1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_SCHED_SIGNAL_H
3#define _LINUX_SCHED_SIGNAL_H
4
5#include <linux/rculist.h>
6#include <linux/signal.h>
7#include <linux/sched.h>
8#include <linux/sched/jobctl.h>
9#include <linux/sched/task.h>
10#include <linux/cred.h>
11#include <linux/refcount.h>
12#include <linux/pid.h>
13#include <linux/posix-timers.h>
14#include <linux/mm_types.h>
15#include <asm/ptrace.h>
16
17/*
18 * Types defining task->signal and task->sighand and APIs using them:
19 */
20
21struct sighand_struct {
22	spinlock_t		siglock;
23	refcount_t		count;
24	wait_queue_head_t	signalfd_wqh;
25	struct k_sigaction	action[_NSIG];
26};
27
28/*
29 * Per-process accounting stats:
30 */
31struct pacct_struct {
32	int			ac_flag;
33	long			ac_exitcode;
34	unsigned long		ac_mem;
35	u64			ac_utime, ac_stime;
36	unsigned long		ac_minflt, ac_majflt;
37};
38
39struct cpu_itimer {
40	u64 expires;
41	u64 incr;
42};
43
44/*
45 * This is the atomic variant of task_cputime, which can be used for
46 * storing and updating task_cputime statistics without locking.
47 */
48struct task_cputime_atomic {
49	atomic64_t utime;
50	atomic64_t stime;
51	atomic64_t sum_exec_runtime;
52};
53
54#define INIT_CPUTIME_ATOMIC \
55	(struct task_cputime_atomic) {				\
56		.utime = ATOMIC64_INIT(0),			\
57		.stime = ATOMIC64_INIT(0),			\
58		.sum_exec_runtime = ATOMIC64_INIT(0),		\
59	}
60/**
61 * struct thread_group_cputimer - thread group interval timer counts
62 * @cputime_atomic:	atomic thread group interval timers.
63 *
64 * This structure contains the version of task_cputime, above, that is
65 * used for thread group CPU timer calculations.
66 */
67struct thread_group_cputimer {
68	struct task_cputime_atomic cputime_atomic;
69};
70
71struct multiprocess_signals {
72	sigset_t signal;
73	struct hlist_node node;
74};
75
76struct core_thread {
77	struct task_struct *task;
78	struct core_thread *next;
79};
80
81struct core_state {
82	atomic_t nr_threads;
83	struct core_thread dumper;
84	struct completion startup;
85};
86
87/*
88 * NOTE! "signal_struct" does not have its own
89 * locking, because a shared signal_struct always
90 * implies a shared sighand_struct, so locking
91 * sighand_struct is always a proper superset of
92 * the locking of signal_struct.
93 */
94struct signal_struct {
95	refcount_t		sigcnt;
96	atomic_t		live;
97	int			nr_threads;
98	int			quick_threads;
99	struct list_head	thread_head;
100
101	wait_queue_head_t	wait_chldexit;	/* for wait4() */
102
103	/* current thread group signal load-balancing target: */
104	struct task_struct	*curr_target;
105
106	/* shared signal handling: */
107	struct sigpending	shared_pending;
108
109	/* For collecting multiprocess signals during fork */
110	struct hlist_head	multiprocess;
111
112	/* thread group exit support */
113	int			group_exit_code;
114	/* notify group_exec_task when notify_count is less or equal to 0 */
115	int			notify_count;
116	struct task_struct	*group_exec_task;
117
118	/* thread group stop support, overloads group_exit_code too */
119	int			group_stop_count;
120	unsigned int		flags; /* see SIGNAL_* flags below */
121
122	struct core_state *core_state; /* coredumping support */
123
124	/*
125	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
126	 * manager, to re-parent orphan (double-forking) child processes
127	 * to this process instead of 'init'. The service manager is
128	 * able to receive SIGCHLD signals and is able to investigate
129	 * the process until it calls wait(). All children of this
130	 * process will inherit a flag if they should look for a
131	 * child_subreaper process at exit.
