xref: /freebsd/sys/compat/linux/linux_signal.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf) 
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 without 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/lock.h>
34 #include <sys/mutex.h>
35 #include <sys/proc.h>
36 #include <sys/signalvar.h>
37 #include <sys/syscallsubr.h>
38 #include <sys/sysproto.h>
39 
40 #include <machine/../linux/linux.h>
41 #include <machine/../linux/linux_proto.h>
42 #include <compat/linux/linux_signal.h>
43 #include <compat/linux/linux_util.h>
44 
45 void
46 linux_to_bsd_sigset(l_sigset_t *lss, sigset_t *bss)
47 {
48 	int b, l;
49 
50 	SIGEMPTYSET(*bss);
51 	bss->__bits[0] = lss->__bits[0] & ~((1U << LINUX_SIGTBLSZ) - 1);
52 	bss->__bits[1] = lss->__bits[1];
53 	for (l = 1; l <= LINUX_SIGTBLSZ; l++) {
54 		if (LINUX_SIGISMEMBER(*lss, l)) {
55 #ifdef __alpha__
56 			b = _SIG_IDX(l);
57 #else
58 			b = linux_to_bsd_signal[_SIG_IDX(l)];
59 #endif
60 			if (b)
61 				SIGADDSET(*bss, b);
62 		}
63 	}
64 }
65 
66 void
67 bsd_to_linux_sigset(sigset_t *bss, l_sigset_t *lss)
68 {
69 	int b, l;
70 
71 	LINUX_SIGEMPTYSET(*lss);
72 	lss->__bits[0] = bss->__bits[0] & ~((1U << LINUX_SIGTBLSZ) - 1);
73 	lss->__bits[1] = bss->__bits[1];
74 	for (b = 1; b <= LINUX_SIGTBLSZ; b++) {
75 		if (SIGISMEMBER(*bss, b)) {
76 #if __alpha__
77 			l = _SIG_IDX(b);
78 #else
79 			l = bsd_to_linux_signal[_SIG_IDX(b)];
80 #endif
81 			if (l)
82 				LINUX_SIGADDSET(*lss, l);
83 		}
84 	}
85 }
86 
87 static void
88 linux_to_bsd_sigaction(l_sigaction_t *lsa, struct sigaction *bsa)
89 {
90 
91 	linux_to_bsd_sigset(&lsa->lsa_mask, &bsa->sa_mask);
92 	bsa->sa_handler = lsa->lsa_handler;
93 	bsa->sa_flags = 0;
94 	if (lsa->lsa_flags & LINUX_SA_NOCLDSTOP)
95 		bsa->sa_flags |= SA_NOCLDSTOP;
96 	if (lsa->lsa_flags & LINUX_SA_NOCLDWAIT)
97 		bsa->sa_flags |= SA_NOCLDWAIT;
98 	if (lsa->lsa_flags & LINUX_SA_SIGINFO)
99 		bsa->sa_flags |= SA_SIGINFO;
100 	if (lsa->lsa_flags & LINUX_SA_ONSTACK)
101 		bsa->sa_flags |= SA_ONSTACK;
102 	if (lsa->lsa_flags & LINUX_SA_RESTART)
103 		bsa->sa_flags |= SA_RESTART;
104 	if (lsa->lsa_flags & LINUX_SA_ONESHOT)
105 		bsa->sa_flags |= SA_RESETHAND;
106 	if (lsa->lsa_flags & LINUX_SA_NOMASK)
107 		bsa->sa_flags |= SA_NODEFER;
108 }
109 
110 static void
111 bsd_to_linux_sigaction(struct sigaction *bsa, l_sigaction_t *lsa)
112 {
113 
114 	bsd_to_linux_sigset(&bsa->sa_mask, &lsa->lsa_mask);
115 	lsa->lsa_handler = bsa->sa_handler;
116 	lsa->lsa_restorer = NULL;	/* unsupported */
117 	lsa->lsa_flags = 0;
118 	if (bsa->sa_flags & SA_NOCLDSTOP)
119 		lsa->lsa_flags |= LINUX_SA_NOCLDSTOP;
120 	if (bsa->sa_flags & SA_NOCLDWAIT)
121 		lsa->lsa_flags |= LINUX_SA_NOCLDWAIT;
122 	if (bsa->sa_flags & SA_SIGINFO)
123 		lsa->lsa_flags |= LINUX_SA_SIGINFO;
124 	if (bsa->sa_flags & SA_ONSTACK)
125 		lsa->lsa_flags |= LINUX_SA_ONSTACK;
126 	if (bsa->sa_flags & SA_RESTART)
127 		lsa->lsa_flags |= LINUX_SA_RESTART;
128 	if (bsa->sa_flags & SA_RESETHAND)
129 		lsa->lsa_flags |= LINUX_SA_ONESHOT;
130 	if (bsa->sa_flags & SA_NODEFER)
131 		lsa->lsa_flags |= LINUX_SA_NOMASK;
132 }
133 
134 int
135 linux_do_sigaction(struct thread *td, int linux_sig, l_sigaction_t *linux_nsa,
136 		   l_sigaction_t *linux_osa)
137 {
138 	struct sigaction act, oact, *nsa, *osa;
139 	int error, sig;
140 
141 	if (linux_sig <= 0 || linux_sig > LINUX_NSIG)
142 		return (EINVAL);
143 
144 	osa = (linux_osa != NULL) ? &oact : NULL;
145 	if (linux_nsa != NULL) {
