xref: /linux/include/linux/sched.h (revision 79b6bb73f888933cbcd20b0ef3976cde67951b72)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_H
3 #define _LINUX_SCHED_H
4 
5 /*
6  * Define 'struct task_struct' and provide the main scheduler
7  * APIs (schedule(), wakeup variants, etc.)
8  */
9 
10 #include <uapi/linux/sched.h>
11 
12 #include <asm/current.h>
13 
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kcov.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/seccomp.h>
22 #include <linux/nodemask.h>
23 #include <linux/rcupdate.h>
24 #include <linux/refcount.h>
25 #include <linux/resource.h>
26 #include <linux/latencytop.h>
27 #include <linux/sched/prio.h>
28 #include <linux/sched/types.h>
29 #include <linux/signal_types.h>
30 #include <linux/mm_types_task.h>
31 #include <linux/task_io_accounting.h>
32 #include <linux/posix-timers.h>
33 #include <linux/rseq.h>
34 
35 /* task_struct member predeclarations (sorted alphabetically): */
36 struct audit_context;
37 struct backing_dev_info;
38 struct bio_list;
39 struct blk_plug;
40 struct capture_control;
41 struct cfs_rq;
42 struct fs_struct;
43 struct futex_pi_state;
44 struct io_context;
45 struct mempolicy;
46 struct nameidata;
47 struct nsproxy;
48 struct perf_event_context;
49 struct pid_namespace;
50 struct pipe_inode_info;
51 struct rcu_node;
52 struct reclaim_state;
53 struct robust_list_head;
54 struct root_domain;
55 struct rq;
56 struct sched_attr;
57 struct sched_param;
58 struct seq_file;
59 struct sighand_struct;
60 struct signal_struct;
61 struct task_delay_info;
62 struct task_group;
63 
64 /*
65  * Task state bitmask. NOTE! These bits are also
66  * encoded in fs/proc/array.c: get_task_state().
67  *
68  * We have two separate sets of flags: task->state
69  * is about runnability, while task->exit_state are
70  * about the task exiting. Confusing, but this way
71  * modifying one set can't modify the other one by
72  * mistake.
73  */
74 
75 /* Used in tsk->state: */
76 #define TASK_RUNNING			0x0000
77 #define TASK_INTERRUPTIBLE		0x0001
78 #define TASK_UNINTERRUPTIBLE		0x0002
79 #define __TASK_STOPPED			0x0004
80 #define __TASK_TRACED			0x0008
81 /* Used in tsk->exit_state: */
82 #define EXIT_DEAD			0x0010
83 #define EXIT_ZOMBIE			0x0020
84 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
85 /* Used in tsk->state again: */
86 #define TASK_PARKED			0x0040
87 #define TASK_DEAD			0x0080
88 #define TASK_WAKEKILL			0x0100
89 #define TASK_WAKING			0x0200
90 #define TASK_NOLOAD			0x0400
91 #define TASK_NEW			0x0800
92 #define TASK_STATE_MAX			0x1000
93 
94 /* Convenience macros for the sake of set_current_state: */
95 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
96 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
97 #define TASK_TRACED			(TASK_WAKEKILL | __TASK_TRACED)
98 
99 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
100 
101 /* Convenience macros for the sake of wake_up(): */
102 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
103 
104 /* get_task_state(): */
105 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
106 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
107 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
108 					 TASK_PARKED)
109 
110 #define task_is_traced(task)		((task->state & __TASK_TRACED) != 0)
111 
112 #define task_is_stopped(task)		((task->state & __TASK_STOPPED) != 0)
113 
114 #define task_is_stopped_or_traced(task)	((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
115 
116 #define task_contributes_to_load(task)	((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
117 					 (task->flags & PF_FROZEN) == 0 && \
118 					 (task->state & TASK_NOLOAD) == 0)
119 
120 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
121 
122 /*
123  * Special states are those that do not use the normal wait-loop pattern. See
124  * the comment with set_special_state().
125  */
126 #define is_special_task_state(state)				\
127 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
128 
129 #define __set_current_state(state_value)			\
130 	do {							\
131 		WARN_ON_ONCE(is_special_task_state(state_value));\
132 		current->task_state_change = _THIS_IP_;		\
133 		current->state = (state_value);			\
134 	} while (0)
135 
136 #define set_current_state(state_value)				\
137 	do {							\
138 		WARN_ON_ONCE(is_special_task_state(state_value));\
139 		current->task_state_change = _THIS_IP_;		\
140 		smp_store_mb(current->state, (state_value));	\
141 	} while (0)
142 
143 #define set_special_state(state_value)					\
144 	do {								\
145 		unsigned long flags; /* may shadow */			\
146 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
147 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
148 		current->task_state_change = _THIS_IP_;			\
149 		current->state = (state_value);				\
150 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
151 	} while (0)
152 #else
153 /*
154  * set_current_state() includes a barrier so that the write of current->state
155  * is correctly serialised wrt the caller's subsequent test of whether to
156  * actually sleep:
157  *
158  *   for (;;) {
159  *	set_current_state(TASK_UNINTERRUPTIBLE);
160  *	if (!need_sleep)
161  *		break;
162  *
163  *	schedule();
164  *   }
165  *   __set_current_state(TASK_RUNNING);
166  *
167  * If the caller does not need such serialisation (because, for instance, the
168  * condition test and condition change and wakeup are under the same lock) then
169  * use __set_current_state().
170  *
171  * The above is typically ordered against the wakeup, which does:
172  *
173  *   need_sleep = false;
174  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
175  *
176  * where wake_up_state() executes a full memory barrier before accessing the
177  * task state.
178  *
179  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
180  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
181  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
182  *
183  * However, with slightly different timing the wakeup TASK_RUNNING store can
184  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
185  * a problem either because that will result in one extra go around the loop
186  * and our @cond test will save the day.
187  *
188  * Also see the comments of try_to_wake_up().
189  */
190 #define __set_current_state(state_value)				\
191 	current->state = (state_value)
192 
193 #define set_current_state(state_value)					\
194 	smp_store_mb(current->state, (state_value))
195 
196 /*
197  * set_special_state() should be used for those states when the blocking task
198  * can not use the regular condition based wait-loop. In that case we must
199  * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
200  * will not collide with our state change.
201  */
202 #define set_special_state(state_value)					\
203 	do {								\
204 		unsigned long flags; /* may shadow */			\
205 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
206 		current->state = (state_value);				\
207 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
208 	} while (0)
209 
210 #endif
211 
212 /* Task command name length: */
213 #define TASK_COMM_LEN			16
214 
215 extern void scheduler_tick(void);
216 
217 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
218 
219 extern long schedule_timeout(long timeout);
220 extern long schedule_timeout_interruptible(long timeout);
221 extern long schedule_timeout_killable(long timeout);
222 extern long schedule_timeout_uninterruptible(long timeout);
223 extern long schedule_timeout_idle(long timeout);
224 asmlinkage void schedule(void);
225 extern void schedule_preempt_disabled(void);
226 asmlinkage void preempt_schedule_irq(void);
227 
228 extern int __must_check io_schedule_prepare(void);
229 extern void io_schedule_finish(int token);
230 extern long io_schedule_timeout(long timeout);
231 extern void io_schedule(void);
232 
233 /**
234  * struct prev_cputime - snapshot of system and user cputime
235  * @utime: time spent in user mode
236  * @stime: time spent in system mode
237  * @lock: protects the above two fields
238  *
239  * Stores previous user/system time values such that we can guarantee
240  * monotonicity.
