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/posix-timers.h>
13#include <linux/mm_types.h>
14#include <asm/ptrace.h>
15
16/*
17 * Types defining task->signal and task->sighand and APIs using them:
18 */
19
20struct sighand_struct {
21 spinlock_t siglock;
22 refcount_t count;
23 wait_queue_head_t signalfd_wqh;
24 struct k_sigaction action[_NSIG];
25};
26
27/*
28 * Per-process accounting stats:
29 */
30struct pacct_struct {
31 int ac_flag;
32 long ac_exitcode;
33 unsigned long ac_mem;
34 u64 ac_utime, ac_stime;
35 unsigned long ac_minflt, ac_majflt;
36};
37
38struct cpu_itimer {
39 u64 expires;
40 u64 incr;
41};
42
43/*
44 * This is the atomic variant of task_cputime, which can be used for
45 * storing and updating task_cputime statistics without locking.
46 */
47struct task_cputime_atomic {
48 atomic64_t utime;
49 atomic64_t stime;
50 atomic64_t sum_exec_runtime;
51};
52
53#define INIT_CPUTIME_ATOMIC \
54 (struct task_cputime_atomic) { \
55 .utime = ATOMIC64_INIT(0), \
56 .stime = ATOMIC64_INIT(0), \
57 .sum_exec_runtime = ATOMIC64_INIT(0), \
58 }
59/**
60 * struct thread_group_cputimer - thread group interval timer counts
61 * @cputime_atomic: atomic thread group interval timers.
62 *
63 * This structure contains the version of task_cputime, above, that is
64 * used for thread group CPU timer calculations.
65 */
66struct thread_group_cputimer {
67 struct task_cputime_atomic cputime_atomic;
68};
69
70struct multiprocess_signals {
71 sigset_t signal;
72 struct hlist_node node;
73};
74
75struct core_thread {
76 struct task_struct *task;
77 struct core_thread *next;
78};
79
80struct core_state {
81 atomic_t nr_threads;
82 struct core_thread dumper;
83 struct completion startup;
84};
85
86/*
87 * NOTE! "signal_struct" does not have its own
88 * locking, because a shared signal_struct always
89 * implies a shared sighand_struct, so locking
90 * sighand_struct is always a proper superset of
91 * the locking of signal_struct.
92 */
93struct signal_struct {
94 refcount_t sigcnt;
95 atomic_t live;
96 int nr_threads;
97 struct list_head thread_head;
98
99 wait_queue_head_t wait_chldexit; /* for wait4() */
100
101 /* current thread group signal load-balancing target: */
102 struct task_struct *curr_target;
103
104 /* shared signal handling: */
105 struct sigpending shared_pending;
106
107 /* For collecting multiprocess signals during fork */
108 struct hlist_head multiprocess;
109
110 /* thread group exit support */
111 int group_exit_code;
112 /* notify group_exec_task when notify_count is less or equal to 0 */
113 int notify_count;
114 struct task_struct *group_exec_task;
115
116 /* thread group stop support, overloads group_exit_code too */
117 int group_stop_count;
118 unsigned int flags; /* see SIGNAL_* flags below */
119
120 struct core_state *core_state; /* coredumping support */
121
122 /*
123 * PR_SET_CHILD_SUBREAPER marks a process, like a service
124 * manager, to re-parent orphan (double-forking) child processes
125 * to this process instead of 'init'. The service manager is
126 * able to receive SIGCHLD signals and is able to investigate
127 * the process until it calls wait(). All children of this
128 * process will inherit a flag if they should look for a
129 * child_subreaper process at exit.
130 */
131 unsigned int is_child_subreaper:1;
132 unsigned int has_child_subreaper:1;
133
134#ifdef CONFIG_POSIX_TIMERS
135
136 /* POSIX.1b Interval Timers */
137 int posix_timer_id;
138 struct list_head posix_timers;
139
140 /* ITIMER_REAL timer for the process */
141 struct hrtimer real_timer;
142 ktime_t it_real_incr;
143
144 /*
145 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
146 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
147 * values are defined to 0 and 1 respectively
148 */
149 struct cpu_itimer it[2];
150
151 /*
152 * Thread group totals for process CPU timers.
153 * See thread_group_cputimer(), et al, for details.
