xref: /linux/include/linux/sched.h (revision a13f2ef168cb2a033a284eb841bcc481ffbc90cf)
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 #include <linux/kcsan.h>
35 
36 /* task_struct member predeclarations (sorted alphabetically): */
37 struct audit_context;
38 struct backing_dev_info;
39 struct bio_list;
40 struct blk_plug;
41 struct capture_control;
42 struct cfs_rq;
43 struct fs_struct;
44 struct futex_pi_state;
45 struct io_context;
46 struct mempolicy;
47 struct nameidata;
48 struct nsproxy;
49 struct perf_event_context;
50 struct pid_namespace;
51 struct pipe_inode_info;
52 struct rcu_node;
53 struct reclaim_state;
54 struct robust_list_head;
55 struct root_domain;
56 struct rq;
57 struct sched_attr;
58 struct sched_param;
59 struct seq_file;
60 struct sighand_struct;
61 struct signal_struct;
62 struct task_delay_info;
63 struct task_group;
64 
65 /*
66  * Task state bitmask. NOTE! These bits are also
67  * encoded in fs/proc/array.c: get_task_state().
68  *
69  * We have two separate sets of flags: task->state
70  * is about runnability, while task->exit_state are
71  * about the task exiting. Confusing, but this way
72  * modifying one set can't modify the other one by
73  * mistake.
74  */
75 
76 /* Used in tsk->state: */
77 #define TASK_RUNNING			0x0000
78 #define TASK_INTERRUPTIBLE		0x0001
79 #define TASK_UNINTERRUPTIBLE		0x0002
80 #define __TASK_STOPPED			0x0004
81 #define __TASK_TRACED			0x0008
82 /* Used in tsk->exit_state: */
83 #define EXIT_DEAD			0x0010
84 #define EXIT_ZOMBIE			0x0020
85 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
86 /* Used in tsk->state again: */
87 #define TASK_PARKED			0x0040
88 #define TASK_DEAD			0x0080
89 #define TASK_WAKEKILL			0x0100
90 #define TASK_WAKING			0x0200
91 #define TASK_NOLOAD			0x0400
92 #define TASK_NEW			0x0800
93 #define TASK_STATE_MAX			0x1000
94 
95 /* Convenience macros for the sake of set_current_state: */
96 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
97 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
98 #define TASK_TRACED			(TASK_WAKEKILL | __TASK_TRACED)
99 
100 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
101 
102 /* Convenience macros for the sake of wake_up(): */
103 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
104 
105 /* get_task_state(): */
106 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
107 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
108 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
109 					 TASK_PARKED)
110 
111 #define task_is_traced(task)		((task->state & __TASK_TRACED) != 0)
112 
113 #define task_is_stopped(task)		((task->state & __TASK_STOPPED) != 0)
114 
115 #define task_is_stopped_or_traced(task)	((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
116 
117 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
118 
119 /*
120  * Special states are those that do not use the normal wait-loop pattern. See
121  * the comment with set_special_state().
122  */
123 #define is_special_task_state(state)				\
124 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
125 
126 #define __set_current_state(state_value)			\
127 	do {							\
128 		WARN_ON_ONCE(is_special_task_state(state_value));\
129 		current->task_state_change = _THIS_IP_;		\
130 		current->state = (state_value);			\
131 	} while (0)
132 
133 #define set_current_state(state_value)				\
134 	do {							\
135 		WARN_ON_ONCE(is_special_task_state(state_value));\
136 		current->task_state_change = _THIS_IP_;		\
137 		smp_store_mb(current->state, (state_value));	\
138 	} while (0)
139 
140 #define set_special_state(state_value)					\
141 	do {								\
142 		unsigned long flags; /* may shadow */			\
143 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
144 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
145 		current->task_state_change = _THIS_IP_;			\
146 		current->state = (state_value);				\
147 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
148 	} while (0)
149 #else
150 /*
151  * set_current_state() includes a barrier so that the write of current->state
152  * is correctly serialised wrt the caller's subsequent test of whether to
153  * actually sleep:
154  *
155  *   for (;;) {
156  *	set_current_state(TASK_UNINTERRUPTIBLE);
157  *	if (!need_sleep)
158  *		break;
159  *
160  *	schedule();
161  *   }
162  *   __set_current_state(TASK_RUNNING);
163  *
164  * If the caller does not need such serialisation (because, for instance, the
165  * condition test and condition change and wakeup are under the same lock) then
166  * use __set_current_state().
167  *
168  * The above is typically ordered against the wakeup, which does:
169  *
170  *   need_sleep = false;
171  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
172  *
173  * where wake_up_state() executes a full memory barrier before accessing the
174  * task state.
175  *
176  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
177  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
178  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
179  *
180  * However, with slightly different timing the wakeup TASK_RUNNING store can
181  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
182  * a problem either because that will result in one extra go around the loop
183  * and our @cond test will save the day.
184  *
185  * Also see the comments of try_to_wake_up().
186  */
187 #define __set_current_state(state_value)				\
188 	current->state = (state_value)
189 
190 #define set_current_state(state_value)					\
191 	smp_store_mb(current->state, (state_value))
192 
193 /*
194  * set_special_state() should be used for those states when the blocking task
195  * can not use the regular condition based wait-loop. In that case we must
196  * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
197  * will not collide with our state change.
198  */
199 #define set_special_state(state_value)					\
200 	do {								\
201 		unsigned long flags; /* may shadow */			\
202 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
203 		current->state = (state_value);				\
204 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
205 	} while (0)
206 
207 #endif
208 
209 /* Task command name length: */
210 #define TASK_COMM_LEN			16
211 
212 extern void scheduler_tick(void);
213 
214 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
215 
216 extern long schedule_timeout(long timeout);
217 extern long schedule_timeout_interruptible(long timeout);
218 extern long schedule_timeout_killable(long timeout);
219 extern long schedule_timeout_uninterruptible(long timeout);
220 extern long schedule_timeout_idle(long timeout);
221 asmlinkage void schedule(void);
222 extern void schedule_preempt_disabled(void);
223 asmlinkage void preempt_schedule_irq(void);
224 
225 extern int __must_check io_schedule_prepare(void);
226 extern void io_schedule_finish(int token);
227 extern long io_schedule_timeout(long timeout);
228 extern void io_schedule(void);
229 
230 /**
231  * struct prev_cputime - snapshot of system and user cputime
232  * @utime: time spent in user mode
233  * @stime: time spent in system mode
234  * @lock: protects the above two fields
235  *
236  * Stores previous user/system time values such that we can guarantee
237  * monotonicity.
238  */
239 struct prev_cputime {
240 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
241 	u64				utime;
242 	u64				stime;
243 	raw_spinlock_t			lock;
244 #endif
245 };
246 
247 enum vtime_state {
248 	/* Task is sleeping or running in a CPU with VTIME inactive: */
249 	VTIME_INACTIVE = 0,
250 	/* Task is idle */
251 	VTIME_IDLE,
252 	/* Task runs in kernelspace in a CPU with VTIME active: */
253 	VTIME_SYS,
254 	/* Task runs in userspace in a CPU with VTIME active: */
255 	VTIME_USER,
256 	/* Task runs as guests in a CPU with VTIME active: */
257 	VTIME_GUEST,
258 };
259 
260 struct vtime {
261 	seqcount_t		seqcount;
262 	unsigned long long	starttime;
263 	enum vtime_state	state;
264 	unsigned int		cpu;
265 	u64			utime;
266 	u64			stime;
267 	u64			gtime;
268 };
269 
270 /*
271  * Utilization clamp constraints.
