1/* $OpenBSD: brk.S,v 1.12 2016/05/07 19:05:21 guenther 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 .text 45 46 .weak brk 47 48ENTRY(brk) 49#ifdef __PIC__ 50 movl 4(%esp),%ecx 51 PIC_PROLOGUE 52 movl PIC_GOT(__minbrk),%edx 53 PIC_EPILOGUE 54 cmpl %ecx,(%edx) 55 jb 1f 56 movl (%edx),%ecx 57 movl %ecx,4(%esp) 581: 59 movl $(SYS_break),%eax 60 int $0x80 61 jc 2f 62 PIC_PROLOGUE 63 movl PIC_GOT(__curbrk),%edx # set up GOT addressing 64 PIC_EPILOGUE 65 xorl %eax,%eax 66 movl %ecx,(%edx) 67 68#else 69 70 movl 4(%esp),%ecx 71 cmpl %ecx,__minbrk 72 jb 1f 73 movl __minbrk,%ecx 74 movl %ecx,4(%esp) 751: 76 movl $(SYS_break),%eax 77 int $0x80 78 jc 2f 79 xorl %eax,%eax 80 movl %ecx,__curbrk 81#endif 82 ret 832: 84 SET_ERRNO() 85 ret 86END(brk) 87