[mirror_ubuntu-bionic-kernel.git] / include / linux / signal.h

#ifndef _LINUX_SIGNAL_H
#define _LINUX_SIGNAL_H

#include <linux/bug.h>
#include <linux/signal_types.h>

struct task_struct;

/* for sysctl */
extern int print_fatal_signals;

#ifndef HAVE_ARCH_COPY_SIGINFO

#include <linux/string.h>

static inline void copy_siginfo(struct siginfo *to, struct siginfo *from)
{
	if (from->si_code < 0)
		memcpy(to, from, sizeof(*to));
	else
		/* _sigchld is currently the largest know union member */
		memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld));
}

#endif

/*
 * 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));
}

#endif /* __HAVE_ARCH_SIG_BITOPS */

static inline int sigisemptyset(sigset_t *set)
{
	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:
		BUILD_BUG();
		return 0;
	}
}

static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
{
	switch (_NSIG_WORDS) {
	case 4:
		return	(set1->sig[3] == set2->sig[3]) &&
			(set1->sig[2] == set2->sig[2]) &&
			(set1->sig[1] == set2->sig[1]) &&
			(set1->sig[0] == set2->sig[0]);
	case 2:
		return	(set1->sig[1] == set2->sig[1]) &&
			(set1->sig[0] == set2->sig[0]);
	case 1:
		return	set1->sig[0] == set2->sig[0];
	}
	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) \
{									\
	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:							\
		BUILD_BUG();						\
	}								\
}

#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_andn(x,y)	((x) & ~(y))
_SIG_SET_BINOP(sigandnsets, _sig_andn)

#undef _SIG_SET_BINOP
#undef _sig_or
#undef _sig_and
#undef _sig_andn

#define _SIG_SET_OP(name, op)						\
static inline void name(sigset_t *set)					\
{									\
	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:							\
		BUILD_BUG();						\
	}								\
}

#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;
}

struct timespec;
struct pt_regs;

extern int next_signal(struct sigpending *pending, sigset_t *mask);
extern int do_send_sig_info(int sig, struct siginfo *info,
				struct task_struct *p, bool group);
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 int do_sigtimedwait(const sigset_t *, siginfo_t *,
				const struct timespec *);
extern int sigprocmask(int, sigset_t *, sigset_t *);
extern void set_current_blocked(sigset_t *);
extern void __set_current_blocked(const sigset_t *);
extern int show_unhandled_signals;

extern int get_signal(struct ksignal *ksig);
extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
extern void exit_signals(struct task_struct *tsk);
extern void kernel_sigaction(int, __sighandler_t);

static inline void allow_signal(int sig)
{
	/*
	 * Kernel threads handle their own signals. Let the signal code
	 * know it'll be handled, so that they don't get converted to
	 * SIGKILL or just silently dropped.
	 */
	kernel_sigaction(sig, (__force __sighandler_t)2);
}

static inline void disallow_signal(int sig)
{
	kernel_sigaction(sig, SIG_IGN);
}

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

#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);

int restore_altstack(const stack_t __user *);
int __save_altstack(stack_t __user *, unsigned long);

#define save_altstack_ex(uss, sp) do { \
	stack_t __user *__uss = uss; \
	struct task_struct *t = current; \
	put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
	put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
	put_user_ex(t->sas_ss_size, &__uss->ss_size); \
	if (t->sas_ss_flags & SS_AUTODISARM) \
		sas_ss_reset(t); \
} while (0);

#ifdef CONFIG_PROC_FS
struct seq_file;
extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
#endif

