1/* $OpenBSD: sbrk.S,v 1.7 2012/08/22 22:26:16 deraadt Exp $ */ 2 3/* 4 * Copyright (c) 1996 Dale Rahn 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include "SYS.h" 29 30 .data 31 .globl _end 32 .globl _ASM_LABEL(__curbrk) 33 .globl minbrk 34_ASM_LABEL(__curbrk): 35 .long _C_LABEL(end) 36_ASM_LABEL(minbrk): 37 .long _C_LABEL(end) 38 39 40 .text 41PREFIX2(sbrk,break) 42 43 /* call break(__curbrk + size) */ 44#ifndef __PIC__ 45 addis 6, 0, _ASM_LABEL(__curbrk)@H 46 ori 6, 6, _ASM_LABEL(__curbrk)@L /* # 6 = &__curbrk */ 47#else 48 mflr 10 49 bl _GLOBAL_OFFSET_TABLE_@local-4 50 mflr 9 51 mtlr 10 52 lwz 6,_ASM_LABEL(__curbrk)@got(9) 53#endif 54 lwz 5, 0(6) /* # 5 = *6 (old_curbrk) */ 55 add 3, 5, 3 /* # 3 = new_curbrk */ 56 mr 7, 3 57 58 sc 59 60 /* check for error */ 61 cmpwi 0, 0 62 beq+ .L_sbrk_ok 63 b PIC_PLT(_ASM_LABEL(__cerror)) 64 65 /* update, __curbrk and return */ 66.L_sbrk_ok: 67 stw 7, 0(6) /* # remember, 6=&__curbrk, 7=new_curbrk */ 68 mr 3, 5 /* # remember, 5=old_curbrk */ 69 blr 70