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 static inline void copy_siginfo_to_external(siginfo_t *to,
28 const kernel_siginfo_t *from)
30 memcpy(to, from, sizeof(*from));
31 memset(((char *)to) + sizeof(struct kernel_siginfo), 0,
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);
53 enum siginfo_layout siginfo_layout(unsigned sig, int si_code);
56 * Define some primitives to manipulate sigset_t.
59 #ifndef __HAVE_ARCH_SIG_BITOPS
60 #include <linux/bitops.h>
62 /* We don't use <linux/bitops.h> for these because there is no need to
64 static inline void sigaddset(sigset_t *set, int _sig)
66 unsigned long sig = _sig - 1;
68 set->sig[0] |= 1UL << sig;
70 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
73 static inline void sigdelset(sigset_t *set, int _sig)
75 unsigned long sig = _sig - 1;
77 set->sig[0] &= ~(1UL << sig);
79 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
82 static inline int sigismember(sigset_t *set, int _sig)
84 unsigned long sig = _sig - 1;
86 return 1 & (set->sig[0] >> sig);
88 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
91 #endif /* __HAVE_ARCH_SIG_BITOPS */
93 static inline int sigisemptyset(sigset_t *set)
95 switch (_NSIG_WORDS) {
97 return (set->sig[3] | set->sig[2] |
98 set->sig[1] | set->sig[0]) == 0;
100 return (set->sig[1] | set->sig[0]) == 0;
102 return set->sig[0] == 0;
109 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
111 switch (_NSIG_WORDS) {
113 return (set1->sig[3] == set2->sig[3]) &&
114 (set1->sig[2] == set2->sig[2]) &&
115 (set1->sig[1] == set2->sig[1]) &&
116 (set1->sig[0] == set2->sig[0]);
118 return (set1->sig[1] == set2->sig[1]) &&
119 (set1->sig[0] == set2->sig[0]);
121 return set1->sig[0] == set2->sig[0];
126 #define sigmask(sig) (1UL << ((sig) - 1))
128 #ifndef __HAVE_ARCH_SIG_SETOPS
130 #define _SIG_SET_BINOP(name, op) \
131 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
133 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
135 switch (_NSIG_WORDS) { \
137 a3 = a->sig[3]; a2 = a->sig[2]; \
138 b3 = b->sig[3]; b2 = b->sig[2]; \
139 r->sig[3] = op(a3, b3); \
140 r->sig[2] = op(a2, b2); \
143 a1 = a->sig[1]; b1 = b->sig[1]; \
144 r->sig[1] = op(a1, b1); \
147 a0 = a->sig[0]; b0 = b->sig[0]; \
148 r->sig[0] = op(a0, b0); \
155 #define _sig_or(x,y) ((x) | (y))
156 _SIG_SET_BINOP(sigorsets, _sig_or)
158 #define _sig_and(x,y) ((x) & (y))
159 _SIG_SET_BINOP(sigandsets, _sig_and)
161 #define _sig_andn(x,y) ((x) & ~(y))
162 _SIG_SET_BINOP(sigandnsets, _sig_andn)
164 #undef _SIG_SET_BINOP
169 #define _SIG_SET_OP(name, op) \
170 static inline void name(sigset_t *set) \
172 switch (_NSIG_WORDS) { \
173 case 4: set->sig[3] = op(set->sig[3]); \
174 set->sig[2] = op(set->sig[2]); \
176 case 2: set->sig[1] = op(set->sig[1]); \
178 case 1: set->sig[0] = op(set->sig[0]); \
185 #define _sig_not(x) (~(x))
186 _SIG_SET_OP(signotset, _sig_not)
191 static inline void sigemptyset(sigset_t *set)
193 switch (_NSIG_WORDS) {
195 memset(set, 0, sizeof(sigset_t));
197 case 2: set->sig[1] = 0;
199 case 1: set->sig[0] = 0;
204 static inline void sigfillset(sigset_t *set)
206 switch (_NSIG_WORDS) {
208 memset(set, -1, sizeof(sigset_t));
210 case 2: set->sig[1] = -1;
212 case 1: set->sig[0] = -1;
217 /* Some extensions for manipulating the low 32 signals in particular. */
219 static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
224 static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
226 set->sig[0] &= ~mask;
229 static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
231 return (set->sig[0] & mask) != 0;