272  * @UCLAMP_MIN:	Minimum utilization
273  * @UCLAMP_MAX:	Maximum utilization
274  * @UCLAMP_CNT:	Utilization clamp constraints count
275  */
276 enum uclamp_id {
277 	UCLAMP_MIN = 0,
278 	UCLAMP_MAX,
279 	UCLAMP_CNT
280 };
281 
282 #ifdef CONFIG_SMP
283 extern struct root_domain def_root_domain;
284 extern struct mutex sched_domains_mutex;
285 #endif
286 
287 struct sched_info {
288 #ifdef CONFIG_SCHED_INFO
289 	/* Cumulative counters: */
290 
291 	/* # of times we have run on this CPU: */
292 	unsigned long			pcount;
293 
294 	/* Time spent waiting on a runqueue: */
295 	unsigned long long		run_delay;
296 
297 	/* Timestamps: */
298 
299 	/* When did we last run on a CPU? */
300 	unsigned long long		last_arrival;
301 
302 	/* When were we last queued to run? */
303 	unsigned long long		last_queued;
304 
305 #endif /* CONFIG_SCHED_INFO */
306 };
307 
308 /*
309  * Integer metrics need fixed point arithmetic, e.g., sched/fair
310  * has a few: load, load_avg, util_avg, freq, and capacity.
311  *
312  * We define a basic fixed point arithmetic range, and then formalize
313  * all these metrics based on that basic range.
314  */
315 # define SCHED_FIXEDPOINT_SHIFT		10
316 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
317 
318 /* Increase resolution of cpu_capacity calculations */
319 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
320 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
321 
322 struct load_weight {
323 	unsigned long			weight;
324 	u32				inv_weight;
325 };
326 
327 /**
328  * struct util_est - Estimation utilization of FAIR tasks
329  * @enqueued: instantaneous estimated utilization of a task/cpu
330  * @ewma:     the Exponential Weighted Moving Average (EWMA)
331  *            utilization of a task
332  *
333  * Support data structure to track an Exponential Weighted Moving Average
334  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
335  * average each time a task completes an activation. Sample's weight is chosen
336  * so that the EWMA will be relatively insensitive to transient changes to the
337  * task's workload.
338  *
339  * The enqueued attribute has a slightly different meaning for tasks and cpus:
340  * - task:   the task's util_avg at last task dequeue time
341  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
342  * Thus, the util_est.enqueued of a task represents the contribution on the
343  * estimated utilization of the CPU where that task is currently enqueued.
344  *
345  * Only for tasks we track a moving average of the past instantaneous
346  * estimated utilization. This allows to absorb sporadic drops in utilization
347  * of an otherwise almost periodic task.
348  */
349 struct util_est {
350 	unsigned int			enqueued;
351 	unsigned int			ewma;
352 #define UTIL_EST_WEIGHT_SHIFT		2
353 } __attribute__((__aligned__(sizeof(u64))));
354 
355 /*
356  * The load/runnable/util_avg accumulates an infinite geometric series
357  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
358  *
359  * [load_avg definition]
360  *
361  *   load_avg = runnable% * scale_load_down(load)
362  *
363  * [runnable_avg definition]
364  *
365  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
366  *
367  * [util_avg definition]
368  *
369  *   util_avg = running% * SCHED_CAPACITY_SCALE
370  *
371  * where runnable% is the time ratio that a sched_entity is runnable and
372  * running% the time ratio that a sched_entity is running.
373  *
374  * For cfs_rq, they are the aggregated values of all runnable and blocked
375  * sched_entities.
376  *
377  * The load/runnable/util_avg doesn't direcly factor frequency scaling and CPU
378  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
379  * for computing those signals (see update_rq_clock_pelt())
380  *
381  * N.B., the above ratios (runnable% and running%) themselves are in the
382  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
383  * to as large a range as necessary. This is for example reflected by
384  * util_avg's SCHED_CAPACITY_SCALE.
385  *
386  * [Overflow issue]
387  *
388  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
389  * with the highest load (=88761), always runnable on a single cfs_rq,
390  * and should not overflow as the number already hits PID_MAX_LIMIT.
391  *
392  * For all other cases (including 32-bit kernels), struct load_weight's
393  * weight will overflow first before we do, because:
394  *
395  *    Max(load_avg) <= Max(load.weight)
396  *
397  * Then it is the load_weight's responsibility to consider overflow
398  * issues.
399  */
400 struct sched_avg {
401 	u64				last_update_time;
402 	u64				load_sum;
403 	u64				runnable_sum;
404 	u32				util_sum;
405 	u32				period_contrib;
406 	unsigned long			load_avg;
407 	unsigned long			runnable_avg;
408 	unsigned long			util_avg;
409 	struct util_est			util_est;
410 } ____cacheline_aligned;
411 
412 struct sched_statistics {
413 #ifdef CONFIG_SCHEDSTATS
414 	u64				wait_start;
415 	u64				wait_max;
416 	u64				wait_count;
417 	u64				wait_sum;
418 	u64				iowait_count;
419 	u64				iowait_sum;
420 
421 	u64				sleep_start;
422 	u64				sleep_max;
423 	s64				sum_sleep_runtime;
424 
425 	u64				block_start;
426 	u64				block_max;
427 	u64				exec_max;
428 	u64				slice_max;
429 
430 	u64				nr_migrations_cold;
431 	u64				nr_failed_migrations_affine;
432 	u64				nr_failed_migrations_running;
433 	u64				nr_failed_migrations_hot;
434 	u64				nr_forced_migrations;
435 
436 	u64				nr_wakeups;
437 	u64				nr_wakeups_sync;
438 	u64				nr_wakeups_migrate;
439 	u64				nr_wakeups_local;
440 	u64				nr_wakeups_remote;
441 	u64				nr_wakeups_affine;
442 	u64				nr_wakeups_affine_attempts;
443 	u64				nr_wakeups_passive;
444 	u64				nr_wakeups_idle;
445 #endif
446 };
447 
448 struct sched_entity {
449 	/* For load-balancing: */
450 	struct load_weight		load;
451 	struct rb_node			run_node;
452 	struct list_head		group_node;
453 	unsigned int			on_rq;
454 
455 	u64				exec_start;
456 	u64				sum_exec_runtime;
457 	u64				vruntime;
458 	u64				prev_sum_exec_runtime;
459 
460 	u64				nr_migrations;
461 
462 	struct sched_statistics		statistics;
463 
464 #ifdef CONFIG_FAIR_GROUP_SCHED
465 	int				depth;
466 	struct sched_entity		*parent;
467 	/* rq on which this entity is (to be) queued: */
468 	struct cfs_rq			*cfs_rq;
469 	/* rq "owned" by this entity/group: */
470 	struct cfs_rq			*my_q;
471 	/* cached value of my_q->h_nr_running */
472 	unsigned long			runnable_weight;
473 #endif
474 
475 #ifdef CONFIG_SMP
476 	/*
477 	 * Per entity load average tracking.
478 	 *
479 	 * Put into separate cache line so it does not
480 	 * collide with read-mostly values above.
481 	 */
482 	struct sched_avg		avg;
483 #endif
484 };
485 
486 struct sched_rt_entity {
487 	struct list_head		run_list;
488 	unsigned long			timeout;
489 	unsigned long			watchdog_stamp;
490 	unsigned int			time_slice;
491 	unsigned short			on_rq;
492 	unsigned short			on_list;
493 
494 	struct sched_rt_entity		*back;
495 #ifdef CONFIG_RT_GROUP_SCHED
496 	struct sched_rt_entity		*parent;
497 	/* rq on which this entity is (to be) queued: */
498 	struct rt_rq			*rt_rq;
499 	/* rq "owned" by this entity/group: */
500 	struct rt_rq			*my_q;
501 #endif
502 } __randomize_layout;
503 
504 struct sched_dl_entity {
505 	struct rb_node			rb_node;
506 
507 	/*
508 	 * Original scheduling parameters. Copied here from sched_attr
509 	 * during sched_setattr(), they will remain the same until
510 	 * the next sched_setattr().
511 	 */
512 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
513 	u64				dl_deadline;	/* Relative deadline of each instance	*/
514 	u64				dl_period;	/* Separation of two instances (period) */
515 	u64				dl_bw;		/* dl_runtime / dl_period		*/
516 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
517 
518 	/*
519 	 * Actual scheduling parameters. Initialized with the values above,
520 	 * they are continuously updated during task execution. Note that
521 	 * the remaining runtime could be < 0 in case we are in overrun.
