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 timer_create_restore_ids:1;
140 atomic_t next_posix_timer_id;
141 struct hlist_head posix_timers;
142 struct hlist_head ignored_posix_timers;
143
144 /* ITIMER_REAL timer for the process */
145 struct hrtimer real_timer;
146 ktime_t it_real_incr;
147
148 /*
149 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
150 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
151 * values are defined to 0 and 1 respectively
152 */
153 struct cpu_itimer it[2];
154
155 /*
156 * Thread group totals for process CPU timers.
157 * See thread_group_cputimer(), et al, for details.
158 */
159 struct thread_group_cputimer cputimer;
160
161#endif
162 /* Empty if CONFIG_POSIX_TIMERS=n */
163 struct posix_cputimers posix_cputimers;
164
165 /* PID/PID hash table linkage. */
166 struct pid *pids[PIDTYPE_MAX];
167
168#ifdef CONFIG_NO_HZ_FULL
169 atomic_t tick_dep_mask;
170#endif
171
172 struct pid *tty_old_pgrp;
173
174 /* boolean value for session group leader */
175 int leader;
176
177 struct tty_struct *tty; /* NULL if no tty */
178
179#ifdef CONFIG_SCHED_AUTOGROUP
180 struct autogroup *autogroup;
181#endif
182 /*
183 * Cumulative resource counters for dead threads in the group,
184 * and for reaped dead child processes forked by this group.
185 * Live threads maintain their own counters and add to these
186 * in __exit_signal, except for the group leader.
187 */
188 seqlock_t stats_lock;
189 u64 utime, stime, cutime, cstime;
190 u64 gtime;
191 u64 cgtime;
192 struct prev_cputime prev_cputime;
193 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
194 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
195 unsigned long inblock, oublock, cinblock, coublock;
196 unsigned long maxrss, cmaxrss;
197 struct task_io_accounting ioac;
198
199 /*
200 * Cumulative ns of schedule CPU time fo dead threads in the
201 * group, not including a zombie group leader, (This only differs
202 * from jiffies_to_ns(utime + stime) if sched_clock uses something
203 * other than jiffies.)
204 */
205 unsigned long long sum_sched_runtime;
206
207 /*
208 * We don't bother to synchronize most readers of this at all,
209 * because there is no reader checking a limit that actually needs
210 * to get both rlim_cur and rlim_max atomically, and either one
211 * alone is a single word that can safely be read normally.
212 * getrlimit/setrlimit use task_lock(current->group_leader) to
213 * protect this instead of the siglock, because they really
214 * have no need to disable irqs.
215 */
216 struct rlimit rlim[RLIM_NLIMITS];
217
218#ifdef CONFIG_BSD_PROCESS_ACCT
219 struct pacct_struct pacct; /* per-process accounting information */
220#endif
221#ifdef CONFIG_TASKSTATS
222 struct taskstats *stats;
223#endif
224#ifdef CONFIG_AUDIT
225 unsigned audit_tty;
226 struct tty_audit_buf *tty_audit_buf;
227#endif
228
229#ifdef CONFIG_CGROUPS
230 struct rw_semaphore cgroup_threadgroup_rwsem;
231#endif
232
233 /*
234 * Thread is the potential origin of an oom condition; kill first on
235 * oom
236 */
237 bool oom_flag_origin;
238 short oom_score_adj; /* OOM kill score adjustment */
239 short oom_score_adj_min; /* OOM kill score adjustment min value.
240 * Only settable by CAP_SYS_RESOURCE. */
241 struct mm_struct *oom_mm; /* recorded mm when the thread group got
242 * killed by the oom killer */
243
244 struct mutex cred_guard_mutex; /* guard against foreign influences on
245 * credential calculations
246 * (notably. ptrace)
247 * Deprecated do not use in new code.
248 * Use exec_update_lock instead.
249 */
250 struct rw_semaphore exec_update_lock; /* Held while task_struct is
251 * being updated during exec,
252 * and may have inconsistent
253 * permissions.
