1#ifndef _LINUX_SIGNAL_H
2#define _LINUX_SIGNAL_H
3
4#include <asm/signal.h>
5#include <asm/siginfo.h>
6
7#ifdef __KERNEL__
8#include <linux/list.h>
9#include <linux/spinlock.h>
10
11/*
12 * Real Time signals may be queued.
13 */
14
15struct 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
25struct 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.  */
39static 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
48static 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
57static inline int sigismember(sigset_t *set, int _sig)
58{
59	unsigned long sig = _sig - 1;
60	if (_NSIG_WORDS == 1)
61		return 1 & (set->sig[0] >> sig);
62	else
63		return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
64}
65
66static inline int sigfindinword(unsigned long word)
67{
68	return ffz(~word);
69}
70
71#endif /* __HAVE_ARCH_SIG_BITOPS */
72
73static inline int sigisemptyset(sigset_t *set)
74{
75	extern void _NSIG_WORDS_is_unsupported_size(void);
76	switch (_NSIG_WORDS) {
77	case 4:
78		return (set->sig[3] | set->sig[2] |
79			set->sig[1] | set->sig[0]) == 0;
80	case 2:
81		return (set->sig[1] | set->sig[0]) == 0;
82	case 1:
83		return set->sig[0] == 0;
84	default:
85		_NSIG_WORDS_is_unsupported_size();
86		return 0;
87	}
88}
89
90#define sigmask(sig)	(1UL << ((sig) - 1))
91
92#ifndef __HAVE_ARCH_SIG_SETOPS
93#include <linux/string.h>
94
95#define _SIG_SET_BINOP(name, op)					\
96static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
97{									\
98	extern void _NSIG_WORDS_is_unsupported_size(void);		\
99	unsigned long a0, a1, a2, a3, b0, b1, b2, b3;			\
100									\
101	switch (_NSIG_WORDS) {						\
102	    case 4:							\
103		a3 = a->sig[3]; a2 = a->sig[2];				\
104		b3 = b->sig[3]; b2 = b->sig[2];				\
105		r->sig[3] = op(a3, b3);					\
106		r->sig[2] = op(a2, b2);					\
107	    case 2:							\
108		a1 = a->sig[1]; b1 = b->sig[1];				\
109		r->sig[1] = op(a1, b1);					\
110	    case 1:							\
111		a0 = a->sig[0]; b0 = b->sig[0];				\
112		r->sig[0] = op(a0, b0);					\
113		break;							\
114	    default:							\
115		_NSIG_WORDS_is_unsupported_size();			\
116	}								\
117}
118
119#define _sig_or(x,y)	((x) | (y))
120_SIG_SET_BINOP(sigorsets, _sig_or)
121
122#define _sig_and(x,y)	((x) & (y))
123_SIG_SET_BINOP(sigandsets, _sig_and)
124
125#define _sig_nand(x,y)	((x) & ~(y))
126_SIG_SET_BINOP(signandsets, _sig_nand)
127
128#undef _SIG_SET_BINOP
129#undef _sig_or
130#undef _sig_and
131#undef _sig_nand
132
133#define _SIG_SET_OP(name, op)						\
134static inline void name(sigset_t *set)					\
135{									\
136	extern void _NSIG_WORDS_is_unsupported_size(void);		\
137									\
138	switch (_NSIG_WORDS) {						\
139	    case 4: set->sig[3] = op(set->sig[3]);			\
140		    set->sig[2] = op(set->sig[2]);			\
141	    case 2: set->sig[1] = op(set->sig[1]);			\
142	    case 1: set->sig[0] = op(set->sig[0]);			\
143		    break;						\
144	    default:							\
145		_NSIG_WORDS_is_unsupported_size();			\
146	}								\
147}
148
149#define _sig_not(x)	(~(x))
150_SIG_SET_OP(signotset, _sig_not)
151
152#undef _SIG_SET_OP
153#undef _sig_not
154
155static inline void sigemptyset(sigset_t *set)
156{
157	switch (_NSIG_WORDS) {
158	default:
159		memset(set, 0, sizeof(sigset_t));
160		break;
161	case 2: set->sig[1] = 0;
162	case 1:	set->sig[0] = 0;
163		break;
164	}
165}
166
167static inline void sigfillset(sigset_t *set)
168{
169	switch (_NSIG_WORDS) {
170	default:
171		memset(set, -1, sizeof(sigset_t));
172		break;
173	case 2: set->sig[1] = -1;
174	case 1:	set->sig[0] = -1;
175		break;
176	}
177}
178
179/* Some extensions for manipulating the low 32 signals in particular.  */
180
181static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
182{
183	set->sig[0] |= mask;
184}
185
186static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
187{
188	set->sig[0] &= ~mask;
189}
190
191static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
192{
193	return (set->sig[0] & mask) != 0;
194}
195
196static inline void siginitset(sigset_t *set, unsigned long mask)
197{
198	set->sig[0] = mask;
199	switch (_NSIG_WORDS) {
200	default:
201		memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
202		break;
203	case 2: set->sig[1] = 0;
204	case 1: ;
205	}
206}
207
208static inline void siginitsetinv(sigset_t *set, unsigned long mask)
209{
210	set->sig[0] = ~mask;
211	switch (_NSIG_WORDS) {
212	default:
213		memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
214		break;
215	case 2: set->sig[1] = -1;
216	case 1: ;
217	}
218}
219
220#endif /* __HAVE_ARCH_SIG_SETOPS */
221
222static inline void init_sigpending(struct sigpending *sig)
223{
224	sigemptyset(&sig->signal);
225	INIT_LIST_HEAD(&sig->list);
226}
227
228extern void flush_sigqueue(struct sigpending *queue);
229
230/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
231static inline int valid_signal(unsigned long sig)
232{
233	return sig <= _NSIG ? 1 : 0;
234}
235
236extern int next_signal(struct sigpending *pending, sigset_t *mask);
237extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
238extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
239extern long do_sigpending(void __user *, unsigned long);
240extern int sigprocmask(int, sigset_t *, sigset_t *);
241
242struct pt_regs;
243extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
244
245extern struct kmem_cache *sighand_cachep;
246
247/*
248 * In POSIX a signal is sent either to a specific thread (Linux task)
249 * or to the process as a whole (Linux thread group).  How the signal
250 * is sent determines whether it's to one thread or the whole group,
251 * which determines which signal mask(s) are involved in blocking it
252 * from being delivered until later.  When the signal is delivered,
253 * either it's caught or ignored by a user handler or it has a default
254 * effect that applies to the whole thread group (POSIX process).
