brk.S revision 1.6
1/* $OpenBSD: brk.S,v 1.6 2015/08/26 01:54:09 guenther Exp $ */ 2/* $NetBSD: brk.S,v 1.9 2000/07/25 20:15:40 mycroft Exp $ */ 3 4/* 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This software was developed by the Computer Systems Engineering group 9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 10 * contributed to Berkeley. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. 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#include <machine/asm.h> 38 39#include "SYS.h" 40 41 .globl __curbrk 42 .globl _C_LABEL(_end) 43 44WEAK_ALIAS(brk, _brk) 45 46 .data 47 .align 8 48__minbrk: 49 .xword _C_LABEL(_end) /* lower brk limit; also for gmon code */ 50 .text 51 52ENTRY(_brk) 53#ifdef __PIC__ 54 PIC_PROLOGUE(%o5,%o4) 55 set __minbrk, %o4 56 ldx [%o5 + %o4], %o4 57 ldx [%o4], %o1 /* %o1 = minbrk */ 58 cmp %o1, %o0 /* if (minbrk > %o0) */ 59 movgu %xcc, %o1, %o0 /* %o0 = minbrk */ 60 mov %o0, %o2 /* save argument to syscall */ 61 mov SYS_break, %g1 62 t ST_SYSCALL 63 set __curbrk, %o3 64 bcc,a,pt %icc, 1f 65 ldx [%o5 + %o3], %o4 66 ERROR() 671: 68 retl /* success, return 0 & record new break */ 69 stx %o2, [%o4] 70#else 71 sethi %hi(__minbrk), %o1 /* %o1 = minbrk */ 72 ldx [%o1 + %lo(__minbrk)], %o1 73 cmp %o1, %o0 /* if (minbrk > %o0) */ 74 movgu %xcc, %o1, %o0 /* %o0 = minbrk */ 75 mov %o0, %o2 /* save argument to syscall */ 76 mov SYS_break, %g1 77 t ST_SYSCALL 78 bcc,a,pt %icc,1f 79 sethi %hi(__curbrk), %g1 80 ERROR() 811: 82 retl /* success, return 0 & record new break */ 83 stx %o2, [%g1 + %lo(__curbrk)] 84#endif 85