1 /*	$NetBSD: compat_16_machdep.c,v 1.15 2009/11/21 04:16:52 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_16_machdep.c,v 1.15 2009/11/21 04:16:52 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/signal.h>
43 #include <sys/signalvar.h>
44 #include <sys/kernel.h>
45 #include <sys/proc.h>
46 #include <sys/mount.h>
47 #include <sys/syscallargs.h>
48 
49 #include <machine/signal.h>
50 #include <machine/frame.h>
51 
52 #if defined(COMPAT_16)
53 #include <compat/sys/signal.h>
54 #include <compat/sys/signalvar.h>
55 
56 #ifdef DEBUG
57 /* See sigdebug.h */
58 #include <sparc64/sparc64/sigdebug.h>
59 #endif
60 
61 #ifdef __arch64__
62 #define STACK_OFFSET	BIAS
63 #define CPOUTREG(l,v)	copyout(&(v), (l), sizeof(v))
64 #undef CCFSZ
65 #define CCFSZ	CC64FSZ
66 #else
67 #define STACK_OFFSET	0
68 #define CPOUTREG(l,v)	copyout(&(v), (l), sizeof(v))
69 #endif
70 
71 struct sigframe_sigcontext {
72 	int	sf_signo;		/* signal number */
73 	int	sf_code;		/* code */
74 #ifndef __arch64__
75 	struct	sigcontext *sf_scp;	/* SunOS user addr of sigcontext */
76 	int	sf_addr;		/* SunOS compat, always 0 for now */
77 #endif
78 	struct	sigcontext sf_sc;	/* actual sigcontext */
79 };
80 
81 /*
82  * Send an interrupt to process.
83  */
84 void
85 sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
86 {
87 	struct lwp *l = curlwp;
88 	struct proc *p = l->l_proc;
89 	struct sigacts *ps = p->p_sigacts;
90 	const void *addr;
91 	struct rwindow *newsp;
92 #ifdef NOT_DEBUG
93 	struct rwindow tmpwin;
94 #endif
95 	int onstack, error;
96 	int sig = ksi->ksi_signo;
97 	struct sigframe_sigcontext *fp = getframe(l, sig, &onstack);
98 	struct sigframe_sigcontext sf;
99 	sig_t catcher = SIGACTION(p, sig).sa_handler;
100 	struct trapframe64 *tf = l->l_md.md_tf;
101 	/* Allocate an aligned sigframe */
102 	fp = (void *)((u_long)(fp - 1) & ~0x0f);
103 
104 #ifdef DEBUG
105 	sigpid = p->p_pid;
106 	if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) {
107 		printf("sendsig_sigcontext: %s[%d] sig %d newusp %p scp %p\n",
108 		    p->p_comm, p->p_pid, sig, fp, &fp->sf_sc);
109 #ifdef DDB
110 		if (sigdebug & SDB_DDB) Debugger();
111 #endif
112 	}
113 #endif
114 
115 	/*
116 	 * Now set up the signal frame.  We build it in kernel space
117 	 * and then copy it out.  We probably ought to just build it
118 	 * directly in user space....
119 	 */
120 	sf.sf_signo = sig;
121 	sf.sf_code = ksi->ksi_trap;
122 #ifndef __arch64__
123 	sf.sf_scp = 0;
124 	sf.sf_addr = 0;			/* XXX */
125 #endif
126 
127 	/*
128 	 * Build the signal context to be used by sigreturn.
129 	 */
130 	sf.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
131 	sf.sf_sc.sc_mask = *mask;
132 #ifdef COMPAT_13
133 	/*
134 	 * XXX We always have to save an old style signal mask because
135 	 * XXX we might be delivering a signal to a process which will
136 	 * XXX escape from the signal in a non-standard way and invoke
137 	 * XXX sigreturn() directly.
138 	 */
139 	native_sigset_to_sigset13(mask, &sf.sf_sc.__sc_mask13);
140 #endif
141 	/* Save register context. */
142 	sf.sf_sc.sc_sp = (long)tf->tf_out[6];
143 	sf.sf_sc.sc_pc = tf->tf_pc;
144 	sf.sf_sc.sc_npc = tf->tf_npc;
145 #ifdef __arch64__
146 	sf.sf_sc.sc_tstate = tf->tf_tstate; /* XXX */
147 #else
148 	sf.sf_sc.sc_psr = TSTATECCR_TO_PSR(tf->tf_tstate); /* XXX */
149 #endif
150 	sf.sf_sc.sc_g1 = tf->tf_global[1];
151 	sf.sf_sc.sc_o0 = tf->tf_out[0];
152 
153 	/*
154 	 * Put the stack in a consistent state before we whack away
155 	 * at it.  Note that write_user_windows may just dump the
156 	 * registers into the pcb; we need them in the process's memory.
