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 * @(#)signalvar.h 8.6 (Berkeley) 2/19/95
32 */
33
34 #ifndef _SYS_SIGNALVAR_H_
35 #define _SYS_SIGNALVAR_H_
36
37 #include <sys/queue.h>
38 #include <sys/_lock.h>
39 #include <sys/_mutex.h>
40 #include <sys/signal.h>
41
42 /*
43 * Kernel signal definitions and data structures.
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 u_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 #ifdef _KERNEL
76
77 #ifdef COMPAT_43
78 typedef struct {
79 struct osigcontext si_sc;
80 int si_signo;
81 int si_code;
82 union sigval si_value;
83 } osiginfo_t;
84
85 struct osigaction {
86 union {
87 void (*__sa_handler)(int);
88 void (*__sa_sigaction)(int, osiginfo_t *, void *);
89 } __sigaction_u; /* signal handler */
90 osigset_t sa_mask; /* signal mask to apply */
91 int sa_flags; /* see signal options below */
92 };
93
94 typedef void __osiginfohandler_t(int, osiginfo_t *, void *);
95 #endif /* COMPAT_43 */
96
97 /* additional signal action values, used only temporarily/internally */
98 #define SIG_CATCH ((__sighandler_t *)2)
99 /* #define SIG_HOLD ((__sighandler_t *)3) See signal.h */
100
101 /*
102 * get signal action for process and signal; currently only for current process
103 */
104 #define SIGACTION(p, sig) (p->p_sigacts->ps_sigact[_SIG_IDX(sig)])
105
106 #endif /* _KERNEL */
107
108 /*
109 * sigset_t manipulation macros.
110 */
111 #define SIGADDSET(set, signo) \
112 ((set).__bits[_SIG_WORD(signo)] |= _SIG_BIT(signo))
113
114 #define SIGDELSET(set, signo) \
115 ((set).__bits[_SIG_WORD(signo)] &= ~_SIG_BIT(signo))
116
117 #define SIGEMPTYSET(set) \
118 do { \
119 int __i; \
120 for (__i = 0; __i < _SIG_WORDS; __i++) \
121 (set).__bits[__i] = 0; \
122 } while (0)
123
124 #define SIGFILLSET(set) \
125 do { \
126 int __i; \
127 for (__i = 0; __i < _SIG_WORDS; __i++) \
128 (set).__bits[__i] = ~0U; \
129 } while (0)
130
131 #define SIGISMEMBER(set, signo) \
132 ((set).__bits[_SIG_WORD(signo)] & _SIG_BIT(signo))
133
134 #define SIGISEMPTY(set) (__sigisempty(&(set)))
135 #define SIGNOTEMPTY(set) (!__sigisempty(&(set)))
136
137 #define SIGSETEQ(set1, set2) (__sigseteq(&(set1), &(set2)))
138 #define SIGSETNEQ(set1, set2) (!__sigseteq(&(set1), &(set2)))
139
140 #define SIGSETOR(set1, set2) \
141 do { \
142 int __i; \
143 for (__i = 0; __i < _SIG_WORDS; __i++) \
144 (set1).__bits[__i] |= (set2).__bits[__i]; \
145 } while (0)
146
147 #define SIGSETAND(set1, set2) \
148 do { \
149 int __i; \
150 for (__i = 0; __i < _SIG_WORDS; __i++) \
151 (set1).__bits[__i] &= (set2).__bits[__i]; \
152 } while (0)
153
154 #define SIGSETNAND(set1, set2) \
155 do { \
156 int __i; \
157 for (__i = 0; __i < _SIG_WORDS; __i++) \
158 (set1).__bits[__i] &= ~(set2).__bits[__i]; \
159 } while (0)
160
161 #define SIGSETLO(set1, set2) ((set1).__bits[0] = (set2).__bits[0])
162 #define SIGSETOLD(set, oset) ((set).__bits[0] = (oset))
