1 /*	$NetBSD: compat_13_machdep.c,v 1.12 2009/11/21 04:16:51 rmind Exp $ */
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: compat_13_machdep.c,v 1.12 2009/11/21 04:16:51 rmind Exp $");
35 
36 #ifdef _KERNEL_OPT
37 #include "opt_compat_netbsd.h"
38 #endif
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/proc.h>
43 #include <sys/kernel.h>
44 #include <sys/mount.h>
45 #include <sys/signal.h>
46 #include <sys/signalvar.h>
47 
48 #include <compat/sys/signal.h>
49 #include <compat/sys/signalvar.h>
50 
51 #include <sys/syscallargs.h>
52 
53 /*
54  * System call to cleanup state after a signal
55  * has been taken.  Reset signal mask and
56  * stack state from context left by sendsig (above),
57  * and return to the given trap frame (if there is one).
58  * Check carefully to make sure that the user has not
59  * modified the state to gain improper privileges or to cause
60  * a machine fault.
61  */
62 /* ARGSUSED */
63 int
64 compat_13_sys_sigreturn(struct lwp *l, const struct compat_13_sys_sigreturn_args *uap, register_t *retval)
65 {
66 	/* {
67 		syscallarg(struct sigcontext13 *) sigcntxp;
68 	} */
69 	struct proc *p = l->l_proc;
70 	struct sigcontext13 sc, *scp;
71 	sigset_t mask;
72 	struct trapframe *tf;
73 	int error;
74 
75 	/* First ensure consistent stack state (see sendsig). */
76 	write_user_windows();
77 	if (rwindow_save(l)) {
78 		mutex_enter(p->p_lock);
79 		sigexit(l, SIGILL);
80 	}
81 
82 	if ((error = copyin(SCARG(uap, sigcntxp), &sc, sizeof sc)) != 0)
83 		return (error);
84 	scp = &sc;
85 
86 	tf = l->l_md.md_tf;
87 	/*
88 	 * Only the icc bits in the psr are used, so it need not be
89 	 * verified.  pc and npc must be multiples of 4.  This is all
90 	 * that is required; if it holds, just do it.
91 	 */
92 	if (((scp->sc_pc | scp->sc_npc) & 3) != 0)
93 		return (EINVAL);
94 	/* take only psr ICC field */
95 	tf->tf_psr = (tf->tf_psr & ~PSR_ICC) | (scp->sc_psr & PSR_ICC);
96 	tf->tf_pc = scp->sc_pc;
97 	tf->tf_npc = scp->sc_npc;
98 	tf->tf_global[1] = scp->sc_g1;
99 	tf->tf_out[0] = scp->sc_o0;
100 	tf->tf_out[6] = scp->sc_sp;
101 
102 	mutex_enter(p->p_lock);
103 	if (scp->sc_onstack & SS_ONSTACK)
104 		l->l_sigstk.ss_flags |= SS_ONSTACK;
105 	else
106 		l->l_sigstk.ss_flags &= ~SS_ONSTACK;
107 	/* Restore signal mask */
108 	native_sigset13_to_sigset(&scp->sc_mask, &mask);
109 	(void) sigprocmask1(l, SIG_SETMASK, &mask, 0);
110 	mutex_exit(p->p_lock);
111 
112 	return (EJUSTRETURN);
113 }
114