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
sigequalsets(const sigset_t * set1,const sigset_t * set2)100 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
101 {
102 switch (_NSIG_WORDS) {
103 case 4:
104 return (set1->sig[3] == set2->sig[3]) &&
105 (set1->sig[2] == set2->sig[2]) &&
106 (set1->sig[1] == set2->sig[1]) &&
107 (set1->sig[0] == set2->sig[0]);
108 case 2:
109 return (set1->sig[1] == set2->sig[1]) &&
110 (set1->sig[0] == set2->sig[0]);
111 case 1:
112 return set1->sig[0] == set2->sig[0];
113 }
114 return 0;
115 }
116
117 #define sigmask(sig) (1UL << ((sig) - 1))
118
119 #ifndef __HAVE_ARCH_SIG_SETOPS
120 #include <linux/string.h>
121
122 #define _SIG_SET_BINOP(name, op) \
123 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
124 { \
125 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
126 \
127 switch (_NSIG_WORDS) { \
128 case 4: \
129 a3 = a->sig[3]; a2 = a->sig[2]; \
130 b3 = b->sig[3]; b2 = b->sig[2]; \
131 r->sig[3] = op(a3, b3); \
132 r->sig[2] = op(a2, b2); \
133 case 2: \
134 a1 = a->sig[1]; b1 = b->sig[1]; \
135 r->sig[1] = op(a1, b1); \
136 case 1: \
137 a0 = a->sig[0]; b0 = b->sig[0]; \
138 r->sig[0] = op(a0, b0); \
139 break; \
140 default: \
141 BUILD_BUG(); \
142 } \
143 }
144
145 #define _sig_or(x,y) ((x) | (y))
_SIG_SET_BINOP(sigorsets,_sig_or)146 _SIG_SET_BINOP(sigorsets, _sig_or)
147
148 #define _sig_and(x,y) ((x) & (y))
149 _SIG_SET_BINOP(sigandsets, _sig_and)
150
151 #define _sig_andn(x,y) ((x) & ~(y))
152 _SIG_SET_BINOP(sigandnsets, _sig_andn)
153
154 #undef _SIG_SET_BINOP
155 #undef _sig_or
156 #undef _sig_and
157 #undef _sig_andn
158
159 #define _SIG_SET_OP(name, op) \
160 static inline void name(sigset_t *set) \
161 { \
162 switch (_NSIG_WORDS) { \
163 case 4: set->sig[3] = op(set->sig[3]); \
164 set->sig[2] = op(set->sig[2]); \
165 case 2: set->sig[1] = op(set->sig[1]); \
166 case 1: set->sig[0] = op(set->sig[0]); \
167 break; \
168 default: \
169 BUILD_BUG(); \
170 } \
171 }
172
173 #define _sig_not(x) (~(x))
174 _SIG_SET_OP(signotset, _sig_not)
175
176 #undef _SIG_SET_OP
177 #undef _sig_not
178
179 static inline void sigemptyset(sigset_t *set)
180 {
181 switch (_NSIG_WORDS) {
182 default:
183 memset(set, 0, sizeof(sigset_t));
184 break;
185 case 2: set->sig[1] = 0;
186 case 1: set->sig[0] = 0;
187 break;
188 }
189 }
190
sigfillset(sigset_t * set)191 static inline void sigfillset(sigset_t *set)
192 {
193 switch (_NSIG_WORDS) {
194 default:
195 memset(set, -1, sizeof(sigset_t));
196 break;
197 case 2: set->sig[1] = -1;
198 case 1: set->sig[0] = -1;
199 break;
200 }
201 }
202
203 /* Some extensions for manipulating the low 32 signals in particular. */
204
sigaddsetmask(sigset_t * set,unsigned long mask)205 static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
206 {
207 set->sig[0] |= mask;
208 }
209
sigdelsetmask(sigset_t * set,unsigned long mask)210 static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
211 {
212 set->sig[0] &= ~mask;
213 }
214
sigtestsetmask(sigset_t * set,unsigned long mask)215 static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
216 {
217 return (set->sig[0] & mask) != 0;
218 }
219
siginitset(sigset_t * set,unsigned long mask)220 static inline void siginitset(sigset_t *set, unsigned long mask)
221 {
222 set->sig[0] = mask;
223 switch (_NSIG_WORDS) {
224 default:
225 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
226 break;
227 case 2: set->sig[1] = 0;
228 case 1: ;
229 }
230 }
231
siginitsetinv(sigset_t * set,unsigned long mask)232 static inline void siginitsetinv(sigset_t *set, unsigned long mask)
233 {
234 set->sig[0] = ~mask;
235 switch (_NSIG_WORDS) {
236 default:
237 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
238 break;
239 case 2: set->sig[1] = -1;
240 case 1: ;
241 }
242 }
243
244 #endif /* __HAVE_ARCH_SIG_SETOPS */
245