241  */
242 struct prev_cputime {
243 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
244 	u64				utime;
245 	u64				stime;
246 	raw_spinlock_t			lock;
247 #endif
248 };
249 
250 enum vtime_state {
251 	/* Task is sleeping or running in a CPU with VTIME inactive: */
252 	VTIME_INACTIVE = 0,
253 	/* Task runs in userspace in a CPU with VTIME active: */
254 	VTIME_USER,
255 	/* Task runs in kernelspace in a CPU with VTIME active: */
256 	VTIME_SYS,
257 };
258 
259 struct vtime {
260 	seqcount_t		seqcount;
261 	unsigned long long	starttime;
262 	enum vtime_state	state;
263 	u64			utime;
264 	u64			stime;
265 	u64			gtime;
266 };
267 
268 /*
269  * Utilization clamp constraints.
270  * @UCLAMP_MIN:	Minimum utilization
271  * @UCLAMP_MAX:	Maximum utilization
272  * @UCLAMP_CNT:	Utilization clamp constraints count
273  */
274 enum uclamp_id {
275 	UCLAMP_MIN = 0,
276 	UCLAMP_MAX,
277 	UCLAMP_CNT
278 };
279 
280 #ifdef CONFIG_SMP
281 extern struct root_domain def_root_domain;
282 extern struct mutex sched_domains_mutex;
283 #endif
284 
285 struct sched_info {
286 #ifdef CONFIG_SCHED_INFO
287 	/* Cumulative counters: */
288 
289 	/* # of times we have run on this CPU: */
290 	unsigned long			pcount;
291 
292 	/* Time spent waiting on a runqueue: */
293 	unsigned long long		run_delay;
294 
295 	/* Timestamps: */
296 
297 	/* When did we last run on a CPU? */
298 	unsigned long long		last_arrival;
299 
300 	/* When were we last queued to run? */
301 	unsigned long long		last_queued;
302 
303 #endif /* CONFIG_SCHED_INFO */
304 };
305 
306 /*
307  * Integer metrics need fixed point arithmetic, e.g., sched/fair
308  * has a few: load, load_avg, util_avg, freq, and capacity.
309  *
310  * We define a basic fixed point arithmetic range, and then formalize
311  * all these metrics based on that basic range.
312  */
313 # define SCHED_FIXEDPOINT_SHIFT		10
314 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
315 
316 /* Increase resolution of cpu_capacity calculations */
317 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
318 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
319 
320 struct load_weight {
321 	unsigned long			weight;
322 	u32				inv_weight;
323 };
324 
325 /**
326  * struct util_est - Estimation utilization of FAIR tasks
327  * @enqueued: instantaneous estimated utilization of a task/cpu
328  * @ewma:     the Exponential Weighted Moving Average (EWMA)
329  *            utilization of a task
330  *
331  * Support data structure to track an Exponential Weighted Moving Average
332  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
333  * average each time a task completes an activation. Sample's weight is chosen
334  * so that the EWMA will be relatively insensitive to transient changes to the
335  * task's workload.
336  *
337  * The enqueued attribute has a slightly different meaning for tasks and cpus:
338  * - task:   the task's util_avg at last task dequeue time
339  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
340  * Thus, the util_est.enqueued of a task represents the contribution on the
341  * estimated utilization of the CPU where that task is currently enqueued.
342  *
343  * Only for tasks we track a moving average of the past instantaneous
344  * estimated utilization. This allows to absorb sporadic drops in utilization
345  * of an otherwise almost periodic task.
346  */
347 struct util_est {
348 	unsigned int			enqueued;
349 	unsigned int			ewma;
350 #define UTIL_EST_WEIGHT_SHIFT		2
351 } __attribute__((__aligned__(sizeof(u64))));
352 
353 /*
354  * The load_avg/util_avg accumulates an infinite geometric series
355  * (see __update_load_avg() in kernel/sched/fair.c).
356  *
357  * [load_avg definition]
358  *
359  *   load_avg = runnable% * scale_load_down(load)
360  *
361  * where runnable% is the time ratio that a sched_entity is runnable.
362  * For cfs_rq, it is the aggregated load_avg of all runnable and
363  * blocked sched_entities.
364  *
365  * [util_avg definition]
366  *
367  *   util_avg = running% * SCHED_CAPACITY_SCALE
368  *
369  * where running% is the time ratio that a sched_entity is running on
370  * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
371  * and blocked sched_entities.
372  *
373  * load_avg and util_avg don't direcly factor frequency scaling and CPU
374  * capacity scaling. The scaling is done through the rq_clock_pelt that
375  * is used for computing those signals (see update_rq_clock_pelt())
376  *
377  * N.B., the above ratios (runnable% and running%) themselves are in the
378  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
379  * to as large a range as necessary. This is for example reflected by
380  * util_avg's SCHED_CAPACITY_SCALE.
381  *
382  * [Overflow issue]
383  *
384  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
385  * with the highest load (=88761), always runnable on a single cfs_rq,
386  * and should not overflow as the number already hits PID_MAX_LIMIT.
387  *
388  * For all other cases (including 32-bit kernels), struct load_weight's
389  * weight will overflow first before we do, because:
390  *
391  *    Max(load_avg) <= Max(load.weight)
392  *
393  * Then it is the load_weight's responsibility to consider overflow
394  * issues.
395  */
396 struct sched_avg {
397 	u64				last_update_time;
398 	u64				load_sum;
399 	u64				runnable_load_sum;
400 	u32				util_sum;
401 	u32				period_contrib;
402 	unsigned long			load_avg;
403 	unsigned long			runnable_load_avg;
404 	unsigned long			util_avg;
405 	struct util_est			util_est;
406 } ____cacheline_aligned;
407 
408 struct sched_statistics {
409 #ifdef CONFIG_SCHEDSTATS
410 	u64				wait_start;
411 	u64				wait_max;
412 	u64				wait_count;
413 	u64				wait_sum;
414 	u64				iowait_count;
415 	u64				iowait_sum;
416 
417 	u64				sleep_start;
418 	u64				sleep_max;
419 	s64				sum_sleep_runtime;
420 
421 	u64				block_start;
422 	u64				block_max;
423 	u64				exec_max;
424 	u64				slice_max;
425 
426 	u64				nr_migrations_cold;
427 	u64				nr_failed_migrations_affine;
428 	u64				nr_failed_migrations_running;
429 	u64				nr_failed_migrations_hot;
430 	u64				nr_forced_migrations;
431 
432 	u64				nr_wakeups;
433 	u64				nr_wakeups_sync;
434 	u64				nr_wakeups_migrate;
435 	u64				nr_wakeups_local;
436 	u64				nr_wakeups_remote;
437 	u64				nr_wakeups_affine;
438 	u64				nr_wakeups_affine_attempts;
439 	u64				nr_wakeups_passive;
440 	u64				nr_wakeups_idle;
441 #endif
442 };
443 
444 struct sched_entity {
445 	/* For load-balancing: */
446 	struct load_weight		load;
447 	unsigned long			runnable_weight;
448 	struct rb_node			run_node;
449 	struct list_head		group_node;
450 	unsigned int			on_rq;
451 
452 	u64				exec_start;
453 	u64				sum_exec_runtime;
454 	u64				vruntime;
455 	u64				prev_sum_exec_runtime;
456 
457 	u64				nr_migrations;
458 
459 	struct sched_statistics		statistics;
460 
461 #ifdef CONFIG_FAIR_GROUP_SCHED
462 	int				depth;
463 	struct sched_entity		*parent;
464 	/* rq on which this entity is (to be) queued: */
465 	struct cfs_rq			*cfs_rq;
466 	/* rq "owned" by this entity/group: */
467 	struct cfs_rq			*my_q;
468 #endif
469 
470 #ifdef CONFIG_SMP
471 	/*
472 	 * Per entity load average tracking.
473 	 *
474 	 * Put into separate cache line so it does not
475 	 * collide with read-mostly values above.