132	 */
133	unsigned int		is_child_subreaper:1;
134	unsigned int		has_child_subreaper:1;
135
136#ifdef CONFIG_POSIX_TIMERS
137
138	/* POSIX.1b Interval Timers */
139	unsigned int		next_posix_timer_id;
140	struct list_head	posix_timers;
141
142	/* ITIMER_REAL timer for the process */
143	struct hrtimer real_timer;
144	ktime_t it_real_incr;
145
146	/*
147	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
148	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
149	 * values are defined to 0 and 1 respectively
150	 */
151	struct cpu_itimer it[2];
152
153	/*
154	 * Thread group totals for process CPU timers.
155	 * See thread_group_cputimer(), et al, for details.
156	 */
157	struct thread_group_cputimer cputimer;
158
159#endif
160	/* Empty if CONFIG_POSIX_TIMERS=n */
161	struct posix_cputimers posix_cputimers;
162
163	/* PID/PID hash table linkage. */
164	struct pid *pids[PIDTYPE_MAX];
165
166#ifdef CONFIG_NO_HZ_FULL
167	atomic_t tick_dep_mask;
168#endif
169
170	struct pid *tty_old_pgrp;
171
172	/* boolean value for session group leader */
173	int leader;
174
175	struct tty_struct *tty; /* NULL if no tty */
176
177#ifdef CONFIG_SCHED_AUTOGROUP
178	struct autogroup *autogroup;
179#endif
180	/*
181	 * Cumulative resource counters for dead threads in the group,
182	 * and for reaped dead child processes forked by this group.
183	 * Live threads maintain their own counters and add to these
184	 * in __exit_signal, except for the group leader.
185	 */
186	seqlock_t stats_lock;
187	u64 utime, stime, cutime, cstime;
188	u64 gtime;
189	u64 cgtime;
190	struct prev_cputime prev_cputime;
191	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
192	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
193	unsigned long inblock, oublock, cinblock, coublock;
194	unsigned long maxrss, cmaxrss;
195	struct task_io_accounting ioac;
196
197	/*
198	 * Cumulative ns of schedule CPU time fo dead threads in the
199	 * group, not including a zombie group leader, (This only differs
200	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
201	 * other than jiffies.)
202	 */
203	unsigned long long sum_sched_runtime;
204
205	/*
206	 * We don't bother to synchronize most readers of this at all,
207	 * because there is no reader checking a limit that actually needs
208	 * to get both rlim_cur and rlim_max atomically, and either one
209	 * alone is a single word that can safely be read normally.
210	 * getrlimit/setrlimit use task_lock(current->group_leader) to
211	 * protect this instead of the siglock, because they really
212	 * have no need to disable irqs.
213	 */
214	struct rlimit rlim[RLIM_NLIMITS];
215
216#ifdef CONFIG_BSD_PROCESS_ACCT
217	struct pacct_struct pacct;	/* per-process accounting information */
218#endif
219#ifdef CONFIG_TASKSTATS
220	struct taskstats *stats;
221#endif
222#ifdef CONFIG_AUDIT
223	unsigned audit_tty;
224	struct tty_audit_buf *tty_audit_buf;
225#endif
226
227	/*
228	 * Thread is the potential origin of an oom condition; kill first on
229	 * oom
230	 */
231	bool oom_flag_origin;
232	short oom_score_adj;		/* OOM kill score adjustment */
233	short oom_score_adj_min;	/* OOM kill score adjustment min value.
234					 * Only settable by CAP_SYS_RESOURCE. */
235	struct mm_struct *oom_mm;	/* recorded mm when the thread group got
236					 * killed by the oom killer */
237
238	struct mutex cred_guard_mutex;	/* guard against foreign influences on
239					 * credential calculations
240					 * (notably. ptrace)
241					 * Deprecated do not use in new code.
242					 * Use exec_update_lock instead.
