xref: /linux/include/linux/sched.h (revision 920c293af8d01942caa10300ad97eabf778e8598)
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/mutex.h>
18 #include <linux/plist.h>
19 #include <linux/hrtimer.h>
20 #include <linux/irqflags.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/syscall_user_dispatch.h>
31 #include <linux/mm_types_task.h>
32 #include <linux/task_io_accounting.h>
33 #include <linux/posix-timers.h>
34 #include <linux/rseq.h>
35 #include <linux/seqlock.h>
36 #include <linux/kcsan.h>
37 #include <asm/kmap_size.h>
38 
39 /* task_struct member predeclarations (sorted alphabetically): */
40 struct audit_context;
41 struct backing_dev_info;
42 struct bio_list;
43 struct blk_plug;
44 struct bpf_local_storage;
45 struct bpf_run_ctx;
46 struct capture_control;
47 struct cfs_rq;
48 struct fs_struct;
49 struct futex_pi_state;
50 struct io_context;
51 struct io_uring_task;
52 struct mempolicy;
53 struct nameidata;
54 struct nsproxy;
55 struct perf_event_context;
56 struct pid_namespace;
57 struct pipe_inode_info;
58 struct rcu_node;
59 struct reclaim_state;
60 struct robust_list_head;
61 struct root_domain;
62 struct rq;
63 struct sched_attr;
64 struct sched_param;
65 struct seq_file;
66 struct sighand_struct;
67 struct signal_struct;
68 struct task_delay_info;
69 struct task_group;
70 
71 /*
72  * Task state bitmask. NOTE! These bits are also
73  * encoded in fs/proc/array.c: get_task_state().
74  *
75  * We have two separate sets of flags: task->state
76  * is about runnability, while task->exit_state are
77  * about the task exiting. Confusing, but this way
78  * modifying one set can't modify the other one by
79  * mistake.
80  */
81 
82 /* Used in tsk->state: */
83 #define TASK_RUNNING			0x0000
84 #define TASK_INTERRUPTIBLE		0x0001
85 #define TASK_UNINTERRUPTIBLE		0x0002
86 #define __TASK_STOPPED			0x0004
87 #define __TASK_TRACED			0x0008
88 /* Used in tsk->exit_state: */
89 #define EXIT_DEAD			0x0010
90 #define EXIT_ZOMBIE			0x0020
91 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
92 /* Used in tsk->state again: */
93 #define TASK_PARKED			0x0040
94 #define TASK_DEAD			0x0080
95 #define TASK_WAKEKILL			0x0100
96 #define TASK_WAKING			0x0200
97 #define TASK_NOLOAD			0x0400
98 #define TASK_NEW			0x0800
99 #define TASK_STATE_MAX			0x1000
100 
101 /* Convenience macros for the sake of set_current_state: */
102 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
103 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
104 #define TASK_TRACED			(TASK_WAKEKILL | __TASK_TRACED)
105 
106 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
107 
108 /* Convenience macros for the sake of wake_up(): */
109 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
110 
111 /* get_task_state(): */
112 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
113 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
114 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
115 					 TASK_PARKED)
116 
117 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
118 
119 #define task_is_traced(task)		((READ_ONCE(task->__state) & __TASK_TRACED) != 0)
120 
121 #define task_is_stopped(task)		((READ_ONCE(task->__state) & __TASK_STOPPED) != 0)
122 
123 #define task_is_stopped_or_traced(task)	((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0)
124 
125 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
126 
127 /*
128  * Special states are those that do not use the normal wait-loop pattern. See
129  * the comment with set_special_state().
130  */
131 #define is_special_task_state(state)				\
132 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
133 
134 #define __set_current_state(state_value)			\
135 	do {							\
136 		WARN_ON_ONCE(is_special_task_state(state_value));\
137 		current->task_state_change = _THIS_IP_;		\
138 		WRITE_ONCE(current->__state, (state_value));	\
139 	} while (0)
140 
141 #define set_current_state(state_value)				\
142 	do {							\
143 		WARN_ON_ONCE(is_special_task_state(state_value));\
144 		current->task_state_change = _THIS_IP_;		\
145 		smp_store_mb(current->__state, (state_value));	\
146 	} while (0)
147 
148 #define set_special_state(state_value)					\
149 	do {								\
150 		unsigned long flags; /* may shadow */			\
151 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
152 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
153 		current->task_state_change = _THIS_IP_;			\
154 		WRITE_ONCE(current->__state, (state_value));		\
155 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
156 	} while (0)
157 #else
158 /*
159  * set_current_state() includes a barrier so that the write of current->state
160  * is correctly serialised wrt the caller's subsequent test of whether to
161  * actually sleep:
162  *
163  *   for (;;) {
164  *	set_current_state(TASK_UNINTERRUPTIBLE);
165  *	if (CONDITION)
166  *	   break;
167  *
168  *	schedule();
169  *   }
170  *   __set_current_state(TASK_RUNNING);
171  *
172  * If the caller does not need such serialisation (because, for instance, the
173  * CONDITION test and condition change and wakeup are under the same lock) then
174  * use __set_current_state().
175  *
176  * The above is typically ordered against the wakeup, which does:
177  *
178  *   CONDITION = 1;
179  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
180  *
181  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
182  * accessing p->state.
183  *
184  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
185  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
186  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
187  *
188  * However, with slightly different timing the wakeup TASK_RUNNING store can
189  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
190  * a problem either because that will result in one extra go around the loop
191  * and our @cond test will save the day.
192  *
193  * Also see the comments of try_to_wake_up().
194  */
195 #define __set_current_state(state_value)				\
196 	WRITE_ONCE(current->__state, (state_value))
197 
198 #define set_current_state(state_value)					\
199 	smp_store_mb(current->__state, (state_value))
200 
201 /*
202  * set_special_state() should be used for those states when the blocking task
203  * can not use the regular condition based wait-loop. In that case we must
204  * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
205  * will not collide with our state change.
206  */
207 #define set_special_state(state_value)					\
208 	do {								\
209 		unsigned long flags; /* may shadow */			\
210 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
211 		WRITE_ONCE(current->__state, (state_value));		\
212 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
213 	} while (0)
214 
215 #endif
216 
217 #define get_current_state()	READ_ONCE(current->__state)
218 
219 /* Task command name length: */
220 #define TASK_COMM_LEN			16
221 
222 extern void scheduler_tick(void);
223 
224 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
225 
226 extern long schedule_timeout(long timeout);
227 extern long schedule_timeout_interruptible(long timeout);
228 extern long schedule_timeout_killable(long timeout);
229 extern long schedule_timeout_uninterruptible(long timeout);
230 extern long schedule_timeout_idle(long timeout);
231 asmlinkage void schedule(void);
232 extern void schedule_preempt_disabled(void);
233 asmlinkage void preempt_schedule_irq(void);
234 
235 extern int __must_check io_schedule_prepare(void);
236 extern void io_schedule_finish(int token);
237 extern long io_schedule_timeout(long timeout);
238 extern void io_schedule(void);
239 
240 /**
241  * struct prev_cputime - snapshot of system and user cputime
242  * @utime: time spent in user mode
243  * @stime: time spent in system mode
244  * @lock: protects the above two fields
245  *
246  * Stores previous user/system time values such that we can guarantee
247  * monotonicity.
248  */
249 struct prev_cputime {
250 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
251 	u64				utime;
252 	u64				stime;
253 	raw_spinlock_t			lock;
254 #endif
255 };
256 
257 enum vtime_state {
258 	/* Task is sleeping or running in a CPU with VTIME inactive: */
259 	VTIME_INACTIVE = 0,
260 	/* Task is idle */
261 	VTIME_IDLE,
262 	/* Task runs in kernelspace in a CPU with VTIME active: */
263 	VTIME_SYS,
264 	/* Task runs in userspace in a CPU with VTIME active: */
265 	VTIME_USER,
266 	/* Task runs as guests in a CPU with VTIME active: */
267 	VTIME_GUEST,
268 };
269 
270 struct vtime {
271 	seqcount_t		seqcount;
272 	unsigned long long	starttime;
273 	enum vtime_state	state;
274 	unsigned int		cpu;
275 	u64			utime;
276 	u64			stime;
277 	u64			gtime;
278 };
279 
280 /*
281  * Utilization clamp constraints.
