55	jb	1f
56	movq	__minbrk(%rip),%rdi
571:
58	SYSTRAP(break)
59	jc	1f
60	movq	%rdi,__curbrk(%rip)
61	xorl	%eax,%eax
62	jmp	2f
631:
64	SET_ERRNO
652:
66	RETGUARD_POP(r11);
67	RETGUARD_CHECK(brk, r11);
68	ret
69END(brk)
70	.weak	brk
71