234 static inline void siginitset(sigset_t *set, unsigned long mask)
237 switch (_NSIG_WORDS) {
239 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
241 case 2: set->sig[1] = 0;
247 static inline void siginitsetinv(sigset_t *set, unsigned long mask)
250 switch (_NSIG_WORDS) {
252 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
254 case 2: set->sig[1] = -1;
260 #endif /* __HAVE_ARCH_SIG_SETOPS */
262 static inline void init_sigpending(struct sigpending *sig)
264 sigemptyset(&sig->signal);
265 INIT_LIST_HEAD(&sig->list);
268 extern void flush_sigqueue(struct sigpending *queue);
270 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
271 static inline int valid_signal(unsigned long sig)
273 return sig <= _NSIG ? 1 : 0;
280 extern int next_signal(struct sigpending *pending, sigset_t *mask);
281 extern int do_send_sig_info(int sig, struct kernel_siginfo *info,
282 struct task_struct *p, enum pid_type type);
283 extern int group_send_sig_info(int sig, struct kernel_siginfo *info,
284 struct task_struct *p, enum pid_type type);
285 extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
286 extern int sigprocmask(int, sigset_t *, sigset_t *);
287 extern void set_current_blocked(sigset_t *);
288 extern void __set_current_blocked(const sigset_t *);
289 extern int show_unhandled_signals;
291 extern bool get_signal(struct ksignal *ksig);
292 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
293 extern void exit_signals(struct task_struct *tsk);
294 extern void kernel_sigaction(int, __sighandler_t);
296 #define SIG_KTHREAD ((__force __sighandler_t)2)
297 #define SIG_KTHREAD_KERNEL ((__force __sighandler_t)3)
299 static inline void allow_signal(int sig)
302 * Kernel threads handle their own signals. Let the signal code
303 * know it'll be handled, so that they don't get converted to
304 * SIGKILL or just silently dropped.
306 kernel_sigaction(sig, SIG_KTHREAD);
309 static inline void allow_kernel_signal(int sig)
312 * Kernel threads handle their own signals. Let the signal code
313 * know signals sent by the kernel will be handled, so that they
314 * don't get silently dropped.
316 kernel_sigaction(sig, SIG_KTHREAD_KERNEL);
319 static inline void disallow_signal(int sig)
321 kernel_sigaction(sig, SIG_IGN);
324 extern struct kmem_cache *sighand_cachep;
326 extern bool unhandled_signal(struct task_struct *tsk, int sig);
329 * In POSIX a signal is sent either to a specific thread (Linux task)
330 * or to the process as a whole (Linux thread group). How the signal
331 * is sent determines whether it's to one thread or the whole group,
332 * which determines which signal mask(s) are involved in blocking it
333 * from being delivered until later. When the signal is delivered,
334 * either it's caught or ignored by a user handler or it has a default
335 * effect that applies to the whole thread group (POSIX process).
337 * The possible effects an unblocked signal set to SIG_DFL can have are:
338 * ignore - Nothing Happens
339 * terminate - kill the process, i.e. all threads in the group,
340 * similar to exit_group. The group leader (only) reports
341 * WIFSIGNALED status to its parent.
342 * coredump - write a core dump file describing all threads using
343 * the same mm and then kill all those threads
344 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
346 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
347 * Other signals when not blocked and set to SIG_DFL behaves as follows.
348 * The job control signals also have other special effects.