#endif /* _LINUX_SIGNAL_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_SIGNAL_H
	2	#define _LINUX_SIGNAL_H
	3
1c3bea0e	4	#include <linux/bug.h>
e6d930b4	5	#include <linux/signal_types.h>
1da177e4	6
1477fcc2 SR	7	struct task_struct;
1477fcc2 SR	8
d33ed52d DY	9	/* for sysctl */
d33ed52d DY	10	extern int print_fatal_signals;
1da177e4	11
ca9eb49a JH	12	#ifndef HAVE_ARCH_COPY_SIGINFO
	13
	14	#include <linux/string.h>
	15
	16	static inline void copy_siginfo(struct siginfo to, struct siginfo from)
	17	{
	18	if (from->si_code < 0)
	19	memcpy(to, from, sizeof(*to));
	20	else
	21	/* _sigchld is currently the largest know union member */
	22	memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld));
	23	}
	24
	25	#endif
	26
1da177e4 LT	27	/*
	28	* Define some primitives to manipulate sigset_t.
	29	*/
	30
	31	#ifndef __HAVE_ARCH_SIG_BITOPS
	32	#include <linux/bitops.h>
	33
	34	/* We don't use <linux/bitops.h> for these because there is no need to
	35	be atomic. */
	36	static inline void sigaddset(sigset_t *set, int _sig)
	37	{
	38	unsigned long sig = _sig - 1;
	39	if (_NSIG_WORDS == 1)
	40	set->sig[0] \|= 1UL << sig;
	41	else
	42	set->sig[sig / _NSIG_BPW] \|= 1UL << (sig % _NSIG_BPW);
	43	}
	44
	45	static inline void sigdelset(sigset_t *set, int _sig)
	46	{
	47	unsigned long sig = _sig - 1;
	48	if (_NSIG_WORDS == 1)
	49	set->sig[0] &= ~(1UL << sig);
	50	else
	51	set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
	52	}
	53
	54	static inline int sigismember(sigset_t *set, int _sig)
	55	{
	56	unsigned long sig = _sig - 1;
	57	if (_NSIG_WORDS == 1)
	58	return 1 & (set->sig[0] >> sig);
	59	else
	60	return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
	61	}
	62
1da177e4 LT	63	#endif /* __HAVE_ARCH_SIG_BITOPS */
1da177e4 LT	64
71fabd5e GA	65	static inline int sigisemptyset(sigset_t *set)
71fabd5e GA	66	{
71fabd5e GA	67	switch (_NSIG_WORDS) {
	68	case 4:
	69	return (set->sig[3] \| set->sig[2] \|
	70	set->sig[1] \| set->sig[0]) == 0;
	71	case 2:
	72	return (set->sig[1] \| set->sig[0]) == 0;
	73	case 1:
	74	return set->sig[0] == 0;
	75	default:
1c3bea0e	76	BUILD_BUG();
71fabd5e GA	77	return 0;
	78	}
	79	}
	80
c7be96af WL	81	static inline int sigequalsets(const sigset_t set1, const sigset_t set2)
	82	{
	83	switch (_NSIG_WORDS) {
	84	case 4:
	85	return (set1->sig[3] == set2->sig[3]) &&
	86	(set1->sig[2] == set2->sig[2]) &&
	87	(set1->sig[1] == set2->sig[1]) &&
	88	(set1->sig[0] == set2->sig[0]);
	89	case 2:
	90	return (set1->sig[1] == set2->sig[1]) &&
	91	(set1->sig[0] == set2->sig[0]);
	92	case 1:
	93	return set1->sig[0] == set2->sig[0];
	94	}
	95	return 0;
	96	}
	97
1da177e4 LT	98	#define sigmask(sig) (1UL << ((sig) - 1))
	99
	100	#ifndef __HAVE_ARCH_SIG_SETOPS
	101	#include <linux/string.h>
	102
	103	#define _SIG_SET_BINOP(name, op) \
	104	static inline void name(sigset_t r, const sigset_t a, const sigset_t *b) \
	105	{ \
1da177e4 LT	106	unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
	107	\
	108	switch (_NSIG_WORDS) { \
1c3bea0e	109	case 4: \
1da177e4 LT	110	a3 = a->sig[3]; a2 = a->sig[2]; \
	111	b3 = b->sig[3]; b2 = b->sig[2]; \
	112	r->sig[3] = op(a3, b3); \
	113	r->sig[2] = op(a2, b2); \
1c3bea0e	114	case 2: \
1da177e4 LT	115	a1 = a->sig[1]; b1 = b->sig[1]; \
1da177e4 LT	116	r->sig[1] = op(a1, b1); \
1c3bea0e	117	case 1: \
1da177e4 LT	118	a0 = a->sig[0]; b0 = b->sig[0]; \
	119	r->sig[0] = op(a0, b0); \
	120	break; \
1c3bea0e ON	121	default: \
1c3bea0e ON	122	BUILD_BUG(); \
1da177e4 LT	123	} \
	124	}
	125