476 	 */
477 	struct sched_avg		avg;
478 #endif
479 };
480 
481 struct sched_rt_entity {
482 	struct list_head		run_list;
483 	unsigned long			timeout;
484 	unsigned long			watchdog_stamp;
485 	unsigned int			time_slice;
486 	unsigned short			on_rq;
487 	unsigned short			on_list;
488 
489 	struct sched_rt_entity		*back;
490 #ifdef CONFIG_RT_GROUP_SCHED
491 	struct sched_rt_entity		*parent;
492 	/* rq on which this entity is (to be) queued: */
493 	struct rt_rq			*rt_rq;
494 	/* rq "owned" by this entity/group: */
495 	struct rt_rq			*my_q;
496 #endif
497 } __randomize_layout;
498 
499 struct sched_dl_entity {
500 	struct rb_node			rb_node;
501 
502 	/*
503 	 * Original scheduling parameters. Copied here from sched_attr
504 	 * during sched_setattr(), they will remain the same until
505 	 * the next sched_setattr().
506 	 */
507 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
508 	u64				dl_deadline;	/* Relative deadline of each instance	*/
509 	u64				dl_period;	/* Separation of two instances (period) */
510 	u64				dl_bw;		/* dl_runtime / dl_period		*/
511 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
512 
513 	/*
514 	 * Actual scheduling parameters. Initialized with the values above,
515 	 * they are continuously updated during task execution. Note that
516 	 * the remaining runtime could be < 0 in case we are in overrun.
517 	 */
518 	s64				runtime;	/* Remaining runtime for this instance	*/
519 	u64				deadline;	/* Absolute deadline for this instance	*/
520 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
521 
522 	/*
523 	 * Some bool flags:
524 	 *
525 	 * @dl_throttled tells if we exhausted the runtime. If so, the
526 	 * task has to wait for a replenishment to be performed at the
527 	 * next firing of dl_timer.
528 	 *
529 	 * @dl_boosted tells if we are boosted due to DI. If so we are
530 	 * outside bandwidth enforcement mechanism (but only until we
531 	 * exit the critical section);
532 	 *
533 	 * @dl_yielded tells if task gave up the CPU before consuming
534 	 * all its available runtime during the last job.
535 	 *
536 	 * @dl_non_contending tells if the task is inactive while still
537 	 * contributing to the active utilization. In other words, it
538 	 * indicates if the inactive timer has been armed and its handler
539 	 * has not been executed yet. This flag is useful to avoid race
540 	 * conditions between the inactive timer handler and the wakeup
541 	 * code.
542 	 *
543 	 * @dl_overrun tells if the task asked to be informed about runtime
544 	 * overruns.
545 	 */
546 	unsigned int			dl_throttled      : 1;
547 	unsigned int			dl_boosted        : 1;
548 	unsigned int			dl_yielded        : 1;
549 	unsigned int			dl_non_contending : 1;
550 	unsigned int			dl_overrun	  : 1;
551 
552 	/*
553 	 * Bandwidth enforcement timer. Each -deadline task has its
554 	 * own bandwidth to be enforced, thus we need one timer per task.
555 	 */
556 	struct hrtimer			dl_timer;
557 
558 	/*
559 	 * Inactive timer, responsible for decreasing the active utilization
560 	 * at the "0-lag time". When a -deadline task blocks, it contributes
561 	 * to GRUB's active utilization until the "0-lag time", hence a
562 	 * timer is needed to decrease the active utilization at the correct
563 	 * time.
564 	 */
565 	struct hrtimer inactive_timer;
566 };
567 
568 #ifdef CONFIG_UCLAMP_TASK
569 /* Number of utilization clamp buckets (shorter alias) */
570 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
571 
572 /*
573  * Utilization clamp for a scheduling entity
574  * @value:		clamp value "assigned" to a se
575  * @bucket_id:		bucket index corresponding to the "assigned" value
576  * @active:		the se is currently refcounted in a rq's bucket
577  * @user_defined:	the requested clamp value comes from user-space
578  *
579  * The bucket_id is the index of the clamp bucket matching the clamp value
580  * which is pre-computed and stored to avoid expensive integer divisions from
581  * the fast path.
582  *
583  * The active bit is set whenever a task has got an "effective" value assigned,
584  * which can be different from the clamp value "requested" from user-space.
585  * This allows to know a task is refcounted in the rq's bucket corresponding
586  * to the "effective" bucket_id.
587  *
588  * The user_defined bit is set whenever a task has got a task-specific clamp
589  * value requested from userspace, i.e. the system defaults apply to this task
590  * just as a restriction. This allows to relax default clamps when a less
591  * restrictive task-specific value has been requested, thus allowing to
592  * implement a "nice" semantic. For example, a task running with a 20%
593  * default boost can still drop its own boosting to 0%.
594  */
595 struct uclamp_se {
596 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
597 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
598 	unsigned int active		: 1;
599 	unsigned int user_defined	: 1;
600 };
601 #endif /* CONFIG_UCLAMP_TASK */
602 
603 union rcu_special {
604 	struct {
605 		u8			blocked;
606 		u8			need_qs;
607 		u8			exp_hint; /* Hint for performance. */
608 		u8			deferred_qs;
609 	} b; /* Bits. */
610 	u32 s; /* Set of bits. */
611 };
612 
613 enum perf_event_task_context {
614 	perf_invalid_context = -1,
615 	perf_hw_context = 0,
616 	perf_sw_context,
617 	perf_nr_task_contexts,
618 };
619 
620 struct wake_q_node {
621 	struct wake_q_node *next;
622 };
623 
624 struct task_struct {
625 #ifdef CONFIG_THREAD_INFO_IN_TASK
626 	/*
627 	 * For reasons of header soup (see current_thread_info()), this
628 	 * must be the first element of task_struct.
629 	 */
630 	struct thread_info		thread_info;
631 #endif
632 	/* -1 unrunnable, 0 runnable, >0 stopped: */
633 	volatile long			state;
634 
635 	/*
636 	 * This begins the randomizable portion of task_struct. Only
637 	 * scheduling-critical items should be added above here.
638 	 */
639 	randomized_struct_fields_start
640 
641 	void				*stack;
642 	refcount_t			usage;
643 	/* Per task flags (PF_*), defined further below: */
644 	unsigned int			flags;
645 	unsigned int			ptrace;
646 
647 #ifdef CONFIG_SMP
648 	struct llist_node		wake_entry;
649 	int				on_cpu;
650 #ifdef CONFIG_THREAD_INFO_IN_TASK
651 	/* Current CPU: */
652 	unsigned int			cpu;
653 #endif
654 	unsigned int			wakee_flips;
655 	unsigned long			wakee_flip_decay_ts;
656 	struct task_struct		*last_wakee;
657 
658 	/*
659 	 * recent_used_cpu is initially set as the last CPU used by a task
660 	 * that wakes affine another task. Waker/wakee relationships can
661 	 * push tasks around a CPU where each wakeup moves to the next one.
662 	 * Tracking a recently used CPU allows a quick search for a recently
663 	 * used CPU that may be idle.
