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