xref: /freebsd/sys/sys/signalvar.h (revision d93a896e)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  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  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)signalvar.h	8.6 (Berkeley) 2/19/95
30  * $FreeBSD$
31  */
32 
33 #ifndef _SYS_SIGNALVAR_H_
34 #define	_SYS_SIGNALVAR_H_
35 
36 #include <sys/queue.h>
37 #include <sys/_lock.h>
38 #include <sys/_mutex.h>
39 #include <sys/signal.h>
40 
41 /*
42  * Kernel signal definitions and data structures.
43  */
44 
45 /*
46  * Logical process signal actions and state, needed only within the process
47  * The mapping between sigacts and proc structures is 1:1 except for rfork()
48  * processes masquerading as threads which use one structure for the whole
49  * group.  All members are locked by the included mutex.  The reference count
50  * and mutex must be last for the bcopy in sigacts_copy() to work.
51  */
52 struct sigacts {
53 	sig_t	ps_sigact[_SIG_MAXSIG];	/* Disposition of signals. */
54 	sigset_t ps_catchmask[_SIG_MAXSIG];	/* Signals to be blocked. */
55 	sigset_t ps_sigonstack;		/* Signals to take on sigstack. */
56 	sigset_t ps_sigintr;		/* Signals that interrupt syscalls. */
57 	sigset_t ps_sigreset;		/* Signals that reset when caught. */
58 	sigset_t ps_signodefer;		/* Signals not masked while handled. */
59 	sigset_t ps_siginfo;		/* Signals that want SA_SIGINFO args. */
60 	sigset_t ps_sigignore;		/* Signals being ignored. */
61 	sigset_t ps_sigcatch;		/* Signals being caught by user. */
62 	sigset_t ps_freebsd4;		/* Signals using freebsd4 ucontext. */
63 	sigset_t ps_osigset;		/* Signals using <= 3.x osigset_t. */
64 	sigset_t ps_usertramp;		/* SunOS compat; libc sigtramp. XXX */
65 	int	ps_flag;
66 	u_int	ps_refcnt;
67 	struct mtx ps_mtx;
68 };
69 
70 #define	PS_NOCLDWAIT	0x0001	/* No zombies if child dies */
71 #define	PS_NOCLDSTOP	0x0002	/* No SIGCHLD when children stop. */
72 #define	PS_CLDSIGIGN	0x0004	/* The SIGCHLD handler is SIG_IGN. */
73 
74 #ifdef _KERNEL
75 
76 #ifdef COMPAT_43
77 typedef struct {
78 	struct osigcontext si_sc;
79 	int		si_signo;
80 	int		si_code;
81 	union sigval	si_value;
82 } osiginfo_t;
83 
84 struct osigaction {
85 	union {
86 		void    (*__sa_handler)(int);
87 		void    (*__sa_sigaction)(int, osiginfo_t *, void *);
88 	} __sigaction_u;		/* signal handler */
89 	osigset_t	sa_mask;	/* signal mask to apply */
90 	int		sa_flags;	/* see signal options below */
91 };
92 
93 typedef void __osiginfohandler_t(int, osiginfo_t *, void *);
94 #endif /* COMPAT_43 */
95 
96 /* additional signal action values, used only temporarily/internally */
97 #define	SIG_CATCH	((__sighandler_t *)2)
98 /* #define SIG_HOLD        ((__sighandler_t *)3) See signal.h */
99 
100 /*
101  * get signal action for process and signal; currently only for current process
102  */
103 #define	SIGACTION(p, sig)	(p->p_sigacts->ps_sigact[_SIG_IDX(sig)])
104 
105 #endif /* _KERNEL */
106 
107 /*
108  * sigset_t manipulation macros.