664 	 */
665 	int				recent_used_cpu;
666 	int				wake_cpu;
667 #endif
668 	int				on_rq;
669 
670 	int				prio;
671 	int				static_prio;
672 	int				normal_prio;
673 	unsigned int			rt_priority;
674 
675 	const struct sched_class	*sched_class;
676 	struct sched_entity		se;
677 	struct sched_rt_entity		rt;
678 #ifdef CONFIG_CGROUP_SCHED
679 	struct task_group		*sched_task_group;
680 #endif
681 	struct sched_dl_entity		dl;
682 
683 #ifdef CONFIG_UCLAMP_TASK
684 	/* Clamp values requested for a scheduling entity */
685 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
686 	/* Effective clamp values used for a scheduling entity */
687 	struct uclamp_se		uclamp[UCLAMP_CNT];
688 #endif
689 
690 #ifdef CONFIG_PREEMPT_NOTIFIERS
691 	/* List of struct preempt_notifier: */
692 	struct hlist_head		preempt_notifiers;
693 #endif
694 
695 #ifdef CONFIG_BLK_DEV_IO_TRACE
696 	unsigned int			btrace_seq;
697 #endif
698 
699 	unsigned int			policy;
700 	int				nr_cpus_allowed;
701 	const cpumask_t			*cpus_ptr;
702 	cpumask_t			cpus_mask;
703 
704 #ifdef CONFIG_PREEMPT_RCU
705 	int				rcu_read_lock_nesting;
706 	union rcu_special		rcu_read_unlock_special;
707 	struct list_head		rcu_node_entry;
708 	struct rcu_node			*rcu_blocked_node;
709 #endif /* #ifdef CONFIG_PREEMPT_RCU */
710 
711 #ifdef CONFIG_TASKS_RCU
712 	unsigned long			rcu_tasks_nvcsw;
713 	u8				rcu_tasks_holdout;
714 	u8				rcu_tasks_idx;
715 	int				rcu_tasks_idle_cpu;
716 	struct list_head		rcu_tasks_holdout_list;
717 #endif /* #ifdef CONFIG_TASKS_RCU */
718 
719 	struct sched_info		sched_info;
720 
721 	struct list_head		tasks;
722 #ifdef CONFIG_SMP
723 	struct plist_node		pushable_tasks;
724 	struct rb_node			pushable_dl_tasks;
725 #endif
726 
727 	struct mm_struct		*mm;
728 	struct mm_struct		*active_mm;
729 
730 	/* Per-thread vma caching: */
731 	struct vmacache			vmacache;
732 
733 #ifdef SPLIT_RSS_COUNTING
734 	struct task_rss_stat		rss_stat;
735 #endif
736 	int				exit_state;
737 	int				exit_code;
738 	int				exit_signal;
739 	/* The signal sent when the parent dies: */
740 	int				pdeath_signal;
741 	/* JOBCTL_*, siglock protected: */
742 	unsigned long			jobctl;
743 
744 	/* Used for emulating ABI behavior of previous Linux versions: */
745 	unsigned int			personality;
746 
747 	/* Scheduler bits, serialized by scheduler locks: */
748 	unsigned			sched_reset_on_fork:1;
749 	unsigned			sched_contributes_to_load:1;
750 	unsigned			sched_migrated:1;
751 	unsigned			sched_remote_wakeup:1;
752 #ifdef CONFIG_PSI
753 	unsigned			sched_psi_wake_requeue:1;
754 #endif
755 
756 	/* Force alignment to the next boundary: */
757 	unsigned			:0;
758 
759 	/* Unserialized, strictly 'current' */
760 
761 	/* Bit to tell LSMs we're in execve(): */
762 	unsigned			in_execve:1;
763 	unsigned			in_iowait:1;
764 #ifndef TIF_RESTORE_SIGMASK
765 	unsigned			restore_sigmask:1;
766 #endif
767 #ifdef CONFIG_MEMCG
768 	unsigned			in_user_fault:1;
769 #endif
770 #ifdef CONFIG_COMPAT_BRK
771 	unsigned			brk_randomized:1;
772 #endif
773 #ifdef CONFIG_CGROUPS
774 	/* disallow userland-initiated cgroup migration */
775 	unsigned			no_cgroup_migration:1;
776 	/* task is frozen/stopped (used by the cgroup freezer) */
777 	unsigned			frozen:1;
778 #endif
779 #ifdef CONFIG_BLK_CGROUP
780 	/* to be used once the psi infrastructure lands upstream. */
781 	unsigned			use_memdelay:1;
782 #endif
783 
784 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
785 
786 	struct restart_block		restart_block;
787 
788 	pid_t				pid;
789 	pid_t				tgid;
790 
791 #ifdef CONFIG_STACKPROTECTOR
792 	/* Canary value for the -fstack-protector GCC feature: */
793 	unsigned long			stack_canary;
794 #endif
795 	/*
796 	 * Pointers to the (original) parent process, youngest child, younger sibling,
797 	 * older sibling, respectively.  (p->father can be replaced with
798 	 * p->real_parent->pid)
799 	 */
800 
801 	/* Real parent process: */
802 	struct task_struct __rcu	*real_parent;
803 
804 	/* Recipient of SIGCHLD, wait4() reports: */
805 	struct task_struct __rcu	*parent;
806 
807 	/*
808 	 * Children/sibling form the list of natural children:
809 	 */
810 	struct list_head		children;
811 	struct list_head		sibling;
812 	struct task_struct		*group_leader;
813 
814 	/*
815 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
816 	 *
817 	 * This includes both natural children and PTRACE_ATTACH targets.
818 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
819 	 */
820 	struct list_head		ptraced;
821 	struct list_head		ptrace_entry;
822 
823 	/* PID/PID hash table linkage. */
824 	struct pid			*thread_pid;
825 	struct hlist_node		pid_links[PIDTYPE_MAX];
826 	struct list_head		thread_group;
827 	struct list_head		thread_node;
828 
829 	struct completion		*vfork_done;
830 
831 	/* CLONE_CHILD_SETTID: */
832 	int __user			*set_child_tid;
833 
834 	/* CLONE_CHILD_CLEARTID: */
835 	int __user			*clear_child_tid;
836 
837 	u64				utime;
838 	u64				stime;
839 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
840 	u64				utimescaled;
841 	u64				stimescaled;
842 #endif
843 	u64				gtime;
844 	struct prev_cputime		prev_cputime;
845 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
846 	struct vtime			vtime;
847 #endif
848 
849 #ifdef CONFIG_NO_HZ_FULL
850 	atomic_t			tick_dep_mask;
851 #endif
852 	/* Context switch counts: */
853 	unsigned long			nvcsw;
854 	unsigned long			nivcsw;
855 
856 	/* Monotonic time in nsecs: */
857 	u64				start_time;
858 
859 	/* Boot based time in nsecs: */
860 	u64				real_start_time;
861 
862 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
863 	unsigned long			min_flt;
864 	unsigned long			maj_flt;
865 
866 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
867 	struct posix_cputimers		posix_cputimers;
868 
869 	/* Process credentials: */
870 
871 	/* Tracer's credentials at attach: */
872 	const struct cred __rcu		*ptracer_cred;
873 
874 	/* Objective and real subjective task credentials (COW): */
875 	const struct cred __rcu		*real_cred;
876 
877 	/* Effective (overridable) subjective task credentials (COW): */
878 	const struct cred __rcu		*cred;
879 
880 #ifdef CONFIG_KEYS
881 	/* Cached requested key. */
882 	struct key			*cached_requested_key;
883 #endif
884 
885 	/*
886 	 * executable name, excluding path.
