sig_machdep.c revision 1.7 
1/*	$NetBSD: sig_machdep.c,v 1.7 2002/07/04 23:32:06 thorpej Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
5 * Copyright (C) 1995, 1996 TooLs GmbH.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by TooLs GmbH.
19 * 4. The name of TooLs GmbH may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include "opt_compat_netbsd.h"
35
36#include <sys/param.h>
37#include <sys/mount.h>
38#include <sys/proc.h>
39#include <sys/syscallargs.h>
40#include <sys/systm.h>
41#include <sys/user.h>
42
43/*
44 * Send a signal to process.
45 */
46void
47sendsig(sig, mask, code)
48	int sig;
49	sigset_t *mask;
50	u_long code;
51{
52	struct proc *p = curproc;
53	struct sigacts *ps = p->p_sigacts;
54	struct trapframe *tf;
55	struct sigframe *fp, frame;
56	int onstack;
57	sig_t catcher = SIGACTION(p, sig).sa_handler;
58
59	tf = trapframe(p);
60
61	/* Do we need to jump onto the signal stack? */
62	onstack =
63	    (p->p_sigctx.ps_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
64	    (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
65
66	/* Allocate space for the signal handler context. */
67	if (onstack)
68		fp = (struct sigframe *)((caddr_t)p->p_sigctx.ps_sigstk.ss_sp +
69						p->p_sigctx.ps_sigstk.ss_size);
70	else
71		fp = (struct sigframe *)tf->fixreg[1];
72	fp = (struct sigframe *)((int)(fp - 1) & ~0xf);
73
74	/* Save register context. */
75	frame.sf_sc.sc_frame = *tf;
76
77	/* Save signal stack. */
78	frame.sf_sc.sc_onstack = p->p_sigctx.ps_sigstk.ss_flags & SS_ONSTACK;
79
80	/* Save signal mask. */
81	frame.sf_sc.sc_mask = *mask;
82
83#ifdef COMPAT_13
84	/*
85	 * XXX We always have to save an old style signal mask because
86	 * XXX we might be delivering a signal to a process which will
87	 * XXX escape from the signal in a non-standard way and invoke
88	 * XXX sigreturn() directly.
89	 */
90	native_sigset_to_sigset13(mask, &frame.sf_sc.__sc_mask13);
91#endif
92
93	if (copyout(&frame, fp, sizeof frame) != 0) {
94		/*
95		 * Process has trashed its stack; give it an illegal
96		 * instructoin to halt it in its tracks.
97		 */
98		sigexit(p, SIGILL);
99		/* NOTREACHED */
100	}
101
102	/*
103	 * Build context to run handler in.  Note the trampoline version
104	 * numbers are coordinated with machine-dependent code in libc.
105	 */
106	switch (ps->sa_sigdesc[sig].sd_vers) {
107#if 1 /* COMPAT_16 */
108	case 0:		/* legacy on-stack sigtramp */
109		tf->fixreg[1] = (int)fp;
110		tf->lr = (int)catcher;
111		tf->fixreg[3] = (int)sig;
112		tf->fixreg[4] = (int)code;
113		tf->fixreg[5] = (int)&fp->sf_sc;
114		tf->srr0 = (int)p->p_sigctx.ps_sigcode;
115		break;
116#endif /* COMPAT_16 */
117
118	case 1:
119		tf->fixreg[1] = (int)fp;
120		tf->lr = (int)catcher;
121		tf->fixreg[3] = (int)sig;
122		tf->fixreg[4] = (int)code;
123		tf->fixreg[5] = (int)&fp->sf_sc;
124		tf->srr0 = (int)ps->sa_sigdesc[sig].sd_tramp;
125		break;
126
127	default:
128		/* Don't know what trampoline version; kill it. */
129		sigexit(p, SIGILL);
130	}
131
132	/* Remember that we're now on the signal stack. */
133	if (onstack)
134		p->p_sigctx.ps_sigstk.ss_flags |= SS_ONSTACK;
135}
136
137/*
138 * System call to cleanup state after a signal handler returns.
139 */
140int
141sys___sigreturn14(p, v, retval)
142	struct proc *p;
143	void *v;
144	register_t *retval;
145{
146	struct sys___sigreturn14_args /* {
147		syscallarg(struct sigcontext *) sigcntxp;
148	} */ *uap = v;
149	struct sigcontext sc;
150	struct trapframe *tf;
151	int error;
152
153	/*
154	 * The trampoline hands us the context.
155	 * It is unsafe to keep track of it ourselves, in the event that a
156	 * program jumps out of a signal hander.
157	 */
158	if ((error = copyin(SCARG(uap, sigcntxp), &sc, sizeof sc)) != 0)
159		return (error);
160
161	/* Restore the register context. */
162	tf = trapframe(p);
163	if ((sc.sc_frame.srr1 & PSL_USERSTATIC) != (tf->srr1 & PSL_USERSTATIC))
164		return (EINVAL);
165	*tf = sc.sc_frame;
166
167	/* Restore signal stack. */
168	if (sc.sc_onstack & SS_ONSTACK)
169		p->p_sigctx.ps_sigstk.ss_flags |= SS_ONSTACK;
170	else
171		p->p_sigctx.ps_sigstk.ss_flags &= ~SS_ONSTACK;
172
173	/* Restore signal mask. */
174	(void) sigprocmask1(p, SIG_SETMASK, &sc.sc_mask, 0);
175
176	return (EJUSTRETURN);
177}
178