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 */
51 struct 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
76 typedef struct {
77 struct osigcontext si_sc;
78 int si_signo;
79 int si_code;
80 union sigval si_value;
81 } osiginfo_t;
82
83 struct 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
92 typedef 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
177 static __inline int
__sigisempty(sigset_t * set)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
189 static __inline int
__sigseteq(sigset_t * set1,sigset_t * set2)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
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 #endif
211
212 typedef 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
244 typedef 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
268 int __sys_sigfastblock(int cmd, void *ptr);
269 #endif
270
271 #ifdef _KERNEL
272 extern 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 */
285 static __inline bool
sigsetmasked(sigset_t * set,sigset_t * mask)286 sigsetmasked(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) \
298 do { \
299 bzero(ksi, sizeof(ksiginfo_t)); \
300 } while (0)
301
302 #define ksiginfo_init_trap(ksi) \
303 do { \
304 ksiginfo_t *kp = ksi; \
305 bzero(kp, sizeof(ksiginfo_t)); \
306 kp->ksi_flags |= KSI_TRAP; \
307 } while (0)
308
309 static __inline void
ksiginfo_copy(ksiginfo_t * src,ksiginfo_t * dst)310 ksiginfo_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
316 static __inline void
ksiginfo_set_sigev(ksiginfo_t * dst,struct sigevent * sigev)317 ksiginfo_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
323 struct pgrp;
324 struct proc;
325 struct sigio;
326 struct 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
338 extern 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 */
359 int sigdeferstop_impl(int mode);
360 void sigallowstop_impl(int prev);
361
362 static inline int
sigdeferstop(int mode)363 sigdeferstop(int mode)
364 {
365
366 if (__predict_false(mode == SIGDEFERSTOP_NOP))
367 return (SIGDEFERSTOP_VAL_NCHG);
368 return (sigdeferstop_impl(mode));
369 }
370
371 static inline void
sigallowstop(int prev)372 sigallowstop(int prev)
373 {
374
375 if (__predict_true(prev == SIGDEFERSTOP_VAL_NCHG))
376 return;
377 sigallowstop_impl(prev);
378 }
379
380 int cursig(struct thread *td);
381 void execsigs(struct proc *p);
382 void killproc(struct proc *p, const char *why);
383 ksiginfo_t *ksiginfo_alloc(int mwait);
384 void ksiginfo_free(ksiginfo_t *ksi);
385 int pksignal(struct proc *p, int sig, ksiginfo_t *ksi);
386 void pgsigio(struct sigio **sigiop, int sig, int checkctty);
387 void pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi);
388 int postsig(int sig);
389 void kern_psignal(struct proc *p, int sig);
390 int ptracestop(struct thread *td, int sig, ksiginfo_t *si);
391 void sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *retmask);
392 struct sigacts *sigacts_alloc(void);
393 void sigacts_copy(struct sigacts *dest, struct sigacts *src);
394 void sigacts_free(struct sigacts *ps);
395 struct sigacts *sigacts_hold(struct sigacts *ps);
396 int sigacts_shared(struct sigacts *ps);
397 int sig_ast_checksusp(struct thread *td);
398 int sig_ast_needsigchk(struct thread *td);
399 void sig_drop_caught(struct proc *p);
400 void sigexit(struct thread *td, int sig) __dead2;
401 int sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **);
402 void sigfastblock_clear(struct thread *td);
403 void sigfastblock_fetch(struct thread *td);
404 int sig_intr(void);
405 void siginit(struct proc *p);
406 void signotify(struct thread *td);
407 void sigqueue_delete(struct sigqueue *queue, int sig);
408 void sigqueue_delete_proc(struct proc *p, int sig);
409 void sigqueue_flush(struct sigqueue *queue);
410 void sigqueue_init(struct sigqueue *queue, struct proc *p);
411 void sigqueue_take(ksiginfo_t *ksi);
412 void tdksignal(struct thread *td, int sig, ksiginfo_t *ksi);
413 int tdsendsignal(struct proc *p, struct thread *td, int sig,
414 ksiginfo_t *ksi);
415 void tdsigcleanup(struct thread *td);
416 void tdsignal(struct thread *td, int sig);
417 void trapsignal(struct thread *td, ksiginfo_t *ksi);
418
419 #endif /* _KERNEL */
420
421 #endif /* !_SYS_SIGNALVAR_H_ */
422