xref: /freebsd-src/sys/sys/signalvar.h (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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  * 4. 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  * not exported to user programs.
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 	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 #if defined(_KERNEL) && defined(COMPAT_43)
76 /*
77  * Compatibility.
78  */
79 typedef struct {
80 	struct osigcontext si_sc;
81 	int		si_signo;
82 	int		si_code;
83 	union sigval	si_value;
84 } osiginfo_t;
85 
86 struct osigaction {
87 	union {
88 		void    (*__sa_handler)(int);
89 		void    (*__sa_sigaction)(int, osiginfo_t *, void *);
90 	} __sigaction_u;		/* signal handler */
91 	osigset_t	sa_mask;	/* signal mask to apply */
92 	int		sa_flags;	/* see signal options below */
93 };
94 
95 typedef void __osiginfohandler_t(int, osiginfo_t *, void *);
96 #endif /* _KERNEL && COMPAT_43 */
97 
98 /* additional signal action values, used only temporarily/internally */
99 #define	SIG_CATCH	((__sighandler_t *)2)
100 #define SIG_HOLD        ((__sighandler_t *)3)
101 
102 /*
103  * get signal action for process and signal; currently only for current process
104  */
105 #define SIGACTION(p, sig)	(p->p_sigacts->ps_sigact[_SIG_IDX(sig)])
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 struct osigevent {
203 	int	sigev_notify;		/* Notification type */
204 	union {
205 		int	__sigev_signo;	/* Signal number */
206 		int	__sigev_notify_kqueue;
207 	} __sigev_u;
208 	union sigval sigev_value;	/* Signal value */
209 };
210 
211 typedef struct ksiginfo {
212 	TAILQ_ENTRY(ksiginfo)	ksi_link;
213 	siginfo_t		ksi_info;
214 	int			ksi_flags;
215 	struct sigqueue		*ksi_sigq;
216 } ksiginfo_t;
217 
218 #define ksi_signo	ksi_info.si_signo
219 #define ksi_errno	ksi_info.si_errno
220 #define ksi_code	ksi_info.si_code
221 #define ksi_pid		ksi_info.si_pid
222 #define ksi_uid		ksi_info.si_uid
223 #define ksi_status      ksi_info.si_status
224 #define ksi_addr        ksi_info.si_addr
225 #define ksi_value	ksi_info.si_value
226 #define ksi_band	ksi_info.si_band
227 #define ksi_trapno	ksi_info.si_trapno
228 #define ksi_overrun	ksi_info.si_overrun
229 #define ksi_timerid	ksi_info.si_timerid
230 #define ksi_mqd		ksi_info.si_mqd
231 
232 /* bits for ksi_flags */
233 #define KSI_TRAP	0x01	/* Generated by trap. */
234 #define	KSI_EXT		0x02	/* Externally managed ksi. */
235 #define KSI_INS		0x04	/* Directly insert ksi, not the copy */
236 #define	KSI_COPYMASK	KSI_TRAP
237 
238 #define	KSI_ONQ(ksi)	((ksi)->ksi_sigq != NULL)
239 
240 typedef struct sigqueue {
241 	sigset_t	sq_signals;	/* All pending signals. */
242 	sigset_t	sq_kill;	/* Legacy depth 1 queue. */
243 	TAILQ_HEAD(, ksiginfo)	sq_list;/* Queued signal info. */
244 	struct proc	*sq_proc;
245 	int		sq_flags;
246 } sigqueue_t;
247 
248 /* Flags for ksi_flags */
249 #define	SQ_INIT	0x01
250 
251 #ifdef _KERNEL
252 
253 /* Return nonzero if process p has an unmasked pending signal. */
254 #define	SIGPENDING(td)							\
255 	(!SIGISEMPTY((td)->td_siglist) &&				\
256 	    !sigsetmasked(&(td)->td_siglist, &(td)->td_sigmask))
257 
258 /*
259  * Return the value of the pseudo-expression ((*set & ~*mask) != 0).  This
260  * is an optimized version of SIGISEMPTY() on a temporary variable
261  * containing SIGSETNAND(*set, *mask).
