resumecontext.S revision 1.8
1 1.8 matt /* $NetBSD: resumecontext.S,v 1.8 2013/07/17 03:04:54 matt 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 * 19 1.2 thorpej * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.2 thorpej * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2 thorpej * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2 thorpej * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.2 thorpej * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.2 thorpej * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.2 thorpej * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.2 thorpej * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.2 thorpej * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.2 thorpej * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.2 thorpej * POSSIBILITY OF SUCH DAMAGE. 30 1.2 thorpej */ 31 1.2 thorpej 32 1.2 thorpej #include <machine/asm.h> 33 1.8 matt #include "assym.h" 34 1.2 thorpej 35 1.2 thorpej #if defined(LIBC_SCCS) && !defined(lint) 36 1.8 matt RCSID("$NetBSD: resumecontext.S,v 1.8 2013/07/17 03:04:54 matt Exp $") 37 1.2 thorpej #endif /* LIBC_SCCS && !lint */ 38 1.2 thorpej 39 1.2 thorpej /* 40 1.2 thorpej * This assembly-language implementation differs from the (obvious) 41 1.2 thorpej * C-language implementation only in not clobbering the previous 42 1.2 thorpej * function's return address (us), which is the point of the exercise. 43 1.2 thorpej */ 44 1.2 thorpej 45 1.2 thorpej ENTRY(_resumecontext) 46 1.8 matt subl #(4 + UC_SIZE),%sp /* retaddr preservation + ucontext_t */ 47 1.6 matt lea (%sp),%a0 48 1.6 matt movl %a0,-(%sp) 49 1.2 thorpej jbsr PIC_PLT(_C_LABEL(_getcontext)) 50 1.8 matt movl (4 + UC_LINK)(%sp),(%sp) /* uc_link */ 51 1.6 matt tstl (%sp) /* check for NULL */ 52 1.4 martin jne 1f 53 1.4 martin jbsr PIC_PLT(_C_LABEL(exit)) /* cleanly exit(0) */ 54 1.4 martin jmp 2f 55 1.4 martin 1: jbsr PIC_PLT(_C_LABEL(setcontext)) 56 1.4 martin /* NOTREACHED */ 57 1.4 martin /* But just in case... */ 58 1.6 matt 2: movl #-1,(%sp) 59 1.4 martin jbsr PIC_PLT(_C_LABEL(_exit)) 60 1.2 thorpej /* NOTREACHED */ 61 1.7 matt END(_resumecontext) 62
Indexes created Mon Sep 29 03:10:08 GMT 2025