summaryrefslogtreecommitdiff
path: root/include/linux/signal.h
blob: 7e095147656cfac8320faab052f5574e79cd6f13 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
#ifndef _LINUX_SIGNAL_H
#define _LINUX_SIGNAL_H

#include <asm/signal.h>
#include <asm/siginfo.h>

#ifdef __KERNEL__
#include <linux/list.h>

/*
 * Real Time signals may be queued.
 */

struct sigqueue {
	struct list_head list;
	int flags;
	siginfo_t info;
	struct user_struct *user;
};

/* flags values. */
#define SIGQUEUE_PREALLOC	1

struct sigpending {
	struct list_head list;
	sigset_t signal;
};

/*
 * Define some primitives to manipulate sigset_t.
 */

#ifndef __HAVE_ARCH_SIG_BITOPS
#include <linux/bitops.h>

/* We don't use <linux/bitops.h> for these because there is no need to
   be atomic.  */
static inline void sigaddset(sigset_t *set, int _sig)
{
	unsigned long sig = _sig - 1;
	if (_NSIG_WORDS == 1)
		set->sig[0] |= 1UL << sig;
	else
		set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
}

static inline void sigdelset(sigset_t *set, int _sig)
{
	unsigned long sig = _sig - 1;
	if (_NSIG_WORDS == 1)
		set->sig[0] &= ~(1UL << sig);
	else
		set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
}

static inline int sigismember(sigset_t *set, int _sig)
{
	unsigned long sig = _sig - 1;
	if (_NSIG_WORDS == 1)
		return 1 & (set->sig[0] >> sig);
	else
		return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
}

static inline int sigfindinword(unsigned long word)
{
	return ffz(~word);
}

#endif /* __HAVE_ARCH_SIG_BITOPS */

static inline int sigisemptyset(sigset_t *set)
{
	extern void _NSIG_WORDS_is_unsupported_size(void);
	switch (_NSIG_WORDS) {
	case 4:
		return (set->sig[3] | set->sig[2] |
			set->sig[1] | set->sig[0]) == 0;
	case 2:
		return (set->sig[1] | set->sig[0]) == 0;
	case 1:
		return set->sig[0] == 0;
	default:
		_NSIG_WORDS_is_unsupported_size();
		return 0;
	}
}

#define sigmask(sig)	(1UL << ((sig) - 1))

#ifndef __HAVE_ARCH_SIG_SETOPS
#include <linux/string.h>

#define _SIG_SET_BINOP(name, op)					\
static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
{									\
	extern void _NSIG_WORDS_is_unsupported_size(void);		\
	unsigned long a0, a1, a2, a3, b0, b1, b2, b3;			\
									\
	switch (_NSIG_WORDS) {						\
	    case 4:							\
		a3 = a->sig[3]; a2 = a->sig[2];				\
		b3 = b->sig[3]; b2 = b->sig[2];				\
		r->sig[3] = op(a3, b3);					\
		r->sig[2] = op(a2, b2);					\
	    case 2:							\
		a1 = a->sig[1]; b1 = b->sig[1];				\
		r->sig[1] = op(a1, b1);					\
	    case 1:							\
		a0 = a->sig[0]; b0 = b->sig[0];				\
		r->sig[0] = op(a0, b0);					\
		break;							\
	    default:							\
		_NSIG_WORDS_is_unsupported_size();			\
	}								\
}

#define _sig_or(x,y)	((x) | (y))
_SIG_SET_BINOP(sigorsets, _sig_or)

#define _sig_and(x,y)	((x) & (y))
_SIG_SET_BINOP(sigandsets, _sig_and)

#define _sig_nand(x,y)	((x) & ~(y))
_SIG_SET_BINOP(signandsets, _sig_nand)