254 */
255} __randomize_layout;
256
257/*
258 * Bits in flags field of signal_struct.
259 */
260#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
261#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
262#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
263/*
264 * Pending notifications to parent.
265 */
266#define SIGNAL_CLD_STOPPED 0x00000010
267#define SIGNAL_CLD_CONTINUED 0x00000020
268#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
269
270#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
271
272#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
273 SIGNAL_STOP_CONTINUED)
274
275static inline void signal_set_stop_flags(struct signal_struct *sig,
276 unsigned int flags)
277{
278 WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);
279 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
280}
281
282extern void flush_signals(struct task_struct *);
283extern void ignore_signals(struct task_struct *);
284extern void flush_signal_handlers(struct task_struct *, int force_default);
285extern int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type);
286
287static inline int kernel_dequeue_signal(void)
288{
289 struct task_struct *task = current;
290 kernel_siginfo_t __info;
291 enum pid_type __type;
292 int ret;
293
294 spin_lock_irq(lock: &task->sighand->siglock);
295 ret = dequeue_signal(mask: &task->blocked, info: &__info, type: &__type);
296 spin_unlock_irq(lock: &task->sighand->siglock);
297
298 return ret;
299}
300
301static inline void kernel_signal_stop(void)
302{
303 spin_lock_irq(lock: &current->sighand->siglock);
304 if (current->jobctl & JOBCTL_STOP_DEQUEUED) {
305 current->jobctl |= JOBCTL_STOPPED;
306 set_special_state(TASK_STOPPED);
307 }
308 spin_unlock_irq(lock: &current->sighand->siglock);
309
310 schedule();
311}
312
313int force_sig_fault_to_task(int sig, int code, void __user *addr,
314 struct task_struct *t);
315int force_sig_fault(int sig, int code, void __user *addr);
316int send_sig_fault(int sig, int code, void __user *addr, struct task_struct *t);
317
318int force_sig_mceerr(int code, void __user *, short);
319int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
320
321int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
322int force_sig_pkuerr(void __user *addr, u32 pkey);
323int send_sig_perf(void __user *addr, u32 type, u64 sig_data);
324
325int force_sig_ptrace_errno_trap(int errno, void __user *addr);
326int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
327int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
328 struct task_struct *t);
329int force_sig_seccomp(int syscall, int reason, bool force_coredump);
330
331extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
332extern void force_sigsegv(int sig);
333extern int force_sig_info(struct kernel_siginfo *);
334extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
335extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
336extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
337 const struct cred *);
338extern int kill_pgrp(struct pid *pid, int sig, int priv);
339extern int kill_pid(struct pid *pid, int sig, int priv);
340extern __must_check bool do_notify_parent(struct task_struct *, int);
341extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
342extern void force_sig(int);
343extern void force_fatal_sig(int);
344extern void force_exit_sig(int);
345extern int send_sig(int, struct task_struct *, int);
346extern int zap_other_threads(struct task_struct *p);
347extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
348
349static inline void clear_notify_signal(void)
350{
351 clear_thread_flag(TIF_NOTIFY_SIGNAL);
352 smp_mb__after_atomic();
353}
354
355/*
356 * Returns 'true' if kick_process() is needed to force a transition from
357 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work.
358 */
359static inline bool __set_notify_signal(struct task_struct *task)
360{
361 return !test_and_set_tsk_thread_flag(tsk: task, TIF_NOTIFY_SIGNAL) &&
362 !wake_up_state(tsk: task, TASK_INTERRUPTIBLE);
363}
364
365/*
366 * Called to break out of interruptible wait loops, and enter the
367 * exit_to_user_mode_loop().