109  */
110 #define	SIGADDSET(set, signo)						\
111 	((set).__bits[_SIG_WORD(signo)] |= _SIG_BIT(signo))
112 
113 #define	SIGDELSET(set, signo)						\
114 	((set).__bits[_SIG_WORD(signo)] &= ~_SIG_BIT(signo))
115 
116 #define	SIGEMPTYSET(set)						\
117 	do {								\
118 		int __i;						\
119 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
120 			(set).__bits[__i] = 0;				\
121 	} while (0)
122 
123 #define	SIGFILLSET(set)							\
124 	do {								\
125 		int __i;						\
126 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
127 			(set).__bits[__i] = ~0U;			\
128 	} while (0)
129 
130 #define	SIGISMEMBER(set, signo)						\
131 	((set).__bits[_SIG_WORD(signo)] & _SIG_BIT(signo))
132 
133 #define	SIGISEMPTY(set)		(__sigisempty(&(set)))
134 #define	SIGNOTEMPTY(set)	(!__sigisempty(&(set)))
135 
136 #define	SIGSETEQ(set1, set2)	(__sigseteq(&(set1), &(set2)))
137 #define	SIGSETNEQ(set1, set2)	(!__sigseteq(&(set1), &(set2)))
138 
139 #define	SIGSETOR(set1, set2)						\
140 	do {								\
141 		int __i;						\
142 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
143 			(set1).__bits[__i] |= (set2).__bits[__i];	\
144 	} while (0)
145 
146 #define	SIGSETAND(set1, set2)						\
147 	do {								\
148 		int __i;						\
149 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
150 			(set1).__bits[__i] &= (set2).__bits[__i];	\
151 	} while (0)
152 
153 #define	SIGSETNAND(set1, set2)						\
154 	do {								\
155 		int __i;						\
156 		for (__i = 0; __i < _SIG_WORDS; __i++)			\
157 			(set1).__bits[__i] &= ~(set2).__bits[__i];	\
158 	} while (0)
159 
160 #define	SIGSETLO(set1, set2)	((set1).__bits[0] = (set2).__bits[0])
161 #define	SIGSETOLD(set, oset)	((set).__bits[0] = (oset))
162 
163 #define	SIG_CANTMASK(set)						\
164 	SIGDELSET(set, SIGKILL), SIGDELSET(set, SIGSTOP)
165 
166 #define	SIG_STOPSIGMASK(set)						\
167 	SIGDELSET(set, SIGSTOP), SIGDELSET(set, SIGTSTP),		\
168 	SIGDELSET(set, SIGTTIN), SIGDELSET(set, SIGTTOU)
169 
170 #define	SIG_CONTSIGMASK(set)						\
171 	SIGDELSET(set, SIGCONT)
172 
173 #define	sigcantmask	(sigmask(SIGKILL) | sigmask(SIGSTOP))
174 
175 #define	SIG2OSIG(sig, osig)	(osig = (sig).__bits[0])
176 #define	OSIG2SIG(osig, sig)	SIGEMPTYSET(sig); (sig).__bits[0] = osig
177 
178 static __inline int
179 __sigisempty(sigset_t *set)
180 {
181 	int i;
182 
183 	for (i = 0; i < _SIG_WORDS; i++) {
184 		if (set->__bits[i])
185 			return (0);
186 	}
187 	return (1);
188 }
189 
190 static __inline int
191 __sigseteq(sigset_t *set1, sigset_t *set2)
192 {
193 	int i;
194 
195 	for (i = 0; i < _SIG_WORDS; i++) {
196 		if (set1->__bits[i] != set2->__bits[i])
197 			return (0);
198 	}
199 	return (1);
200 }
201 
202 #ifdef COMPAT_FREEBSD6
203 struct osigevent {
204 	int	sigev_notify;		/* Notification type */
205 	union {
206 		int	__sigev_signo;	/* Signal number */
207 		int	__sigev_notify_kqueue;
208 	} __sigev_u;
209 	union sigval sigev_value;	/* Signal value */
210 };
211 #endif
212 
213 typedef struct ksiginfo {
214 	TAILQ_ENTRY(ksiginfo)	ksi_link;
215 	siginfo_t		ksi_info;
216 	int			ksi_flags;
217 	struct sigqueue		*ksi_sigq;
