xref: /netbsd-src/sys/arch/mips/mips/compat_16_machdep.c (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /*	$NetBSD: compat_16_machdep.c,v 1.13 2008/11/21 06:57:35 he Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 2001 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 and by Chris Demetriou.
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 /*
34  * Copyright 1996 The Board of Trustees of The Leland Stanford
35  * Junior University. All Rights Reserved.
36  *
37  * Permission to use, copy, modify, and distribute this
38  * software and its documentation for any purpose and without
39  * fee is hereby granted, provided that the above copyright
40  * notice appear in all copies.  Stanford University
41  * makes no representations about the suitability of this
42  * software for any purpose.  It is provided "as is" without
43  * express or implied warranty.
44  */
45 
46 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
47 
48 __KERNEL_RCSID(0, "$NetBSD: compat_16_machdep.c,v 1.13 2008/11/21 06:57:35 he Exp $");
49 
50 #ifdef _KERNEL_OPT
51 #include "opt_cputype.h"
52 #include "opt_compat_netbsd.h"
53 #include "opt_compat_ultrix.h"
54 #endif
55 
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/kernel.h>
59 #include <sys/proc.h>
60 #include <sys/user.h>
61 #include <sys/signal.h>
62 #include <sys/signalvar.h>
63 #include <sys/mount.h>
64 #include <sys/syscallargs.h>
65 
66 #include <compat/sys/signal.h>
67 #include <compat/sys/signalvar.h>
68 
69 #include <machine/cpu.h>
70 
71 #include <mips/regnum.h>
72 #include <mips/frame.h>
73 
74 #ifdef DEBUG
75 int sigdebug = 0;
76 int sigpid = 0;
77 #define SDB_FOLLOW	0x01
78 #define SDB_KSTACK	0x02
79 #define SDB_FPSTATE	0x04
80 #endif
81 
82 /*
83  * Send a signal to process.
84  */
85 void
86 sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *returnmask)
87 {
88 	int sig = ksi->ksi_signo;
89 	struct lwp *l = curlwp;
90 	struct proc *p = l->l_proc;
91 	struct sigacts *ps = p->p_sigacts;
92 	int onstack, error;
93 	struct sigcontext *scp = getframe(l, sig, &onstack), ksc;
94 	struct frame *f;
95 	sig_t catcher = SIGACTION(p, sig).sa_handler;
96 
97 	f = (struct frame *)l->l_md.md_regs;
98 
99 	scp--;
100 
101 #ifdef DEBUG
102 	if ((sigdebug & SDB_FOLLOW) ||
103 	    ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid))
104 		printf("sendsig(%d): sig %d ssp %p scp %p\n",
105 		       p->p_pid, sig, &onstack, scp);
106 #endif
107 
108 	/* Build stack frame for signal trampoline. */
109 	ksc.sc_pc = f->f_regs[_R_PC];
110 	ksc.mullo = f->f_regs[_R_MULLO];
111 	ksc.mulhi = f->f_regs[_R_MULHI];
112 
113 	/* Save register context. */
114 	ksc.sc_regs[_R_ZERO] = 0xACEDBADE;		/* magic number */
115 	memcpy(&ksc.sc_regs[1], &f->f_regs[1],
116 	    sizeof(ksc.sc_regs) - sizeof(ksc.sc_regs[0]));
117 
118 	/* Save the FP state, if necessary, then copy it. */
119 #ifndef SOFTFLOAT
120 	ksc.sc_fpused = l->l_md.md_flags & MDP_FPUSED;
121 	if (ksc.sc_fpused) {
122 		/* if FPU has current state, save it first */
123 		if (l == fpcurlwp)
124 			savefpregs(l);
125 		*(struct fpreg *)ksc.sc_fpregs = l->l_addr->u_pcb.pcb_fpregs;
126 	}
127 #else
128 	*(struct fpreg *)ksc.sc_fpregs = l->l_addr->u_pcb.pcb_fpregs;
129 #endif
130 
131 	/* Save signal stack. */
132 	ksc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
133 
134 	/* Save signal mask. */
135 	ksc.sc_mask = *returnmask;
136 
137 #if defined(COMPAT_13) || defined(COMPAT_ULTRIX)
138 	/*
139 	 * XXX We always have to save an old style signal mask because
140 	 * XXX we might be delivering a signal to a process which will
141 	 * XXX escape from the signal in a non-standard way and invoke
142 	 * XXX sigreturn() directly.
143 	 */
144 	native_sigset_to_sigset13(returnmask, &ksc.__sc_mask13);
145 #endif
146 
147 	sendsig_reset(l, sig);
148 
149 	mutex_exit(p->p_lock);
150 	error = copyout(&ksc, (void *)scp, sizeof(ksc));
151 	mutex_enter(p->p_lock);
152 
153 	if (error != 0) {
154 		/*
155 		 * Process has trashed its stack; give it an illegal
156 		 * instruction to halt it in its tracks.
