xref: /netbsd-src/sys/compat/linux/common/linux_signal.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
1 /*	$NetBSD: linux_signal.c,v 1.32 2001/11/13 02:08:59 lukem Exp $	*/
2 /*-
3  * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The NetBSD Foundation
7  * by Frank van der Linden and Eric Haszlakiewicz.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the NetBSD
20  *	Foundation, Inc. and its contributors.
21  * 4. Neither the name of The NetBSD Foundation nor the names of its
22  *    contributors may be used to endorse or promote products derived
23  *    from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 /*
38  * heavily from: svr4_signal.c,v 1.7 1995/01/09 01:04:21 christos Exp
39  */
40 
41 /*
42  *   Functions in multiarch:
43  *	linux_sys_signal	: linux_sig_notalpha.c
44  *	linux_sys_siggetmask	: linux_sig_notalpha.c
45  *	linux_sys_sigsetmask	: linux_sig_notalpha.c
46  *	linux_sys_pause		: linux_sig_notalpha.c
47  *	linux_sys_sigaction	: linux_sigaction.c
48  *
49  */
50 
51 /*
52  *   Unimplemented:
53  *	linux_sys_rt_sigtimedwait	: sigsuspend w/timeout.
54  */
55 
56 #include <sys/cdefs.h>
57 __KERNEL_RCSID(0, "$NetBSD: linux_signal.c,v 1.32 2001/11/13 02:08:59 lukem Exp $");
58 
59 #define COMPAT_LINUX 1
60 
61 #include <sys/param.h>
62 #include <sys/systm.h>
63 #include <sys/namei.h>
64 #include <sys/proc.h>
65 #include <sys/filedesc.h>
66 #include <sys/ioctl.h>
67 #include <sys/mount.h>
68 #include <sys/kernel.h>
69 #include <sys/signal.h>
70 #include <sys/signalvar.h>
71 #include <sys/malloc.h>
72 
73 #include <sys/syscallargs.h>
74 
75 #include <compat/linux/common/linux_types.h>
76 #include <compat/linux/common/linux_signal.h>
77 #include <compat/linux/common/linux_siginfo.h>
78 #include <compat/linux/common/linux_util.h>
79 
80 #include <compat/linux/linux_syscallargs.h>
81 
82 /* Locally used defines (in bsd<->linux conversion functions): */
83 #define	linux_sigemptyset(s)	memset((s), 0, sizeof(*(s)))
84 #define	linux_sigismember(s, n)	((s)->sig[((n) - 1) / LINUX__NSIG_BPW]	\
85 					& (1 << ((n) - 1) % LINUX__NSIG_BPW))
86 #define	linux_sigaddset(s, n)	((s)->sig[((n) - 1) / LINUX__NSIG_BPW]	\
87 					|= (1 << ((n) - 1) % LINUX__NSIG_BPW))
88 
89 /* Note: linux_to_native_sig[] is in <arch>/linux_sigarray.c */
90 const int native_to_linux_sig[NSIG] = {
91 	0,
92 	LINUX_SIGHUP,
93 	LINUX_SIGINT,
94 	LINUX_SIGQUIT,
95 	LINUX_SIGILL,
96 	LINUX_SIGTRAP,
97 	LINUX_SIGABRT,
98 	0,			/* SIGEMT */
99 	LINUX_SIGFPE,
100 	LINUX_SIGKILL,
101 	LINUX_SIGBUS,
102 	LINUX_SIGSEGV,
103 	0,			/* SIGSYS */
104 	LINUX_SIGPIPE,
105 	LINUX_SIGALRM,
106 	LINUX_SIGTERM,
107 	LINUX_SIGURG,
108 	LINUX_SIGSTOP,
109 	LINUX_SIGTSTP,
110 	LINUX_SIGCONT,
111 	LINUX_SIGCHLD,
112 	LINUX_SIGTTIN,
113 	LINUX_SIGTTOU,
114 	LINUX_SIGIO,
115 	LINUX_SIGXCPU,
116 	LINUX_SIGXFSZ,
117 	LINUX_SIGVTALRM,
118 	LINUX_SIGPROF,
119 	LINUX_SIGWINCH,
120 	0,			/* SIGINFO */
121 	LINUX_SIGUSR1,
122 	LINUX_SIGUSR2,
123 	LINUX_SIGPWR,
124 };
125 
126 /*
127  * Convert between Linux and BSD signal sets.