522 	 */
523 	s64				runtime;	/* Remaining runtime for this instance	*/
524 	u64				deadline;	/* Absolute deadline for this instance	*/
525 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
526 
527 	/*
528 	 * Some bool flags:
529 	 *
530 	 * @dl_throttled tells if we exhausted the runtime. If so, the
531 	 * task has to wait for a replenishment to be performed at the
532 	 * next firing of dl_timer.
533 	 *
534 	 * @dl_boosted tells if we are boosted due to DI. If so we are
535 	 * outside bandwidth enforcement mechanism (but only until we
536 	 * exit the critical section);
537 	 *
538 	 * @dl_yielded tells if task gave up the CPU before consuming
539 	 * all its available runtime during the last job.
540 	 *
541 	 * @dl_non_contending tells if the task is inactive while still
542 	 * contributing to the active utilization. In other words, it
543 	 * indicates if the inactive timer has been armed and its handler
544 	 * has not been executed yet. This flag is useful to avoid race
545 	 * conditions between the inactive timer handler and the wakeup
546 	 * code.
547 	 *
548 	 * @dl_overrun tells if the task asked to be informed about runtime
549 	 * overruns.
550 	 */
551 	unsigned int			dl_throttled      : 1;
552 	unsigned int			dl_boosted        : 1;
553 	unsigned int			dl_yielded        : 1;
554 	unsigned int			dl_non_contending : 1;
555 	unsigned int			dl_overrun	  : 1;
556 
557 	/*
558 	 * Bandwidth enforcement timer. Each -deadline task has its
559 	 * own bandwidth to be enforced, thus we need one timer per task.
560 	 */
561 	struct hrtimer			dl_timer;
562 
563 	/*
564 	 * Inactive timer, responsible for decreasing the active utilization
565 	 * at the "0-lag time". When a -deadline task blocks, it contributes
566 	 * to GRUB's active utilization until the "0-lag time", hence a
567 	 * timer is needed to decrease the active utilization at the correct
568 	 * time.
569 	 */
570 	struct hrtimer inactive_timer;
571 };
572 
573 #ifdef CONFIG_UCLAMP_TASK
574 /* Number of utilization clamp buckets (shorter alias) */
575 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
576 
577 /*
578  * Utilization clamp for a scheduling entity
579  * @value:		clamp value "assigned" to a se
580  * @bucket_id:		bucket index corresponding to the "assigned" value
581  * @active:		the se is currently refcounted in a rq's bucket
582  * @user_defined:	the requested clamp value comes from user-space
583  *
584  * The bucket_id is the index of the clamp bucket matching the clamp value
585  * which is pre-computed and stored to avoid expensive integer divisions from
586  * the fast path.
587  *
588  * The active bit is set whenever a task has got an "effective" value assigned,
589  * which can be different from the clamp value "requested" from user-space.
590  * This allows to know a task is refcounted in the rq's bucket corresponding
591  * to the "effective" bucket_id.
592  *
593  * The user_defined bit is set whenever a task has got a task-specific clamp
594  * value requested from userspace, i.e. the system defaults apply to this task
595  * just as a restriction. This allows to relax default clamps when a less
596  * restrictive task-specific value has been requested, thus allowing to
597  * implement a "nice" semantic. For example, a task running with a 20%
598  * default boost can still drop its own boosting to 0%.
599  */
600 struct uclamp_se {
601 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
602 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
603 	unsigned int active		: 1;
604 	unsigned int user_defined	: 1;
605 };
606 #endif /* CONFIG_UCLAMP_TASK */
607 
608 union rcu_special {
609 	struct {
610 		u8			blocked;
611 		u8			need_qs;
612 		u8			exp_hint; /* Hint for performance. */
613 		u8			need_mb; /* Readers need smp_mb(). */
614 	} b; /* Bits. */
615 	u32 s; /* Set of bits. */
616 };
617 
618 enum perf_event_task_context {
619 	perf_invalid_context = -1,
620 	perf_hw_context = 0,
621 	perf_sw_context,
622 	perf_nr_task_contexts,
623 };
624 
625 struct wake_q_node {
626 	struct wake_q_node *next;
627 };
628 
629 struct task_struct {
630 #ifdef CONFIG_THREAD_INFO_IN_TASK
631 	/*
632 	 * For reasons of header soup (see current_thread_info()), this
633 	 * must be the first element of task_struct.
634 	 */
635 	struct thread_info		thread_info;
636 #endif
637 	/* -1 unrunnable, 0 runnable, >0 stopped: */
638 	volatile long			state;
639 
640 	/*
641 	 * This begins the randomizable portion of task_struct. Only
642 	 * scheduling-critical items should be added above here.
643 	 */
644 	randomized_struct_fields_start
645 
646 	void				*stack;
647 	refcount_t			usage;
648 	/* Per task flags (PF_*), defined further below: */
649 	unsigned int			flags;
650 	unsigned int			ptrace;
651 
652 #ifdef CONFIG_SMP
653 	int				on_cpu;
654 	struct __call_single_node	wake_entry;
655 #ifdef CONFIG_THREAD_INFO_IN_TASK
656 	/* Current CPU: */
657 	unsigned int			cpu;
658 #endif
659 	unsigned int			wakee_flips;
660 	unsigned long			wakee_flip_decay_ts;
661 	struct task_struct		*last_wakee;
662 
663 	/*
664 	 * recent_used_cpu is initially set as the last CPU used by a task
665 	 * that wakes affine another task. Waker/wakee relationships can
666 	 * push tasks around a CPU where each wakeup moves to the next one.
667 	 * Tracking a recently used CPU allows a quick search for a recently
668 	 * used CPU that may be idle.