887 	 *
888 	 * - normally initialized setup_new_exec()
889 	 * - access it with [gs]et_task_comm()
890 	 * - lock it with task_lock()
891 	 */
892 	char				comm[TASK_COMM_LEN];
893 
894 	struct nameidata		*nameidata;
895 
896 #ifdef CONFIG_SYSVIPC
897 	struct sysv_sem			sysvsem;
898 	struct sysv_shm			sysvshm;
899 #endif
900 #ifdef CONFIG_DETECT_HUNG_TASK
901 	unsigned long			last_switch_count;
902 	unsigned long			last_switch_time;
903 #endif
904 	/* Filesystem information: */
905 	struct fs_struct		*fs;
906 
907 	/* Open file information: */
908 	struct files_struct		*files;
909 
910 	/* Namespaces: */
911 	struct nsproxy			*nsproxy;
912 
913 	/* Signal handlers: */
914 	struct signal_struct		*signal;
915 	struct sighand_struct		*sighand;
916 	sigset_t			blocked;
917 	sigset_t			real_blocked;
918 	/* Restored if set_restore_sigmask() was used: */
919 	sigset_t			saved_sigmask;
920 	struct sigpending		pending;
921 	unsigned long			sas_ss_sp;
922 	size_t				sas_ss_size;
923 	unsigned int			sas_ss_flags;
924 
925 	struct callback_head		*task_works;
926 
927 #ifdef CONFIG_AUDIT
928 #ifdef CONFIG_AUDITSYSCALL
929 	struct audit_context		*audit_context;
930 #endif
931 	kuid_t				loginuid;
932 	unsigned int			sessionid;
933 #endif
934 	struct seccomp			seccomp;
935 
936 	/* Thread group tracking: */
937 	u32				parent_exec_id;
938 	u32				self_exec_id;
939 
940 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
941 	spinlock_t			alloc_lock;
942 
943 	/* Protection of the PI data structures: */
944 	raw_spinlock_t			pi_lock;
945 
946 	struct wake_q_node		wake_q;
947 
948 #ifdef CONFIG_RT_MUTEXES
949 	/* PI waiters blocked on a rt_mutex held by this task: */
950 	struct rb_root_cached		pi_waiters;
951 	/* Updated under owner's pi_lock and rq lock */
952 	struct task_struct		*pi_top_task;
953 	/* Deadlock detection and priority inheritance handling: */
954 	struct rt_mutex_waiter		*pi_blocked_on;
955 #endif
956 
957 #ifdef CONFIG_DEBUG_MUTEXES
958 	/* Mutex deadlock detection: */
959 	struct mutex_waiter		*blocked_on;
960 #endif
961 
962 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
963 	int				non_block_count;
964 #endif
965 
966 #ifdef CONFIG_TRACE_IRQFLAGS
967 	unsigned int			irq_events;
968 	unsigned long			hardirq_enable_ip;
969 	unsigned long			hardirq_disable_ip;
970 	unsigned int			hardirq_enable_event;
971 	unsigned int			hardirq_disable_event;
972 	int				hardirqs_enabled;
973 	int				hardirq_context;
974 	unsigned long			softirq_disable_ip;
975 	unsigned long			softirq_enable_ip;
976 	unsigned int			softirq_disable_event;
977 	unsigned int			softirq_enable_event;
978 	int				softirqs_enabled;
979 	int				softirq_context;
980 #endif
981 
982 #ifdef CONFIG_LOCKDEP
983 # define MAX_LOCK_DEPTH			48UL
984 	u64				curr_chain_key;
985 	int				lockdep_depth;
986 	unsigned int			lockdep_recursion;
987 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
988 #endif
989 
990 #ifdef CONFIG_UBSAN
991 	unsigned int			in_ubsan;
992 #endif
993 
994 	/* Journalling filesystem info: */
995 	void				*journal_info;
996 
997 	/* Stacked block device info: */
998 	struct bio_list			*bio_list;
999 
1000 #ifdef CONFIG_BLOCK
1001 	/* Stack plugging: */
1002 	struct blk_plug			*plug;
1003 #endif
1004 
1005 	/* VM state: */
1006 	struct reclaim_state		*reclaim_state;
1007 
1008 	struct backing_dev_info		*backing_dev_info;
1009 
1010 	struct io_context		*io_context;
1011 
1012 #ifdef CONFIG_COMPACTION
1013 	struct capture_control		*capture_control;
1014 #endif
1015 	/* Ptrace state: */
1016 	unsigned long			ptrace_message;
1017 	kernel_siginfo_t		*last_siginfo;
1018 
1019 	struct task_io_accounting	ioac;
1020 #ifdef CONFIG_PSI
1021 	/* Pressure stall state */
1022 	unsigned int			psi_flags;
1023 #endif
1024 #ifdef CONFIG_TASK_XACCT
1025 	/* Accumulated RSS usage: */
1026 	u64				acct_rss_mem1;
1027 	/* Accumulated virtual memory usage: */
1028 	u64				acct_vm_mem1;
1029 	/* stime + utime since last update: */
1030 	u64				acct_timexpd;
1031 #endif
1032 #ifdef CONFIG_CPUSETS
1033 	/* Protected by ->alloc_lock: */
1034 	nodemask_t			mems_allowed;
1035 	/* Seqence number to catch updates: */
1036 	seqcount_t			mems_allowed_seq;
1037 	int				cpuset_mem_spread_rotor;
1038 	int				cpuset_slab_spread_rotor;
1039 #endif
1040 #ifdef CONFIG_CGROUPS
1041 	/* Control Group info protected by css_set_lock: */
1042 	struct css_set __rcu		*cgroups;
1043 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1044 	struct list_head		cg_list;
1045 #endif
1046 #ifdef CONFIG_X86_CPU_RESCTRL
1047 	u32				closid;
1048 	u32				rmid;
1049 #endif
1050 #ifdef CONFIG_FUTEX
1051 	struct robust_list_head __user	*robust_list;
1052 #ifdef CONFIG_COMPAT
1053 	struct compat_robust_list_head __user *compat_robust_list;
1054 #endif
1055 	struct list_head		pi_state_list;
1056 	struct futex_pi_state		*pi_state_cache;
1057 #endif
1058 #ifdef CONFIG_PERF_EVENTS
1059 	struct perf_event_context	*perf_event_ctxp[perf_nr_task_contexts];
1060 	struct mutex			perf_event_mutex;
1061 	struct list_head		perf_event_list;
1062 #endif
1063 #ifdef CONFIG_DEBUG_PREEMPT
1064 	unsigned long			preempt_disable_ip;
1065 #endif
1066 #ifdef CONFIG_NUMA
1067 	/* Protected by alloc_lock: */
1068 	struct mempolicy		*mempolicy;
1069 	short				il_prev;
1070 	short				pref_node_fork;
1071 #endif
1072 #ifdef CONFIG_NUMA_BALANCING
1073 	int				numa_scan_seq;
1074 	unsigned int			numa_scan_period;
1075 	unsigned int			numa_scan_period_max;
1076 	int				numa_preferred_nid;
1077 	unsigned long			numa_migrate_retry;
1078 	/* Migration stamp: */
1079 	u64				node_stamp;
1080 	u64				last_task_numa_placement;
1081 	u64				last_sum_exec_runtime;
1082 	struct callback_head		numa_work;
1083 
1084 	/*
1085 	 * This pointer is only modified for current in syscall and
1086 	 * pagefault context (and for tasks being destroyed), so it can be read
1087 	 * from any of the following contexts:
1088 	 *  - RCU read-side critical section
1089 	 *  - current->numa_group from everywhere
1090 	 *  - task's runqueue locked, task not running
1091 	 */
1092 	struct numa_group __rcu		*numa_group;
1093 
1094 	/*
1095 	 * numa_faults is an array split into four regions:
1096 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1097 	 * in this precise order.
1098 	 *
1099 	 * faults_memory: Exponential decaying average of faults on a per-node
1100 	 * basis. Scheduling placement decisions are made based on these
1101 	 * counts. The values remain static for the duration of a PTE scan.
1102 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1103 	 * hinting fault was incurred.
1104 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1105 	 * during the current scan window. When the scan completes, the counts
1106 	 * in faults_memory and faults_cpu decay and these values are copied.
1107 	 */
1108 	unsigned long			*numa_faults;
1109 	unsigned long			total_numa_faults;
1110 
1111 	/*
1112 	 * numa_faults_locality tracks if faults recorded during the last
1113 	 * scan window were remote/local or failed to migrate. The task scan
1114 	 * period is adapted based on the locality of the faults with different
1115 	 * weights depending on whether they were shared or private faults
1116 	 */
1117 	unsigned long			numa_faults_locality[3];
1118 
1119 	unsigned long			numa_pages_migrated;
1120 #endif /* CONFIG_NUMA_BALANCING */
1121 
1122 #ifdef CONFIG_RSEQ
1123 	struct rseq __user *rseq;
1124 	u32 rseq_sig;
1125 	/*
1126 	 * RmW on rseq_event_mask must be performed atomically
1127 	 * with respect to preemption.