262  */
263 static __inline int
264 sigsetmasked(sigset_t *set, sigset_t *mask)
265 {
266 	int i;
267 
268 	for (i = 0; i < _SIG_WORDS; i++) {
269 		if (set->__bits[i] & ~mask->__bits[i])
270 			return (0);
271 	}
272 	return (1);
273 }
274 
275 #define ksiginfo_init(ksi)			\
276 do {						\
277 	bzero(ksi, sizeof(ksiginfo_t));		\
278 } while(0)
279 
280 #define ksiginfo_init_trap(ksi)			\
281 do {						\
282 	ksiginfo_t *kp = ksi;			\
283 	bzero(kp, sizeof(ksiginfo_t));		\
284 	kp->ksi_flags |= KSI_TRAP;		\
285 } while(0)
286 
287 static __inline void
288 ksiginfo_copy(ksiginfo_t *src, ksiginfo_t *dst)
289 {
290 	(dst)->ksi_info = src->ksi_info;
291 	(dst)->ksi_flags = (src->ksi_flags & KSI_COPYMASK);
292 }
293 
294 struct pgrp;
295 struct thread;
296 struct proc;
297 struct sigio;
298 struct mtx;
299 
300 extern int sugid_coredump;	/* Sysctl variable kern.sugid_coredump */
301 extern struct mtx	sigio_lock;
302 extern int kern_logsigexit;	/* Sysctl variable kern.logsigexit */
303 
304 /*
305  * Lock the pointers for a sigio object in the underlying objects of
306  * a file descriptor.
307  */
308 #define SIGIO_LOCK()	mtx_lock(&sigio_lock)
309 #define SIGIO_TRYLOCK()	mtx_trylock(&sigio_lock)
310 #define SIGIO_UNLOCK()	mtx_unlock(&sigio_lock)
311 #define SIGIO_LOCKED()	mtx_owned(&sigio_lock)
312 #define SIGIO_ASSERT(type)	mtx_assert(&sigio_lock, type)
313 
314 /*
315  * Machine-independent functions:
316  */
317 int	cursig(struct thread *td);
318 void	execsigs(struct proc *p);
319 void	gsignal(int pgid, int sig);
320 void	killproc(struct proc *p, char *why);
321 void	pgsigio(struct sigio **, int signum, int checkctty);
322 void	pgsignal(struct pgrp *pgrp, int sig, int checkctty);
323 void	postsig(int sig);
324 void	psignal(struct proc *p, int sig);
325 int	psignal_event(struct proc *p, struct sigevent *, ksiginfo_t *);
326 struct sigacts *sigacts_alloc(void);
327 void	sigacts_copy(struct sigacts *dest, struct sigacts *src);
328 void	sigacts_free(struct sigacts *ps);
329 struct sigacts *sigacts_hold(struct sigacts *ps);
330 int	sigacts_shared(struct sigacts *ps);
331 void	sigexit(struct thread *td, int signum) __dead2;
332 int	sig_ffs(sigset_t *set);
333 void	siginit(struct proc *p);
334 void	signotify(struct thread *td);
335 int	tdsignal(struct proc *p, struct thread *td, int sig,
336 	    ksiginfo_t *ksi);
337 void	trapsignal(struct thread *td, ksiginfo_t *);
338 int	ptracestop(struct thread *td, int sig);
339 ksiginfo_t * ksiginfo_alloc(int);
340 void	ksiginfo_free(ksiginfo_t *);
341 void	sigqueue_init(struct sigqueue *queue, struct proc *p);
342 void	sigqueue_flush(struct sigqueue *queue);
343 void	sigqueue_delete_proc(struct proc *p, int sig);
344 void	sigqueue_delete_set(struct sigqueue *queue, sigset_t *set);
345 void	sigqueue_delete(struct sigqueue *queue, int sig);
346 void	sigqueue_move_set(struct sigqueue *src, sigqueue_t *dst, sigset_t *);
347 int	sigqueue_get(struct sigqueue *queue, int sig, ksiginfo_t *info);
348 int	sigqueue_add(struct sigqueue *queue, int sig, ksiginfo_t *info);
349 void	sigqueue_collect_set(struct sigqueue *queue, sigset_t *set);
350 void	sigqueue_move(struct sigqueue *, struct sigqueue *, int sig);
351 void	sigqueue_delete_set_proc(struct proc *, sigset_t *);
352 void	sigqueue_delete_stopmask_proc(struct proc *);
353 void	sigqueue_take(ksiginfo_t *ksi);
354 int	kern_sigtimedwait(struct thread *, sigset_t,
355 		ksiginfo_t *, struct timespec *);
356 
357 /*
358  * Machine-dependent functions:
359  */
360 void	sendsig(sig_t, ksiginfo_t *, sigset_t *retmask);
361 
362 #endif /* _KERNEL */
363 
364 #endif /* !_SYS_SIGNALVAR_H_ */
365