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;
273extern bool pt_attach_transparent;
274
275/* Return nonzero if process p has an unmasked pending signal. */
276#define SIGPENDING(td) \
277 ((!SIGISEMPTY((td)->td_siglist) && \
278 !sigsetmasked(&(td)->td_siglist, &(td)->td_sigmask)) || \
279 (!SIGISEMPTY((td)->td_proc->p_siglist) && \
280 !sigsetmasked(&(td)->td_proc->p_siglist, &(td)->td_sigmask)))
281/*
282 * Return the value of the pseudo-expression ((*set & ~*mask) == 0). This
283 * is an optimized version of SIGISEMPTY() on a temporary variable
284 * containing SIGSETNAND(*set, *mask).
285 */
286static __inline bool
287sigsetmasked(sigset_t *set, sigset_t *mask)
288{
289 int i;
290
291 for (i = 0; i < _SIG_WORDS; i++) {
292 if (set->__bits[i] & ~mask->__bits[i])
293 return (false);
294 }
295 return (true);
296}
297
298#define ksiginfo_init(ksi) \
299do { \
300 bzero(ksi, sizeof(ksiginfo_t)); \
301} while (0)
302
303#define ksiginfo_init_trap(ksi) \
304do { \
305 ksiginfo_t *kp = ksi; \
306 bzero(kp, sizeof(ksiginfo_t)); \
307 kp->ksi_flags |= KSI_TRAP; \
308} while (0)
309
310static __inline void
311ksiginfo_copy(ksiginfo_t *src, ksiginfo_t *dst)
312{
313 (dst)->ksi_info = src->ksi_info;
314 (dst)->ksi_flags = (src->ksi_flags & KSI_COPYMASK);
315}
316
317static __inline void
318ksiginfo_set_sigev(ksiginfo_t *dst, struct sigevent *sigev)
319{
320 dst->ksi_signo = sigev->sigev_signo;
321 dst->ksi_value = sigev->sigev_value;
322}
323
324struct pgrp;
325struct proc;
326struct sigio;
327struct thread;
328
329/*
330 * Lock the pointers for a sigio object in the underlying objects of
331 * a file descriptor.
332 */
333#define SIGIO_LOCK() mtx_lock(&sigio_lock)
334#define SIGIO_TRYLOCK() mtx_trylock(&sigio_lock)
335#define SIGIO_UNLOCK() mtx_unlock(&sigio_lock)
336#define SIGIO_LOCKED() mtx_owned(&sigio_lock)
337#define SIGIO_ASSERT_LOCKED() mtx_assert(&sigio_lock, MA_OWNED)
338
339extern struct mtx sigio_lock;
340
341/* Flags for kern_sigprocmask(). */
342#define SIGPROCMASK_OLD 0x0001
343#define SIGPROCMASK_PROC_LOCKED 0x0002
344#define SIGPROCMASK_PS_LOCKED 0x0004
345#define SIGPROCMASK_FASTBLK 0x0008
346
347/*
348 * Modes for sigdeferstop(). Manages behaviour of
349 * thread_suspend_check() in the region delimited by
350 * sigdeferstop()/sigallowstop(). Must be restored to
351 * SIGDEFERSTOP_OFF before returning to userspace.
352 */
353#define SIGDEFERSTOP_NOP 0 /* continue doing whatever is done now */
354#define SIGDEFERSTOP_OFF 1 /* stop ignoring STOPs */
355#define SIGDEFERSTOP_SILENT 2 /* silently ignore STOPs */
356#define SIGDEFERSTOP_EINTR 3 /* ignore STOPs, return EINTR */
357#define SIGDEFERSTOP_ERESTART 4 /* ignore STOPs, return ERESTART */
358
359#define SIGDEFERSTOP_VAL_NCHG (-1) /* placeholder indicating no state change */
360int sigdeferstop_impl(int mode);
361void sigallowstop_impl(int prev);
362
363static inline int
364sigdeferstop(int mode)
365{
366
367 if (__predict_false(mode == SIGDEFERSTOP_NOP))
368 return (SIGDEFERSTOP_VAL_NCHG);
369 return (sigdeferstop_impl(mode));
370}
371
372static inline void
373sigallowstop(int prev)
374{
375
376 if (__predict_true(prev == SIGDEFERSTOP_VAL_NCHG))
377 return;
378 sigallowstop_impl(prev);
379}
380
381int cursig(struct thread *td);
382void execsigs(struct proc *p);
383void killproc(struct proc *p, const char *why);
384ksiginfo_t *ksiginfo_alloc(int mwait);
385void ksiginfo_free(ksiginfo_t *ksi);
386int pksignal(struct proc *p, int sig, ksiginfo_t *ksi);
387void pgsigio(struct sigio **sigiop, int sig, int checkctty);
388void pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi);
389int postsig(int sig);
390void kern_psignal(struct proc *p, int sig);
391int ptracestop(struct thread *td, int sig, ksiginfo_t *si);
392void sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *retmask);
393struct sigacts *sigacts_alloc(void);
394void sigacts_copy(struct sigacts *dest, struct sigacts *src);
395void sigacts_free(struct sigacts *ps);
396struct sigacts *sigacts_hold(struct sigacts *ps);
397int sigacts_shared(struct sigacts *ps);
398int sig_ast_checksusp(struct thread *td);
399int sig_ast_needsigchk(struct thread *td);
400void sig_drop_caught(struct proc *p);
401void sigexit(struct thread *td, int sig) __dead2;
402int sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **);
403void sigfastblock_clear(struct thread *td);
404void sigfastblock_fetch(struct thread *td);
405int sig_intr(void);
406bool sig_do_core(int);
407void siginit(struct proc *p);
408void signotify(struct thread *td);
409void sigqueue_delete(struct sigqueue *queue, int sig);
410void sigqueue_delete_proc(struct proc *p, int sig);
411void sigqueue_flush(struct sigqueue *queue);
412void sigqueue_init(struct sigqueue *queue, struct proc *p);
413void sigqueue_take(ksiginfo_t *ksi);
414void tdksignal(struct thread *td, int sig, ksiginfo_t *ksi);
415int tdsendsignal(struct proc *p, struct thread *td, int sig,
416 ksiginfo_t *ksi);
417void tdsigcleanup(struct thread *td);
418void tdsignal(struct thread *td, int sig);
419void trapsignal(struct thread *td, ksiginfo_t *ksi);
420
421#endif /* _KERNEL */
422
423#endif /* !_SYS_SIGNALVAR_H_ */