resumecontext.S revision 1.5
1 1.5 drochner /* $NetBSD: resumecontext.S,v 1.5 2006/11/08 20:28:03 drochner Exp $ */ 2 1.2 thorpej 3 1.2 thorpej /*- 4 1.2 thorpej * Copyright (c) 1999 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 1.5 drochner #include "SYS.h" 41 1.2 thorpej 42 1.2 thorpej #if defined(LIBC_SCCS) && !defined(lint) 43 1.5 drochner RCSID("$NetBSD: resumecontext.S,v 1.5 2006/11/08 20:28:03 drochner Exp $") 44 1.2 thorpej #endif /* LIBC_SCCS && !lint */ 45 1.2 thorpej 46 1.2 thorpej /* 47 1.2 thorpej * This assembly-language implementation differs from the (obvious) 48 1.2 thorpej * C-language implementation only in not clobbering the previous 49 1.2 thorpej * function's return address (us), which is the point of the exercise. 50 1.2 thorpej */ 51 1.2 thorpej 52 1.2 thorpej NENTRY(_resumecontext) /* profiling prologue would clobber TOS */ 53 1.4 kleink leal -(4 + 776)(%esp),%ecx /* retaddr + sizeof (ucontext_t) */ 54 1.4 kleink andl $~(0xf),%ecx /* align on _UC_UCONTEXT_ALIGN */ 55 1.4 kleink movl %ecx,%esp 56 1.2 thorpej PIC_PROLOGUE 57 1.2 thorpej pushl %ecx 58 1.2 thorpej #ifdef PIC 59 1.2 thorpej call PIC_PLT(_C_LABEL(_getcontext)) 60 1.2 thorpej #else 61 1.2 thorpej call _C_LABEL(_getcontext) 62 1.2 thorpej #endif 63 1.2 thorpej addl $4,%esp 64 1.2 thorpej PIC_EPILOGUE 65 1.4 kleink movl 4(%esp),%ecx /* uc_link */ 66 1.2 thorpej PIC_PROLOGUE 67 1.5 drochner pushl %ecx /* argument for exit() or setcontext() */ 68 1.5 drochner testl %ecx,%ecx /* link end? */ 69 1.5 drochner jnz 9f /* watch out for local label use in PIC_* */ 70 1.5 drochner 71 1.5 drochner /* normal exit */ 72 1.5 drochner #ifdef PIC 73 1.5 drochner call PIC_PLT(_C_LABEL(exit)) 74 1.5 drochner #else 75 1.5 drochner call _C_LABEL(exit) 76 1.5 drochner #endif 77 1.5 drochner /* NOTREACHED */ 78 1.5 drochner 79 1.5 drochner 9: 80 1.2 thorpej #ifdef PIC 81 1.2 thorpej call PIC_PLT(_C_LABEL(setcontext)) 82 1.2 thorpej #else 83 1.2 thorpej call _C_LABEL(setcontext) 84 1.2 thorpej #endif 85 1.2 thorpej /* NOTREACHED */ 86 1.5 drochner 87 1.5 drochner /* something is wrong, pull the brake */ 88 1.5 drochner pushl $-1 89 1.5 drochner pushl %eax /* unused return address */ 90 1.5 drochner SYSTRAP(exit) 91
Indexes created Mon Sep 29 21:09:56 GMT 2025