128  */
129 #if LINUX__NSIG_WORDS > 1
130 void
131 linux_old_extra_to_native_sigset(lss, extra, bss)
132 	const linux_old_sigset_t *lss;
133 	const unsigned long *extra;
134 	sigset_t *bss;
135 {
136 	linux_sigset_t lsnew;
137 
138 	/* convert old sigset to new sigset */
139 	linux_sigemptyset(&lsnew);
140 	lsnew.sig[0] = *lss;
141 	if (extra)
142 		bcopy(extra, &lsnew.sig[1],
143 			sizeof(linux_sigset_t) - sizeof(linux_old_sigset_t));
144 
145 	linux_to_native_sigset(&lsnew, bss);
146 }
147 
148 void
149 native_to_linux_old_extra_sigset(bss, lss, extra)
150 	const sigset_t *bss;
151 	linux_old_sigset_t *lss;
152 	unsigned long *extra;
153 {
154 	linux_sigset_t lsnew;
155 
156 	native_to_linux_sigset(bss, &lsnew);
157 
158 	/* convert new sigset to old sigset */
159 	*lss = lsnew.sig[0];
160 	if (extra)
161 		bcopy(&lsnew.sig[1], extra,
162 			sizeof(linux_sigset_t) - sizeof(linux_old_sigset_t));
163 }
164 #endif
165 
166 void
167 linux_to_native_sigset(lss, bss)
168 	const linux_sigset_t *lss;
169 	sigset_t *bss;
170 {
171 	int i, newsig;
172 
173 	sigemptyset(bss);
174 	for (i = 1; i < LINUX__NSIG; i++) {
175 		if (linux_sigismember(lss, i)) {
176 			newsig = linux_to_native_sig[i];
177 			if (newsig)
178 				sigaddset(bss, newsig);
179 		}
180 	}
181 }
182 
183 void
184 native_to_linux_sigset(bss, lss)
185 	const sigset_t *bss;
186 	linux_sigset_t *lss;
187 {
188 	int i, newsig;
189 
190 	linux_sigemptyset(lss);
191 	for (i = 1; i < NSIG; i++) {
192 		if (sigismember(bss, i)) {
193 			newsig = native_to_linux_sig[i];
194 			if (newsig)
195 				linux_sigaddset(lss, newsig);
196 		}
197 	}
198 }
199 
200 /*
201  * Convert between Linux and BSD sigaction structures. Linux sometimes
202  * has one extra field (sa_restorer) which we don't support.
203  */
204 void
205 linux_old_to_native_sigaction(lsa, bsa)
206 	struct linux_old_sigaction *lsa;
207 	struct sigaction *bsa;
208 {
209 
210 	bsa->sa_handler = lsa->sa_handler;
211 	linux_old_to_native_sigset(&lsa->sa_mask, &bsa->sa_mask);
212 	bsa->sa_flags = 0;
213 	if ((lsa->sa_flags & LINUX_SA_NOCLDSTOP) != 0)
214 		bsa->sa_flags |= SA_NOCLDSTOP;
215 	if ((lsa->sa_flags & LINUX_SA_ONSTACK) != 0)
216 		bsa->sa_flags |= SA_ONSTACK;
217 	if ((lsa->sa_flags & LINUX_SA_RESTART) != 0)
218 		bsa->sa_flags |= SA_RESTART;
219 	if ((lsa->sa_flags & LINUX_SA_ONESHOT) != 0)
220 		bsa->sa_flags |= SA_RESETHAND;
221 	if ((lsa->sa_flags & LINUX_SA_NOMASK) != 0)
222 		bsa->sa_flags |= SA_NODEFER;
223 	if ((lsa->sa_flags & LINUX_SA_SIGINFO) != 0)
224 		bsa->sa_flags |= SA_SIGINFO;
225 #ifdef DEBUG_LINUX
226 	if ((lsa->sa_flags & ~LINUX_SA_ALLBITS) != 0)
227 /*XXX*/		printf("linux_old_to_native_sigaction: extra bits ignored\n");
228 	if (lsa->sa_restorer != 0)
229 /*XXX*/		printf("linux_old_to_native_sigaction: sa_restorer ignored\n");
230 #endif
231 }
232 
233 void
234 native_to_linux_old_sigaction(bsa, lsa)
235 	struct sigaction *bsa;
236 	struct linux_old_sigaction *lsa;
237 {
238 
239 	/* Clear sa_flags and sa_restorer (if it exists) */
