xref: /freebsd/sys/compat/linux/linux_signal.c (revision 74bf4e164ba5851606a27d4feff27717452583e5) 
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 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/proc.h>
37 #include <sys/signalvar.h>
38 #include <sys/syscallsubr.h>
39 #include <sys/sysproto.h>
40 
41 #include "opt_compat.h"
42 
43 #if !COMPAT_LINUX32
44 #include <machine/../linux/linux.h>
45 #include <machine/../linux/linux_proto.h>
46 #else
47 #include <machine/../linux32/linux.h>
48 #include <machine/../linux32/linux32_proto.h>
49 #endif
50 #include <compat/linux/linux_signal.h>
51 #include <compat/linux/linux_util.h>
52 
53 void
54 linux_to_bsd_sigset(l_sigset_t *lss, sigset_t *bss)
55 {
56 	int b, l;
57 
58 	SIGEMPTYSET(*bss);
59 	bss->__bits[0] = lss->__bits[0] & ~((1U << LINUX_SIGTBLSZ) - 1);
60 	bss->__bits[1] = lss->__bits[1];
61 	for (l = 1; l <= LINUX_SIGTBLSZ; l++) {
62 		if (LINUX_SIGISMEMBER(*lss, l)) {
63 #ifdef __alpha__
64 			b = _SIG_IDX(l);
65 #else
66 			b = linux_to_bsd_signal[_SIG_IDX(l)];
67 #endif
68 			if (b)
69 				SIGADDSET(*bss, b);
70 		}
71 	}
72 }
73 
74 void
75 bsd_to_linux_sigset(sigset_t *bss, l_sigset_t *lss)
76 {
77 	int b, l;
78 
79 	LINUX_SIGEMPTYSET(*lss);
80 	lss->__bits[0] = bss->__bits[0] & ~((1U << LINUX_SIGTBLSZ) - 1);
81 	lss->__bits[1] = bss->__bits[1];
82 	for (b = 1; b <= LINUX_SIGTBLSZ; b++) {
83 		if (SIGISMEMBER(*bss, b)) {
84 #if __alpha__
85 			l = _SIG_IDX(b);
86 #else
87 			l = bsd_to_linux_signal[_SIG_IDX(b)];
88 #endif
89 			if (l)
90 				LINUX_SIGADDSET(*lss, l);
91 		}
92 	}
93 }
94 
95 static void
96 linux_to_bsd_sigaction(l_sigaction_t *lsa, struct sigaction *bsa)
97 {
98 
99 	linux_to_bsd_sigset(&lsa->lsa_mask, &bsa->sa_mask);
100 	bsa->sa_handler = PTRIN(lsa->lsa_handler);
101 	bsa->sa_flags = 0;
102 	if (lsa->lsa_flags & LINUX_SA_NOCLDSTOP)
103 		bsa->sa_flags |= SA_NOCLDSTOP;
104 	if (lsa->lsa_flags & LINUX_SA_NOCLDWAIT)
105 		bsa->sa_flags |= SA_NOCLDWAIT;
106 	if (lsa->lsa_flags & LINUX_SA_SIGINFO)
107 		bsa->sa_flags |= SA_SIGINFO;
108 	if (lsa->lsa_flags & LINUX_SA_ONSTACK)
109 		bsa->sa_flags |= SA_ONSTACK;
110 	if (lsa->lsa_flags & LINUX_SA_RESTART)
111 		bsa->sa_flags |= SA_RESTART;
112 	if (lsa->lsa_flags & LINUX_SA_ONESHOT)
113 		bsa->sa_flags |= SA_RESETHAND;
114 	if (lsa->lsa_flags & LINUX_SA_NOMASK)
115 		bsa->sa_flags |= SA_NODEFER;
116 }
117 
118 static void
119 bsd_to_linux_sigaction(struct sigaction *bsa, l_sigaction_t *lsa)
120 {
121 
122 	bsd_to_linux_sigset(&bsa->sa_mask, &lsa->lsa_mask);
123 #if COMPAT_LINUX32
124 	lsa->lsa_handler = (uintptr_t)bsa->sa_handler;
125 #else