282  * @UCLAMP_MIN:	Minimum utilization
283  * @UCLAMP_MAX:	Maximum utilization
284  * @UCLAMP_CNT:	Utilization clamp constraints count
285  */
286 enum uclamp_id {
287 	UCLAMP_MIN = 0,
288 	UCLAMP_MAX,
289 	UCLAMP_CNT
290 };
291 
292 #ifdef CONFIG_SMP
293 extern struct root_domain def_root_domain;
294 extern struct mutex sched_domains_mutex;
295 #endif
296 
297 struct sched_info {
298 #ifdef CONFIG_SCHED_INFO
299 	/* Cumulative counters: */
300 
301 	/* # of times we have run on this CPU: */
302 	unsigned long			pcount;
303 
304 	/* Time spent waiting on a runqueue: */
305 	unsigned long long		run_delay;
306 
307 	/* Timestamps: */
308 
309 	/* When did we last run on a CPU? */
310 	unsigned long long		last_arrival;
311 
312 	/* When were we last queued to run? */
313 	unsigned long long		last_queued;
314 
315 #endif /* CONFIG_SCHED_INFO */
316 };
317 
318 /*
319  * Integer metrics need fixed point arithmetic, e.g., sched/fair
320  * has a few: load, load_avg, util_avg, freq, and capacity.
321  *
322  * We define a basic fixed point arithmetic range, and then formalize
323  * all these metrics based on that basic range.
324  */
325 # define SCHED_FIXEDPOINT_SHIFT		10
326 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
327 
328 /* Increase resolution of cpu_capacity calculations */
329 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
330 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
331 
332 struct load_weight {
333 	unsigned long			weight;
334 	u32				inv_weight;
335 };
336 
337 /**
338  * struct util_est - Estimation utilization of FAIR tasks
339  * @enqueued: instantaneous estimated utilization of a task/cpu
340  * @ewma:     the Exponential Weighted Moving Average (EWMA)
341  *            utilization of a task
342  *
343  * Support data structure to track an Exponential Weighted Moving Average
344  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
345  * average each time a task completes an activation. Sample's weight is chosen
346  * so that the EWMA will be relatively insensitive to transient changes to the
347  * task's workload.
348  *
349  * The enqueued attribute has a slightly different meaning for tasks and cpus:
350  * - task:   the task's util_avg at last task dequeue time
351  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
352  * Thus, the util_est.enqueued of a task represents the contribution on the
353  * estimated utilization of the CPU where that task is currently enqueued.
354  *
355  * Only for tasks we track a moving average of the past instantaneous
356  * estimated utilization. This allows to absorb sporadic drops in utilization
357  * of an otherwise almost periodic task.
358  *
359  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
360  * updates. When a task is dequeued, its util_est should not be updated if its
361  * util_avg has not been updated in the meantime.
362  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
363  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
364  * for a task) it is safe to use MSB.
365  */
366 struct util_est {
367 	unsigned int			enqueued;
368 	unsigned int			ewma;
369 #define UTIL_EST_WEIGHT_SHIFT		2
370 #define UTIL_AVG_UNCHANGED		0x80000000
371 } __attribute__((__aligned__(sizeof(u64))));
372 
373 /*
374  * The load/runnable/util_avg accumulates an infinite geometric series
375  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
376  *
377  * [load_avg definition]
378  *
379  *   load_avg = runnable% * scale_load_down(load)
380  *
381  * [runnable_avg definition]
382  *
383  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
384  *
385  * [util_avg definition]
386  *
387  *   util_avg = running% * SCHED_CAPACITY_SCALE
388  *
389  * where runnable% is the time ratio that a sched_entity is runnable and
390  * running% the time ratio that a sched_entity is running.
391  *
392  * For cfs_rq, they are the aggregated values of all runnable and blocked
393  * sched_entities.
394  *
395  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
396  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
397  * for computing those signals (see update_rq_clock_pelt())
398  *
399  * N.B., the above ratios (runnable% and running%) themselves are in the
400  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
401  * to as large a range as necessary. This is for example reflected by
402  * util_avg's SCHED_CAPACITY_SCALE.
403  *
404  * [Overflow issue]
405  *
406  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
407  * with the highest load (=88761), always runnable on a single cfs_rq,
408  * and should not overflow as the number already hits PID_MAX_LIMIT.
409  *
410  * For all other cases (including 32-bit kernels), struct load_weight's
411  * weight will overflow first before we do, because:
412  *
413  *    Max(load_avg) <= Max(load.weight)
414  *
415  * Then it is the load_weight's responsibility to consider overflow
416  * issues.
417  */
418 struct sched_avg {
419 	u64				last_update_time;
420 	u64				load_sum;
421 	u64				runnable_sum;
422 	u32				util_sum;
423 	u32				period_contrib;
424 	unsigned long			load_avg;
425 	unsigned long			runnable_avg;
426 	unsigned long			util_avg;
427 	struct util_est			util_est;
428 } ____cacheline_aligned;
429 
430 struct sched_statistics {
431 #ifdef CONFIG_SCHEDSTATS
432 	u64				wait_start;
433 	u64				wait_max;
434 	u64				wait_count;
435 	u64				wait_sum;
436 	u64				iowait_count;
437 	u64				iowait_sum;
438 
439 	u64				sleep_start;
440 	u64				sleep_max;
441 	s64				sum_sleep_runtime;
442 
443 	u64				block_start;
444 	u64				block_max;
445 	u64				exec_max;
446 	u64				slice_max;
447 
448 	u64				nr_migrations_cold;
449 	u64				nr_failed_migrations_affine;
450 	u64				nr_failed_migrations_running;
451 	u64				nr_failed_migrations_hot;
452 	u64				nr_forced_migrations;
453 
454 	u64				nr_wakeups;
455 	u64				nr_wakeups_sync;
456 	u64				nr_wakeups_migrate;
457 	u64				nr_wakeups_local;
458 	u64				nr_wakeups_remote;
459 	u64				nr_wakeups_affine;
460 	u64				nr_wakeups_affine_attempts;
461 	u64				nr_wakeups_passive;
462 	u64				nr_wakeups_idle;
463 #endif
464 };
465 
466 struct sched_entity {
467 	/* For load-balancing: */
468 	struct load_weight		load;
469 	struct rb_node			run_node;
470 	struct list_head		group_node;
471 	unsigned int			on_rq;
472 
473 	u64				exec_start;
474 	u64				sum_exec_runtime;
475 	u64				vruntime;
476 	u64				prev_sum_exec_runtime;
477 
478 	u64				nr_migrations;
479 
480 	struct sched_statistics		statistics;
481 
482 #ifdef CONFIG_FAIR_GROUP_SCHED
483 	int				depth;
484 	struct sched_entity		*parent;
485 	/* rq on which this entity is (to be) queued: */
486 	struct cfs_rq			*cfs_rq;
487 	/* rq "owned" by this entity/group: */
488 	struct cfs_rq			*my_q;
489 	/* cached value of my_q->h_nr_running */
490 	unsigned long			runnable_weight;
491 #endif
492 
493 #ifdef CONFIG_SMP
494 	/*
495 	 * Per entity load average tracking.
496 	 *
497 	 * Put into separate cache line so it does not
498 	 * collide with read-mostly values above.
499 	 */
500 	struct sched_avg		avg;
501 #endif
502 };
503 
504 struct sched_rt_entity {
505 	struct list_head		run_list;
506 	unsigned long			timeout;
507 	unsigned long			watchdog_stamp;
508 	unsigned int			time_slice;
509 	unsigned short			on_rq;
510 	unsigned short			on_list;
511 
512 	struct sched_rt_entity		*back;
513 #ifdef CONFIG_RT_GROUP_SCHED
514 	struct sched_rt_entity		*parent;
515 	/* rq on which this entity is (to be) queued: */
516 	struct rt_rq			*rt_rq;
517 	/* rq "owned" by this entity/group: */
518 	struct rt_rq			*my_q;
519 #endif
520 } __randomize_layout;
521 
522 struct sched_dl_entity {
523 	struct rb_node			rb_node;
524 
525 	/*
526 	 * Original scheduling parameters. Copied here from sched_attr
527 	 * during sched_setattr(), they will remain the same until
528 	 * the next sched_setattr().
529 	 */
530 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
531 	u64				dl_deadline;	/* Relative deadline of each instance	*/
532 	u64				dl_period;	/* Separation of two instances (period) */
533 	u64				dl_bw;		/* dl_runtime / dl_period		*/
534 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
535 
536 	/*
537 	 * Actual scheduling parameters. Initialized with the values above,
538 	 * they are continuously updated during task execution. Note that
539 	 * the remaining runtime could be < 0 in case we are in overrun.
540 	 */
541 	s64				runtime;	/* Remaining runtime for this instance	*/
542 	u64				deadline;	/* Absolute deadline for this instance	*/
543 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
544 
545 	/*
546 	 * Some bool flags:
547 	 *
548 	 * @dl_throttled tells if we exhausted the runtime. If so, the
549 	 * task has to wait for a replenishment to be performed at the
550 	 * next firing of dl_timer.