218 } ksiginfo_t;
219 
220 #define	ksi_signo	ksi_info.si_signo
221 #define	ksi_errno	ksi_info.si_errno
222 #define	ksi_code	ksi_info.si_code
223 #define	ksi_pid		ksi_info.si_pid
224 #define	ksi_uid		ksi_info.si_uid
225 #define	ksi_status      ksi_info.si_status
226 #define	ksi_addr        ksi_info.si_addr
227 #define	ksi_value	ksi_info.si_value
228 #define	ksi_band	ksi_info.si_band
229 #define	ksi_trapno	ksi_info.si_trapno
230 #define	ksi_overrun	ksi_info.si_overrun
231 #define	ksi_timerid	ksi_info.si_timerid
232 #define	ksi_mqd		ksi_info.si_mqd
233 
234 /* bits for ksi_flags */
235 #define	KSI_TRAP	0x01	/* Generated by trap. */
236 #define	KSI_EXT		0x02	/* Externally managed ksi. */
237 #define	KSI_INS		0x04	/* Directly insert ksi, not the copy */
238 #define	KSI_SIGQ	0x08	/* Generated by sigqueue, might ret EAGAIN. */
239 #define	KSI_HEAD	0x10	/* Insert into head, not tail. */
240 #define	KSI_PTRACE	0x20	/* Generated by ptrace. */
241 #define	KSI_COPYMASK	(KSI_TRAP | KSI_SIGQ | KSI_PTRACE)
242 
243 #define	KSI_ONQ(ksi)	((ksi)->ksi_sigq != NULL)
244 
245 typedef struct sigqueue {
246 	sigset_t	sq_signals;	/* All pending signals. */
247 	sigset_t	sq_kill;	/* Legacy depth 1 queue. */
248 	sigset_t	sq_ptrace;	/* Depth 1 queue for ptrace(2). */
249 	TAILQ_HEAD(, ksiginfo)	sq_list;/* Queued signal info. */
250 	struct proc	*sq_proc;
251 	int		sq_flags;
252 } sigqueue_t;
253 
254 /* Flags for ksi_flags */
255 #define	SQ_INIT	0x01
256 
257 #ifdef _KERNEL
258 
259 /* Return nonzero if process p has an unmasked pending signal. */
260 #define	SIGPENDING(td)							\
261 	((!SIGISEMPTY((td)->td_siglist) &&				\
262 	    !sigsetmasked(&(td)->td_siglist, &(td)->td_sigmask)) ||	\
263 	 (!SIGISEMPTY((td)->td_proc->p_siglist) &&			\
264 	    !sigsetmasked(&(td)->td_proc->p_siglist, &(td)->td_sigmask)))
265 /*
266  * Return the value of the pseudo-expression ((*set & ~*mask) != 0).  This
267  * is an optimized version of SIGISEMPTY() on a temporary variable
268  * containing SIGSETNAND(*set, *mask).
269  */
270 static __inline int
271 sigsetmasked(sigset_t *set, sigset_t *mask)
272 {
273 	int i;
274 
275 	for (i = 0; i < _SIG_WORDS; i++) {
276 		if (set->__bits[i] & ~mask->__bits[i])
277 			return (0);
278 	}
279 	return (1);
280 }
281 
282 #define	ksiginfo_init(ksi)			\
283 do {						\
284 	bzero(ksi, sizeof(ksiginfo_t));		\
285 } while(0)
286 
287 #define	ksiginfo_init_trap(ksi)			\
288 do {						\
289 	ksiginfo_t *kp = ksi;			\
290 	bzero(kp, sizeof(ksiginfo_t));		\
291 	kp->ksi_flags |= KSI_TRAP;		\
292 } while(0)
293 
294 static __inline void
295 ksiginfo_copy(ksiginfo_t *src, ksiginfo_t *dst)
296 {
297 	(dst)->ksi_info = src->ksi_info;
298 	(dst)->ksi_flags = (src->ksi_flags & KSI_COPYMASK);
299 }
300 
301 static __inline void
302 ksiginfo_set_sigev(ksiginfo_t *dst, struct sigevent *sigev)
303 {
304 	dst->ksi_signo = sigev->sigev_signo;
305 	dst->ksi_value = sigev->sigev_value;
306 }
307 
308 struct pgrp;
309 struct proc;
310 struct sigio;
311 struct thread;
312 
313 /*
314  * Lock the pointers for a sigio object in the underlying objects of
315  * a file descriptor.