126 	lsa->lsa_handler = bsa->sa_handler;
127 #endif
128 	lsa->lsa_restorer = 0;		/* unsupported */
129 	lsa->lsa_flags = 0;
130 	if (bsa->sa_flags & SA_NOCLDSTOP)
131 		lsa->lsa_flags |= LINUX_SA_NOCLDSTOP;
132 	if (bsa->sa_flags & SA_NOCLDWAIT)
133 		lsa->lsa_flags |= LINUX_SA_NOCLDWAIT;
134 	if (bsa->sa_flags & SA_SIGINFO)
135 		lsa->lsa_flags |= LINUX_SA_SIGINFO;
136 	if (bsa->sa_flags & SA_ONSTACK)
137 		lsa->lsa_flags |= LINUX_SA_ONSTACK;
138 	if (bsa->sa_flags & SA_RESTART)
139 		lsa->lsa_flags |= LINUX_SA_RESTART;
140 	if (bsa->sa_flags & SA_RESETHAND)
141 		lsa->lsa_flags |= LINUX_SA_ONESHOT;
142 	if (bsa->sa_flags & SA_NODEFER)
143 		lsa->lsa_flags |= LINUX_SA_NOMASK;
144 }
145 
146 int
147 linux_do_sigaction(struct thread *td, int linux_sig, l_sigaction_t *linux_nsa,
148 		   l_sigaction_t *linux_osa)
149 {
150 	struct sigaction act, oact, *nsa, *osa;
151 	int error, sig;
152 
153 	if (linux_sig <= 0 || linux_sig > LINUX_NSIG)
154 		return (EINVAL);
155 
156 	osa = (linux_osa != NULL) ? &oact : NULL;
157 	if (linux_nsa != NULL) {
158 		nsa = &act;
159 		linux_to_bsd_sigaction(linux_nsa, nsa);
160 	} else
161 		nsa = NULL;
162 
163 #ifndef __alpha__
164 	if (linux_sig <= LINUX_SIGTBLSZ)
165 		sig = linux_to_bsd_signal[_SIG_IDX(linux_sig)];
166 	else
167 #endif
168 		sig = linux_sig;
169 
170 	error = kern_sigaction(td, sig, nsa, osa, 0);
171 	if (error)
172 		return (error);
173 
174 	if (linux_osa != NULL)
175 		bsd_to_linux_sigaction(osa, linux_osa);
176 
177 	return (0);
178 }
179 
180 
181 #ifndef __alpha__
182 int
183 linux_signal(struct thread *td, struct linux_signal_args *args)
184 {
185 	l_sigaction_t nsa, osa;
186 	int error;
187 
188 #ifdef DEBUG
189 	if (ldebug(signal))
190 		printf(ARGS(signal, "%d, %p"),
191 		    args->sig, (void *)(uintptr_t)args->handler);
192 #endif
193 
194 	nsa.lsa_handler = args->handler;
195 	nsa.lsa_flags = LINUX_SA_ONESHOT | LINUX_SA_NOMASK;
196 	LINUX_SIGEMPTYSET(nsa.lsa_mask);
197 
198 	error = linux_do_sigaction(td, args->sig, &nsa, &osa);
199 	td->td_retval[0] = (int)(intptr_t)osa.lsa_handler;
200 
201 	return (error);
202 }
203 #endif	/*!__alpha__*/
204 
205 int
206 linux_rt_sigaction(struct thread *td, struct linux_rt_sigaction_args *args)
207 {
208 	l_sigaction_t nsa, osa;
209 	int error;
210 
211 #ifdef DEBUG
212 	if (ldebug(rt_sigaction))
213 		printf(ARGS(rt_sigaction, "%ld, %p, %p, %ld"),
214 		    (long)args->sig, (void *)args->act,
215 		    (void *)args->oact, (long)args->sigsetsize);
216 #endif
217 
218 	if (args->sigsetsize != sizeof(l_sigset_t))
219 		return (EINVAL);
220 
221 	if (args->act != NULL) {