551 	 *
552 	 * @dl_boosted tells if we are boosted due to DI. If so we are
553 	 * outside bandwidth enforcement mechanism (but only until we
554 	 * exit the critical section);
555 	 *
556 	 * @dl_yielded tells if task gave up the CPU before consuming
557 	 * all its available runtime during the last job.
558 	 *
559 	 * @dl_non_contending tells if the task is inactive while still
560 	 * contributing to the active utilization. In other words, it
561 	 * indicates if the inactive timer has been armed and its handler
562 	 * has not been executed yet. This flag is useful to avoid race
563 	 * conditions between the inactive timer handler and the wakeup
564 	 * code.
565 	 *
566 	 * @dl_overrun tells if the task asked to be informed about runtime
567 	 * overruns.
568 	 */
569 	unsigned int			dl_throttled      : 1;
570 	unsigned int			dl_yielded        : 1;
571 	unsigned int			dl_non_contending : 1;
572 	unsigned int			dl_overrun	  : 1;
573 
574 	/*
575 	 * Bandwidth enforcement timer. Each -deadline task has its
576 	 * own bandwidth to be enforced, thus we need one timer per task.
577 	 */
578 	struct hrtimer			dl_timer;
579 
580 	/*
581 	 * Inactive timer, responsible for decreasing the active utilization
582 	 * at the "0-lag time". When a -deadline task blocks, it contributes
583 	 * to GRUB's active utilization until the "0-lag time", hence a
584 	 * timer is needed to decrease the active utilization at the correct
585 	 * time.
586 	 */
587 	struct hrtimer inactive_timer;
588 
589 #ifdef CONFIG_RT_MUTEXES
590 	/*
591 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
592 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
593 	 * to (the original one/itself).
594 	 */
595 	struct sched_dl_entity *pi_se;
596 #endif
597 };
598 
599 #ifdef CONFIG_UCLAMP_TASK
600 /* Number of utilization clamp buckets (shorter alias) */
601 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
602 
603 /*
604  * Utilization clamp for a scheduling entity
605  * @value:		clamp value "assigned" to a se
606  * @bucket_id:		bucket index corresponding to the "assigned" value
607  * @active:		the se is currently refcounted in a rq's bucket
608  * @user_defined:	the requested clamp value comes from user-space
609  *
610  * The bucket_id is the index of the clamp bucket matching the clamp value
611  * which is pre-computed and stored to avoid expensive integer divisions from
612  * the fast path.
613  *
614  * The active bit is set whenever a task has got an "effective" value assigned,
615  * which can be different from the clamp value "requested" from user-space.
616  * This allows to know a task is refcounted in the rq's bucket corresponding
617  * to the "effective" bucket_id.
618  *
619  * The user_defined bit is set whenever a task has got a task-specific clamp
620  * value requested from userspace, i.e. the system defaults apply to this task
621  * just as a restriction. This allows to relax default clamps when a less
622  * restrictive task-specific value has been requested, thus allowing to
623  * implement a "nice" semantic. For example, a task running with a 20%
624  * default boost can still drop its own boosting to 0%.
625  */
626 struct uclamp_se {
627 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
628 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
629 	unsigned int active		: 1;
630 	unsigned int user_defined	: 1;
631 };
632 #endif /* CONFIG_UCLAMP_TASK */
633 
634 union rcu_special {
635 	struct {
636 		u8			blocked;
637 		u8			need_qs;
638 		u8			exp_hint; /* Hint for performance. */
639 		u8			need_mb; /* Readers need smp_mb(). */
640 	} b; /* Bits. */
641 	u32 s; /* Set of bits. */
642 };
643 
644 enum perf_event_task_context {
645 	perf_invalid_context = -1,
646 	perf_hw_context = 0,
647 	perf_sw_context,
648 	perf_nr_task_contexts,
649 };
650 
651 struct wake_q_node {
652 	struct wake_q_node *next;
653 };
654 
655 struct kmap_ctrl {
656 #ifdef CONFIG_KMAP_LOCAL
657 	int				idx;
658 	pte_t				pteval[KM_MAX_IDX];
659 #endif
660 };
661 
662 struct task_struct {
663 #ifdef CONFIG_THREAD_INFO_IN_TASK
664 	/*
665 	 * For reasons of header soup (see current_thread_info()), this
666 	 * must be the first element of task_struct.
667 	 */
668 	struct thread_info		thread_info;
669 #endif
670 	unsigned int			__state;
671 
672 	/*
673 	 * This begins the randomizable portion of task_struct. Only
674 	 * scheduling-critical items should be added above here.
675 	 */
676 	randomized_struct_fields_start
677 
678 	void				*stack;
679 	refcount_t			usage;
680 	/* Per task flags (PF_*), defined further below: */
681 	unsigned int			flags;
682 	unsigned int			ptrace;
683 
684 #ifdef CONFIG_SMP
685 	int				on_cpu;
686 	struct __call_single_node	wake_entry;
687 #ifdef CONFIG_THREAD_INFO_IN_TASK
688 	/* Current CPU: */
689 	unsigned int			cpu;
690 #endif
691 	unsigned int			wakee_flips;
692 	unsigned long			wakee_flip_decay_ts;
693 	struct task_struct		*last_wakee;
694 
695 	/*
696 	 * recent_used_cpu is initially set as the last CPU used by a task
697 	 * that wakes affine another task. Waker/wakee relationships can
698 	 * push tasks around a CPU where each wakeup moves to the next one.
699 	 * Tracking a recently used CPU allows a quick search for a recently
700 	 * used CPU that may be idle.
701 	 */
702 	int				recent_used_cpu;
703 	int				wake_cpu;
704 #endif
705 	int				on_rq;
706 
707 	int				prio;
708 	int				static_prio;
709 	int				normal_prio;
710 	unsigned int			rt_priority;
711 
712 	const struct sched_class	*sched_class;
713 	struct sched_entity		se;
714 	struct sched_rt_entity		rt;
715 	struct sched_dl_entity		dl;
716 
717 #ifdef CONFIG_SCHED_CORE
718 	struct rb_node			core_node;
719 	unsigned long			core_cookie;
720 	unsigned int			core_occupation;
721 #endif
722 
723 #ifdef CONFIG_CGROUP_SCHED
724 	struct task_group		*sched_task_group;
725 #endif
726 
727 #ifdef CONFIG_UCLAMP_TASK
728 	/*
729 	 * Clamp values requested for a scheduling entity.
730 	 * Must be updated with task_rq_lock() held.
731 	 */
732 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
733 	/*
734 	 * Effective clamp values used for a scheduling entity.
735 	 * Must be updated with task_rq_lock() held.
736 	 */
737 	struct uclamp_se		uclamp[UCLAMP_CNT];
738 #endif
739 
740 #ifdef CONFIG_PREEMPT_NOTIFIERS
741 	/* List of struct preempt_notifier: */
742 	struct hlist_head		preempt_notifiers;
743 #endif
744 
745 #ifdef CONFIG_BLK_DEV_IO_TRACE
746 	unsigned int			btrace_seq;
747 #endif
748 
749 	unsigned int			policy;
750 	int				nr_cpus_allowed;
751 	const cpumask_t			*cpus_ptr;
752 	cpumask_t			cpus_mask;
753 	void				*migration_pending;
754 #ifdef CONFIG_SMP
755 	unsigned short			migration_disabled;
756 #endif
757 	unsigned short			migration_flags;
758 
759 #ifdef CONFIG_PREEMPT_RCU
760 	int				rcu_read_lock_nesting;
761 	union rcu_special		rcu_read_unlock_special;
762 	struct list_head		rcu_node_entry;
763 	struct rcu_node			*rcu_blocked_node;
764 #endif /* #ifdef CONFIG_PREEMPT_RCU */
765 
766 #ifdef CONFIG_TASKS_RCU
767 	unsigned long			rcu_tasks_nvcsw;
768 	u8				rcu_tasks_holdout;
769 	u8				rcu_tasks_idx;
770 	int				rcu_tasks_idle_cpu;
771 	struct list_head		rcu_tasks_holdout_list;
772 #endif /* #ifdef CONFIG_TASKS_RCU */
773 
774 #ifdef CONFIG_TASKS_TRACE_RCU
775 	int				trc_reader_nesting;
776 	int				trc_ipi_to_cpu;
777 	union rcu_special		trc_reader_special;
778 	bool				trc_reader_checked;
779 	struct list_head		trc_holdout_list;
780 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
781 
782 	struct sched_info		sched_info;
783 
784 	struct list_head		tasks;
785 #ifdef CONFIG_SMP
786 	struct plist_node		pushable_tasks;
787 	struct rb_node			pushable_dl_tasks;
788 #endif
789 
790 	struct mm_struct		*mm;
791 	struct mm_struct		*active_mm;
792 
793 	/* Per-thread vma caching: */
794 	struct vmacache			vmacache;
795 
796 #ifdef SPLIT_RSS_COUNTING
797 	struct task_rss_stat		rss_stat;
798 #endif
799 	int				exit_state;
800 	int				exit_code;
801 	int				exit_signal;
802 	/* The signal sent when the parent dies: */
803 	int				pdeath_signal;
804 	/* JOBCTL_*, siglock protected: */
805 	unsigned long			jobctl;
806 
807 	/* Used for emulating ABI behavior of previous Linux versions: */
808 	unsigned int			personality;
809 
810 	/* Scheduler bits, serialized by scheduler locks: */
811 	unsigned			sched_reset_on_fork:1;
812 	unsigned			sched_contributes_to_load:1;
813 	unsigned			sched_migrated:1;
814 #ifdef CONFIG_PSI
815 	unsigned			sched_psi_wake_requeue:1;
816 #endif
817 
818 	/* Force alignment to the next boundary: */
819 	unsigned			:0;
820 
821 	/* Unserialized, strictly 'current' */
822 
823 	/*
824 	 * This field must not be in the scheduler word above due to wakelist
825 	 * queueing no longer being serialized by p->on_cpu. However:
826 	 *
827 	 * p->XXX = X;			ttwu()
828 	 * schedule()			  if (p->on_rq && ..) // false
829 	 *   smp_mb__after_spinlock();	  if (smp_load_acquire(&p->on_cpu) && //true
830 	 *   deactivate_task()		      ttwu_queue_wakelist())
831 	 *     p->on_rq = 0;			p->sched_remote_wakeup = Y;
832 	 *
833 	 * guarantees all stores of 'current' are visible before
834 	 * ->sched_remote_wakeup gets used, so it can be in this word.
