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
8struct task_struct;
9
10/* for sysctl */
11extern int print_fatal_signals;
12/*
13 * Real Time signals may be queued.
14 */
15
16struct 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
26struct 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
35static 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.  */
55static 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
64static 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
73static 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
84static 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)					\
106static 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))
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)						\
143static 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
162static 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
174static 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
188static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
189{
190	set->sig[0] |= mask;
191}
192
193static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
194{
195	set->sig[0] &= ~mask;
196}
197
198static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
199{
200	return (set->sig[0] & mask) != 0;
201}
202
203static 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
215static 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
229static inline void init_sigpending(struct sigpending *sig)
230{
231	sigemptyset(&sig->signal);
232	INIT_LIST_HEAD(&sig->list);
233}
234
235extern void flush_sigqueue(struct sigpending *queue);
236
237/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
238static inline int valid_signal(unsigned long sig)
239{
240	return sig <= _NSIG ? 1 : 0;
241}
242
243struct timespec;
244struct pt_regs;
245
246extern int next_signal(struct sigpending *pending, sigset_t *mask);
247extern int do_send_sig_info(int sig, struct siginfo *info,
248				struct task_struct *p, bool group);
249extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
250extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
251extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
252				const struct timespec *);
253extern int sigprocmask(int, sigset_t *, sigset_t *);
254extern void set_current_blocked(sigset_t *);
255extern void __set_current_blocked(const sigset_t *);
256extern int show_unhandled_signals;
257extern int sigsuspend(sigset_t *);
258
259struct sigaction {
260#ifndef __ARCH_HAS_IRIX_SIGACTION
261	__sighandler_t	sa_handler;
262	unsigned long	sa_flags;
263#else
264	unsigned int	sa_flags;
265	__sighandler_t	sa_handler;
266#endif
267#ifdef __ARCH_HAS_SA_RESTORER
268	__sigrestore_t sa_restorer;
269#endif
270	sigset_t	sa_mask;	/* mask last for extensibility */
271};
272
273struct k_sigaction {
274	struct sigaction sa;
275#ifdef __ARCH_HAS_KA_RESTORER
276	__sigrestore_t ka_restorer;
277#endif
278};
279
280#ifdef CONFIG_OLD_SIGACTION
281struct old_sigaction {
282	__sighandler_t sa_handler;
283	old_sigset_t sa_mask;
284	unsigned long sa_flags;
285	__sigrestore_t sa_restorer;
286};
287#endif
288
289struct ksignal {
290	struct k_sigaction ka;
291	siginfo_t info;
292	int sig;
293};
294
295extern int get_signal(struct ksignal *ksig);
296extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
297extern void exit_signals(struct task_struct *tsk);
298extern void kernel_sigaction(int, __sighandler_t);
299
300static inline void allow_signal(int sig)
301{
302	/*
303	 * Kernel threads handle their own signals. Let the signal code
304	 * know it'll be handled, so that they don't get converted to
305	 * SIGKILL or just silently dropped.
306	 */
307	kernel_sigaction(sig, (__force __sighandler_t)2);
308}
309
310static inline void disallow_signal(int sig)
311{
312	kernel_sigaction(sig, SIG_IGN);
313}
314
315extern struct kmem_cache *sighand_cachep;
316
317int unhandled_signal(struct task_struct *tsk, int sig);
318
319/*
320 * In POSIX a signal is sent either to a specific thread (Linux task)
321 * or to the process as a whole (Linux thread group).  How the signal
322 * is sent determines whether it's to one thread or the whole group,
323 * which determines which signal mask(s) are involved in blocking it
324 * from being delivered until later.  When the signal is delivered,
325 * either it's caught or ignored by a user handler or it has a default
326 * effect that applies to the whole thread group (POSIX process).
327 *
328 * The possible effects an unblocked signal set to SIG_DFL can have are:
329 *   ignore	- Nothing Happens
330 *   terminate	- kill the process, i.e. all threads in the group,
331 * 		  similar to exit_group.  The group leader (only) reports
332 *		  WIFSIGNALED status to its parent.
333 *   coredump	- write a core dump file describing all threads using
334 *		  the same mm and then kill all those threads
335 *   stop 	- stop all the threads in the group, i.e. TASK_STOPPED state
336 *
337 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
338 * Other signals when not blocked and set to SIG_DFL behaves as follows.
339 * The job control signals also have other special effects.