669 	 */
670 	int				recent_used_cpu;
671 	int				wake_cpu;
672 #endif
673 	int				on_rq;
674 
675 	int				prio;
676 	int				static_prio;
677 	int				normal_prio;
678 	unsigned int			rt_priority;
679 
680 	const struct sched_class	*sched_class;
681 	struct sched_entity		se;
682 	struct sched_rt_entity		rt;
683 #ifdef CONFIG_CGROUP_SCHED
684 	struct task_group		*sched_task_group;
685 #endif
686 	struct sched_dl_entity		dl;
687 
688 #ifdef CONFIG_UCLAMP_TASK
689 	/* Clamp values requested for a scheduling entity */
690 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
691 	/* Effective clamp values used for a scheduling entity */
692 	struct uclamp_se		uclamp[UCLAMP_CNT];
693 #endif
694 
695 #ifdef CONFIG_PREEMPT_NOTIFIERS
696 	/* List of struct preempt_notifier: */
697 	struct hlist_head		preempt_notifiers;
698 #endif
699 
700 #ifdef CONFIG_BLK_DEV_IO_TRACE
701 	unsigned int			btrace_seq;
702 #endif
703 
704 	unsigned int			policy;
705 	int				nr_cpus_allowed;
706 	const cpumask_t			*cpus_ptr;
707 	cpumask_t			cpus_mask;
708 
709 #ifdef CONFIG_PREEMPT_RCU
710 	int				rcu_read_lock_nesting;
711 	union rcu_special		rcu_read_unlock_special;
712 	struct list_head		rcu_node_entry;
713 	struct rcu_node			*rcu_blocked_node;
714 #endif /* #ifdef CONFIG_PREEMPT_RCU */
715 
716 #ifdef CONFIG_TASKS_RCU
717 	unsigned long			rcu_tasks_nvcsw;
718 	u8				rcu_tasks_holdout;
719 	u8				rcu_tasks_idx;
720 	int				rcu_tasks_idle_cpu;
721 	struct list_head		rcu_tasks_holdout_list;
722 #endif /* #ifdef CONFIG_TASKS_RCU */
723 
724 #ifdef CONFIG_TASKS_TRACE_RCU
725 	int				trc_reader_nesting;
726 	int				trc_ipi_to_cpu;
727 	union rcu_special		trc_reader_special;
728 	bool				trc_reader_checked;
729 	struct list_head		trc_holdout_list;
730 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
731 
732 	struct sched_info		sched_info;
733 
734 	struct list_head		tasks;
735 #ifdef CONFIG_SMP
736 	struct plist_node		pushable_tasks;
737 	struct rb_node			pushable_dl_tasks;
738 #endif
739 
740 	struct mm_struct		*mm;
741 	struct mm_struct		*active_mm;
742 
743 	/* Per-thread vma caching: */
744 	struct vmacache			vmacache;
745 
746 #ifdef SPLIT_RSS_COUNTING
747 	struct task_rss_stat		rss_stat;
748 #endif
749 	int				exit_state;
750 	int				exit_code;
751 	int				exit_signal;
752 	/* The signal sent when the parent dies: */
753 	int				pdeath_signal;
754 	/* JOBCTL_*, siglock protected: */
755 	unsigned long			jobctl;
756 
757 	/* Used for emulating ABI behavior of previous Linux versions: */
758 	unsigned int			personality;
759 
760 	/* Scheduler bits, serialized by scheduler locks: */
761 	unsigned			sched_reset_on_fork:1;
762 	unsigned			sched_contributes_to_load:1;
763 	unsigned			sched_migrated:1;
764 	unsigned			sched_remote_wakeup:1;
765 #ifdef CONFIG_PSI
766 	unsigned			sched_psi_wake_requeue:1;
767 #endif
768 
769 	/* Force alignment to the next boundary: */
770 	unsigned			:0;
771 
772 	/* Unserialized, strictly 'current' */
773 
774 	/* Bit to tell LSMs we're in execve(): */
775 	unsigned			in_execve:1;
776 	unsigned			in_iowait:1;
777 #ifndef TIF_RESTORE_SIGMASK
778 	unsigned			restore_sigmask:1;
779 #endif
780 #ifdef CONFIG_MEMCG
781 	unsigned			in_user_fault:1;
782 #endif
783 #ifdef CONFIG_COMPAT_BRK
784 	unsigned			brk_randomized:1;
785 #endif
786 #ifdef CONFIG_CGROUPS
787 	/* disallow userland-initiated cgroup migration */
788 	unsigned			no_cgroup_migration:1;
789 	/* task is frozen/stopped (used by the cgroup freezer) */
790 	unsigned			frozen:1;
791 #endif
792 #ifdef CONFIG_BLK_CGROUP
793 	unsigned			use_memdelay:1;
794 #endif
795 #ifdef CONFIG_PSI
796 	/* Stalled due to lack of memory */
797 	unsigned			in_memstall:1;
798 #endif
799 
800 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
801 
802 	struct restart_block		restart_block;
803 
804 	pid_t				pid;
805 	pid_t				tgid;
806 
807 #ifdef CONFIG_STACKPROTECTOR
808 	/* Canary value for the -fstack-protector GCC feature: */
809 	unsigned long			stack_canary;
810 #endif
811 	/*
812 	 * Pointers to the (original) parent process, youngest child, younger sibling,
813 	 * older sibling, respectively.  (p->father can be replaced with
814 	 * p->real_parent->pid)
815 	 */
816 
817 	/* Real parent process: */
818 	struct task_struct __rcu	*real_parent;
819 
820 	/* Recipient of SIGCHLD, wait4() reports: */
821 	struct task_struct __rcu	*parent;
822 
823 	/*
824 	 * Children/sibling form the list of natural children:
825 	 */
826 	struct list_head		children;
827 	struct list_head		sibling;
828 	struct task_struct		*group_leader;
829 
830 	/*
831 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
832 	 *
833 	 * This includes both natural children and PTRACE_ATTACH targets.
834 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
835 	 */
836 	struct list_head		ptraced;
837 	struct list_head		ptrace_entry;
838 
839 	/* PID/PID hash table linkage. */
840 	struct pid			*thread_pid;
841 	struct hlist_node		pid_links[PIDTYPE_MAX];
842 	struct list_head		thread_group;
843 	struct list_head		thread_node;
844 
845 	struct completion		*vfork_done;
846 
847 	/* CLONE_CHILD_SETTID: */
848 	int __user			*set_child_tid;
849 
850 	/* CLONE_CHILD_CLEARTID: */
851 	int __user			*clear_child_tid;
852 
853 	u64				utime;
854 	u64				stime;
855 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
856 	u64				utimescaled;
857 	u64				stimescaled;
858 #endif
859 	u64				gtime;
860 	struct prev_cputime		prev_cputime;
861 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
862 	struct vtime			vtime;
863 #endif
864 
865 #ifdef CONFIG_NO_HZ_FULL
866 	atomic_t			tick_dep_mask;
867 #endif
868 	/* Context switch counts: */
869 	unsigned long			nvcsw;
870 	unsigned long			nivcsw;
871 
872 	/* Monotonic time in nsecs: */
873 	u64				start_time;
874 
875 	/* Boot based time in nsecs: */
876 	u64				start_boottime;
877 
878 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
879 	unsigned long			min_flt;
880 	unsigned long			maj_flt;
881 
882 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
883 	struct posix_cputimers		posix_cputimers;
884 
885 	/* Process credentials: */
886 
887 	/* Tracer's credentials at attach: */
888 	const struct cred __rcu		*ptracer_cred;
889 
890 	/* Objective and real subjective task credentials (COW): */
891 	const struct cred __rcu		*real_cred;
892 
893 	/* Effective (overridable) subjective task credentials (COW): */
894 	const struct cred __rcu		*cred;
895 
896 #ifdef CONFIG_KEYS
897 	/* Cached requested key. */
898 	struct key			*cached_requested_key;
899 #endif
900 
901 	/*
902 	 * executable name, excluding path.