154 */
155 struct thread_group_cputimer cputimer;
156
157#endif
158 /* Empty if CONFIG_POSIX_TIMERS=n */
159 struct posix_cputimers posix_cputimers;
160
161 /* PID/PID hash table linkage. */
162 struct pid *pids[PIDTYPE_MAX];
163
164#ifdef CONFIG_NO_HZ_FULL
165 atomic_t tick_dep_mask;
166#endif
167
168 struct pid *tty_old_pgrp;
169
170 /* boolean value for session group leader */
171 int leader;
172
173 struct tty_struct *tty; /* NULL if no tty */
174
175#ifdef CONFIG_SCHED_AUTOGROUP
176 struct autogroup *autogroup;
177#endif
178 /*
179 * Cumulative resource counters for dead threads in the group,
180 * and for reaped dead child processes forked by this group.
181 * Live threads maintain their own counters and add to these
182 * in __exit_signal, except for the group leader.
183 */
184 seqlock_t stats_lock;
185 u64 utime, stime, cutime, cstime;
186 u64 gtime;
187 u64 cgtime;
188 struct prev_cputime prev_cputime;
189 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
190 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
191 unsigned long inblock, oublock, cinblock, coublock;
192 unsigned long maxrss, cmaxrss;
193 struct task_io_accounting ioac;
194
195 /*
196 * Cumulative ns of schedule CPU time fo dead threads in the
197 * group, not including a zombie group leader, (This only differs
198 * from jiffies_to_ns(utime + stime) if sched_clock uses something
199 * other than jiffies.)
200 */
201 unsigned long long sum_sched_runtime;
202
203 /*
204 * We don't bother to synchronize most readers of this at all,
205 * because there is no reader checking a limit that actually needs
206 * to get both rlim_cur and rlim_max atomically, and either one
207 * alone is a single word that can safely be read normally.
208 * getrlimit/setrlimit use task_lock(current->group_leader) to
209 * protect this instead of the siglock, because they really
210 * have no need to disable irqs.
211 */
212 struct rlimit rlim[RLIM_NLIMITS];
213
214#ifdef CONFIG_BSD_PROCESS_ACCT
215 struct pacct_struct pacct; /* per-process accounting information */
216#endif
217#ifdef CONFIG_TASKSTATS
218 struct taskstats *stats;
219#endif
220#ifdef CONFIG_AUDIT
221 unsigned audit_tty;
222 struct tty_audit_buf *tty_audit_buf;
223#endif
224
225 /*
226 * Thread is the potential origin of an oom condition; kill first on
227 * oom
228 */
229 bool oom_flag_origin;
230 short oom_score_adj; /* OOM kill score adjustment */
231 short oom_score_adj_min; /* OOM kill score adjustment min value.
232 * Only settable by CAP_SYS_RESOURCE. */
233 struct mm_struct *oom_mm; /* recorded mm when the thread group got
234 * killed by the oom killer */
235
236 struct mutex cred_guard_mutex; /* guard against foreign influences on
237 * credential calculations
238 * (notably. ptrace)
239 * Deprecated do not use in new code.
240 * Use exec_update_lock instead.
241 */
242 struct rw_semaphore exec_update_lock; /* Held while task_struct is
243 * being updated during exec,
244 * and may have inconsistent
245 * permissions.
246 */
247} __randomize_layout;
248
249/*
250 * Bits in flags field of signal_struct.
251 */
252#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
253#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
254#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
255/*
256 * Pending notifications to parent.
257 */
258#define SIGNAL_CLD_STOPPED 0x00000010
259#define SIGNAL_CLD_CONTINUED 0x00000020
260#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
261
262#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
263
264#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
265 SIGNAL_STOP_CONTINUED)
266
267static inline void signal_set_stop_flags(struct signal_struct *sig,
268 unsigned int flags)
269{
270 WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);
271 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
272}
273
274extern void flush_signals(struct task_struct *);
275extern void ignore_signals(struct task_struct *);
276extern void flush_signal_handlers(struct task_struct *, int force_default);
277extern int dequeue_signal(struct task_struct *task, sigset_t *mask,
278 kernel_siginfo_t *info, enum pid_type *type);
279
280static inline int kernel_dequeue_signal(void)
281{
282 struct task_struct *task = current;
283 kernel_siginfo_t __info;
284 enum pid_type __type;
285 int ret;
286
287 spin_lock_irq(&task->sighand->siglock);
288 ret = dequeue_signal(task, &task->blocked, &__info, &__type);
289 spin_unlock_irq(&task->sighand->siglock);
290
291 return ret;
292}
293
294static inline void kernel_signal_stop(void)
295{
296 spin_lock_irq(&current->sighand->siglock);
297 if (current->jobctl & JOBCTL_STOP_DEQUEUED) {
298 current->jobctl |= JOBCTL_STOPPED;
299 set_special_state(TASK_STOPPED);
300 }
301 spin_unlock_irq(&current->sighand->siglock);
302
303 schedule();
304}
305#ifdef __ia64__
306# define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3
307#else
308# define ___ARCH_SI_IA64(_a1, _a2, _a3)
309#endif
310
311int force_sig_fault_to_task(int sig, int code, void __user *addr
312 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
313 , struct task_struct *t);
314int force_sig_fault(int sig, int code, void __user *addr
315 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr));
316int send_sig_fault(int sig, int code, void __user *addr
317 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