	126	#define _sig_or(x,y) ((x) \| (y))
	127	_SIG_SET_BINOP(sigorsets, _sig_or)
	128
	129	#define _sig_and(x,y) ((x) & (y))
	130	_SIG_SET_BINOP(sigandsets, _sig_and)
	131
702a5073 ON	132	#define _sig_andn(x,y) ((x) & ~(y))
702a5073 ON	133	_SIG_SET_BINOP(sigandnsets, _sig_andn)
1da177e4 LT	134
	135	#undef _SIG_SET_BINOP
	136	#undef _sig_or
	137	#undef _sig_and
702a5073	138	#undef _sig_andn
1da177e4 LT	139
	140	#define _SIG_SET_OP(name, op) \
	141	static inline void name(sigset_t *set) \
	142	{ \
1da177e4	143	switch (_NSIG_WORDS) { \
1c3bea0e ON	144	case 4: set->sig[3] = op(set->sig[3]); \
	145	set->sig[2] = op(set->sig[2]); \
	146	case 2: set->sig[1] = op(set->sig[1]); \
	147	case 1: set->sig[0] = op(set->sig[0]); \
1da177e4	148	break; \
1c3bea0e ON	149	default: \
1c3bea0e ON	150	BUILD_BUG(); \
1da177e4 LT	151	} \
	152	}
	153
	154	#define _sig_not(x) (~(x))
	155	_SIG_SET_OP(signotset, _sig_not)
	156
	157	#undef _SIG_SET_OP
	158	#undef _sig_not
	159
	160	static inline void sigemptyset(sigset_t *set)
	161	{
	162	switch (_NSIG_WORDS) {
	163	default:
	164	memset(set, 0, sizeof(sigset_t));
	165	break;
	166	case 2: set->sig[1] = 0;
	167	case 1: set->sig[0] = 0;
	168	break;
	169	}
	170	}
	171
	172	static inline void sigfillset(sigset_t *set)
	173	{
	174	switch (_NSIG_WORDS) {
	175	default:
	176	memset(set, -1, sizeof(sigset_t));
	177	break;
	178	case 2: set->sig[1] = -1;
	179	case 1: set->sig[0] = -1;
	180	break;
	181	}
	182	}
	183
	184	/* Some extensions for manipulating the low 32 signals in particular. */
	185
	186	static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
	187	{
	188	set->sig[0] \|= mask;
	189	}
	190
	191	static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
	192	{
	193	set->sig[0] &= ~mask;
	194	}
	195
	196	static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
	197	{
	198	return (set->sig[0] & mask) != 0;
	199	}
	200
	201	static inline void siginitset(sigset_t *set, unsigned long mask)
	202	{
	203	set->sig[0] = mask;
	204	switch (_NSIG_WORDS) {
	205	default:
	206	memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
	207	break;
	208	case 2: set->sig[1] = 0;
	209	case 1: ;
	210	}
	211	}
	212
	213	static inline void siginitsetinv(sigset_t *set, unsigned long mask)
	214	{
215	set->sig[0] = ~mask;
216	switch (_NSIG_WORDS) {
217	default:
218	memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
219	break;
220	case 2: set->sig[1] = -1;
221	case 1: ;
222	}
223	}
224
225	#endif /* __HAVE_ARCH_SIG_SETOPS */
226
227	static inline void init_sigpending(struct sigpending *sig)
228	{
229	sigemptyset(&sig->signal);
230	INIT_LIST_HEAD(&sig->list);
231	}
232
6a14c5c9 ON	233	extern void flush_sigqueue(struct sigpending *queue);
6a14c5c9 ON	234
e5bdd883 JJ	235	/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
	236	static inline int valid_signal(unsigned long sig)
	237	{
	238	return sig <= _NSIG ? 1 : 0;
	239	}
	240
b2b07e4f ON	241	struct timespec;
	242	struct pt_regs;
	243
fba2afaa	244	extern int next_signal(struct sigpending pending, sigset_t mask);
4a30debf ON	245	extern int do_send_sig_info(int sig, struct siginfo *info,
4a30debf ON	246	struct task_struct *p, bool group);
1da177e4 LT	247	extern int group_send_sig_info(int sig, struct siginfo info, struct task_struct p);
1da177e4 LT	248	extern int __group_send_sig_info(int, struct siginfo , struct task_struct );
943df148 ON	249	extern int do_sigtimedwait(const sigset_t , siginfo_t ,
943df148 ON	250	const struct timespec *);
1da177e4	251	extern int sigprocmask(int, sigset_t , sigset_t );