903 	 *
904 	 * - normally initialized setup_new_exec()
905 	 * - access it with [gs]et_task_comm()
906 	 * - lock it with task_lock()
907 	 */
908 	char				comm[TASK_COMM_LEN];
909 
910 	struct nameidata		*nameidata;
911 
912 #ifdef CONFIG_SYSVIPC
913 	struct sysv_sem			sysvsem;
914 	struct sysv_shm			sysvshm;
915 #endif
916 #ifdef CONFIG_DETECT_HUNG_TASK
917 	unsigned long			last_switch_count;
918 	unsigned long			last_switch_time;
919 #endif
920 	/* Filesystem information: */
921 	struct fs_struct		*fs;
922 
923 	/* Open file information: */
924 	struct files_struct		*files;
925 
926 	/* Namespaces: */
927 	struct nsproxy			*nsproxy;
928 
929 	/* Signal handlers: */
930 	struct signal_struct		*signal;
931 	struct sighand_struct __rcu		*sighand;
932 	sigset_t			blocked;
933 	sigset_t			real_blocked;
934 	/* Restored if set_restore_sigmask() was used: */
935 	sigset_t			saved_sigmask;
936 	struct sigpending		pending;
937 	unsigned long			sas_ss_sp;
938 	size_t				sas_ss_size;
939 	unsigned int			sas_ss_flags;
940 
941 	struct callback_head		*task_works;
942 
943 #ifdef CONFIG_AUDIT
944 #ifdef CONFIG_AUDITSYSCALL
945 	struct audit_context		*audit_context;
946 #endif
947 	kuid_t				loginuid;
948 	unsigned int			sessionid;
949 #endif
950 	struct seccomp			seccomp;
951 
952 	/* Thread group tracking: */
953 	u64				parent_exec_id;
954 	u64				self_exec_id;
955 
956 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
957 	spinlock_t			alloc_lock;
958 
959 	/* Protection of the PI data structures: */
960 	raw_spinlock_t			pi_lock;
961 
962 	struct wake_q_node		wake_q;
963 
964 #ifdef CONFIG_RT_MUTEXES
965 	/* PI waiters blocked on a rt_mutex held by this task: */
966 	struct rb_root_cached		pi_waiters;
967 	/* Updated under owner's pi_lock and rq lock */
968 	struct task_struct		*pi_top_task;
969 	/* Deadlock detection and priority inheritance handling: */
970 	struct rt_mutex_waiter		*pi_blocked_on;
971 #endif
972 
973 #ifdef CONFIG_DEBUG_MUTEXES
974 	/* Mutex deadlock detection: */
975 	struct mutex_waiter		*blocked_on;
976 #endif
977 
978 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
979 	int				non_block_count;
980 #endif
981 
982 #ifdef CONFIG_TRACE_IRQFLAGS
983 	unsigned int			irq_events;
984 	unsigned int			hardirq_threaded;
985 	unsigned long			hardirq_enable_ip;
986 	unsigned long			hardirq_disable_ip;
987 	unsigned int			hardirq_enable_event;
988 	unsigned int			hardirq_disable_event;
989 	int				hardirqs_enabled;
990 	int				hardirq_context;
991 	u64				hardirq_chain_key;
992 	unsigned long			softirq_disable_ip;
993 	unsigned long			softirq_enable_ip;
994 	unsigned int			softirq_disable_event;
995 	unsigned int			softirq_enable_event;
996 	int				softirqs_enabled;
997 	int				softirq_context;
998 	int				irq_config;
999 #endif
1000 
1001 #ifdef CONFIG_LOCKDEP
1002 # define MAX_LOCK_DEPTH			48UL
1003 	u64				curr_chain_key;
1004 	int				lockdep_depth;
1005 	unsigned int			lockdep_recursion;
1006 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1007 #endif
1008 
1009 #ifdef CONFIG_UBSAN
1010 	unsigned int			in_ubsan;
1011 #endif
1012 
1013 	/* Journalling filesystem info: */
1014 	void				*journal_info;
1015 
1016 	/* Stacked block device info: */
1017 	struct bio_list			*bio_list;
1018 
1019 #ifdef CONFIG_BLOCK
1020 	/* Stack plugging: */
1021 	struct blk_plug			*plug;
1022 #endif
1023 
1024 	/* VM state: */
1025 	struct reclaim_state		*reclaim_state;
1026 
1027 	struct backing_dev_info		*backing_dev_info;
1028 
1029 	struct io_context		*io_context;
1030 
1031 #ifdef CONFIG_COMPACTION
1032 	struct capture_control		*capture_control;
1033 #endif
1034 	/* Ptrace state: */
1035 	unsigned long			ptrace_message;
1036 	kernel_siginfo_t		*last_siginfo;
1037 
1038 	struct task_io_accounting	ioac;
1039 #ifdef CONFIG_PSI
1040 	/* Pressure stall state */
1041 	unsigned int			psi_flags;
1042 #endif
1043 #ifdef CONFIG_TASK_XACCT
1044 	/* Accumulated RSS usage: */
1045 	u64				acct_rss_mem1;
1046 	/* Accumulated virtual memory usage: */
1047 	u64				acct_vm_mem1;
1048 	/* stime + utime since last update: */
1049 	u64				acct_timexpd;
1050 #endif
1051 #ifdef CONFIG_CPUSETS
1052 	/* Protected by ->alloc_lock: */
1053 	nodemask_t			mems_allowed;
1054 	/* Seqence number to catch updates: */
1055 	seqcount_t			mems_allowed_seq;
1056 	int				cpuset_mem_spread_rotor;
1057 	int				cpuset_slab_spread_rotor;
1058 #endif
1059 #ifdef CONFIG_CGROUPS
1060 	/* Control Group info protected by css_set_lock: */
1061 	struct css_set __rcu		*cgroups;
1062 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1063 	struct list_head		cg_list;
1064 #endif
1065 #ifdef CONFIG_X86_CPU_RESCTRL
1066 	u32				closid;
1067 	u32				rmid;
1068 #endif
1069 #ifdef CONFIG_FUTEX
1070 	struct robust_list_head __user	*robust_list;
1071 #ifdef CONFIG_COMPAT
1072 	struct compat_robust_list_head __user *compat_robust_list;
1073 #endif
1074 	struct list_head		pi_state_list;
1075 	struct futex_pi_state		*pi_state_cache;
1076 	struct mutex			futex_exit_mutex;
1077 	unsigned int			futex_state;
1078 #endif
1079 #ifdef CONFIG_PERF_EVENTS
1080 	struct perf_event_context	*perf_event_ctxp[perf_nr_task_contexts];
1081 	struct mutex			perf_event_mutex;
1082 	struct list_head		perf_event_list;
1083 #endif
1084 #ifdef CONFIG_DEBUG_PREEMPT
1085 	unsigned long			preempt_disable_ip;
1086 #endif
1087 #ifdef CONFIG_NUMA
1088 	/* Protected by alloc_lock: */
1089 	struct mempolicy		*mempolicy;
1090 	short				il_prev;
1091 	short				pref_node_fork;
1092 #endif
1093 #ifdef CONFIG_NUMA_BALANCING
1094 	int				numa_scan_seq;
1095 	unsigned int			numa_scan_period;
1096 	unsigned int			numa_scan_period_max;
1097 	int				numa_preferred_nid;
1098 	unsigned long			numa_migrate_retry;
1099 	/* Migration stamp: */
1100 	u64				node_stamp;
1101 	u64				last_task_numa_placement;
1102 	u64				last_sum_exec_runtime;
1103 	struct callback_head		numa_work;
1104 
1105 	/*
1106 	 * This pointer is only modified for current in syscall and
1107 	 * pagefault context (and for tasks being destroyed), so it can be read
1108 	 * from any of the following contexts:
1109 	 *  - RCU read-side critical section
1110 	 *  - current->numa_group from everywhere
1111 	 *  - task's runqueue locked, task not running
1112 	 */
1113 	struct numa_group __rcu		*numa_group;
1114 
1115 	/*
1116 	 * numa_faults is an array split into four regions:
1117 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1118 	 * in this precise order.
1119 	 *
1120 	 * faults_memory: Exponential decaying average of faults on a per-node
1121 	 * basis. Scheduling placement decisions are made based on these
1122 	 * counts. The values remain static for the duration of a PTE scan.
1123 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1124 	 * hinting fault was incurred.
1125 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1126 	 * during the current scan window. When the scan completes, the counts
1127 	 * in faults_memory and faults_cpu decay and these values are copied.
1128 	 */
1129 	unsigned long			*numa_faults;
1130 	unsigned long			total_numa_faults;
1131 
1132 	/*
1133 	 * numa_faults_locality tracks if faults recorded during the last
1134 	 * scan window were remote/local or failed to migrate. The task scan
1135 	 * period is adapted based on the locality of the faults with different
1136 	 * weights depending on whether they were shared or private faults
1137 	 */
1138 	unsigned long			numa_faults_locality[3];
1139 
1140 	unsigned long			numa_pages_migrated;
1141 #endif /* CONFIG_NUMA_BALANCING */
1142 
1143 #ifdef CONFIG_RSEQ
1144 	struct rseq __user *rseq;
1145 	u32 rseq_sig;
1146 	/*
1147 	 * RmW on rseq_event_mask must be performed atomically
1148 	 * with respect to preemption.
1149 	 */
1150 	unsigned long rseq_event_mask;
1151 #endif
1152 
1153 	struct tlbflush_unmap_batch	tlb_ubc;
1154 
1155 	union {
1156 		refcount_t		rcu_users;
1157 		struct rcu_head		rcu;
1158 	};
1159 
1160 	/* Cache last used pipe for splice(): */
1161 	struct pipe_inode_info		*splice_pipe;
1162 
1163 	struct page_frag		task_frag;
1164 
1165 #ifdef CONFIG_TASK_DELAY_ACCT
1166 	struct task_delay_info		*delays;
1167 #endif
1168 
1169 #ifdef CONFIG_FAULT_INJECTION
1170 	int				make_it_fail;
1171 	unsigned int			fail_nth;
1172 #endif
1173 	/*
1174 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1175 	 * balance_dirty_pages() for a dirty throttling pause:
1176 	 */
1177 	int				nr_dirtied;
1178 	int				nr_dirtied_pause;
1179 	/* Start of a write-and-pause period: */
1180 	unsigned long			dirty_paused_when;
1181 
1182 #ifdef CONFIG_LATENCYTOP
1183 	int				latency_record_count;
1184 	struct latency_record		latency_record[LT_SAVECOUNT];
1185 #endif
1186 	/*
1187 	 * Time slack values; these are used to round up poll() and
1188 	 * select() etc timeout values. These are in nanoseconds.
