1/* $NetBSD: swapcontext.S,v 1.6 2014/05/22 15:01:56 uebayasi Exp $ */ 2 3/* 4 * Copyright (c) 2003 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Frank van der Linden for Wasabi Systems, Inc. 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. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38#include <machine/asm.h> 39 40#if defined(LIBC_SCCS) && !defined(lint) 41 RCSID("$NetBSD: swapcontext.S,v 1.6 2014/05/22 15:01:56 uebayasi Exp $") 42#endif /* LIBC_SCCS && !lint */ 43 44/* 45 * 56 == offsetof(ucontext_t, uc_mcontext) 46 * 21 == _REG_RIP 47 * 24 == _REG_URSP 48 */ 49 50ENTRY(swapcontext) 51 pushq %rdi /* preserve oucp */ 52 pushq %rsi /* preserve ucp */ 53#ifdef __PIC__ 54 call PIC_PLT(_C_LABEL(_getcontext)) 55#else 56 call _C_LABEL(_getcontext) 57#endif 58 popq %rsi 59 popq %rdi 60 testl %eax,%eax 61 jnz 2f 62 movq 0(%rsp),%r11 63 movq %r11,(56 + 21 * 8)(%rdi) 64 leaq 8(%rsp),%r11 65 movq %r11,(56 + 24 * 8)(%rdi) 66 movq %rsi,%rdi 67#ifdef __PIC__ 68 call PIC_PLT(_C_LABEL(setcontext)) 69#else 70 call _C_LABEL(setcontext) 71#endif 722: 73 ret 74END(swapcontext) 75