resumecontext.S revision 1.4
1 1.4 martin /* $NetBSD: resumecontext.S,v 1.4 2006/12/13 10:48:02 martin Exp $ */ 2 1.2 thorpej 3 1.2 thorpej /*- 4 1.2 thorpej * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 1.2 thorpej * All rights reserved. 6 1.2 thorpej * 7 1.2 thorpej * This code is derived from software contributed to The NetBSD Foundation 8 1.2 thorpej * by Klaus Klein. 9 1.2 thorpej * 10 1.2 thorpej * Redistribution and use in source and binary forms, with or without 11 1.2 thorpej * modification, are permitted provided that the following conditions 12 1.2 thorpej * are met: 13 1.2 thorpej * 1. Redistributions of source code must retain the above copyright 14 1.2 thorpej * notice, this list of conditions and the following disclaimer. 15 1.2 thorpej * 2. Redistributions in binary form must reproduce the above copyright 16 1.2 thorpej * notice, this list of conditions and the following disclaimer in the 17 1.2 thorpej * documentation and/or other materials provided with the distribution. 18 1.2 thorpej * 3. All advertising materials mentioning features or use of this software 19 1.2 thorpej * must display the following acknowledgement: 20 1.2 thorpej * This product includes software developed by the NetBSD 21 1.2 thorpej * Foundation, Inc. and its contributors. 22 1.2 thorpej * 4. Neither the name of The NetBSD Foundation nor the names of its 23 1.2 thorpej * contributors may be used to endorse or promote products derived 24 1.2 thorpej * from this software without specific prior written permission. 25 1.2 thorpej * 26 1.2 thorpej * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 1.2 thorpej * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 1.2 thorpej * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 1.2 thorpej * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 1.2 thorpej * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 1.2 thorpej * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 1.2 thorpej * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 1.2 thorpej * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 1.2 thorpej * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 1.2 thorpej * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 1.2 thorpej * POSSIBILITY OF SUCH DAMAGE. 37 1.2 thorpej */ 38 1.2 thorpej 39 1.2 thorpej #include <machine/asm.h> 40 1.2 thorpej 41 1.2 thorpej #if defined(LIBC_SCCS) && !defined(lint) 42 1.4 martin RCSID("$NetBSD: resumecontext.S,v 1.4 2006/12/13 10:48:02 martin Exp $") 43 1.2 thorpej #endif /* LIBC_SCCS && !lint */ 44 1.2 thorpej 45 1.2 thorpej /* 46 1.2 thorpej * This assembly-language implementation differs from the (obvious) 47 1.2 thorpej * C-language implementation only in not clobbering the previous 48 1.2 thorpej * function's return address (us), which is the point of the exercise. 49 1.2 thorpej */ 50 1.2 thorpej 51 1.2 thorpej ENTRY(_resumecontext) 52 1.3 kleink subl #(4 + 1024),%sp /* retaddr preservation + ucontext_t */ 53 1.2 thorpej lea %sp@,%a0 54 1.2 thorpej movl %a0,%sp@- 55 1.2 thorpej jbsr PIC_PLT(_C_LABEL(_getcontext)) 56 1.4 martin movl %sp@(4 + 4),%sp@ /* uc_link */ 57 1.4 martin tstl %sp@ /* check for NULL */ 58 1.4 martin jne 1f 59 1.4 martin jbsr PIC_PLT(_C_LABEL(exit)) /* cleanly exit(0) */ 60 1.4 martin jmp 2f 61 1.4 martin 1: jbsr PIC_PLT(_C_LABEL(setcontext)) 62 1.4 martin /* NOTREACHED */ 63 1.4 martin /* But just in case... */ 64 1.4 martin 2: movl #-1,%sp@ 65 1.4 martin jbsr PIC_PLT(_C_LABEL(_exit)) 66 1.2 thorpej /* NOTREACHED */ 67
Indexes created Sat Sep 27 22:09:54 GMT 2025