init_sigpending(struct sigpending * sig)246 static inline void init_sigpending(struct sigpending *sig)
247 {
248 sigemptyset(&sig->signal);
249 INIT_LIST_HEAD(&sig->list);
250 }
251
252 extern void flush_sigqueue(struct sigpending *queue);
253
254 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
valid_signal(unsigned long sig)255 static inline int valid_signal(unsigned long sig)
256 {
257 return sig <= _NSIG ? 1 : 0;
258 }
259
260 struct timespec;
261 struct pt_regs;
262
263 extern int next_signal(struct sigpending *pending, sigset_t *mask);
264 extern int do_send_sig_info(int sig, struct siginfo *info,
265 struct task_struct *p, bool group);
266 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
267 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
268 extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
269 const struct timespec *);
270 extern int sigprocmask(int, sigset_t *, sigset_t *);
271 extern void set_current_blocked(sigset_t *);
272 extern void __set_current_blocked(const sigset_t *);
273 extern int show_unhandled_signals;
274
275 struct sigaction {
276 #ifndef __ARCH_HAS_IRIX_SIGACTION
277 __sighandler_t sa_handler;
278 unsigned long sa_flags;
279 #else
280 unsigned int sa_flags;
281 __sighandler_t sa_handler;
282 #endif
283 #ifdef __ARCH_HAS_SA_RESTORER
284 __sigrestore_t sa_restorer;
285 #endif
286 sigset_t sa_mask; /* mask last for extensibility */
287 };
288
289 struct k_sigaction {
290 struct sigaction sa;
291 #ifdef __ARCH_HAS_KA_RESTORER
292 __sigrestore_t ka_restorer;
293 #endif
294 };
295
296 #ifdef CONFIG_OLD_SIGACTION
297 struct old_sigaction {
298 __sighandler_t sa_handler;
299 old_sigset_t sa_mask;
300 unsigned long sa_flags;
301 __sigrestore_t sa_restorer;
302 };
303 #endif
304
305 struct ksignal {
306 struct k_sigaction ka;
307 siginfo_t info;
308 int sig;
309 };
310
311 extern int get_signal(struct ksignal *ksig);
312 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
313 extern void exit_signals(struct task_struct *tsk);
314 extern void kernel_sigaction(int, __sighandler_t);
315
316 #define SIG_KTHREAD ((__force __sighandler_t)2)
317 #define SIG_KTHREAD_KERNEL ((__force __sighandler_t)3)
318
allow_signal(int sig)319 static inline void allow_signal(int sig)
320 {
321 /*
322 * Kernel threads handle their own signals. Let the signal code
323 * know it'll be handled, so that they don't get converted to
324 * SIGKILL or just silently dropped.
325 */
326 kernel_sigaction(sig, SIG_KTHREAD);
327 }
328
allow_kernel_signal(int sig)329 static inline void allow_kernel_signal(int sig)
330 {
331 /*
332 * Kernel threads handle their own signals. Let the signal code
333 * know signals sent by the kernel will be handled, so that they
334 * don't get silently dropped.
335 */
336 kernel_sigaction(sig, SIG_KTHREAD_KERNEL);
337 }
338
disallow_signal(int sig)339 static inline void disallow_signal(int sig)
340 {
341 kernel_sigaction(sig, SIG_IGN);
342 }
343
344 extern struct kmem_cache *sighand_cachep;
345
346 int unhandled_signal(struct task_struct *tsk, int sig);
347
348 /*
349 * In POSIX a signal is sent either to a specific thread (Linux task)
350 * or to the process as a whole (Linux thread group). How the signal
351 * is sent determines whether it's to one thread or the whole group,
352 * which determines which signal mask(s) are involved in blocking it
353 * from being delivered until later. When the signal is delivered,
354 * either it's caught or ignored by a user handler or it has a default
355 * effect that applies to the whole thread group (POSIX process).
356 *
357 * The possible effects an unblocked signal set to SIG_DFL can have are:
358 * ignore - Nothing Happens
359 * terminate - kill the process, i.e. all threads in the group,
360 * similar to exit_group. The group leader (only) reports
361 * WIFSIGNALED status to its parent.
