xref: /freebsd-src/sys/sys/signalvar.h (revision cbfe997563d24cdbfe77d1763f2582fbace3ee2f)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)signalvar.h	8.6 (Berkeley) 2/19/95
32  */
33 
34 #ifndef _SYS_SIGNALVAR_H_
35 #define	_SYS_SIGNALVAR_H_
36 
37 #include <sys/queue.h>
38 #include <sys/_lock.h>
39 #include <sys/_mutex.h>
40 #include <sys/signal.h>
41 
42 /*
43  * Kernel signal definitions and data structures.
44  */
45 
46 /*
47  * Logical process signal actions and state, needed only within the process
48  * The mapping between sigacts and proc structures is 1:1 except for rfork()
49  * processes masquerading as threads which use one structure for the whole
50  * group.  All members are locked by the included mutex.  The reference count
51  * and mutex must be last for the bcopy in sigacts_copy() to work.
52  */
53 struct sigacts {
54 	sig_t	ps_sigact[_SIG_MAXSIG];	/* Disposition of signals. */
55 	sigset_t ps_catchmask[_SIG_MAXSIG];	/* Signals to be blocked. */
56 	sigset_t ps_sigonstack;		/* Signals to take on sigstack. */
57 	sigset_t ps_sigintr;		/* Signals that interrupt syscalls. */
58 	sigset_t ps_sigreset;		/* Signals that reset when caught. */
59 	sigset_t ps_signodefer;		/* Signals not masked while handled. */
60 	sigset_t ps_siginfo;		/* Signals that want SA_SIGINFO args. */
61 	sigset_t ps_sigignore;		/* Signals being ignored. */
62 	sigset_t ps_sigcatch;		/* Signals being caught by user. */
63 	sigset_t ps_freebsd4;		/* Signals using freebsd4 ucontext. */
64 	sigset_t ps_osigset;		/* Signals using <= 3.x osigset_t. */
65 	sigset_t ps_usertramp;		/* SunOS compat; libc sigtramp. XXX */
66 	int	ps_flag;
67 	u_int	ps_refcnt;
68 	struct mtx ps_mtx;
69 };
70 
71 #define	PS_NOCLDWAIT	0x0001	/* No zombies if child dies */
72 #define	PS_NOCLDSTOP	0x0002	/* No SIGCHLD when children stop. */
73 #define	PS_CLDSIGIGN	0x0004	/* The SIGCHLD handler is SIG_IGN. */
74 
75 #ifdef _KERNEL
76 
77 #ifdef COMPAT_43
78 typedef struct {
79 	struct osigcontext si_sc;
80 	int		si_signo;
81 	int		si_code;
82 	union sigval	si_value;
83 } osiginfo_t;
84 
85 struct osigaction {
86 	union {
87 		void    (*__sa_handler)(int);
88 		void    (*__sa_sigaction)(int, osiginfo_t *, void *);
89 	} __sigaction_u;		/* signal handler */
90 	osigset_t	sa_mask;	/* signal mask to apply */
91 	int		sa_flags;	/* see signal options below */
92 };
93 
94 typedef void __osiginfohandler_t(int, osiginfo_t *, void *);
95 #endif /* COMPAT_43 */
96 
97 /* additional signal action values, used only temporarily/internally */
98 #define	SIG_CATCH	((__sighandler_t *)2)
99 /* #define SIG_HOLD        ((__sighandler_t *)3) See signal.h */
100 
101 /*
102  * get signal action for process and signal; currently only for current process
103  */
104 #define	SIGACTION(p, sig)	(p->p_sigacts->ps_sigact[_SIG_IDX(sig)])
105 
106 #endif /* _KERNEL */
107 
108 /*
109  * sigset_t manipulation macros.
