signalvar.h revision 315949 
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: stable/11/sys/sys/signalvar.h 315949 2017-03-25 13:33:23Z badger $
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 */
52struct 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
77typedef struct {
78	struct osigcontext si_sc;
79	int		si_signo;
80	int		si_code;
81	union sigval	si_value;
82} osiginfo_t;
83
84struct 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
93typedef 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
178static __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
190static __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
203struct 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
213typedef 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
245typedef 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 */
270static __inline int
271sigsetmasked(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)			\
283do {						\
284	bzero(ksi, sizeof(ksiginfo_t));		\
285} while(0)
286
287#define	ksiginfo_init_trap(ksi)			\
288do {						\
289	ksiginfo_t *kp = ksi;			\
290	bzero(kp, sizeof(ksiginfo_t));		\
291	kp->ksi_flags |= KSI_TRAP;		\
292} while(0)
293
294static __inline void
295ksiginfo_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
301static __inline void
302ksiginfo_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
308struct pgrp;
309struct proc;
310struct sigio;
311struct 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
323extern 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 */
343int	sigdeferstop_impl(int mode);
344void	sigallowstop_impl(int prev);
345
346static inline int
347sigdeferstop(int mode)
348{
349
350	if (mode == SIGDEFERSTOP_NOP)
351		return (SIGDEFERSTOP_VAL_NCHG);
352	return (sigdeferstop_impl(mode));
353}
354
355static inline void
356sigallowstop(int prev)
357{
358
359	if (prev == SIGDEFERSTOP_VAL_NCHG)
360		return;
361	sigallowstop_impl(prev);
362}
363
364int	cursig(struct thread *td);
365void	execsigs(struct proc *p);
366void	gsignal(int pgid, int sig, ksiginfo_t *ksi);
367void	killproc(struct proc *p, char *why);
368ksiginfo_t * ksiginfo_alloc(int wait);
369void	ksiginfo_free(ksiginfo_t *ksi);
370int	pksignal(struct proc *p, int sig, ksiginfo_t *ksi);
371void	pgsigio(struct sigio **sigiop, int sig, int checkctty);
372void	pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi);
373int	postsig(int sig);
374void	kern_psignal(struct proc *p, int sig);
375int	ptracestop(struct thread *td, int sig, ksiginfo_t *si);
376void	sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *retmask);
377struct sigacts *sigacts_alloc(void);
378void	sigacts_copy(struct sigacts *dest, struct sigacts *src);
379void	sigacts_free(struct sigacts *ps);
380struct sigacts *sigacts_hold(struct sigacts *ps);
381int	sigacts_shared(struct sigacts *ps);
382void	sigexit(struct thread *td, int sig) __dead2;
383int	sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **);
384int	sig_ffs(sigset_t *set);
385void	siginit(struct proc *p);
386void	signotify(struct thread *td);
387void	sigqueue_delete(struct sigqueue *queue, int sig);
388void	sigqueue_delete_proc(struct proc *p, int sig);
389void	sigqueue_flush(struct sigqueue *queue);
390void	sigqueue_init(struct sigqueue *queue, struct proc *p);
391void	sigqueue_take(ksiginfo_t *ksi);
392void	tdksignal(struct thread *td, int sig, ksiginfo_t *ksi);
393int	tdsendsignal(struct proc *p, struct thread *td, int sig,
394	   ksiginfo_t *ksi);
395void	tdsigcleanup(struct thread *td);
396void	tdsignal(struct thread *td, int sig);
397void	trapsignal(struct thread *td, ksiginfo_t *ksi);
398
399#endif /* _KERNEL */
400
401#endif /* !_SYS_SIGNALVAR_H_ */
402