1128 	 */
1129 	unsigned long rseq_event_mask;
1130 #endif
1131 
1132 	struct tlbflush_unmap_batch	tlb_ubc;
1133 
1134 	union {
1135 		refcount_t		rcu_users;
1136 		struct rcu_head		rcu;
1137 	};
1138 
1139 	/* Cache last used pipe for splice(): */
1140 	struct pipe_inode_info		*splice_pipe;
1141 
1142 	struct page_frag		task_frag;
1143 
1144 #ifdef CONFIG_TASK_DELAY_ACCT
1145 	struct task_delay_info		*delays;
1146 #endif
1147 
1148 #ifdef CONFIG_FAULT_INJECTION
1149 	int				make_it_fail;
1150 	unsigned int			fail_nth;
1151 #endif
1152 	/*
1153 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1154 	 * balance_dirty_pages() for a dirty throttling pause:
1155 	 */
1156 	int				nr_dirtied;
1157 	int				nr_dirtied_pause;
1158 	/* Start of a write-and-pause period: */
1159 	unsigned long			dirty_paused_when;
1160 
1161 #ifdef CONFIG_LATENCYTOP
1162 	int				latency_record_count;
1163 	struct latency_record		latency_record[LT_SAVECOUNT];
1164 #endif
1165 	/*
1166 	 * Time slack values; these are used to round up poll() and
1167 	 * select() etc timeout values. These are in nanoseconds.
1168 	 */
1169 	u64				timer_slack_ns;
1170 	u64				default_timer_slack_ns;
1171 
1172 #ifdef CONFIG_KASAN
1173 	unsigned int			kasan_depth;
1174 #endif
1175 
1176 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1177 	/* Index of current stored address in ret_stack: */
1178 	int				curr_ret_stack;
1179 	int				curr_ret_depth;
1180 
1181 	/* Stack of return addresses for return function tracing: */
1182 	struct ftrace_ret_stack		*ret_stack;
1183 
1184 	/* Timestamp for last schedule: */
1185 	unsigned long long		ftrace_timestamp;
1186 
1187 	/*
1188 	 * Number of functions that haven't been traced
1189 	 * because of depth overrun:
1190 	 */
1191 	atomic_t			trace_overrun;
1192 
1193 	/* Pause tracing: */
1194 	atomic_t			tracing_graph_pause;
1195 #endif
1196 
1197 #ifdef CONFIG_TRACING
1198 	/* State flags for use by tracers: */
1199 	unsigned long			trace;
1200 
1201 	/* Bitmask and counter of trace recursion: */
1202 	unsigned long			trace_recursion;
1203 #endif /* CONFIG_TRACING */
1204 
1205 #ifdef CONFIG_KCOV
1206 	/* Coverage collection mode enabled for this task (0 if disabled): */
1207 	unsigned int			kcov_mode;
1208 
1209 	/* Size of the kcov_area: */
1210 	unsigned int			kcov_size;
1211 
1212 	/* Buffer for coverage collection: */
1213 	void				*kcov_area;
1214 
1215 	/* KCOV descriptor wired with this task or NULL: */
1216 	struct kcov			*kcov;
1217 #endif
1218 
1219 #ifdef CONFIG_MEMCG
1220 	struct mem_cgroup		*memcg_in_oom;
1221 	gfp_t				memcg_oom_gfp_mask;
1222 	int				memcg_oom_order;
1223 
1224 	/* Number of pages to reclaim on returning to userland: */
1225 	unsigned int			memcg_nr_pages_over_high;
1226 
1227 	/* Used by memcontrol for targeted memcg charge: */
1228 	struct mem_cgroup		*active_memcg;
1229 #endif
1230 
1231 #ifdef CONFIG_BLK_CGROUP
1232 	struct request_queue		*throttle_queue;
1233 #endif
1234 
1235 #ifdef CONFIG_UPROBES
1236 	struct uprobe_task		*utask;
1237 #endif
1238 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1239 	unsigned int			sequential_io;
1240 	unsigned int			sequential_io_avg;
1241 #endif
1242 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1243 	unsigned long			task_state_change;
1244 #endif
1245 	int				pagefault_disabled;
1246 #ifdef CONFIG_MMU
1247 	struct task_struct		*oom_reaper_list;
1248 #endif
1249 #ifdef CONFIG_VMAP_STACK
1250 	struct vm_struct		*stack_vm_area;
1251 #endif
1252 #ifdef CONFIG_THREAD_INFO_IN_TASK
1253 	/* A live task holds one reference: */
1254 	refcount_t			stack_refcount;
1255 #endif
1256 #ifdef CONFIG_LIVEPATCH
1257 	int patch_state;
1258 #endif
1259 #ifdef CONFIG_SECURITY
1260 	/* Used by LSM modules for access restriction: */
1261 	void				*security;
1262 #endif
1263 
1264 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1265 	unsigned long			lowest_stack;
1266 	unsigned long			prev_lowest_stack;
1267 #endif
1268 
1269 	/*
1270 	 * New fields for task_struct should be added above here, so that
1271 	 * they are included in the randomized portion of task_struct.
1272 	 */
1273 	randomized_struct_fields_end
1274 
1275 	/* CPU-specific state of this task: */
1276 	struct thread_struct		thread;
1277 
1278 	/*
1279 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1280 	 * structure.  It *MUST* be at the end of 'task_struct'.
1281 	 *
1282 	 * Do not put anything below here!
1283 	 */
1284 };
1285 
1286 static inline struct pid *task_pid(struct task_struct *task)
1287 {
1288 	return task->thread_pid;
1289 }
1290 
1291 /*
1292  * the helpers to get the task's different pids as they are seen
1293  * from various namespaces
1294  *
1295  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1296  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1297  *                     current.
1298  * task_xid_nr_ns()  : id seen from the ns specified;
1299  *
1300  * see also pid_nr() etc in include/linux/pid.h
1301  */
1302 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1303 
1304 static inline pid_t task_pid_nr(struct task_struct *tsk)
1305 {
1306 	return tsk->pid;
1307 }
1308 
1309 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1310 {
1311 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1312 }
1313 
1314 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1315 {
1316 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1317 }
1318 
1319 
1320 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1321 {
1322 	return tsk->tgid;
1323 }
1324 
1325 /**
1326  * pid_alive - check that a task structure is not stale
1327  * @p: Task structure to be checked.
1328  *
1329  * Test if a process is not yet dead (at most zombie state)
1330  * If pid_alive fails, then pointers within the task structure
1331  * can be stale and must not be dereferenced.
1332  *
1333  * Return: 1 if the process is alive. 0 otherwise.
1334  */
1335 static inline int pid_alive(const struct task_struct *p)
1336 {
1337 	return p->thread_pid != NULL;
1338 }
1339 
1340 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1341 {
1342 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1343 }
1344 
1345 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1346 {
1347 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1348 }
1349 
1350 
1351 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1352 {
1353 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1354 }
1355 
1356 static inline pid_t task_session_vnr(struct task_struct *tsk)
1357 {
1358 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1359 }
1360 
1361 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1362 {
1363 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1364 }
1365 
1366 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1367 {
1368 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1369 }
1370 
1371 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1372 {
1373 	pid_t pid = 0;
1374 
1375 	rcu_read_lock();
1376 	if (pid_alive(tsk))
1377 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1378 	rcu_read_unlock();
1379 
1380 	return pid;
1381 }
1382 
1383 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1384 {
1385 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1386 }
1387 
1388 /* Obsolete, do not use: */
1389 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1390 {
1391 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1392 }
1393 
1394 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1395 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1396 
1397 static inline unsigned int task_state_index(struct task_struct *tsk)
1398 {
1399 	unsigned int tsk_state = READ_ONCE(tsk->state);
1400 	unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1401 
1402 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1403 
1404 	if (tsk_state == TASK_IDLE)
1405 		state = TASK_REPORT_IDLE;
1406 
1407 	return fls(state);
1408 }
1409 
1410 static inline char task_index_to_char(unsigned int state)
1411 {
1412 	static const char state_char[] = "RSDTtXZPI";
1413 
1414 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1415 
1416 	return state_char[state];
1417 }
1418 
1419 static inline char task_state_to_char(struct task_struct *tsk)
1420 {
1421 	return task_index_to_char(task_state_index(tsk));
1422 }
1423 
1424 /**
1425  * is_global_init - check if a task structure is init. Since init
1426  * is free to have sub-threads we need to check tgid.
