Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_SIGNAL_H
3 : #define _LINUX_SIGNAL_H
4 :
5 : #include <linux/bug.h>
6 : #include <linux/signal_types.h>
7 : #include <linux/string.h>
8 :
9 : struct task_struct;
10 :
11 : /* for sysctl */
12 : extern int print_fatal_signals;
13 :
14 1062 : static inline void copy_siginfo(kernel_siginfo_t *to,
15 : const kernel_siginfo_t *from)
16 : {
17 530 : memcpy(to, from, sizeof(*to));
18 532 : }
19 :
20 926 : static inline void clear_siginfo(kernel_siginfo_t *info)
21 : {
22 926 : memset(info, 0, sizeof(*info));
23 : }
24 :
25 : #define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo))
26 :
27 : static inline void copy_siginfo_to_external(siginfo_t *to,
28 : const kernel_siginfo_t *from)
29 : {
30 : memcpy(to, from, sizeof(*from));
31 : memset(((char *)to) + sizeof(struct kernel_siginfo), 0,
32 : SI_EXPANSION_SIZE);
33 : }
34 :
35 : int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from);
36 : int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from);
37 :
38 : enum siginfo_layout {
39 : SIL_KILL,
40 : SIL_TIMER,
41 : SIL_POLL,
42 : SIL_FAULT,
43 : SIL_FAULT_MCEERR,
44 : SIL_FAULT_BNDERR,
45 : SIL_FAULT_PKUERR,
46 : SIL_CHLD,
47 : SIL_RT,
48 : SIL_SYS,
49 : };
50 :
51 : enum siginfo_layout siginfo_layout(unsigned sig, int si_code);
52 :
53 : /*
54 : * Define some primitives to manipulate sigset_t.
55 : */
56 :
57 : #ifndef __HAVE_ARCH_SIG_BITOPS
58 : #include <linux/bitops.h>
59 :
60 : /* We don't use <linux/bitops.h> for these because there is no need to
61 : be atomic. */
62 4866 : static inline void sigaddset(sigset_t *set, int _sig)
63 : {
64 4866 : unsigned long sig = _sig - 1;
65 4866 : if (_NSIG_WORDS == 1)
66 4405 : set->sig[0] |= 1UL << sig;
67 : else
68 : set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
69 4070 : }
70 :
71 530 : static inline void sigdelset(sigset_t *set, int _sig)
72 : {
73 530 : unsigned long sig = _sig - 1;
74 530 : if (_NSIG_WORDS == 1)
75 530 : set->sig[0] &= ~(1UL << sig);
76 : else
77 : set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
78 0 : }
79 :
80 16305 : static inline int sigismember(sigset_t *set, int _sig)
81 : {
82 16305 : unsigned long sig = _sig - 1;
83 16305 : if (_NSIG_WORDS == 1)
84 7128 : return 1 & (set->sig[0] >> sig);
85 : else
86 : return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
87 : }
88 :
89 : #endif /* __HAVE_ARCH_SIG_BITOPS */
90 :
91 550 : static inline int sigisemptyset(sigset_t *set)
92 : {
93 550 : switch (_NSIG_WORDS) {
94 : case 4:
95 : return (set->sig[3] | set->sig[2] |
96 : set->sig[1] | set->sig[0]) == 0;
97 : case 2:
98 : return (set->sig[1] | set->sig[0]) == 0;
99 : case 1:
100 550 : return set->sig[0] == 0;
101 : default:
102 : BUILD_BUG();
103 : return 0;
104 : }
105 : }
106 :
107 2732 : static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
108 : {
109 2732 : switch (_NSIG_WORDS) {
110 : case 4:
111 : return (set1->sig[3] == set2->sig[3]) &&
112 : (set1->sig[2] == set2->sig[2]) &&
113 : (set1->sig[1] == set2->sig[1]) &&
114 : (set1->sig[0] == set2->sig[0]);
115 : case 2:
116 : return (set1->sig[1] == set2->sig[1]) &&
117 : (set1->sig[0] == set2->sig[0]);
118 : case 1:
119 2732 : return set1->sig[0] == set2->sig[0];
120 : }
121 : return 0;
122 : }
123 :
124 : #define sigmask(sig) (1UL << ((sig) - 1))
125 :
126 : #ifndef __HAVE_ARCH_SIG_SETOPS
127 : #include <linux/string.h>
128 :
129 : #define _SIG_SET_BINOP(name, op) \
