xref: /freebsd/sys/compat/linux/linux_signal.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675) 
1 /*-
2  * Copyright (c) 1994-1995 S�ren Schmidt
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software withough specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/sysproto.h>
34 #include <sys/proc.h>
35 #include <sys/signalvar.h>
36 
37 #include <i386/linux/linux.h>
38 #include <i386/linux/linux_proto.h>
39 #include <i386/linux/linux_util.h>
40 
41 static void
42 linux_to_bsd_sigset(linux_sigset_t *lss, sigset_t *bss)
43 {
44 	int b, l;
45 
46 	SIGEMPTYSET(*bss);
47 	bss->__bits[0] = lss->__bits[0] & ~((1U << LINUX_SIGTBLSZ) - 1);
48 	bss->__bits[1] = lss->__bits[1];
49 	for (l = 1; l <= LINUX_SIGTBLSZ; l++) {
50 		if (LINUX_SIGISMEMBER(*lss, l)) {
51 			b = linux_to_bsd_signal[_SIG_IDX(l)];
52 			if (b)
53 				SIGADDSET(*bss, b);
54 		}
55 	}
56 }
57 
58 static void
59 bsd_to_linux_sigset(sigset_t *bss, linux_sigset_t *lss)
60 {
61 	int b, l;
62 
63 	LINUX_SIGEMPTYSET(*lss);
64 	lss->__bits[0] = bss->__bits[0] & ~((1U << LINUX_SIGTBLSZ) - 1);
65 	lss->__bits[1] = bss->__bits[1];
66 	for (b = 1; b <= LINUX_SIGTBLSZ; b++) {
67 		if (SIGISMEMBER(*bss, b)) {
68 			l = bsd_to_linux_signal[_SIG_IDX(b)];
69 			if (l)
70 				LINUX_SIGADDSET(*lss, l);
71 		}
72 	}
73 }
74 
75 static void
76 linux_to_bsd_sigaction(linux_sigaction_t *lsa, struct sigaction *bsa)
77 {
78 
79 	linux_to_bsd_sigset(&lsa->lsa_mask, &bsa->sa_mask);
80 	bsa->sa_handler = lsa->lsa_handler;
81 	bsa->sa_flags = 0;
82 	if (lsa->lsa_flags & LINUX_SA_NOCLDSTOP)
83 		bsa->sa_flags |= SA_NOCLDSTOP;
84 	if (lsa->lsa_flags & LINUX_SA_NOCLDWAIT)
85 		bsa->sa_flags |= SA_NOCLDWAIT;
86 	if (lsa->lsa_flags & LINUX_SA_SIGINFO)
87 		bsa->sa_flags |= SA_SIGINFO;
88 	if (lsa->lsa_flags & LINUX_SA_ONSTACK)
89 		bsa->sa_flags |= SA_ONSTACK;
90 	if (lsa->lsa_flags & LINUX_SA_RESTART)
91 		bsa->sa_flags |= SA_RESTART;
92 	if (lsa->lsa_flags & LINUX_SA_ONESHOT)
93 		bsa->sa_flags |= SA_RESETHAND;
94 	if (lsa->lsa_flags & LINUX_SA_NOMASK)
95 		bsa->sa_flags |= SA_NODEFER;
96 }
97 
98 static void
99 bsd_to_linux_sigaction(struct sigaction *bsa, linux_sigaction_t *lsa)
100 {
101 
102 	bsd_to_linux_sigset(&bsa->sa_mask, &lsa->lsa_mask);
103 	lsa->lsa_handler = bsa->sa_handler;
104 	lsa->lsa_restorer = NULL;	/* unsupported */
105 	lsa->lsa_flags = 0;
106 	if (bsa->sa_flags & SA_NOCLDSTOP)
107 		lsa->lsa_flags |= LINUX_SA_NOCLDSTOP;
108 	if (bsa->sa_flags & SA_NOCLDWAIT)
109 		lsa->lsa_flags |= LINUX_SA_NOCLDWAIT;
110 	if (bsa->sa_flags & SA_SIGINFO)
111 		lsa->lsa_flags |= LINUX_SA_SIGINFO;
112 	if (bsa->sa_flags & SA_ONSTACK)
113 		lsa->lsa_flags |= LINUX_SA_ONSTACK;
114 	if (bsa->sa_flags & SA_RESTART)
115 		lsa->lsa_flags |= LINUX_SA_RESTART;
116 	if (bsa->sa_flags & SA_RESETHAND)
117 		lsa->lsa_flags |= LINUX_SA_ONESHOT;
118 	if (bsa->sa_flags & SA_NODEFER)
119 		lsa->lsa_flags |= LINUX_SA_NOMASK;
120 }
121 
122 static int
123 linux_do_sigaction(struct proc *p, int linux_sig, linux_sigaction_t *linux_nsa,
124 		   linux_sigaction_t *linux_osa)
125 {
126 	struct sigaction *nsa, *osa, sa;
127 	struct sigaction_args sa_args;
128 	int error;
129 	caddr_t sg = stackgap_init();
130 
131 	if (linux_sig <= 0 || linux_sig > LINUX_NSIG)
132 		return (EINVAL);
133 
134 	if (linux_osa != NULL)
135 		osa = stackgap_alloc(&sg, sizeof(struct sigaction));
136 	else
137 		osa = NULL;
138 
139 	if (linux_nsa != NULL) {
140 		nsa = stackgap_alloc(&sg, sizeof(struct sigaction));
141 		linux_to_bsd_sigaction(linux_nsa, &sa);
142 		error = copyout(&sa, nsa, sizeof(struct sigaction));
143 		if (error)
