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longjmp.c revision 1.6 
      1 /*	$NetBSD: longjmp.c,v 1.6 2011/04/30 23:39:08 martin 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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include "namespace.h"
     33 #include <sys/types.h>
     34 #include <ucontext.h>
     35 #include <signal.h>
     36 #include <stdlib.h>
     37 #include <string.h>
     38 #include <stdio.h>
     39 #include <stddef.h>
     40 
     41 #define __LIBC12_SOURCE__
     42 #include <setjmp.h>
     43 #include <compat/include/setjmp.h>
     44 
     45 typedef struct {
     46 	__greg_t	g3;
     47 	__greg_t	g6;
     48 	__greg_t	g7;
     49 	__greg_t	dummy;
     50 	__greg_t	save_mask;
     51 } __jmp_buf_regs_t;
     52 
     53 /*
     54  * setjmp.S uses hard coded offsets into the jump_buf,
     55  * make sure any changes cause a compile failure here
     56  */
     57 __CTASSERT(0x68 == offsetof(__jmp_buf_regs_t,save_mask)+
     58 	sizeof(struct sigcontext));
     59 __CTASSERT(sizeof(sigjmp_buf) >= sizeof(__jmp_buf_regs_t) +
     60 	sizeof(struct sigcontext));
     61 
     62 void
     63 __longjmp14(jmp_buf env, int val)
     64 {
     65 	struct sigcontext *sc = (void *)env;
     66 	__jmp_buf_regs_t *r = (void *)&sc[1];
     67 	ucontext_t uc;
     68 
     69 	/* Ensure non-zero SP */
     70 	if (sc->sc_sp == 0)
     71 		goto err;
     72 
     73 	/*
     74 	 * Set _UC_CPU. No FPU data saved, so we can't restore
     75 	 * that. Set _UC_{SET,CLR}STACK according to SS_ONSTACK
     76 	 */
     77 	memset(&uc, 0, sizeof(uc));
     78 	uc.uc_flags = _UC_CPU | (sc->sc_onstack ? _UC_SETSTACK : _UC_CLRSTACK);
     79 
     80 	/*
     81 	 * Set the signal mask - this is a weak symbol, so don't use
     82 	 * _UC_SIGMASK in the mcontext, libpthread might override sigprocmask.
     83 	 */
     84 	sigprocmask(SIG_SETMASK, &sc->sc_mask, NULL);
     85 
     86 	/* Fill other registers */
     87 	uc.uc_mcontext.__gregs[_REG_CCR] = sc->sc_tstate;
     88 	uc.uc_mcontext.__gregs[_REG_PC] = sc->sc_pc;
     89 	uc.uc_mcontext.__gregs[_REG_nPC] = sc->sc_pc+4;
     90 	uc.uc_mcontext.__gregs[_REG_G1] = sc->sc_g1;
     91 	uc.uc_mcontext.__gregs[_REG_G2] = sc->sc_o0;
     92 	uc.uc_mcontext.__gregs[_REG_G3] = r->g3;
     93 	uc.uc_mcontext.__gregs[_REG_G4] = 0;
     94 	uc.uc_mcontext.__gregs[_REG_G5] = 0;
     95 	uc.uc_mcontext.__gregs[_REG_G6] = r->g6;
     96 	uc.uc_mcontext.__gregs[_REG_G7] = r->g7;
     97 	uc.uc_mcontext.__gregs[_REG_O6] = sc->sc_sp;
     98 
     99 
    100 	/* Make return value non-zero */
    101 	if (val == 0)
    102 		val = 1;
    103 
    104 	/* Save return value in context */
    105 	uc.uc_mcontext.__gregs[_REG_O0] = val;
    106 
    107 	setcontext(&uc);
    108 
    109  err:
    110 	longjmperror();
    111 	abort();
    112 	/* NOTREACHED */
    113 }
    114