1427  * @tsk: Task structure to be checked.
1428  *
1429  * Check if a task structure is the first user space task the kernel created.
1430  *
1431  * Return: 1 if the task structure is init. 0 otherwise.
1432  */
1433 static inline int is_global_init(struct task_struct *tsk)
1434 {
1435 	return task_tgid_nr(tsk) == 1;
1436 }
1437 
1438 extern struct pid *cad_pid;
1439 
1440 /*
1441  * Per process flags
1442  */
1443 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1444 #define PF_EXITING		0x00000004	/* Getting shut down */
1445 #define PF_EXITPIDONE		0x00000008	/* PI exit done on shut down */
1446 #define PF_VCPU			0x00000010	/* I'm a virtual CPU */
1447 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1448 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1449 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1450 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1451 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1452 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1453 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1454 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1455 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1456 #define PF_USED_ASYNC		0x00004000	/* Used async_schedule*(), used by module init */
1457 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1458 #define PF_FROZEN		0x00010000	/* Frozen for system suspend */
1459 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1460 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1461 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1462 #define PF_LESS_THROTTLE	0x00100000	/* Throttle me less: I clean memory */
1463 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1464 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1465 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
1466 #define PF_MEMSTALL		0x01000000	/* Stalled due to lack of memory */
1467 #define PF_UMH			0x02000000	/* I'm an Usermodehelper process */
1468 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1469 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1470 #define PF_MEMALLOC_NOCMA	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
1471 #define PF_IO_WORKER		0x20000000	/* Task is an IO worker */
1472 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
1473 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1474 
1475 /*
1476  * Only the _current_ task can read/write to tsk->flags, but other
1477  * tasks can access tsk->flags in readonly mode for example
1478  * with tsk_used_math (like during threaded core dumping).
1479  * There is however an exception to this rule during ptrace
1480  * or during fork: the ptracer task is allowed to write to the
1481  * child->flags of its traced child (same goes for fork, the parent
1482  * can write to the child->flags), because we're guaranteed the
1483  * child is not running and in turn not changing child->flags
1484  * at the same time the parent does it.
1485  */
1486 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1487 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1488 #define clear_used_math()			clear_stopped_child_used_math(current)
1489 #define set_used_math()				set_stopped_child_used_math(current)
1490 
1491 #define conditional_stopped_child_used_math(condition, child) \
1492 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1493 
1494 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1495 
1496 #define copy_to_stopped_child_used_math(child) \
1497 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1498 
1499 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1500 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1501 #define used_math()				tsk_used_math(current)
1502 
1503 static inline bool is_percpu_thread(void)
1504 {
1505 #ifdef CONFIG_SMP
1506 	return (current->flags & PF_NO_SETAFFINITY) &&
1507 		(current->nr_cpus_allowed  == 1);
1508 #else
1509 	return true;
1510 #endif
1511 }
1512 
1513 /* Per-process atomic flags. */
1514 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1515 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1516 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1517 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1518 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1519 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1520 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1521 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1522 
1523 #define TASK_PFA_TEST(name, func)					\
1524 	static inline bool task_##func(struct task_struct *p)		\
1525 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1526 
1527 #define TASK_PFA_SET(name, func)					\
1528 	static inline void task_set_##func(struct task_struct *p)	\
1529 	{ set_bit(PFA_##name, &p->atomic_flags); }
1530 
1531 #define TASK_PFA_CLEAR(name, func)					\
1532 	static inline void task_clear_##func(struct task_struct *p)	\
1533 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1534 
1535 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1536 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1537 
1538 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1539 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1540 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1541 
1542 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1543 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1544 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1545 
1546 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1547 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1548 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1549 
1550 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1551 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1552 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1553 
1554 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1555 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1556 
1557 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1558 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1559 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1560 
1561 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1562 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1563 
1564 static inline void
1565 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1566 {
1567 	current->flags &= ~flags;
1568 	current->flags |= orig_flags & flags;
1569 }
1570 
1571 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1572 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1573 #ifdef CONFIG_SMP
1574 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1575 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1576 #else
1577 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1578 {
1579 }
1580 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1581 {
1582 	if (!cpumask_test_cpu(0, new_mask))
1583 		return -EINVAL;
1584 	return 0;
1585 }
1586 #endif
1587 
1588 extern int yield_to(struct task_struct *p, bool preempt);
1589 extern void set_user_nice(struct task_struct *p, long nice);
1590 extern int task_prio(const struct task_struct *p);
1591 
1592 /**
1593  * task_nice - return the nice value of a given task.
1594  * @p: the task in question.
1595  *
1596  * Return: The nice value [ -20 ... 0 ... 19 ].
1597  */
1598 static inline int task_nice(const struct task_struct *p)
1599 {
1600 	return PRIO_TO_NICE((p)->static_prio);
1601 }
1602 
1603 extern int can_nice(const struct task_struct *p, const int nice);
1604 extern int task_curr(const struct task_struct *p);
1605 extern int idle_cpu(int cpu);
1606 extern int available_idle_cpu(int cpu);
1607 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1608 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1609 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1610 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1611 extern struct task_struct *idle_task(int cpu);
1612 
1613 /**
1614  * is_idle_task - is the specified task an idle task?
1615  * @p: the task in question.
1616  *
1617  * Return: 1 if @p is an idle task. 0 otherwise.
1618  */
1619 static inline bool is_idle_task(const struct task_struct *p)
1620 {
1621 	return !!(p->flags & PF_IDLE);
1622 }
1623 
1624 extern struct task_struct *curr_task(int cpu);
1625 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1626 
1627 void yield(void);
1628 
1629 union thread_union {
1630 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1631 	struct task_struct task;
1632 #endif
1633 #ifndef CONFIG_THREAD_INFO_IN_TASK
1634 	struct thread_info thread_info;
1635 #endif
1636 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1637 };
1638 
1639 #ifndef CONFIG_THREAD_INFO_IN_TASK
1640 extern struct thread_info init_thread_info;
1641 #endif
1642 
1643 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1644 
1645 #ifdef CONFIG_THREAD_INFO_IN_TASK
1646 static inline struct thread_info *task_thread_info(struct task_struct *task)
1647 {
1648 	return &task->thread_info;
1649 }
1650 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1651 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1652 #endif
1653 
1654 /*
1655  * find a task by one of its numerical ids
1656  *
1657  * find_task_by_pid_ns():
1658  *      finds a task by its pid in the specified namespace
1659  * find_task_by_vpid():
1660  *      finds a task by its virtual pid
1661  *
1662  * see also find_vpid() etc in include/linux/pid.h
1663  */
1664 
1665 extern struct task_struct *find_task_by_vpid(pid_t nr);
1666 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1667 
1668 /*
1669  * find a task by its virtual pid and get the task struct
1670  */
1671 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1672 
1673 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1674 extern int wake_up_process(struct task_struct *tsk);
1675 extern void wake_up_new_task(struct task_struct *tsk);
1676 
1677 #ifdef CONFIG_SMP
1678 extern void kick_process(struct task_struct *tsk);
1679 #else
1680 static inline void kick_process(struct task_struct *tsk) { }
1681 #endif
1682 
1683 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1684 
1685 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1686 {
1687 	__set_task_comm(tsk, from, false);
1688 }
1689 
1690 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1691 #define get_task_comm(buf, tsk) ({			\
1692 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
1693 	__get_task_comm(buf, sizeof(buf), tsk);		\
1694 })
1695 
1696 #ifdef CONFIG_SMP
1697 void scheduler_ipi(void);
1698 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1699 #else
1700 static inline void scheduler_ipi(void) { }
1701 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1702 {
1703 	return 1;
1704 }
1705 #endif
1706 
1707 /*
1708  * Set thread flags in other task's structures.