163
164 #define SIG_CANTMASK(set) \
165 SIGDELSET(set, SIGKILL), SIGDELSET(set, SIGSTOP)
166
167 #define SIG_STOPSIGMASK(set) \
168 SIGDELSET(set, SIGSTOP), SIGDELSET(set, SIGTSTP), \
169 SIGDELSET(set, SIGTTIN), SIGDELSET(set, SIGTTOU)
170
171 #define SIG_CONTSIGMASK(set) \
172 SIGDELSET(set, SIGCONT)
173
174 #define sigcantmask (sigmask(SIGKILL) | sigmask(SIGSTOP))
175
176 #define SIG2OSIG(sig, osig) (osig = (sig).__bits[0])
177 #define OSIG2SIG(osig, sig) SIGEMPTYSET(sig); (sig).__bits[0] = osig
178
179 static __inline int
__sigisempty(sigset_t * set)180 __sigisempty(sigset_t *set)
181 {
182 int i;
183
184 for (i = 0; i < _SIG_WORDS; i++) {
185 if (set->__bits[i])
186 return (0);
187 }
188 return (1);
189 }
190
191 static __inline int
__sigseteq(sigset_t * set1,sigset_t * set2)192 __sigseteq(sigset_t *set1, sigset_t *set2)
193 {
194 int i;
195
196 for (i = 0; i < _SIG_WORDS; i++) {
197 if (set1->__bits[i] != set2->__bits[i])
198 return (0);
199 }
200 return (1);
201 }
202
203 #ifdef COMPAT_FREEBSD6
204 struct osigevent {
205 int sigev_notify; /* Notification type */
206 union {
207 int __sigev_signo; /* Signal number */
208 int __sigev_notify_kqueue;
209 } __sigev_u;
210 union sigval sigev_value; /* Signal value */
211 };
212 #endif
213
214 typedef struct ksiginfo {
215 TAILQ_ENTRY(ksiginfo) ksi_link;
216 siginfo_t ksi_info;
217 int ksi_flags;
218 struct sigqueue *ksi_sigq;
219 } ksiginfo_t;
220
221 #define ksi_signo ksi_info.si_signo
222 #define ksi_errno ksi_info.si_errno
223 #define ksi_code ksi_info.si_code
224 #define ksi_pid ksi_info.si_pid
225 #define ksi_uid ksi_info.si_uid
226 #define ksi_status ksi_info.si_status
227 #define ksi_addr ksi_info.si_addr
228 #define ksi_value ksi_info.si_value
229 #define ksi_band ksi_info.si_band
230 #define ksi_trapno ksi_info.si_trapno
231 #define ksi_overrun ksi_info.si_overrun
232 #define ksi_timerid ksi_info.si_timerid
233 #define ksi_mqd ksi_info.si_mqd
234
235 /* bits for ksi_flags */
236 #define KSI_TRAP 0x01 /* Generated by trap. */
237 #define KSI_EXT 0x02 /* Externally managed ksi. */
238 #define KSI_INS 0x04 /* Directly insert ksi, not the copy */
239 #define KSI_SIGQ 0x08 /* Generated by sigqueue, might ret EAGAIN. */
240 #define KSI_HEAD 0x10 /* Insert into head, not tail. */
241 #define KSI_PTRACE 0x20 /* Generated by ptrace. */
242 #define KSI_COPYMASK (KSI_TRAP | KSI_SIGQ | KSI_PTRACE)
243
244 #define KSI_ONQ(ksi) ((ksi)->ksi_sigq != NULL)
245
246 typedef struct sigqueue {
247 sigset_t sq_signals; /* All pending signals. */
248 sigset_t sq_kill; /* Legacy depth 1 queue. */
249 sigset_t sq_ptrace; /* Depth 1 queue for ptrace(2). */
250 TAILQ_HEAD(, ksiginfo) sq_list;/* Queued signal info. */
251 struct proc *sq_proc;
252 int sq_flags;
253 } sigqueue_t;
254
255 /* Flags for ksi_flags */
256 #define SQ_INIT 0x01
257
258 /*
259 * Fast_sigblock