835 	 */
836 	unsigned			sched_remote_wakeup:1;
837 
838 	/* Bit to tell LSMs we're in execve(): */
839 	unsigned			in_execve:1;
840 	unsigned			in_iowait:1;
841 #ifndef TIF_RESTORE_SIGMASK
842 	unsigned			restore_sigmask:1;
843 #endif
844 #ifdef CONFIG_MEMCG
845 	unsigned			in_user_fault:1;
846 #endif
847 #ifdef CONFIG_COMPAT_BRK
848 	unsigned			brk_randomized:1;
849 #endif
850 #ifdef CONFIG_CGROUPS
851 	/* disallow userland-initiated cgroup migration */
852 	unsigned			no_cgroup_migration:1;
853 	/* task is frozen/stopped (used by the cgroup freezer) */
854 	unsigned			frozen:1;
855 #endif
856 #ifdef CONFIG_BLK_CGROUP
857 	unsigned			use_memdelay:1;
858 #endif
859 #ifdef CONFIG_PSI
860 	/* Stalled due to lack of memory */
861 	unsigned			in_memstall:1;
862 #endif
863 #ifdef CONFIG_PAGE_OWNER
864 	/* Used by page_owner=on to detect recursion in page tracking. */
865 	unsigned			in_page_owner:1;
866 #endif
867 
868 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
869 
870 	struct restart_block		restart_block;
871 
872 	pid_t				pid;
873 	pid_t				tgid;
874 
875 #ifdef CONFIG_STACKPROTECTOR
876 	/* Canary value for the -fstack-protector GCC feature: */
877 	unsigned long			stack_canary;
878 #endif
879 	/*
880 	 * Pointers to the (original) parent process, youngest child, younger sibling,
881 	 * older sibling, respectively.  (p->father can be replaced with
882 	 * p->real_parent->pid)
883 	 */
884 
885 	/* Real parent process: */
886 	struct task_struct __rcu	*real_parent;
887 
888 	/* Recipient of SIGCHLD, wait4() reports: */
889 	struct task_struct __rcu	*parent;
890 
891 	/*
892 	 * Children/sibling form the list of natural children:
893 	 */
894 	struct list_head		children;
895 	struct list_head		sibling;
896 	struct task_struct		*group_leader;
897 
898 	/*
899 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
900 	 *
901 	 * This includes both natural children and PTRACE_ATTACH targets.
902 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
903 	 */
904 	struct list_head		ptraced;
905 	struct list_head		ptrace_entry;
906 
907 	/* PID/PID hash table linkage. */
908 	struct pid			*thread_pid;
909 	struct hlist_node		pid_links[PIDTYPE_MAX];
910 	struct list_head		thread_group;
911 	struct list_head		thread_node;
912 
913 	struct completion		*vfork_done;
914 
915 	/* CLONE_CHILD_SETTID: */
916 	int __user			*set_child_tid;
917 
918 	/* CLONE_CHILD_CLEARTID: */
919 	int __user			*clear_child_tid;
920 
921 	/* PF_IO_WORKER */
922 	void				*pf_io_worker;
923 
924 	u64				utime;
925 	u64				stime;
926 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
927 	u64				utimescaled;
928 	u64				stimescaled;
929 #endif
930 	u64				gtime;
931 	struct prev_cputime		prev_cputime;
932 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
933 	struct vtime			vtime;
934 #endif
935 
936 #ifdef CONFIG_NO_HZ_FULL
937 	atomic_t			tick_dep_mask;
938 #endif
939 	/* Context switch counts: */
940 	unsigned long			nvcsw;
941 	unsigned long			nivcsw;
942 
943 	/* Monotonic time in nsecs: */
944 	u64				start_time;
945 
946 	/* Boot based time in nsecs: */
947 	u64				start_boottime;
948 
949 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
950 	unsigned long			min_flt;
951 	unsigned long			maj_flt;
952 
953 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
954 	struct posix_cputimers		posix_cputimers;
955 
956 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
957 	struct posix_cputimers_work	posix_cputimers_work;
958 #endif
959 
960 	/* Process credentials: */
961 
962 	/* Tracer's credentials at attach: */
963 	const struct cred __rcu		*ptracer_cred;
964 
965 	/* Objective and real subjective task credentials (COW): */
966 	const struct cred __rcu		*real_cred;
967 
968 	/* Effective (overridable) subjective task credentials (COW): */
969 	const struct cred __rcu		*cred;
970 
971 #ifdef CONFIG_KEYS
972 	/* Cached requested key. */
973 	struct key			*cached_requested_key;
974 #endif
975 
976 	/*
977 	 * executable name, excluding path.