110  */
111 #define	SIGADDSET(set, signo)						\
112 	((set).__bits[_SIG_WORD(signo)] |= _SIG_BIT(signo))
113 
114 #define	SIGDELSET(set, signo)						\
115 	((set).__bits[_SIG_WORD(signo)] &= ~_SIG_BIT(signo))
116 
117 #define	SIGEMPTYSET(set)						\
118 	do {								\
119 		int __i;						\
120 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
121 			(set).__bits[__i] = 0;				\
122 	} while (0)
123 
124 #define	SIGFILLSET(set)							\
125 	do {								\
126 		int __i;						\
127 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
128 			(set).__bits[__i] = ~0U;			\
129 	} while (0)
130 
131 #define	SIGISMEMBER(set, signo)						\
132 	((set).__bits[_SIG_WORD(signo)] & _SIG_BIT(signo))
133 
134 #define	SIGISEMPTY(set)		(__sigisempty(&(set)))
135 #define	SIGNOTEMPTY(set)	(!__sigisempty(&(set)))
136 
137 #define	SIGSETEQ(set1, set2)	(__sigseteq(&(set1), &(set2)))
138 #define	SIGSETNEQ(set1, set2)	(!__sigseteq(&(set1), &(set2)))
139 
140 #define	SIGSETOR(set1, set2)						\
141 	do {								\
142 		int __i;						\
143 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
144 			(set1).__bits[__i] |= (set2).__bits[__i];	\
145 	} while (0)
146 
147 #define	SIGSETAND(set1, set2)						\
148 	do {								\
149 		int __i;						\
150 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
151 			(set1).__bits[__i] &= (set2).__bits[__i];	\
152 	} while (0)
153 
154 #define	SIGSETNAND(set1, set2)						\
155 	do {								\
156 		int __i;						\
157 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
158 			(set1).__bits[__i] &= ~(set2).__bits[__i];	\
159 	} while (0)
160 
161 #define	SIGSETLO(set1, set2)	((set1).__bits[0] = (set2).__bits[0])
162 #define	SIGSETOLD(set, oset)	((set).__bits[0] = (oset))
163 
164 #define	SIG_CANTMASK(set)						\
165 	SIGDELSET(set, SIGKILL), SIGDELSET(set, SIGSTOP)
166 
167 #define	SIG_STOPSIGMASK(set)						\
168 	SIGDELSET(set, SIGSTOP), SIGDELSET(set, SIGTSTP),		\
169 	SIGDELSET(set, SIGTTIN), SIGDELSET(set, SIGTTOU)
170 
171 #define	SIG_CONTSIGMASK(set)						\
172 	SIGDELSET(set, SIGCONT)
173 
174 #define	sigcantmask	(sigmask(SIGKILL) | sigmask(SIGSTOP))
175 
176 #define	SIG2OSIG(sig, osig)	(osig = (sig).__bits[0])
177 #define	OSIG2SIG(osig, sig)	SIGEMPTYSET(sig); (sig).__bits[0] = osig
178 
179 static __inline int
180 __sigisempty(sigset_t *set)
181 {
182 	int i;
183 
184 	for (i = 0; i < _SIG_WORDS; i++) {
185 		if (set->__bits[i])
186 			return (0);
187 	}
188 	return (1);
189 }
190 
191 static __inline int
192 __sigseteq(sigset_t *set1, sigset_t *set2)
193 {
194 	int i;
195 
196 	for (i = 0; i < _SIG_WORDS; i++) {
197 		if (set1->__bits[i] != set2->__bits[i])
198 			return (0);
199 	}
200 	return (1);
201 }
202 
203 #ifdef COMPAT_FREEBSD6
204 struct osigevent {
205 	int	sigev_notify;		/* Notification type */
206 	union {
207 		int	__sigev_signo;	/* Signal number */
208 		int	__sigev_notify_kqueue;
209 	} __sigev_u;
210 	union sigval sigev_value;	/* Signal value */
211 };
212 #endif
213 
214 typedef struct ksiginfo {
215 	TAILQ_ENTRY(ksiginfo)	ksi_link;
216 	siginfo_t		ksi_info;
217 	int			ksi_flags;
218 	struct sigqueue		*ksi_sigq;
219 } ksiginfo_t;
220 
221 #define	ksi_signo	ksi_info.si_signo
222 #define	ksi_errno	ksi_info.si_errno
223 #define	ksi_code	ksi_info.si_code
224 #define	ksi_pid		ksi_info.si_pid