318 , struct task_struct *t);
319
320int force_sig_mceerr(int code, void __user *, short);
321int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
322
323int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
324int force_sig_pkuerr(void __user *addr, u32 pkey);
325int send_sig_perf(void __user *addr, u32 type, u64 sig_data);
326
327int force_sig_ptrace_errno_trap(int errno, void __user *addr);
328int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
329int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
330 struct task_struct *t);
331int force_sig_seccomp(int syscall, int reason, bool force_coredump);
332
333extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
334extern void force_sigsegv(int sig);
335extern int force_sig_info(struct kernel_siginfo *);
336extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
337extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
338extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
339 const struct cred *);
340extern int kill_pgrp(struct pid *pid, int sig, int priv);
341extern int kill_pid(struct pid *pid, int sig, int priv);
342extern __must_check bool do_notify_parent(struct task_struct *, int);
343extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
344extern void force_sig(int);
345extern void force_fatal_sig(int);
346extern void force_exit_sig(int);
347extern int send_sig(int, struct task_struct *, int);
348extern int zap_other_threads(struct task_struct *p);
349extern struct sigqueue *sigqueue_alloc(void);
350extern void sigqueue_free(struct sigqueue *);
351extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
352extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
353
354static inline void clear_notify_signal(void)
355{
356 clear_thread_flag(TIF_NOTIFY_SIGNAL);
357 smp_mb__after_atomic();
358}
359
360/*
361 * Returns 'true' if kick_process() is needed to force a transition from
362 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work.
363 */
364static inline bool __set_notify_signal(struct task_struct *task)
365{
366 return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
367 !wake_up_state(task, TASK_INTERRUPTIBLE);
368}
369
370/*
371 * Called to break out of interruptible wait loops, and enter the
372 * exit_to_user_mode_loop().
373 */
374static inline void set_notify_signal(struct task_struct *task)
375{
376 if (__set_notify_signal(task))
377 kick_process(task);
378}
379
380static inline int restart_syscall(void)
381{
382 set_tsk_thread_flag(current, TIF_SIGPENDING);
383 return -ERESTARTNOINTR;
384}
385
386static inline int task_sigpending(struct task_struct *p)
387{
388 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
389}
390
391static inline int signal_pending(struct task_struct *p)
392{
393 /*
394 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same
395 * behavior in terms of ensuring that we break out of wait loops
396 * so that notify signal callbacks can be processed.
397 */
398 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL)))
399 return 1;
400 return task_sigpending(p);
401}
402
403static inline int __fatal_signal_pending(struct task_struct *p)
404{
405 return unlikely(sigismember(&p->pending.signal, SIGKILL));
406}
407
408static inline int fatal_signal_pending(struct task_struct *p)
409{
410 return task_sigpending(p) && __fatal_signal_pending(p);
411}
412
413static inline int signal_pending_state(unsigned int state, struct task_struct *p)
414{
415 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
416 return 0;
417 if (!signal_pending(p))
418 return 0;
419
420 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
421}
422
423/*
424 * This should only be used in fault handlers to decide whether we
425 * should stop the current fault routine to handle the signals
426 * instead, especially with the case where we've got interrupted with
427 * a VM_FAULT_RETRY.
428 */
429static inline bool fault_signal_pending(vm_fault_t fault_flags,
430 struct pt_regs *regs)
431{
432 return unlikely((fault_flags & VM_FAULT_RETRY) &&
433 (fatal_signal_pending(current) ||
434 (user_mode(regs) && signal_pending(current))));
435}
436
437/*
438 * Reevaluate whether the task has signals pending delivery.
439 * Wake the task if so.
440 * This is required every time the blocked sigset_t changes.
441 * callers must hold sighand->siglock.
442 */
443extern void recalc_sigpending_and_wake(struct task_struct *t);
444extern void recalc_sigpending(void);
445extern void calculate_sigpending(void);
446
447extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
448
449static inline void signal_wake_up(struct task_struct *t, bool fatal)
450{
451 unsigned int state = 0;
452 if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {
453 t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);
454 state = TASK_WAKEKILL | __TASK_TRACED;
455 }
456 signal_wake_up_state(t, state);
457}
458static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
459{
460 unsigned int state = 0;
461 if (resume) {
462 t->jobctl &= ~JOBCTL_TRACED;
463 state = __TASK_TRACED;
464 }
465 signal_wake_up_state(t, state);
466}
467
468void task_join_group_stop(struct task_struct *task);
469
470#ifdef TIF_RESTORE_SIGMASK
471/*
472 * Legacy restore_sigmask accessors. These are inefficient on
473 * SMP architectures because they require atomic operations.