157 		 */
158 #ifdef DEBUG
159 		if ((sigdebug & SDB_FOLLOW) ||
160 		    ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid))
161 			printf("sendsig(%d): copyout failed on sig %d\n",
162 			    p->p_pid, sig);
163 #endif
164 		sigexit(l, SIGILL);
165 		/* NOTREACHED */
166 	}
167 
168 	/*
169 	 * Set up the registers to directly invoke the signal
170 	 * handler.  The return address will be set up to point
171 	 * to the signal trampoline to bounce us back.
172 	 */
173 	f->f_regs[_R_A0] = sig;
174 	f->f_regs[_R_A1] = ksi->ksi_trap;
175 	f->f_regs[_R_A2] = (intptr_t)scp;
176 	f->f_regs[_R_A3] = (intptr_t)catcher;		/* XXX ??? */
177 
178 	f->f_regs[_R_PC] = (intptr_t)catcher;
179 	f->f_regs[_R_T9] = (intptr_t)catcher;
180 	f->f_regs[_R_SP] = (intptr_t)scp;
181 
182 	switch (ps->sa_sigdesc[sig].sd_vers) {
183 	case 0:		/* legacy on-stack sigtramp */
184 		f->f_regs[_R_RA] = (intptr_t)p->p_sigctx.ps_sigcode;
185 		break;
186 #ifdef COMPAT_16
187 	case 1:
188 		f->f_regs[_R_RA] = (intptr_t)ps->sa_sigdesc[sig].sd_tramp;
189 		break;
190 #endif
191 	default:
192 		/* Don't know what trampoline version; kill it. */
193 		sigexit(l, SIGILL);
194 	}
195 
196 	/* Remember that we're now on the signal stack. */
197 	if (onstack)
198 		l->l_sigstk.ss_flags |= SS_ONSTACK;
199 
200 #ifdef DEBUG
201 	if ((sigdebug & SDB_FOLLOW) ||
202 	    ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid))
203 		printf("sendsig(%d): sig %d returns\n",
204 		       p->p_pid, sig);
205 #endif
206 }
207 
208 #ifdef COMPAT_16 /* not needed if COMPAT_ULTRIX only */
209 /*
210  * System call to cleanup state after a signal
211  * has been taken.  Reset signal mask and
212  * stack state from context left by sendsig (above).
213  * Return to previous pc and psl as specified by
214  * context left by sendsig. Check carefully to
215  * make sure that the user has not modified the
216  * psl to gain improper privileges or to cause
217  * a machine fault.
218  */
219 /* ARGSUSED */
220 int
221 compat_16_sys___sigreturn14(struct lwp *l, const struct compat_16_sys___sigreturn14_args *uap, register_t *retval)
222 {
223 	/* {
224 		syscallarg(struct sigcontext *) sigcntxp;
225 	} */
226 	struct sigcontext *scp, ksc;
227 	struct frame *f;
228 	struct proc *p = l->l_proc;
229 	int error;
230 
231 	/*
232 	 * The trampoline code hands us the context.
233 	 * It is unsafe to keep track of it ourselves, in the event that a
234 	 * program jumps out of a signal handler.
235 	 */
236 	scp = SCARG(uap, sigcntxp);
237 #ifdef DEBUG
238 	if (sigdebug & SDB_FOLLOW)
239 		printf("sigreturn: pid %d, scp %p\n", l->l_proc->p_pid, scp);
240 #endif
241 	if ((error = copyin(scp, &ksc, sizeof(ksc))) != 0)
242 		return (error);
243 
244 	if ((u_int) ksc.sc_regs[_R_ZERO] != 0xacedbadeU)/* magic number */
245 		return (EINVAL);
246 
247 	/* Restore the register context. */
248 	f = (struct frame *)l->l_md.md_regs;
249 	f->f_regs[_R_PC] = ksc.sc_pc;
250 	f->f_regs[_R_MULLO] = ksc.mullo;
251 	f->f_regs[_R_MULHI] = ksc.mulhi;
252 	memcpy(&f->f_regs[1], &scp->sc_regs[1],
253 	    sizeof(scp->sc_regs) - sizeof(scp->sc_regs[0]));
254 #ifndef	SOFTFLOAT
255 	if (scp->sc_fpused) {
256 		/* Disable the FPU to fault in FP registers. */
257 		f->f_regs[_R_SR] &= ~MIPS_SR_COP_1_BIT;
258 		if (l == fpcurlwp)
259 			fpcurlwp = NULL;
260 		l->l_addr->u_pcb.pcb_fpregs = *(struct fpreg *)scp->sc_fpregs;
261 	}
262 #else
263 	l->l_addr->u_pcb.pcb_fpregs = *(struct fpreg *)scp->sc_fpregs;
264 #endif
265 
266 	mutex_enter(p->p_lock);
267 	/* Restore signal stack. */
268 	if (ksc.sc_onstack & SS_ONSTACK)
269 		l->l_sigstk.ss_flags |= SS_ONSTACK;
270 	else
271 		l->l_sigstk.ss_flags &= ~SS_ONSTACK;
272 	/* Restore signal mask. */
273 	(void) sigprocmask1(l, SIG_SETMASK, &ksc.sc_mask, 0);
274 	mutex_exit(p->p_lock);
275 
276 	return (EJUSTRETURN);
277 }
278 #endif /* COMPAT_16 */
279