144 			return (error);
145 	}
146 	else
147 		nsa = NULL;
148 
149 	if (linux_sig <= LINUX_SIGTBLSZ)
150 		sa_args.sig = linux_to_bsd_signal[_SIG_IDX(linux_sig)];
151 	else
152 		sa_args.sig = linux_sig;
153 
154 	sa_args.act = nsa;
155 	sa_args.oact = osa;
156 	error = sigaction(p, &sa_args);
157 	if (error)
158 		return (error);
159 
160 	if (linux_osa != NULL) {
161 		error = copyin(osa, &sa, sizeof(struct sigaction));
162 		if (error)
163 			return (error);
164 		bsd_to_linux_sigaction(&sa, linux_osa);
165 	}
166 
167 	return (0);
168 }
169 
170 int
171 linux_sigaction(struct proc *p, struct linux_sigaction_args *args)
172 {
173 	linux_osigaction_t osa;
174 	linux_sigaction_t act, oact;
175 	int error;
176 
177 #ifdef DEBUG
178 	printf("Linux-emul(%ld): sigaction(%d, %p, %p)\n", (long)p->p_pid,
179 	       args->sig, (void *)args->nsa, (void *)args->osa);
180 #endif
181 
182 	if (args->nsa != NULL) {
183 		error = copyin(args->nsa, &osa, sizeof(linux_osigaction_t));
184 		if (error)
185 			return (error);
186 		act.lsa_handler = osa.lsa_handler;
187 		act.lsa_flags = osa.lsa_flags;
188 		act.lsa_restorer = osa.lsa_restorer;
189 		LINUX_SIGEMPTYSET(act.lsa_mask);
190 		act.lsa_mask.__bits[0] = osa.lsa_mask;
191 	}
192 
193 	error = linux_do_sigaction(p, args->sig,
194 				   args->nsa ? &act : NULL,
195 				   args->osa ? &oact : NULL);
196 
197 	if (args->osa != NULL && !error) {
198 		osa.lsa_handler = oact.lsa_handler;
199 		osa.lsa_flags = oact.lsa_flags;
200 		osa.lsa_restorer = oact.lsa_restorer;
201 		osa.lsa_mask = oact.lsa_mask.__bits[0];
202 		error = copyout(&osa, args->osa, sizeof(linux_osigaction_t));
203 	}
204 
205 	return (error);
206 }
207 
208 int
209 linux_signal(struct proc *p, struct linux_signal_args *args)
210 {
211 	linux_sigaction_t nsa, osa;
212 	int error;
213 
214 #ifdef DEBUG
215 	printf("Linux-emul(%ld): signal(%d, %p)\n",
216 	       (long)p->p_pid, args->sig, (void *)args->handler);
217 #endif
218 
219 	nsa.lsa_handler = args->handler;
220 	nsa.lsa_flags = LINUX_SA_ONESHOT | LINUX_SA_NOMASK;
221 	LINUX_SIGEMPTYSET(nsa.lsa_mask);
222 
223 	error = linux_do_sigaction(p, args->sig, &nsa, &osa);
224 	p->p_retval[0] = (int)osa.lsa_handler;
225 
226 	return (error);
227 }
228 
229 int
230 linux_rt_sigaction(struct proc *p, struct linux_rt_sigaction_args *args)
231 {
232 	linux_sigaction_t nsa, osa;
233 	int error;
234 
235 #ifdef DEBUG
236 	printf("Linux-emul(%ld): rt_sigaction(%d, %p, %p, %d)\n",
237 	       (long)p->p_pid, args->sig, (void *)args->act,
238 	       (void *)args->oact, args->sigsetsize);
239 #endif
240 
241 	if (args->sigsetsize != sizeof(linux_sigset_t))
242 		return (EINVAL);
243 
244 	if (args->act != NULL) {
245 		error = copyin(args->act, &nsa, sizeof(linux_sigaction_t));
246 		if (error)
247 			return (error);
248 	}
249 
250 	error = linux_do_sigaction(p, args->sig,
251 				   args->act ? &nsa : NULL,
252 				   args->oact ? &osa : NULL);
253 
254 	if (args->oact != NULL && !error) {
255 		error = copyout(&osa, args->oact, sizeof(linux_sigaction_t));
256 	}
257 
258 	return (error);
259 }
260 
261 static int
262 linux_do_sigprocmask(struct proc *p, int how, linux_sigset_t *new,
263 		     linux_sigset_t *old)
264 {
265 	int error, s;
266 	sigset_t mask;
267 
268 	error = 0;
269 	p->p_retval[0] = 0;
270 
271 	if (old != NULL)
272 		bsd_to_linux_sigset(&p->p_sigmask, old);
273 
274 	if (new != NULL) {
275 		linux_to_bsd_sigset(new, &mask);
276 
277 		s = splhigh();
278 
279 		switch (how) {
280 		case LINUX_SIG_BLOCK:
281 			SIGSETOR(p->p_sigmask, mask);
282 			SIG_CANTMASK(p->p_sigmask);
