xref: /netbsd-src/lib/libc/arch/sparc/gen/longjmp.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: longjmp.c,v 1.2 2008/04/28 20:22:57 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 
39 #define __LIBC12_SOURCE__
40 #include <setjmp.h>
41 #include <compat/include/setjmp.h>
42 
43 /*
44  * Use setcontext to reload the stack pointer, program counter <pc,npc>, and
45  * set the return value in %o0.  The %i and %l registers will be reloaded
46  * from the place to which %sp points.
47  */
48 void
49 __longjmp14(jmp_buf env, int val)
50 {
51 	struct sigcontext *sc = (void *)env;
52 	ucontext_t uc;
53 
54 	/* Ensure non-zero SP */
55 	if (sc->sc_sp == 0)
56 		goto err;
57 
58 	/* Initialise the fields we're going to use */
59 	uc.uc_link = 0;
60 
61 	/*
62 	 * Set _UC_{SET,CLR}STACK according to SS_ONSTACK.
63 	 *
64 	 * Restore the signal mask with sigprocmask() instead of _UC_SIGMASK,
65 	 * since libpthread may want to interpose on signal handling.
66 	 */
67 	uc.uc_flags = _UC_CPU | (sc->sc_onstack ? _UC_SETSTACK : _UC_CLRSTACK);
68 
69 	sigprocmask(SIG_SETMASK, &sc->sc_mask, NULL);
70 
71 	/* Extract PSR, PC, NPC and SP from jmp_buf */
72 	uc.uc_mcontext.__gregs[_REG_PSR] = sc->sc_psr;
73 	uc.uc_mcontext.__gregs[_REG_PC] = sc->sc_pc;
74 	uc.uc_mcontext.__gregs[_REG_nPC] = sc->sc_npc;
75 	uc.uc_mcontext.__gregs[_REG_O6] = sc->sc_sp;
76 
77 	/* Set the return value; make sure it's non-zero */
78 	uc.uc_mcontext.__gregs[_REG_O0] = (val != 0 ? val : 1);
79 
80 	setcontext(&uc);
81 
82 err:
83 	longjmperror();
84 	abort();
85 	/* NOTREACHED */
86 }
87