340 *
341 *	+--------------------+------------------+
342 *	|  POSIX signal      |  default action  |
343 *	+--------------------+------------------+
344 *	|  SIGHUP            |  terminate	|
345 *	|  SIGINT            |	terminate	|
346 *	|  SIGQUIT           |	coredump 	|
347 *	|  SIGILL            |	coredump 	|
348 *	|  SIGTRAP           |	coredump 	|
349 *	|  SIGABRT/SIGIOT    |	coredump 	|
350 *	|  SIGBUS            |	coredump 	|
351 *	|  SIGFPE            |	coredump 	|
352 *	|  SIGKILL           |	terminate(+)	|
353 *	|  SIGUSR1           |	terminate	|
354 *	|  SIGSEGV           |	coredump 	|
355 *	|  SIGUSR2           |	terminate	|
356 *	|  SIGPIPE           |	terminate	|
357 *	|  SIGALRM           |	terminate	|
358 *	|  SIGTERM           |	terminate	|
359 *	|  SIGCHLD           |	ignore   	|
360 *	|  SIGCONT           |	ignore(*)	|
361 *	|  SIGSTOP           |	stop(*)(+)  	|
362 *	|  SIGTSTP           |	stop(*)  	|
363 *	|  SIGTTIN           |	stop(*)  	|
364 *	|  SIGTTOU           |	stop(*)  	|
365 *	|  SIGURG            |	ignore   	|
366 *	|  SIGXCPU           |	coredump 	|
367 *	|  SIGXFSZ           |	coredump 	|
368 *	|  SIGVTALRM         |	terminate	|
369 *	|  SIGPROF           |	terminate	|
370 *	|  SIGPOLL/SIGIO     |	terminate	|
371 *	|  SIGSYS/SIGUNUSED  |	coredump 	|
372 *	|  SIGSTKFLT         |	terminate	|
373 *	|  SIGWINCH          |	ignore   	|
374 *	|  SIGPWR            |	terminate	|
375 *	|  SIGRTMIN-SIGRTMAX |	terminate       |
376 *	+--------------------+------------------+
377 *	|  non-POSIX signal  |  default action  |
378 *	+--------------------+------------------+
379 *	|  SIGEMT            |  coredump	|
380 *	+--------------------+------------------+
381 *
382 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
383 * (*) Special job control effects:
384 * When SIGCONT is sent, it resumes the process (all threads in the group)
385 * from TASK_STOPPED state and also clears any pending/queued stop signals
386 * (any of those marked with "stop(*)").  This happens regardless of blocking,
387 * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
388 * any pending/queued SIGCONT signals; this happens regardless of blocking,
389 * catching, or ignored the stop signal, though (except for SIGSTOP) the
390 * default action of stopping the process may happen later or never.
391 */
392
393#ifdef SIGEMT
394#define SIGEMT_MASK	rt_sigmask(SIGEMT)
395#else
396#define SIGEMT_MASK	0
397#endif
398
399#if SIGRTMIN > BITS_PER_LONG
400#define rt_sigmask(sig)	(1ULL << ((sig)-1))
401#else
402#define rt_sigmask(sig)	sigmask(sig)
403#endif
404#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
405
406#define SIG_KERNEL_ONLY_MASK (\
407	rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))
408
409#define SIG_KERNEL_STOP_MASK (\
410	rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
411	rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )
412
413#define SIG_KERNEL_COREDUMP_MASK (\
414        rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
415	rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
416        rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
417	rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
418        rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
419	SIGEMT_MASK				       )
420
421#define SIG_KERNEL_IGNORE_MASK (\
422        rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
423	rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )
424
425#define sig_kernel_only(sig) \
426	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
427#define sig_kernel_coredump(sig) \
428	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
429#define sig_kernel_ignore(sig) \
430	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
431#define sig_kernel_stop(sig) \
432	(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
433
434#define sig_user_defined(t, signr) \
435	(((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&	\
436	 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
437
438#define sig_fatal(t, signr) \
439	(!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
440	 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
441
442void signals_init(void);
443
444int restore_altstack(const stack_t __user *);
445int __save_altstack(stack_t __user *, unsigned long);
446
447#define save_altstack_ex(uss, sp) do { \
448	stack_t __user *__uss = uss; \
449	struct task_struct *t = current; \
450	put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
451	put_user_ex(sas_ss_flags(sp), &__uss->ss_flags); \
452	put_user_ex(t->sas_ss_size, &__uss->ss_size); \
453} while (0);
454
455#ifdef CONFIG_PROC_FS
456struct seq_file;
457extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
458#endif
459
460#endif /* _LINUX_SIGNAL_H */
461