283 			break;
284 		case LINUX_SIG_UNBLOCK:
285 			SIGSETNAND(p->p_sigmask, mask);
286 			break;
287 		case LINUX_SIG_SETMASK:
288 			p->p_sigmask = mask;
289 			SIG_CANTMASK(p->p_sigmask);
290 			break;
291 		default:
292 			error = EINVAL;
293 			break;
294 		}
295 
296 		splx(s);
297 	}
298 
299 	return (error);
300 }
301 
302 int
303 linux_sigprocmask(struct proc *p, struct linux_sigprocmask_args *args)
304 {
305 	linux_osigset_t mask;
306 	linux_sigset_t set, oset;
307 	int error;
308 
309 #ifdef DEBUG
310 	printf("Linux-emul(%d): sigprocmask(%d, *, *)\n", p->p_pid, args->how);
311 #endif
312 
313 	if (args->mask != NULL) {
314 		error = copyin(args->mask, &mask, sizeof(linux_osigset_t));
315 		if (error)
316 			return (error);
317 		LINUX_SIGEMPTYSET(set);
318 		set.__bits[0] = mask;
319 	}
320 
321 	error = linux_do_sigprocmask(p, args->how,
322 				     args->mask ? &set : NULL,
323 				     args->omask ? &oset : NULL);
324 
325 	if (args->omask != NULL && !error) {
326 		mask = oset.__bits[0];
327 		error = copyout(&mask, args->omask, sizeof(linux_osigset_t));
328 	}
329 
330 	return (error);
331 }
332 
333 int
334 linux_rt_sigprocmask(struct proc *p, struct linux_rt_sigprocmask_args *args)
335 {
336 	linux_sigset_t set, oset;
337 	int error;
338 
339 #ifdef DEBUG
340 	printf("Linux-emul(%ld): rt_sigprocmask(%d, %p, %p, %d)\n",
341 	       (long)p->p_pid, args->how, (void *)args->mask,
342 	       (void *)args->omask, args->sigsetsize);
343 #endif
344 
345 	if (args->sigsetsize != sizeof(linux_sigset_t))
346 		return EINVAL;
347 
348 	if (args->mask != NULL) {
349 		error = copyin(args->mask, &set, sizeof(linux_sigset_t));
350 		if (error)
351 			return (error);
352 	}
353 
354 	error = linux_do_sigprocmask(p, args->how,
355 				     args->mask ? &set : NULL,
356 				     args->omask ? &oset : NULL);
357 
358 	if (args->omask != NULL && !error) {
359 		error = copyout(&oset, args->omask, sizeof(linux_sigset_t));
360 	}
361 
362 	return (error);
363 }
364 
365 int
366 linux_siggetmask(struct proc *p, struct linux_siggetmask_args *args)
367 {
368 	linux_sigset_t mask;
369 
370 #ifdef DEBUG
371 	printf("Linux-emul(%d): siggetmask()\n", p->p_pid);
372 #endif
373 
374 	bsd_to_linux_sigset(&p->p_sigmask, &mask);
375 	p->p_retval[0] = mask.__bits[0];
376 	return (0);
377 }
378 
379 int
380 linux_sigsetmask(struct proc *p, struct linux_sigsetmask_args *args)
381 {
382 	linux_sigset_t lset;
383 	sigset_t bset;
384 	int s;
385 
386 #ifdef DEBUG
387 	printf("Linux-emul(%ld): sigsetmask(%08lx)\n",
388 	       (long)p->p_pid, (unsigned long)args->mask);
389 #endif
390 
391 	bsd_to_linux_sigset(&p->p_sigmask, &lset);
392 	p->p_retval[0] = lset.__bits[0];
393 	LINUX_SIGEMPTYSET(lset);
394 	lset.__bits[0] = args->mask;
395 	linux_to_bsd_sigset(&lset, &bset);
396 	s = splhigh();
397 	p->p_sigmask = bset;
398 	SIG_CANTMASK(p->p_sigmask);
399 	splx(s);
400 	return (0);
401 }
402 
403 int
404 linux_sigpending(struct proc *p, struct linux_sigpending_args *args)
405 {
406 	sigset_t bset;
407 	linux_sigset_t lset;
408 	linux_osigset_t mask;
409 
410 #ifdef DEBUG
411 	printf("Linux-emul(%d): sigpending(*)\n", p->p_pid);
412 #endif
413 
414 	bset = p->p_siglist;
415 	SIGSETAND(bset, p->p_sigmask);
416 	bsd_to_linux_sigset(&bset, &lset);
417 	mask = lset.__bits[0];
418 	return (copyout(&mask, args->mask, sizeof(mask)));
419 }
420 
421 /*
422  * Linux has two extra args, restart and oldmask.  We dont use these,
423  * but it seems that "restart" is actually a context pointer that
424  * enables the signal to happen with a different register set.
