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