1/* $NetBSD: resumecontext.S,v 1.2 2004/02/27 21:23:05 drochner Exp $ */ 2 3/*- 4 * Copyright (c) 1999 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Klaus Klein. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 * 38 * Modified for x86-64 by fvdl@wasabisystems.com 39 */ 40 41#include <machine/asm.h> 42 43#if defined(LIBC_SCCS) && !defined(lint) 44 RCSID("$NetBSD: resumecontext.S,v 1.2 2004/02/27 21:23:05 drochner Exp $") 45#endif /* LIBC_SCCS && !lint */ 46 47/* 48 * This assembly-language implementation differs from the (obvious) 49 * C-language implementation only in not clobbering the previous 50 * function's return address (us), which is the point of the exercise. 51 */ 52 53NENTRY(_resumecontext) /* profiling prologue would clobber TOS */ 54 leaq -(8 + 784)(%rsp),%rdi /* retaddr + sizeof (ucontext_t) */ 55 andq $~15,%rdi /* align on _UC_UCONTEXT_ALIGN */ 56 movq %rdi,%rsp 57#ifdef PIC 58 call PIC_PLT(_C_LABEL(_getcontext)) 59#else 60 call _C_LABEL(_getcontext) 61#endif 62 movq 8(%rsp),%rdi 63#ifdef PIC 64 call PIC_PLT(_C_LABEL(setcontext)) 65#else 66 call _C_LABEL(setcontext) 67#endif 68 /* NOTREACHED */ 69