240 	bzero(lsa, sizeof(struct linux_old_sigaction));
241 
242 	/* ...and fill in the mask and flags */
243 	native_to_linux_old_sigset(&bsa->sa_mask, &lsa->sa_mask);
244 	if ((bsa->sa_flags & SA_NOCLDSTOP) != 0)
245 		lsa->sa_flags |= LINUX_SA_NOCLDSTOP;
246 	if ((bsa->sa_flags & SA_ONSTACK) != 0)
247 		lsa->sa_flags |= LINUX_SA_ONSTACK;
248 	if ((bsa->sa_flags & SA_RESTART) != 0)
249 		lsa->sa_flags |= LINUX_SA_RESTART;
250 	if ((bsa->sa_flags & SA_NODEFER) != 0)
251 		lsa->sa_flags |= LINUX_SA_NOMASK;
252 	if ((bsa->sa_flags & SA_RESETHAND) != 0)
253 		lsa->sa_flags |= LINUX_SA_ONESHOT;
254 	if ((bsa->sa_flags & SA_SIGINFO) != 0)
255 		lsa->sa_flags |= LINUX_SA_SIGINFO;
256 	lsa->sa_handler = bsa->sa_handler;
257 }
258 
259 /* ...and the new sigaction conversion funcs. */
260 void
261 linux_to_native_sigaction(lsa, bsa)
262 	struct linux_sigaction *lsa;
263 	struct sigaction *bsa;
264 {
265 
266 	bsa->sa_handler = lsa->sa_handler;
267 	linux_to_native_sigset(&lsa->sa_mask, &bsa->sa_mask);
268 	bsa->sa_flags = 0;
269 	if ((lsa->sa_flags & LINUX_SA_NOCLDSTOP) != 0)
270 		bsa->sa_flags |= SA_NOCLDSTOP;
271 	if ((lsa->sa_flags & LINUX_SA_ONSTACK) != 0)
272 		bsa->sa_flags |= SA_ONSTACK;
273 	if ((lsa->sa_flags & LINUX_SA_RESTART) != 0)
274 		bsa->sa_flags |= SA_RESTART;
275 	if ((lsa->sa_flags & LINUX_SA_ONESHOT) != 0)
276 		bsa->sa_flags |= SA_RESETHAND;
277 	if ((lsa->sa_flags & LINUX_SA_NOMASK) != 0)
278 		bsa->sa_flags |= SA_NODEFER;
279 	if ((lsa->sa_flags & LINUX_SA_SIGINFO) != 0)
280 		bsa->sa_flags |= SA_SIGINFO;
281 #ifdef DEBUG_LINUX
282 	if ((lsa->sa_flags & ~LINUX_SA_ALLBITS) != 0)
283 /*XXX*/		printf("linux_to_native_sigaction: extra bits ignored\n");
284 	if (lsa->sa_restorer != 0)
285 /*XXX*/		printf("linux_to_native_sigaction: sa_restorer ignored\n");
286 #endif
287 }
288 
289 void
290 native_to_linux_sigaction(bsa, lsa)
291 	struct sigaction *bsa;
292 	struct linux_sigaction *lsa;
293 {
294 
295 	/* Clear sa_flags and sa_restorer (if it exists) */
296 	bzero(lsa, sizeof(struct linux_sigaction));
297 
298 	/* ...and fill in the mask and flags */
299 	native_to_linux_sigset(&bsa->sa_mask, &lsa->sa_mask);
300 	if ((bsa->sa_flags & SA_NOCLDSTOP) != 0)
301 		lsa->sa_flags |= LINUX_SA_NOCLDSTOP;
302 	if ((bsa->sa_flags & SA_ONSTACK) != 0)
303 		lsa->sa_flags |= LINUX_SA_ONSTACK;
304 	if ((bsa->sa_flags & SA_RESTART) != 0)
305 		lsa->sa_flags |= LINUX_SA_RESTART;
306 	if ((bsa->sa_flags & SA_NODEFER) != 0)
307 		lsa->sa_flags |= LINUX_SA_NOMASK;
308 	if ((bsa->sa_flags & SA_RESETHAND) != 0)
309 		lsa->sa_flags |= LINUX_SA_ONESHOT;
310 	if ((bsa->sa_flags & SA_SIGINFO) != 0)
311 		lsa->sa_flags |= LINUX_SA_SIGINFO;
312 	lsa->sa_handler = bsa->sa_handler;
313 }
314 
315 /* ----------------------------------------------------------------------- */
316 
317 /*
318  * The Linux sigaction() system call. Do the usual conversions,
319  * and just call sigaction(). Some flags and values are silently
320  * ignored (see above).
