brk.S revision 81586
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 37#if defined(SYSLIBC_RCS) && !defined(lint) 38 .text 39 .asciz "$FreeBSD: head/lib/libc/i386/sys/brk.S 81586 2001-08-13 14:06:34Z ru $" 40#endif /* SYSLIBC_RCS and not lint */ 41 42#include "SYS.h" 43 44 .globl HIDENAME(curbrk) 45 .globl HIDENAME(minbrk) 46ENTRY(_brk) 47 jmp ok 48 49ENTRY(brk) 50#ifdef PIC 51 movl 4(%esp),%eax 52 PIC_PROLOGUE 53 movl PIC_GOT(HIDENAME(curbrk)),%edx # set up GOT addressing 54 movl PIC_GOT(HIDENAME(minbrk)),%ecx # 55 PIC_EPILOGUE 56 cmpl %eax,(%ecx) 57 jbe ok 58 movl (%ecx),%eax 59 movl %eax,4(%esp) 60ok: 61 lea SYS_break,%eax 62 KERNCALL 63 jb err 64 movl 4(%esp),%eax 65 movl %eax,(%edx) 66 movl $0,%eax 67 ret 68err: 69 PIC_PROLOGUE 70 jmp PIC_PLT(HIDENAME(cerror)) 71 72#else 73 74 movl 4(%esp),%eax 75 cmpl %eax,HIDENAME(minbrk) 76 jbe ok 77 movl HIDENAME(minbrk),%eax 78 movl %eax,4(%esp) 79ok: 80 lea SYS_break,%eax 81 KERNCALL 82 jb err 83 movl 4(%esp),%eax 84 movl %eax,HIDENAME(curbrk) 85 movl $0,%eax 86 ret 87err: 88 jmp HIDENAME(cerror) 89#endif 90