243					 */
244	struct rw_semaphore exec_update_lock;	/* Held while task_struct is
245						 * being updated during exec,
246						 * and may have inconsistent
247						 * permissions.
248						 */
249} __randomize_layout;
250
251/*
252 * Bits in flags field of signal_struct.
253 */
254#define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
255#define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
256#define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
257/*
258 * Pending notifications to parent.
259 */
260#define SIGNAL_CLD_STOPPED	0x00000010
261#define SIGNAL_CLD_CONTINUED	0x00000020
262#define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
263
264#define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
265
266#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
267			  SIGNAL_STOP_CONTINUED)
268
269static inline void signal_set_stop_flags(struct signal_struct *sig,
270					 unsigned int flags)
271{
272	WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);
273	sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
274}
275
276extern void flush_signals(struct task_struct *);
277extern void ignore_signals(struct task_struct *);
278extern void flush_signal_handlers(struct task_struct *, int force_default);
279extern int dequeue_signal(struct task_struct *task, sigset_t *mask,
280			  kernel_siginfo_t *info, enum pid_type *type);
281
282static inline int kernel_dequeue_signal(void)
283{
284	struct task_struct *task = current;
285	kernel_siginfo_t __info;
286	enum pid_type __type;
287	int ret;
288
289	spin_lock_irq(&task->sighand->siglock);
290	ret = dequeue_signal(task, &task->blocked, &__info, &__type);
291	spin_unlock_irq(&task->sighand->siglock);
292
293	return ret;
294}
295
296static inline void kernel_signal_stop(void)
297{
298	spin_lock_irq(&current->sighand->siglock);
299	if (current->jobctl & JOBCTL_STOP_DEQUEUED) {
300		current->jobctl |= JOBCTL_STOPPED;
301		set_special_state(TASK_STOPPED);
302	}
303	spin_unlock_irq(&current->sighand->siglock);
304
305	schedule();
306}
307
308int force_sig_fault_to_task(int sig, int code, void __user *addr,
309			    struct task_struct *t);
310int force_sig_fault(int sig, int code, void __user *addr);
311int send_sig_fault(int sig, int code, void __user *addr, struct task_struct *t);
312
313int force_sig_mceerr(int code, void __user *, short);
314int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
315
316int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
317int force_sig_pkuerr(void __user *addr, u32 pkey);
318int send_sig_perf(void __user *addr, u32 type, u64 sig_data);
319
320int force_sig_ptrace_errno_trap(int errno, void __user *addr);
321int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
322int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
323			struct task_struct *t);
324int force_sig_seccomp(int syscall, int reason, bool force_coredump);
325
326extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
327extern void force_sigsegv(int sig);
328extern int force_sig_info(struct kernel_siginfo *);
329extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
330extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
331extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
332				const struct cred *);
333extern int kill_pgrp(struct pid *pid, int sig, int priv);
334extern int kill_pid(struct pid *pid, int sig, int priv);
335extern __must_check bool do_notify_parent(struct task_struct *, int);
336extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
337extern void force_sig(int);
338extern void force_fatal_sig(int);
339extern void force_exit_sig(int);
340extern int send_sig(int, struct task_struct *, int);
341extern int zap_other_threads(struct task_struct *p);
342extern struct sigqueue *sigqueue_alloc(void);
343extern void sigqueue_free(struct sigqueue *);
344extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
345extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
346
347static inline void clear_notify_signal(void)
348{
349	clear_thread_flag(TIF_NOTIFY_SIGNAL);
350	smp_mb__after_atomic();
351}
352
353/*
354 * Returns 'true' if kick_process() is needed to force a transition from
355 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work.
356 */
357static inline bool __set_notify_signal(struct task_struct *task)
358{
359	return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
360	       !wake_up_state(task, TASK_INTERRUPTIBLE);
361}
362
363/*
364 * Called to break out of interruptible wait loops, and enter the
365 * exit_to_user_mode_loop().