1189 	 */
1190 	u64				timer_slack_ns;
1191 	u64				default_timer_slack_ns;
1192 
1193 #ifdef CONFIG_KASAN
1194 	unsigned int			kasan_depth;
1195 #endif
1196 #ifdef CONFIG_KCSAN
1197 	struct kcsan_ctx		kcsan_ctx;
1198 #endif
1199 
1200 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1201 	/* Index of current stored address in ret_stack: */
1202 	int				curr_ret_stack;
1203 	int				curr_ret_depth;
1204 
1205 	/* Stack of return addresses for return function tracing: */
1206 	struct ftrace_ret_stack		*ret_stack;
1207 
1208 	/* Timestamp for last schedule: */
1209 	unsigned long long		ftrace_timestamp;
1210 
1211 	/*
1212 	 * Number of functions that haven't been traced
1213 	 * because of depth overrun:
1214 	 */
1215 	atomic_t			trace_overrun;
1216 
1217 	/* Pause tracing: */
1218 	atomic_t			tracing_graph_pause;
1219 #endif
1220 
1221 #ifdef CONFIG_TRACING
1222 	/* State flags for use by tracers: */
1223 	unsigned long			trace;
1224 
1225 	/* Bitmask and counter of trace recursion: */
1226 	unsigned long			trace_recursion;
1227 #endif /* CONFIG_TRACING */
1228 
1229 #ifdef CONFIG_KCOV
1230 	/* See kernel/kcov.c for more details. */
1231 
1232 	/* Coverage collection mode enabled for this task (0 if disabled): */
1233 	unsigned int			kcov_mode;
1234 
1235 	/* Size of the kcov_area: */
1236 	unsigned int			kcov_size;
1237 
1238 	/* Buffer for coverage collection: */
1239 	void				*kcov_area;
1240 
1241 	/* KCOV descriptor wired with this task or NULL: */
1242 	struct kcov			*kcov;
1243 
1244 	/* KCOV common handle for remote coverage collection: */
1245 	u64				kcov_handle;
1246 
1247 	/* KCOV sequence number: */
1248 	int				kcov_sequence;
1249 
1250 	/* Collect coverage from softirq context: */
1251 	unsigned int			kcov_softirq;
1252 #endif
1253 
1254 #ifdef CONFIG_MEMCG
1255 	struct mem_cgroup		*memcg_in_oom;
1256 	gfp_t				memcg_oom_gfp_mask;
1257 	int				memcg_oom_order;
1258 
1259 	/* Number of pages to reclaim on returning to userland: */
1260 	unsigned int			memcg_nr_pages_over_high;
1261 
1262 	/* Used by memcontrol for targeted memcg charge: */
1263 	struct mem_cgroup		*active_memcg;
1264 #endif
1265 
1266 #ifdef CONFIG_BLK_CGROUP
1267 	struct request_queue		*throttle_queue;
1268 #endif
1269 
1270 #ifdef CONFIG_UPROBES
1271 	struct uprobe_task		*utask;
1272 #endif
1273 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1274 	unsigned int			sequential_io;
1275 	unsigned int			sequential_io_avg;
1276 #endif
1277 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1278 	unsigned long			task_state_change;
1279 #endif
1280 	int				pagefault_disabled;
1281 #ifdef CONFIG_MMU
1282 	struct task_struct		*oom_reaper_list;
1283 #endif
1284 #ifdef CONFIG_VMAP_STACK
1285 	struct vm_struct		*stack_vm_area;
1286 #endif
1287 #ifdef CONFIG_THREAD_INFO_IN_TASK
1288 	/* A live task holds one reference: */
1289 	refcount_t			stack_refcount;
1290 #endif
1291 #ifdef CONFIG_LIVEPATCH
1292 	int patch_state;
1293 #endif
1294 #ifdef CONFIG_SECURITY
1295 	/* Used by LSM modules for access restriction: */
1296 	void				*security;
1297 #endif
1298 
1299 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1300 	unsigned long			lowest_stack;
1301 	unsigned long			prev_lowest_stack;
1302 #endif
1303 
1304 #ifdef CONFIG_X86_MCE
1305 	u64				mce_addr;
1306 	__u64				mce_ripv : 1,
1307 					mce_whole_page : 1,
1308 					__mce_reserved : 62;
1309 	struct callback_head		mce_kill_me;
1310 #endif
1311 
1312 	/*
1313 	 * New fields for task_struct should be added above here, so that
1314 	 * they are included in the randomized portion of task_struct.
1315 	 */
1316 	randomized_struct_fields_end
1317 
1318 	/* CPU-specific state of this task: */
1319 	struct thread_struct		thread;
1320 
1321 	/*
1322 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1323 	 * structure.  It *MUST* be at the end of 'task_struct'.
1324 	 *
1325 	 * Do not put anything below here!
1326 	 */
1327 };
1328 
1329 static inline struct pid *task_pid(struct task_struct *task)
1330 {
1331 	return task->thread_pid;
1332 }
1333 
1334 /*
1335  * the helpers to get the task's different pids as they are seen
1336  * from various namespaces
1337  *
1338  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1339  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1340  *                     current.
1341  * task_xid_nr_ns()  : id seen from the ns specified;
1342  *
1343  * see also pid_nr() etc in include/linux/pid.h
1344  */
1345 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1346 
1347 static inline pid_t task_pid_nr(struct task_struct *tsk)
1348 {
1349 	return tsk->pid;
1350 }
1351 
1352 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1353 {
1354 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1355 }
1356 
1357 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1358 {
1359 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1360 }
1361 
1362 
1363 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1364 {
1365 	return tsk->tgid;
1366 }
1367 
1368 /**
1369  * pid_alive - check that a task structure is not stale
1370  * @p: Task structure to be checked.
1371  *
1372  * Test if a process is not yet dead (at most zombie state)
1373  * If pid_alive fails, then pointers within the task structure
1374  * can be stale and must not be dereferenced.
1375  *
1376  * Return: 1 if the process is alive. 0 otherwise.
1377  */
1378 static inline int pid_alive(const struct task_struct *p)
1379 {
1380 	return p->thread_pid != NULL;
1381 }
1382 
1383 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1384 {
1385 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1386 }
1387 
1388 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1389 {
1390 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1391 }
1392 
1393 
1394 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1395 {
1396 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1397 }
1398 
1399 static inline pid_t task_session_vnr(struct task_struct *tsk)
1400 {
1401 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1402 }
1403 
1404 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1405 {
1406 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1407 }
1408 
1409 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1410 {
1411 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1412 }
1413 
1414 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1415 {
1416 	pid_t pid = 0;
1417 
1418 	rcu_read_lock();
1419 	if (pid_alive(tsk))
1420 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1421 	rcu_read_unlock();
1422 
1423 	return pid;
1424 }
1425 
1426 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1427 {
1428 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1429 }
1430 
1431 /* Obsolete, do not use: */
1432 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1433 {
1434 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1435 }
1436 
1437 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1438 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1439 
1440 static inline unsigned int task_state_index(struct task_struct *tsk)
1441 {
1442 	unsigned int tsk_state = READ_ONCE(tsk->state);
1443 	unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1444 
1445 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1446 
1447 	if (tsk_state == TASK_IDLE)
1448 		state = TASK_REPORT_IDLE;
1449 
1450 	return fls(state);
1451 }
1452 
1453 static inline char task_index_to_char(unsigned int state)
1454 {
1455 	static const char state_char[] = "RSDTtXZPI";
1456 
1457 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1458 
1459 	return state_char[state];
1460 }
1461 
1462 static inline char task_state_to_char(struct task_struct *tsk)
1463 {
1464 	return task_index_to_char(task_state_index(tsk));
1465 }
1466 
1467 /**
1468  * is_global_init - check if a task structure is init. Since init
1469  * is free to have sub-threads we need to check tgid.