#undef _SIG_SET_BINOP
#undef _sig_or
#undef _sig_and
#undef _sig_nand

#define _SIG_SET_OP(name, op)						\
static inline void name(sigset_t *set)					\
{									\
	extern void _NSIG_WORDS_is_unsupported_size(void);		\
									\
	switch (_NSIG_WORDS) {						\
	    case 4: set->sig[3] = op(set->sig[3]);			\
		    set->sig[2] = op(set->sig[2]);			\
	    case 2: set->sig[1] = op(set->sig[1]);			\
	    case 1: set->sig[0] = op(set->sig[0]);			\
		    break;						\
	    default:							\
		_NSIG_WORDS_is_unsupported_size();			\
	}								\
}

#define _sig_not(x)	(~(x))
_SIG_SET_OP(signotset, _sig_not)

#undef _SIG_SET_OP
#undef _sig_not

static inline void sigemptyset(sigset_t *set)
{
	switch (_NSIG_WORDS) {
	default:
		memset(set, 0, sizeof(sigset_t));
		break;
	case 2: set->sig[1] = 0;
	case 1:	set->sig[0] = 0;
		break;
	}
}

static inline void sigfillset(sigset_t *set)
{
	switch (_NSIG_WORDS) {
	default:
		memset(set, -1, sizeof(sigset_t));
		break;
	case 2: set->sig[1] = -1;
	case 1:	set->sig[0] = -1;
		break;
	}
}

/* Some extensions for manipulating the low 32 signals in particular.  */

static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
{
	set->sig[0] |= mask;
}

static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
{
	set->sig[0] &= ~mask;
}

static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
{
	return (set->sig[0] & mask) != 0;
}

static inline void siginitset(sigset_t *set, unsigned long mask)
{
	set->sig[0] = mask;
	switch (_NSIG_WORDS) {
	default:
		memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
		break;
	case 2: set->sig[1] = 0;
	case 1: ;
	}
}

static inline void siginitsetinv(sigset_t *set, unsigned long mask)
{
	set->sig[0] = ~mask;
	switch (_NSIG_WORDS) {
	default:
		memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
		break;
	case 2: set->sig[1] = -1;
	case 1: ;
	}
}

#endif /* __HAVE_ARCH_SIG_SETOPS */

static inline void init_sigpending(struct sigpending *sig)
{
	sigemptyset(&sig->signal);
	INIT_LIST_HEAD(&sig->list);
}

extern void flush_sigqueue(struct sigpending *queue);

/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
static inline int valid_signal(unsigned long sig)
{
	return sig <= _NSIG ? 1 : 0;
}

extern int next_signal(struct sigpending *pending, sigset_t *mask);
extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
extern long do_sigpending(void __user *, unsigned long);
extern int sigprocmask(int, sigset_t *, sigset_t *);
extern int show_unhandled_signals;

struct pt_regs;
extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);

extern struct kmem_cache *sighand_cachep;

int unhandled_signal(struct task_struct *tsk, int sig);