368 */
369static inline void set_notify_signal(struct task_struct *task)
370{
371 if (__set_notify_signal(task))
372 kick_process(tsk: task);
373}
374
375static inline int restart_syscall(void)
376{
377 set_tsk_thread_flag(current, TIF_SIGPENDING);
378 return -ERESTARTNOINTR;
379}
380
381static inline int task_sigpending(struct task_struct *p)
382{
383 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
384}
385
386static inline int signal_pending(struct task_struct *p)
387{
388 /*
389 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same
390 * behavior in terms of ensuring that we break out of wait loops
391 * so that notify signal callbacks can be processed.
392 */
393 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL)))
394 return 1;
395 return task_sigpending(p);
396}
397
398static inline int __fatal_signal_pending(struct task_struct *p)
399{
400 return unlikely(sigismember(&p->pending.signal, SIGKILL));
401}
402
403static inline int fatal_signal_pending(struct task_struct *p)
404{
405 return task_sigpending(p) && __fatal_signal_pending(p);
406}
407
408static inline int signal_pending_state(unsigned int state, struct task_struct *p)
409{
410 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
411 return 0;
412 if (!signal_pending(p))
413 return 0;
414
415 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
416}
417
418/*
419 * This should only be used in fault handlers to decide whether we
420 * should stop the current fault routine to handle the signals
421 * instead, especially with the case where we've got interrupted with
422 * a VM_FAULT_RETRY.
423 */
424static inline bool fault_signal_pending(vm_fault_t fault_flags,
425 struct pt_regs *regs)
426{
427 return unlikely((fault_flags & VM_FAULT_RETRY) &&
428 (fatal_signal_pending(current) ||
429 (user_mode(regs) && signal_pending(current))));
430}
431
432/*
433 * Reevaluate whether the task has signals pending delivery.
434 * Wake the task if so.
435 * This is required every time the blocked sigset_t changes.
436 * callers must hold sighand->siglock.
437 */
438extern void recalc_sigpending(void);
439extern void calculate_sigpending(void);
440
441extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
442
443static inline void signal_wake_up(struct task_struct *t, bool fatal)
444{
445 unsigned int state = 0;
446 if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {
447 t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);
448 state = TASK_WAKEKILL | __TASK_TRACED;
449 }
450 signal_wake_up_state(t, state);
451}
452static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
453{
454 unsigned int state = 0;
455 if (resume) {
456 t->jobctl &= ~JOBCTL_TRACED;
457 state = __TASK_TRACED;
458 }
459 signal_wake_up_state(t, state);
460}
461
462void task_join_group_stop(struct task_struct *task);
463
464#ifdef TIF_RESTORE_SIGMASK
465/*
466 * Legacy restore_sigmask accessors. These are inefficient on
467 * SMP architectures because they require atomic operations.
468 */
469
470/**
471 * set_restore_sigmask() - make sure saved_sigmask processing gets done
472 *
473 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
474 * will run before returning to user mode, to process the flag. For
475 * all callers, TIF_SIGPENDING is already set or it's no harm to set
476 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
477 * arch code will notice on return to user mode, in case those bits
478 * are scarce. We set TIF_SIGPENDING here to ensure that the arch
479 * signal code always gets run when TIF_RESTORE_SIGMASK is set.
