brk.S revision 1.6
1/* $OpenBSD: brk.S,v 1.6 2015/08/26 01:54:09 guenther Exp $ */ 2/*- 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Ralph Campbell. 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 __curbrk 37 38 .data 39__minbrk: 40 PTR_VAL _C_LABEL(end) 41 .text 42 43FRAMESZ= MKFSIZ(1,1) 44GPOFF= FRAMESZ-2*REGSZ 45 46WEAK_ALIAS(brk, _brk) 47 48LEAF(_brk, FRAMESZ) 49 PTR_SUBU sp, FRAMESZ 50 SETUP_GP64(GPOFF, _brk) 51 .set reorder 52 PTR_L v0, __minbrk 53 bgtu a0, v0, 1f 54 55 move a0, v0 # dont allow break < minbrk 561: 57 li v0, SYS_break 58 syscall 59 bne a3, zero, 2f 60 PTR_S a0, __curbrk 61 move v0, zero 62 RESTORE_GP64 63 PTR_ADDU sp, FRAMESZ 64 j ra 652: 66 LA t9, CERROR 67 RESTORE_GP64 68 PTR_ADDU sp, FRAMESZ 69 jr t9 70END(_brk) 71