1/*	$OpenBSD: brk.S,v 1.16 2023/12/10 16:45:51 deraadt Exp $ */
2/*-
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "SYS.h"
35
36	.globl	_end
37	.globl	__curbrk
38
39	.data
40__minbrk:
41	.long	_end
42	END(__minbrk)
43	.type	__minbrk,@object
44
45ENTRY_NB(brk)
46#ifdef __PIC__
47	movl	4(%esp),%ecx
48	PIC_PROLOGUE
49	movl	PIC_GOT(__minbrk),%edx
50	PIC_EPILOGUE
51	cmpl	%ecx,(%edx)
52	jb	1f
53	movl	(%edx),%ecx
54	movl	%ecx,4(%esp)
551:
56	movl	$(SYS_break),%eax
5799:	int	$0x80
58	PINSYSCALL(SYS_break, 99b)
59	jc	2f
60	PIC_PROLOGUE
61	movl	PIC_GOT(__curbrk),%edx	# set up GOT addressing
62	PIC_EPILOGUE
63	xorl	%eax,%eax
64	movl	%ecx,(%edx)
65
66#else
67
68	movl	4(%esp),%ecx
69	cmpl	%ecx,__minbrk
70	jb	1f
71	movl	__minbrk,%ecx
72	movl	%ecx,4(%esp)
731:
74	movl	$(SYS_break),%eax
7598:	int	$0x80
76	PINSYSCALL(SYS_break, 98b)
77	jc	2f
78	xorl	%eax,%eax
79	movl	%ecx,__curbrk
80#endif
81	ret
822:
83	SET_ERRNO()
84	ret
85END(brk)
86	.weak	brk
87