222 		error = copyin(args->act, &nsa, sizeof(l_sigaction_t));
223 		if (error)
224 			return (error);
225 	}
226 
227 	error = linux_do_sigaction(td, args->sig,
228 				   args->act ? &nsa : NULL,
229 				   args->oact ? &osa : NULL);
230 
231 	if (args->oact != NULL && !error) {
232 		error = copyout(&osa, args->oact, sizeof(l_sigaction_t));
233 	}
234 
235 	return (error);
236 }
237 
238 static int
239 linux_do_sigprocmask(struct thread *td, int how, l_sigset_t *new,
240 		     l_sigset_t *old)
241 {
242 	sigset_t omask, nmask;
243 	sigset_t *nmaskp;
244 	int error;
245 
246 	td->td_retval[0] = 0;
247 
248 	switch (how) {
249 	case LINUX_SIG_BLOCK:
250 		how = SIG_BLOCK;
251 		break;
252 	case LINUX_SIG_UNBLOCK:
253 		how = SIG_UNBLOCK;
254 		break;
255 	case LINUX_SIG_SETMASK:
256 		how = SIG_SETMASK;
257 		break;
258 	default:
259 		return (EINVAL);
260 	}
261 	if (new != NULL) {
262 		linux_to_bsd_sigset(new, &nmask);
263 		nmaskp = &nmask;
264 	} else
265 		nmaskp = NULL;
266 	error = kern_sigprocmask(td, how, nmaskp, &omask, 0);
267 	if (error == 0 && old != NULL)
268 		bsd_to_linux_sigset(&omask, old);
269 
270 	return (error);
271 }
272 
273 #ifndef __alpha__
274 int
275 linux_sigprocmask(struct thread *td, struct linux_sigprocmask_args *args)
276 {
277 	l_osigset_t mask;
278 	l_sigset_t set, oset;
279 	int error;
280 
281 #ifdef DEBUG
282 	if (ldebug(sigprocmask))
283 		printf(ARGS(sigprocmask, "%d, *, *"), args->how);
284 #endif
285 
286 	if (args->mask != NULL) {
287 		error = copyin(args->mask, &mask, sizeof(l_osigset_t));
288 		if (error)
289 			return (error);
290 		LINUX_SIGEMPTYSET(set);
291 		set.__bits[0] = mask;
292 	}
293 
294 	error = linux_do_sigprocmask(td, args->how,
295 				     args->mask ? &set : NULL,
296 				     args->omask ? &oset : NULL);
297 
298 	if (args->omask != NULL && !error) {
299 		mask = oset.__bits[0];
300 		error = copyout(&mask, args->omask, sizeof(l_osigset_t));
301 	}
302 
303 	return (error);
304 }
305 #endif	/*!__alpha__*/
306 
307 int
308 linux_rt_sigprocmask(struct thread *td, struct linux_rt_sigprocmask_args *args)
309 {
310 	l_sigset_t set, oset;
311 	int error;
312 
313 #ifdef DEBUG
314 	if (ldebug(rt_sigprocmask))
315 		printf(ARGS(rt_sigprocmask, "%d, %p, %p, %ld"),
316 		    args->how, (void *)args->mask,
317 		    (void *)args->omask, (long)args->sigsetsize);
318 #endif
319 
320 	if (args->sigsetsize != sizeof(l_sigset_t))
321 		return EINVAL;
322 
323 	if (args->mask != NULL) {
324 		error = copyin(args->mask, &set, sizeof(l_sigset_t));
325 		if (error)
326 			return (error);
327 	}
328 
329 	error = linux_do_sigprocmask(td, args->how,