366 */
367static inline void set_notify_signal(struct task_struct *task)
368{
369	if (__set_notify_signal(task))
370		kick_process(task);
371}
372
373static inline int restart_syscall(void)
374{
375	set_tsk_thread_flag(current, TIF_SIGPENDING);
376	return -ERESTARTNOINTR;
377}
378
379static inline int task_sigpending(struct task_struct *p)
380{
381	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
382}
383
384static inline int signal_pending(struct task_struct *p)
385{
386	/*
387	 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same
388	 * behavior in terms of ensuring that we break out of wait loops
389	 * so that notify signal callbacks can be processed.
390	 */
391	if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL)))
392		return 1;
393	return task_sigpending(p);
394}
395
396static inline int __fatal_signal_pending(struct task_struct *p)
397{
398	return unlikely(sigismember(&p->pending.signal, SIGKILL));
399}
400
401static inline int fatal_signal_pending(struct task_struct *p)
402{
403	return task_sigpending(p) && __fatal_signal_pending(p);
404}
405
406static inline int signal_pending_state(unsigned int state, struct task_struct *p)
407{
408	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
409		return 0;
410	if (!signal_pending(p))
411		return 0;
412
413	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
414}
415
416/*
417 * This should only be used in fault handlers to decide whether we
418 * should stop the current fault routine to handle the signals
419 * instead, especially with the case where we've got interrupted with
420 * a VM_FAULT_RETRY.
421 */
422static inline bool fault_signal_pending(vm_fault_t fault_flags,
423					struct pt_regs *regs)
424{
425	return unlikely((fault_flags & VM_FAULT_RETRY) &&
426			(fatal_signal_pending(current) ||
427			 (user_mode(regs) && signal_pending(current))));
428}
429
430/*
431 * Reevaluate whether the task has signals pending delivery.
432 * Wake the task if so.
433 * This is required every time the blocked sigset_t changes.
434 * callers must hold sighand->siglock.
435 */
436extern void recalc_sigpending(void);
437extern void calculate_sigpending(void);
438
439extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
440
441static inline void signal_wake_up(struct task_struct *t, bool fatal)
442{
443	unsigned int state = 0;
444	if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {
445		t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);
446		state = TASK_WAKEKILL | __TASK_TRACED;
447	}
448	signal_wake_up_state(t, state);
449}
450static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
451{
452	unsigned int state = 0;
453	if (resume) {
454		t->jobctl &= ~JOBCTL_TRACED;
455		state = __TASK_TRACED;
456	}
457	signal_wake_up_state(t, state);
458}
459
460void task_join_group_stop(struct task_struct *task);
461
462#ifdef TIF_RESTORE_SIGMASK
463/*
464 * Legacy restore_sigmask accessors.  These are inefficient on
465 * SMP architectures because they require atomic operations.
466 */
467
468/**
469 * set_restore_sigmask() - make sure saved_sigmask processing gets done
470 *
471 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
472 * will run before returning to user mode, to process the flag.  For
473 * all callers, TIF_SIGPENDING is already set or it's no harm to set
474 * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
475 * arch code will notice on return to user mode, in case those bits
476 * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
477 * signal code always gets run when TIF_RESTORE_SIGMASK is set.