321  */
322 int
323 linux_sys_rt_sigaction(p, v, retval)
324 	struct proc *p;
325 	void *v;
326 	register_t *retval;
327 {
328 	struct linux_sys_rt_sigaction_args /* {
329 		syscallarg(int) signum;
330 		syscallarg(const struct linux_sigaction *) nsa;
331 		syscallarg(struct linux_sigaction *) osa;
332 		syscallarg(size_t) sigsetsize;
333 	} */ *uap = v;
334 	struct linux_sigaction nlsa, olsa;
335 	struct sigaction nbsa, obsa;
336 	int error, sig;
337 
338 	if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t))
339 		return (EINVAL);
340 
341 	if (SCARG(uap, nsa)) {
342 		error = copyin(SCARG(uap, nsa), &nlsa, sizeof(nlsa));
343 		if (error)
344 			return (error);
345 		linux_to_native_sigaction(&nlsa, &nbsa);
346 	}
347 	sig = SCARG(uap, signum);
348 	if (sig < 0 || sig >= LINUX__NSIG)
349 		return (EINVAL);
350 	if (sig > 0 && !linux_to_native_sig[sig]) {
351 		/* Pretend that we did something useful for unknown signals. */
352 		obsa.sa_handler = SIG_IGN;
353 		sigemptyset(&obsa.sa_mask);
354 		obsa.sa_flags = 0;
355 	} else {
356 		error = sigaction1(p, linux_to_native_sig[sig],
357 		    SCARG(uap, nsa) ? &nbsa : NULL, SCARG(uap, osa) ? &obsa : NULL);
358 		if (error)
359 			return (error);
360 	}
361 	if (SCARG(uap, osa)) {
362 		native_to_linux_sigaction(&obsa, &olsa);
363 		error = copyout(&olsa, SCARG(uap, osa), sizeof(olsa));
364 		if (error)
365 			return (error);
366 	}
367 	return (0);
368 }
369 
370 int
371 linux_sigprocmask1(p, how, set, oset)
372 	struct proc *p;
373 	int how;
374 	const linux_old_sigset_t *set;
375 	linux_old_sigset_t *oset;
376 {
377 	linux_old_sigset_t nlss, olss;
378 	sigset_t nbss, obss;
379 	int error;
380 
381 	switch (how) {
382 	case LINUX_SIG_BLOCK:
383 		how = SIG_BLOCK;
384 		break;
385 	case LINUX_SIG_UNBLOCK:
386 		how = SIG_UNBLOCK;
387 		break;
388 	case LINUX_SIG_SETMASK:
389 		how = SIG_SETMASK;
390 		break;
391 	default:
392 		return (EINVAL);
393 	}
394 
395 	if (set) {
396 		error = copyin(set, &nlss, sizeof(nlss));
397 		if (error)
398 			return (error);
399 		linux_old_to_native_sigset(&nlss, &nbss);
400 	}
401 	error = sigprocmask1(p, how,
402 	    set ? &nbss : NULL, oset ? &obss : NULL);
403 	if (error)
404 		return (error);
405 	if (oset) {
406 		native_to_linux_old_sigset(&obss, &olss);
407 		error = copyout(&olss, oset, sizeof(olss));
408 		if (error)
409 			return (error);
410 	}
411 	return (error);
412 }
413 
414 int
415 linux_sys_rt_sigprocmask(p, v, retval)
416 	struct proc *p;
417 	void *v;
418 	register_t *retval;
419 {
420 	struct linux_sys_rt_sigprocmask_args /* {
421 		syscallarg(int) how;
422 		syscallarg(const linux_sigset_t *) set;
423 		syscallarg(linux_sigset_t *) oset;
424 		syscallarg(size_t) sigsetsize;
425 	} */ *uap = v;
426 
427 	linux_sigset_t nlss, olss, *oset;
428 	const linux_sigset_t *set;
429 	sigset_t nbss, obss;
430 	int error, how;
431 
432 	if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t))