425  */
426 int
427 linux_sigsuspend(struct proc *p, struct linux_sigsuspend_args *args)
428 {
429 	struct sigsuspend_args bsd;
430 	sigset_t *sigmask;
431 	linux_sigset_t mask;
432 	caddr_t sg = stackgap_init();
433 
434 #ifdef DEBUG
435 	printf("Linux-emul(%ld): sigsuspend(%08lx)\n",
436 	       (long)p->p_pid, (unsigned long)args->mask);
437 #endif
438 
439 	sigmask = stackgap_alloc(&sg, sizeof(sigset_t));
440 	LINUX_SIGEMPTYSET(mask);
441 	mask.__bits[0] = args->mask;
442 	linux_to_bsd_sigset(&mask, sigmask);
443 	bsd.sigmask = sigmask;
444 	return (sigsuspend(p, &bsd));
445 }
446 
447 int
448 linux_rt_sigsuspend(p, uap)
449 	struct proc *p;
450 	struct linux_rt_sigsuspend_args *uap;
451 {
452 	linux_sigset_t lmask;
453 	sigset_t *bmask;
454 	struct sigsuspend_args bsd;
455 	caddr_t sg = stackgap_init();
456 	int error;
457 
458 #ifdef DEBUG
459 	printf("Linux-emul(%ld): rt_sigsuspend(%p, %d)\n", (long)p->p_pid,
460 	       (void *)uap->newset, uap->sigsetsize);
461 #endif
462 
463 	if (uap->sigsetsize != sizeof(linux_sigset_t))
464 		return (EINVAL);
465 
466 	error = copyin(uap->newset, &lmask, sizeof(linux_sigset_t));
467 	if (error)
468 		return (error);
469 
470 	bmask = stackgap_alloc(&sg, sizeof(sigset_t));
471 	linux_to_bsd_sigset(&lmask, bmask);
472 	bsd.sigmask = bmask;
473 	return (sigsuspend(p, &bsd));
474 }
475 
476 int
477 linux_pause(struct proc *p, struct linux_pause_args *args)
478 {
479 	struct sigsuspend_args bsd;
480 	sigset_t *sigmask;
481 	caddr_t sg = stackgap_init();
482 
483 #ifdef DEBUG
484 	printf("Linux-emul(%d): pause()\n", p->p_pid);
485 #endif
486 
487 	sigmask = stackgap_alloc(&sg, sizeof(sigset_t));
488 	*sigmask = p->p_sigmask;
489 	bsd.sigmask = sigmask;
490 	return sigsuspend(p, &bsd);
491 }
492 
493 int
494 linux_kill(struct proc *p, struct linux_kill_args *args)
495 {
496 	struct kill_args /* {
497 	    int pid;
498 	    int signum;
499 	} */ tmp;
500 
501 #ifdef DEBUG
502 	printf("Linux-emul(%d): kill(%d, %d)\n",
503 	       p->p_pid, args->pid, args->signum);
504 #endif
505 
506 	/*
507 	 * Allow signal 0 as a means to check for privileges
508 	 */
509 	if (args->signum < 0 || args->signum > LINUX_NSIG)
510 		return EINVAL;
511 
512 	if (args->signum > 0 && args->signum <= LINUX_SIGTBLSZ)
513 		tmp.signum = linux_to_bsd_signal[_SIG_IDX(args->signum)];
514 	else
515 		tmp.signum = args->signum;
516 
517 	tmp.pid = args->pid;
518 	return (kill(p, &tmp));
519 }
520