225 #define	ksi_uid		ksi_info.si_uid
226 #define	ksi_status      ksi_info.si_status
227 #define	ksi_addr        ksi_info.si_addr
228 #define	ksi_value	ksi_info.si_value
229 #define	ksi_band	ksi_info.si_band
230 #define	ksi_trapno	ksi_info.si_trapno
231 #define	ksi_overrun	ksi_info.si_overrun
232 #define	ksi_timerid	ksi_info.si_timerid
233 #define	ksi_mqd		ksi_info.si_mqd
234 
235 /* bits for ksi_flags */
236 #define	KSI_TRAP	0x01	/* Generated by trap. */
237 #define	KSI_EXT		0x02	/* Externally managed ksi. */
238 #define	KSI_INS		0x04	/* Directly insert ksi, not the copy */
239 #define	KSI_SIGQ	0x08	/* Generated by sigqueue, might ret EAGAIN. */
240 #define	KSI_HEAD	0x10	/* Insert into head, not tail. */
241 #define	KSI_PTRACE	0x20	/* Generated by ptrace. */
242 #define	KSI_COPYMASK	(KSI_TRAP | KSI_SIGQ | KSI_PTRACE)
243 
244 #define	KSI_ONQ(ksi)	((ksi)->ksi_sigq != NULL)
245 
246 typedef struct sigqueue {
247 	sigset_t	sq_signals;	/* All pending signals. */
248 	sigset_t	sq_kill;	/* Legacy depth 1 queue. */
249 	sigset_t	sq_ptrace;	/* Depth 1 queue for ptrace(2). */
250 	TAILQ_HEAD(, ksiginfo)	sq_list;/* Queued signal info. */
251 	struct proc	*sq_proc;
252 	int		sq_flags;
253 } sigqueue_t;
254 
255 /* Flags for ksi_flags */
256 #define	SQ_INIT	0x01
257 
258 /*
259  * Fast_sigblock
260  */
261 #define	SIGFASTBLOCK_SETPTR	1
262 #define	SIGFASTBLOCK_UNBLOCK	2
263 #define	SIGFASTBLOCK_UNSETPTR	3
264 
265 #define	SIGFASTBLOCK_PEND	0x1
266 #define	SIGFASTBLOCK_FLAGS	0xf
267 #define	SIGFASTBLOCK_INC	0x10
268 
269 #ifndef _KERNEL
270 int __sys_sigfastblock(int cmd, void *ptr);
271 #endif
272 
273 #ifdef _KERNEL
274 extern bool sigfastblock_fetch_always;
275 
276 /* Return nonzero if process p has an unmasked pending signal. */
277 #define	SIGPENDING(td)							\
278 	((!SIGISEMPTY((td)->td_siglist) &&				\
279 	    !sigsetmasked(&(td)->td_siglist, &(td)->td_sigmask)) ||	\
280 	 (!SIGISEMPTY((td)->td_proc->p_siglist) &&			\
281 	    !sigsetmasked(&(td)->td_proc->p_siglist, &(td)->td_sigmask)))
282 /*
283  * Return the value of the pseudo-expression ((*set & ~*mask) == 0).  This
284  * is an optimized version of SIGISEMPTY() on a temporary variable
285  * containing SIGSETNAND(*set, *mask).
286  */
287 static __inline bool
288 sigsetmasked(sigset_t *set, sigset_t *mask)
289 {
290 	int i;
291 
292 	for (i = 0; i < _SIG_WORDS; i++) {
293 		if (set->__bits[i] & ~mask->__bits[i])
294 			return (false);
295 	}
296 	return (true);
297 }
298 
299 #define	ksiginfo_init(ksi)			\
300 do {						\
301 	bzero(ksi, sizeof(ksiginfo_t));		\
302 } while (0)
303 
304 #define	ksiginfo_init_trap(ksi)			\
305 do {						\
306 	ksiginfo_t *kp = ksi;			\
307 	bzero(kp, sizeof(ksiginfo_t));		\
308 	kp->ksi_flags |= KSI_TRAP;		\
309 } while (0)
310 
311 static __inline void
312 ksiginfo_copy(ksiginfo_t *src, ksiginfo_t *dst)
313 {
314 	(dst)->ksi_info = src->ksi_info;
315 	(dst)->ksi_flags = (src->ksi_flags & KSI_COPYMASK);
316 }
317 
318 static __inline void
319 ksiginfo_set_sigev(ksiginfo_t *dst, struct sigevent *sigev)
320 {
321 	dst->ksi_signo = sigev->sigev_signo;
322 	dst->ksi_value = sigev->sigev_value;
323 }
324 
325 struct pgrp;
326 struct proc;
327 struct sigio;
328 struct thread;
329 
330 /*
331  * Lock the pointers for a sigio object in the underlying objects of
332  * a file descriptor.