316  */
317 #define	SIGIO_LOCK()	mtx_lock(&sigio_lock)
318 #define	SIGIO_TRYLOCK()	mtx_trylock(&sigio_lock)
319 #define	SIGIO_UNLOCK()	mtx_unlock(&sigio_lock)
320 #define	SIGIO_LOCKED()	mtx_owned(&sigio_lock)
321 #define	SIGIO_ASSERT(type)	mtx_assert(&sigio_lock, type)
322 
323 extern struct mtx	sigio_lock;
324 
325 /* Flags for kern_sigprocmask(). */
326 #define	SIGPROCMASK_OLD		0x0001
327 #define	SIGPROCMASK_PROC_LOCKED	0x0002
328 #define	SIGPROCMASK_PS_LOCKED	0x0004
329 
330 /*
331  * Modes for sigdeferstop().  Manages behaviour of
332  * thread_suspend_check() in the region delimited by
333  * sigdeferstop()/sigallowstop().  Must be restored to
334  * SIGDEFERSTOP_OFF before returning to userspace.
335  */
336 #define	SIGDEFERSTOP_NOP	0 /* continue doing whatever is done now */
337 #define	SIGDEFERSTOP_OFF	1 /* stop ignoring STOPs */
338 #define	SIGDEFERSTOP_SILENT	2 /* silently ignore STOPs */
339 #define	SIGDEFERSTOP_EINTR	3 /* ignore STOPs, return EINTR */
340 #define	SIGDEFERSTOP_ERESTART	4 /* ignore STOPs, return ERESTART */
341 
342 #define	SIGDEFERSTOP_VAL_NCHG	(-1) /* placeholder indicating no state change */
343 int	sigdeferstop_impl(int mode);
344 void	sigallowstop_impl(int prev);
345 
346 static inline int
347 sigdeferstop(int mode)
348 {
349 
350 	if (mode == SIGDEFERSTOP_NOP)
351 		return (SIGDEFERSTOP_VAL_NCHG);
352 	return (sigdeferstop_impl(mode));
353 }
354 
355 static inline void
356 sigallowstop(int prev)
357 {
358 
359 	if (prev == SIGDEFERSTOP_VAL_NCHG)
360 		return;
361 	sigallowstop_impl(prev);
362 }
363 
364 int	cursig(struct thread *td);
365 void	execsigs(struct proc *p);
366 void	gsignal(int pgid, int sig, ksiginfo_t *ksi);
367 void	killproc(struct proc *p, char *why);
368 ksiginfo_t * ksiginfo_alloc(int wait);
369 void	ksiginfo_free(ksiginfo_t *ksi);
370 int	pksignal(struct proc *p, int sig, ksiginfo_t *ksi);
371 void	pgsigio(struct sigio **sigiop, int sig, int checkctty);
372 void	pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi);
373 int	postsig(int sig);
374 void	kern_psignal(struct proc *p, int sig);
375 int	ptracestop(struct thread *td, int sig, ksiginfo_t *si);
376 void	sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *retmask);
377 struct sigacts *sigacts_alloc(void);
378 void	sigacts_copy(struct sigacts *dest, struct sigacts *src);
379 void	sigacts_free(struct sigacts *ps);
380 struct sigacts *sigacts_hold(struct sigacts *ps);
381 int	sigacts_shared(struct sigacts *ps);
382 void	sigexit(struct thread *td, int sig) __dead2;
383 int	sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **);
384 int	sig_ffs(sigset_t *set);
385 void	siginit(struct proc *p);
386 void	signotify(struct thread *td);
387 void	sigqueue_delete(struct sigqueue *queue, int sig);
388 void	sigqueue_delete_proc(struct proc *p, int sig);
389 void	sigqueue_flush(struct sigqueue *queue);
390 void	sigqueue_init(struct sigqueue *queue, struct proc *p);
391 void	sigqueue_take(ksiginfo_t *ksi);
392 void	tdksignal(struct thread *td, int sig, ksiginfo_t *ksi);
393 int	tdsendsignal(struct proc *p, struct thread *td, int sig,
394 	   ksiginfo_t *ksi);
395 void	tdsigcleanup(struct thread *td);
396 void	tdsignal(struct thread *td, int sig);
397 void	trapsignal(struct thread *td, ksiginfo_t *ksi);
398 
399 #endif /* _KERNEL */
400 
401 #endif /* !_SYS_SIGNALVAR_H_ */
402