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