474 */
475
476/**
477 * set_restore_sigmask() - make sure saved_sigmask processing gets done
478 *
479 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
480 * will run before returning to user mode, to process the flag. For
481 * all callers, TIF_SIGPENDING is already set or it's no harm to set
482 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
483 * arch code will notice on return to user mode, in case those bits
484 * are scarce. We set TIF_SIGPENDING here to ensure that the arch
485 * signal code always gets run when TIF_RESTORE_SIGMASK is set.
486 */
487static inline void set_restore_sigmask(void)
488{
489 set_thread_flag(TIF_RESTORE_SIGMASK);
490}
491
492static inline void clear_tsk_restore_sigmask(struct task_struct *task)
493{
494 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
495}
496
497static inline void clear_restore_sigmask(void)
498{
499 clear_thread_flag(TIF_RESTORE_SIGMASK);
500}
501static inline bool test_tsk_restore_sigmask(struct task_struct *task)
502{
503 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
504}
505static inline bool test_restore_sigmask(void)
506{
507 return test_thread_flag(TIF_RESTORE_SIGMASK);
508}
509static inline bool test_and_clear_restore_sigmask(void)
510{
511 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
512}
513
514#else /* TIF_RESTORE_SIGMASK */
515
516/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
517static inline void set_restore_sigmask(void)
518{
519 current->restore_sigmask = true;
520}
521static inline void clear_tsk_restore_sigmask(struct task_struct *task)
522{
523 task->restore_sigmask = false;
524}
525static inline void clear_restore_sigmask(void)
526{
527 current->restore_sigmask = false;
528}
529static inline bool test_restore_sigmask(void)
530{
531 return current->restore_sigmask;
532}
533static inline bool test_tsk_restore_sigmask(struct task_struct *task)
534{
535 return task->restore_sigmask;
536}
537static inline bool test_and_clear_restore_sigmask(void)
538{
539 if (!current->restore_sigmask)
540 return false;
541 current->restore_sigmask = false;
542 return true;
543}
544#endif
545
546static inline void restore_saved_sigmask(void)
547{
548 if (test_and_clear_restore_sigmask())
549 __set_current_blocked(&current->saved_sigmask);
550}
551
552extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
553
554static inline void restore_saved_sigmask_unless(bool interrupted)
555{
556 if (interrupted)
557 WARN_ON(!signal_pending(current));
558 else
559 restore_saved_sigmask();
560}
561
562static inline sigset_t *sigmask_to_save(void)
563{
564 sigset_t *res = &current->blocked;
565 if (unlikely(test_restore_sigmask()))
566 res = &current->saved_sigmask;
567 return res;
568}
569
570static inline int kill_cad_pid(int sig, int priv)
571{
572 return kill_pid(cad_pid, sig, priv);
573}
574
575/* These can be the second arg to send_sig_info/send_group_sig_info. */
576#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
577#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
578
579static inline int __on_sig_stack(unsigned long sp)
580{
581#ifdef CONFIG_STACK_GROWSUP
582 return sp >= current->sas_ss_sp &&
583 sp - current->sas_ss_sp < current->sas_ss_size;
584#else
585 return sp > current->sas_ss_sp &&
586 sp - current->sas_ss_sp <= current->sas_ss_size;
587#endif
588}
589
590/*
591 * True if we are on the alternate signal stack.
592 */
593static inline int on_sig_stack(unsigned long sp)
594{
595 /*
596 * If the signal stack is SS_AUTODISARM then, by construction, we
597 * can't be on the signal stack unless user code deliberately set
598 * SS_AUTODISARM when we were already on it.
599 *
600 * This improves reliability: if user state gets corrupted such that
601 * the stack pointer points very close to the end of the signal stack,
602 * then this check will enable the signal to be handled anyway.