/*
 * In POSIX a signal is sent either to a specific thread (Linux task)
 * or to the process as a whole (Linux thread group).  How the signal
 * is sent determines whether it's to one thread or the whole group,
 * which determines which signal mask(s) are involved in blocking it
 * from being delivered until later.  When the signal is delivered,
 * either it's caught or ignored by a user handler or it has a default
 * effect that applies to the whole thread group (POSIX process).
 *
 * The possible effects an unblocked signal set to SIG_DFL can have are:
 *   ignore	- Nothing Happens
 *   terminate	- kill the process, i.e. all threads in the group,
 * 		  similar to exit_group.  The group leader (only) reports
 *		  WIFSIGNALED status to its parent.
 *   coredump	- write a core dump file describing all threads using
 *		  the same mm and then kill all those threads
 *   stop 	- stop all the threads in the group, i.e. TASK_STOPPED state
 *
 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
 * Other signals when not blocked and set to SIG_DFL behaves as follows.
 * The job control signals also have other special effects.
 *
 *	+--------------------+------------------+
 *	|  POSIX signal      |  default action  |
 *	+--------------------+------------------+
 *	|  SIGHUP            |  terminate	|
 *	|  SIGINT            |	terminate	|
 *	|  SIGQUIT           |	coredump 	|
 *	|  SIGILL            |	coredump 	|
 *	|  SIGTRAP           |	coredump 	|
 *	|  SIGABRT/SIGIOT    |	coredump 	|
 *	|  SIGBUS            |	coredump 	|
 *	|  SIGFPE            |	coredump 	|
 *	|  SIGKILL           |	terminate(+)	|
 *	|  SIGUSR1           |	terminate	|
 *	|  SIGSEGV           |	coredump 	|
 *	|  SIGUSR2           |	terminate	|
 *	|  SIGPIPE           |	terminate	|
 *	|  SIGALRM           |	terminate	|
 *	|  SIGTERM           |	terminate	|
 *	|  SIGCHLD           |	ignore   	|
 *	|  SIGCONT           |	ignore(*)	|
 *	|  SIGSTOP           |	stop(*)(+)  	|
 *	|  SIGTSTP           |	stop(*)  	|
 *	|  SIGTTIN           |	stop(*)  	|
 *	|  SIGTTOU           |	stop(*)  	|
 *	|  SIGURG            |	ignore   	|
 *	|  SIGXCPU           |	coredump 	|
 *	|  SIGXFSZ           |	coredump 	|
 *	|  SIGVTALRM         |	terminate	|
 *	|  SIGPROF           |	terminate	|
 *	|  SIGPOLL/SIGIO     |	terminate	|
 *	|  SIGSYS/SIGUNUSED  |	coredump 	|
 *	|  SIGSTKFLT         |	terminate	|
 *	|  SIGWINCH          |	ignore   	|
 *	|  SIGPWR            |	terminate	|
 *	|  SIGRTMIN-SIGRTMAX |	terminate       |
 *	+--------------------+------------------+
 *	|  non-POSIX signal  |  default action  |
 *	+--------------------+------------------+
 *	|  SIGEMT            |  coredump	|
 *	+--------------------+------------------+
 *
 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
 * (*) Special job control effects:
 * When SIGCONT is sent, it resumes the process (all threads in the group)
 * from TASK_STOPPED state and also clears any pending/queued stop signals
 * (any of those marked with "stop(*)").  This happens regardless of blocking,
 * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
 * any pending/queued SIGCONT signals; this happens regardless of blocking,
 * catching, or ignored the stop signal, though (except for SIGSTOP) the
 * default action of stopping the process may happen later or never.
 */

#ifdef SIGEMT
#define SIGEMT_MASK	rt_sigmask(SIGEMT)
#else
#define SIGEMT_MASK	0
#endif

#if SIGRTMIN > BITS_PER_LONG
#define rt_sigmask(sig)	(1ULL << ((sig)-1))
#else
#define rt_sigmask(sig)	sigmask(sig)
#endif
#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))

#define SIG_KERNEL_ONLY_MASK (\
	rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))

#define SIG_KERNEL_STOP_MASK (\
	rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
	rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )

#define SIG_KERNEL_COREDUMP_MASK (\
        rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
	rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
        rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
	rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
        rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
	SIGEMT_MASK				       )

#define SIG_KERNEL_IGNORE_MASK (\
        rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
	rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )

#define sig_kernel_only(sig) \
	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
#define sig_kernel_coredump(sig) \
	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
#define sig_kernel_ignore(sig) \
	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
#define sig_kernel_stop(sig) \
	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))

#define sig_needs_tasklist(sig)	((sig) == SIGCONT)

#define sig_user_defined(t, signr) \
	(((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&	\
	 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))

#define sig_fatal(t, signr) \
	(!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
	 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)

void signals_init(void);

#endif /* __KERNEL__ */

#endif /* _LINUX_SIGNAL_H */