260 */
261 #define SIGFASTBLOCK_SETPTR 1
262 #define SIGFASTBLOCK_UNBLOCK 2
263 #define SIGFASTBLOCK_UNSETPTR 3
264
265 #define SIGFASTBLOCK_PEND 0x1
266 #define SIGFASTBLOCK_FLAGS 0xf
267 #define SIGFASTBLOCK_INC 0x10
268
269 #ifndef _KERNEL
270 int __sys_sigfastblock(int cmd, void *ptr);
271 #endif
272
273 #ifdef _KERNEL
274 extern sigset_t fastblock_mask;
275 extern bool sigfastblock_fetch_always;
276
277 /* Return nonzero if process p has an unmasked pending signal. */
278 #define SIGPENDING(td) \
279 ((!SIGISEMPTY((td)->td_siglist) && \
280 !sigsetmasked(&(td)->td_siglist, &(td)->td_sigmask)) || \
281 (!SIGISEMPTY((td)->td_proc->p_siglist) && \
282 !sigsetmasked(&(td)->td_proc->p_siglist, &(td)->td_sigmask)))
283 /*
284 * Return the value of the pseudo-expression ((*set & ~*mask) == 0). This
285 * is an optimized version of SIGISEMPTY() on a temporary variable
286 * containing SIGSETNAND(*set, *mask).
287 */
288 static __inline bool
sigsetmasked(sigset_t * set,sigset_t * mask)289 sigsetmasked(sigset_t *set, sigset_t *mask)
290 {
291 int i;
292
293 for (i = 0; i < _SIG_WORDS; i++) {
294 if (set->__bits[i] & ~mask->__bits[i])
295 return (false);
296 }
297 return (true);
298 }
299
300 #define ksiginfo_init(ksi) \
301 do { \
302 bzero(ksi, sizeof(ksiginfo_t)); \
303 } while(0)
304
305 #define ksiginfo_init_trap(ksi) \
306 do { \
307 ksiginfo_t *kp = ksi; \
308 bzero(kp, sizeof(ksiginfo_t)); \
309 kp->ksi_flags |= KSI_TRAP; \
310 } while(0)
311
312 static __inline void
ksiginfo_copy(ksiginfo_t * src,ksiginfo_t * dst)313 ksiginfo_copy(ksiginfo_t *src, ksiginfo_t *dst)
314 {
315 (dst)->ksi_info = src->ksi_info;
316 (dst)->ksi_flags = (src->ksi_flags & KSI_COPYMASK);
317 }
318
319 static __inline void
ksiginfo_set_sigev(ksiginfo_t * dst,struct sigevent * sigev)320 ksiginfo_set_sigev(ksiginfo_t *dst, struct sigevent *sigev)
321 {
322 dst->ksi_signo = sigev->sigev_signo;
323 dst->ksi_value = sigev->sigev_value;
324 }
325
326 struct pgrp;
327 struct proc;
328 struct sigio;
329 struct thread;
330
331 /*
332 * Lock the pointers for a sigio object in the underlying objects of
333 * a file descriptor.
334 */
335 #define SIGIO_LOCK() mtx_lock(&sigio_lock)
336 #define SIGIO_TRYLOCK() mtx_trylock(&sigio_lock)
337 #define SIGIO_UNLOCK() mtx_unlock(&sigio_lock)
338 #define SIGIO_LOCKED() mtx_owned(&sigio_lock)
339 #define SIGIO_ASSERT_LOCKED() mtx_assert(&sigio_lock, MA_OWNED)
340
341 extern struct mtx sigio_lock;
342
343 /* Flags for kern_sigprocmask(). */
344 #define SIGPROCMASK_OLD 0x0001
345 #define SIGPROCMASK_PROC_LOCKED 0x0002
346 #define SIGPROCMASK_PS_LOCKED 0x0004
347 #define SIGPROCMASK_FASTBLK 0x0008
348
349 /*
350 * Modes for sigdeferstop(). Manages behaviour of
351 * thread_suspend_check() in the region delimited by
352 * sigdeferstop()/sigallowstop(). Must be restored to
353 * SIGDEFERSTOP_OFF before returning to userspace.
