1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SIGNAL_H
3 #define _LINUX_SIGNAL_H
6 #include <linux/signal_types.h>
7 #include <linux/string.h>
12 extern int print_fatal_signals;
14 static inline void copy_siginfo(kernel_siginfo_t *to,
15 const kernel_siginfo_t *from)
17 memcpy(to, from, sizeof(*to));
20 static inline void clear_siginfo(kernel_siginfo_t *info)
22 memset(info, 0, sizeof(*info));
25 #define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo))
27 int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from);
28 int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from);
43 enum siginfo_layout siginfo_layout(unsigned sig, int si_code);
46 * Define some primitives to manipulate sigset_t.
49 #ifndef __HAVE_ARCH_SIG_BITOPS
50 #include <linux/bitops.h>
52 /* We don't use <linux/bitops.h> for these because there is no need to
54 static inline void sigaddset(sigset_t *set, int _sig)
56 unsigned long sig = _sig - 1;
58 set->sig[0] |= 1UL << sig;
60 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
63 static inline void sigdelset(sigset_t *set, int _sig)
65 unsigned long sig = _sig - 1;
67 set->sig[0] &= ~(1UL << sig);
69 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
72 static inline int sigismember(sigset_t *set, int _sig)
74 unsigned long sig = _sig - 1;
76 return 1 & (set->sig[0] >> sig);
78 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
81 #endif /* __HAVE_ARCH_SIG_BITOPS */
83 static inline int sigisemptyset(sigset_t *set)
85 switch (_NSIG_WORDS) {
87 return (set->sig[3] | set->sig[2] |
88 set->sig[1] | set->sig[0]) == 0;
90 return (set->sig[1] | set->sig[0]) == 0;
92 return set->sig[0] == 0;
99 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
101 switch (_NSIG_WORDS) {
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]);
108 return (set1->sig[1] == set2->sig[1]) &&
109 (set1->sig[0] == set2->sig[0]);
111 return set1->sig[0] == set2->sig[0];
116 #define sigmask(sig) (1UL << ((sig) - 1))
118 #ifndef __HAVE_ARCH_SIG_SETOPS
119 #include <linux/string.h>
121 #define _SIG_SET_BINOP(name, op) \
122 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
124 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
126 switch (_NSIG_WORDS) { \
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); \
133 a1 = a->sig[1]; b1 = b->sig[1]; \
134 r->sig[1] = op(a1, b1); \
136 a0 = a->sig[0]; b0 = b->sig[0]; \
137 r->sig[0] = op(a0, b0); \
144 #define _sig_or(x,y) ((x) | (y))
145 _SIG_SET_BINOP(sigorsets, _sig_or)
147 #define _sig_and(x,y) ((x) & (y))
148 _SIG_SET_BINOP(sigandsets, _sig_and)
150 #define _sig_andn(x,y) ((x) & ~(y))
151 _SIG_SET_BINOP(sigandnsets, _sig_andn)
153 #undef _SIG_SET_BINOP
158 #define _SIG_SET_OP(name, op) \
159 static inline void name(sigset_t *set) \
161 switch (_NSIG_WORDS) { \
162 case 4: set->sig[3] = op(set->sig[3]); \
163 set->sig[2] = op(set->sig[2]); \
164 case 2: set->sig[1] = op(set->sig[1]); \
165 case 1: set->sig[0] = op(set->sig[0]); \
172 #define _sig_not(x) (~(x))
173 _SIG_SET_OP(signotset, _sig_not)
178 static inline void sigemptyset(sigset_t *set)
180 switch (_NSIG_WORDS) {
182 memset(set, 0, sizeof(sigset_t));
184 case 2: set->sig[1] = 0;
185 case 1: set->sig[0] = 0;
190 static inline void sigfillset(sigset_t *set)
192 switch (_NSIG_WORDS) {
194 memset(set, -1, sizeof(sigset_t));
196 case 2: set->sig[1] = -1;
197 case 1: set->sig[0] = -1;
202 /* Some extensions for manipulating the low 32 signals in particular. */
204 static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
209 static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
211 set->sig[0] &= ~mask;
214 static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
216 return (set->sig[0] & mask) != 0;
219 static inline void siginitset(sigset_t *set, unsigned long mask)
222 switch (_NSIG_WORDS) {
224 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
226 case 2: set->sig[1] = 0;
231 static inline void siginitsetinv(sigset_t *set, unsigned long mask)
234 switch (_NSIG_WORDS) {
236 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
238 case 2: set->sig[1] = -1;
243 #endif /* __HAVE_ARCH_SIG_SETOPS */
245 static inline void init_sigpending(struct sigpending *sig)
247 sigemptyset(&sig->signal);
248 INIT_LIST_HEAD(&sig->list);
251 extern void flush_sigqueue(struct sigpending *queue);
253 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
254 static inline int valid_signal(unsigned long sig)
256 return sig <= _NSIG ? 1 : 0;
263 extern int next_signal(struct sigpending *pending, sigset_t *mask);
264 extern int do_send_sig_info(int sig, struct kernel_siginfo *info,
265 struct task_struct *p, enum pid_type type);
266 extern int group_send_sig_info(int sig, struct kernel_siginfo *info,
267 struct task_struct *p, enum pid_type type);
268 extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
269 extern int sigprocmask(int, sigset_t *, sigset_t *);
270 extern void set_current_blocked(sigset_t *);
271 extern void __set_current_blocked(const sigset_t *);
272 extern int show_unhandled_signals;
274 extern bool get_signal(struct ksignal *ksig);
275 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
276 extern void exit_signals(struct task_struct *tsk);
277 extern void kernel_sigaction(int, __sighandler_t);
279 static inline void allow_signal(int sig)
282 * Kernel threads handle their own signals. Let the signal code
283 * know it'll be handled, so that they don't get converted to
284 * SIGKILL or just silently dropped.