330 				     args->mask ? &set : NULL,
331 				     args->omask ? &oset : NULL);
332 
333 	if (args->omask != NULL && !error) {
334 		error = copyout(&oset, args->omask, sizeof(l_sigset_t));
335 	}
336 
337 	return (error);
338 }
339 
340 #ifndef __alpha__
341 int
342 linux_sgetmask(struct thread *td, struct linux_sgetmask_args *args)
343 {
344 	struct proc *p = td->td_proc;
345 	l_sigset_t mask;
346 
347 #ifdef DEBUG
348 	if (ldebug(sgetmask))
349 		printf(ARGS(sgetmask, ""));
350 #endif
351 
352 	PROC_LOCK(p);
353 	bsd_to_linux_sigset(&td->td_sigmask, &mask);
354 	PROC_UNLOCK(p);
355 	td->td_retval[0] = mask.__bits[0];
356 	return (0);
357 }
358 
359 int
360 linux_ssetmask(struct thread *td, struct linux_ssetmask_args *args)
361 {
362 	struct proc *p = td->td_proc;
363 	l_sigset_t lset;
364 	sigset_t bset;
365 
366 #ifdef DEBUG
367 	if (ldebug(ssetmask))
368 		printf(ARGS(ssetmask, "%08lx"), (unsigned long)args->mask);
369 #endif
370 
371 	PROC_LOCK(p);
372 	bsd_to_linux_sigset(&td->td_sigmask, &lset);
373 	td->td_retval[0] = lset.__bits[0];
374 	LINUX_SIGEMPTYSET(lset);
375 	lset.__bits[0] = args->mask;
376 	linux_to_bsd_sigset(&lset, &bset);
377 	td->td_sigmask = bset;
378 	SIG_CANTMASK(td->td_sigmask);
379 	signotify(td);
380 	PROC_UNLOCK(p);
381 	return (0);
382 }
383 
384 /*
385  * MPSAFE
386  */
387 int
388 linux_sigpending(struct thread *td, struct linux_sigpending_args *args)
389 {
390 	struct proc *p = td->td_proc;
391 	sigset_t bset;
392 	l_sigset_t lset;
393 	l_osigset_t mask;
394 
395 #ifdef DEBUG
396 	if (ldebug(sigpending))
397 		printf(ARGS(sigpending, "*"));
398 #endif
399 
400 	PROC_LOCK(p);
401 	bset = p->p_siglist;
402 	SIGSETOR(bset, td->td_siglist);
403 	SIGSETAND(bset, td->td_sigmask);
404 	PROC_UNLOCK(p);
405 	bsd_to_linux_sigset(&bset, &lset);
406 	mask = lset.__bits[0];
407 	return (copyout(&mask, args->mask, sizeof(mask)));
408 }
409 #endif	/*!__alpha__*/
410 
411 int
412 linux_kill(struct thread *td, struct linux_kill_args *args)
413 {
414 	struct kill_args /* {
415 	    int pid;
416 	    int signum;
417 	} */ tmp;
418 
419 #ifdef DEBUG
420 	if (ldebug(kill))
421 		printf(ARGS(kill, "%d, %d"), args->pid, args->signum);
422 #endif
423 
424 	/*
425 	 * Allow signal 0 as a means to check for privileges
426 	 */
427 	if (args->signum < 0 || args->signum > LINUX_NSIG)
428 		return EINVAL;
429 
430 #ifndef __alpha__
431 	if (args->signum > 0 && args->signum <= LINUX_SIGTBLSZ)
432 		tmp.signum = linux_to_bsd_signal[_SIG_IDX(args->signum)];
433 	else
434 #endif
435 		tmp.signum = args->signum;
436 
437 	tmp.pid = args->pid;
438 	return (kill(td, &tmp));
439 }
440