480 */
481static inline void set_restore_sigmask(void)
482{
483 set_thread_flag(TIF_RESTORE_SIGMASK);
484}
485
486static inline void clear_tsk_restore_sigmask(struct task_struct *task)
487{
488 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
489}
490
491static inline void clear_restore_sigmask(void)
492{
493 clear_thread_flag(TIF_RESTORE_SIGMASK);
494}
495static inline bool test_tsk_restore_sigmask(struct task_struct *task)
496{
497 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
498}
499static inline bool test_restore_sigmask(void)
500{
501 return test_thread_flag(TIF_RESTORE_SIGMASK);
502}
503static inline bool test_and_clear_restore_sigmask(void)
504{
505 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
506}
507
508#else /* TIF_RESTORE_SIGMASK */
509
510/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
511static inline void set_restore_sigmask(void)
512{
513 current->restore_sigmask = true;
514}
515static inline void clear_tsk_restore_sigmask(struct task_struct *task)
516{
517 task->restore_sigmask = false;
518}
519static inline void clear_restore_sigmask(void)
520{
521 current->restore_sigmask = false;
522}
523static inline bool test_restore_sigmask(void)
524{
525 return current->restore_sigmask;
526}
527static inline bool test_tsk_restore_sigmask(struct task_struct *task)
528{
529 return task->restore_sigmask;
530}
531static inline bool test_and_clear_restore_sigmask(void)
532{
533 if (!current->restore_sigmask)
534 return false;
535 current->restore_sigmask = false;
536 return true;
537}
538#endif
539
540static inline void restore_saved_sigmask(void)
541{
542 if (test_and_clear_restore_sigmask())
543 __set_current_blocked(&current->saved_sigmask);
544}
545
546extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
547
548static inline void restore_saved_sigmask_unless(bool interrupted)
549{
550 if (interrupted)
551 WARN_ON(!signal_pending(current));
552 else
553 restore_saved_sigmask();
554}
555
556static inline sigset_t *sigmask_to_save(void)
557{
558 sigset_t *res = &current->blocked;
559 if (unlikely(test_restore_sigmask()))
560 res = &current->saved_sigmask;
561 return res;
562}
563
564static inline int kill_cad_pid(int sig, int priv)
565{
566 return kill_pid(pid: cad_pid, sig, priv);
567}
568
569/* These can be the second arg to send_sig_info/send_group_sig_info. */
570#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
571#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
572
573static inline int __on_sig_stack(unsigned long sp)
574{
575#ifdef CONFIG_STACK_GROWSUP
576 return sp >= current->sas_ss_sp &&
577 sp - current->sas_ss_sp < current->sas_ss_size;
578#else
579 return sp > current->sas_ss_sp &&
580 sp - current->sas_ss_sp <= current->sas_ss_size;
581#endif
582}
583
584/*
585 * True if we are on the alternate signal stack.
586 */
587static inline int on_sig_stack(unsigned long sp)
588{
589 /*
590 * If the signal stack is SS_AUTODISARM then, by construction, we
591 * can't be on the signal stack unless user code deliberately set
592 * SS_AUTODISARM when we were already on it.
593 *
594 * This improves reliability: if user state gets corrupted such that
595 * the stack pointer points very close to the end of the signal stack,
596 * then this check will enable the signal to be handled anyway.
597 */
598 if (current->sas_ss_flags & SS_AUTODISARM)
599 return 0;
600
601 return __on_sig_stack(sp);
602}
603
604static inline int sas_ss_flags(unsigned long sp)
605{
606 if (!current->sas_ss_size)
607 return SS_DISABLE;
608
609 return on_sig_stack(sp) ? SS_ONSTACK : 0;
610}
611
612static inline void sas_ss_reset(struct task_struct *p)
613{
614 p->sas_ss_sp = 0;
615 p->sas_ss_size = 0;
616 p->sas_ss_flags = SS_DISABLE;
617}
618
619static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
620{
621 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
622#ifdef CONFIG_STACK_GROWSUP
623 return current->sas_ss_sp;
624#else
625 return current->sas_ss_sp + current->sas_ss_size;
626#endif
627 return sp;
628}
629
630extern void __cleanup_sighand(struct sighand_struct *);
631extern void flush_itimer_signals(void);
632
633#define tasklist_empty() \
634 list_empty(&init_task.tasks)
635
636#define next_task(p) \
637 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
638
639#define for_each_process(p) \
640 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
641
642extern bool current_is_single_threaded(void);
643
644/*
645 * Without tasklist/siglock it is only rcu-safe if g can't exit/exec,
646 * otherwise next_thread(t) will never reach g after list_del_rcu(g).