433 		return (EINVAL);
434 
435 	switch (SCARG(uap, how)) {
436 	case LINUX_SIG_BLOCK:
437 		how = SIG_BLOCK;
438 		break;
439 	case LINUX_SIG_UNBLOCK:
440 		how = SIG_UNBLOCK;
441 		break;
442 	case LINUX_SIG_SETMASK:
443 		how = SIG_SETMASK;
444 		break;
445 	default:
446 		return (EINVAL);
447 	}
448 
449 	set = SCARG(uap, set);
450 	oset = SCARG(uap, oset);
451 
452 	if (set) {
453 		error = copyin(set, &nlss, sizeof(nlss));
454 		if (error)
455 			return (error);
456 		linux_to_native_sigset(&nlss, &nbss);
457 	}
458 	error = sigprocmask1(p, how,
459 	    set ? &nbss : NULL, oset ? &obss : NULL);
460 	if (!error && oset) {
461 		native_to_linux_sigset(&obss, &olss);
462 		error = copyout(&olss, oset, sizeof(olss));
463 	}
464 	return (error);
465 }
466 
467 int
468 linux_sys_rt_sigpending(p, v, retval)
469 	struct proc *p;
470 	void *v;
471 	register_t *retval;
472 {
473 	struct linux_sys_rt_sigpending_args /* {
474 		syscallarg(linux_sigset_t *) set;
475 		syscallarg(size_t) sigsetsize;
476 	} */ *uap = v;
477 	sigset_t bss;
478 	linux_sigset_t lss;
479 
480 	if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t))
481 		return (EINVAL);
482 
483 	sigpending1(p, &bss);
484 	native_to_linux_sigset(&bss, &lss);
485 	return copyout(&lss, SCARG(uap, set), sizeof(lss));
486 }
487 
488 int
489 linux_sys_sigpending(p, v, retval)
490 	struct proc *p;
491 	void *v;
492 	register_t *retval;
493 {
494 	struct linux_sys_sigpending_args /* {
495 		syscallarg(linux_old_sigset_t *) mask;
496 	} */ *uap = v;
497 	sigset_t bss;
498 	linux_old_sigset_t lss;
499 
500 	sigpending1(p, &bss);
501 	native_to_linux_old_sigset(&bss, &lss);
502 	return copyout(&lss, SCARG(uap, set), sizeof(lss));
503 }
504 
505 int
506 linux_sys_sigsuspend(p, v, retval)
507 	struct proc *p;
508 	void *v;
509 	register_t *retval;
510 {
511 	struct linux_sys_sigsuspend_args /* {
512 		syscallarg(caddr_t) restart;
513 		syscallarg(int) oldmask;
514 		syscallarg(int) mask;
515 	} */ *uap = v;
516 	linux_old_sigset_t lss;
517 	sigset_t bss;
518 
519 	lss = SCARG(uap, mask);
520 	linux_old_to_native_sigset(&lss, &bss);
521 	return (sigsuspend1(p, &bss));
522 }
523 int
524 linux_sys_rt_sigsuspend(p, v, retval)
525 	struct proc *p;
526 	void *v;
527 	register_t *retval;
528 {
529 	struct linux_sys_rt_sigsuspend_args /* {
530 		syscallarg(linux_sigset_t *) unewset;
531 		syscallarg(size_t) sigsetsize;
532 	} */ *uap = v;
533 	linux_sigset_t lss;
534 	sigset_t bss;
535 	int error;
536 
537 	if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t))
538 		return (EINVAL);
539 
540 	error = copyin(SCARG(uap, unewset), &lss, sizeof(linux_sigset_t));
541 	if (error)
542 		return (error);
543 
544 	linux_to_native_sigset(&lss, &bss);
545 
546 	return (sigsuspend1(p, &bss));
547 }
548 
549 /*
550  * Once more: only a signal conversion is needed.
551  * Note: also used as sys_rt_queueinfo.  The info field is ignored.
