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