1709  * See asm/thread_info.h for TIF_xxxx flags available:
1710  */
1711 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1712 {
1713 	set_ti_thread_flag(task_thread_info(tsk), flag);
1714 }
1715 
1716 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1717 {
1718 	clear_ti_thread_flag(task_thread_info(tsk), flag);
1719 }
1720 
1721 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1722 					  bool value)
1723 {
1724 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
1725 }
1726 
1727 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1728 {
1729 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1730 }
1731 
1732 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1733 {
1734 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1735 }
1736 
1737 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1738 {
1739 	return test_ti_thread_flag(task_thread_info(tsk), flag);
1740 }
1741 
1742 static inline void set_tsk_need_resched(struct task_struct *tsk)
1743 {
1744 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1745 }
1746 
1747 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1748 {
1749 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1750 }
1751 
1752 static inline int test_tsk_need_resched(struct task_struct *tsk)
1753 {
1754 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1755 }
1756 
1757 /*
1758  * cond_resched() and cond_resched_lock(): latency reduction via
1759  * explicit rescheduling in places that are safe. The return
1760  * value indicates whether a reschedule was done in fact.
1761  * cond_resched_lock() will drop the spinlock before scheduling,
1762  */
1763 #ifndef CONFIG_PREEMPTION
1764 extern int _cond_resched(void);
1765 #else
1766 static inline int _cond_resched(void) { return 0; }
1767 #endif
1768 
1769 #define cond_resched() ({			\
1770 	___might_sleep(__FILE__, __LINE__, 0);	\
1771 	_cond_resched();			\
1772 })
1773 
1774 extern int __cond_resched_lock(spinlock_t *lock);
1775 
1776 #define cond_resched_lock(lock) ({				\
1777 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1778 	__cond_resched_lock(lock);				\
1779 })
1780 
1781 static inline void cond_resched_rcu(void)
1782 {
1783 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1784 	rcu_read_unlock();
1785 	cond_resched();
1786 	rcu_read_lock();
1787 #endif
1788 }
1789 
1790 /*
1791  * Does a critical section need to be broken due to another
1792  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
1793  * but a general need for low latency)
1794  */
1795 static inline int spin_needbreak(spinlock_t *lock)
1796 {
1797 #ifdef CONFIG_PREEMPTION
1798 	return spin_is_contended(lock);
1799 #else
1800 	return 0;
1801 #endif
1802 }
1803 
1804 static __always_inline bool need_resched(void)
1805 {
1806 	return unlikely(tif_need_resched());
1807 }
1808 
1809 /*
1810  * Wrappers for p->thread_info->cpu access. No-op on UP.
1811  */
1812 #ifdef CONFIG_SMP
1813 
1814 static inline unsigned int task_cpu(const struct task_struct *p)
1815 {
1816 #ifdef CONFIG_THREAD_INFO_IN_TASK
1817 	return READ_ONCE(p->cpu);
1818 #else
1819 	return READ_ONCE(task_thread_info(p)->cpu);
1820 #endif
1821 }
1822 
1823 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1824 
1825 #else
1826 
1827 static inline unsigned int task_cpu(const struct task_struct *p)
1828 {
1829 	return 0;
1830 }
1831 
1832 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1833 {
1834 }
1835 
1836 #endif /* CONFIG_SMP */
1837 
1838 /*
1839  * In order to reduce various lock holder preemption latencies provide an
1840  * interface to see if a vCPU is currently running or not.
1841  *
1842  * This allows us to terminate optimistic spin loops and block, analogous to
1843  * the native optimistic spin heuristic of testing if the lock owner task is
1844  * running or not.
1845  */
1846 #ifndef vcpu_is_preempted
1847 static inline bool vcpu_is_preempted(int cpu)
1848 {
1849 	return false;
1850 }
1851 #endif
1852 
1853 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1854 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1855 
1856 #ifndef TASK_SIZE_OF
1857 #define TASK_SIZE_OF(tsk)	TASK_SIZE
1858 #endif
1859 
1860 #ifdef CONFIG_RSEQ
1861 
1862 /*
1863  * Map the event mask on the user-space ABI enum rseq_cs_flags
1864  * for direct mask checks.
1865  */
1866 enum rseq_event_mask_bits {
1867 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
1868 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
1869 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
1870 };
1871 
1872 enum rseq_event_mask {
1873 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
1874 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
1875 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
1876 };
1877 
1878 static inline void rseq_set_notify_resume(struct task_struct *t)
1879 {
1880 	if (t->rseq)
1881 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
1882 }
1883 
1884 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
1885 
1886 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1887 					     struct pt_regs *regs)
1888 {
1889 	if (current->rseq)
1890 		__rseq_handle_notify_resume(ksig, regs);
1891 }
1892 
1893 static inline void rseq_signal_deliver(struct ksignal *ksig,
1894 				       struct pt_regs *regs)
1895 {
1896 	preempt_disable();
1897 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
1898 	preempt_enable();
1899 	rseq_handle_notify_resume(ksig, regs);
1900 }
1901 
1902 /* rseq_preempt() requires preemption to be disabled. */
1903 static inline void rseq_preempt(struct task_struct *t)
1904 {
1905 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
1906 	rseq_set_notify_resume(t);
1907 }
1908 
1909 /* rseq_migrate() requires preemption to be disabled. */
1910 static inline void rseq_migrate(struct task_struct *t)
1911 {
1912 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
1913 	rseq_set_notify_resume(t);
1914 }
1915 
1916 /*
1917  * If parent process has a registered restartable sequences area, the
1918  * child inherits. Only applies when forking a process, not a thread.
1919  */
1920 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1921 {
1922 	if (clone_flags & CLONE_THREAD) {
1923 		t->rseq = NULL;
1924 		t->rseq_sig = 0;
1925 		t->rseq_event_mask = 0;
1926 	} else {
1927 		t->rseq = current->rseq;
1928 		t->rseq_sig = current->rseq_sig;
1929 		t->rseq_event_mask = current->rseq_event_mask;
1930 	}
1931 }
1932 
1933 static inline void rseq_execve(struct task_struct *t)
1934 {
1935 	t->rseq = NULL;
1936 	t->rseq_sig = 0;
1937 	t->rseq_event_mask = 0;
1938 }
1939 
1940 #else
1941 
1942 static inline void rseq_set_notify_resume(struct task_struct *t)
1943 {
1944 }
1945 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1946 					     struct pt_regs *regs)
1947 {
1948 }
1949 static inline void rseq_signal_deliver(struct ksignal *ksig,
1950 				       struct pt_regs *regs)
1951 {
1952 }
1953 static inline void rseq_preempt(struct task_struct *t)
1954 {
1955 }
1956 static inline void rseq_migrate(struct task_struct *t)
1957 {
1958 }
1959 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1960 {
1961 }
1962 static inline void rseq_execve(struct task_struct *t)
1963 {
1964 }
1965 
1966 #endif
1967 
1968 void __exit_umh(struct task_struct *tsk);
1969 
1970 static inline void exit_umh(struct task_struct *tsk)
1971 {
1972 	if (unlikely(tsk->flags & PF_UMH))
1973 		__exit_umh(tsk);
1974 }
1975 
1976 #ifdef CONFIG_DEBUG_RSEQ
1977 
1978 void rseq_syscall(struct pt_regs *regs);
1979 
1980 #else
1981 
1982 static inline void rseq_syscall(struct pt_regs *regs)
1983 {
1984 }
1985 
1986 #endif
1987 
1988 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
1989 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
1990 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
1991 
1992 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
1993 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
1994 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
1995 
1996 int sched_trace_rq_cpu(struct rq *rq);
1997 
1998 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
1999 
2000 #endif
2001