255 *
256 * The possible effects an unblocked signal set to SIG_DFL can have are:
257 *   ignore	- Nothing Happens
258 *   terminate	- kill the process, i.e. all threads in the group,
259 * 		  similar to exit_group.  The group leader (only) reports
260 *		  WIFSIGNALED status to its parent.
261 *   coredump	- write a core dump file describing all threads using
262 *		  the same mm and then kill all those threads
263 *   stop 	- stop all the threads in the group, i.e. TASK_STOPPED state
264 *
265 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
266 * Other signals when not blocked and set to SIG_DFL behaves as follows.
267 * The job control signals also have other special effects.
268 *
269 *	+--------------------+------------------+
270 *	|  POSIX signal      |  default action  |
271 *	+--------------------+------------------+
272 *	|  SIGHUP            |  terminate	|
273 *	|  SIGINT            |	terminate	|
274 *	|  SIGQUIT           |	coredump 	|
275 *	|  SIGILL            |	coredump 	|
276 *	|  SIGTRAP           |	coredump 	|
277 *	|  SIGABRT/SIGIOT    |	coredump 	|
278 *	|  SIGBUS            |	coredump 	|
279 *	|  SIGFPE            |	coredump 	|
280 *	|  SIGKILL           |	terminate(+)	|
281 *	|  SIGUSR1           |	terminate	|
282 *	|  SIGSEGV           |	coredump 	|
283 *	|  SIGUSR2           |	terminate	|
284 *	|  SIGPIPE           |	terminate	|
285 *	|  SIGALRM           |	terminate	|
286 *	|  SIGTERM           |	terminate	|
287 *	|  SIGCHLD           |	ignore   	|
288 *	|  SIGCONT           |	ignore(*)	|
289 *	|  SIGSTOP           |	stop(*)(+)  	|
290 *	|  SIGTSTP           |	stop(*)  	|
291 *	|  SIGTTIN           |	stop(*)  	|
292 *	|  SIGTTOU           |	stop(*)  	|
293 *	|  SIGURG            |	ignore   	|
294 *	|  SIGXCPU           |	coredump 	|
295 *	|  SIGXFSZ           |	coredump 	|
296 *	|  SIGVTALRM         |	terminate	|
297 *	|  SIGPROF           |	terminate	|
298 *	|  SIGPOLL/SIGIO     |	terminate	|
299 *	|  SIGSYS/SIGUNUSED  |	coredump 	|
300 *	|  SIGSTKFLT         |	terminate	|
301 *	|  SIGWINCH          |	ignore   	|
302 *	|  SIGPWR            |	terminate	|
303 *	|  SIGRTMIN-SIGRTMAX |	terminate       |
304 *	+--------------------+------------------+
305 *	|  non-POSIX signal  |  default action  |
306 *	+--------------------+------------------+
307 *	|  SIGEMT            |  coredump	|
308 *	+--------------------+------------------+
309 *
310 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
311 * (*) Special job control effects:
312 * When SIGCONT is sent, it resumes the process (all threads in the group)
313 * from TASK_STOPPED state and also clears any pending/queued stop signals
314 * (any of those marked with "stop(*)").  This happens regardless of blocking,
315 * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
316 * any pending/queued SIGCONT signals; this happens regardless of blocking,
317 * catching, or ignored the stop signal, though (except for SIGSTOP) the
318 * default action of stopping the process may happen later or never.
319 */
320
321#ifdef SIGEMT
322#define SIGEMT_MASK	rt_sigmask(SIGEMT)
323#else
324#define SIGEMT_MASK	0
325#endif
326
327#if SIGRTMIN > BITS_PER_LONG
328#define rt_sigmask(sig)	(1ULL << ((sig)-1))
329#else
330#define rt_sigmask(sig)	sigmask(sig)
331#endif
332#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
333
334#define SIG_KERNEL_ONLY_MASK (\
335	rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))
336
337#define SIG_KERNEL_STOP_MASK (\
338	rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
339	rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )
340
341#define SIG_KERNEL_COREDUMP_MASK (\
342        rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
343	rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
344        rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
345	rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
346        rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
347	SIGEMT_MASK				       )
348
349#define SIG_KERNEL_IGNORE_MASK (\
350        rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
351	rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )
352
353#define sig_kernel_only(sig) \
354	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
355#define sig_kernel_coredump(sig) \
356	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
357#define sig_kernel_ignore(sig) \
358	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
359#define sig_kernel_stop(sig) \
360	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
361
362#define sig_needs_tasklist(sig)	((sig) == SIGCONT)
363
364#define sig_user_defined(t, signr) \
365	(((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&	\
366	 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
367
368#define sig_fatal(t, signr) \
369	(!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
370	 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
371
372#endif /* __KERNEL__ */
373
374#endif /* _LINUX_SIGNAL_H */
375