350 * +--------------------+------------------+
351 * | POSIX signal | default action |
352 * +--------------------+------------------+
353 * | SIGHUP | terminate |
354 * | SIGINT | terminate |
355 * | SIGQUIT | coredump |
356 * | SIGILL | coredump |
357 * | SIGTRAP | coredump |
358 * | SIGABRT/SIGIOT | coredump |
359 * | SIGBUS | coredump |
360 * | SIGFPE | coredump |
361 * | SIGKILL | terminate(+) |
362 * | SIGUSR1 | terminate |
363 * | SIGSEGV | coredump |
364 * | SIGUSR2 | terminate |
365 * | SIGPIPE | terminate |
366 * | SIGALRM | terminate |
367 * | SIGTERM | terminate |
368 * | SIGCHLD | ignore |
369 * | SIGCONT | ignore(*) |
370 * | SIGSTOP | stop(*)(+) |
371 * | SIGTSTP | stop(*) |
372 * | SIGTTIN | stop(*) |
373 * | SIGTTOU | stop(*) |
374 * | SIGURG | ignore |
375 * | SIGXCPU | coredump |
376 * | SIGXFSZ | coredump |
377 * | SIGVTALRM | terminate |
378 * | SIGPROF | terminate |
379 * | SIGPOLL/SIGIO | terminate |
380 * | SIGSYS/SIGUNUSED | coredump |
381 * | SIGSTKFLT | terminate |
382 * | SIGWINCH | ignore |
383 * | SIGPWR | terminate |
384 * | SIGRTMIN-SIGRTMAX | terminate |
385 * +--------------------+------------------+
386 * | non-POSIX signal | default action |
387 * +--------------------+------------------+
388 * | SIGEMT | coredump |
389 * +--------------------+------------------+
391 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
392 * (*) Special job control effects:
393 * When SIGCONT is sent, it resumes the process (all threads in the group)
394 * from TASK_STOPPED state and also clears any pending/queued stop signals
395 * (any of those marked with "stop(*)"). This happens regardless of blocking,
396 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
397 * any pending/queued SIGCONT signals; this happens regardless of blocking,
398 * catching, or ignored the stop signal, though (except for SIGSTOP) the
399 * default action of stopping the process may happen later or never.
403 #define SIGEMT_MASK rt_sigmask(SIGEMT)
405 #define SIGEMT_MASK 0
408 #if SIGRTMIN > BITS_PER_LONG
409 #define rt_sigmask(sig) (1ULL << ((sig)-1))
411 #define rt_sigmask(sig) sigmask(sig)
414 #define siginmask(sig, mask) \
415 ((sig) > 0 && (sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
417 #define SIG_KERNEL_ONLY_MASK (\
418 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
420 #define SIG_KERNEL_STOP_MASK (\
421 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
422 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
424 #define SIG_KERNEL_COREDUMP_MASK (\
425 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
426 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
427 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
428 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
429 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
432 #define SIG_KERNEL_IGNORE_MASK (\
433 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
434 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
436 #define SIG_SPECIFIC_SICODES_MASK (\
437 rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \
438 rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \
439 rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \
440 rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \
443 #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
444 #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
445 #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
446 #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
447 #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK)
449 #define sig_fatal(t, signr) \
450 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
451 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
453 void signals_init(void);
455 int restore_altstack(const stack_t __user *);
456 int __save_altstack(stack_t __user *, unsigned long);
458 #define unsafe_save_altstack(uss, sp, label) do { \
459 stack_t __user *__uss = uss; \
460 struct task_struct *t = current; \
461 unsafe_put_user((void __user *)t->sas_ss_sp, &__uss->ss_sp, label); \
462 unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \
463 unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \
466 #ifdef CONFIG_DYNAMIC_SIGFRAME
467 bool sigaltstack_size_valid(size_t ss_size);
469 static inline bool sigaltstack_size_valid(size_t size) { return true; }
470 #endif /* !CONFIG_DYNAMIC_SIGFRAME */
472 #ifdef CONFIG_PROC_FS
474 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
477 #ifndef arch_untagged_si_addr
479 * Given a fault address and a signal and si_code which correspond to the
480 * _sigfault union member, returns the address that must appear in si_addr if
481 * the signal handler does not have SA_EXPOSE_TAGBITS enabled in sa_flags.
483 static inline void __user *arch_untagged_si_addr(void __user *addr,
485 unsigned long si_code)
491 #endif /* _LINUX_SIGNAL_H */