978 	 *
979 	 * - normally initialized setup_new_exec()
980 	 * - access it with [gs]et_task_comm()
981 	 * - lock it with task_lock()
982 	 */
983 	char				comm[TASK_COMM_LEN];
984 
985 	struct nameidata		*nameidata;
986 
987 #ifdef CONFIG_SYSVIPC
988 	struct sysv_sem			sysvsem;
989 	struct sysv_shm			sysvshm;
990 #endif
991 #ifdef CONFIG_DETECT_HUNG_TASK
992 	unsigned long			last_switch_count;
993 	unsigned long			last_switch_time;
994 #endif
995 	/* Filesystem information: */
996 	struct fs_struct		*fs;
997 
998 	/* Open file information: */
999 	struct files_struct		*files;
1000 
1001 #ifdef CONFIG_IO_URING
1002 	struct io_uring_task		*io_uring;
1003 #endif
1004 
1005 	/* Namespaces: */
1006 	struct nsproxy			*nsproxy;
1007 
1008 	/* Signal handlers: */
1009 	struct signal_struct		*signal;
1010 	struct sighand_struct __rcu		*sighand;
1011 	sigset_t			blocked;
1012 	sigset_t			real_blocked;
1013 	/* Restored if set_restore_sigmask() was used: */
1014 	sigset_t			saved_sigmask;
1015 	struct sigpending		pending;
1016 	unsigned long			sas_ss_sp;
1017 	size_t				sas_ss_size;
1018 	unsigned int			sas_ss_flags;
1019 
1020 	struct callback_head		*task_works;
1021 
1022 #ifdef CONFIG_AUDIT
1023 #ifdef CONFIG_AUDITSYSCALL
1024 	struct audit_context		*audit_context;
1025 #endif
1026 	kuid_t				loginuid;
1027 	unsigned int			sessionid;
1028 #endif
1029 	struct seccomp			seccomp;
1030 	struct syscall_user_dispatch	syscall_dispatch;
1031 
1032 	/* Thread group tracking: */
1033 	u64				parent_exec_id;
1034 	u64				self_exec_id;
1035 
1036 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1037 	spinlock_t			alloc_lock;
1038 
1039 	/* Protection of the PI data structures: */
1040 	raw_spinlock_t			pi_lock;
1041 
1042 	struct wake_q_node		wake_q;
1043 
1044 #ifdef CONFIG_RT_MUTEXES
1045 	/* PI waiters blocked on a rt_mutex held by this task: */
1046 	struct rb_root_cached		pi_waiters;
1047 	/* Updated under owner's pi_lock and rq lock */
1048 	struct task_struct		*pi_top_task;
1049 	/* Deadlock detection and priority inheritance handling: */
1050 	struct rt_mutex_waiter		*pi_blocked_on;
1051 #endif
1052 
1053 #ifdef CONFIG_DEBUG_MUTEXES
1054 	/* Mutex deadlock detection: */
1055 	struct mutex_waiter		*blocked_on;
1056 #endif
1057 
1058 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1059 	int				non_block_count;
1060 #endif
1061 
1062 #ifdef CONFIG_TRACE_IRQFLAGS
1063 	struct irqtrace_events		irqtrace;
1064 	unsigned int			hardirq_threaded;
1065 	u64				hardirq_chain_key;
1066 	int				softirqs_enabled;
1067 	int				softirq_context;
1068 	int				irq_config;
1069 #endif
1070 #ifdef CONFIG_PREEMPT_RT
1071 	int				softirq_disable_cnt;
1072 #endif
1073 
1074 #ifdef CONFIG_LOCKDEP
1075 # define MAX_LOCK_DEPTH			48UL
1076 	u64				curr_chain_key;
1077 	int				lockdep_depth;
1078 	unsigned int			lockdep_recursion;
1079 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1080 #endif
1081 
1082 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1083 	unsigned int			in_ubsan;
1084 #endif
1085 
1086 	/* Journalling filesystem info: */
1087 	void				*journal_info;
1088 
1089 	/* Stacked block device info: */
1090 	struct bio_list			*bio_list;
1091 
1092 #ifdef CONFIG_BLOCK
1093 	/* Stack plugging: */
1094 	struct blk_plug			*plug;
1095 #endif
1096 
1097 	/* VM state: */
1098 	struct reclaim_state		*reclaim_state;
1099 
1100 	struct backing_dev_info		*backing_dev_info;
1101 
1102 	struct io_context		*io_context;
1103 
1104 #ifdef CONFIG_COMPACTION
1105 	struct capture_control		*capture_control;
1106 #endif
1107 	/* Ptrace state: */
1108 	unsigned long			ptrace_message;
1109 	kernel_siginfo_t		*last_siginfo;
1110 
1111 	struct task_io_accounting	ioac;
1112 #ifdef CONFIG_PSI
1113 	/* Pressure stall state */
1114 	unsigned int			psi_flags;
1115 #endif
1116 #ifdef CONFIG_TASK_XACCT
1117 	/* Accumulated RSS usage: */
1118 	u64				acct_rss_mem1;
1119 	/* Accumulated virtual memory usage: */
1120 	u64				acct_vm_mem1;
1121 	/* stime + utime since last update: */
1122 	u64				acct_timexpd;
1123 #endif
1124 #ifdef CONFIG_CPUSETS
1125 	/* Protected by ->alloc_lock: */
1126 	nodemask_t			mems_allowed;
1127 	/* Sequence number to catch updates: */
1128 	seqcount_spinlock_t		mems_allowed_seq;
1129 	int				cpuset_mem_spread_rotor;
1130 	int				cpuset_slab_spread_rotor;
1131 #endif
1132 #ifdef CONFIG_CGROUPS
1133 	/* Control Group info protected by css_set_lock: */
1134 	struct css_set __rcu		*cgroups;
1135 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1136 	struct list_head		cg_list;
1137 #endif
1138 #ifdef CONFIG_X86_CPU_RESCTRL
1139 	u32				closid;
1140 	u32				rmid;
1141 #endif
1142 #ifdef CONFIG_FUTEX
1143 	struct robust_list_head __user	*robust_list;
1144 #ifdef CONFIG_COMPAT
1145 	struct compat_robust_list_head __user *compat_robust_list;
1146 #endif
1147 	struct list_head		pi_state_list;
1148 	struct futex_pi_state		*pi_state_cache;
1149 	struct mutex			futex_exit_mutex;
1150 	unsigned int			futex_state;
1151 #endif
1152 #ifdef CONFIG_PERF_EVENTS
1153 	struct perf_event_context	*perf_event_ctxp[perf_nr_task_contexts];
1154 	struct mutex			perf_event_mutex;
1155 	struct list_head		perf_event_list;
1156 #endif
1157 #ifdef CONFIG_DEBUG_PREEMPT
1158 	unsigned long			preempt_disable_ip;
1159 #endif
1160 #ifdef CONFIG_NUMA
1161 	/* Protected by alloc_lock: */
1162 	struct mempolicy		*mempolicy;
1163 	short				il_prev;
1164 	short				pref_node_fork;
1165 #endif
1166 #ifdef CONFIG_NUMA_BALANCING
1167 	int				numa_scan_seq;
1168 	unsigned int			numa_scan_period;
1169 	unsigned int			numa_scan_period_max;
1170 	int				numa_preferred_nid;
1171 	unsigned long			numa_migrate_retry;
1172 	/* Migration stamp: */
1173 	u64				node_stamp;
1174 	u64				last_task_numa_placement;
1175 	u64				last_sum_exec_runtime;
1176 	struct callback_head		numa_work;
1177 
1178 	/*
1179 	 * This pointer is only modified for current in syscall and
1180 	 * pagefault context (and for tasks being destroyed), so it can be read
1181 	 * from any of the following contexts:
1182 	 *  - RCU read-side critical section
1183 	 *  - current->numa_group from everywhere
1184 	 *  - task's runqueue locked, task not running
1185 	 */
1186 	struct numa_group __rcu		*numa_group;
1187 
1188 	/*
1189 	 * numa_faults is an array split into four regions:
1190 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1191 	 * in this precise order.
1192 	 *
1193 	 * faults_memory: Exponential decaying average of faults on a per-node
1194 	 * basis. Scheduling placement decisions are made based on these
1195 	 * counts. The values remain static for the duration of a PTE scan.
1196 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1197 	 * hinting fault was incurred.
1198 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1199 	 * during the current scan window. When the scan completes, the counts
1200 	 * in faults_memory and faults_cpu decay and these values are copied.
1201 	 */
1202 	unsigned long			*numa_faults;
1203 	unsigned long			total_numa_faults;
1204 
1205 	/*
1206 	 * numa_faults_locality tracks if faults recorded during the last
1207 	 * scan window were remote/local or failed to migrate. The task scan
1208 	 * period is adapted based on the locality of the faults with different
1209 	 * weights depending on whether they were shared or private faults
1210 	 */
1211 	unsigned long			numa_faults_locality[3];
1212 
1213 	unsigned long			numa_pages_migrated;
1214 #endif /* CONFIG_NUMA_BALANCING */
1215 
1216 #ifdef CONFIG_RSEQ
1217 	struct rseq __user *rseq;
1218 	u32 rseq_sig;
1219 	/*
1220 	 * RmW on rseq_event_mask must be performed atomically
1221 	 * with respect to preemption.
1222 	 */
1223 	unsigned long rseq_event_mask;
1224 #endif
1225 
1226 	struct tlbflush_unmap_batch	tlb_ubc;
1227 
1228 	union {
1229 		refcount_t		rcu_users;
1230 		struct rcu_head		rcu;
1231 	};
1232 
1233 	/* Cache last used pipe for splice(): */
1234 	struct pipe_inode_info		*splice_pipe;
1235 
1236 	struct page_frag		task_frag;
1237 
1238 #ifdef CONFIG_TASK_DELAY_ACCT
1239 	struct task_delay_info		*delays;
1240 #endif
1241 
1242 #ifdef CONFIG_FAULT_INJECTION
1243 	int				make_it_fail;
1244 	unsigned int			fail_nth;
1245 #endif
1246 	/*
1247 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1248 	 * balance_dirty_pages() for a dirty throttling pause:
1249 	 */
1250 	int				nr_dirtied;
1251 	int				nr_dirtied_pause;
1252 	/* Start of a write-and-pause period: */
1253 	unsigned long			dirty_paused_when;
1254 
1255 #ifdef CONFIG_LATENCYTOP
1256 	int				latency_record_count;
1257 	struct latency_record		latency_record[LT_SAVECOUNT];
1258 #endif
1259 	/*
1260 	 * Time slack values; these are used to round up poll() and
1261 	 * select() etc timeout values. These are in nanoseconds.