130 : static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
131 : { \
132 : unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
133 : \
134 : switch (_NSIG_WORDS) { \
135 : case 4: \
136 : a3 = a->sig[3]; a2 = a->sig[2]; \
137 : b3 = b->sig[3]; b2 = b->sig[2]; \
138 : r->sig[3] = op(a3, b3); \
139 : r->sig[2] = op(a2, b2); \
140 : fallthrough; \
141 : case 2: \
142 : a1 = a->sig[1]; b1 = b->sig[1]; \
143 : r->sig[1] = op(a1, b1); \
144 : fallthrough; \
145 : case 1: \
146 : a0 = a->sig[0]; b0 = b->sig[0]; \
147 : r->sig[0] = op(a0, b0); \
148 : break; \
149 : default: \
150 : BUILD_BUG(); \
151 : } \
152 : }
153 :
154 : #define _sig_or(x,y) ((x) | (y))
155 1130 : _SIG_SET_BINOP(sigorsets, _sig_or)
156 :
157 : #define _sig_and(x,y) ((x) & (y))
158 551 : _SIG_SET_BINOP(sigandsets, _sig_and)
159 :
160 : #define _sig_andn(x,y) ((x) & ~(y))
161 342 : _SIG_SET_BINOP(sigandnsets, _sig_andn)
162 :
163 : #undef _SIG_SET_BINOP
164 : #undef _sig_or
165 : #undef _sig_and
166 : #undef _sig_andn
167 :
168 : #define _SIG_SET_OP(name, op) \
169 : static inline void name(sigset_t *set) \
170 : { \
171 : switch (_NSIG_WORDS) { \
172 : case 4: set->sig[3] = op(set->sig[3]); \
173 : set->sig[2] = op(set->sig[2]); \
174 : fallthrough; \
175 : case 2: set->sig[1] = op(set->sig[1]); \
176 : fallthrough; \
177 : case 1: set->sig[0] = op(set->sig[0]); \
178 : break; \
179 : default: \
180 : BUILD_BUG(); \
181 : } \
182 : }
183 :
184 : #define _sig_not(x) (~(x))
185 38 : _SIG_SET_OP(signotset, _sig_not)
186 :
187 : #undef _SIG_SET_OP
188 : #undef _sig_not
189 :
190 42729 : static inline void sigemptyset(sigset_t *set)
191 : {
192 42729 : switch (_NSIG_WORDS) {
193 : default:
194 : memset(set, 0, sizeof(sigset_t));
195 : break;
196 : case 2: set->sig[1] = 0;
197 42729 : fallthrough;
198 42729 : case 1: set->sig[0] = 0;
199 39187 : break;
200 : }
201 1716 : }
202 :
203 0 : static inline void sigfillset(sigset_t *set)
204 : {
205 0 : switch (_NSIG_WORDS) {
206 : default:
207 : memset(set, -1, sizeof(sigset_t));
208 : break;
209 : case 2: set->sig[1] = -1;
210 0 : fallthrough;
211 0 : case 1: set->sig[0] = -1;
212 0 : break;
213 : }
214 : }
215 :
216 : /* Some extensions for manipulating the low 32 signals in particular. */
217 :
218 0 : static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
219 : {
220 0 : set->sig[0] |= mask;
221 0 : }
222 :
223 5673 : static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
224 : {
225 5673 : set->sig[0] &= ~mask;
226 0 : }
227 :
228 : static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
229 : {
230 : return (set->sig[0] & mask) != 0;
231 : }
232 :
233 15 : static inline void siginitset(sigset_t *set, unsigned long mask)
234 : {
235 15 : set->sig[0] = mask;
236 15 : switch (_NSIG_WORDS) {
237 : default:
238 : memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
239 : break;
240 : case 2: set->sig[1] = 0;
241 : break;
242 15 : case 1: ;
243 : }
244 0 : }
245 :
246 : static inline void siginitsetinv(sigset_t *set, unsigned long mask)
247 : {
248 : set->sig[0] = ~mask;
249 : switch (_NSIG_WORDS) {
250 : default:
251 : memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
252 : break;
253 : case 2: set->sig[1] = -1;
254 : break;
255 : case 1: ;
256 : }
257 : }
258 :
259 : #endif /* __HAVE_ARCH_SIG_SETOPS */
260 :
261 1826 : static inline void init_sigpending(struct sigpending *sig)
262 : {
263 1826 : sigemptyset(&sig->signal);