603 */
604 if (current->sas_ss_flags & SS_AUTODISARM)
605 return 0;
606
607 return __on_sig_stack(sp);
608}
609
610static inline int sas_ss_flags(unsigned long sp)
611{
612 if (!current->sas_ss_size)
613 return SS_DISABLE;
614
615 return on_sig_stack(sp) ? SS_ONSTACK : 0;
616}
617
618static inline void sas_ss_reset(struct task_struct *p)
619{
620 p->sas_ss_sp = 0;
621 p->sas_ss_size = 0;
622 p->sas_ss_flags = SS_DISABLE;
623}
624
625static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
626{
627 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
628#ifdef CONFIG_STACK_GROWSUP
629 return current->sas_ss_sp;
630#else
631 return current->sas_ss_sp + current->sas_ss_size;
632#endif
633 return sp;
634}
635
636extern void __cleanup_sighand(struct sighand_struct *);
637extern void flush_itimer_signals(void);
638
639#define tasklist_empty() \
640 list_empty(&init_task.tasks)
641
642#define next_task(p) \
643 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
644
645#define for_each_process(p) \
646 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
647
648extern bool current_is_single_threaded(void);
649
650/*
651 * Careful: do_each_thread/while_each_thread is a double loop so
652 * 'break' will not work as expected - use goto instead.
653 */
654#define do_each_thread(g, t) \
655 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
656
657#define while_each_thread(g, t) \
658 while ((t = next_thread(t)) != g)
659
660#define __for_each_thread(signal, t) \
661 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
662
663#define for_each_thread(p, t) \
664 __for_each_thread((p)->signal, t)
665
666/* Careful: this is a double loop, 'break' won't work as expected. */
667#define for_each_process_thread(p, t) \
668 for_each_process(p) for_each_thread(p, t)
669
670typedef int (*proc_visitor)(struct task_struct *p, void *data);
671void walk_process_tree(struct task_struct *top, proc_visitor, void *);
672
673static inline
674struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
675{
676 struct pid *pid;
677 if (type == PIDTYPE_PID)
678 pid = task_pid(task);
679 else
680 pid = task->signal->pids[type];
681 return pid;
682}
683
684static inline struct pid *task_tgid(struct task_struct *task)
685{
686 return task->signal->pids[PIDTYPE_TGID];
687}
688
689/*
690 * Without tasklist or RCU lock it is not safe to dereference
691 * the result of task_pgrp/task_session even if task == current,
692 * we can race with another thread doing sys_setsid/sys_setpgid.
693 */
694static inline struct pid *task_pgrp(struct task_struct *task)
695{
696 return task->signal->pids[PIDTYPE_PGID];
697}
698
699static inline struct pid *task_session(struct task_struct *task)
700{
701 return task->signal->pids[PIDTYPE_SID];
702}
703
704static inline int get_nr_threads(struct task_struct *task)
705{
706 return task->signal->nr_threads;
707}
708
709static inline bool thread_group_leader(struct task_struct *p)
710{
711 return p->exit_signal >= 0;
712}
713
714static inline
715bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
716{
717 return p1->signal == p2->signal;
718}
719
720static inline struct task_struct *next_thread(const struct task_struct *p)
721{
722 return list_entry_rcu(p->thread_group.next,
723 struct task_struct, thread_group);
724}
725
726static inline int thread_group_empty(struct task_struct *p)
727{
728 return list_empty(&p->thread_group);
729}
730
731#define delay_group_leader(p) \
732 (thread_group_leader(p) && !thread_group_empty(p))
733
734extern bool thread_group_exited(struct pid *pid);
735
736extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
737 unsigned long *flags);
738
739static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
740 unsigned long *flags)
741{
742 struct sighand_struct *ret;
743
744 ret = __lock_task_sighand(task, flags);
745 (void)__cond_lock(&task->sighand->siglock, ret);
746 return ret;
747}
748
749static inline void unlock_task_sighand(struct task_struct *task,
750 unsigned long *flags)
751{
752 spin_unlock_irqrestore(&task->sighand->siglock, *flags);
753}
754
755#ifdef CONFIG_LOCKDEP
756extern void lockdep_assert_task_sighand_held(struct task_struct *task);
757#else
758static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { }
759#endif
760
761static inline unsigned long task_rlimit(const struct task_struct *task,
762 unsigned int limit)
763{
764 return READ_ONCE(task->signal->rlim[limit].rlim_cur);
765}
766
767static inline unsigned long task_rlimit_max(const struct task_struct *task,
768 unsigned int limit)
769{
770 return READ_ONCE(task->signal->rlim[limit].rlim_max);
771}
772
773static inline unsigned long rlimit(unsigned int limit)
774{
775 return task_rlimit(current, limit);
776}
777
778static inline unsigned long rlimit_max(unsigned int limit)
779{
780 return task_rlimit_max(current, limit);
781}
782
783#endif /* _LINUX_SCHED_SIGNAL_H */
784

source code of linux/include/linux/sched/signal.h