146 		nsa = &act;
147 		linux_to_bsd_sigaction(linux_nsa, nsa);
148 	} else
149 		nsa = NULL;
150 
151 #ifndef __alpha__
152 	if (linux_sig <= LINUX_SIGTBLSZ)
153 		sig = linux_to_bsd_signal[_SIG_IDX(linux_sig)];
154 	else
155 #endif
156 		sig = linux_sig;
157 
158 	error = kern_sigaction(td, sig, nsa, osa, 0);
159 	if (error)
160 		return (error);
161 
162 	if (linux_osa != NULL)
163 		bsd_to_linux_sigaction(osa, linux_osa);
164 
165 	return (0);
166 }
167 
168 
169 #ifndef __alpha__
170 int
171 linux_signal(struct thread *td, struct linux_signal_args *args)
172 {
173 	l_sigaction_t nsa, osa;
174 	int error;
175 
176 #ifdef DEBUG
177 	if (ldebug(signal))
178 		printf(ARGS(signal, "%d, %p"),
179 		    args->sig, (void *)args->handler);
180 #endif
181 
182 	nsa.lsa_handler = args->handler;
183 	nsa.lsa_flags = LINUX_SA_ONESHOT | LINUX_SA_NOMASK;
184 	LINUX_SIGEMPTYSET(nsa.lsa_mask);
185 
186 	error = linux_do_sigaction(td, args->sig, &nsa, &osa);
187 	td->td_retval[0] = (int)osa.lsa_handler;
188 
189 	return (error);
190 }
191 #endif	/*!__alpha__*/
192 
193 int
194 linux_rt_sigaction(struct thread *td, struct linux_rt_sigaction_args *args)
195 {
196 	l_sigaction_t nsa, osa;
197 	int error;
198 
199 #ifdef DEBUG
200 	if (ldebug(rt_sigaction))
201 		printf(ARGS(rt_sigaction, "%ld, %p, %p, %ld"),
202 		    (long)args->sig, (void *)args->act,
203 		    (void *)args->oact, (long)args->sigsetsize);
204 #endif
205 
206 	if (args->sigsetsize != sizeof(l_sigset_t))
207 		return (EINVAL);
208 
209 	if (args->act != NULL) {
210 		error = copyin(args->act, &nsa, sizeof(l_sigaction_t));
211 		if (error)
212 			return (error);
213 	}
214 
215 	error = linux_do_sigaction(td, args->sig,
216 				   args->act ? &nsa : NULL,
217 				   args->oact ? &osa : NULL);
218 
219 	if (args->oact != NULL && !error) {
220 		error = copyout(&osa, args->oact, sizeof(l_sigaction_t));
221 	}
222 
223 	return (error);
224 }
225 
226 static int
227 linux_do_sigprocmask(struct thread *td, int how, l_sigset_t *new,
228 		     l_sigset_t *old)
229 {
230 	int error;
231 	sigset_t mask;
232 	struct proc *p = td->td_proc;
233 
234 	error = 0;
235 	td->td_retval[0] = 0;
236 
237 	PROC_LOCK(p);
238 	if (old != NULL)
239 		bsd_to_linux_sigset(&p->p_sigmask, old);
240 
241 	if (new != NULL) {
242 		linux_to_bsd_sigset(new, &mask);
243 
244 		switch (how) {
245 		case LINUX_SIG_BLOCK:
246 			SIGSETOR(p->p_sigmask, mask);
247 			SIG_CANTMASK(p->p_sigmask);
248 			break;
249 		case LINUX_SIG_UNBLOCK:
250 			SIGSETNAND(p->p_sigmask, mask);
251 			signotify(p);
252 			break;
253 		case LINUX_SIG_SETMASK:
254 			p->p_sigmask = mask;
255 			SIG_CANTMASK(p->p_sigmask);
256 			signotify(p);
257 			break;
258 		default:
259 			error = EINVAL;
260 			break;
261 		}
262 	}
263 	PROC_UNLOCK(p);
264 
265 	return (error);
266 }
267 
268 #ifndef __alpha__
269 int
270 linux_sigprocmask(struct thread *td, struct linux_sigprocmask_args *args)
271 {
272 	l_osigset_t mask;
273 	l_sigset_t set, oset;
274 	int error;
275 
276 #ifdef DEBUG
277 	if (ldebug(sigprocmask))
278 		printf(ARGS(sigprocmask, "%d, *, *"), args->how);
279 #endif
280 
281 	if (args->mask != NULL) {
282 		error = copyin(args->mask, &mask, sizeof(l_osigset_t));
283 		if (error)
284 			return (error);
285 		LINUX_SIGEMPTYSET(set);
286 		set.__bits[0] = mask;
287 	}
288 
289 	error = linux_do_sigprocmask(td, args->how,
290 				     args->mask ? &set : NULL,