286 kernel_sigaction(sig, (__force __sighandler_t)2);
289 static inline void disallow_signal(int sig)
291 kernel_sigaction(sig, SIG_IGN);
294 extern struct kmem_cache *sighand_cachep;
296 extern bool unhandled_signal(struct task_struct *tsk, int sig);
299 * In POSIX a signal is sent either to a specific thread (Linux task)
300 * or to the process as a whole (Linux thread group). How the signal
301 * is sent determines whether it's to one thread or the whole group,
302 * which determines which signal mask(s) are involved in blocking it
303 * from being delivered until later. When the signal is delivered,
304 * either it's caught or ignored by a user handler or it has a default
305 * effect that applies to the whole thread group (POSIX process).
307 * The possible effects an unblocked signal set to SIG_DFL can have are:
308 * ignore - Nothing Happens
309 * terminate - kill the process, i.e. all threads in the group,
310 * similar to exit_group. The group leader (only) reports
311 * WIFSIGNALED status to its parent.
312 * coredump - write a core dump file describing all threads using
313 * the same mm and then kill all those threads
314 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
316 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
317 * Other signals when not blocked and set to SIG_DFL behaves as follows.
318 * The job control signals also have other special effects.
320 * +--------------------+------------------+
321 * | POSIX signal | default action |
322 * +--------------------+------------------+
323 * | SIGHUP | terminate |
324 * | SIGINT | terminate |
325 * | SIGQUIT | coredump |
326 * | SIGILL | coredump |
327 * | SIGTRAP | coredump |
328 * | SIGABRT/SIGIOT | coredump |
329 * | SIGBUS | coredump |
330 * | SIGFPE | coredump |
331 * | SIGKILL | terminate(+) |
332 * | SIGUSR1 | terminate |
333 * | SIGSEGV | coredump |
334 * | SIGUSR2 | terminate |
335 * | SIGPIPE | terminate |
336 * | SIGALRM | terminate |
337 * | SIGTERM | terminate |
338 * | SIGCHLD | ignore |
339 * | SIGCONT | ignore(*) |
340 * | SIGSTOP | stop(*)(+) |
341 * | SIGTSTP | stop(*) |
342 * | SIGTTIN | stop(*) |
343 * | SIGTTOU | stop(*) |
344 * | SIGURG | ignore |
345 * | SIGXCPU | coredump |
346 * | SIGXFSZ | coredump |
347 * | SIGVTALRM | terminate |
348 * | SIGPROF | terminate |
349 * | SIGPOLL/SIGIO | terminate |
350 * | SIGSYS/SIGUNUSED | coredump |
351 * | SIGSTKFLT | terminate |
352 * | SIGWINCH | ignore |
353 * | SIGPWR | terminate |
354 * | SIGRTMIN-SIGRTMAX | terminate |
355 * +--------------------+------------------+
356 * | non-POSIX signal | default action |
357 * +--------------------+------------------+
358 * | SIGEMT | coredump |
359 * +--------------------+------------------+
361 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
362 * (*) Special job control effects:
363 * When SIGCONT is sent, it resumes the process (all threads in the group)
364 * from TASK_STOPPED state and also clears any pending/queued stop signals
365 * (any of those marked with "stop(*)"). This happens regardless of blocking,
366 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
367 * any pending/queued SIGCONT signals; this happens regardless of blocking,
368 * catching, or ignored the stop signal, though (except for SIGSTOP) the
369 * default action of stopping the process may happen later or never.
373 #define SIGEMT_MASK rt_sigmask(SIGEMT)
375 #define SIGEMT_MASK 0
378 #if SIGRTMIN > BITS_PER_LONG
379 #define rt_sigmask(sig) (1ULL << ((sig)-1))
381 #define rt_sigmask(sig) sigmask(sig)
384 #define siginmask(sig, mask) \
385 ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
387 #define SIG_KERNEL_ONLY_MASK (\
388 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
390 #define SIG_KERNEL_STOP_MASK (\
391 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
392 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
394 #define SIG_KERNEL_COREDUMP_MASK (\
395 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
396 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
397 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
398 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
399 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
402 #define SIG_KERNEL_IGNORE_MASK (\
403 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
404 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
406 #define SIG_SPECIFIC_SICODES_MASK (\
407 rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \
408 rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \
409 rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \
410 rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \
413 #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
414 #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
415 #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
416 #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
417 #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK)
419 #define sig_fatal(t, signr) \
420 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
421 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
423 void signals_init(void);
425 int restore_altstack(const stack_t __user *);
426 int __save_altstack(stack_t __user *, unsigned long);
428 #define save_altstack_ex(uss, sp) do { \
429 stack_t __user *__uss = uss; \
430 struct task_struct *t = current; \
431 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
432 put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
433 put_user_ex(t->sas_ss_size, &__uss->ss_size); \
434 if (t->sas_ss_flags & SS_AUTODISARM) \
438 #ifdef CONFIG_PROC_FS
440 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
443 #endif /* _LINUX_SIGNAL_H */