1470  * @tsk: Task structure to be checked.
1471  *
1472  * Check if a task structure is the first user space task the kernel created.
1473  *
1474  * Return: 1 if the task structure is init. 0 otherwise.
1475  */
1476 static inline int is_global_init(struct task_struct *tsk)
1477 {
1478 	return task_tgid_nr(tsk) == 1;
1479 }
1480 
1481 extern struct pid *cad_pid;
1482 
1483 /*
1484  * Per process flags
1485  */
1486 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1487 #define PF_EXITING		0x00000004	/* Getting shut down */
1488 #define PF_VCPU			0x00000010	/* I'm a virtual CPU */
1489 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1490 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1491 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1492 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1493 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1494 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1495 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1496 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1497 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1498 #define PF_USED_ASYNC		0x00004000	/* Used async_schedule*(), used by module init */
1499 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1500 #define PF_FROZEN		0x00010000	/* Frozen for system suspend */
1501 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1502 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1503 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1504 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1505 						 * I am cleaning dirty pages from some other bdi. */
1506 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1507 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1508 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
1509 #define PF_UMH			0x02000000	/* I'm an Usermodehelper process */
1510 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1511 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1512 #define PF_MEMALLOC_NOCMA	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
1513 #define PF_IO_WORKER		0x20000000	/* Task is an IO worker */
1514 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
1515 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1516 
1517 /*
1518  * Only the _current_ task can read/write to tsk->flags, but other
1519  * tasks can access tsk->flags in readonly mode for example
1520  * with tsk_used_math (like during threaded core dumping).
1521  * There is however an exception to this rule during ptrace
1522  * or during fork: the ptracer task is allowed to write to the
1523  * child->flags of its traced child (same goes for fork, the parent
1524  * can write to the child->flags), because we're guaranteed the
1525  * child is not running and in turn not changing child->flags
1526  * at the same time the parent does it.
1527  */
1528 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1529 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1530 #define clear_used_math()			clear_stopped_child_used_math(current)
1531 #define set_used_math()				set_stopped_child_used_math(current)
1532 
1533 #define conditional_stopped_child_used_math(condition, child) \
1534 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1535 
1536 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1537 
1538 #define copy_to_stopped_child_used_math(child) \
1539 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1540 
1541 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1542 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1543 #define used_math()				tsk_used_math(current)
1544 
1545 static inline bool is_percpu_thread(void)
1546 {
1547 #ifdef CONFIG_SMP
1548 	return (current->flags & PF_NO_SETAFFINITY) &&
1549 		(current->nr_cpus_allowed  == 1);
1550 #else
1551 	return true;
1552 #endif
1553 }
1554 
1555 /* Per-process atomic flags. */
1556 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1557 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1558 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1559 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1560 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1561 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1562 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1563 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1564 
1565 #define TASK_PFA_TEST(name, func)					\
1566 	static inline bool task_##func(struct task_struct *p)		\
1567 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1568 
1569 #define TASK_PFA_SET(name, func)					\
1570 	static inline void task_set_##func(struct task_struct *p)	\
1571 	{ set_bit(PFA_##name, &p->atomic_flags); }
1572 
1573 #define TASK_PFA_CLEAR(name, func)					\
1574 	static inline void task_clear_##func(struct task_struct *p)	\
1575 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1576 
1577 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1578 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1579 
1580 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1581 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1582 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1583 
1584 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1585 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1586 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1587 
1588 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1589 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1590 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1591 
1592 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1593 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1594 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1595 
1596 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1597 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1598 
1599 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1600 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1601 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1602 
1603 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1604 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1605 
1606 static inline void
1607 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1608 {
1609 	current->flags &= ~flags;
1610 	current->flags |= orig_flags & flags;
1611 }
1612 
1613 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1614 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1615 #ifdef CONFIG_SMP
1616 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1617 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1618 #else
1619 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1620 {
1621 }
1622 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1623 {
1624 	if (!cpumask_test_cpu(0, new_mask))
1625 		return -EINVAL;
1626 	return 0;
1627 }
1628 #endif
1629 
1630 extern int yield_to(struct task_struct *p, bool preempt);
1631 extern void set_user_nice(struct task_struct *p, long nice);
1632 extern int task_prio(const struct task_struct *p);
1633 
1634 /**
1635  * task_nice - return the nice value of a given task.
1636  * @p: the task in question.
1637  *
1638  * Return: The nice value [ -20 ... 0 ... 19 ].
1639  */
1640 static inline int task_nice(const struct task_struct *p)
1641 {
1642 	return PRIO_TO_NICE((p)->static_prio);
1643 }
1644 
1645 extern int can_nice(const struct task_struct *p, const int nice);
1646 extern int task_curr(const struct task_struct *p);
1647 extern int idle_cpu(int cpu);
1648 extern int available_idle_cpu(int cpu);
1649 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1650 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1651 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1652 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1653 extern struct task_struct *idle_task(int cpu);
1654 
1655 /**
1656  * is_idle_task - is the specified task an idle task?
1657  * @p: the task in question.
1658  *
1659  * Return: 1 if @p is an idle task. 0 otherwise.
1660  */
1661 static inline bool is_idle_task(const struct task_struct *p)
1662 {
1663 	return !!(p->flags & PF_IDLE);
1664 }
1665 
1666 extern struct task_struct *curr_task(int cpu);
1667 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1668 
1669 void yield(void);
1670 
1671 union thread_union {
1672 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1673 	struct task_struct task;
1674 #endif
1675 #ifndef CONFIG_THREAD_INFO_IN_TASK
1676 	struct thread_info thread_info;
1677 #endif
1678 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1679 };
1680 
1681 #ifndef CONFIG_THREAD_INFO_IN_TASK
1682 extern struct thread_info init_thread_info;
1683 #endif
1684 
1685 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1686 
1687 #ifdef CONFIG_THREAD_INFO_IN_TASK
1688 static inline struct thread_info *task_thread_info(struct task_struct *task)
1689 {
1690 	return &task->thread_info;
1691 }
1692 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1693 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1694 #endif
1695 
1696 /*
1697  * find a task by one of its numerical ids
1698  *
1699  * find_task_by_pid_ns():
1700  *      finds a task by its pid in the specified namespace
1701  * find_task_by_vpid():
1702  *      finds a task by its virtual pid
1703  *
1704  * see also find_vpid() etc in include/linux/pid.h
1705  */
1706 
1707 extern struct task_struct *find_task_by_vpid(pid_t nr);
1708 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1709 
1710 /*
1711  * find a task by its virtual pid and get the task struct
1712  */
1713 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1714 
1715 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1716 extern int wake_up_process(struct task_struct *tsk);
1717 extern void wake_up_new_task(struct task_struct *tsk);
1718 
1719 #ifdef CONFIG_SMP
1720 extern void kick_process(struct task_struct *tsk);
1721 #else
1722 static inline void kick_process(struct task_struct *tsk) { }
1723 #endif
1724 
1725 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1726 
1727 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1728 {
1729 	__set_task_comm(tsk, from, false);
1730 }
1731 
1732 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1733 #define get_task_comm(buf, tsk) ({			\
1734 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
1735 	__get_task_comm(buf, sizeof(buf), tsk);		\
1736 })
1737 
1738 #ifdef CONFIG_SMP
1739 static __always_inline void scheduler_ipi(void)
1740 {
1741 	/*
1742 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1743 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
1744 	 * this IPI.