1262 	 */
1263 	u64				timer_slack_ns;
1264 	u64				default_timer_slack_ns;
1265 
1266 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1267 	unsigned int			kasan_depth;
1268 #endif
1269 
1270 #ifdef CONFIG_KCSAN
1271 	struct kcsan_ctx		kcsan_ctx;
1272 #ifdef CONFIG_TRACE_IRQFLAGS
1273 	struct irqtrace_events		kcsan_save_irqtrace;
1274 #endif
1275 #endif
1276 
1277 #if IS_ENABLED(CONFIG_KUNIT)
1278 	struct kunit			*kunit_test;
1279 #endif
1280 
1281 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1282 	/* Index of current stored address in ret_stack: */
1283 	int				curr_ret_stack;
1284 	int				curr_ret_depth;
1285 
1286 	/* Stack of return addresses for return function tracing: */
1287 	struct ftrace_ret_stack		*ret_stack;
1288 
1289 	/* Timestamp for last schedule: */
1290 	unsigned long long		ftrace_timestamp;
1291 
1292 	/*
1293 	 * Number of functions that haven't been traced
1294 	 * because of depth overrun:
1295 	 */
1296 	atomic_t			trace_overrun;
1297 
1298 	/* Pause tracing: */
1299 	atomic_t			tracing_graph_pause;
1300 #endif
1301 
1302 #ifdef CONFIG_TRACING
1303 	/* State flags for use by tracers: */
1304 	unsigned long			trace;
1305 
1306 	/* Bitmask and counter of trace recursion: */
1307 	unsigned long			trace_recursion;
1308 #endif /* CONFIG_TRACING */
1309 
1310 #ifdef CONFIG_KCOV
1311 	/* See kernel/kcov.c for more details. */
1312 
1313 	/* Coverage collection mode enabled for this task (0 if disabled): */
1314 	unsigned int			kcov_mode;
1315 
1316 	/* Size of the kcov_area: */
1317 	unsigned int			kcov_size;
1318 
1319 	/* Buffer for coverage collection: */
1320 	void				*kcov_area;
1321 
1322 	/* KCOV descriptor wired with this task or NULL: */
1323 	struct kcov			*kcov;
1324 
1325 	/* KCOV common handle for remote coverage collection: */
1326 	u64				kcov_handle;
1327 
1328 	/* KCOV sequence number: */
1329 	int				kcov_sequence;
1330 
1331 	/* Collect coverage from softirq context: */
1332 	unsigned int			kcov_softirq;
1333 #endif
1334 
1335 #ifdef CONFIG_MEMCG
1336 	struct mem_cgroup		*memcg_in_oom;
1337 	gfp_t				memcg_oom_gfp_mask;
1338 	int				memcg_oom_order;
1339 
1340 	/* Number of pages to reclaim on returning to userland: */
1341 	unsigned int			memcg_nr_pages_over_high;
1342 
1343 	/* Used by memcontrol for targeted memcg charge: */
1344 	struct mem_cgroup		*active_memcg;
1345 #endif
1346 
1347 #ifdef CONFIG_BLK_CGROUP
1348 	struct request_queue		*throttle_queue;
1349 #endif
1350 
1351 #ifdef CONFIG_UPROBES
1352 	struct uprobe_task		*utask;
1353 #endif
1354 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1355 	unsigned int			sequential_io;
1356 	unsigned int			sequential_io_avg;
1357 #endif
1358 	struct kmap_ctrl		kmap_ctrl;
1359 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1360 	unsigned long			task_state_change;
1361 #endif
1362 	int				pagefault_disabled;
1363 #ifdef CONFIG_MMU
1364 	struct task_struct		*oom_reaper_list;
1365 #endif
1366 #ifdef CONFIG_VMAP_STACK
1367 	struct vm_struct		*stack_vm_area;
1368 #endif
1369 #ifdef CONFIG_THREAD_INFO_IN_TASK
1370 	/* A live task holds one reference: */
1371 	refcount_t			stack_refcount;
1372 #endif
1373 #ifdef CONFIG_LIVEPATCH
1374 	int patch_state;
1375 #endif
1376 #ifdef CONFIG_SECURITY
1377 	/* Used by LSM modules for access restriction: */
1378 	void				*security;
1379 #endif
1380 #ifdef CONFIG_BPF_SYSCALL
1381 	/* Used by BPF task local storage */
1382 	struct bpf_local_storage __rcu	*bpf_storage;
1383 	/* Used for BPF run context */
1384 	struct bpf_run_ctx		*bpf_ctx;
1385 #endif
1386 
1387 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1388 	unsigned long			lowest_stack;
1389 	unsigned long			prev_lowest_stack;
1390 #endif
1391 
1392 #ifdef CONFIG_X86_MCE
1393 	void __user			*mce_vaddr;
1394 	__u64				mce_kflags;
1395 	u64				mce_addr;
1396 	__u64				mce_ripv : 1,
1397 					mce_whole_page : 1,
1398 					__mce_reserved : 62;
1399 	struct callback_head		mce_kill_me;
1400 #endif
1401 
1402 #ifdef CONFIG_KRETPROBES
1403 	struct llist_head               kretprobe_instances;
1404 #endif
1405 
1406 	/*
1407 	 * New fields for task_struct should be added above here, so that
1408 	 * they are included in the randomized portion of task_struct.
1409 	 */
1410 	randomized_struct_fields_end
1411 
1412 	/* CPU-specific state of this task: */
1413 	struct thread_struct		thread;
1414 
1415 	/*
1416 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1417 	 * structure.  It *MUST* be at the end of 'task_struct'.
1418 	 *
1419 	 * Do not put anything below here!
1420 	 */
1421 };
1422 
1423 static inline struct pid *task_pid(struct task_struct *task)
1424 {
1425 	return task->thread_pid;
1426 }
1427 
1428 /*
1429  * the helpers to get the task's different pids as they are seen
1430  * from various namespaces
1431  *
1432  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1433  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1434  *                     current.
1435  * task_xid_nr_ns()  : id seen from the ns specified;
1436  *
1437  * see also pid_nr() etc in include/linux/pid.h
1438  */
1439 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1440 
1441 static inline pid_t task_pid_nr(struct task_struct *tsk)
1442 {
1443 	return tsk->pid;
1444 }
1445 
1446 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1447 {
1448 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1449 }
1450 
1451 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1452 {
1453 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1454 }
1455 
1456 
1457 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1458 {
1459 	return tsk->tgid;
1460 }
1461 
1462 /**
1463  * pid_alive - check that a task structure is not stale
1464  * @p: Task structure to be checked.
1465  *
1466  * Test if a process is not yet dead (at most zombie state)
1467  * If pid_alive fails, then pointers within the task structure
1468  * can be stale and must not be dereferenced.
1469  *
1470  * Return: 1 if the process is alive. 0 otherwise.
1471  */
1472 static inline int pid_alive(const struct task_struct *p)
1473 {
1474 	return p->thread_pid != NULL;
1475 }
1476 
1477 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1478 {
1479 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1480 }
1481 
1482 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1483 {
1484 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1485 }
1486 
1487 
1488 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1489 {
1490 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1491 }
1492 
1493 static inline pid_t task_session_vnr(struct task_struct *tsk)
1494 {
1495 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1496 }
1497 
1498 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1499 {
1500 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1501 }
1502 
1503 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1504 {
1505 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1506 }
1507 
1508 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1509 {
1510 	pid_t pid = 0;
1511 
1512 	rcu_read_lock();
1513 	if (pid_alive(tsk))
1514 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1515 	rcu_read_unlock();
1516 
1517 	return pid;
1518 }
1519 
1520 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1521 {
1522 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1523 }
1524 
1525 /* Obsolete, do not use: */
1526 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1527 {
1528 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1529 }
1530 
1531 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1532 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1533 
1534 static inline unsigned int task_state_index(struct task_struct *tsk)
1535 {
1536 	unsigned int tsk_state = READ_ONCE(tsk->__state);
1537 	unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1538 
1539 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1540 
1541 	if (tsk_state == TASK_IDLE)
1542 		state = TASK_REPORT_IDLE;
1543 
1544 	return fls(state);
1545 }
1546 
1547 static inline char task_index_to_char(unsigned int state)
1548 {
1549 	static const char state_char[] = "RSDTtXZPI";
1550 
1551 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1552 
1553 	return state_char[state];
1554 }
1555 
1556 static inline char task_state_to_char(struct task_struct *tsk)
1557 {
1558 	return task_index_to_char(task_state_index(tsk));
1559 }
1560 
1561 /**
1562  * is_global_init - check if a task structure is init. Since init
1563  * is free to have sub-threads we need to check tgid.
1564  * @tsk: Task structure to be checked.
