brk.S revision 50476
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $FreeBSD: head/lib/libc/i386/sys/brk.S 50476 1999-08-28 00:22:10Z peter $ 37 */ 38 39#if defined(SYSLIBC_RCS) && !defined(lint) 40 .text 41 .asciz "$FreeBSD: head/lib/libc/i386/sys/brk.S 50476 1999-08-28 00:22:10Z peter $" 42#endif /* SYSLIBC_RCS and not lint */ 43 44#include "SYS.h" 45 46 .globl HIDENAME(curbrk) 47 .globl HIDENAME(minbrk) 48ENTRY(_brk) 49 jmp ok 50 51ENTRY(brk) 52#ifdef PIC 53 movl 4(%esp),%eax 54 PIC_PROLOGUE 55 movl PIC_GOT(HIDENAME(curbrk)),%edx # set up GOT addressing 56 movl PIC_GOT(HIDENAME(minbrk)),%ecx # 57 PIC_EPILOGUE 58 cmpl %eax,(%ecx) 59 jbe ok 60 movl (%ecx),%eax 61 movl %eax,4(%esp) 62ok: 63 lea SYS_break,%eax 64 KERNCALL 65 jb err 66 movl 4(%esp),%eax 67 movl %eax,(%edx) 68 movl $0,%eax 69 ret 70err: 71 PIC_PROLOGUE 72 jmp PIC_PLT(HIDENAME(cerror)) 73 74#else 75 76 movl 4(%esp),%eax 77 cmpl %eax,HIDENAME(minbrk) 78 jbe ok 79 movl HIDENAME(minbrk),%eax 80 movl %eax,4(%esp) 81ok: 82 lea SYS_break,%eax 83 KERNCALL 84 jb err 85 movl 4(%esp),%eax 86 movl %eax,HIDENAME(curbrk) 87 movl $0,%eax 88 ret 89err: 90 jmp HIDENAME(cerror) 91#endif 92