478 */
479static inline void set_restore_sigmask(void)
480{
481	set_thread_flag(TIF_RESTORE_SIGMASK);
482}
483
484static inline void clear_tsk_restore_sigmask(struct task_struct *task)
485{
486	clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
487}
488
489static inline void clear_restore_sigmask(void)
490{
491	clear_thread_flag(TIF_RESTORE_SIGMASK);
492}
493static inline bool test_tsk_restore_sigmask(struct task_struct *task)
494{
495	return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
496}
497static inline bool test_restore_sigmask(void)
498{
499	return test_thread_flag(TIF_RESTORE_SIGMASK);
500}
501static inline bool test_and_clear_restore_sigmask(void)
502{
503	return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
504}
505
506#else	/* TIF_RESTORE_SIGMASK */
507
508/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
509static inline void set_restore_sigmask(void)
510{
511	current->restore_sigmask = true;
512}
513static inline void clear_tsk_restore_sigmask(struct task_struct *task)
514{
515	task->restore_sigmask = false;
516}
517static inline void clear_restore_sigmask(void)
518{
519	current->restore_sigmask = false;
520}
521static inline bool test_restore_sigmask(void)
522{
523	return current->restore_sigmask;
524}
525static inline bool test_tsk_restore_sigmask(struct task_struct *task)
526{
527	return task->restore_sigmask;
528}
529static inline bool test_and_clear_restore_sigmask(void)
530{
531	if (!current->restore_sigmask)
532		return false;
533	current->restore_sigmask = false;
534	return true;
535}
536#endif
537
538static inline void restore_saved_sigmask(void)
539{
540	if (test_and_clear_restore_sigmask())
541		__set_current_blocked(&current->saved_sigmask);
542}
543
544extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
545
546static inline void restore_saved_sigmask_unless(bool interrupted)
547{
548	if (interrupted)
549		WARN_ON(!signal_pending(current));
550	else
551		restore_saved_sigmask();
552}
553
554static inline sigset_t *sigmask_to_save(void)
555{
556	sigset_t *res = &current->blocked;
557	if (unlikely(test_restore_sigmask()))
558		res = &current->saved_sigmask;
559	return res;
560}
561
562static inline int kill_cad_pid(int sig, int priv)
563{
564	return kill_pid(cad_pid, sig, priv);
565}
566
567/* These can be the second arg to send_sig_info/send_group_sig_info.  */
568#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
569#define SEND_SIG_PRIV	((struct kernel_siginfo *) 1)
570
571static inline int __on_sig_stack(unsigned long sp)
572{
573#ifdef CONFIG_STACK_GROWSUP
574	return sp >= current->sas_ss_sp &&
575		sp - current->sas_ss_sp < current->sas_ss_size;
576#else
577	return sp > current->sas_ss_sp &&
578		sp - current->sas_ss_sp <= current->sas_ss_size;
579#endif
580}
581
582/*
583 * True if we are on the alternate signal stack.
584 */
585static inline int on_sig_stack(unsigned long sp)
586{
587	/*
588	 * If the signal stack is SS_AUTODISARM then, by construction, we
589	 * can't be on the signal stack unless user code deliberately set
590	 * SS_AUTODISARM when we were already on it.
591	 *
592	 * This improves reliability: if user state gets corrupted such that
593	 * the stack pointer points very close to the end of the signal stack,
594	 * then this check will enable the signal to be handled anyway.
595	 */
596	if (current->sas_ss_flags & SS_AUTODISARM)
597		return 0;
598
599	return __on_sig_stack(sp);
600}
601
602static inline int sas_ss_flags(unsigned long sp)
603{
604	if (!current->sas_ss_size)
605		return SS_DISABLE;
606
607	return on_sig_stack(sp) ? SS_ONSTACK : 0;
608}
609
610static inline void sas_ss_reset(struct task_struct *p)
611{
612	p->sas_ss_sp = 0;
613	p->sas_ss_size = 0;
614	p->sas_ss_flags = SS_DISABLE;
615}
616
617static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
618{
619	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
620#ifdef CONFIG_STACK_GROWSUP
621		return current->sas_ss_sp;
622#else
623		return current->sas_ss_sp + current->sas_ss_size;
624#endif
625	return sp;
626}
627
628extern void __cleanup_sighand(struct sighand_struct *);
629extern void flush_itimer_signals(void);
630
631#define tasklist_empty() \
632	list_empty(&init_task.tasks)
633
634#define next_task(p) \
635	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
636
637#define for_each_process(p) \
638	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
639
640extern bool current_is_single_threaded(void);
641
642/*
643 * Without tasklist/siglock it is only rcu-safe if g can't exit/exec,
644 * otherwise next_thread(t) will never reach g after list_del_rcu(g).