157 	 * We also need to make sure that when we start the signal handler,
158 	 * its %i6 (%fp), which is loaded from the newly allocated stack area,
159 	 * joins seamlessly with the frame it was in when the signal occurred,
160 	 * so that the debugger and _longjmp code can back up through it.
161 	 */
162 	sendsig_reset(l, sig);
163 	mutex_exit(p->p_lock);
164 	newsp = (struct rwindow *)((vaddr_t)fp - sizeof(struct rwindow));
165 	write_user_windows();
166 #ifdef DEBUG
167 	if ((sigdebug & SDB_KSTACK))
168 	    printf("sendsig: saving sf to %p, setting stack pointer %p to %p\n",
169 		   fp, &(((struct rwindow *)newsp)->rw_in[6]),
170 		   (void *)(unsigned long)tf->tf_out[6]);
171 #endif
172 	error = (rwindow_save(l) || copyout((void *)&sf, (void *)fp, sizeof sf) ||
173 #ifdef NOT_DEBUG
174 	    copyin(oldsp, &tmpwin, sizeof(tmpwin)) || copyout(&tmpwin, newsp, sizeof(tmpwin)) ||
175 #endif
176 	    CPOUTREG(&(((struct rwindow *)newsp)->rw_in[6]), tf->tf_out[6]));
177 	mutex_enter(p->p_lock);
178 
179 	if (error) {
180 		/*
181 		 * Process has trashed its stack; give it an illegal
182 		 * instruction to halt it in its tracks.
183 		 */
184 #ifdef DEBUG
185 		mutex_exit(p->p_lock);
186 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
187 			printf("sendsig: window save or copyout error\n");
188 		printf("sendsig: stack was trashed trying to send sig %d, sending SIGILL\n", sig);
189 #ifdef DDB
190 		if (sigdebug & SDB_DDB) Debugger();
191 #endif
192 		mutex_enter(p->p_lock);
193 #endif
194 		sigexit(l, SIGILL);
195 		/* NOTREACHED */
196 	}
197 
198 #ifdef DEBUG
199 	if (sigdebug & SDB_FOLLOW) {
200 		printf("sendsig: %s[%d] sig %d scp %p\n",
201 		       p->p_comm, p->p_pid, sig, &fp->sf_sc);
202 	}
203 #endif
204 
205 	/*
206 	 * Arrange to continue execution at the code copied out in exec().
207 	 * It needs the function to call in %g1, and a new stack pointer.
208 	 */
209 	switch (ps->sa_sigdesc[sig].sd_vers) {
210 	case 0:		/* legacy on-stack sigtramp */
211 		addr = p->p_sigctx.ps_sigcode;
212 		break;
213 
214 	case 1:
215 		addr = ps->sa_sigdesc[sig].sd_tramp;
216 		break;
217 
218 	default:
219 		addr = NULL; /* XXX: gcc */
220 		/* Don't know what trampoline version; kill it. */
221 		sigexit(l, SIGILL);
222 	}
223 
224 	tf->tf_global[1] = (vaddr_t)catcher;
225 	tf->tf_pc = (const vaddr_t)addr;
226 	tf->tf_npc = (const vaddr_t)addr + 4;
227 	tf->tf_out[6] = (vaddr_t)newsp - STACK_OFFSET;
228 
229 	/* Remember that we're now on the signal stack. */
230 	if (onstack)
231 		l->l_sigstk.ss_flags |= SS_ONSTACK;
232 
233 #ifdef DEBUG
234 	if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) {
235 		mutex_exit(p->p_lock);
236 		printf("sendsig: about to return to catcher %p thru %p\n",
237 		       catcher, (void *)(unsigned long)addr);
238 #ifdef DDB
239 		if (sigdebug & SDB_DDB) Debugger();
240 #endif
241 		mutex_enter(p->p_lock);
242 	}
243 #endif
244 }
245 
246 /*
247  * System call to cleanup state after a signal
248  * has been taken.  Reset signal mask and
249  * stack state from context left by sendsig (above),
250  * and return to the given trap frame (if there is one).
251  * Check carefully to make sure that the user has not
252  * modified the state to gain improper privileges or to cause
253  * a machine fault.