264 1826 : INIT_LIST_HEAD(&sig->list);
265 : }
266 :
267 : extern void flush_sigqueue(struct sigpending *queue);
268 :
269 : /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
270 4606 : static inline int valid_signal(unsigned long sig)
271 : {
272 4606 : return sig <= _NSIG ? 1 : 0;
273 : }
274 :
275 : struct timespec;
276 : struct pt_regs;
277 : enum pid_type;
278 :
279 : extern int next_signal(struct sigpending *pending, sigset_t *mask);
280 : extern int do_send_sig_info(int sig, struct kernel_siginfo *info,
281 : struct task_struct *p, enum pid_type type);
282 : extern int group_send_sig_info(int sig, struct kernel_siginfo *info,
283 : struct task_struct *p, enum pid_type type);
284 : extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
285 : extern int sigprocmask(int, sigset_t *, sigset_t *);
286 : extern void set_current_blocked(sigset_t *);
287 : extern void __set_current_blocked(const sigset_t *);
288 : extern int show_unhandled_signals;
289 :
290 : extern bool get_signal(struct ksignal *ksig);
291 : extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
292 : extern void exit_signals(struct task_struct *tsk);
293 : extern void kernel_sigaction(int, __sighandler_t);
294 :
295 : #define SIG_KTHREAD ((__force __sighandler_t)2)
296 : #define SIG_KTHREAD_KERNEL ((__force __sighandler_t)3)
297 :
298 : static inline void allow_signal(int sig)
299 : {
300 : /*
301 : * Kernel threads handle their own signals. Let the signal code
302 : * know it'll be handled, so that they don't get converted to
303 : * SIGKILL or just silently dropped.
304 : */
305 : kernel_sigaction(sig, SIG_KTHREAD);
306 : }
307 :
308 : static inline void allow_kernel_signal(int sig)
309 : {
310 : /*
311 : * Kernel threads handle their own signals. Let the signal code
312 : * know signals sent by the kernel will be handled, so that they
313 : * don't get silently dropped.
314 : */
315 : kernel_sigaction(sig, SIG_KTHREAD_KERNEL);
316 : }
317 :
318 : static inline void disallow_signal(int sig)
319 : {
320 : kernel_sigaction(sig, SIG_IGN);
321 : }
322 :
323 : extern struct kmem_cache *sighand_cachep;
324 :
325 : extern bool unhandled_signal(struct task_struct *tsk, int sig);
326 :
327 : /*
328 : * In POSIX a signal is sent either to a specific thread (Linux task)
329 : * or to the process as a whole (Linux thread group). How the signal
330 : * is sent determines whether it's to one thread or the whole group,
331 : * which determines which signal mask(s) are involved in blocking it
332 : * from being delivered until later. When the signal is delivered,
333 : * either it's caught or ignored by a user handler or it has a default
334 : * effect that applies to the whole thread group (POSIX process).
335 : *
336 : * The possible effects an unblocked signal set to SIG_DFL can have are:
337 : * ignore - Nothing Happens
338 : * terminate - kill the process, i.e. all threads in the group,
339 : * similar to exit_group. The group leader (only) reports
340 : * WIFSIGNALED status to its parent.
341 : * coredump - write a core dump file describing all threads using
342 : * the same mm and then kill all those threads
343 : * stop - stop all the threads in the group, i.e. TASK_STOPPED state
344 : *
345 : * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
346 : * Other signals when not blocked and set to SIG_DFL behaves as follows.
347 : * The job control signals also have other special effects.
