xref: /openbsd/lib/libc/arch/aarch64/sys/brk.S (revision 4cfece93)
1/*	$OpenBSD: brk.S,v 1.5 2018/08/12 17:15:10 mortimer Exp $	*/
2/*	$NetBSD: brk.S,v 1.7 2003/12/26 11:23:44 martin Exp $	*/
3
4/*-
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
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. 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 *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
33 */
34
35#include "SYS.h"
36
37	.globl	_C_LABEL(_end)
38	.globl	__curbrk
39
40	.data
41	.align	3
42	.type	__minbrk,#object
43__minbrk:
44	.quad	_C_LABEL(_end)
45	END(__minbrk)
46
47/*
48 * Change the data segment size
49 */
50ENTRY(brk)
51	RETGUARD_SETUP(brk, x15)
52#ifdef __PIC__
53	/* Setup the GOT */
54	adrp	x3, :got:__minbrk
55	ldr	x1, [x3, #:got_lo12:__minbrk]
56#else
57	ldr	x1, .Lminbrk
58#endif
59	/* Get the minimum allowable brk address */
60	ldr	x1, [x1]
61
62	/*
63	 * Valid the address specified and set to the minimum
64	 * if the address is below minbrk.
65	 */
66	cmp	x0, x1
67	b.ge	1f
68	mov	x0, x1
691:
70	mov	x2, x0
71	SYSTRAP(break)
72	bcs	CERROR
73
74#ifdef __PIC__
75	adrp	x3, :got:__curbrk
76	ldr	x1, [x3, #:got_lo12:__curbrk]
77#else
78	ldr	x1, .Lcurbrk
79#endif
80	/* Store the new address in curbrk */
81	str	x2, [x1]
82
83	/* Return 0 for success */
84	mov	x0, #0x00000000
85	RETGUARD_CHECK(brk, x15)
86	ret
87
88	.align	3
89#if !defined(__PIC__)
90.Lminbrk:
91	.quad	__minbrk
92.Lcurbrk:
93	.quad	__curbrk
94#endif
95END(brk)
96	.weak	brk
97