1565  *
1566  * Check if a task structure is the first user space task the kernel created.
1567  *
1568  * Return: 1 if the task structure is init. 0 otherwise.
1569  */
1570 static inline int is_global_init(struct task_struct *tsk)
1571 {
1572 	return task_tgid_nr(tsk) == 1;
1573 }
1574 
1575 extern struct pid *cad_pid;
1576 
1577 /*
1578  * Per process flags
1579  */
1580 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1581 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1582 #define PF_EXITING		0x00000004	/* Getting shut down */
1583 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1584 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1585 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1586 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1587 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1588 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1589 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1590 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1591 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1592 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1593 #define PF_USED_ASYNC		0x00004000	/* Used async_schedule*(), used by module init */
1594 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1595 #define PF_FROZEN		0x00010000	/* Frozen for system suspend */
1596 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1597 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1598 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1599 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1600 						 * I am cleaning dirty pages from some other bdi. */
1601 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1602 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1603 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
1604 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1605 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1606 #define PF_MEMALLOC_PIN		0x10000000	/* Allocation context constrained to zones which allow long term pinning. */
1607 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
1608 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1609 
1610 /*
1611  * Only the _current_ task can read/write to tsk->flags, but other
1612  * tasks can access tsk->flags in readonly mode for example
1613  * with tsk_used_math (like during threaded core dumping).
1614  * There is however an exception to this rule during ptrace
1615  * or during fork: the ptracer task is allowed to write to the
1616  * child->flags of its traced child (same goes for fork, the parent
1617  * can write to the child->flags), because we're guaranteed the
1618  * child is not running and in turn not changing child->flags
1619  * at the same time the parent does it.
1620  */
1621 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1622 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1623 #define clear_used_math()			clear_stopped_child_used_math(current)
1624 #define set_used_math()				set_stopped_child_used_math(current)
1625 
1626 #define conditional_stopped_child_used_math(condition, child) \
1627 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1628 
1629 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1630 
1631 #define copy_to_stopped_child_used_math(child) \
1632 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1633 
1634 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1635 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1636 #define used_math()				tsk_used_math(current)
1637 
1638 static inline bool is_percpu_thread(void)
1639 {
1640 #ifdef CONFIG_SMP
1641 	return (current->flags & PF_NO_SETAFFINITY) &&
1642 		(current->nr_cpus_allowed  == 1);
1643 #else
1644 	return true;
1645 #endif
1646 }
1647 
1648 /* Per-process atomic flags. */
1649 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1650 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1651 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1652 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1653 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1654 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1655 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1656 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1657 
1658 #define TASK_PFA_TEST(name, func)					\
1659 	static inline bool task_##func(struct task_struct *p)		\
1660 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1661 
1662 #define TASK_PFA_SET(name, func)					\
1663 	static inline void task_set_##func(struct task_struct *p)	\
1664 	{ set_bit(PFA_##name, &p->atomic_flags); }
1665 
1666 #define TASK_PFA_CLEAR(name, func)					\
1667 	static inline void task_clear_##func(struct task_struct *p)	\
1668 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1669 
1670 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1671 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1672 
1673 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1674 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1675 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1676 
1677 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1678 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1679 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1680 
1681 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1682 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1683 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1684 
1685 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1686 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1687 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1688 
1689 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1690 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1691 
1692 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1693 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1694 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1695 
1696 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1697 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1698 
1699 static inline void
1700 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1701 {
1702 	current->flags &= ~flags;
1703 	current->flags |= orig_flags & flags;
1704 }
1705 
1706 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1707 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1708 #ifdef CONFIG_SMP
1709 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1710 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1711 #else
1712 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1713 {
1714 }
1715 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1716 {
1717 	if (!cpumask_test_cpu(0, new_mask))
1718 		return -EINVAL;
1719 	return 0;
1720 }
1721 #endif
1722 
1723 extern int yield_to(struct task_struct *p, bool preempt);
1724 extern void set_user_nice(struct task_struct *p, long nice);
1725 extern int task_prio(const struct task_struct *p);
1726 
1727 /**
1728  * task_nice - return the nice value of a given task.
1729  * @p: the task in question.
1730  *
1731  * Return: The nice value [ -20 ... 0 ... 19 ].
1732  */
1733 static inline int task_nice(const struct task_struct *p)
1734 {
1735 	return PRIO_TO_NICE((p)->static_prio);
1736 }
1737 
1738 extern int can_nice(const struct task_struct *p, const int nice);
1739 extern int task_curr(const struct task_struct *p);
1740 extern int idle_cpu(int cpu);
1741 extern int available_idle_cpu(int cpu);
1742 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1743 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1744 extern void sched_set_fifo(struct task_struct *p);
1745 extern void sched_set_fifo_low(struct task_struct *p);
1746 extern void sched_set_normal(struct task_struct *p, int nice);
1747 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1748 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1749 extern struct task_struct *idle_task(int cpu);
1750 
1751 /**
1752  * is_idle_task - is the specified task an idle task?
1753  * @p: the task in question.
1754  *
1755  * Return: 1 if @p is an idle task. 0 otherwise.
1756  */
1757 static __always_inline bool is_idle_task(const struct task_struct *p)
1758 {
1759 	return !!(p->flags & PF_IDLE);
1760 }
1761 
1762 extern struct task_struct *curr_task(int cpu);
1763 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1764 
1765 void yield(void);
1766 
1767 union thread_union {
1768 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1769 	struct task_struct task;
1770 #endif
1771 #ifndef CONFIG_THREAD_INFO_IN_TASK
1772 	struct thread_info thread_info;
1773 #endif
1774 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1775 };
1776 
1777 #ifndef CONFIG_THREAD_INFO_IN_TASK
1778 extern struct thread_info init_thread_info;
1779 #endif
1780 
1781 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1782 
1783 #ifdef CONFIG_THREAD_INFO_IN_TASK
1784 static inline struct thread_info *task_thread_info(struct task_struct *task)
1785 {
1786 	return &task->thread_info;
1787 }
1788 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1789 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1790 #endif
1791 
1792 /*
1793  * find a task by one of its numerical ids
1794  *
1795  * find_task_by_pid_ns():
1796  *      finds a task by its pid in the specified namespace
1797  * find_task_by_vpid():
1798  *      finds a task by its virtual pid
1799  *
1800  * see also find_vpid() etc in include/linux/pid.h
1801  */
1802 
1803 extern struct task_struct *find_task_by_vpid(pid_t nr);
1804 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1805 
1806 /*
1807  * find a task by its virtual pid and get the task struct
1808  */
1809 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1810 
1811 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1812 extern int wake_up_process(struct task_struct *tsk);
1813 extern void wake_up_new_task(struct task_struct *tsk);
1814 
1815 #ifdef CONFIG_SMP
1816 extern void kick_process(struct task_struct *tsk);
1817 #else
1818 static inline void kick_process(struct task_struct *tsk) { }
1819 #endif
1820 
1821 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1822 
1823 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1824 {
1825 	__set_task_comm(tsk, from, false);
1826 }
1827 
1828 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1829 #define get_task_comm(buf, tsk) ({			\
1830 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
1831 	__get_task_comm(buf, sizeof(buf), tsk);		\
1832 })
1833 
1834 #ifdef CONFIG_SMP
1835 static __always_inline void scheduler_ipi(void)
1836 {
1837 	/*
1838 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1839 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
1840 	 * this IPI.
1841 	 */
1842 	preempt_fold_need_resched();
1843 }
1844 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
1845 #else
1846 static inline void scheduler_ipi(void) { }
1847 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state)
1848 {
1849 	return 1;
1850 }
1851 #endif
1852 
1853 /*
1854  * Set thread flags in other task's structures.
1855  * See asm/thread_info.h for TIF_xxxx flags available:
1856  */
1857 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1858 {
1859 	set_ti_thread_flag(task_thread_info(tsk), flag);
1860 }
1861 
1862 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1863 {
1864 	clear_ti_thread_flag(task_thread_info(tsk), flag);
1865 }
1866 
1867 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1868 					  bool value)
1869 {
1870 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
1871 }
1872 
1873 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1874 {
1875 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1876 }
1877 
1878 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1879 {
1880 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1881 }
1882 
1883 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1884 {
1885 	return test_ti_thread_flag(task_thread_info(tsk), flag);
1886 }
1887 
1888 static inline void set_tsk_need_resched(struct task_struct *tsk)
1889 {
1890 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1891 }
1892 
1893 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1894 {
1895 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1896 }
1897 
1898 static inline int test_tsk_need_resched(struct task_struct *tsk)
1899 {
1900 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1901 }
1902 
1903 /*
1904  * cond_resched() and cond_resched_lock(): latency reduction via
1905  * explicit rescheduling in places that are safe. The return
1906  * value indicates whether a reschedule was done in fact.