348 : *
349 : * +--------------------+------------------+
350 : * | POSIX signal | default action |
351 : * +--------------------+------------------+
352 : * | SIGHUP | terminate |
353 : * | SIGINT | terminate |
354 : * | SIGQUIT | coredump |
355 : * | SIGILL | coredump |
356 : * | SIGTRAP | coredump |
357 : * | SIGABRT/SIGIOT | coredump |
358 : * | SIGBUS | coredump |
359 : * | SIGFPE | coredump |
360 : * | SIGKILL | terminate(+) |
361 : * | SIGUSR1 | terminate |
362 : * | SIGSEGV | coredump |
363 : * | SIGUSR2 | terminate |
364 : * | SIGPIPE | terminate |
365 : * | SIGALRM | terminate |
366 : * | SIGTERM | terminate |
367 : * | SIGCHLD | ignore |
368 : * | SIGCONT | ignore(*) |
369 : * | SIGSTOP | stop(*)(+) |
370 : * | SIGTSTP | stop(*) |
371 : * | SIGTTIN | stop(*) |
372 : * | SIGTTOU | stop(*) |
373 : * | SIGURG | ignore |
374 : * | SIGXCPU | coredump |
375 : * | SIGXFSZ | coredump |
376 : * | SIGVTALRM | terminate |
377 : * | SIGPROF | terminate |
378 : * | SIGPOLL/SIGIO | terminate |
379 : * | SIGSYS/SIGUNUSED | coredump |
380 : * | SIGSTKFLT | terminate |
381 : * | SIGWINCH | ignore |
382 : * | SIGPWR | terminate |
383 : * | SIGRTMIN-SIGRTMAX | terminate |
384 : * +--------------------+------------------+
385 : * | non-POSIX signal | default action |
386 : * +--------------------+------------------+
387 : * | SIGEMT | coredump |
388 : * +--------------------+------------------+
389 : *
390 : * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
391 : * (*) Special job control effects:
392 : * When SIGCONT is sent, it resumes the process (all threads in the group)
393 : * from TASK_STOPPED state and also clears any pending/queued stop signals
394 : * (any of those marked with "stop(*)"). This happens regardless of blocking,
395 : * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
396 : * any pending/queued SIGCONT signals; this happens regardless of blocking,
397 : * catching, or ignored the stop signal, though (except for SIGSTOP) the
398 : * default action of stopping the process may happen later or never.
399 : */
400 :
401 : #ifdef SIGEMT
402 : #define SIGEMT_MASK rt_sigmask(SIGEMT)
403 : #else
404 : #define SIGEMT_MASK 0
405 : #endif
406 :
407 : #if SIGRTMIN > BITS_PER_LONG
408 : #define rt_sigmask(sig) (1ULL << ((sig)-1))
409 : #else
410 : #define rt_sigmask(sig) sigmask(sig)
411 : #endif
412 :
413 : #define siginmask(sig, mask) \
414 : ((sig) > 0 && (sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
415 :
416 : #define SIG_KERNEL_ONLY_MASK (\
417 : rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
418 :
419 : #define SIG_KERNEL_STOP_MASK (\
420 : rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
421 : rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
422 :
423 : #define SIG_KERNEL_COREDUMP_MASK (\
424 : rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
425 : rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
426 : rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
427 : rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
428 : rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
429 : SIGEMT_MASK )
430 :
431 : #define SIG_KERNEL_IGNORE_MASK (\
432 : rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
433 : rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
434 :
435 : #define SIG_SPECIFIC_SICODES_MASK (\
436 : rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \
437 : rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \
438 : rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \
439 : rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \
440 : SIGEMT_MASK )
441 :
442 : #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
443 : #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
444 : #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
445 : #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
446 : #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK)
447 :
448 : #define sig_fatal(t, signr) \
449 : (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
450 : (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
451 :
452 : void signals_init(void);
453 :
454 : int restore_altstack(const stack_t __user *);
455 : int __save_altstack(stack_t __user *, unsigned long);
456 :
457 : #define unsafe_save_altstack(uss, sp, label) do { \
458 : stack_t __user *__uss = uss; \
459 : struct task_struct *t = current; \
460 : unsafe_put_user((void __user *)t->sas_ss_sp, &__uss->ss_sp, label); \
461 : unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \
462 : unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \
463 : if (t->sas_ss_flags & SS_AUTODISARM) \
464 : sas_ss_reset(t); \
465 : } while (0);
466 :
467 : #ifdef CONFIG_PROC_FS
468 : struct seq_file;
469 : extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
470 : #endif
471 :
472 : #ifndef arch_untagged_si_addr
473 : /*
474 : * Given a fault address and a signal and si_code which correspond to the
475 : * _sigfault union member, returns the address that must appear in si_addr if
476 : * the signal handler does not have SA_EXPOSE_TAGBITS enabled in sa_flags.
477 : */
478 : static inline void __user *arch_untagged_si_addr(void __user *addr,
479 : unsigned long sig,
480 : unsigned long si_code)
481 : {
482 : return addr;
483 : }
484 : #endif
485 :
486 : #endif /* _LINUX_SIGNAL_H */
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