362 * coredump - write a core dump file describing all threads using
363 * the same mm and then kill all those threads
364 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
365 *
366 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
367 * Other signals when not blocked and set to SIG_DFL behaves as follows.
368 * The job control signals also have other special effects.
369 *
370 * +--------------------+------------------+
371 * | POSIX signal | default action |
372 * +--------------------+------------------+
373 * | SIGHUP | terminate |
374 * | SIGINT | terminate |
375 * | SIGQUIT | coredump |
376 * | SIGILL | coredump |
377 * | SIGTRAP | coredump |
378 * | SIGABRT/SIGIOT | coredump |
379 * | SIGBUS | coredump |
380 * | SIGFPE | coredump |
381 * | SIGKILL | terminate(+) |
382 * | SIGUSR1 | terminate |
383 * | SIGSEGV | coredump |
384 * | SIGUSR2 | terminate |
385 * | SIGPIPE | terminate |
386 * | SIGALRM | terminate |
387 * | SIGTERM | terminate |
388 * | SIGCHLD | ignore |
389 * | SIGCONT | ignore(*) |
390 * | SIGSTOP | stop(*)(+) |
391 * | SIGTSTP | stop(*) |
392 * | SIGTTIN | stop(*) |
393 * | SIGTTOU | stop(*) |
394 * | SIGURG | ignore |
395 * | SIGXCPU | coredump |
396 * | SIGXFSZ | coredump |
397 * | SIGVTALRM | terminate |
398 * | SIGPROF | terminate |
399 * | SIGPOLL/SIGIO | terminate |
400 * | SIGSYS/SIGUNUSED | coredump |
401 * | SIGSTKFLT | terminate |
402 * | SIGWINCH | ignore |
403 * | SIGPWR | terminate |
404 * | SIGRTMIN-SIGRTMAX | terminate |
405 * +--------------------+------------------+
406 * | non-POSIX signal | default action |
407 * +--------------------+------------------+
408 * | SIGEMT | coredump |
409 * +--------------------+------------------+
410 *
411 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
412 * (*) Special job control effects:
413 * When SIGCONT is sent, it resumes the process (all threads in the group)
414 * from TASK_STOPPED state and also clears any pending/queued stop signals
415 * (any of those marked with "stop(*)"). This happens regardless of blocking,
416 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
417 * any pending/queued SIGCONT signals; this happens regardless of blocking,
418 * catching, or ignored the stop signal, though (except for SIGSTOP) the
419 * default action of stopping the process may happen later or never.
420 */
421
422 #ifdef SIGEMT
423 #define SIGEMT_MASK rt_sigmask(SIGEMT)
424 #else
425 #define SIGEMT_MASK 0
426 #endif
427
428 #if SIGRTMIN > BITS_PER_LONG
429 #define rt_sigmask(sig) (1ULL << ((sig)-1))
430 #else
431 #define rt_sigmask(sig) sigmask(sig)
432 #endif
433 #define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
434
435 #define SIG_KERNEL_ONLY_MASK (\
436 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
437
438 #define SIG_KERNEL_STOP_MASK (\
439 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
440 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
441
442 #define SIG_KERNEL_COREDUMP_MASK (\
443 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
444 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
445 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
446 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
447 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
448 SIGEMT_MASK )
449
450 #define SIG_KERNEL_IGNORE_MASK (\
451 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
452 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
453
454 #define sig_kernel_only(sig) \
455 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
456 #define sig_kernel_coredump(sig) \
457 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
458 #define sig_kernel_ignore(sig) \
459 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
460 #define sig_kernel_stop(sig) \
461 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
462
463 #define sig_user_defined(t, signr) \
464 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \
465 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
466
467 #define sig_fatal(t, signr) \
468 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
469 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
470
471 void signals_init(void);
472
473 int restore_altstack(const stack_t __user *);
474 int __save_altstack(stack_t __user *, unsigned long);
475
476 #define save_altstack_ex(uss, sp) do { \
477 stack_t __user *__uss = uss; \
478 struct task_struct *t = current; \
479 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
480 put_user_ex(sas_ss_flags(sp), &__uss->ss_flags); \
481 put_user_ex(t->sas_ss_size, &__uss->ss_size); \
482 } while (0);
483
484 #ifdef CONFIG_PROC_FS
485 struct seq_file;
486 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
487 #endif
488
489 #endif /* _LINUX_SIGNAL_H */
490