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