1*0d34bfa2Suebayasi/* $NetBSD: resumecontext.S,v 1.8 2014/05/23 02:34:19 uebayasi Exp $ */ 23fdac2b8Sthorpej 33fdac2b8Sthorpej/*- 43fdac2b8Sthorpej * Copyright (c) 1999 The NetBSD Foundation, Inc. 53fdac2b8Sthorpej * All rights reserved. 63fdac2b8Sthorpej * 73fdac2b8Sthorpej * This code is derived from software contributed to The NetBSD Foundation 83fdac2b8Sthorpej * by Klaus Klein. 93fdac2b8Sthorpej * 103fdac2b8Sthorpej * Redistribution and use in source and binary forms, with or without 113fdac2b8Sthorpej * modification, are permitted provided that the following conditions 123fdac2b8Sthorpej * are met: 133fdac2b8Sthorpej * 1. Redistributions of source code must retain the above copyright 143fdac2b8Sthorpej * notice, this list of conditions and the following disclaimer. 153fdac2b8Sthorpej * 2. Redistributions in binary form must reproduce the above copyright 163fdac2b8Sthorpej * notice, this list of conditions and the following disclaimer in the 173fdac2b8Sthorpej * documentation and/or other materials provided with the distribution. 183fdac2b8Sthorpej * 193fdac2b8Sthorpej * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 203fdac2b8Sthorpej * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 213fdac2b8Sthorpej * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 223fdac2b8Sthorpej * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 233fdac2b8Sthorpej * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 243fdac2b8Sthorpej * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 253fdac2b8Sthorpej * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 263fdac2b8Sthorpej * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 273fdac2b8Sthorpej * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 283fdac2b8Sthorpej * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 293fdac2b8Sthorpej * POSSIBILITY OF SUCH DAMAGE. 303fdac2b8Sthorpej */ 313fdac2b8Sthorpej 323fdac2b8Sthorpej#include <machine/asm.h> 33ac9d7f2fSdrochner#include "SYS.h" 343fdac2b8Sthorpej 353fdac2b8Sthorpej#if defined(LIBC_SCCS) && !defined(lint) 36*0d34bfa2Suebayasi RCSID("$NetBSD: resumecontext.S,v 1.8 2014/05/23 02:34:19 uebayasi Exp $") 373fdac2b8Sthorpej#endif /* LIBC_SCCS && !lint */ 383fdac2b8Sthorpej 393fdac2b8Sthorpej/* 403fdac2b8Sthorpej * This assembly-language implementation differs from the (obvious) 413fdac2b8Sthorpej * C-language implementation only in not clobbering the previous 423fdac2b8Sthorpej * function's return address (us), which is the point of the exercise. 433fdac2b8Sthorpej */ 443fdac2b8Sthorpej 453fdac2b8SthorpejNENTRY(_resumecontext) /* profiling prologue would clobber TOS */ 46326194c6Skleink leal -(4 + 776)(%esp),%ecx /* retaddr + sizeof (ucontext_t) */ 47326194c6Skleink andl $~(0xf),%ecx /* align on _UC_UCONTEXT_ALIGN */ 48326194c6Skleink movl %ecx,%esp 493fdac2b8Sthorpej PIC_PROLOGUE 503fdac2b8Sthorpej pushl %ecx 514d12bfcdSjoerg#ifdef __PIC__ 523fdac2b8Sthorpej call PIC_PLT(_C_LABEL(_getcontext)) 533fdac2b8Sthorpej#else 543fdac2b8Sthorpej call _C_LABEL(_getcontext) 553fdac2b8Sthorpej#endif 563fdac2b8Sthorpej addl $4,%esp 573fdac2b8Sthorpej PIC_EPILOGUE 58326194c6Skleink movl 4(%esp),%ecx /* uc_link */ 593fdac2b8Sthorpej PIC_PROLOGUE 60ac9d7f2fSdrochner pushl %ecx /* argument for exit() or setcontext() */ 61ac9d7f2fSdrochner testl %ecx,%ecx /* link end? */ 62ac9d7f2fSdrochner jnz 9f /* watch out for local label use in PIC_* */ 63ac9d7f2fSdrochner 64ac9d7f2fSdrochner /* normal exit */ 654d12bfcdSjoerg#ifdef __PIC__ 66ac9d7f2fSdrochner call PIC_PLT(_C_LABEL(exit)) 67ac9d7f2fSdrochner#else 68ac9d7f2fSdrochner call _C_LABEL(exit) 69ac9d7f2fSdrochner#endif 70ac9d7f2fSdrochner /* NOTREACHED */ 71ac9d7f2fSdrochner 72ac9d7f2fSdrochner9: 734d12bfcdSjoerg#ifdef __PIC__ 743fdac2b8Sthorpej call PIC_PLT(_C_LABEL(setcontext)) 753fdac2b8Sthorpej#else 763fdac2b8Sthorpej call _C_LABEL(setcontext) 773fdac2b8Sthorpej#endif 783fdac2b8Sthorpej /* NOTREACHED */ 79ac9d7f2fSdrochner 80ac9d7f2fSdrochner /* something is wrong, pull the brake */ 81ac9d7f2fSdrochner pushl $-1 82ac9d7f2fSdrochner pushl %eax /* unused return address */ 83ac9d7f2fSdrochner SYSTRAP(exit) 84*0d34bfa2SuebayasiEND(_resumecontext) 85