xref: /netbsd/lib/libc/arch/x86_64/sys/brk.S (revision bf9ec67e)
1/*	$NetBSD: brk.S,v 1.1 2001/06/19 00:25:06 fvdl Exp $	*/
2
3/*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * William Jolitz.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
39 */
40
41#include <machine/asm.h>
42#if defined(SYSLIBC_SCCS) && !defined(lint)
43	RCSID("$NetBSD: brk.S,v 1.1 2001/06/19 00:25:06 fvdl Exp $")
44#endif /* SYSLIBC_SCCS and not lint */
45
46#include "SYS.h"
47
48	.globl	_end
49	.globl	_C_LABEL(__minbrk)
50	.globl	CURBRK
51
52#ifdef WEAK_ALIAS
53WEAK_ALIAS(brk, _brk)
54#endif
55
56	.data
57_C_LABEL(__minbrk):
58	.quad	_end
59	.text
60
61ENTRY(_brk)
62#ifdef PIC
63	movq	PIC_GOT(_C_LABEL(__minbrk)),%rdx
64	cmpq	%rdi,(%rdx)
65	jb	1f
66	movq	(%rdx),%rdi
671:
68	SYSTRAP(break)
69	jc	err
70	movq	PIC_GOT(CURBRK),%rdx	# set up GOT addressing
71	movl	%ecx,(%rdx)
72	xorl	%eax,%eax
73	ret
74err:
75	movq	PIC_GOT(CERROR),%rdx
76	jmp	*%rdx
77#else
78	cmpq	%rdi,_C_LABEL(__minbrk)(%rip)
79	jb	1f
80	movq	_C_LABEL(__minbrk)(%rip),%rdi
811:
82	SYSTRAP(break)
83	jc	err
84	movq	%rdi,CURBRK(%rip)
85	xorl	%eax,%eax
86	ret
87err:
88	jmp	CERROR
89#endif
90