1907  * cond_resched_lock() will drop the spinlock before scheduling,
1908  */
1909 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
1910 extern int __cond_resched(void);
1911 
1912 #ifdef CONFIG_PREEMPT_DYNAMIC
1913 
1914 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
1915 
1916 static __always_inline int _cond_resched(void)
1917 {
1918 	return static_call_mod(cond_resched)();
1919 }
1920 
1921 #else
1922 
1923 static inline int _cond_resched(void)
1924 {
1925 	return __cond_resched();
1926 }
1927 
1928 #endif /* CONFIG_PREEMPT_DYNAMIC */
1929 
1930 #else
1931 
1932 static inline int _cond_resched(void) { return 0; }
1933 
1934 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */
1935 
1936 #define cond_resched() ({			\
1937 	___might_sleep(__FILE__, __LINE__, 0);	\
1938 	_cond_resched();			\
1939 })
1940 
1941 extern int __cond_resched_lock(spinlock_t *lock);
1942 extern int __cond_resched_rwlock_read(rwlock_t *lock);
1943 extern int __cond_resched_rwlock_write(rwlock_t *lock);
1944 
1945 #define cond_resched_lock(lock) ({				\
1946 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1947 	__cond_resched_lock(lock);				\
1948 })
1949 
1950 #define cond_resched_rwlock_read(lock) ({			\
1951 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
1952 	__cond_resched_rwlock_read(lock);			\
1953 })
1954 
1955 #define cond_resched_rwlock_write(lock) ({			\
1956 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
1957 	__cond_resched_rwlock_write(lock);			\
1958 })
1959 
1960 static inline void cond_resched_rcu(void)
1961 {
1962 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1963 	rcu_read_unlock();
1964 	cond_resched();
1965 	rcu_read_lock();
1966 #endif
1967 }
1968 
1969 /*
1970  * Does a critical section need to be broken due to another
1971  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
1972  * but a general need for low latency)
1973  */
1974 static inline int spin_needbreak(spinlock_t *lock)
1975 {
1976 #ifdef CONFIG_PREEMPTION
1977 	return spin_is_contended(lock);
1978 #else
1979 	return 0;
1980 #endif
1981 }
1982 
1983 /*
1984  * Check if a rwlock is contended.
1985  * Returns non-zero if there is another task waiting on the rwlock.
1986  * Returns zero if the lock is not contended or the system / underlying
1987  * rwlock implementation does not support contention detection.
1988  * Technically does not depend on CONFIG_PREEMPTION, but a general need
1989  * for low latency.
1990  */
1991 static inline int rwlock_needbreak(rwlock_t *lock)
1992 {
1993 #ifdef CONFIG_PREEMPTION
1994 	return rwlock_is_contended(lock);
1995 #else
1996 	return 0;
1997 #endif
1998 }
1999 
2000 static __always_inline bool need_resched(void)
2001 {
2002 	return unlikely(tif_need_resched());
2003 }
2004 
2005 /*
2006  * Wrappers for p->thread_info->cpu access. No-op on UP.
2007  */
2008 #ifdef CONFIG_SMP
2009 
2010 static inline unsigned int task_cpu(const struct task_struct *p)
2011 {
2012 #ifdef CONFIG_THREAD_INFO_IN_TASK
2013 	return READ_ONCE(p->cpu);
2014 #else
2015 	return READ_ONCE(task_thread_info(p)->cpu);
2016 #endif
2017 }
2018 
2019 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2020 
2021 #else
2022 
2023 static inline unsigned int task_cpu(const struct task_struct *p)
2024 {
2025 	return 0;
2026 }
2027 
2028 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2029 {
2030 }
2031 
2032 #endif /* CONFIG_SMP */
2033 
2034 extern bool sched_task_on_rq(struct task_struct *p);
2035 
2036 /*
2037  * In order to reduce various lock holder preemption latencies provide an
2038  * interface to see if a vCPU is currently running or not.
2039  *
2040  * This allows us to terminate optimistic spin loops and block, analogous to
2041  * the native optimistic spin heuristic of testing if the lock owner task is
2042  * running or not.
2043  */
2044 #ifndef vcpu_is_preempted
2045 static inline bool vcpu_is_preempted(int cpu)
2046 {
2047 	return false;
2048 }
2049 #endif
2050 
2051 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2052 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2053 
2054 #ifndef TASK_SIZE_OF
2055 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2056 #endif
2057 
2058 #ifdef CONFIG_SMP
2059 /* Returns effective CPU energy utilization, as seen by the scheduler */
2060 unsigned long sched_cpu_util(int cpu, unsigned long max);
2061 #endif /* CONFIG_SMP */
2062 
2063 #ifdef CONFIG_RSEQ
2064 
2065 /*
2066  * Map the event mask on the user-space ABI enum rseq_cs_flags
2067  * for direct mask checks.
2068  */
2069 enum rseq_event_mask_bits {
2070 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2071 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2072 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2073 };
2074 
2075 enum rseq_event_mask {
2076 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
2077 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
2078 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
2079 };
2080 
2081 static inline void rseq_set_notify_resume(struct task_struct *t)
2082 {
2083 	if (t->rseq)
2084 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2085 }
2086 
2087 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2088 
2089 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2090 					     struct pt_regs *regs)
2091 {
2092 	if (current->rseq)
2093 		__rseq_handle_notify_resume(ksig, regs);
2094 }
2095 
2096 static inline void rseq_signal_deliver(struct ksignal *ksig,
2097 				       struct pt_regs *regs)
2098 {
2099 	preempt_disable();
2100 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2101 	preempt_enable();
2102 	rseq_handle_notify_resume(ksig, regs);
2103 }
2104 
2105 /* rseq_preempt() requires preemption to be disabled. */
2106 static inline void rseq_preempt(struct task_struct *t)
2107 {
2108 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2109 	rseq_set_notify_resume(t);
2110 }
2111 
2112 /* rseq_migrate() requires preemption to be disabled. */
2113 static inline void rseq_migrate(struct task_struct *t)
2114 {
2115 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2116 	rseq_set_notify_resume(t);
2117 }
2118 
2119 /*
2120  * If parent process has a registered restartable sequences area, the
2121  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2122  */
2123 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2124 {
2125 	if (clone_flags & CLONE_VM) {
2126 		t->rseq = NULL;
2127 		t->rseq_sig = 0;
2128 		t->rseq_event_mask = 0;
2129 	} else {
2130 		t->rseq = current->rseq;
2131 		t->rseq_sig = current->rseq_sig;
2132 		t->rseq_event_mask = current->rseq_event_mask;
2133 	}
2134 }
2135 
2136 static inline void rseq_execve(struct task_struct *t)
2137 {
2138 	t->rseq = NULL;
2139 	t->rseq_sig = 0;
2140 	t->rseq_event_mask = 0;
2141 }
2142 
2143 #else
2144 
2145 static inline void rseq_set_notify_resume(struct task_struct *t)
2146 {
2147 }
2148 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2149 					     struct pt_regs *regs)
2150 {
2151 }
2152 static inline void rseq_signal_deliver(struct ksignal *ksig,
2153 				       struct pt_regs *regs)
2154 {
2155 }
2156 static inline void rseq_preempt(struct task_struct *t)
2157 {
2158 }
2159 static inline void rseq_migrate(struct task_struct *t)
2160 {
2161 }
2162 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2163 {
2164 }
2165 static inline void rseq_execve(struct task_struct *t)
2166 {
2167 }
2168 
2169 #endif
2170 
2171 #ifdef CONFIG_DEBUG_RSEQ
2172 
2173 void rseq_syscall(struct pt_regs *regs);
2174 
2175 #else
2176 
2177 static inline void rseq_syscall(struct pt_regs *regs)
2178 {
2179 }
2180 
2181 #endif
2182 
2183 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2184 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2185 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2186 
2187 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2188 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2189 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2190 
2191 int sched_trace_rq_cpu(struct rq *rq);
2192 int sched_trace_rq_cpu_capacity(struct rq *rq);
2193 int sched_trace_rq_nr_running(struct rq *rq);
2194 
2195 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2196 
2197 #ifdef CONFIG_SCHED_CORE
2198 extern void sched_core_free(struct task_struct *tsk);
2199 extern void sched_core_fork(struct task_struct *p);
2200 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2201 				unsigned long uaddr);
2202 #else
2203 static inline void sched_core_free(struct task_struct *tsk) { }
2204 static inline void sched_core_fork(struct task_struct *p) { }
2205 #endif
2206 
2207 #endif
2208