552  */
553 int
554 linux_sys_rt_queueinfo(p, v, retval)
555 	struct proc *p;
556 	void *v;
557 	register_t *retval;
558 {
559 	/* XXX XAX This isn't this really int, int, siginfo_t *, is it? */
560 #if 0
561 	struct linux_sys_rt_queueinfo_args /* {
562 		syscallarg(int) pid;
563 		syscallarg(int) signum;
564 		syscallarg(siginfo_t *) uinfo;
565 	} */ *uap = v;
566 #endif
567 
568 	/* XXX To really implement this we need to	*/
569 	/* XXX keep a list of queued signals somewhere.	*/
570 	return (linux_sys_kill(p, v, retval));
571 }
572 
573 int
574 linux_sys_kill(p, v, retval)
575 	struct proc *p;
576 	void *v;
577 	register_t *retval;
578 {
579 	struct linux_sys_kill_args /* {
580 		syscallarg(int) pid;
581 		syscallarg(int) signum;
582 	} */ *uap = v;
583 	struct sys_kill_args ka;
584 	int sig;
585 
586 	SCARG(&ka, pid) = SCARG(uap, pid);
587 	sig = SCARG(uap, signum);
588 	if (sig < 0 || sig >= LINUX__NSIG)
589 		return (EINVAL);
590 	SCARG(&ka, signum) = linux_to_native_sig[sig];
591 	return sys_kill(p, &ka, retval);
592 }
593 
594 #ifdef LINUX_SS_ONSTACK
595 static void linux_to_native_sigaltstack __P((struct sigaltstack *,
596     const struct linux_sigaltstack *));
597 static void native_to_linux_sigaltstack __P((struct linux_sigaltstack *,
598     const struct sigaltstack *));
599 
600 static void
601 linux_to_native_sigaltstack(bss, lss)
602 	struct sigaltstack *bss;
603 	const struct linux_sigaltstack *lss;
604 {
605 	bss->ss_sp = lss->ss_sp;
606 	bss->ss_size = lss->ss_size;
607 	if (lss->ss_flags & LINUX_SS_ONSTACK)
608 	    bss->ss_flags = SS_ONSTACK;
609 	else if (lss->ss_flags & LINUX_SS_DISABLE)
610 	    bss->ss_flags = SS_DISABLE;
611 	else
612 	    bss->ss_flags = 0;
613 }
614 
615 static void
616 native_to_linux_sigaltstack(lss, bss)
617 	struct linux_sigaltstack *lss;
618 	const struct sigaltstack *bss;
619 {
620 	lss->ss_sp = bss->ss_sp;
621 	lss->ss_size = bss->ss_size;
622 	if (bss->ss_flags & SS_ONSTACK)
623 	    lss->ss_flags = LINUX_SS_ONSTACK;
624 	else if (bss->ss_flags & SS_DISABLE)
625 	    lss->ss_flags = LINUX_SS_DISABLE;
626 	else
627 	    lss->ss_flags = 0;
628 }
629 
630 int
631 linux_sys_sigaltstack(p, v, retval)
632 	struct proc *p;
633 	void *v;
634 	register_t *retval;
635 {
636 	struct linux_sys_sigaltstack_args /* {
637 		syscallarg(const struct linux_sigaltstack *) ss;
638 		syscallarg(struct linux_sigaltstack *) oss;
639 	} */ *uap = v;
640 	struct linux_sigaltstack ss;
641 	struct sigaltstack nss, oss;
642 	int error;
643 
644 	if (SCARG(uap, ss) != NULL) {
645 		if ((error = copyin(SCARG(uap, ss), &ss, sizeof(ss))) != 0)
646 			return error;
647 		linux_to_native_sigaltstack(&nss, &ss);
648 	}
649 
650 	error = sigaltstack1(p,
651 	    SCARG(uap, ss) ? &nss : NULL, SCARG(uap, oss) ? &oss : NULL);
652 	if (error)
653 		return error;
654 
655 	if (SCARG(uap, oss) != NULL) {
656 		native_to_linux_sigaltstack(&ss, &oss);
657 		if ((error = copyout(&ss, SCARG(uap, oss), sizeof(ss))) != 0)
658 			return error;
659 	}
660 	return 0;
661 }
662 #endif
663