645 */
646#define while_each_thread(g, t) \
647	while ((t = next_thread(t)) != g)
648
649#define for_other_threads(p, t)	\
650	for (t = p; (t = next_thread(t)) != p; )
651
652#define __for_each_thread(signal, t)	\
653	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node, \
654		lockdep_is_held(&tasklist_lock))
655
656#define for_each_thread(p, t)		\
657	__for_each_thread((p)->signal, t)
658
659/* Careful: this is a double loop, 'break' won't work as expected. */
660#define for_each_process_thread(p, t)	\
661	for_each_process(p) for_each_thread(p, t)
662
663typedef int (*proc_visitor)(struct task_struct *p, void *data);
664void walk_process_tree(struct task_struct *top, proc_visitor, void *);
665
666static inline
667struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
668{
669	struct pid *pid;
670	if (type == PIDTYPE_PID)
671		pid = task_pid(task);
672	else
673		pid = task->signal->pids[type];
674	return pid;
675}
676
677static inline struct pid *task_tgid(struct task_struct *task)
678{
679	return task->signal->pids[PIDTYPE_TGID];
680}
681
682/*
683 * Without tasklist or RCU lock it is not safe to dereference
684 * the result of task_pgrp/task_session even if task == current,
685 * we can race with another thread doing sys_setsid/sys_setpgid.
686 */
687static inline struct pid *task_pgrp(struct task_struct *task)
688{
689	return task->signal->pids[PIDTYPE_PGID];
690}
691
692static inline struct pid *task_session(struct task_struct *task)
693{
694	return task->signal->pids[PIDTYPE_SID];
695}
696
697static inline int get_nr_threads(struct task_struct *task)
698{
699	return task->signal->nr_threads;
700}
701
702static inline bool thread_group_leader(struct task_struct *p)
703{
704	return p->exit_signal >= 0;
705}
706
707static inline
708bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
709{
710	return p1->signal == p2->signal;
711}
712
713/*
714 * returns NULL if p is the last thread in the thread group
715 */
716static inline struct task_struct *__next_thread(struct task_struct *p)
717{
718	return list_next_or_null_rcu(&p->signal->thread_head,
719					&p->thread_node,
720					struct task_struct,
721					thread_node);
722}
723
724static inline struct task_struct *next_thread(struct task_struct *p)
725{
726	return __next_thread(p) ?: p->group_leader;
727}
728
729static inline int thread_group_empty(struct task_struct *p)
730{
731	return thread_group_leader(p) &&
732	       list_is_last(&p->thread_node, &p->signal->thread_head);
733}
734
735#define delay_group_leader(p) \
736		(thread_group_leader(p) && !thread_group_empty(p))
737
738extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
739							unsigned long *flags);
740
741static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
742						       unsigned long *flags)
743{
744	struct sighand_struct *ret;
745
746	ret = __lock_task_sighand(task, flags);
747	(void)__cond_lock(&task->sighand->siglock, ret);
748	return ret;
749}
750
751static inline void unlock_task_sighand(struct task_struct *task,
752						unsigned long *flags)
753{
754	spin_unlock_irqrestore(&task->sighand->siglock, *flags);
755}
756
757#ifdef CONFIG_LOCKDEP
758extern void lockdep_assert_task_sighand_held(struct task_struct *task);
759#else
760static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { }
761#endif
762
763static inline unsigned long task_rlimit(const struct task_struct *task,
764		unsigned int limit)
765{
766	return READ_ONCE(task->signal->rlim[limit].rlim_cur);
767}
768
769static inline unsigned long task_rlimit_max(const struct task_struct *task,
770		unsigned int limit)
771{
772	return READ_ONCE(task->signal->rlim[limit].rlim_max);
773}
774
775static inline unsigned long rlimit(unsigned int limit)
776{
777	return task_rlimit(current, limit);
778}
779
780static inline unsigned long rlimit_max(unsigned int limit)
781{
782	return task_rlimit_max(current, limit);
783}
784
785#endif /* _LINUX_SCHED_SIGNAL_H */
786