77097ae5 AV	252	extern void set_current_blocked(sigset_t *);
77097ae5 AV	253	extern void __set_current_blocked(const sigset_t *);
abd4f750	254	extern int show_unhandled_signals;
1da177e4	255
828b1f65	256	extern int get_signal(struct ksignal *ksig);
2ce5da17	257	extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
d12619b5	258	extern void exit_signals(struct task_struct *tsk);
b4e74264 ON	259	extern void kernel_sigaction(int, __sighandler_t);
	260
	261	static inline void allow_signal(int sig)
	262	{
	263	/*
	264	* Kernel threads handle their own signals. Let the signal code
	265	* know it'll be handled, so that they don't get converted to
	266	* SIGKILL or just silently dropped.
	267	*/
	268	kernel_sigaction(sig, (__force __sighandler_t)2);
	269	}
	270
	271	static inline void disallow_signal(int sig)
	272	{
	273	kernel_sigaction(sig, SIG_IGN);
	274	}
1da177e4	275
298ec1e2 CL	276	extern struct kmem_cache *sighand_cachep;
298ec1e2 CL	277
abd4f750 MAS	278	int unhandled_signal(struct task_struct *tsk, int sig);
abd4f750 MAS	279
55c0d1f8 RM	280	/*
	281	* In POSIX a signal is sent either to a specific thread (Linux task)
	282	* or to the process as a whole (Linux thread group). How the signal
	283	* is sent determines whether it's to one thread or the whole group,
	284	* which determines which signal mask(s) are involved in blocking it
	285	* from being delivered until later. When the signal is delivered,
	286	* either it's caught or ignored by a user handler or it has a default
	287	* effect that applies to the whole thread group (POSIX process).
	288	*
	289	* The possible effects an unblocked signal set to SIG_DFL can have are:
	290	* ignore - Nothing Happens
	291	* terminate - kill the process, i.e. all threads in the group,
	292	* similar to exit_group. The group leader (only) reports
	293	* WIFSIGNALED status to its parent.
	294	* coredump - write a core dump file describing all threads using
	295	* the same mm and then kill all those threads
	296	* stop - stop all the threads in the group, i.e. TASK_STOPPED state
	297	*
	298	* SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
	299	* Other signals when not blocked and set to SIG_DFL behaves as follows.
	300	* The job control signals also have other special effects.
	301	*
	302	* +--------------------+------------------+
	303	* \| POSIX signal \| default action \|
	304	* +--------------------+------------------+
	305	* \| SIGHUP \| terminate \|
	306	* \| SIGINT \| terminate \|
	307	* \| SIGQUIT \| coredump \|
	308	* \| SIGILL \| coredump \|
	309	* \| SIGTRAP \| coredump \|
	310	* \| SIGABRT/SIGIOT \| coredump \|
	311	* \| SIGBUS \| coredump \|
	312	* \| SIGFPE \| coredump \|
	313	* \| SIGKILL \| terminate(+) \|
	314	* \| SIGUSR1 \| terminate \|
	315	* \| SIGSEGV \| coredump \|
	316	* \| SIGUSR2 \| terminate \|
	317	* \| SIGPIPE \| terminate \|
	318	* \| SIGALRM \| terminate \|
	319	* \| SIGTERM \| terminate \|
	320	* \| SIGCHLD \| ignore \|
	321	* \| SIGCONT \| ignore(*) \|
	322	* \| SIGSTOP \| stop(*)(+) \|
	323	* \| SIGTSTP \| stop(*) \|
	324	* \| SIGTTIN \| stop(*) \|
	325	* \| SIGTTOU \| stop(*) \|
	326	* \| SIGURG \| ignore \|
	327	* \| SIGXCPU \| coredump \|
	328	* \| SIGXFSZ \| coredump \|
	329	* \| SIGVTALRM \| terminate \|
	330	* \| SIGPROF \| terminate \|
	331	* \| SIGPOLL/SIGIO \| terminate \|
	332	* \| SIGSYS/SIGUNUSED \| coredump \|
	333	* \| SIGSTKFLT \| terminate \|
	334	* \| SIGWINCH \| ignore \|
	335	* \| SIGPWR \| terminate \|
	336	* \| SIGRTMIN-SIGRTMAX \| terminate \|