354 */
355 #define SIGDEFERSTOP_NOP 0 /* continue doing whatever is done now */
356 #define SIGDEFERSTOP_OFF 1 /* stop ignoring STOPs */
357 #define SIGDEFERSTOP_SILENT 2 /* silently ignore STOPs */
358 #define SIGDEFERSTOP_EINTR 3 /* ignore STOPs, return EINTR */
359 #define SIGDEFERSTOP_ERESTART 4 /* ignore STOPs, return ERESTART */
360
361 #define SIGDEFERSTOP_VAL_NCHG (-1) /* placeholder indicating no state change */
362 int sigdeferstop_impl(int mode);
363 void sigallowstop_impl(int prev);
364
365 static inline int
sigdeferstop(int mode)366 sigdeferstop(int mode)
367 {
368
369 if (__predict_false(mode == SIGDEFERSTOP_NOP))
370 return (SIGDEFERSTOP_VAL_NCHG);
371 return (sigdeferstop_impl(mode));
372 }
373
374 static inline void
sigallowstop(int prev)375 sigallowstop(int prev)
376 {
377
378 if (__predict_true(prev == SIGDEFERSTOP_VAL_NCHG))
379 return;
380 sigallowstop_impl(prev);
381 }
382
383 int cursig(struct thread *td);
384 void execsigs(struct proc *p);
385 void killproc(struct proc *p, const char *why);
386 ksiginfo_t *ksiginfo_alloc(int mwait);
387 void ksiginfo_free(ksiginfo_t *ksi);
388 int pksignal(struct proc *p, int sig, ksiginfo_t *ksi);
389 void pgsigio(struct sigio **sigiop, int sig, int checkctty);
390 void pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi);
391 int postsig(int sig);
392 void kern_psignal(struct proc *p, int sig);
393 int ptracestop(struct thread *td, int sig, ksiginfo_t *si);
394 void sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *retmask);
395 struct sigacts *sigacts_alloc(void);
396 void sigacts_copy(struct sigacts *dest, struct sigacts *src);
397 void sigacts_free(struct sigacts *ps);
398 struct sigacts *sigacts_hold(struct sigacts *ps);
399 int sigacts_shared(struct sigacts *ps);
400 int sig_ast_checksusp(struct thread *td);
401 int sig_ast_needsigchk(struct thread *td);
402 void sig_drop_caught(struct proc *p);
403 void sigexit(struct thread *td, int sig) __dead2;
404 int sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **);
405 void sigfastblock_clear(struct thread *td);
406 void sigfastblock_fetch(struct thread *td);
407 void sigfastblock_setpend(struct thread *td, bool resched);
408 int sig_intr(void);
409 void siginit(struct proc *p);
410 void signotify(struct thread *td);
411 void sigqueue_delete(struct sigqueue *queue, int sig);
412 void sigqueue_delete_proc(struct proc *p, int sig);
413 void sigqueue_flush(struct sigqueue *queue);
414 void sigqueue_init(struct sigqueue *queue, struct proc *p);
415 void sigqueue_take(ksiginfo_t *ksi);
416 void tdksignal(struct thread *td, int sig, ksiginfo_t *ksi);
417 int tdsendsignal(struct proc *p, struct thread *td, int sig,
418 ksiginfo_t *ksi);
419 void tdsigcleanup(struct thread *td);
420 void tdsignal(struct thread *td, int sig);
421 void trapsignal(struct thread *td, ksiginfo_t *ksi);
422
423 #endif /* _KERNEL */
424
425 #endif /* !_SYS_SIGNALVAR_H_ */
426