647 */
648#define while_each_thread(g, t) \
649 while ((t = next_thread(t)) != g)
650
651#define for_other_threads(p, t) \
652 for (t = p; (t = next_thread(t)) != p; )
653
654#define __for_each_thread(signal, t) \
655 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node, \
656 lockdep_is_held(&tasklist_lock))
657
658#define for_each_thread(p, t) \
659 __for_each_thread((p)->signal, t)
660
661/* Careful: this is a double loop, 'break' won't work as expected. */
662#define for_each_process_thread(p, t) \
663 for_each_process(p) for_each_thread(p, t)
664
665typedef int (*proc_visitor)(struct task_struct *p, void *data);
666void walk_process_tree(struct task_struct *top, proc_visitor, void *);
667
668static inline
669struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
670{
671 struct pid *pid;
672 if (type == PIDTYPE_PID)
673 pid = task_pid(task);
674 else
675 pid = task->signal->pids[type];
676 return pid;
677}
678
679static inline struct pid *task_tgid(struct task_struct *task)
680{
681 return task->signal->pids[PIDTYPE_TGID];
682}
683
684/*
685 * Without tasklist or RCU lock it is not safe to dereference
686 * the result of task_pgrp/task_session even if task == current,
687 * we can race with another thread doing sys_setsid/sys_setpgid.
688 */
689static inline struct pid *task_pgrp(struct task_struct *task)
690{
691 return task->signal->pids[PIDTYPE_PGID];
692}
693
694static inline struct pid *task_session(struct task_struct *task)
695{
696 return task->signal->pids[PIDTYPE_SID];
697}
698
699static inline int get_nr_threads(struct task_struct *task)
700{
701 return task->signal->nr_threads;
702}
703
704static inline bool thread_group_leader(struct task_struct *p)
705{
706 return p->exit_signal >= 0;
707}
708
709static inline
710bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
711{
712 return p1->signal == p2->signal;
713}
714
715/*
716 * returns NULL if p is the last thread in the thread group
717 */
718static inline struct task_struct *__next_thread(struct task_struct *p)
719{
720 return list_next_or_null_rcu(&p->signal->thread_head,
721 &p->thread_node,
722 struct task_struct,
723 thread_node);
724}
725
726static inline struct task_struct *next_thread(struct task_struct *p)
727{
728 return __next_thread(p) ?: p->group_leader;
729}
730
731static inline int thread_group_empty(struct task_struct *p)
732{
733 return thread_group_leader(p) &&
734 list_is_last(list: &p->thread_node, head: &p->signal->thread_head);
735}
736
737#define delay_group_leader(p) \
738 (thread_group_leader(p) && !thread_group_empty(p))
739
740extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
741 unsigned long *flags);
742
743static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
744 unsigned long *flags)
745{
746 struct sighand_struct *ret;
747
748 ret = __lock_task_sighand(task, flags);
749 (void)__cond_lock(&task->sighand->siglock, ret);
750 return ret;
751}
752
753static inline void unlock_task_sighand(struct task_struct *task,
754 unsigned long *flags)
755{
756 spin_unlock_irqrestore(lock: &task->sighand->siglock, flags: *flags);
757}
758
759#ifdef CONFIG_LOCKDEP
760extern void lockdep_assert_task_sighand_held(struct task_struct *task);
761#else
762static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { }
763#endif
764
765static inline unsigned long task_rlimit(const struct task_struct *task,
766 unsigned int limit)
767{
768 return READ_ONCE(task->signal->rlim[limit].rlim_cur);
769}
770
771static inline unsigned long task_rlimit_max(const struct task_struct *task,
772 unsigned int limit)
773{
774 return READ_ONCE(task->signal->rlim[limit].rlim_max);
775}
776
777static inline unsigned long rlimit(unsigned int limit)
778{
779 return task_rlimit(current, limit);
780}
781
782static inline unsigned long rlimit_max(unsigned int limit)
783{
784 return task_rlimit_max(current, limit);
785}
786
787#endif /* _LINUX_SCHED_SIGNAL_H */
788