1745 	 */
1746 	preempt_fold_need_resched();
1747 }
1748 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1749 #else
1750 static inline void scheduler_ipi(void) { }
1751 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1752 {
1753 	return 1;
1754 }
1755 #endif
1756 
1757 /*
1758  * Set thread flags in other task's structures.
1759  * See asm/thread_info.h for TIF_xxxx flags available:
1760  */
1761 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1762 {
1763 	set_ti_thread_flag(task_thread_info(tsk), flag);
1764 }
1765 
1766 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1767 {
1768 	clear_ti_thread_flag(task_thread_info(tsk), flag);
1769 }
1770 
1771 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1772 					  bool value)
1773 {
1774 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
1775 }
1776 
1777 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1778 {
1779 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1780 }
1781 
1782 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1783 {
1784 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1785 }
1786 
1787 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1788 {
1789 	return test_ti_thread_flag(task_thread_info(tsk), flag);
1790 }
1791 
1792 static inline void set_tsk_need_resched(struct task_struct *tsk)
1793 {
1794 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1795 }
1796 
1797 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1798 {
1799 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1800 }
1801 
1802 static inline int test_tsk_need_resched(struct task_struct *tsk)
1803 {
1804 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1805 }
1806 
1807 /*
1808  * cond_resched() and cond_resched_lock(): latency reduction via
1809  * explicit rescheduling in places that are safe. The return
1810  * value indicates whether a reschedule was done in fact.
1811  * cond_resched_lock() will drop the spinlock before scheduling,
1812  */
1813 #ifndef CONFIG_PREEMPTION
1814 extern int _cond_resched(void);
1815 #else
1816 static inline int _cond_resched(void) { return 0; }
1817 #endif
1818 
1819 #define cond_resched() ({			\
1820 	___might_sleep(__FILE__, __LINE__, 0);	\
1821 	_cond_resched();			\
1822 })
1823 
1824 extern int __cond_resched_lock(spinlock_t *lock);
1825 
1826 #define cond_resched_lock(lock) ({				\
1827 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1828 	__cond_resched_lock(lock);				\
1829 })
1830 
1831 static inline void cond_resched_rcu(void)
1832 {
1833 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1834 	rcu_read_unlock();
1835 	cond_resched();
1836 	rcu_read_lock();
1837 #endif
1838 }
1839 
1840 /*
1841  * Does a critical section need to be broken due to another
1842  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
1843  * but a general need for low latency)
1844  */
1845 static inline int spin_needbreak(spinlock_t *lock)
1846 {
1847 #ifdef CONFIG_PREEMPTION
1848 	return spin_is_contended(lock);
1849 #else
1850 	return 0;
1851 #endif
1852 }
1853 
1854 static __always_inline bool need_resched(void)
1855 {
1856 	return unlikely(tif_need_resched());
1857 }
1858 
1859 /*
1860  * Wrappers for p->thread_info->cpu access. No-op on UP.
1861  */
1862 #ifdef CONFIG_SMP
1863 
1864 static inline unsigned int task_cpu(const struct task_struct *p)
1865 {
1866 #ifdef CONFIG_THREAD_INFO_IN_TASK
1867 	return READ_ONCE(p->cpu);
1868 #else
1869 	return READ_ONCE(task_thread_info(p)->cpu);
1870 #endif
1871 }
1872 
1873 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1874 
1875 #else
1876 
1877 static inline unsigned int task_cpu(const struct task_struct *p)
1878 {
1879 	return 0;
1880 }
1881 
1882 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1883 {
1884 }
1885 
1886 #endif /* CONFIG_SMP */
1887 
1888 /*
1889  * In order to reduce various lock holder preemption latencies provide an
1890  * interface to see if a vCPU is currently running or not.
1891  *
1892  * This allows us to terminate optimistic spin loops and block, analogous to
1893  * the native optimistic spin heuristic of testing if the lock owner task is
1894  * running or not.
1895  */
1896 #ifndef vcpu_is_preempted
1897 static inline bool vcpu_is_preempted(int cpu)
1898 {
1899 	return false;
1900 }
1901 #endif
1902 
1903 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1904 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1905 
1906 #ifndef TASK_SIZE_OF
1907 #define TASK_SIZE_OF(tsk)	TASK_SIZE
1908 #endif
1909 
1910 #ifdef CONFIG_RSEQ
1911 
1912 /*
1913  * Map the event mask on the user-space ABI enum rseq_cs_flags
1914  * for direct mask checks.
1915  */
1916 enum rseq_event_mask_bits {
1917 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
1918 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
1919 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
1920 };
1921 
1922 enum rseq_event_mask {
1923 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
1924 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
1925 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
1926 };
1927 
1928 static inline void rseq_set_notify_resume(struct task_struct *t)
1929 {
1930 	if (t->rseq)
1931 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
1932 }
1933 
1934 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
1935 
1936 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1937 					     struct pt_regs *regs)
1938 {
1939 	if (current->rseq)
1940 		__rseq_handle_notify_resume(ksig, regs);
1941 }
1942 
1943 static inline void rseq_signal_deliver(struct ksignal *ksig,
1944 				       struct pt_regs *regs)
1945 {
1946 	preempt_disable();
1947 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
1948 	preempt_enable();
1949 	rseq_handle_notify_resume(ksig, regs);
1950 }
1951 
1952 /* rseq_preempt() requires preemption to be disabled. */
1953 static inline void rseq_preempt(struct task_struct *t)
1954 {
1955 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
1956 	rseq_set_notify_resume(t);
1957 }
1958 
1959 /* rseq_migrate() requires preemption to be disabled. */
1960 static inline void rseq_migrate(struct task_struct *t)
1961 {
1962 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
1963 	rseq_set_notify_resume(t);
1964 }
1965 
1966 /*
1967  * If parent process has a registered restartable sequences area, the
1968  * child inherits. Unregister rseq for a clone with CLONE_VM set.
1969  */
1970 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1971 {
1972 	if (clone_flags & CLONE_VM) {
1973 		t->rseq = NULL;
1974 		t->rseq_sig = 0;
1975 		t->rseq_event_mask = 0;
1976 	} else {
1977 		t->rseq = current->rseq;
1978 		t->rseq_sig = current->rseq_sig;
1979 		t->rseq_event_mask = current->rseq_event_mask;
1980 	}
1981 }
1982 
1983 static inline void rseq_execve(struct task_struct *t)
1984 {
1985 	t->rseq = NULL;
1986 	t->rseq_sig = 0;
1987 	t->rseq_event_mask = 0;
1988 }
1989 
1990 #else
1991 
1992 static inline void rseq_set_notify_resume(struct task_struct *t)
1993 {
1994 }
1995 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1996 					     struct pt_regs *regs)
1997 {
1998 }
1999 static inline void rseq_signal_deliver(struct ksignal *ksig,
2000 				       struct pt_regs *regs)
2001 {
2002 }
2003 static inline void rseq_preempt(struct task_struct *t)
2004 {
2005 }
2006 static inline void rseq_migrate(struct task_struct *t)
2007 {
2008 }
2009 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2010 {
2011 }
2012 static inline void rseq_execve(struct task_struct *t)
2013 {
2014 }
2015 
2016 #endif
2017 
2018 void __exit_umh(struct task_struct *tsk);
2019 
2020 static inline void exit_umh(struct task_struct *tsk)
2021 {
2022 	if (unlikely(tsk->flags & PF_UMH))
2023 		__exit_umh(tsk);
2024 }
2025 
2026 #ifdef CONFIG_DEBUG_RSEQ
2027 
2028 void rseq_syscall(struct pt_regs *regs);
2029 
2030 #else
2031 
2032 static inline void rseq_syscall(struct pt_regs *regs)
2033 {
2034 }
2035 
2036 #endif
2037 
2038 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2039 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2040 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2041 
2042 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2043 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2044 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2045 
2046 int sched_trace_rq_cpu(struct rq *rq);
2047 
2048 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2049 
2050 #endif
2051