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longjmp.c revision 1.1 
      1 /*	$NetBSD: longjmp.c,v 1.1 2005/10/15 22:11:22 uwe Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christian Limpach.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include "namespace.h"
     40 #include <sys/types.h>
     41 #include <ucontext.h>
     42 #include <signal.h>
     43 #include <stdlib.h>
     44 #include <string.h>
     45 
     46 #define __LIBC12_SOURCE__
     47 #include <setjmp.h>
     48 #include <compat/include/setjmp.h>
     49 
     50 /*
     51  * Use setcontext to reload the stack pointer, program counter <pc,npc>, and
     52  * set the return value in %o0.  The %i and %l registers will be reloaded
     53  * from the place to which %sp points.
     54  */
     55 void
     56 __longjmp14(jmp_buf env, int val)
     57 {
     58 	struct sigcontext *sc = (void *)env;
     59 	ucontext_t uc;
     60 
     61 	/* Ensure non-zero SP */
     62 	if (sc->sc_sp == 0)
     63 		goto err;
     64 
     65 	/* Initialise the fields we're going to use */
     66 	uc.uc_link = 0;
     67 
     68 	/*
     69 	 * Set _UC_{SET,CLR}STACK according to SS_ONSTACK.
     70 	 *
     71 	 * Restore the signal mask with sigprocmask() instead of _UC_SIGMASK,
     72 	 * since libpthread may want to interpose on signal handling.
     73 	 */
     74 	uc.uc_flags = _UC_CPU | (sc->sc_onstack ? _UC_SETSTACK : _UC_CLRSTACK);
     75 
     76 	sigprocmask(SIG_SETMASK, &sc->sc_mask, NULL);
     77 
     78 	/* Extract PSR, PC, NPC and SP from jmp_buf */
     79 	uc.uc_mcontext.__gregs[_REG_PSR] = sc->sc_psr;
     80 	uc.uc_mcontext.__gregs[_REG_PC] = sc->sc_pc;
     81 	uc.uc_mcontext.__gregs[_REG_nPC] = sc->sc_npc;
     82 	uc.uc_mcontext.__gregs[_REG_O6] = sc->sc_sp;
     83 
     84 	/* Set the return value; make sure it's non-zero */
     85 	uc.uc_mcontext.__gregs[_REG_O0] = (val != 0 ? val : 1);
     86 
     87 	setcontext(&uc);
     88 
     89 err:
     90 	longjmperror();
     91 	abort();
     92 	/* NOTREACHED */
     93 }
     94