254  */
255 int compat_16_sys___sigreturn14(struct lwp *, const struct compat_16_sys___sigreturn14_args *, register_t *);
256 
257 /* ARGSUSED */
258 int
259 compat_16_sys___sigreturn14(struct lwp *l, const struct compat_16_sys___sigreturn14_args *uap, register_t *retval)
260 {
261 	/* {
262 		syscallarg(struct sigcontext *) sigcntxp;
263 	} */
264 	struct sigcontext sc, *scp;
265 	struct trapframe64 *tf;
266 	int error = EINVAL;
267 	struct proc *p = l->l_proc;
268 
269 	/* First ensure consistent stack state (see sendsig). */
270 	write_user_windows();
271 	if (rwindow_save(l)) {
272 #ifdef DEBUG
273 		printf("sigreturn14: rwindow_save(%p) failed, sending SIGILL\n", p);
274 #ifdef DDB
275 		if (sigdebug & SDB_DDB) Debugger();
276 #endif
277 #endif
278 		mutex_enter(p->p_lock);
279 		sigexit(l, SIGILL);
280 	}
281 #ifdef DEBUG
282 	if (sigdebug & SDB_FOLLOW) {
283 		printf("sigreturn14: %s[%d], sigcntxp %p\n",
284 		    p->p_comm, p->p_pid, SCARG(uap, sigcntxp));
285 #ifdef DDB
286 		if (sigdebug & SDB_DDB) Debugger();
287 #endif
288 	}
289 #endif
290 	scp = SCARG(uap, sigcntxp);
291  	if ((vaddr_t)scp & 3 || (error = copyin((void *)scp, &sc, sizeof sc) != 0))
292 #ifdef DEBUG
293 	{
294 		printf("sigreturn14: copyin failed: scp=%p\n", scp);
295 #ifdef DDB
296 		if (sigdebug & SDB_DDB) Debugger();
297 #endif
298 		return (error);
299 	}
300 #else
301 		return (error);
302 #endif
303 	scp = &sc;
304 
305 	tf = l->l_md.md_tf;
306 	/*
307 	 * Only the icc bits in the psr are used, so it need not be
308 	 * verified.  pc and npc must be multiples of 4.  This is all
309 	 * that is required; if it holds, just do it.
310 	 */
311 	if (((sc.sc_pc | sc.sc_npc) & 3) != 0 || (sc.sc_pc == 0) || (sc.sc_npc == 0))
312 #ifdef DEBUG
313 	{
314 		printf("sigreturn14: pc %p or npc %p invalid\n",
315 		   (void *)(unsigned long)sc.sc_pc,
316 		   (void *)(unsigned long)sc.sc_npc);
317 #ifdef DDB
318 		if (sigdebug & SDB_DDB) Debugger();
319 #endif
320 		return (EINVAL);
321 	}
322 #else
323 		return (EINVAL);
324 #endif
325 	/* take only psr ICC field */
326 #ifdef __arch64__
327 	tf->tf_tstate = (uint64_t)(tf->tf_tstate & ~TSTATE_CCR) | (scp->sc_tstate & TSTATE_CCR);
328 #else
329 	tf->tf_tstate = (uint64_t)(tf->tf_tstate & ~TSTATE_CCR) | PSRCC_TO_TSTATE(scp->sc_psr);
330 #endif
331 	tf->tf_pc = (uint64_t)scp->sc_pc;
332 	tf->tf_npc = (uint64_t)scp->sc_npc;
333 	tf->tf_global[1] = (uint64_t)scp->sc_g1;
334 	tf->tf_out[0] = (uint64_t)scp->sc_o0;
335 	tf->tf_out[6] = (uint64_t)scp->sc_sp;
336 #ifdef DEBUG
337 	if (sigdebug & SDB_FOLLOW) {
338 		printf("sigreturn14: return trapframe pc=%p sp=%p tstate=%llx\n",
339 		       (void *)(unsigned long)tf->tf_pc,
340 		       (void *)(unsigned long)tf->tf_out[6],
341 		       (unsigned long long)tf->tf_tstate);
342 #ifdef DDB
343 		if (sigdebug & SDB_DDB) Debugger();
344 #endif
345 	}
346 #endif
347 
348 	mutex_enter(p->p_lock);
349 	/* Restore signal stack. */
350 	if (sc.sc_onstack & SS_ONSTACK)
351 		l->l_sigstk.ss_flags |= SS_ONSTACK;
352 	else
353 		l->l_sigstk.ss_flags &= ~SS_ONSTACK;
354 	/* Restore signal mask. */
355 	(void) sigprocmask1(l, SIG_SETMASK, &sc.sc_mask, 0);
356 	mutex_exit(p->p_lock);
357 
358 	return (EJUSTRETURN);
359 }
360 #endif /* COMPAT_16 */
361