	337	* +--------------------+------------------+
	338	* \| non-POSIX signal \| default action \|
	339	* +--------------------+------------------+
	340	* \| SIGEMT \| coredump \|
	341	* +--------------------+------------------+
	342	*
	343	* (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
344	* (*) Special job control effects:
345	* When SIGCONT is sent, it resumes the process (all threads in the group)
346	* from TASK_STOPPED state and also clears any pending/queued stop signals
347	* (any of those marked with "stop(*)"). This happens regardless of blocking,
348	* catching, or ignoring SIGCONT. When any stop signal is sent, it clears
349	* any pending/queued SIGCONT signals; this happens regardless of blocking,
350	* catching, or ignored the stop signal, though (except for SIGSTOP) the
351	* default action of stopping the process may happen later or never.
352	*/
353
354	#ifdef SIGEMT
355	#define SIGEMT_MASK rt_sigmask(SIGEMT)
356	#else
357	#define SIGEMT_MASK 0
358	#endif
359
360	#if SIGRTMIN > BITS_PER_LONG
361	#define rt_sigmask(sig) (1ULL << ((sig)-1))
362	#else
363	#define rt_sigmask(sig) sigmask(sig)
364	#endif
5c8ccefd ON	365
	366	#define siginmask(sig, mask) \
	367	((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
55c0d1f8 RM	368
	369	#define SIG_KERNEL_ONLY_MASK (\
	370	rt_sigmask(SIGKILL) \| rt_sigmask(SIGSTOP))
	371
	372	#define SIG_KERNEL_STOP_MASK (\
	373	rt_sigmask(SIGSTOP) \| rt_sigmask(SIGTSTP) \| \
	374	rt_sigmask(SIGTTIN) \| rt_sigmask(SIGTTOU) )
	375
	376	#define SIG_KERNEL_COREDUMP_MASK (\
	377	rt_sigmask(SIGQUIT) \| rt_sigmask(SIGILL) \| \
	378	rt_sigmask(SIGTRAP) \| rt_sigmask(SIGABRT) \| \
	379	rt_sigmask(SIGFPE) \| rt_sigmask(SIGSEGV) \| \
	380	rt_sigmask(SIGBUS) \| rt_sigmask(SIGSYS) \| \
	381	rt_sigmask(SIGXCPU) \| rt_sigmask(SIGXFSZ) \| \
	382	SIGEMT_MASK )
	383
	384	#define SIG_KERNEL_IGNORE_MASK (\
	385	rt_sigmask(SIGCONT) \| rt_sigmask(SIGCHLD) \| \
	386	rt_sigmask(SIGWINCH) \| rt_sigmask(SIGURG) )
	387
5c8ccefd ON	388	#define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
	389	#define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
	390	#define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
	391	#define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
55c0d1f8	392
55c0d1f8 RM	393	#define sig_user_defined(t, signr) \
	394	(((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \
	395	((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
	396
	397	#define sig_fatal(t, signr) \
	398	(!siginmask(signr, SIG_KERNEL_IGNORE_MASK\|SIG_KERNEL_STOP_MASK) && \
	399	(t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
	400
a1c9eea9 AB	401	void signals_init(void);
a1c9eea9 AB	402
5c49574f	403	int restore_altstack(const stack_t __user *);
c40702c4	404	int __save_altstack(stack_t __user *, unsigned long);
5c49574f	405
bd1c149a AV	406	#define save_altstack_ex(uss, sp) do { \
	407	stack_t __user *__uss = uss; \
	408	struct task_struct *t = current; \
	409	put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
2a742138	410	put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
bd1c149a	411	put_user_ex(t->sas_ss_size, &__uss->ss_size); \
2a742138 SS	412	if (t->sas_ss_flags & SS_AUTODISARM) \
2a742138 SS	413	sas_ss_reset(t); \
bd1c149a AV	414	} while (0);
bd1c149a AV	415
34db8aaf DH	416	#ifdef CONFIG_PROC_FS
	417	struct seq_file;
	418	extern void render_sigset_t(struct seq_file , const char , sigset_t *);
	419	#endif
	420
1da177e4	421	#endif /* _LINUX_SIGNAL_H */