333  */
334 #define	SIGIO_LOCK()	mtx_lock(&sigio_lock)
335 #define	SIGIO_TRYLOCK()	mtx_trylock(&sigio_lock)
336 #define	SIGIO_UNLOCK()	mtx_unlock(&sigio_lock)
337 #define	SIGIO_LOCKED()	mtx_owned(&sigio_lock)
338 #define	SIGIO_ASSERT_LOCKED() mtx_assert(&sigio_lock, MA_OWNED)
339 
340 extern struct mtx	sigio_lock;
341 
342 /* Flags for kern_sigprocmask(). */
343 #define	SIGPROCMASK_OLD		0x0001
344 #define	SIGPROCMASK_PROC_LOCKED	0x0002
345 #define	SIGPROCMASK_PS_LOCKED	0x0004
346 #define	SIGPROCMASK_FASTBLK	0x0008
347 
348 /*
349  * Modes for sigdeferstop().  Manages behaviour of
350  * thread_suspend_check() in the region delimited by
351  * sigdeferstop()/sigallowstop().  Must be restored to
352  * SIGDEFERSTOP_OFF before returning to userspace.
353  */
354 #define	SIGDEFERSTOP_NOP	0 /* continue doing whatever is done now */
355 #define	SIGDEFERSTOP_OFF	1 /* stop ignoring STOPs */
356 #define	SIGDEFERSTOP_SILENT	2 /* silently ignore STOPs */
357 #define	SIGDEFERSTOP_EINTR	3 /* ignore STOPs, return EINTR */
358 #define	SIGDEFERSTOP_ERESTART	4 /* ignore STOPs, return ERESTART */
359 
360 #define	SIGDEFERSTOP_VAL_NCHG	(-1) /* placeholder indicating no state change */
361 int	sigdeferstop_impl(int mode);
362 void	sigallowstop_impl(int prev);
363 
364 static inline int
365 sigdeferstop(int mode)
366 {
367 
368 	if (__predict_false(mode == SIGDEFERSTOP_NOP))
369 		return (SIGDEFERSTOP_VAL_NCHG);
370 	return (sigdeferstop_impl(mode));
371 }
372 
373 static inline void
374 sigallowstop(int prev)
375 {
376 
377 	if (__predict_true(prev == SIGDEFERSTOP_VAL_NCHG))
378 		return;
379 	sigallowstop_impl(prev);
380 }
381 
382 int	cursig(struct thread *td);
383 void	execsigs(struct proc *p);
384 void	killproc(struct proc *p, const char *why);
385 ksiginfo_t *ksiginfo_alloc(int mwait);
386 void	ksiginfo_free(ksiginfo_t *ksi);
387 int	pksignal(struct proc *p, int sig, ksiginfo_t *ksi);
388 void	pgsigio(struct sigio **sigiop, int sig, int checkctty);
389 void	pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi);
390 int	postsig(int sig);
391 void	kern_psignal(struct proc *p, int sig);
392 int	ptracestop(struct thread *td, int sig, ksiginfo_t *si);
393 void	sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *retmask);
394 struct sigacts *sigacts_alloc(void);
395 void	sigacts_copy(struct sigacts *dest, struct sigacts *src);
396 void	sigacts_free(struct sigacts *ps);
397 struct sigacts *sigacts_hold(struct sigacts *ps);
398 int	sigacts_shared(struct sigacts *ps);
399 int	sig_ast_checksusp(struct thread *td);
400 int	sig_ast_needsigchk(struct thread *td);
401 void	sig_drop_caught(struct proc *p);
402 void	sigexit(struct thread *td, int sig) __dead2;
403 int	sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **);
404 void	sigfastblock_clear(struct thread *td);
405 void	sigfastblock_fetch(struct thread *td);
406 int	sig_intr(void);
407 void	siginit(struct proc *p);
408 void	signotify(struct thread *td);
409 void	sigqueue_delete(struct sigqueue *queue, int sig);
410 void	sigqueue_delete_proc(struct proc *p, int sig);
411 void	sigqueue_flush(struct sigqueue *queue);
412 void	sigqueue_init(struct sigqueue *queue, struct proc *p);
413 void	sigqueue_take(ksiginfo_t *ksi);
414 void	tdksignal(struct thread *td, int sig, ksiginfo_t *ksi);
415 int	tdsendsignal(struct proc *p, struct thread *td, int sig,
416 	   ksiginfo_t *ksi);
417 void	tdsigcleanup(struct thread *td);
418 void	tdsignal(struct thread *td, int sig);
419 void	trapsignal(struct thread *td, ksiginfo_t *ksi);
420 
421 #endif /* _KERNEL */
422 
423 #endif /* !_SYS_SIGNALVAR_H_ */
424