291 				     args->omask ? &oset : NULL);
292 
293 	if (args->omask != NULL && !error) {
294 		mask = oset.__bits[0];
295 		error = copyout(&mask, args->omask, sizeof(l_osigset_t));
296 	}
297 
298 	return (error);
299 }
300 #endif	/*!__alpha__*/
301 
302 int
303 linux_rt_sigprocmask(struct thread *td, struct linux_rt_sigprocmask_args *args)
304 {
305 	l_sigset_t set, oset;
306 	int error;
307 
308 #ifdef DEBUG
309 	if (ldebug(rt_sigprocmask))
310 		printf(ARGS(rt_sigprocmask, "%d, %p, %p, %ld"),
311 		    args->how, (void *)args->mask,
312 		    (void *)args->omask, (long)args->sigsetsize);
313 #endif
314 
315 	if (args->sigsetsize != sizeof(l_sigset_t))
316 		return EINVAL;
317 
318 	if (args->mask != NULL) {
319 		error = copyin(args->mask, &set, sizeof(l_sigset_t));
320 		if (error)
321 			return (error);
322 	}
323 
324 	error = linux_do_sigprocmask(td, args->how,
325 				     args->mask ? &set : NULL,
326 				     args->omask ? &oset : NULL);
327 
328 	if (args->omask != NULL && !error) {
329 		error = copyout(&oset, args->omask, sizeof(l_sigset_t));
330 	}
331 
332 	return (error);
333 }
334 
335 #ifndef __alpha__
336 int
337 linux_sgetmask(struct thread *td, struct linux_sgetmask_args *args)
338 {
339 	struct proc *p = td->td_proc;
340 	l_sigset_t mask;
341 
342 #ifdef DEBUG
343 	if (ldebug(sgetmask))
344 		printf(ARGS(sgetmask, ""));
345 #endif
346 
347 	PROC_LOCK(p);
348 	bsd_to_linux_sigset(&p->p_sigmask, &mask);
349 	PROC_UNLOCK(p);
350 	td->td_retval[0] = mask.__bits[0];
351 	return (0);
352 }
353 
354 int
355 linux_ssetmask(struct thread *td, struct linux_ssetmask_args *args)
356 {
357 	struct proc *p = td->td_proc;
358 	l_sigset_t lset;
359 	sigset_t bset;
360 
361 #ifdef DEBUG
362 	if (ldebug(ssetmask))
363 		printf(ARGS(ssetmask, "%08lx"), (unsigned long)args->mask);
364 #endif
365 
366 	PROC_LOCK(p);
367 	bsd_to_linux_sigset(&p->p_sigmask, &lset);
368 	td->td_retval[0] = lset.__bits[0];
369 	LINUX_SIGEMPTYSET(lset);
370 	lset.__bits[0] = args->mask;
371 	linux_to_bsd_sigset(&lset, &bset);
372 	p->p_sigmask = bset;
373 	SIG_CANTMASK(p->p_sigmask);
374 	signotify(p);
375 	PROC_UNLOCK(p);
376 	return (0);
377 }
378 
379 /*
380  * MPSAFE
381  */
382 int
383 linux_sigpending(struct thread *td, struct linux_sigpending_args *args)
384 {
385 	struct proc *p = td->td_proc;
386 	sigset_t bset;
387 	l_sigset_t lset;
388 	l_osigset_t mask;
389 
390 #ifdef DEBUG
391 	if (ldebug(sigpending))
392 		printf(ARGS(sigpending, "*"));
393 #endif
394 
395 	PROC_LOCK(p);
396 	bset = p->p_siglist;
397 	SIGSETAND(bset, p->p_sigmask);
398 	bsd_to_linux_sigset(&bset, &lset);
399 	PROC_UNLOCK(p);
400 	mask = lset.__bits[0];
401 	return (copyout(&mask, args->mask, sizeof(mask)));
402 }
403 #endif	/*!__alpha__*/
404 
405 int
406 linux_kill(struct thread *td, struct linux_kill_args *args)
407 {
408 	struct kill_args /* {
409 	    int pid;
410 	    int signum;
411 	} */ tmp;
412 
413 #ifdef DEBUG
414 	if (ldebug(kill))
415 		printf(ARGS(kill, "%d, %d"), args->pid, args->signum);
416 #endif
417 
418 	/*
419 	 * Allow signal 0 as a means to check for privileges
420 	 */
421 	if (args->signum < 0 || args->signum > LINUX_NSIG)
422 		return EINVAL;
423 
424 #ifndef __alpha__
425 	if (args->signum > 0 && args->signum <= LINUX_SIGTBLSZ)
426 		tmp.signum = linux_to_bsd_signal[_SIG_IDX(args->signum)];
427 	else
428 #endif
429 		tmp.signum = args->signum;
430 
431 	tmp.pid = args->pid;
432 	return (kill(td, &tmp));
433 }
434